Cryogenic cooler system

Claim 1

A cryogenic cooler system for providing substantially continuous and uninterrupted cryogenic cooling regardless of individual compressor functional failure including: at least two cryogenic compressors, each including a compressor gas port and power coupling, where at any one time one of the compressors is active to provide a working gas pressure modulated by piston action of the working compressor to the compressor gas port; an expander associated with each compressor, each expander including an expander gas port and a cooling surface, where working gas pressure expansion from the active compressor is expanded within the expander so as to cool the cooling surface thereon; a first conduit means coupling each compressor gas port to each respective expander gas port to provide working gas connection between each compressor and associated expander; a second conduit means coupled at one end to each expander cooling surface for the transfer of a coolant fluid therewithin so as to transfer cooling away from the expander cooling surface; a means coupled to the other end of all second conduit means to provide a cooling load; a temperature sensing means coupled to the means to provide a cooling load for sensing the temperature of the means to provide a cooling load; a thermal switch means coupled to each of the second conduit means for controlling the coolant fluid flow therein; a means for coupling all thermal switch means and power couplings to the temperature sensing means such that upon sensing a temperature threshold level by the temperature sensing means the currently operating compressor is no longer powered, and another compressor is simultaneously powered and its associated thermal switch activated, also the associated thermal switch of the previous compressor is closed whereby substantially continuous and uninterrupted cryogenic cooling to the means to provide a cooling load.