Motorisch angetriebenes Schraubgerät

1,121,782. Screwdrivers. ROBERT BOSCH G.m.b.H. 19 Oct., 1965 [24 Oct., 1964], No. 44162/65. Heading B3N. [Also in Divisions B4 and F2] A screwdriver comprises a housing 2, a reversible electric motor 1 in the housing, which drives an output spindle 7 through gearing 6, and opposite hand one way clutches 12, 13, for connecting spindle 7 to housing 2, so that when the motor is stationary, the screwdriver can be manually operated. A friction clutch may be provided between motor 1 and spindle 7 to absorb excessive torque. Each of the clutches 12, 13 comprises a body 14 rotatably mounted on spindle 7, and having rollers 16, carried in pockets 15 which taper in the circumferential direction, each of the rollers being biased towards the narrow section of its pocket by a spring and plunger 18, 19. A sleeve 27 is keyed for axial movement in housing 2, and carries two lugs 30 which engage in grooves 31 in clutch bodies 14, of either clutch 12 or clutch 13. Sleeve 27 is actuated by a spring 24 which is compressed by the leg 22 of a slidable switch 20, the latter also actuating a reversing contact 4 for the motor drive. In a modification, the screwdriver operates in one direction and only one clutch is provided.