High speed necking configuration

#The present technology relates to a multi-stage can necking machine. More particularly, the present technology relates to a horizontal multi-stage can necking machine configured for high speed operations.

#Metal beverage cans are designed and manufactured to withstand high internal pressure—typically 90 or 100 psi. Can bodies are commonly formed from a metal blank that is first drawn into a cup. The bottom of the cup is formed into a dome and a standing ring, and the sides of the cup are ironed to a desired can wall thickness and height. After the can is filled, a can end is placed onto the open can end and affixed with a seaming process.

#It has been conventional practice to reduce the diameter at the top of the can to reduce the weight of the can end in a process referred to as necking. Cans may be necked in a “spin necking” process in which cans are rotated with rollers that reduce the diameter of the neck. Most cans are necked in a “die necking” process in which cans are longitudinally pushed into dies to gently reduce the neck diameter over several stages. For example, reducing the diameter of a can neck from a conventional body diameter of 2 11/16th inches to 2 6/16th inches (that is, from a 211 to a 206 size) often requires multiple stages, often 14.

#FIG. 1 is a perspective view depicting a multi-stage can necking machine;

#FIG. 2 is a perspective view depicting a necking station and gear mounted on a main turret shaft of the multi-stage necking machine shown in FIG. 1, with surrounding and supporting parts removed for clarity;

#FIG. 3 is a perspective view depicting a transfer starwheel and gear mounted on a starwheel shaft of the multi-stage necking machine shown in FIG. 1, with surrounding and supporting parts removed for clarity;

#A preferred configuration for driving a multi-stage can necking machine is provided. The multi-stage can necking machine incorporates technology that overcomes the many shortcomings of known multi-stage can necking machines. The present invention is not limited to the disclosed configuration, but rather encompasses use of the technology disclosed, in any manufacturing application according to the language of the claims.

#As shown in FIG. 1, a multi-stage can necking machine 10 may include several necking stages 14. Each necking stage 14 includes a necking station 18 and a transfer starwheel 22. Each one of the necking stations 18 is adapted to incrementally reduce the diameter of an open end of a can body, and the transfer starwheels 22 are adapted to transfer the can body between adjacent necking stations 18, and optionally at the inlet and outlet of necking machine 10. Conventional multi-stage can necking machines, in general, include an input station and a waxer station at an inlet of the necking stages, and optionally include a bottom reforming station, a flanging station, and a light testing station positioned at an outlet of the necking stages. Accordingly, multi-stage can necking machine 10, may include in addition to necking stages 14, other operation stages such as an input station, a bottom reforming station, a flanging station, and a light testing station of the type that are found in conventional multi-stage can necking machines (not shown). The term “operation stage” or “operation station” and its derivative is used herein to encompass the necking station 14, bottom reforming station, a flanging station, and a light testing station, and the like. Preferably, multi-stage can necking machine 10 is operative to neck and move at least 2800 cans per minute, more preferably at least 3200 cans per minute, and even more preferably at least 3400 cans per minute.

#FIG. 2 is a detailed view depicting operative parts of one of the necking stations 18. As shown, each necking station 18 includes a main turret 26, a set of pusher rams 30, and a set of dies 34. The main turret 26, the pusher rams 30, and the dies 34 are each mounted on a main turret shaft 38. As shown, the main turret 26 has a plurality of pockets 42 formed therein. Each pocket 42 has a pusher ram 30 on one side of the pocket 42 and a corresponding die 34 on the other side of the pocket 42. In operation, each pocket 42 is adapted to receive a can body and securely holds the can body in place by mechanical means, such as by the action pusher ram and the punch and die assembly, and compressed air, as is understood in the art. During the necking operation, the open end of the can body is brought into contact with the die 34 by the pusher ram 30 as the pocket 42 on main turret 26 carries the can body through an arc along a top portion of the necking station 18.