US2314120A - Press unloader - Google Patents

Description

March 16,1943.` F, w, BRAUN PRESS UNLOADER 3 Sheets-Sheet 2 INV ENT OR.

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Filed Feb. 13. 1940 Wuldwllllr l J s Patented Mar. 16, 1943 293 PRESS UNLOADER Frederick W. Braun, Dearborn, Mich., assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Application February 13, 1940, Serial No. 318,778

3 Claims. 113-50) 'This invention relates to a press unloader and t more particularly to a device for automatically unloading metal stampings from a press. Presses for stamping or'drawing sheet metal have proved dangerous instrumentalities and in- .s

tion-of the unloader when the press is closed.

Fig. 2 is a front elevation of the press and 'press unloader showing in the full lines the po-I sition of the unloader when the press is open and showing in the dotted lines the position of the parts of the unloader when the press is closed.

Fig. 3 is `a plan view of the press and unloading device.

Fig. 4 is a side elevation of a modified form of" unloader showing in the full lines the operative position of the unloader when the dies are opened and showing in the dotted lines the position of the unloader when the press is closed.

Referring more particularly to the drawings there is shown a press having a lower composite die comprising stationary member I in which is yieldably mounted on springs 53 the die member 5I and an upper reciprocating die member 2. The particular stamping that the dies are designed to form is the center pillar 3 of an automobile body.

Preparatory to automatically unloading the stamping fromthe press it is essential that the center pillar stamping 3 be elevated with the vertically reciprocating die 2 which is commonly called the male die or punch. To this end the die 2 is provided with two pairs of fingers 4 which are iixed on vertical shafts 5 journaled in the die member 2. A crank B is xed to the upper end of each shaft 5. The cranks 'ii are pivctally connected to the sliding bars 'I as at II. The bars l are slidable in grooves 8 in the upper face of die 2 and retained therein by plates 9. The bars 'i are connected at their outer end by the cross bar I.' The lower dieis recessed as at I2 to receive fingers 4 when the press is closed and to permit the fing-ers 4 to swing inwardly beneath the pillar stamping 3.

For swinging the fingers 4 inwardly against the stamping 3 and for swinging them outwardly to release the stamping 3, there is provided a lever fI3 pivotally mounted on bracket Iii which is fixed on die 2. The upper end of lever I3 is pivotally connected as at I5 to cross bar I3. The lower end of the lever I3 is preferably provided with a roller I6 arranged to roll along the cam member I1 which is xed to the lower stationary die I. The cam member I'I' is provided at the top and bott-om with the inclined cam surfaces I8 and I9 respectively. The fingers ll are normally held in released position by the compression spring 2Q positioned between the lever I3 and the face of the upper die 2.

As shown in the dotted lines Fig. 2, the press is closed and the metal sheet has been formed into the center pillar 3. At this time roller I6 is below cam surface I9 and the lingers 4 are in released position as shown in Fig. 3. As the upper die 2 rises, springs 50 rais-e die 5i a short distance of about one and one-half inches and roller IS ridesupwardly and outwardly along cam `surface I9, thus through lever I3 shiftingslides l to the left, Figs. 2 and 3, and rotating fingers 4 about shafts 5 so that they clamp stamping 3 against die 2. Hence, as the die 2 moves upwardly, stamping 3 is withdrawn from the lower die member I and carried upwardly by fingers Il, see Fig. 2. The fingers 4 continue to clamp stamping 3 against die 2 as long as the roller I roll; along the straightaway surface 2| of cam Il. As roller IIB reaches cam surface I3, the lever I3 is swung clockwise by spring 20 thus sliding slides 'l to the right, Figs. 2 and 3. As slides 1 are shifted to the right, Fig. 3, fingers l are withdrawn from clamping contact against the stamping 3 and it falls downwardly upon the press unloader platform 33 which will now be described.

The press unloader platform 33 comprises a plate which is supported at each end by arms 3I.

. Arms 3l are welded or otherwise xed to links 32. Each link 32 has one end pivotally connected to the die 2, as at 33, and the other end pivotallyl connected to link 3i, as at 35. The lower end of link 34 is pivotally connected as at 35 to the lower die I.

The operation of the device is as follows: As shown in the dotted lines, Figs. 1 and 2, the press is closed, the pillar 3 has been formed and the press unloader 33 is swung outwardly to inoperative position because the links 32 and 341 at this time are jackknifed or collapsed. As the die 2 rises, lingers swing inwardly against the stamping 3, raising the same with the die 2 as above described. Upward movement of the die 2 causes the links 32 and 34 to straighten, thereby swinging the arm 3l and unloader platform 3U inwardly beneath the upper die 2, as shown in Fig. l, where the unloader receives the stamping 3 as it is released by the outward swinging of fingers 4, as above described. The stamping slides by gravity down the platform 30 to discharge the same from the press.

As the die 2 moves downwardly, roller l5 slides downwardly and outwardly on cam I8 and along surface 2| and then down cam i9 which through lever I3 and slides 1 retract fingers 4. Rollei' I6 reaches cam IS about the time that die 2 rst contacts the raised lower die portion l. As soon as the stamping operation on pillar S is complete, the die 2 rises and the cycle is repeated as above described.

In Fig. 4 there is shown a modified form of unloader platform. In this form the uploader platform 4G is adjustably secured on arm 4| pivotally mounted as at 42 on a member 43 fixed to the stationary frame 44 of the press. An arm 45 is` fixed to the arm 4I. Arm 45 is pivotally connected as at 46 to link 41 which is pivotally connected as at 48 to the upper vertically reciprocating die 49.

In the full line showing of Fig. 4 the press is open and the upper die 48 is raised so that the platform 40 is positioned beneath the upper die 49 to receive the stamping 3 as it is discharged from the upper die by the means and in the manner above described. After the stamping 3 has been deposited on the platform 40, the upper die 49 again descends whereby link lil swings arm 4I and platform 49 to the dotted line position, Fig. 4, causing the stamping 3 to slide olf of the platform 40.

The term die is used broadly herein to include not only the member which actually forms the metal but also the support for such member.

I claim:

1. In a press comprising a lower stationary die and an upper die member movable downwardly toward and upwardly away from the lower die, an unloader for removing the work from the press in the form of a platform, a pair of substantially vertical normally disaligned links pivotally connected to each other and to the said upper and lower die members, said platform being rigidly fixed to said upper link whereby as the upper die moves upwardly from the lower die the links straighten and move the platform into work receiving position between the dies and as the upper die moves downwardly the links jackknife and Withdraw the platform from between the dies.

2. In a press having cooperating dies relatively movable toward and away from each other, an unloader for removing the work from the press comprising a toggle having two legs, one end of the toggle being pivotally fastened to one of said dies and the other end of the toggle being pivotally fastened to the other die, said toggle being substantially but not completely straightened when said dies are in a position away from each other, a platform fastened to a leg of said toggle, said platform being positioned between the dies and extending outwardly and downwardly when the latter are in a position away from each other whereby the toggle is jack-knifed and the platform is withdrawn from between the dies when said dies move toward each other.

3. In a press having cooperating dies relatively movable toward and away from each other, an unloader for removing the work from the press comprising a toggle having two legs, one end of the toggle being pivotally fastened to one of said dies and the other end of the toggle being pivotally fastened to the other die, said toggle being substantially but not completely straightened when said dies are in a position away from each other, an arm fixed to one of said legs and extending between the dies when the dies are in a position away from each other, a platform mounted on the arm and being positioned between the dies when the latter are in a position away from each other whereby the toggle is jackknifed and the said arm and platform are withdrawn froml between the dies when the said dies move toward each other.

FREDERICK W. BRAUN.

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