GB2289427A

GB2289427A - Self-cleaning nozzle having pin actuated by fluid flow

Info

Publication number: GB2289427A
Application number: GB9411994A
Authority: GB
Inventors: Robert Richard Chicken
Original assignee: Individual
Current assignee: Individual
Priority date: 1994-05-13
Filing date: 1994-06-15
Publication date: 1995-11-22
Also published as: GB9411994D0; GB9409571D0

Abstract

A pin which moves in and out of the aperture of a nozzle has its movement controlled by means of the fluid pressure. A typical example is a self cleaning screen washer for vehicles to prevent the ingress of dirt into the nozzle, comprising a body 1, a nozzle 2 and pin 3 which normally rests within the nozzle cavity. When water is pumped from the reservoir via tube 8, the pressure forces the piston 4 down the sleeve 9, drawing the pin out of the nozzle cavity, and allowing water to flow out of the nozzle, and on to the screen. When the water ceases to flow, the spring 6 forces the piston to return to its original position, and the pin to return to its rest position within the nozzle aperture. In this position, the pin prevents any ingress of dirt into the nozzle. A second example is where the fluid is held in a pressurised container 12, such as spray on adhesives used in the advertising industry, and has the discharge of fluid controlled by a valve 13. A third example is where the fluid is pumped from a reservoir using a manually operated pump 19 such as insecticide sprays. <IMAGE>

Description

IHPROVEHWTS RELATING TO NOZZLES The invention relates to nozzles Nozzles generally and screen washer jets on vehicles in particular are susceptible to unexpected failure due to the ingress of dirt in the outlet nozzle of the jet. This is particularly common in wet and wintry conditions when clear windscreens on vehicles are important for safety purposes.

In the UK it is illegal to drive on the roads with windscreen washers which do not work. This means that under the current rules any driver can, at any time, be in a situation of inadvertently breaking the law due to the misfortune of ingesting dirt into a windsreen washer jet.

According to the invention there is provided a screen washer jet comprising a body having the nozzle within it, and a pin which slides in and out of the nozzle. When the screen jet is not in use, the pin normally rests in the nozzle aperture, preventing any ingestion of dirt. When the jet is in use, the pin is moved clear of the nozzle, allowing water to flow on to the screen, in the normal manner of a screen washer jet. Immediately after the jet ceases to flow, the pin is normally allowed to return to a rest position in the nozzle aperture, the motion clearing that area of any remaining particles which may have been carried with the water and then preventing any ingestion of dirt.

Embodiments of the invention will now be described by way of examples with reference to the accompanying drawing in which: Figure 1 shows a cross sectional view of a screen washer jet with the pin at rest in the nozzle aperture.

Figure 2 shows the screen washer jet components in a position when water is being discharged through the nozzle.

Figure 3 shows a typical application where the fluid is held in a pressurised container.

Figure 4 shows a typical application where the fluid pressure is created by a manually operated pump.

Referring to figures 1 and 2 in the drawing, the screen washer jet comprises a moulded body 1, (held in the vehicle body 11), which has the nozzle 2 formed within it, a pin 3 which slides within the nozzle aperture, a piston 4 which is solidly attached to the pin, a seal 5 to prevent water passing around the piston, a spring 6 to control the movement of the piston and rod 7 to contain the spring, piston, and pin in the sleeve 9. Other items not shown are the water reservoir and pump.

When the pump is switched on, water is pumped into the screen washer jet body via the tube 8. The water pressure in cavity 10 forces the piston to move down the sleeve 9 against the spring, and drawing the pin out of the nozzle aperture. See figure 2.

When the water ceases to flow, the spring forces the piston back into the position shown in figure 1, and the pin returns to its rest position in the nozzle aperture.

Spray on adhesives used in the advertising industry suffer from blocked nozzles due to the glue drying out in the nozzle aperture after use.

Referring to figure 3, the fluid to be discharged is held in a pressurised container 12 and controlled by valve 13.

When the valve is opened, pressure in the container causes fluid to flow along the tube 14 to the nozzle housing 15 where a pin 16, which is attached to the piston and spring arrangement 18, resting in the nozzle aperture 17, is forced out of the nozzle by means of the fluid pressure acting on the piston, allowing the fluid to be discharged through the nozzle.

When the valve is closed, the pressure in the tube drops allowing the spring to move the piston and pin back to their original positions. The movement clears the nozzle aperture of any remaining fluid and other particles.

Insecticide sprays can suffer from nozzles getting blocked due to particles of dirt being mixed with the solution and then forming a plug in the nozzle aperture as the solution is pumped.

Referring to figure 4, the manually operated pump 19, operated by the handle 26, draws fluid from a reservoir via the inlet tube 20, and forces it along tube 21 to the nozzle housing 22 where a pin 23, which is attached to the piston and spring arrangement 25, resting in the nozzle aperture 24, is forced out of the nozzle by means of the fluid pressure acting on the piston, allowing the fluid to be discharged through the nozzle.

When operation of the pump ceases, the pressure in the tube drops, allowing the spring to move the piston and the pin back to their original positions. The movement clears the nozzle aperture of any remaining fluid and other particles.

Claims

1. Apparatus including a nozzle having an aperture through which pressurised fluid can be discharged, incorporating a pin and means controlled by the pressure of the fluid to be discharged to move the pin within the aperture of the nozzle.

2. Apparatus according to claim 1 wherein the pressure of the fluid to be discharged acts upon a piston or diaphragm to produce movement of the pin.

3. Apparatus according to claim 1 wherein a spring acts in opposition to the action of the fluid pressure on the piston or diaphragm.

4. Apparatus according to claim 1 wherein a pin attached to a piston or diaphragm moves within the nozzle aperture.

5. Apparatus according to claim 1 wherein a nozzle housing contains a nozzle aperture, pin, and means by which to control the movement of the pin using the pressure of the discharging fluid.

6. Apparatus according to all previous claims wherein an arrangement as described in figures 1 and 2 is used for a self clean screen washer jet for motor vehicles.

7. Apparatus according to claim 1 wherein the pressure of the fluid is generated by means of an electric pump.

8. Apparatus according to claim 1 wherein the fluid to be discharged is held in a pressurised container.

9. Apparatus according to claim 1 and claim 8 wherein the discharging of the fluid is controlled by means of a valve.

10. Apparatus according to claim 1, claim 8 and claim 9 substantially as described with reference to figure 3.

11. Apparatus according to claim 1 wherein the pressure of the fluid is generated by means of a manually operated pump.

12. Apparatus according to claim 1 and claim 11 substantially as described with reference to figure 4.

13. Apparatus according to claim 1, claim 7 and claim 11 wherein the fluid to be discharged is held in a reservoir.

14. Apparatus according to claim 1, claim 7 and claim 11 wherein the fluid to be discharged is transferred to the pump from the reservoir via a tube.

15. Apparatus according to claim 1, claim 7, claim 8 and claim 11 wherein the fluid to be discharged is transferred from the pump to the nozzle housing via a tube.