GB1124949A - Multi-stage pneumatic nut runner assembly - Google Patents

Abstract

1,124,949. Multi-stage nut runner assembly. DESOUTTER BROS. Ltd. 27 Feb., 1967 [21 March, 1966], No. 12327/66. Heading B3N. A multi-stage multiple nut runner comprises a plurality of pneumatically operated tools, Fig. 1, mounted between a manifold 2, and a baseplate 1, the constant pressure air supply to the tool motors being interrupted automatically at the completion of each stage to stop the motors, and valve means which then automatically restart the motors. Each tool comprises a head portion 4 and a base portion 5 joined by a body 3, the portions. being. connected by pipes 35, 36, 68, and the tools are connected by pipes 65, 73. Head portion 4 has valves 54, 70, Figs. 10, 11, and base portion 5 is formed by parts 9, 13, Fig. 7, rotatable relative to each other, and an extension 18 on part 13, Figs. 4, 5, carries valves 22 and 51. Valve 22 is actuated when parts 9, 13 pivot relatively to each other against a spring 26 due to the applied torque, and air passes into pipe 35 and thence to bore 61, Fig. 10 leading.to valve 54 in head portion 4, to thus stop the motor when the required torque of the stage is reached. Valve 22, Fig. 4, is made to open at different relative positions of parts 9, 13 corresponding to each stage, by a cam 3, which is cyclically indexed by a pawl 44 actuated by a pneumatic piston 41, Fig. 5, supplied by pipes 67, 68, Fig. 1. The valves of all too's are connected in series. In operation, air is supplied to the bore 72 of the first tool, Fig. 11, from the main supply via a pipe 79, Fig. 1, and as soon as the nut is tightened to its initial torque stage, the motor stops, valve 70, Fig. 11 opens, and air is passed to piston 41, Fig. 5, to actuate pawl 44 so as to index cam 49, and also passes by way of pipes 73, Fig. 1, to the valves 70 of the second and subsequent tools. Three stages of torque are completed due to the indexing of the cam 49, and each tool comprises a micro-switch (63), Fig. 9 (not shown) which is actuated when valve 54, Fig. 10, is closed, and the operation is completed, and a light is observed on a pictorial display.