Fluid operated logic device

Claim 1

A fluid logic system including a logic device for selecting a single output signal from two fluid input signal paths, said device having a common chamber, two separate fluid inlets and a common outlet opening for producing a controlled fluid output comprising, means defining a first fluid flow path from a first of said inlets to said output opening, means defining a second fluid flow path from the second of said inlets to said output opening, said first and second flow paths passing through said common chamber, said chamber including fluid impervious diaphragm means positioned therein for blocking one of said first and second flow paths within said chamber and for isolating said first flow path from said second flow path within said chamber, said diaphragm means being movable in response to fluid movement into said chamber, means introducing first and second logic input signals comprising discrete fluid flow on-off signals at substantially the same pressure to both said paths whereby fluid flowing through at least one of said first and second flow paths provides to said outlet opening fluid at said input pressure to produce an output signal of the same pressure at said outlet opening, and means operable by fluid flow signals at said pressure coupled with said outlet opening to receive output signals consisting of transfer of fluid flow at said pressure from at least one of said logic input signals flowing through said logic device.