Capacity control valve for a variable capacity refrigerant compressor

A capacity control valve for adjustably changing the capacity of a variable capacity refrigerant compressor comprising a suction chamber for a refrigerant gas before compression, a discharge chamber for the refrigerant gas after compression and a crank chamber capable of communicating with the suction and discharge chambers, said capacity control valve being incorporated in said variable capacity refrigerant compressor, comprising:

• a suction pressure responsive means arranged for exhibiting a first forward movement and a second reverse movement in response to a change in suction pressure of the refrigerant gas, a valve means arranged for controlling opening and closing of a gas-supply passageway means extending between said discharge chamber and said crank chamber of the variable capacity refrigerant compressor, said valve means reducing an opening area of said gas supply passageway means according to the first forward movement of said suction pressure responsive means when the suction pressure of the refrigerant gas is above a predetermined suction pressure level, and increasing the opening area of said gas-supply passageway means according to the second reverse movement of said suction pressure responsive means when the suction pressure of the refrigerant gas is below the predetermined suction pressure level so as to control the pressure level prevailing in said crank chamber of said compressor to thereby adjustably change the compressor capacity and a discharge pressure responsive means arranged to exhibit forward and backward movements in response to changes in discharge pressure of the refrigerant gas, said discharge pressure responsive means being operatively coupled with said valve means in such a manner that said valve means reduces the opening area of said gas-supply passageway means in response to one of said forward and backward movements of said discharge pressure responsive means only when the discharge pressure of the refrigerant gas is below a predetermined discharge pressure.