Patent ID: 6904980

Claim:
A pneumatically actuated linerbolt removing tool including: a housing; a moil supported for reciprocal movement along a hammer axis by the housing; an inertial body mounted for reciprocating movement in said housing along said hammer axis; a piston assembly movable within said inertial body along the hammer axis between a striking position at which the piston assembly strikes the moil and a retracted position remote from the moil; a gas-charged accumulator adjacent said piston assembly and tending to urge said piston assembly toward said moil; working air supply means to a cylinder associated with said housing and adapted to urge a biasing piston on said inertial body relative to the housing and toward said moil, said inertial body ported whereby said working air is supplied to a front face of said piston assembly to urge the piston assembly to a cocked position away from said moil and whereby said accumulator is in its compressed state; and selectively operable porting means adapted to equalize pressure between said front face and a rear face of said piston assembly whereby said piston assembly accelerates forward under accumulator force to strike said moil while said inertial body accelerates away from said moil, said porting means being adapted to continuously allow transfer of air between said faces while in operation.