GB2187158A - Method of and apparatus for collecting workpieces - Google Patents

Abstract

Workpieces from a press or other machine are discharged into one of a number of containers (11) on an endless track (12-15). After a selected number of cycles of the machine, the containers are advanced around the track. A predetermined number or weight of articles are deposited in the container at one station, whereupon the container is moved from the station and replaced by another container. The track is preferably polygonal including upper and lower runs 12, 13 connected by vertical runs 14, 15. Reciprocating pushers are used to move the containers on the track. <IMAGE>

Description

SPECIFICATION Method of and apparatus for collecting workpieces The present invention relates to the collection of workpieces from a work station and is especially useful in a case where the manufacture of articles is completed at the work station.

In a method according to a first aspect ofthe invention of collecting workpieces from a work station, there is provided a track, a plurality of containers on the track, drive means for moving the containers along the track and control means responsive to the quantity ofworkpieces discharged from the work station, workpieces are discharged from the work station into a first container on the track until a predetermined quantity ofworkpieces has been discharged, the first container is then moved along the track and a second container is moved into the position previously occupied by the first container and workpieces are discharged from the work station into the second container until said predetermined quantity of workpieces has been so discharged subsequent to movement ofthe containers, the second container also then being moved along the track.

The invention enables a predetermined number of workpiecesto be collected in each container. The first container may be returned subsequently to the position in which itreceivesworkpiecesfromthe work station. In this way, there can be collected inthe containeranumberofworkpieceswhich is a multiple of the number of operations of the work station which occurs whilst a container is stationary and receiving workpieces from the work station.

When the container has been moved from the position at which it receives workpieces from the work station, the contents of the container may be inspected. Furthermore, a partition may be placed in the container to divide from workpieces already in the container a further number of workpieces which will be discharged subsequently into the container.

This is particularly useful when the workpieces are of a form such that they can easily become entangled with one another. It is then advantageous to divide the workpieces in the container into relatively shallow layers, by means of partitions.

The control means may include a counterfor counting operations at the work station, in which case the predetermined quantity ofworkpieces is a predetermined number of workpieces. Alternatively or additionally, the control means may include a load cell or other device responsive to the weight of workpieces accummulated in a container, the predetermined quantity being a predetermined weight of workpieces.

The track preferably defines a circuit around which the containers are moved.

During performance ofthe method ofthe invention, there is preferably executed a number of cycles, during each of which a common sequence of movements occurs. One movement of the sequence may be raising of a containerfrom a lower level to a higher level and another movement lowering of another container from the higher level to the lower level. The workpieces may be discharged from the workstation into a container at the higher level or, alternatively, into a container at the lower level.

According to a second aspect of the invention, there is provided apparatusforcollecting workpieces from a work station, the apparatus comprising means defining a track, a plurality of containers on the track, drive means for moving the containers along the track and control meansfor controlling operation of the drive means, wherein the control means includes a counterfor counting operationsattheworkstation and/oradevice responsive to the weight of the contents of a container and the control means is adapted to cause the drive means to move the containers along the track. The control means may be adapted to move each containerthrough a distance substantially equal to the length oftrack occupied by one container.Alternatively, the drive means may be adapted to move one container through a distance substantially greater than the distance through which another of the containers is moved.

During each cycle of operation of the drive means, several containers may each be moved horizontally through a distance substantially equal to the length of track occupied by a single container and further containers may be moved vertically through a distance which is somewhat greaterthan the length of track occupied by a single container.

Two examples of apparatus according to the second aspect of the invention and which are used in a method according to the first aspect will now be described, with reference to the accompanying drawings,whernin: Figure 1 shows diagrammatically an end view of the first example of apparatus; Figure 2 shows a perspective view of the apparatus of Figure 1, all but one of a number of containers of the apparatus being omitted from Figure 2; and Figure 3 shows diagrammatically a plan view of the second example of apparatus; The apparatus illustrated in Figures 1 and 2 ofthe accompanying drawings, comprises a frame 10 which defines a polygonal track. On the track is a number of containers 11. The containers may be identical one with another and, in the example illustrated, are square, as viewed in plan. Each container comprises four side walls and a bottom wall.The track defined by the illustrated example of apparatus is rectangular. Each containerfully occupies the width of the track but the containers do not collectively occupy the entire length of the track.

Thetrackdefined bytheframelOincludesa substantially horizontal part 12 at an upper level, a part 13 which is parallel to the part 12 and which is at a lower level and parts 14 and 15 which extend upwardly from respective end portions of the lower part 13 to respective end portions ofthe upper part 12. Each of the track parts 1 2 to 15 is rectilinear.The width of each part of the track is substantially equal to the width of a container, so that the containers occupythe full width ofthe track. Substantiallythe entire length ofthe part 120fthetrackmay befully occupied by the containers when the containers are stationary but an end portion ofthe lower horizontal part 13 sufficiently large to receive a container is vacant. This vacant end portion may be adjacentto the vertical part 14 of the track. The vertical parts also are both vacant. Thus, the number of containers in thetrackis lessthanthe maximum number of containers which could be accommodated in the track.

The frame 10 is positioned for use adjacentto a machine which defines at least one work station for operating on workpieces. The machine may, for example, be a press. The machine is represented in the drawing at 16 and has a delivery chute 17, down which successive workpieces are discharged from the work station to a container 11 disposed beneath the discharge end of the chute. The container into which workpieces are discharged may be in the upper part 12 ofthe trackor in the lower part 13 ofthe track.

Sensing means 18 is associated with the machine 16for providing an electrical signal representing each cycle of operation of the machine. The sensing means may be a limit switch, a reed switch or a photo-electric device. The sensing means forms a part of control means ofthe apparatus.

The control meansfurther comprises a control panel 19 mounted in a readily accessible position and an electronic counter incorporated in the control panel. The control panel includes a key pad or other meansforreceiving information representing the required number ofworkpieces to be discharged into one of the containers 11 whilst that container is stationary below the chute 17. Signals produced by the sensing means 18 are fed to the counter and the control means provides an output signal when the required number of cycles of the machine 16 has been counted. The counter is then reset.

There is provided for each of the rectilinear parts 12to 15 of the track a respective pusher for pushing a containerora number of containers along that part ofthe track. A first pusher is shown at20 and is arranged for reciprocation along an end portion of the upper horizontal part 12 of the track, this end portion being adjacent to the vertical part 14 ofthe track. An hydraulically or pneumatically operated actuator 21 is provided for reciprocating the pusher 20 through a stroke which is equal to the length of a single container 11. The actuator lies below the level ofthe upper part 12 of the track but sufficientlyfar above the lower part 13 to clearthe containers on that lower part.

The pusher 20 is adapted to support a container 11 in the corresponding end portion ofthe upper part 12 ofthe track. In the example illustrated, the pusher comprises a pair of rectilinear rails 22 and 23 each secured at one of its ends to a movable part of the actuator 21 and having at its opposite end an abutment, 24 and 25 respectively, which protrudes upwardly for engagement with a container occupying the end portion ofthe upper part 12ofthe trackand resting on the rails 22 and 23. Between their ends, the rails are supported on a crosspiecewhich is fixed with respect to the frame 10. When resting on the rails 22 and 23, a container is at the same level as are the other containers of the row of containers occupying the upper part 12 of the track.

The containers occupying an intermediate portion ofthe upper part 12 of the track rest on fixed parts, namely opposed, horizontal flanges which project from side members 27 and 28 ofthe frame 10. The flange on the side member 27 is indicated at 29. Itwill be noted thatthe flanges terminate at positions spaced from opposite ends of the upper part 12 of the track by a distance slightly greater than the length of one container so that containers can be moved vertically into and out of end portions ofthe upper part 12 ofthetrack.

For supporting the container in that end portion of the upper part 12 of the track which is adjacenttothe vertical part 15, there is provided a movable plafform 30 which may consist of a pair of rectilinear rails, similarto the rails 22 and 23. However, the platform 30 does not have any upwardly protruding portions which would interfere with horizontal movement of the rails relative to a container resting on the rails.

For reciprocating the platform 30 through a horizontal stroke extending longitudinally of the upper part 12 of the track and having a length substantially equal to the length of a container, there is provided a further pneumatically or hydraulically operated actuator 31. This actuator also is mounted in a position just below the upper part 12 ofthetrack.

The pusher 32 associated with the vertical part 14 of the track also is arranged as a platform on which one of the containers 11 can rest. The platform is arranged for reciprocation upwardly and downwardly along the vertical part 14 ofthetrack between a lowermost position in which it supports a container at the same level as are other containers in the lower part 13 of the track and an upper position in which it supports the container at a level somewhat above the level at which the container can be supported by the pusher 20. As shown, the pusher 32 also may comprise a pair of mutually parallel rails.

These rails are mounted on a carriage 33 arranged for vertical movement on a column 34 incorporated in the vertical part 14 of the track. Afluid pressure-operated actuator or other drive means provided for moving the carriage relative to the column. A chain or otherflexible element may be used fortransmitting force between the actuator and the carriage.

The rails ofthe pusher 32 are separated by a gap through which the rails 22 and 23 can pass when the pusher 32 begins a decent from its uppermost position.

For supporting a row of containers 11 on the lower horizontal part ? 3 13 ofthetrack, opposed, horizontal flanges are provided on side members 35 and 36 of the frame 10. One of these flanges is indicated at 37.

These flanges extend along thefull length of the lower part 13 of the track, since containers are not required to descend below this part of the track. The pusher associated with the lower part 13 ofthe track is indicated at 38 and an actuator for reciprocating the pusher 38 horizontally through a stroke substantially equal to the length of a single container is indicated at 39. Itwill be understood thatthe pusher 38 is not required to support containers and therefore consists essentially of an upward projection which is engageable with a side wall of a container.The actuator 39 is disposed just below an end portion ofthe lower part 13 of the track and moves the pusher longitudinally of this part of the track between a position in which the pusher is at an extreme end of this part of the track adjacent to the vertical part 15 and a further position in which the pusher is nearer two the vertical part 14 ofthe track.

There is associated with thevertical part 15 ofthe track a pusher 40 which may be identical with the pusher 32, being mounted on a carriage 41 which is movable upwardly and downwardly on a column 42.

In its lowermost position,the pusher 40 is arranged forsupporting a container at the same level as are other containers on the lower part 13 of the track. In its uppermost position, the pusher 40 is arranged for supporting a container at the same level as are other containers of a row on the upper part 12 ofthetrack.

Thepusher40isarrangedtomoveupwardlytothe level of the platform 30 without i nterference between the platform and the pusher 40.

Atthe commencement of a cycle of operation of theapparatus,theupperpartl2ofthetrackis occupied entirely by a row of containers 11 and the lower part 13 ofthe track, except for the end portion thereof adjacent to the vertical part 1 of the track, also is occupied by a further row of containers. The space at the end of the lower part ofthe track is sufficient for a single container. The platform 30 is in the position illustrated in Figure 2, supporting a container in an end portion of the upper part ofthe track. Each of the pushers also is in the position illustrated in Figure 2.When the required number of workpieces has been discharged down the chute 17 into one ofthe containers, the control means provides an outputsignal to initiate a cycle of operation of the drive means. The control means includes appropriate electrically operated valves for controlling the supply ofairand/orhydraulicfluidto the actuators and also includes limit switches responsive to execution of a stroke of an actuator.

For simplicity of illustration, these components of the control means are omitted from the drawings.

The cycle commences with operation of the actuator 39 to move the pusher38 along the corresponding end portion of the lower part 13 ofthe track until that end portion is vacant and the opposite end portion is occupied by a container which is directlyaboveoris resting on the pusher32. Ifthe chute 17 discharges into a container on the lower part of the track, this movement advances a charged containerfrom the position beneath the chute and brings a fresh container into that position.

Once the pusher 38 has completed its stroke, it is returned to the initial position and the pusher 40 is raised through its stroke into engagement with the underside of a container resting on the platform 30.

The pusher 40 relieves the platform 30 oftheweight ofthis container. The platform 30 is then retracted from beneath the container now resting on the pusher 40. When the actuator 31 has completed its stroke,the pusher40 is caused to descend to its initial position, carrying the containerfrom the upper part 12 of the track to the vacant space in the lower part 13 of the track.

Once the pusher 40 has returned to its initial position, the platform 30 is extended once more to the position illustrated in Figure 2. The actuator 21 is then operated to cause the pusher 20 to execute a stroke and push the row of containers in the upper part 12 ofthetracktothe right, as viewed in Figure2, so thatthe vacant space abovethe platform 30 becomes occupied by a container at one of the row and a space at the opposite end of the upper part of the track is vacated by a container at the other end of the row. The pusher 32 is then raised through its stroke to lift a container from the lower part 13 ofthe track into the vacant space in the upper part ofthe track. Once the pusher 32 has completed its stroke, the actuator 21 is operated once more to return the pusher 20 to the position shown in Figure 2.During the return stroke of the pusher 20, the pusher 32 holdsthe container resting on that pusher clear of the path of travel ofthe pusher 20. When the return stroke ofthe pusher 20 has been completed, the pusher 32 is caused to descend to its initial position.

As the pusher 32 passes the pusher 20, it deposits the container on the rails 22 and 23.

In a case where the chute 17 discharges workpieces into a container on the upper part 12 of the track, the forward stroke of the pusher 20 advances a charged container from the position beneath the chute and brings a fresh container into that position. The pusher stroke which advances a container into the position beneath the chute 17 may be affected more quickly than are other pusher strokes. It will be noted that the strokes ofthe pushers 32 and 40 are greater than the strokes ofthe pushers 20 and 38.

By repeated cycles of operation of the drive means, each container can be moved completely around the circuit defined by the track. After a particular container has moved past the discharge chute 17 a selected number of times, that container may be removed from the track and replaced by an empty container or emptied and then replaced on the track. It will be noted that it is unnecessary forthe container to be emptied or removed immediately the container has left the discharge chute. Workpieces can beaccummulated in the containers for a relatively long period without attention by an operator. If required, the contents ofthe containers can be inspected occassionally. lnthisway, workpieceswhich are near to the bottom ofthe container can be inspected conveniently. When a number of containers contain sufficientworkpieces to be regarded as fully charged, all of these containers can be removed from the track and either replaced by fresh containers or emptied and returned to the track.

As shown, the frame 10 may be provided with castors or other rolling elements so that the frame can be moved easily awayfromthe machine 16if work is to be carried out on the machine.

Furthermore, after the containers supported by the frame 10 have been charged with workpieces,the frame 10 may be wheeled away from the machine and replaced by a further frame supporting empty containers. For clarity of illustration, some structural parts of the frame 10 have been omitted from Figure 2.

Whilst apparatus in which the upper part ofthe track lies directly above the lower part of the track has been illustrated, it will be understoodthatthese parts may be offsetfrom each other laterally if required. In addition to the members which define the track proper, there may be provided guard rails to ensure that no container is tipped from the track.

The apparatus has an odd number ofcontainers.

Generally, there will be at least five contai ners supported on the frame 10 and there may be considerably more containers. The length of the horizontal parts 12 and 13 of the track can be varied to accommodate the required number of containers.

The apparatus illustrated in the accompanying drawing may be modified by the provision, in association with the upper part 12 of the track, of a weighing device which either provides an output dependent on the weight of the container into which workpieces are being discharged and the contents of that container or which responds when subjected to a predetermined downward load. The outputfrom this device may be used to initiate operation of the pushers. The device may be a known load cell incorporated in the track or interposed between a partofthetrackandtheframe 10.

In a case where the control means includes a weighing device, the counter and the sensing means may be omitted. Alternatively, the control means may be arranged to initiate operation ofthe pushers when a predetermined number of cycles ofthe machine 16 has occurred and the weight ofthe contents ofthe container into which the workpieces are being discharged has reached a predetermined value.

Afurther modification ofthe apparatus is illustrated in Figure 3. Certain parts of the apparatus illustrated in Figure 3 correspond to parts hereinbefore described. Such corresponding parts are indicated in Figure 3 by like reference numerals with the prefix 1 and the preceding description is deemed to apply, exceptforthe differences hereinafter mentioned.

All four of the rectilinear parts ofthetrack of the apparatus shown in Figure 3 are horizontal. As viewed in plan,the track forms a closed loop and the machine 216 from which workpieces are collected may be disposed within the loop. Rectilinear parts of track may be releasably secured together, so that the loop can be opened and the apparatus readily moved away from the machine.

It is unnecessaryfor any of the pushers 120,132, 138 and 140 to be capable of supporting a container.

The containers can rest on the track in all positions adopted by containers during operation ofthe apparatus. The four pushers may be identical one with another and arranged in a mannersimilarto that in which the pusher 38 is arranged. Respective fluid-pressure actuators are provided forthe pushers.

Whilstworkpieces are being discharged down the chutell7intothecontainerllla,thereisattheend ofthe part 113 ofthetrack remote from the pusher 138 a space sufficiently large to accommodate a single container. When the output signal is provided bythe control means, the pusher 138 is advanced rapidly towards the chute 1 to move the corresponding row of containers quickly along the track part 113 to bring a second container into a position below the chute. The pusher 138 is then returned to the position illustrated in Figure 3.

Completion of movement of the pusher 138 is signalled, for example buy a limit switch, to the control means and the control meansthen initiates movement ofthe pusher associated with the track part 114. The pushers are operated in sequence in a similar manner until each container has been moved a distance corresponding to the length oftrack occupied by one container. Movement of the containers along the track parts 114,112 and 115 may be effected slowly, relative to movement ofthe containers along the track part 113.

The apparatus illustrated in Figures 1 and 2 and the modified apparatus illustrated in Figure 3 both define endless tracks for the containers. In a further alternative arrangement, the track has opposite ends and containers are moved from one end to the other.

Such a track may be rectilinear, in which case only a single pusher is required, or comprise a numberof rectilinear parts, in which case a corresponding number of pushers is required.

The features disclosed in the foregoing description, orthefollowing claims, orthe accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, as appropriate, may, separately or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims (16)

1. A method of collecting workpieces from a work station wherein there is provided a track, a plurality of containers on the track, drive means for moving the containers along thetrackand control means responsive to the quantity ofworkpieces discharged from the work station, workpieces are discharged from the work station into a first container on the track until a predetermined quantity of workpieces has been discharged, the first container is then moved along the track and a second container is moved into the position previously occupied by the first container, and workpieces are discharged from the workstation into the second container until said quantity of workpieces has been so discharged subsequentto movement of the containers, the second containerthen being moved along the track.

2. A method according to Claim 1 wherein the track defines a circuit and the containers are moved around the circuit.

3. A method according to Claim 2 wherein the containers are moved through more than one complete circuit.

4. A method according to Claim 2 wherein the track defines a polygonal circuit and a first row of containers on a first rectilinear part ofthetrack is moved more rapidly than are rows of containers on other parts of the track and wherqin workpiecesfrom the work station are received by a container of said first row.

5. A method according to any preceding Claim wherein a number of cycles are executed and wherein, during each cycle, a common sequence of movements occurs.

6. Amethod according to Claim 5wherein one movement of said sequence is the raising of a containerfrom a lower level to a higher level and another movement of the sequence is lowering of another container from the higher level to the lower level.

7. A method according to Claim wherein, during each cycle, at least one of said containers is moved through a distance greater than the distance through which at least one other container is moved.

8. Apparatus for collecting workpieces from a work station, the apparatus comprising means defining atrack, a plurality of containers on the track drive means for moving the containers along the track and control means for controlling operation of the drive means, wherein the control means includes a counter for counting operations at the work station and/or a device responsive to the weight ofthe contents of a container and the control means is adapted to cause the drive means to move the containers along the track.

9. Apparatus according to Claim 8 wherein the track is endless.

10. Apparatus according to Claim 8 wherein the track is polygonal and each rectilinear length of the track is provided with a respective reciprocating pusherforthe containers.

11. Apparatus according to any one of Claims 8 to 10 wherein one part of said track is arranged for supporting containers at an upper level and a second partofthetrackisarrangedforsupporting containers at a lower level.

12. Apparatus according to Claim 11 wherein further parts of said track are vertical.

13. Apparatus substantially as herein described with reference to the Figures 1 and 2 ofthe accompanying drawings.

14. Apparatus according to Claim 13, modified substantially as herein described with reference to Figure3 ofthe accompanying drawings.

15. A method substantially as herein described with reference to Figures 1 and 2 or with reference to Figure 3 of the accompanying drawings.

16. Any novel feature or novel combination of features disclosed herein or in the accompanying drawing.