Christensen, Inc.

Eastman Christensen Company

Norton Christensen, Inc.

John S Davis

Craig R Hyland

Richard H Grappendorf

Jacob T Chow

Lawrence Frear

Gordon G Sirrine

An improved universal ball joint especially adapted to be used in the transmission of high torque, as in oil field use, includes a driving and driven shaft. One of the shafts, which may be the driving shaft includes a spherical ball received in a housing provided in the other shaft, which may be the driven shaft. The opposed surfaces of the ball and housing include axially extending grooves of essentially the same depth and length forming therebetween a plurality of chambers. Each chamber receives a pin which is tapered at each end and which forms the driving connection between the shafts. The shafts and the ball may include a bore for flow of fluid through the assembly, the ball being sealed in the ball chamber by seals to provide a sealed ball chamber which may be filled with lubricant, the ball being seated on a bearing and retained in the chamber by a retainer member which prevents relative axial movement between the shafts. Various forms are described including arrangements for flexible drill strings, reamer/stabilizer combination, mill tool combination and an arrangement for use in converting eccentric rotation to concentric rotation for use in a downhole motor.

Universal ball joint

An improved core catcher for use within a coring tool is provided by shaping the lower portion of the core catcher so as to form a collapsible lower section. The collapsible lower section is structurally collapsed as the core catcher is longitudinally displaced within the coring tool to exert a radially compressive force against the core and to thereby seize the core and retain it within the coring tool. In one embodiment, the collapsible lower section is resilient so that it collapses and after operation resumes its original configuration for reuse. In another embodiment, the collapsible lower section is crushable and is therefore not reusable after the first use. The reusable core catcher is devised by providing the lower section of the core catcher with a plurality of thin slots appropriately aligned and extending through the lower section of the core catcher. The nonreusable core catcher is designed to provide a plurality of crushable longitudinal segments of the lower section of the core catcher, and in one embodiment to allow the entire lower section of the core catcher to be crushable.

Core catcher for use with an hydraulically displaced inner tube in a

An improved bearing system for the driven shaft of a downhole motor is shown that provides a main thrust and radial bearing system having means for sealing the bearings in oil at equal or slight pressure above that of the drilling mud inside the drill pipe and insulating the fluid seals and bearings from all possibility of contact with cuttings and debris from the drilling operation. A durable seal having a restricted flow path permitting slow leakage is positioned below the main bearing system in such a relationship to the drilling fluid distribution path that the seals for the oil bath for the bearings are subjected to essentially the same pressure on all sides.

Bearing system for a downhole motor

A drill bit (10) comprises a cast body (12) with full length wide overlapping integral spiral stabilizer lands (14) between intervening spiral grooves (16), integral short, strong, stubby spiral fingers (18) reinforced by additional web portions (12a) angularly spaced about a short core receiving bore (b) and the longitudinal axis of the body (21). An inclined core ejection passage (P) extends radially outwardly from a spherical inlet end thereof connected to the core receiving bore (b) and at which an inclined hard core cutter breaker inserted within a pocket is situated. The leading sides of the fingers have support surfaces (18a) and shoulders (18b) for supporting engagement with composite abrasive compact cutters comprised of a carbide backing (30a) bonded to the support surfaces (18a) and layers of bonded polycrystalline abrasive particles at opposite cutting sides (30b) inclined at a negative rake angle. The body is also provided with flushing fluid passages (24) and a central bore at its drive end adapted with means (22) to connect drive means, with a flushing fluid passage therein to drive the drill bit (10).

Growing community of inventors

Sandy, UT, United States of America

John S Davis