Abstract: A rotary power tong for use in well drilling operations to make up and break out drill strings or similar axially elongated objects having a housing receiving a rotor assembly therein for actuating jaw members into the drill string for rotation of the drill string. The rotor assembly has a generally annular rotor with a plurality of axial bores therethrough positioned in a generally circular pattern adjacent the outer periphery of the rotor. Each axial bore receives a roller assembly comprising a shaft received through the axial bore and secured to the rotor and a roller bearing secured to the bottom of the shaft extending below the rotor. The roller bearing rotates relative to the shaft and rotor. The rotor assembly is received within a circular guide track within the housing such that the rotor assembly load is balanced evenly within the housing providing for a smooth rotational operation of the power tong.

Abstract: A rotary tong used in well-drilling operations to make-up and break-out drill strings which incorporates readily-interchangeable sets of jaws, one of which may be used for drill pipe and the other of which can be used for relatively thin-walled well casing.