Abstract: A heat sink subassembly may include a retainer comprising several attachment points, a heat sink coupled to the retainer, and a force-generating device. The heat sink includes several fins, one of which is shorter than the other fins. The force-generating device is coupled to at least one of the attachment points and to the first fin. The force-generating device is configured to exert a force that keeps the heat sink securely coupled to the retainer when the force-generating device is coupled to the attachment points.

Abstract: In the representative embodiment of the new and improved apparatus disclosed herein, a multi-section MWD tool is cooperatively arranged to include a plurality of separable tool bodies respectively carrying a pressure-tight enclosure with one or more electrical means and adapted to be tandemly coupled together to assemble a particular MWD tool. Mating electrical connectors connected to the electrical means are cooperatively supported in the threaded end portions of each tool body by mounting means uniquely arranged for selective manual adjustment to ensure reliable electrical connection to the connector in the next-adjacent tool body as well as to prevent the male threaded end portion of the adjacent tool body from damaging the connector in the female threaded end portion of the first tool body as the two bodies are being coupled together.

Abstract: An electronics packaging system suitable for the hostile operating environment of downhole MWD tools is disclosed which has a "Y"-shaped cross-sectional chassis on the periphery of which are attached a plurality of electronics modules in a "delta" configuration to give a rigid, high density assembly with convenient cabling channels running axially of the chassis. Roller supports or annular shoe supports provided on the chassis isolate the electronics from the vibration and shock forces experienced by the housing. The metal-elastomer-metal construction of the supports offers the resiliency needed for vibration dampening and shock absorption, as well as the rigidity needed for rolling and controlling the direction of application of the undissipated forces. Heat sinks are provided both above and below electronics elements to rapidly disseminate localized heat and to radiate heat generally through the housing walls to an external cooling medium.