CA1201677A - Zero pressure accumulation conveyor and brake assembly - Google Patents
Zero pressure accumulation conveyor and brake assemblyInfo
- Publication number
- CA1201677A CA1201677A CA000410233A CA410233A CA1201677A CA 1201677 A CA1201677 A CA 1201677A CA 000410233 A CA000410233 A CA 000410233A CA 410233 A CA410233 A CA 410233A CA 1201677 A CA1201677 A CA 1201677A
- Authority
- CA
- Canada
- Prior art keywords
- torque tube
- drive shaft
- conveyor
- pressure accumulation
- zero pressure
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65G—TRANSPORT OR STORAGE DEVICES, e.g. CONVEYORS FOR LOADING OR TIPPING, SHOP CONVEYOR SYSTEMS OR PNEUMATIC TUBE CONVEYORS
- B65G47/00—Article or material-handling devices associated with conveyors; Methods employing such devices
- B65G47/22—Devices influencing the relative position or the attitude of articles during transit by conveyors
- B65G47/26—Devices influencing the relative position or the attitude of articles during transit by conveyors arranging the articles, e.g. varying spacing between individual articles
- B65G47/261—Accumulating articles
- B65G47/263—Accumulating articles the conveyor drive is taken from a longitudinally extending shaft
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65G—TRANSPORT OR STORAGE DEVICES, e.g. CONVEYORS FOR LOADING OR TIPPING, SHOP CONVEYOR SYSTEMS OR PNEUMATIC TUBE CONVEYORS
- B65G13/00—Roller-ways
- B65G13/075—Braking means
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Rollers For Roller Conveyors For Transfer (AREA)
- Braking Arrangements (AREA)
- Attitude Control For Articles On Conveyors (AREA)
- Devices For Conveying Motion By Means Of Endless Flexible Members (AREA)
Abstract
"ZERO PRESSURE ACCUMULATION CONVEYOR & BRAKE ASSEMBLY
Donn R. Van Der Schie ABSTRACT OF THE DISCLOSURE
A live roller zero pressure accumulation conveyor and brake assembly are described. The brake assembly includes a rotatable drive shaft surrounded by a tubular torque tube. The drive shaft extends into the torgue tube and has a diameter such that the cylindrical surface of the drive shaft is capable of frictionally engaging the interior of the torque tube to rotate the torque tube when the drive shaft is rotated, but to slip relative to the torque tube when rotation of the torque tube is restrained. Clamping means surrounds the torque tube and is movable relative to the exterior surface of the torque tube between a first position in which its clamping surfaces are moved out of contact with the tongue tube and the rotating drive shaft rotates the torque tube, and a second position in which the clamping surfaces move into contact with the exterior of the torque tube to restrain the torque tube from rotating with the drive shaft. The drive shaft is preferably formed of steel and the torque tube of nylon. A plurality of roller sections having live rotatable rollers are drive by endless belts looped about the rollers and pulleys on the torque tube and by independently rotating torque tubes in each of the sections. Each of the sections includes one of the brake assemblies and a trigger assembly for controlling movement of the rollers in a section. The conveyor may be operated to handle articles in either a slug or singulation mode.
Donn R. Van Der Schie ABSTRACT OF THE DISCLOSURE
A live roller zero pressure accumulation conveyor and brake assembly are described. The brake assembly includes a rotatable drive shaft surrounded by a tubular torque tube. The drive shaft extends into the torgue tube and has a diameter such that the cylindrical surface of the drive shaft is capable of frictionally engaging the interior of the torque tube to rotate the torque tube when the drive shaft is rotated, but to slip relative to the torque tube when rotation of the torque tube is restrained. Clamping means surrounds the torque tube and is movable relative to the exterior surface of the torque tube between a first position in which its clamping surfaces are moved out of contact with the tongue tube and the rotating drive shaft rotates the torque tube, and a second position in which the clamping surfaces move into contact with the exterior of the torque tube to restrain the torque tube from rotating with the drive shaft. The drive shaft is preferably formed of steel and the torque tube of nylon. A plurality of roller sections having live rotatable rollers are drive by endless belts looped about the rollers and pulleys on the torque tube and by independently rotating torque tubes in each of the sections. Each of the sections includes one of the brake assemblies and a trigger assembly for controlling movement of the rollers in a section. The conveyor may be operated to handle articles in either a slug or singulation mode.
Description
BACKGR0UND AND SU~1MARY OF THE INVE~lTIO~
The present invention relates to live roller conveyors used to transport articles along a predetermined path and, more particularly, to zero pressure accumulation conveyors and brake assemblies therefor.
Live roller conveyors and, even more ~articularly, accumulation conveyors are well known in the art. Such accumulation conveyors have, in the past, employe~ various ~echanisms for controlling the rotation of the conveyor rollers to allow them to be selectively rotated or stopped to accommodate accumulation of the articles beins conveyed by the conveyors. The rollers are rotated to convey the articles to a collection or accumulation location and, once one or more of the articles have reachéd that location, the rollers are stopped to provide for accumulation.
One such mechanism is shown in U.S. Patent No.
3,650,375 (Fleischauer et al). That ~atent discloses live rollers, each of which is d~iven by a resilient O-belt looped abo-~t a pulley beneath the rollers. The pulley is movahle axially along a driven shat. When articles are being conveyed by the rollers, the pulley axially sliaes , along the driven shaft to assume a position in which it is frictionally engaged with the driven shaft to cause the pulley to rotate with the drive shaft and, thereby, arive the rollers by way of the O-belt. Once an article is accumulated at a desired location on the conveyor, movement ~2~
of the article is prevented either by engagement of the article with a conveyor discharge gate or by contact of the article with a preceding artiele. When this latter condition occurs, the rollers beneath the article which has now stopped experience a frictional counter Iorce on their cylindrical surfaces due to the weight of the overlying article which causes the axially movable pulleys to move axially along the driven shaft to such point that their ~rictional engauement with the driven shaft is no longer sufficient to allow the pullevs to rotate with the driven shaft, thereby causing the pulleys to slip relative to the driven shaft and to cease to impart driving force to the live rollers through the O-belts.
The aforementioned construction is perfectly acceptable in most uses. However, it relies to a principal extent upon some measure of restraining contaet of the articles, either with a conveyor discharge gate or between the articles themselves. Such contact is of some concern, however, wherè the articles are extremely delicate, for example, electronics equipment in which extremely delicate handling of the articles is necess'ary to avoid damage. ~or such delicate equipment, it is desirable to eliminate all ,~ contact of the articles with a gate or with other articles to eliminate any possibility of impact or jarring of the equipment. In addition, such mechanisms rely upon frequent or continuous slippage of various elements of the drive system relative to other elements when the articles have reached their accumulation location. Such slippage ~V~ 7 may result in early wear and the need for early replacement of the elements.
Vari~us mechanisms have been employed in the past ~or positively controlling the rotation of the driven shaft, either in combination with such slidable pulleys or otherwise, in an attempt to o~ercome at least some of the aforementioned disadvantages. One such mechanism employing a clutch assembly is sh~wn in U S. Patent No. 3,840,110 (Molt et al). In that patent, several relatively com~lex clutching mechanisms are disclosed which operate to couple the driven shaft and its pulleys with a drive shaft to drive the driven shaft, its pulleys, O-belts and conveyor rollers when it is desired to move an article along the conveyor, but to positively uncou~le the drivenshaft ~n response to the actuation of suitable triggering mechanisms which sense the arrival of an article at a desired accl~mulation location. Although such clutching mechanisms minimize contact~et~7een the articles being conveyed and reduce frictional heat buildup and wear of the drive elements, such mechanisms are relatively complex with the attendant need to stock a large number of repair parts, an~ the increased difficulty of assem~ly and 4 maintenance which always accompanies mechanisms of relatively complex construction.
Brake assemblies have also ~een employed in the pas~inconjunction with such conveyor drive and driven shafts. One such brake assembly is shown, for example, in -~l.S. Patent No. 3,696,912 ~Fleischauer et al). In that patent a hrake assembly is disclosed which is mechanically actuated by a suitable trigger element which senses the presence of the article at its desired accumulation location, The trigger is mechanically coupled by a cable or chain which is connected to the brake assembly to cause the brake to engage a key on the driven shaft to lock the driven shaft against rotation. Although this mechanical key brake construction is, likewise, acceptable in a wide range of uses, it has the disadvantage of the need ~or relatively frequent maintenance and adjustment and some jarring of the elements and of the articles results from the positive key locking action.
~he zero pressure accumulation conveyor and brake assembly of the present in~ention overcome the constrUc-several aforementioned disadvantages of the prior c~L~u~-tions. A zero pressure accumulation conveyor and brake assembly constructed in accordance with the principles of the present invention minimize frictional heat and wear between the elements which slip relative to each other, thus resulting in a decrease in the need for maintenance and repair. In a zero pressure accumulation conveyor and .~ brake assembly incorporating the principles of the present invention, positive and rapid braking action is imparted to ~5 the drive elements of the conveyor to achieve rapid deceleration of the articles without damage to the articles, even though sufficient slip between the drive elements is 6~7 retained with its attendant advantages, A zero pressure accumulation conveyor and brake assembly constructed in accordance with the principles of the present invention is safe, quiet and simple in construction, thereby substan-tially reducing the need for maintenance and in time in assembling of the conveyor, and the need for maintaining a substantial spare parts inventory is also reduced, In one principal aspect of the present invention, a ~rake asse~bly comprises rotatable ~rive shaft means having a substantially cylindrical surface and torque tu~e means, The torque tube means also define a substantially cylindrical exterior surface and the drive shaft means extends axially into the torque tube means, The diameter of the cylindrical surface of the drive shaft means is slightly less than the internal diameter of the torque tube means such that the drive shaft means is capable of frictionally engaging the interior or the torque tube means to rotate the torque tube means when the drive shaft means is rotated, but is capable of slipping relative to the torque tube means when rotation of the torque tube means is restrained, Clamping surface means substantially surround at least a porticn of the exterior surface of the torque tube means and the clampi~g surface means is movable relative to that exterior surface between a first position in which the clamping surface means is moved out of contact with the exterior of the torque tube means and the rotating drive shaft means rotates the torque tube means, and a second position in which the clamping surface means is moved into contact with the exterior of the torque tube means to restrain the torque tube means from rotating with the drive shaft means, ~2~
In another principal aspect o~ the present invention, the aforementioned torque tube means is formed of an organic polymer, preferably nylon, and the drive shaft is a hard metal, preferably steel.
In still another principal aspect of the present invention, at least one pulley is mounted on the exterior surlace of the tor~ue tube means and the pulley is axially movable on the tor~ue tube means so as to frictionally engage the exterior surface of the tor~ue tube means to rotate therewith when the torque tube means rotates.
However, the pulley is slippable rotationally relative to the exterior sur~ace of the tor~ue tube means when the clamping surface means is moved to its second position.
In still another principal aspect of the present 1~ invention, the aforementioned brake assemblies are employed in combination with a plurality of live rotatable rollers for supporting and conveying an article along a plane and a plurality of endless resilient belts are looped about these rollers and the toraue tube means to drive the rollers when the torque tube means is rotated by the drive shaft means.
In still another principal aspect o~ the present invent;on, trigger means are included in the last mPntioned combination for sensing the presenc~ of an article being conveyed by the rollers and control means are responsive to the trigger means to move the cla~ping surface means between its first an~ second positions, the trigger means, clamping ~2~)~6~7`7 surface means and torque tube means being constructed and arranged to operate the rollers in either a singulation mode or a slug mode.
These and other objects, features and advantages of the present invention will become apparent upon considera-tion of the detailed description of the invention to follow.
BRIli:F` DESCPIPTION OF THE DRAWINGS
In the course of this description, the drawings will be frequently referred to in which:
FIG. 1 is a fraamentary perspective view of a S live roller accumulation conveyor incorporating the principles of the present invention;
FIG. 2 is a fragmentary plan view of the accumula-tion conveyor, with certain elements thereof bro~en away, as viewed substantially along line 2-. in FIG. l;
FIG. 3 is a partial side elevational view of the accumulation conveyor, with portions thereof broken away, as viewed substantially along line 3-3 in FIG. l;
FIG. 4 is a partial broken plan view of one full section and two partial ad~itional~sections of the drive shaft, driven shaft and pulleys in the preferred embodiment ,~ of accumulation conveyor of the present invention;
FIG 5 is partial broken end elevational view of a preferred embodiment of brake assembly incorporating the principles of the present invention as viewed substantially 2Q along line 5-5 in FI~. 2;
-~Z~6~
FIG. 6 is a partially broken side elevational view of the brake assembly as viewed substantially along line 6-6 in line 5;
FI~ 7 is a partially broken end elevational view of a triager mechanism for use in the slug mode of operation of the conveyor of the present invention and as viewed substantially along line 7-7 in FIG. 2;
FIG. 8 is a broken side elevational view of the last-mentioned trigger assernbly as viewed substantially alons line ~-8 in FIG. 7;
FIG. 9 is a partially broken end elevational vie~
of a trigger mechanism for use in the singulation mode of operation of the conveyor of the present invention;
FIG. 10 is a broken side elevational view of the 1ast-mentioned trigger assembly as viewed substantially along line 10-10 of FIG. 9;
FIG~ 11 is a schematic view showing a preferring pneumatic control system for four accunulation conveyor sections for controlling the conveyor in the slug mode;
FIG. 12 is a partial plan view of a preferred embodiment of conveyor of the present invention showing the positioning of the control elements shown in FIG. 11 for the slug mode of operation;
FIG. 13 is a partial cross sectioned side elevational view of the conveyor as viewed substantially along line 13-13 in FI~. 12;
~V~77 FIG. 14 is a schematic view showinq a preferred pneumatic control system for four accumulation conveyor sections for controlling the conveyor in the singulation mode;
FIG. 15is a partial plan view of a preferred embodiment of conveyor of the present invention showing the positioning of the control elements shown in FIG. 14 for the singulation mode of operation; and FIG. 16 is a partial cross sectionea side elevation view of the conveyor as viewed substantially along line 16-16 in FIG 15 DESCRIPTION OF THE PREFERRED ~BODI~NTS
Preferred embodiments of the present invention are shown in the urawings. With particular reference to FIGS. 1-3, a preferred embodiment of live roller zero pressure accumulation conveyor is shown incorporating the principles of the present invention.
The conveyor, in generzl, includes a frame having a pair of spaced parallel side channels 10 ana 12 which support a plurality of individually powered transverse rollers 14 for rotation. The upper surface of the individual .' rollers 14 are positioned in a common plane to define a path line as shown by the unnumbered arrows in the drawings along which conveyed articles are propelled in a direction as indicated by the arrows. In aadition, components of the _g_ ~2~ '7 preferred embodiment of the zero pressure accumulation conveyors showm in FIGS.1-3 include, generally, a trigger asse~bly 16 which senses the presence of an article at a specified location on tne conveyor, a brake assembly 18 which restrains the motion of the rollers 14, and a drive mechanis~., aenerally 20, for imparting power to the rollers 14 to drive them.
The Drive Assembly The preferred embodiment of drive assembly 20 will first be discussed in detail.
~.s shown best in FIGS. 1-4, the drive assembly 20 includes a cylindrical lineshaft or drive shaft 22 which preferably extends continuously over the entire length of the conveyor. The drive shaft 2c is preferably formed of a hard metal, such as cold rolled steel.
A plurality of independent torgue tubes, generally 24 as shown in ~IGS. 5 and 6, are positioned concentrically over the drive shaft 22, one torque tube 24a-24c each being located in longitudinally spaced sections a-c of the conveyor as shown in FIGS. 1-4. The torque tubes for each of these sections a-c are denoted by the numerals 24a-24c, respectively, in`FIGS. 1-4. Each of the respective torgue tubes is preferably formed of an organic polymer of which nylon is preferred. A suitable nylon may, for example, ke nylon 6/6LNP RL-4540, although it~will be-understood that other nylons as wellas other organic poly~lers may be selected by one skilled in the art in the manufacture of the tvrgue tubes 24 after that person has ap~reciated fully ~ZV167~
the invention disclosed herein. The internal diameter of the torque tubes 24 and the external diameter of the drive shaft Z2 are dimensioned and the materials from which the drive shaft 22 and torque tubes 24 are made as well as the surface characteristics of theseele~ents are selected such that when the drive shaft 22 is rotated, it will ~rive the respective torque tubes 24 by frictional engagement of the cylindrical surface of the drive shaft 22 with the interior surface of the torgue tubes 24.
Each of the torque tubes 24a-24c rotates indepen-dently of each other. This is accomplished by terminating the torque tubes 24 such that separate independent tubes are provided for each section a-c as shown in FIGS. 1-4. The ends of the torgue tubes 24 at the boundaries of each section a-c are preferably mounted in a suitable bearing 26 attached to the frame of the conveyor by suitable means (not shown).
A pluraliiy of slidable pulleys 28 are mounted on each of the torque tubes 24a-24c as shown in FIGS. 1-4.
The pulleys 28 are axially slidable back and forth alon~
their respective torque tubes 24 such that when they are positioned axially in one location they frictionally engage their torque tube to rotate with their respective torque tubes, but when they are displaced from that axial `
position, they slip relative to their torque tubes so that they do not rotate in unison with the latter. Such operation is more concisely described in the afore~entioned V.S. Patent N~. 3,650,375 ~Fleischauer et al). The pulleys 28 are also preferably formed of an organic polymer material, such as an acetal resin of which Delrln~is one suitable form.
A resilient belt 30, preferably formea of an elastomeric maierial, is looped about each of the pulleys and a circumferential groove 31 in an overlying roller 1~
of the conveyor as shown in FIGS. 1-4. Each of the belts 30 preferably comprises an O-belt in cross-section.
Although a plurality of pulleys 28 are shown in the drawings on the torque tubes`24, it will be understood that the pulleys may be replaced by indentations cast integrally with each of the torque tubes as is known in the art.
Where the pulleys 28 are employed, it may also i5 be desirable to provide spaced collars 32, as shown in FIGS. 2-4, fi~ed to the exterior surface of the torgue tubes at spaced locations to limit the axial movement of the pulleys 28 and prevent interference between adjacent pulleys.
It will be seen rom the preceding description of the drive assembly 20 that the drive belts 30 and rollers 14, the drive belts 30 and pulleys 23, the pulleys
The present invention relates to live roller conveyors used to transport articles along a predetermined path and, more particularly, to zero pressure accumulation conveyors and brake assemblies therefor.
Live roller conveyors and, even more ~articularly, accumulation conveyors are well known in the art. Such accumulation conveyors have, in the past, employe~ various ~echanisms for controlling the rotation of the conveyor rollers to allow them to be selectively rotated or stopped to accommodate accumulation of the articles beins conveyed by the conveyors. The rollers are rotated to convey the articles to a collection or accumulation location and, once one or more of the articles have reachéd that location, the rollers are stopped to provide for accumulation.
One such mechanism is shown in U.S. Patent No.
3,650,375 (Fleischauer et al). That ~atent discloses live rollers, each of which is d~iven by a resilient O-belt looped abo-~t a pulley beneath the rollers. The pulley is movahle axially along a driven shat. When articles are being conveyed by the rollers, the pulley axially sliaes , along the driven shaft to assume a position in which it is frictionally engaged with the driven shaft to cause the pulley to rotate with the drive shaft and, thereby, arive the rollers by way of the O-belt. Once an article is accumulated at a desired location on the conveyor, movement ~2~
of the article is prevented either by engagement of the article with a conveyor discharge gate or by contact of the article with a preceding artiele. When this latter condition occurs, the rollers beneath the article which has now stopped experience a frictional counter Iorce on their cylindrical surfaces due to the weight of the overlying article which causes the axially movable pulleys to move axially along the driven shaft to such point that their ~rictional engauement with the driven shaft is no longer sufficient to allow the pullevs to rotate with the driven shaft, thereby causing the pulleys to slip relative to the driven shaft and to cease to impart driving force to the live rollers through the O-belts.
The aforementioned construction is perfectly acceptable in most uses. However, it relies to a principal extent upon some measure of restraining contaet of the articles, either with a conveyor discharge gate or between the articles themselves. Such contact is of some concern, however, wherè the articles are extremely delicate, for example, electronics equipment in which extremely delicate handling of the articles is necess'ary to avoid damage. ~or such delicate equipment, it is desirable to eliminate all ,~ contact of the articles with a gate or with other articles to eliminate any possibility of impact or jarring of the equipment. In addition, such mechanisms rely upon frequent or continuous slippage of various elements of the drive system relative to other elements when the articles have reached their accumulation location. Such slippage ~V~ 7 may result in early wear and the need for early replacement of the elements.
Vari~us mechanisms have been employed in the past ~or positively controlling the rotation of the driven shaft, either in combination with such slidable pulleys or otherwise, in an attempt to o~ercome at least some of the aforementioned disadvantages. One such mechanism employing a clutch assembly is sh~wn in U S. Patent No. 3,840,110 (Molt et al). In that patent, several relatively com~lex clutching mechanisms are disclosed which operate to couple the driven shaft and its pulleys with a drive shaft to drive the driven shaft, its pulleys, O-belts and conveyor rollers when it is desired to move an article along the conveyor, but to positively uncou~le the drivenshaft ~n response to the actuation of suitable triggering mechanisms which sense the arrival of an article at a desired accl~mulation location. Although such clutching mechanisms minimize contact~et~7een the articles being conveyed and reduce frictional heat buildup and wear of the drive elements, such mechanisms are relatively complex with the attendant need to stock a large number of repair parts, an~ the increased difficulty of assem~ly and 4 maintenance which always accompanies mechanisms of relatively complex construction.
Brake assemblies have also ~een employed in the pas~inconjunction with such conveyor drive and driven shafts. One such brake assembly is shown, for example, in -~l.S. Patent No. 3,696,912 ~Fleischauer et al). In that patent a hrake assembly is disclosed which is mechanically actuated by a suitable trigger element which senses the presence of the article at its desired accumulation location, The trigger is mechanically coupled by a cable or chain which is connected to the brake assembly to cause the brake to engage a key on the driven shaft to lock the driven shaft against rotation. Although this mechanical key brake construction is, likewise, acceptable in a wide range of uses, it has the disadvantage of the need ~or relatively frequent maintenance and adjustment and some jarring of the elements and of the articles results from the positive key locking action.
~he zero pressure accumulation conveyor and brake assembly of the present in~ention overcome the constrUc-several aforementioned disadvantages of the prior c~L~u~-tions. A zero pressure accumulation conveyor and brake assembly constructed in accordance with the principles of the present invention minimize frictional heat and wear between the elements which slip relative to each other, thus resulting in a decrease in the need for maintenance and repair. In a zero pressure accumulation conveyor and .~ brake assembly incorporating the principles of the present invention, positive and rapid braking action is imparted to ~5 the drive elements of the conveyor to achieve rapid deceleration of the articles without damage to the articles, even though sufficient slip between the drive elements is 6~7 retained with its attendant advantages, A zero pressure accumulation conveyor and brake assembly constructed in accordance with the principles of the present invention is safe, quiet and simple in construction, thereby substan-tially reducing the need for maintenance and in time in assembling of the conveyor, and the need for maintaining a substantial spare parts inventory is also reduced, In one principal aspect of the present invention, a ~rake asse~bly comprises rotatable ~rive shaft means having a substantially cylindrical surface and torque tu~e means, The torque tube means also define a substantially cylindrical exterior surface and the drive shaft means extends axially into the torque tube means, The diameter of the cylindrical surface of the drive shaft means is slightly less than the internal diameter of the torque tube means such that the drive shaft means is capable of frictionally engaging the interior or the torque tube means to rotate the torque tube means when the drive shaft means is rotated, but is capable of slipping relative to the torque tube means when rotation of the torque tube means is restrained, Clamping surface means substantially surround at least a porticn of the exterior surface of the torque tube means and the clampi~g surface means is movable relative to that exterior surface between a first position in which the clamping surface means is moved out of contact with the exterior of the torque tube means and the rotating drive shaft means rotates the torque tube means, and a second position in which the clamping surface means is moved into contact with the exterior of the torque tube means to restrain the torque tube means from rotating with the drive shaft means, ~2~
In another principal aspect o~ the present invention, the aforementioned torque tube means is formed of an organic polymer, preferably nylon, and the drive shaft is a hard metal, preferably steel.
In still another principal aspect of the present invention, at least one pulley is mounted on the exterior surlace of the tor~ue tube means and the pulley is axially movable on the tor~ue tube means so as to frictionally engage the exterior surface of the tor~ue tube means to rotate therewith when the torque tube means rotates.
However, the pulley is slippable rotationally relative to the exterior sur~ace of the tor~ue tube means when the clamping surface means is moved to its second position.
In still another principal aspect of the present 1~ invention, the aforementioned brake assemblies are employed in combination with a plurality of live rotatable rollers for supporting and conveying an article along a plane and a plurality of endless resilient belts are looped about these rollers and the toraue tube means to drive the rollers when the torque tube means is rotated by the drive shaft means.
In still another principal aspect o~ the present invent;on, trigger means are included in the last mPntioned combination for sensing the presenc~ of an article being conveyed by the rollers and control means are responsive to the trigger means to move the cla~ping surface means between its first an~ second positions, the trigger means, clamping ~2~)~6~7`7 surface means and torque tube means being constructed and arranged to operate the rollers in either a singulation mode or a slug mode.
These and other objects, features and advantages of the present invention will become apparent upon considera-tion of the detailed description of the invention to follow.
BRIli:F` DESCPIPTION OF THE DRAWINGS
In the course of this description, the drawings will be frequently referred to in which:
FIG. 1 is a fraamentary perspective view of a S live roller accumulation conveyor incorporating the principles of the present invention;
FIG. 2 is a fragmentary plan view of the accumula-tion conveyor, with certain elements thereof bro~en away, as viewed substantially along line 2-. in FIG. l;
FIG. 3 is a partial side elevational view of the accumulation conveyor, with portions thereof broken away, as viewed substantially along line 3-3 in FIG. l;
FIG. 4 is a partial broken plan view of one full section and two partial ad~itional~sections of the drive shaft, driven shaft and pulleys in the preferred embodiment ,~ of accumulation conveyor of the present invention;
FIG 5 is partial broken end elevational view of a preferred embodiment of brake assembly incorporating the principles of the present invention as viewed substantially 2Q along line 5-5 in FI~. 2;
-~Z~6~
FIG. 6 is a partially broken side elevational view of the brake assembly as viewed substantially along line 6-6 in line 5;
FI~ 7 is a partially broken end elevational view of a triager mechanism for use in the slug mode of operation of the conveyor of the present invention and as viewed substantially along line 7-7 in FIG. 2;
FIG. 8 is a broken side elevational view of the last-mentioned trigger assernbly as viewed substantially alons line ~-8 in FIG. 7;
FIG. 9 is a partially broken end elevational vie~
of a trigger mechanism for use in the singulation mode of operation of the conveyor of the present invention;
FIG. 10 is a broken side elevational view of the 1ast-mentioned trigger assembly as viewed substantially along line 10-10 of FIG. 9;
FIG~ 11 is a schematic view showing a preferring pneumatic control system for four accunulation conveyor sections for controlling the conveyor in the slug mode;
FIG. 12 is a partial plan view of a preferred embodiment of conveyor of the present invention showing the positioning of the control elements shown in FIG. 11 for the slug mode of operation;
FIG. 13 is a partial cross sectioned side elevational view of the conveyor as viewed substantially along line 13-13 in FI~. 12;
~V~77 FIG. 14 is a schematic view showinq a preferred pneumatic control system for four accumulation conveyor sections for controlling the conveyor in the singulation mode;
FIG. 15is a partial plan view of a preferred embodiment of conveyor of the present invention showing the positioning of the control elements shown in FIG. 14 for the singulation mode of operation; and FIG. 16 is a partial cross sectionea side elevation view of the conveyor as viewed substantially along line 16-16 in FIG 15 DESCRIPTION OF THE PREFERRED ~BODI~NTS
Preferred embodiments of the present invention are shown in the urawings. With particular reference to FIGS. 1-3, a preferred embodiment of live roller zero pressure accumulation conveyor is shown incorporating the principles of the present invention.
The conveyor, in generzl, includes a frame having a pair of spaced parallel side channels 10 ana 12 which support a plurality of individually powered transverse rollers 14 for rotation. The upper surface of the individual .' rollers 14 are positioned in a common plane to define a path line as shown by the unnumbered arrows in the drawings along which conveyed articles are propelled in a direction as indicated by the arrows. In aadition, components of the _g_ ~2~ '7 preferred embodiment of the zero pressure accumulation conveyors showm in FIGS.1-3 include, generally, a trigger asse~bly 16 which senses the presence of an article at a specified location on tne conveyor, a brake assembly 18 which restrains the motion of the rollers 14, and a drive mechanis~., aenerally 20, for imparting power to the rollers 14 to drive them.
The Drive Assembly The preferred embodiment of drive assembly 20 will first be discussed in detail.
~.s shown best in FIGS. 1-4, the drive assembly 20 includes a cylindrical lineshaft or drive shaft 22 which preferably extends continuously over the entire length of the conveyor. The drive shaft 2c is preferably formed of a hard metal, such as cold rolled steel.
A plurality of independent torgue tubes, generally 24 as shown in ~IGS. 5 and 6, are positioned concentrically over the drive shaft 22, one torque tube 24a-24c each being located in longitudinally spaced sections a-c of the conveyor as shown in FIGS. 1-4. The torque tubes for each of these sections a-c are denoted by the numerals 24a-24c, respectively, in`FIGS. 1-4. Each of the respective torgue tubes is preferably formed of an organic polymer of which nylon is preferred. A suitable nylon may, for example, ke nylon 6/6LNP RL-4540, although it~will be-understood that other nylons as wellas other organic poly~lers may be selected by one skilled in the art in the manufacture of the tvrgue tubes 24 after that person has ap~reciated fully ~ZV167~
the invention disclosed herein. The internal diameter of the torque tubes 24 and the external diameter of the drive shaft Z2 are dimensioned and the materials from which the drive shaft 22 and torque tubes 24 are made as well as the surface characteristics of theseele~ents are selected such that when the drive shaft 22 is rotated, it will ~rive the respective torque tubes 24 by frictional engagement of the cylindrical surface of the drive shaft 22 with the interior surface of the torgue tubes 24.
Each of the torque tubes 24a-24c rotates indepen-dently of each other. This is accomplished by terminating the torque tubes 24 such that separate independent tubes are provided for each section a-c as shown in FIGS. 1-4. The ends of the torgue tubes 24 at the boundaries of each section a-c are preferably mounted in a suitable bearing 26 attached to the frame of the conveyor by suitable means (not shown).
A pluraliiy of slidable pulleys 28 are mounted on each of the torque tubes 24a-24c as shown in FIGS. 1-4.
The pulleys 28 are axially slidable back and forth alon~
their respective torque tubes 24 such that when they are positioned axially in one location they frictionally engage their torque tube to rotate with their respective torque tubes, but when they are displaced from that axial `
position, they slip relative to their torque tubes so that they do not rotate in unison with the latter. Such operation is more concisely described in the afore~entioned V.S. Patent N~. 3,650,375 ~Fleischauer et al). The pulleys 28 are also preferably formed of an organic polymer material, such as an acetal resin of which Delrln~is one suitable form.
A resilient belt 30, preferably formea of an elastomeric maierial, is looped about each of the pulleys and a circumferential groove 31 in an overlying roller 1~
of the conveyor as shown in FIGS. 1-4. Each of the belts 30 preferably comprises an O-belt in cross-section.
Although a plurality of pulleys 28 are shown in the drawings on the torque tubes`24, it will be understood that the pulleys may be replaced by indentations cast integrally with each of the torque tubes as is known in the art.
Where the pulleys 28 are employed, it may also i5 be desirable to provide spaced collars 32, as shown in FIGS. 2-4, fi~ed to the exterior surface of the torgue tubes at spaced locations to limit the axial movement of the pulleys 28 and prevent interference between adjacent pulleys.
It will be seen rom the preceding description of the drive assembly 20 that the drive belts 30 and rollers 14, the drive belts 30 and pulleys 23, the pulleys
2~ and the exterior surface of torgue tubes 24a-24c, and the interior surface of torque tubes 24a-24c and the suxface of drive shaft 22 are all in frictional engagement with each other and will rotate in unlson with each other due to such engagement, but may slip relative to each other under ra de ~/7ar/~ -~
~l2~6~7'7 certain conditlons o~ restraint of certain of the elements as will be described in more detail to follo~.
The Brake Assembly The brake assembly 18 is sho~n in detail in FIGS. 5 and 6. The brake assembly 18 includes an L-shaped bracket 34, the vertical leg of which is preferably T-shaped and is bolted by bolts 36 to one o~ the side channels 12. An air cylinder 38 which receives air from one ~f the trigger assemblies 16 throuah conduit 40 is mounted to the horizontal lea of the bracket 34 and a piston roa ~t2 extends downwardly from the cylinder 38 as shown in FIGS 5 and 6.
The horizontal portion of the bracket includes a Fair o~ downwardlyextendin~ flanges 44 bet~een which clamping ~eans 46 of the present invention are mo~mted The clamping means comprise a pair D* shoes 48 and 50 wllich ~ay be formed of an organic polymer or other suitable ~.aterial The shoes are preferably formed of tough nylon. The shoes 4~ and 50 are ~oupled to each other at one side by a pivot pin 52. ~ach of the shoes 48 and 50 includes a substantially semi-cylindrical portion having a curved clamping surface 54 as shown in FIG. 5 which is adapted to be pivoted about pivot pin 52 into and out of contacting relationship with a cylindrical sleeve 56 located at each of the bxake assembly locations. The cylindrical sleeve 56 is fixed to the torque tube 2~ and the sleeve is pre~erably ~ormed of metal, such 25 aluminum. The sleeve 56 is preferably bondea to its tor~e tube by a suitable adhesive such as, for ~xample~ LOCTlTE 326~acihesive, activated by LOCTITE 707 activator Thus, the sleeve 56 always rotates with the torgue tube 24.
.r~acle MarK
'7 The shoes 48 and 50 each include arms 58 and 60 extending from the cylindrical portion of the shoes o~posite the pivot pin 52 as shown in FIG. 5. The end of the arm 60 on the botto~ shoe 50 is pivotally fixed adjacent the bottom of downwardly extending flange 44 by a pin 62 between the flanges and the upper arm 58 on the upper shoe 48 is fixed to the piston rod 42 and is movable in the vertical direction by the piston rod between the flanges 44.
Thus, dependin~ upon whether air is present or absent in the conduit 40 fror~. a given trigger assembly 16, the up~er shoe 48 will be ~ivoted by piston xod 42 into either a first position in which the clamping surfaces 54 are ~oved out of contact with the outer surface of sleeve 56 to allow the sleeve and its torque tube 24 to be rotated by the drive shaft 22, or to a second position in which the clamping surfaces 5~ engage the sleeve 56 to restrain their rotation by the drive shaft.
~he Trigger Assembly The trigger assembly 16 will now be described, first by referring in particular~to FIGS. 7 and 8 which show the trigger assembly for the slug ~.ode of operation of the conveyor;
The trigaer assembly shown in FIGS 7 ana 8 includes a horizontally disposed ~-shaped cam 64 adjacent each of the side channels 10 and 12. The ca~ 64 includes ~2~:~L6~7 three upwardly extending legs of the E, legs 66, 6~ and 70 in descending order of length. The longest of the legs 66 includes a cam roller 72 which e~tends across the width of the conveyor and is rotatably mounted between the extremities of the legs 66 on opposite sides of the conveyor as shown in FIG. 7. The upper sur~ace of the roller 72, when an article is absent, extends slightly above the plane of the tops of the rollers 14 as shown in FIG. 8, but will be biased downwardly by an article which is being conveyed when the article is positioned over the roller 72. The roller 72 preferably rises above the upper surfaces of the roller 14 by approxi-mately 3/~ inch.
The intermediate leg 68 of the E-shaped cam 64 is the pivot mounting for the cam. A rod 74 extends transversely 1, across the conveyor and is mounted between the side channels lC and 12 as shown in FIG. 7 to pivotally mount the cam 64 to the side channels and allow the cam and, in particular, its roller 7? to pivot to the position sho~ in FIG. 8 as well as to a lowèr position in which the upper surface of roller 72 lies in the sa~e plane as the upper surfaces of rollers 14.
The shortest leg 70 of the trigger assembly 16 includes a counterbalancing weight i6 in the for~ of a rod ,~ or tube which also extenas transversely across the conveyor and couples the legs 70 of the cams 64 on both sides of the conveyor bed. The weight of the counterbalance 76 and its spacing from ca~ Fivot rod 74 is such th~t the roller 72 will be biased to its upward position as sho~ in FIG. 8 in the a~sence of any other forces.
~l2~6~7'7 certain conditlons o~ restraint of certain of the elements as will be described in more detail to follo~.
The Brake Assembly The brake assembly 18 is sho~n in detail in FIGS. 5 and 6. The brake assembly 18 includes an L-shaped bracket 34, the vertical leg of which is preferably T-shaped and is bolted by bolts 36 to one o~ the side channels 12. An air cylinder 38 which receives air from one ~f the trigger assemblies 16 throuah conduit 40 is mounted to the horizontal lea of the bracket 34 and a piston roa ~t2 extends downwardly from the cylinder 38 as shown in FIGS 5 and 6.
The horizontal portion of the bracket includes a Fair o~ downwardlyextendin~ flanges 44 bet~een which clamping ~eans 46 of the present invention are mo~mted The clamping means comprise a pair D* shoes 48 and 50 wllich ~ay be formed of an organic polymer or other suitable ~.aterial The shoes are preferably formed of tough nylon. The shoes 4~ and 50 are ~oupled to each other at one side by a pivot pin 52. ~ach of the shoes 48 and 50 includes a substantially semi-cylindrical portion having a curved clamping surface 54 as shown in FIG. 5 which is adapted to be pivoted about pivot pin 52 into and out of contacting relationship with a cylindrical sleeve 56 located at each of the bxake assembly locations. The cylindrical sleeve 56 is fixed to the torque tube 2~ and the sleeve is pre~erably ~ormed of metal, such 25 aluminum. The sleeve 56 is preferably bondea to its tor~e tube by a suitable adhesive such as, for ~xample~ LOCTlTE 326~acihesive, activated by LOCTITE 707 activator Thus, the sleeve 56 always rotates with the torgue tube 24.
.r~acle MarK
'7 The shoes 48 and 50 each include arms 58 and 60 extending from the cylindrical portion of the shoes o~posite the pivot pin 52 as shown in FIG. 5. The end of the arm 60 on the botto~ shoe 50 is pivotally fixed adjacent the bottom of downwardly extending flange 44 by a pin 62 between the flanges and the upper arm 58 on the upper shoe 48 is fixed to the piston rod 42 and is movable in the vertical direction by the piston rod between the flanges 44.
Thus, dependin~ upon whether air is present or absent in the conduit 40 fror~. a given trigger assembly 16, the up~er shoe 48 will be ~ivoted by piston xod 42 into either a first position in which the clamping surfaces 54 are ~oved out of contact with the outer surface of sleeve 56 to allow the sleeve and its torque tube 24 to be rotated by the drive shaft 22, or to a second position in which the clamping surfaces 5~ engage the sleeve 56 to restrain their rotation by the drive shaft.
~he Trigger Assembly The trigger assembly 16 will now be described, first by referring in particular~to FIGS. 7 and 8 which show the trigger assembly for the slug ~.ode of operation of the conveyor;
The trigaer assembly shown in FIGS 7 ana 8 includes a horizontally disposed ~-shaped cam 64 adjacent each of the side channels 10 and 12. The ca~ 64 includes ~2~:~L6~7 three upwardly extending legs of the E, legs 66, 6~ and 70 in descending order of length. The longest of the legs 66 includes a cam roller 72 which e~tends across the width of the conveyor and is rotatably mounted between the extremities of the legs 66 on opposite sides of the conveyor as shown in FIG. 7. The upper sur~ace of the roller 72, when an article is absent, extends slightly above the plane of the tops of the rollers 14 as shown in FIG. 8, but will be biased downwardly by an article which is being conveyed when the article is positioned over the roller 72. The roller 72 preferably rises above the upper surfaces of the roller 14 by approxi-mately 3/~ inch.
The intermediate leg 68 of the E-shaped cam 64 is the pivot mounting for the cam. A rod 74 extends transversely 1, across the conveyor and is mounted between the side channels lC and 12 as shown in FIG. 7 to pivotally mount the cam 64 to the side channels and allow the cam and, in particular, its roller 7? to pivot to the position sho~ in FIG. 8 as well as to a lowèr position in which the upper surface of roller 72 lies in the sa~e plane as the upper surfaces of rollers 14.
The shortest leg 70 of the trigger assembly 16 includes a counterbalancing weight i6 in the for~ of a rod ,~ or tube which also extenas transversely across the conveyor and couples the legs 70 of the cams 64 on both sides of the conveyor bed. The weight of the counterbalance 76 and its spacing from ca~ Fivot rod 74 is such th~t the roller 72 will be biased to its upward position as sho~ in FIG. 8 in the a~sence of any other forces.
3~2~ 7 The axes of the pivot rod 74, of rotation of the conveyor rollers 14 and of the cam roller 72 are preferablv positioned in a predetermined relationship to each other.
The axis of pivot rod 79 is preferably located in a plane in or above the planedefined by the axes y of the rollers 14, and the axis z of rotation of the cam roller 72 is preferably in a planebelow the planeof the upper surface of the rollers 14 when roller 72 is in its uppermost position.
Such positioning, together with the configuration of the E-shaped cam 64, allows the trigger to ~e mounted on a conveyor without particular concern as to the direction of flow of the articles. Such positioning and configuration will allow and not impair the movement o~ articles in either direction on the conveyor as, for example, i~ it is ~esired to manually backu~ some of the articles which have already been accumulated.
It will also be noted that the configuration of the E-shaped cam 64 is such that it is not necessary to remove any of the powere~ live rollers 1~ to accomodate the trigger assembly. This is particularly advantaqeous where the articles being handled are of short dimension in the direction of thè path in which they are being conveyed.
The trigger assembly shown in FIGS. 7 and 8 also includes an ~-shaped bracket 78 which is mounted by bolts 80 to the side channel 12. Although it is preferred that the bracXet 7~ and the operating components of the trigger assembly be mounted to the side channel 12, rather than the ~2~ 7'7 side channel 10 to which the brake assembly 18 has been mounte~, it will be understood that both the trigger assembly and the brake assembly may be mounted on the same side channel. Mounting of these respective assemblies to o~posite side channels is preferre~,however, because it facilitates assembly and maintenance. The L-shaped brac~et 78 also includes a horizontal leg upon which a pneumatic air valve assembly, generally 82, and an adjustable limit stop 84 are also mounted.
The air valve assembly 82 includes a valve body 86 having a T-fitting 8~ with two conduits 40, as previously described, and 90 coupled to the fitting. As previously described, conduit 40 is coupled to the air cylinder 38 of a brake assembly 18 as shown in ~IGS. 5 and 6. Conduit 90 is coupled to the bottom of the valve body 86 as shown in FIGS. 7 and 8, but of the valve body of the triager in the next upstream section of the conveyor. As shown in FIGS. 7 and 8, the conduit 90 entering the bottom of the valve body is from either the T-fittina on the next downstream trigger assembly or from the air supply as shown in FIG. 11, and the conduit 90 extending horizontally-to the left of the T-fitting 88 is to the next upstream trigger assembly.
Pivotally mounted at 9~ on the hori~ontal leg of the bracket 78 is a cam ollower arm 96 and rollèr 9~. A
plunger rod 100 extenas into the valve body 86, ~as shown in FIGS. 7 and 8, to operate the valve in the valve body 8Ç
The plunaer rod 100 is preferably spring loaded up~araly to force the cam roller 9~ against the underside of the cam 6~ as shown in FIG. ~.
The limit stop 84 preferably includes a bolt 102 which is threaaed upwardly through t~e horizontal leg of the bracket 78 to act as an adjustable limit stop for the pivotal movement of cam 64. The bolt 102 is adjusted so that it also contacts the underside of the cam 64 as shown in FIG. 8 such that the cam roller 72 projects above the plane of the tops of the rollers 14 by the desired distance as previously described. Once the bolt 102 is moved to its desired adjusted position, it is secured in that position by lock nuts 104.
As previously mentioned, the trigger assembly 15 shown in FI~S 7 and 8 is the trigger assembly which is preferably employed in the slug mode of operation of the conveyor. The preferred trigaer assembly 16' for use in the singulation mode of operation of the conveyor is show in FIGS. 9 and 10. ~umerous ones of the components in the singulation mode trigger assembly 16' are identical to those previously described in the slug mode assembly 16 shown ln FIGS. 7 and 8. Accordingly, like reference numerals will be employed to designate substantially like components -' and where the cGmponents do differ in some respect between the singulation and slug modes, the superscript "'" will - be employed to designate such components in the singulation trigger assembly 16' which will now be described.
i'7'~
Essentially, the major differences bet~een the previously described slug mode trigger assembly 16 and the singulation trigger asserbly 16' are somewhat different air conduit couplings and the provision of an additional S pilot valve asse~bly 106 in the singulation trigger assembly 16'.
~he valve body 86l of the singulation trigger assembly 16' incluaes a down~Jardly aepenaing T-fitting ~8' having a pair of conduits 108 which couple the valve bodies 86' of the trigger assemblies 16' in adjacent conveyor sections to each other.
As shown in FIG. 9, a third conduit 110 extends from valve body 86' to a T-fitting 112 on a pilot actutator lla on each of the pilot valve assemblies 106. The other conduit 116, extending from the T-fitting 112 as sho~m in FI~. 10, ports air from the T-fitting 112 to the bottom of the valve body llg of the pilot valve assembly 106 in the next downstream trigger assembly 16' as sho~n in FIGS. 1, 10 and la With the mechanical elements of the preferred embodi-ments of zero pressure accumulation conveyors and brake assembly of the invention having now been aescribed, a description of the operation of the conveyor and its control circuitry in both the slua and singulation modes will now be described.
~2~)~67~7 The O~eration in the Slu~ Mode Although reference may be occasionally made to other figures in the drawings, the principal figures relied upon in the description of operation in the slug mode are FIGS. 11-13 and, to some extent~ FI~S. 7 and 8 of the slug mode trigger assembly 16~ The brake assembly 18 and drive assembly 20 are substantially identical to each other in both the slug and singulation modes.
Prior to describing the sequence of operation in the slug mode, it should be stated that the general manner of operation in that mode is that anytime an article A is removed ~rom the conveyor, all of the upstream articles will advance one position simultaneously.
Referring now particularly to FIGS. 11-13, it will be initially assumed that an article A is located in each of the accumulator sections a-d as shown. Thus, an article ~a will be positioned over the cam roller 72 of trigger assembly 16 in section a, an article Ab will ke positioned over cam roller 72 of trigger assernbly 16 in section b, etc.
~hen these cam rollers i2 are depressed by the articles A, the cam follower arms 96 of each of the respec-~ tive valve bodies 86 will also be depressed and, referring to FIGS. 7 and 8, the valve in the valve body 86 will be 2~ opened~ allowing air to pass from the air supply shown in FI~. 11, through conduit 90 to and through the valve ~ody 86 in section a,the T-fitting 88 and conduit 40, to the cylinder ~LZ~ 7 3B of the brake assembly 18 also in sectio~ a. Thus, cylinder 38 of brake assembly 18 will be actuated to cause the piston rod 42, shown in FIGS. 5 and 6, to move downwardly and to cause the clamping surfaces 54 of shoes 48 and 50 to clamp and restrain the sleeve 56 and tor~ue tube 24a in section a, thus restraining rotation of torque tube 24a and isolating the driving force imparted by the continuously rotating drive shaft 22 from the conveyor rollers 14.
In this condition, air also passes from the ~-fitting 88 in section a through conduit 90 to valve body 86 of the trigger assembly 16 in section b. Because its cam follower 96 is also depressed by article Ab positioned over roller 72 of the cam, the valve in valve body 86 in section b will, likewise, be opened, porting air to its T-fitting 88 to energize the brake assembly 18 in section b to secure power to the rollers 14 in that section Air~ will also be ported through conduit 90 to the next upstream valve body 86 in section c Thus, it will be seen that all of the valves in valve bodies 86 in each of the sections and will be opened to port air to the brake assemblies 18 in each o~ the sections, stopping all of the rollers 14 because all of the arti.cles Aa-Ad desired to be accumulated have been accumulated.
hen article Aa is removed from the discharge section a of the conveyor, the roller 72 of the trigaer assembly 16 in section a will rise due to the force exterted by the counterbalance 76 shown in ~IG. 8. ~hen the roller 72 rises, the cam follower 96 in section a will also rise and ~;2Q~7 the plunaer rod 100, as shown in FIGS. 7 and 8, will move upwardly by spring ~ressure closing the valve in valve body 86 in section a. When this valve is closed, the air supply will be cut off to the entire system because all of the valve bodies 86 are connected in series. Accordingly, air will no longer be supplied to conduit 40 to the cylinder 38 of the bra~e assembly 18 in section a and thepiston rod a2, as shown in FIGS. 5 and 6, will rise causing the shoes 48 and 5D to pivot apart and move out of contact with sleeve 59. Sleeve 54 is now no longer restrained by the brake assembly and the driving action of the continuously rotating drive shaft 22 operates upon the interior of the torque tube 24a to cause the torque tube to rotate along with its pullies, O-belts and the rollers 14 in section a.
As previously mentioned, when air is cut of to the valve body 86 in section a, air will no longer pass through the T-fittin~ 88 of that valve body and conduit 90 to the next upstrea~ valve body 86 o. trigaer assembly 16 in section b.
Thus, even though the cam follower 96 is still depressed by the article Ab in section b, air is now absent from conduit 40 due to the closing of the valve-in valve body 86 in section à. Absent such air, cylinder 38 of brake assembly 18 ,. in section b cayses the piston rod 42 of the brake assembly to move u~wardly in similar fashion as did the rod 42 in section a to remove the restraint from the torque tube 24b in section b. Thus, it ~ill be seen that because the respective trigger assemblies in this slug mode are effectively couple~ to each other in series, when air is shut off at the ~Z~3~6~7'~
valve body 86 in section a, the air will be secured throughout the entire system. Once this air is secured, all of the hra~e assemblies will be deenersized, causing all of the articles A~-~d to advance simultaneously until the then next leaZ article Ab enters section a and contacts the roller 72 of the trigger assembly 16 in section a.
Once the article Ab contacts the roller 72 in section a, the valve in-valve body 86 in that section will again be opened to port air via T-~itting 8~ to the conduit 40 and cylinder 3 to reseet the brake assembly 18 in section a, and through conduit 90 to the valve body 86 in section b.
If article Ac has not yet arrived at cam roller 7 ~ in section b, the valve in vlave body ~6 in section b will remain closed, causing the brake zssembly 1~ in section b to remain deenergized and allowing the rollers 14 in section b to continue to operate until article Ac contacts roller 72 in section b.
Operation in the Singulation ~ode In describing the operation in the sin~ulation mode, frequent reference will be made primarily to FIGC. 14-16 and also to FIGS. 9 and 10 In the singulation mode, only one of the articles A will advance at a time. Once it has left its previous at-~5 rest position and is enroute to its destined accu~lation position, the next article will begin to advance to replace the enroute article. The articles do not all advance simultaneously as in the Freviously descri~ed slug mode.
6~7 Again, it ~ill initially be 2ssurned that articles Aa--Ad are present and occupy each o~ the respective accumu-lation positions in eachof-th~ sections a-d as shown i~
~IGS. 15 and 16. In this condition, article Pa in sectiona will have moved over cam roller 72 of triqger asser~l~ 16' in section a, article ~ will have moved over cam roller 72 in trigger asse~ly 16' in section b, etc.
In the sinqulation mode, air is supplied to all of the trigaer valves simultaneously and in parallel from the air sup~ly shown in FIG. 14 via condu:its 108. Thus, unlike the slug node, all of the valve bodies 86` are eneroized and ready to port 2ir depending upon whether an article ~ is abscnt or present in their respec~ive conveyor sections. A conduit 116 from the air supply to the valve body 118 of pilot valve assembly 106 in section a also supPlies air to that valve body ready ~or opening of the valve.
Because article ~.a has depressed cam roller 72 in section a, cam follower 96 will also be depressec. Thus, plunger rod 100 shown in FI~S. ~ and 10 will, likewise, be depressed to opèn the valve in valve body 86' in sectiun a causing air to pass through conduit 110 to r-fitting 112 on the pilot actuator 114 of pilot valve assembl~ 106 in sectio~
a When air is supplied to the pilot actuator114, it actuates the valve in valve body 118 of pilot valve assembly 106 to open that valve allo~ing air to pass frOJn conduit 116 from the air su~ply though conduit 40 to cylin~er 3~ of the brake -~4-~2C~'7~
assembly 1~ in section a. Air to cylind~r 3~, as shown in ~IGS. ~ and 6, causes piston rod 4, to move downwardly and the shoes 48 and 50 to move together to clam~ sleeve 56 and torque tube 24a in section a. This cla~ping motion restrains the movement of t~rque tube 24a allo~ing the continuously rotating drive shaft 22 to slip relative to the tor~ue tube and denergize the conveyor rollers 14 in section a.
In this fully loaded condition, i.e. ~rticles Aa-Ad on each of sections a-d, air will also be ~orted ~rom the T-fittin~ 112 in section a through conduit 116 to tne valve body 118 of pilot valve assembly 106 in section b.
As previously mentioned, air is continuously ported via conduit 10~ from the T-fitting ~8' in section a to ~-fitting 88' in section b.
Because the article Ab in section b, likewise, is overlying the cam roller 72 in section b, ca~. roller 96 of the trigger asse~bly 16' in section b wi.ll be depressed, openin~ the valve in valve body 86' in section b to cause air to pass through conduit 110 to the T-fitting 112 on the Filot actuator 114 of the pilot valve assembly 106 in section b Air to this T-fitting 112 actuates the pilot .~ actuator 114 to open the valve in valve body 11~, causing air to pass through conduit 4~to the cylinder38 of the brake assembly 1~ in section b. This air, thereby, causes piston rod 42 of cylinder 38 in section b to move downwardly clampin~
~L2~6'7~7 the sleeve 56 and tor~ue tube 24b to, likewise, restrain its movement and allow driveshaft 22 to slip relative to the torgue tube deenergizing the rollers 14 in section b.
This same sequence follows upstream and, thus, all o~ the rollers 14 in each of the sections a-d are stopped because they each have an article Aa-Ad accumulated thereon It will now be assumed that article Aa is removec from the conveyor section a. When the article Aa is removed, cam roller 72 will rise in section a causing the cam follower 96 on the valve body 86' in section a also to rise.
When this happens, the valve ir. valve body 86' in section a will closd to secure air to conduit 110 to the ~-fitting 112 on the pilot actuator 114 of the pilot valve assembly 106 in section a. ~?hen this ha~ens, the valve in the valve ~d~ of the pilot valve assembly 10~ will also close to secure air from the air supply and conduit 116 to conduit 40 and the cylinder 38 of the brake assembly 18 in section a.
With the brake assembly 18 deenergized, the piston rod 42 of the brake asse~bly, as shown in FIGS. 5 and 6, will move upwardly, causinq the shoes 48 and 50 to move apart to release the sleeve 56 and torque tu~e 24a and allow them to aqain be rotated by the drive shaft 22 energizing rollers 14 in section a.
When the valve in valve body 86' in sectiona is closed, air is not only secured to the T-fitting 112 of the pilot actuator 114 in section a, but it is also secured to conduit 116 which leads to the valve body 118 of the pilot ~2~ 7 valve assembly 106 in section b. Absent such air, c~nduit
The axis of pivot rod 79 is preferably located in a plane in or above the planedefined by the axes y of the rollers 14, and the axis z of rotation of the cam roller 72 is preferably in a planebelow the planeof the upper surface of the rollers 14 when roller 72 is in its uppermost position.
Such positioning, together with the configuration of the E-shaped cam 64, allows the trigger to ~e mounted on a conveyor without particular concern as to the direction of flow of the articles. Such positioning and configuration will allow and not impair the movement o~ articles in either direction on the conveyor as, for example, i~ it is ~esired to manually backu~ some of the articles which have already been accumulated.
It will also be noted that the configuration of the E-shaped cam 64 is such that it is not necessary to remove any of the powere~ live rollers 1~ to accomodate the trigger assembly. This is particularly advantaqeous where the articles being handled are of short dimension in the direction of thè path in which they are being conveyed.
The trigger assembly shown in FIGS. 7 and 8 also includes an ~-shaped bracket 78 which is mounted by bolts 80 to the side channel 12. Although it is preferred that the bracXet 7~ and the operating components of the trigger assembly be mounted to the side channel 12, rather than the ~2~ 7'7 side channel 10 to which the brake assembly 18 has been mounte~, it will be understood that both the trigger assembly and the brake assembly may be mounted on the same side channel. Mounting of these respective assemblies to o~posite side channels is preferre~,however, because it facilitates assembly and maintenance. The L-shaped brac~et 78 also includes a horizontal leg upon which a pneumatic air valve assembly, generally 82, and an adjustable limit stop 84 are also mounted.
The air valve assembly 82 includes a valve body 86 having a T-fitting 8~ with two conduits 40, as previously described, and 90 coupled to the fitting. As previously described, conduit 40 is coupled to the air cylinder 38 of a brake assembly 18 as shown in ~IGS. 5 and 6. Conduit 90 is coupled to the bottom of the valve body 86 as shown in FIGS. 7 and 8, but of the valve body of the triager in the next upstream section of the conveyor. As shown in FIGS. 7 and 8, the conduit 90 entering the bottom of the valve body is from either the T-fittina on the next downstream trigger assembly or from the air supply as shown in FIG. 11, and the conduit 90 extending horizontally-to the left of the T-fitting 88 is to the next upstream trigger assembly.
Pivotally mounted at 9~ on the hori~ontal leg of the bracket 78 is a cam ollower arm 96 and rollèr 9~. A
plunger rod 100 extenas into the valve body 86, ~as shown in FIGS. 7 and 8, to operate the valve in the valve body 8Ç
The plunaer rod 100 is preferably spring loaded up~araly to force the cam roller 9~ against the underside of the cam 6~ as shown in FIG. ~.
The limit stop 84 preferably includes a bolt 102 which is threaaed upwardly through t~e horizontal leg of the bracket 78 to act as an adjustable limit stop for the pivotal movement of cam 64. The bolt 102 is adjusted so that it also contacts the underside of the cam 64 as shown in FIG. 8 such that the cam roller 72 projects above the plane of the tops of the rollers 14 by the desired distance as previously described. Once the bolt 102 is moved to its desired adjusted position, it is secured in that position by lock nuts 104.
As previously mentioned, the trigger assembly 15 shown in FI~S 7 and 8 is the trigger assembly which is preferably employed in the slug mode of operation of the conveyor. The preferred trigaer assembly 16' for use in the singulation mode of operation of the conveyor is show in FIGS. 9 and 10. ~umerous ones of the components in the singulation mode trigger assembly 16' are identical to those previously described in the slug mode assembly 16 shown ln FIGS. 7 and 8. Accordingly, like reference numerals will be employed to designate substantially like components -' and where the cGmponents do differ in some respect between the singulation and slug modes, the superscript "'" will - be employed to designate such components in the singulation trigger assembly 16' which will now be described.
i'7'~
Essentially, the major differences bet~een the previously described slug mode trigger assembly 16 and the singulation trigger asserbly 16' are somewhat different air conduit couplings and the provision of an additional S pilot valve asse~bly 106 in the singulation trigger assembly 16'.
~he valve body 86l of the singulation trigger assembly 16' incluaes a down~Jardly aepenaing T-fitting ~8' having a pair of conduits 108 which couple the valve bodies 86' of the trigger assemblies 16' in adjacent conveyor sections to each other.
As shown in FIG. 9, a third conduit 110 extends from valve body 86' to a T-fitting 112 on a pilot actutator lla on each of the pilot valve assemblies 106. The other conduit 116, extending from the T-fitting 112 as sho~m in FI~. 10, ports air from the T-fitting 112 to the bottom of the valve body llg of the pilot valve assembly 106 in the next downstream trigger assembly 16' as sho~n in FIGS. 1, 10 and la With the mechanical elements of the preferred embodi-ments of zero pressure accumulation conveyors and brake assembly of the invention having now been aescribed, a description of the operation of the conveyor and its control circuitry in both the slua and singulation modes will now be described.
~2~)~67~7 The O~eration in the Slu~ Mode Although reference may be occasionally made to other figures in the drawings, the principal figures relied upon in the description of operation in the slug mode are FIGS. 11-13 and, to some extent~ FI~S. 7 and 8 of the slug mode trigger assembly 16~ The brake assembly 18 and drive assembly 20 are substantially identical to each other in both the slug and singulation modes.
Prior to describing the sequence of operation in the slug mode, it should be stated that the general manner of operation in that mode is that anytime an article A is removed ~rom the conveyor, all of the upstream articles will advance one position simultaneously.
Referring now particularly to FIGS. 11-13, it will be initially assumed that an article A is located in each of the accumulator sections a-d as shown. Thus, an article ~a will be positioned over the cam roller 72 of trigger assembly 16 in section a, an article Ab will ke positioned over cam roller 72 of trigger assernbly 16 in section b, etc.
~hen these cam rollers i2 are depressed by the articles A, the cam follower arms 96 of each of the respec-~ tive valve bodies 86 will also be depressed and, referring to FIGS. 7 and 8, the valve in the valve body 86 will be 2~ opened~ allowing air to pass from the air supply shown in FI~. 11, through conduit 90 to and through the valve ~ody 86 in section a,the T-fitting 88 and conduit 40, to the cylinder ~LZ~ 7 3B of the brake assembly 18 also in sectio~ a. Thus, cylinder 38 of brake assembly 18 will be actuated to cause the piston rod 42, shown in FIGS. 5 and 6, to move downwardly and to cause the clamping surfaces 54 of shoes 48 and 50 to clamp and restrain the sleeve 56 and tor~ue tube 24a in section a, thus restraining rotation of torque tube 24a and isolating the driving force imparted by the continuously rotating drive shaft 22 from the conveyor rollers 14.
In this condition, air also passes from the ~-fitting 88 in section a through conduit 90 to valve body 86 of the trigger assembly 16 in section b. Because its cam follower 96 is also depressed by article Ab positioned over roller 72 of the cam, the valve in valve body 86 in section b will, likewise, be opened, porting air to its T-fitting 88 to energize the brake assembly 18 in section b to secure power to the rollers 14 in that section Air~ will also be ported through conduit 90 to the next upstream valve body 86 in section c Thus, it will be seen that all of the valves in valve bodies 86 in each of the sections and will be opened to port air to the brake assemblies 18 in each o~ the sections, stopping all of the rollers 14 because all of the arti.cles Aa-Ad desired to be accumulated have been accumulated.
hen article Aa is removed from the discharge section a of the conveyor, the roller 72 of the trigaer assembly 16 in section a will rise due to the force exterted by the counterbalance 76 shown in ~IG. 8. ~hen the roller 72 rises, the cam follower 96 in section a will also rise and ~;2Q~7 the plunaer rod 100, as shown in FIGS. 7 and 8, will move upwardly by spring ~ressure closing the valve in valve body 86 in section a. When this valve is closed, the air supply will be cut off to the entire system because all of the valve bodies 86 are connected in series. Accordingly, air will no longer be supplied to conduit 40 to the cylinder 38 of the bra~e assembly 18 in section a and thepiston rod a2, as shown in FIGS. 5 and 6, will rise causing the shoes 48 and 5D to pivot apart and move out of contact with sleeve 59. Sleeve 54 is now no longer restrained by the brake assembly and the driving action of the continuously rotating drive shaft 22 operates upon the interior of the torque tube 24a to cause the torque tube to rotate along with its pullies, O-belts and the rollers 14 in section a.
As previously mentioned, when air is cut of to the valve body 86 in section a, air will no longer pass through the T-fittin~ 88 of that valve body and conduit 90 to the next upstrea~ valve body 86 o. trigaer assembly 16 in section b.
Thus, even though the cam follower 96 is still depressed by the article Ab in section b, air is now absent from conduit 40 due to the closing of the valve-in valve body 86 in section à. Absent such air, cylinder 38 of brake assembly 18 ,. in section b cayses the piston rod 42 of the brake assembly to move u~wardly in similar fashion as did the rod 42 in section a to remove the restraint from the torque tube 24b in section b. Thus, it ~ill be seen that because the respective trigger assemblies in this slug mode are effectively couple~ to each other in series, when air is shut off at the ~Z~3~6~7'~
valve body 86 in section a, the air will be secured throughout the entire system. Once this air is secured, all of the hra~e assemblies will be deenersized, causing all of the articles A~-~d to advance simultaneously until the then next leaZ article Ab enters section a and contacts the roller 72 of the trigger assembly 16 in section a.
Once the article Ab contacts the roller 72 in section a, the valve in-valve body 86 in that section will again be opened to port air via T-~itting 8~ to the conduit 40 and cylinder 3 to reseet the brake assembly 18 in section a, and through conduit 90 to the valve body 86 in section b.
If article Ac has not yet arrived at cam roller 7 ~ in section b, the valve in vlave body ~6 in section b will remain closed, causing the brake zssembly 1~ in section b to remain deenergized and allowing the rollers 14 in section b to continue to operate until article Ac contacts roller 72 in section b.
Operation in the Singulation ~ode In describing the operation in the sin~ulation mode, frequent reference will be made primarily to FIGC. 14-16 and also to FIGS. 9 and 10 In the singulation mode, only one of the articles A will advance at a time. Once it has left its previous at-~5 rest position and is enroute to its destined accu~lation position, the next article will begin to advance to replace the enroute article. The articles do not all advance simultaneously as in the Freviously descri~ed slug mode.
6~7 Again, it ~ill initially be 2ssurned that articles Aa--Ad are present and occupy each o~ the respective accumu-lation positions in eachof-th~ sections a-d as shown i~
~IGS. 15 and 16. In this condition, article Pa in sectiona will have moved over cam roller 72 of triqger asser~l~ 16' in section a, article ~ will have moved over cam roller 72 in trigger asse~ly 16' in section b, etc.
In the sinqulation mode, air is supplied to all of the trigaer valves simultaneously and in parallel from the air sup~ly shown in FIG. 14 via condu:its 108. Thus, unlike the slug node, all of the valve bodies 86` are eneroized and ready to port 2ir depending upon whether an article ~ is abscnt or present in their respec~ive conveyor sections. A conduit 116 from the air supply to the valve body 118 of pilot valve assembly 106 in section a also supPlies air to that valve body ready ~or opening of the valve.
Because article ~.a has depressed cam roller 72 in section a, cam follower 96 will also be depressec. Thus, plunger rod 100 shown in FI~S. ~ and 10 will, likewise, be depressed to opèn the valve in valve body 86' in sectiun a causing air to pass through conduit 110 to r-fitting 112 on the pilot actuator 114 of pilot valve assembl~ 106 in sectio~
a When air is supplied to the pilot actuator114, it actuates the valve in valve body 118 of pilot valve assembly 106 to open that valve allo~ing air to pass frOJn conduit 116 from the air su~ply though conduit 40 to cylin~er 3~ of the brake -~4-~2C~'7~
assembly 1~ in section a. Air to cylind~r 3~, as shown in ~IGS. ~ and 6, causes piston rod 4, to move downwardly and the shoes 48 and 50 to move together to clam~ sleeve 56 and torque tube 24a in section a. This cla~ping motion restrains the movement of t~rque tube 24a allo~ing the continuously rotating drive shaft 22 to slip relative to the tor~ue tube and denergize the conveyor rollers 14 in section a.
In this fully loaded condition, i.e. ~rticles Aa-Ad on each of sections a-d, air will also be ~orted ~rom the T-fittin~ 112 in section a through conduit 116 to tne valve body 118 of pilot valve assembly 106 in section b.
As previously mentioned, air is continuously ported via conduit 10~ from the T-fitting ~8' in section a to ~-fitting 88' in section b.
Because the article Ab in section b, likewise, is overlying the cam roller 72 in section b, ca~. roller 96 of the trigger asse~bly 16' in section b wi.ll be depressed, openin~ the valve in valve body 86' in section b to cause air to pass through conduit 110 to the T-fitting 112 on the Filot actuator 114 of the pilot valve assembly 106 in section b Air to this T-fitting 112 actuates the pilot .~ actuator 114 to open the valve in valve body 11~, causing air to pass through conduit 4~to the cylinder38 of the brake assembly 1~ in section b. This air, thereby, causes piston rod 42 of cylinder 38 in section b to move downwardly clampin~
~L2~6'7~7 the sleeve 56 and tor~ue tube 24b to, likewise, restrain its movement and allow driveshaft 22 to slip relative to the torgue tube deenergizing the rollers 14 in section b.
This same sequence follows upstream and, thus, all o~ the rollers 14 in each of the sections a-d are stopped because they each have an article Aa-Ad accumulated thereon It will now be assumed that article Aa is removec from the conveyor section a. When the article Aa is removed, cam roller 72 will rise in section a causing the cam follower 96 on the valve body 86' in section a also to rise.
When this happens, the valve ir. valve body 86' in section a will closd to secure air to conduit 110 to the ~-fitting 112 on the pilot actuator 114 of the pilot valve assembly 106 in section a. ~?hen this ha~ens, the valve in the valve ~d~ of the pilot valve assembly 10~ will also close to secure air from the air supply and conduit 116 to conduit 40 and the cylinder 38 of the brake assembly 18 in section a.
With the brake assembly 18 deenergized, the piston rod 42 of the brake asse~bly, as shown in FIGS. 5 and 6, will move upwardly, causinq the shoes 48 and 50 to move apart to release the sleeve 56 and torque tu~e 24a and allow them to aqain be rotated by the drive shaft 22 energizing rollers 14 in section a.
When the valve in valve body 86' in sectiona is closed, air is not only secured to the T-fitting 112 of the pilot actuator 114 in section a, but it is also secured to conduit 116 which leads to the valve body 118 of the pilot ~2~ 7 valve assembly 106 in section b. Absent such air, c~nduit
4~ leading from the valve b~dy 118 to the cylinder 38 of brake assembly 18 in section b will also be without air.
This will cause the cylinder 38 of the brake assembly 18 also to be deener~ized, thereby removing the restr2ining ~orce ~rom torque tube 24b and allowing the drive shaft 22 to rotate the toraue tube 24b in section ~, causing the rollers 14 in section b to be energized. Thus, the next article Ab will be a~vanced from section b to replace the removed article Aa in section a.
It will be seen, however,that none of the remaining articles in sections c and d will move at this time. They will not move until article Ab has cleared the cam ~ollower roller 72 in section b. So long as article Ab is still present to aepress the cam roller 72 and its cam follower 96 in section b, the valve in valve body 86' will be open to port air from conduit 108, through valve 86' in section b, conduit 110, T-fittin~ 112 on the pilot actuator 114 of the pilot valve assembly 106 in section b through conduit 116 to the valve body 118 in section c. Because the pilot valve assembly 106 in section c is open, this air will continue to ~ass through the ~alve body 118, conduit 40 to the cylinder ~' 38 of brake assembly 18 in section c to actuate the brake assembly to restrain rotation of the torque tube 24c in ~5 section c.
~nce article Ab has left the cam roller 72 in section b, the ca~, roller will mo~e up~ardly, causing the valve in valve body 86' in section b to close. When this valve closes, air will be secured to conduit 110, T-fittins 112 and conduit 116 to the valve body 118 of pilot valve asse~bly 106 in section c. ~ven though this valve remains open because it is receivin~ air from conduit 110 Irom the depressed cam follo~er 96 in valve body 86' in section c, air will no longer be present in conduit 40 to cylinder 38 of the brake assembly 1~ in section c, deener~izing the brake assembly and alloT,~ing the tor~ue tube 24c in section c to now commence rotation to rotate the rollers 1~ in section c and begin moving article Ac toward section b to replace article Ab ~hich has been moved to section a.
Thus, it will be seen that each of the articles will move individually, one by one,in this sinqulation mode It will also be seen that even if articles have been accumulated, for example in sections a and b,and the rollers 14 in those sections have been sto~ped, articles Ac and Ad will continue to mcve to the upstream sections until all of the sections are filled. ~his is because conduits 108 from the air supply as shown in FIC. 14 are coupled in parallel to each of the valve bodies 86' so that the valve bodies are ready to act anytime their respective cam followers 96 are not depressed.
Accordin~ly, assuming articles Aa and Ab are in ~5 their respective accumulated position in sections a and b, but that article ~c has not yet arrived at its position in section c, cam roller 72 in section c will not be depressed.
In this condition, cam follower 96 in section c will be raised, elosine the valve in valve body ~6' in section c, thereby seeuring air to conduit 110 to the T-fitting 112 o~ the pilot actuator 114 of the pilot valve assembly 106 in section c. In the absence of sueh air, the pilot actuator 114 ~-ill elose the valve in valve body 118 secur.ing air to conduit 40 and the cylinder 3~ of brake assembly 1~ in section c, deenergizina the brake and allowing the tor~ue tube 24e in section c to be rotated by the drive shaft 22 to energize rollers 14 in section c Thereby, article Ac is fed until it depresses eam roller 72 in seetion~c at which time the rollers 1~ in section e will be deener~ized.
It will be appreciated that although only four sections of the conveyor have been shown in_FIGS. 11~
that the number of seetions may be increased or decreased as desired ~-ithout departing fro~ the prineiples of the present invention. It will also be appreclated that although the control eireuitry of the present invention has been cescribed in terms of a pneumatie system only, hydraulie, electrical and mechanieal controls instead may be empLoyed and may be readily selected by those ski]led in the art, onee they have fully appreeiated the teaehings of this disclosure.
.- From the foreyoing description, it will be seen that the zero pressure accumulation conveyors and brake .assembly described herein realize aistinet advantages in positively preventing the contaet of artieles being accu~ula-ted with each other by providing a construction for positively decelerating the live rollers 14 when each of the articles arrives at their accumulation position. ~loreover, the brake assembly of the present invention realizes a minimum of frictional slippage between the various elements of the present invention, positively reducing wear and heat builaup and conse~uent maintenance requirements.
It will be understood that the embodiments of the present invention which have been described are merely illustrative of a few of the applications of the principles of the present invention. ~3umerous modifications may be made by those skilled in the art without departing from the true spirit and scope of the invention.
This will cause the cylinder 38 of the brake assembly 18 also to be deener~ized, thereby removing the restr2ining ~orce ~rom torque tube 24b and allowing the drive shaft 22 to rotate the toraue tube 24b in section ~, causing the rollers 14 in section b to be energized. Thus, the next article Ab will be a~vanced from section b to replace the removed article Aa in section a.
It will be seen, however,that none of the remaining articles in sections c and d will move at this time. They will not move until article Ab has cleared the cam ~ollower roller 72 in section b. So long as article Ab is still present to aepress the cam roller 72 and its cam follower 96 in section b, the valve in valve body 86' will be open to port air from conduit 108, through valve 86' in section b, conduit 110, T-fittin~ 112 on the pilot actuator 114 of the pilot valve assembly 106 in section b through conduit 116 to the valve body 118 in section c. Because the pilot valve assembly 106 in section c is open, this air will continue to ~ass through the ~alve body 118, conduit 40 to the cylinder ~' 38 of brake assembly 18 in section c to actuate the brake assembly to restrain rotation of the torque tube 24c in ~5 section c.
~nce article Ab has left the cam roller 72 in section b, the ca~, roller will mo~e up~ardly, causing the valve in valve body 86' in section b to close. When this valve closes, air will be secured to conduit 110, T-fittins 112 and conduit 116 to the valve body 118 of pilot valve asse~bly 106 in section c. ~ven though this valve remains open because it is receivin~ air from conduit 110 Irom the depressed cam follo~er 96 in valve body 86' in section c, air will no longer be present in conduit 40 to cylinder 38 of the brake assembly 1~ in section c, deener~izing the brake assembly and alloT,~ing the tor~ue tube 24c in section c to now commence rotation to rotate the rollers 1~ in section c and begin moving article Ac toward section b to replace article Ab ~hich has been moved to section a.
Thus, it will be seen that each of the articles will move individually, one by one,in this sinqulation mode It will also be seen that even if articles have been accumulated, for example in sections a and b,and the rollers 14 in those sections have been sto~ped, articles Ac and Ad will continue to mcve to the upstream sections until all of the sections are filled. ~his is because conduits 108 from the air supply as shown in FIC. 14 are coupled in parallel to each of the valve bodies 86' so that the valve bodies are ready to act anytime their respective cam followers 96 are not depressed.
Accordin~ly, assuming articles Aa and Ab are in ~5 their respective accumulated position in sections a and b, but that article ~c has not yet arrived at its position in section c, cam roller 72 in section c will not be depressed.
In this condition, cam follower 96 in section c will be raised, elosine the valve in valve body ~6' in section c, thereby seeuring air to conduit 110 to the T-fitting 112 o~ the pilot actuator 114 of the pilot valve assembly 106 in section c. In the absence of sueh air, the pilot actuator 114 ~-ill elose the valve in valve body 118 secur.ing air to conduit 40 and the cylinder 3~ of brake assembly 1~ in section c, deenergizina the brake and allowing the tor~ue tube 24e in section c to be rotated by the drive shaft 22 to energize rollers 14 in section c Thereby, article Ac is fed until it depresses eam roller 72 in seetion~c at which time the rollers 1~ in section e will be deener~ized.
It will be appreciated that although only four sections of the conveyor have been shown in_FIGS. 11~
that the number of seetions may be increased or decreased as desired ~-ithout departing fro~ the prineiples of the present invention. It will also be appreclated that although the control eireuitry of the present invention has been cescribed in terms of a pneumatie system only, hydraulie, electrical and mechanieal controls instead may be empLoyed and may be readily selected by those ski]led in the art, onee they have fully appreeiated the teaehings of this disclosure.
.- From the foreyoing description, it will be seen that the zero pressure accumulation conveyors and brake .assembly described herein realize aistinet advantages in positively preventing the contaet of artieles being accu~ula-ted with each other by providing a construction for positively decelerating the live rollers 14 when each of the articles arrives at their accumulation position. ~loreover, the brake assembly of the present invention realizes a minimum of frictional slippage between the various elements of the present invention, positively reducing wear and heat builaup and conse~uent maintenance requirements.
It will be understood that the embodiments of the present invention which have been described are merely illustrative of a few of the applications of the principles of the present invention. ~3umerous modifications may be made by those skilled in the art without departing from the true spirit and scope of the invention.
Claims (16)
1. A zero pressure accumulation conveyor comprising:
a rotatable drive shaft defining a substantially cylindrical exterior surface;
a tubular torque tube, said torque tube having substantially cylindrical interior and exterior surfaces, said drive shaft extending into said torque tube, the diameter of the exterior cylindrical surfaces of said drive shaft being slightly less than the internal diameter of said torque tube such that said drive shaft is capable of fric-tionally engaging said interior surface of said torque tube to rotate said torque tube when said drive shaft is rotated, but to slip relative to said torque tube when rotation of the latter is restrained;
at least one pulley mounted on the exterior surface of said torque tube, said pulley being axially movable on said torque tube and frictionally engaging said exterior surface of said torque tube to rotate therewith when said torque tube rotates, but slippable rotationally relative to said exterior surface of said torque tube when rotation of said torque tube is restrained;
a frame carrying a plurality of rotatable con-veyor rollers rotatably mounted thereon and disposed in parallel spaced relation adjacent said drive shaft, the axis of each of said rollers being substantially perpen-dicular to the axis of said drive shaft, said rollers thus defining an elongated conveyor surface, the longitudinal axis of said conveyor surface being parallel to said axis of said drive shaft;
at least one endless resilient belt looped over and engaging said pulley and at least one of said conveyor rollers, said conveyor roller being driven thereby;
a brake assembly having a clamping surface, said clamping surface substantially circumferentially surrounding an axial portion of the exterior surface of said torque tube, said clamping surface being radially movable relative to said exterior surface between a first position in which said clamping surface is moved radially out of contact with the exterior of said torque tube and said rotating drive shaft rotates said torque tube, and a second position in which said clamping surface is moved radially into contact with said exterior surface of said torque tube to restrain said torque tube from rotating with said drive shaft; and actuating means coupled to said brake assembly for radially moving said clamping surface between said first and second position in response to an applied control signal, whereby rotation of said torque tube may be selectively permitted or prevented in response to applica-tion of said control signal.
a rotatable drive shaft defining a substantially cylindrical exterior surface;
a tubular torque tube, said torque tube having substantially cylindrical interior and exterior surfaces, said drive shaft extending into said torque tube, the diameter of the exterior cylindrical surfaces of said drive shaft being slightly less than the internal diameter of said torque tube such that said drive shaft is capable of fric-tionally engaging said interior surface of said torque tube to rotate said torque tube when said drive shaft is rotated, but to slip relative to said torque tube when rotation of the latter is restrained;
at least one pulley mounted on the exterior surface of said torque tube, said pulley being axially movable on said torque tube and frictionally engaging said exterior surface of said torque tube to rotate therewith when said torque tube rotates, but slippable rotationally relative to said exterior surface of said torque tube when rotation of said torque tube is restrained;
a frame carrying a plurality of rotatable con-veyor rollers rotatably mounted thereon and disposed in parallel spaced relation adjacent said drive shaft, the axis of each of said rollers being substantially perpen-dicular to the axis of said drive shaft, said rollers thus defining an elongated conveyor surface, the longitudinal axis of said conveyor surface being parallel to said axis of said drive shaft;
at least one endless resilient belt looped over and engaging said pulley and at least one of said conveyor rollers, said conveyor roller being driven thereby;
a brake assembly having a clamping surface, said clamping surface substantially circumferentially surrounding an axial portion of the exterior surface of said torque tube, said clamping surface being radially movable relative to said exterior surface between a first position in which said clamping surface is moved radially out of contact with the exterior of said torque tube and said rotating drive shaft rotates said torque tube, and a second position in which said clamping surface is moved radially into contact with said exterior surface of said torque tube to restrain said torque tube from rotating with said drive shaft; and actuating means coupled to said brake assembly for radially moving said clamping surface between said first and second position in response to an applied control signal, whereby rotation of said torque tube may be selectively permitted or prevented in response to applica-tion of said control signal.
2. A zero pressure accumulation conveyor as defined in claim 1, wherein said brake assembly includes a rigid substantially cylindrical sleeve surrounding said torque tube and fixed to said exterior surface thereof, said clamping surface being movable out of and into contact with the outer surface of said sleeve when said clamping surface is moved between said first and second positions, respectively.
3. A zero pressure accumulation conveyor as defined in claim 2 wherein said clamping surface comprises at least a pair of clamping surfaces and pivot means, said pivot means mounting said pair of clamping surfaces for pivotal movement between said first and second positions.
4. A zero pressure accumulation conveyor as defined in claim 1 wherein said actuating means include a movable piston rod attached to at least one of said clamping surfaces for moving said surfaces between said first and second positions.
5. A zero pressure accumulation conveyor as defined in claim 4, wherein said movable piston rod is attached to one of said clamping surfaces and the other one of said clamping surfaces is attached to said frame.
6. A zero pressure accumulation conveyor as defined in claim 5, wherein said piston rod is coupled to a pneumatically actuated air cylinder, said air cylinder being responsive to said control signal applied thereto.
7. A zero pressure accumulation conveyor as defined in claim 6, wherein said control signal comprises a compressed gas.
8. A zero pressure accumulation conveyor as defined in claim 7, wherein said compressed gas is air.
9. A zero pressure accumulation conveyor as defined in claim 4, wherein said control signal is applied to said actuating means in response to an article carried on said conveyor surface reaching a predetermined position thereon.
10. A zero pressure accumulation conveyor as defined in claim 8, wherein said control signal is applied to said air cylinder in response to an article carried on said conveyor surface reaching a predetermined position thereon.
11. A zero pressure accumulation conveyor as defined in claim 9, wherein said torque tube is formed of an organic polymer.
12. A zero pressure accumulation conveyor as defined in claim 11, wherein said polymer is nylon.
13. A zero pressure accumulation conveyor as defined in claim 12, wherein said drive shaft is a hard metal.
14. A zero pressure accumulation conveyor as defined in claim 10, wherein said torque tube is formed of an organic polymer.
15. A zero pressure accumulation conveyor as defined in claim 14, wherein said polymer is nylon.
16. A zero pressure accumulation conveyor as defined in claim 15, wherein said drive shaft is a hard metal.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US34322282A | 1982-01-27 | 1982-01-27 | |
| US343,222 | 1982-01-27 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1201677A true CA1201677A (en) | 1986-03-11 |
Family
ID=23345201
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000410233A Expired CA1201677A (en) | 1982-01-27 | 1982-08-26 | Zero pressure accumulation conveyor and brake assembly |
Country Status (7)
| Country | Link |
|---|---|
| JP (2) | JPS58137629A (en) |
| KR (1) | KR930000936B1 (en) |
| AU (1) | AU557275B2 (en) |
| CA (1) | CA1201677A (en) |
| DE (1) | DE3237599A1 (en) |
| GB (1) | GB2114084B (en) |
| MX (1) | MX158571A (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0217047B1 (en) * | 1985-08-01 | 1989-05-24 | Conveyor Units Limited | Live roller conveyor |
| GB9026520D0 (en) * | 1990-12-05 | 1991-01-23 | Conveyor Mfg Co Ltd | Braking system for live roller conveyor |
| DE10210402A1 (en) * | 2002-03-08 | 2003-10-02 | Abus Kransysteme Gmbh & Co Kg | Running wheel for use on overhead transportation system has conical running surface engaging overhead rail and has flexible braking ring engaging two wheels close together |
| CN110203627B (en) * | 2019-07-20 | 2024-07-12 | 湖南创一电子科技股份有限公司 | Typesetting system for plastic sucking disc |
Family Cites Families (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS4936389B1 (en) * | 1969-03-03 | 1974-09-30 | ||
| US3650375A (en) * | 1969-05-05 | 1972-03-21 | Ermanco Inc | Drive for roller conveyors |
| US3696912A (en) * | 1969-05-05 | 1972-10-10 | Fred J Fleischauer | Brake for roller conveyors |
| JPS4936389U (en) * | 1972-07-03 | 1974-03-30 | ||
| US3840110A (en) * | 1972-07-24 | 1974-10-08 | Ermanco Inc | Conveyor apparatus |
| JPS5439331B2 (en) * | 1972-09-09 | 1979-11-27 | ||
| JPS4946061A (en) * | 1972-09-12 | 1974-05-02 | ||
| JPS5418781U (en) * | 1977-07-08 | 1979-02-06 |
-
1982
- 1982-08-26 CA CA000410233A patent/CA1201677A/en not_active Expired
- 1982-08-27 GB GB08224694A patent/GB2114084B/en not_active Expired
- 1982-08-30 AU AU87852/82A patent/AU557275B2/en not_active Ceased
- 1982-10-11 DE DE19823237599 patent/DE3237599A1/en active Granted
-
1983
- 1983-01-26 MX MX196038A patent/MX158571A/en unknown
- 1983-01-27 JP JP58012085A patent/JPS58137629A/en active Pending
- 1983-01-27 KR KR1019830000316A patent/KR930000936B1/en not_active IP Right Cessation
-
1992
- 1992-05-06 JP JP1992029423U patent/JPH0747366Y2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| GB2114084B (en) | 1985-08-29 |
| JPS58137629A (en) | 1983-08-16 |
| KR840003209A (en) | 1984-08-20 |
| GB2114084A (en) | 1983-08-17 |
| AU8785282A (en) | 1983-08-04 |
| MX158571A (en) | 1989-02-15 |
| AU557275B2 (en) | 1986-12-18 |
| DE3237599C2 (en) | 1993-08-05 |
| JPH0747366Y2 (en) | 1995-11-01 |
| DE3237599A1 (en) | 1983-08-04 |
| KR930000936B1 (en) | 1993-02-11 |
| JPH07932U (en) | 1995-01-06 |
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| US4828103A (en) | Conveyor drive unit and method for operation thereof |
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| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry | ||
| MKEX | Expiry |
Effective date: 20030311 |