Background Art [002] Beverages such as beer and carbonated soft drinks are commonly packaged in two- piece cans formed from aluminium material. Two-piece cans are typically man- ufactured by attaching a circular lid to an open end of a generally cylindrical can body formed by a drawing and ironing process.

[003] The diameter of the open end of the can body can be reduced prior to attaching the lid thereto. Reducing the diameter of the open end facilitates the use of a smaller- diameter lid than would otherwise be possible (thereby reducing the amount of raw material needed to manufacture the lid). The process by which the diameter of the can end is reduced is known as"necking." [004] Necking is typically performed in a number of incremental steps, with the diameter of the can end being reduced only slightly in each step. Necking the can end in this manner reduces the potential for the can end to become wrinkled or otherwise distorted as its diameter is reduced.

[005] Necking can be performedin several different manners. For example, a process known as"die necking"is disclosed in U. S. Patent Nos. 5,755, 130 (Tung et al. ) ;<BR> 4,519, 232 (Traczyk et al. ) ; and 4,774, 839 (Caleffi et al. ), each of which is incorporated by reference herein in its entirety. Die necking involves forcing an open end of a can body into a die so that an inwardly tapered surface of the die permanently deforms the open end inward. (Necking operations can also be performed using techniques broadly referred to as"spin necking.") [006] A variety of machines have been developed for necking can ends. For example, Figures 1-3 depict a five-stage necking machine 3 for performing a die necking process on a can body 2. (The can body 2 is depicted as entering the necking machine 3 in Figure 1, with the direction of travel of the can body 2 denoted by the arrow 4).

[007] Necking machines such as the necking machine 3 are available from Belvac Production Machinery of Lynchburg, Virginia, as model 595. A necking machine sub- stantially similar to the necking machine 3 is described in detail in U. S. Patent No.

6,085, 563 (Heiberger et al. ), which is incorporated by reference herein in its entirety.

[008] The necking machine 3 comprises a unitary base 5, and a bearing plate 9 fixedly coupled to a top surface of the base 5. The base 5 forms an enclosure for containing a vacuum generated by an external source (not pictured). In other words, the base 5 has a sealed internal volume for containing an externally-generated vacuum (see Figure 2).

(The purpose of this feature is explained below.) [009] Three pipes 58 extend into and out of the base 5 by way of through holes formed in end plates 5a of the base 5 (see Figure 3). The uppermost pipe 58 conveys vacuum, and the remaining pipes convey positive or pressurized air to the necking machine 3.

[010] The necking machine 3 further comprises an input chute 7 and an input module 11 (see Figure 1). The input module 11 comprises a feed wheel 6 having a plurality of pockets 25 formed therein. The pockets 25 each receive a respective can body 2 from the input chute 7. The feed wheel 6 rotates in a counter clockwise direction (from the perspective of Figure 1). (Rotational directions are denoted in the figures by arrows 12.) [011] The can bodies 2 are retained in the pockets 25 by a vacuum force. More par- ticularly, a port (not shown) is defined in the surface that defines each of the respective pockets 25. The port is in fluid communication with the internal volume within the base 5 by way of a hose (not shown) coupled to the internal volume, and a rotary manifold (not shown) within the feed wheel 6. The vacuum is transmitted to the port by the hose and the rotary manifold, and generates a suction force that retains the can body 2 in the pocket 25.

[012] The necking machine 3 further comprises a first, second, third, fourth, and fifth necking module, respectively designated 17a, 17b, 17c, 17d, 17e (see Figure 1). The necking modules 17a, 17b, 17c, 17d, 17e each comprise a necking station, respectively designated 16a, 16b, 16c, 16d, 16e. The necking stations 16a, 16b, 16c, 16d, 16e in- crementally reduce the diameter of the open end of the can body 2.

[013] The necking stations 16a, 16b, 16c, 16d, 16e each include a turret 19. Each turret 19 has twelve pockets 27 formed therein for receiving the can bodies 2. Each turret 19 is fixedly coupled to a respective shaft 8. The shafts 8 are each rotatably coupled to the base 5 and the bearing plate 9 by bearings (not shown). This arrangement permits'the turrets 19 to rotate in a clockwise direction (from the perspective of Figure 1) during necking operations.

[014] The feed wheel 6 carries the can bodies 2 through an arc of approximately 210 degrees, and deposits each can body 2 into a corresponding one of the pockets 27 of the necking station 16a.

[015] An open end of the can body 2 is brought into contact with a die of a necking assembly on the necking station 16a, using techniques well known in the art of can making. The turret 19 carries the can body 2 through an arc of approximately 180 degrees. The noted contact between the can body 2 and the die slightly reduces the diameter of the open (upper) end of the can body 2. (The process by which the diameter of the can body 2 is reduced, as noted above, is commonly referred to as "necking.") [016] Figures 5 and 6 depict a necking assembly 170 that can be used to reduce the diameter of the can body 2. The necking station 16a can comprise twelve of the necking assemblies 170. Each of the necking assemblies 170 is associated with a cor- responding one of the pockets 27.

[017] The twelve necking assemblies 170 are substantially identical. Each necking assembly 170 comprises a deforming element 172 for engaging the upper end of the can body 2. The deforming element 172 comprises a sleeve 176 and a die 178. The sleeve 176 is fixedly coupled to a periphery of the turret 19. The die 178 is secured to an end of the sleeve 176 by a cap 180. The die 178 has a necking surface 182 formed along an inner periphery thereof.

[018] Each necking assembly 170 also comprises a support member 174 for engaging a bottom wall of the can body 2. The support member 174 includes a sleeve 190. The sleeve 190 is fixedly coupled to a periphery of the turret 19 so that a longitudinal axis of the sleeve 190 is substantially aligned with a longitudinal axis of the sleeve 176.

[019] The support member 174 also includes a shaft 192, and a platform 194 secured to a first end of the shaft 192. The shaft 192 reciprocates within the sleeve 190. The support member 174 further includes a cam block 193 and cams 196,197. The cams 196,197 are mechanically coupled to a second end of the shaft 192 by way of the cam block iv1 193.

[020] The necking assembly 170 further comprises a cam plate 199. The cam 196 contacts a camming surface 198 formed on cam plate 199. The cam plate 199 is fixedly coupled to a periphery of a hub 154 of the base 5 (the cam plate 199 thus remains stationary in relation to the support member 174 as the turret 19 rotates).

[021] The cam plate 199 is configured so that the distance between the camming surface 198 and the deforming element 172 varies along the length (circumference) of the camming surface 198. This feature causes the cam plate 199 to drive the support member 174 between a first and a second position (shown respectively on the left and right-hand sides of Figure 5) during each revolution of the turret 19, by way of the cam 196. In other words, the cam plate 199 drives support member 174 toward and away from the deforming element 172 (and the die 178) during each revolution of the turret 19.

[022] The noted movement of the support member 174 toward the deforming element 172 brings the necking surface 182 of the die 178 into contact with the upper end of the can body 2. Further movement of the support member 174 toward the deforming element 172 forces the upper end of the can body 2 into the die 178. The tapered profile of the necking surface 182 reduces the diameter of the upper end as the upper end is forced into the die 178.

[023] A plug (knockout punch) 200 can be used to remove the can body 2 from the die 178. The plug 200 is secured to an end of a shaft 202. The shaft 202 reciprocates within the sleeve 176 (a suitable bearing 204 is positioned between the sleeve 176 and the shaft 202 to permit relative movement therebetween).

[024] The plug 200 is secured to a first end of the shaft 202 by a screw 208. A cam 210 is secured to a second end of the shaft 202 by way of a cam block 212. The cam 210 contacts a camming surface 214 formed along an outer periphery of a plate 160 of the base 5. This contact causes the plug 200 to move between a first and a second position, shown respectively on the left and right hand sides of Figure 5, during each revolution of the turret 19. Contact between the plug 200 and the upper edge of the can body 2 as the plug 200 moves from its second to its first position can urge the can body 2 toward the support member 174.

[025] The camming surface 214 has a substantially identical configuration to the camming surface 198 on the cam plate 199, with the following exception. The camming surface 214 is offset with respect to the surface 198 so that the movement of the plug 200 away from the deforming element 172 trails that of the support platform 174. The plug 200 thus moves from its second to its first position after the can body 2 has been necked by the die 178 as described above.

[026] The can body 2 can also be removed from the die 178 by pressurized air. The pressurized air is directed into the can body 2 by way of a ring 220. The ring 220 is positioned within an annular slot 222 formed in the plate 160. The ring 220 has a cir- cumferentially-extending groove 224 of predetermined length formed therein.

[027] A plate 226 is secured to the turret 19 so that a surface of the plate 226 abuts an adjacent surface of the ring 220. The contact between the plate 226 and the ring 220 forms a seal therebetween. The contact force between the plate 226 and the ring 220 is increased by springs 225 located between the ring 220 and the plate 160.

[028] The plate 226 has a plurality of circumferentially-spaced openings 228 formed therein. Rotation of the turret 19 causes the openings 228 to align with the groove 224 of the ring 220 on an intermittent basis. Hence, the openings 228 are in fluid com- munication with the groove 224 on an intermittent basis, as the turret 19 rotates. The openings 228 each adjoin a conduit 230 of the associated necking assembly 170. Each conduit 230, in turn, adjoins an axially-extending passage 232 formed in the associated shaft 202 and screw 208.

[029] Pressurized air is supplied to the partial annular groove 224 from a source (not shown). The pressurized air flows from the groove 224 to the openings 228 on an in- termittent basis. The pressurized air subsequently flows from each opening 228 to the associated conduit 230 and passages 232, and is discharged into the can body 2. (The ring 220 is configured so that the groove 224 aligns with each of the openings 228 of the necking assemblies 170 in a manner that causes the air to be discharged into the can body 2 as the support platform 174 is drawn away from the deforming element 172 following the necking operation.) [030] The pressurized air can be used as the primary means for removing the can body 2 from the die 178. The pressurized air can also help to ensure that the can body 2 remains supported on the platform 194 as the support member 174 moves away from the deforming element 172 following the necking operation. The plug 200 can assist in removing the can body 2 when the pressurized air, by itself, is insufficient to remove the can body from the die 178, e. g. , when the upper end of the can body 2 jams in the die 178 due to misalignment between the die 178 and the can body 2 during the necking process.

[031] The necking station 16a includes a guide rail that extends around an upper periphery of the turret 19. The guide rail helps to ensure that the can bodies 2 are positively held on the platforms 194 in substantial alignment with the die 178 (the guide rail is not shown in the figures, for clarity).

[032] The necking stations 16b, 16c, 16d, 16e are configured in a substantially identical manner to the necking station 16a, with the following exception. The diameters of the dies in the necking assemblies of the necking stations 16b, 16c, 16d, 16e become pro- gressively smaller toward the final necking station, i. e. , toward the necking station 16e, to effect further incremental reductions in the diameter of the end of the can body 2 as the can body 2 passes through the necking machine 3.

[033] The necking assembly 170 has been described in detail for exemplary purposes only. The necking machine 3 can be equipped with necking assemblies having other configurations.

[034] The necking machine 3 also comprises first, second, third, and fourth intermediate, or transfer, modules, respectively designated 19a, 19b, 19c, 19d. The transfer modules 19a, 19b, 19c, 19d each comprise an intermediate, or transfer, wheel, respectively designated 18a, 18b, 18c, 18d (see Figure 1). The transfer wheels 18a, 18b, 18c, 18d each rotate in a counter clockwise direction (from the perspective of Figure 1).

[035] Each of the transfer wheels 18a, 18b, 18c, 18d has a plurality of pockets 29 formed therein. The pockets 29 receive the can body 2. The can body 2 is retained in the pockets 29 in a manner substantially identical to that described above with respect to the pockets 25 of the feed wheel 6.

[036] The transfer modules 19a, 19b, 19c, 19d are each located between a respective pair of the necking modules 17a, 17b, 17c, 17d, 17e, as depicted in Figure 1. The necking station 16a deposits the can body 2 into one of the pockets 29 of the transfer wheel 18a after the necking station 16a has reduced the diameter of the end of the can body 2 as described above.

[037] The transfer wheel 18a carries the can body 2 through an arc of approximately 180 degrees, and deposits the can body 2 into one of the pockets 27 of the necking station 16b. The necking station 16b further reduces the diameter of the end of the can body 2 in a manner substantially identical to that noted above with respect to the necking station 16a.

[038] The can body 2 is subsequently transferred between the necking stations 16b, 16c, 16d, 16e by the transfer wheels 18b, 18c, 18d, in a manner substantially identical to that described above with respect to the transfer wheel 18a. The diameter of the end of the can body 2 is further reduced by the necking stations 16c, 16d, 16e, in a manner substantially identical to that noted above with respect to the necking station 16a.

[039] The necking machine 3 further comprises a discharge module 21 located im- mediately downstream of the necking station 16e, and a discharge chute 22. The discharge module 21 comprises a discharge wheel 20 having a plurality of pockets 31 formed therein. The pockets 31 receive the can body 2 from the necking station 16e.

The can body 2 is retained in the pockets 31 in a manner substantially identical to that described above with respect to the pockets 25 of the feed wheel 6.

[040] The discharge wheel 20 rotates in a counter clockwise direction (from the perspective of Figure 1). The discharge wheel 20 carries the can body 2 through an arc of approximately 180 degrees, and deposits the can body 2 in the discharge chute 22.

Therdischarge chute 22 subsequently guides the can body 2 out of the necking machine 3.

[041] The input feed wheel 6, the transfer wheels 18a, 18b, 18c, 18d, and the discharge wheel 20 are each driven by a respective shaft 32 that, in turn, is driven by a cor- responding gear 24 (see Figures 2 and 3). The shafts 8 of the necking stations 16a, 16b, 16c, 16d, 16e are each driven by a corresponding gear 24 (see Figures 3 and 4C).

[042] The gear 24 associated with the transfer module 19c is coupled to and driven by a motor 28 by way of a gearbox 26 and a drive belt 30 (see Figure 3; the motor 28, gearbox 26, and drive belt 30 are not shown in Figure 2, for clarity). The motor-driven gear 24 drives the two immediately adjacent gears 24 which, in turn, drive the next gears 24, and so on.

[043] The shafts 32,8 are each rotatably coupled to bearings (not shown) mounted on the bearing plate 9. The necking stations 16a, 16b, 16c, 16d, 16e each support an end of their associated shaft 8 by way of a respective bearing housing (not shown). The transfer modules 19a, 19b, 19c, 19d each support an end of their associated drive shaft 32 by way of a respective bearing housing (not shown).

[044] The necking machine 3 can operate at a throughout of up to 2,400 can bodies per minute. In other words, the necking machine 3 can neck 2,400 cans each minute in the above-noted manner. The necking machine 3 may not be required to operate at its maximum throughput, however, in many potential applications. For example, the necking machine 3 may be required to operate at only half of its maximum throughput (or less), i. e. , at a throughput of approximately 1,200 can bodies per minute (or less), in a particular application.

[045] The necking machine 3, as configured in the above-described manner, cannot perform more than five diameter reductions on each can body 2, regardless of the throughput at which the necking machine 3 is operated. A second necking machine (not shown) is therefore required in applications requiring, for example, ten diameter reductions. (The second necking machine can be equipped with dies 178 sized ap- propriately for the additional diameter reductions performed by the second necking machine. The second necking machine can be operably coupled to the necking machine 3 using any of the conventional techniques commonly known to those skilled in the relevant art).

[046] Operating a necking machine such as the necking machine 3 at less than its maximum throughput results in unused capacity in the necking machine 3. Necking machines such as the necking machine 3, in general, are relatively expensive to procure, operate, and maintain. Necking machines can also require a relatively large amount of floor space in a manufacturing or processing plant. Hence, unused capacity in a necking machine such as the necking machine 3 can represent a substantial under- utilization or waste of resources.

Disclosure of Invention [047] A preferred embodiment of an apparatus for necking a can body comprises a first necking station comprising a first and a second die for reducing a diameter of an end of the can body. The first die has a first diameter and the second die has a second diameter less than the first diameter. The apparatus also comprises a second necking station comprising a third and a fourth die for reducing the diameter of the end of the can body. The third die has a third diameter and the fourth die has a fourth diameter less than the third diameter.

[048] The apparatus further comprises a transfer wheel for transporting the can body at least part of the way between the first and the second necking stations, and a conveying mechanism for transporting the can body at least part of the way between the second and the first necking stations after the diameter of the can body has been reduced by the third die.

[049] Another preferred embodiment of an apparatus for necking a can body comprises a first necking station for reducing a diameter of an end of the can body, and a second necking station for further reducing the diameter of the end of the can body. The apparatus further comprises at least one transfer wheel for transferring the can body from the first necking station to the second necking station after the diameter of the end of the can body has been reduced by the first die. The second necking station is mechanically coupled to the first necking station so that the first necking station receives the can body after the diameter of the can body has been reduced by the second necking station.

[050] A preferred embodiment of an apparatus for necking can bodies comprises a first necking station comprising a first plurality of dies for reducing a diameter of un- necked ones of the can bodies, and a second plurality of dies for reducing a diameter of partially-necked ones of the can bodies. The second plurality of dies has a nominal diameter less than a nominal diameter of the first plurality of dies. The apparatus also comprises an input portion comprising a first and a second input wheel and a first and a second transfer wheel.

[051] The first input wheel receives the un-necked ones of the can bodies and transports the un-necked ones of the can bodies to the first transfer wheel, and the first transfer wheel transports the un-necked ones of the can bodies to the second transfer wheel.

The second input wheel receives the partially-necked ones of the can bodies from a second necking machine of the apparatus and transports the partially-necked ones of the can bodies to the second transfer wheel, and the second transfer wheel transports the un-necked and partially-necked ones of the can bodies to the first necking station.

[052] Another preferred embodiment of an'apparatus for necking can bodies comprises a first necking station comprising a first plurality of dies for reducing a diameter of a first plurality of the can bodies, and a second plurality of dies for reducing a diameter of a second plurality of the can bodies having an end diameter less than an end diameter of the first plurality of the can bodies. The apparatus also comprises a discharge portion comprising a first and a second transfer wheel and a first and a second discharge wheel.

[053] The first transfer wheel receives the first and the second pluralities of the can bodies from the first necking station and transports the first and the second pluralities of the can bodies to the second transfer wheel. The second transfer wheel transports the first plurality of the can bodies to the first discharge wheel, and the second transfer wheel transports the second plurality of the can bodies to the second discharge wheel. The first discharge wheel directs the second plurality of the can bodies at least part of the way to a second necking station of the apparatus, and the second discharge wheel directs the first plurality of the can bodies at least a part of the way to a discharge point on the apparatus.

[054] Another preferred embodiment of an apparatus for necking a can body comprises a first necking station comprising a first and a second die for reducing a diameter of an end of the can body. The first die has a first diameter and the second die has a second diameter less than the first diameter. The apparatus also comprises a second necking station comprising a third and a fourth die for reducing the diameter of the end of the can body. The third die has a third diameter and the fourth die has a fourth diameter less than the third diameter.

[055] The second necking station receives the can body after the diameter of the can body has been reduced by the first die, and the first necking station receives the can body before and after the diameter of the can body has been reduced by the third die.

[056] A preferred method for necking a can body comprises reducing a diameter of an end of the can body using a first die of a first necking station of a necking machine, and transferring the can body from the first necking station to a second necking station of the necking machine. The preferred method also comprises further reducing the diameter of the end of the can body using a first die of a second necking station of the necking machine, and transferring the can body from the second necking station to the first necking station. The preferred method also comprises further reducing the diameter of the end of the can body using a second die of the first necking station after transferring the can body from the second necking station to the first necking station.

Brief Description of the Drawings [057] The foregoing summary, as well as the following detailed description of a presently-preferred embodiment, is better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, the drawings show an embodiment that is presently preferred. The invention is not limited, however, to the specific instrumentalities disclosed in the drawings. In the drawings: [058] Fig. 1 is a front view of a conventional five-stage necking machine; [059] Fig. 2 is a rear view of the necking machine shown in Fig. 1, with a motor, gearbox, and drive belt of the necking machine not depicted, for clarity; [060] Fig. 3 is a side view of the necking machine shown in Figs. I and 2; [061] Fig. 4 is a front view of a preferred embodiment of a necking machine in accordance with the present invention; [062] Fig. 5 is a top, cross-sectional view of a necking station of the necking machines shown in Figs. 1-4 ; and [063] Fig. 6 is a magnified view of the area designated"A"in Fig. 5.

Mode for the Invention [064] A preferred embodiment of a necking machine 3'is depicted in Figures 4-6. The necking machine 3'can be used to perform necking operations on a can body such as the can body 2.

[065] The necking machine 3'is configured so that each can body 2 passes through the necking machine 3'twice. An initial series of necking operations (diameter reductions) take place during the initial pass through the necking machine 3, and further diameter reductions take place during the second pass. More specifically, the diameter of an end of the can body 5 is reduce five times during its initial pass through the necking machine 3', and another five times during its second pass.

[066] The necking machine 3'comprises a base 5'and a bearing plate 9' (see Figure 4).

The necking machine 3'also comprises an input portion 100. The input portion 100 includes a first input chute 106a and a first input module 108a. The first input module 108a comprises a first feed wheel 1 lOa having six pockets 112a formed therein.

[067] The first input chute 106a receives the can bodies 2 before any necking operations have been performed thereon. Each pocket 112a of the first feed wheel I I Oa receives a respective one of the can bodies 2 from the first input chute 106a. The first feed wheel 1 lOa rotates in a counter clockwise direction (from the perspective of Figure 4).

[068] The can bodies 2 are retained in the pockets 112a by a vacuum force, in a manner substantially identical to that described above in connection with the pockets 25 in the feed wheel 6 of the necking machine 3.

[069] The input portion 100 of the necking machine 3'also comprises a second input chute 106b and a second input module 108b. The second input module 108b comprises a second feed wheel 1 lOb having six pockets 112b formed therein.

[070] The second input chute 106b receives the can bodies 2 after an initial series of necking. operations have been performed thereon by the necking machine. (the mechanism and process by which the partially-necked can bodies 2 are fed to the second input chute 108b are discussed below).

[071] Each pocket 112b of the second feed wheel 1 lOb receives a respective one of the can bodies 2 from the second input chute 106b (the second feed wheel 1 lOb thus receives the can bodies 2 in a partially-necked condition). The can bodies 2 are retained in the pockets 112b in the manner described above in connection with the feed wheel 6 of the necking machine 3. The second feed wheel 1 lOb rotates in a clockwise direction (from the perspective of Figure 4).

[072] The input portion 100 of the necking machine 3'further comprises a first transfer (intermediate) module 114a, and a second transfer module 114b. The first transfer module 114a comprises a first transfer (intermediate) wheel 116a, and the second transfer module 114b comprises a second transfer wheel 116b. The first transfer wheel 116a rotates in a clockwise direction, and the second transfer wheel 116b rotates in a counter clockwise direction (from the perspective of Figure 4).

[073] The first transfer wheel 116a has twelve pockets 118a formed therein for receiving the can bodies 2. The second transfer wheel 116b likewise has twelve pockets 118b formed therein for receiving the can bodies 2. The can bodies 2 are retained in the pockets 118a, 118b in the manner described above in connection with the feed wheel 6 of the necking machine 3.

[074] The first transfer wheel 116a receives the can bodies 2 from the first feed wheel I lOa. In particular, the first feed wheel 1 lOa and the first transfer wheel 116a are indexed so that the first feed wheel 1 lOa deposits the can bodies 2 in alternate ones, i. e. , every other one, of the pockets 118a in the first transfer wheel 116a.

[075] The second transfer wheel 116b receives the can bodies 2 from both the first transfer wheel 116a and the second feed wheel 1 l Ob. The first transfer wheel 116a and the second transfer wheel 116b are indexed so that the first transfer wheel 116a deposits the can bodies 2 into alternate ones of the pockets 118b in the second transfer wheel 116b. In addition, the second feed wheel 1 lOb and the second transfer wheel 116b are indexed so that the second feed wheel I lOb deposits the can bodies 2 into the pockets 118b that are not occupied by the can bodies 2 received from the first transfer wheel 116a.

[076] The can bodies 2 that are fed to the first feed wheel 1 lOa from the first input chute 106a have not undergone any necking operations, as discussed above. Hence, the can bodies 2 that are received by the second transfer wheel 116b from the first transfer wheel 116a have not undergone any necking operations.

[077] The can bodies 2 that are fed to the second feed wheel 1 lOb from the second input chute 106b are partially necked, as discussed above. Hence, the can bodies 2 that are received by the second transfer wheel 116b from thQsecond feed wheel 1 lOb are partially necked. Adjacent ones of the pockets 118b of the second transfer wheel 116b thus receive an un-necked can body 2 and a partially-necked can body 2. In other words, every other pocket 118b of the second transfer wheel 116b receives an un- necked can body 2, and the remaining pockets 118b each receive a partially-necked can body 2.

[078] The necking machine 3'comprises a gearbox 26, a motor 28, and a drive belt 30 as described above in connection with the necking machine 3. The first and second feed wheels 1 lOa, 1 lOb and the first and second transfer wheels 116a, 116b each include a respective gear 24 and a shaft 32 as described above in connection with the necking machine 3. The first and second feed wheels 1 lOa, 1 lOb and the first and second transfer wheels 116a, 116b can be driven by the gearbox 26, motor 28, and drive belt 30, by way of the respective gears 24 and shafts 32.

[079] The necking machine 3'further comprises a first necking module 17a' (see Figure 4). The first necking module 17a'includes a first necking station 16a'. The first necking station 16a'comprises twelve necking assemblies 170'. Each necking assembly 170'is substantially identical to the necking assembly 170 described above in connection with the necking machine 3, with the below-noted exceptions. The above description of the necking assembly 170, and the depiction of the necking assembly 170 in the figures thus apply equally to the necking assembly 170', except as otherwise noted. Moreover, the above description of the first necking module 17a and the first necking station 16a, and the depictions of the first necking module 17a and the first necking station 16a in the figures, apply equally to the first necking module 17a and the first necking station 16a, except as otherwise noted.

[080] Six of the necking assemblies 170'of the first necking station 16a'each comprise a die 178a (see Figure 5). Each die 178a has a necking surface 182a formed along an inner periphery thereof. The necking surfaces 182a each have a first nominal diameter.

The remaining six necking assemblies 170'of the first necking station 16a'each comprise a die 178b (see Figures 5 and 6). Each die 178b has a necking surface 182b formed along an inner periphery thereof. The necking surfaces 182b each have a second nominal diameter. The second nominal diameter is less than the first nominal diameter.

[081] The dies 178a are each associated with alternating ones of the pockets 27 of the necking station 16a'. The dies 178b likewise are each associated with alternating ones of the pockets 27. Hence, each die 178a is positioned between two of the dies 178b around the periphery of the turret 19. Each die 178b is likewise positioned between two of the dies 178a around the periphery of the turret 19. In other words, every other one of the pockets 27 of the necking station 16a'is associated with one of the dies so- : : l78a, and the remaining pockets 27 are each associated with one of the dies 178b.

[082] The necking station 16a'receives the can bodies 2 from the second transfer wheel 116b of the second transfer module 114b. Every other pocket 118b of the second transfer wheel 116b carries an un-necked can body 2, and the remaining pockets 118b each carry a partially-necked can body 2, as discussed above.

[083] The second transfer wheel 116b and the turret 19 of the necking station 16a'are indexed so that the un-necked can bodies 2 are deposited in the pockets 27 associated with the dies 178a, and the partially-necked can bodies 2 are deposited in the pockets 27 associated with the dies 178b. Hence, the can bodies 2 that have not yet been undergone any reduction in diameter are necked by the larger-diameter dies 178a (the dies 178a are thus sized appropriately for the initial diameter reduction in the necking process). The partially-necked can bodies 2 are necked by the relatively smaller- diameter dies 178b (the dies 178b are thus sized appropriately for the further diameter reduction appropriate for this stage of the necking process).

[084] The necking machine 3 further comprises a second, third, fourth, and fifth necking module, respectively designated 17b', 17c', 17d', 17e'. The necking modules 17b', 17c', 17d', 17e'each comprise a necking station, respectively designated 16b', 16c', 16d', 16e' (see Figure 4).

[085] The necking modules 17b', 17c', 17d', 17e'are substantially identical to the respective necking modules 17b, 17c, 17d, 17e of the necking machine 3, with the following exceptions. The die assemblies 170 of each necking station 16b', 16c', 16d', 16e'are equipped with die assemblies 170 having a first set of relatively large- diameter dies 178a, and a second set of relatively small-diameter dies 178b. The dies 178a, 178b are arranged in the alternating (staggered) manner described above in connection with the necking station 16a'.

[086] The necking machine 3'further comprises the first, second, third, and fourth transfer modules 19a, 19b, 19c, 19d, as described above in connection with the necking machine 3.

[087] The first transfer module 19a receives the can bodies 2 from the necking station 16a'after the necking station 16a'has reduced (or further reduced) is diameters of the can bodies 2 in the above-described manner. The transfer wheel 18a of the first transfer module 19a carries the can bodies 2 through an arc of approximately 180 degrees, and deposits each can body 2 into a corresponding one of the pockets 27 of the necking station 16b'.

[088] The transfer wheel 18a and the turret 19 of the necking station 16b'are indexed so that the pockets 27 associated with the larger-diameter dies 178a receive the can bodies 2 that have undergone only one diameter reduction, i. e. , the can bodies that were received by the necking station 16a'in the previous operation in an un-necked condition. The remaining pockets 27 receive the remaining can bodies 2, i. e., the can bodies 2 that have previously undergone multiple diameter reductions.

[089] The necking station 16b'further reduces the diameters of the can bodies 2, in the manner described above in connection with the necking module 16a. The dies 178a, 178b of the necking station 16b'are sized appropriately for the further diameter reductions required at this stage of the necking process for each of the two differently- sized sets of can bodies 2. (The dies 178a of the necking station 16b'are thus sized in- crementally smaller than the dies 178a of the necking station 16a'. The dies 178b of the necking station 16b'are likewise sized incrementally smaller than the dies 178b of the necking station 16a'.) [090] The can bodies 2 are subsequently transferred to the third, fourth, and fifth necking modules 17c', 17d', 17e'by the respective second, third, and fourth transfer modules 19b, 19c, 19d. Further diameter reductions are performed on the can bodies 2 by each of the necking stations 16c', 16d', 16e'. The further diameter reductions are performed using a combination of differently-sized dies 178a, 178b appropriate for the progressive diameter reductions required at each subsequent stage of the necking process, for each differently-sized set of can bodies 2 (as described above in connection with the necking modules 17a', 17b'). (The dies 178a of the necking stations 16a'-16e'thus become progressively smaller moving from the necking station 16a'to the necking station 16e'. The dies 178b of the necking stations 16a'-16e' likewise become progressively smaller moving from the necking station 16a'to the necking station 16e'.) [091] The necking machine 3'further comprises a discharge portion 122 (see Figure 4).

The discharge portion 122 comprises a first transfer module 124a and a second transfer module 124b. The first transfer module 124a comprises a first transfer wheel 126a, and the second transfer module 124b comprises a second transfer wheel 126b. The first transfer wheel 126a rotates in a counter clockwise direction, and the second transfer wheel 126b rotates in a clockwise direction (from the perspective of Figure 4).

[092] The first transfer wheel 126a has twelve pockets 128a formed therein for receiving the can bodies 2. The second transfer wheel 126b likewise has twelve pockets 128b formed therein for receiving the can bodies 2. The can bodies 2 are retained in the pockets 128a, 128b in the manner described above in connection with the feed wheel 6 of the necking machine 3.

[093] The pockets 128a of the first transfer wheel 126a receive the can bodies 2 from the necking station 16e'of the fifth necking module 17e'. Half of the can bodies 2 received by the first transfer wheel 126a have an relatively large-diameter end, and the remaining can bodies 2 have a relatively small-diameter end due to the alternating ar- rangement of the relatively large and small dies 178a, 178b on the necking station 16e' (discussed above).

[094] The can bodies 2 having the relatively small-diameter ends have passed through each of the necking stations 16a', 16b', 16c', 16d', 16e'twice by this point in the necking process. The ends of these can bodies 2 have thus been reduced in size to their final configuration, and the can bodies 2 are ready to be discharged from the necking machine 3'. (These can bodies 2 are hereinafter referred to as"the finished can bodies 2. ") The remaining can bodies 2, as discussed below, are recirculated through the necking stations 16a', 16b', 16c', 16d', 16e'for additional diameter reductions. (These can bodies 2 are hereinafter referred to as"the partially-necked can bodies 2.") [095] The first transfer wheel 126a carries the can bodies 2 through an arc of ap- proximately 180 degrees, to the second transfer wheel 126b. The can bodies 2 are received by the pockets 128b of the second transfer wheel 126b.

[096] The discharge portion 122 also comprises a first discharge module 132a and a second discharge module 132b. The first discharge module 132a comprises a first discharge wheel 134a, and the second discharge module 132b comprises a second discharge wheel 134b. The first discharge wheel 134a rotates in a counter clockwise direction, and the second discharge wheel 134b rotates in a counter clockwise direction (from the perspective of Figure 4).

[097] The first discharge wheel 134a has twelve pockets 136a formed therein. The second discharge wheel 134b likewise has twelve pockets 136b formed therein. The can bodies 2 can be retained in the pockets 136a, 136b in the manner described above in connection with the feed wheel 6 of the necking machine 3.

[098] The first discharge wheel 134a receives the partially-necked can bodies 2 from the second transfer wheel 126b. More particularly, the second transfer wheel 126b carries the partially-necked can bodies 2 through an arc of approximately 90 degrees, to the first discharge wheel 134a. The second transfer wheel 126b and the first discharge wheel 134a are indexed so that the partially-necked can bodies 2 are received in al- ternating ones of the pockets 136a of the first discharge wheel 134a. (The vacuum to the remaining pockets 136a of the first discharge wheel 134a is deactivated to preclude the finished can bodies 2 from being picked up by the first discharge wheel 134a.) [099] The discharge portion 122 further comprises a first discharge chute 138a mounted on the first discharge module 132a. The second discharge wheel 134b carries the partially-necked can bodies 2 upward, through an arc of approximately 90 degrees, and deposits the partially-necked can bodies 2 in the first discharge chute 138a. (The partially-necked can bodies 2 are subsequently returned to the first necking module 17a', as discussed below.) [100] The finished can bodies 2 are carried through an arc of approximately 180 degrees by the second transfer wheel 126b, to the second discharge wheel 136b. The second transfer wheel 126b and the second discharge wheel 136bare indexed so that the finished can bodies 2 are received in alternating pockets 136b of the second discharge wheel 134b.

[101] The discharge portion 122 further comprises a second discharge chute 138b mounted on the second discharge module 132b. The second discharge wheel 134b carries the finished can bodies 2 through an arc of approximately 180 degrees, and deposits the finished can bodies 2 in the second discharge chute 138b. The second discharge chute 22 guides the finished can bodies 2 out of the necking machine 3'.

[102] The first and second transfer wheels 126a, 126b and the first and second discharge wheels 134a, 134b each include a respective gear 24 and a shaft 32 as described above in connection with the necking machine 3. The first and second transfer wheels 126a, 126b and the first and second discharge wheels 134a, 134b can be driven by the gearbox 26, the motor 30, and the drive belt 30, by way of the respective gears 24 and shafts 32.

[103] The necking machine 3'further comprises a conveying mechanism 142. The conveying mechanism 142 receives the partially-necked can bodies 2 from the first discharge chute 138a. The conveying mechanism 142 transports the partially-necked can bodies 2 to the second input chute 106b of the input portion 100. The conveying mechanism 142 can be any suitable mechanism capable of transporting the can bodies 2 from the first discharge chute 138a to the second input chute 106b. For example, the conveying mechanism 142 can be a series of transfer turrets, a mass conveyor, a single-track conveyor, another type of conventional conveyor, a tunnel track, a pocket chain, a pin chain, etc.

[104] The second input chute 106b guides the partially-necked can bodies 2 to the second feed wheel 1 Ob of the second input module 108b. The partially-necked can bodies 2 are received by the pockets 112b of second feed wheel 1 l Ob. The partially-necked can bodies 2 are subsequently transported to the necking station 16a'by the second feed wheel 1 lOb and the second transfer wheel 116b, as described above. The end of the partially necked can body 2 undergoes further reductions in diameter as it subsequently passes through the necking stations 16a', 16b', 16c', 16d', 16e', as also described above.

[105] Other suitable arrangements for directing the un-necked and partially-necked can bodies 2 to the first station 16a'in the required sequence can be used in the alternative to the input portion 100. Moreover, other suitable arrangements for recirculating and discharging the partially-necked and finished can bodies 2 can be used in the al- ternative to the discharge portion 122. For example, the first discharge module 132a can be positioned directly above the first transfer module 124a (from the perspective of Figure 4) so that the first discharge module 132a receives the partially-necked can bodies directly from the first transfer module 124a. Moreover, the first and second discharge wheels 134a, 134b can be configured with less than twelve of the respective pockets 136a, 136b.

[106] Each of the necking stations 16a', 16b', 16c', 16d', 16e'can include dies having more than two different sizes in alternative embodiments of the necking machine 3'.

For example, each necking station 16a', 16b', 16c', 16d', 16e'can be equipped with three (or more) sets of dies. Each set can include four (or less than four) dies. The nominal diameters of the dies in each set can differ from those of the dies in the other two (or more) sets. The dies can be sequenced on the turrets 19 of the necking stations 16a', 16b', 16c', 16d', 16e'so that dies of particular nominal diameter are located between dies of the other two nominal diameters. In other words, dies having a first, a second, and a third nominal diameter can be located in consecutive positions around the turret 19. The can bodies 2 can be circulated through the necking stations 16a', 16b', 16c', 16d', 16e'three (or more) times, using the techniques described above in connection with the necking machine 3'.

[107] Recirculating the can bodies 2 through a necking machine in the above-described manner can increase the number of diameter reductions that can be performed on the can body 2 using the necking machine. This feature can be particularly advantageous where the required throughout in a particular application is approximately half (or less) than the maximum throughput of the necking machines available for that application.

[108] For example, the maximum throughput of the necking machine 3 is approximately 2,400 can bodies per minute. The necking machine 3 can perform no more than five diameter reductions on the can bodies 2 passing therethrough, regardless of its throughput in a particular application. Hence, the necking machine 3 is limited to five diameter reductions when operated at half (or less than half) of its maximum throughput, i. e. , when operated at a throughput of approximately 1,200 can bodies per minute or less. Two of the necking machines 3 must therefore be used in applications requiring ten diameter reductions, regardless of the required throughput, when the necking machines 3 are configured and operated in a conventional manner.

[109] Recirculating the can body 2 through the necking machine 3'allows the necking machine 3'to perform ten diameter reductions, at a throughput of approximately 1,200 can bodies per minute or less. The necking machine 3'can thus perform the same number of diameter reductions on an equivalent number of can bodies 2 as two of the necking machines 3, under this particular set of operating conditions.

[110] The use of the present invention, in certain applications, can thus facilitate necking operations using fewer necking machines than would otherwise be required. The substantial expenses associated with procuring, operating, and maintaining additional necking machines can thus be eliminated through the use of the present invention. The need to allocate floor space for the additional necking machines can also be eliminated.

In other words, the use of the invention can, in some applications, eliminate the under- utilization and waste of resources that can occur when operating multiple necking machines at less than their full capacities. (Similar, or greater savings can be achieved in applications where the can body 2 is recirculated through the necking machine 3 three or more times.) [111] The foregoing description is provided for the purpose of explanation and is not to be construed as limiting the invention. Those skilled in the relevant art, having the benefit of the teachings of this specification, may effect numerous modifications to the invention as described herein, and changes may be made without departing from the scope and spirit of the invention as defined by the appended claims.

[112] For example, the present invention has been described in connection with a necking machine that performs ten diameter reduction using five necking modules. Alternative embodiments can be configured to perform less or more than ten necking operations using less or more than five necking modules. Also, the direction of circulation of the can bodies 2 can be reversed in alternative embodiments.