Patent ID: 7665514

Claim:
A drill stem engaging apparatus for connection to an elongated feed beam of a drilling apparatus for one of guiding and wrenching a drill stem, said apparatus comprising: a frame; opposed actuators supported on said frame, said actuators comprising pressure fluid operated piston and cylinder actuators; spaced apart jaw support members connected to said actuators for movement toward and away from each other to engage a drill stem and to move away from said drill stem; actuator support members for said actuators disposed on said frame and adapted to position said actuators in one of at least two selected positions to accommodate a range of one of diameter or cross-sectional shape of said drill stem; wherein said actuators include opposed trunnions engaged with respective bearing bores on said actuator support members; and said actuator support members include a generally cylindrical boss formed thereon and said bearing bores are disposed eccentric to said boss whereby said support members may be disposed relative to said frame in a first position and in a second position rotated 180° from said first position.