Abstract: A downhole tool assembly has a component that is sensitive to shock and vibration. A reciprocating element is coupled to the component. The reciprocating element has an axial internal passage and an outer surface. A housing has an internal axial bore for receiving the reciprocating element for axial reciprocal motion therein. A retainer is mounted to the housing and seals the housing between the component and the reciprocating element. A first spring is located between the housing and the reciprocating element. A second spring is located between the reciprocating element and the retainer. A first reciprocating seal is located between the reciprocating element and the housing. A second reciprocating seal is located between the connector and the retainer. A fluid is contained by the reciprocating seals inside the housing. The reciprocating element permits a limited amount of fluid to flow between sides thereof.

Abstract: A drill bit string has an internal steering module for measurement while drilling. A chassis is inserted into a modified drill collar from the axial end, rather than through the side. The chassis has external pockets machined into it from its outer diameter. The size of the longitudinally milled slots in the chassis is determined by the size of the components. The mud flow path is positioned off-center because of the component slots. The geometric shape of the flow path through the tool is shaped to optimize the flow area and maintain a wall thickness that can withstand the mud pressure. The wall thickness surrounding the flow area is proportional to the maximum hydrostatic pressure and the circulation pressure.

Abstract: A drill bit string has an internal steering module for measurement while drilling. A chassis is inserted into a modified drill collar from the axial end, rather than through the side. The chassis has external pockets machined into it from its outer diameter The size of the longitudinally milled slots in the chassis is determined by the size of the components. The mud flow path is positioned off-center because of the component slots. The geometric shape of the flow path through the tool is shaped to optimize the flow area and maintain a wall thickness that can withstand the mud pressure. The wall thickness surrounding the flow area is proportional to the maximum hydrostatic pressure and the circulation pressure.

Abstract: The gap sub assembly comprises a pair of electrically conductive subs. Each sub has a threaded pin and box. A pin and box are threaded together to form a connection. An electrically insulating, woven fabric overlies and conforms with the threads of the connection pin. An electrically insulating, annular washer separates the seal faces of the connection. The assembly functions to provide an electrical discontinuity when incorporated into a conductive drill string.