1. FIELD OF THE INVENTION
This invention relates to the cryogenic field, and more particularly, to an arrangement for effecting a low thermal impedance path between two relatively movable cryogenic heat pipes within a vacuum environment.
2. DESCRIPTION OF THE PRIOR ART
Heat transfer has been effectively achieved in space and other low vacuum conditions by the use of a heat pipe consisting of an envelope or tube carrying internally on the surface or by separate member a capillary flow path and being provided with a mass of vaporizable working fluid such that by heating one end of the tube, working fluid in liquid form is vaporized and travels through the internal space of the tube to its other end, where heat is rejected during condensation of the working fluid. The condensed working fluid by capillary action travels back to the end of the tube being subjected to heat input and is again vaporized to repeat the process.
Conventionally, wick material such as a porous mesh screen or the like forms the capillary transport structure internally of the heat pipe tube and extends from end to end. Such heat pipes have been employed particularly in the cryogenic field under spacecraft applications where heat may be transmitted in the absence of a gravity field, since the liquid moves by capillary or wick effect, irrespective of the presence or absence of gravity. Obviously, in a static arrangement, a heat conductive member such as metal may be employed for connecting the end of one heat pipe to the end of another to effect a low thermal impedance path between multiple heat pipes in a given system. However, where the heat pipes are carried by members which continuously move relative to each other or which may be angularly adjusted relative to each other, the means permitting such relative movement creates a very high thermal impedance path at the interface between the two moving members forming elements of the joint means between respective heat pipes.