Abstract: Maximum rate of drill bit penetration in high speed coring is achieved by precise control of bit weight and bit speed. The automatic drilling system of this invention makes it possible to quickly reach and maintain this optimum combination or "sweet-point" each time the core bit is started. The required speed and weight is input into the system by the operator. A controller electronically senses the bit weight and provides instantaneous feedback to a hydraulically driven drawworks which is capable of maintaining a precise weight on the bit throughout varying penetration modes. The drilling system uses a combination of equipment that includes a hydraulic system for the control of the drawworks; a solid-state strain gauge load cell apparatus built into the swivel assembly for continuously weighing the drill string; an electronic load control circuitry for determining the bit weight, drill string weight, and for maintaining the bit weight control; and, a top drive system for high speed rotation of the string.

Abstract: Apparatus by which a check valve assembly of a reciprocating pump can be removed. A valve stem of the valve assembly is received within a valve guide which is mounted in a valve guide bracket. The bracket is pivotally attached to a yoke. The yoke is removably fastened to an adaptor. The adaptor is seated in an access port arranged perpendicular respective to the passageway within which the valve seat is mounted. The compressive force of the valve spring maintains the bracket and yoke in assembled configuration respective to the adaptor. The bracket and yoke can be pivoted apart, against the spring force, and removed through the adaptor and then the adaptor can be removed from the access port, thereby gaining access to the remainder of the valve assembly.