CA1225828A - Miniature spray guns - Google Patents
Miniature spray gunsInfo
- Publication number
- CA1225828A CA1225828A CA000462816A CA462816A CA1225828A CA 1225828 A CA1225828 A CA 1225828A CA 000462816 A CA000462816 A CA 000462816A CA 462816 A CA462816 A CA 462816A CA 1225828 A CA1225828 A CA 1225828A
- Authority
- CA
- Canada
- Prior art keywords
- valve
- valve body
- sleeve
- gas
- flow
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
- B05B7/00—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas
- B05B7/02—Spray pistols; Apparatus for discharge
- B05B7/12—Spray pistols; Apparatus for discharge designed to control volume of flow, e.g. with adjustable passages
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
- B05B7/00—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas
- B05B7/24—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas with means, e.g. a container, for supplying liquid or other fluent material to a discharge device
- B05B7/2402—Apparatus to be carried on or by a person, e.g. by hand; Apparatus comprising containers fixed to the discharge device
- B05B7/2405—Apparatus to be carried on or by a person, e.g. by hand; Apparatus comprising containers fixed to the discharge device using an atomising fluid as carrying fluid for feeding, e.g. by suction or pressure, a carried liquid from the container to the nozzle
- B05B7/2429—Apparatus to be carried on or by a person, e.g. by hand; Apparatus comprising containers fixed to the discharge device using an atomising fluid as carrying fluid for feeding, e.g. by suction or pressure, a carried liquid from the container to the nozzle the carried liquid and the main stream of atomising fluid being brought together after discharge
Abstract
ABSTRACT OF THE DISCLOSURE
An external mix miniature spray gun of the airbrush type obtains a spray of paint by directing a jet of gas from a source over a nozzle 9. A control valve for the flow of gas is connected at one end 26 to the source and an outlet 29 at the other end for discharge into the body of the gun. The valve includes a body of circular end profile with the inlet 26 leading to first generally radial flow passages 27 opening to the side of the valve body and second generally radial flow passages 28 leading from the side of the valve body to the outlet 29. A sleeve 2 is rotatably retained on the valve body by means 30 defining interengaging threads and spans between the first and second radial passages 27, 28 to define an internal space for gas flow therebetween. A tapered surface 35 in the gas flow space on the interior of the sleeve is arranged to approach or withdraw from a portion of the valve body to enlarge or diminish the gap therebetween as the sleeve is rotated relative to the body. At small degrees of valve opening the radial bores 28 are masked by the threads 30 of the sleeve so that the threads provide a flow resistance facilitating control at low gas flow rates. With a valve of the above kind the flow of air through the airbrush can be shut off in the airbrush itself rather than at source, the pressure can be adjusted in accordance with the fluid being sprayed and if the source is an aerosol type bottle the pressure can be regulated to maximise the aerosol life.
An external mix miniature spray gun of the airbrush type obtains a spray of paint by directing a jet of gas from a source over a nozzle 9. A control valve for the flow of gas is connected at one end 26 to the source and an outlet 29 at the other end for discharge into the body of the gun. The valve includes a body of circular end profile with the inlet 26 leading to first generally radial flow passages 27 opening to the side of the valve body and second generally radial flow passages 28 leading from the side of the valve body to the outlet 29. A sleeve 2 is rotatably retained on the valve body by means 30 defining interengaging threads and spans between the first and second radial passages 27, 28 to define an internal space for gas flow therebetween. A tapered surface 35 in the gas flow space on the interior of the sleeve is arranged to approach or withdraw from a portion of the valve body to enlarge or diminish the gap therebetween as the sleeve is rotated relative to the body. At small degrees of valve opening the radial bores 28 are masked by the threads 30 of the sleeve so that the threads provide a flow resistance facilitating control at low gas flow rates. With a valve of the above kind the flow of air through the airbrush can be shut off in the airbrush itself rather than at source, the pressure can be adjusted in accordance with the fluid being sprayed and if the source is an aerosol type bottle the pressure can be regulated to maximise the aerosol life.
Description
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FIELD OF THE INVE~TION
This in~ention relates to a spray gun for producing a fine controlled spray of paint or dye in a pattern small enough to enable the gun to be used as an artist's tool.
Such spray guns will be referred to as airbrushes.
BACKGROUND OF THE INVENTION
Representative airbrushes of the prior art are shown in Patent Specifications Nos. GB-B-2020578 (Rebold) and US-A-2550404 (Chasan). Representative gas flow control devices are shown in Patent Specifications Nos. GB-A-841895 (Beech) and US-A-3987999 (Savage).
It is an object of the invention to provide an airbrush of the kind in which there is one control for the compressed gas and a separate control for the gas/air mixture in which the principal gas valve parts may be moulded in plastics but in which the gas valve has a performance approximate to that of a needle~valve and is effective at low flow rates.
BRIEF DESCRIPTION OF THE INVENTION
Broadly stated the invention comprises a miniature spray gun including a body carrying a nozzle and means definlng a compressed gas path leading through the body to the nozzle, the gas path leading successively through reduc1ng and control valves, the reducing valve being operable by rotation of an external sleeve on ~he body to vary the~length of a flow resistance defined at least over part~of the range of travel of the valve by interenyaging :
: ~ , 4 ~ 32~3 threaded members to preset a resistance to gas flow and the control valve being manually operable to control spraying at the preset flow resi.stance of the reducing valve.
The invention further comprises an external mix miniature spray gun including a body carrying an air nozzle and having means defining a flow path for compressed gas from a compressed gas source through a reducing valve into said body and thence through a separate trigger-operated valve to said air nozzle so that upon actuation of said trigger-operated valve a jet of gas from the compressed gas source is directed over a capillary paint nozzle, said reducing valve having a gas inlet at one end thereof for connection to the source and a gas outlet at the other end thereof for discharge into the body of the spray gun, said other end of said reducing valve being gas tightly fitted into said body of the spray gun, said reducing valve including a valve body of circular end profile with said inlet leading from said one end of said reducing valve to first generally radial flow passages that are defined within said valve body and open into the side of said valve body, second generally radial flow passages defined within said valve body in spaced relation to said first generally radial flow passages and opening from said side of said valve body nearer said other end of said reducing valve, said second generally radial flow passages leading to said gas outlet, and a sleeve that is rotatably retained on said valve body to open and close said reducing valve, said sleeve having threads thereon that are in engagement with threads on the side of said valve body, said valve body threads including threads that are located between said first and second radial passages, the second flow passages opening through the threaded region of the valve body that i5 covered by the threaded region of the sleeve when the reducing valve is closed, the interengaging threads of said sleeve and valve body defining a flow path upstream of said second passages for the flow of gas along said . .
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interengaging threads from said first passages to said second passages at small degrees of valve opening, said flow path exhibiting a flow resistance which is dependent upon the length of the said interengaging threads upstream of said second passages, said flow resistance being varied by rotation of said sleeve relative to said valve body to vary the length of said interengaging threads along which gas flows upstream of said second passages thereby to control the gas flow at small degrees of opening of said reducing valve, and a tapered surface on the interior of said sleeve between said first and second passages upstream of said interengaging threads, such that said tapered surface approaches or withdraws from a portion of said valve body to diminish or enlarge the gap between said surface and said valve body as said sleeve is rotated relative to said valve body to control the gas flow at large degrees of opening of said reducing valve.
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The invention yet further provides an external mix miniature spray gun in which a spray is obtained by directing a jet o~ gas from a compressed gas source over a capillary paint nozzle, wherein control of the flow of gas from the source is achieved by means of a control valve having a gas inlet at one end for connection to the source and a gas outlet at the other end for discharge into a body of the spray gun into which said oth~r end gas tightly fits, said control valve including a valve body of . 10 circular end profile with said inlet leading from said one end to first generally radial flow passages opening to the side of said valve body and with second generally radial flow passages opening from said side of said valve body nearer said other end and leading to said gas outlet and a sleeve that is rotatably retained on said valve body by means defining interengaging threads and that spans between said first and second radial passages to define an internal space for gas flow therebetween, a tapered surface in the gas flow space on the interior of the sleeve being arranged to approach or withdraw from a portion of said valve body to enlarge or diminish the gap therebetween as said sleeve is rotated relative to said valve bod~.
In the above gun the valve sleeve that rotates externally on the handle and the handle itself are intended to be moulded in plastics where fine mating threads are not practical from a moulding standpoint. A
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performance approximate ~o that of a conventional needle valve can be provided if the second flow passages open through the threaded region of the valve body that i8 covered by the threaded region of ~he sleeve when the valve is closed whereby at least at small degxees of valve opening gas passes along the threads to the second flow passages. Preferably the second flow passages are positioned along the threaded region of the valve body so that they become exposed as the sleeve is moved to a fully 10 open position.
With the above arrangement it has been found that the flow of gas through the airbrush can be shut-off from the airbrush itself rather than at the aerosol cannister or other gas supply normally used, that the pressure can be adjusted to take account of the fluid being sprayed, and that the pressure can be regulated to maximise aerosol lifeO
The included angle between the spray nozzle and the fluid nozzle is about 90 but versions of the spray gun in ~0 which the included angle is about 75 may also be used in some applications.
DESCRIPTION OF THE DRAWINGS
An embodiment of the invention will now be described, by way of example only, with reference to the accompa~nying drawings, in which:
~s Flgure 1 is a view of an airbrush in longitudinal vertical section, , , - ~z~s~
Figure 2 is a vertical section on the line 2-2 of Figure l, and Figure 3 is a graph showing the relationship between throughput of the control valve of the airbrush and number of turns of the valve sleeve for various input pressures.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the drawings, a control valve body 1 of circular end profile is formed at its back end with a hollow threaded nipple 25 to fit onto a threaded end cap of a hose leading from an aerosol bottle, air line or other compressed gas source. ~ gas inlet passage 26 leads forwardly through the nipple 25 to radial gas flow passages 27 and opens to the side surface of the valve body l. Towards the front end of the valve body second radial gas flow passages 28 lead from the side surface to an axial gas outlet passage 29 that opens towards the front end of the valve body l. The body 1 is formed on its side surface with a threaded region 30 that engages internal threads on a valve sleeve 2 which is sealed at opposed ends to the valve body l by means of front and rear O-rings 18, 20 that locate in grooves in the valve body. Between the sleeve 2 and the body l is defined an annular gas flow space that permits gas to flow under pressure between the radial tubes 27 and 28.
It will be noted that the rear.rmost region 35 of the sleeve 2 has a very gentle forwardly convergent taper or draft angle o$ typically 1-3 and there is a matching '` ' ~, 8 ~ 8 taper on the underlying wall of the valve body 1.
Accordingly, as the sleeve 2 is rotated relative to the body 1, the internal surface of 35 the sleeve 2 approaches and withdraws from the ends of the radial gas flow passages 27, offering an increased or reduced resistance to gas flow. Further, a third O-ring 19 supported in a groove in the body 1 approaches or withdraws from a more steeply tapering face 36. The adjustment thread on the sleeve 2 may also pass over the radial flow passages 28 for part of the total adjustment provided.
Thus the tapered rearmost region 35 of the sleeve 2 together with the underlying surface of the valve body act as a needle valve, in which at any given axial position the amount of air that is allowed to pass will be dependent on the diameter of the valve at the control orifice. In the valve for the present spraygun the body 1 and sleeve 2 are to be moulded in plastics and the mating threads 30 have to be of relatively large diameter and pitch to allow them to be moulded. But such coarse threads 30 cannot themselves provide fine control of the airflow at the small flow rates required for special ~ffects spraying using the airbrush. In the valve of Figure 1 the radial passages 28 open through the threaded region of the body partway along it, and in the illustrated closed posltion of the valve thes~ passages 28 are covered by the threaded region of the sleeve 2. As the valve starts to open the air that enters the valve has ..
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to pass along the threads 30 before it can enter the passages 28, the length of threads that the air has to pass being adjustable depending upon the number of turns through which the sleeve rotates. As the valve is further opened, the passages 28 are exposed, and a maximum flow rate is achieved. Thus three regions can be expected on the gas flow/sleeve axial position curve. At low degrees of opening there is a region in which the resistance to flow of the threads and resulting back-pressure principally determines the rate of through flow.At an intermediate range of sleeve positions the flow changes as the threads of sleeve 2 disengage from the passages 28. Finally at large valve openings there is another region where the valve acts effectively as a needle valve. The characteristics of such a valve are shown in Figure 3 which illustrates for various applied pressures the air flow rate through the valve as a function of number of turns from a fully closed position.
These show that with careful design a useful control of ~0 flow rate over a range of about 3 turns can be obtained whereas with simpler designs regulation may be extrémely coarse and may occupy half-turn only from fully off to maximum flow. The valve body 1 and sleeve are moulded in nylon or polypropylene which are materials that assist in giving complete flow shut-off when required.
The forward end of the valve body 1 fits gas-tightly into a gun body 3 in which there is an internal chamber 10 ~ 2~3 whose outlet is controlled by a poppet-like air valve 4 which is slidably guided in a spacer member 6 sealed to ~he body by O-ring lS. The head of the valve 4 is urged against a seat 5 at the rear end of spacer 6 by m~ans of a partially compressed coil spring 16 and may be lifted therefrom by rearward movement of a trigger 7 pivoted at 40 (Figure 2) to the valve body 3 and having at about its mid-length an abutment formation 41 that bears on the end of the stem of the air valve 4. An additional O-ring 14 at the front of the spacer member 6 seals the forward end of the valve stem, thereby preventing escape of gas when the valve is actuated. On depression of the trigger 7 gas flows through passages 43, 44, 45 to the air nozzle 8 from which it emerges as a jet.
A fluid cup 13 threadedly engages a holder portion of the gun body that locates the fluid nozzle 9 and depending fluid tube 12 as shown. The fluid nozzle 9 may be adjusted in vertical position by rotation of star wheel 10 attached thereto, the nozzle 9 threadedly engaging a fixed bush 21 so that it rises or falls as it rotates in the fixed bush 21. By raising or lowering the nozzle 9 relative to the air jet 8 which is fixed in position the amount of fluid sprayed can easily be regulated and the width of the spray pattern can be adjusted within a range of line widths of 6 - 1 with a generally consistant fluid ; coverage per unit area over this range. Furthermore, by adjustment of the valve sleeve 2 further control may be ::
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exercised over fluid atomisation to enable speckle or spatter effects to be produced eg to represen~ concrete or brickwork. This control provided on the brush handle enables the user to set the airbrush more easily to produce the texture desired.
It has been found as a result of experimentation that the included angle between the fluid nozzle 9 and the air or gas nozzle 8 should be about 90. The horizontal distance between the nozzles 8, 9 may be between a maximum distance of ~.25 cm (0.100 inch) and a minimum distance of 0.15 cm (0.060 inch) and the air nozzle 8 may have a diameter of 0.05-0.075 cm (0.020-0.030 inch). The pattern sprayed is of basically circular form with a fairly well defined spot. The airbrush is capable of operating at pressures from 69-480 KPa (10 to 70 lbf/in~) and has an air consumption of 11 litres/min (0.4 cubic ft/min) of air and resultant fluid (water) flow rate of about 13.5mllmin of water at 275 KPa (40 psi~. A particular set of preferred characteristics for the airbrush is as follows:
20 Air noz7.1e orifice = 0.76 cm (0.30 inch) diameter Air flow rate = approximately 12 litres/min (0.43 cubic ft/min) at 275 KPa (40 psi).
Fluid tip orifice = O.0444 cm (O.0175 inch) diameter Fluid flow - approximately 13.5 ml/min of water at
FIELD OF THE INVE~TION
This in~ention relates to a spray gun for producing a fine controlled spray of paint or dye in a pattern small enough to enable the gun to be used as an artist's tool.
Such spray guns will be referred to as airbrushes.
BACKGROUND OF THE INVENTION
Representative airbrushes of the prior art are shown in Patent Specifications Nos. GB-B-2020578 (Rebold) and US-A-2550404 (Chasan). Representative gas flow control devices are shown in Patent Specifications Nos. GB-A-841895 (Beech) and US-A-3987999 (Savage).
It is an object of the invention to provide an airbrush of the kind in which there is one control for the compressed gas and a separate control for the gas/air mixture in which the principal gas valve parts may be moulded in plastics but in which the gas valve has a performance approximate to that of a needle~valve and is effective at low flow rates.
BRIEF DESCRIPTION OF THE INVENTION
Broadly stated the invention comprises a miniature spray gun including a body carrying a nozzle and means definlng a compressed gas path leading through the body to the nozzle, the gas path leading successively through reduc1ng and control valves, the reducing valve being operable by rotation of an external sleeve on ~he body to vary the~length of a flow resistance defined at least over part~of the range of travel of the valve by interenyaging :
: ~ , 4 ~ 32~3 threaded members to preset a resistance to gas flow and the control valve being manually operable to control spraying at the preset flow resi.stance of the reducing valve.
The invention further comprises an external mix miniature spray gun including a body carrying an air nozzle and having means defining a flow path for compressed gas from a compressed gas source through a reducing valve into said body and thence through a separate trigger-operated valve to said air nozzle so that upon actuation of said trigger-operated valve a jet of gas from the compressed gas source is directed over a capillary paint nozzle, said reducing valve having a gas inlet at one end thereof for connection to the source and a gas outlet at the other end thereof for discharge into the body of the spray gun, said other end of said reducing valve being gas tightly fitted into said body of the spray gun, said reducing valve including a valve body of circular end profile with said inlet leading from said one end of said reducing valve to first generally radial flow passages that are defined within said valve body and open into the side of said valve body, second generally radial flow passages defined within said valve body in spaced relation to said first generally radial flow passages and opening from said side of said valve body nearer said other end of said reducing valve, said second generally radial flow passages leading to said gas outlet, and a sleeve that is rotatably retained on said valve body to open and close said reducing valve, said sleeve having threads thereon that are in engagement with threads on the side of said valve body, said valve body threads including threads that are located between said first and second radial passages, the second flow passages opening through the threaded region of the valve body that i5 covered by the threaded region of the sleeve when the reducing valve is closed, the interengaging threads of said sleeve and valve body defining a flow path upstream of said second passages for the flow of gas along said . .
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interengaging threads from said first passages to said second passages at small degrees of valve opening, said flow path exhibiting a flow resistance which is dependent upon the length of the said interengaging threads upstream of said second passages, said flow resistance being varied by rotation of said sleeve relative to said valve body to vary the length of said interengaging threads along which gas flows upstream of said second passages thereby to control the gas flow at small degrees of opening of said reducing valve, and a tapered surface on the interior of said sleeve between said first and second passages upstream of said interengaging threads, such that said tapered surface approaches or withdraws from a portion of said valve body to diminish or enlarge the gap between said surface and said valve body as said sleeve is rotated relative to said valve body to control the gas flow at large degrees of opening of said reducing valve.
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The invention yet further provides an external mix miniature spray gun in which a spray is obtained by directing a jet o~ gas from a compressed gas source over a capillary paint nozzle, wherein control of the flow of gas from the source is achieved by means of a control valve having a gas inlet at one end for connection to the source and a gas outlet at the other end for discharge into a body of the spray gun into which said oth~r end gas tightly fits, said control valve including a valve body of . 10 circular end profile with said inlet leading from said one end to first generally radial flow passages opening to the side of said valve body and with second generally radial flow passages opening from said side of said valve body nearer said other end and leading to said gas outlet and a sleeve that is rotatably retained on said valve body by means defining interengaging threads and that spans between said first and second radial passages to define an internal space for gas flow therebetween, a tapered surface in the gas flow space on the interior of the sleeve being arranged to approach or withdraw from a portion of said valve body to enlarge or diminish the gap therebetween as said sleeve is rotated relative to said valve bod~.
In the above gun the valve sleeve that rotates externally on the handle and the handle itself are intended to be moulded in plastics where fine mating threads are not practical from a moulding standpoint. A
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performance approximate ~o that of a conventional needle valve can be provided if the second flow passages open through the threaded region of the valve body that i8 covered by the threaded region of ~he sleeve when the valve is closed whereby at least at small degxees of valve opening gas passes along the threads to the second flow passages. Preferably the second flow passages are positioned along the threaded region of the valve body so that they become exposed as the sleeve is moved to a fully 10 open position.
With the above arrangement it has been found that the flow of gas through the airbrush can be shut-off from the airbrush itself rather than at the aerosol cannister or other gas supply normally used, that the pressure can be adjusted to take account of the fluid being sprayed, and that the pressure can be regulated to maximise aerosol lifeO
The included angle between the spray nozzle and the fluid nozzle is about 90 but versions of the spray gun in ~0 which the included angle is about 75 may also be used in some applications.
DESCRIPTION OF THE DRAWINGS
An embodiment of the invention will now be described, by way of example only, with reference to the accompa~nying drawings, in which:
~s Flgure 1 is a view of an airbrush in longitudinal vertical section, , , - ~z~s~
Figure 2 is a vertical section on the line 2-2 of Figure l, and Figure 3 is a graph showing the relationship between throughput of the control valve of the airbrush and number of turns of the valve sleeve for various input pressures.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the drawings, a control valve body 1 of circular end profile is formed at its back end with a hollow threaded nipple 25 to fit onto a threaded end cap of a hose leading from an aerosol bottle, air line or other compressed gas source. ~ gas inlet passage 26 leads forwardly through the nipple 25 to radial gas flow passages 27 and opens to the side surface of the valve body l. Towards the front end of the valve body second radial gas flow passages 28 lead from the side surface to an axial gas outlet passage 29 that opens towards the front end of the valve body l. The body 1 is formed on its side surface with a threaded region 30 that engages internal threads on a valve sleeve 2 which is sealed at opposed ends to the valve body l by means of front and rear O-rings 18, 20 that locate in grooves in the valve body. Between the sleeve 2 and the body l is defined an annular gas flow space that permits gas to flow under pressure between the radial tubes 27 and 28.
It will be noted that the rear.rmost region 35 of the sleeve 2 has a very gentle forwardly convergent taper or draft angle o$ typically 1-3 and there is a matching '` ' ~, 8 ~ 8 taper on the underlying wall of the valve body 1.
Accordingly, as the sleeve 2 is rotated relative to the body 1, the internal surface of 35 the sleeve 2 approaches and withdraws from the ends of the radial gas flow passages 27, offering an increased or reduced resistance to gas flow. Further, a third O-ring 19 supported in a groove in the body 1 approaches or withdraws from a more steeply tapering face 36. The adjustment thread on the sleeve 2 may also pass over the radial flow passages 28 for part of the total adjustment provided.
Thus the tapered rearmost region 35 of the sleeve 2 together with the underlying surface of the valve body act as a needle valve, in which at any given axial position the amount of air that is allowed to pass will be dependent on the diameter of the valve at the control orifice. In the valve for the present spraygun the body 1 and sleeve 2 are to be moulded in plastics and the mating threads 30 have to be of relatively large diameter and pitch to allow them to be moulded. But such coarse threads 30 cannot themselves provide fine control of the airflow at the small flow rates required for special ~ffects spraying using the airbrush. In the valve of Figure 1 the radial passages 28 open through the threaded region of the body partway along it, and in the illustrated closed posltion of the valve thes~ passages 28 are covered by the threaded region of the sleeve 2. As the valve starts to open the air that enters the valve has ..
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to pass along the threads 30 before it can enter the passages 28, the length of threads that the air has to pass being adjustable depending upon the number of turns through which the sleeve rotates. As the valve is further opened, the passages 28 are exposed, and a maximum flow rate is achieved. Thus three regions can be expected on the gas flow/sleeve axial position curve. At low degrees of opening there is a region in which the resistance to flow of the threads and resulting back-pressure principally determines the rate of through flow.At an intermediate range of sleeve positions the flow changes as the threads of sleeve 2 disengage from the passages 28. Finally at large valve openings there is another region where the valve acts effectively as a needle valve. The characteristics of such a valve are shown in Figure 3 which illustrates for various applied pressures the air flow rate through the valve as a function of number of turns from a fully closed position.
These show that with careful design a useful control of ~0 flow rate over a range of about 3 turns can be obtained whereas with simpler designs regulation may be extrémely coarse and may occupy half-turn only from fully off to maximum flow. The valve body 1 and sleeve are moulded in nylon or polypropylene which are materials that assist in giving complete flow shut-off when required.
The forward end of the valve body 1 fits gas-tightly into a gun body 3 in which there is an internal chamber 10 ~ 2~3 whose outlet is controlled by a poppet-like air valve 4 which is slidably guided in a spacer member 6 sealed to ~he body by O-ring lS. The head of the valve 4 is urged against a seat 5 at the rear end of spacer 6 by m~ans of a partially compressed coil spring 16 and may be lifted therefrom by rearward movement of a trigger 7 pivoted at 40 (Figure 2) to the valve body 3 and having at about its mid-length an abutment formation 41 that bears on the end of the stem of the air valve 4. An additional O-ring 14 at the front of the spacer member 6 seals the forward end of the valve stem, thereby preventing escape of gas when the valve is actuated. On depression of the trigger 7 gas flows through passages 43, 44, 45 to the air nozzle 8 from which it emerges as a jet.
A fluid cup 13 threadedly engages a holder portion of the gun body that locates the fluid nozzle 9 and depending fluid tube 12 as shown. The fluid nozzle 9 may be adjusted in vertical position by rotation of star wheel 10 attached thereto, the nozzle 9 threadedly engaging a fixed bush 21 so that it rises or falls as it rotates in the fixed bush 21. By raising or lowering the nozzle 9 relative to the air jet 8 which is fixed in position the amount of fluid sprayed can easily be regulated and the width of the spray pattern can be adjusted within a range of line widths of 6 - 1 with a generally consistant fluid ; coverage per unit area over this range. Furthermore, by adjustment of the valve sleeve 2 further control may be ::
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exercised over fluid atomisation to enable speckle or spatter effects to be produced eg to represen~ concrete or brickwork. This control provided on the brush handle enables the user to set the airbrush more easily to produce the texture desired.
It has been found as a result of experimentation that the included angle between the fluid nozzle 9 and the air or gas nozzle 8 should be about 90. The horizontal distance between the nozzles 8, 9 may be between a maximum distance of ~.25 cm (0.100 inch) and a minimum distance of 0.15 cm (0.060 inch) and the air nozzle 8 may have a diameter of 0.05-0.075 cm (0.020-0.030 inch). The pattern sprayed is of basically circular form with a fairly well defined spot. The airbrush is capable of operating at pressures from 69-480 KPa (10 to 70 lbf/in~) and has an air consumption of 11 litres/min (0.4 cubic ft/min) of air and resultant fluid (water) flow rate of about 13.5mllmin of water at 275 KPa (40 psi~. A particular set of preferred characteristics for the airbrush is as follows:
20 Air noz7.1e orifice = 0.76 cm (0.30 inch) diameter Air flow rate = approximately 12 litres/min (0.43 cubic ft/min) at 275 KPa (40 psi).
Fluid tip orifice = O.0444 cm (O.0175 inch) diameter Fluid flow - approximately 13.5 ml/min of water at
2~5 KPa (40 psi) Angular relationship between air and fluid nozzles = 90 Spray patterns sizes at 414 KPa (60 psi):
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12 ~2~5i8~3 0.5-2.5 cms (3/16 to 1 inch) diameter at 6 cms (2 1/2 inches) spray distance;
6 cms (2 1/2 inches) diameter at 13-15 cms (5 to 6 inches) spray distance.
Air control adjustment = 2 3/4 turns - effective from closed position to full flow.
Fluid tip adjustment = 2/3 turn - effective turns from centre-line to below centre-line.
Various modifications may, of course, be made to the embodiment described above. For example, increased fluid flows are possible by po~itioning the nozzles 8, 9 in other angular relationships to that shown and when this angle is approximately 75 it has been found that the increased 10w thus obtained is not dependant on critical manufacturing tolerances in the distance between the tip of the fluid nozzle 9 and the centre line of the air nozzle 8 so that they may each be fixed in a position with no adjustment provided. Thus the invention contemplates that angles hetween 75 and 90 may be used.
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12 ~2~5i8~3 0.5-2.5 cms (3/16 to 1 inch) diameter at 6 cms (2 1/2 inches) spray distance;
6 cms (2 1/2 inches) diameter at 13-15 cms (5 to 6 inches) spray distance.
Air control adjustment = 2 3/4 turns - effective from closed position to full flow.
Fluid tip adjustment = 2/3 turn - effective turns from centre-line to below centre-line.
Various modifications may, of course, be made to the embodiment described above. For example, increased fluid flows are possible by po~itioning the nozzles 8, 9 in other angular relationships to that shown and when this angle is approximately 75 it has been found that the increased 10w thus obtained is not dependant on critical manufacturing tolerances in the distance between the tip of the fluid nozzle 9 and the centre line of the air nozzle 8 so that they may each be fixed in a position with no adjustment provided. Thus the invention contemplates that angles hetween 75 and 90 may be used.
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Claims (6)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. An external mix miniature spray gun including a body carrying an air nozzle and having means defining a flow path for compressed gas from a compressed gas source through a reducing valve into said body and thence through a separate trigger-operated valve to said air nozzle so that upon actuation of said trigger-operated valve a jet of gas from the compressed gas source is directed over a capillary paint nozzle, said reducing valve having a gas inlet at one end thereof for connection to the source and a gas outlet at the other end thereof for discharge into the body of the spray gun, said other end of said reducing valve being gas tightly fitted into said body of the spray gun, said reducing valve including a valve body of circular end profile with said inlet leading from said one end of said reducing valve to first generally radial flow passages that are defined within said valve body and open into the side of said valve body, second generally radial flow passages defined within said valve body in spaced relation to said first generally radial flow passages and opening from said side of said valve body nearer said other end of said reducing valve, said second generally radial flow passages leading to said gas outlet, and a sleeve that is rotatably retained on said valve body to open and close said reducing valve, said sleeve having threads thereon that are in engagement with threads on the side of said valve body, said valve body threads including threads that are located between said first and second radial passages, the second flow passages opening through the threaded region of the valve body that is covered by the threaded region of the sleeve when the reducing valve is closed, the interengaging threads of said sleeve and valve body defining a flow path upstream of said second passages for the flow of gas along said interengaging threads from said first passages to said second passages at small degrees of valve opening, said flow path exhibiting a flow resistance which is dependent upon the length of the said interengaging threads upstream of said second passages, said flow resistance being varied by rotation of said sleeve relative to said valve body to vary the length of said interengaging threads along which gas flows upstream of said second passages thereby to control the gas flow at small degrees of opening of said reducing valve, and a tapered surface on the interior of said sleeve between said first and second passages upstream of said interengaging threads, such that said tapered surface approaches or withdraws from a portion of said valve body to diminish or enlarge the gap between said surface and said valve body as said sleeve is rotated relative to said valve body to control the gas flow at large degrees of opening of said reducing valve.
2. A spray gun according to claim 1 wherein first and second O-rings of resilient material seal the ends of the sleeve to the valve body.
3. A spray gun according to claim 2, wherein a third O-ring of resilient material located in a groove in said valve body opposes the tapered surface in the sleeve to permit the gas flow to be adjusted or cut off.
4. A spray gun according to claim 1, wherein the sleeve and the valve body are of moulded plastics material.
5. A spray gun according to claim 1, wherein the gas outlet discharges into a chamber within the body, said chamber being closed off by a spring-loaded poppet valve slideably guided in the body and having a stem actuated by a release lever pivoted to the body to lift the head of said poppet valve from a seat and permit gas to flow to said air nozzle.
6. A spray gun according to claim 1, wherein the air nozzle is directed at an angle of about 75° to the capillary paint nozzle.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB838324265A GB8324265D0 (en) | 1983-09-09 | 1983-09-09 | Miniature spray guns |
GB8324265 | 1983-09-09 |
Publications (1)
Publication Number | Publication Date |
---|---|
CA1225828A true CA1225828A (en) | 1987-08-25 |
Family
ID=10548587
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CA000462816A Expired CA1225828A (en) | 1983-09-09 | 1984-09-10 | Miniature spray guns |
Country Status (6)
Country | Link |
---|---|
US (1) | US4606501A (en) |
EP (1) | EP0140547A1 (en) |
JP (1) | JPS60156575A (en) |
CA (1) | CA1225828A (en) |
ES (1) | ES8600971A1 (en) |
GB (2) | GB8324265D0 (en) |
Families Citing this family (52)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
IT206322Z2 (en) * | 1985-09-24 | 1987-08-10 | Azzimonti Giovanni Mec Srl | AIR DELIVERY ADJUSTMENT DEVICE IN A SPRAY GUN. |
GB8920007D0 (en) * | 1989-09-05 | 1989-10-18 | Devilbiss Co | Spraygun |
US6081281A (en) * | 1991-12-30 | 2000-06-27 | Vutek, Inc. | Spray head for a computer-controlled automatic image reproduction system |
US5255852A (en) * | 1992-07-20 | 1993-10-26 | The Testor Corporation | Spray-type dispensing apparatus |
US6021776A (en) * | 1997-09-09 | 2000-02-08 | Intertex Research, Inc. | Disposable atomizer device with trigger valve system |
US6291088B1 (en) | 1998-09-30 | 2001-09-18 | Xerox Corporation | Inorganic overcoat for particulate transport electrode grid |
US6523928B2 (en) | 1998-09-30 | 2003-02-25 | Xerox Corporation | Method of treating a substrate employing a ballistic aerosol marking apparatus |
US6265050B1 (en) | 1998-09-30 | 2001-07-24 | Xerox Corporation | Organic overcoat for electrode grid |
US6751865B1 (en) | 1998-09-30 | 2004-06-22 | Xerox Corporation | Method of making a print head for use in a ballistic aerosol marking apparatus |
US6511149B1 (en) | 1998-09-30 | 2003-01-28 | Xerox Corporation | Ballistic aerosol marking apparatus for marking a substrate |
US6454384B1 (en) | 1998-09-30 | 2002-09-24 | Xerox Corporation | Method for marking with a liquid material using a ballistic aerosol marking apparatus |
US6290342B1 (en) | 1998-09-30 | 2001-09-18 | Xerox Corporation | Particulate marking material transport apparatus utilizing traveling electrostatic waves |
US6416157B1 (en) | 1998-09-30 | 2002-07-09 | Xerox Corporation | Method of marking a substrate employing a ballistic aerosol marking apparatus |
US6340216B1 (en) | 1998-09-30 | 2002-01-22 | Xerox Corporation | Ballistic aerosol marking apparatus for treating a substrate |
US6416156B1 (en) | 1998-09-30 | 2002-07-09 | Xerox Corporation | Kinetic fusing of a marking material |
US6116718A (en) * | 1998-09-30 | 2000-09-12 | Xerox Corporation | Print head for use in a ballistic aerosol marking apparatus |
US6136442A (en) * | 1998-09-30 | 2000-10-24 | Xerox Corporation | Multi-layer organic overcoat for particulate transport electrode grid |
US6467862B1 (en) | 1998-09-30 | 2002-10-22 | Xerox Corporation | Cartridge for use in a ballistic aerosol marking apparatus |
US6293659B1 (en) | 1999-09-30 | 2001-09-25 | Xerox Corporation | Particulate source, circulation, and valving system for ballistic aerosol marking |
US6328436B1 (en) | 1999-09-30 | 2001-12-11 | Xerox Corporation | Electro-static particulate source, circulation, and valving system for ballistic aerosol marking |
US6969160B2 (en) * | 2003-07-28 | 2005-11-29 | Xerox Corporation | Ballistic aerosol marking apparatus |
US7296760B2 (en) | 2004-11-17 | 2007-11-20 | Illinois Tool Works Inc. | Indexing valve |
US7296759B2 (en) * | 2004-11-19 | 2007-11-20 | Illinois Tool Works Inc. | Ratcheting retaining ring |
US20060202060A1 (en) * | 2004-12-06 | 2006-09-14 | Alexander Kevin L | Dispensing device handle assembly |
US7757973B2 (en) * | 2005-04-04 | 2010-07-20 | Illinois Tool Works Inc. | Hand-held coating dispensing device |
US7460924B2 (en) * | 2005-06-16 | 2008-12-02 | Illinois Tool Works Inc. | In-gun power supply control |
US20070034649A1 (en) * | 2005-08-15 | 2007-02-15 | Smith Scott E | Ergonomic dispenser |
US7364098B2 (en) * | 2005-10-12 | 2008-04-29 | Illinois Tool Works Inc. | Material dispensing apparatus |
US7607591B2 (en) * | 2005-10-26 | 2009-10-27 | Hallmark Cards, Incorporated | Airbrush |
US7455249B2 (en) | 2006-03-28 | 2008-11-25 | Illinois Tool Works Inc. | Combined direct and indirect charging system for electrostatically-aided coating system |
US7988075B2 (en) | 2008-03-10 | 2011-08-02 | Illinois Tool Works Inc. | Circuit board configuration for air-powered electrostatically aided coating material atomizer |
US8496194B2 (en) | 2008-03-10 | 2013-07-30 | Finishing Brands Holdings Inc. | Method and apparatus for retaining highly torqued fittings in molded resin or polymer housing |
US8590817B2 (en) | 2008-03-10 | 2013-11-26 | Illinois Tool Works Inc. | Sealed electrical source for air-powered electrostatic atomizing and dispensing device |
US8016213B2 (en) | 2008-03-10 | 2011-09-13 | Illinois Tool Works Inc. | Controlling temperature in air-powered electrostatically aided coating material atomizer |
US8770496B2 (en) | 2008-03-10 | 2014-07-08 | Finishing Brands Holdings Inc. | Circuit for displaying the relative voltage at the output electrode of an electrostatically aided coating material atomizer |
USD608858S1 (en) | 2008-03-10 | 2010-01-26 | Illinois Tool Works Inc. | Coating material dispensing device |
US7926748B2 (en) | 2008-03-10 | 2011-04-19 | Illinois Tool Works Inc. | Generator for air-powered electrostatically aided coating dispensing device |
US7918409B2 (en) | 2008-04-09 | 2011-04-05 | Illinois Tool Works Inc. | Multiple charging electrode |
EP2274039A2 (en) | 2008-05-06 | 2011-01-19 | Wilson-Cook Medical Inc. | Apparatus and methods for delivering therapeutic agents |
US8361054B2 (en) | 2008-12-23 | 2013-01-29 | Cook Medical Technologies Llc | Apparatus and methods for containing and delivering therapeutic agents |
US8225968B2 (en) | 2009-05-12 | 2012-07-24 | Illinois Tool Works Inc. | Seal system for gear pumps |
US9101744B2 (en) | 2009-05-29 | 2015-08-11 | Cook Medical Technologies Llc | Systems and methods for delivering therapeutic agents |
US8118777B2 (en) | 2009-05-29 | 2012-02-21 | Cook Medical Technologies Llc | Systems and methods for delivering therapeutic agents |
US20140044865A1 (en) * | 2012-01-31 | 2014-02-13 | Hossam Haick | Method for manufacturing a nano-wire array and a device that comprises a nano-wire array |
US9352343B2 (en) | 2013-01-22 | 2016-05-31 | Carlisle Fluid Technologies, Inc. | Liquid supply system for a gravity feed spray device |
US8985397B2 (en) | 2013-03-08 | 2015-03-24 | Guardian 8 Corporation | Systems and methods for spraying an aerosol |
US9867931B2 (en) | 2013-10-02 | 2018-01-16 | Cook Medical Technologies Llc | Therapeutic agents for delivery using a catheter and pressure source |
WO2015077701A1 (en) * | 2013-11-22 | 2015-05-28 | Craftwell, Inc. | Airbrush effect system |
US9358557B2 (en) * | 2013-12-20 | 2016-06-07 | Young Living Essential Oils, Lc | Liquid diffuser |
CH713113A1 (en) * | 2016-11-08 | 2018-05-15 | Chemspeed Tech Ag | Spray method for coating a substrate with a substance atomized in a gas stream. |
US10099233B2 (en) | 2016-11-22 | 2018-10-16 | Dah Cherng Stationery Co., Ltd. | Cosmetic air brush |
EP3508278B1 (en) * | 2018-01-05 | 2022-04-13 | Dah Cherng Stationery Co., Ltd. | Cosmetic air brush |
Family Cites Families (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR447305A (en) * | 1912-07-26 | 1912-12-30 | Pierre Pouget | Vaporizer and humidifier device for rooms where textile materials are worked |
US2341394A (en) * | 1938-03-08 | 1944-02-08 | Sloan Valve Co | Throttling device |
US2332114A (en) * | 1942-06-03 | 1943-10-19 | William J Robb | Valve and strainer construction |
US2550404A (en) * | 1947-06-19 | 1951-04-24 | Chasan Isaac | Attachment for airbrushes |
US2987999A (en) * | 1959-02-12 | 1961-06-13 | Jr Ralph O Robinson | Protective cover |
US3111980A (en) * | 1961-12-12 | 1963-11-26 | Air Reduction | Gas torch and valve |
GB1537274A (en) * | 1975-05-06 | 1978-12-29 | Humbrol Ltd | Spray gun |
US3987999A (en) * | 1975-09-22 | 1976-10-26 | Savage Harry A | Precision metering valve structure |
US4037623A (en) * | 1976-01-08 | 1977-07-26 | Beswick Paul R | Variable O-ring control valve |
US4171097A (en) * | 1978-05-11 | 1979-10-16 | Cbs Inc. | Airbrush |
SE422359B (en) * | 1978-09-13 | 1982-03-01 | Gambro Dialysatoren | HOSE OR SIMILAR CONNECTOR |
JPS5865375A (en) * | 1981-10-12 | 1983-04-19 | Sankin Kogyo Kk | Flow-rate control valve |
-
1983
- 1983-09-09 GB GB838324265A patent/GB8324265D0/en active Pending
-
1984
- 1984-09-07 GB GB08422700A patent/GB2146271B/en not_active Expired
- 1984-09-07 ES ES535761A patent/ES8600971A1/en not_active Expired
- 1984-09-07 US US06/648,392 patent/US4606501A/en not_active Expired - Fee Related
- 1984-09-07 EP EP84306144A patent/EP0140547A1/en not_active Ceased
- 1984-09-10 CA CA000462816A patent/CA1225828A/en not_active Expired
- 1984-09-10 JP JP59189485A patent/JPS60156575A/en active Pending
Also Published As
Publication number | Publication date |
---|---|
ES535761A0 (en) | 1985-10-16 |
JPS60156575A (en) | 1985-08-16 |
US4606501A (en) | 1986-08-19 |
GB2146271A (en) | 1985-04-17 |
GB8324265D0 (en) | 1983-10-12 |
GB2146271B (en) | 1986-07-30 |
GB8422700D0 (en) | 1984-10-10 |
ES8600971A1 (en) | 1985-10-16 |
EP0140547A1 (en) | 1985-05-08 |
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Legal Events
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MKEX | Expiry |