Abstract: A dual acting hydraulic jarring enhancer which is particularly well suited for coiled tubing application. A common annular chamber is formed between reciprocating cylindrical assemblies, and a piston is positioned within the annular chamber. The inner cylindrical assembly has a member to contact the piston and move it relative to the outer cylindrical assembly in one direction while the outer cylindrical assembly has a member to prohibit longitudinal movement of the piston relative to the inner cylindrical assembly in a second direction. In this manner, the present invention provides a tool with overall minimal length by using a singular annular chamber capable of being divided into two other chambers and providing an accelerating effect to a hammer/anvil of an associated jarring tool in either an upjarring or downjarring mode.

Abstract: A dual acting hydraulic jarring tool which includes dual acting metering devices and is particularly well suited for coiled tubing application. A common annular chamber is formed between reciprocating cylindrical assemblies and dual engaging and metering devices are used to engage and meter hydraulic fluid at a predetermined rate flowing from one chamber to another chamber defined within the annular space. An improved retarding and metering mechanism is also disclosed which serves to retard relative telescoping movement of one cylindrical assembly relative to the other cylindrical assembly and meter the hydraulic fluid at the predetermined rate. The present invention is particularly well suited for coiled tubing application due to its low load requirements, minimal overall length and enlarged interior bore for the passage of downhole tools; however, the present invention is well suited for use with conventional drilling strings as well.

Abstract: A hydraulic circuit that includes cylinders that allow for continuous fluid circulation therethrough as well as fluid flow control devices that also allow for continuous fluid circulation therethrough. The cylinders are designed with two fluid connections in such a way as to allow fluid to enter the cylinder through one connection passing through the chamber of the cylinder and out through the other connection thus allowing the oil to circulate rather than remaining stagnant. The circulating oil will stay warmer and more flowable. To control the application of pressure to the cylinders, a lever-operated pressure relief valve is installed in the fluid conductor line connected to the exit connection of the cylinders. By using the lever to reduce the flow of fluid in the circuit, a pressure is built up in the cylinders causing them to operate.

Abstract: Apparatus for automatically compensating or adjusting for the slack or added travel as frictional material on brake pads wears during repetitive brake applications. A stack of snap rings each having a gap in its periphery is collapsed or compressed and assembled onto the inside diameter of a wall of a hydraulic pressure applied cylinder portion. The wall inside diameter has a shoulder with a first diameter that holds the snap rings in their compressed condition. Contiguous to that section is a second wall section having a diameter larger than the first section such that as the cylinder is extended further during a braking action because of wearing of the brake pads, one of the snap rings is forced into the larger diameter area thus expanding it and preventing the wall portion of the cylinder from returning to its original position, thus maintaining the gap constant.

Abstract: Drawworks transmission shifting apparatus is described that provides an arrangement of control valves, cylinders, clutches and brakes which permit the rig operator to shift the drawworks transmission into the desired setting and to lock the transmission in those positions by the use of remotely controlled pneumatically powered cylinders.