US 4,046,495 A · Dispenser pump

Abstract

A fluid dispenser pump having a piston extending from one end of a cylinder with resilient means urging the piston from the cylinder to its extended position for manual movement into the cylinder to its retracted position, said piston and cylinder being elastomeric plastic members, with complementary cylindrical walls forming a sequence of chambers. An inlet chamber communicates with a fluid supply. An auxiliary pressure chamber is normally sealed from the inlet chamber, but it communicates with the inlet chamber whenever the piston is at its fully extended position. An operating chamber communicates with the auxiliary pressure chamber and a first check valve means between the chamber permits flow from the auxiliary pressure chamber to the working chamber, but prevents a reversal of such flow. A discharge chamber communicates with the working chamber and a second check valve means between the chambers permits flow from the working chamber to the discharge chamber but prevents a reversal of such flow. There is also an outlet from the discharge chamber. The check valve means are formed as thinwall sleeve members embracing stem portions and said sleeve members expand responsive to fluid pressure, to move away from the stem portions to permit fluid flow therepast.

Claims8

Dependent claims

a. an inlet chamber to communicate with a fluid supply;
b. an auxiliary pressure chamber normally sealed from the inlet chamber but communicating with the inlet chamber whenever the piston is at its fully extended position;
c. an operating chamber communicating with the auxiliary pressure chamber and a first check valve means between the operating and auxiliary pressure chambers which permits flow from the auxiliary pressure chamber to the operating chamber but prevents a reversal of such flow;
d. a discharge chamber communicating with the operating chamber and a second check valve means between the discharge and operating chambers which permits flow from the operating chamber to the discharge chamber but prevents a reversal of such flow;
and
e. an outlet from the discharge chamber;
wherein
f. said auxiliary pressure chamber and said operating chamber increase in volume when the piston is being extended and decrease in volume when the piston is being retracted whereby reciprocation of the piston into the cylinder pumps fluid past the check valve means and through the pump;
and
g. said check valve means are formed as thinwall sleeve members embracing stem portions, said sleeve members expanding responsive to fluid pressure, to move away from the stem portions to permit fluid flow therepast.

7 more elements

Dependencies are inferred from the claim text.

Dispenser pump

Life of this patent

Dispenser pump

Life of this patent

Abstract

Claims8