US2681027A - Metal shaping or drawing dies - Google Patents

Description

June 1954 v. J. BOLL 2,631,027

METAL SHAPING OR DRAWING DIES Filed April 1, 1950 2 Sheets-Sheet 1 INVENTDR ma [M June 15, 1954 v. J. sou.

METAL SHAPING OR DRAWING DIES 2 Sheets-Sheet 2 Filed April 1, 1950 Patented June 15, 1954 UNITED STATES ATENT OFFICE METAL SHAPING R DRAWING DIES Victor J. Boll, Dayton, Ohio, assignor to The Sheffield Corporation, Dayton, Ohio, a corporation of Ohio 4 Claims.

This invention relates to the shaping of metal sheets and the like and more particularly to dies for use in a single-action press.

One object of the invention resides in the method of forming a blank into a predetermined shape, in which the blank is first drawn or shaped to provide a body portion having an outer rim with an out-turned flange on the rim, then in one operation of a single acting press bending the flange into substantial alignment with the rim while holding the body portion at opposite sides thereof and then turning the flange inwardly from the rim while continuing to hold the body portion.

Another object is the provision of a pair of cooperating dies for use in a single-action press, one of the dies having expansible blank holding portions to engage the outer rim on a formed metal sheet while the other die is provided with means for reversely turning an outstanding flange on the rim of the sheet under the control of cam devices carried partly by one of the dies and partly by the other die.

Another object is the provision of a pair of cooperating dies of the character mentioned having a flange turning ring for bending a substantially continuous peripheral flange through about one quarter of a turn, together with drawing slides on one of the dies and controlled by cams on the other die for turning the flange I through a further quarter of a turn.

Other objects and advantages of the invention will be apparent from the following description, the appended claims and the accompanying drawing, in which Fig. 1 is a view on a reduced scale showing a press equipped with dies embodying and for carrying out the present invention;

Fig. 2 is a central transverse section through the upper and lower dies, showing the relative position of the parts shortly after a press cycle has been started;

Fig. 3 is a similar view of the parts showing the relative positions after the flange has been down-turned and just before the flange drawing slides move inwardly;

Fig. 4 is a similar View showing one of the flange drawing slides in its inner position;

Fig. 5 is a similar view showing the position of the parts at the end of a cycle of operation before removing the formed work;

Fig. 6 is a top plan View of a portion of the lower die;

Fig. 7 is the bottom plan view of a portion of the upper die; and

Fig. 8 is a view corresponding to Fig. 7 but showing only the edges of the flange drawing slides in their two extreme positions of movements.

Referring more particularly to the drawing in which the same reference numerals are applied to like parts in the different views, l9 generally designates a single-action press of any suitable character having provision for supporting upper and lower dies and having a series of pressure pins H which operate through holes in the bed 12 under the control of suitable air cushion I3 which may be of any suitable character. Arranged on the bed I2 is the subplate M of the lower die which is generally designated by the reference numeral I5. This die cooperates with the upper die 16 which is controlled as a whole by the ram of the press. The ram is secured to the carrying plate i! of the upper die in' any conventional manner.

Arranged above the subplate M of the lower die is a bottom plate H! which rests on the pressure pins Ii so that normally, when there is an adequate air supply to the air cushion, the parts I 4 and I9 assume spaced relation as shown in Fig. 2 for example. Operably supported by the bottom plate l9 are movable blank holding elements 26. As shown, these elements are slides each connected through pivot pins 22 and 23 to a rotatable hub 24, see Figs. 4 and 6. Thus by rotating the hub through about one quarter of a turn the blank holding elements will be moved from their inner retracted positions as shown in Fig. 5 for example to outer or extended positions as shown in Figs. 2 and 6. This movement takes place under the manual control of the operator before he starts a press cycle of operation. The hub 24 is provided with gear teeth 25 engaged by a rack 26, controlled by an air pressure cylinder 27. In their retracted positions the blank holding elements it permit the convenient application of a sheet metal blank 28 which has been given a preliminary shaping or drawing operation to provide a body portion 29, an outer rim 30, and an out-turned flange 3! that extends generally in the same direction as the body portion. Such a blank may be formed by a usual drawing operation in which the peripheral portions of the sheet are held between blank holders while the inner portion of the sheet is formed, the outwardly extending flange 3! being suitably trimmed in the formation of the blank that is supplied to the die It for further forming. Having applied this blank on top of the holding elements 20, the press operation is then started and the holding elements are moved outwardly into holding engagement with the peripheral rim 30.

As the upper die I6 descends, the top of the body portion 29 is first engaged by the blank holder 33 which is slidably carried in the outer die portion 3a which is mounted on the carrying plate 11. Springs 35 are interposed between the carrying plate and the blank holder 33 so that the die portion 34 can continue its downward travel after the blank holder 33 engages the blank and the springs 35 are compressed.

Promptly after the blank holder 33 engages the blank, the out-turned flange 3! which extends continuously throughout the entire periphery of the blank, is engaged by a downwardly facing surface or surfaces of the die portion 3 constituting a flange turning ring. This ring may be a continuous ring plate 35 fixed to the die portion 34 or may be constituted by the lower sides of the several flange turning slides. The first forming action that takes place is therefore the turning of the flange through about one quarter of a turn from the position shown in Fig. 2 into the position shown in Fig. 3.

ter turning the flange 3| downwardly, the ring 3 engages one or more abutments 37 on the bottom plate is so that during the remaining downtravel of the upper slide, the bottom plate and the parts carried thereby travel downwardly with the outer die portion 34 and the blank holder 33, the force on the die portion 32 overcoming the pressure of the pins I i so that the space that normally exists between the bottom plate [9 and the subplate E4 is taken up and the parts reach the position shown in Fig. 4. During this movement, the downturned flange BI is turned further through about one quarter of a turn into the position shown in Fig. 4, by means of flange drawing slides 39 at the sides and flange drawing slides 39 at the corner portions having cam portions 4E3 controlled by cam portions 4! on the cam posts 42 which extend up from the subplate 4. The operation of the cam portions 5!] and ll is such that the flange turning slides 33 and 39' are projected inwardly to turn or draw the flange against the overhung portions or lips i3 of the holding elements, turning the corner portions as well as the straight portions of the flang into general parallelism with the body portion of the blank so that the formed part that is produced can be used as a door or panel or the like.

During the upward travel of the upper die, the action of parts is reversed. The first action that takes place is the withdrawal of the flange drawing slides 35, the ascent of the die portion at being followed by the bottom plate E9 of the lower die until there is again a normal space between the bottom plate Iii and the subplate 14. As the upper die continues to move upwardly, the blank holder 33 is carried away from the upper side of the blank and at the end of the press cycle the parts assume the position shown in Fig. 5, the withdrawing of the holding elements 2t taking place at the end of this movement so that the formed part can be readily lifted from the lower die.

As will be more apparent from Fig. 6, the lower die has four of the holder elements 20, three of which are illustrated, for holding the sides of the blank, and at each of the corners of the lower die is an auxiliary holding element 44 which is controlled by the adjacent elements so as to move outwardly and inwardly with those adjacent elements and to a corresponding extent, it

being understood that the adjacent holding elements 20 are provided with T headed projections 20 extending into T slots or grooves 54' provided in the corner holding elements it, the corner elements being guided by studs i'i extending into 45 degree slots in those elements so that the corner elements are compelled to follow the movements of the side elements in expanding and contracting. This figure also shows the cam posts 42, one at each corner of the die and two at each side of the die. These cam posts project through openings. in the ring 3% of the outer die and engage the cam portions on the slides 39 as shown in Fig. 3. The slide 39 which draws one of the corner portions of the inturned flange, as shown in Fig. '7, moves at 45 degrees to the two adjacent side slides 39 constituting a continuation of the side slides so that all the corner portions of the flange will be contacted and drawn inwardly without a gap or break occurring in the flange turning operation. The upper and lower dies are preferably provided with conventional aligning holes 52 and guide posts 53. Fig, 8 shows the inner edges or the flange drawing slides in their outer or extended positions while the inner positions of these slides, assumed after the flanges have been turned in, are illustrated in dash lines.

In accordance with the present invention it will thus be apparent that in one press operation and on a single acting press a partially formed or shaped blank having an out-turned flange on a peripheral rim can be shaped so that that flange which extends entirely around the periphery is first turned about one quarter of a turn and then turned through another quarter of a turn so its terminal ends thus project inwardly instead of outwardly. l-leretofore in making a door panel for example, in which the outer edge of the metal sheet is turned inwardly to give a smooth continuous exterior or periphery, it has been customary to first draw a blank and trim the peripheral edges of the blank to provide a blank substantially as shown in Fig. 2, and then in a second operation and on a second press the peripheral out-turned flange is drawn downwardly. Then in a third operation and on another press the down-turned flange is tucked inwardly. This requires three different loading and handling operations as well as three different presses to handle the complete panel shaping, but in accordance with the present invention it will be apparent that one complete handling operation and one complete pressing operation, as well as one complete press is eliminated and by the use of comparatively simple arrangement of parts and with out requiring the use of expensive double or triple acting presses.

As will be noted from Fig, 5, there is preferably a limit switch 48 on the lower die controlled by a lug 49 on the rack 26. The switch 43 is normally open but is closed when engaged by the lug 49 so that the switch is only closed when the holding elements 26 are in their outer extended position. The switch 2-3 is for connection in series with the press starting switch. In series with this switch there is also another safety switch 58, shown in Fig. 4, and carried by the bottom plate 18 and operated by one of the pressure pins H. This switch 53 is normally closed so that a starting circuit can be completed when the operator presses the starting switch of the press but if there is no air or if there is insuflicient air in the air cushion l3, then the bottom plate [9 will not be held in its elevated position and the switch 50 will be opened by the pin H which in this instance would project up far enough to cause operation of this switch for the purpose intended. Obviously the holding circuits ordinarily employed in press starting systems permit the switch 59 to open after the cycle has started without stopping the press cycle.

While the form of apparatus and the method herein described constitute a preferred embodiment and operation of the invention, it is to be understood that the invention is not limited to this precise form of apparatus and method, and that changes may be made therein without departing from the scope of the invention which is defined in the appended claims.

What is claimed is:

1. A pair of cooperating press dies for use in a single acting press to reverse a flange projecting outwardly from the body portion of a metal blank, comprising a lower die having a fixed subplate, a bottom plate normally spaced above the subplate and adapted for support on pressure pins, blank holding portions mounted on said bottom plate and having projecting lips, and an upper die having a blank holder, a carrying plate, yielding means interposed between the blank holder and the carrying plate, and an outer die portion on the carrying plate and around the blank holder, said outer die portion having a turning surface facing downwardly and operative during die approach after the blank holder engages the blank to turn the flange about a quarter of a turn into substantial alignment with the direction of die travel, said outer die portion including draw slides movable generally transverse of the direction of die travel, stop means on the bottom plate of the lower die engageable with the outer die portion of the upper die, cam portions on said draw slides, and cooperating cam portions on the subplate for moving the draw slides inwardly and along the projecting lips of said blank holding portions after the stop means on the bottom plate is engaged by the outer die portion of the upper plate.

2. A pair of cooperating press dies for use in a single acting press to reverse a flange projecting outwardly from the body portion of a metal blank, comprising a lower die having a flxed subplate, a bottom plate normally spaced above the subplate and adapted for support on pressure pins, blank holding portions slidably mounted on said bottom plate and having projecting lips, means for moving said blank holding portions outwardly and inwardly, and an upper die having a blank holder, a carrying plate, yielding means interposed between the blank holder and the carrying plate, and an outer die portion on the carrying plate and around the blank holder, said outer die portion having a turning surface facing downwardly and operative during die ap proach after the blank holder engages the blank to turn the flange about a quarter of a turn into substantial alignment with the direction of die travel, said outer die portion including draw slides movable generally transverse of the direction of die travel there being at least one corner forming slide between adjacent side forming slides with the corner forming slide guided for movement at an angle to the paths of sliding movement of the side forming slides, stop means on the bottom plate of the lower die engageable with the outer die portion of the upper die, cam portions on said draw slides, and cooperating cam portions on the subplate for moving the draw slides inwardly and along the projecting lips of said blank holding portions after the stop means on the bottom plate is engaged by the outer die portion of the upper die.

3. A pair of cooperating press dies for use in a single acting press to reverse a flange projecting outwardly from the entire periphery of the body portion of a metal blank, comprising a lower die having a fixed subplate, a bottom plate normally spaced above the subplate and adapted for support on pressure pins, blank holding portions slidably mounted on said bottom plate and having projecting lips, means for moving said blank holding portions outwardly and inwardly, and an upper die having a blank holder, a carrying plate, yielding means interposed between the blank holder and the carrying plate, an outer die portion on the carrying plate and around the blank holder, said outer die portion having a continuous ring provided with a turning surface facing downwardly and operative during die approach after the blank holder engages the blank to turn the flange about a quarter of a turn into substantial alignment with the direction of die travel, said outer die portion also including draw slides above said ring movable generally transverse of the direction of die travel there being at least one corner forming slide between adjacent side forming slides with the corner forming slide guided for movement at an angle to the paths of sliding movement of the side forming slides, stop means on the bottom plate of the lower die engageable with the outer die portion of the upper die, cam portions on said draw slides, and cooperating cam portions on the subplate for moving the draw slides inwardly and along the projecting lips of said blank holding portions after the stop means on the bottom plate is engaged by the outer die portion of the upper die.

4. A pair of cooperating press dies as set forth in claim 1, and a limit switch on the lower die for connection in the starting circuit of the press and means for controlling said switch when less than a normal spacing exists between the subplate and the bottom plate of the lower die.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 307,198 Jordan Oct. 28, 1884 318,088 Cooper May 19, 1885 1,163,933 Kurschus Dec. 14, 1915 1,749,184 Hansen et al Mar. 4, 1930 1,787,151 Groehn Dec, 30, 1930 1,807,824 Booth June 2, 1931 1,854,630 Siokler et al Apr. 19, 1932 1,946,991 Tormyn et al Feb. 13, 1934 2,101,888 Ambrosius Dec. 14, 1937 2,105,289 Lobdell Jan. 11, 1938 2,272,547 Coordes Feb. 10, 1942 2,518,422 Greene Aug. 8, 1950

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