Wall mounted mixer valve with pressure balance

A mixer valve system comprising:

• (a) a body having a plurality of coupling portions extending from a base portion, said coupling portions including:
• mixer valve seat, cold water inlet coupling, hot water inlet coupling, shower-bath outlet coupling, and spout outlet coupling portions;
• said mixer valve seat defining a mixing chamber;
• said base portion having formed therein an axially extended circular accommodation slot and a pair of shallow circular slots extending annularly about and intermediate section thereof, said base portion having formed therein a pair of water inlet passages and a pair of water outlet passages, said water inlet passages extending respectively between said cold and how water inlet coupling portions and said shallow circular slots, said water outlet passages each extending between said accommodation slot and said mixing chamber, said base portion further having formed within said accommodation slot a threaded inner edge section and a bottom section having a shutoff valve member protruding axially therefrom;
• and,
• (b) a pressure balance device disposed within said accommodation slot of said base portion of said body, said pressure balance device including:
• (1) an outer sleeve having a plurality of solid sections, adjacent ones of said solid sections defining therebetween a perforated slot section, said outer sleeve having formed at an axial end thereof an externally threaded hollow section;
• (2) an inner sleeve disposed in coaxially displaceable manner within said outer sleeve for displacement relative to said outer sleeve between open and shutoff positions, said inner sleeve having formed therein a pair of perforated slot sections separated one from the other by an intermediate partition disposed therebetween, each said inner sleeve perforated slot section in said open position communicating with one said outer sleeve perforated slot section, at least one said inner sleeve perforated slot section in said shutoff position being blocked by one said outer sleeve solid section, said inner sleeve in said shutoff position abutting said axially protruding shutoff valve member;
• and,
• (3) a lid threadedly engaging said externally threaded hollow section of said outer sleeve, said lid having formed therein a plurality of water outlet gaps communicating with at least one of said water outlet passages;
• whereby said pressure balance device is automatically displaceable responsive to relative water pressures developed on opposing sides of said intermediate partition thereof to, in said open position, concurrently pass the flow of hot and cold water respectively from said water inlet coupling portions thereof to said mixing chamber, and to, in said shutoff position, block the flow of water at least from one of said water inlet coupling portions to said mixing chamber.