Can bodymaker

Abstract

A can bodymaker, which includes a disc feed (1) for feeding a disc (5) directly to the bodymaker itself. A locator (9) positions the disc (5) centrally to a blankholder (12) and a draw pad (10) clamps the disc (5) against a draw die (11). The blankholder (12) then forms the disc into a cup (20) and clamps the cup against a redraw die (14) ready to be picked up by a punch and carried through dies for forming a can body.

Claims

1. A can bodymaker with a ram which carries a punch for forming a can from a cup, the can bodymaker comprising: a disc feed being adapted to feed a metal disc directly into a channel of the bodymaker, wherein the metal disc is unlubricated, the disc feed comprising: a vacuum feed for separating metal discs, and a flighted belt for pushing the discs along; a blankholder; a locator for positioning the disc centrally to the blankholder; and a draw pad for clamping the disc against a draw die, wherein the blankholder is adapted to move towards a redraw die and thus, together with the redraw die, form the disc into a cup and to clamp the cup against the redraw die thereby allowing the cup to be picked up by the punch on the ram and carried through the redraw die and at least one ironing die for forming a can body.

2. The can bodymaker according to claim 1, in which the disc feed comprises a feed plate with a spring loaded element that holds the disc against the locator.

3. The can bodymaker according to claim 1, in which the disc feed includes a positioning cam and a spring loaded cushion.

4. The can bodymaker according to claim 1, further comprising: two sets of rollers that grip and drive the disc to the locator.

5. The can bodymaker according to claim 4, in which one or more of the sets of rollers is off-center.

6. A method of forming a can body comprising: lifting an unlubricated flat disc off a feed plate by vacuum and pushing the disc along a flighted belt; spraying lubricant on both sides of the disc; pushing the disc into a can bodymaker; positioning the disc centrally to a blankholder; clamping the disc against a draw die; moving a blankholder towards a redraw die and thus, together with the draw die, form the disc into a cup; clamping the cup against the redraw die; picking up the cup on a punch on a ram; and ironing the cup by carrying the cup through at least one ironing die to form the cup into a can body.

7. The method according to claim 6, wherein the pushing step comprises moving the disc from the feed plate through rollers into the bodymaker.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) Preferred embodiments of the invention will now be described, by way of example only, with reference to the drawings, in which:

(2) FIG. 1 is a schematic side view of a disc feed which uses a feed plate and rollers;

(3) FIG. 2 is the disc feed of FIG. 1, showing the disc pushing back a pawl as it passes through the rollers;

(4) FIG. 3 shows the disc clamped by a draw pad;

(5) FIG. 4 shows the disc as a blankholder moves forward to form a cup;

(6) FIG. 5 is the embodiment of FIGS. 1 to 4, with an off-centre feed;

(7) FIG. 6 is the off-centre feed of FIG. 5 with spring-loaded cushion to prevent the disc from bouncing;

(8) FIG. 7 is the off-centre feed of FIGS. 5 and 6, showing mechanical positioning of the disc by a cam; and

(9) FIG. 8 is an alternative embodiment of the invention which uses vacuum feed and a flighted belt.

DESCRIPTION OF EMBODIMENTS

(10) The embodiment of FIGS. 1 to 7 uses a roller feed arrangement 1 and feed plate slide 2. The discs are stacked in a hopper 3, which is located above the infeed sitting on a dead plate. Down the centre of the dead plate is a slot with a short stroke slide. The slide would have a recess or spring-loaded finger or pawl, which would protrude the thickness of the disc 5.

(11) When the slide 2 moves forward it pushes the disc into the top set of rollers 6 which grip the disc 5 and drive it forward around the guide to the second set of rollers 7. The rollers 6, 7 move the disc 5 around a small curve and are easy to drive. The large rollers of the pairs are driven and dictate the disc speed. The small rollers are spring-loaded to supply the nip for gripping the disc. The small rollers maintain contact with the disc or drive roller to avoid skidding.

(12) In FIG. 2, the second set of rollers 7 grips the disc 5 and drives it downwards into a locator 9 (FIG. 3) which positions the disc centrally to a blank holder (FIG. 4). The spring loaded element 8 (e.g. pawl) at the top would be pushed back as the disc is fed through and then would spring back above the disc. This holds the disc down against the locator. In a first example, only the pawl 8 holds the disc in place once the disc is fed down the centre line.

(13) A hydraulic clamp or draw pad 10 is mounted in the support plate shown in FIG. 3 just below the bottom small roller 7′. When the disc is in position, the draw pad 10 clamps the disc 5 against the draw die 11. In FIG. 4, the blank holder 12 is moving forward as shown by the arrow to turn the disc into a cup 20. The blank holder 12 continues forward to clamp the cup against the redraw die 14. In the example of FIG. 4, the blank holder 12 is mounted on a hydraulic hold down mechanism such as is described in EP 1292405 B (CROWN PACKAGING TECHNOLOGY, INC.).

(14) Alternatively, the blank holder could be mounted on a cam-driven mechanism.

(15) The actions of FIGS. 1 to 4 all occur while the ram 33 (which carries the punch 34) on the bodymaker is returning to the back of its stroke. The cup 20 is ironed by carrying the cup through at least one ironing die 35 thereby forming the cup into a can body. FIGS. 5 to 7 demonstrate additional features, which may be necessary for positive location if the disc is travelling quickly and if the pawl 8 is a little slow in reacting. If this happens, the disc 5 might bounce out of position.

(16) In FIG. 5, the disc 5 is fed off-centre by the rollers 7 in order to avoid the draw pad hitting spring-loaded cushion 15. The cushion clamp 16 prevents the disc 5 from bouncing (FIG. 6) while the cam 17 rotates as indicated by the arrow in FIG. 7 in order to position the disc correctly for cup formation.