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 bodymarker comprising: a ram which carries a punch for forming a can from a cup using a forward stroke of the ram; a disc feed which is adapted to feed a flat metal disc along a feed axis directly into the bodymaker, the bodymaker defining a channel that extends through the bodymaker along a body axis, the body axis being perpendicular to the feed axis, the disc feed being aligned with the bodymaker such that a center of the channel positioned on the body axis is offset from the feed axis, wherein when the disc is fed directly into the bodymaker a center of the disc is off-set from the center of the channel; a blankholder; a locator for positioning the disc centrally to the blankholder; a draw pad for clamping the disc against a draw die; and at least one ironing die, wherein the blankholder is adapted to move towards a redraw die and thus, together with the draw die, form the disc into a cup and 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 the at least one ironing die for forming a can body.

2. A can bodymaker comprising: a ram which carries a punch for forming a can from a cup using a forward stroke of the ram; a disc feed which is adapted to feed a metal disc along a feed axis directly into the bodymaker, the bodymaker defining a channel that extends through the bodymaker along a body axis, the body axis being perpendicular to the feed axis, the disc feed being aligned with the bodymaker such that a center of the channel positioned on the body axis is offset from the feed axis, wherein when the disc is fed into the bodymaker a center of the disc is off-set from the center of the channel; a blankholder; a locator for positioning the disc centrally to the blankholder; a draw pad for clamping the disc against a draw die; at least one ironing die; and two sets of rollers that grip and drive the disc to the locator, wherein the blankholder is adapted to move towards a redraw die and thus, together with the draw die, form the disc into a cup and 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 the at least one ironing die for forming a can body.

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

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

5. The bodymaker according to claim 2, in which one or more of the sets of rollers is off-centre.

6. The bodymaker according to claim 3, wherein the spring loaded element is a pawl.

7. The bodymaker according to claim 4, wherein the positioning cam is adapted to rotate and contact the metal disc to align the center of the metal disc with the center of the channel of the bodymaker.

8. A method of forming a can body comprising: feeding a flat disc along a feed axis directly into a can bodymaker, the bodymaker defining a channel that extends through the bodymaker along a body axis, the body axis being perpendicular to the feed axis, wherein a center of the channel positioned on the body axis is offset from the feed axis, and wherein the disc is fed into the bodymaker such that a center of the disc is off-set from the center of the channel; positioning the disc centrally to a blankholder; clamping the disc against a draw die; moving the 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; ironing the cup by carrying the cup through at least one ironing die to form the cup into a can body.

9. The method according to claim 8, in which the feeding step comprises moving the disc from a 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

DESCRIPTION OF EMBODIMENTS

(9) 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.

(10) 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.

(11) 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 pawl 8 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.

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

(13) 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 die 32 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.

(14) 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.