Pump type dispenser with continuous flow feature

Claim 1

A pump type dispenser for dispensing a spray of liquid, comprising a container for containing the liquid to be dispensed, a pump body member mounted on said container, a pump plunger member movable relative to said pump body member into and out of said pump body, one end of said pump plunger member and said pump body member cooperating to define therebetween a piston-cylinder means, a spring means between said members urging them apart, said pump body member having a liquid flow path therethrough having one end communicating with the container and the other end communicating with the piston-cylinder means, a check valve in said liquid flow path for blocking flow of liquid in said liquid flow path in the direction toward said container, a dispensing head integral with said pump body member and having a free piston chamber therein, a pressurized liquid flow path from said piston-cylinder means into one end of said free piston chamber, a further check valve in said pressurized liquid flow path for blocking flow of liquid in the direction toward the piston-cylinder means, a free piston slidable in said free piston chamber, a free piston spring in said free piston chamber urging said free piston toward and into engagement with said one end of said free piston chamber, and nozzle means opening out of said free piston chamber through said dispensing head member from a position just above said one end of said free piston chamber, said free piston in the position in engagement with said one end of the free piston chamber obturating the fluid flow between said pressurized liquid flow path nozzle means.