AU694180B2 - Spray valve - Google Patents

Description

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT Applicant: MATTHEWS BROS ENGINEERING PTY LTD A.C.N. 004 636 926 t r t 4 t Invention Title: SPRAY VALVTE The following statement is a full description of this invention, including the best method of performing it known to us: ROP67(937'0 04 5 9 SPRAY VALVE This invention relates to a spray valve, and more particularly a valve for use in a distributing system for applying, in the form of sprays, fluid surfacing or binding materials, such as bitumen, to a roadway or the like.

One difficulty which has been encountered with such distributing systems is unwanted cooling and therefore solidification of the bitumous material in the valve and associated spray nozzle, particularly when the valve is closed during those times when bitumen is not being sprayed onto the road surface.

One solution to this problem has involved circulating the hot bitumen being pumped from the bitumen supply tank, and usually mounted on a vehicle, continuously past the valves even when not open to maintain the body of the valve hot thus preventing cooling and therefore solidification of the bitumen in the valve and the associated spray nozzle. This is achieved by utilising a hollow spray bar which acts as a supply conduit for a 20 plurality of valve operated spray nozzles mounted along the length of the bar and having a supply passage extending longitudinally within the bar and a return passage also i t extending longitudinally within the bar and separated from the supply passage by a partition wall for a majority of heleingth of the br o prtitio mli srajgor iy i the length of the bar whereby hot bitumen supplied to, and flowing along, the supply passage to one end thereof flows around the end of the partition wall and back along the length of the return passage.

The pump for the hot bitumen therefore continues to circulate hot bitumen even when the valves of the spray nozzles are closed. When the valves are opened bitumen flows through the valves and associated spray nozzles to be sprayed onto the road surface in accordance with a predetermined spray pattern.

Although this solution to has to some degree been successful, it is dependent on sufficient heat conduction staffonnelkeep/PM5468 i c- r c 2 through the body of the valve to the bitumen in the valve chamber and if heat conduction is not sufficient, or not sufficiently rapid, cooling and solidification of the bitumen in the valve can still occur.

It is therefore an object of the present invention to provide a spray valve for continuously delivering hot fluid surfacing or binding materials to spray nozzles for spraying the material onto a road surface and which prevents, or at least minimises, cooling and solidification of the material within the valve and associated nozzle, and which involves maintaining a continuous circulation of hot material not only through the supply and return passages within the spray bar but also through the body of the valve itself.

15 The invention therefore envisages a spray valve for cortrolling the flow of hot fluid surfacing or binding material to a spray nozzle, said valve including a valve body having a valve chamber, a valve inlet passage communicating with the valve chamber and, when in use, with a supply passage of an associated spray bar, and a valve outlet passage also communicating with the valve chamber S' and, in use, with the spray nozzle which is mounted on the I r valve body, a valve member within said valve chamber and movable to open and close communication between the inlet and outlet passages to and from the valve chamber, and i wherein a by-pass passage is provided in communication with the valve chamber and the exterior of the valve body, whereby when the valve member is in the closed position hot.

material is by-passed back to a return passage of the associated spray bar, and wherein the valve body also includes a supply passage for compressed air communicating with the outlet passage for the hot material and incorporating a valve mechanism adapted to supply air when required to the outlet passage to expel hot material from the outlet passage and through the associated spray nozzle when the valve member is in the closed position.

It will be appreciated that by maintaining RAn H:\susan\keep\speci\17838-95-NGM.l.DOC 27/05/98 i rV i^ o i I. i 3 circulation of hot material directly through the valve body and the valve chamber, even when the valve is in the closed.

position, maintains the temperature of the hot material at a level which prevents solidification thereof as well as maintaining the valve body at a relatively high temperature.

It has also been recognised that if hot fluid surfacing or binding materials, such as bitumen, are mixed with water to form a foam emulsion the binding effect of the bitumen on a granulated road surfacing material is enhanced.

Therefore, preferably the valve body of the present invention supports a water nozzle adjacent the associated spray nozzle and orientated whereby water will 15 be sprayed into the spray of the hot material issuing from the spray nozzle to form a hot material/water emulsion on o the road surface.

One preferred embodiment of the invention, will i °•4 now be described with reference to the accompanying d- 'wings: Figure 1 is a side elevational view of a section I "i of the length of the spray bar on which are mounted a plurality of spray valves in accordance with the preferred embodiment of the invention together with associated spray nozzles, water nozzles and a valve actuating mechanism, Figure 2 is an enlarged view of on. of the spray valves, spray nozzle and water nozzle assemblies of Figure 1, Figure 3 is a side cross-sectional view of the assembly of Figure 2, Figure 4 is a cross-sectional view taken along line 4-4 of Figure 3 with the spray valve in the open position, and Figure 5 is a cross-sectional view similar to H:\ausan\keep\speci\17838-95-NGM.l.DOC 27/05/98 1- ar -L 4 that of Figure 4 with a spray valve in the closed position.

Turning to Figures 1, 2 and 3 of the drawings, the spray valves 10 in accordance with this preferred embodiment of the invention are mounted on a hollow spray bar 11 partitioned internally by a partition wall 12 extending along the majority of the length of the spray bar, to form a lower supply passage 13 for hot bitumen and an upper return passage 14 for the bitumen (see Figure 3), and whereby hot bitumen entering one end of the lower supply of the passage 13 flows along that passage to the other end thereof and then around the end of the partition wall and back along the return passage 14. The hot bitumen is pumped into the supply passage 13 from a supply of hot bitumen in a tank (not shown), and usually mounted on a vehicle, with the spray bar suspended from and extending laterally of the rear of the vehicle whereby hot bitumen will be sprayed onto a road surface as the vehicle is driven along the road surface.

A plurality of spray valves 10 in accordance with this preferred embodiment of the invention are attached by one or more bolts 15 to the spray bar 11 via a spacer plate 16 having aperture 17 therethrough aligned with outlet ports 18 through the wall of the spray bar communicating with the return passage 14 therein, and also aligned with a 25 by-pass passage 19 within a valve body 20 of the spray valve. The by-pass passage communicates with a valve chamber 21 within the valve body and of a tapered S: configuration. One end of the valve chamber 21 communicates with, and is aligned with, an aperture 22 through the spacer plate 16 which in turn is aligned with an inlet port 23 through the wall of the spray bar communicating with the supply passage 13.

With reference to Figures 3, 4 and 5 of the drawings, the hollow conical valve member 24 is received within the correspondingly tapered valve chamber 21, with one end open to the aperture 22 and port 23, and with the staff/ennelkeep/PM5468 j i I- I I I 5 other end closed and connected to a valve spindle extending through a bore 25a through a spindle housing 26 forming part of the valve body and held in place by a lock nut 27 engaging a correspondingly threaded portion 28 along part of the length of the valve spindle.

The other end of the valve spindle is coupled to an actuating valve mechanism 32 to later described, and which rotates the spindle and turns the valve member to an open position in which a port 29 through the wall of the valve member communicates with a supply passage 30 through the valve body and into which a spray nozzle is 50 screwed.

When the actuating mechanism 32 is actuated to rotate the spindle and valve member to closed position, the port 29 aligns with the by-pass passage 19 whereby hot bitumen from the supply passage 13 will be by-passed through the by-pass passage to the return passage 14.

The valve body also includes an air supply passage 33 for compressed air which in turn communicates with the supply passage 30 to the spray nozzle 50. The supply passage 33 incorporates a valve mechanism 34 consisting of a valve seat member 35 screwed into the passage 33 and having a passage 38 therethrough through which compressed air can be intermittently supplied from a 2 5 supply tube and connector 37. The passage 38 is normally closed by a valve member 39 urged against the end of the seat member 35 by a compression spring 40 captured between the valve member 39 and a ledge 41 formed within the passage 33. The valve member has a valve stem 39a loosely received within the passage 38 through the valve seat member 35, whilst an enlarged valve head 39b of the valve member is loosely received within the passage 33, whilst the ledge 39c formed at the transition between the valve stem 39a and the head 39b of the valve member carries a sealing O-ring 39d to sealingly seat on the end of the valve seat member 35 surrounding the passage 38 therethrough when the valve mechanism 34 is in the closed staWennefkeePM5468 e r-Y.A C naa)--r---arwu~ 6 position as shown in Figure 4. The valve member is completed by a guide portion 39e on the opposite side of the valve head 39b to that of the valve stem 39a and extending down within the compression spring 40 to retain and guide the spring during compression and relaxation thereof as the valve mechanism opens and closes. Due to the loose fitting of the valve stem 39a and valve head 39b an annular space of relatively large tolerance is provided between the valve stem and the valve head and the respective passages in which they are received to allow compressed air to pass the valve member 39 when in the open position as shown in Figure 5 with the sealing O-ring disengaged from the end of the valve seat member Also with reference to Figure 5 of the drawings, when the valve member 24 is rotated to the closed position, compressed air is simultaneously supplied to the valve mechanism and the valve member 39 is forced off the valve 2 seat member 35 against the biasing action of the spring thus allowing the compressed air to pass the valve member and through the air supply passage 33 to the supply passage 30 for the spray nozzle 50 and to blow out any bitumen remaining in the passage 30 and the spray nozzle As an alternative to the valve mechanism 34 of this preferred embodiment, a ball valve mechanism may be 25 utilised and incorporating a ball in place of the valve member 39 and urged by a compression spring such a spring against the valve seat member 35 to open and close the passage 38 therethrough.

In addition it has been found that if air is continually introduced into passage 30 through passage 33 during normal spraying operations when valve port 29 is open there is a marked improvement in transverse distribution across the full width of the spray pattern from the nozzles 50 providing a better distribution of material across the road surface.

In accordance with this preferred embodiment of staWenne/keepPM5468

A

i I -7the invention, the valve body carries a water sray assembly 42 having a mounting member 43 bolted by bolts 44 to the valve body and carrying a water nozzle 45 to which water is pumped from a water supply tank through a water supply tube 46 and operable to spray water into the spray of bitumen issuing from the spray nozzle in timed sequence with the opening of the bitumen spray to form the bitumen/water emulsion as discussed above.

The actuating mechanism 32 of this preferred embodiment of the invention comprises a lever arm 47, one for each spray valve and coupled at one end to flats machined on the ends of the respective valve spindles and coupled at their other ends to an actuating rod 48, which in turn is longitudinally movable by a pneumatic ram (not shown) to swing the lever arms 47 to and from positions whereby the valve spindles 24 rotate the valve members 24 within the spray valves between the open and closed positions. The actuating rod 48 on the opposite I side to the lever arms 47 is in turn supported by a support lever 49 rotatably engaging about the spindle housing 26 and held in place by a lock nut 51.

In addition, in order to disable a respective valve, the lever arm 47 of the valve is rotatably connected, via a bolt 52 to the end of the associated valve 25 spindle 25, whilst the opposite end of the lever arm has an aperture 53 therein which, when the valve is to be operative, is received on a pin 54 carried by the water supply tube 46. A compression coil spring 55 is provided between a pair of washers 56, one bearing against the side of the arm 47, and the other against a ledge 57 formed on the valve spindle, whereby the spring biases the arm to a position in engagement with the pin 54 as shown in Figure 3. The arm 47 may be swung against the biasing action of the spring to the position 47', shown dotted lines in Figure 3, to disable the valve, and is held in that position by the biasing action of the spring 55 which then slafennelkeepPM5468 -i -8 acts on the end of the lever arm.

It should be appreciated that alternative forms of actuating mechanisms and valve mechanisms may be used, including more sophisticated solenoid valve mechanisms that can be controlled to select individual spray valves as required for any particular situation and operable from a control panel within the cabin of the vehicle on which the spray system is situated.

4 a*t e t t I f t 1 staWennekeep/PM5468 I

Claims (1)

1. 9- rr t rr rr ~I r r a so rrr THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS: 1. A spray valve for controlling the flow of hot fluid surfacing or binding material to a spray nozzle, said valve including a valve body having a valve chamber, a valve inlet passage communicating with the valve chamber and, when in use, with a supply passage of an associated spray bar, and a valve outlet passage also communicating with the valve chamber and, in use, with the spray nozzle which is mounted on the valve body, a valve member within said valve chamber and movable to open and close communication between the inlet and outlet passages to and from the valve chamber, and wherein a by-pass passage is provided in communication with the valve chamber and the exterior of the valve body, whereby when the valve member 15 is in the closed position hot material is by-passed back to a return passage of the associated spray bar, and wherein the valve body also includes a supply passage for compressed air communicating with the outlet passage for the hot material and incorporating a valve mechanism adapted to supply air when required to the outlet passage to expel hot material from the outlet passage and through the associated spray nozzle when the valve member is in the closed position. 2. A spray valve as claimed in Claim 1, wherein the valve mechanism incorporates a valve member urged by a compression spring against a valve seat to open and close a passage therethrough as compressed air is selectively applied to, and shut off from, said valve mechanism. 3. A spray valve as claimed in Claim wherein the 30 valve member of the valve mechanism carries a sealing ring adapted to engage said valve seat in the closed position of the valve mechanism. 4. A spray valve as claimed in Claim 3, wherein the valve member of the valve mechanism is a ball forming part of a ball valve mechanism. A spray valve as claimed in any one of the preceding claims, wherein the valve body supports a water Hl\susan\keep\speci\17838-95-NGM.1.DOC 27/05/98 y1 0OV. T* RAL, 'V O nozzle adjacent the associated spray nozzle and orientated whereby water will be sprayed into the spray of the hot material issuing from the spray nozzle to form a hot material/water emulsion on a road surface. 6. A spray valve substantially as hereinbefore described with reference to the accompanying drawings. 7. A distribution system for applying, in the form of sprays, fluid surfacing or binding materials, incorporating one or more spray valves as defined in any one of the preceding claims. 8. A distribution system for applying, in the form of sprays, fluid surfacing or binding materials, substantially as hereinbefore described with reference to the accompanying drawings. ao *4 C. I 4,44 *4 44 4 Dated this 29th day of May 1998 MATTHEWS BROS ENGINEERING PTY LTD By their Patent Attorneys 20 GRIFFITH HACK Fellows Institute of Patent Attorneys of Australia -77U rZ Z 4 i H:\Susan\Keep\speci\17838-95-NGM. 1.DOC 29/05/98 I It ABSTRACT A spray valve (10) for controlling the flow of hot fluid surfacing or binding material to a spray nozzle and including a valve body (20) having a valve chamber a valve inlet passage (22) communicating with the valve chamber (21) and the supply passage (13) of an associated spray bar and a valve outlet passage also communicating with the valve chamber (21) and with the spray nozzle A valve member (24) is provided within the valve chamber (21) and is movable to open and close communication between the inlet and outlet passages (22 and to and from the valve chamber. The valve body (20) has a by-pass passage (19) in communication with the valve chamber (21) and the exterior of the valve body, whereby when the valve member is in the closed position hot material is by-passed back to a return passage (14) of the associated spray bar The valve body also includes a supply passage (33) for compressed air and incorporating a valve mechanism (39) adapted to supply air when required to 0 Oq 20 the outlet passage (30) to expel hot material from the U outlet passage and associated spray nozzle C t a