CA2053801A1 - Pneumatically controlled spray gun - Google Patents
Pneumatically controlled spray gunInfo
- Publication number
- CA2053801A1 CA2053801A1 CA002053801A CA2053801A CA2053801A1 CA 2053801 A1 CA2053801 A1 CA 2053801A1 CA 002053801 A CA002053801 A CA 002053801A CA 2053801 A CA2053801 A CA 2053801A CA 2053801 A1 CA2053801 A1 CA 2053801A1
- Authority
- CA
- Canada
- Prior art keywords
- duct
- spray
- air
- spray gun
- compressed
- 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.)
- Abandoned
Links
Classifications
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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
- B05B7/02—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
- B05B7/2435—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 by parallel conduits placed one inside the other
- B05B7/2437—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 by parallel conduits placed one inside the other and a secondary stream of atomising fluid being brought together in the container or putting the carried fluid under pressure in the container
Landscapes
- Nozzles (AREA)
Abstract
ABSTRACT
The invention concerns a spray gun for atomized spraying of flowable spray substances. The spray gun is equipped with a pneumatically controlled spray supply valve. For this purpose, the internal pressure of the storage receptacle containing the spray can be continuously adjusted as excess or negative pressure by closing or opening an outlet opening connected with a ventilating and air control duct. The spray gun can also be used as a pen for drawing or marking. When using fine-granular sand as a spray substance, the spray gun can be used as a sandblasting device.
The invention concerns a spray gun for atomized spraying of flowable spray substances. The spray gun is equipped with a pneumatically controlled spray supply valve. For this purpose, the internal pressure of the storage receptacle containing the spray can be continuously adjusted as excess or negative pressure by closing or opening an outlet opening connected with a ventilating and air control duct. The spray gun can also be used as a pen for drawing or marking. When using fine-granular sand as a spray substance, the spray gun can be used as a sandblasting device.
Description
~3æ3l, - l -The invention concerns a spray gun for atomized spraying of a flowable spray substance.
A conventional sprayer of this type is known e.g. from German patent application DE 39 22 561 Al.
S Conventional sprayers are used for applying, in particular, varnishes and paints, uniformly and extensively to work surfaces. To accomplish this, the spray substance is supplied from a storage receptacle connected to a nozzle device and compressed air is supplied for atomizing the spray substance. The measured supply of the spray quantity is controlled via a mechanically operated valve system. The valve system described in German patent application DE 39 22 561 Al has a sealing rod which is axially displaceable in the sprayer and which is operated by a radial compression of an elastically deformable sleeve of an apparatus. The front end of the sealing rod rises from the outlet opening located in the mouthpiece of the nozzle device and frees it for the preferably liquid spray substance.
It is di~ficult with this type of a spray flow control to maintain the pressure to be exerted radially onto the apparatus in order to attain a constantly uniform measured quantity and, at the same time, an exact control of the lines.
Spray guns are also known in which the flow of the spray is controlled by means of a cross-sectional surface area variation of a needle which is displaceable in a diaphragm or in a conical channel. In this case, the needle is controlled by means of an underset lever, preferably manually. A prerequisite in this case is that the nozzle device and the needle must be clean, i.e. in particular free of dried paint. Cleaning the needle in these devices is most often cumbersome. In addition, the needle can be easily damaged when doing this. A further problem which arises here is that, with :
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A conventional sprayer of this type is known e.g. from German patent application DE 39 22 561 Al.
S Conventional sprayers are used for applying, in particular, varnishes and paints, uniformly and extensively to work surfaces. To accomplish this, the spray substance is supplied from a storage receptacle connected to a nozzle device and compressed air is supplied for atomizing the spray substance. The measured supply of the spray quantity is controlled via a mechanically operated valve system. The valve system described in German patent application DE 39 22 561 Al has a sealing rod which is axially displaceable in the sprayer and which is operated by a radial compression of an elastically deformable sleeve of an apparatus. The front end of the sealing rod rises from the outlet opening located in the mouthpiece of the nozzle device and frees it for the preferably liquid spray substance.
It is di~ficult with this type of a spray flow control to maintain the pressure to be exerted radially onto the apparatus in order to attain a constantly uniform measured quantity and, at the same time, an exact control of the lines.
Spray guns are also known in which the flow of the spray is controlled by means of a cross-sectional surface area variation of a needle which is displaceable in a diaphragm or in a conical channel. In this case, the needle is controlled by means of an underset lever, preferably manually. A prerequisite in this case is that the nozzle device and the needle must be clean, i.e. in particular free of dried paint. Cleaning the needle in these devices is most often cumbersome. In addition, the needle can be easily damaged when doing this. A further problem which arises here is that, with :
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small quantities of spray, the passage of the spray substance must take place through a diaphragm which has only been opened slightly to a narrow annular clearance, whereby larger paint particles are held back from the S annular clearance. It is thereby difficult to attain a uniform, continuous flow of paint.
The needle valve-control mechanism is, moreover, problematic when the position of the needle is changed. As a result of the movement of the needle, e.g. the spray substance is displaced in the spray duct and the spraying pressure increased for a short time, as a result of which the spray jet portion becomes larger not smaller.
It is an object of the invention to create a spray gun of the above type which does not have the above-noted disadvantages, is easy to handle and inexpensive to make.
In accordance with an embodiment of the invention, a spray gun for atomized spraying of a flowable spray substance is comprised of a storage receptacle for the spray substance, a nozzle device which has a nozzle duct passing over into a mouthpiece in which a spray duct extending axially leading from the storage receptacle to the mouthpiece is placed, and of a compressed-air duct which can be connected, at the one end, to a compressed-air source and opening, at the other end, into the nozzle duct, a ventilating duct connecting the storage receptacle to ambient air via an outlet opening and a control air duct which, at the one end, is connected to a compressed-air source and opens, at the other end, into the ventilating duct in such a way that the compressed air coming out of the control air duct flows in a preferred direction to the outlet opening into the ventilating duct, whereby the internal 3s pressure of the storage receptacle can be adjusted as
small quantities of spray, the passage of the spray substance must take place through a diaphragm which has only been opened slightly to a narrow annular clearance, whereby larger paint particles are held back from the S annular clearance. It is thereby difficult to attain a uniform, continuous flow of paint.
The needle valve-control mechanism is, moreover, problematic when the position of the needle is changed. As a result of the movement of the needle, e.g. the spray substance is displaced in the spray duct and the spraying pressure increased for a short time, as a result of which the spray jet portion becomes larger not smaller.
It is an object of the invention to create a spray gun of the above type which does not have the above-noted disadvantages, is easy to handle and inexpensive to make.
In accordance with an embodiment of the invention, a spray gun for atomized spraying of a flowable spray substance is comprised of a storage receptacle for the spray substance, a nozzle device which has a nozzle duct passing over into a mouthpiece in which a spray duct extending axially leading from the storage receptacle to the mouthpiece is placed, and of a compressed-air duct which can be connected, at the one end, to a compressed-air source and opening, at the other end, into the nozzle duct, a ventilating duct connecting the storage receptacle to ambient air via an outlet opening and a control air duct which, at the one end, is connected to a compressed-air source and opens, at the other end, into the ventilating duct in such a way that the compressed air coming out of the control air duct flows in a preferred direction to the outlet opening into the ventilating duct, whereby the internal 3s pressure of the storage receptacle can be adjusted as
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negative or excess pressure by opening and closing the outlet opening, as a result of which the amount of flow of the spray substance coming out of the spray duct can be continuously controlled.
S In a spray gun of the invention, the spray flow from the storage receptacle to the nozzle device is only operated by controlling an air stream flowing in the air duct distributing system formed in the spray gun. To this end, the spray gun of the invention has a ventilating duct connecting the storage receptacle with the ambient air via an outlet opening. An air control duct leads into the ventilating duct from which compressed air is introduced into the ventilating duct in a preferred direction to the outlet opening. A
negative pressure is produced by this directed air stream in the storage receptacle and in the part of the ventilating duct situated between the storage receptacle and the air control duct. By closing or opening the outlet opening, the internal pressure of the storage receptacle can be continuously adjusted, as a result of which the intake pressure produced in the spray channel can be preferably completely compensated.
Advantageously, a needle in the spray stream having the above disadvantages is not required in the spray gun of ; 25 the invention. In particular, the opening of the spray - duct projecting into the nozzle device can be reduced to about l/lO of a conventional aperture diameter, without the danger of clogging, so that even particularly small ` quantities of spray can be metered out and applied uniformly. For simple operation, the outlet opening is preferably made in the form of a ram slot which can be covered e.g. by means of a fingertip placed on it. As a result of this, it is possible to operate and control the paint flow regulator with one hand. The ventilating ~ 35 duct can be easily extended e.g. by a flexible .~:
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negative or excess pressure by opening and closing the outlet opening, as a result of which the amount of flow of the spray substance coming out of the spray duct can be continuously controlled.
S In a spray gun of the invention, the spray flow from the storage receptacle to the nozzle device is only operated by controlling an air stream flowing in the air duct distributing system formed in the spray gun. To this end, the spray gun of the invention has a ventilating duct connecting the storage receptacle with the ambient air via an outlet opening. An air control duct leads into the ventilating duct from which compressed air is introduced into the ventilating duct in a preferred direction to the outlet opening. A
negative pressure is produced by this directed air stream in the storage receptacle and in the part of the ventilating duct situated between the storage receptacle and the air control duct. By closing or opening the outlet opening, the internal pressure of the storage receptacle can be continuously adjusted, as a result of which the intake pressure produced in the spray channel can be preferably completely compensated.
Advantageously, a needle in the spray stream having the above disadvantages is not required in the spray gun of ; 25 the invention. In particular, the opening of the spray - duct projecting into the nozzle device can be reduced to about l/lO of a conventional aperture diameter, without the danger of clogging, so that even particularly small ` quantities of spray can be metered out and applied uniformly. For simple operation, the outlet opening is preferably made in the form of a ram slot which can be covered e.g. by means of a fingertip placed on it. As a result of this, it is possible to operate and control the paint flow regulator with one hand. The ventilating ~ 35 duct can be easily extended e.g. by a flexible .~:
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elastically deformable tube with which, in particular, the paint supply can be adjusted by regulating the mouth.
According to the invention, a particularly S simple, compact and thus inexpensive structure of the spray gun results if the air control duct is directly connected with the compressed-air duct conducting the spray pressure.
In order to be able to very accurately measure the spray flow, an adjustable valve is provided in the ventilating duct with which an exact adjustment between the internal pressure of the storage receptacle and the intake pressure is possible. To restrict the spray flow to a maximum value, an adjustable outlet valve is provided parallel to the outlet opening with which the excess pressure forming in the ventilating duct is restricted to a maximum pressure.
The spray gun of the invention can also be used as a drawing pen. For this purpose, the spray duct projects from the air nozzle like a paint tube, so that the coloured liquid an be directly applied, via its tip, to a drawing pad without the pressure of a spray.
The spray gun of the invention can also be used as a sandblasting device. To do this, the sand used as spray substance is whirled in a storage receptacle with the supplied control air to a sand/air mixture which is brought out via the nozzle duct projecting into the storage receptacle.
In order to be able to adjust the air jet pressure to the respective use, the spray gun has a pressure-relief valve which is continuously adjustable and is inserted between a conventional compressed-air source and the compressed-air inlet of the spray gun.
- S - 2~33~1 The invention is described in greater detail below with reference to two preferred embodiments illustrated in the drawings, in which:
Figure 1 shows a schematically illustrated pneumatic arrangement in a spray gun of the invention, Figure 2 shows an axial section with partial side view of a spray gun according to a first embodiment, Figure 3 shows a sectional view along the line III-III of Figure 2, Figure 4 shows the embodiment shown in Figure 2, in perspective view, Figure 5 shows in an enlarged section, the control head of the embodiment shown in Figure 2, Figure 6 shows a tube for the control head according to Figure 5, shown partially in section, Figure 7 shows in an enlarged perspective illustration, the spray duct shown in Figure 5 and the guide sleeve, Figure ~ shows in an enlarged perspective illustration, a detail view of the duct mounting shown in Figure 5, Figure 9 shows an axial section of a second embodiment, Figure 10 shows a section along the line X-X
in Figure 11, Figure 11 shows a side view of an axially cut pressure-relief valve, Figure 12 shows a section of a variant of a shutoff device of the receptacle part shown in Figure 9, Figure 13 shows an axial section of the control head shown in Figure 9 according to a further embodiment, in an enlarged illustration, and -6~ 31 Figure 14 shows an axial section of a receptacle part in an enlarged illustration according to a second variant.
The principle construction of a pneumatically S controlled spray gun is shown in Figure 1. It includes a nozzle duct 16 which tapers conically toward its front end to a mouthpiece 14. In the nozzle duct 16, the spray duct 26 is coaxially fixed which, at one end, leads to a storage receptacle 10 and, at the other end, leads to the mouthpiece 14. The compressed air fed to the nozzle duct 16 via a compressed-air duct 20, which is connected with it, circulates about the spray duct 26 in axial direction and passes out from the mouthpiece 14 while a suction effect is being exerted on the spray duct 26 from the nozzle duct 16. In this case, the emergent air stream pulls the spray coming out from the spray duct along, as a result of which this spray substance is atomized and mixed with air, so that it can e.g. be applied to work surfaces. To gauge the spray quantity coming out of the receptacle lO into the spray duct 26, the internal pressure P1 of the receptacle 10 can be adjusted by means of a ventilating duct 22 which connects the receptacle 10 with the ambient air P2 in the vicinity of its outlet opening 28. Compressed air flows into the ventilating duct 22, as symbolically indicated with vector arrows, via an air control duct 24 connected, on the one end, with the ventilating duct 22 and, on the other end, with the compressed-air duct 20, whereby the air stream is directed in the direction of the outlet opening 28. As a result, an air stream directed toward the outlet opening 28 occurs in the ventilating duct 22. By varying the effective cross-sectional surface of the outlet opening 28, the amount of air stream can be continuously adjusted between a maximum negative pressure, when the outlet opening 28 is , ' , -7- 2C~$3~
completely opened, and a maximum excess pressure, when the outlet opening 28 is closed.
The spray gun shown in Figure 4 consists of an apparatus 30 having a control head 32, a receptacle part S 34 situated at its back end and a grip part 36 which can be interlocked with the receptacle part 34 by means of a bayonet lock 37. A nozzle head 38 is screwed into its front end. The construction of the air duct distributor system, found in the nozzle head 38 and in the control head 32, is shown in Figures 2 and 5. This compresses the nozzle duct 42 and 42' situated coaxially in the control head 32 and continuing axially into the nozzle head 38 (Figure 5), the compressed-air intake connection 41 inserted into the control head 32 and ending in the nozzle duct 42, a ventilating duct 44 and 44' passing essentially coaxially through the control head 32 and receptacle part 34 and into one another so as to be aligned, as well as an air control duct 45 connecting the nozzle duct 42 with the ventilating duct 44. In order to effect a defined air stream in the ventilating duct 44, the air control duct 45 points, with its inlet opening, in the direction of the outlet opening 46 which seals off the ventilating duct 44 at the atmospheric end. On the side turned away from the outlet opening 46, the ventilating duct 44 passes over into an annular duct 25 which is placed coaxially in the control head 32 in its rear end. The inside surface of the annular duct 25 has an internal winding 23 into which the receptacle part 34 with the filtering element 64 can be screwed.
The outside winding 21 of the filtering element 64 is interrupted by an axially extending longitudinal gr~ove 35 (Figure 3) which continues in the storage receptacle 40 as a tubular-shaped ventilating duct 44'.
The outlet opening 46 is in the form of a ram slot 63 for manually controlling the internal pressure -8- 2~53~31.
P1 of the storage receptacle 40. By means of a valve rod 57, which can be screwed into the ventilating duct 44 with its milled head 47, the internal pressure P1 can be adjusted independent of the fact whether or not the S ram slot 63 is covered. The annular duct 25 and the receptacle part 34 are sealed airtight by means o~ an annular seal 62a placed coaxially in the annular duct 25 and an annular seal 62b placed coaxially in the control head 32.
The spray duct system has a spray duct 49 which passes through the nozzle duct 42, 42' and is disposed coaxially in the control head 32. The spray duct 49 is inserted, inside the control head 32, into a duct mounting 27 which is screwed into the nozzle duct 42. On the side of the nozzle head, the spray duct 49 rests in a guide sleeve 60 which is pressed against the inner surface of the nozzle head 38 by means of a coil spring 59 stayed on the duct mounting 27. At its front end, the guide sleeve 60 (see Figure 7) has axially running cut grooves 61a, 61b by means of which a compressed-air flow from the nozzle duct 42 to nozzle duct 42' is maintained.
The filtering device 50 disposed coaxially on the receptacle part 34 consists essentially of the filter element 64 and a boring disk 19.
By means of the tube 68 shown in Figure 6, the ventilating duct 44 can be extended at its outlet opening 46. To accomplish this, an adapter 17 is inserted on the one end into the tube 68, it being possible to insert or screw the adapter into the outlet opening 46. As a result of the pressure Fl exerted radially on the tube sleeve 67, the effective cross-sectional surface of the outlet opening can be varied.
The spray gun shown in Figure 9 consists of an essentially two-part apparatus 70, namely, a control `
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head 72 and a receptacle part 74. At its front end, the control head 72 has a receiving bore into which a nozzle head 76 with a one-piece formed insertable part is inserted. At its back end, th~ control head 72 is S shaped into a one-piece formed coupling part 13 whose outer surface has a circular ring attachment 15. The coupling part 13 is to be inserted into a receiving part 11 formed at the front end of the receptacle part 74 for producing a firm connection with the receptacle part 74.
The receptacle part 74 is sealed pressure-resistant at its back end by means of a receptacle cap 29a.
The air duct distributor system formed in the control head 72 and in the receptacle part 74 consists of a compressed-air duct 82 into which a nipple 80 is inserted at the inlet side for connection to a compressed-air supply 9. At the other end, the compressed-air duct 82 passes over into the nozzle duct 81 formed and placed axially in the nozzle head 76.
Parallel to the nozzle duct 81, a ventilating duct 83 is formed in the upper part of the control head 72, which ventilating duct leads to an outlet opening 86 at the front end of the control head 72. At the other end, the ventilating duct 83 continues into the venti'ating duct 83' which projects into the receptacle part 74.
Furthermore, in the control head 72, an air control duct 84 is provided which opens, at the one end, into the compressed-air duct 82 and, at the other end, into the ventilating duct 83 with a bent outlet opening 8. the outlet opening 8 is thereby adjusted in the direction of the outlet opening 86, as a result of which the air stream flowing in the ventilating duct is given a preferred direction.
The air mass flowing through the ventilating duct 83, 83' can be adjusted by means of a valve placed on the top of the control head 72.
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In addition, a valve rod 88 which i5 screwed into the control head 72 and formed, at the one end, into a tapered conical seal 89 and has, at the other end, a milled head 87, projects into the ventilating S duct 83. By manipulating the milled head 87, the effective cross-sectional surface of the ventilating duct 83 can be varied, as a result of which the flow of air in the ventilating duct 83 and 83' and, thus, the internal pressure P1 can be adjusted. In particular, by operating the valve rod 88, the intake pressure P3 produced at the mouthpiece 93 can be completely compensated. The outlet valve 73, which i5 screwed into a ram air duct 85 branching off from the ventilating duct 83 in the control head 72, is used to restrict the internal pressure Pl to a maximum value. By operating the milled head 75 connected with the outlet valve 73, the maximum attainable ram pressure in the ventilating duct 83 is set.
To operate the spray gun, compressed-air is fed from a conventional compressed-air source via the compressed-air feed 9, the nipple 80, to compressed-air duct 82 to the nozzle duct 81 and blown out of the mouthpiece 93 of the nozzle head 76. As a result of the suction effect of the compressed-air jet, a negative pressure is produced in the spray duct 90c, 90b axially displaced in the nozzle duct 81, and as a result of this negative pressure, spray substance is drawn from the storage receptacle 71 via the spray duct 90a and the filtering device 91 in the receptacle part 74. The spray coming out of the spray duct 90c is sprayed in fine droplets which are mixed with the compressed air and carried away. To control the spraying pressure, a pressure-relief valve 69 is provided between the compressed-air source and the compressed-air supply. As shown in Figures lO and ll, the pressure-relief valve 69 .
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consists essentially of a basic body 6 in which a tube 66 consisting preferably of an elastic material is placed so as to extend axially. Perpendicular to the axial direction of the basic body 6, a taper pin 65 is inserted which is displaceable in the basic body. The tube 66 rests on the inclined plane 5 of the taper pin and is varied in its cross-sectional surface depending on the respective position of the taper pin 65, by means of which the flow quantity and pressure in the compressed-air line 9 can be adjusted.
In order to be able to replace the receptacle part 74, e.g. for cleaning the storage receptacle 71, a shutoff valve which, as shown in Figure 9, consists of a manually operable flow duct 52, is provided between the IS filtering device 91 and the receiving part 11.
According to Figure 12, the shutoff valve is constructed as a ball valve 53 which has a sealing ball 54 and a coil spring 55. The sealing ball 54 is thereby pressed by the coil spring 55 into its closed position, when the control head 72 is removed from the receptacle part 74, and, when these parts are coupled, it is again lifted off from the sealing surface 4.
Figure 13 shows a nozzle head 78 inserted into the control head 72 which is formed in such a way that the spray gun can be used as a tubular drawing instrument. For this purpose, a spray duct 90c projecting out of the nozzle head 78 and in the form of a paint tube is inserted into the nozzle head 78.
The spray gun can also be used as a sand blasting device when the r~ceptacle part 95 o~ the storage receptacle 96 is formed as shown in Figure 14.
This storage receptacle 96 can be filled with fine-grained solid substances, preferably sand particles.
The control air is conducted into the storage receptacle 96 via the ventilating duct 97' and the air-permeable .
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spray filter 9~ located be~ween the ventilating duct 97' and the storage receptacle 96. The control air flowing in whirls the sand particles into a spray sand mixture which flows into the nozzle duct 99', extending almost S over the entire axial length of the receptacle part, as a flowable air/sand mixture. To fill or refill the storage receptacle 96, the receptacle cap 29b which seals the receptacle part 95 can be removed.
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elastically deformable tube with which, in particular, the paint supply can be adjusted by regulating the mouth.
According to the invention, a particularly S simple, compact and thus inexpensive structure of the spray gun results if the air control duct is directly connected with the compressed-air duct conducting the spray pressure.
In order to be able to very accurately measure the spray flow, an adjustable valve is provided in the ventilating duct with which an exact adjustment between the internal pressure of the storage receptacle and the intake pressure is possible. To restrict the spray flow to a maximum value, an adjustable outlet valve is provided parallel to the outlet opening with which the excess pressure forming in the ventilating duct is restricted to a maximum pressure.
The spray gun of the invention can also be used as a drawing pen. For this purpose, the spray duct projects from the air nozzle like a paint tube, so that the coloured liquid an be directly applied, via its tip, to a drawing pad without the pressure of a spray.
The spray gun of the invention can also be used as a sandblasting device. To do this, the sand used as spray substance is whirled in a storage receptacle with the supplied control air to a sand/air mixture which is brought out via the nozzle duct projecting into the storage receptacle.
In order to be able to adjust the air jet pressure to the respective use, the spray gun has a pressure-relief valve which is continuously adjustable and is inserted between a conventional compressed-air source and the compressed-air inlet of the spray gun.
- S - 2~33~1 The invention is described in greater detail below with reference to two preferred embodiments illustrated in the drawings, in which:
Figure 1 shows a schematically illustrated pneumatic arrangement in a spray gun of the invention, Figure 2 shows an axial section with partial side view of a spray gun according to a first embodiment, Figure 3 shows a sectional view along the line III-III of Figure 2, Figure 4 shows the embodiment shown in Figure 2, in perspective view, Figure 5 shows in an enlarged section, the control head of the embodiment shown in Figure 2, Figure 6 shows a tube for the control head according to Figure 5, shown partially in section, Figure 7 shows in an enlarged perspective illustration, the spray duct shown in Figure 5 and the guide sleeve, Figure ~ shows in an enlarged perspective illustration, a detail view of the duct mounting shown in Figure 5, Figure 9 shows an axial section of a second embodiment, Figure 10 shows a section along the line X-X
in Figure 11, Figure 11 shows a side view of an axially cut pressure-relief valve, Figure 12 shows a section of a variant of a shutoff device of the receptacle part shown in Figure 9, Figure 13 shows an axial section of the control head shown in Figure 9 according to a further embodiment, in an enlarged illustration, and -6~ 31 Figure 14 shows an axial section of a receptacle part in an enlarged illustration according to a second variant.
The principle construction of a pneumatically S controlled spray gun is shown in Figure 1. It includes a nozzle duct 16 which tapers conically toward its front end to a mouthpiece 14. In the nozzle duct 16, the spray duct 26 is coaxially fixed which, at one end, leads to a storage receptacle 10 and, at the other end, leads to the mouthpiece 14. The compressed air fed to the nozzle duct 16 via a compressed-air duct 20, which is connected with it, circulates about the spray duct 26 in axial direction and passes out from the mouthpiece 14 while a suction effect is being exerted on the spray duct 26 from the nozzle duct 16. In this case, the emergent air stream pulls the spray coming out from the spray duct along, as a result of which this spray substance is atomized and mixed with air, so that it can e.g. be applied to work surfaces. To gauge the spray quantity coming out of the receptacle lO into the spray duct 26, the internal pressure P1 of the receptacle 10 can be adjusted by means of a ventilating duct 22 which connects the receptacle 10 with the ambient air P2 in the vicinity of its outlet opening 28. Compressed air flows into the ventilating duct 22, as symbolically indicated with vector arrows, via an air control duct 24 connected, on the one end, with the ventilating duct 22 and, on the other end, with the compressed-air duct 20, whereby the air stream is directed in the direction of the outlet opening 28. As a result, an air stream directed toward the outlet opening 28 occurs in the ventilating duct 22. By varying the effective cross-sectional surface of the outlet opening 28, the amount of air stream can be continuously adjusted between a maximum negative pressure, when the outlet opening 28 is , ' , -7- 2C~$3~
completely opened, and a maximum excess pressure, when the outlet opening 28 is closed.
The spray gun shown in Figure 4 consists of an apparatus 30 having a control head 32, a receptacle part S 34 situated at its back end and a grip part 36 which can be interlocked with the receptacle part 34 by means of a bayonet lock 37. A nozzle head 38 is screwed into its front end. The construction of the air duct distributor system, found in the nozzle head 38 and in the control head 32, is shown in Figures 2 and 5. This compresses the nozzle duct 42 and 42' situated coaxially in the control head 32 and continuing axially into the nozzle head 38 (Figure 5), the compressed-air intake connection 41 inserted into the control head 32 and ending in the nozzle duct 42, a ventilating duct 44 and 44' passing essentially coaxially through the control head 32 and receptacle part 34 and into one another so as to be aligned, as well as an air control duct 45 connecting the nozzle duct 42 with the ventilating duct 44. In order to effect a defined air stream in the ventilating duct 44, the air control duct 45 points, with its inlet opening, in the direction of the outlet opening 46 which seals off the ventilating duct 44 at the atmospheric end. On the side turned away from the outlet opening 46, the ventilating duct 44 passes over into an annular duct 25 which is placed coaxially in the control head 32 in its rear end. The inside surface of the annular duct 25 has an internal winding 23 into which the receptacle part 34 with the filtering element 64 can be screwed.
The outside winding 21 of the filtering element 64 is interrupted by an axially extending longitudinal gr~ove 35 (Figure 3) which continues in the storage receptacle 40 as a tubular-shaped ventilating duct 44'.
The outlet opening 46 is in the form of a ram slot 63 for manually controlling the internal pressure -8- 2~53~31.
P1 of the storage receptacle 40. By means of a valve rod 57, which can be screwed into the ventilating duct 44 with its milled head 47, the internal pressure P1 can be adjusted independent of the fact whether or not the S ram slot 63 is covered. The annular duct 25 and the receptacle part 34 are sealed airtight by means o~ an annular seal 62a placed coaxially in the annular duct 25 and an annular seal 62b placed coaxially in the control head 32.
The spray duct system has a spray duct 49 which passes through the nozzle duct 42, 42' and is disposed coaxially in the control head 32. The spray duct 49 is inserted, inside the control head 32, into a duct mounting 27 which is screwed into the nozzle duct 42. On the side of the nozzle head, the spray duct 49 rests in a guide sleeve 60 which is pressed against the inner surface of the nozzle head 38 by means of a coil spring 59 stayed on the duct mounting 27. At its front end, the guide sleeve 60 (see Figure 7) has axially running cut grooves 61a, 61b by means of which a compressed-air flow from the nozzle duct 42 to nozzle duct 42' is maintained.
The filtering device 50 disposed coaxially on the receptacle part 34 consists essentially of the filter element 64 and a boring disk 19.
By means of the tube 68 shown in Figure 6, the ventilating duct 44 can be extended at its outlet opening 46. To accomplish this, an adapter 17 is inserted on the one end into the tube 68, it being possible to insert or screw the adapter into the outlet opening 46. As a result of the pressure Fl exerted radially on the tube sleeve 67, the effective cross-sectional surface of the outlet opening can be varied.
The spray gun shown in Figure 9 consists of an essentially two-part apparatus 70, namely, a control `
. , ~ ' ~.
, 9 ~ 31.
head 72 and a receptacle part 74. At its front end, the control head 72 has a receiving bore into which a nozzle head 76 with a one-piece formed insertable part is inserted. At its back end, th~ control head 72 is S shaped into a one-piece formed coupling part 13 whose outer surface has a circular ring attachment 15. The coupling part 13 is to be inserted into a receiving part 11 formed at the front end of the receptacle part 74 for producing a firm connection with the receptacle part 74.
The receptacle part 74 is sealed pressure-resistant at its back end by means of a receptacle cap 29a.
The air duct distributor system formed in the control head 72 and in the receptacle part 74 consists of a compressed-air duct 82 into which a nipple 80 is inserted at the inlet side for connection to a compressed-air supply 9. At the other end, the compressed-air duct 82 passes over into the nozzle duct 81 formed and placed axially in the nozzle head 76.
Parallel to the nozzle duct 81, a ventilating duct 83 is formed in the upper part of the control head 72, which ventilating duct leads to an outlet opening 86 at the front end of the control head 72. At the other end, the ventilating duct 83 continues into the venti'ating duct 83' which projects into the receptacle part 74.
Furthermore, in the control head 72, an air control duct 84 is provided which opens, at the one end, into the compressed-air duct 82 and, at the other end, into the ventilating duct 83 with a bent outlet opening 8. the outlet opening 8 is thereby adjusted in the direction of the outlet opening 86, as a result of which the air stream flowing in the ventilating duct is given a preferred direction.
The air mass flowing through the ventilating duct 83, 83' can be adjusted by means of a valve placed on the top of the control head 72.
- lo ~
In addition, a valve rod 88 which i5 screwed into the control head 72 and formed, at the one end, into a tapered conical seal 89 and has, at the other end, a milled head 87, projects into the ventilating S duct 83. By manipulating the milled head 87, the effective cross-sectional surface of the ventilating duct 83 can be varied, as a result of which the flow of air in the ventilating duct 83 and 83' and, thus, the internal pressure P1 can be adjusted. In particular, by operating the valve rod 88, the intake pressure P3 produced at the mouthpiece 93 can be completely compensated. The outlet valve 73, which i5 screwed into a ram air duct 85 branching off from the ventilating duct 83 in the control head 72, is used to restrict the internal pressure Pl to a maximum value. By operating the milled head 75 connected with the outlet valve 73, the maximum attainable ram pressure in the ventilating duct 83 is set.
To operate the spray gun, compressed-air is fed from a conventional compressed-air source via the compressed-air feed 9, the nipple 80, to compressed-air duct 82 to the nozzle duct 81 and blown out of the mouthpiece 93 of the nozzle head 76. As a result of the suction effect of the compressed-air jet, a negative pressure is produced in the spray duct 90c, 90b axially displaced in the nozzle duct 81, and as a result of this negative pressure, spray substance is drawn from the storage receptacle 71 via the spray duct 90a and the filtering device 91 in the receptacle part 74. The spray coming out of the spray duct 90c is sprayed in fine droplets which are mixed with the compressed air and carried away. To control the spraying pressure, a pressure-relief valve 69 is provided between the compressed-air source and the compressed-air supply. As shown in Figures lO and ll, the pressure-relief valve 69 .
- ll - x~
consists essentially of a basic body 6 in which a tube 66 consisting preferably of an elastic material is placed so as to extend axially. Perpendicular to the axial direction of the basic body 6, a taper pin 65 is inserted which is displaceable in the basic body. The tube 66 rests on the inclined plane 5 of the taper pin and is varied in its cross-sectional surface depending on the respective position of the taper pin 65, by means of which the flow quantity and pressure in the compressed-air line 9 can be adjusted.
In order to be able to replace the receptacle part 74, e.g. for cleaning the storage receptacle 71, a shutoff valve which, as shown in Figure 9, consists of a manually operable flow duct 52, is provided between the IS filtering device 91 and the receiving part 11.
According to Figure 12, the shutoff valve is constructed as a ball valve 53 which has a sealing ball 54 and a coil spring 55. The sealing ball 54 is thereby pressed by the coil spring 55 into its closed position, when the control head 72 is removed from the receptacle part 74, and, when these parts are coupled, it is again lifted off from the sealing surface 4.
Figure 13 shows a nozzle head 78 inserted into the control head 72 which is formed in such a way that the spray gun can be used as a tubular drawing instrument. For this purpose, a spray duct 90c projecting out of the nozzle head 78 and in the form of a paint tube is inserted into the nozzle head 78.
The spray gun can also be used as a sand blasting device when the r~ceptacle part 95 o~ the storage receptacle 96 is formed as shown in Figure 14.
This storage receptacle 96 can be filled with fine-grained solid substances, preferably sand particles.
The control air is conducted into the storage receptacle 96 via the ventilating duct 97' and the air-permeable .
-12- ~ ~ ~3~
spray filter 9~ located be~ween the ventilating duct 97' and the storage receptacle 96. The control air flowing in whirls the sand particles into a spray sand mixture which flows into the nozzle duct 99', extending almost S over the entire axial length of the receptacle part, as a flowable air/sand mixture. To fill or refill the storage receptacle 96, the receptacle cap 29b which seals the receptacle part 95 can be removed.
.: :
: . . .
.
~ '
Claims (19)
1. A spray gun for atomized spraying of a flowable spray substance, comprised of a storage receptacle for the spray substance, a nozzle device which has a nozzle duct passing over into a mouthpiece in which a spray duct extending axially leading from the storage receptacle to the mouthpiece is placed, and of a compressed-air duct which can be connected, at the one end, to a compressed-air source and opening, at the other end, into the nozzle duct, a ventilating duct connecting the storage receptacle to ambient air via an outlet opening and a control air duct which, at the one end, is connected to a compressed-air source and opens, at the other end, into the ventilating duct in such a way that the compressed air coming out of the control air duct flows in a preferred direction to the outlet opening into the ventilating duct, whereby the internal pressure of the storage receptacle can be adjusted as negative or excess pressure by opening and closing the outlet opening, as a result of which the amount of flow of the spray substance coming out of the spray duct can be continuously controlled.
2. A spray gun as defined in claim 1, further including means in the ventilating duct for controlling the air stream, via which the internal pressure can be adjusted in such a way that the intake pressure produced in the spray duct by the air stream coming out of the mouthpiece can be completely compensated.
3. A spray gun as defined in claim 1 or 2, further including means at the ventilating duct via which the internal pressure can be restricted to a maximum pressure value.
4. A spray gun as defined in one of claims 1 or 2, in which the control air duct is connected at the inlet and with one of the compressed-air duct and the nozzle duct.
5. A spray gun as defined in one of claims 1 or 2, further including a filtering device situated in the spray duct, by means of which the spray substance flowing out of the storage receptacle can be filtered.
6. A spray gun s defined in one of claims 1 or 2, further including a compressed-air supply opening, at the one end, into the compressed-air duct and which is, at the other end, connected to a compressed-air source.
7. A spray gun as defined in one of claims 1 or 2, further including a pressure-relief valve inserted into the compressed-air supply, by means of which the quantity of compressed air supplied from a compressed-air source can be continuously adjusted.
8. A spray gun according to one of claims 1 or 2, in which the outlet opening is in the form of a ram slot which can be covered by a fingertip in such a way that the cross-sectional surface of the outlet opening can be varied according to a logarithmic function course and the internal pressure can be adjusted.
9. A spray gun as defined in one of claims 1 or 2, in which the ventilating duct can be extended by means of a flexible tube comprised of an elastically deformable material, whereby the cross-sectional surface of the outlet opening can be varied and the internal pressure adjusted by radially exerting pressure on the tube sleeve.
10. A spray gun comprising a control head having a nozzle head axially aligned at its front end and a receptacle part axially aligned at its back end with a storage receptacle, whereby an air duct distribution system is formed in the control head and in the receptacle part which has a compressed-air intake connection, nozzle ducts passing over coaxially and in alignment in one another in the nozzle head and in the control head, a compressed-air duct formed in the control head and connecting the compressed-air intake connection with the nozzle ducts, a ventilating duct passing through the control head and a receptacle part essentially coaxially and in alignment with one another, a control air duct connecting the nozzle duct with the ventilating duct, and a valve rod projecting into the ventilating duct between the control air duct and the outlet opening which can be operated by a milled head and which is preferably formed into a tapered conical seal at the end, and whereby a spray duct system is formed in the control head and in the receptacle part which has a spray duct disposed coaxially in the nozzle duct which opens, at the one end, into the nozzle head and, at the other end, into a filtering device.
11. A spray gun as defined in claim 5, further comprising a shutoff valve located between the spray duct and the filtering device, by means of which the storage receptacle can be closed by disconnecting the control head from the receptacle part.
12. A spray gun as defined in claim 11, in which the shutoff valve is comprised essentially of a regulating cock which is pivoted in the receptacle part and which has a flow duct.
13. A spray gun as defined in claim 11, in which the shutoff valve is constructed as a ball valve which has a sealing ball which can be pressed, preferably by a coil spring, into its sealing position when the receptacle part is disconnected from the control head, and can be pressed out of its sealing position when the receptacle part is put on against the force of the spring.
14. A spray gun as defined in one of claims 1, 2 or 10 further comprising an air-permeable fine-mesh spray filter located between the ventilating duct and the storage receptacle in which the fine-grained solid substances, preferably sand particles, are contained as spray substance, and that the nozzle duct projects into the storage receptacle almost over its entire length.
15. A spray gun as defined in one of claims 1, 2 or 10 characterized thereby that a grip part is locked, preferably by means of a bayonet lock on the receptacle part.
16. A spray gun as defined in one of claims l, 2 or 10 in which the nozzle head is formed into an insertable part at its back end which is inserted or screwed into an opening formed in the front end of the control head.
17. A spray gun as defined in claim 1, in which the spray duct projects from the front end of the nozzle head in form of a paint tube with a drawing tip.
18. A spray gun as defined in one of the claims l, 2 or 10 in which at least the control head and the receptacle part consist of injection molded plastic.
19. A spray gun as defined in one of the claims l, 2 or 10 in which the nozzle duct has a Teflon coating.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE9014663U DE9014663U1 (en) | 1990-10-23 | 1990-10-23 | Pneumatically controlled spray gun |
| DEG9014663.8 | 1990-10-23 | ||
| DE19914130973 DE4130973A1 (en) | 1991-09-18 | 1991-09-18 | Pneumatically controlled liq. spray gun |
| DEP4130973.1 | 1991-09-18 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2053801A1 true CA2053801A1 (en) | 1992-04-24 |
Family
ID=25907419
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002053801A Abandoned CA2053801A1 (en) | 1990-10-23 | 1991-10-21 | Pneumatically controlled spray gun |
Country Status (6)
| Country | Link |
|---|---|
| EP (1) | EP0482569B1 (en) |
| JP (1) | JPH04265169A (en) |
| AT (1) | ATE133092T1 (en) |
| AU (1) | AU8605191A (en) |
| CA (1) | CA2053801A1 (en) |
| DE (1) | DE59107282D1 (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20060071096A1 (en) * | 2002-03-26 | 2006-04-06 | Antonin Vavra | Control device for dispersing a liquid in a fluid |
| DE102005038162A1 (en) | 2005-08-12 | 2007-02-15 | Kriesmair, Bernd, Dipl.-Ing. | Device for spraying pigmented liquids |
| MX2009009972A (en) | 2007-04-11 | 2009-11-02 | Bernd Kriesmair | Device for spraying pigmented fluids. |
| CN109877260B (en) * | 2019-03-21 | 2023-11-03 | 中信戴卡股份有限公司 | Rotary spray disc device for mold lubricant |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE97344C (en) * | ||||
| US1561039A (en) * | 1924-11-11 | 1925-11-10 | Walker Edward | Spraying apparatus |
| GB647339A (en) * | 1948-01-02 | 1950-12-13 | Hoover Ltd | Improvements relating to spraying devices |
| CH284542A (en) * | 1949-12-05 | 1952-07-31 | Herrli Hans | Spray gun. |
| FR1589319A (en) * | 1968-10-14 | 1970-03-23 |
-
1991
- 1991-10-21 CA CA002053801A patent/CA2053801A1/en not_active Abandoned
- 1991-10-22 DE DE59107282T patent/DE59107282D1/en not_active Expired - Fee Related
- 1991-10-22 AU AU86051/91A patent/AU8605191A/en not_active Abandoned
- 1991-10-22 AT AT91117968T patent/ATE133092T1/en active
- 1991-10-22 JP JP3274310A patent/JPH04265169A/en active Pending
- 1991-10-22 EP EP91117968A patent/EP0482569B1/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| EP0482569A1 (en) | 1992-04-29 |
| EP0482569B1 (en) | 1996-01-17 |
| DE59107282D1 (en) | 1996-02-29 |
| AU8605191A (en) | 1992-04-30 |
| ATE133092T1 (en) | 1996-02-15 |
| JPH04265169A (en) | 1992-09-21 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| FZDE | Discontinued |