US3402591A

US3402591A - Apparatus for making drawn and ironed cans or containers

Info

Publication number: US3402591A
Application number: US407194A
Authority: US
Inventors: Edward G Maeder
Original assignee: Reynolds Metals Co
Current assignee: Reynolds Metals Co
Priority date: 1964-10-28
Filing date: 1964-10-28
Publication date: 1968-09-24
Anticipated expiration: 1985-09-24

Description

Sept. 24, 1968 E. G. MAEDER APPARATUS FOR MAKING DRAWN AND IRONED CANS OR CONTAINERS Filed Oct. 28; 1964 2 Sheets-Sheet l INVENTOR. MAEDER EDWARD G.

IIIIII HIS ATTORNEYS United States Patent Ofice 3,402,591 APPARATUS FOR MAKING DRAWN AND IRONED CANS OR CONTAINERS Edward G. Maeder, Chesterfield County, Va., assignor to Reynolds Metals Company, Richmond, Va., a corporation of Delaware Filed Oct. 28, 1964, Ser. No. 407,194 Claims. (Cl. 72345) ABSTRACT OF THE DISCLOSURE The disclosed apparatus comprises a reciprocating punch head, a set of die rings around the punch head for drawing the sidewall of the can body, and stripping means for removing the can body at the end of the drawing operation. The punch head is relieved adjacent the open end of the can body for the purpose of trickening the sidewall of the can body adjacent its open end.

This invention concerns a drawn and ironed container or closed end can having a thickened flange or open end.

An improved apparatus and method are provided by this invention for producing such a container.

An advantage of this invention is that the can, container or tube with a thickened open end is efliciently stripped off a punch head over which said container is drawn as the punch head relatively moves through a die.

This invention is particularly useful when used in connection with containers having extremely thin main walls, and particularly when such containers are formed from hard aluminum alloys.

Other advantages are apparent from this description and/or the accompanying drawings, in which:

FIGURE 1 is a top diagrammatic view of an apparatus for practicing this invention.

FIGURE 2 is a side view of FIGURE 1.

FIGURE 3 is an enlarged cross section of a portion of FIGURE 2 and showing a drawn container and press parts in the final stage of the forward stroke.

FIGURE 4 is an enlarged cross section similar to FIG- URE 3 and showing an initial stripping action of the internal stripper.

FIGURE 5 is a cross section somewhat similar to a portion of FIGURE 4, and showing a complete with drawal of the punch head from the tube after the internal stripper has performed an initial stripping action as shown in FIGURE 4.

FIGURE 6 is a cross section somewhat similar to a portion of FIGURE 4, and showing the use of compressed fluid to complete the stripping action after the initial stripping action of FIGURE 4.

FIGURE 7 is a diagrammatic illustration of the selective stripper activating and deactivating means.

Certain words are used in this application which describe direction, relative position, etc. Such words are used for the sake of brevity and clearness. They describe directions, relative positions, etc., as shown in the drawings. However, it is to be understood that the actual devices may have different directions and relative positions and still come within the scope of the invention. Examples of such words are: vertical, horizontal, upper, lower, rightward, leftward, etc.

According to this invention an apparatus and method are provided in which a closed ended and open ended tube 32 is formed over a punch head 22 which is relatively movable through a die assembly 20. A thickened portion 38 is produced adjacent the open end 44 of the container. Such thickened portion is obtained by providing a reduced diameter portion 28 on the punch head 22 at a distance from the leading end 24 of the punch head cor- Patented Sept. 24, 1968 responding to the desired length of the relatively thin wall 36 of the container being formed.

An advantage to be gained by such thickened portion is that a container and the like may be die flanged without cracking the flange area.

Another advantage is that somewhat harder alloys of aluminum can be used by providing the thickened end portion. Hard aluminum alloys may be used, such as Nos. 3004-H32 or 3004H36 as well as 5052-H32 or 5052- H36 and 5086-H32 or 5086-H36.

The invention may be used to produce thin wall containers or cans. It has been discovered that these thin wall containers present a problem of stripping them off a punch head 22 which has an undercut portion 28 without injuring the thin wall. For example, the problem becomes acute where extremely thin walls are used, such as from .0067 to .008 inch in thickness for the thin wall with a thicker edge which is two or three thousandths of an inch thicker.

This invention provides an internal stripper 40 within the punch head 22 that is mechanically relatively movable with respect to the punch head. Such stripper 40 may push the bottom or closed end 34 of the tube off the punch head, or the bottom or closed end of the container may be held in place by the stripper while the punch head is withdrawn partly or entirely from the container.

Tht internal stripper may be used by itself or in combination with compressed fluid means 46 such as compressed air means.

The internal stripper may work just enough to pull the reinforced or thicker portion 38 of the container 32 out of the recess 28 in the punch. There-after, the container may be removed by compressed fluid means 46 within the punch head 22. Alternatively, the internal stripper 40 may produce the entire relative stripping action from the punch head and, if desired, the container may be removed from the internal stripper by additional means such as the compressed fluid means 46.

The following advantages are to be noted:

(a) A thickened or reinforced flange 39 is obtained which provides a stronger product since the bending strength of the flange area is very critical.

(b) Alloys of aluminum can be worked and can be flanged without splitting, principally because there is less cold working of the metal. Ordinarily, according to previous practice, there is as much as cold working of the 'wall portion of a container, which em'brittles the metal, and forming an outwardly extending flange with a die normally causes cracking of such a brittle container or can. There is less working of a thickened flange area 39 because it has not been previously cold worked down to final thickness of the main wall 36. Therefore, the metal has more ductility in the flange area, permitting die flanging without cracking.

(c) The length of the wall becomes irregular in the drawing operations and there is danger of tearing off a portion of the end of the container as it becomes very thin. By having a thickened portion 38 in the final drawing operation, the pulling or tearing force on the irregular edge of the can is not so great when that edge passes the die; therefore, the danger of tearing off a portion of the edge is minimized. That is, the metal is pushed into the recess 28 rather than stretched or drawn thinner so that there are fewer rejects with the thickened end cans. Without the reinforced or thicker flange area 38, the wall on cans having an unequal height would be pulled off or fractured. If a can would tear of, some of its scrap would probably remain in the die assembly and on the next cycle when another container is being drawn, the scrap would interfere and cause further breakages. This invention permits greater tolerance in the alignment of the dies. Pure aluminum and aluminum alloy No. 3003 can also be used, but since these are low strength metals, they do not provide all the benefits inherent in the strong-- er alloys.

For example, a die 20 may be provided through which a punch head 22 is relatively movable forward and backward through the die 20. The punch head may have a container closed end forming means or end rim 24, a container relatively thin wall forming means or cylindraceous surface 26 and a container relatively thick wall forming means or bead forming recess 28.

When this punch head 22 is moved relatively forward through the die 20, it acts upon a blank 30, such as a relatively thick cup-shaped blank 30 as shown in FIG- URES 1 and 2, and forms a cylindraceous container 32 over the punch head 22 with a closed end 34, a container relatively thin wall body 36 and a container relatively thick wall 38. The thin wall 36 is formed over the thin wall body forming means 26, and the thick wall forming means 28.

An internal stripper 40 is relatively reciprocable within the punch head 22 and has a stripper end 42, which may be enlarged or conical, and which is held relatively stationary while the punch head is relatively moving backward, such as to position 22A of FIGURE 4.

The relatively thick wall 38 may form an open end 44 for the container 32.

If desired, a compressed fluid means or passage 46 may be provided to produce a stripping action on the container 32, as illustrated in FIGURE 6. The compressed fluid may be compressed air if desired, and such compressed fluid may be made effective to complete the stripping action both from the punch head 22 and from the internal stripper 40, after the internal stripper has performed an initial stripping action. This initial stripping action may be sufficient to move the inward relatively thick wall or bead 38 out of the recess 28.

If desired, means (elsewhere more fully described) may be provided to hold the internal stripper 40 relatively stationary, as in the position shown in FIGURE 4, while punch head 22 is partially removed from the container as in FIGURE 4, and then both the punch head 22 and the internal stripper 40 may be-simultaneously and completely removed from the container 32.

If desired, the internal stripper 40 may be held relatively stationary, as in the position shown in FIGURE 4, while the punch head 22 is completely removed from the tube, as shown in FIGURE 5.

Means may be provided relatively to remove the internal stripper from the container 32 and such means may take the form of the compressed fluid means 46, which may be used to blow the container 32 off the internal stripper 40 as indicated in FIGURE 6.

As shown in FIGURE 6, the internal stripper 40 may be held relatively stationary while the punch head 22 is partially removed from the container 32 to perform an initial stripping action, and then compressed fluid may 'be used to remove the container from the punch head 22 and from the stripper 40.

The punch head 22 has a head or thick wall forming recess 28, which is spaced from the front end 24 of the punch head a suflicient distance to provide the desired length of thin wall 36. The forward movement of the punch head 22 with the internal stripper 40, through the die 20 forms a closed end and open end container 32 around the punch head with an inward bead or annular relatively thick wall 38 around the punch head. The internal stripper 40 may have an enlarged end 42 which is a container closedend holding means to hold the stripper end relatively stationary in engagement with the closed end 34 of the container while relatively moving the punch head 22 backward, as shown in FIGURE 4, to strip the inward bead or thick wall 38 from the recess 28.

Means are provided first partially relatively to move the punch head 22 backward out of the container 32 while said container 32 and the stripper 40 are held relatively stationary by said container closed end holding means. Such means are diagrammatically illustrated in FIGURES I4, and are elsewhere more fully described.

Any suitable mechanism may be used for producing the relative movements between the punch head 22 and the internal stripper 40 to produce the various movements described in connection with this invention.

One such mechanism is illustrated in FIGURES 1 to 4. For example, a power rocked lever 52, of proper throw, may be connected to a link 54 by pin 56 and may oscillate the pin 58 which drives the slidable carriage 60 to which the punch 62 is connected as by a chuck-like member 64. The punch 62 may be fixedly connected to the punch head 22 by any suitable construction. The throw of the rod 52 is such that the punch 22 is reciprocated the correct distance to provide the proper length of travel of the punch head 22 through the die 20. The distance may be such as to have the punch head 22 fully retracted, as in FIGURE 1, and to be fully moved rightwardly, as in FIGURE 3.

The internal stripper 40 may be carried by a tube 63 within the punch 62 and relatively reciprocable therein. The left end of the tube 63 may be threaded into another tube 66, which is connected to a frame 68 which is slidable on the bars 70 which are carried in fixed relationship to the frame 60. The

tubes

63 and 66 may be connected to a suitable supply of compressed fluid, such as compressed air, not shown, by means of a flexible tube 72 under the control of any valving mechanism, which, if desired, may be made automatically to release the compressed fluid at the proper time, as desired. A continuous passageway is provided from the flexible tube 72 to the passageway 46, and exhaust opening 47 in the internal stripper 40.

If desired, a blank holder 74 may be carried by a frame 76 which is fixedly secured at 134 on the bars 80. One or more pneumatic cylinders 82 may be provided with pistons and piston shafts 83 to actuate the frame 76 and drive the blank holder 74 to the position 74A of FIG- URES 1 and 2, to hold the thick cup-like blank 30 in place to receive the punch head as it passes into the die 20. The cylinders '82 may be actuated at the proper time to hold the blank 30, as the blank 30 may be automatically fed into position by any suitable feeder 84, FIGURE 3.

The main punch frame 60 may slide on a suitable supporting structure, not shown, which may be grooved if desired to produce a guided straight stroke.

The front end flanges 128 of the punch frame 60 actuate the bars to force a leftward movement on the bars 80 on the return stroke of the frame 60 and to release the bars 80 on the forward stroke of frame 60. The bar heads 131 provide the pulling action on the leftward stroke.

The bars 80 are guided in

brackets

132 and 133 which are supported on a stationary part of the mechanism. The lugs 134 form a part of the

frame

135 and 76 and are fixedly connected to the bars 80. The bar heads 131 are engaged by the flanges 128 of the punch frame 60 and force to move leftward the

frame

134, 135, 76 and 74 assembly against the pressure of the pistons and piston shafts 83 in the stationary cylinders 82. The slidable members 134, movable bars 135, and plate 76 and the blank holder 74 may form a guide and support for the front punch head 22 while the punch is moved to its rightward positions.

The slidable frame 68 may be so actuated as to produce the relative movements desired between the punch head 22 and the internal stripper 40. For example, on the rightward or forward stroke, the internal stripper 40 follows the punch head 22, because of the cone-shaped engagement at 86, FIGURE 3.

On the return stroke, the internal stripper 40 may be held temporarily stationary by an'extension which is fixed on the frame 68 and engages the end construction 92 of a pair of levers which are fulcrumed on the stationary bar 96, which is supported by a stationary part of the machine. The end construction 92 arrests the member 90 and the frame 68 because the levers 94 are upwardly biased by the compression spring 98, which acts on a rigid member 99 which connects the levers 94, so that the end construction 92 snaps behind the member 90, as the rightward end of the stroke is reached substantially as shown in FIGURE 3.

On the return stroke, the end construction 92 holds the frame 68 and the internal stripper 40 in substantially their most rightward position, while the punch head 22 is being withdrawn leftwardly by the leftward movement of the frame 60, while the bars 70' of the frame 60 slide through the frame 68. As a result, the internal stripper 40 remains in the position shown in FIGURES 3 and 4, while the punch head 22 is moved from the position of FIGURE 3, to the position 22A of FIGURE 4. Therefore, an initial stripping action is performed by the partial withdrawal of the punch head 22 to force the thick wall 38 outwardly to the position of FIGURE 4 because of the slanting edge 100 of the recess 28.

As the position of FIGURE 4 is reached, a bar 102, which may be cylindrical and which is carried by the frame 60, engages wedge constructions 104 on the levers 94 and forces the levers down to disengage the member 90 as is about to take place in FIGURE 4, where the dotted line release position of the levers 94 is shown at 94A. The release of the frame 68 permits the compression spring 88 to push the tube 66 and frame 68 leftward from the position in FIGURE 4 and to pull with them the tube 64 and the internal stripper 40. Therefore, both the punch head 22 and the internal stripper 40 may thereafter be pulled leftwardly together and simultaneously to the leftmost position of the stroke.

On the other hand, the positions of the cam construction 104 and of the bars 102 may be varied, so that the internal stripper 40 may be held in its rightmost position for a longer period of time, and so the punch head 22 may be withdrawn to the position of FIGURE 5, for example, before the internal stripper 40 is released by the action of the wedge 104 and bar 102.

The internal stripper 40 and the punch head 22 may be rendered rotationally keyed and longitudinally relatively movable by the key construction 140.

While a specific mechanism has been disclosed for producing the required relative movement between the various parts of the punch construction, other mechanisms may be used to provide these motions, as is obvious.

The die assembly 20 may have within it more than one ring die similar to ring die 50. A plurality of progressively smaller internal diameter ring dies may be provided within the die assembly 20 progressively to draw the container to relatively thinner wall constructions, as the punch pulls the tube construction past such plurality of ring dies, not shown. It is therefore to be understood that by the time the container has been pulled through the final ring die 50, the thin wall 36 may be extremely thin, and may correspond to the thin dimensions given elsewhere.

Thus, it is to be seen that a new and useful tube or container, and apparatus and method of producing the same have been provided.

Means 95 are provided selectively to cause the punch head 22 and the internal stripper 40 to travel in unison throughout the rightward, or inward, stroke and also throughout the leftward, or outward, stroke, or selectively to cause the punch head 22 and internal stripper 40 to travel relatively to each other, as previously described, to produce the stripping action shown in FIGURES 4-6.

Sometimes it may be desired to operate the punch head 22 and the internal stripper 40 in unison, in the relationship shown at 22 and 24 in FIGURE 3, throughout the rightward and leftward strokes. This may be desired, for example, when cans are to be formed, wherein the cans 6 do not require the stripping action of the stripper head 42 and stripper end 42, as shown in FIGURES 4-6.

The means 95 may include a cam 95A which allows the bars 94 to move up and down as previously described when the cam 95A is in full line position. Such cam 95A may be rotated a sufficient amount to hold the bars 94 in a sufficiently low position so that the stripper operating bar 102 cannot strike the bar ends 92 during the reciprocation of the punch operating frame 60.

The cam 95A may be held in axially fixed position and rotatably actuated by a shaft 95B (shown in perspective), which shaft may be rotated by its crank handle 95C from the full line position of handle 95C to its dotted line position 95D. The shaft 95B may be held axially fixed but rotationally free by the fixed bearing 97.

When the handle 95C is rotated to dotted line position 95D, the cam 95A is also rotated about the fixed axis of shaft 95B and presses down the bracket 95E which is fixed to the bars 94. The bracket 95E pulls down the bars 94 and holds them so the ends 92 of the bars 92 cannot arrest the extension of the stripper actuating frame 68.

The crank handle 95C may rest on the stationary stop 97A in either of its

positions

95C or 95E.

Therefore, when the handle 95C is selectively placed in the full line, or right-hand position 95C, the stripper 40 and its end 42 are effective to strip the cans off the punch head 22. However, when the crank handle is placed in its dotted line position 95, the stripper 40 remains in its retracted position of FIGURE 3 throughout the rightward and leftward strokes. The stripper is deactivated when not needed in order to prevent wear and tear on the mechanism.

Phrases such as relatively movable, relatively stationary, relatively reciprocable, as used in the specification and claims, are intended to apply to die formations, punch head formations, internal stripper formations in which any of such formations may be stationary while other of said formations move, and vice versa, in order to accomplish the desired stripping action, drawing action, etc. Also, these phrases are intended to apply to any of such formations in which differential speed of travel of any such formations relatively to other of such formations, and vice versa, may be used in order to accomplish the desired stripping action, drawing action, etc.

It is also to be noted that the pneumatic stripping system, including

pipes

66, 63 and air discharge means 46 may be used to strip cans off the punch head 22 without using the mechanical stripping action illustrated in FIG- URES 46. That is, the stripper 40 may be mechanically deactivated by the use of the means 95, but the pneumatic stripping action of air dischargemeans 46 may be used at that time, if desired. However, if desired, the pneumatic stripping action may also be deactivated at the same time that the mechanical stripping action is deactivated. These selections are usable at the option of the operator, and can be varied to suit the nature of the cans being formed. A master controller valve, not shown, may be placed in the feed line 72 to select whether the pneumatic stripping system is to be activated or deactivated. Such master controller valve may be manually closed when it is desired to deactivate the pneumatic system, and may be opened when it is desired to activate the pneumatic system.

While the form of the invention now preferred has been disclosed, as required by statute, other forms may be used, all coming within the scope of the claims which follow.

What is claimed is:

1. An apparatus for forming a seamless, thin-walled metal can body from a workpiece, the can body having an integral closed end and an opposite open end adapted to be flanged and seamed to a closure, the apparatus comprising:

(a)an annular die assembl of drawing and ironing dies; (b) an elongated cylindrically-shaped punch mounted for reciprocal movement and arranged to cooperate with the die assembly to draw and iron a workpiece into a can body having a thin sidewall, an integral closed end, and an opposite open end;

(c) the punch having a relatively large diameter portion along most of its length that supports the workpiece sidewall and cooperates with the dies in thinning and elongating the sidewall as the punch moves through the dies;

(d) the punch also having a recessed portion of smaller diameter adjacent the open end of the workpiece so that a portion of the sidewall adjacent the open end of the workpiece is not as severely thinned as the remainder of the sidewall and retains a greater thickness to improve its capability of later being flanged and seamed to a closure;

(e) fluid-pressure stripping means for stripping the workpiece from the punch comprising a passageway for directing fluid under pressure into the interior of the workpiece, the fluid exerting suflicient force against the inside of the closed end of the workpiece to strip the workpiece from the punch;

(f) internal mechanical stripping means also for stripping the workpiece from the punch comprising an internal stripping member having reciprocal longitudinal movement within the punch and stripper arresting means for arresting movement of the stripping member when the punch begins its backward stroke, whereby the stripping member engages the inside of the closed end of the workpiece to strip the workpiece from the punch; and

(g) stripping member deactivating means for deactivating the internal mechanical stripping means throughout the punch cycle of operation, the stripping member deactivating means being operable to selectively deactivate the internal stripping member,

so that the fluid-pressure stripping means can operate as the sole stripping means to'strip theworkpiece from'the punch.

2. The invention as defined in claim 1, which also includes fluid-pressure deactivating means for selectively deactivating the fluid-pressure stripping means, throughout the punch cycle of operation, so that the internal stripping member can operate as the sole stripping means to strip the workpiece from the punch. 1

' 3. The invention as defined in claim 1, in which the stripper arresting means arrests movement of the stripping member through a suflicient distance of the backward stroke of the punch to strip the relatively thick open end of the workpiece from the recessed portion of the punch.

4. The invention as defined in claim 1, in which the stripper arresting means arrests movement of the stripping member through a suflicient distance of the backward stroke of the punch to strip the'entire workpiece free of the punch.

5. The invention as defined in claim 1, in which the fluid of the fluid-pressure stripping means is a gas under pressure.

References Cited UNITED STATES PATENTS 398,229 2/1889 Chambers 72345 1,295,430 2/1919 Carlson 72345 1,492,230 4/ 1924 Towne 113120 1,944,527 1/ 1934 Pfaendler 72 -347 2,347,272 4/ 1944 Longfield 72345 2,979,188 4/1961 Duflield 72347 3,232,260 2/ 1966 Siemonsen 1137 3,270,544 9/1966 Maeder et a1. 72346 3,314,274 4/ 1967 Langewis 72349 RICHARD J. HERBST, Primary Examiner.