Apparatus for rotating a container body

An apparatus for rotating a container body that utilizes frictional forces rather than the engagement of gears to rotate the container body is provided. Such an apparatus may include a stationary housing and a turret rotating on a shaft proximate to the housing. The turret may have a plurality of pockets and a roller assembly disposed within each pocket. Each roller assembly may have a body portion and a drive roller portion. Each body portion may have a contact portion for contacting a container body received in a respective pocket. Each drive roller may be in contact with the housing such that as the turret rotates, friction between the drive rollers and the housing causes each roller assembly to rotate.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is related by subject matter to the inventions disclosed in the following commonly assigned applications, each of which is filed on even date herewith: U.S. patent application Ser. No. 12/108,950 entitled “Adjustable Transfer Assembly For Container Manufacturing Process”, U.S. patent application Ser. No. 12/109,058 entitled “Distributed Drives For A Multi-Stage Can Necking Machine”, U.S. patent application Ser. No. 12/108,926 and entitled “Container Manufacturing Process Having Front-End Winder Assembly”, U.S. patent application Ser. No. 12/109,131 and entitled “Systems And Methods For Monitoring And Controlling A Can Necking Process” and U.S. patent application Ser. No. 12/109,176 entitled “High Speed Necking Configuration.” The disclosure of each application is incorporated by reference herein in its entirety.

FIELD OF THE TECHNOLOGY

The present technology relates to apparatuses for manufacturing containers. More particularly, the present technology relates to apparatuses for rotating container bodies as the containers are being manufactured.

BACKGROUND

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 the 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 11/16thinches to 2 6/16thinches (that is, from a 211 to a 206 size) often requires multiple stages, often 14.

Each of the necking stages typically includes a main turret shaft that carries a starwheel for holding the can bodies, a die assembly that includes the tooling for reducing the diameter of the open end of the can, and a pusher ram to push the can into the die tooling. Each necking stage also typically includes a transfer starwheel to transfer cans between turret starwheels. Often, a waxer station is positioned at the inlet of the necking stages, and a bottom reforming station, a flanging station and a light testing station are positioned at the outlet of the necking stages.

The waxer station is positioned at the inlet of the necking stages and coats an open end of can bodies with a lubricant to prepare the can bodies for necking. Typical waxer stations include a starwheel mounted on a rotating shaft and having a plurality of pockets (for example 12 pockets is common) formed therein. Each pocket is adapted to receive a can body from an input chute as the starwheel rotates. Each pocket typically includes two can rollers that rotate the can bodies as the starwheel rotates. Thus, the can bodies rotate within each pocket as the starwheel rotates. Such rotation allows the entire open end of each can body to be lubricated as the can bodies pass a lubricating station.

To rotate the can bodies, each can roller includes a gear that meshes with gear teeth extending from a housing positioned proximate to the starwheel. As the starwheel rotates, the gears of the can rollers engage the gear teeth of the housing thereby causing the can rollers to rotate.

During the waxing process, debris may be lodged between the gear teeth of the can rollers and housing. As a result, the gear teeth may fracture, thus requiring an operator to either change the gears of every can roller or change the housing. Such tasks are time consuming and may be costly to the manufacturer.

SUMMARY

An apparatus for rotating a container body that utilizes frictional forces rather than the engagement of gears to rotate the container body is provided. Such an apparatus may be a waxer assembly used in a multi-stage can necking machine.

For example, such an apparatus may include a housing, a turret mounted on a rotating shaft, and a lubricating station. The housing may be mounted on shaft or concentric to the shaft, and may have a peripheral surface. The turret may include a peripheral pocket formed therein. The pocket may be adapted to receive a container body and may include a roller assembly. The roller assembly may include a body portion and a drive roller extending from the body portion. A contact portion of the body portion may be positioned within the pocket such that the contact portion may be adapted to contact an outer surface of the can body that is received in the pocket. The driver roller that extends from the body portion may be in contact with the peripheral surface of the housing such that as the turret rotates, friction between the drive roller and the peripheral surface of the housing causes the roller assembly to rotate. A lubricating station may also be positioned proximate to the turret and may lubricate an open end of the can body as the turret rotates about the shaft.

In some embodiments, the peripheral surface of the housing may include an O-ring and the drive roller may be in contact with the O-ring such that as the waxer turret rotates, friction between the drive roller and the O-ring causes the can roller to rotate. In a preferred embodiment, the O-ring is made of rubber and is removeably attached to the peripheral surface of the housing. For example, the peripheral surface of the housing may include a groove formed between a first wall extending from a body of the housing and a second wall extending from the body of the housing, and the O-ring may be removeably secured within the groove.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

A preferred structure for rotating a container body is described herein. An embodiment of a waxer for a multi-stage can necking machine that employs this technology is also described. The present invention is not limited to the disclosed configuration of waxer or can necking machine, but rather encompasses use of the technology disclosed in any container manufacturing application according to the language of the claims.

As shown inFIGS. 1 and 2, a multi-stage can necking machine10may include several necking stages14. Each necking stage14includes a necking station18and a transfer starwheel22. The necking stations18are adapted to incrementally reduce the diameter of an open end of a can body24, and the transfer starwheels22are adapted to transfer the can body24between adjacent necking stations18.

Each necking station18includes a turret having a plurality of pockets formed therein. Each pocket is adapted to receive the can body24and securely holds the can body24in place by mechanical means and compressed air, as is understood in the art. Using techniques well known in the art of can making, an open end of the can body24is brought into contact with a die by a pusher ram as the turret carries the can body24through an arc along a top portion of the necking station18. The inside of a typical die is typically designed, in longitudinal cross section, to have a lower (that is, outboard) cylindrical surface with a nominal dimension capable of receiving the can body24, a curved transition zone, and a reduced diameter upper cylindrical surface above the transition zone. During the necking operation, the can body24is moved into the die such that the open end of the can body24is placed into touching contact with the transition zone of the die. As the can body24is moved further upward into the die, the upper region of the can body is forced past the transition zone into a snug position between the inner reduced diameter surface of the die and a form control member or sleeve located at the lower portion of the punch. The diameter of the upper region of the can is thereby given a reduced dimension by the die. A curvature is formed in the can wall corresponding to the surface configuration of the transition zone of the die. The can is then pushed out of the die.

As shown inFIG. 2, after the diameter of the end of the can body24has been reduced by a first necking station18athe turret deposits the can body24into a pocket26of the transfer starwheel22. The pocket26is adapted to receive the can body24and retains the can body24using a vacuum force. The transfer starwheel22then carries the can body24through an arc on the lower portion of starwheel22, and deposits the can body24into one of the pockets of the turret of an adjacent necking station18b. The necking station18bfurther reduces the diameter of the end of the can body24in a manner substantially identical to that noted above.

The can body24may be passed through any number of necking stations18depending on the desired diameter of the open end of the can body24. For example, multi-stage can necking machine10shown in the figures includes eight stages14, and each stage incrementally reduces the diameter of the open end of the can body24as described above.

As shown inFIG. 3, the multi-stage can necking machine10may include several motors32to drive the starwheels and turrets of each necking stage14. As shown, there may be one motor32per every four necking stages14.

Each motor32is coupled to and drives a first gear36by way of a gear box40. The motor driven gear36then drives an adjacent second gear44which in turn drives a third gear48and so on. As shown, motor32adrives the gears of four necking stages14and motor32bdrives the gears of the remaining four necking stages14. The gears of the turrets and transfer starwheels are engaged in a continuous gear train.

Conventional multi-stage can necking machines, in general, include an input station and a waxer station at an inlet of the necking stages, and 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 machine10, may include in addition to necking stages14, an input station, a bottom reforming station, a flanging station, and a light testing station. The input station, bottom reforming station, flanging station, and light testing stations (not shown in the figures) may be conventional. Machine10may also include a waxer assembly50.

Shown inFIGS. 4-7is an example waxer assembly50that may be coupled to an inlet of a multi-stage can necking machine. As shown, the waxer assembly50includes an input station54and a waxer station58adjacent to and in communication with the input station54.

The input station54includes an input starwheel62mounted on a rotating shaft66and an input chute68. As shown, the input starwheel62includes a plurality of pockets72formed therein, each pocket72being adapted for receiving a can body. As the input starwheel62rotates, each pocket72receives a can body from the input chute68. The input starwheel62then rotates and delivers the can body to the waxer station58. The input station54preferably delivers up to 3400 cans per minute to the waxer station58.

As shown inFIG. 4, the waxer station58includes a housing70mounted on or concentric to a rotating shaft74, a turret78mounted on the shaft74, and a lubricating station82mounted proximate to the turret78. The waxer station58lubricates an open end of a can body84in preparation for the necking stages to follow.

As shown inFIG. 5, the housing70includes a housing body86and a peripheral surface88. As shown, the housing body86may be fastened to the shaft74such that housing70remains stationary as the turret78and the shaft74rotate. The peripheral surface88of the housing70preferably includes an O-ring90. The O-ring90may be made from a variety of materials. For example, the O-ring90may be made of rubber or other conventional O-ring material, and preferably is resilient. The O-ring may be circular in transverse cross section, however, is not limited to such a shape.

As shown inFIG. 5, the turret78is mounted on the shaft74proximate to the housing70. The turret78includes a plurality of curved surfaces91that define pockets92formed therein, wherein each pocket92is adapted to receive a can body from the input starwheel62of the input station54. The can bodies are retained in each pocket92using a vacuum force from a central vacuum source. The connection of the vacuum source to pockets92may be as generally described in co-pending application Ser. No. 12/108,926, filed concurrently herewith) or may be by conventional means, as will be understood by persons familiar with can necking and waxer equipment and processes. As the turret78rotates, the can bodies are carried through an arc and delivered to a turret of a first necking stage at the end of the arc. While the can bodies are carried through the arc, the open ends of the can bodies are lubricated by the lubricating station82.

As shown inFIGS. 5 and 6, each pocket92includes two roller assemblies94rotateably mounted therein. Each roller assembly94includes a body portion96and a drive roller98extending from the body portion96. Each body portion96has a contact portion102that protrudes through surface91of a respective pocket92. The contact portions102are adapted to contact the surface of a can body. Because each pocket92preferably includes two roller assemblies94, each can body will have a surface that is in contact with a contact portion102of two separate roller assemblies94. As the turret78rotates, each roller assembly94will rotate within its respective pocket92. Therefore, as the roller assemblies94rotate within their pockets92, frictional forces between the roller contact portions102and the surface of the can bodies retained in the pockets92will enable the can bodies to rotate within each pocket92as the turret78rotates.

The roller assemblies94are driven using frictional contact between the drive rollers98and the housing70. As shown, each drive roller98extends from a respective body portion96and protrudes from a side surface110of the turret78. Each drive roller98has a surface114that is in contact with the peripheral surface88of the housing70. In the embodiment shown, the surface114of each drive roller98is in contact with the O-ring90of the peripheral surface88. The contact between the drive rollers98and the O-ring90should be strong enough to create a frictional force between the drive rollers98and the O-ring90such that as the turret78rotates, the drive rollers98, and thus the roller assemblies94, rotate within each pocket92. Accordingly, this frictional force enables O-ring90transmits torque sufficient to drive the components.

Referring back toFIG. 4, the lubricating station82may be positioned proximate to the turret78and may include a lubricant housing120. As shown, the lubricating station82is preferably positioned below the turret78and the lubricant housing120is spaced apart from the turret78a distance to allow the can body to pass therebetween. The lubricant housing120preferably includes a lubricant for coating the open end of the can body as the can body passes by the lubricant housing120. Example lubricants may include wax, oil or any other suitable lubricant. Accordingly, as the turret78rotates, the roller assemblies94rotate the can bodies within the turret pocket92, and as the can body passes through the lubricant housing120, the lubricant will be applied to the entire open end of the rotating can body.

In a preferred embodiment, the waxer station may be designed for cost effective maintenance. For example, the O-ring and the drive rollers may be easily replaced.FIG. 7is a cross-sectional view of an example waxer station having a replaceable O-ring and replaceable drive rollers. As shown, a waxer station210includes a turret214mounted on a rotating shaft218and a housing222mounted proximate to the turret214. The turret214includes pockets (not shown) formed therein and roller assemblies226rotateably mounted within the pockets. Each roller assembly226has a body portion230and a drive roller234extending from the body portion230. As shown, each drive roller234may be releaseably attached to a respective body portion230by a fastener238. Therefore, if the drive rollers234are damaged, the fastener238may be removed and the drive rollers234can be replaced.

As shown, the housing222may be mounted on the shaft218proximate to the turret214. The housing222includes a stationary housing body242and a peripheral surface246. The peripheral surface246preferably includes an O-ring250positioned in a groove254formed between an inner wall258and an outer wall262. Both the inner wall258and the outer wall262extend up from the housing body242. As shown, the drive rollers234of the roller assemblies226may contact the O-ring250. After multiple rotations of the turret214, the O-ring250may become damaged thereby requiring it to be replaced. Accordingly, the outer wall262may be removed to allow access to the O-ring250so that it can be replaced with a new O-ring250. To remove the outer wall262, fasteners266are removed. Such a configuration may allow for an easy, quick, and cost effective repair of the waxer station, which was not possible with the gear configuration of the prior art.

The present disclosure illustrates the present invention, but the scope of the present invention is not limited to the particular structure illustrated herein. For just one example, O-rings are disclosed as structure to mutual contact. The present invention is not limited to conventional O-ring structure or materials. In this regard, the present invention encompasses structures that do not have the transverse cross section of conventional o-rings, encompasses materials that are not associated with conventional o-rings, and the like.