GB2087779A

GB2087779A - Metal trimmer

Info

Publication number: GB2087779A
Application number: GB8037336A
Authority: GB
Original assignee: Joseph Rhodes Ltd
Current assignee: Joseph Rhodes Ltd
Priority date: 1980-11-20
Filing date: 1980-11-20
Publication date: 1982-06-03
Also published as: DE3146057A1; GB2087779B

Abstract

Apparatus for trimming the edges of sheet metal containers, such as battery cases, comprises a rotatable carrier 1 and, mounted on the carrier, container cutters 9, each comprising a rotatable cutting member 11 and a rotatable can-supporting mandrel 15 equipped with a cutting portion 17. The peripheral speeds of the mandrel 15 and the cutting member 11 are substantially equal but in opposite directions. The drive to the rotating members is arranged so that the speed of rotation of the mandrel can be changed by replacement of a single gear, to enable different sized mandrels to be used for containers of different sizes. <IMAGE>

Description

SPECIFICATION Metal trimmer This invention relates to devices for cutting sheet metal and in particular to devices for trimming edges of sheet metal containers.

Circular wailed metal cans or cases, for instance metal cases for batteries, may be made by impact extruding small relatively thick metal discs. Zinc is a commonly used metal for batter" cases, and aluminium and also zinc are used for various cans. The containers which are formed by impact extruding or in any other way normally have irregular or otherwise deformed free edges and it is therefore neces sarytotrim a short circular cylindrical section from the container in order to obtain a container with a clean edge substantially free from burrs.

In known trimming devices the containers are fed onto a mandrel which is arranged for relative movement towards and away from a circular or elongate cutter having a periphe -al cutting edge. The mandrel carries a peripherally extending cutting edge and may itself be arranged for longitudinal reciprocating movement. Means are provided to feed a container onto the mandrel when the cutter moves away from the mandrel or when the mandrel withdraws from the cutter. Wher the cutter or mandrel returns to its closest position to the mandrel or cutting member respectively the cutting edges of the cutting member and the mandrel co-operate to trim the container.

However, when it is desired to adapt the device to trim containers of an increased or decreased diameter, it is necessary to adjust the speed of rotation of one or both of the mandrel and the co-operating cutter. Preferably the peripheral :;peeds of the mandrel and the cutter should be substantially the same so as to avoid skidding of the respective cutting surfaces over the container which will result in an irregular cut being obtained. This is undesirable for any containers but is particularly the case for containers for electrical batteries or cells where an irregular edge to the container may result in the premature discharge of the battery.

In order to match the speeds of the mandrel and co-operating cutter when the mandrel diameter is increased or decreased to accorr modate a differently sized container, it has hitherto been necessary to make considerable adjustments to the driving mechanism for the relevant part or parts of the machine. For a machine with a single mandrel and co-operating cutter, a change of container size has required the replacement of a set of change gears (with the minimum of two gears by a new set. If a machine is to be provided with a plurality of mandrels, and co-operating cutters, in order to increase the rate at which the co 7trainers can be trimmed, such a machine will require a number of sets of change gears corresponding to the number of mandrels on the machine.Accordingly for a machine with four mandrels at least eight change gears is required for each size of container.

According to the present invention there is provided apparatus for trimming the edge of a sheet metal container, the apparatus having a plurality of mandrels mounted on a carrier, the carrier adapted to be rotatably driven, each mandrel being adapted to receive a container and having a peripherally extending cutting edge, each mandrel having associated therewith a cutting member, each cutting member also being mounted on the carrier, and means for effecting rotation of each mandrel and its associated cutting member at substantially equal peripheral speeds co-operatively to trim a container located on the mandrel.

Preferably the carrier is arranged to be driven substantially continually during operation of the apparatus.

Preferably each mandrel has associated therewith means for loading a container onto said mandrel, said loading means being located on a common support means, said support means being spaced from and adapted to be rotated at the same speed as the carrier. More preferably the loading means includes pushing means mounted for movement towards and away from the associated mandrel in order to push a container onto said mandrel. The pushing means may, for instance, include a cam follower arranged to follow a cam in order to effect the reciprocation of the pushing means.

Preferably the means for rotating the carrier is drivingly connected to both the mandrel and the cutting member to effect rotation thereof. More preferably the rotating means are arranged to effect rotation of the cutting member by one complete revolution for each complete revolution of the carrier. Most preferably the direction of rotation of the cutting member is opposite to that of the carrier.

Preferably each cutting member is rotated in a direction opposite to the direction of rotation of its associated mandrel.

Preferably the rotating means are connected to each mandrel via a common gear train. This gear train can be such as to drive the mandrel at the same peripheral speed as the cutting member. Preferably the gear train includes a single replacable gear which may be changed to enable different diameter mandrels to be driven at a different rotational speed to match the peripheral speed of the cutting members.

Preferably each cutting member is shaped so that its periphery includes a contacting portion which co-operates with the cutting edge of the mandrel to trim the container, said periphery also including, peripherally adjacent said contacting portion, a non-contacting portion which, during said rotation, does not make contact with the container. With such an arrangement there is no need to move the mandrel and cutting member relatively apart during the operations of loading the container onto and unloading the container from the mandrel. Accordingly, the accuracy of the cutting operation is not reduced by additional clerances which could have been necessary if the mandrel and cutting member have to be moved apart during loading and unloading.

The length of the contacting portion of the cutting member should be approximately equal to the container circumference and is preferably slightly greater than the container circumference, to ensure that the whole of the circumference of the container is properly trimmed.

Preferably the cutting member undergoes one revolution for a single cycle of loading, trimming and unloading of a container. Such an arrangement together with the rotation of the carrier by one revolution in the same time as the completion of one revolution by the cutting member, means that the movements of the various parts of the apparatus can be fully synchronised to allow rapid, automatic loading and unloading of the container of the mandrel.

Although, during operation of the device, the cutting member and its associated mandrel are maintained with their centres at fixed distances from each other, the cutting member is nonetheless -prnfernbly mounted for movement towards and away from the mandrel in both lateral and vertical directions. Such an arrangement allows a particular mandrel to be replaced by one of a smaller or larger diameter or a longer or shorter length to accommo date a can of a different diameter, length of wall thickness. Preferably means are provided to lock the cutting member in position relative to the mandrel during the actual operation of the apparatus.

An embodiment of the present invention will now be described, by way of example only, and with reference to the accompanying drawings, in which Figure 1 shows in diagrammatic form apparatus in accordance with the present invention; Figures 2 to 5show stages in the operation of part of the apparatus of Figure 1; and Figure 6 also illustrates the stages of operation of Figures 2 to 5.

Referring to Figure 1 of the drawings, apparatus in accordance with the present invention is for trim ming the edges of sheet metal containers, such as metal cases for batteries. The apparatus includes a carrier 1 which has a large diameter circular cylin drically shaped forward end 3 and a smaller dia meter circular cylindrical rearward projection 5.

Carrier 1 is mounted for rotation abouts its longitu dinal axis on fixed sleeve 7. Provided on the carrier are four pairs of container cutters 9 (only one pair being shown in Figure 1). Each pair of cutters 9 includes a cutting member 11 carrying a segmented cutter 13 and a mandrel 15 to the rear end of which is a circular cutter 17 which is positioned to co-operate with cutter 13 in order to trim a can 19 located on mandrel 15.

The carrier 1 is driven from power input shaft 21 which extends through housing 22. The drive mechanism is indicated by the arrows in Figure 1 and extends from power input shaft 21 to main drive spindle 27 via gears 23 and 25 which are both inclined gears and whose longitudinal axies are at right angles. At the front end of main drive spindle 27 is located gear 29 which engages gear 30 at the rear end of carrier 1. The overall gear ratio "C" determines the speed of rotation of carrier 1 and therefore the speed of production of trimmed con tainers.

Also engaging gear 30 is a gear 31 located at a front end of spindle 33. Gear 31 forms the starting point of a drive mechanism from gear 30, and therefore originally from power input shaft 21 to the mandrel 15. This mechanism further includes a change gear 35 located on the rear end of shaft 33.

This change gear 35 transmits drive via idle gear 37 to a gear 39 located at the rear end of a drive spindle 41. Drive spindle 41 extends into the central bore located in fixed sleeve 7 and emerges from fixed sleeve 7 within the hollow interior of front section 3 of carrier 1. At its front end drive spindle 41 terminates in a gear 43. Gear 43 meshes with a further gear 45 which is fixed to a spindle 47 at a position close to the enlarged end 49 of the spindle.

Spindle 47 extends through the front wall 51 of carrier 1, the front portion of this spindle forming the mandrel 15 and carrying adjacent thereto the circular cutter 17.

This last-described drive mechanism is indicated by the arrows "A" and the direction of rotation of the spindles is also indicated. It can be seen thatthe sense of rotation of mandrel 15 is the same as that of carrier 1. The overall gear ratio of "A" determines the rotational speed of mandrel 15 and can be easily changed by replacing change gear 35 by a different change gear and adjusting the position of idle gear 37 which is mounted on an adjustable centre. A further drive mechanism "B" is provided for rotating cutting member 11. This rotation derives originally from power input shaft 21 and its associated drive mechanism "C". In this case a short spindle 51 is mounted within the relatively narrow diameter portion 5 of carrier 1 and extends therefrom into the hollow interior of the front portion 3 of carrier 1.At its front end spindle 51 is provided with gear 53 which is arranged to mesh with gear 55 located at the front end of fixed sleeve 7. As the carrier 1 rotates about fixed sleeve 7 drive is transmitted from gear 53 to gear 57 located at the rear end of a drive shaft arrangement 59. Arrangement 59 includes a universally jointed section 61 and a spindle 63 extending therefrom through the front wall of carrier 1. Located on the front end of spindle 63 is the cutting member 11 carrying the segmented cutter 13.

It will be seen that the direction of rotation of cutting member 11 is opposite to that of carrier 1.

The gear ratio "B" is such that carrier 1 completes one revolution for each complete revolution of cutting member 11, that is say, the cutting member 11 does not rotate relative to a fixed point, its actual rotation being compensated for by the opposite and equal rotation of carrier 1.

The provision of universally jointed section 61 allows the radial position of cutting member 11 to be easily adjusted when the mandrel size is altered in order to accommodate a differently sized container.

Once an adjustment of this sort has been made the cutting member 11 may be locked in its radial position and during operation of the apparatus the centres of the cutting member 11 and the mandrel 15 remain fixed relative to each other.

The frame 22 of the apparatus supports not only carrier 1 and the above-described parts associated therewith but also transporter drum 71 and support member 73 which carry the mechanism for loading untrimmed cans onto mandrel 15 and removing trimmed scraps of metal from the mandrel 15. This support structure is spaced from a position forwardly of carrier 1 and mounted for rotation on a drive spindle 75 which at its rear end is fixed to the centre of the front wall 51 of carrier 1. Arrows in Figure 1 indicate the transmission of drive from carrier 1 to spindle 75 and the direction of rotation of spindle 75 and it will be appreciated that carrier 1, transporter drum 71 and support member 73 all rotate together at the same speed.

Associated with each mandrel 15 and mounted on transporter drum 71 and support member 73 is the pusher/ejector arrangement 81. Arrangement 81 includes rod 83 mounted for movement towards and away from mandrel 15. At its rear end rod 83 carries can loading pusher 85 which, during movement towards mandrel 15 pushes can 19 onto the mandrel from a longitudinal groove 87 located at the periphery of transporter drum 71.

Depending downwardly from rod 83 is a short arm 89. Extending rearwardlyfrom arm 89 is rod 91 which carries at its rearward end an upwardly extending arm 93 having its upper end 95 in the form of a ring completely surrounding spindle 47. The forks of end ring 95 lie close to and on opposite sides of spindle 47. During movement of rod 83 in a direction away from mandrel 15, which results in a movement in the same direction of arm 93, the end ring 95 of arm 93 act to move a trimmed ring of scrap metal 97 forwardly with respect to mandrel 15 and off the front end thereof where it may drop into a suitable receptacle located below the apparatus.The reciprocating movement of rod 83 is effected as a result of a cam follower 99, located at the front end of rod 83 following the inclined groove 101 in the peripheral surface of a fixed cylindrical body 103. As drive spindle 75 rotates so does transporter drum 71 and support member 73 carrying with them rod 83 and the parts associated therewith. It will be seen that the movement of cam follower 99 in groove 101 results in the above-mentioned reciprocating movement of rod 83 and parts connected thereto.

Referring to Figures 2 to 6, various stages in the operation of the above-described apparatus are shown. Figure 8 illustrates a front view of each of the stages of Figures 2 to 5. Figure 6 also illustrates the nature of the segmented cutter 13 located on cutting member 11. This segmented cutter 13 extends radially outwardly from the body of cutting member 11 and extends about perhaps one quarter to one third of the periphery of member 11. The length of the segmented cutter 13 is slightly greater than the circumference of the can to be accommodated on the mandrel 15. Position 1 of Figure 6 and Figure 2 illustrate the loading of can 19 onto mandrel 15 just after can 19 has dropped from magazine 111 into one of the grooves 87 located on transporter drum 71.At this position the segmented cutter 13 is positioned away from mandrel 15 as a result of which there is a gap between mandrel 15 and the cutting member 11 so that the can 19 can be loaded onto the mandrel 15.

Position 2 at Figures 1,3 and 6 illustrates the commencement of the trimming of the can by the segmented cutter 13 located on cutting member 11.

Further rotation of carrier 1, as well as cutting member 11 of mandrel 15, effects the complete trimming of container 19, a stage near the end of this trimming process being illustrated at position 2A in Figure 6. When position 3 is reached (Figure 6 and Figure 4) the trimming of the can has been completed and there is once again a gap between mandrel 15 and cutting member 11. At this point the pusher 85 and arm 93 move in a forward direction.

Compressed air is fed into a longitudinal bore 121 of mandrel 15. Bore 121 opens into the forward end of mandrel 15 and accordingly the can 19 is blown off the end of the mandrel into an appropriately positioned receptacle. The forward movement of arm 93 causes the end ring 95 of this arm to push the ring of scrap metal 97 off the end of mandrel 15 subsequent to the ejection of the trimmed container 19.

Position 4 (Figure 6 and Figure 5) illustrate the final stage of the removal of the container 19 and the scrap metal ring 97.

The above-describd apparatus is operated with the carrier 1 rotating continuously, it being unnecessary to index the carrier to stationary positions for loading, trimming and ejecting the containers.

By ensuring that the contacting surfaces of the cutter located at the rear end of the mandrel and the corresponding segmented cutter move at substantially the same speed, a true rolling action takes place between these contacting surfaces so that an accurate and clean cut is achieved.

Claims

1. Apparatus for trimming the edge of a sheet metal container, the apparatus having a plurality of mandrels mounted on a carrier, the carrier adapted to be rotatably driven, each mandrel being adapted to receive a container and having a peripherally extending cutting edge, and each mandrel having associated therewith a cutting member, mounted on the carrier, and means for effecting rotation of each mandrel and its associated cutting member at substantially equal peripheral speeds cooperatively to trim a container located on the mandrel.

2. Apparatus according to claim 1 wherein the carrier is arranged to be driven substantially continually during operation of the apparatus.

3. Apparatus according to claim 1 or claim 2 wherein each mandrel has associated therewith means for loading a container onto said mandrel, said loading means being located on a common support means, said support means being spaced from and adapted to be rotated at the same speed as the carrier.

4. Apparatus according to claim 3 wherein the loading means includes pushing means mounted for movement towards and away from the associated mandrel in order to push a container onto said mandrel.

5. Apparatus according to claim 4 wherein the pushing means include a cam follower arranged to follow a cam in order to effect the reciprocation of the pushing means.

6. Apparatus according to any one of the preced ing claims wherein the means for rotating the mandrel is drivingly connected to both the mandrel and the cutting member to effect rotation thereof.

7. Apparatus according to claim 6 wherein the rotating means are arranged to effect rotation of the cutting member by one complete revolution for each complete revolution of the carrier.

8. Apparatus according to claim 7 wherein the direction of rotation of the cutting member is opposite to that of the carrier.

9. Apparatus according to any of the preceding claims wheren the direction of the cutting member is opposite to that of the associated mandrel.

10. Apparatus according to any of the preceding claims wherein the rotating means are connected to each mandrel via a common gear train.

11. Apparatus according to claim 10 wherein the geartrain drives the mandrel atthesame peripheral speed as the cutting member.

12. Apparatus according to claim 10 or claim 11 wherein the gear train includes a single replaceable gear which may be changed to enable different diameter mandrels to be driven at a different rotational speed to correspond to the peripheral speed of the cutting members.

13. Apparatus according to any preceding claim wherein each cutting member is shaped so that its periphery includes a contacting portion which cooperates with the cutting edge of the mandrel to trim the container, said periphery also including, peripherally adjacent said contacting portion, a non-contacting portion which, during said rotation, does not make contact with the container.

14. Apparatus according to claim 13 wherein the length of the contacting portion of the cutting member is approximately equal to the circumference of the container to be trimmed.

15. Apparatus according to claim 13 wherein the length of the contacting portion of the cutting member is greater than the container circumference.

16. Apparatus according to any preceding claim wherein the cutting member undergoes one revolution for a single cycle of loading, trimming and unloading of a container.

17. Apparatus according to claim 16 wherein the carrier undergoes one revolution in the same time as the cutting member.

18. Apparatus according to any preceding claims wherein the cutting member is mounted for move menttowards and away from the mandrel in both lateral and substantially vertical directions.

19. Apparatus according to claim 18 wherein there are provided means for loading the cutting member in position relative to the mandrel during the operation of the apparatus.

20. Apparatus according to claim 1 and substantially as herein described.

21. Apparatus for trimming the edge of a sheet metal container substantially as herein described and with reference to the accompanying drawings.