Fluid flow control device

Claim 1

A fluid flow control device comprising a housing peripherally enclosing an interior area, normally planar flexible wall means extending across said interior area to compartmentalize said interior area into first and second chambers, means for forming a first upstanding ridge in said first chamber terminating in a generally planar first surface which faces said flexible wall means in a normally noncontiguous relationship, means for forming second and third upstanding ridges in said first chamber positioned, respectively, concentrically inwardly and concentrically outwardly of said first upstanding ridge, forming an inner fluid flow path between said first and second upstanding ridges and an outer fluid flow path between said first and third upstanding ridges, said second and third upstanding ridges terminating, respectively, in generally planar second and third surfaces, each of which faces said flexible wall means in generally said same normally noncontiguous relationship as said first generally planar surface, means for forming in said first upstanding ridge an inlet passage having an opening which extends through said first generally planar surface to conduct a first fluid into each of said inner and outer fluid flow paths subject to a determinable pressure, means for forming in said first upstanding ridge an outlet passage having an opening which extends through said first generally planar surface in a region spaced from said inlet passage opening to conduct the first fluid from each of said inner and outer fluid flow paths, PG,23 means for forming spaced passages communication with said said second chamber for conducting a second fluid through said second chamber subject to a determinable pressure, said flexible wall means being operative in response to fluid pressure differentials between said first and second chambers for displacement out of its normally planar position into farther and closer association with said openings of said inlet passage and said outlet passage in said first upstanding ridge to restrict the conduction of fluid through said inlet and outlet passages to establish and thereafter maintain substantial equilibrum between the pressure of the first fluid and the pressure of the second fluid, and said first, second, and third ridges being operative for supporting said flexible wall means in a generally coplanar position while said flexible wall means is displaced in its closest association with said openings of said inlet and outlet passages.