Patent GB-999025-A (GB)
Title: Spin welding plastic closures
IPC: B29C65/06
Filed: 1964-01-23
Abstract: 999,025. Applying closures. CONTINENTAL CAN CO. Inc. Jan. 23, 1964 [March 1, 1963], No. 3011/64. Heading B8T. A closure of plastics material is welded to a container of material which will bond to a melted plastics material by forcing the closure into engagement with the container neck, rotating the closure relative the container to effect melting by friction of at least the surface of the closure which is engaged with the container and discontinuing the rotation while maintaining the pressure engagement until the melted plastics material has set. Containers 29, Figs. 1 and 5, are delivered from a conveyer 22 to a conveyer 23 where perforated closures 33 are loosely applied, and the assemblies are fed by a turret 188 to a turret 74 of a closure applying machine. During rotation of the turret 74 the closures are welded to the containers and the sealed assemblies are transferred to a discharge turret 189 supplying a conveyer 190. The turret 74 forms part of a rotary assembly which includes a sleeve 44 driven from a motor via gearing 60, 61, 51, 50, and the turret has circumferentially spaced pockets around its periphery to receive the containers. The latter are supported by pads 103 and are retained in the pockets by a stationary but vertically adjustable surrounding wall 78. Each pad is mounted on a vertical shaft upstanding from a bracket attached to a slide 92 vertically slidable on a T-bar 67 attached to the rotary sleeve 44. As the turret 74 rotates a cam follower 97 on the slide engages a stationary cam track 91 to vertically move the pad and its associated container to bring it into, and remove it from, association with an aligned spinning head 120. The spinning heads are secured to a part 110 of the rotary structure which is vertically adjustable on the sleeve 44 by means of a double-threaded screw 112 interconnecting the sleeve and the part 110. Each spinning head depends from a flange 117 and includes a rotary shaft 142 driven from the central shaft 171 via drive gearing 169, 145; each head is supported within stationary housings 131, 134. The shaft 171 is motor driven via gearing 183, 176. A non- rotary container locating sleeve 135 is urged downwardly by a spring 138, and an assembly including a pressure ring 153 is urged downwardly by a spring 155 and acts on a further spring 156 which forces a vertically movable chuck 146 to its lower position. As a container support pad 103 moves upwardly the sleeve 135 clamps the container and prevents its rotation, the sleeve and container are then moved upwardly and the closure then engages the pressure ring 153; as the pad continues its upward movement a central pin 198 of the chuck engages the central opening 36 of the closure followed by the engagement of a driving pin 199 on the chuck within an opening 37 of the closure. The latter is then rotated together with the ring 153. After the heating step the pad is lowered slightly to disengage the chuck drive, but not sufficient for the pressure engagement of the ring which holds the closure against the container until the weld sets. The pad is then finally lowered to disengage the closure from the head for transfer to the turret 189.