Abstract: An hydraulic, bolt tensioning device comprising a reaction component which in use bears against the member from which the bolt shank protrudes, the reaction component having a shank receiving bore extending therethrough, an annular, axially moveable component carried by said reaction component and moveable axially relative thereto by the introduction of hydraulic fluid under pressure between said components, a cam ring secured to said axially moveable component for axial movement therewith, and rotatable relative to said component about the axis thereof, and, a tensioning nut secured to said cam ring for movement therewith, said tensioning nut being divided into at least two relatively displaceable segments moveable relative to said cam ring between an open position in which the shank of a bolt to be tensioned can pass freely between said segments, and an operative position in which the thread portions on said segments mate with the thread of said bolt shank, said cam ring cooperating with said nut segments w

Abstract: A hydraulic nut 16 (FIG. 2) or (bolt 70 FIG. 5) has a body 17 including an annular recess 20 to define, with an annular piston body 28, a chamber 29. The piston terminates in annular metal webs 30, 31 which define seals capable of withstanding high temperatures for long periods between chamber pressurizations. A locking ring 32 carried by the piston abuts the end face 35 of nut body wall portion 24 to support a bolt tension induced by hydraulic pressure in the chamber when such pressure is reduced. The end 33 of the locking ring is recessed, as is the corresponding face portion 35 of the nut body, to ensure that if the body wall portion 24 is deflected outwardly by chamber pressure it is able to relax and slide inwardly over the ring surface, despite the axial load being transmitted when the chamber pressure is reduced.

Abstract: A long link pin for a vehicle track is extracted cold from interference fit in bosses by means of a high pressure, short stroke hydraulic ram mechanism which includes a guide tube defining a guide enclosure into which short drift blocks may be loaded through a window on successive ram reciprocations. The drift blocks stack to form a drift which displaces the link pin. One drift block is arranged to bridge the side boss and guide tube, providing lateral support for the apparatus. The exposed part of the drift is short, thereby reducing risk of bending, and the ram is always close to the pin irrespective of pin length making a compact length displacement arrangement.

Abstract: A nut splitter (FIG. 1) incorporates a cutter blade (11), the working edge (16) (FIG. 4) of which is of a blunt, rounded profile. The blade (11) is preferably an equilateral triangle in section, with a cutting edge (16) formed at each apex, thereby enabling use of a blade holder (10) which allows easy change of the working edge (16).

Abstract: A spacer washer 20 (FIG. 2) for disposing between a nut and a turbine casing flange (16, 12 FIG. 5) has a foot end 24 corresponding to the footprint of the nut and extends with wall thickness 25 in one radial direction 28 no further than the nut footprint, to permit minimum spacing pitch, but extends in the orthogonal direction 29 with greater wall thickness 30 to provide support outside the nut footprint for a hydraulic bolt tensioner in a plane displaced from the flange and possibly overhanging part of the casing. The length of the spacer washer may vary from bolt to bolt along the flange to bring nuts from a stepped flange to the same plane and/or increasing the effective bolt length to the nut enables tensile stress to be introduced easier and more accurately.

Abstract: A hydraulic bolt tensioner in the form of an annular hydraulic jack includes a bridge piece constituted by a plate assembly having at least one support leg which in use serves to transmit the reaction from the piston and cylinder of the jack to hardware associated with the bolt which is to be stressed. The support leg is preferably axially adjustable in length.

Abstract: Hydraulic bolt tightening means comprises a body, a piston mounted in the body, the piston and the body being of generally annular configuration to allow the device to be assembled in encircling fashion to a bolt or like components, and an annular chamber between the body and the piston for the admission of fluid under pressure to effect relative axial displacement of the body and the piston whereby the axial dimension is increased, the piston comprising an inner part having a pressure area which is subject to the pressure in said chamber and an outer part to which the fluid pressure is transmitted via said inner part and an interposed mass of solid, yielding and substantially incompressible material whose effective pressure area is less than that of said inner piston part whereby, in use, said mass is caused to expand radially so as to seal against leakage of fluid from the chamber while at the same time transmitting the pressure to the outer piston part.