KRAFTSCHRAUBER.

摘要

The power driven screwdriver or nut runner, has a driving shaft (23) with two pinions (24,25) which engage gear wheels (26) and (27) respectively so that these gear wheels (26,27) rotate at different speeds. The gear wheel (26) is connected to the output shaft (28) by a coupling (33,34) which is held in engagement by a spring (38). When a preset torque is exceeded the axial force of the spring is overcome allowing the sleeve (34) to slide axially and disengage the coupling (33,34). At the same time the teeth (35) on the sleeve flange engage teeth (35) on the gear face (27) to transmit the drive to the shaft (28) through the gear wheel (27). A higher final torque at a lower speed is then transmitted to the nut or bolt.