Drill attachment for fitting heavy duty masonry bolts has a drive shaft with sliding fit inside an outer support tube and with a torque limited drive

摘要

A drill attachment for fitting heavy duty masonry bolts has a drive shaft (3) with sliding fit on a second drive shaft fitted to a torque limiting drive (2) and secured into the chuck of a power hand drill. The free end of the first drive shaft is fitted with a drive head (5) to fit the masonry bolt while the other end is driven into the outer position by a spring (17). The drive system is inside a fixed support tube (6) which is grips the sleeve of the masonry bolt via a grip flange and two grip pins (13). The operator presses the tool head onto the bolt, with the drive shaft pushed in against spring pressure, and operates the drill to set the bolt with a controlled torque.