US869916A - Sheet-metal-stamping die. - Google Patents

Description

\ PATENTED NOV. 5, 1 907. lD. R. LEVIN.

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UNITED STATES DAVID R. LEVIN, OF CHICAGO, ILLINOIS.

SHEET-METAL-STAMPING DIE.

Specification of Letters Patent.

Patented Nov. 5, 1907.

Application led March 28, 1907. Serial No. 364,983.

To all whom it may concern:

Be it known that I, DAVID R. LEvrN, a citizen of the United States of America, and a resident of Chicago, Cook county, and State of Illinois, have invented certain new and useful Improvements in Sheet-Metal- Stamping Dies, of which the following is a specification.

The main obj ect of this invention is to provide a die mechanism which will, at one operation, form from flat sheet metal stock a downwardly flanged box-lid or can cap with a short outwardly projecting lip upon its fianged edge; which will operate upon either plain or enameled stock without wrinkling the metal and without scratching or cracking the enamel. This object is accomplished by the device shown in the accompanying drawings, in which:

Figure l is a vertical central section of die mechanism embodying this invention and adapted for making.

circular caps. Fig. 2 is a perspective, partly broken away, of the member which serves both as the male cutting die and the female forming die, the same being shown in an inverted position. Fig. 3 is a perspective of the flange-drawing ring. Fig. 4 is a perspective of a sheet-metal box whose cover is formed by the dies herein shown. Fig. 5 is a section ofthe cover of the box on the plane of the lines a-a of Fig. 4.

In the construction shown, the die mechanism comprises an upper or active die 18, and a lower or passive die; which last named die comprises three principal die members, 1, 4 and 5. The die member 1 Will be herein termed the male flanging die; the member 4, the female cutting die; die 18, the female flanging and male cutting die, combined; and member 5, a yieldable drawing ring or companion to the die 18, which coacts with the die 18 in smoothly drawing down the flange of the box cover and in giving the peculiar lipped shape to the flange.

The lower die member 1 is supported by and seated within a recess in a heavy plate or shoe 2, which is fastened to the bed of the press in the usual manner, not illustrated. The base of the die member 1 is outwardly flanged, as shown at 3. The die 4, fits over the flange 3 and rests solidly upon an annular surface 6 of the plate 2 to which it is secured by suitable screws. The annular drawing ring 5 is supported by aplurality of pins 7, which extend down and slidably throughholes in the flange 3 and the shoe 2, their lower ends being screwed into a metal plate 8 below the shoe 2. A bolt 9, threaded into the shoe 2, extends down and supports a metal plate 10, between which and the plate 8 is interposed a stiff elastic cushion 11 preferably in the form of a block of rubber.

The die 5 is depressible within the die 4 when suflcient pressure is brought upon it. It is shown in its normal position, in which the greater part of its upper surface is ush with that of the die 4. Its upward movement is limited by shoulders 12, and its rotation is prevented by a plurality of guide pins 13, secured thereto and passing slidably through holes 14 in the ange 3 and the shoe 2. The upper surface ofthe die 5, with the exception of a short projection or rise 16, is normal and is preferably slightly conical, being inclined outwardly. The rise 16 is elevated above the normal surface 17 as is shown in Fig. 3.

The movable die 18 which is mounted on the Inovable head of the press coacts with dies 1 and 5 in giving the peculiar conformation to the cap. The outer periphery of this die is shaped and sized to slidably fit within the bore of cutting die 4 when depressed, -and has an exterior cutting edge 19 which coacts with the cut-ting edge l5 of said die 4, to cut a disk of material from a sheet or strip, for making the cover. The die 18 is fixed upon a head 20, which is reciprocated toward and away from the lower die members by suitable mechanism not shown. The die 18 is madehollow, with a bore which is slightly larger than the diameter of the male flange-forming die 1 to allow for the thickness of the metal operated upon. The die 18 is the coacting female flange-forming die, with respect to the male flange-forming die 1, and it also coacts with die 4 in cutting out the disks, and with the peculiarly formed yielding drawing ring 5 in producing the lip 24 on the finished cap 25, as shown in Fig. 4. For this purpose said die 18 is formed with a normal annular end surface 27, and with a depression or recess 28, which is shaped to form the lip on the cap-flange, as hereinafter described. Said recess is alined with the rise 16 on the ring 5 so as to register therewith when die 18 is depressed. The rise 16 on the ring 5 is shaped to fit into the recess 28 of the die 18.

Within the die 18 is the ipper 2l, having a vertically slidable stem 22, held up by a stop pin 23 resting upon the head 20.

The dies 18 and 1 are provided with air-holes 29 and 30 respectively, for the inflow and escape-of air.

When fed by hand, one or more guides 31 are provided, by the aid of which the operator sets the sheet or strip of material in correct register with the dies for each operation. These guides are mounted on the shoe 2.

The operation of the device shown is as follows: The die 18 being raised, a sheet or strip of sheet metal is placed upon the lower die. As the die 18 descends, its cutting edge 19, together with cutting edge 15 of the female die 4, punch out a disk of the metal of tbe proper diameter. The height of the Harige that is to be formed is predetermined by the relative size of the cutting dies to that of the male Hanging die 1. The edges of the disk are held tightly between the die 18 and the ring 5; the latter yields to the pressure-of the former, depressing pins 7 and plate 8, and compressing the elastic block 11. The part of the disk which forms the ange is forced down over the rounded upper edge 33 of die 1. Continued movement of the die 18 causes the edges of the disk of metal to be drawn inward in all directions and to be compressed into a cylindrical of the die 1,8 without even scratching an enameled siuface of the sheet metal operated upon. ln practice the movement of the jaw oi'l the press upon which the die 18 is mounted is so adjusted that it comes to a stop when the normal lower surface 27 oi said die has come into register with the edge of the completed flange 84. An ordinary flange of the required shape has thus been formed, except at that part which is adjacent to the rise 16 of ring 5 and the recess 28 of die 18. The recessed part 28 of die 18 has not moved as far down as its normal surface 27 and therefore has not moved far enough to turn down the lower edge ofthe flange thereunder. Accordingly, a lip, as 24, has been left pro-i jecting outwardly between the recess 28 of die 18 and the closely under-fitting rise 1G of die 5, which 1s heldup with great pressure by the elastic block 11. The lip 24 takes its arch ed or bowed form from the contour or' the rise 16 and recess 28. When die 18 ascends, the ring 5 also rises until it is arrested by the shoulders 12. The edge 82 of the ring 5 engages the lower edge ofthe flange of the cap 25 and causes the cap to be withdrawn with the die 18. During the upward movement of the die 18, the stem 22 is forced down by mechanism of the press (not shown), whereupon the flipper 21, which had been elevated by contact with the cap, will eject the finished cap from the die. Itis usual in presses of this class to mount the dies in an inclined position from that shown in the drawing so that wh en thus ejected the finished article will fall from between the dies.

The dies described have been proved in practice to form flanged box caps from enameled and printed sheet metal stock Without causing the slightest scratching or cracking el' the enamel.

Fig. 4 shows a tin box provided with one of these novel covers. The box 26 has a bead 26/ adjacent to the edge of the cap when closed. The cap may be readily pried off by placing the edge of a small coin between the lip and the bead and giving a sharp twist to the coin.

What I claim as my invention and desire to secure by Letters Patent, is:

1. A device for forming sheet metal caps, comprising coacting male and female hanging dies, a drawing ring surrounding the male die and normally urged outward to yicldingly oppose the movement of the female die with respect to the male so as to prevent buckling of the edges of an interposed sheet of metal during the hanging operation, the opposed faces of said female die and ring being provided respectively with a recess and a rise to leave a transverse lip on the flange at a limited part of the periphery of the cap when the dies have moved together sufficiently to completely flange the remainder of the periphery.

2. A device for forming sheet metal caps, comprising coacting male and female hanging dies, a drawing ring surrounding the male die and normally urged outward to yieldingly oppose the movement of the female die with respect to the male so as to prevent buckling of the edges of an interposed sheet of metal during the flanging operation, the opposed faces of said female die and ring being normal throughout their major part and being respectively formed at a certain other part with a recess and a rise to form a transverse lip odset from the rim of the flange when the dies have moved together suinciently to complete the part of the flange of the cap which is adjacent to said major part of said faces.

3. A device for forming sheet metal box caps, comprising a iixed hanging die, a yielding drawing ring outside of said die, and a cutting die outside ef said ring, in combination with a movable Hanging die coacting with said fixed die and yielding ring and having a cutting edge coacting with said cutting die, said movable die and ring being directly opposed and being provided respectively with a recess and a rise to form on the box cap a normal flange having a transverse lip on a limited part ot' its periphery.

4. The combination of a female Hanging die, a male Hanging die coacting therewith, and a yieldable drawing die opposed to said female die and embracing said male Hanging die, said female hanging die and opposed drawing die being formed with major normal surfaces and with respectively intertting recess and rise.

5. The combination of a combined female Hanging and male cutting die, a male nanging die coacting therewith, a yieldable drawing. die opposed to said rst named die and embracing said male hanging die, and a female cutting die embracing said yieldable die and coacting with said first named die, said first named die and opposed yieldable die being formed with major normal surfaces and with respective intertting recess and rise.

6. The combination of concentric unyielding cutting-out and flanging dies spaced apart, a yieldable die concentrically interposed between said cutting and hanging dies, an active cutting and hanging die opposed to said yieldable die, an ejector within said movable die, and means normally urging said yieldable die to a certain normal position, said active and yieldable dies being formed with opposed major normal surfaces and with respective interitting recess and rise.

7. A die for making flanged can-caps, comprising means for cutting out a blank from sheet metal, means for drawing an endless flange upon such blank, and means for offsetting a limited fractional part of such flange to form a lip, said means coacting with each other to form a com` plete cap at one operation.

S. In a device for stamping can-caps, the combination or' a drawing ring, a pair `of opposed cutting-out dies adapted for cutting out can-cap blanks, one of said cuttingout dies embracing said drawing ring, the other being mounted to reciprocate toward and from the drawing ring, said other cutting-out die being formed 'with a forming recess, a male forming die within said drawing ring, being adapted to enter said recess to coact in forming a flange upon the blank, said other cutting-out die and drawing ring being shaped to form an outwardly disposed lip upon a limited fractional part of the periphery of such flange, through the operation of said dies.

9. A device of the class described comprising a male flanging die, a female Hanging die movable toward and away from said male die in axial alinement therewith, a drawing ring surrounding said male die and slidable iaxially thereon, said female die having a normal end surface and a depression at one side thereof, said drawing ring being formed with a normal surface opposed to the normal surface of said female die and havingl a rise registering with the depression in said female die, a cushion of resilient material yieldingly urging said drawing ring toward said female die, anda stop for limiting the move'- ment of said drawing ring during the return movement of said female die.

10. A device for forming sheet metal caps of the class described, comprising a male Hanging die having a substantially cylindrical periphery, a drawing ring fitting the lperiphery of said male die and slidably mounted thereon, a

female cutting die surrounding said drawing ring and extending beyond the free end of said male die, a stop adapted to limit the outward movement of said drawing ring to a position adjacent to the face of said female cut- Ating die, a resilient cushion yieldinglyurging said drawing ring toward said stop, a tubular die member mounted in axial alinement with said male die, having an inner periphery adapted to coact with said male die for hanging an interposed disk of metal, and having an outer periphery provided with a cutting edge adapted to coact with said female cutting die for cutting such disk from a sheet of metal, the major part of the cutting face of said female die being normal and having therein a depression extending across the same between its inner and outer peripheries, the opposed face of vsaid drawing ring being formed to fit that of said female die, and all being arranged to form a transversely extending lip at one side pf the flange of the cap.

11. The combination of a female anging die. a male anging die eoacting therewith, a yielding drawing ring opposed to said female die and embracing said male dang ing die, the opposed surfaces of said female Hanging die and drawing ring being normal throughout the major part thereof and being formed at another part with respective intertting recess and rise, and guiding means controlling the movement of said drawing ring and adapted to prevent the same from turning out of registeringposition with respect to said female die.

12. The combination of a supporting plate, a male die rigidly mounted thereon and having a free end, a drawing ring fitting the periphery of said male die and axially movable thereon, a female cutting die surrounding said drawing ring and rigidly mounted on said plate, a female Hanging die mounted in axial alinement with said male die and movable relatively thereof in an axial directiomsaid drawing ring and female Hanging die being formed with opposed major normal surfaces and provided with respective intertting recess and rise, a plate movably mounted below said first plate and having parts extending through said first plate into engagement with said drawing ring, and a cushion of resilient material mounted below said second plate and adapted to yieldingly urge said drawing ring toward the upper end of said male die.

Signed at Chicago this 23d day of March 1907.

DAVID R. LEVI Witnesses GERTRUDE L. Yoann, E. A. RUMMLER.

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