US1969390A

US1969390A - Grid trimming press

Info

Publication number: US1969390A
Application number: US636837A
Authority: US
Inventors: Alfred R Willard
Original assignee: Willard Storage Battery Co
Current assignee: Willard Storage Battery Co
Priority date: 1932-10-08
Filing date: 1932-10-08
Publication date: 1934-08-07
Anticipated expiration: 1951-08-07

Description

Aug. 7, 1934.

A. R. .WILLARD GRID TRIMMING PRESS Filed Oct. 8, 1932 5 Sheets-Sheet l Haj.

Aug- 7, 1934- A. R. wlLLARD GRID TRIMMING PRESS Filed Oct. 8, 1952 5 Sheets-Sheet 2 Aug 7, 1934. A. R. WILLARD 1,969,390

GRID TRIMMING PRESS Filed Oct. 8, 1932 Sheets-Sheet 3 avid/mmf@ Aug 7, 1934- A. R. WILLARD 1 1,969,390 I GRID TRIMMING PRESS v /NVENTOE ,4L Flei @IMM/F12 @'Mmym Aug- 7, 1934- A A. R. WILLARD 1,969,390

l GRID TRIMMING PREss Filed 0G13. 8, 1932' 5 Sheets-Sheet 5 iatented Aug. 7,l 1934 UNITED STATES GRID TRIMM'ING PRESS Alfred R. Willard, East Cleveland, Ohio, assignor to Willard Storage Battery Company, Cleveland, Ohio, a corporation of West Virginia Application October 8,

Z Claims.

This invention relates to improvements in grid trimming presses, that is to say presses for trimming off excess or waste metal from grids for storage batteries, which are cast ordinarily from leadv or lead alloy.

One of the objects of the invention is to provide mechanical means for feeding the grids to the press and for collecting them in stacked relation after the trimming operation is performed.

Another object is the provision of means for maintaining the grids in stacked relation in a magazine and presenting them one at a time from said magazine to the action of a transfer mechanism which abstracts them from the magazine and carries them into position for being trimmed.

. Another object of the invention is the provision of transfer mechanism capable of swinging through a predetermined angle into a plane parallel with the plane of the trimming die, and then traveling bodily to carry the grid parallel to itself into trimming position, and thereafter returning to its initial position.

A further object of the invention is the provision of means for timing the operations of the press to conform with those of the magazine and transfer portions of the machine.

Another object is the provision of special means for dislodgingthe grids from the press and assisting them in their travel onto the collecting apparatus.

Still another object is the provision of means for stripping the trimmed metal from the grid and from the trimming knife when the cut has been made.

Other objects and features of novelty will appear as I proceed with the description of that embodiment of the invention which, for the pur- I poses of the present application, I have illustrated in the accompanying drawings, invwhich Figure 1 isa side elevational view of a machine embodying my invention, showing the transfer ngers in position to deposit a grid upon the trimming die.

Fig. 2 is a front elevational view of the machine. l

Fig. 3 is a fragmental detail side elevational view on a larger scale, showing the transfer fingers in gripping position upon a grid and the transfer mechanism just upon the point of swinging the grid rout of the magazine.

Fig. 4 is a sectional view on a large scale, of a fragment of the press, showing the die and punch and the stripper mechanism, and

Figs. 5 to 9 inolusiveare detail views of cam .mechanisms employed in the machine.

1932, Serial No. 636,837

Similar reference characters refer to like parts throughout the views.

A press of the more or lessA conventional form is indicated at 10, mounted upon a frame or base 11. The latter is in turn mounted upon asubbase 12, to which is also attached a frame 13 positioned directly in front of the frame 11 and rigidly connected thereto through the intermediacy of the sub-base 12. The press 10 may be provided with guides 14, within which slides a head 15 that is adapted to be reciprocated by connecting rods 16 having eccentric connections with the main shaft 17 of the press, The latter shaft may be driven in the ordinary manner from an electric motor 18, having a pinion 19 meshingv 70 with a large gear on a fly-wheel 20 that is loose on the shaft 17 and adapted to be operatively connected therewith by a clutch 9 during a single revolution of the shaft, a trip mechanism, being employed to set the clutch, and automatic means being employed to disengage it at the end of its revolution, all in a marmer and by mechanism known in the art' and not herein illustrated in detail.

In the press 10 there is a bed 2l to which 80 is suitably secured a die 22 carrying a pair of stops 23 which project upwardly from the surface of the die and are adapted to support a grid G by engagement with its lugs. 'I'he punch 15 may comprise a forward knifef 24 for trim- 85 ming the upper edge of the grid and a pair of short lateral knives 25 for cutting the grid lugs to length. The bed of the press laterally of the die is provided with

inclined surfaces

26 and 27 in order to more readily discharge any trimmings that may be deposited thereon.

Near the center ofthe die 22 I form an opening within which is mounted upon a hinge pin 28 a sort of trap door 29, the upper surface of which is ush with the upper surface of the main portion of the die when the door is closed. At its forward end it is pivotally connected with a rod 30. When the latter rod rises, as it does in the operation of the press, the trap door 29 swings upon its pin 28 and the grid G is lifted sufd- 100 ciently to dislodge it from the die and to disengage it from the stops 23, whereupon gravity 'causes it to be discharged.

On the plunger 15 I mount a bracket 31, upon which is pivotally supported a stripper plate 32, the free end of the latter being secured, as shown in Fig. 4, to a coil spring 33 which bears at its upper end against an angle bar support 34, also carried by thel plunger 15. When the knife 24 descends to .makeI a cut the hinge pinpof the 11 ".ofhthepr'ess, I employ a pair lof jogger rails 56 plate 32 descends with it, but inasmuch as the spring 33 is relatively light the plate 32 swings upwardly, storing up energy in the spring while the cut is being made. As soon as the knife 24 starts on the return stroke however the energy thus built up becomes effective to snap the trimming T downward into a suitable waste receptacle, not shown.

The grids, when they are discharged from the press as above explained, may be collected and stacked by any suitable means for the purpose, but I prefer to employ that illustrated in the drawings wherein I utilize a frame 35. attached to the press 10 and supported at its outer end by inclined braces 36 running to the base 11 of the press. Upon this frame I mount a shaft 37 which is adjustable therein and which carries a pair of sprocket wheels, no t shown, over which run two endless chains 38, the inner bights of which run upon sprockets carried by a shaft 39. The two chains 38 are spaced apart just far enough to receive grids G between them and to support the grids by their lugs.

On the shaft 39 there is loosely mounted an arm 40, to which is pivotally connected a pawl 41 that is adapted to cooperate with aratchet wheel 42 which is secured upon shaft 39. To the outer end of arm 40 there is pivotally connected an adjustable link 43 that is connected to the lower end of a long lever 44 that is pivoted upon the press 10 at 45, and is provided at its upper end with a follower 46 running upon an eccentric or cam 47 secured to shaft 17. It will be obvious that each time the shaft 17 makes a revolution the arm 40 is caused to oscillate, and that the ratchet wheel 42 with its shaft 39 is thereby rotated through a certain small angle, advancing the chains 38 accordingly, so that there is always room for the next grid to be deposited upon the chains.

The connecting rod 30 for the trap door 29 is also operated by the shaft 17, being connected at its lower end with a rock lever 48 pivoted to the press 10 at 49, the other arm of the lever being pivoted to a connecting rod 50 which` is eccentrically mounted at 51 upon the end of shaft 17. The trap door 29 by this means is `therefore swung upwardly once for each reciprocation of the head of the press.

The grid magazine, and the mechanism for transferring grids therefrom to the trimming press, will now be described.'

At the top of the frame 13 I mount', partially upon a brace rod 52 of the frame, a pair of grid supporting rails 53, which are inclined downwardly away from the front of the machine. These two rails are rigidly mounted' and are spaced apart far enough to receive grids between them with the lugs of the grids resting upon the upper surfaces of the rails. On account of the inclined position of the rails the grids tend to slide down to the forward end thereof. At such forward end there are stops 54 so positioned at either side of the magazine as to engage the lugs of the foremost grid when resting upon the rails, and there is also a bottom stop 55 adapted to engage the bottom edge of the foremost grid. Hence, if the foremost grid is raised, far enough to clear the stop 55 and to enable its lugs to clear the two side stops 54, it may be extracted from l the magazine.

In order t maintain the grids in the magazine in closely stacked relation at the lower end thereof so-that there will be no interruption to the action which are pivotally mounted at their rear ends upon trunnions 57 carried b'y the rigid portion of the magazine. At their forward ends these jogger rails are pivoted to connecting rods 58 which are caused to move up and down at regular intervals, as will be presently explained. When the rails 56 move upwardly they engage the lower edges of the grids in the magazine and lift thegrids sufficiently to disengage their lugs from the xed rails 53. The upper edges of the raised grids then tend to fall forwardly tottake up any space there may be between the upper edges of the grids. the rails 56 descend however they lower the lugs of the grids onto the fixed rails 53 and then swing out of engagement with the lower edges of the grids, which may then swing forward by gravity to take up any space between the lower edges of the grids. Thus, the grids are continuously jogged into closely packed relation at the lower or forward end of the magazine.

At the forward end of the rails 53 there are also a pair lof top stops 59 which have downturned rear ends that receive adjusting screws 60, by means of which the stops 59 may be moved forwardly or rearwardly to a limited extent. In practice they are so adjusted as to extend over the upper ends of all of the forward grids except the foremost one, which is thus free to rise. But when the foremost grid is raised the stops 59 prevent any of the grids behind it from being raised also, by friction or otherwise.

Slidable in guides at the forward end of th magazine there are a pair of push fingers 61 which are adapted to engage beneath the lugs of the foremost grid. When these lingers are caused to rise simultaneously, by means hereinafter described, the foremost grid is lifted out of engagement with the lside stops 54 and the bottom stop 55 and into position to be grasped by the transfer fingers.

At each side of the press 10 I mount a bracket in which is supported a rearwardly projecting bar 62. In the present instance one of these brackets is mounted outside the press and the other inside', as will be seen from Fig; 2. On the bars 62 there are mounted two slides 63, which are connected by a rock shaft 64 that is free to turn in bearings carried by the slides; Each slide 63 has a depending projection to which is pivotally connected an adjustable link 65, which is also pivotally attached to a swing arm 66. These two swing arms are keyed at their lower ends to the extremities of a a shaft 67, which is mounted in bearings in the frame 13. To this shaft 67 there is also keyed a link arm 68, in the free end of which there is an anti-friction follower 69 that engages the periphery of a cam 70 which is keyed or pinned to a shaft 71 that is also mounted in bearings in the Hence, as the shaft 71 revolves, the cam 70 swings the arm 66 back and forth, causing the slides 63 to reciprocate upon the bars 62.

There are two sets of transfer fingers adapted to grip the lugs of the grid. 'Ihese sets each consist of a. rigid finger 72 (see Fig. 3) that is secured to or forms part of a bracket 73 which is keyed to the rock shaft 64, and a swinging finger 74 that is pivotally connected to the same bracket. On the nger 72 I provide a stop 75 which is adapted to engage the upper edge o f the grid lug to determine accurately the extent to which the grid may enter the transfer fingers. Each bracket 73 also carries an air cylinder 76 having a piston, not shown, which drives a piston rod 77 that is pivotally connected at its lower end with a short crank 78 secured to the pivot for the finger 74. A con- When nection 79 is provided in the upper portion of the.. cylinder 76, by means of which air under pressure" may be admitted to swing the crank 78 downward to close the fingers. The return of the latter to open position, when the air pressure is removed, is effected by a retractile spring 80 attached at its upper end to a pin 81 on the bracket 73 and at its lower end to the pivot pin between the piston rod 77 and the crank 78. The upper ends of the brackets 73 are preferably joined together by a brace rod 82 which supports a union 83 from which air conductors 84 lead to the air connections 79 on the two cylinders, and from which a flexible hose 85 extends downwardly to the air valve, later to be described. It will be obvious, of course, that vacuum action may be substituted for fluid pressure action in the operation of these fingers.

The actuation of the transfer fingers necessitates theswinging of the rock shaft 64, and this is effected by means of a crank 86 that is secured to one end of the shaft and carries at its free end a crank pin 87 that runs in a guide slot in a swinging guide bar 88 that is pivoted at 89 to a bracket on the outer side of the press 10. 'I'he two extreme positions ofu the swinging guide 88 are shown in full and dotted lines in Fig. 3, and the corresponding positions of the brackets 73 and transfer fingers are also similarly shown in that figure.

For swinging the guide bar 88, I attach to the lower side thereof by any suitable means a connecting rod 90 that is, for convenience, made adjustable as to length, and is pivoted at its lower` end to a crank 91 that is keyed to a short shaft 92 journaled in one side member of the frame 13. Inside of this frame member this'same shaft carries a second crank arm 93, in the free end of which is mounted a follower 94 that runs upon the peripheral surface of a cam 95 which is keyed to shaft 71. p

On one end of cam shaft 71 there is keyed a cam 96, with which a follower 97 cooperates.

This follower is mounted upon a lever 98 that swings upon a trunnion 99 carried by the frame 13 or a bracket supported thereon. This lever carries an adjustable Contact4 pin 100 which engages the operating pin of a slide valve that is housed in a valve casing 101, to which the hose 85 is connected. Another air conductor 102 leads from the valve to any convenient supply or source of compressed air or vacuum. It will be understood that the movement of the pin 100 in one direction serves to connect the

uid conductors

85 and 102, while its movement in the opposite direction breaks that connection and opens the conductor 85 to atmosphere.

The clutch 9 connecting the fly-wheel 20 with the' shaft 17, to set the press in operation for one reciprocation of the plunger head, is tripped in the conventional manner, and this tripping action is effected in properly timed relation to the other functions of the machine by a push rod 103, which is pivoted at itslower extremity to a crank 104 that is keyed or pinned to a rock shaft 105 journaled in the frame 13. A second crank arm 106 is also 4' secured upon the shaft4 105, and is connected by a link 107 to the lowerl end of a bifurcated lever 108, between the bifurcations of which there is mounted a roller follower 109. The lever 108 has a loose bearing at its upper end upon a shaft 110, likewise journaled in the frame 13. The follower 109 contacts with the periphery of a cam 111 keyed to shaft 71. As will be seen in Fig. 8, the high spot of this cam has a short angular dimension. Its

purpose is to give a quick, short impulse to the push rod 103 to trip the press/ Referring again to the jogger mechanism which assists gravity in packing the grids together in the magazine, the connecting rods 58 that are pivotally connected to the forward ends of the jogger rails 56 are pivoted at their lower ends toy cranks 112 formed integral with a relatively long hub 113 which is loosely journaled upon shaft 67, see Figs. 2 and 7. The hub 113 also carries an arm 114 with a cam follower 115 at its lower end that runs upon a cam 116 keyed to shaft 71. This mechanism, it will be observed, is such that a regular up and down motion is transmitted to the joggerrails 56.

The push fingers 61, which serve to' raise the foremost grid in the magazine at the proper time, are somewhat flexible and are attached directly to brackets 116 carried at the outer ends of crank arms 117 that are keyed to shaft 110, see Figs. 2 and 6. On the same shaft there is keyed another crank arm 118 which has a follower 119 rimning upon a cam 120 that is keyed to cam shaft 71. M

'I'he cam shaft and its associated parts are driven in this instance by a separate motor 121, the shaft of which carries a pinion 122 that meshes with a gear'123 on a shaft 124. This shaft, if desired, may run through, the housing of and operate an air pump 125, used' for supplying pressure fluid to the cylinders 76. A sleeve 126 surrounds shaft 124, to which it may be connected by means of a clutch 127 of any suitable type, adapted to be operated by a clutch lever 128. At the outer end of this sleeve I mount a sprocket wheel 129 over which runs an endless chain 130, which transmits driving force to a. sprocket 131 keyed to an 'outer end of cam shaft 7l.

Operation-It is the duty of the attendant t'o keep a supply of grids in the magazine and periodically to remove trimmedvgrids from the forward end of the delivery apparatus. A cycle of operations may be described as follows: The push fingers 61 are caused to rise, and by their en- 120 gagement with the lugs of the foremost grid, they raise the grid sufficiently to expose the lugs and to free the grid .from the side and bottom stops 54 and 55 respectively. At this time the

transfer fingers

72 and 74 are in the position illustrated 125 in Fig. 3, except that the fingers 74 are retracted by the springs 80. At this instant cam`96 acts to operate the air valve to admit pressure fluid to hose connection 85, whereby the piston; rods 77 are forced downwardly and the cranks 78 are 130 operated to swing the fingers 74 to closed position, gripping the lugs "of the grid. Now, with the

fingers

72, 74 remaining closed, the high spot of cam 95 comes into engagement with the follower 94 of arm 93, and the swinging guide 135 bar 88 .is thereby raised from its full line position of Fig. 3 to its dotted line position. This movement ofthe guide bar acts through the pin and slot connection with crank 86 to vswing rock 140 shaft 64 in an anti-clockwise direction, as. viewed in Fig. 3. The transfer fingers are thereby swung from the'full line position of Fig. 3 up to a position substantially in line with 'the dotted line position of thatv flgure. v After theswinging guide 88 is moved to full line position (Fig. 3) or it may be while this is occurring, the low part of cam 70 begins to engage its follower, and the arm" 66 begins to swing from its full line position toward its dotted line 150 position, Fig. 3, the movement in this direction being effected by springs'or the like, not shown.

J When the parts reach the dotted line position of Fig. 3 the cam 96 acts to operate valve 101 in the opposite direction, opening the cylinders '76 Y to exhaust, whereupon the fingers '74 swing to asv open position under the iniiuence of springs 80. The cam 70 then acts to again swing the arms 66 toward the right in Fig. 3, moving the slides 63 back to their initial position, where they remain a major portion of the time of each cycle.

As soon vas the transfer lingers are out of the` way, cam 111 operates through the mechanism heretofore described to trip the press, and the plunger head 15 thereof descends, makes its cut, and returns to its upper position, when the clutch 9 between the fiy-wheel 20 and the shaft 17 is automatically disengaged. The revolution of the shaft 17 however operates through lever 44 and connecting rod 50 to advance the deliverychains 38 and to operate the trap door ejector 29.

'Ihe cycle is then completed and a new cyclei begins. During each cycle however the cam 116 raises and lowers the jogger rails 56, in order to insure the close stacking of the grids in the magazine. y

In the foregoing description I have necessarily gone somewhat into detail in order to explain fully the particular embodiments of the invenvmeans for raising the forward grid in the magazine part way out of the stack, gripping means adapted to receive the said grid as it is raised and to grasp it when raised, and means for causing the said gripping means to move to another position, to place the grid on the trimming die and to release the grid.

2. In a press for trimming storage battery grids, a trimming die, a magazine for supporting the grids on edge -in closely' stacked relation, means for raising the forward grid in the maga- Zine part way out of the stack, and gripping means mounted to have both swinging and bodily movement arranged to receive the said grid as it iscausing said mechanism to grasp the forward grid in said magazine at one edge of the grid, to swing the same thereafter into a plane parallel with the plane of said die and to advance the grid in the latter plane the opposite edge foremost' into operative position between said die and punch.

4. Inra press for trimming storage battery grids, a trimming die set in a given plane, a trimming punch cooperating therewith, amagazine for supporting the grids on edge one behind the other in planes at an angle to the plane of the die, grid transfer mechanism, means for causing said mechanism to grasp the forward grid in said magazine at one edge of the grid, to swing the. same thereafter into a plane parallel with the plane of said die and to advance the grid in the latter plane the opposite edge foremost into operative position upon the die, and means timed with the operation of said transfer mechanism for tripping the press to cause said punch to advance on its working stroke after the grid is in position upon the die.

5. In a machine of the class described, a magazine for supporting a series of grids on edge one behind the other, means for maintaining the grids in the magazine in closely packed relation, stops at the forward end of the magazine, means for raising the forward grid parallel to itself suinciently to clear said stops, and transfer mechanism timed in its action to receive the forward grid as it is raised and to transfer it bodily into position to be operated upon.

6. In a machine of the class described, a fixed guide, a slide mounted thereon, a pair of grid grippers pivotally mounted on said slide, a pivoted guide, a crank carried by said grid grippers, a crank pin in said crank arranged toslidably contact with said pivoted guide, means for swinging said pivoted guide, and means for causing said slide to travel upon said fixed guide whereby the grid grippers are caused to swing from one transverse plane to another and to travel bodily.

7. In a press for trimming storage battery grids, a magazine adapted to support grids on edge, and

means for transferring grids one at a time fromsaid magazine to position for trimming, comprising transfer fingers adapted t0 swing and to move bodily, a shaft, means for rotating the same, a series of cams mounted on said shaft, means actuatedby one of said cams for opening and closing the fingers, means actuated by another of said cams for swinging the fingers, and means actuated by still another of said cams for moving the ngers bodily.

. 8. In a press for trimming storage battery grids, a trimming die and punch, a magazine adapted to support grids on edge, transfer fingers adapted to swing and to move bodily for transferring the forward grid out of the magazine into position to be trimmed, a shaft, means for rotating the same, a series of cams mounted on said shaft, means actuated by one of said cams for opening and closing the fingers, means actuated by another of said cams for swinging the fingers, means actuated by another of said cams for moving the iingers'bodily, and' means actuated by still another of said cams for tripping the press to cause the ,punch to be advanced to the work and then retracted.

9. In a press for trimming storage battery grids, a trimming die4 and punch, a .magazine adapted to support grids on edge one directly behind the other, means for lifting the foremost grid, transfer fingers adapted to receive and grasp said grid and to swing and to move bodily, whereby the grids may be transferred one at a time from said magazine to trimming position between said die and punch, a shaft, means for rotating the same, a series of cams mounted on said shaft, means actuated by one of said cams for operating said grid lifting means, means actuated by another of saidv cams for opening and closing the transfer lingers,l means actuated by another of said cams for swinging the fingers,

means actuated by another of said cams for moving the fingers bodily, and means actuated by still another of said cams for tripping the press to cause the punch to be advanced to the Work and then retracted.

10. In a press for trimming storage battery grids, a trimming die and punch, a magazine having inclined rails for supporting grids on edge, means for jogging the grids so as to cause them to pack closely one behind another at the lower end of the magazine, means for lifting the foremost grid, transfer fingers adapted to receive and grasp said grid and to swing and move bodily, whereby the grids may be transferred one at a time from said magazine to trimming position between said die and punch, a shaft, means for rotating the same, a series of cams mounted on said shaft, means actuated by one of said cams for operating said jogging means, means actuated by another' of said cams for operating said grid lifting means, means actuated by another of said cams for opening and closing the transfer fingers, means actuated by another of said cams for swinging the iingers, means actuated by another of said cams for moving the ngers bodily, and means actuated by still another of said cams for tripping the press to cause the punch t0 be advanced to the work and then retracted.

11. In mechanism for transferring grids one at a time from a magazine to a work position in a plane at an angle to the grids in the magazine, which comprises a bodly movable element, a member pivoted thereon carrying one finger, a second nger hinged t'o said member, a uid pressure cylinder carried by said member operatively connected with said second finger, a exible pressure fiuid connection to said cylinder, me-

chanical means for moving said element bodily and for swinging said member, and means controlled in timed relation to said bodily movement and swinging movement for supplying pressure uid to said cylinder and exhausting it therefrom to open and close the ngers.

12. In a grid trimming press, a trimming die upon which the grid is to be supported, a trimming punch, means to reciprocate the latter toward and away from the die, means operatively connected with said reciprocating means for dislodging and discharging the grid from the die -after the cut is made, a pair of parallel chains spaced apart a distance approximately the same as the spacing of the lugs on the grids and positioned to catch the grids by their lugs as they are discharged from the die, and means also driven by said reciprocating means for advancing the chains slowly in proportion to the operations of the press.

13. In a grid trimming press, a trimming die set at a small angle to the horizontal, stops projecting from the die for engagement with the lugs on the grids, a trimming punch, means to reciprocate the latter toward and away from the die, means operatively connected with said reciprocating means for moving the grid and stops relatively to each other in order that the trimmed grid may be discharged by gravity from the die, a pair of parallel chains spaced apart a distance approximately the same as the spacing of the lugs on the grids, and positioned to catch the grids by their lugs as they are discharged from the die, and means also driven by said reciprocating means for advancing the chains slowly in proportion to the operations of the press.

14. In a grid trimming press, a trimming die upon which the grid is to be supported, a trimming punch, means to reciprocate the latter toward and away from the die, means operatively. connected with said reciprocating means for dislodging and discharging the grid from the die after the cut is made, a pair of parallel chains spaced apart a distance approximately the same as the spacing of `the lugs on the grids and positioned to catch the vgrids by their lugs as they are discharged from the die, and pawl and ratchet means driven by said reciprocating means for advancing the chains step by step in proportion to the number of operations of the press.

15. In a grid trimming press, a trimming die set at a small angle to the'horizontal, a pair of stops projecting upwardly from the die for engagement with the lugs on the grid, a trimming punch, means to reciprocate the latter toward and away from the die, means operatively connected with said reciprocating means for raising the grid sufciently to dislodge it from the die and to clear said stops, whereby the trimmed grid may be discharged by gravity from the die, a pair of parallel chains spaced apart a distance approximately the same as the spacing of the lugs on the grids and positioned to catch the grids by their lugs as they are discharged from the die, and means also driven by said reciprocating means for advancing the chains slowly in proportion to the operations of the press.

16. In a grid trimming press, a trimming die set at a small angle to the horizontal, a pair of stops projecting upwardly from the die for engagement with the lugs on the grid, a trimming punch, means to reciprocate the latter toward and away from the die, a trap door in the die hinged at its lower edge to lie below the normal position of the grid upon the die, and means operatively connected with said reciprocating means for swinging said trap door upwardly to dislodge the grid from the die and to tilt the higher end of the grid upwardly far enough to clear said stops, whereby the trimmed grid may be discharged by gravity from the die.

17. In a grid trimming press, a xed die, a reciprocating punch carrying a knife adapted to cut away a portion of the grid overhanging one edge of the die, and means for positively removing the trimmings comprising a stripper carried by the punch in position to engage the portions of the grid to be trimmed as the punch descends to the work, and resilient means for storing up energy behind said stripper while the cut is being made, whereby the stripper remains in engagement with the'trimmings during the retraction of the punch, and thereby strips the trimmings from the punch.

18. In a grid trimming press, a fixed die, a reciprocating punch cooperating therewith carrying a knife adapted to cut away a portion of the grid overhanging one edge of the die, and means for positively removing the trimmings comprising a stripper plate hinged to the punch in position to engage the material to be removed from the grid by trimming, and means also carried by the punch for resiliently resisting the swinging of the stripper plate, and thereby storing up energy behind said stripper plate as the latter swings during the making oi' the cut, whereby the stripper plate tends to snap off the trimmings when the punch recedes from the work. 19 In a machine of the class described, a magazine for supporting a series of twin grids on edge one behind another, said magazine comprising a pair of rails for engagement with the lower edges of the lugs of the grids, stops at the forward endl of the magazine in front of the lugs and lower edge of the foremost grid, means for raising the the grids, stops at the forward end of the magal zine in front of the lugs and lower edge of the foremost grid, means for raising the foremost grid suiciently to clear said stops, and transfer mechanism timed in its action to receive the foremost grid as it is raised, to swing it into a plane 'parallel with the plane of said die, and to advance it in the latter plane into operative position between said die and punch.

ALFRED R. WILLARD.