| 摘要 |
<p>A universal joint (21) between adjacent, electrically connected instrument housings (17, 18) for downhole operations allow the connected housings to bend longitudinally as required to traverse an arced section of a well bore but does not permit relative elongation or twisting about the longitudinal axis of the housings. In one embodiment, a fluid impermeable open passage space (31) at atmospheric pressure surrounds electrical signal carriers linking the instrument circuitry within the two housings. The passage (31) is constructed as a high-pressure fluid hose (40). In another embodiment, a fluid impermeable sheath (90) surrounds the signal carriers and encapsulates the signal carriers by a resilient solid (92). The articulation structure comprises a Cardan-type of universal joint wherein two fingers (72) project longitudinally from the end of each of the housings. The fingers are meshed and pivotally joined to respective spindles projecting radially from the open center of a ring spyder (29). The protective bellows (80), hose (40) or resilient compound filled sheath (90) secured at opposite ends to bore plugs in the respective instrument housings. Between the instrument housings, the hose, bellows or filled sheath passes through the open center of the spyder ring.</p> |
