Screw driver with torque restrictor includes magnetic coupling with inner and outer bodies joined in one piece of magnetic material and with permanent magnets oppositely pole with inner body moved steplessly by adjuster

摘要

The screw driver has a drive part as handle (6) or shaft and an output part (7) as tool shaft connected through a torque restrictor formed as a magnetic coupling with inner and outer axially concentric bodies. The inner body (1) has several radially outwardly aligned permanent magnets (4) and the outer body has several inwardly directed permanent magnets (3). The two bodies are formed in one piece from magnetic material with plastics bonding and has an initially amorphous structure with several magnets produced in the bodies by locally magnetising the magnetic material. The magnets in the inner bodies are oppositely poled to those in the outer body. The inner body can be moved steplessly or in very small steps axially relative to the outer body through a scaled adjusting device which can be operated from outside the handle.