US3515056A - Bundling machines - Google Patents

Description

June Z, 1970 F. P. JOHNSON 3,515,056

BUNDLING MACHINES Filed March l2, 1968 7 Sheets-Shee l June Z, 1970 F. P. JOHNSON 3,515,056

BUNDLING MACHINES Filed March 12, 196e 7 sheets-sheet a June 2, 1970 F. P. JOHNSON 3,515,056

BUNDLING MACHINES Filed March 12. 1968 7 SheeLs-Shee?l 5 rf 1 Y FIG. 3

June 2, 1970 F. P. .JOHNSON BUNDLING MACHINES 7 Sheets-Sheet L Filed March 12. 1968 NGN June 2, 1970 F. P4. JOHNSON 3,515,056

BUNDLI'NG MACHINES Filed March 12, 1968 7 sheets-sheet s FIG, 5

vJune 2, 1970 F. P. JOHNSON 3,515,056

BUNDLING MACHINES Filed March 12, 1968 7 Sheets-Sheet 6 June 2, 1970 F. P. JOHNSON 3,515,056

BUNDLING MAcHINEs Filed March 12, 1968 7 Sheets-Sheet 7 @UVE/235 FIG. 7

United States Patent O 3,515,056 BUNDLING MACHINES Frederick Paul Johnson, Manchester, England, assignor to Henry Simon Limited, Cheadle Heath, England, a British company Filed Mar. 12, 1968, Ser. No. 712,500 Claims priority, application Great Britain, Mar. 16, 1967, 12,282/ 67 Int. Cl. B65b 13/20 U.S. Cl. 100-4 12 Claims ABSTRACT F THE DISCLOSURE A machine for tying bundles of articles together in which a bundle of articles is conveyed to a tying mechanism at which its movement is arrested. The tying mechanism is operated by a sensor -to tie the stationary bundle and when tied the bundle of articles is delivered out 0f the machine.

This invention relates to article tying machines,

In particular it relates to a machine for tying articles such as bundles of stacked boxboard carton blanks by conveying the articles in succession into and out of a tying unit forming part of the machine.

In a known form of article tying unit a closed loop of twine is formed around an article by the vmanual movement of an article into an open loop of the twine and then by the downward lmovement of a needle carrying the twine bringing together two adjacent portions of the twine, which adjacent portions are clamped together by a metal clip formed by the unit from a reel of metal strip. Such a tying unit is the subject of British Pat. No. 947,093 (Hood), and is referred to hereafter in this specification as a tying unit of the kind specified.

It is an object of the present invention to provide a method of `tying articles by conveying the articles automatically and in succession into and out of a tying unit, for example a tying unit of the kind specified.

It is a further object of the invention to provide an article tying machine adapted for continuous in-line operation and incorporating a tying unit, for example a tying unit of the kind specified.

Requirements which may arise in the automatic conveying of articles into and out of a tying unit include (a) the positive holding of an article while it is being tied, (b) the precise location of a stationary article at a tying station in the machine and (c) the ability to handle articles varying to some extent in height or length or configuration.

According to the present invention there is provided a method of tying articles passing in succession into a tying machine, and including the steps of conveying an article into the machine, stopping the article at a tying station in the machine, tying the article, and conveying the article out of the machine.

More particularly, it is preferred to employ in the method a tying machine incorporating a tying unit of the kind specified, the method including the steps of positively holding and conveying an article into the machines, sensing the passage of a trailing extremity of the article, stopping the article at a tying station in the machine when said trailing extremity of the article is at a predetermined location in the machine, tying the article, and conveying the article out of the machine.

Also according to the present invention there is prov ided an article tying machine, Vcomprising conveyor means adapted to convey articles through the machine, a tying station within the run of said conveyors, tying means adapted to tie an article located at said tying station, a sensor adapted to sense the passage of an article ice and to stop said conveyors when the article is at the tying station, and means operable to restart the conveyors when the article has been tied.

More particularly, it is preferred that the article tying machine be adapted for in-line operation, and comprise an upper and lower conveyor adapted positively to hold and to convey an article linearly through the machine, a tying station within the run of said conveyor means, a tying unit of the kind specified adapted to tie an article located at said tying station, a sensor adapted to sense the passage of a trailing extremity of the article and to emit a stop signal operative to stop the conveyor means when said trailing extremity of the article is at a predetermined location relative to the line of action of the needle of said tying unit, and means operative to restart the conveyor means when the article has been tied.

Embodiments of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which:

FIG. 1 shows a general arrangement in side elevation of a bundle tying machine in accordance with the present invention;

FIG. 2 is an enlarged view of parts of FIG. 1;

FIG. 3 is a cross section on the line 3-3 of FIG. 1;

FIG. 4 is a diagrammatic side elevation of a modified construction of bundle tying machine;

FIG. 5 is a detail view, to an enlarged scale, of parts of FIG. 4;

FIG. 6 is a diagram of the hydraulic circuit of the tying machine of FIGS. 4 and 5; and

FIG. 7 is a diagram of the pneumatic circuit of the tying machine of FIGS. 4 and 5.

The machine of FIGS. 1 to 3 is a bundle compressing and tying machine adapted for continuous in-line operation, and is intended to receive and tie bundles of box board carton blanks passed in succession into the machine.

Referring now to FIGS. 1 to 3 of the drawings in particular the machine comprises an upper conveyor 10 and a lower conveyor 12, both mounted on a frame. At a location along the run of the conveyors 10 and 12 therevis disposed a tying unit comprising a needle assembly 14 located above the upper conveyor -10 and a clipping assembly 16 located below the lower conveyor 12. Also disposed below the lower conveyor 12 is a hydraulic unit 18 which actuates the needle assembly 14 Aand the clipping assembly 16, and an electrical control box I20 from which the operating sequence of the machine is controlled.

The frame of the machine is mounted onfour pulleys 22 which run on two inverted angle iron rail-s 24 to permit sideways adjustment of the position of .the machine with respect to the position of bundles being fed into the machine.

The lower conveyor 12 comprises two spaced endless strip conveyor belts 26 (FIG. 3) runningon a series, of rollers 28, the bels 26 being driven bya drive motor 30 having a brake 32 incorporated therein. The lower conveyor 12 is rigidly secured to the frame kof themachinle.

The upper conveyor 10 comprises twospaced endless strip conveyor belts 34 (FIG. 3) running over ,aseries of rollers 36, the belt 34 being driven by-:a drive vmotor 38 incorporating a brake 40. Theupper conveyor 1,0 is adapted for vertical movementl on two-vertical arms 42 attached to the frame. Rollers 44 are attached-` to veach of the two horizontal arms .46 supporting-the upper conveyor, and roll on vertical runways 45 attached to the vertical arms 42. n

Upward and downward movement ofthe upper conveyor 10 is controlled by two conveyor lifting assemblies, the parts of which will now be described. Above each of two horizontal arms 48 (FIGS) rigidly attached 4to the vertical arms 42, there is mounted a linkage including jointed bars 50, 52, a rod 54 partly screw thraeded and adapted to slide in a bore in the horizontal arm 48, a pneumatic lift cylinder 56, a handwheel 58 and a spring 60. The handwheel 58 is secured to a bush 59 which is screw threadedly rotatable on the screw threaded portion of the rod 54. The cylinder 56 is a double acting cylinder, and air supply to the lower side of its associated piston is via an inlet 62, while air supply tothe upper side of the piston is by an inlet line 64 which includes a pressure gauge 65 and an adjustable constant pressure outlet valve 66. The piston of the pneumatic lift cylinder 56 is attached by means of a piston rod and knuckle joint to the bar 52 of the linkage.

Admittance of air through the inlet 62 of each conveyor lifting assembly serves to raise the upper conveyor clear of the maximum height of bundles to be passed through the machine. Admittance of air through the inlet 64 causes the upper conveyor to be moved in a downward direction to exert a predetermined pressure on bundles passing through the machine, by suitable settings of the adjustable valve 66 and the handwheel 58.

Actuation of the handwheel 58 adjusts the height of the upper conveyor l10 above the lower conveyor 12 to a suitable height to receive bundles to be passed through the machine.

An upwardly angled entry conveyor 68 serves to receive bundles entering the machine. The entry conveyor 68 includes three spaced strip conveyor belts 70 running over four rollers. The belts 70 of the entry conveyor 68 are arranged to run at a slightly higher speed than that of the belts 34 of the upper conveyor 10 and the belts 26 of the lower conveyor 12. This result is achieved by arranging that drive to the belts 70 of the entry conveyor 68 is from -stepped sections of an end roller 37 of the upper conveyor 10, the stepped sections having a diameter greater than the diameter of those sections over which the belts 34 pass. By this means any tendency for the angled entry conveyor 68 to retard upper blanks of a bundle is minimised.

The angled entry conveyor `68 is arranged to swivel about the axis of the end roller 37, under the action of a spring 72, the arrangement providing that upward movement of the conveyor 68 compresses the spring 72.

The needle assembly 14 and clipping assembly 16 form part of a commercially available bundle tying unit, the subject of the aforementioned British Pat. No. 947,093. The needle assembly 14 includes an eyed needle 80 which carries twine 82 which is supplied to the needle from a twine reel 84, the needle being arranged for near-vertical movement by hydraulic actuation. In a modication of the unit, the needle is pneumatically operated.

From a clip metal reel 86 a strip of metal 88 is fed to the clipping assembly 16. The clipping assembly 16 includes a hydraulically operated clipper rarn 910 and an anvil 92 which co-operate to form a metal clip around two adjacent portions of twine within the clipping assemblythe clip being formed from the metal strip 88. The clipping assembly also includes means to sever twine at a position below the formed metal clip. Actuation of the ram 90 is from a hydraulic cylinder 91 through a pivoted arm 93. n In the operation of the machine, a bundle 94 enters the space between the entry conveyor 68 and the lower conveyor 12 and iscarried through the conveyors 10 and 12. During the movementof the bundle past the needle assembly 14, the leading face of the bundle meets a length of twine extending from the needle to the clipping assembly and carries this twine forward with it until the upper and lower sides of the bundle as well as its leading face become lfolded in a loop of twine 83, the twine running from the twine supply reel through the eye of the needle 80. `A lower end of the twine loop 83 is attached in the clipping assembly.

The bundle now reaches a tying station when a trail- Ving extremity 96 of the bundle has passed to a predetermined distance beyond the line of action 98 of the needle (FIG. 2). Under the action of control means to be described, the two conveyor motors 30, 38 are braked thus stopping the conveyors 10, 12 and 68 when the bundle is at the tying station.

At this stage the needle descends to pass the twine round the trailing face of the bundle and to form two adjacent portions of twine in the clipping assembly round which portions a metal clip is formed and secured, the metal forming the clip being first severed from the strip 88. Following this operation, the twine 82 is severed below the clip.

The needle now ascends to its raised position shown in FIG. 1, the two conveyor drive motors 30, 38 are started, and the tied bundle proceeds along the remainder of the conveyor run and emerges from the machine.

The hydraulic unit 18 which provides hydraulic power for the movement of the needle 80 and of the clipping and severing mechanism comprises an electric motor 100 driving a hydraulic pump 102, supply of hydraulic fluid to which is from a ten gallon reservoir 104. The unit also comprises a pressure gauge 106.

The sequence of operation of various parts of the machine are controlled by limit switches, relays and a photoelectric cell forming part of electrical circuitry of the machine.

A light source 108 (FIG. 2) is arranged in the run of the lower conveyor, and a photo-electric cell 110 is mounted above the upper conveyor and vertically above the light source 108. The light source is arranged to direct a light beam on to the photo-electric cell 110, 'which beam is interrupted by the passage of a bundle 94 through the machine prior to its reaching the tying station. The photo-electric cell acts as a sensor adapted to sense the passage of a bundle or a part of a bundle passing beneath it.

Three limit switches 112, 114 and 116 (FIG. 2), are' located with their operating levers or rollers projecting slightly beneath the upper conveyor 10` so that they are actuatedv by the passage of a bundle. A further limit switch 118 is located with its operating lever projecting slightly above the lower conveyor 12. A limit switch 120 (FIG. 1) is mounted in conjunction with the needle assembly 14 and is actuated by the needle upon its descent.

Within the clipping assembly, forward motion of the clipper ram 90 operates a limit switch 122. Return motion of the clipper ram operates a further limit switch A limit switch 126 (FIG. 3) is located in the run of the twine 82, and is operated if the twine breaks or if the twine supply 84 runs out.

Within the control box 20 is situated a solid state timing device, and a dial 128 located on the panel of the control box 20 permits variation of a delay period provided by the timing device.

'I'he function of the photo-electric cell 110` is to pass a signal to the timer when the trailing extremity 96 (FIG.

2) of a moving bundle 94 moves clear of the light beam. Following a predetermined time delay set on the timer dial 128, the two conveyor drive motors 30, 38 are braked and the bundle is stopped at the tying station. y

In order to achieve the most satisfactory results from the tying unit it is advisable that the trailing face of a bundle is stopped as near vas possible to the line of action 98 of the needle 80, since the greater the separation of these elements the less tightly will the bundle be tied. It is also necessary that the bundle should not be stopped before its trailing extremity have moved passed the line of action of the needle, otherwise the needle will penetrate at least part of the bundle. e

In an initial run of `bundles through the machine, the timer is set to a value which provides a satisfactory separation of the trailing face of each bundle from the line of action of the needle. In some cases the machine may receive a bundle which has not been carefully stacked, so that, for example, some of the blanks in the bundle are projecting beyond the rest of the blanks at the trailing face of the bundle. Thiscondition is illustrated in FIGS. 1 and 2. Since the signal from the photo-electric cell 110 is initiated by the trailing extremity of the bundle, i.e. that part which projects to the greatest extent from the trailing face of the bundle, it will be realised that the method of sensing by photo-electric cell is able to take account of irregularities at any level in the staking of individual bundles.

To achieve a desired tightness of tying of the bundles, it is necessary that these be compressed while they are tied. Also, during the tying operation considerable forces are exerted on a bundle, so each bundle must be positively held between the conveyors while it is at the tying station. Such compression and positive holding is achieved by the action of the two pneumatic lift cylinders 56 which cause the upper conveyor 10 to exert a downward force on the bundles as they pass through the machine. The vertical movement of the upper conveyor 10 also permits the machine to handle bundles having some variation in height.

The angled entry conveyor 68 which is hinged to the conveyor 10 permits some variation of the angle between the conveyors 68 and 10, but a limit switch 130 (FIG. 1) which is arranged to be operated by undue upward movement of the conveyor 68 acts as a safety device to brake the conveyor drive motors 30, 38 if an oversized object attempts to enter the machine.

The operation of the machine will now be described in more detail, to include the operating sequence of the limit switches.

OPERATING SEQUENCE (l) A bundle 94 enters the machine and the light beam to the photo-electric cell |110 is broken. This resets a relay (not shown) in the control box 20 associated with the photo-electric cell circuit.

(2) Limit switch 112 is operated by the bundle leading edge, and prepares the photo-electric cell 110I to take control of the conveyor motors 30, 38.

(3) The trailing face of the bundle passes clear of the light beam, and the photo-electric cell initiates a timing sequence, the timing period being dependent on the setting of the timer dial 128.

(4) The limit switches 114 and 118 are operated by the bundle, and serve to prevent the needle 80 from descending while the bundle is passing under the needle.

(5) Limit switch 116 is operated by the bundle leading edge. This limit switch is in the same circuit as limit switch i112, which is then closed by passage of the bundle trailing edge.

(6) The pre-set timer period ends, and the conveyor drive motors 30, 38 are braked to bring the bundle to rest at the tying station.

(7) Limit switches 114 and 118 are released by the trailing edges of the bundle, a solenoid valve (not shown) is energised and hydraulic actuation of the needle commences. The needle thus begins to descend.

(8) When the needle reaches the bottom of its stroke, limit switch 120 is operated to energise a further solenoid valve (not shown) which initiates forward motion of the `clipper ram 90 of the clipping assembly 16.

(9) At the end of the clipper ram stroke, limit switch 122 operates and serves to stop the forward motion of the ram, to initiate a return stroke of the ram and to cause a blast of air to be directed to the clipper mechanism for the purpose of clearing the mechanism of loose twine.

(10) At the end of the clipper rams return stroke, limit switch 124 is operated and the two solenoid valves previously referred to are de-energised. The needle now ascends and the air blast is cut off.

(11) Limit switch 120 is released as the needle ascends, and this causes the conveyor motors 30, 38 to start up.

(12) 'Ihe bundle is conveyed out of the machine, and the trailing edge released limit switch 116 serving to reset relays in the control circuit ready for a further sequence of operations in association with the next bundle.

For the machine described, this sequence of operations covers bundles of below a specied length. When the machine handles longer bundles, the sequence of operations of the photo-electric cell and limit switches 112 and 116 varies, but the result is the same in terms of machine performance.

Reference is now made to FIGS. 4 to 7 of the drawings. In this embodiment, the machine is a free standing unit, being tted with castor wheels 200 for movement. It is provided with bayonet connectors of known construction (not shown) for the necessary compressed air and electricity services. If desired, an air compressor may be built into the machine so that only an electricity connection is required.

The machine has a regid fabricated base constituted by an oil tank of, for example, thirty gallons capacity mounted on the castors 200, which are of roller bearing form and which permit vertical adjustment of the machine, for example three inches.

Four rectangular section members 202 secured together and carried by uprights 203 of the base support a lower conveyor 204. The conveyor 204 has two side-byside belts 205 supported on rollers 206 and/or other known convenient supports, for example flat plates. The conveyor 204 is driven by a hydraulic motor of known construction (not shown) which is in hydraulic communication with the tank 20-1.

It will be manifest that due to the vertical adjustability of the castors 200 the maximum horizontal height of conveyor 204 is three inches higher than its minimum horizontal height. It will also be manifest that by an uneven adjustment of the castors 200 the conveyor 204 can be tilted to give different lead-in heights.

A substantial vertical column 207 is fixed to the base and supports a cantilevered member 208 which carries an upper conveyor 209 and which houses a pneumatic cylinder V210-, linkage 211 and -a sliding guide 212 for the upper conveyor 209. The latter is similar to lower conveyor 204, that is, it has two side-by-side endless belts 213 supported on rollers 214 or other known convenient supports (not sho-wn), for example Hat plates, and the conveyor 209 is driven by a hydraulic motor 2.15 in circuit with the tank 201.

The upper conveyor 209 is vertically adjustable along the column 207 relative to the cantilevered member 208 and in FIG. 5 it is shown in its highest position. The conveyor 209 is conveniently guided and supported during its vertical movement. yIt will be manifest that if the piston of cylinder 210 is retracted, it will pivot the linkage 211 about axis 216 causing guide 212 to slide down its vertical slot 217. This will similarly cause linkage 218 to pivot about axis 219. Thus, upper conveyor 209 can easily be adjusted vertically. The cylinder 210 is, of

course, connected to a compressed air supply (not shown).

Linkage 218 is connected rvia a screw-threaded springloaded element 220` screw-engaging a stationary part of member 208 to a handwheel 221. Rotation of the handwheel 221 and element 220 adjusts and xes the top height of conveyor 209, to suit various bundle heights. A scale 222 allows the upper limiting position of conveyor 209 to be set accurately by the handwheel 221.

The tying unit is of the kind specified, and the pneumatically operated needle 223 is attached to the side of cantilevered member 208 in line with the clipper box 224 which is suspended from the lower conveyor 204.

The upper conveyor 209 has an angled lead-in conveyor section 225 of similar construction to the conveyor 209 but driven at a slightly faster speed than the latter so that a square bundle delivered to the machine is maintained.

The control panel for the machine is indicated at 226, and the required solenoid-operated hydraulic and pneumatic valves (not shown) are accessibly located in or around the bottom of column 207.

A motor-driven hydraulic pump is indicated at 227 and is supported on tank 201.

The vertical column 207 is hollow to recei-ve three vertically superimposed reels of twine T, and coiled clip metal C is stored in a dispenser 228 suspended beneath the lower conveyor 204 The above described machine is therefore provided with hydraulic, pneumatic and electricity supplies, and the sequence of operations can be adjusted and pre-set by the controls at panel 226.

Reference will now be made in particular to FIG. 4 which shows the positioning of various limit switches and a photo-electric cell, and'to FIGS. 6 and 7 showing respectively the hydraulic and pneumatic circuits of the machine.

The operation of the machine will rstly be described generally and then in detailed step-by-step.

By turning the handwheel 221, the height of the top conveyor 209 is set against the scale 222 to suit the height of bundles B to be tied. If the delivery line for the bundles is fixed, the machine must be positioned so that the tie coincides with the centre of the bundles B. These are the only adjustments required when adjusting for different sized bundles B. The twine T and clip metal C having been threaded and with the controls in the operating position, a squaredup bundle B is fed into the machine. The angled leadin 225 of the top conveyor 209 progressively compresses the bundle B until suilicient load is applied to provide traction. Twine T passing from needle `223 and held in clipper box 224, is contacted by the leading edge of the bundle B and forward motion of the bundle B causes the twine T to be wrapped around the bottom, leading edge and top of the bundle B. Just prior to reaching the tying position, the trailing edge of the bundle B releases a limit switch which causes the conveyor hydraulic motors 215 to go into slow speed. The bundle B proceeds at reduced speed until the tying position is reached when a photo-electric cell signals the conveyor motors 215 to stop. Simultaneously with the motors 215 stopping, the top conveyor 209 is pneumatically loaded by cylinder 210 and linkages 211 and 218 acting on guide 212 to further compress the bundle B and the needle 223 descends. The needle 223- enters the clipper box 224 and at the end of its stroke, a cycle is instigated which causes a clip to be formed to secure the two ends of the twine encircling the bundle B in known manner. The twine T is then severed below the clip and as the tying unit returns to its initial state, the needle 223 ascends leaving twine T for the next bundle secured in the clipper box 224.

As the needle 223 commences its ascent, the pneumatic loading of the top conveyor 209 is relieved and the conveyor motors 215 start up in high speed. The tied bundle B is carried out of the machine and the next bundle B entering causes the cycle to repeat.

The detailed operating sequence of the above described machine is as follows:

(l) The po'wer for the machine is switched on, the pump 227 is rendered operative and the needle and clipper controls are turned to automatic functioning. Solenoid 9 is energised thus driving the hydraulic motors 215 and eecting high speed running of the conveyors 204 and 209.

(2) A bundle B enters between the conveyors 204 and 209 and operates limit switch 230 thus placing the photoelectric cell 23-1 in control of a slow speed solenoid 232.

(3) The bundle B breaks the photo-electric cell beam which sets the photo-electric cell relay.

(4) Limit switch 233 is now tripped by the bundle B and takes over from limit switch 230.

(5) The limit switch 230 drops olf the trailing edge of thebundle B causing the solenoid 229 to be de-energised and solenoidv 232 to be energised. l

(6) The bundle B now proceeds at slow speed until the photo-electric cell beam is Vre-made by the trailing edge of the bundle B. Solenoid 232 is de-energised and solenoid 229 remains de-energised thus putting the valve 234 controlled by the solenoids 229, 232 in aA condition at which the motors 215 and consequently the conveyors 204, 209 stop.

Air solenoids 235 and 236 are simultaneously energised to operate valves 235V and 236V and the needle 223 descends and the double-acting cylinder 210 causes downward movement of the conveyor 209 to apply extra cornpression to the bundle B.

(7) Limit switch 237 is tripped as the needle 223 reaches the bottom of its stroke and solenoid 238 is energised to operate valve 239 and cause forward motion of the clipper ram 240.

(8) At the end of the stroke of the ram 240, limit switch 241 is operated to de-energise the solenoid 238 and energise air solenoid 242. The ram 240 commences its return stroke and operation of valve 242V causes a blast of air to be directed to the clipper box as indicated at 243.

(9) At the end of the return stroke of the ram 240, a limit switch 244 is operated to de-energise air solenoids 242, 236 and 235. The needle 223 ascends, the extra compression applied by cylinder 210 to the top conveyor 209 is relieved and the air blast at 243 is cut-01T. v

(10) Limit switch 237 is released as the needle 223 ascends, and the solenoid 229 is energised causing the conveyors 204 and 209 to run at high speed.

(11) The bundle B is propelled out of the machine and the trailing edge thereof releases limit switch 233 resetting the control relays.

The machine is nowready to accept the next bundle B.

A limit switch 245 is arranged at the junction of conveyors 209 and 225 to be operated by undue upward movement of the conveyor 225 to de-energise solenoids 229 and 232 and thus acts as a safety device to brake the conveyor motors 2215 and stop the conveyors 204 and 209 if an oversized object attempts to enter the machine.

The pneumatic 'circuit has a connector 246 for connection to an air supply, a lilter 247, and a manuallyoperable blow gun 248 connected to the circuit by a flexible hose.

The hydraulic circuit incorporates a strainer 249 at the tank 201 and a lter 250.

In a modification of the machines intended for faster throughput of articles, a two speed conveyor drive is incorporated, the method of operation being such that an article is conveyed rapidly to a location up-stream of the tying station, when a'slow speed conveyor drive takes over to convey the article to its precise location at the tying station. In this 'modification when applied to the machine of FIGS. 1 to 3 the photo-electric cell y110 is located adjacent the tying station and limit switches 114 and 118 are omitted.

v`The invention is not limited to the tying of stacked carton blanks. The machine described is for example capable of tying certain other articles or bundles having slightly varying heights and varied trailing face configurations.

Due particularly to its in-line form of operation, the machine described permits a higher capacity in terms of rate of throughput of articles'than certain known forms of tying machines in one of which, for example, an article is brought manually intothemachine along a given entry path and is conveyed manually out of the machine on an exit path at right angles to the entry path.

What is claimed is:

1. An article tying machine adapted for in-line operation, comprising upper and lower conveyor means for positively holding and 4conveying an article linearly through the machine, a tying station within the run of the conveyor means incorporating a tying means including a needle and twine for tying an article loc-ated at the tying station, a sensor means for sensing the passage of a trailing extremity of the article and emitting a stop signal operative to stop the conveyor means when said trailing extremity of the article is at a predetermined location relative to the line of action of said needle of said tying means, and means operative to restart the conveyor means when the article has been tied.

2. A machine as claimed in claim 1, further including guide means for supporting said upper conveyor means in guided vvertical movement relative to said lower conveyor means, an adjusting means for adjusting and limiting the height of said upper conveyor means above said lower conveyor means, and pneumatic means for adjusting said upper conveyor means vertically' relative to said lower conveyor means below its set height to accommodate diierently-sized articles and to exert a predetermined pressure on the articles being moved through the machine by the conveyor means.

3. A m-achine as claimed in claim 2 in which said adjusting means includes a spring-loaded screw device, a linkage system operatively interconnecting said springloaded screw device between a stationary part of the machine and the vertic-ally-movable upper conveyor means.

4. A machine as claimed in claim 3, wherein said pneumatic means includes a pneumatic ram operatively connected to said linkage system to provide the vertical adjustment of said upper conveyor means below its set maximum height.

5. A machine as claimed in claim 2 further including two horizontally extending members supporting said upper conveyor means and slidingly carried by said guide means said adjusting means raising and lowering said horizontally extending members on said guide means.

6. A machine as claimed in claim 2 further including a cantilevered member supporting said upper conveyor means, said upper conveyor means being slidingly carried by said guide means for vertical movement relative to said cantilevered member, and said adjusting means raising and lowering said upper conveyor means on said guide means.

7. A machine as claimed in claim 1 in which said upper conveyor means includes an angled conveyor means at the feed-in end of the machine, means for moving said angled conveyor means faster than said upper and lower conveyor means to avoid any tendency of said angled conveyor means to retard the article, a safety means operatively associated with said angled conveyor means for stopping the machine if an article of excessive size is presented to the machine.

8. A machine as claimed in claim 1 further including a motor means incorporating a brake means operatively connected to said upper and lower conveyor means for driving same.

9. A machine as claimed in claim 1, further including variable speed hydraulic motor means operatively connected to said upper and lower conveyor means for driving same.

10. A machine as claimed in claim 1 wherein said tying means includes needle and twine supply supported by said upper conveyor means and a clipper land metal strip supply supported by said lower conveyor means.

11. A machine as claimed in claim 1, further including a wheeled support for the machine so that it can be readily moved.

12. A machine as claimed in claim 1, further including limit switch means for effecting said feeding, stopping, tying and delivery functions in pre-set timed relationship, said limit switch means being operated by movements of the article and said needle of said tying means.

References Cited UNITED STATES PATENTS 2,662,468 12/ 1953 Shenigo.

2,818,795 1/ 1958 Gustafson 100-4 3,077,157 2/ 1963 Gordon 100-4 3,114,308 12/1963 Saxton et al. 100--7 XR 3,115,085 12/1963 Van de Bilt 100-7 XR 13,330,205 7/ 1967 Smith 100-4 BILLY I. WILHITE, Primary Examiner U.S. Cl. X.R. 10Q- 3, 7,19, 53,153

Images