US3116823A

US3116823A - Power erected accumulator

Info

Publication number: US3116823A
Application number: US205341A
Authority: US
Inventors: Donald A Schneider
Original assignee: Rapids Standard Co Inc
Current assignee: Rapids Standard Co Inc
Priority date: 1962-06-26
Filing date: 1962-06-26
Publication date: 1964-01-07
Anticipated expiration: 1981-01-07
Also published as: GB1036466A

Description

1964 D. A. SCHNEIDER 3,116,823

POWER ERECTED ACCUMULATOR- 3 Sheets-Sheei 1 Filed June 26, 1962 ATTO/P/UEK? 1964 D. A. SCHNEIDER POWER EREC'I'ED ACCUMULATQR 3 Sheets-Sheet 2 Filed June 26, 1962 1964 I D. A. SCHNEIDER 3,

POWER ERECTED ACCUMULATOR Filed June 26, 1962 3 Sheets-Sheet I5 INVENTOR. 901/410 4. 50/4 4705? United States Patent M 3,116,823 POWER ERECTED ACCUMULATOR Donald A. Schneider, Ada Township, Kent County, Mich, assignor to The Rapids-Standard Company, Inc., Grand Rapids, Mich., a corporation of Michigan Filed June 26, 1962, Ser. No. 265,341 13 Claims. (Cl. 198-160) This invention relates to accumulator type conveyors, and more particularly to a means by which the power available in a continuously moving endless propelling member may be tapped to provide the power necessary to operate the propelling member supports.

This invention solves a problem which has been encountered in accumulator type conveyors. In this type of conveyor, the propelling member is supported in such a manner that it is movable toward and away from the articles to control the application of propelling force to the articles. Means are provided to sense the presence of an article and in response to this means the propelling member is shifted to either stop or initiate movement of articles on the conveyor. The sensing of the articles may be done by mechanical means which is physically moved by the articles or by other means which generates a signal, such for example as interruption of a light beam or the tripping of an electrical switch. In the former situation, the weight of the article is normally utilized as the energy source for effecting the physical movement of the propelling member. In the latter case, an auxiliary power source such as a motor, air cylinder or solenoid has been provided to effect movement of the propelling member. These auxiliary power sources are expensive units and also require an available energy source as for example an electrical conductor or a compressed air line.

In those applications utilizing the weight of the article as the energy source, there is a conflict of purpose be tween the sensors and the actuation propelling member supporting units. If the articles are of reasonably uniform size and weight, the problem does not occur. Where, however, articles of widely varying size and weight are conveyed, the force required to support the propelling member in article propelling position must be such as to assure movement of the heavier and more bulky articles. Since the sensing units must mechanically shift the propelling member from this position, this force must be supplied entirely by the weight of the article actuating the sensing unit. In the case of the small or lightweight articles, it has been found that this force may be more than that which the article can supply with the result that the lighter articles become hungup on the sensing units. In some cases where only very lightweight articles are involved, the articles are incapable of shifting even the weight of the propelling member itself.

This invention overcomes these problems by providing a means by which the power of the propelling member itself is utilized to effect the shifting of the propelling member between propelling and non-propelling positions. The sensing units are freed of the necessity of providing this force and can be designed to operate with very light pressures. Thus, they are sensitive and can be made to operate with small and light articles.

This invention taps the forward or primary run of 3,116,823 Patented Jan. 7, 1964 the propelling member for its power. This makes the position of the return run immaterial. It is particularly adaptable to conveyors in which the endless conveyor member is arranged in a closed loop all parts of which lie in the same general plane as contrasted with conveyors in which the forward and return runs are arranged in an over and under relationship. This arrangement also permits the unit to be exceptionally compact and characterized by a minimal of structure.

Thus, the invention provides a simple, dependable and lightweight mechanism for accumulator conveyors. It is adaptable to conversion of existing conveyor equipment from conventional operation to accumulation. This may be accomplished with very little reworking or reconstruction of the existing structure.

These and other objects and advantages of this invention will be immediately understood by those acquainted with conveyor design and usage upon reading the following specification and drawings.

In the drawings:

FIG. 1 is a fragmentary plan view of a conveyor equipped with this invention;

FIG. 2 is a fragmentary sectional elevation view taken along the plane IIII of FIG. 1;

FIG. 3 is a sectional elevation view taken along the plane III-III of FIG. 7 showing the unit in retracted position;

FIG. 4 is a view similar to FIG. 3 with the exception that the unit is shown with the ratchet in initial engagement;

FIG. 5 is a view similar to FIG. 3 showing the unit partially erected and the ratchet at maximum erected position;

FIG. 6 is a view similar to FIG. 3 showing the unit in fully erected position;

FIG. 7 is a sectional elevation view taken along the plane VII-VII of FIG. 1;

FIG. 8 is a fragmentary perspective view of one of the support assemblies;

FIG. 9 is a sectional elevation view similar to FIG. 7 but showing a modified construction for this invention;

FIG. 10 is a sectional elevation view taken along the plane XX of FIG. 9 showing the unit in retracted position;

FIG. 11 is a view similar to FIG. 10 showing the unit in partially erected position and the ratchet at maximum erection;

FIG. 12 is a view similar to FIG. 10 showing the unit just before disengagement of the ratchet;

FIG. 13 is a view similar to FIG. 10 showing the unit fully erected; and

FIG. 14 is a schematic side elevation view similar to FIG. 2 showing this invention applied to a conveyor having an article transporting surface made up entirely of rollers.

In executing the objects and purposes of this invention, there is provided a conveyor having a driven endless propelling member the primary or driving run of which is supported in such a manner that it can be shifted between raised to lowered positions. The supporting structure for the propelling member includes supporting elements which are pivotally mounted for swinging movement in the direction of movement of the propelling member. Each of these supports is equipped with a Wheel which makes contact with the propelling member and has a ratchet engaging stop on it. A ratchet is provided which when shifted into engagement with the stop, prevents relative rotation between the wheel and its support causing the wheel to travel lineally with the propelling member. This movement erects the support and raises the belt. As the support nears erected position, the ratchet is forced to disengage and freeing the wheel for rotation relative to its supporting structure and the force of the belt and the arrangement of the support in relation to its mounting causes the unit to remain erected until it is forcibly shifted to retracted position.

Referring specifically to FIG. 1, it will be seen that the invention is incorporated into a conventional conveyor having side rails 11 between which extend axles 12. Rotatably mounted on the axles are conveyor wheels 13. At the center of the conveyor is a medial lane 14 along which travels the propelling member 15. The portions of the conveyor bed on each side of the propelling member 15 constitute article supporting surfaces over which the articles may move with minimal frictional resistance. It will be recognized that the conveyor wheels in this area may be replaced with rollers or any other type of low-friction, article-supporting means.

The propelling member 15 is constantly driven by any suitable prime mover, and it will be understood that it is of the endless variety passing over pulleys at each end of the conveyor. These particular features are not illustrated inasmuch as they are conventional and are Wellknown in the conveyor art.

The propelling member at periodic intervals along the conveyor 10 is supported from beneath by support assemblies 20. Between the support assemblies the propelling member 15 may be supported by auxiliary support members 40.

Each of the support assemblies has a frame 22 consisting of a pair of spaced plates 23 which may be secured in any suitable manner to the primary structure of the conveyor. One way of mounting this frame is to hang the plates between a pair of the axles 12 as suggested in FIG. 8. Near its lower extremity the frame has a pair of bolts each surounded by a spacer. These properly space the plates 23 and hold them together in an assembly. The bolt 24 serves as the pivot for both the support arms 25 and the ratchet bracket 26. The bolt 27 serves as the stop pin for both the support arms and the ratchet bracket.

At their upper ends, the support arms 25 rotatably mount the sprocket 28. The sprocket has teeth which engage the teeth which depend from and form the medial rib of the propelling member 15 (FIGS. 37).

The ratchet bracket 26 is a U-shaped member with a cross bar 30 extending laterally of the sprocket 28. At its lower end and on the opposite side of the pivot 24, the ratchet arm has a stop 31 designed to cooperate With the bolt 27 for limiting upward or extending movement of the ratchet. The lower ends of the support arms 25 have a cutout 32 forming a pair of opposed stop shoulders 33 and 33a which also cooperate with the bolt 27. The stop shoulder 33 limits the retractive movement of the support arms while the stop shoulders 33a limit movement of the support arms as they are erected. The ratchet bracket has an aperture on each side above the pivot 24. These apertures receive the ends of the connecting rods 35. The connecting rods also project through the sides of the support arms 25 where an elongated opening 36 is provided permitting a limited degree of travel of the connecting rod with relation to the support arms. An elongated clearance opening 37 is also provided in the plates 23 for the connecting rods.

As is suggested in FIGS. 1 and 2, more than one propelling member support may be operated by a single support assembly. Thus, auxiliary support members 40 may be provided. Each of these is supported by a pivoted lever 41 and connected to one of the support assemblies by a connecting bar 42. The connecting bar is secured to the support assembly by the pin mounting the sprocket 23.

Each of the support assemblies is linked by the connecting rods 35 to a sensing unit 43. The sensing units are biased into raised or erected position by a spring 44. In raised position the sensing units project a short distance above the plane of the conveyor surface defined by the top of the conveyor wheels 13. The spring 44 only has to have sufficient strength to support the sensing unit 43 and to be able to shift the connecting rods 35 and the attached ratchet bracket 26 to engagement with the sprocket 28. Thus, it can be a light spring making the sensing unit 43 sensitive and easy to operate.

FZGS. 9 through 13 illustrate a modified construction for this invention. The support assemblies 20a each have a frame 22a consisting of a pair of side plates 23a. These are very similar to the corresponding parts in the support assemblies 20, except for a change in shape and dimension adapting them to the particular construction of the support assembly. The frame 22a is secured to the conveyor by attachment to a pair of the axles 12 (FIG. 10). The plates of the frame are connected by a bolt 50. This acts as a pivotal mounting for both the support bracket 51 and the ratchet bracket 52. The support bracket 51 at its upper end mounts the sprocket 53. The sprocket 53 is normally freely rotatable with respect to the support bracket. The sprocket 53 has teeth to engage the depending teeth 2) formed in the median rib of the propelling member 15.

The support bracket 51 is generally triangular in shape, and at one corner has a stop rod 54. When the support bracket is in lowered or retracted position, the ends of the stop rod 54 rest against a stop wall 55 on each of the plates 23 (FIG. 10).

The ratchet bracket has a finger designed to engage the teeth of the sprocket 53. It also has a pair of holes to receive the ends of the connecting rods 61. The connecting rods have ends coming in from both sides of the support assembly with one end connecting with each side of the ratchet bracket (FIG. 9). A clearance hole 62 (FIG. 10) is provided in each of the plates 23, to allow the rod 61 sutficient freedom of movement for shifting the ratchet bracket 52.

When auxiliary propelling member supports are to be connected to this support assembly for simultaneous operation, as is suggested by the auxiliary units 40 in FIGS. 1 and 2, the stop pin 54 may be extended and one or both ends are connected to the auxiliary support. This will effect simultaneous operation. In this construction the extended ends of the stop pin will serve the same purpose as the connecting bars 42 shown in FIGS. 1 and 2.

Operation When the support assemblies 20 are raised they support the propelling member at a level which is coplanar with or slightly above the top surfaces of the conveyor wheels 13. When the propelling member is retracted or depressed it moves below this plane disengaging the articles supported on the conveyor wheels 13. Such a condition is shown at the left end of FIG. 2. This is basic to the operation of the forms of this invention illustrated in FIGS. 1-13.

The operation of the support assembly illustrated in FIGS. 3 through 8 is quite simple. The unit, as illustrated in FIG. 3, is retracted. In this position, the support bracket 25 is pivoted to the left, lowering the sprocket 28 and the propelling member 15. The sprocket 28 maintains driven engagement with the propelling member whether erected or retracted. To raise the support assembly 20, the ratchet bracket 26 is shifted to engage the ratchet bar 30 with the teeth of the sprocket 28 as suggested in FIG. 4. This prevents the sprocket 28 from rotating with relation to the support bracket 25. Thereafter, the sprocket being locked against rotation, will be forced to travel with the constantly moving propelling member in the direction of the arrows indicated in FIGS. 3 and 4. This is indicated in FIG. 5 where it will be seen by the shift in relative positions of the centerlines A and B that the support bracket 25 has moved upwardly and to the right. The line A represents a plane connecting the center of rotation as the sprocket 28 and the center of the pivot 24. The line B passes through the center of the pivot 24 and is perpendicular to the propelling member 15.

FIG. 5 illustrates the maximum upward movement permitted the ratchet bracket 26. This limit is determined by contact between the stop surface 31 and the stop pin 27. The continued movement of the propelling member, however, will carry the sprocket and the support bracket 25 to the right until the support bracket reaches at least a fully erected position, at which point the lines A and B are superimposed (FIG. 6). Just before the sprocket reaches this position, its continued movement to the right disengages from the ratchet bracket 26, again freeing the sprocket to rotate. The continued motion of the belt will hold the sprocket and support bracket 25 in erected position.

The continued movement of the support bracket 25 after the ratchet bracket 26 has reached its limit of travel occurs by reason of the lost motion slots 36. In this operation the ends of the connecting rods 35, being stationary, are in effect shifted from the right-hand to the lefthand end of these slots.

To return the support assembly 20 to retracted position it is only necessary to shift the connecting rods 35 to the left. The existing contact between the left end of the lost motion slots 36 and the ends of the connecting rods 35 will force the support bracket 25 and the ratchet bracket 26 to pivot to the left. Since no lost motion is permitted between the connecting rods 35 and the ratchet bracket 26, the ratchet bracket, during retraction, is held against shifting into engagement with the sprocket 28.

The principles and mode of operation of the construction illustrated in FIGS. 9-13 is quite similar to that just described. FIG. 10 illustrates the assembly in retracted position. In this position both the support bracket and the ratchet bracket are pivoted upstream of the direction of movement of the propelling member as indicated by the arrow. While so retracted, the sprocket 53 maintains operative contact with the propelling member 15. The support bracket is held against further retraction by the stop pin 54. The ratchet bracket 52 is also retracted and its further retraction is also limited by contact with the stop pin 54. The connecting rod 61 is secured to a suitable sensing unit such as the sensing unit 43 illustrated in FIGS. 1 and 2. In the position of the support assembly illustrated in FIG. 10 the sensing unit is activated and depressed by an article. When the article relieves the sensing unit, it returns to its original position by reason of action of the attached spring. This shifts the rod 61 to the right as illustrated in FIGS. 10 through 13. As shown in FIG. 11 this pivots the ratchet bracket upwardly bringing the finger 61) into engagement with one of the teeth of the sprocket 53. This action prevents further rotation of the sprocket with relation to the support bracket. However, continued forward movement of the propelling member 15 causes the sprocket to travel with the propelling member, pivoting the support assembly toward erected position.

The initial position of the components of the support assembly is indicated by the lines C and D which correspond respectively to the lines A and B in FIG. 3. It will be noted in FIG. 11, that the line C has moved closer to the line D. This view illustrates the maximum erected movement of the ratchet bracket. Further movement of the ratchet bracket is prevented by the resistance of the connecting rods 61. However, engagement between the sprocket and the propelling member continues to move the sprocket to the right as illustrated in FIGS. 10 through 13. FIG. 12 shows that this initiates disengagement of the sprocket from the finger 60 of the ratchet bracket. In FIG. 12, the sprocket is shown passing over center above the pivot 50. At the same time the sprocket disengages from the finger 60. FIG. 13 illustrates the limit of travel of the sprocket to the right. It will be noted that the centerline E has passed to the right of the centerline D indicating that the sprocket has passed over-center. At this point, the stop pin 54 has now engaged the upper limit wall 65 of the side plates 23. The over-center feature of the sprocket insures positive stability of the sprocket against downward movement, since it cannot move to the left because of influence of the propelling member, and cannot move to the right because of the limit imposed by the stop pin 54.

To retract the support assembly, it is only necessary to move the connecting rods 61 to the left. This automatically forces the ratchet bracket downwardly. Since it is resting on the stop pin 54, this also forces the support bracket to the left, moving the sprocket back over-center. Once having passed over-center to the left, the weight of the propelling member will cause it to move the remaining distance into retracted position.

FIG. 14 schematically illustrates the application of this invention to a solid roll conveyor 89. In this construction the propelling member 15 instead of making direct contact with the articles drives the rollers 81 which form the article conveying and supporting surface of the conveyor. The direction of movement of the articles is indicated by the arrow E and of the driving run 15b of the propelling member by the arrow F. The driving run 15 of the propelling member is supported by support assemblies 20 and connected auxiliary supports 40. The sensing elements 43a control the erection and retraction of the support assemblies. When the support assemblies are erected the propelling member is held in driving contact with the rollers 81. When they are retracted the propelling member is disengaged from the rollers 31 as indicated at the letf end of FIG. 14. When the sensing unit 43a is released the spring 82 erects it, and moves the ratchet bracket into engagement with the sprocket to efifect erection of the connected support assembly 20. When a sensing unit 43a is depressed it pulls the support assembly in retracted position.

It will be understood from the above description that the sensing element merely has to provide sufiicient en ergy to shift the ratchet bracket from retracted position into engagement with the sprocket to effect erection of the support assembly. Once engagement has occurred, the energy necessary to lift the support bracket and the propelling member to the raised or erected position, is supplied by the propelling member itself. Thus, the sensing unit can be quite sensitive and very light, small articles will be quite capable of tripping the sensing unit. Thus, even though the sensing unit may be tripped effectively by a lightweight article, the propelling unit will provide sufiicient energy to positively lift the supporting unit and the propelling member into operating position, even though the propelling member is quite heavy and there may be a heavy article resting on the propelling member at this point. Thus, the invention provides an effective means of divorcing the power source for erection of the support assemblies from the force necessary to hold the sensing unit'in the erected position, even though the two are mechanically linked together. Even though some means is used other than a mechanical linkage to connect the sensing unit and the support assembly, such for example as a sensing unit consisting of a microswitch and a solenoid for operating the connecting rod 61, the construction of the unit is such that the solenoid may be of a low power, low energy type. Such units are less bulky, less expensive than the type that would be required to lift the full weight of the propelling member and of any article which might be resting on it.

It will also be recognized that this invention provides a relatively inexpensive, compact, self-contained unit which may be used with original equipment or may be used to convert existing equipment from conventional operation to accumulator type operation. The compactness, lightweight and adaptability of this invention are particularly recommended to use on conveyor systems, whether small or large.

While two embodiments of this invention have been illustrated and described, it will be recognized that various modifications of this invention may be made without departing from the principles of this invention. Such modifications as embody the principles of this invention are to be considered as included in the hereinafter appended claims, unless these claims, by their language, expressly state otherwise.

I claim:

1. In a conveyor for articles, said conveyor having an endless driven article propelling member; a support having an element engaging said propelling member, said support being pivotable between retracted and erected positions; means, when said support is retracted, for locking said element to said propelling member for lineal travel therewith and pivoting said support to erected position, a stop member for disengaging said means from said element as said support reaches erected position.

2. A conveyor as described in claim 1 wherein limit means is provided to limit travel of said element when said element reaches erected position.

3. A conveyor as described in claim 1 wherein said support as it aproaches its erected position passes a line perpendicular to said propelling member and passing through the axis about which said support is pivoted whereby said support is retained in erected position by having passed over-center when its travel is stopped by said limit means.

4. A conveyor as described in claim 1 wherein said element is a wheel rotatably engaging said propelling member and said means, when engaged therewith, holds said wheel against rotation relative to said support.

5. A conveyor as described in claim 1 wherein said element is a sprocket and said propelling member has toothed sprocket receivers 'for positively engaging the teeth of said sprocket; said means engaging a tooth of said sprocket for holding said sprocket against rotation relative to said support.

6. A conveyor as described in claim 1 wherein said support, as it approaches its erected position, passing a line perpendicular to said propelling member and passing through the axis about which said support is pivoted whereby said support is retained in erected position by having passed over-center when its travel is stopped by said limit means; a restraining element preventing said means from following said support as it passes beyond said line.

7. A conveyor as described in claim 1 wherein said propelling member is endless and has a forward run and a return run and said element engages beneath said forward run, said retracted position being a lowered position and said erected position being a raised position.

8. A conveyor as described in claim 1 wherein said propelling member is endless and has a forward run and a return run and said element engages beneath said forward run, said retracted position being a lowered position and said erected position being a raised position; said article propelling member when said support is erected being in article propelling position and when said support is retracted being in article non-propelling position.

9. A conveyor as described in claim 1 wherein said propelling member is endless and has a forward run and :a return run and said element engages beneath said forward run, said retracted position being a lowered position :and said erected position. being a raised position; said conveyor having an article transporting surface, said propelling member when said support is erected engaging and propelling articles on said transporting surface and when said support is retracted being disengaged from such articles.

10. A conveyer as described in claim 1 wherein a sensing means is provided responsive to articles on said conveyor; said sensing means being operatively connected to said support for pivoting said support to retracted position upon activation of said sensing means by an article and also connected to said element for causing said means to lock said element to said propelling member for travel to erected position when said sensing means is deactivated.

11. In a conveyor for articles having an endless driven article propelling member, a frame; a wheel engaging and rotatably driven by said propelling member; means mounting said wheel for swinging pivotal movement between extended and retracted positions; said wheel being rotatable with respect to said mounting means; a ratchet engageable with said wheel in retracted position and holding said wheel against rotation relative to said mounting means whereby said wheel and mounting means are caused to pivot to erected position by the movement of said propelling member; limit means for disengaging said ratchet as said wheel and mounting means approach erected position; sensing means operatively connected to said ratchet for shifting it into engagement with said wheel and connected to said mounting means for retraction thereof.

12. In a conveyor for articles having an endless driven article propelling member, a frame; a support member and a ratchet arm each pivotally mounted to said support element; a circular member rotatably mounted on said support member and engaging and driven by said propelling member, said circular member supporting said propelling member and being movable with said propelling member, said support element and the propelling member supported thereby being movable upon pivotal movement of said support element from an article propelling position to an article non-propelling position; stop means on said circular member engageablc by said ratchet arm for holding said circular member against rotation relative to said support member; whereby said circular member and said support element will shift laterally with said propelling member; actuation means for pivoting said ratchet into engagement with said circular member and holding said circular member against rotation when said circular member and said propelling member are in article non-propelling position, said circular member and support member being pivoted into erected position by said propelling member and said propelling member being thereby shifted into article propelling position; release means disengaging said ratchet from said stop means as said circular member, support member and propelling member approach erected position.

13. In a conveyor for articles, said conveyor having a driven, endless, article propelling member having a forward run and a return run; said propelling member having a central nib characterized by tooth receiving means; a support beneath said forward run of said propelling member; said support having a sprocket engaging said tooth receiving means; a stationary frame pivotally mounting said support for swinging movement between a lowered position and a raised position; said propelling member being supported by said sprocket and support, and vertically movable therewith, the pivotal movement of said support toward its raised position being in the same direction as the travel of said propelling member; a ratchet pivotally mounted on said frame and shiftable between sprocket engaging and disengaging positions; said sprocket as said support approaches erected position passing a line perpendicular to said forward run of said propelling member and passing through the axis about which said support pivots whereby said support is retained in raised position by having passed over-center;

9 a sensing element responsive to articles on said conveyor, said sensing element being operative-1y connected to both said support and said ratchet; said sensing element when activated by an article shifting said support to lowered position and, upon deactivation by the article, shifiting said ratchet into engagement with said sprocket for holding said sprocket against rotation, said sprocket when so held moving lineally with said propelling member for shifting said support to erected position; restraining means disengaging said ratchet from said sprocket as said sprocket 10 passes over thecenter of the pivotal mounting of said support; stop means limiting travel of said support with said propelling member when said support reaches erected position.

References Cited in the file of this patent UNITED STATES PATENTS 1,855,808 Schwan Apr. 26, 1932 2,895,593 McKnight July 21, 1959 3,000,480 Poel Sept. 19, 1961

Claims

1. IN A CONVEYOR FOR ARTICLES, SAID CONVEYOR HAVING AN ENDLESS DRIVEN ARTICLE PROPELLING MEMBER; A SUPPORT HAVING AN ELEMENT ENGAGING SAID PROPELLING MEMBER, SAID SUPPORT BEING PIVOTABLE BETWEEN RETRACTED AND ERECTED POSITIONS; MEANS, WHEN SAID SUPPORT IS RETRACTED, FOR LOCK-