Defrost thermostat used in a reversible refrigerating cycle for heat pumps
AssigneeKabushiki Kaisha Saginomiya Seisakusho
InventorsShigeki Machida, Takeo Makita
Life of this patent
Estimating the term…
Abstract
A defrost thermostat provided with a timer driven cam mechanism for preventing repetition of defrosting operation shortly after the completion thereof which is apt to be caused due to the temperature lowering of the external unit acting as an evaporator during the indoor heating operation. The cam mechanism includes a masking member coaxially mounted on the disc cam to block the cam recess while leaving a gap for permitting an initial defrost operation. During the defrost operation, the cam follower goes out of engagement until it rides over the masking member. Once the defrost operation is completed, it will not be repeated immediately thereafter, thus ensuring stable normal indoor heating operations.
Claims9
A defrost thermostat used in a reversible refrigerating cycle for heat pumps comprising
- a snap-action toggle switch mechanism having a movable contact plate normally urged toward a selected one of two positions;
- an actuator means for actuating said movable contact plate;
- thermally responsive means to move said actuating means;
- and
- a timer driven cam arrangement to move said actuating means, said timer driven cam arrangement including a disc cam having recesses at predetermined intervals in a periphery thereof, a first masking member provided coaxially with said disc cam and having a corresponding number of masking portions to mask said recesses in the disc periphery, each masking portion being adapted to define an unmasked gap in the recess.
Dependencies are inferred from the claim text.