Patent GB-1428912-A (GB)
Title: Closure cap applying apparatus
IPC: B67B3/18
Filed: 1974-03-22
Abstract: 1428912 Capping apparatus CHERRY-BURRELL CORP 22 March 1974 [3 April 1973] 12840/74 Heading B8T A closure applying apparatus for forming a screw-thread and pilfer ring in the cap of a threaded container, comprises toggle means for preventing damage to the container and thread forming rollers, should a container of above a preselected height be encountered during the capping process. The apparatus comprises a housing 30 rotated about a vertical axis, by the engagement of a friction ring 82 with a rub rail 80. The housing 30 includes an annular spring housing 32 containing a compression spring 48, and terminating in a transverse plate 34 to which is threaded a longitudinally extending support member 40. The upper end of support member 40 is slidable within a spring-retaining member 42 which is in turn attached rotatably to an arm 70 fixed to a support block 72 which is free to slide vertically along a shaft 74, the vertical displacement being governed by the profile of a rail 78 along which a cam follower 76 secured rotatably to support block 72 is caused to travel. The lower end of spring 48 abuts a spring retaining nut 50 which is adjustably threaded to support member 40 to vary the spring tension. An annular flange 36 integral with the lower end of housing 30 supports a platform 54 via nut-and-bolt assemblies 56 and spacer sleeve 58. Platform 54 serves as a support for two thread-forming rollers 102, a pilfer ring forming roller 104 and a pressure head device 86 which is mounted rotatably on platform 54 and which during the capping operation holds the cap and its seal 26 in firm engagement with the container rim, pressure being provided by compression of spring 48. A rod 168 slidable within support member 40 is attached at its lower end to a clevis block 196 held in engagement with the lower side of transverse plate 34 by a compression spring 180. A thrust block 176 secured rotatably to the upper end of rod 168, carries a cam follower 186 which engages a rail 192 and thereby causes rod 168 and clevis block 196 to move vertically in accordance with the profile of rail 192. Each thread forming roller 102 (Fig. 6) is mounted rotatably on a shaft 108 which can slide within a sleeve 114 and is held in position by means of a coil spring 120. Sleeve 114 is threaded in an arm 118 which is in turn adjustably secured at a desired orientation to a shaft 130 which is journalled in the platform 54. Shaft 108 is tilted relative to shaft 130 at an angle approximately equal to the angle which the thread on the container makes with the horizontal. A lever 140 fixed to the shaft 130 is connected via a bolt 150 to an upstanding leg portion 148 (Fig. 2) integral with a lever 144 which is mounted rotatably on shaft 130. A spring 154 disposed about bolt 150 holds levers 140, 144 in position relative to each other, a nut 156 providing adjustment for the spring tension. The pilfer ring forming roller 104 is mounted similarly, but with shafts 108 and 130 parallel. Yoke legs 146 integral with the levers 144 are connected to the clevis block 196 via toggle linkages 198. During the capping operation, housing 30 is lowered by the action of rail 78 on cam follower 76 until pressure head device 86 engages the cap 12. The engagement of rail 192 with cam follower 186 then causes downward movement of the clevis block 196 which in turn acts upon the toggle linkages 198 to produce outward movement of yoke legs 146; the resulting rotation of levers 144 is transmitted to corresponding levers 140 via springs 154 causing thread forming rollers 102 and pilfer ring forming roller 104 to move inward and engage the skirt 20 of cap 12. Rotation of the apparatus caused by engagement of friction ring 82 with rub rail 80 results in the formation of a thread and pilfer ring in the skirt of cap 12. Adjustment of tension in springs 48, 154 and the position of arm 118 on shaft 130 is provided so that the apparatus may be adapted to fit a range of container sizes. However, should a container of greater height than that for which the apparatus has been adjusted be encountered during the capping operation, premature engagement of the pressure head device with the cap will occur causing clevis block 196 to descend relative to platform 54 until the toggle means moves over centre. This results in rollers 102, 104 releasing their pressure on the container cap thereby minimizing possible damage to rollers and container.