US1999229A - Process and apparatus for making tubular shells from sheet metal - Google Patents

Description

April 30, 1935. BENEDICT 9 PROCESS AND APPARATUS FOR MAKING TUBULAR SHELLS FROM SHEET METAL Filed Aug. 29, 1931 2 Sheets-Sheet l IN VEN TOR.

E A TTORNEYS.

B. BENEDICT 1,999,229

PROCESS AND APPARATUS FOR MAKING TUBULAR SHELLS FROM SHEET METAL April 30, 1935.

Filed Aug. 29, 1931 2 Sheets-Sheet 2 3% ATTORNEYE.

11 atented Apr. 30, 1935 STATES AENT DFFICE PROCESS AND APPARATUS FOR MAKING TUBULAR SHELLS FROM SHEET METAL s 16 Claims.

This invention relates to processes and apparatus for making tubular shells, such as battery electrodes and the like articles, from flat sheet metal.

An object of this invention is to provide a process whereby sheet metal such as steel and the like metals maybe formed into tubular shells without unduly stretching the metal or disturbing the grain-thereof and in a continuous operation without necessitating annealing or the like intermediate softening operations, whereby such tubular shells may be made easily, efficiently and economically.

A further object of this invention is to provide a highly improved apparatus of the character described, for forming seamless cups or shells of hard metal, such as steel, copper, iron and brass, which shall be smooth and positive in action, comprise comparatively few and simple parts, which shall be relatively inexpensive to manufacture and yet. practical and eflicient to a high degree in use. I

Other objects of this invention will in part be obvious and in part hereinafter pointed out.

The invention accordingly consists'in the features of construction, combinations of elements, and arrangement of parts which will be exemplified in the construction hereinafter described, and of which the scope of application will be indicated in the following claims.

In the*accompanying drawings in which is shown one of the various possible illustrative embodiments of this invention,

Fig. 1 is an elevational, cross-sectional view of the apparatus embodying the invention;

Fig. 2 is a top plan view of the apparatus shown in Fig. 1 with parts of the yoke in crosssection; v

Fig. 3 is an end view of the cup formed with the die mechanism embodying my invention and illustrating an intermediate step in the formation of the finished shell;

Fig. 4 is a side elevational view partially in cross-section of the cup. shown in Fig. 3;

Fig. 5 is a side elevational view (partly broken away) of the finished shell formed with my improved apparatus and process;

Fig. 6 is a view taken on line 66 of Fig. 1;

Fig. '7 is an elevational, cross-sectional view of the die mechanism embodying my invention for forming the cup shown in Fig. 3; and

Fig. 8 is an elevational, cross sectional view illustrating an intermediate position of a portion of the apparatus shown in Fig. 1, showing intermediate positions of the plungers.

Referring now in detail to the drawings, Ml designates a die embodying the invention for making the cup H shown in Figs. 3 and 4, from flat sheet metal; and i2 designates the drawing apparatus embodying the invention for making the tubular shell M of said cup H. The die it] comprises a base plate l5 formed with an upwardly extending, integral cylindrical flange l6 and an axial screw-threaded opening N. Screwed in said opening I! and extending downwardly from the plate is a rod 18 provided with a nut 19 at the lower end thereof and a washer 2n resting on said'nut. Slidably mounted on said rod I8 is an annular member 2| having a flange portion 22. Upstanding from and fixed to said flange 22 are a plurality of pins 24 slidably extending through parallel openings 25 formed in said plate 15. A strong coil compression spring 26 interposed between the member 21 and the washer 20 serves to normally urge the a member 21 into contact with the underside of the plate 15. The pins 24, as clearly shown in Fig. 7, are disposed on the inside of the cylindrical wall 16, and are preferably of equal height. A ring member 21 may be supported on the top ends of said pins, and preferably has a sliding fit with the inner wall of said flange l6.

Mounted on the plate l5 and within the flange i6 is a male die member 28 having acylindrical portion 29 provided with an upper stepped die portion 29a. The surface 290. is formed with radially or transversely curved annular steps, the steps decreasing in diameter toward the top. Preferably, each step is formed with a cylindrical side surface and with an annular top surface, of substantially semi-circular cross-section. The die portion 29a. is preferably formed with an axial cylindrical opening 30 slidably receiving a plunger member 31 having an integral flange 82 contacting the inner horizontal surface of the die and forming the top step of the die member 28. The top edge of the plunger may likewise be curved similarly to the other steps of the die. A coil compression spring 33 interposed between the plate l5 and the underside of the member 3!, serves to normally lift said member 3!. Preferably, however, in the lifted position shown in Fig. 7, the plunger 3l forms a taller step than the remaining steps of the die.

A complementary punching and die member 35 is suitably mounted for vertical sliding movement for coaction with the die member 28. Said member 35 comprises an outer annular member '36 adapted to register with the ring member 21,

Slidably mounted within the member 36 is the female die portion 31 having steps 38 similarly shaped and adapted to cooperate with the steps of die portion 29a. A rod 40 maybe fixed to said member 31 so that after the cup II is formed in the manner hereinafter described, the rod 40 may be pushed downwardly in any suitable manner to lower said die member 31 and release the cup.

The method of forming said cup I I with the die mechanism or press III will now be described. A piece of fiat sheet metal is placed on top of the plunger 3| (with the punch and die member 35 lifted away from the lower die member 28). Said member 35 is then lowered first to the position shown in Fig. 7. This operation causes the sheet plate to bend into the form shown in Fig. 7. The spring 33 retains the plunger 3| in lifted position so as to draw the metal inwardly and form a frusto conical surface shown in dotted lines in Fig. 7.

The formation of said conical surface provides extra metal to permit formation of the curved steps without causing undue strain on the metal.

'Continued downward movement of the member 35 will thereafter cause the sheet metal to be sheared or punched annularly at the outer edge of the cylindrical portion 36, and the formation of the steps when the die portions 29a and 38 are pressed together. During this action, the

plunger 3| will be pushed downwardly against die portion 36, which is somewhat spaced from the outer cylindrical surface 42 of the lower die member 28. The cup shaped member H may thereafter be removed from the die by lowering the rod 40. Said cup shaped member thus preformed from the fiat metal sheet is then formed into the shell M on the apparatus I2 in the manner hereinafter described.

Said apparatus l2 comprises a supporting frame 50 provided at the bottom thereof with a fixed guide 5i having a horizontal longitudinal 'groove 52.

Slidably mounted on said guide 5| is a substantially rectangular yoke 53 having a bottom wall v54 received within the groove 52, a front upright wall portion 55, a rear upright wall portion 56 and a top portion 51. For reciprocating said yoke 53, there is provided a horizontal shaft 59 suitably journalled on the frame 50. Mounted on the outer ends of the shaft 59 are similar gears 60 meshing with small gears 61 mounted on shafts 62 suitably journalled on opposite sides of the frame 50. Fixed to said shafts 32 are large gears 53 meshing with small gears 64 mounted on shafts B5 likewise suitably journalled on opposite sides of the frame 50. Fixed to said shaft 65 are large gears 66 meshing with gears BI mounted on a common shaft 58, connected to any suitable driving mechanism. Thus, the driving shaft 68 is connected through the balanced reducing gears 6|, 63, 54, 66 and 51, to the shaft 59.

Mounted on said shaft 59 is a 180 rock-cam l0 interposed between rollers H and 12 suitably mounted on the rear and front walls 56 and 55 respectively of the yoke. Thus, upon rotating the shaft 59 in the direction shown by the arrow, in Fig. 1, the yoke will be reciprocated back and forth, since the cam will engage one roller during 180 rotation and another roller during the next 180 rotation. Attached to the wall 55 of the yoke is a horizontal central plunger 14 extending forwardly therefrom, for the purpose hereinafter described. g

Slidably mounted on said plunger 14 is a'tubular plunger 15 to the rear end of which is screwed a disc 11. Slidably mounted on the tubular plunger 15, is a tubular plunger 18 to the rear end of which there is screwed a disc 19 and slidably mounted on said plunger 18 is a plunger to the rear end of which there is screwed a disc 8|, and slidably mounted on the plunger 80 is a tubular plunger 83 to the rear end of which there is screwed a disc 84. The plungers I4, I5, 18, 80, and 83am of successively increasing diameter as shown in Fig. l, and the discs l1, 19, BI and 84 are normally spaced from one another. The diameter of the plunger 14 is substantially equal to the diameter of the plunger 3| so that the front end 85 thereof may fit within the smallest step Ha, lie of the cup II. The forward ends of plungers 15, 18, 80 and 83 are of semi-circular transverse cross-section. In normal position, the forward ends of the plungers are such that the cup ll may be fitted over the curved ends of said plungers for contacting the same. Thus, the five plungers will contact the entire inner surface of the cup so that the cup may be tightly fitted on said plungers as shown in Fig. 1 of the drawings.

The plungers are adapted to be advanced in the manner hereinafter described, for cooperation with spaced die members 90, 9|, 92 and 93, fixedly secured to the frame 50 in any suitable manner. The member 93 is provided with a ring 94 having a somewhat greater inner diameter than the outer diameter of inner or central plunger 14, to allow for the thickness of the shell l4 to be formed. The member 92 is provided with a ring 95 having an inner diameter likewise somewhat greater than the outer diameter of the plunger 15. The member 9| is provided with a ring member 96 having an inner diameter somewhat greater than the outer diameter of the plunger 18, and the member is provided with a ring member 91 having an inner diameter somewhat greater than the'outer diameter of the plunger 80. The ring members 94, 95, 96 and 91 are preferably made of hard metal and are coaxial with one another and with the plungers.

Means is provided for advancing all of the plungers simultaneously until the forward end of the plunger 83 of largest'diameter presses the outer annular ring portion Ilb of the cup ll against the adjacent surface 91a of the ring 91; for thereafter simultaneously advancing the plungers I4, 15, i3, and 80 until the forward end of the plunger 89 presses the next annular portion lib of the cup ll against the surface 960. of the ring 96; then simultaneously advancing the plungers 18, I5 and 14 forwardly until the forward end of the plunger 18 presses the next annular portion ilb of the cup ll, against the ring then simultaneously advancing the To this end there is fixedly mounted on the shaft 59 on opposite sides of the central ca'm I0, a pair of similar cams I00, each of said cams having a cammed surface III! and a dwell or circular surface I02. Fixed to the disc 11 on opposite sides of the yoke 55 are parallel rearwardly extending plates N13- to the rear ends whereof are attached rollers I84 adapted to contact the cam I00, so that upon rotating the shaft 59, the cammed surface IOI will first engage the rollers I04 for pushing the plates I03 and consequently the disc TII forwardly, until the dwell portion I02 of the cam engages the rollers. Obviously, during the period of contact between the dwell portion I02 and the rollers, the disc II will not be advanced. Fixedly mounted on said shaft 59 on opposite sides of the cams I are a pair of similar cams I each likewise provided with a cammed surface I06 and a dwell surface IIII. Said cams I05 are adapted to coact with the rollers I08 mounted at the ends of parallel plates I89, disposed on opposite sides of plates I03 and fixed at the forward ends thereof to the disc I9. A pair of similar cams IIII mounted on said shaft 59 on opposite sides of the cams I05 are likewise provided with cammed surfaces I II and dwell surfaces I I2, and are adapted to cooperate with rollers'I I3 fixed at the ends of parallel plates H4. Plates H4 are disposed on opposite sides of plates I09 and are likewise fixed at the forward ends thereof to the next disc 8I so that-said disc will be advanced upon rotating the shaft 59. A pair of cams II5 are likewise mounted on the shaft 59 and provided with cammed surfaces I I6 and dwell surfaces I I I. Said cams I I5 are adapted to cooperatewith rollers I I0 mounted at the rear ends of parallel rods I I8, the forward ends of said rods being fixed to the front disc 84. w

The cams I0, I00, I05, III! and II5 are so arranged that as the shaft 59 is rotated, the yoke 58 with its central plunger II will begin moving together with the discs II, I9, 8 I and 64. This simultaneous movement of all the plungers will continue until the dwell portions I II of the smallest cams II5 engage rollers II8 of the rods II9.=... At this point, the plunger 83..will press the cup against the first ring 9I, thereafter, the disc 84 and its plunger 83 will not be advanced, but the four inner plungers will continue movement together. until the dwell portion II 2 of the cam IIO en.- gages its rollers I I3, and the forward end of the plunger 86 presses the cup against the next ring 96. During this last named movement, the portion Hit of the cup and the outer transversely curved annular portion Nb of the cup have been shaped to form the cup I Is shown in dotted lines in Fig. 8, thus reducing the outer diameter of the cup by one step. The portion I Id and the outermost curved annular portion III) of the cup are shaped or formed around the surfaceela'of the ring .97! and the cup is reduced in diameter by one step.

Continued movement of the shaft 59 will cause the three inner plungers I8, and I4 only to be simultaneously advanced until the dwell portions IIII of the cams I05 engages rollers I08 and the cup is pressed against the ring 95. The three outer plungers then remain stationary and the two inner plungers are advanced for eliminating anotherouter step'of the cup until the dwell portion'S IIIZ of the cag sglfllcontact the rollers 1'04. The plunger I5 then in turn'becomes stationary and the inner plunger I4 alone is advanced by the advanced position, the discs 11, I9, 8| and 84 are substantially in contact with one another. Thus, the operation of the apparatus I2 thus far described shapes out the steps successively beginning with the outer step to form the cup into a tubular shell by holding each step in a sliding grip between the several plungers and rings while gradually forcing said step out of said grip.

The entire action in forming the shell I4 from the cup I I occurs during 180 rotation of the shaft 59. Duringthe second half of the turn, or the next 180, the yoke 53 is returned to its original position, drawing therewith the plunger I4. The outer disc 84 is returned to its original position by means of tension springs I attached at the forward ends thereof to the rods H9 and at the rear thereof to fixed portions of the frame 50. For returning the discs 11, I9, and 8| to their original positions, shown in Fig. 1, there is provided a rod I fixed at the rear end thereof to the wall 55 of the yoke 58. Attached to said rod are cross members I26, I2I and I28 normally disposed in front of said discs II, I9 and 8| respectively. The disc therethrough, and the cross piece I26 is adapted to engage the front surface of said disc 11, for returning said disc to its original position upon drawing the yoke rearwardly. [The disc I9 likevwise has a bore I 3I of sufficient width to permit the cross piece I26 to pass therethrough. The cross piece I2I however, is somewhat longer than the cross'piece I26 so that upon moving the yoke rearwardly, the cross piece I26 will pass through said opening I3I and the outer ends of the cross piece I2I will engage the disc I9 for moving the same rearwardly. The disc BI is provided with an opening I82 large enough to permit both the cross pieces I26 and I2I to pass therethrough, but

the cross piece I28 is somewhat longer than'the cross piece I2I so that the outer ends of the cross piece I28 will engage the disc 8I for moving the same rearwardly upon returning the yoke to its rearward position.

Thus after all of the plungers are advanced to the forward position for forming the tubular shell I4, the rearward movement of the yoke 53 will retract the central plunger I4 as well as the rod I25. Upon moving the yoke 53, the plunger I4 and the rod I25 rearwardly, the cross piece I26 will pass through the openings I32 and I3I in the discs 8| and I9 respectively. The cross piece I26 is adapted to contact the disc 11 for moving said disc, together with its plunger I5 rearwardly. This movement continues until the cross piece I2I, which is adapted to pass through the opening I32 in the disc 8|, contacts thedisc I9 for moving the sametogether with its plunger I8, rearwardly. The yoke 53 and plungers I4, I5, and I8 then move rearwardly together until the cross piece I28 engages the disc 8| for also moving said disc together with its plunger 80 rearwardly. During this latter movement, the disc 84 with its plunger 83 will also be moved rearwardly by the springs I20. The disc 84, however, will stop in the normal rearward position thereof, as shownin Fig. 1, and the disc 8|, together with the discs I9, TI and plungers I8, 15 and I4 continue movement rearwardly until the yoke 53, the discs 11, I9 and 0|, and the plungers reach their normal rearward positions.

It will thus be noted that the plunger I4 moves rearwardly until the plunger I5 is carried rearwardly therewith, andthereatfer the plungers I4,

action of the cam 10 for drawing-the-final steppfr"I5move1'earwardly together until the plunger I8 the cup and producing the tubular shell I4. In

begins moving rearwardly. Thereafter the three inner plungers 14, I5, I8 move rearwardly together until the plungers 80 and 83 begin to move rearwardly therewith. Thereafter all of the plungers move rearwardly together until the disc 84 reaches its rearward position. Thereafter, the four inner plungers move rearwardly together until they all reach their rearward normal positions. The frame is provided with suitable stop means to retain the discs 11,19, BI and 84 in the rearward positions thereof.

Obviously after the shell I4 is formed, the same may be removed from the forwardend of the plunger I4 in any suitable manner and the rear rough edge thereof may be suitably trimmed. The shell I4 obviously may be made for a large variety of uses, such as cartridge shells, cups and the like.

A dominant feature of the invention is the making of the cup I I having transversely curved, annular steps, and thereafter forming the shell I 4 by eliminating the steps, one step at a time,

beginning with the outermost step. The curved portions I lb of the steps provide-sufiicient metal so that during the forming processes on the machine I2, excessive strain due to stretching of the metal is substantially eliminated, and the compression on the metal during the forming processes which usually hardenes the metal and renders the same brittle, is greatly reduced. The tube I l may thus be formed without the metal hardening to such a degree as to become brittle or breaking or cracking, and the steps may hence be shaped out without the necessity for annealing.

.The steps of the cup I I may thus be shaped out or eliminated successively without interrupting the processes for annealing purposes. Ihe curvature of the portions I lb supplies the extra metal necessary, so that the steps may be shaped out by the action of the plungers and rings of the machine I2 without actually causing a high degree of stretching of the said metal, which often causes defects and breakage during the forming processes. Obviously, the curved, radial portions III) of the cup may be angular or corrugated, or otherwise suitably shaped, and the dies 29a and 31 and the ends of the plungers correspondingly shaped to provide the cup with extra metal. In other 7' words, the portions I Ihshould bani transverse non-rectilinear cross-section. l nrther'frioreahe provision of the curved or transversely nonstraight surfaces IIb provides sufficient metal so as to prevent the thinning of the metal during the forming processes, usually resulting from stretching.

Another dominant feature of the invention is that the movable plunger 3| in the die I!) forming a frustoconical surface prior to the dieing operation provides a sufiiciency of metal to relieve the strain caused during the dieing operation.

My improved process and apparatus is particularly adapted for hard metal such as sheet steel whichwith methods or apparatus heretofore known cannot be drawninto cupsiof considerable length as compared with their diameter without intermediate annealing and other practical difiiculties and disadvantages. With my improved process and apparatus, I have found it possible to form sheet steel, for example, into a shell of length equal to approximately three times mitsjiameter with a continuous operation withi e p io mnd win s an out annealing of the metal.

It will thus be seen that there is provided a device in which the several objects of this invention are achieved, and which is well adapted to meet the conditions of practical use.

As various possible embodiments might be made of the above invention, and as various changes might be made in the embodiment above set forth, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

Having thus described my invention, I claim as new and desire to secure by Letters Patent:

1. The art of making tubular metal forms from sheet metal consisting in preforming from the sheet a cup having a plurality of annular steps, and then shaping out the steps successively beginning with the outer step by holding each step in a sliding grip while gradually forcing said step out. of said grip to form said cup into a' tubular shell.

2. The art of making tubular metal forms from sheet metal consisting in preforming from the sheet a cup having a plurality of annular steps having radial portions of non-rectilinear crosssection, and then shaping out the steps successively beginning with the outer step by holding each step in a sliding grip while gradually forcing said step out of said grip to form said cup into a tubular shell.

3. The art of making tubular shells from flat sheet metal consisting in preforming from the sheet a cup having a plurality of radially nonrectilinear annular portions and interconnected by annular cylindrical portions and constituting annular steps, then shaping out the steps beginning with the outer step by holding each step in a sliding grip while gradually forcing said step out of said grip to reduce the diameter and increase the depth of the cup.

4. The art of making tubular shells from flat sheet metal consisting in preforming from the 1 sheet a cup having a plurality of radially nonrectilinear annular portions and interconnected by annular cylindrical portions and constituting annular steps, then pressing against opposite sides of one step and against one side of the contiguous annular step of lesser diameter for shaping out the first mentioned step, and repeating this operation for the next step.

5. .The art of making tubular shells from fiat sheet metal consisting in preforming from the sheet a cup having a plurality of radially nonrectilinear annular portions and interconnected by annular cylindrical portions and constituting annular steps, then pressing against opposite sides of one step and against one side of the con tiguous annular step of lesser diameter for shaping out the first mentioned step, and repeating said operation successively on each annular portion until all of the steps have been shaped out..

radial pcrtitms of non-rectilinear cr0ss-secti6n', 70

and thereafter shaping out the steps successively begirming with the outer step by holding each stepifi a sliding grip while gradually forcing said step out of said grip to form. said cup into a tubular shell.

8. The art of making tubular shells from flat sheet metal consisting in forming a disc of metal into a frusto-conical cup, then die stamping said cup to preform a plurality of annular transversely curved steps thereon, and then shaping out the steps successively beginning with the outer step by holding each step in a sliding grip while gradually forcing said step out of said grip to form the tubular shell.

9. The art of making tubular shells from fiat sheet metal consisting in die punching a sheet to preform a cup having a plurality of radially nonrectilinear annular portions interconnected by annular cylindrical portions and constituting annular steps, and then shaping out the steps, beginning with the outer step, by holding each step in a sliding grip While gradually forcing said step out of said grip to reduce the diameter and increase the depth of the shell.

10. The art of making tubular shells from fiat sheet metal consisting in die punching a sheet to preform a cup having a plurality of radially non-rectilinear annular portions interconnected by annular cylindrical portions and constituting annular steps of successively decreasing diameter, then clamping one of said non-rectilinear portions between two annular members disposed on both sides of said portion, and then pressing a plunger against the inner surface of the next non-rectilinear portion of lesser diameter for shaping out the first mentioned non-rectilinear portion.

11. The art of making tubular shells from flat sheet metal consisting in preforming a cup having a plurality of steps of successively decreasing diameter, each step comprising a non-rectilinear portion and an annular cylindrical portion, and then pressing a non-rectilinear portion of one of said steps against an annular ring and forcing a member against the non-rectilinear portion of the next step of lesser diameter for shaping out the first named step.

12. In apparatus of the character described, a central plunger, a plurality of tubular telescoping plungers slidably mounted thereon, said tubular plungers being of successively decreasing length, discs at the rear ends of said tubular plungers, a member attached to the rear of said central plunger, cammed means for moving said member, a rod attached to said member, parallel to said central plunger and having a plurality of spaced, cross pieces thereon, each cross piece being adapted to engage one of said discs, each disc being formed with an opening adapted to permit the crosspiece for each of said discs rearwardly thereof, to pass therethrough.

13. In apparatus of the character described, a central plunger, a plurality of tubular telescoping plungers slidably mounted thereon, a yoke attached to the rear of said central plunger,

cammed means for advancing said yoke,andaplu- I rality of cams associated with said cammed means for advancing said tubular plungers in predetermined relation to said first plunger, and a member associated with said yoke and having a lost motion connection with said tubular plunger for moving said tubular plungers rearwardly to the normal rearward positions thereof.

14. In apparatus of the character described, a plurality of slidably mounted telescoping plungers the ends of said plungers forming a stepped annular surface adapted to receive a cup formed with a series of annular steps, fitted thereon, a plurality of fixed, spaced annular rings of gradually decreasing diameter, coaxial with said plungers and disposed forwardly thereof, means for advancing said plungers until the outer plunger presses the outer step of said cup against the first ring of greatest diameter, means for thereafter retaining the first plunger stationary, and advancing the remaining plungers simultaneously for shaping out the outer step of said cup, until the next inner plunger presses the next step of the cup against the next ring-of lesser diameter, then holding the two outer plungers stationary and advancing the remaining inner plungers for shaping out the next step of the cup, until the next inner plunger presses the next step of the cup against thgfnext ring of said still lesser diameter.

15. In apparatus of the character described, a plurality ofslidably mounted telescoping plungers, the ends of said plungers forming a stepped annular surface adapted to receive a cup formed with a series of annular steps, a plurality of spaced, fixed annular ring portions of successively decreasing diameters coaxial with said plunger and disposed forwardly thereof, means, for advancing said plungers simultaneously until the outer plunger presses the outer step of said cup against the first ring of greatest diameter, means for thereafter retaining the first plunger stationary, and advancing the remaining plungers simultaneously for shaping out the outer step of said cup until the inner plunger presses the next step of the cup against the next ring of lesser diameter, means for then holding the two outer flanges stationary and advancing the remaining inner plungers for shaping out the next step of the cup until the next inner plunger presses the next step of the cup against the next ring of still lesser diameter, and means for thereafter moving the plungers rearwardly to return the same to the normal rearward positions thereof.

16. In apparatus of the character described, a plurality of slidably mounted telescoping plungers having transversely, non-rectilinear end portions adapted to receive a cup formed with a series of transversely, non-rectilinear annular steps, and a plurality of fixed, spaced, annular rings of successively decreasing diameters coaxial with said plungers and disposed forwardly thereof, the ring of greatest diameter being disposed adjacent said plungers, means for advancing the plungers until the outer plunger presses the outer step of the cup against the first ring, means for thereafter retaining the first plunger stationary and advancing the remaining plungers for drawing out the outer step of the cup until the next inner plunger presses the next stepof the cup against the next ring.

BERNARD BENEDICT.

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