Patent ID: 7013985

Claim:
A pneumatically operated screw driver comprising: an outer frame; a pneumatic motor disposed in the outer frame and rotatable about its axis; a cylindrical rotary member extending in an axial direction of the pneumatic motor and rotatable within the outer frame by the rotation of the pneumatic motor, the rotary member having an inner peripheral surface formed with a rotation transmission portion, the rotary member comprising a main rotary member made from a plastic material having an end at a side opposite to the pneumatic motor, and a sliding segment fixed to the end of the main rotary member and made from a metal; a rotation slide member disposed within the rotary member and slidable in the axial direction relative to the rotary member, the rotation slide member having an engagement portion engaged with the rotation transmission portion so as to be rotatable together with the rotation of the rotary member; a shaft member having one end portion connected to the rotation slide member and another end portion provided with a driver bit holding section and a piston section; a driver bit connected to the driver bit holding section; and a cylinder fixedly disposed in the outer frame and extending in the axial direction, one of the outer frame and the cylinder providing a contact part with which an end face of the sliding segment is in rotational sliding contact.