US3664171A

US3664171A - Stripper for apparatus such as metallic can body formers

Info

Publication number: US3664171A
Application number: US89259A
Authority: US
Inventors: Elpidifor Paramonoff
Original assignee: Standun Inc
Current assignee: Sequa Corp
Priority date: 1970-11-13
Filing date: 1970-11-13
Publication date: 1972-05-23
Anticipated expiration: 1989-05-23

Abstract

A series of circumferentially aligned, generally T-shaped cross section stripper members are positioned in a retainer ring with stripper member finger extensions projecting into a central opening of the retainer ring through which a ram end passes rearwardly with a cup-shaped article thereon and forwardly during stripping of the article from the ram end. The stripper members are received in an annular, inwardly opening recess of the retainer ring, T-shaped in cross section generally corresponding to the stripper members. A circumferentially surrounding garter spring normally urges the stripper members radially inwardly with axially spaced, radially inwardly facing stripper member surfaces abutting corresponding retainer ring recess walls, axially opposite stripper member ends abutting corresponding retainer ring recess end walls and the stripper member finger extensions projecting angularly rearwardly into the retainer ring central opening to a diameter less than the outer diameter of the cupshaped articles carried by the ram end. During movement of the cup-shaped articles rearwardly through the stripper members by the ram end, the stripper members pivot outwardly about an arcuate surface on the forward ends thereof and over the retainer ring corresponding recess wall, while stripper member rearward arcuate end surfaces slide radially along the retainer ring corresponding recess wall and other surfaces and walls separate permitting such pivoting. After the cup-shaped articles have passed rearwardly the stripper members return generally to normal position so as to engage the ends of the cup-shaped articles upon forward return movement of the ram end with the stripper member finger extensions, thereby forcing the cup shaped articles from the ram end.

Description

United States Patent Paramonoff [54] STRIPPER FOR APPARATUS SUCH AS METALLIC CAN BODY FORMERS Elpidifor Paramonoff, Los Angeles, Calif.

[73] Assignee: Standum, lnc., Compton, Calif.

[22] Filed: Nov. 13, 1970 [21] Appl. No.: 89,259

[72] Inventor:

Primary ExaminerRichard J. Herbst Attorney-Mahoney, Hombaker & Schick ABSTRACT A series of circumferentially aligned, generally T-shaped cross May 23, 1972 section stripper members are positioned in a retainer ring with stripper member finger extensions projecting into a central opening of the retainer ring through which a ram end passes rearwardly with a cup-shaped article thereon and forwardly during stripping of the article from the ram end. The stripper members are received in an annular, inwardly opening recess of the retainer ring, T-shaped in cross section generally corresponding to the stripper members. A circumferentially surrounding garter spring normally urges the stripper members radially inwardly with axially spaced, radially inwardly facing stripper member surfaces abutting corresponding retainer ring recess walls, axially opposite stripper member ends abutting corresponding retainer ring recess end walls and the stripper member finger extensions projecting angularly rearwardly into the retainer ring central opening to a diameter less than the outer diameter of the cup-shaped articles carried by the ram end. During movement of the cup-shaped articles rearwardly through the stripper members by the ram end, the stripper members pivot outwardly about an arcuate surface on the forward ends thereof and over the retainer ring corresponding recess wall, while stripper member rearward arcuate end surfaces slide radially along the retainer ring corresponding recess wall and other surfaces and walls separate permitting such pivoting. After the cup-shaped articles have passed rearwardly the stripper members return generally to normal position so as to engage the ends of the cup-shaped articles upon forward return movement of the ram end with the stripper member finger extensions, thereby forcing the cup shaped articles from the ram end.

15 Claims, 11 Drawing Figures PATiminmzs-xsrz 3,664,171

' sum 1 UF 3 IN VENTOR.

EL PIDIFOR PARAMONOFF MAHONEY, HORNBA KER AND SCH/CK ATTORNEYS PMENTEDMM 231972 SHEET 2 (IF 3 .FI6.4.Y

AND ScHlcK ATTORNEYS STRIPPER FOR APPARATUS SUCH AS METALLIC CAN BODY FORMERS BACKGROUND OF THE INVENTION This invention relates to an improved stripper for apparatus such as metallic can body formers and more particularly, to such a stripper adapted for operating in a unique manner to perform its stripping function of stripping cup-shaped articles from the ends of axially moving rams in an improved manner and under high speed conditions. Furthermore, the stripper of the present invention includes stripper members which are positively controlled in all positions thereof to exactly and accurately perform the stripping functions without damage to the relatively thin walled metallic can bodies being stripped from the ram end. Still further, not only does this positive control of the stripper members in all positions thereof provide the stripper members capable of resisting the necessary forces encountered during the stripping operations in order to exactly and accurately perform such stripping operations, but the same positive control of the stripper members permit accurate movement thereof with minimum wear so that the stripper of the present invention is serviceable over an extended period of use with minimum maintenance problems.

Generally, in the metal forming arts, various forms of strippers have been used in conjunction with metal forming dies in order to strip the finished metal parts from the dies after proper format on thereof, and this is particularly true where the metal forming operation is incorporated in an automatic, mass production line. Obviously, if the metal forming press or other mechanism is operating on an automatic feed, part form and part strip or ejection cycle, a failure of any of the operating mechanisms can cause metal part jamming resulting in serious damage to the various equipment. This is particularly true in the case of metallic can body forming mechanisms which incorporate multiple stage dies and operate at relatively high speeds.

For instance, in a metallic can body forming mechanism where aluminum can bodies are being formed, there might be incorporated an initial redraw die followed by as many as three ironing dies, still further followed by a stripper. In such operation, a semi-formed cup-shaped blank is fed to the apparatus and is picked up by a ram end which forces the cupshaped blank progressively through the redraw and various ironing dies to ultimately reduce the diameter, thin the walls and elongate the walls of the cup-shaped blank into a properly formed can body. After the finished can body has been finally formed by the last of the series of ironing dies, such finished can body must be stripped from the ram end in order for the ram to reciprocally return through the dies and commence the next can body forming operation, thus requiring the stripper for removing the finished can body from the ram end.

It is clear that if the stripper does not properly perform its function, the finally formed can body will begin to return reversely through the ironing dies with the returning ram end and if this occurs, it is clear that serious damage can result to quite expensive die equipment as well as other mechanism parts. Even if the stripper can complete the stripping operation of removal of the finished can body from the ram end, but does so in an unsatisfactory manner, the finished can bodies being so stripped can be damaged destroying the usefulness of the entire can body forming operation. If the can bodies being formed are made from tinplate or similar more difficult materials to be formed, the results of improper stripper operation are substantially the same or more serious.

Substantially all strippers used in metallic can body forming apparatus include a retainer ring mounting a plurality of circumferentially adjacent stripper members thereon, which stripper members project radially inwardly into a central ram opening of the retainer ring. As the ram of the can body forming apparatus forces the cup-shaped metal part through the final of the ironing dies, it then proceeds to force the finally formed can body through the stripper forcing the stripper members slightly radially outwardly to permit such passage.

Immediately upon the finally formed can body completing its passage through the stripper, the stripper members return radially inwardly closely adjacent the ram outer surface so that when the ram reverses and passes reversely forwardly through the stripper, the stripper members engage the finally formed can body forcing the same from the ram end as the ram end completes its passage reversely forwardly through the stripper.

It can be seen, therefore, that the movements of the stripper members must be extremely exactly controlled and this can be even more greatly appreciated when it is considered that the thicknesses of the walls of the finished can bodies are quite small, usually a matter of a few thousandths thickness. Furthmore, the entire engagement of the stripper members with the finished can bodies is at the end surface thereof so that the can surface engaged is constituted by a very thin ring closely surrounding the ram outer surface. Still in addition, not only must the stripper members properly engage the thin finished can body ends, but these stripper members must exert sufficient force thereon to endwise slide the can bodies from the ram end over which such can bodies have been formed, and this becomes increasingly more difficult as the ram speeds increase in the more modern metallic can body forming apparatus, as well as with the formation of can bodies from the more difficult to form metals such as tinplate and the like.

Certain of the prior strippers used in metallic can body forming apparatus have included the mounting of the stripper members for quite a complex cushioned movement in an effort to reduce wear by reducing shock loads thereon encountered during the stripping operation. These prior stripper constructions have not, however, been totally satisfactory. Although the cushioning approach solves certain of the problems involved, the major problems of exact and predictable stripper member movements are more greatly complicated due to the less predictability of stripper member movement and control.

A still further goal sought to be accomplished by metallic can body forming apparatus not heretofore discussed is the proper forming of the final can bodies with proper dimensioning and proper shapes, while still providing a finished outer metal surface free from scratches and preferably polished. Obviously, any slight misalignments of the stripper members, particularly during the passage of the final can bodies therethrough in advancement of the final stripping operations, can frustrate this goal. This is particularly true when can bodies are being formed from the softer metals, such as aluminum.

OBJECTS AND SUMMARY OF THE INVENTION It is, therefore, an object of this invention to provide an improved stripper for apparatus such as metallic can body formers wherein the stripper members of the stripper are exactly and positively controlled in all movements thereof, both during the passage of the final can bodies therethrough, as well as during the reverse return final stripping operation thereof. During the passage of the finally formed can bodies on the ram end rearwardly through the stripper during the ram rearward movement from the last of the ironing dies, the surrounding stripper members are engaged by the can bodies and move smoothly outwardly to permit such can body passage. Immediately upon the can bodies being transported therethrough in such rearward travel, the stripper members, due to the positive control thereof, immediately return inwardly closely adjacent the ram outer surface and ready for the ram reverse movement and the can body engagement by such stripper members for carrying out the stripping operation.

It is a further object of this invention to provide an improved stripper for apparatus such as metallic can body formers of the foregoing general character wherein the positive action and completely predictable movements of the stripper members is maintained at all speeds of operation of the particular forming apparatus including the increased and higher speeds of present day constructions particularly in metallic can body formers. Due to a unique formation and extension of the stripper members in their inward projections into the necessary normal interference with the finally formed can body passages therethrough, the stripper members are required to only slightly pivot in a combined axial and radial movement to permit the finally formed can body passage, and only a return slight pivoting to be properly positioned ready for engagement with the can body ends in carrying out the stripping operations. This combined axial and radial pivoting action, as opposed to straight outward and inward radial action, is provided by a particular rearward angled extension of the stripper members of the portions thereof engaged by the finally formed can bodies, preferably combined with a particular surface formation of such stripper members and resulting in a minimum required movement requiring minimum time to accomplish.

It is also an object of this invention to provide an improved stripper for apparatus such as metallic can body formers wherein the stripper members required to move in an exact manner and resist the forces encountered during the accomplishment of the stripping operations are at all times in solid abutting contact with the stripper retainer ring mounting and positioning the same so that erratic movement thereof can never occur and complete predictable movements will always be assured. A unique cooperating formation between the stripper members and the retainer ring maintains secure abutment positioning of the stripper members in their normal inward projecting positions prior to the nearly finally formed can bodies being formed passing therethrough, and also preferably while the stripper members are being approached from rearwardly thereof by the now finally formed can bodies on the return strokes of the ram and during the actual stripping operations. This same unique cooperating formation between the stripper members and the retainer ring also maintains secure abutment between various of the stripper member surfaces and the retainer ring throughout the necessary movements of the stripper members relative to the retainer ring, again ensuring a constant maintenance of proper and predictable stripper member position throughout all phases ofthe stripping operations.

It is still a further object of the present invention to provide an improved stripper for apparatus such as metallic can body formers having all of the foregoing advantageous features and unique characteristics inherently resulting in proper stripper functioning with minimum wear between the moving parts thereof. Despite the fact that during every stripping operation, it is necessary for all of the stripper members to pivot first outwardly for the nearly finally formed can body passages therethrough, then return inwardly preparatory to engaging the now finally formed can bodies during the actual stripping operations, and while at the same time resisting the forces encountered during the actual stripping operations, the minimum movements of the stripper members and the constant abutting relationships maintained between the stripper members and the retainer ring reduce wear therebetween to a minimum heretofore impossible with prior stripper constructions. Required maintenance operations are, therefore, likewise reduced to a minimum and the strippers of the present invention are thereby serviceable for performing their stripping functions over a long period of use.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a typical metallic can body former incorporating a preferred embodiment of the improved stripper of the present invention;

FIG. 2 is an enlarged, fragmentary, somewhat schematic sectional view primarily of the die pack of the metallic can body former of FIG. 1 generally taken along the direction of the arrows 2-2 in FIG. 1;

FIG. 3 is a view similar to FIG. 2, but of the rearward portion of the die pack containing the stripper of the present invention and illustrating a finally formed can body in broken lines rearward of the stripper ready for forward return stripping movement;

FIG. 4 is a view similar to FIG. 3, but showing the finally formed can body in broken lines intermediate the actual stripping operation;

FIG. 5 is an enlarged, vertical sectional view looking in the direction of the arrows 5-5 in FIG. 2 and showing the embodiment of stripper of the present invention in normal positron;

FIG. 6 is a vertical sectional view looking in the direction of the arrows 6-6 in FIG. 5;

FIG. 7 is an enlarged, fragmentary, vertical sectional view taken from the central portion of FIG. 6 and showing a ram of the metallic can body former with a nearly finally formed can body on an end thereof just engaging stripper members of the stripper of the present invention during rearward movement of the ram;

FIG. 8 is a view similar to FIG. 7, but with the nearly finally formed can body passing through the stripper;

FIG. 9 is a view similar to FIG. 7, but with the nearly finally formed can body having passed through the stripper with only a portion of the ram located therein;

FIG. 10 is a view similar to FIG. 7, but with the finally formed can body having returned to the stripper and the actual stripping operation taking place; and

FIG. 11 is an enlarged view of one of the stripper members taken from the stripper of the present invention.

DESCRIPTION OF THE BEST EMBODIMENT CONTEMPLATED Referring to FIG. 1 of the drawings, a typical metallic can body former is generally indicated at 20 and for purposes of defining the environment of the improved stripper of the present invention, includes a ram guide and drive assembly generally indicated at 22, a die pack generally indicated at 24 and a part feed assembly generally indicated at 26. Generally, also referring to a somewhat diagrammatic sectional view of the die pack 24 shown in FIG. 2, a ram 28 is reciprocally driven by the ram guide and drive assembly 22 horizontally rearwardly and then returned forwardly through the die pack 24 with semi-formed one-piece metallic can bodies 30 being fed downwardly by the part feed assembly 26 into the forward end of the die pack to be transported rearwardly through the die pack by the ram and formed into finally formed can bodies as will be hereinafter described.

The can body former 20, as well as the die pack 24 included therein, are formed of usual materials and in the usual manner appropriate for the use intended.

Referring more particularly to FIG. 2, the die pack 24, beginning at the forward end thereof or the left-hand end as shown in FIG. 2, is comprised of a redraw draw pad 32 working in conjunction with a redraw die ring 34, a first ironing die ring 36, a second ironing die ring 38, a third ironing die ring 40, an embodiment of the improved stripper of the present invention 42 and a doming or bottom forming die 44. The various draw pad, die rings, stripper and forming die are positioned and supported in the die pack by usual fixtures and spacers in a somewhat conventional manner properly aligned for carrying out the required redraw, wall ironing and bottom forming functions. The general operation thereof will be hereinafter described after a more detailed description of the stripper 42 and along with the description of the operation of the stripper.

More particularly to the principles of the present invention and referring to FIGS. 5 through II, the stripper 42 constituting a preferred embodiment of the present invention includes a housing ring 46 radially telescoping an axially separable retainer ring 48, the split retainer ring being normally secured together by series of circumferentially spaced bolts 50. In the particular embodiment shown, the retainer ring 48 is formed with the stepped circumference thereof spaced slightly inwardly, from the housing ring 46, and a resilient O-ring 52 is positioned radially therebetween for providing slight flexible mounting of the retainer ring within the housing ring, but with axial abutment being maintained therebetween. This slight flexible mounting by the O-ring 52 of the retainer ring 48 within the housing ring 46 may be provided in certain instances for compensating for slight misalignments of the stripper 42 within the die pack 24, or may be eliminated where the stripper includes usual radial alignment means for obtaining the exact alignment desired, the important thing being that the flexible mounting disclosed is a matter of choice under the particular circumstances and either flexible or solid mounting will satisfy the environment for the present invention.

The retainer ring 48 is formed with a radially inwardly opening, annual recess 54 generally T-shaped in radial cross section and receiving and positioning a plurality of circumferentially adjacent, radially inwardly projecting, stripper members 56. The stripper members 56 each have generally T- shaped control portions 58 generally conforming to the retainer ring T-shaped recess 54 and angular finger portions or extensions 60 normally projecting angularly inwardly and rearwardly into a central axial opening 62 of the retainer ring 48. A continuous garter spring 64 surrounds the stripper members 56 normally resiliently urging the stripper members radially inwardly to their normal positions, but permitting radial rocking of the stripper members within the retainer ring recess in a uniquely controlled manner as will be hereinafter described more in detail.

Thus, with the stripper members 56 in normal positions within the retainer ring recess 54 as shown in FIGS. 6, 7, 9 and 10, generally radially extending, axially forwardly and rearwardly facing, end surfaces 66 and 68 of the stripper members 56 at least partially axially abut corresponding generally radially extending, forward and rearward end wall surfaces 70 and 72 of the retainer ring recess 54, while at the same time in this normal position, axially spaced and extending, inner surfaces 74 abut corresponding inner wall surfaces 76 ofthe retainer ring recess and axially extending, outer surfaces 78 of the stripper members are spaced radially inwardly from corresponding outer wall surfaces of the retainer ring recess. Still at the same time in the normal positions of the stripper members 56, forward radial surfaces 82 of inwardly extending parts on the stripper member T-shaped control portions 58 forwardly axially abut corresponding forward radial wall surfaces 84 of the retainer ring recess 54 and similar rearward radial surfaces 86 of the stripper members are axially spaced forwardly from rearward radial wall surfaces 88 of the retainer ring recess. With the T-shaped control portions 58 of the stripper members 56 thusly normally positioned in the retainer ring recess 54, the stripper member finger extensions 60 angle radially inwardly and axially rearwardly into the retainer ring central opening 62 presenting radially inwardly facing, axial engagement surfaces 90 and axially rearwardly facing, radial engagement surfaces 92.

Completing the particulars of the formations of the stripper members 56, the forward end surfaces 66 thereof are preferably radially arcuate throughout the radial extents thereof arcuately blending inwardly and outwardly into the inner and

outer surfaces

74 and 78. The stripper member rearward end surfaces 68 are also radially arcuate throughout the radial extent thereof, but it will be noted that the forward end surfaces 66 are formed on a shorter radius and, therefore, more markedly arcuate than the rearward end surfaces 68, Thus, with these particular formations of the stripper member forward and rearward end surfaces 66 and 68, in combination with the hereinbefore described spacing between certain of the other stripper member surfaces and the corresponding retainer ring recess wall surfaces, the stripper members 56 are permitted to pivotally rock over the arcuate forward end surfaces 66 thereof against the forward end wall surfaces 70 of the retainer ring recess 54 while tight abutment is maintained therebetween and while slidable movement takes place between the stripper member rearward end surfaces 68 and the rearward end wall surfaces 72 of the retainer ring recess even though these latter surfaces remain closely adjacent.

Of course, prior to and after the above described rocking movement of the stripper members 56, that is, during the normal positioning of the stripper members, the stripper members are maintained firmly controlled by the retainer ring 48 through the end surface abutments, the spaced inner surface abutments and the radial surface between the stripper members and retainer ring, such being particularly important during the actual stripping operations as will be hereinafter described. Furthermore, during the generally radial rocking or pivoting of the stripper members 56, such rocking is permitted by, but resiliently resisted by, the garter spring 64 surrounding the stripper members. The stripper members 56 will, therefore, always assume their normal positions securely retained positively positioned by the retainer ring 48 except when urged to pivot radially outwardly by forces on the stripper member finger extensions 60.

In general operation of the can body former 20 in forming metallic can bodies from the semi-formed can bodies 30 to finally formed can bodies indicated at 94 in FIGS. 4 and 10, a can forming cycle begins with the ram 28 at its forwardmost withdrawn position forwardly clear of the die pack 24. During the period of time that the ram 28 is forwardly clear of the die pack 24, one of the semi-formed can bodies 30 in supply chute 96 of the part feed assembly 26 is fed downwardly into part positioning yoke 98, an open end 100 of the can body facing forwardly and a closed end 102 thereof facing rearwardly. The redraw die pad 32 then moves rearwardly ahead of the ram 28 and enters the open end 100 of the semi-formed can body 30 with the ram 28 following through the now-positioned redraw die pad to engage the closed end 102 of the semi-formed can body as shown in FIG. 2.

The ram 28 proceeding on its rearward movement through the redraw die pad 32 moves the semi-formed can body 30 from the redraw die pad rearwardly through the redraw die ring 34 carrying out an initial redraw operation, followed by movement of the can body by the ram progressively rearwardly through the first, second and third ironing die

rings

36, 38 and 40 to carry out progressive ironing operations on the can body. As the can body and the ram 28 leave the third ironing die ring 40, they begin entering the stripper 42 with the can body engaging the stripper members 56 which, up to this point, are in their normal positions projecting inwardly into the retainer ring central opening 62, a maximum distance with the stripper member axial engagement surfaces projecting inwardly to a diameter less than the outer diameter of the can body as shown in FIG. 7. As shown in FIG. 8, continued progressive rearward movement of the can body and the ram 28 causes the stripper members 56 to pivot radially outwardly by the stripper member forward end surfaces 66 rocking over the forward end wall surfaces 70 of the retainer ring recess 54 as previously described so that the stripper member axial engagement surfaces 90 eventually rest on the can body outer surface as shown during passage of the can body rearwardly therethrough.

During final rearward movement of the can body and the ram 28 rearwardly of the stripper 42 and against the doming or bottom forming die 44 as shown in FIG. 3, the stripper members 56 once again pivotally rock back inwardly substantially to their normal positions as shown in FIG. 9, once again assuming the securely retained abutting surface positioning both axially and radially inwardly with the various wall surfaces of the retainer ring recess 54. During the contact of the can body with the doming or bottom forming die 44, the can body bottom is inwardly domed to complete the can body formation resulting in the finally formed can body 94. Immediately thereafter, the ram 28 begins its return forward movement through the die pack 24 so as to carry the finally formed can body 94 forwardly until the can body open end engages the stripper member radial engagement surfaces 92 which commences stripping of the finally formed can body from the ram as shown in FIGS. 4 and 10.

Thus, as the ram 28 continues its forward movement through the stripper 42 with the finally formed can body 94 being retained stationary by the stripper members 56 through the engagement therebetween, the finally formed can body is stripped from the ram. Furthermore, during this stripping operation, it will be noted that the stripper members 56 are preferably in their normal positions so that the stripper members through the abutting surface relationship with the retainer ring 48 are capable of resisting the forces exerted thereagainst and cleanly perform their stripping operation. The cycle is completed by the ram 28 proceeding forwardly through the remainder of the die pack 24 and from the redraw draw pad 32 ready for the next cycle commencement, with the now stripped finally formed can body 94 dropping from the die pack and being transported from the can body former 20.

According to the principles of the present invention, there fore, an improved stripper is provided for apparatus such as metallic can body formers and the like wherein the stripper is adapted for operating in a positive manner, all movements of the functioning stripper members 56 thereof being completely predictable and controlled so that the stripper members pivot smoothly outwardly to permit passage of the particular semiformed can body 30, yet are securely and firmly repositioned in their normal positions for proper engagement with the open end 100 of the finally formed can bodies 94 to properly strip the same from the end of the ram 28 as the ram progresses forwardly in its return strokes. As hereinbefore pointed out and described, the outward pivoting of the stripper members 56 for permitting the rearward moving passage of the end of the ram 28 with the semi-formed can bodies 30 thereon is controlled through constant abutment of stripper member surfaces and the corresponding surfaces of the stripper retainer ring 48, while other stripper member and retainer ring surfaces provide sliding action therebetween while remaining closely adjacent. Still at the same time, as the stripper members 56 return to their normal inwardly pivoted positions ready for the actual stripping operation on the return movement of the ram 28 and the now finally formed can bodies 94, the stripper members are positively positioned and maintained secure capable of resisting the necessary forces for carrying out the stripping operation by various predicted surface abutments between the stripper members and the retainer ring 48, again as hereinbefore described.

The overall result of the unique pivotal movement of the stripper members 56 within and controlled by the retainer ring 48 is that not only is the stripping operation precisely and exactly controlled so that the semi-formed can bodies 30 passing rearwardly therethrough and the finally fonned can bodies 94 being stripped from the end of the ram 28 are not damaged, but the stripper members required to move outwardly and inwardly during each semi-formed can body passage and each stripping operation are subjected to a minimum of wear, as are the retainer ring surfaces, despite such movements. Certain of these exact movement and minimum wear qualities relative to the stripper members 56 and the retainer ring 48 are obtained by the particular rearwardly angled projection of the stripper member finger extensions 60. Such stripper member finger extensions 60 present rearwardly angled surfaces for smoothly pivoting the stripper members 56 in their required outward pivotal travel as forced by the semi-finished can bodies 30 passing therethrough, and radially flat engagement surfaces 92 on the stripper members are perfectly positioned thereby to perform the actual stripping operation upon the stripper members returning to normal positions, the combined surfaces and rearwardly angled fingers extensions transmitting the stripping forces through the stripper members and to the various firmly maintained abutting surfaces.

I claim:

1. In a stripper device of the type for stripping cup-shaped articles from the end of an axially forwardly and rearwardly moving ram; the combination of: a retainer ring having an axial ram opening therethrough spaced larger than outer diameters of said ram end and a cup-shaped article thereon;

an annular, generally T-shaped cross section recess in said retainer ring having a leg portion opening into said ram opening; a plurality of generally T-shaped cross section stripper members received in said recess having leg portions terminating inwardly in finger extensions projecting into said ram opening; facing surface means formed partially by wall surfaces of said retainer ring recess and partially by corresponding stripper member surfaces, certain of said surface means abutting during normal positioning of said stripper members with said finger extensions projecting a maximum distance into said ram opening to a diameter less than said cup-shaped article outer diameter, said certain surface means abuttingly axially confining and abuttingly radially inwardly restricting said stripper members in said normal position, certain others of said surface means being spaced apart in said stripper member normal positions, said certain other surface means permitting generally radially outward rocking of said stripper members from said normal positions moving said finger extensions to a diameter greater than said cup-shaped article outer diameter, said stripper members rocking outwardly about and maintaining abutment at all times at a part of said certain surface means while separating different of said certain surface means during said outward rocking; and yieldable means for normally urging said stripper members to said normal positions.

2. A stripper device as defined in claim 1 in which said certain surface means abutingly radially inwardly restricting said stripper members in said normal position include spaced axially extending facing surface means.

3. A stripper device as defined in claim 1 in which said part of said certain surface means about which said stripper members rock while at all times maintaining abutment include generally radially extending facing surface means at forward extremities of said stripper members.

4. A stripper device as defined in claim 1 in which said part of said certain surface rneans about which said stripper members rock while at all times maintaining abutment include generally radially extending facing surface means at forward extremities of said stripper members; and in which said certain surface means include facing surface means extending generally radially at rearward extremities of said stripper members abutingly rearwardly axially confining said stripper members in said normal positions and sliding relative to each other during said stripper member outward rocking.

5. A stripper device as defined in claim 1 in which said finger extensions of said stripper members angle axially rearwardly and radially inwardly from said stripper member leg portions and move generally radially outwardly during said stripper member rocking.

6. A stripper device as defined in claim 1 in which said part of said certain surface means about which said stripper members rock includes forward generally radial facing surface means at forward extremities of said stripper members, said surface means on said stripper member forward extremities being at least partially radially arcuate.

7. A stripper device as defined in claim 1 in which said part of said certain surface means about which said stripper members rock includes forward generally radial facing surface means at forward extremities of said stripper members, said surface means on said stripper member forward extremities being at least partially radially arcuate; and in which said certain surface means include generally radially extending facing surface means at rearward extremities of said stripper members, said surface means on said stripper member rearward extremities being at least partially radially arcuate.

8. A stripper device as defined in claim 1 in which said part of said certain surface means about which said stripper members rock includes forward generally radial facing surface means at forward extremities of said stripper members, said surface means on said stripper member forward extremities being at least partially radially arcuate; in which said certain surface means include generally radially extending facing surface means at rearward extremities of said stripper members,

said surface means on said stripper member rearward extremities being at least partially radially arcuate; and in which said finger extensions of said stripper members angle axially rearwardly from said stripper member leg portions.

9. In a stripper device of the type for stripping cup-shaped articles from the end of an axially forwardly and rearwardly moving ram; the combination of: a retainer ring having an axial ram opening therethrough spaced larger than outer diameters of said ram end and a cup-shaped article thereon; an annular, generally T-shaped cross section recess in said retainer ring outwardly adjacent said ram opening, said recess having an axial portion defined by generally radially extending endwalls terminating radially inwardly in generally axially extending inner walls axially spaced apart, said inner wall axial spacing defining axial extremities of a recess radial portion opening into said retainer ring ram opening; a plurality of generally T-shaped cross section stripper members received in said recess having corresponding axial and radial portions with said radial portions terminating inwardly in finger extensions projecting into said retainer ring ram opening, at least partially arcuate ends of said stripper member axial portions and inner surfaces of said stripper member axial portions normally abutting corresponding of said end and inner walls of said recess axial portion during normal inward projection of said stripper member finger extensions to a diameter less than said cup-shaped article outer diameter, certain other stripper member surfaces and recess walls being normally spaced permitting axially rearward and radially outward rocking movement of said stripper member finger extensions to a diameter larger than said cup-shaped article during radially outward rocking of a forward and radially outward sliding of a rearward of said stripper member axial portion ends along said corresponding recess axial portion end walls; and yieldable means for normally urging said stripper members to said recess wall normal abutments.

10. A stripper device as defined in claim 9 in which said forward of said stripper member axial portion ends are continuously arcuate radially over at least outer radial parts thereof including outer radial extremities thereof.

11. A stripper device as defined in claim 9 in which said rearward of said stripper member axial portion ends are arcuate radially over at least radially inward parts thereof including radially inward extremities thereof.

12. A stripper device as defined in claim 9 in which said forward of said stripper member axial portion ends are radially arcuate over at least outer radial parts thereof including outer radial extremities thereof; and in which said rearward of said stripper member axial portion ends are radially arcuate over at least radially inward parts thereof including radially inward extremities thereof.

13. A stripper device as defined in claim 9 in which said stripper member finger extensions project inwardly from said stripper member radial portions angled axially rearwardly from said stripper member radial portions.

14. A stripper device as defined in claim 9 in which said forward of said stripper member axial portion ends are radially arcuate over at least outer radial parts thereof including outer radial extremities thereof; in which said rearward of said rearward of said stripper member axial portion ends are radially arcuate over at least radially inward parts thereof including radially inward extremities thereof; and in which said yieldable means includes an annular resilient member axially centrally surrounding said stripper member axial portions normally urging said stripper members to said recess wall normal abutments.

15. A stripper device as defined in claim 9 in which said stripper member finger extensions project inwardly axially angled from said stripper member radial portions; in which said yieldable means includes an annular resilient member axially centrally surrounding said stripper member axial portions normally urging said stripper members to said recess wall normal abutments; in which said forward of said stripper member axial portion ends are radially arcuate over at least outer radia1 parts thereof including outer radial extremities thereof; and

in which said rearward of said stripper member axial portion ends are radially arcuate over at least inward radial parts thereof including inward radial extremities thereof.

Claims

1. In a stripper device of the type for stripping cup-shaped articles from the end of an axially forwardly and rearwardly moving ram; the combination of: a retainer ring having an axial ram opening therethrough spaced larger than outer diameters of said ram end and a cup-shaped article thereon; an annular, generally T-shaped cross section recess in said retainer ring having a leg portion opening into said ram opening; a plurality of generally T-shaped cross section stripper members received in said recess having leg portions terminating inwardly in finger extensions projecting into said ram opening; facing surface means formed partially by wall surfaces of said retainer ring recess and partially by corresponding stripper member surfaces, certain of said surface means abutting during normal positioning of said stripper members with said finger extensions proJecting a maximum distance into said ram opening to a diameter less than said cupshaped article outer diameter, said certain surface means abuttingly axially confining and abuttingly radially inwardly restricting said stripper members in said normal position, certain others of said surface means being spaced apart in said stripper member normal positions, said certain other surface means permitting generally radially outward rocking of said stripper members from said normal positions moving said finger extensions to a diameter greater than said cup-shaped article outer diameter, said stripper members rocking outwardly about and maintaining abutment at all times at a part of said certain surface means while separating different of said certain surface means during said outward rocking; and yieldable means for normally urging said stripper members to said normal positions.

4. A stripper device as defined in claim 1 in which said part of said certain surface means about which said stripper members rock while at all times maintaining abutment include generally radially extending facing surface means at forward extremities of said stripper members; and in which said certain surface means include facing surface means extending generally radially at rearward extremities of said stripper members abutingly rearwardly axially confining said stripper members in said normal positions and sliding relative to each other during said stripper member outward rocking.

8. A stripper device as defined in claim 1 in which said part of said certain surface means about which said stripper members rock includes forward generally radial facing surface means at forward extremities of said stripper members, said surface means on said stripper member forward extremities being at least partially radially arcuate; in which said certain surface means include generally radially extending facing surface means at rearward extremities of said stripper members, said surface means on said stripper member rearward extremities being at least partially radially arcuate; and in which said finger extensions of said stripper members angle axially rearwardly from said stripper member leg portions.

15. A stripper device as defined in claim 9 in which said stripper member finger extensions project inwardly axially angled from said stripper member radial portions; in which said yieldable means includes an annular resilient member axially centrally surrounding said stripper member axial portions normally urging said stripper members to said recess wall normal abutments; in which said forward of said stripper member axial portion ends are radially arcuate over at least outer radial parts thereof including outer radial extremities thereof; and in which said rearward of said stripper member axial portion ends Are radially arcuate over at least inward radial parts thereof including inward radial extremities thereof.