US3664172A

US3664172A - Apparatus for and method of forming cup-shaped articles

Info

Publication number: US3664172A
Application number: US41949A
Authority: US
Inventors: Daniel S Cvacho
Original assignee: Reynolds Metals Co
Current assignee: Reynolds Metals Co
Priority date: 1970-06-01
Filing date: 1970-06-01
Publication date: 1972-05-23
Anticipated expiration: 1989-05-23

Abstract

An apparatus and method is provided wherein a circular sheet blank is formed into a cup-shaped article which is substantially free of defects. The apparatus and method utilize a pair of cooperating die assemblies having a pair of rings provided with a pair of cooperating blank-engaging surfaces each defined by a plurality of alternating concentric grooves and projections. The grooves and projections of one of the surfaces partially intermeshes with associated projections and grooves respectively of the other of the surfaces to define concentric undulations in the peripheral portion of the blank. One of the die assemblies has a male member provided as a part thereof and the other assembly has a cooperating die cavity whereby upon relatively moving the assemblies together the blank is drawn by the male member into the die cavity enabling the undulations to serve as integral columnar members which allow controlled flow of the peripheral portion to define a tubular wall of the cup-shaped article which is free of defects.

Description

United States Patent Cvacho 1451 May 23, 1972 [54] APPARATUS FOR AND METHOD OF FORMING CUP-SHAPED ARTICLES [21] Appl. N0.: 41,949

Primary Examiner-Richard J. l-lerbst Attorney-Glenn, Palmer, Lyne, Gibbs & Thompson [57] ABSTRACT An apparatus and method is provided wherein a circular sheet blank is formed into a cup-shaped article which is substantially free of defects. The apparatus and method utilize a pair of cooperating die assemblies having a pair of rings provided with a pair of cooperating blank-engaging surfaces each defined by a plurality of alternating concentric grooves and 52 us. 01. ..72/350, 113/12011 proiections- The grooves and Projectim of one of the [51] lntcl faces partially intermeshes with associated projections and [58] Field of Search ..72/347, 350, 351; 1 13 120 H grooves respectively of the other of the surfaces to define centric undulations in the peripheral portion of the blank. One I 56] References Cited of the die assemblies has a male member provided as a part thereof and the other assembly has'a cooperating die cavity UNITED STATES PATENTS whereby upon relatively moving the assemblies together the l 571 171 H1926 Stru e 72/350 blank is drawn by the male member into the die cavity 3,420,088 H1969 Hofipn "72/349 enabling the undulations to serve as integral columnar bers which allow controlled flow of the peripheral portion to FOREIGN PATENTS OR APPLICATIONS define a tubular wall of the cup-shaped article which is free of defects. 471,720 2/1951 Canada ..72/348 18 Claim, 15 Drawing Figures L Z w V l \l\ l l I i 52 55 56 57 54 53 86 so Z9 I 77 I f l PATENTEBMM 23 1912 3,664,172

INVENTO DANIEL S. CVAC HIS ATTORNEYS PATENTEUMAYZ IBYZ $664,172

' mm 2 UF 3 v 3 @035 FIG'B- I INVEN DANIEL 3. CV 0 BY OW Q HIS ATTORNEYS APPARATUS FOR AND METHOD OF FORMING CUP- SHAPED ARTICLES BACKGROUND OF THE INVENTION Present apparatus and methods used to form cup-shaped articles or cups from a circular sheet blank generally use a cooperating pair of die assemblies wherein each die assembly has an outer clamping ring provided with a planar surface. The planar clamping surfaces engage the peripheral portion of the circular blank and firmly clamp such peripheral portion while a punch comprising one of the die assemblies draws the blank into a die cavity provided in the other assembly. Present cups formed in this manner often have numerous defects which include substantial wrinkles which extend longitudinally along the tubular wall of the cup, scores, ears and sharp edges at the top of the tubular wall, etc. These defects and particularly the wrinkles often cause failures such as punchouts during subsequent forming operations because the wrinkles will not allow smooth metal flow. In addition, it is often impossible to redraw or iron cups which have even a small number of such wrinkles.

It has also been found that present apparatus and methods require precisely controlled lubrication on the outside surface of the sheet blank; and, in the event an excessive amount of lubricating oil is used the wrinkling is aggravated because there is no place for the incompressible oil to move during the drawing action. It is also very important with current apparatus and methods that the clamping pressure applied by the clamping rings during drawing be precisely controlled because substantial variations in such clamping pressure tend to aggravate the tendency to produce longitudinal wrinkles.

SUMMARY This invention provides a simple and economical improved apparatus for and method of making cup-shaped articles which are substantially free of defects such as longitudinal wrinkles, for example. The apparatus and method utilize a pair of cooperating die assemblies having a pair of rings provided with a pair of cooperating blank-engaging surfaces each defined by a plurality of alternating concentric grooves and projections. The grooves and projections of one of the surfaces partially intermeshes with associated projections and grooves respectively of the other of the surfaces to define concentric undulations in the peripheral portion of the blank. One of the die assemblies has a male member provided as a part thereof and the other assembly has a cooperating die cavity whereby upon relatively moving the assemblies together the blank is drawn by the male member into the die cavity enabling the undulations to serve as integral columnar members which allow controlled flow of said peripheral portion to define a tubular wall of the cup-shaped article which is free of wrinkles.

Other details, uses, and advantages of this invention will become apparent as the following description of the exemplary embodiments thereof presented in the accompanying drawings proceeds.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings show present exemplary embodiments of this invention, in which FIG. 1 is a perspective view with parts broken away of a machine in the form of a press which utilizes one exemplary embodiment of the apparatus and is particularly adapted to enable carrying out the method of this invention;

FIG. 2 is a fragmentary perspective view of a strip of sheet metal stock which is automatically fed into the press of FIG. 1 with holes shown therein to indicate circular blanks punched therefrom to enable forming of cup-shaped articles or cups and also illustrating a typical circular blank cut from the sheet metal, a partially formed cup, and a completely formed cup to indicate various phases of cup manufacture;

FIG. 3 is a greatly enlarged fragmentary perspective view of a wedge-shaped portion of the partially formed cup as illustrated in FIG. 2 to highlight the main problem encountered during the drawing action;

FIG. 4 is a view with parts in cross section, parts in elevation, and parts broken away illustrating a pair of cooperating die assemblies (i.e., a set of cooperating assemblies) which comprise the four sets of cooperating die assemblies provided in the press of FIG. I with the sheet stock moved into position and prior to blanking a circular blank from such sheet stock;

FIG. 5 is a cross-sectional view similar to FIG. 4 and illustrating the blanking action which produces a circular blank;

FIG. 6 is an enlarged fragmentary cross-sectional view of the blanking action illustrated in FIG. 5 showing the action of the blank-engaging rings comprising the cooperating die assemblies;

FIG. 7 is a fragmentary perspective view illustrating slight undulations provided in the peripheral portion of a circular blank during the blanking action;

FIG. 8 is a cross-sectional view similar to FIG. 4 illustrating the cooperating die assemblies at a later stage of the forming cycle wherein a cup has been partially formed and has a configuration essentially as illustrated in FIG. 2;

FIG. 9 is an enlarged fragmentary cross-sectional view of the die assemblies in the position illustrated in FIG. 6;

FIG. 10 is a perspective view of the partially formed cup as defined in the position of the cooperating die assemblies shown in FIGS. 8 and 9 and illustrating heavy undulations defined by the workpiece-engaging surfaces of the rings comprising such assemblies;

FIG. 11 is a cross-sectional view similar to FIG. 4 showing the die assemblies at a later stage in the cycle with the cup completely formed and with dotted lines illustrating such cup being blown, using compressed air, into a discharge chute for ejection from the press;

FIG. 12 is a perspective view of a completely formed cup made by the apparatus and method of this invention and which is free of defects;

FIG. 13 is an enlarged fragmentary cross-sectional view of associated portions of the blank-engaging surfaces comprising the rings of each pair of cooperating die assemblies and illustrating the manner in which the grooves serve as reservoirs for the lubricating oil; 7

FIG. 14 is an enlarged fragmentary cross-sectional view il- Iustrating another embodiment of the blank-engaging surfaces which may be provided on the holding rings of the die assemblies of this invention; and

FIG. 15 is an enlarged fragmentary cross-sectional view illustrating still another embodiment of the blank-engaging surfaces which may be provided on the holding rings of the die assemblies of this invention.

DESCRIPTION OF ILLUSTRATED EMBODIMENTS Reference is now made to FIG. 1 of the drawings which illustrates an exemplary forming machine or press which is designated generally by the reference numeral 20 and which utilizes the apparatus of this invention as a part thereof and which enables carrying out the method steps in accordance with the teachings of this invention. The press 20 has a supporting structure 21 which supports a slide assembly 22 for reciprocating horizontal movement and the slide assembly 22 is operatively connected to a shaft 23 which is moved in a reciprocating manner by a crank mechanism 24. The mechanism 24 is suitably mechanically connected to a flywheel 25 which is driven by a motor 26 and a suitable clutch may be provided for engaging and disengaging the crank mechanism 24 from the flywheel and a brake may also be provided for stopping the flywheel 25.

The slide assembly 22 has a plurality of four die assemblies each designated generally by, the reference numeral 30 and the assemblies 30 are built as an integral part of the slide assembly 22. Thus, the die assemblies 32 are moved in a simultaneous manner by the crank mechanism 24.

The press also has a die shoe assembly 31 which includes a plurality of four die assemblies each designated generally by the reference numeral 32 and each having a hydraulic cylinder 33 associating therewith. Each hydraulic cylinder controls the operation of its associated die assembly 32 as it operatively associates with a cooperating die assembly to enable the forming of an associated cup-shaped article which is free of wrinkles and in a manner to be subsequently described.

The press 20 has a plurality of die posts 34 which hold the slide assembly 22 in precise alignment with the die shoe assembly during reciprocating movement of assembly 22 by the crank mechanism. The press 20 is supplied with metal sheet stock 35 from an associated supply roll thereof in any suitable manner known in the art and the opposed outside surfaces of the metal sheet are lubricated with lubricating oil by a pair of lubricating rolls 36 rotatably supported on opposite sides of the sheet 35 and being supplied with lubricatingoil in any well known manner.

The operation of the press 20 is such that the sheet 35 is indexed into position between the

assemblies

22 and 31 whereupon the mechanism 24 and cylinders 33 move their associated die assemblies to simultaneously define a plurality of four cups from the sheet with circular blanks being cut from the sheet 35 essentially in the pattern illustrated in FIG. 2. By exploded perspective, FIG. 2 also illustrates a circular blank 40 which has been cut from sheet 35, a partially formed cup 41, and a completely formed cup-shaped article or cup 42 as formed at successive stages of forming.

As previously mentioned, a plurality of four cups 42 are formed simultaneously and in an identical manner by the cooperating action of the die

assemblies

30 and 32 as the slide 22 is reciprocated back and forth by the mechanism 24. Therefore, to simplify the presentation the detailed description will proceed with the manner in which a single cooperating pair of die

assemblies

30 and 32 operate, with it being understood that such detailed description is fully applicable to all four sets of cooperating assemblies. In addition, this detailed description will focus on certain stages of forming which illustrate initial stages where a circular blank is cut, an intermediate stage showing a cup-shaped article, and a final stage showing a substantially completely formed cup. However, it is to be understood that the forming action provided by each cooperating pair of

assemblies

30 and 32 is continuous.

To highlight the problems which exist in forming a cup 42 from a circular planar blank 40, reference is now made to FIG. 3 of the drawings which illustrates a substantially pie-shaped wedge 43 which is cut from the partially formed cup 41 illustrated in FIG. 2. In order that the completed cup 42 may have a bottom wall 42A and a right circular cylindrical side wall 428, also see FIG. 12, it is necessary during the drawing action to the press 20 for any section such as the arcuate portion having an outer arcuate length indicated at 44 to be compressed to a corresponding arcuate length 45 which represents a circumferential portion of the cylindrical side wall 42B in the completed cup 42. It will be appreciated that this compressing action must be achieved so that the shaded area indicated at 46 in FIG. 3 will flow smoothly and in a non-buckling nonwrinkling manner, otherwise the side wall of the completed cup will have wrinkles and irregularities which will render such cup unacceptable for further drawing. Only a pie-shaped wedge 43 is illustrated in FIG. 3 to explain the drawing problem; however, it will be appreciated that the entire annular portion 47 of the circular blank 40, see FIG. 2, must be changed from a planar surface to a right circular cylindrical surface in forming blank 40 to define cup 42.

Each die assembly 30 is fixed to a structural plate assembly 51 comprised of a plurality of

structural plates

52, 53 and 54 which are suitably fixed together as by threaded bolts. The assembly 30 has a ring 55 which is suitably detachably fixed to a ring holder 56 as by a plurality of bolts and the ring holder 56 is in turn fixed to member 54 of the plate assembly 51. The assembly 30 also has a tubular sleeve insert 57 suitably fixed in position so that its outside cylindrical surface engages associated inside cylindrical surfaces of ring 55 and ring holder 56 and the insert 57 has an inside cylindrical surface 58 which defines a die cavity 60 for the die assembly 30.

The assembly 30 also has a stripper ring or stripper 61 supported concentrically around the ring 55 for axial sliding movement and the ring 61 is normally urged outwardly by a plurality of stripper piston rods 62 only one of which is illustrated in the drawings. Each stripper rod 62 has a threaded outer end portion 63 which is threadedly received in a threaded opening 64 in the stripper 61 and has a lock nut 65 for locking the rod in position. The opposite end of the rod 62 has a piston head 66 which is received in a bore 67 provided in a supporting housing 70 which is supported by a support 71 and the support 71 is suitably fixed to the supporting plate 54.

Air supply means is provided for the piston head 66 and includes an air line 72 which is suitably operatively connected to a source of air under regulated pressure and the line 72 communicates with an internal passage 73 which supplies air to the head 66 whereby the rod 62 and stripper 61 are yieldingly urged outwardly so that the annular front face of stripper 61 extends beyond the forward annular surface of the ring 55, The extent of outward movement of stripper 61 is controlled by each piston head 66 bottoming against housing 70 and such movement may be adjusted by the amount that rods 62 are threaded within stripper 61.

The die assembly 30 has another tubular insert 74 provided therein and arranged in alignment with the insert 57 to define a cylindrical passage 75 which in essence serves as an extension of the die cavity 60. The passage 75 communicates with a vertically extending passage 76 provided at the rear of the plate assembly 51 and allows completed cups 42 to drop therethrough as indicated by the dotted arrow 77 in FIGS. 1 and 4 and onto suitable conveying means in the form of either a chute, a belt conveyor, or the like arranged at the bottom of the press to enable movement of the completed cups 42 away from the press 20.

Each die assembly 32 has a male member 80 which has an outside cylindrical surface 81 and the member 80 is adapted to be received within an associated die cavity 60 so that circular blanks 40 may be drawn between the outside cylindrical surface of member 80 and the inside surface 58 of the die assembly 30 defining die cavity 60. The die assembly 32 also has a ring 82 supported concentrically around the male member 80 which allows axial sliding movement of the member 80 therethrough.

The die assembly 32 has a cutting ring 83 supported concentrically around the ring 82 by a ring holder 84 and the ring 82 is axially movable with respect to the cutting ring 83. The cutting ring 83 has a cutting edge 84 which shears or cuts the sheet stock 35 as the

die assemblies

30 and 32 are relatively moved together and in a manner to be described in more detail subsequently.

In general, the rings which are similar to

rings

55 and 82 and which have been provided in drawing apparatus and methods proposed heretofore have simple annular clamping surfaces which are substantially planar and serve to tightly clamp the peripheral portion of a blank such as a circular blank 40 tightly therebetween to enable the drawing action to take place. The prior art rings apply substantially high clamping forces against the peripheral portion of a circular blank throughout the entire drawing action and it should be emphasized that it is very difficult to precisely control such force whereby poor control of this clamping force has resulted in the production of defective cups.

To avoid the problems encountered heretofore in producing cups such as cup 42 the apparatus and method of this invention provides a pair of cooperating blank-engaging

surfaces

85 and 86 on the

rings

55 and 82 respectively and each

surface

85 and 86 has a plurality of alternating concentric annular grooves 90 and projections 91, see FIGS. 6 and 9. The grooves and projections comprising one of the surfaces such as surface 85, for example, partially interrnesh with associated projections and grooves respectively of the other surface 86 and vice versa to define concentric undulations in the peripheral portion 47 of the blank as illustrated in FIGS. 6 and 7 and such undulations may be considered as comparatively small undulations 92, i.e.. each undulation 92 has a small amplitude, during the initial forming of the flat blank; however, larger undulations 93 are provided immediately following the initial forming and as shown in FIGS. 9 and 10.

The cooperating

assemblies

30 and 32 are provided with means for relatively moving such assemblies toward and away from each other to enable complete forming of each cup 42 nd in this example of the invention the four die assemblies 30 are moved by the crank mechanism 24 while each of the cooperating four die assemblies 32 has component portions thereof moved in a controlled manner by an associated cylinder 33 to provide the forming action which will be described in more detail subsequently. During the forming or drawing of a particular blank 40, first the small undulations 92 and then the larger undulations 93 are provided. and such undulations are in essence integral columnarmembers 92 and 93. These columnar members allow a thickening and cold flow of the metal in a smooth manner so that the peripheral portion 47 of the blank 40 defines a cylindrical side wall 42A in each completed cup 42 which is free of wrinkles, undulations, and the like.

The blank-engaging

surfaces

85 and 86 of

rings

55 and 82 respectively have planar

annular strips

95 and 96 respectively, see FIGS. 4 and 6, defining their peripheral edge portions or edges. The

strips

95 and 96 may be of equal or unequal areas depending upon the detailed configuration of the remainder of their associated surfaces and the purpose of such strips will be explained-in detail subsequently.

Having described the detailed component portions of the

die assemblies

30 and 32 and their associated structure, the description will now proceed by describing in detail the manner in which sheet stock 35 is cut to define circular sheet metal blanks 40 and the manner in which each pair of cooperating

assemblies

30 and 32 operate on a particular blank 40 to define a completed cup 42. j

As seen in FIG. 4, the sheet stock 35 is suitably moved into position in accordance with a predetermined sequence to enable cutting of circular blanks 40 therefrom essentially in the manner illustrated in FIG. 2 and so as to eliminate wasted sheet stock. As the sheet stock 35 is moved in position between the cooperating die

assemblies

30 and 32. the slide assembly 22 is moved to the left as viewed in FIG. 4 causing artial telescoping of the ring 55 within the cutting ring 83 whereby the circular cutting edge 84 cuts a circular blank 40 essentially as shown in FIG. 5 of the drawings.

The presentation of FIG. 5 is illustrated in enlarged detail in FIG. 6 wherein it will be seen that the stripper 61 has been" moved to the right with respect to ring 55 by the cutting ring 83 overriding the action of its rods 62 tending to urge stripper 61 outwardly. During this initial forming the

annular strips

95 and 96 have been previously adjusted during the initial setup of the press so that they cooperate to firmly clamp, i.e., v pinch, as it is popularly referred to, the outer edge portion of he circular blank 40 while the inner portions of the surfaces .45 and 86, i.e., the portions arranged inwardly of

strips

95 and 96, cooperate to define the previously mentioned small undulations 92 in the peripheral portion 37 of the blank 40, as-illustrated in FIG. 7.

This action of defining undulations or integral columns 92 assures that the peripheral portion of the blank 40 may be compressed and formed with minimum likelihood of buckling and/or wrinkling. Further, relative movementof each pair of cooperating

die assemblies

30 and 32 together, and in this extially formed cup is also shown in FIG. 2 and designated by the reference numeral 41. As the cup is partially formed, the circumferential edge portion of the blank is moved away from the firm compressing or pinching action provided by the

annular strips

95 and 96 whereupon strips 95 and 96 move into firm contact with each other.

The

strips

95 and 96 and their associated

surfaces

85 and 86 respectively are constructed and arranged so that with movement of the peripheral portion of a blank radially inwardly away therefrom such strips, the above-mentioned firm contact is provided and as shown at 100 in H0. 8 whereby the strips serve to precisely control. by limiting, the movement of the

rings

55 and 82 toward each other. This limiting action allows the inner portions of their respective blank-engaging surfaces to define the previously mentioned larger undulations or integral columnar members 93 and as illustrated in FIGS. 8 -10.

As the cooperating die

assemblies

30 and 32 are further relatively moved together the male member80 is extended further within the die cavity 60 and the larger undulations or columnar members 93 are in essence moved radially outwardly toward the periphery of the blank. During this phase of the drawing operation the inner portions of the blank engaging surfaces Mind 86 more firmly engage the peripheral portion ample such relative movement is caused by further leftward I movement of the die assembly 32 as well as controlled rightward movement of the male member by its associated cylinder 33, causes the drawing and partial forming of a cup For purposes of illustration, FIG. 8 illustrates the stage of forming where a cup has been partially formed and such parof the blank in what is popularly referred to as a "heavy kiss which is particularly effective in preventing flapping or oscillating movement of such peripheral portion during the drawingaction.

The heavy kiss type engagement provided by the surfaces and 86 is achieved in a non-compressing manner whereby the forming of the cup 42 may be achieved without requiring precise control of the clamping pressureexerted by the

surfaces

85 and 86 of

rings

55 and 82 respectively.

Thus, it is seen that this invention enables forming a completed cup 42 in a simple and efficient manner and as seen particularly in FIG. 12, such cup is substantially free of defects such as wrinkles, for example.

To assure rapid removal of each completed cup 42 from its associated cooperating die

assemblies

30 and 32 air under a regulated high pressure is provided through a conduit 101 threadedly connected at 102 in the male member 80 and communicating with a passage 103which exits a front face 104 of the male member 80. Once the forming action is completed air under pressure is provided through the conduit I01 and such air propels the cup 42 through the rear portion of the die cavity 60 and through extension passage 75 into the passage 76. The passage 76 is provided with either suction means or pressure means which act against the cup 42 to move it out of the press 20. '1

The conduit 101 is provided with air under regulated pressure from any suitable pressure source and has a flexible portion 7 remote from the male member 80 which allows reciprocating movement of the male member without disrupting the flow of pressurized air. The press20 may also use detectors such as limit switches, photoelectric detectors, etc., in each passage 76 to detect any jamming of completed cups 42 and thereby prevent prolonged shutdown of the press 20 to remove any jam which may occur during operation of the press.

Once a particular cup 42 has been formed the associated assembli'es 30 and 32 are moved apart to the initial position illustrated in FIG. 4 whereupon the stripper 61 is yieldingly urged outwardly by its rods 62 to thereby move the sheet stock 35 therewith from its position illustrated at 105 in FIG. 11 and allow the sheet stock to return essentially to the position shown in FIG. 5. In this latter position the sheet stock can again be moved in any desired manner to enable cutting thereof in the manner previously described to define circular blanks 40.

As previously mentioned, a serious problem with previous apparatus and methods is that lubricating oil applied on the external surfaces of the sheet stock 35 and hence lubricating oil on the opposed surfaces of the blank 40 is often trapped between peripheral portions of the blank and the planar clamping surfaces of such prior apparatus. This trapped lubricating oil being incompressible causes buckling and excessive wrinkling during the forming action. However. as illustrated in FIG. 13 of the drawings. the cooperating grooves 90 of the blank-engaging surfaces serve as reservoirs for any ex cessive lubricating oil present on the surface of the blank 40. In addition during the forming of the blank. movement of the peripheral portion thereof as indicated by the arrow at 106 serves to provide substantially automatic metering of any required lubricating oil as shown at 107 and thereby prevent introduction of substantial amounts of oil whereby wrinkling and buckling is effectively prevented As seen in FIGS. 6 and 9 of the drawings each projection 91 comprising

surfaces

85 and 86 has a substantially semicircular configuration as viewed in cross section and each groove 90 comprising these surfaces has a roughly U-shaped cross-sectional configuration. However, it will be appreciated that the grooves 90 need not necessarily have a U-shaped configuration wherein the base thereof is defined as a substantially flat portion as indicated at 90A in FIGS. 6 and 9. In particular. such grooves may have base portions or an entire cross-sectional configuration which is arcuate. such as semicircular or semielliptical, for example.

The exemplary grooves 90 provided in each

ring

55 or 82 and the projections 91 provided in each

ring

55 or 82 have substantially equal cross-sectional areas. However. it will be appreciated that it may be desirable some applications of. this invention. depending upon the metallic sheet material being used to form the cups 42, to provide any desired plurality of grooves and projections in each ring having many different cooperating combinations of cross-sectional areas, configurations. and arrangements.

Another exemplary embodiment of this invention is illustrated in FIG. 14 wherein a pair of cooperating

rings

55M and 82M are provided with annular surfaces 85M and 86M respectively. For simplicity, the separate associated members and components portions of

rings

55M and 82M which are very similar to previously described parts will be given the same reference numerals as before followed by the letter, designation m" and not described again. In each

ring

55M and 82M the radius of each annular projection comprising surface 85M and 86M and arranged remote from the center thereof is smaller than a projection arranged closer to the center of such ring. In particular. it will be seen that each exemplary surface 85M and 86M has a plurality of three semicircular projections 1 M. 111M and 112M as viewed in cross-section. The innermost projection 110M has the largest radius. the outermost projection 112M has the smallest radius. and the intermediate projection has an intermediate radius.

Still another exemplary embodiment of this invention is illustrated in FIG. I5 wherein a pair of cooperating

rings

55M and 82N are provided with annular surfaces 85N and 86N respectively. In this example. the radius of each annular projection comprising surface 85N and 86M and arranged remote from the center of its associated ring is larger than a projection arranged closer to the center of such ring. Thus. it will be seen that each exemplary surface 85N and 86N has a plurality of three semicircular projections IION. lllN and XIZN as viewed in cross section. The innermost projection llON has the smallest radius. the outermost projection 1 UN has the largest radius. and the intermediate projection has an. intermediate radius. r

In the embodiment of this invention presented in FIGS. l-12. the projections 91 comprising the surface 85 of ring 55 have equal radii which are larger than the radii of the projections 91 on the ring 82. also of equal radii. However. as previously mentioned. it will be appreciated that the detailed dimensions of these projections and of their associated grooves may be varied as desired while also taking into account the structural characteristics of the metal being formed.

In this disclosure of the invention the various annular grooves and projections are shown as having a substantially circular peripheral outline; however, it will be appreciated that the various annular grooves and projections may have noncircular peripheral outlines. such as elliptical. oval, and rectangular, for example.

In this presentation of the invention the various sources of power for the drive motor 26. the hydraulic fluid and fluid pressurizing means therefor for the cylinders 33. the prime mover for the sheet stock 35. the various air supplies and connections. etc., have not been illustrated. However.- it will be appreciated that any suitable means known in the art may be utilized to provide the various required sources of energy. connections, and the like whereby it is considered unnecessary to describe such items in detail.

The apparatus and method of this invention is particularly adapted to the forming of single piece cups from flat blanks of sheet material such as metallic material containing aluminum and 3004-HI9 aluminum alloy has been used successfully for producing cups in mass production quantities. However. it will be appreciated that the apparatus and method of this invention is fully applicable in making cups of other non-ferrous metallic materials as well as ferrous metallic materials.

While present exemplary embodiments of this invention. and method of practicing the same. have been illustrated and described. it will be recognized that this invention may be otherwise variously embodied and practiced within the scope of the following claims.

lclaim:

1. An apparatus for forming cup-shaped articles from sheet blanks comprising, a first die assembly having adie cavity therein and having a first peripheral ring,a second die assembly having a male member adapted to be received within said die cavity and having a second peripheral ring. a pair of cooperating blank-engaging surfaces on said rings with each of said surfaces having a plurality of alternating annular grooves and projections, said projections comprising each blank-engaging surface having outer edges which are roughly coplanar.

said grooves and projections comprising one of said surfaces partially intermeshing with associated projections and grooves respectively of the other of said surfaces to define a plurality of concentric undulations in the peripheral portion of an associated blank. said undulations being arranged so that they may be bisected by an imaginary plane coplanar with the central portion of said blank, and means relatively moving said assemblies toward each other causing said blank to be drawn between said male member and a tubular surface defining said die cavity enabling said undulations to serve as integral columnar members which allow controlled flow of said peripheral portion to define a tubular wall of a cup-shaped article made from said blank.

2. An apparatus as set forth in claim 1 in which each projection has a substantially semicircular cross-sectional configuratron.

3. Ari apparatus as set forth in claim I in which each projection' has a substantially semicircular cross-sectional configuration and each groove has a roughly U-shaped cross-sectional configuration. I

4. An apparatus as set forth in claim 2 in which said projections comprising each blank-engaging surface have semicircular ems-sectional configurations which have different radii.

5. Anapparatus as set forth in claim 4 in which the radius of a particular projection which is arranged remote from the center of said blank is smaller than the radius of a projection arranged closer to saidcenter.

6. An apparatus-as set forth in claim 4 in which the radius of a particular projection which is arranged remote from the center of said blank is larger than the radius of a projection arranged closer to said center.

7. An apparatus as set forth in claim 2 in which said blank comprises a circular blank and each of said surfaces has a planar annular strip defining its peripheral edge. said strips cooperating to pinch the outer edge portion of said blank while the inner portions of said blank-engaging surfaces cooperate to define small undulations in said peripheral portion of said-blank during initial movement of said assemblies together, and upon moving said male member within said die cavity a comparatively small axial length said annular strips move into firm contact and precisely control the movement of said rings toward each other while allowing said inner portions of said blank-engaging surfaces to define larger undulations in said peripheral portion of said blank so that with continued movement of said male member within said cavity said larger undulations are moved radially outwardly toward the periphery of said blank and the inner portions of said blankengaging surfaces heavily kiss said blank in a non-compressing manner to thus provide, a cup-shaped article which is free of wrinkles.

8. An apparatus as set forth in claim 7 in which said circular blank is made of a metallic material containing aluminum and further comprising means for ejecting said cup-shaped article from said die cavity.

9. A press for forming metal cups from sheet metal blanks each having opposed surfaces coated with a liquid lubricant comprising, a first die assembly having a cylindrical inside surface defining a die cavity therein and having a first peripheral ring, a second die assembly having a male member adapted to be received within said die cavity and having a second peripheral ring, a pair of cooperating blank-engaging surfaces on said rings with each of said surfaces having a plurality of alternating concentric annular grooves and projections, said projections comprising each blank-engaging surface having outer edges which are roughly coplanar, said grooves and projections comprising one of said surfaces partially intermeshing with associated projections and grooves respectively of the other said surfaces to define a plurality of concentric undulations in the peripheral portion of an associated blank, said undulations being arranged so that they may be bisected by an imaginary plane coplanar with the central portion of said blank, each of said grooves having a volume which is greater than the volume of its associated projection so that with each projection intermeshed within its groove with the associated blank interposed therebetween each of said grooves serves as a local reservoir for any excessive amount of lubricant on its associated exposed surface, and means relatively moving said assemblies toward each other causing said blank to be drawn between said male member and said cylindrical surface enabling said undulations to serve as integral columnar members which allow controlled flow of said peripheral portion to define a tubular wall of a cup made from said blank and movement of said peripheral portion serves to provide substantially automatic metering of only the required amount of lubricant from within said grooves to thereby prevent wrinkling and buckling ofsaid tubular wall.

10. A press as set forth in claim 9 wherein said first and second die assemblies define a cooperating set and said press has a plurality of four cooperating sets of die assemblies which simultaneously form a plurality of four cups during each operating cycle 11. A press as set forth in claim 9 in which each projection has a substantially semicircular cross-sectional configuration and each groove has a roughly U-shaped cross-sectional configuration.

12. A press as set forth in claim 9 and further comprising means for supplying air under regulated pressure through said male member to enable ejecting each completed cup from said die cavity and out of said press.

13. A method of making a metal cup from a circular blank having exposed surfaces coated with a liquid lubricant, said method comprising the steps of, providing a first die assembly having a die cavity therein and having a first peripheral ring, providing a second die assembly having a male member adapted to be received within said die cavity and having a second peripheral ring, forming a pair of cooperating blankengaging surfaces on said rings by forming a plurality of alternating concentric annular grooves and projections on each of said surfaces, said projections comprising each blank-engaging surface having outer edges which are roughly coplanar.

holding said blank between said blank-engaging surfaces, and relatively moving said assemblies toward each other causing said grooves and projections comprising one of said surfaces to be partially intenneshed with associated projections and grooves respectively of the other of said surfaces with said blank held between said surfaces to define a plurality of concentric undulations in the peripheral portion of said blank during the initial portion of said relatively moving step, said undulations being arranged so that they may be bisected by an imaginary plane coplanar with the central portion of said blank, each of said grooves having a volume which is greater than the volume of its associated projection so that with each projection intermeshed within its groove with said blank interposed therebetween each of said grooves serves as a local reservoir for any excessive amount of lubricant on its associated exposed surface, and during the latter portion of said relatively moving step said blank is drawn between said male member and a tubular surface defining said die cavity enabling said undulations to serve as integral columnar members which allow controlled flow of said peripheral portion to define a tubular wall of a cup made from said blank and movement of said peripheral portion serves to provide substantially automatic metering of only the required amount of lubricant from within said grooves to thereby prevent wrinkling and buckling of said tubular wall.

14. A method as set forth in claim 13 in which said forming step comprises forming each projection with a substantially semicircular cross-sectional configuration.

15. A method as set forth in claim 13 in which said forming step comprises forming each projection with a substantially semicircular cross-sectional configuration and each groove with a roughly U-shaped cross-sectional configuration.

16. A method as set forth in claim 13 in which said forming step comprises forming said projections of each blank-engaging surface with semicircular cross-sectional configurations having different radii.

17. A method as set forth in claim 13 in which said forming step comprises forming a planar annular strip as the peripheral edge of each of said surfaces, said strips cooperating to pinch the outer edge portion of said blank while the inner portions of said blank-engaging surfaces cooperate to define small undulations in said peripheral portion of said blank during the initial portion of said relatively moving step, and during the latter portion of said relatively moving step said annular strips move into firm contact and precisely control the movement of said rings toward each other while allowing said inner portions of said blank-engaging surfaces to define larger undulations in said peripheral portion of said blank so that with continued movement of said male member within said cavity said larger undulations are moved radially outwardly toward the periphery of said blank and the inner portions of said blankengaging surfaces heavily kiss said blank in a non-compressing manner to provide said cup which is free of wrinkles.

18. A method as set forth in claim 17 and comprising the further steps of relatively moving said die assemblies apart and ejecting said cup from said die cavity using compressed air.

Claims

1. An apparatus for forming cup-shaped articles from sheet blanks Comprising, a first die assembly having a die cavity therein and having a first peripheral ring, a second die assembly having a male member adapted to be received within said die cavity and having a second peripheral ring, a pair of cooperating blank-engaging surfaces on said rings with each of said surfaces having a plurality of alternating annular grooves and projections, said projections comprising each blank-engaging surface having outer edges which are roughly coplanar, said grooves and projections comprising one of said surfaces partially intermeshing with associated projections and grooves respectively of the other of said surfaces to define a plurality of concentric undulations in the peripheral portion of an associated blank, said undulations being arranged so that they may be bisected by an imaginary plane coplanar with the central portion of said blank, and means relatively moving said assemblies toward each other causing said blank to be drawn between said male member and a tubular surface defining said die cavity enabling said undulations to serve as integral columnar members which allow controlled flow of said peripheral portion to define a tubular wall of a cup-shaped article made from said blank.

2. An apparatus as set forth in claim 1 in which each projection has a substantially semicircular cross-sectional configuration.

3. An apparatus as set forth in claim 1 in which each projection has a substantially semicircular cross-sectional configuration and each groove has a roughly U-shaped cross-sectional configuration.

4. An apparatus as set forth in claim 2 in which said projections comprising each blank-engaging surface have semicircular cross-sectional configurations which have different radii.

5. An apparatus as set forth in claim 4 in which the radius of a particular projection which is arranged remote from the center of said blank is smaller than the radius of a projection arranged closer to said center.

6. An apparatus as set forth in claim 4 in which the radius of a particular projection which is arranged remote from the center of said blank is larger than the radius of a projection arranged closer to said center.

7. An apparatus as set forth in claim 2 in which said blank comprises a circular blank and each of said surfaces has a planar annular strip defining its peripheral edge, said strips cooperating to pinch the outer edge portion of said blank while the inner portions of said blank-engaging surfaces cooperate to define small undulations in said peripheral portion of said blank during initial movement of said assemblies together, and upon moving said male member within said die cavity a comparatively small axial length said annular strips move into firm contact and precisely control the movement of said rings toward each other while allowing said inner portions of said blank-engaging surfaces to define larger undulations in said peripheral portion of said blank so that with continued movement of said male member within said cavity said larger undulations are moved radially outwardly toward the periphery of said blank and the inner portions of said blank-engaging surfaces heavily kiss said blank in a non-compressing manner to thus provide a cup-shaped article which is free of wrinkles.

9. A press for forming metal cups from sheet metal blanks each having opposed surfaces coated with a liquid lubricant comprising, a first die assembly having a cylindrical inside surface defining a die cavity therein and having a first peripheral ring, a second die assembly having a male member adapted to be received within said die cavity and having a second peripheral ring, a pair of cooperating blank-engaging surfaces on said rings with each of said surfaces having a plurality of alternating concentric annular grooves and projections, said prOjections comprising each blank-engaging surface having outer edges which are roughly coplanar, said grooves and projections comprising one of said surfaces partially intermeshing with associated projections and grooves respectively of the other said surfaces to define a plurality of concentric undulations in the peripheral portion of an associated blank, said undulations being arranged so that they may be bisected by an imaginary plane coplanar with the central portion of said blank, each of said grooves having a volume which is greater than the volume of its associated projection so that with each projection intermeshed within its groove with the associated blank interposed therebetween each of said grooves serves as a local reservoir for any excessive amount of lubricant on its associated exposed surface, and means relatively moving said assemblies toward each other causing said blank to be drawn between said male member and said cylindrical surface enabling said undulations to serve as integral columnar members which allow controlled flow of said peripheral portion to define a tubular wall of a cup made from said blank and movement of said peripheral portion serves to provide substantially automatic metering of only the required amount of lubricant from within said grooves to thereby prevent wrinkling and buckling of said tubular wall.

10. A press as set forth in claim 9 wherein said first and second die assemblies define a cooperating set and said press has a plurality of four cooperating sets of die assemblies which simultaneously form a plurality of four cups during each operating cycle.

11. A press as set forth in claim 9 in which each projection has a substantially semicircular cross-sectional configuration and each groove has a roughly U-shaped cross-sectional configuration.

13. A method of making a metal cup from a circular blank having exposed surfaces coated with a liquid lubricant, said method comprising the steps of, providing a first die assembly having a die cavity therein and having a first peripheral ring, providing a second die assembly having a male member adapted to be received within said die cavity and having a second peripheral ring, forming a pair of cooperating blank-engaging surfaces on said rings by forming a plurality of alternating concentric annular grooves and projections on each of said surfaces, said projections comprising each blank-engaging surface having outer edges which are roughly coplanar, holding said blank between said blank-engaging surfaces, and relatively moving said assemblies toward each other causing said grooves and projections comprising one of said surfaces to be partially intermeshed with associated projections and grooves respectively of the other of said surfaces with said blank held between said surfaces to define a plurality of concentric undulations in the peripheral portion of said blank during the initial portion of said relatively moving step, said undulations being arranged so that they may be bisected by an imaginary plane coplanar with the central portion of said blank, each of said grooves having a volume which is greater than the volume of its associated projection so that with each projection intermeshed within its groove with said blank interposed therebetween each of said grooves serves as a local reservoir for any excessive amount of lubricant on its associated exposed surface, and during the latter portion of said relatively moving step said blank is drawn between said male member and a tubular surface defining said die cavity enabling said undulations to serve as integral columnar members which allow controlled flow of said peripheral portion to define a tubular wall of a cup made from said blank and movement of said peripheral portion serves to provide substantially automatic metering of onLy the required amount of lubricant from within said grooves to thereby prevent wrinkling and buckling of said tubular wall.

17. A method as set forth in claim 13 in which said forming step comprises forming a planar annular strip as the peripheral edge of each of said surfaces, said strips cooperating to pinch the outer edge portion of said blank while the inner portions of said blank-engaging surfaces cooperate to define small undulations in said peripheral portion of said blank during the initial portion of said relatively moving step, and during the latter portion of said relatively moving step said annular strips move into firm contact and precisely control the movement of said rings toward each other while allowing said inner portions of said blank-engaging surfaces to define larger undulations in said peripheral portion of said blank so that with continued movement of said male member within said cavity said larger undulations are moved radially outwardly toward the periphery of said blank and the inner portions of said blank-engaging surfaces heavily kiss said blank in a non-compressing manner to provide said cup which is free of wrinkles.