GB1233974A - - Google Patents

Abstract

1,233,974. Spanners. TORQUE TENSION (U.K.) Ltd. 9 Feb., 1970 [14 Feb., 1969], No. 8276/69. Heading B3N. [Also in Division F2] A device for tensioning a bolt 5 and tightening a nut 6 on the bolt whilst it is tensioned comprises jaws 10 which can be hydraulically operated to grip the bolt and to move parallel to the axis of the bolt when the bolt is gripped by the jaws, and an hydraulically operable spanner 8 for engaging the nut and tightening the nut relative to the bolt. As shown, the jaws 10 which may be provided with gripping pads 4 of copper or preformed with serrations are pivotally mounted on a block 12 which is rotatably supported by keys and keyways 16, 18 in an annular trough-shaped member 14 defining an annular chamber 14A. A tubular member 20 so abuts the outer surface of the jaws 10 and projects into the annular chamber 14A that when hydraulic fluid is supplied to the chamber 14A under pressure, the jaws 10 are urged by the member 20 to grip the bolt 5. The bolt 5 is then tensioned by supplying hydraulic flud under pressure to each of a plurality of cylinders 24 which are fixed to and spaced circumferentially around the annular member 14 and in which are slidable a plurality of pistons 26 which are positioned in abutment with a surface of a structure 2 into which the bolt 5 extends. With the bolt tensioned, hydraulic fluid is supplied to the spanner 8 to tighten the nut on to the bolt. The spanner may comprise a rotor (31) (Fig. 2, not shown) having radially outwardly projecting vanes (32) which are acted upon by a liquid supplied under pressure to a chamber defined by a cylindrical member 28, the member 28 being slidable, but not rotatable, relative to the cylinders 24. The rotor (31) is connected by a one-way drive system comprising balls engaging tapered slots to an inner member (34) having a hard rubber centre defining a nut-receiving socket.