US2200886A - Grid-trimming apparatus - Google Patents

Description

M. o. KUHN 2.200.886

GRID-TRIMMING APPARATUS Filed Jan. 8, 1938 5 Sheets-Sheet 1 o 0 O J 8 4 a. 711ufitrizla m m u rl I I l l J E I m W 5 v m: 0 L f m M m m H w o Q. m m w INVENTOR 0.14%

' ATTORNEY May 14;i 94o.

y 4, 1940- M. o. KUHN 2.200.886

GRID-TRIMMING APPARATUS Filed Jan. 8, 1938 5 Sheets-Sheet 2 INVENTOR ATTORNEY May 14, 1940. M, o. KUHN GRID-TRIMMING APPARATUS Filed Jan. 8, 1938 5 Sheets-Sheet 4 I I INVENTORY zl/zv dZz/fi QM ATTORNEY May 14, 1940. Q KUHN 2,200,886

. GRID-TRIMMING APPARATUS Filed Jan. '8, 1938 s SheetsShet 5 Qua INVENTOR 1%221 dig/My ATTORNEY Patented May 14,

UNITED STATES PATENT OFFICE 2,200,886 GRID-TRIMMING APPARATUS Max 0.

mesne assignments,

Rubber Company, Akron,

of Ohio Kuhn, Cuyahoga Falls, Ohio, assignor, by to The Firestone Tire &

Ohio, a corporation Application Jam-5, s, 1938, Serial No. 184,054 8 Claims. (01. 164-20) This invention relates to grid-trimming apparatus, and more especially it for removing surplus metal employed grids such as are relates to apparatus from the margins of in storage batteries.

Apparatus heretofore employed for the purpose mentioned has been of the punch type wherein a downwardly moving punch severed the grid from a casting, and

then elevated the scrap material, by reason of the frictional engagement of the latter with punch,

grid to permit the removal plane of the died-out above the of the grid, the scrap subsequently being stripped from the punch and removed from the machine. The apparatus is satisfactory so long as the scrap is of suflicient size or piece. It is desirable,

-width to remain in one however, that the scrap or surplus metal on the grid-castings be as small as possible to avoid re-heating of the same. since one of the elements of the casting alloy is somewhat volatile. When the grid-castings are so constructed the trimming apparatus described operates but imperfectly due crumbling of the scrap metal.

to fracture and The chief objects of this invention are to avoid waste of material such as occurs when the grid-castings include excessive material requiring to be trimmed therefrom; and to provide improved grid-trimming apparatus.

the invention aims to provide gridtrimming apparatus wherein cifically,

More spethe trimmed grid and ,the scrap material are separated and removed without requiring the lifting or the scrap or trimmings from its support.

Other objects will be manifest as" the specification proceeds.

Of the accompanying drawings: Figure l is a front elevation of bodying the invention,

therein apparatus emin its preferred form, in and the work Figure 2 is a front elevation, on a larger scale, of the trimming instrumentallties, in inoperative position;

. Figure 3 is a view similar to Figure 2 showing the parts in the initial phase of operation;

Figure 4 I is a plan view of a portion of the trimming instrumentalities, on a lar scale,

as viewed from the line 5-4 of Figure 2;

Figure 5 is a section on the line 5-5 of Figure 4;

Figure 6 is a section. on a larger scale, on the eration;,

Figure 7 is a section similar to- Figure 6- show- 10 shows the grid casting as a grid casting before trimmed.

Referring first to Figure 1 of the drawings, 10 there is shown a press which is generally of wellknown construction. It comprises a frame it in which is mounted a vertically reciprocaole press head IS. A crank shaft i1 mounted in the top of the press is employed to reciprocate press head it, said crank shaft carrying a gear it on one end thereof by means of which it is driven from a primary source of power (not shown), as is well known in the art. The press also includes a bed plate it that is positioned below the press head it, and carries a die that cooperates with a punch. carried by the said press head for trimming surplus material from the grid castings, as subsequently will be explained.

Referring now to Figure 9,- there is shown a grid casting 2i in the u'ntrimmedcondition in which it is presented to the grid trimming apparatus. As shown, each grid casting 2! is provided near one end, at oppositesides thereof, with centering or guide holes 22, 22, and at the other end with securing indentations 23, 23, the latter being provided for engagement with respective pins on a conveyor mechanism that carries the grid castings to the press, and carries the trim or scrap material away therefrom. Figure it appears after been trimmed therethe surplus material has from. V

The grid castings 2! are carried to the trimming mechanism by means of an endless conveyor 25 to which is secured a succession of upstanding pointed studs or prongs 26, 26. The latter are so spaced that the indentations 23 of the grid castings 2| will engage the adjacent sides of two spaced prongs. The prongs 2d are positioned at one lateral margin of the conveyor 25 and serve to propell the grid castings along a platform (not shown) disposed beside the com- .veyor, and into position betweenv a punch and die presently to be described. The conveyor 25 is mounted upon suitable pulleys of which two pulleys, 2i and 29, are'shown in Figure 1. The conveyor 25 is advanced intermittently a determinate distance'in timed relation to the reciprocation of the press head It so. as to present sucu downwardly toward the cessive grid castings and to this end the a shaft 29 that also 38. The latter is engaged by a pawl 3| carried by an arm 32 that is pivotally mounted upon said shaft 29, the free end of arm 32 being connected by a link 33 to a lever arm 34 pivotally mounted at 35 on the frame of press l5. The lever arm 34 is connected by a link 36 to one end of a vertically reciprocable slide 3 one end of which carries a cam roller 38 and the other end of which carries a cam roller 39. Cam rollers 38, 39 are engaged by respective earns 48, 4| that are mounted upon a shaft 42 journaled in a support 43 on one side of the frame of press l5, said shaft 42 being driven by means of a bevel gear 44 that is mounted thereon and meshed with a 45 carried by crank shaft I! on the opposite end of the latter from gear IS. The arrangement is such that cam 40 moves. slide 31 downwardly and cam 4| moves it upwardly, in alternation, to effect oscillation of the lever arm 34 and thereby to turn the shaft 29 and pulley 21 thereon angularly a determinate distance. A spring-tensioned automatically operated stop-pawl 46 may be provided for holdingthe shaft 29in fixed position after it has been turned angularly by the pawl 3|.

Mounted upon the bottom of the press head I6 is an elongate punch holder 48 that extends-laterally beyond the press head, at the end thereof from which the grid castings 2| approach the trimming station, and is provided thereat with a yieldingly mounted presser pad 49. The latter is connected to the punch holder 48 by means of stud bolts 50, 50, and spacer members 5|, 5|- of elastic material, such as rubber, are mounted upon the stud bolts 50 between the pad and the punch holder. through the punch holder, the arrangement being such that the pad may be forced toward the latter against the yielding pressure of the spacer members 5|. The presser pad 49 cooperates with a fixedly mounted plate 52 positioned atop of the bed plate, I9 for pressing and flattening successive grid castings.2| immediately prior to the moving of the latter to trimming position.

- Trimming of the grid castings 2| is effected by means: ofa punch and die of which the punch member 55'is secured to the punch holder 48 and the die member 5B'is mounted upon the bed plate IS. *The die 'member 56 is formed with a die opening 51, best shown in Figure 4, for cooperation with the punch 55, the latter having the same profile as said die opening 51, The punch holder 48 also carries a per .plate 58 that centrally apertured to enable the punch 55 to move therethrough. The stripper plate 58 is-secured to the punch holder 48 by means of headed'pins 59, 59 that extend slidingly through suitable apertures in the punch holder, and respective compression springs 60 are mounted between the punch holder and stripper plate for urging the latter normally cutting end of the punch, which downward movement is limited by' the heads of "pins 59. ;Intheinoperative, elevated position ,of the punch holder and punch, the

strip'perplate is disposed somewhat below the cuttingend of the an'd Fig'ure 8.' The punch, as shown in Figure 2 arrangement is such that the operation; and isnot .lifted from the trimmed -surplus'material, after the trimming operation,

until the punch has been withdrawn therefrom.

the die opening 51 bevel gear,

The stud bolts extend freely yieldingly mounted strip-.

bottom of slot 66,

-joined,through the At each side of the punch 55 is a stud 6| that projects below the cutting end of the punch and is accommodated in a suitable aperture through the stripper plate 58. The function of the studs 6| is to enter the respective apertures 22 in the grid castings 2| and accurately to position the latter for engagement with the punch, the die 56 being formed with bores 63, 63 (Figure 4), for receiving said studs during the punching or trimming operation.

As shown in Figures 5 to ,8 inclusive, the die structure 56 is cut away on its under side, from to the rear of the structure, and a filler block 65 is mounted in a part of the cut-away space and secured to the bed plate I 9. The arrangementis such as to provide an internal slot 66 through the rear of the die block 56, and said slot 6] formed in the bed plate l9, said s1ot 6'| constituting a continuationof slot 66-and extending to the rear marginal face of said bed plate.

' that are threaded into the bed plate l9 and have their heads disposed in sockets formed in respec-' tive bosses 1| that project downwardly from the under side of the die pad, the bed plate recessed at 72, 12, Figure 5, to receive said bosses in the depressed position of the die pad. Yield ingly mounted in suitable slots in the top face of .the die pad 68 are metal strips 13, 13 that extend transversely of the pad from the front margin to the rear margin thereof. The strips 13 normally are disposed slightly above the top face of the die pad, but may be depressed under pressure, as when the a grid casting, the function of the strips being to break the adhesion between the grid casting and the die pad in case the casting should stick to the latter. One upper corner of each strip "is beveled, as'shown in Figure 5, so as to enable the grid castings readily to slide thereover while being moved into trimming position beneath the punch. The stroke of the press head I6 is such that in the operation of trimming a die casting, the punch 55 will force the die pad 68-downwardly into the die opening almost to the bottom of the latter, and in this position the top face of the die pad is substantiallyin alignment with the so that a trimmed grid casting may be moved rearwardly off the die bad ,and into said slot.

In order to move the die pad and into slot 66, it is necessary to retain the die pad in its depressed position, for'a brief interval. at least, after the punch '55 has been lifted. To this end the die pad is provided with two, downwardly projecting studs or posts 15, 15 that extend freely through respective bores in the bed plate |9. The lower end of each post 15 is agency of an adjustable connection 16, with a slotted yoke 11 that is slid-' is aligned with an internal slot l9 being plurality of/ 25 punch 55 operates to trim trimmed grids off the ably mounted for reciprocatory movement in a bracket-like frame member 18 mounted upon the bottom face of the bed plate l9. Each yoke 11 carries a cam roller 19 that is engageable with a rotary cam 80, said; cams being mounted gear l8,

upon a driven shaft 8| that is journaled in the frame member 18. Exteriorly of said frame member the shaft 8| extends laterally toward that side of the press that carries the driving and is there journaled in a bearing bracket 82 and provided with a sprocket 88. A sprocket chain 84 connects sprocket 83 with a sprocket 85 on a countershaft 88, and a second sprocket 81 on the latter is connected by sprocket chain '88 with a sprocket 89 mounted upon the crank shaft I1, beside gear l8 thereon.

The arrangement is such that the crank shaft |1 rotates the two cams 88 in determinate time relation to the up and down movement of the press head l6 and punch 55. The cams 80 are identical in shape and are arranged in the same angular position with relation to shaft 8|. The chain 84 is driven in the direction indicated by the arrows in Figures 6 and 7 so that .the cams 80 are driven in counter-clockwise direction as viewed in the said Figures 6 and 7 The cams 80 are out of. engagement with the cam rollers 19 the die pad 68 with the trimmed throughout most of their rotative movement, with the result that the springs 89 support the die pad 68 in elevated position, as. shown in Figure 8, which is the normal inoperative position'of the pad; During a grid trimming operation, the

punch 55 descends upon the grid casting 2| upon the .die structure, thus shearing the surplus material about the margins of the grid, and forcing grid thereon downwardly to the position shown in Figure 6.

Immediately the die pad reaches this position the cams 80 engage the cam rollers 19, so that as the punch 55 rises the die pad is retained in depressed position, against the pressure of springs 69, by said cams, as shown in Figure '1. It is during this interval that the strips 13, which have been depressed by the pressure of the punch 55 thereon, resume their normal positions above the top face of the die pad and thus break any adhesion that may be present between the die pad and the trimmed grid thereon. While the die pad is still depressed, the grid thereon is removed in a manner presently to be described,

the grid moving rearwardly and edgewise through the slots 68, 81 to the rear of the apparatus. Thereafter the cams 80 move out of. engagement with the cam rollers 19 and the springs 69 elevate the die pad to the inoperative position shown -in Figure 6.

The removal of trimmed grids from the die pad. 68 isfaoilitated by having the press l5 disposed at an angle such that the die pad and slots 86, 61 slope downwardly toward the rear of the press, as shown in Figures 6 to 8, sothat the grids readily slide by gravity through said slots after being given an initial tial impetus to air is formed interiorly with a passage 9| extending from the rear of the pad alongside one end of the die opening 51 and across the front of the latter, there being a series of ports or delivery, orifices 92, 92 extending from said passage to the die opening, said ports being disposed just above the the trimmed grids 2l, a blast of top of the die pad 68 when the latter is in the, de-

pressed position shown in Figures 6 and '7, The inlet to the passage 92, at the rear of the die block, connects with a pipe 93 extending to a source of pressure fluid (not shown), a portion of said pipe being mounted upon the front of the press, as shown in Figure 1, and there provided with a valve 94 having an operating lever that projects into thepath of a dog 95 carriedby the impetus. For imparting the ini-.

is utilized, and to this end the die block 58 of parallel downwardly inclined rails, such as the rail 91, Figure 7, which rails are arranged to engage the respective ears at opposite ends of the grids and thereby pendulously to support them. Mounted between the rails 91, and extending rearwardly from the delivery orifice of the slot 81, is a downwardly'sloping plate 98 adapted frictionally to engage the trailing margin of the grids 2|, as the latter slide down the inclined rails 91, and gradually to guide the grids to vertical position.

When the die pad 68 is depressed by the punch 55 during the trimming of a grid 2|, the lower face of the die is-spaced slightly above the bottom of the die opening. If, however, a trimmed grid adheres so tenaciously to the die pad as not to be removed therefrom by the means provided, the trimming of a second grid atop of the grid on the die pad will'force the latter to the bottom of the die opening. When this occurs it is desirableto stop the apparatus and remove the grid that is adhered to the die pad, the stopping of the apparatus being effected automatically by means of a spring pressed plunger 99. The head or upper end of the latter extends into the die opening the proper distance to be engaged and depressed by the .die pad only when the latter is forced below its normal depressed position.

The plunger 99 extends through the bed plate l9 and bracket frame 18 and has its lower end positioned adjacent the end of an operating lever I08 atively interposed in the electrical circuit that provides the power for operating the press. The arrangement is such that when the plunger 99 is depressed it moves lever I00 to open switch IM and thereby to cut off operating power to the press, to bring the latter to a standstill.

In the operation of the apparatus, the intermittently moving conveyor 25 brings the untrimmed grid castings to trimming position beneath the punch 55 while the press head I6 is in--raised position Upon descent of the press head, it is the stripper plate 58 that first engages the gridcalsting, and holds the marginal portions thereof firmly against the top face of the die block 56, the punch then passing through the stripper plate and into the die opening 51 to shear the surplus marginal portion from the grid.

open the valve only during the initial on the press head momentarily opens valve 94,

with the result that a'blast of air from the oriflces 92 is directed against the adjacent margin of the trimmed grid 2|, and the grid thereby projected through the slots 66, 61 to be received upon the rails 91'at the, rear of the press. As the press head continues to rise, the die 55 is with-,- drawn .from the-.- die opening 51 and from the scrap material that has been. trimmed from the grid, said scrap material being firmly held by the stripper plate 58 until the punch is withdrawn. Subsequent to the withdrawal of the punch from the die, the cams 80 pass out of engagement with the cam rollers 19 and the springs ,69 restore the die pad 68 to its elevated, inop-- I scrap material, during the trimming operation, it

is possible to dispose of the scrap material without lifting or flexing it, with the result that breakage is avoided even when the trimmed scrap is relatively thin and narrow. Thus the trim of the grid castings may be held to a relatively small proportion of the casting, with the result that losses due to re-heating are reduced.

Modification may be resorted to without departing from the spirit of the invention, or the scope thereof as defined by the appended claims.

What is claimed is:

1. In grid-trimming apparatus, the combination of a die having an opening therein'defining the outline of the grid to be trimmed, a reciprocable punch operating through said opening, a die pad in alignment with said opening, yielding means normally urging said die pad out of said opening, and rotary power-driven means operating indeterminate time relation to the movement of the punch and adapted mechanically to engage the pad structure for restraining movement of the pad in opposition to said yielding means.

2. In grid-trimming apparatus, the combination of a diehaving an opening therein defining the outline of the grid to be trimmed, a reciprocable punch operating through said opening, a die pad in alignment with said opening, supporting means for said die pad normally urging it out of said die opening, and enabling it to.be displaced under pressure of the punch, andcam means for retaining the pad in displaced position for a de terminate interval after pressure of the punch is removed therefrom, said means having adjustable connection with the pad structure.

3. In grid-trimming apparatus, the combination of a .die having an opening therein defining the profile of the grid to be trimmed, a reciprocable punch operating through said opening, a die pad in alignment with said' opening, supporting means for said die pad normally urging it out of said die opening and enabling it to be depressed under pressure of the punch, means for retaining the pad in depressed position for a determinate interval after pressure of the punch is removed therefrom, and means for sliding a trimmed grid off the die pad while thelatter is in depressed position.

4. In grid-trimming apparatus, the combination ,of a die having an opening therein defining the profile of a grid to be trimmed, and formed with a slot coextensivewith one side of said opening and extending laterally therefrom through the die wall, a reciprocable punch operating through said opening, a die pad in alignment with said opening, yielding means normally urging said die pad out of said die opening and enabling said pad to be'depressed by pressure of the punch thereon, means for retaining the die pad in depressed position as the punch rises therefrom, and means for moving a trimmed grid laterally ofi" said die pad and through the die slot while the die pad is retained in depressed position.

5. In grid-trimming apparatus, the combination of a punch, a die, a yieldingly mounted die pad within the die opening against which the trimmed grid is pressed by the punch, and a plurality of parallel strips extending locally across the die pad and normally yieldinglyurged to a position above the work-engaging surface thereof for breaking the adhesion thereto of. a trimmed grid thereon.

6. A combination as defined in claim 5 in which the punch, die, and die pad are disposed in inclined position to enable trimmed grids to slide from the die pad, the yieldingly mounted strips on the latter being disposed parallel to the inclination of the pad.

7. In grid-trimming apparatus, the combination of a punch, a die, a-yieldingly mounted die pad within the die opening against which the trimmed grid is pressed by the punch, and a plurality of strips extending across thedie pad and yieldingly urged to a position above the workengaging surface thereof for breaking the adhesion thereto of a trimmed grid thereon, each of said strips being beveled along one upper margin thereof to enable untrimmed grids readily to slide thereon in moving to trimming position beneath the'punch.

8. In grid-trimming apparatus, the combination of a die having an opening therein defining the profile of the grid to be trimmed, a reciprocable punch operating through said die opening, a die pad in alignment with said opening, a yieldingsupport for said pad normally urging it out of said opening and enabling it to be displaced by pressure of the punch thereon, and cam means operating in determinate timed relation to the reciprocation of the punch and engageable with the die pad structure, when the latter is displaced, to retain it in displaced position for a determinateinterval after the pressure of the punch is removed therefrom. 1

' MAX 0. KUHN.

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