Patent ID: 7814964

Claim:
A system comprising an isolation valve in combination with a main and auxiliary vehicle air conditioning system having a vehicle engine connected to a vehicle compressor having a discharge line and a suction line, an air conditioning condenser, refrigerant lines extending from the vehicle compressor through said air conditioning condenser to an air conditioning unit in the vehicle, said air conditioning unit having an inlet line extending from said air conditioning condenser to said vehicle air conditioning unit and a discharge line extending back to the vehicle compressor; an auxiliary power plant on the vehicle including an auxiliary engine connected to an auxiliary compressor having a discharge line and a suction line, an auxiliary air conditioning condenser, auxiliary refrigerant lines extending from the auxiliary compressor through said auxiliary air conditioning condenser to said vehicle air conditioning unit and extending from the vehicle air conditioning unit back to the auxiliary compressor, whereby refrigerant can be independently supplied to the vehicle air conditioning unit from the auxiliary compressor of the auxiliary power plant when the auxiliary power plant is operated; and a single isolation valve body having four separate valves contained therein in the refrigerant lines between the vehicle compressor and said air conditioning unit and between the auxiliary compressor and said air conditioning unit for restricting back flow of refrigerant between the two said compressors, said isolation valve comprising an electrically operated spindle rotatably mounted in said body, said body having a plurality of ports communicating with the auxiliary compressor discharge line, the vehicle air conditioning unit inlet line, the vehicle compressor discharge line, the auxiliary compressor suction line, the discharge line of said air conditioning unit, and the vehicle compressor suction line; said spindle having a plurality of grooves and lands providing four separate valves arranged and configured to simultaneously and selectively open and close the body ports such that the auxiliary refrigerant compressor and auxiliary air conditioning condenser are connected to said air conditioning unit while isolating the vehicle compressor and air conditioning condenser, or the vehicle compressor and air conditioning condenser are connected to said air conditioning unit while isolating the auxiliary refrigerant compressor and auxiliary air conditioning condenser.