US3913372A

US3913372A - Method and apparatus for forming a receptacle closure

Info

Publication number: US3913372A
Application number: US520163A
Authority: US
Inventors: Charles T Baker
Original assignee: VERMONT MARBLE Co
Current assignee: VERMONT MARBLE Co
Priority date: 1974-11-01
Filing date: 1974-11-01
Publication date: 1975-10-21
Anticipated expiration: 1992-10-21

Abstract

A cup-shaped receptacle closure is formed from a blank of sheet material by placing the blank between relatively movable punch and die members, with the periphery of the blank gripped between the punch member and an annular draw ring carried by the die member. The closure is formed over a forming post assembly carried by the die member, and as formed has an annular wastage ring thereon in the gripped region of the blank. The forming post assembly is circumferentially spaced from the annular draw ring, and has cutter means thereon for subsequently cutting the annular wastage ring into pieces, which pieces are then removed through the annular space between the assembly and the draw ring.

Description

United States Patent Baker Oct. 21 1975 [54] METHOD AND APPARATUS FOR FORMING 3,372,569 3/1968 Bozek .r 1 13/120 HX A RECEPTACLE CLOSURE 3,855,862 12/1974 Moller 72/349 X [75] Inventor: Charles T. Baker, Rutland, Vt. Primary Examiner vict0r Dipalma [73] Assignee: Vermont Marble Company, Proctor, Attorney, 8 of FirmBaC0n & T o a Vt. 22 Filed: Nov. 1, 1974 [57] ABSTRACT A cup-shaped receptacle closure 1s formed from a PP 520,163 blank of sheet material by placing the blank between relatively movable punch and die members, with the 52 US. Cl. 72/349- 72/324 72/348- Periphery the blank gttPPed between the Pttheh 113/12O A member and an annular draw ring carried by the die 51 Int. (:1. B21D 22/00; B21D 22/21 member The eleeute is termed ever 3 forming Pest 581 Field of Search 72/347 348 349 324- aesemhly eettied by the the member, and as termed 1 13/120 6 E has an annular wastage ring thereon in the gripped region of the blank. The forming post assembly is cir- [56] References Cited cumferentially spaced from the annular draw ring, and has cutter means thereon for subsequently cutting the UNITED STATES PATENTS annular wastage ring into pieces, which pieces are l 8 then removed through the annular space between the e 2,312,749 3/1943 Bullockm 113/120 H assembly and the draw 2,321,085 6/1943 Hubbard 113/120 1-1 10 Claims, 6 Drawing Figures U.SQ Patent Oct. 21, 1975 SheetlofZ 3,913,372

\IFIIIIII METHOD AND APPARATUS FOR FORMING A RECEPTACLE CLOSURE BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to a method and apparatus for forming cup-shaped receptacle closures from sheet material, of the type generally shown in US. Pat. No. 3,303,955. More particularly, it relates to a method and apparatus including a unique concept for removing from the forming machine the annular wastage ring remaining on a newly formed closure, so

that the ring cannot interfere with the normal operation of the forming machine.

2. Description of the Prior Art Generally cup-shaped receptacle closures of the type to which the present invention relates are known in the art, and are normally formed by a machine including a punch member mounted for relative movement into a die member. A blank is placed between the two members, and is formed into a closure on a forming post assembly mounted within the die member. During the forming process the periphery of the blank is gripped to ensure proper material flow and avoid wrinkling, and at the end of the formation cycle an annular wastage ring remains on the closure where it was so gripped.

This annular wastage ring must be removed from the closure, and this is normally accomplished with a simple trim cutter mounted on either the die member or the punch member. The wastage ring is cut free, and is then expected to fall forwardly out of the machine when the punch member and the die member are separated. Usually, this will occur. However, it sometimes happens that the trimmed annular wastage ring does not fall free, but rather hangs up on either the die member or the punch member. Then, when the two members are next brought together, jamming of the machine occurs, sometimes accompanied by damage that can mean considerable machine down time to repair.

Obviously, it would be more desirable to effect positive and sure removal of the trimmed annular wastage ring in such a manner that jamming of the forming machine cannot occur. It is to a method and apparatus for accomplishing this that the present invention relates.

SUMMARY OF THE INVENTION According to the method and apparatus of the present invention, a blank is formed into a cup-shaped receptacle closure by a machine including a punch member and a die member, mounted for relative movement to bring the punch member into the die member. The die member has an open ended die cup thereon, within which an annular draw ring is slidably mounted. The draw ring is biased toward the open end of the die cup by a coil spring acting through push rods in the usual manner, and functions together with the front face of the punch member to grip the periphery of the blank when the punch member is initially relatively moved into the die member.

Mounted within the annular draw ring is a forming post assembly, which is circumferentially spaced from the draw ring so as to form an annular clearance or space therebetween. The rear end of this annular clearance is connected to a discharge opening on the die member. Carried on the forming post assembly, in addition to a mandrel for shaping the closure, is a first cutter means for cutting the annular wastage ring from the closure at the end of the forming process. When this occurs, the trimmed annular wastage ring is received on and thereafter is carried by the forming post assembly.

Also mounted on the forming post assembly rearwardly of the first cutter means are a plurality of circumferentially spaced, forwardly facing cutter knives. Relative movement of the punch member into the die member subsequently to trimming of the annular wastage ring from the closure, either during the same operating cycle or during a later cycle, depending on the position of the cutter knives, will cause the punch member-backed annular wastage ring to forcefully impinge on the cutter knives, resulting in the annular ring being cut into pieces. The cut pieces then fall through the annular clearance between the forming post assembly and the annular draw ring, and pass out through the discharge opening. They are thus removed in such a manner that they cannot interfere with the mating front faces of the punch member and the die member.

The present invention thus offers a novel method for forming a cup-shaped receptacle closure from a blank of sheet material, a method that differs from any known heretofore, and which includes the following steps: forming the blank into a cup-shaped closure on a forming part assembly by moving a punch member relatively into a die member having the assembly mounted therein, the periphery of the blank being gripped during such formation, and the closure thus formed having an annular wastage ring thereon where the periphery of the blank was gripped; trimming the annular wastage ring from the closure by further relative movement of the punch member into the die member, such further movement being sufficient to place the trimmed annular wastage ring on the forming plug assembly; subsequently cutting the annular ring into pieces for easy removal; and removing the cut pieces through an annular space provided about the forming plug assembly.

It is an object of the present invention to provide a method and apparatus for forming a cup-like receptacle cover from sheet material, whereby wastage material resulting from the formation process is removed and disposed of in such a manner as to ensure it cannot interfere with normal operations.

A further object is to provide a method and apparatus for effecting removal and disposal of an annular wastage ring from a closure formed within a forming machine, whereby the removed wastage ring cannot get between the confronting punch and die members of the machine and cause jamming.

Other objects and many of the attendant advantages of the present invention will become readily apparent from the following Description of the Preferred Embodiment, when taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary elevational view of the closure forming apparatus of the present invention;

FIG. 2 is an enlarged fragmentary vertical sectional view of the apparatus of FIG. 1, illustrating the finishing step of trimming the annular wastage ring from the completed cup-shaped receptacle closure;

FIG. 3 is a fragmentary, horizontal sectional view taken on the line 3-3 of FIG. 2, showing in particular the circumferentially spaced cutter knives for cutting the annular wastage ring into pieces;

view of the. finished receptacle closure and the trimmed annular wastage ring.

DESCRIPTION OF THE PREFERRED EMBODIMENT The method and apparatus of the present invention is directed toward the making of a cup-shaped receptacle enclosure from a blank of sheet material, such as is shown at 2 in FIG. 6 of the drawings, reference to which is made. The closure 2 is seen to include a bot tom wall 4 formed with a generally cylindrical side wall 6 connected thereto, the side wall 6 having an enlarged skirt 8 thereon.

In the normal process for forming the closure 2 a circular blank is gripped on its periphery, while the central portion of the blank is formed over the mandrel of a forming post assembly by the action of an encircling punch member element. This results in an annular wastage ring being formed in the region where the blank is peripherally gripped, and the thus-formed ring must be removed from the closure to complete the manufacture thereof. Referring again to FIG. 6, the wastage ring 10 is shown therein, after being trimmed from the closure 2.

Referring now to FIGS. 1-5, a machine for forming the closure 2 is indicated generally at 12, and includes a punch member 14 and a die member 16 arranged for .relative movement toward each other to engage the punch member 14 with the die member 16. Normally, the die member 16 .will be stationary, and the punch member 14 will be designed to be moved toward and I the punch cup having a cylindrical outer surface 24 and a cylindrical bore 26 therethro ugh that terminates at the outer end of the punch cup in a reduced diameter cylindrical collar 28. Press fitted within the cylindrical bore 26 and abutting against the collar 28 in an annular forming sleeve 30, and the end face of the punch cup is flat to form a gripping surface 32.

The die member 16 includes a frame plate 34 having a flanged die cup 36 secured thereto by bolts 38, the die cup 36 having a cylindrical bore 40 therethrough terminating at its other end in a reduced cylindrical collar 43. The cylindrical collar 42 has an interval diameter just slightly greater than the diameter of the punch cup 20, and the die cup 36 has a flat upper surface 44 thereon. The frame plate 34 has a cylindrical socket 46 therein of a like diameter to the cylindrical bore 40, and, which includes an annularend wall 48 disposed about a reduced diameter cylindrical bore 50. Slidingly received within thedie cup bore 40, the socket 46 and the reduced diameter bore 40 is an annular draw ring 52.

The annular draw ring 52 has a flat gripping surface 54 on its upper end, and has a cylindrical bore 56 that extends therethrough and which is enlarged at its lower end to form a socket 58 within which the upper end of a cylindrical skirt 60 is seated. The skirt 60 is of a size to Slidingly-fit within the reduced diameter bore 50, and functions to ensure that no exposed gap can be formed between the bottom face 62 of the draw ring 52 and the end wall 48. If desired, the skirt 60 can of course be formed integrally with the draw ring 52.

Secured to the lower face of the frame plate 38 by bolts 64 is a pressure pad 66 having a centrally mounted shaft 68 projecting therefrom, the outer end of the shaft 68 being threaded for reception of awasher 70 and nut 72. The upperface of the pressure pad 66 has an annular cut-out 74 therein surrounding a cylindrical mounting post 76, and adischarge opening 78 leads from the cut-out 74 to the exterior of the pad. Slidingly mounted on the shaft 68 is a cylindrical collar 80, and received on the shaft 68 between the collar 80 and the washer 70 is a coil spring 82.

The purpose for the coil spring 82 is to exert resilient pressure on the draw ring 52, to urge it toward the open outer end of the die cup 36. The frame plate 38 has a plurality of circumferentially spaced, axial bores 84 therethrough which open on the end wall 48, and which are in alignment with similar axial bores 86 in the pressure pad 66. Cylindrical push rods 88 are received in the

aligned bores

84 and 86, the lower ends thereof being engaged by the collar 80 and the upper ends thereof impinging on the bottom face 62 of the draw ring. The upper end of the draw ring 52 has a reduced diameter portion 90 that is receivable through the cylindrical collar 42, and which terminates in a stop shoulder 92. When the punch member 14 is withdrawn fromthe die member 16 so that the end face 32 of the punch cup 20 is above the top surface 44 6f the die cup 36, the gripping surface 54 6f the uraw ring 52 willlie flush with the surrounding upper end face 32.

Mounted within the die member 16 and carried by the mounting post 76 is a forming post assembly 94, comprising a cylindrical spacer 96 connected to the mounting post 76 by machine screws 98, a cylindrical cutter body l00 connected to the spacer 96 by machine screws 102, and a forming mandrel 104. The cutter body 100 has a cylindrical socket 106 formed in the upper end thereof, and the forming mandrel 104 has a reduced diameter portion 108 on the lower end thereof that is received in the socket 106, the forming mandrel being secured to the cutter body 100 by machine screws (not shown).

Referring now to FIG. 4, it is seen that the forming mandrel 104 has a diameter such that it will be telescopically received in the forming sleeve 30 of the punch member 14 with the closure 2 therebetween. A shoulder 110 extends between the main portion of the mandrel 104 and the reduced diameter portion 108 thereof, and a shallow, socket-like seat 112 is formed on the upper end of the cutter body 100 to confront the shoulder 110. Clamped between the seat 112 and the shoulder 110 is an annular trimming cutter member 1 14, designed to cooperate with the sharp outer corner 116 of the punch cup collar bore 28 to trim the annular wastage ring 10 from the closure 2 at the termination of the formation step for the closure 2.

The external diameters of the. forming post assembly components, that is, of the spacer 96, the cutter body 100 and the mandrel 104, are all substantially less than the inner diameter of the bore 56, the skirt 60 and the annular chamber 74, whereby a substantial annular space or channel 118 is present about the forming post assembly 94, the lower end of the annular channel 1 18 opening to the discharge opening 78. It is through this annular channel 118 and the discharge opening 78 that the annular wastage ring is removed, after it has been cut into pieces.

In use, the machine 2 of the invention functions as follows. Initially, the punch member 14 is separated from the die member, so that the end face 32 is spaced above the end face 44 of the die cup 36. A sheet of material is then fed into the die cup end face 44, and the punch member 14 is moved relatively toward the die member 16. The first thing to occur is impingement of the punch cup end face 32 on the sheet of stock material, resulting in a circular blank being punched from the sheet.

It will be appreciated that, instead, already formed circular blanks can simply be placed on the draw ring end face 54. Normally, however, a strip of stock material will be progressively fed across the surface 44.

The circular blank is clamped on its periphery between the punch cup end face 32 and the upper gripping face 54 of the annular draw ring 52 as the punch member 14 continues its relative movement into the die member 16, this continuous gripping action being assured by the coil spring 82. In the course of such relative movement the blank is engaged by the mandrel 104, and the mandrel 104 and the blank then move into the forming collar 30, continuing until the closure 2 is formed. The gripped periphery of the blank is progressively withdrawn from between the draw ring face 24 and the punch cup face'32 during formation of the closure 2, but nevertheless the remaining gripping action assures a smooth and even draw for the closure. At the end of the formation of the closure 2, the annular wastage ring 10 remains thereon.

As has been explained, upon further relative movement of the punch member 14 toward the die member 16, the annular trim cutter 114 is effective to sever or trim the annular ring 10 from the closure 2, whereupon it is placed upon and is carried by the forming post assembly 94.

In order to remove the annular wastage ring 10 from the machine 2 through the channel 118 and the discharge opening 78, it must first be cut into pieces. For this purpose, the cutter body 100 has formed thereon below or rearwardly of the trim cutter 114 a plurality of axially extending, circumferentially spaced ribs 120, each terminating at its upper end in a cutter knife edge 122. The cutter knives 122 are effective upon a final degree of relative movement of the punch member 14 toward the die member 16 to cut the annular wastage ring 10 into a plurality of small pieces, which can then easily fall through the annular channel 118 and out through the discharge opening 78.

Whether or not cutting of the annular wastage ring 10 into pieces occurs during the same closure-forming cycle or a later one depends on several factors, including the positioning of the cutter knives 122 and the thickness of the blank. In FIG. 4 it is assumed that a build-up of several annular wastage rings 10 will occur on the forming post assembly 94, before the bottommost one is actually out into pieces during an operating cycle. This arrangement tends to cushion the end face 32 of the punchcup 24 from damage by the cutter knives 122, thus prolonging the life thereof. However, if desired the cutter knives 122 can be arranged in FIG. 4 so that cutting of the annular wastage ring 10 will occur during the same operating cycle in which it is formed, as will be appreciated.

In any instance, it is seen that when using the method and apparatus of the invention the annular wastage ring 10 is removed from the rear of the die member 16, so that it never has an opportunity to interfere with the smooth mating operation of the punch member 14 with the die member 16. Usually, the machine 2 can be so positioned that the cut pieces of the annular wastage ring 10 can simply fall through the annular channel 118 and out through the discharge opening 78. However, if desired, it is to be understood that movement of the ring pieces can be assisted by moving air, or other similar means.

The machine 2 is also equipped with means to assure removal of the completed closure 2 from either the die member 16 or the punch member 14, depending upon which it might be carried by. Turning first to the punch member 14, the cylindrical bore 26 of the punch cup 20 contains a pusher head 124 comprising a base portion 126 and a reduced diameter nose portion 128 that is receivable in the forming collar 30. A push rod 130 is connected to the pusher head 124, and passes through a bore 132 in the frame plate 18. The push rod 130 is activated on the withdrawal stroke of the punch member 14, whereupon the nose portion 128 of the head 124 moves into the forming collar 30 and is effective to dislodge a closure 2 therefrom.

Similarly, the shaft 68 and the forming post assembly 94 has an axial bore 134 extending completely therethrough, and which terminates in a socket 136 in the upper end of the mandrel 104. Received in the socket 136 is a pusher head 138, and connected thereto is a push rod 140 that extends through the bore 134. Upon separation of the punch and die

members

14 and 16, the push rod 140 is activated to elevate the pusher head 138, whereby to lift a formed closure 2 from the mandrel 104.

Obviously, many modifications and variations of the present invention are possible.

I claim:

1. The method of forming a blank cut from a sheet of material into a cup-shaped receptacle closure, comprising the steps of:

applying draw forming means to said blank while the periphery thereof is gripped, whereby to form a generally cup-shaped closure having an annular wastage ring thereon where the periphery of said blank was gripped;

trimming said annular wastage ring from said closure at the end of said forming step; and

thereafter cutting said annular wastage ring into segments, and removing it from said draw forming means.

2. The method of forming a blank cut from a sheet of material into a cup-shaped receptacle closure utilizing draw forming means including a punch member, a die member for receiving said punch member, and a forming plug assembly mounted within said die member, comprising the steps of:

forming said blank into a cup-shaped closure by relatively moving said punch member into said die member while the blank is disposed therebetween, whereby said blank is formed over said forming plug assembly, the periphery of said blank being gripped between said punch member and said die member, and the closure thus formed having an annular wastage ring thereon where the periphery of said blank was gripped; i I

trimming said annular wastage ring from said cupshaped closure by further relatively moving said punch member into said die member, such further movement also being sufficient to place the trimmed annular wastage ring on said forming plug assembly; and

subsequently cutting said annular wastage ring into pieces for easy removal thereof while such is positioned on said forming plug assembly, by relative movement of said punch member into said die member to engage said annular ring with cutting teeth carried on said forming plug.

3. The method as recited in claim 2, wherein said forming plug assembly has an annular channel therearound leading to a discharge opening, said pieces of said annular wastage ring being removable through said annular channel and said discharge opening.

4. The method as recited in claim 2, wherein said draw forming means is designed for repeated opera- ,tion, said annular wastage rings building up on said forming plug assembly during repeated cycles of operation, and only the bottom-most annular wastage ring being cut into pieces during said last-mentioned step.

5. A machine for forming a blank cut from a sheet of material into a cup-shaped receptacle closure, said machine comprising: a punch member, including a punch cup open at its outer end; and a die member for receiving said punch member, said punch member and said die member being relatively movable toward each other to cause said punch member to enter said die member, and said die member including: a die cup open at its outer end, and adapted to receive said punch cup; an annular draw ring received within said die cup, and adapted to grip the periphery of said blank between it and said punch cup when said punch member is relatively moved into said die member; a forming post assembly mounted within said annular draw ring, said forming post assembly having a substantially smaller diameter than said annular draw ring'whereby an annular channel is formed therebetween, said annular channel communicating with a discharge opening;

first cutter means on said forming post assembly, said blank being formed into a cup-shaped receptacle closure on said forming post assembly during relative movement of said punch member into said die member, the thus formed closure having an annular wastage ring thereon in the region where the periphery thereof is gripped, said first cutter means being effective to trim said annular wastage ring from said formed closure during relative movement of said punch member into said die member whereupon the thus trimmed annular wastage ring is' received on said forming post assembly; and second cutter means behind said first cutter means, and subsequently effective upon relative movement of said punch member into said die member to cut said annular wastage ring into pieces for removal through said annular channel and said discharge opening.

6. A machine as recited in claim 5, wherein said second cutter means is carried by said forming post assembly.

7. A machine as recited in claim 5, wherein said second cutter means comprises a plurality of circumferentially spaced, forwardly facing cutter knives mounted on the periphery of said forming post assembly behind said first cutter means, and effective to cut said annular wastage ring into pieces when relative movement of said punch member toward said die member forcefully engages said annular wastage ring with said cutter knives.

8. A machine as recited in claim 5, wherein addition ally said punch member and said die member include means effective to cut said blank from a sheet of material disposed therebetween, upon initial relative movement of said punch member into said die member at the beginning of an operating cycle.

9. A machine as recited in claim 5, further including means carried by said punch member and by said die member effective upon conclusion of a forming cycle to eject the formed closure therefrom.

10. A machine as recited in claim 5, wherein said annular draw ring is slidingly mounted within said die member, and is resiliently biased toward said punch member.

Claims

1. The method of forming a blank cut from a sheet of material into a cup-shaped receptacle closure, comprising the steps of: applying draw forming means to said blank while the periphery thereof is gripped, whereby to form a generally cup-shaped closure having an annular wastage ring thereon where the periphery of said blank was gripped; trimming said annular wastage ring from said closure at the end of said forming step; and thereafter cutting said annular wastage ring into segments, and removing it from said draw forming means.

2. The method of forming a blank cut from a sheet of material into a cup-shaped receptacle closure utilizing draw forming means including a punch member, a die member for receiving said punch member, and a forming plug assembly mounted within said die member, comprising the steps of: forming said blank into a cup-shaped closure by relatively moving said punch member into said die member while the blank is disposed therebetween, whereby said blank is formed over said forming plug assembly, the periphery of said blank being gripped between said punch member and said die member, and the closure thus formed having an annular wastage ring thereon where the periphery of said blank was gripped; trimming said annular wastage ring from said cup-shaped closure by further relatively moving said punch member into said die member, such further movement also being sufficient to place the trimmed annular wastage ring on said forming plug assembly; and subsequently cutting said annular wastage ring into pieces for easy removal thereof while such is positioned on said forming plug assembly, by relative movement of said punch member into said die member to engage said annular ring with cutting teeth carried on said forming plug.

4. The method as recited in claim 2, wherein said draw forming means is designed for repeated operation, said annular wastage rings building up on said forming plug assembly during repeated cycles of operation, and only the bottom-most annular wastage ring being cut into pieces during said last-mentioned step.

5. A machine for forming a blank cut from a sheet of material into a cup-shaped receptacle closure, said machine comprising: a punch member, including a punch cup open at its outer end; and a die member for receiving said punch member, said punch member and said die member being relatively movable toward each other to cause said punch member to enter said die member, and said die member including: a die cup open at its outer end, and adapted to receive said punch cup; an annular draw ring received within said die cup, and adapted to grip the periphery of said blank between it and said punch cup when said punch member is relatively moved into said die member; a forming post assembly mounted within said annular draw ring, said forming post assembly having a substantially smaller diameter than said annular draw ring whereby an annular channel is formed therebetween, said annular channel communicating with a discharge opening; first cutter means on said forming post assembly, said blank being formed into a cup-shaped receptacle closure on said forming post assembly during relative movement of said punch member into said die member, the thus formed closure having an annular wastage ring thereon in the region where the periphery thereof is gripped, said first cutter means being effective to trim said annular wastage ring from said formed closure during relative movement of said punch member into said die member whereupon the thus trimmed annular wastage ring is received on said forming post assembly; and second cutter means behind said first cutter means, And subsequently effective upon relative movement of said punch member into said die member to cut said annular wastage ring into pieces for removal through said annular channel and said discharge opening.

8. A machine as recited in claim 5, wherein additionally said punch member and said die member include means effective to cut said blank from a sheet of material disposed therebetween, upon initial relative movement of said punch member into said die member at the beginning of an operating cycle.