GB2148150A - Spray nozzle - Google Patents

Abstract

A spray nozzle for spraying binder on to road surfaces comprises a body 1 having a vortex chamber 2 which receives a swirl chamber 4 having a tangential inlet 4 and an outlet formed by a spray jet 6. An upper end of the chamber 2 forms a seat which co-operates with a seal 8 of a poppet valve 9 which controls the flow of pressurised binder or the like which enters via supply passages 11 to an axial bore 12. The valve is solid with a piston 16 which operates within an upper cylinder 17 formed in the body under pneumatic pressure supplied through closure cap 14. A spring 18 urges the piston and valve 9 to shut down the flow of binder to the nozzle on release of the pneumatic pressure, the binder serving to reinforce the action of the spring to provide a rapid shut off of the nozzle. <IMAGE>

Description

SPECIFICATION Spray Nozzle This invention relates to spray nozzles for spraying binder and the like onto roads, footpaths and similar surfaces in either single or multiple units.

Such spray nozzles normally include a valve which controls the flow of pressurised binder to the nozzle itself. The conventional method of controlling such a spray nozzle is by mechanically lifting its valve spindie clear of its seat or by applying air to an air cylinder or diaphragm type air actuator fitted externally to the valve spindle.

Such arrangements are not wholly satisfactory since there is a tendency to leak and the operation is not instantaneous. Leakage or unwanted flow of the binder leads to messy operating conditions.

According to one aspect of the present invention, there is provided a spray nozzle having a body including a spray jet and a control valve upstream of the spray jet, the control valve being connected solidly to a spring loaded pneumatically operated piston mounted in a cylinder formed in the body.

Preferably, the cylinder is exposed to supply of pressurised liquid to be dispensed by the spring nozzle.

According to another aspect of the invention, there is provided a method of applying a layer of binder or the like to a surface such as a road or footpath, using a spray nozzle according to the invention as set forth above.

The invention will be further described with reference to the accompanying drawing which is a sectional view of a preferred form of a spray nozzle in accordance with the invention shown in the open or operative position.

As shown in the drawing, a body 1 is bored out to provide a vortex chamber 2, and within the vortex chamber there is mounted a further body 3 which defines a swirl chamber 4 communicating with the vortex chamber 2 by means of a generally tangential inlet 5. The open end of the body 3 is provided with a spray jet 6 of generally conventional venturi form.

An upper end of the vortex chamber 2 is defined by a shoulder7 which acts as a seat co-operating with a sealing member 8 carried on a valve member 9 to provide control of the flow of pressurised binder or the like entering via supply passages 11 to an axial bore 12. Above the supply passages 11 and axial bore 12, the body is bored out from the opposite end to form an air cylinder 13 provided with a sealed closure cap 14 carrying a union 15 for attachment to a compressed air supply. A piston 16 operates within the cylinder 13 and has a piston rod 17 extending through the axial bore 12 and connected to the valve member 9. The piston 16 is biassed by a spring 18 towards the closed position of the valve in which the sealing member 8 is compressed against the seat formed by the shoulder 7.

It will be seen that the axial bore 12 extends from the ducts 11 both towards the vortex chamber 4 and towards the cylinder 13.

When no air pressure is supplied through the union 15 to the upper end of the cylinder 13, the piston 16 is urged upwardly by the spring 18 and also by the hydrostatic pressure of the binder supplied to the ducts 11. The seal 8 is thus firmly pressed against the seat formed by the shoulder 7.

When air pressure is supplied to the upper part of the cylinder 13, the piston moves downwardly against the spring bias and the hydrostatic pressure and the valve is opened so that the spray nozzle becomes operative as the binder passes through the vortex chamber and swirl chamber to the spray jet 6.

When the air supply is cut off, the pressure of the spring 18 and the hydrostatic pressure combine to cause rapid closure of the valve.

The piston 16 has two ring grooves 19 which carry high temperature viton rubber sealing rings 20, having an operating temperature range of -20 to +200 . It has been found preferable to provide a plurality of such rings to ensure a good seal to separate the compressed air and binder. Also, a gasket 21 is provided to ensure an adequate tight seal between the piston rod 17 and the piston 16.

1. A spray nozzle having a body including a spray jet and a control valve upstream of the spray jet, the control valve being connected solidly to a spring loaded pneumatically operated piston mounted in a cylinder formed in the body.

2. A spray nozzle as claimed in Claim 1, wherein the cylinder is exposed to supply of pressurised liquid to be dispensed by the spring nozzle.

3. A spray nozzle as claimed in claim 1 or 2, wherein a plurality of sealing rings are provided between the piston and the cylinder.

4. A spray nozzle as claimed in claim 1,2 or 3 wherein the valve is a poppet valve.

5. A spray nozzle comprising a body having an axial bore, a spray nozzle mounted at the end of the bore, a radial conduit midway of the bore for the input of liquid to be sprayed from the nozzle, a valve member positioned between the radial conduit and the nozzles and connected to a pneumatically operated piston member which is received within the axial bore at the end thereof.

6. A spray nozzle as claimed in any one of claims 1 to 5, wherein the nozzle comprises a vortex chamber having a swirl chamber mounted therein, the swirl chamber being connected to a venturi-form spray jet.

7. A spray nozzle, substantially as hereinbefore described with reference to the accompanying drawings.

8. A method of applying a layer of binder or the like to a surface such as a road or footpath, using a spray nozzle as defined in any one of claims 1 to 7.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (8)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Spray Nozzle This invention relates to spray nozzles for spraying binder and the like onto roads, footpaths and similar surfaces in either single or multiple units. Such spray nozzles normally include a valve which controls the flow of pressurised binder to the nozzle itself. The conventional method of controlling such a spray nozzle is by mechanically lifting its valve spindie clear of its seat or by applying air to an air cylinder or diaphragm type air actuator fitted externally to the valve spindle. Such arrangements are not wholly satisfactory since there is a tendency to leak and the operation is not instantaneous. Leakage or unwanted flow of the binder leads to messy operating conditions. According to one aspect of the present invention, there is provided a spray nozzle having a body including a spray jet and a control valve upstream of the spray jet, the control valve being connected solidly to a spring loaded pneumatically operated piston mounted in a cylinder formed in the body. Preferably, the cylinder is exposed to supply of pressurised liquid to be dispensed by the spring nozzle. According to another aspect of the invention, there is provided a method of applying a layer of binder or the like to a surface such as a road or footpath, using a spray nozzle according to the invention as set forth above. The invention will be further described with reference to the accompanying drawing which is a sectional view of a preferred form of a spray nozzle in accordance with the invention shown in the open or operative position. As shown in the drawing, a body 1 is bored out to provide a vortex chamber 2, and within the vortex chamber there is mounted a further body 3 which defines a swirl chamber 4 communicating with the vortex chamber 2 by means of a generally tangential inlet 5. The open end of the body 3 is provided with a spray jet 6 of generally conventional venturi form. An upper end of the vortex chamber 2 is defined by a shoulder7 which acts as a seat co-operating with a sealing member 8 carried on a valve member 9 to provide control of the flow of pressurised binder or the like entering via supply passages 11 to an axial bore 12. Above the supply passages 11 and axial bore 12, the body is bored out from the opposite end to form an air cylinder 13 provided with a sealed closure cap 14 carrying a union 15 for attachment to a compressed air supply. A piston 16 operates within the cylinder 13 and has a piston rod 17 extending through the axial bore 12 and connected to the valve member 9. The piston 16 is biassed by a spring 18 towards the closed position of the valve in which the sealing member 8 is compressed against the seat formed by the shoulder 7. It will be seen that the axial bore 12 extends from the ducts 11 both towards the vortex chamber 4 and towards the cylinder 13. When no air pressure is supplied through the union 15 to the upper end of the cylinder 13, the piston 16 is urged upwardly by the spring 18 and also by the hydrostatic pressure of the binder supplied to the ducts 11. The seal 8 is thus firmly pressed against the seat formed by the shoulder 7. When air pressure is supplied to the upper part of the cylinder 13, the piston moves downwardly against the spring bias and the hydrostatic pressure and the valve is opened so that the spray nozzle becomes operative as the binder passes through the vortex chamber and swirl chamber to the spray jet 6. When the air supply is cut off, the pressure of the spring 18 and the hydrostatic pressure combine to cause rapid closure of the valve. The piston 16 has two ring grooves 19 which carry high temperature viton rubber sealing rings 20, having an operating temperature range of -20 to +200 . It has been found preferable to provide a plurality of such rings to ensure a good seal to separate the compressed air and binder. Also, a gasket 21 is provided to ensure an adequate tight seal between the piston rod 17 and the piston 16. CLAIMS

1. A spray nozzle having a body including a spray jet and a control valve upstream of the spray jet, the control valve being connected solidly to a spring loaded pneumatically operated piston mounted in a cylinder formed in the body.

2. A spray nozzle as claimed in Claim 1, wherein the cylinder is exposed to supply of pressurised liquid to be dispensed by the spring nozzle.

3. A spray nozzle as claimed in claim 1 or 2, wherein a plurality of sealing rings are provided between the piston and the cylinder.

4. A spray nozzle as claimed in claim 1,2 or 3 wherein the valve is a poppet valve.

5. A spray nozzle comprising a body having an axial bore, a spray nozzle mounted at the end of the bore, a radial conduit midway of the bore for the input of liquid to be sprayed from the nozzle, a valve member positioned between the radial conduit and the nozzles and connected to a pneumatically operated piston member which is received within the axial bore at the end thereof.

6. A spray nozzle as claimed in any one of claims 1 to 5, wherein the nozzle comprises a vortex chamber having a swirl chamber mounted therein, the swirl chamber being connected to a venturi-form spray jet.

7. A spray nozzle, substantially as hereinbefore described with reference to the accompanying drawings.

8. A method of applying a layer of binder or the like to a surface such as a road or footpath, using a spray nozzle as defined in any one of claims 1 to 7.