Hot and cold mixing valve for feeding a shower head, bath tub or the like

Claim 1

A hot and cold water mixing valve for connection to hot and cold water lines for feeding a shower head, bath tub or the like comprising a hollow valve body having a stem rotatable therein from an off position, upper and lower valve discs spaced axially from one another to provide a mixing space between them and coupled to the stem for rotation in unison, means defining an upper inlet opening in the valve body terminating at the upwardly presented face of the upper disc, means defining a lower inlet opening in the valve body terminating at the downwardly presented face of the lower disc, the inlet openings being in substantial alignment with one another in the axial direction, each of the discs having an arcuate through-opening of tapering width so as to define a wide head and a narrow tail subtending a control arc of at least 180° and with a dead sector between the tail and head, means defining an outlet port in the valve body in communication with the mixing space between the discs, the through-openings in the two discs being oriented head-opposite-tail in complementary overlapping relation so that the dead sectors are simultaneously alignable with the inlet openings to define the off position for the valve and so that movement of the stem from the off position exposes one of the inlet openings at its maximum width and the other inlet opening at its minimum width with progressive rotation of the stem gradually reversing the proportion of exposed width and hence the ratio of hot to cold water which flows through the outlet port thereby gradually changing the water temperature while maintaining the total flow substantially constant.