Method And Apparatus For Forming A Fully Curled Neck On A Drawn And Ironed Pressure Can

Abstract

A method and apparatus for forming a conical shoulder and a fully curled neck on an end of a preformed metal cup wherein external and internal mating die assemblies are provided at a first station which operate to reform the end panel of said cup into a conical shoulder and a top flat central panel formed integral with said shoulder, draw said top central panel into an upstanding cylindrical throat, having a first predetermined height, and a top flat center panel formed integral with said throat, remove a centrally-located, circular portion of said top flat center panel to leave a top annular rim formed integral with said upstanding cylindrical throat, and draw said cylindrical throat having said integrally-formed top annular rim into an open-ended upstanding cylindrical throat having a second predetermined height which is greater than said first predetermined height, and wherein, at a second station, a mating internal support mandrel and a mating external sleeve member support said conical shoulder of said reformed end panel and align said open-ended upstanding cylindrical throat, integrally-formed with said shoulder, with an external curling groove surface, having a toroidal profile, on an external curling member, said mating internal support mandrel and mating external sleeve member being displaceable relative to said external curling member to force said open-ended throat in contact with said groove surface along the toroidal path defined by said surface to form an outwardly-extending, fully curled neck on said conical shoulder.

Description

BACKGROUND OF THE INVENTION

The present invention broadly relates to a method and apparatus for reforming the end panel of a preformed metal cup and more particularly is concerned with forming a conical shoulder and a fully curled neck on an integrally-formed end of a preformed metal cup, for instance, a fully curled neck on the integral top end of a drawn and ironed, two-piece pressure can, in a minimum number of forming operations.

One method and apparatus for forming a short open tubular neck or throat on the integral top end of a drawn and ironed, two-piece pressure can, involving a minimum number of operations, is disclosed in U.S. Pat. No. 3,191,422.

However, no satisfactory method and apparatus, involving a limited number of operations, has been heretofore originated to secure enough metal into an upstanding throat feature on the integrally-formed end of a drawn and ironed, two-piece pressure can to reform the throat into a fully curled neck on the can end. In other words, the art has been unable to come up with a method and apparatus for obtaining sufficient throat height from which to form the fully curled neck. Consequently, drawn and ironed, two-piece pressure cans have heretofore been made with special non-standard hemmed necks rather than with fully curled necks which meet current industry standards. The provision of a non-standard hemmed neck on the integral top end of a drawn and ironed pressure can has the disadvantage of not permitting the interchanging of industry standard size can closure parts used on a conventional, three-piece pressure can, nor the use of conventional filling and closing equipment used in conjunction with a conventional three-piece pressure can, without making appropriate adjustments thereto.

Furthermore, certain prior art methods and apparatus used, for example, in the fabrication of drawn pressure cans, are unsatisfactory in that they require from eight to 12 stations and operations, such as illustrated by U.S. Pat. Nos. 2,359,775 and 2,384,810, since the provision of sufficient neck height by these methods and apparatus involve simultaneously elongating and reducing the diameter of the neck until the desired height is achieved.

In contrast to the above, the present invention has the advantage of providing an industry standard, fully curled neck on the integral top end of a drawn and ironed cup by using only two stations and five operations.

SUMMARY OF THE INVENTION

The present invention provides a method and apparatus for forming a conical shoulder and a fully curled neck on an integrally-formed end of a preformed metal cup in four operations at a first station, wherein said operations are performed sequentially and continuously along a linear path of travel in one direction, and one operation at a second station. The four operations performed at the first station comprise, first, reforming the end panel of the preformed cup into a conical shoulder and a top flat central panel formed integral with said shoulder, second, drawing said top central panel into an upstanding cylindrical throat, having a first predetermined height, and a top flat center panel formed integral with said throat, third, removing a centrally-located, circular portion of said top flat center panel to leave a top annular rim formed integral with said cylindrical throat, and, fourth, drawing said cylindrical throat having said integrally-formed top annular rim into an open-ended upstanding cylindrical throat having a second predetermined height which is greater than said first predetermined height. The single operation performed at the second station comprises moving the top of said open-ended cylindrical throat outwardly along a toroidal path to form an outwardly-extending, fully curled neck on said conical shoulder.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a fragmentary side elevational view of the integrally-formed end of the preformed cup;

FIG. 2 is a fragmentary side elevational view partially in section of the integrally-formed end of the cup after the first operation performed at the first station;

FIG. 3 is a fragmentary side elevational view partially in section of the integrally-formed end of the cup after the second operation performed at the first station;

FIG. 4 is a fragmentary side elevational view partially in section of the integrally-formed end of the cup after the third operation performed at the first station;

FIG. 5 is a fragmentary side elevational view partially in section of the integrally-formed end of the cup after the fourth operation performed at the first station;

FIG. 6 is a fragmentary side elevational view partially in section of the integrally-formed end of the cup after the single operation performed at the second station;

FIG. 7 is a side elevational view partially in section of mating external and internal die assemblies, positioned at the first station, showing the preformed cup of FIG. 1 partially mounted on said internal die assembly;

FIG. 8 is a side elevational view partially in section of said mating external and internal die assemblies immediately before the first operation;

FIG. 9 is a side elevational view partially in section of said mating external and internal die assemblies immediately after the first operation and before the second operation with the cup being in the form shown in FIG. 2;

FIG. 10 is a side elevational view partially in section of said mating external and internal die assemblies showing the relative positions of the several components of said mating external and internal die assemblies immediately after the second operation and before the third operation with the cup being in the form shown in FIG. 3;

FIG. 11 is a side elevational view partially in section of said mating external and internal die assemblies showing the relative positions of the several components of said mating external and internal die assemblies immediately after the third operation and before the fourth operation with the cup being in the form shown in FIG. 4;

FIG. 12 is a side elevational view partially in section of said mating external and internal die assemblies showing the relative positions of the several components of said mating external and internal die assemblies immediately after the fourth operation with the cup being in the form shown in FIG. 5;

FIG. 13 is a side elevational view partially in section of the internal support mandrel and the external sleeve and curling members, positioned at the second station, showing the cup of FIG. 5 mounted on said internal support mandrel;

FIG. 14 is a side elevational view partially in section of said internal support mandrel and said external sleeve and curling members showing their relative positions immediately before the single operation to be performed at said second station; and

FIG. 15 is a side elevational view partially in section of said internal support mandrel and said external sleeve and curling members showing their relative positions immediately after the single operation performed at said second station with the cup being in the form shown in FIG. 6.

DESCRIPTION OF THE PREFERRED EMBODIMENT

As a preferred and exemplary embodiment of the instant invention, the drawings disclose a two-station method and apparatus for producing on the integral end of a preformed metal cup, generally designated A, for example, a drawn and ironed metal cup, a conical shoulder B and a fully curled neck C (FIG. 6), by the performance of five operations at said two stations (FIGS. 9 through 12 and 15).

In accordance with the two-station method of the instant invention, at the first station, generally designated 10 (FIGS. 9 through 12), the preformed end panel, generally designated D, of the cup A, for example, an end D having a flat panel E and a bevelled edge F integrally formed therewith and with the can sidewall G (FIG. 1), is reformed into a conical shoulder B and a top flat central panel H formed integral with said shoulder B (FIG. 2), in the first operation (FIG. 9). In the second operation (FIG. 10), the top flat central panel H is drawn into an upstanding cylindrical throat I, having a first predetermined height, and a top flat center panel J formed integral with said upstanding throat I (FIG. 3). In the third operation (FIG. 11), a centrally-located, circular portion K of the top flat center panel J is removed to leave a top annular rim L formed integral with the upstanding cylindrical throat I (FIG. 4). In the fourth and final operation (FIG. 12) at the first station 10, the upstanding cylindrical throat I having the integrally-formed top annular rim L is drawn into an open-ended upstanding cylindrical throat I' (FIG. 5) having a second predetermined height which is greater than the first predetermined height of the throat I, the drawing action wiping out the top annular rim L. At the second station, generally designated 12 (FIGS. 13 through 15), in a single operation (FIG. 15), the top M of the open-ended upstanding cylindrical throat I' is moved outwardly along a toroidal path to form an outwardly-extending, fully curled neck C on the conical shoulder B of the metal cup A (FIG. 6).

In accordance with the apparatus of the instant invention, at the first station 10 is positioned a mating external die assembly, generally designated 14, and a mating internal die assembly, generally designated 16, said die assemblies 14, 16 being axially aligned and relatively moveable toward and away from each other into and out of a mated position (FIG. 9), and, also, when mated, said die assemblies 14, 16 are movable in a direction parallel to the direction of their axial alignment.

The mating internal die assembly 16 includes a reforming die component 18, a throat drawing die component 20 positioned within a bore 22 defined in said reforming die component 18 and displaceable relative to said reforming die component 18, and a male piercing punch component 24 positioned within a bore 26 defined in said throat drawing die component 20 and displaceable relative to both said reforming die component 18 and said throat drawing die component 20.

The mating external die assembly 14 includes a reforming die component 28 and a female cut-edge die component 30 positioned within a bore 32 defined in said reforming die component 28 and displaceable relative to said reforming die component 28. The female cut-edge die component 30 has a bore 34 defined therein for receiving the internal male piercing punch component 24 during the third operation of removing the centrally-located, circular portion K of the top flat center panel J (FIG. 11).

The external reforming die component 28 is axially aligned with the internal reforming die component 18, the external female cut-edge die component 30 is axially aligned with the internal throat drawing die component 20, and the bore 34 defined in the external female cut-edge die component 30 is axially aligned with the internal male piercing punch component 24 such that all the respective components of the external and internal die assemblies 14, 16 are aligned along a common axis.

The external die assembly 14 may be slideably mounted on suitable guide means (not shown) and moved by hydraulic fluid pressure or any other suitable means (not shown). Likewise, the internal die assembly 16 may be slideably mounted on suitable guide means (not shown) and moved by hydraulic fluid pressure or any other suitable means (not shown). Alternatively, either one of the external and internal die assemblies 14, 16 may be stationarily positioned and only the other of said assemblies 14, 16 slideably mounted and moveable relative to the one of said assemblies 14, 16.

In the preferred form of the instant invention, at the first station 10, the internal and external die assemblies 16, 14 are displaced from one another far enough apart to allow for the infeed of the preformed cup A by any suitable feeding mechanism (not shown), such as a rotary, multipocketed turret, between the die assemblies 16, 14. Then the internal die assembly 16 is initially moved toward the external die assembly 14 to mount the preformed cup A on the internal die assembly 16 and bring the preformed end panel D between and immediately adjacent the mating surfaces of the external and internal die assemblies 14, 16 (FIGS. 7 and 8), the external die assembly 14 having a concavely-conical mating surface profile and the internal die assembly 16 having a convexly-conical mating surface profile. As the internal die assembly 16 continues to advance toward the external die assembly 14 from their relative positions shown in FIG. 8 to that shown in FIG. 9, the assemblies 16, 14 press the end panel D of the cup A therebetween, thereby reforming the end panel D into a conical shoulder B and a top flat central panel H formed integral with said shoulder B (FIGS. 2 and 9). After this first operation is completed, the internal reforming die component 18 and the external reforming die component 28 now clamp the conical shoulder B therebetween and maintain their clamping position throughout the remaining three operations to be performed at the first station 10.

By the application of increasing force to the internal die assembly 16, for example, by the application of greater hydraulic fluid pressure, the internal throat drawing die component 20, which is yieldably mounted within the internal reforming die component 18 by any suitable means, such as a spring 36, is displaced relative to the external and internal reforming die components 28, 18 from its relative position shown in FIG. 9 to that shown in FIG. 10, and exposed to the top central panel H, thereby drawing the top central panel H into an upstanding cylindrical throat I, having a first predetermined height, and a top flat center panel J formed integral with said throat I (FIGS. 3 and 10). After this second operation is completed, the internal throat drawing die component 20 and the external female cut-edge die component 30 now clamp the periphery of the top flat center panel J therebetween and maintain their clamping position throughout the remaining two operations to be performed at the first station 10.

In the third operation, by the application of further increasing force to the internal die assembly 16, the internal male piercing punch component 24 is displaced relative to the external and internal reforming die components 28, 18 and internal throat drawing die and external female cut-edge die components 20, 30 from its relative position shown in FIG. 10 to that shown in FIG. 11, and is inserted into the bore 34 defined by the cut-edge 38 of the external female die component 30, thereby, in cooperation with the cut-edge 38, perforating and removing the centrally-located, circular portion K of the top flat center panel J and leaving the top annular rim L formed integral with the upstanding cylindrical throat I (FIGS. 4 and 11).

In the fourth operation, by the application of still further increasing force to the internal die assembly 16, the external female cut-edge die component 30, which is yieldably mounted within the external reforming die component 28 by any suitable means (not shown), is displaced, by the further movement of the internal throat drawing die component 20 against said female component 30, relative to the external and internal reforming die components 28, 18 from its relative position shown in FIG. 11 to that shown in FIG. 12, whereby the upstanding cylindrical throat I is, in effect, pulled past the internal throat drawing die component 20 and drawn into an open-ended upstanding cylindrical throat I', having a second predetermined height which is greater than the first predetermined height of the throat I (FIGS. 5 and 12). The pulling action thus wipes out the top annular rim L. Also, simultaneously with the above, the internal male piercing punch component 24 is displaced relative to the internal throat drawing die component 20 and the external female cut-edge die component 30 from its relative position shown in FIG. 11 to that shown in FIG. 12, and ejects the circular panel portion K from the bore 34.

After the completion of this fourth operation at the first station 10 (FIG. 12), the external and internal die assemblies 14, 16 retract to their initial positions and the cup A is removed by any suitable stripping mechanism (not shown) and transferred by any suitable means (not shown) to the second station 12.

In the preferred embodiment set forth above, the respective components of the internal die assembly 16 have been described as moving toward the respective components of the external die assembly 14 during the performance of the four operations at the first station 10. However, it must be understood that the respective components of the external die assembly 14 could, instead, be moved by the application of any suitable force toward the respective components of the internal die assembly 16, wherein in such movement the order of relative displacement between the respective components of the internal die assembly 16 during the performance of the four operations at the first station 10 would be the same as that described above. Furthermore, the external and internal die assemblies 14, 16 may be modified such that the internal throat drawing die and the internal male piercing punch components 20, 24 replace the external female cut-edge die component 30 in the external die assembly 14 and the external female cut-edge die component 30 replaces the internal throat drawing die and the internal male piercing punch components 20, 24 in the internal die assembly 16.

In the preferred embodiment, at the second station 12, an internal mating support mandrel 40 is axially aligned with, and movable toward and away from, an external curling assembly, generally designated 42 (FIG. 13). The mandrel 40 may be slideably mounted on suitable guide means (not shown) and moved by hydraulic fluid pressure or any other suitable mechanism (not shown). The external curling assembly 42 includes an external mating sleeve member 44 slideably mounted on a stationary base member 46 and moveable relative to said base member 46, said sleeve member being further yieldably mounted on said base member 46 by means of a resilient spring 48. An external curling member 50 in the curling assembly 42 is secured to the stationary base member 46 by means of a shoulder screw 52 and disposed within a bore 54 defined in the sleeve member 44. The curling member 50 has an external curling groove surface 56 defined therein having a toroidal surface profile and a central bore 58 defined therein, wherein shoulder screw 52 fixes the curling member 50 to the base member 46.

The internal support mandrel 40 has a convexly-conical mating support surface profile for supporting the conical shoulder B of the reformed cup A when said cup A is infed to the second station 12 by any suitable feeding mechanism (not shown). The external sleeve member 44 has a concavely-conical mating surface profile, so that when the reformed cup A is positioned on the internal support mandrel 40 and the support mandrel 40 is moved to a position immediately adjacent the sleeve member 44 (FIG. 14), a peripheral portion of the conical shoulder B is clamped between the mandrel 40 and the sleeve member 44. Simultaneously with the above-described clamping action, a locating pin 60, disposed in a central recess 62 defined in the internal support mandrel 40, inserts into the central bore 58 of the curling member 50 to insure proper alignment between the internal support mandrel 40 and the sleeve member 44. Also, concurrently with the above, the top M of the open-ended, upstanding throat I' is moved into contact with the curling groove surface 56 of the curling member 50.

By the continuing forward movement of the internal support mandrel 40 which retracts the external sleeve member 44 from their relative positions shown in FIG. 14 to that shown in FIG. 15, the open-ended, upstanding throat I' is forced outwardly in contact with the groove surface 56 along the toroidal path defined by said surface 56 to form an outwardly-extending, fully curled neck C on the conical shoulder B of the cup A.

After the completion of this single operation at the second station 12 (FIG. 15), the internal support mandrel 40 retracts to its initial position and the cup A is removed by any suitable stripping mechanism (not shown).

In the preferred embodiment set forth above, the internal support mandrel 40 has been described as moving toward the external curling assembly 42 during the performance of the single (and fifth) operation at the second station 12. However, it must be understood that the external curling assembly 42 could, instead, be moved by the application of any suitable force, toward the internal support mandrel 40 which would be stationarily positioned.

It is thought that the invention and many of its attendant advantages will be understood from the foregoing description and it will be apparent that various changes may be made in the form, construction and arrangement of the parts and that changes may be made in the steps of the method described and their order of accomplishment without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the form hereinbefore described being merely a preferred or exemplary embodiment thereof.

Claims

We claim.

1. A two-station method of forming a conical shoulder and a fully curled neck on an end of a preformed cup, comprising:

the steps performed at the first station including

reforming the end panel of said cup into a conical shoulder and a top flat central panel formed integral with said shoulder,

drawing said top central panel into an upstanding cylindrical throat, having a first predetermined height, and a top flat center panel formed integral with said throat,

removing a centrally located, circular portion of said top flat center panel to leave a top annular rim formed integral with said upstanding cylindrical throat, and

drawing said cylindrical throat having said integrally-formed top annular rim into an open-ended upstanding cylindrical throat having a second predetermined height which is greater than said first predetermined height; and

the steps performed at the second station including

moving the top of said open-ended upstanding cylindrical throat along a toroidal path to form a fully curled neck on said conical shoulder,

said moving step is achieved by

supporting said conical shoulder of said reformed end panel on an internal support mandrel, said mandrel having a convexly-conical support surface profile,

clamping said conical shoulder of said reformed end panel between said mandrel surface and an external sleeve member, said member having a concavely-conical mating surface profile, to align said open-ended cylindrical throat, integrally-formed with said shoulder, with an external curling groove surface having a toroidal profile of an external curling member, and

forcing said open-ended throat in contact with said groove surface along the toroidal path defined by said surface.

2. A two-station method of forming a conical shoulder and a fully curled neck on an end of a preformed cup, according to claim 1, wherein at said first station

said reforming step is achieved by pressing the end panel of said preformed cup between mating external and internal die assemblies, said external die assembly having a concavely-conical mating surface profile and said internal die assembly having a convexly-conical mating surface profile,

said first drawing step is achieved by exposing an internal throat drawing die component of said internal die assembly, to said top central panel of said reformed end,

said removing step is achieved by perforating said circular portion of said top center panel with an internal male piercing punch component of said internal die assembly in cooperation with a cut-edge defined on an external female die component of said external die assembly, and

said second drawing step is achieved by pulling said cylindrical throat having said internally formed top annular rim past said internal throat drawing die component, which action wipes out said top annular rim.

3. A two-station method of forming a conical shoulder and a fully curled neck on an end of a preformed cup, according to claim 1, wherein at said first station

said reforming step is achieved by pressing the end panel of said preformed cup between mating external and internal die assemblies, said external die assembly having a concavely-conical mating surface profile and said internal die assembly having a convexly-conical mating surface profile,

said first drawing step is achieved by exposing an internal female die component of said internal die assembly, to said top central panel of said reformed end,

said removing step is achieved by perforating said circular portion of said top center panel with an external male piercing punch component of said external die assembly in cooperation with a cut-edge defined on the internal female die component of said internal die assembly, and

said second drawing step is achieved by pulling said cylindrical throat having said integrally-formed top annular rim past said internal female die component, which action wipes out said top annular rim.

4. A two-station method of forming a conical shoulder and a fully curled neck on an end of a preformed cup, according to claim 1, wherein said steps performed at the first station are performed sequentially and continuously along a linear path of travel in one direction.

5. A two-station method of forming a conical shoulder and a fully curled neck on an end of a preformed cup, according to claim 2, wherein said steps performed at the first station are performed sequentially and continuously along a linear path of travel in one direction.

6. A two-station method of forming a conical shoulder and a fully curled neck on an end of a preformed cup, according to claim 3, wherein said steps performed at the first station are performed sequentially and continuously along a linear path of travel in one direction.

7. Apparatus positioned at two stations for forming a conical shoulder and a fully curled neck on an end of a preformed cup, comprising:

the apparatus positioned at the first station including

means for reforming the end panel of said cup into a conical shoulder and a top flat central panel formed integral with said shoulder,

means for drawing said top central panel into an upstanding cylindrical throat, having a first predetermined height, and a top flat center panel formed integral with said throat,

means for removing a centrally located, circular portion of said top flat center panel to leave a top annular rim formed integral with said cylindrical throat, and

means for drawing said cylindrical throat having said integrally formed top annular rim into an open-ended upstanding cylindrical throat having a second predetermined height which is greater than said first predetermined height; and

the apparatus positioned at the second station including

means for moving the top of said open-ended upstanding cylindrical throat along a toroidal path to form a fully curled neck on said conical shoulder, said moving means comprises:

a mating internal support mandrel and a mating external sleeve member for supporting and clamping said conical shoulder of said reformed end panel therebetween, said internal support mandrel having a convexly-conical mating surface profile and said external sleeve member having a concavely-conical mating surface profile; and

an external curling member including an external curling groove surface having a toroidal surface profile, said internal support mandrel positioned relative to said external curling member to align said open-ended cylindrical throat with said curling groove surface and one of said external curling member and internal support mandrel displaceable relative to the other to force said open-ended throat in contact with said groove surface along the toroidal path defined by said surface.

8. Apparatus positioned at two stations for forming a conical shoulder and a fully curled neck on an end of a preformed cup, according to claim 7, wherein at said first station,

said reforming means comprises mating external and internal die assemblies for pressing the end panel of said preformed cup therebetween, said external die assembly having a concavely-conical mating surface profile and said internal die assembly having a convexly-conical mating surface profile,

said first drawing means comprises an internal throat drawing die component of said internal die assembly, which is displaceable relative to mating external and internal reforming die components of said respective external and internal die assemblies,

said removing means comprises an internal male piercing punch component of said internal die assembly, which is displaceable relative to said mating external and internal reforming die components and said internal throat drawing die component and insertable into an external female cut-edge die component of said external die assembly, and

said second drawing means comprises said internal throat drawing die component, which is further displaceable relative to said mating external and internal reforming die components.

9. Apparatus positioned at two stations for forming a conical shoulder and a fully curled neck on an end of a preformed cup, according to claim 7, wherein at said first station,

said reforming means comprises mating external and internal die assemblies for pressing the end panel of said preformed cup therebetween, said external die assembly having a concavely-conical mating surface profile and said internal die assembly having a convexly-conical mating surface profile,

said first drawing means comprises an internal female die component of said internal die assembly, which is displaceable relative to mating external and internal reforming die components of said respective external and internal die assemblies,

said removing means comprises an external male piercing punch component of said external die assembly, which is displaceable relative to said mating external and internal reforming die components and said internal female die component and insertable into said internal female die component to cooperate with a cut-edge defined on the internal female die component, and

said second drawing means comprises said internal female die component, which is further displaceable relative to said mating external and internal reforming die components and said external male piercing punch component.

10. Apparatus positioned at two stations for forming a conical shoulder and a fully curled neck on an end of a preformed cup, according to claim 7, wherein the component means of said apparatus positioned at the first station operate sequentially and continuously along a linear path of travel in one direction.

11. Apparatus positioned at two stations for forming a conical shoulder and a fully curled neck on an end of a preformed cup, according to claim 8, wherein the component means of said apparatus positioned at the first station operate sequentially and continuously along a linear path of travel in one direction.

12. Apparatus positioned at two stations for forming a conical shoulder and a fully curled neck on an end of a preformed cup, according to claim 9, wherein the component means of said apparatus positioned at the first station operate sequentially and continuously along a linear path of travel in one direction.