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.
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- 11/16th inches to 2- 6/16th inches (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.
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.
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 in
Each necking station 18 includes a turret having a plurality of pockets formed therein. Each pocket is adapted to receive the can body 24 and securely holds the can body 24 in 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 body 24 is brought into contact with a die by a pusher ram as the turret carries the can body 24 through an arc along a top portion of the necking station 18. 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 body 24, a curved transition zone, and a reduced diameter upper cylindrical surface above the transition zone. During the necking operation, the can body 24 is moved into the die such that the open end of the can body 24 is placed into touching contact with the transition zone of the die. As the can body 24 is 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 in
The can body 24 may be passed through any number of necking stations 18 depending on the desired diameter of the open end of the can body 24. For example, multi-stage can necking machine 10 shown in the figures includes eight stages 14, and each stage incrementally reduces the diameter of the open end of the can body 24 as described above.
As shown in
Each motor 32 is coupled to and drives a first gear 36 by way of a gear box 40. The motor driven gear 36 then drives an adjacent second gear 44 which in turn drives a third gear 48 and so on. As shown, motor 32a drives the gears of four necking stages 14 and motor 32b drives the gears of the remaining four necking stages 14. 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 machine 10, may include in addition to necking stages 14, 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. Machine 10 may also include a waxer assembly 50.
Shown in
The input station 54 includes an input starwheel 62 mounted on a rotating shaft 66 and an input chute 68. As shown, the input starwheel 62 includes a plurality of pockets 72 formed therein, each pocket 72 being adapted for receiving a can body. As the input starwheel 62 rotates, each pocket 72 receives a can body from the input chute 68. The input starwheel 62 then rotates and delivers the can body to the waxer station 58. The input station 54 preferably delivers up to 3400 cans per minute to the waxer station 58.
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The roller assemblies 94 are driven using frictional contact between the drive rollers 98 and the housing 70. As shown, each drive roller 98 extends from a respective body portion 96 and protrudes from a side surface 110 of the turret 78. Each drive roller 98 has a surface 114 that is in contact with the peripheral surface 88 of the housing 70. In the embodiment shown, the surface 114 of each drive roller 98 is in contact with the O-ring 90 of the peripheral surface 88. The contact between the drive rollers 98 and the O-ring 90 should be strong enough to create a frictional force between the drive rollers 98 and the O-ring 90 such that as the turret 78 rotates, the drive rollers 98, and thus the roller assemblies 94, rotate within each pocket 92. Accordingly, this frictional force enables O-ring 90 transmits torque sufficient to drive the components.
Referring back to
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.
As shown, the housing 222 may be mounted on the shaft 218 proximate to the turret 214. The housing 222 includes a stationary housing body 242 and a peripheral surface 246. The peripheral surface 246 preferably includes an O-ring 250 positioned in a groove 254 formed between an inner wall 258 and an outer wall 262. Both the inner wall 258 and the outer wall 262 extend up from the housing body 242. As shown, the drive rollers 234 of the roller assemblies 226 may contact the O-ring 250. After multiple rotations of the turret 214, the O-ring 250 may become damaged thereby requiring it to be replaced. Accordingly, the outer wall 262 may be removed to allow access to the O-ring 250 so that it can be replaced with a new O-ring 250. To remove the outer wall 262, fasteners 266 are 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.
This application is related by subject matter to the inventions disclosed in the following commonly assigned applications: U.S. patent application Ser. No. ______ (Attorney Docket No. CC-5163) filed on Apr. 24, 2008 and entitled “Adjustable Transfer Assembly For Container Manufacturing Process”, U.S. patent application Ser. No. ______ (Attorney Docket No. CC-5164) filed on Apr. 24, 2008 and entitled “Distributed Drives For A Multi-Stage Can Necking Machine”, U.S. patent application Ser. No. ______ (Attorney Docket No. CC-5165) filed on Apr. 24, 2008 and entitled “Container Manufacturing Process Having Front-End Winder Assembly”, U.S. patent application Ser. No. ______ (Attorney Docket No. CC-5166) filed on Apr. 24, 2008 and entitled “Systems And Methods For Monitoring And Controlling A Can Necking Process” and U.S. patent application Ser. No. ______ (Attorney Docket No. CC-5167) filed on Apr. 24, 2008 and entitled “High Speed Necking Configuration.” The disclosure of each application is incorporated by reference herein in its entirety.