Refrigeration means

In an engine powered vehicle having a storage battery and a geneerator connected to said engine and battery and a refrigerated compartment and a refrigeration system therefor including a cooling coil, a compressor connected by a conduit to the outlet of said cooling coil, an alternating current motor operatively connected to said compressor, a condensor connected by conduit to the outlet of said compressor and to the inlet of said cooling coil, and an expansion valve to adiabatically expand a refrigerant in the conduit to said cooling coil, the improvement comprising:

• a. a second compressor mounted on said vehicle, said second compressor connected by conduit to said condensor and to said cooling coil in parallel with said first named compressor,
• b. means operatively connecting said second compressor to said vehicle engine to be driven by said engine when said engine is in operation, said second compressor having a clutch means to operably connect and disconnect said second compressor and said engine,
• c. control means operatively connected to said system to intermittently operate said second compressor relative to the refrigeration demand of said system when said engine is operating and to intermittently operate said first named compressor relative to the refrigeration demand of the system when said alternating current is connected to a source of alternating current electric power,
• d. said control means having a thermostat switch means communicably connected to said cooling unit, said thermostat switch being electrically connected to said alternating current electric motor to intermittenly operate same, and being electrically connected to said clutch means to intermittently engage same,
• e. a first check valve means communicably connected to said conduit from said outlet to said first named compressor to compress fluids from said first named compressor to said condensor,
• f. a second check valve means connected to the outlet of said second compressor to pass fluid from said second compressor to said condensor,
• g. a first solenoid actuated valve means communicably connected in said conduit between said cooling coil and said second compressor and electrically connected to said control means,
• h. a second solenoid actuated valve means communicably connected in said conduit between said second compressor and said condensor and electrically connected to said control means, said control means being operable to close said firt solenoid actuated valve and said second solenoid actuated valve when said alternating current motor is connected to a source of electricity, and
• i. said second compressor is constructed and adapted to be operable during periods when said alternating current motor is disconnected from a source of alternating current electricity and said vehicle engine operating.