Low pressure spray tip configurations

Patent metadata

Field	Value
Publication number	US-10913079-B2
Application number	US-201615132894-A
Country	US
Kind code	B2
Filing date	Apr 19, 2016
Priority date	Apr 20, 2015
Publication date	Feb 9, 2021
Grant date	Feb 9, 2021

Abstract

A spray tip configuration for a low pressure fluid sprayer is presented. The spray tip configuration comprises an inlet orifice configured to receive a fluid and to produce a turbulent flow at a known operating point. The spray tip configuration also comprises an outlet orifice configured to emit the fluid in a spray pattern at a turbulence intensity. The spray tip configuration also comprises a passageway fluidically coupling the inlet orifice to the outlet orifice, with a plurality of portions configured to produce the turbulence intensity at the outlet orifice. The passageway comprises a first portion comprising an expansion chamber configured to provide an expanding cross-section from a first portion first end to a first portion second end. The passageway also comprises a second portion comprising a first hydraulic diameter, wherein the second portion is fluidically coupled, on a second portion first end, to the first portion second end. The passageway also comprises a third portion comprising a second hydraulic diameter, wherein the third portion fluidically couples to the second portion at a third portion second end. The passageway also comprises a fourth portion comprising a spray tip, wherein the fourth portion is fluidically coupled, on a fourth portion first end, to a third portion second end, and, on a fourth portion second end, to the outlet orifice.

First claim

What is claimed is:

1. An airless spray tip configuration for a low pressure fluid sprayer comprising:
an inlet orifice that receives a fluid;
an outlet orifice that emits the fluid in a spray pattern at a terminal turbulence intensity; and
a passageway fluidically coupling the inlet orifice to the outlet orifice, the passageway comprising a plurality of portions that receive the fluid at an initial turbulence intensity, produce a maximum turbulence intensity that is greater than the terminal turbulence and produce the terminal turbulence intensity at the outlet orifice, the plurality of portions comprising:
a first portion comprising an expansion chamber having a cross section that expands from a first hydraulic diameter to a second hydraulic diameter that is larger than the first hydraulic diameter;
a second portion comprising a first cylinder having a third hydraulic diameter that is larger than the second hydraulic, diameter, wherein the second portion is fluidically coupled to, and downstream of the first portion;
a third portion comprising a convergent cross-section that converges from the third hydraulic diameter, to a fourth hydraulic diameter that is smaller than the third hydraulic diameter, wherein the third portion is fluidically coupled to, and downstream of the second portion; and
a fourth portion comprising a second cylinder having a fifth hydraulic diameter that is smaller than the fourth hydraulic diameter fluidically coupled to, and immediately downstream of the third portion such that a surface generally perpendicular to the passageway is formed between the third and fourth portion.

2. The airless spray tip configuration of claim 1 , and further comprising:
a fifth portion comprising a third cylinder having a diameter equal to the first hydraulic diameter, wherein the fifth portion is fluidically coupled to, upstream of the first portion.

3. The airless spray tip configuration of claim 1 , wherein the spray pattern is a uniform spray pattern.

4. The airless spray tip configuration of claim 1 , wherein low pressure comprises fluid pressure below 2,000 pounds per square inch (PSI).

5. A method for airlessly spraying a latex paint at low spray pressures, the method comprising the steps of:
receiving, at an inlet of a spray gun, the latex paint pressurized at a low spraying pressure;
actuating the spray gun such that latex paint is discharged in an even spray pattern; and
wherein the spray gun comprises a pre-orifice spray tip configuration with a fluid flow channel, and wherein the fluid flow channel comprises a first portion with a first hydraulic diameter, coupled to a second portion with an expanding cross-section from a second hydraulic diameter to a third hydraulic diameter, coupled to a third cylindrical portion immediately downstream of the second portion, with a fourth hydraulic diameter that is larger than the third hydraulic diameter, coupled to a fourth portion with a contracting cross-section, coupled to a fifth portion with a fifth hydraulic diameter, coupled to a spheroid portion.

6. An airless spray tip configuration for a low pressure fluid sprayer comprising:
an inlet configured to receive a fluid;
an outlet orifice configured to emit the fluid in a spray pattern; and
a passageway fluidically coupling the inlet to the outlet orifice, such that fluid flows downstream from the inlet to the outlet orifice, the passageway comprising a plurality of fluidically coupled portions, the plurality of portions, in order from upstream to downstream, comprising at least:
a first portion, downstream from the inlet, comprising a first truncated cone configured to provide an expanding cross-sectional area to a first hydraulic diameter as fluid flows through the first portion;
a second portion, comprising a first cylinder, the first cylinder having a second hydraulic diameter, wherein the second hydraulic diameter is larger than the first hydraulic diameter such that a surface generally perpendicular to the passageway is formed between the first portion and second portion;
a third portion comprising a second truncated cone, the second truncated cone narrowing from the second hydraulic diameter at a first end to a third hydraulic diameter at a second end, wherein the third portion is downstream from the second portion;
a fourth portion comprising a second cylinder, wherein the fourth portion is downstream from the third portion; and
a fifth portion downstream from the fourth portion, wherein the fifth portion comprises the outlet orifice.

7. The airless spray tip configuration of claim 6 , wherein the second truncated cone is configured to provide a contracting cross-sectional area as fluid flows downstream through the third portion.

8. The airless spray tip configuration of claim 6 , wherein the fifth portion comprises a partial spheroid portion.

9. The airless spray tip configuration of claim 6 , and further comprising a sixth portion, located upstream from the first portion, the sixth portion comprising a third cylinder.

10. The airless spray tip configuration of claim 9 , wherein the sixth portion has a sixth portion diameter that is substantially the same as an inlet diameter of the first truncated cone.

11. The airless spray tip configuration of claim 10 , wherein the second cylinder comprises a fourth portion diameter that is greater than the sixth portion diameter.

12. The airless spray tip configuration of claim 6 , wherein a fourth portion diameter is substantially the same as a fifth portion inlet diameter.

13. A pre-orifice chamber for an airless paint spray tip, the pre-orifice chamber comprising:
an inlet configured to receive a flow of paint;
an outlet configured to spray the flow of paint; and
a fluidic passageway coupling the inlet and outlet, wherein the fluidic passageway comprises a plurality of geometric portions comprising at least:
a first cylinder located downstream from the inlet;
a first truncated cone located downstream of the first cylinder, the first truncated cone increasing in diameter from a first hydraulic diameter to a second hydraulic diameter;
a second cylinder located downstream from the first truncated cone;
a second truncated cone located wholly downstream of the first truncated cone and the second cylinder, the second truncated cone decreasing in diameter from a third hydraulic diameter to a fourth hydraulic diameter, wherein the third hydraulic diameter is larger than the second hydraulic diameter; and
a third cylinder located downstream from the second truncated cone.

14. The pre-orifice chamber of claim 13 , and further comprising a partial spheroid, wherein the partial spheroid comprises the outlet.

15. The pre-orifice chamber of claim 13 , wherein the first truncated cone comprises an expansion chamber, and wherein the second truncated cone comprises a contraction chamber.

16. An airless spray tip for a hand-held paint spray gun, the spray tip comprising:
an inlet configured to receive a pressurized flow of paint;
an outlet configured to spray the pressurized flow of paint; and
a fluid pathway fluidically coupling the inlet and the outlet such that the pressurized flow of paint flows downstream from the inlet to the outlet, and wherein the fluid pathway comprises at least:
a first chamber comprising a cylinder;
a second chamber, downstream from the first chamber, comprising a truncated cone that narrows in a downstream direction;
a third chamber, downstream from the second chamber, wherein the third chamber has a third chamber inlet diameter greater than an outlet diameter of the second chamber such t

Assignees

• Wagner Spray Tech Corp

Inventors

• Wenzel Everett A
• Rossner Ross D
• Liu Wanjiao

Classifications

• B05B1/048

  having a flow conduit with, immediately behind the outlet orifice, an elongated cross section, e.g. of oval or elliptic form, of which the major axis is perpendicular to the plane of the jet · CPC title

• B05B9/01

  Spray pistols, {discharge devices}(B05B9/03 takes precedence) · CPC title

• B05B1/262

  with fixed deflectors · CPC title

• B05B1/34 Primary

  designed to influence the nature of flow of the liquid or other fluent material, e.g. to produce swirl (designed to control volume of flow B05B1/30) · CPC title