Patent ID: 7611068

Claim:
A temperature adjustment handle autorotation prevention device for an automatic hot and cold water mixing valve, the automatic hot and cold water mixing valve comprising: a body comprising a cylindrical shaped case having a bottom and a cylindrical shaped valve seat connected to an open end of the cylindrical shaped case, wherein a hot water inlet and a cold water inlet are provided in the cylindrical shaped case of the body; a cylindrical shaped control valve body fitted within the body so as to be able to move in an axial direction; a temperature sensitive spring whose first end is coupled to a first end of the control valve body in the axial direction thereof; a bias spring whose first end is coupled to a second end of the control valve body in the axial direction thereof; an adjusting screw that supports a proximal end of the bias spring; and a temperature adjustment handle provided at an end of the body, wherein the control valve body is held in a position determined by an equilibrium of the temperature sensitive spring and the bias spring, and the adjustment screw is displaced in the axial direction by rotation of the temperature adjustment handle to set a desired temperature setting, wherein a restraint member, that is prevented from moving in a circumferential direction of the body and that is pressed by a spring in a radial direction against a periphery of an adjusting screw receiver forming a rotation shaft of the temperature adjustment handle incorporated in the body or a connecting sleeve connected to the adjusting screw receiver and the temperature adjusting handle, with sufficient force to oppose the force in the rotational direction causing autorotation in the temperature adjustment handle when the temperature is set, so as to prevent autorotation of the temperature adjustment handle, wherein a plurality of mating projections are formed continuously in the circumferential direction on the peripheral surface of the adjusting screw receiver that is connected to the temperature adjustment handle via the connecting sleeve, the mating projections having a shape substantially similar to teeth of a gear; the restraint member, which is pressed against the plurality of mating projections on the periphery of the adjusting screw receiver, is held in a case incorporated in an internal cavity of the body, the restraint member being freely movable in a forward and backward direction with respect to the peripheral surface of the adjusting screw receiver, and said restraint member is urged to be pressed against the mating projections of the peripheral surface of the adjusting screw receiver by a spring.