GB2241039A - Cleaning apparatus and valves for use therewith - Google Patents

Abstract

Cleaning apparatus for spray guns comprises a generally frusto conical chamber 1 whose upper end is closed by a lid 23. The chamber 1 is preferably supported within the open upper end of an inverted frustoconical base 2 and includes a manifold 4 which is supported by the converging walls of the chamber 1 at a location intermediate the upper and lower extents thereof. The manifold 4 is connected to a source of fluid solvent which is discharged as discrete jets through nozzles formed in the manifold surface. A valve 40, Fig 7 which may be used to operate the primary cleaning cycle (eg using pump 10) is described. A piston 54 forced to the right by pressurized air against a spring 62 to allow communication between passageways 64, 65 to initiate the pump 10 is returned slowly to the left by fluid returning from a reservoir 42 via a restricted passageway 46. An extractor conduit 25 removes solvent fumes. <IMAGE>

Description

Improvements in and relating to Cleaning Apparatus and to Valves Suitable for Use Therewith This invention relates to cleaning apparatus and more especially, but not exclusively, to apparatus for cleaning paint spray assemblies and component parts thereof. The invention also relates to valves suitable for use, for example, with such cleaning apparatus.

Spray guns are used in the automobile and other industries for applying paint to, for example, car bodies.

These spray guns require repeated cleaning using liquid solvents which are generally both flammable and nauseous.

Since considerable quantities of solvents are employed, fire and health hazards to operatives are considerable.

The present invention sets out to provide apparatus for cleaning spray guns and the like which minimise such hazards.

According to the present invention in one aspect, there is provided cleaning apparatus which comprises a generally frusto conical chamber whose upper end is closed by a lid, a support for the chamber and a manifold which is supported by the converging walls of the chamber at a location intermediate the upper and lower extents thereof and is connected to a source of fluid solvent, the solvent being discharged as discrete jets through nozzles formed in the manifold surface.

In a preferred construction, the frusto-conical chamber is supported within the open upper end of an inverted frusto-conical base. The lower section of the chamber preferably defines a reservoir for solvent to be recycled via a pump to the manifold, solvent being drawn from the reservoir through an outlet pipe upstanding from the floor of the chamber. A filter is preferably positioned on the open end of the outlet pipe to remove contaminants from the flow of solvent to the pump.

A tray for carrying components to be cleaned may be supported by the manifold. In this arrangement, the manifold preferably comprises a array of pipes which extend generally radially of the chamber to define a gallery. Alternatively, the manifold itself includes one or more generally plain surfaces for carrying components to be cleaned. Where only one such surface is provided, it may extend across substantially the full width of the chamber, an annular space being left between the manifold side and the adjacent chamber wall for the removal of used solvent. The surface(s) may be slightly convex to assist the dispersal of solvents.

A drain aperture normally closed by a stopper or the like is preferably positioned in the floor of the chamber to remove waste products therefrom. The chamber floor may be inclined, at least in part, to encourage the flow of fluid to the drain aperture.

Additional spray nozzles for solvent may be positioned towards the upper extent of the chamber, these being operable to inject relatively clean liquid solvent downwardly into the chamber. These spray nozzles may be operated independently of the manifold nozzles and may be connected to a source of compressed air to cause liquid solvent to be drawn from a supply of relatively clean liquid solvent separate from the chamber.

According to the present invention in another aspect, there is provided cleaning apparatus comprising a cleaning chamber closed by a lid into which liquid solvent is injected as discrete jets to clean components located therein, and a fume extraction conduit positioned immediately above the lid in the vicinity of the seating between the chamber rim and the lid to collect and disperse solvent fume leaving the chamber during operation of the apparatus.

The extraction conduit preferably comprises an annular pipe formed with a series of openings in its lower surface, the conduit being supported between the outer rim of the lid and the upper rim of the chamber and being connectable to a source of suction to convey solvent fumes away from the vicinity of the chamber.

In a preferred arrangement, the upper rim of the chamber includes an inwardly extending generally concave annular lip against which the rim of the lid seats when in its closed position, the conduit being positioned within the concavity of the lip. The upper surface of the lid may be generally convex whereby the conduit locates within the concavity of the lip adjacent to convex edge of the lid.

In a further aspect, the invention provides cleaning apparatus comprising a cleaning chamber closed by a lid into which solvent is injected as discrete jets to clean components located therein, the undersurface of the lid defining a labyrinth seal to inhibit the escape of solvent fume from the chamber to atmosphere.

In a preferred construction, the undersurface of the lid is of generally concave construction its rim seating upon a complementary inwardly extending lip of the chamber, the lid also including a sealing member of generally concave construction depending from its under surface, the shape and configuration of the lid and sealing member together defining the labyrinth seal to inhibit the escape of solvent fumes from the chamber.

In a still further aspect, the invention provides cleaning apparatus comprising a chamber closed by a lid into which liquid solvent is injected as discrete jets from a manifold located internally within the chamber, the apparatus further comprising one or more additional nozzles positioned above tEe manifold and connected to supply clean solvent to the chamber.

In a yet further aspect, there is provided a cut-off valve comprising a housing which includes a reservoir for hydraulic fluid, a working chamber swept by a piston, and a gallery for placing the reservoir in communication with the working chamber, a restricted flow passageway for controlling the rate of flow of hydraulic fluid through the gallery and a non-return valve for permitting hydraulic fluid to pass from the chamber to the reservoir, the housing including passageways connectable into an air flow line to place a waisted central section of the piston in communication with a source of air under pressure and a pump or the like to be supplied with air under pressure, the arrangement being such that the piston is initially moved in one direction to displace hydraulic fluid through the non-return valve into the reservoir and to place the pump or the like in communication with the source of air under pressure via the said passageways, and is then gradually moved in the other direction by hydraulic fluid returning to the working chamber via the restricted flow passageway to close off communication between the air source and the pump or the like after a given time interval.

The invention will now be described by way of example only with reference to the accompanying diagrammatic drawings in which; Figure 1 is a front elevational view partly in section of cleaning apparatus in accordance with the invention with the lid of the apparatus raised; Figure 2 is a side elevational view partly in section of the apparatus illustrated in Figure 1 with the lid of the apparatus lowered; Figure 3 is a plan view taken from above to an enlarged scale of the apparatus illustrated in Figures 1 and 2; Figure 4 is a rear view of the upper portion of the apparatus illustrated in Figures 1 to 3 with the lid of the apparatus raised; Figure 5 is a flow diagram which schematically illustrates the manner in which cleaning fluid and air under pressure is supplied to the apparatus illustrated in Figures 1 to 4; ; Figure 6 is a flow diagram which schematically illustrates an alternative system for supplying cleaning fluid and air under pressure to apparatus in accordance with the invention; Figure 7 is a side view in section of a valve for use with apparatus in accordance with the invention; and Figure 8 is a section taken along line VIII - VIII of Figure 7 with certain parts of the valve removed for the sake of clarity.

The cleaning apparatus illustrated in Figures 1 to 5 of the drawings includes a frusto-conical chamber 1 of, for example, stainless steel whose lower end seats within the open upper end of an inverted frusto-conical base 2.

The base may also be produced from stainless steel. The chamber 1 is secured to the base 2 by anchor bolts (not shown). A tray 3 for supporting components to be cleaned is positioned within the chamber 1 and is supported on a network of pipes defining 2 manifold 4 through which cleaning fluid passes during use of the apparatus. The manifold 4 is suported by the tapering conical walls of the chamber. No additional fixing is required.

Components to be cleaned are located on the tray 3 and fluid solvent used in the cleaning process is collected in the lower portion of the chamber for recirculation. The frusto conical nature of the chamber leads to improved operation, reduced manufacturing costs and greatly assists in the maintenance o-f the apparatus.

In addition, the conical construction ensures that all sediment removed from components to be cleaned is collected in the bottom of the chamber and does not collect on chamber surfaces as is the case of other machines.

The manifold 4 comprises three equi-spaced pipes 5,6,7 (see Figure 3) each of which is formed with a radially extending generally horizontal section and an upstanding section which lies in contact with the internal surface of the chamber. Each pipe includes one or more outlet nozzles 8 (see Figure 3) through which cleaning fluid (e.g. recycled gun wash solvent known as HAZCHEM 1263) can be directed onto components on the tray 3 to be cleaned. For primary cleaning, fluid solvent is supplied to the manifold through a flexible pipe 9 connected to a pump 10 mounted on the internal wall of the base 2. The pump is pneumatically operated and essentially comprises a linear air motor coupled to drive a linear solvent pump.

Air under pressure is supplied from an air line to the linear air motor through a flexible pipe 11 and re-cycled cleaning fluid present in the bottom of the chamber 1 is supplied to the linear solvent pump through a conduit 12 which passes through the floor of the chamber 1. A filter 13 is positioned at the open end of the conduit 12 to prevent contaminants being passed to the pump. Operation of the pump causes re-cycled cleaning fluid to flow to the manifold 4 and to be ejected as discrete jets through the nozzles 8. Operation of the pump and its associated control system will be described in more detail below with reference to Figure 5 of the drawings.

The tray 3 includes openings to enable cleaning fluid to pass from the manifold nozzles 8 to clean components on the tray, this fluid then passing under gravity to the bottom of the chamber for re-circulation.

In an alternative arrangement, the manifold 4 comprises a circular plate having a generally flat but slightly convex upper surface and a lower surface spaced from the upper surface to define a chamber into which solvent is supplied via the pipe 9. The upper surface includes threaded openings into which are fitted the solvent discharge nozzles 8. One nozzle may also define a support for the nozzle of a grease gun to be cleaned.

Three or more solvent conveying pipes are positioned about the circumference of the plate manifold, these including orifices for the discharge of solvent. The upstanding nozzles effectively space the plate manifold from the side wall of the chamber 1 to define an annular gap to allow solvent and sediment to pass to the lower portion of the chamber for collection and, where appropriate, recycling.

The plate manifold provides a direct support for components to be cleaned thereby doing away with the need for the tray 3. Alternatives to a plate manifold are, of course, possible. Thus, a manifold including one or more discrete component supporting surfaces could be employed.

As will be seen from Figures 1 and 2, one or more additional cleaning fluid discharge nozzles 14 are positioned adjacent the upper rim of the chamber 1 and are each directed downwardly at an angle of, for example, 45c towards the chamber interior to provide secondary cleaning of components after completion of the primary cleaning cycle. The or each nozzle 14 is designed to give a low vapour wet spray and is connected by flexible piping 15 (see Figure 2) to a separate tank 16 containing clean solvent. Cleaning fluid directed onto components on the tray 3 by the nozzles 14 passes under gravity to the bottom of the chamber for re-circulation. The tank 16 sits within the confines of the base and can readily be recovered therefrom as and when required. Typically, the tank will hold approximately 10 litres of liquid solvent.

The or each nozzle 14 is connected to receive air under pressure from an air line 17 (see Figures 2 and 5) when a valve 18 mounted on the front of the base 2 is operated manually. The compressed air from the air line passes to the or each nozzle 14 and flows over the end of the pipe 15 to cause fluid solvent to be drawn from the tank 16 and to be ejected downwardly into the chamber interior.

The floor of the chamber 1 is inclined to cause cleaning fluid present in the chamber to flow towards a drain hole 19. Opening and closing of the drain 19 is controlled by a tap 20. An opening 21 (shown in chain dotted line in Figure 2) is formed in the front of the support 2 to provide access to its interior for removal of the container 16 and to assist during servicing of the apparatus. For removal of the fluid and contaminants present in the chamber 1 the container 16 is replaced with a suitable receptacle and the drain 19 opened by operation of the tap 20.

The upper open end of the chamber 1 includes a generally concave inwardly extending annular lip 22 which provides a seating for a pivotably mounted lid 23 (of, for example, stainless steel) when in its lowered position.

The external surface of the lid is of generally convex configuration. Attached to the internal generally concave face of the lid 23 is a generally concave sealing member 24 whose lower edge extends downwardly to a position below the level of the lip 22. The sealing member 24 defines with the lid a labyrinth seal to inhibit the egress of liquid solvent from the chamber during use thereof.

Set within the confines of the concave lip 22 and adjoining convex edge of the lid 23 is an extractor conduit 25 formed with graded apertures in its lower face and connected by a flexible tube (not shown) to a source of suction (e.g. an extractor fan or fume extraction plant). The extractor conduit operates to transport any noxious fumes which may be emitted from the chamber away from the environs of the cleaning apparatus. The conduit 25 may be detachably mounted on the curved rim of the lid 23 so that its pressure does not inhibit access to the chamber 1 when the lid is raised. The conduit preferably extends around the major circumference of the lid and may be produced from plastics, metal or any other suitable material.

As will be seen more clearly from Figure 4 of the drawings, the lid 23 is attached to the rim of the chamber 1 by a double strap hinge including struts 26. The struts 26 carry an arm 27 which, when the lid is in its closed position, makes contact with the free end of a rod 28 to move the rod downwardly through guides 29. In its lowered position, the end of the rod 28 remote from the lid 23 holds an air cut-off valve 30 to place the pump 10 in communication with its source of air under pressure.

Opening of the lid 23, however, moves the rod 28 out of its contact with the cut-off valve 30 te cut off air to the pump (and therefore the flow of solvent to the chamber) thereby minimising the escape of solvent from the chamber.

As will be seen from Figure 5, the pump 10 is supplied with air under pressure from a source 31. When the apparatus is started by operation of a push-button 32 on the front face of the support 2 (see Figure 2), air under pressure flows from the source 31 to charge an accumulator 34 (See also Figure 1). As soon as the pressure within the accumulator 34 reaches a predetermined value, a pilot valve 35 opens to permit air to flow through a conduit 36 direct to the pump 10 through the cut-off valve 30. Air from the accumulator 34 leaks to atmosphere through a bleed valve 39. When the pressure of air within the accumulator 34 falls to a predetermined value, so the valve 35 operates to close off the supply of air to the pump 10. The degree of leakage through the bleed valve 39 is controlled by a simple screw-fitting 38 to vary the ON-TIME of the apparatus.

In operation of the apparatus, for primary washing of components, liquid solvent present in the base of the chamber 1 passes via the filter 13 and pipe 12 to the pump 10 and is conveyed under pressure to the manifold 4 through conduit 9. On entering the pipes 5, 6, 7, the solvent is discharged as discrete jets through the nozzles 8. The primary wash continues for so long as the pressure of air within the accumulator 34 remains above the preset valve. Flow of cleaning fluid for secondary washing through the nozzles 14 is effected independently and selectively by manual operation of the push-button 18 on the front face of the support 2. Secondary washing continues for so long as the push button 18 is pressed inwardly.

Should, for some reason or other, the lid 23 be opened during the primary wash cycle, the cut-off valve 30 operates automatically to switch off the cleaning cyle.

Harmful solvent fumes leaving the chamber 1 are automatically removed from the vicinity of the apparatus by the extractor conduit 25 to a conventional fume extractor. The opportunity for hazardous fumes to escape from the chamber 1 is reduced significantly by the shape and configuration of the lid 23 and its seating on the lip 21 and by the presence of the labyrinth seal defined by the lid 23 and the member 24.

Turning now to Figure 6, the fluid and air flow system illustrated is similar to that shown in Figure 5 and like integers to those illustrated in Figure 5 have been given the same reference numerals to those used in Figure 5. In the system illustrated in Figure 6, the accumulator 34, bleed valve 39 and pilot valve 35 are essentially replaced by a single hydraulic valve 40. As will be seen from Figures 7 and 8, the hydraulic valve 40 comprises a housing 41 including a first cylinder 42 defining a reservoir for hydraulic fluid a gallery 43, and a second working cylinder 44 in communication with one another via passageways 45,46. Passageway 45 includes a seating 47 for a ball valve 48 which is urged into contact with the seating 47 by a spring 49.The force imposed by the spring 49 on the ball 48 can be varied by tightening or loosening a screw threaded closure member 50. The flow area of the passageway 46 can be varied by driving a screw threaded throttle valve 51 selectively into and out of the passageway 46.

The ends of the cylinders 42,44 remote from the gallery 43 are closed by screw threaded closure members 52,53 respectively.

Positioned within the working cylinder 44 is a piston 54 formed with two end sections 55,56 of diameter just less than the internal diameter of the cylinder 44 and a waisted central section 57. '0' rings 58 seat within circumferential grooves formed in the end sections 55,56 to seal these sections to the internal surface of the working cylinder 44.

The end of the piston 54 remote from the gallery 46 includes a stem 59 against which abuts the stem 60 of a push-button 61 which protrudes through the closure member 53 to a position on the external surface of the frustoconical base 2. The piston 54 is free to slide within the working cylinder 44 and is biassed to the position shown in Figure 7 by a spring 62.

Extending through the wall of the cylinder 44 are passageways 63,64 and 65. These passageways communicate respectively with conduits 66,67 and 68 of Figure 6.

As will be seen from Figures 7 and 8 the passageways 63,64 are positioned one to each side of the cylinder 44 and are offset along the length of the cylinder. A bleed passageway 69 is also provided, this passageway being open to the atmosphere.

In operation of the system illustrated in Figures 6 to 8, the reservoir 42, gallery 43 and that length of the cylinder 44 to the right hand side of the piston 54 are partially filled with hydraulic fluid. Operation of the push-button valve 32 places the passageway 63 in communication with air under pressure from the air line 31. The piston 54 is moved to the right by the compressed air against the action of the spring 62 to cause hydraulic fluid to displace the ball 48 off from its seating 47 and to pass from the right hand side of the cylinder 44 to the reservoir 42. The ball 48 returns to its seating after the displaced hydraulic fluid has passed to the reservoir.

At the same time, the passageways 64,65 are placed in communication with one another by the waisted section 57 of the piston 54 to enable air under pressure to pass to the pump 10 to initiate operation of the primary cleaning cycle. As hydraulic fluid slowly returns to the right hand side of the working cylinder 44 through the restricted passageway 46, so the piston 54 is slowly moved to the left to clcse-off after a given period of time the flow of compressed air to the pump and to iscontin the primary cleaning cycle.

The rate at which hydraulic fluid is permitted to return to the working chamber (and therefore the "ON-TIME" of the primary cleaning cycle) may be controlled by means of the throttle valve 51.

Other time-based controls could, of course, be adopted. Thus, a simple clock-work controller operable to cause an interruption to the air supply to the apparatus, possibly by causing the lid 23 to open, could be used.

Alternatively, a mechanical, pneumatic or even electrical time-based controller associated with the supply of air rather than the cleaning apparatus itself could be adopted.

It is to be understood that the foregoing is merely exemplary of cleaning apparatus in accordance with the invention and that modifications can readily be made thereto without departing from the true scope of the invention.

Claims (25)

1. Cleaning apparatus comprising a generally frusto conical chamber whose upper end is closed by a lid, a support for the chamber and a manifold which is supported by the converging walls of the chamber at a location intermediate the upper and lower extents thereof and is connected to a source of fluid solvent, the solvent being discharged as discrete jets through nozzle. formed in the manifold surface.

2. Apparatus as claimed in Claim 1 wherein the manifold comprises a base and a plurality of upwardly extending arms so inclined that they lie in contact with the converging side walls of the chamber tc support the manifold within the chamber.

3. Apparatus as claimed in Claim 2 wherein each upwardly extending arm is formed with at least one inwardly facing outlet for the flow of solvent.

4. Apparatus as claimed in Claim 2 or Claim 3 wherein the base includes at least two upwardly projecting nozzles for the throughflow of solvent.

5. Apparatus as claimed in Claim 4 wherein at least one of the nozzles defines a support for the barrel of a gun to be cleaned.

6. Apparatus as claimed in any one of Claims 2 to 5 wherein the base of the manifold comprises a plurality of generally horizontal pipes which support a tray for carrying articles to be cleaned.

7. Apparatus as claimed in any one of Claims 2 to 5 wherein the base of the manifold comprises a generally flat plate spaced from the sides of the chamber to define a generally annular slot therebetween.

8. Apparatus as claimed in Claim 7 wherein the upper surface of the plate manifold is convex.

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9. Apparatus as claimed in any one of Claims 1 to 8 wherein the frusto-conical chamber is supported within an open upper end of an inverted frusto-conical base.

10. Apparatus as claimed in any one of Claims 1 to 9 wherein the lower section of the chamber defines a reservoir for solvent to be recycled via a pump to the manifold.

11. Apparatus as claimed in Claim 10 wherein solvent is drawn from the reservoir through an open ended outlet pipe upstanding from the floor of the chamber.

12. Apparatus as claimed in Claim 11 wherein a filter is positioned on the open end of the outlet pipe to remove contaminants from the flow of solvent passing to the pump.

13. Apparatus as claimed in any one of the preceding claims wherein a drain aperture is positioned in the floor of the chamber to remove waste products therefrom.

14. Apparatus as claimed in Claim 13 wherein the chamber floor is inclined1 at least in part, to encourage the flow of fluid to the drain aperture.

15. Apparatus as claimed in any one of the preceding claims wherein additional spray nozzles for solvent are positioned towards the upper extent of the chamber, these being operable to inject relatively clean liquid solvent downwardly into the chamber.

16. Apparatus as claimed in Claim 15 wherein the additional spray nozzles are operated independently of the manifold nozzles and are connected to a source of compressed air to cause liquid solvent to be drawn from a supply of relatively clean liquid solvent separate from the chamber.

17. Cleaning apparatus comprising a cleaning chamber closed by a lid into which liquid solvent is -l injected as discrete jets to clean components located therein, and a fume extraction conduit positioned immediately above the lid in the vicinity of the seating between the chamber rim and the lid to collect and disperse solvent fume leaving the chamber during operation of the apparatus.

18. Apparatus as claimed in Claim 17 wherein the extraction conduit comprises an annular pipe formed with a series of openings in its lower surface, the conduit being supported between the outer rim of the lid and the upper rim of the chamber and being connectable to a source of suction to convey solvent fumes away from the vicinity of the chamber.

19. Apparatus as claimed in Claim 17 or Claim 18 wherein the upper rim of the chamber includes an inwardly extending generally concave annular lip against which the rim of the lid seats when in its closed position, the conduit being positioned within the concavity of the lip.

20. Apparatus as claimed in any one of Claims 17 to 19 wherein the upper surface of the lid is generally convex whereby the conduit locates within the concavity of the lip adjacent to convex edge of the lid.

21. Cleaning apparatus comprising a cleaning chamber closed by a lid into which solvent is injected as discrete jets to clean components located therein, the undersurface of the lid defining a labyrinth seal to inhibit the escape of solvent fume from the chamber to atmosphere.

22. Apparatus as claimed in Claim 21 wherein the undersurface of the lid is of generally concave construction with its rim seating upon a complementary inwardly extending lip of the chamber, the lid also including a sealing member of generally concave construction depending from its under surface, the shape and configuration of the lid and sealing member together defining the labyrinth seal to inhibit the escape of solvent fumes from the chamber.

23. Cleaning apparatus comprising a chamber closed by a lid into which liquid solvent is injected as discrete jets from a manifold located internally within the chamber, the apparatus further comprising one or more additional nozzles positioned above the manifold and connected to supply clean solvent to the chamber.

24. A cut-off valve comprising a housing which includes a reservoir for hydraulic fluid, a working chamber swept by a piston, and a gallery for placing the reservoir in communication with the working chamber, a restricted flow passageway for controlling the rate of flow of hydraulic fluid through the gallery and a nonreturn valve for permitting hydraulic fluid to pass from the chamber to the reservoir, the housing including passageways connectable into an air flow line to place a waisted central section of the piston in communication with a source of air under pressure and a pump or the like to be supplied with air under pressure, the arrangement being such that the piston is initially moved in one direction to displace hydraulic fluid through the nor- return valve into the reservoir and to place the pump or the like in communication with the source of air under pressure via the said passageways, and is then gradually moved in the other direction by hydraulic fluid returning to the working chamber via the restricted flow passageway to close off communication between the air source and the pump or the like after a given time interval.

25. Cleaning apparatus substantially as herein described with reference to Figures 1 to 8 of the accompanying drawings.