Turret power tool for tightening preloaded bolts - has grips to rotate bolt head and uses short stroke jack to compensate for bolt weight

摘要

The turret type power tool is for tightening large dia. bolts esp. of the pre-loaded variety holding down nuclear pressure vessel covers. the tool is equipped to grip and rotate the bolt head, to apply a torque and an axial force to the bolt, to compensate for bolt weight and to effect guidage with axial displacement. The bolt weight compensation mechanism may comprise one or more jacks acting parallel to the axis of the bolt tightening mechanism. the force applied by the jacks is adjustable and sufficient to displace both the bolt tightening and gripping mechanism, serving to promote axial displacement. a single small short-stroke jack may be mounted between the spindles of the bolt tightening and gripping mechanisms. the advance of the turret is thus equated to bolt pitch.