Pneumatic spraying assembly, restrictor for such an assembly and installation for projecting a coating product comprising such an assembly or such a restrictor

Patent metadata

Field	Value
Publication number	US-10315207-B2
Application number	US-201715792783-A
Country	US
Kind code	B2
Filing date	Oct 25, 2017
Priority date	Nov 4, 2016
Publication date	Jun 11, 2019
Grant date	Jun 11, 2019

Abstract

A pneumatic spraying assembly for a coating product including a pneumatic sprayer and a supply line for the pneumatic sprayer from a pressurized coating product source to which the supply line is connected by its upstream end, the pneumatic sprayer including a sprayer body and a control valve for controlling flow of the coating product toward a spraying area for the coating product, the controlling valve including a needle selectively closing off an outlet orifice of an inner volume of the sprayer body and the spraying assembly defining a flow path for the coating product, from the upstream end of the supply line to the outlet orifice of the inner volume, wherein a restrictor for restricting flow of the coating product is mounted on the flow path to create a pressure loss upstream from the outlet orifice.

First claim

The invention claimed is:

1. A pneumatic spraying assembly for a coating product, comprising:
a pneumatic sprayer for spraying the coating product, comprising;
a sprayer body; and
a control valve for controlling flow of the coating product toward a spraying area for the coating product, comprising a needle for selectively closing off an outlet orifice of an inner volume of the sprayer body, and

a supply line for supplying said pneumatic sprayer from a pressurized coating product source to which the supply line is connected by an upstream end of the supply line,
wherein the pneumatic spraying assembly defines a flow path for the coating product, from the upstream end of said supply line to the outlet orifice of the inner volume, the flow path comprising the inner volume and a connecting member for connecting said supply line on said sprayer body, and
wherein a restrictor for restricting flow of the coating product is mounted in the connecting member, to create a pressure loss upstream from the outlet orifice, the restrictor being made from a material more flexible than a material of the connecting member.

2. The assembly according to claim 1 , wherein the restrictor is mounted in the inner volume of the sprayer body.

3. The assembly according to claim 2 , wherein the restrictor is mounted reversibly in the inner volume.

4. The assembly according to claim 2 , wherein the restrictor divides the inner volume into two chambers and connects the two chambers by at least one calibrated pipe.

5. The assembly according to claim 1 , wherein the connecting member is configured to cooperate with a mechanism arranged at an outlet of said supply line, in order to connect said pneumatic sprayer to said supply line, both in absence of the restrictor, and when the restrictor is mounted in the connecting member.

6. The assembly according to claim 5 , wherein the restrictor has a mouth having a geometry that is the same as a geometry of a mouth of the connecting member.

7. The assembly according to claim 1 , wherein the restrictor is made from a synthetic material.

8. The assembly according to claim 1 , wherein the restrictor is formed by a piece that defines at least one tubular-shaped calibrated pipe with a constant transverse section for flow of a coating product, the inner volume having a diameter strictly larger than the maximum transverse dimension of the calibrated pipe, and
wherein the restrictor is mounted reversibly in the connecting member.

9. The assembly according to claim 1 , wherein a cross-section of the flow path decreases gradually between that of a portion situated upstream from the restrictor and that of a calibrated pipe formed by the restrictor.

10. A restrictor for a pneumatic spraying assembly, the restrictor being formed by a piece that defines at least one tubular-shaped calibrated pipe with a constant transverse section for flow of a coating product, the calibrated pipe having a length between 1 and 25 mm and having a maximum transverse dimension less than 2 mm,
the restrictor defining an inner volume between a mouth of the restrictor and the calibrated pipe, the inner volume having a diameter strictly larger than the maximum transverse dimension of the calibrated pipe,
wherein the pneumatic spraying assembly comprises a pneumatic sprayer for spraying the coating product and a supply line for supplying the pneumatic sprayer from a pressurized coating product source to which the supply line is connected by an upstream end of the supply line, wherein the pneumatic sprayer comprises a sprayer body and a control valve for controlling flow of the coating product toward a spraying area for the coating product, wherein the control valve comprises a needle for selectively closing off an outlet orifice of the inner volume of the sprayer body, the pneumatic spraying assembly defining a flow path for the coating product, from the upstream end of the supply line to the outlet orifice of the inner volume, and wherein the restrictor restricts flow of the coating product and is mounted on the flow path, to create a pressure loss upstream from the outlet orifice.

11. The restrictor according to claim 10 , wherein the length of the at least one calibrated pipe is comprised between 8 and 15 mm.

12. The restrictor according to claim 10 , wherein the length of the at least one calibrated pipe is 10 mm.

13. The restrictor according to claim 10 , wherein the maximum transverse dimension of the at least one calibrated pipe is comprised between 0.5 and 1.8 mm.

14. The restrictor according to claim 10 , wherein an end of the restrictor, which defines a mouth thereof, has frustoconical outer and inner shapes which have apical angles having a same value.

15. An installation for spraying a coating product, comprising:
at least one reservoir for the coating product;
at least one pneumatic sprayer for the coating product, each pneumatic sprayer comprising:
a sprayer body; and
a control valve for controlling flow of the coating product toward a spraying area for the coating product, the control valve comprising a needle for selectively closing off an outlet orifice of an inner volume of said sprayer body;

a supply pump for supplying the at least one pneumatic sprayer with the coating product from the at least one reservoir; and
a supply line for supplying the at least one pneumatic sprayer from the supply pump,
wherein said at least one pneumatic sprayer and said supply line form an assembly defining at least one flow path for the coating product, from the upstream end of the supply line to the outlet orifice of the at least one inner volume, each flow path comprising a connecting member for connecting said supply line on each sprayer body, and wherein a restrictor for restricting flow of the coating product is mounted on each flow path to create a pressure loss upstream from the outlet orifice, the restrictor being made from a material more flexible than a material of the connecting member.

16. The installation according to claim 15 , wherein the supply pump is equipped, at an outlet of the supply pump, with a pressure regulator adjusted to deliver the coating product to the supply line, under a first pressure comprised between 0.5 and 3 bars, and wherein the restrictor is configured to deliver the coating product to the outlet orifice under a second pressure below 1 bar.

17. The installation according to claim 16 , wherein the second pressure under which the restrictor is configured to deliver the coating product to the outlet orifice is between 0.3 and 0.7 bars.

Assignees

• Exel Ind

Inventors

• Le Cardinal Johan
• Cognon Thibault

Classifications

• B05B7/0416

  with arrangements for mixing one gas and one liquid · CPC title

• B05B7/02

  Spray pistols; Apparatus for discharge (for spraying particulate material B05B7/14; with means for heating the material to be sprayed B05B7/16; with means for supplying fluent material to a discharge device B05B7/24) · CPC title

• B05B1/30

  designed to control volume of flow, e.g. with adjustable passages {(B05B11/0094 takes precedence)} · CPC title

• B05B7/12 Primary

  designed to control volume of flow, e.g. with adjustable passages · CPC title

• B05B7/2489

  an atomising fluid, e.g. a gas, being supplied to the discharge device (B05B7/2402, B05B7/2483, B05B7/262 take precedence) · CPC title