Spray valve

Abstract

A spray valve includes an inner body, a liquid chamber located within the inner body, an outlet orifice in the inner body, an outer housing, a pressure activation chamber located within the outer housing, substantially fluid-tight seals preventing the travel of fluid between the liquid chamber and the pressure activation chamber, and an outlet orifice in the outer housing. When a pressurised gas or liquid fills the pressure activation chamber, the outer housing moves relative to the inner body into an activated orientation, in which the inner body outlet orifice becomes aligned with the outer housing outlet orifice, allowing liquid from the liquid chamber to pass out through the aligned outlet orifices. When the pressurised gas or liquid is exhausted, the outer housing moves into a deactivated orientation, and the outer housing prevents liquid in the liquid chamber from passing through the outlet orifices.

Description

SPRAY VALVEFIELD OF THE INVENTION

[0001] This invention relates to spray valves. It relates particularly but not exclusively to water spray valves suitable for mounting to mobile water delivery systems such as water trucks for consistent and controlled water dispersal for operations such as dust suppression and road base preparation on mining and construction haul roads and agricultural spraying applications. Its design and construction permits effective spraying of many liquids other than water, such as chemicals, water additives, caustic liquids or acidic liquids.BACKGROUND TO THE INVENTION

[0002] Truck mounted spray systems include a liquid reservoir, such as a water tank, a pressurised water system, such as a water pump, to feed the liquid to the valve via a piping manifold system and a method for operating control valves to turn the spray of the liquid on and off.

[0003] Manual control valves are operated by hand using a lever or knob. They have a simple design, often used for less complex systems. They allow the operator to stop, start, or adjust the flow manually. However, they require the driver to stop the truck to open or close the valves.

[0004] Current conventional spray systems include a control circuit to allow the individual water valves to be opened or closed using switches located in the truck's cabin. Vehicles with air compressors typically use an electric solenoid or air valve to supply and exhaust pressurised air to the water valves, causing the water valves to open or close. Vehicles which have no air compressors typically rely on hydraulic system pressure and electric power supply. For this reason, a typical system replaces the air supply with a hydraulic system manifold energised by electric solenoid valves. Another method of controlling water valves is to divert pump-fed pressurised water via a solenoid to pilot the open / closed function of the water valves.

[0005] Mobile water trucks engaged in spraying operations typically use 2-position singleacting normally-open pressure control valves. When air or hydraulic pressure is applied to adiaphragm or sealing disc within a valve, the valve closes to overcome spring and water pressure, preventing water from being sprayed. When the air or hydraulic pressure is exhausted, the valve is opened by pressurised water flow, and water sprays out of the spray valve orifice.

[0006] In such valves, the diaphragm is the only membrane that separates the pressurised air or hydraulic fluid from the pressurised water. If a leak develops, pressurised water can potentially contaminate the truck system electrics, hydraulics or compressed air system, causing extensive damage to OEM system components and failed system operations on the truck.SUMMARY OF THE INVENTION

[0007] According to the present invention, there is provided a spray valve including:(a) an inner body;(b) a liquid chamber located within the inner body;(c) an outlet orifice in the inner body;(d) an outer housing;(e) a pressure activation chamber located within the outer housing;(f) substantially fluid-tight seals preventing the travel of fluid between the liquid chamber and the pressure activation chamber; and(g) an outlet orifice in the outer housingwherein, when a pressurised gas or liquid fills the pressure activation chamber, the outer housing moves relative to the inner body into an activated orientation, in which the inner body outlet orifice becomes aligned with the outer housing outlet orifice, allowing liquid from the liquid chamber to pass out through the aligned outlet orifices;and when the pressurised gas or liquid is exhausted from the pressure activation chamber, the outer housing moves relative to the inner body into a deactivated orientation, so that the inner body outlet orifice becomes misaligned with the outer housing outlet orifice, and the outer housing prevents liquid in the liquid chamber from exiting through the outlet orifices.

[0008] When the pressurised gas or liquid is exhausted from the pressure activation chamber, the outer housing may be motivated to move relative to the inner body into a deactivated orientation by any suitable motivating force. In preferred arrangements, springs acting between the inner body and the outer housing exert a biasing force to bias the relative positions of the outer housing and inner body towards the deactivated orientation.

[0009] Any suitable means may be used to retain the inner body and outer housing in the appropriate positions to ensure that the inner body outlet orifice and the outer housing outlet orifice are aligned when the pressure activation chamber is filled. This function may be performed by one or more limiting members which prevent the outer housing from moving relative to the inner body past the activated orientation when the pressure activation chamber is filled with a pressurised gas or liquid.

[0010] In order to ensure substantially watertight engagement between the inner body and the outer housing, it is preferred that O-rings are used. When the valve is oriented such that the pressure activation chamber is above the liquid chamber, it is preferred that one O-ring be provided above the level of the inner body outlet orifice, to prevent liquid from passing through the inner body outlet orifice and between the inner body and outer housing into the pressure activation chamber, and another O-ring be provided below the level of the inner body outlet orifice, to prevent liquid leaking out the bottom of the valve via the inner body outlet orifice and between the inner body and outer housing.

[0011] Any suitable means may be used to control the liquid spray pattern and flow rate produced by the valve. Any suitable outlet flow guide may be fitted to the outer housing causing liquid exiting the outer housing to produce a spray pattern with particular width and flow characteristics. The means for controlling the liquid spray pattern do not form part of the invention.

[0012] The various parts of the spray valve may be made from any suitable material or combination of materials. Suitable materials include but are not limited to plastics, steels, alloys, bronze and stainless steels.

[0013] As another preferred feature, the spray valve may include an inlet filter which prevents particles larger than the dimensions of the outlet orifices from entering the liquidchamber. This reduces the likelihood of the valve becoming blocked if the liquid is contaminated with particulate matter.

[0014] As another preferred feature, the spray valve may include a pressure activation chamber inlet filter which prevents foreign particles entering the pressure activation chamber. This reduces the likelihood of contaminating pilot operated valves if the gas or liquid is contaminated with particulate matter. Ideally the filter would prevent particles larger than 10 micron from entering the pressure activation chamber.

[0015] The liquid to be sprayed by the spray valve may be any suitable type of liquid or liquid additive. It may be water, but it may also include liquids other than water, including caustic liquids and acidic liquids.

[0016] The pressurised gas or liquid which is used to fill the pressure activation chamber may be any suitable type of gas or liquid. For trucks with compressors, compressed air is a suitable type of gas. For trucks with hydraulic systems, hydraulic fluid is a suitable type of liquid. In other applications, the liquid may be pressurised water. For trucks wanting to use pilot operated pressurised pump water this option is also now uniquely available.

[0017] Examples of the invention will now be described by reference to the accompanying figures. It is to be understood that the particularity of those figures does not supersede the generality of the preceding description.BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a front view of a spray valve according to an embodiment of the invention, in the deactivated (closed orifice) orientation.

[0019] Figure 2 shows a front view of the spray valve of Figure 1 in the activated (open orifice) orientation.

[0020] Figure 3 is a partial cross-sectional view of the spray valve of Figure 1 in the deactivated (closed) orientation, taken along the line A-A.

[0021] Figure 4 is a partial cross-sectional view of the spray valve of Figure 2 in the activated (open) orientation, taken along the line B-B.

[0022] Figure 5 is a perspective view of a spray valve according to an embodiment of the invention, incorporating an outlet flow guide.

[0023] Figure 6 is a top view of the spray valve of Figure 5.

[0024] Figure 7 is a front view of the spray valve of Figure 5.

[0025] Figure 8 is a cross-sectional view of the spray valve of Figure 5, taken along the line C-C.

[0026] Figure 9 is an exploded view of the spray valve of Figures 5 to 8, showing the various component parts.DETAILED DESCRIPTION

[0027] Referring firstly to Figures 1 to 4, there is shown a spray valve 1 which includes an inner body 2 and an outer housing 3. A liquid chamber 4 is located within inner body 2. Inner body 2 also has an inner body outlet orifice 5 (not visible in Figure 1).

[0028] A pressure activation chamber 6 is located within outer housing 3. Outer housing 3 also has an outer housing outlet orifice 7.

[0029] When a pressurised gas or liquid fills pressure activation chamber 6, outer housing 3 moves relative to inner body 2 into an activated orientation, illustrated in Figures 2 and 4, in which inner body outlet orifice 5 becomes aligned with outer housing outlet orifice 7, allowing liquid in liquid chamber 4 to exit through the aligned outlet orifices 5 / 7.

[0030] When the pressurised gas or liquid is exhausted from pressure activation chamber 6, outer housing 3 moves relative to inner body 2 into a deactivated orientation, illustrated in Figures 1 and 3, so that inner body outlet orifice 5 is not aligned with outer housing outlet orifice 7, and outer housing 3 prevents liquid in liquid chamber 4 from exiting through the outlet orifices 5, 7.

[0031] In the embodiment illustrated in Figures 1 to 4, springs 8 acting between inner body 2 and outer housing 3 exert a biasing force to bias the relative positions of outer housing 3 and inner body 2 towards the deactivated orientation. As shown in Figures 3 and 4, springs 8 run between a ring base 9, which is fixed to outer housing 3 and a flange 10 on inner body 2.

[0032] When spray valve 1 is in its activated orientation, as illustrated in Figure 4, springs 8 are compressed, exerting a biasing force on the outer housing urging it to return to the deactivated orientation illustrated in Figure 3. In order for spray valve 1 to move from its deactivated orientation to its activated orientation, the amount of force applied in pressure activation chamber 6 by the pressurised gas or liquid must be sufficient to overcome the force exerted by springs 8.

[0033] The embodiment of the invention illustrated in Figures 1 to 4 further includes limiting members 11 which prevent outer housing 3 from moving relative to inner body 2 past the activated orientation when pressure activation chamber 6 is filled with a pressurised gas or liquid. As shown in Figures 3 and 4, limiting members 11 abut either directly or through other components against ring base 9, which is fixed to outer housing 3. When outer housing 3 reaches the activated orientation in which inner body outlet orifice 5 becomes aligned with outer housing outlet orifice 7, limiting members 11 also abut against flange 10, which is a fixed part of inner body 2, and prevents outer housing 3 from moving relative to inner body 2 past the activated orientation.

[0034] The embodiment of the invention illustrated in Figures 1 to 4 further includes O-rings 12, 13 which provide substantially gas and liquid tight (watertight) engagement between the inner body 2 and outer housing 3. As shown in Figure 4, O-ring 12 provides a watertight seal below the level of inner body outlet orifice 5, to prevent liquid leaking out of inner body outlet orifice 5 and out near the bottom of outer housing 3. O-rings 13, of which there are two in the illustrated embodiment, provide a gas and liquid tight (watertight) seal above the level of inner body outlet orifice 5, to prevent liquid leaking out of inner body outlet orifice 5 and up into pressure activation chamber 6. O-rings 13 also prevent pressurised gas or liquid from pressure activation chamber 6 leaking through inner body outlet orifice 5 into liquid chamber4.

[0035] A tell hole 22 is provided in the side of outer housing 3 at a location which is higher than the highest travel point of the lower of O-rings 13 and lower than the lowest travel point of the higher of O-rings 13. Tell hole 22 enables ready detection of leakage if a fluid starts to leak between pressure activation chamber 6 and liquid chamber 4. This notifies the operator that it is time to change the failing seal.

[0036] It will be appreciated that the present invention provides a significant improvement over conventional spray valves in that the liquid being sprayed and the pressure activation gas or liquid are separated into different chambers, instead of simply being separated by a single membrane (diaphragm or similar). In conventional valves, failure of the diaphragm can result in rapid contamination of the truck's electrical, pneumatic or hydraulic systems, resulting in serious damage, whereas failure of an O-ring in the present invention can result in a slight leak which can be deliberately detected by its design and ameliorated before any significant damage occurs to the OEM vehicle control systems.

[0037] Figures 5 to 8 show essentially the same embodiment of the invention together with a particular embodiment of an outlet flow guide, although the outlet flow guide may take many different forms, and the present invention is not limited to any one particular type of outlet flow guide. It is envisaged that any number of customised outlet flow guides may be fitted to outer housing 3.

[0038] Figure 5 shows an outlet flow guide 15 which is fitted over outer housing 3 and communicates with outer housing outlet orifice 7 causing liquid exiting outer housing outlet orifice 7 to produce a spray pattern with particular width and flow characteristics.

[0039] Outlet flow guide 15 includes multiple different spray orifices 16, each of which is designed to produce a spray pattern with particular width and flow characteristics, wherein a desired one of the spray orifices 16 is selected by moving outlet flow guide 15 until the selected spray orifice is positioned over outer housing outlet orifice 7.

[0040] In this particular arrangement, outlet flow guide 15 is adjusted by manual movement of outlet flow guide 15 relative to outer housing 3. When outlet flow guide 15 has been adjusted as desired, it can be locked into place using a manual over centre style locking lever 17.

[0041] The spray valve may further include an inlet filter (not shown) which prevents particles larger than the dimensions of the outlet orifices from entering the liquid chamber. This can help reduce the likelihood of the valve becoming blocked if the liquid is contaminated with particulate matter.

[0042] The spray valve may further include a pressure activation chamber inlet filter (not shown) which prevents foreign particles larger than 10 micron entering the pressure activation chamber. This reduces the likelihood of contaminating pilot operated valves if the gas or liquid is contaminated with particulate matter.

[0043] Referring now to Figure 9, the figure provides an exploded view of the components of this particular embodiment of the invention.

[0044] Starting at the top, outlet flow guide 15 includes one or more spray orifices 16, each of which is designed to produce a spray pattern with particular width and flow characteristics. Cam locking lever 17 cooperates with dome nut 18 to lock outlet flow guide 15 into place. Flow guide 15 fits onto the outside of outer housing 3.

[0045] Outer housing 3 includes a tell hole 22, designed to enable early detection of leakage if fluid starts leaking due to deterioration of one or more of O-rings 13.

[0046] Inner body 2 is located inside outer housing 3. Figure 9 shows a larger O-ring 12 and two smaller O-rings 13, which achieve gas and liquid tight (watertight) seals between the outer surface of inner body 2 and the inner surface of outer housing 3. Inner body 2 also has outer flange 10 which is used in conjunction with springs and limiting pins. In the lower part of inner body 2 there are channels 19 designed to securely house the springs and limiting pins.

[0047] Springs 8 are inserted into channels 19 and fixed at their upper ends to flange 10. Limiting pins 11 travel freely in channels 19 located centrally within springs 8. The quantity of springs may be varied with the size of the valve, increasing in number as the dimensions of the valve increase to ensure effective operating spring pressures.

[0048] Base ring 9 is fixed to the bottom of outer housing 3 when the valve is assembled. Base ring 9 includes inner lugs 21 which locate the bottom ends of springs 8 and are shaped to travel up and down within channels 19 when the valve is in operation. Screws 20 are inserted through base ring 9 to securely fasten it to outer housing 3.

Claims

CLAIMS1. A spray valve including:(a) an inner body;(b) a liquid chamber located within the inner body;(c) an outlet orifice in the inner body;(d) an outer housing;(e) a pressure activation chamber located within the outer housing;(f) substantially fluid-tight seals preventing the travel of fluid between the liquid chamber and the pressure activation chamber; and(g) an outlet orifice in the outer housingwherein, when a pressurised gas or liquid fills the pressure activation chamber, the outer housing moves relative to the inner body into an activated orientation, in which the inner body outlet orifice becomes aligned with the outer housing outlet orifice, allowing liquid from the liquid chamber to pass out through the aligned outlet orifices;and when the pressurised gas or liquid is exhausted from the pressure activation chamber, the outer housing moves relative to the inner body into a deactivated orientation, so that the inner body outlet orifice becomes misaligned with the outer housing outlet orifice, and the outer housing prevents liquid in the liquid chamber from passing through the outlet orifices.

2. A spray valve according to claim 1 further including springs acting between the inner body and the outer housing which exert a biasing force to bias the relative positions of the outer housing and inner body towards the deactivated orientation.

3. A spray valve according to claim 1 further including one or more limiting members which prevent the outer housing from moving relative to the inner body past the activated orientation when the pressure activation chamber is filled with a pressurised gas or liquid.

4. A spray valve according to claim 1 wherein substantially fluid-tight engagement between the inner body and the outer housing is achieved by means of O-rings.

5. A spray valve according to claim 1 further including a tell hole in the outer housing to enable detection of leakage of fluid between the liquid chamber and the pressure activation chamber.

5. A spray valve according to claim 1 further including an inlet filter which prevents particles larger than the dimensions of the outlet orifices from entering the liquid chamber.

6. A spray valve according to claim 1 further including a pressure activation chamber inlet filter which prevents particles larger than 10 micron entering the pressure activation chamber.

7. A spray valve according to claim 1 wherein, when the spray valve is mounted on a vehicle, the inner body is fixed relative to the vehicle while the outer housing moves relative to the vehicle when the pressure activation chamber is filled and emptied.

8. A spray valve according to claim 1 wherein, when the spray valve is mounted on a vehicle, the outer housing is fixed relative to the vehicle while the inner body moves relative to the vehicle when the pressure activation chamber is filled and emptied.

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