Patent GB-607634-A (GB)
Title: A machine for tightening or slackening a tapered or screwed plug or stopper on a bottle, container or similar article
IPC: B67B3/20
Filed: 1946-02-06
Abstract: 607,634. Screwing-up and unscrewing screws etc.; chucks. CADNEY, W. Feb. 6, 1946, No. 3720. [Class 83 (iii)] A machine for tightening or slackening a screwed plug on a container comprises means for gripping and rotating the container in either direction and for holding the plug against rotation while allowing axial movement relative to the container, and means operated by the plugholder for automatically stopping rotation of the container at a predetermined point in the tightening or slackening operation and for releasing the container-gripping and plug-holding means. The container may be an oxygen cylinder A, Fig. 1, in which a plug B containing a control valve is fitted. The cylinder A is held in a chuck 13 rotated through a flexible and splined coupling 14b, Fig. 1a, from an electric motor 4 which also drives an air compressor 5 supplying air to two storage cylinders 3; alternatively, compressed air may be taken from an outside source through a valve 88. For the tightening operation, a switch 26a is set so that the motor drives the chuck in a clockwise direction and the cylinder is placed in the chuck 13, thus depressing a lever 60, Fig. 1, and opening a spring-loaded valve 61 in a pipe from the compressed air cylinders; the plug, loosely screwed in place, rests in a cradle 19 swingably and slidably mounted on a bracket 17 and carrying a pair of pivoted jaws 20. A pedal 12 is now depressed and through linkage 11, 9, 7 operates a master valve 6 so that air is supplied to a spring-loaded plunger 25 that actuates a switch 26 to start the motor, to a cylinder 27 that actuates a sliding carriage 14 on which the chuck is mounted and moves it to the left, to a spring-loaded cylinder 21, Fig. 2, that is connected to the jaws 20 below their pivots and closes them on the plug, and to a second valve 29. Towards the end of movement of the carriage 14, a pin 30 thereon, Fig. 1a, operates the valve 29 so that air is supplied to two cylinders 80 carried on either side of the chuck housing and connected to a ring 51, Fig. 6, mounted on a ball bearing on a ring 49 having a tapered bore engaging a split collet 48, thus closing the collet on the cylinder. The movement of the carriage also brings a wedge connected thereto between the depending arms of the jaws at 90, Fig. 2, and holds them in the clamping position. As the plug is screwed into the cylinder, the cradle 19 is displaced to the right against the action of a spring 22, and, when the plug is tightened by the required amount, the cradle swings clockwise against the torque applied by a weighted lever 39, Fig. 2, connected to an arm 35 on the cradle. A projection 43, Fig. 1, on the lever then engages the lever 9 in the pedal linkage and returns the valve 6 to its original position, thus restoring the operating parts to their original positions and stopping the motor. A dashpot 59, Fig. 1, smooths out the fall of the weighted lever 39. For the unscrewing operation, the switch 26a, is set for anti-clockwise rotation of the chuck, the weighted lever mechanism and the swinging movement of the cradle are rendered inoperative by a bracket 53 and, at the end of the operation, the valve 6 is re-set by the axial movement of the plug to the left, which moves the cradle against the action of springs 34 and operates a lever 54 connected to the valve 6.