IMPACT-ACTION SCREW DRIVER Russian patent published in 1996 - IPC

FIELD: hand tool intended for fitter's work at dismantling of difficult-to-unscrew threaded fastening members. SUBSTANCE: functioning of the screw driver is based on impact-turning action on the screw driver blade and creation of torque sufficient to shift the fastening member in the thread. The impact- action screw driver represents a spring-loaded rod mounted in the casing; in the lower part the rod is connected to replaceable blade and in the upper part - to detachable striker. The screw driver casing has helical ducts with a helix angle of 60 to 70 per cent, closed with a safety bush. The blade attachment assembly is mounted in the lower end of the safety bush installed inside the casing. The safety bush may be made in the form of a polyhedral prism. EFFECT: enhanced convenience in use. 3 dwg