Pressure differential valve for swimming pool

Claim 2

A pressure differential valve comprising in combination: a valve body comprising three plastic T-shaped pipe sections defining a hollow straight cylindrical closed ended passageway, said pipe sections being interconnected to jointly form said passageway, said valve body having a first pair of fluid inlet ports spacedly arranged in said valve body along said passageway, and a fluid outlet port positioned in said valve body along said passageway at a point between said pair of inlet ports, a piston rod mounted in said valve body for movement longitudinally of said passageway, three pistons mounted on said piston rod, one at each end thereof and one at a point adjacent said fluid outlet port, one end of said piston rod being threaded, stop means threadedly mounted on said piston rod for controlling the range of movement of said third piston relative to said fluid outlet port, a pair of control inlet ports to said passageway one formed in each end of said valve body, and means for controlling the fluid flow through said control inlet ports for regulating the movement of the associated piston juxtapositioned to said fluid outlet port for controlling the position of said three pistons to control the fluid flow from said inlet ports through said fluid outlet port of the valve.

Claim 3

Apparatus for controlling fluid flow between two pools of water comprising in combination: first and second pools, inlet and outlet ports for each of said pools, a pressure differential valve comprising in combination: a valve body defining a straight hollow passageway closed at both ends, said valve body having a first pair of fluid inlet ports spacedly arranged in said valve body along said passageway, and a fluid outlet port positioned in said valve body along said passageway at a point between said pair of inlet ports, a piston rod mounted in said valve body for movement longitudinally of said passageway, three pistons mounted on said piston rod, one at each end thereof and one at a point adjacent said fluid outlet port, a pair of control inlet ports to said passageway one formed in each end of said valve body, a first pair of pipe means for connecting each of said pair of fluid inlet ports of said valve body to a different one of said outlet ports of said pools, a second pair of pipe means for connecting said fluid outlet port of said valve body selectively to each of said inlet ports of said pools, a third pair of pipe means for connecting each of said control inlet ports to a different one of said second pair of pipe means for controlling the fluid flow through said control inlet ports for regulating the movement of the associated piston juxtapositioned to said control inlet port for controlling the position of said three pistons to control fluid flow from said inlet ports to said valve body through said fluid outlet port, a pump, heater and filtering means connected between said fluid outlet port of said valve body and said second pair of pipe means for conditioning fluid flow to each of said pools.

Claim 4

Apparatus for controlling fluid flow between two pools of water comprising in combination: first and second pools, inlet and outlet ports for each of said pools, a pressure differential valve comprising in combination: a valve body defining a straight hollow passageway closed at both ends, said valve body having a first pair of fluid inlet ports spacedly arranged in said valve body along said passageway, and a fluid outlet port positioned in said valve body along said passageway at a point between said pair of inlet ports, a piston rod mounted in said valve body for movement longitudinally of said passageway, three pistons mounted on said piston rod, one at each end thereof and one at a point adjacent said fluid outlet port, a pair of control inlet ports to said passageway one formed in each end of said valve body, a first pair of pipe means for connecting each of said pair of fluid inlet ports of said valve body to a different one of said outlet ports of said pools, a second pair of pipe means for connecting said fluid outlet port of said valve body selectively to each of said inlet ports of said pools, a third pair of pipe means for connecting each of said control inlet ports to a different one of said second pair of pipe means for controlling the fluid flow through said control inlet ports for regulating the movement of the associated piston juxtapositioned to said control inlet port for controlling the position of said three pistons to control fluid flow from said inlet ports to said valve body through said fluid outlet port, a pump, heater and filtering means connected between said fluid outlet port of said valve body and said second pair of pipe means for conditioning fluid flow to each of said pools.