Abstract: An electromechanically controlled thermostatic mixing valve (10) comprises a movable mixing valve member (114) resiliently held between a temperature responsive coiled spring (132) and a bias spring (134). The temperature responsive spring is made of a material such as a shape memory alloy (SMA) having a modulus of elasticity that varies with temperature. The bias spring is supported by an electric drive (46) controlled by an electric control circuit (32) to adjust the preload on the bias spring. In contrast to the bias spring which is subjected to deformation from its free state to its fully compressed state, the SMA spring is held in such a manner that it is subjected to a limited strain throughout the stroke of the valve member. As a result, premature fatigue of the SMA spring is avoided. Transient fluctuation in water temperature is primarily compensated for by a mechanical feedback control performed by the SMA spring.

Abstract: A hand-held shower unit (12; 250; 504; 540) is disclosed which comprises a rotatable shower head (94) provided with a plurality of spray heads (132; 134; 136; 138) having different spray or water delivery characteristics. The rotatable head (94) is mounted on a shaft (122) driven by a micromotor (190) received in an inner cavity (64) which is formed in a handle casing (52; 252) by offsetting a water conduit (58). Upon pressing a control button (200), the rotatable head (94) is rotated such that water is delivered through selected one of the spray heads (132; 134; 136; 138). To establish a fluid tight seal between the rotary head (94) and the water conduit (58) while avoiding frictional contact therebetween in order to reduce the torque required for the micromotor (190) to rotate the head (94), a water pressure-responsive movable sealing member (104; 260) is arranged. Also disclosed is a shower bath system (10; 500) including in combination the hand-held shower unit ( 12; 250; 504; 540).

Abstract: Device for preventing water hammer while regulating water pressure includes valve element biasing means which substantially consists of a pressure adjusting spring with a small spring constant and a water hammer preventing spring with a large spring constant which are disposed in series in a valve casing. The valve element biasing means is capable of varying the opening area of a communicating passage between an upstream passage and a downstream passage to as to adjust the pressure in the communicating passage while preventing the occurrence of water hammer in piping water supply equipment.