Abstract: Disclosed herein is a power feed system for translating a rotary drill head along the length of a guide tower. The system utilizes a compound balanced area, end fed hydraulic cylinder as the actuating means. This arrangement provides a large ratio of fixed overall length to usable travel distance, balanced feed force in both directions, direct connection of the rotary head to the outer stage of the cylinder, and drift-free operation, all without the need for moving hydraulic hoses.

Abstract: A drill pipe handling mechanism for a drilling rig includes spaced apart upper and lower arms mounted on a shaft which is mounted for pivotal and limited axial movement with respect to an axis which is spaced from and parallel to the drilling axis. The lower arm includes a receptacle for the lower end of a drill pipe section. The upper arm includes a drill pipe holder having a power actuated movable gate section. A drill pipe retainer is pivotally mounted on the shaft above the pipe holder and is operated by a separate power actuator. Opposed power actuated pipe gripping and holding wrenches are disposed on the lower part of the rig mast for gripping and holding a drill pipe section while threaded joints are broken loose by a rotary head connected to the upper end of the drill string. A power actuated wrench is mounted for pivotal movement into pipe gripping position for breaking loose threaded joints which cannot be loosened by the rotary head.

Abstract: A drill pipe handling mechanism for a drilling rig includes spaced apart upper and lower arms mounted on a shaft which is mounted for pivotal and limited axial movement with respect to an axis which is spaced from and parallel to the drilling axis. The lower arm includes a receptacle for the lower end of a drill pipe section. The upper arm includes a drill pipe holder having a power actuated movable gate section. A drill pipe retainer is pivotally mounted on the shaft above the pipe holder and is operated by a separate power actuator. Opposed power actuated pipe gripping and holding wrenches are disposed on the lower part of the rig mast for gripping and holding a drill pipe section while threaded joints are broken loose by a rotary head connected to the upper end of the drill string. A power actuated wrench is mounted for pivotal movement into pipe gripping position for breaking loose threaded joints which cannot be loosened by the rotary head.