Piston engaging with valve for self-priming in fluid sprayers

Patent metadata

Field	Value
Publication number	US-10422325-B2
Application number	US-201715704649-A
Country	US
Kind code	B2
Filing date	Sep 14, 2017
Priority date	Sep 14, 2016
Publication date	Sep 24, 2019
Grant date	Sep 24, 2019

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.

First claim

The invention claimed is:

1. 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.

2. The pump of claim 1 , wherein the downstream end is configured to impact and displace the first valve member during a priming stroke of the first piston.

3. The pump of claim 2 , wherein:
the first piston is drawn rearward through the first axial bore during a suction stroke and is configured to draw a fluid into the first axial bore during the suction stroke; and
the first piston is driven forward through the first axial bore during a pressure stroke and is configured build a pressure in the fluid and drive the fluid downstream out of the first axial bore through the first check valve during the pressure stroke.

4. The pump of claim 3 , wherein a portion of the first cylinder disposed between the downstream end of the first piston and the ball is devoid of the fluid during the priming stroke and is filled with the fluid during the pressure stroke, and wherein the first piston does not impact the first valve member during the pressure stroke.

5. The pump of claim 4 , wherein the first piston is configured to build a fluid pressure between the downstream end of the first piston and the first valve member during the pressure stroke of the first piston, the fluid pressure configured to drive the valve member from the closed position to the open position during the pressure stroke of the first piston.

6. The pump of claim 1 , wherein the downstream face of the first cylinder forms a seat for the first valve member such that the first valve member contacts the downstream face when the first valve member is in the closed position.

7. The pump of claim 1 , wherein the first check valve further comprises:
a cage, the ball at least partially disposed within the cage; and
a spring disposed within the cage and configured to urge the ball towards the closed position.

8. The pump of claim 7 , wherein:
the cage includes a plurality of ligaments; and
a flowpath extends from the first axial bore and into the cage past the ball, and downstream out of the first check valve between the plurality of ligaments.

9. The pump of claim 1 , wherein the downstream face of the first cylinder includes a sealing lip configured to mate with a curvature of the ball such that a portion of the ball extends into the cylinder.

10. The pump of claim 1 , further comprising:
a second piston disposed within a second axial bore of the pump body, the second piston having a downstream end movable within the second axial bore;
a second check valve disposed at an exit of the second axial bore, the second check valve including a second valve member;
a second cylinder disposed within the second axial bore, wherein the second piston extends into the second cylinder, and wherein a downstream face of the second cylinder forms a seat for the second valve member such that the second valve member contacts the downstream face when the second valve member is in the closed position; and
a first valve retainer secured within a downstream end of the second axial bore and configured to retain the second check valve within the second axial bore;
wherein the downstream end of the second piston is configured to impact the second valve member to drive the second valve member from a closed position to an open position during a priming stroke of the second valve member;
wherein the second piston is drawn upstream through the second cylinder during a suction stroke and is configured to draw a fluid into the second cylinder during the suction stroke; and
wherein the second piston is driven downstream through the second cylinder during a pressure stroke and is configured build a pressure in the fluid and drive the fluid downstream out of the second cylinder through the second check valve during the pressure stroke.

11. 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.

12. The handheld sprayer of claim 11 , wherein a portion of the axial bore disposed between the downstream end of the piston and the valve member is devoid of the fluid during the priming stroke.

13. The handheld sprayer of claim 12 , wherein:
the piston is drawn upstream through the first axial bore by the drive during the suction stroke, and the piston is configured to draw the fluid from the reservoir and into the axial bore during the suction stroke;
the piston is driven downstream through the axial bore by the drive during the pressure stroke, and the piston is configured to drive the fluid downstream from the axial bore through the check valve during the pressure stroke; and
the downstream end is configured to not contact the valve member during the suction stroke and the pressure stroke.

14. The handheld sprayer of claim 13 , wherein a downstream face of the cylinder forms a seat for the valve member such that the valve member contacts the downstream face when the valve member is in the closed position.

15. The handheld sprayer of claim 14 , wherein the piston is configured to build a fluid pressure between the downstream end of the piston and the valve member during the pressure stroke such that the fluid pressure drives the valve member from the closed position to the open position during the pressure stroke.

16. The handheld sprayer of claim 11 , wherein the drive c

Assignees

• Graco Minnesota Inc
• Grace Minnesota Inc

Inventors

• Luczak Mariusz J

Classifications

• B05B9/0861 Primary

  the motor being electric · CPC title

• B05B9/0855

  the pump being motor-driven (B05B9/0866, B05B9/0872 take precedence) · CPC title

• F04B49/03

  by means of valves · CPC title

• F16K15/044

  spring-loaded · CPC title

• F04B53/101

  having means for limiting the opening height · CPC title