Piston engaging with valve for self-priming in fluid sprayers
AssigneeGrace Minnesota Inc.
InventorMariusz J. Luczak
Life of this patent
Estimating the term…
Abstract
A pump draws fluid from a reservoir and drives the fluid downstream to a spray tip where the fluid is applied to a surface. A piston is driven in a reciprocating manner to pump the fluid. A check valve is disposed downstream of the piston to regulate a flow of the fluid downstream from the piston. The pump is initially dry and is primed with fluid prior to operation. To facilitate priming, the piston is dimensioned to impact the ball and unseat a valve member of the check valve during a priming stroke, thereby ejecting any air from the pump through the check valve. With the air ejected from the pump, a vacuum is formed during a suction stroke of the piston, which draws fluid downstream from the reservoir to prime the pump.
Claims25
A pump for a fluid sprayer, the pump comprising:
- a first piston disposed within a first axial bore of a pump body, the first piston having a downstream end;
- a first cylinder disposed within the first axial bore, the first piston extending into the first cylinder such that the downstream end of the piston is disposed in the first cylinder;
- a first check valve disposed within the pump body at an exit of the first axial bore, the first check valve including a first valve member;
- wherein the first valve member is a ball, and the downstream end of the first piston is configured to impact the first valve member to drive the first valve member from a closed position to an open position;
- and
- wherein the downstream end of the first piston when in a downstream-most stroke position is one of aligned with a downstream face of the first cylinder or disposed upstream of the downstream face of the first cylinder.
A handheld sprayer comprising:
- a sprayer body, the sprayer body including a handle configured to support the sprayer body;
- a spray tip attached to the sprayer body and configured to spray a fluid;
- a reservoir connected to the sprayer body and configured to store a supply of the fluid;
- and
- a pump disposed within the sprayer body and configured to draw the fluid from the reservoir and drive the fluid downstream to the spray tip, the pump comprising:
- a pump body mounted within the sprayer body, the pump body including an axial bore and an inlet channel configured to fluidly connect the axial bore and the reservoir;
- a cylinder disposed within the first axial bore;
- a piston extending into the cylinder, the piston having an upstream end connected to a drive and a downstream end configured to reciprocate within the cylinder, the piston configured to draw the fluid from the reservoir during a suction stroke and to drive the fluid downstream to the spray tip during a pressure stroke;
- and
- a check valve disposed within the axial bore downstream of the piston, the check valve including a valve member;
- wherein the downstream end of the piston is configured to impact the valve member and drive the valve member from a closed position to an open position during a priming stroke of the piston;
- and
- wherein the downstream end of the first piston when in a downstream-most stroke position is one of aligned with a downstream face of a seat of the valve member or disposed upstream of the downstream face of the seat of the valve member.
A method of priming a paint pump, the method comprising:
- driving a piston forward within an axial bore and through a priming stroke;
- impacting a valve member with the piston to drive the valve member from a closed position to an open position during the priming stroke, thereby opening a flowpath for air to flow downstream from the axial bore past the valve member;
- pulling the piston rearward through the axial bore and through a suction stoke to draw paint fluid downstream from a reservoir and into the axial bore to prime the pump;
- and
- driving the piston forward within the axial bore and through a pressure stroke such that the piston builds a pressure in the paint fluid in the axial bore such that the paint fluid drives the valve member from the closed position to the open position, wherein the piston does not contact the valve member during the pressure stroke.
Dependencies are inferred from the claim text.