Pumping apparatus

Claim 2

A positive displacement piston pump for pumping fluid comprising cylinder means having a forward end and a rearward end and an axially extending bore, a piston having a forward end portion slidably received by said bore, the piston sized to provide a substantially fluid-tight seal with the bore, and means for axially moving the piston within the bore, the bore of the cylinder means being provided with an enlarged inlet chamber and an enlarged circumferentially extending outlet chamber spaced axially rearwardly of the inlet chamber, said cylinder means having inlet port means for communicating the inlet chamber with a source of the fluid to be pumped and outlet port means for withdrawing fluid from the outlet chamber, said piston having a bore extending axially through the center of the piston from the forward end thereof and an opening for communicating the piston bore with the bore of the cylinder means, the opening in the piston being provided in an annular groove in the piston, and sealing means within said pump for sealing the annular groove in the piston and the piston opening from the outlet chamber until the forward piston end passes forwardly of the inlet chamber, the annular groove in the piston permitting circumferential flow of fluid from the groove to the outlet chamber when the groove communicates with the outlet chamber.

Claim 3

The pump of claim 5 in which the sealing means is positioned in the bore of the cylinder means rearwardly of the outlet chamber, the distance between the forward end of the piston and the annular groove in the piston being greater than the distance between the forward end of the inlet chamber and the sealing means whereby the sealing means seals the annular groove in the piston from the outlet chamber until the forward piston end passes the forward end of the inlet chamber.

Claim 4

A positive displacement piston pump for pumping fluid comprising cylinder means having a forward end and a rearward end and an axially extending bore, a piston having a forward end portion slidably received by said bore, the piston sized to provide a substantially fluid-tight seal with the bore, and means for axially moving the piston within the bore, the bore of the cylinder means being provided with an enlarged inlet chamber and an enlarged outlet chamber spaced axially rearwardly of the inlet chamber, said cylinder means having inlet port means for communicating the inlet chamber with a source of the fluid to be pumped and outlet port means for withdrawing fluid from the outlet chamber, said piston having a bore extending axially through the center of the piston from the forward end thereof and an opening for communicating the piston bore with the bore of the cylinder means, and sealing means within said pump for sealing the piston opening from the outlet chamber until the forward piston end passes forwardly of the inlet chamber, the bore of the cylinder means including an enlarged flushing chamber spaced axially rearwardly of the sealing means, a cylindrical sleeve within the flushing chamber, the piston being slidably received by the sleeve, and an O-ring within the flushing chamber rearwardly of the sleeve, the O-ring sealingly engaging the piston and being restrained against forward movement by the sleeve, the cylinder means having a solvent inlet port for communicating the flushing chamber with a solvent and a solvent outlet port communicating with the flushing chamber for removing solvent from the flushing chamber whereby solvent washes the piston as it reciprocates within the flushing chamber.

Claim 5

A positive displacement piston pump for pumping fluid comprising cylinder means having a forward end and a rearward end and an axially extending bore, a piston having a forward end portion slidably received by said bore, the piston sized to provide a substantially fluid-tight seal with the bore, and means for axially moving the piston within the bore, the bore of the cylinder means being provided with an enlarged inlet chamber and an enlarged outlet chamber spaced axially rearwardly of the inlet chamber, said cylinder means having inlet port means for communicating the inlet chamber with a source of the fluid to be pumped and outlet port means for withdrawing fluid from the outlet chamber, said piston having a bore extending axially through the center of the piston from the forward end thereof and an opening for communicating the piston bore with the bore of the cylinder means, and sealing means within said pump for sealing the piston opening from the outlet chamber until the forward piston end passes forwardly of the inlet chamber, the bore of the cylinder means including an enlarged flushing chamber spaced axially rearwardly of the sealing means, a cylindrical sleeve within the flushing chamber, the piston being slidably received by the sleeve, and an O-ring within the flushing chamber rearwardly of the sleeve, the O-ring sealingly engaging the piston and being restrained against forward movement by the sleeve, the cylinder means having a solvent inlet port for communicating the flushing chamber with a solvent and a solvent outlet port communicating with the flushing chamber for removing solvent from the flushing chamber whereby solvent washes the piston as it reciprocates within the flushing chamber.

Claim 6

The pump of claim 3 in which the sleeve is provided with a plurality of openings to permit substantially free solvent flow between the sleeve and the piston.

Claim 7

A positive displacement piston pump for pumping fluid comprising cylinder means having a forward end and a rearward end and an axially extending bore, a piston having a forward end portion slidably received by said bore, the piston sized to provide a substantially fluid-tight seal with the bore, and means for axially moving the piston within the bore, the bore of the cylinder means being provided with an enlarged inlet chamber and an enlarged outlet chamber spaced axially rearwardly of the inlet chamber, said cylinder means having inlet port means for communicating the inlet chamber with a source of the fluid to be pumped and outlet port means for withdrawing fluid from the outlet chamber, said piston having a bore extending axially through the center of the piston from the forward end thereof and an opening for communicating the piston bore with the bore of the cylinder means, and sealing means within said pump for sealing the piston opening from the outlet chamber until the forward piston end passes forwardly of the inlet chamber, the sealing means including a generally cylindrical sleeve having a central bore positioned within the cylinder means, the piston being slidably received by the sleeve, the sleeve being provided with an annular groove extending radially outwardly from the sleeve bore, and an O-ring positioned within the annular groove of the sleeve and sealingly engaging the piston.

Claim 8

A positive displacement piston pump for pumping fluid comprising cylinder means having a forward end and a rearward end and an axially extending bore, a piston having a forward end portion slidably received by said bore, the piston sized to provide a substantially fluid-tight seal with the bore, and means for axially moving the piston within the bore, the bore of the cylinder means being provided with an enlarged inlet chamber and an enlarged outlet chamber spaced axially rearwardly of the inlet chamber, said cylinder means having inlet port means for communicating the inlet chamber with a source of the fluid to be pumped and outlet port means for withdrawing fluid from the outlet chamber, said piston having a bore extending axially through the center of the piston from the forward end thereof and an opening for communicating the piston bore with the bore of the cylinder means, and sealing means within said pump for sealing the piston opening from the outlet chamber until the forward piston end passes forwardly of the inlet chamber, the sealing means including a generally cylindrical sleeve having a central bore positioned within the cylinder means, the piston being slidably received by the sleeve, the sleeve being provided with an annular groove extending radially outwardly from the sleeve bore, and an O-ring positioned within the annular groove of the sleeve and sealingly engaging the piston.

Claim 9

The pump of claim 5 in which the sleeve includes a second annular groove extending radially outwardly from the sleeve bore, and a second O-ring positioned within the second annular groove of the sleeve and sealingly engaging the piston.

Claim 10

The pump of claim 5 in which the piston is provided with a radially inwardly extending annular groove, the piston opening being provided through the annular groove whereby the piston opening is sealed from the outlet chamber until the annular groove of the piston passes forwardly of the O-ring.

Claim 11

A positive displacement piston pump for pumping fluid comprising cylinder means having a forward end and a rearward end and an axially extending bore, a piston having a forward end portion slidably received by said bore, the piston sized to provide a substantially fluid-tight seal with the bore, and means for axially moving the piston within the bore, the bore of the cylinder means being provided with an enlarged inlet chamber and an enlarged outlet chamber spaced axially rearwardly of the inlet chamber, said cylinder means having inlet port means for communicating the inlet chamber with a source of the fluid to be pumped and outlet port means for withdrawing fluid from the outlet chamber, said piston having a bore extending axially through the center of the piston from the forward end thereof and an opening for communicating the piston bore with the bore of the cylinder means, and sealing means within said pump for sealing the piston opening from the outlet chamber until the forward piston end passes forwardly of the inlet chamber, check valve means within the bore of the piston for permitting fluid flow from the forward end of the piston toward the piston opening when the piston is moving forwardly but preventing fluid flow from the piston opening toward the forward end of the piston when the piston is moving rearwardly, the check valve means including an externally threaded generally cylindrical plug threadedly received by the forward end of the piston bore and provided with a central opening therethrough, the rearward end of the plug being generally concave to provide a valve seat having an opening therethrough, a ball having a diameter greater than the opening through the plug and having a radius of curvature less than the radius of curvature of the concave end of the plug, the ball being resiliently biased forwardly against the valve seat to close the opening therethrough.

Claim 12

A positive displacement piston pump for pumping fluid comprising cylinder means having a forward end and a rearward end and an axially extending bore, a piston having a forward end portion slidably received by said bore, the piston sized to provide a substantially fluid-tight seal with the bore, and means for axially moving the piston within the bore, the bore of the cylinder means being provided with an enlarged inlet chamber and an enlarged outlet chamber spaced axially rearwardly of the inlet chamber, said cylinder means having inlet port means for communicating the inlet chamber with a source of the fluid to be pumped and outlet port means for withdrawing fluid from the outlet chamber, said piston having a bore extending axially through the center of the piston from the forward end thereof and an opening for communicating the piston bore with the bore of the cylinder means, and sealing means within said pump for sealing the piston opening from the outlet chamber until the forward piston end passes forwardly of the inlet chamber, check valve means within the bore of the piston for permitting fluid flow from the forward end of the piston toward the piston opening when the piston is moving forwardly but preventing fluid flow from the piston opening toward the forward end of the piston when the piston is moving rearwardly, the check valve means including an externally threaded generally cylindrical plug threadedly received by the forward end of the piston bore and provided with a central opening therethrough, the rearward end of the plug being generally concave to provide a valve seat having an opening therethrough, a ball having a diameter greater than the opening through the plug and having a radius of curvature less than the radius of curvature of the concave end of the plug, the ball being resiliently biased forwardly against the valve seat to close the opening therethrough.

Claim 13

The pump of claim 8 including a rod extending forwardly within the piston bore from the rear end of the bore, the diameter of the rod being less than the diameter of the piston bore, and a spring carried by the forward end of the rod resiliently biasing the ball against the valve seat.

Claim 14

A positive displacement piston pump for pumping fluid comprising cylinder means having a forward end and a rearward end and an axially extending bore, a piston having a forward end portion slidably received by said bore, the piston sized to provide a substantially fluid-tight seal with the bore, and means for axially moving the piston within the bore, the bore of the cylinder means being provided with an enlarged inlet chamber and an enlarged outlet chamber spaced axially rearwardly of the inlet chamber, said cylinder means having inlet port means for communicating the inlet chamber with a source of the fluid to be pumped and outlet port means for withdrawing fluid from the outlet chamber, said piston having a bore extending axially through the center of the piston from the forward end thereof and an opening for communicating the piston bore with the bore of the cylinder means, and sealing means within said pump for sealing the piston opening from the outlet chamber until the forward piston end passes forwardly of the inlet chamber, the means for axially moving the piston including a motor having a reciprocating piston rod, a pivotally mounted lever arm having a pair of ends, one end of the lever arm being pivotally connected to the piston rod of the motor, the other end of the lever arm being provided with an elongated slot, connecting means carried by the slotted end of the lever arm and secured to the piston, and means for selectively securing the connecting means in a predetermined position along the slot.

Claim 15

A positive displacement piston pump for pumping fluid comprising cylinder means having a forward end and a rearward end and an axially extending bore, a piston having a forward end portion slidably received by said bore, the piston sized to provide a substantially fluid-tight seal with the bore, and means for axially moving the piston within the bore, the bore of the cylinder means being provided with an enlarged inlet chamber and an enlarged outlet chamber spaced axially rearwardly of the inlet chamber, said cylinder means having inlet port means for communicating the inlet chamber with a source of the fluid to be pumped and outlet port means for withdrawing fluid from the outlet chamber, said piston having a bore extending axially through the center of the piston from the forward end thereof and an opening for communicating the piston bore with the bore of the cylinder means, and sealing means within said pump for sealing the piston opening from the outlet chamber until the forward piston end passes forwardly of the inlet chamber, the means for axially moving the piston including a motor having a reciprocating piston rod, a pivotally mounted lever arm having a pair of ends, one end of the lever arm being pivotally connected to the piston rod of the motor, the other end of the lever arm being provided with an elongated slot, connecting means carried by the slotted end of the lever arm and secured to the piston, and means for selectively securing the connecting means in a predetermined position along the slot.

Claim 16

A pumping apparatus comprising a frame, cylinder means on the frame having an axially extending bore, a piston slidably received by the bore, means for reciprocating the piston within the bore, the cylinder means having inlet port means for communicating the bore with a source of fluid to be pumped and circumferentially extending outlet port means communicating with the bore for permitting fluid to be pumped from the bore, said piston having a bore extending axially through the center of the piston from the forward end thereof and having an opening for communicating the piston bore with the bore of the cylinder means whereby fluid may flow from the inlet port through the bore of the piston to the outlet port, the opening in the piston being provided in an annular groove in the piston, sealing means between the cylinder means and the piston for sealing the annular groove in the piston and the piston opening from the outlet port means when the annular groove in the piston is positioned rearwardly of the sealing means, the bore of the cylinder means including an enlarged flushing chamber spaced axially rearwardly of the sealing means, the cylinder means having a solvent inlet port for communicating the flushing chamber with a solvent and a solvent outlet port communicating with the flushing chamber for removing solvent from the flushing chamber whereby solvent washes the piston as it reciprocates within the flushing chamber.

Claim 17

A pumping apparatus comprising a frame, cylinder means on the frame having an axially extending bore, a piston slidably received by the bore, means for reciprocating the piston within the bore, the cylinder means having inlet port means for communicating the bore with a source of fluid to be pumped and circumferentially extending outlet port means communicating with the bore for permitting fluid to be pumped from the bore, said piston having a bore extending axially through the center of the piston from the forward end thereof and having an opening for communicating the piston bore with the bore of the cylinder means whereby fluid may flow from the inlet port through the bore of the piston to the outlet port, the opening in the piston being provided in an annular groove in the piston, sealing means between the cylinder means and the piston for sealing the annular groove in the piston and the piston opening from the outlet port means when the annular groove in the piston is positioned rearwardly of the sealing means, the bore of the cylinder means including an enlarged flushing chamber spaced axially rearwardly of the sealing means, the cylinder means having a solvent inlet port for communicating the flushing chamber with a solvent and a solvent outlet port communicating with the flushing chamber for removing solvent from the flushing chamber whereby solvent washes the piston as it reciprocates within the flushing chamber.

Claim 18

The apparatus of claim 11 including check valve means within the bore of the piston for permitting fluid flow from the forward end of the piston toward the piston opening when the piston is moving forwardly but preventing fluid flow from the piston opening toward the forward end of the piston when the piston is moving rearwardly.