Abstract: An improved fluid actuated rock drill hammer as shown having a cylinder housing, a reciprocal piston, and a centralized air distributing control tube axially extending through a central bore in the piston for controlling the operation of the piston. The control tube is mounted for assured concentricity of the tube within the piston bore and comprises a unitary mounting portion and tubular portion. The mounting portion includes a piloting section for concentric fit within the cylinder as received on a shoulder therein and the tubular portion extends concentric and perpendicular to the piloted section.

Abstract: A rotary rock bit having the load bearing elements between the axle and the cone cutter encased in a permeable porous plastic material having lubricant in the pores thereof, with the material substantially filling a portion of the bearing cavity to seal the cavity and a lubricant reservoir in the bit with a lubricant flow passage therefrom to adjacent said material to replenish the lubricant lost from the pores during use.

Abstract: An improved lubrication and seal system for a rock bit that includes a bit body arranged to be connected to a drilling string or the like and having an axle portion thereon. A cutting member is journaled on the axle portion and provides a cavity between the axle portion and cutting member in which there are disposed a bearings for rotatably supporting the loads on the cutting member on the axle portion. A pressurized fluid passageway extends through the bit body to the cavity for transmitting bearing conditioning fluid to the bearings. A permeable material having a lubricant in the pores in the material is disposed in the available space between bearings in the cavity in contact with the load carrying bearing and in the fluid passageway whereby the lubricant in the pores is gradually deposited on the bearing to provide a generally continuous in situ lubrication thereof.