Simultaneous tightening machine for bolts of pressure vessel - has hydraulic ram for each bolt socket which has rotary actuator, meshing with socket outer toothing

摘要

The cover (2) of a pressure vessel is secured by bolts (1) with nuts (5). Each bolt is first pretensioned by applying hydraulic pressure to a piston (14) which acts on a second nut (19) at the upper end of the bolt. All the bolts and nuts which retain the cover are simultaneously tightened by chain drives from a common motor (34) through gears (25) which engage teeth on the nut. The upper nuts are also simultaneously tightened in a similar manner through the chain wheel (40A).