HYDRAULIC BOLT TENSIONING ARRANGEMENT

摘要

A hydraulic bolt tensioning arrangement (20) of the tandem-piston type has mechanically coupled inboard and outboard pistons (27, 31) defining with inboard and outboard cylinder bodies (25 and 30) piston extending chambers (40 and 41). An axially extending puller bar (21) having an inboard end adapted to engage with bolt (11) to be tensioned supports pistons (27 and 31) and contains a fluid passage (50) jointing the chambers. A retraction spring (43) between the inboard piston and outboard cylinder body acts to retract both pistons with respect to their respective cylinder bodies by virtue of the coupling with the puller bar. Carriage means, handle (55), connected to the outboard piston enables the arrangement to be disposed on the end of the bolt and rotated as a whole to thread the puller bar onto the bolt and be removed after tensioning, the piston retraction spring means ensuring all fluid is vented from the chambers and the components of the arrangement remain intact.