Four-way valve for reversible refrigeration cycle

Claim 1

A four-way valve for reversible refrigeration cycle which comprises a casing having a small diameter section and a large diameter section; a delivery tube in communication with a compressor and opening into said casing; a suction tube in communicating with said compressor and opening into said casing; a pair of tubes in communication with two heat exchangers, respectively, and opening into said casing one on each side of the suction tube; a valve means for communicating said suction tube selectively with either one of said pair of tubes; a two-way pilot valve including electromagnetic means and a plunger tube longitudinally mounted and extending with respect to the large diameter section of the casing, a plunger slidably fitted within said plunger tube, a plug provided to block the large diameter section to define a chamber in cooperation with said plunger tube; said plug being formed with a first passageway to provide communication between the chamber and the large diameter section of the casing, said plunger normally being biased to close the first passageway while adapted to retract to open the first passageway by energization of the electromagnetic means, said first passageway having a larger diameter section on a plunger side of the plug and a smaller diameter section on a casing side of the plug, and a rod snugly and slidably received in said smaller diameter section of said first passageway to project from either one side of the plug; said plug being further formed with a second passageway branching off the large diameter section of the first passsageway to provide communication between the large diameter section of the casing and the chamber of the two-way pilot valve; said plug being still further formed with a third passageway to admit high pressure refrigerant from the compressor by way of said chamber and the second passageway into the large diameter section of the casing; said plug being still further formed with a fourth passageway to admit low pressure refrigerant from the compressor directly into the large diameter section of the casing; and said plug having a leaf spring attached thereto on a casing side thereof at its one end and carrying a flat valve disc at its other end, said leaf spring biasing said flat valve disc to close the fourth passageway upon energization of the electromagnetic means and being adapted to open the same upon de-energization of the electromagnet means.