US3892359A

US3892359A - Spray apparatus operable by pressurized air

Info

Publication number: US3892359A
Application number: US409188A
Authority: US
Inventors: Jr John Robert Dwyer; Alvydas Petras Karasa; Jonathan Durand Bell; James Lawson Allen
Original assignee: Black and Decker Manufacturing Co
Current assignee: Black and Decker Corp
Priority date: 1973-10-24
Filing date: 1973-10-24
Publication date: 1975-07-01
Anticipated expiration: 1992-07-01
Also published as: CA1017720A; CA1016910A; FR2248881A1; DE2446533A1; IT1030720B; FR2248881B1; CA1014119A; US3869089A; BR7408422D0; CA1001128A; BR7408423A; JPS50128813A; JPS5073929A; IT1025070B; DE2446534A1; GB1486332A

Abstract

A paint spray gun operable by pressurized air is provided. The paint spray gun includes a container for holding paint and pressurized air and a paint spray head for receiving paint from the container and mixing the paint with a continuous flow of pressurized air to produce a paint spray. First and second fluid paths are provided between the container and the spray head to allow paint and air, respectively, to flow from the container to the paint spray head. In a preferred embodiment, a manually operable valve is provided in the first fluid path for controlling the flow of paint from the container to the paint spray head. The paint spray head is mounted on a displaceable actuator of the valve and a manually operable trigger mechanism is provided for engaging and moving the paint spray head to displace the actuator to open the valve to permit paint to flow to the paint spray head.

Description

United States Patent Dwyer, Jr. et al.

July 1, 1975 1 SPRAY APPARATUS OPERABLE BY PRESSURIZED AIR [75] Inventors: John Robert Dwyer, .lr. Timonium;

Alvydas Petras Karasa, Baltimore; Jonathan Durand Bell, Towson; James Lawson Allen, Cockeysville. all of Md.

[73] Assignee: The Black and Decker Manufacturing Company, Towson. Md.

[22] Filed: Oct. 24, 1973 [21] Appl. N0.: 409,188

[52] US. Cl 239/342; 239/346 1511 Int. Cl 1305b 7/30 [58] Field of Search 239/346, 373, 526, 375,

[56] References Cited UNITED STATES PATENTS 2,372,678 4/1945 McKay 239/342 3,491,951 1/1970 Knibb 239/346 Primary Examiner-Lloyd L. King Attorney, Agent. or Firm-Joseph R. Slotnik; Edward D. Murphy; Leonard Bloom [57] ABSTRACT A paint spray gun operable by pressurized air is pr0- vided. The paint spray gun includes a container for holding paint and pressurized air and a paint spray head for receiving paint from the container and mix ing the paint with a continuous flow of pressurized air to produce a paint spray. First and second fluid paths are provided between the container and the spray head to allow paint and air. respectively. to flow from the container to the paint spray head. In a preferred embodiment, a manually operable valve is provided in the first fluid path for controlling the flow of paint from the container to the paint spray head. The paint spray head is mounted on a displaceable actuator of the valve and a manually operable trigger mechanism is provided for engaging and moving the paint spray head to displace the actuator to open the valve to per mit paint to flow to the paint spray head.

8 Claims, 6 Drawing Figures SPRAY APPARATUS OPERABLE BY PRESSURIZED AIR The present invention relates to a paint spray apparatus and, more particularly, to a paint spray gun operable by pressurized air.

In the art of paint spray apparatus, paint spray guns have been developed which are driven by pressurized air to eject a paint spray. Generally, the prior art paint spray guns have been complicated in structure and, therefore, difficult and expensive to manufacture. The paint spray guns have typically included intricate nozzle structures for combining paint and pressurized air to produce a paint spray and complex valve arrangements for controlling the flow of paint to the nozzles. Because of the intricate nozzle and valve designs, the prior art paint spray guns have been prone to clog during painting operations. Further, the complicated structure of the paint spray guns has made it extremely difficult to disassemble the guns for cleaning after painting operations are completed.

It has been common in the prior art to construct paint spray guns of metal. The metal components of the guns have been expensive to manufacture because of the various metal working operations required to produce the components.

In view of the recent development of inexpensive compressed air sources for general use, it has become desirable to provide paint spray apparatus operable by pressurized air for general applications, including home use. To avoid the disadvantages occurring in the prior art resulting from the complex structure of previous paint spray guns and to provide paint spray apparatus suitable for general use, particularly for use in home workshops, it is necessary to provide a paint spray gun which is inexpensive to manufacture and has minimum cleaning requirements. It is also extremely desirable to provide a paint spray gun which is compact in size, readily assembled and disassembled, and constructed of easily replaceable functioning components. It is further desirable to provide a paint spray apparatus which can be made of easily moldable material, such as plastic, and which is constructed to strongly resist internal pressure and renders the device attractive in appearance, light in weight, easily serviceable, and relatively inexpensive.

It is an object of the present invention to provide an improved paint spray gun which is operable by pressurized air.

It is also an object of the present invention to provide an inexpensive paint spray gun with minimum cleaning requirements.

It is another object of the present invention to provide a paint spray gun which includes a common container for holding paint and pressurized air and separate fluid paths between the container and a paint spray head for supplying paint and pressurized air to the paint spray head.

It is a further object of the present invention to provide a paint spray gun which is compact in size, attractive in appearance, readily assembled and disassembled. and constructed of easily interchangeable components.

It is a still further object of the present invention to provide a paint spray gun incorporating components which can be formed by inexpensive manufacturing techniques. such as molding, which is constructed to strongly resist internal pressure.

The present invention provides a paint spray apparatus which includes a paint spray head for receiving paint and pressurized air to produce a paint spray. a container for holding paint and pressurized air, means for providing a first fluid path between the container and the paint spray head to allow paint to flow from the container to the paint spray head, and means for providing a second fluid path between the container and the paint spray head to allow pressurized air to flow from the container to the paint spray head. In addition, the apparatus includes means for supplying pressurized air to the container to cause paint to flow to the paint spray head through the first fluid path and pressurized air to flow to the paint spray head through the second fluid path to be mixed by the paint spray head to produce a paint spray.

In a preferred embodiment, the container comprises a canister-like base for receiving paint and a cover including an air inlet for receiving pressurized air to be supplied to the canister-like base and an integral, hollow handle extending upwardly from the cover to enable the paint spray apparatus to be manually gripped. The paint spray head is mounted at the top of the bandle. A first conduit extends downwardly from the paint spray head through the interior of the hollow handle into the canister-like base to permit paint to flow from the canister-like base to the paint spray head. A second conduit connects the paint spray head to the interior of the handle to permit pressurized air to flow from the canister-like base through the handle to the paint spray head.

Preferably, the handle supports a manually operable valve for controlling the flow of paint from the container to the paint spray head through the first fluid path. This manually operable valve is embodied as an aerosol valve in fluid communication with the paint spray head. The aerosol valve includes a displaceable actuator for opening the valve, and the paint spray head is mounted on the actuator. A manually operable trigger mechanism is provided on the handle for engaging and moving the paint spray head to displace the actuator to open the aerosol valve to permit paint to flow to the paint spray head.

The present invention provides a paint spray gun which is inexpensive to manufacture, compact in size, readily disassembled to permit easy access for cleaning, and comprised of easily replaceable components. The paint spray head and aerosol valve are particularly inexpensive so that, if desired, these components can be discarded after use and replaced by new components without the prohibitive cost involved in the prior art devices. In addition, it is possible to fabricate the components of the paint spray gun from plastic by conventional molding techniques to minimize the cost of manufacture.

The accompanying drawings illustrate a preferred embodiment of the invention and, together with the description, serve to explain the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an overall perspective view of a paint spray gun constructed according to the principles of the present invention;

FIG. 2 is an enlarged vertical section, partially cutaway, of the paint spray gun of FIG. I illustrating a container for holding paint and pressurized air, a cover for the container including an integral hollow handle, a paint spray head for receiving paint and pressurized air from the container, an aerosol valve for controlling the flow of paint from the container to the paint spray head, and a manually operable trigger mechanism for actuating the aerosol valve to permit the flow of paint to the paint spray head;

FIG. 3 is an enlarged side elevation, partially cutaway, of the paint spray head, aerosol valve, and trigger mechanism of FIG. 2;

FIG. 4 is an enlarged vertical section of the paint spray head;

FIG. 5 is an exploded, perspective view of the components of the trigger mechanism; and

FIG. 6 is a perspective view of the bottom of the container illustrating a knurled edge and a pair of radially extending ribs which facilitate manual assembly and disassembly of the container from the spray gun.

Referring to FIG. 1, the paint spray gun comprises, in general, a container for holding paint and pressurized air, a cover 22 for closing the container, an integral handle 24 extending upward from cover 22 to enable the paint spray gun to be manually gripped, and a manually operable trigger mechanism 26 mounted at the top of handle 24 to enable the paint spray gun to be manually operated As shown in FIGS. 1 and 2, container 20 comprises a generally cylindrical canister-like base including a cylindrical side wall 28 with an open top end for receiving paint and a closed bottom end 30 having an elliptical contour to resist forces generated by pressurized air supplied to the container. As indicated in FIG. 2, cylindrical wall 28 of the canister-like base is slightly tapered. A set of external threads 32 is provided on the exterior of cylindrical side wall 28 near the top of the container.

As shown in FIG. 6, container 20 is provided with an exterior knurled portion 33 formed at its bottom edge to facilitate manual turning of the container relative to cover 22. The elliptical contour of closed end 30 of the container provides a hollow area at the container bottom. A pair of radially disposed ribs 34 extend inwardly from cylindrical wall 28 and downwardly from bottom end 30 of the container in this hollow area. The ribs can be manually engaged to facilitate turning of the container relative to the cover.

Referring to FIG. 2, cover 22 comprises a domeshaped upper wall 35 provided with an annular rim 36 extending downwardly from the circular periphery of the cover. Annular rim 36 is provided with a set of internal threads 38 for engaging external threads 32 on the canister-like base to secure the cover to the base.

In the preferred embodiment, external threads 32 on container 20 are buttress threads. Each thread includes a flat, horizontal lower edge and an upwardly and inwardly inclined upper edgev Similarly, internal threads 38 on annular rim 36 of cover 22 are buttress threads. Each thread includes a flat, horizontal upper edge and a downwardly and outwardly inclined lower edge. The buttress threads provide a threaded connection between the container and cover of increased strength, in comparison with conventional threads, to provide substantially greater resistance to forces on the threads generated by pressurized air supplied to the container.

An O-ring seal 40 is provided at the top of cylindrical wall 28 of container 20. As shown in FIG. 2, the outer edge at the top of cylindrical wall 28 is tapered to provide an upwardly and inwardly inclined exterior surface 41 for engaging the interior of O-ring seal 40. Preferably, exterior surface 4! is inclined at approximately 30 to the vertical. Upon threading of container 20 into annular rim 36 of cover 22, O-ring seal 40 is compressed radially and axially into engagement with the interior of the cover to provide an air-tight seal. Since the edge of container 20 is in angular contact with the O-ring seal, the axial movement of the container required to achieve an adequate seal is increased relative to the corresponding movement of a conventional apparatus in which the O-ring seal rests directly on top of the container with the advantage that the torque necessary to effect the seal is substantially reduced.

Referring to FIGS. 1 and 2, cover 22 includes an air inlet 42 through which pressurized air is supplied to the interior of container 20. As shown in FIG. 2, air inlet 42 comprises a hollow cylindrical stem extending outwardly from annular rim 36 of the cover. An air inlet opening 44 extends through annular rim 36 to provide fluid communication between air inlet 42 and the interior of container 20. A coupling member 46 is threadably received in the hollow cylindrical stem. The outer end of coupling member 42 is threaded to facilitate connection of the coupling member to a tube 48 coupled to a source of pressurized air (not shown).

As shown in FIG. 2, handle 24 integrally formed on cover 22 is hollow and extends vertically upward from dome-shaped upper wall 35 of the cover. Handle 24 terminates at its upper end in a hollow cylindrical portion 50 provided with a top, circular opening.

In accordance with the invention, the paint spray gun includes a paint spray head for receiving paint and pressurized air and for mixing the paint and pressurized air to produce a paint spray. A preferred embodiment of the paint spray head includes a first inlet for receiv ing paint, a second inlet for receiving pressurized air, and an outlet for ejecting a paint spray consisting of a mixture of paint and air.

In the preferred embodiment of the paint spray gun, a paint spray head or nozzle, generally 52, is provided. Referring to FIGS. 3 and 4, the paint spray head or nozzle comprises an elongated body 54, a cap 56, a plug 58, and a plug retainer 60. Body 54 is provided with a first set of external threads 62 (FIG. 4) adjacent to its front end. Cap 56 is generally cylindrical in shape and provided with internal threads for engaging external threads 62 to secure the cap to the body. Cap 56 has a knurled exterior surface, shown in FIGS. 1-3, to facilitate manual threading of the cap on external threads 62. In addition, body 54 is provided with a second set of external threads 64 (FIG. 4) adjacent to its rear end. Plug retainer is generally annular in shape and provided with internal threads for engaging external threads 64 to secure the plug retainer to body 54 and to hold plug 58 against the rear end of the body. Plug retainer 60 also has a knurled exterior surface, shown in FIGS. 1-3, to facilitate manual threading of the plug retainer on external threads 64.

Referring to FIG. 4, elongated body 54 includes a first fluid passage 66 and a second fluid passage 68 extending therethrough for receiving paint and pressurized air, respectively. A recess 70 is provided at the rear end of body 54. Fluid passage 66 extends from a first, enlarged opening formed in the recess and gradually tapers as it extends toward the front end of body 54. Similarly, fluid passage 68 extends from a second,

enlarged opening formed in the recess and tapers gradually as it extends toward the front end of the body.

The front end of body 54 comprises a flat, circular base 72 provided with a cone-shaped extension 74 projecting forward from the face. Cone-shaped extension 74 is centrally located on circular face 72 of the body and terminates in a cylindrical tip 76. Fluid passage 66 extends from its larger opening in recess 70 through body 54 to a smaller exit opening in cylindrical tip 76. Similarly, fluid passage 68 extends from its enlarged opening in recess 70 to a smaller exit opening in circular face 72.

in addition, body 54 is provided with a stem 78 projecting downwardly from the body. A passsageway 80 extends through stem 78 into fluid communication with fluid passage 66 and constitutes the first inlet of the paint spray head. Passageway 80 includes an enlarged diameter section 82 which extends inwardly from the outer end of stem 78 and a reduced diameter section 84 which begins approximately midway between the outer end of the stern and fluid passage 66 to provide an annular ledge 86.

Cap 56 is mounted on the front end of elongated body 54 and has a hollow interior to provide a mixing chamber for paint and pressurized air adjacent to the front end of the body. The cap includes a tapered front wall 88 provided with a coneshaped interior surface 90 which, in cooperation with flat, circular face 72 and cone-shaped extension 74 of body 54, provides a mixing chamber for paint and pressurized air. The front wall of cap 56 includes a central opening 92 in axial alignment with the exit opening of fluid passage 66 in cylindrical tip 76 of the cone-shaped extension to form a paint spray from paint and pressurized air supplied to the mixing chamber. Spray opening 92 constitutes the outlet of the paint spray head.

Plug 58 includes a front face 94 which sealingly engages in recess 70 at the rear end of body 54 to cover the enlarged openings of

fluid passages

66 and 68. A cylindrical inlet member 96 extends rearwardly from the plug. A passageway 98 extends through the cylindrical inlet member into fluid communication with the enlarged opening of fluid passage 68. This passageway constitutes the second inlet of the paint spray head. In addition, plug 58 includes a plug-like projection 100 extending forwardly from its front face 94. Plug-like projection 100 is tapered in shape to be received in the enlarged opening of fluid passage 66 to seal the open- Plug retainer 60, which is generally annular in shape, includes a rear wall 102 provided with a circular opening 104 to permit inlet member 96 to extend beyond the plug retainer. Rear wall 102 of plug retainer 60 engages the outer edge of plug 58 to retain the plug in engagement with the rear end of body 54.

The paint spray gun of the present invention includes means for providing a first fluid path between the container and the paint spray head to allow paint to flow to the paint spray head. In accordance with a preferred embodiment of the invention, this means includes a manually operable valve for controlling the flow of paint to the paint spray head. Preferably, a manually operable aerosol valve in fluid communication with the first inlet of the paint spray head is provided for controlling the flow of paint to the first inlet. The aerosol valve includes a displaceable actuator, and the paint spray head is mounted on the actuator.

Referring to FIGS. 2 and 3, the preferred embodiment of the paint spray gun is provided with a conventional aerosol valve, generally 105, mounted within the top circular opening of cylindrical portion 50 of handle 24. The aerosol valve comprises a hollow, generally cylindrical valve body 106 supported in an annular support member or metal ring 107. The ring includes a rounded annular rim 108 which rests on the top of hollow cylindrical portion 50 of the handle. A removable cap or valve retainer 109 is threadably received on external threads provided on cylindrical portion 50 of the handle to retain the rim of metal ring 107 firmly in engagement with the upper edge of the cylindrical portion to provide an air-tight seal.

Aerosol valve includes a displaceable actuator 110 (FIG. 3) mounted within valve body 106 and extending upwardly through a central opening in metal ring 107. An annular gasket 111 interposed between the upper end of valve body 106 and metal ring 107 surrounds a reduced diameter portion 112 of actuator 110. The actuator is normally urged upwardly by a coil spring 113 located between an internal shoulder 114 provided within valve body 106 and an enlarged cylindrical portion 115 formed on actuator 110. The actuator includes a passageway 116 extending axially therethrough which terminates at its reduced diameter portion 112. A plurality of inlet orifices 118 is formed at the reduced diameter portion of actuator 110 in fluid communication with passageway 116.

Actuator 110 is normally urged upwardly by coil spring 113 to maintain enlarged cylindrical portion 115 in sealing engagement with gasket 111 to preclude fluid communication between the interior of valve body 106 and inlet orifices 118. When actuator 110 is displaced by downward forces against the compression of coil spring 113, cylindrical portion 115 of the actuator is moved out of sealing engagement with gasket 111, and reduced diameter portion 112 is moved downwardly to permit fluid communication between the interior of valve body 106 and passageway 116 of the actuator through inlet orifices 118. At the same time, a tapered surface 119 of the actuator moves downwardly into sealing engagement with the gasket 111. Upon release of the downward forces on actuator 110, coil spring 113 returns the actuator to its normally upward position with enlarged portion 115 of the actuate: in sealing engagement with gasket 111.

As shown in FIG. 4, a paint spray head 52 is mounted on actuator 110 of the aerosol valve by inserting the actuator into passageway 80 provided in stem 78. The actuator is received in large diameter portion 82 of the passageway. Annular ledge 86 limits the extent to which the actuator can be inserted into passageway 80.

Referring to FIG. 2, a first conduit or tube 120 extends from aerosol valve 105 through the interior of handle 24 into container 20 for supplying paint from the container to the aerosol valve. The upper end of tube 120 is fastened on valve body 106 while the lower end of the tube extends substantially to the bottom of the container. When pressurized air is supplied to the container through inlet opening 44, paint is forced under pressure through tube 120 to aerosol valve 105. The aerosol valve and tube thus constitute first conduit means for providing a first fluid path between the container and the paint spray head to allow paint to flow from the container to the paint spray head.

The paint spray gun of the present invention also includes means for providing a second fluid path between the container and the paint spray head to allow pressurized air to flow to the paint spray head. In the preferred embodiment, a second conduit is connected to the paint spray head and to the interior of the handle for supplying pressurized air from the container to the paint spray head. Referring to FIG. 2, the second conduit is embodied as a tube 122 connected at its opposite ends to cylindrical inlet member 96 of the paint spray head and to a cylindrical outlet member 124 provided on cylindrical portion 50 of handle 24. A passageway 126 extends through outlet member 124 into fluid communication with the interior of the handle. When pressurized air is supplied to container through inlet opening 44, the interior of handle 24 also receives pressurized air and, as a result, there is a continuous flow of pressurized air through passageway 126 of outlet member 124 and tube 122 into inlet member 96 of the paint spray head. The interior of handle 24, passageway 126, and tube 122 thus constitute second conduit means for providing a second fluid path between the container and the paint spray head to allow pressurized air to flow from the container to the paint spray head.

The preferred embodiment of the paint spray gun includes a manually operable trigger mechanism for em gaging and moving the paint spray head to displace the actuator to open the aerosol valve to permit paint to flow through the passageway in the actuator to the paint spray head. Referring to FIGS. 1 and S, trigger mechanism 26 comprises a trigger member 128 pivotally supported by a housing or trigger saddle 130 mounted at the top of handle 24. Trigger saddle 130 comprises a generally cup-shaped member having a split front end which enables the trigger saddle to be fit around the handle. A screw 132 (FIG. 2) is provided to fasten the trigger saddle to the handle.

Referring to FIGS. 1 and 2, trigger member 128 is generally in the form of a hood having an inclined front face provided with a rectangular opening 134 which permits the front end of body 54 and cap 56 of the paint spray head to project forward through the trigger member. A gripping member 136 extends downward from the top oftrigger member 128 for engaging body 154 ofthe paint spray head. A transverse bar 137 (FIG. 5) extends between opposite sides at the rear of the trigger member. At the rear end of trigger saddle 130, an outer pair of ribs 138 is provided with slots and an inner pair of ribs 139 is provided with upper hook ends suitable for receiving transverse bar 137 to allow the trigger member to pivot relative to the trigger saddle. The cup-shaped trigger saddle and hood-shaped trigger member provide a protective housing surrounding paint spray head 52 and tube 122 to prevent inadvertent disconnection of these components from the paint spray gun.

Trigger member 128 includes a finger engageable lever 140 (FIGS. 1 and 2) extending downwardly from its front face and received in a recess 142 provided in the front of handle 24. As shown in FIG. 3, a knob 144 is attached to a shaft 146 rotatably mounted in an opening provided in lever 140. If desired, this connection between knob I44 and shaft 146 can be a slip clutch to prevent shaft 146 from pulling out of knob 144 upon continued turning of knob 144 after shaft 148 seats against lever 140. The knob is manually rotatable to control the position of an adjustable stop memher 148 threadably mounted on shaft 146. The position of adjustable stop 148 can be varied by manually turning knob 144 to control the extent of pivotal movement available to lever 140.

In the operation of the paint spray gun, container 20 is unthreaded from cover 22 and filled with paint. Container 20 is then threaded into annular rim 136 of the cover to force O-ring seal 40 into engagement with the interior of the cover to provide an air-tight seal. Next, the paint spray gun is connected to a source of pressurized air (not shown) via tube 48.

Referring to FIG. 2, pressurized air is supplied to the interior of container 20 and handle 24 through inlet opening 44. The pressure within the container and handle builds up to a level substantially equal to the pressure level of the source. At the same time, a small amount of air continuously flows through passageway 126 of cylindrical outlet member 124 and through tube 122 to inlet member 96 of the paint spray head.

Referring to FIG. 4, the pressurized air supplied to inlet member 96 flows through passageway 98 and fluid passage 68 into the mixing chamber provided at the front end of the spray nozzle. From the mixing chamher, the air exits through spray opening 92. Thus, by virtue of the pressurized air supplied to container 20 and handle 24, there is a continuous flow of air through the paint spray head.

Because the flow of air from the container and the handle is restricted by the small size of exit passageway 126, a back pressure is maintained within the container and handle on the paint in the container. This back pressure results in the paint being supplied through tube 120 to aerosol valve under pressure.

When it is desired to produce a paint spray, lever 140 is manually depressed to pivot trigger member 128 about transverse bar 137 to move gripping member 136 downward into engagement with body 54 of the paint spray head. This downward movement of member 136 is transmitted by body 54 and stem 78 of the paint spray head to actuator of the aerosol valve. Upon downward displacement of actuator 110, the aerosol valve is opened to supply paint under pressure to the paint spray head. Referring to FIG. 3, the paint flows from tube 120 through the interior of valve body 106 and around enlarged cylindrical portion of actuator 110 into inlet orifices 118 to passageway 116 in the actuator. The flow of paint continues through passageway 116 in actuator 110 and passageway 80 (FIG. 4) in the stern into fluid passage 66. The paint is then driven through fluid passage 66 and out of the exit opening in cylindrical tip 76 of cone-shaped extension 74 into the mixing chamber. It is mixed in the chamber with the continuous flow of pressurized air and is ejected with the air through spray opening 92 to produce a paint spray. The flow rate of paint to the paint spray head is controlled by the amount of pivotal movement manually imparted to trigger member 128.

The container, cover, paint spray head, trigger mechanism and valve retainer are preferably formed of a suitable plastic material to which paint does not readily adhere, e.g., an acetal polymer. This type of material enables the components of the paint spray gun to be readily cleaned. In addition, the removable plug and plug retainer of the paint spray head permits easy access to the tapered passages in the body and the removable cap permits easy access to the mixing chamber to facilitate cleaning of the paint spray head.

Each of the plastic components of the paint spray gun can be manufactured by molding techniques rather than expensive drilling or welding operations. The capability of manufacturing these components of the paint spray gun by molding permits the nozzle to be manufactured at minimum cost. in addition, the aerosol valve is conventional in structure and inexpensively fabricated to minimize the cost of manufacture of the paint spray gun.

Although the invention has been described in the context of a paint spray gun, it will be apparent that the spray gun can be used for other liquids, e.g., stains, varnishes, and water solutions such as garden sprays. Thus, the utility of the invention is not intended to be con fined to the field of paint spray apparatus.

The invention in its broader aspects is not limited to the specific details shown and described, and modifications may be made in the details of the paint spray gun without departing from the principles of the present invention.

We claim:

1. A paint spray apparatus, including:

a container for holding paint and pressurized air, said container comprising a canister-like base including an open end for receiving the paint and a cover for closing said open end of said canister-like base;

said cover including an air inlet for receiving pressurized air to be supplied to said canister-like base and an integral handle extending upward from said cover to enable the paint spray apparatus to be manually gripped, said handle having a hollow interior in fluid communication with said canister-like base;

a paint spray head mounted at the top of said handle for receiving paint and pressurized air from said container and for mixing the paint and air to produce a paint spray;

first conduit means extending downwardly from said paint spray head through the interior of said handle into said canister-like base to permit paint to flow from said canister-like base to said paint spray head; and

second conduit means for connecting said paint spray head to the interior of said handle to permit pressurized air to flow from said canister-like base through said handle to said paint spray head.

2. A paint spray apparatus as claimed in claim 1 wherein said second conduit includes a restrictive orifice to permit a continuous flow of pressurized air through said second conduit and through said paint spray head while producing a regulated back pressure within said hollow handle.

3. A paint spray apparatus as claimed in claim i wherein said container comprises a one-piece, plastic. molded canister having buttress threads formed on an external surface thereof and wherein said cover includes internal buttress threads for cooperation therewith.

4. A paint spray apparatus operable by pressurized air. comprising:

a container for holding paint and pressurized air;

a handle projecting from said contain er to permit the paint spray apparatus to be manually gripped. said handle having a hollow interior in fluid communi' cation with said container;

a paint spray head mounted on said handle for receiving paint and pressurized air from said container and for mixing the paint and pressurized air to produce a paint spray;

5 a manually operable aerosol valve mounted on said handle in fluid communication with said paint spray head for controlling the flow of paint to said paint spray head;

a first conduit extending from said aerosol valve through the interior of said handle into said container for supplying paint from said container to said aerosol valve;

a second conduit connected to said paint spray head and to the interior of said handle for supplying pressurized air from said container to said paint spray head; and

means for supplying pressurized air to said container to cause paint to flow under pressure from said container through said first conduit to said paint spray head upon manual operation of said aerosol valve and pressurized air to flow from said container through said handle and second conduit to said paint spray head to be mixed by said paint spray head to produce a paint spray.

5. A paint spray apparatus as claimed in claim 4 wherein said second conduit comprises an open, restrictive orifice for permitting constant flow of pressurized air from said handle through said nozzle while producing a controlled back pressure within said container.

6. A paint spray apparatus, including:

a container for holding paint and pressurized air, said container comprising a canister-like base including an open end for receiving the paint and a cover for closing said open end of said canister-like base, said base including a closed bottom end having an elliptical contour to resist forces generated by pressurized air;

7. A paint spray apparatus operable by pressurized air, comprising:

a container for holding paint and pressurized air, said container including a closed bottom end having an elliptical contour to resist forces generated by pressurized air:

a handle projecting from said container to permit the paint spray apparatus to be manually gripped, said 1 1 l2 handle having a hollow interior in fluid communisaid top; cation with said container; a handle projecting from said container to permit the a paint spray head mounted on said handle for receivpaint spray apparatus to be manually gripped, said ing paint and pressurized air from said container handle having a hollow interior in fluid communiand for mixing the paint and pressurized air to pro- 5 cation with said container, said handle including duce a paint spray; buttress threads formed on an internal surface a manually operable aerosol valve mounted on said thereof for mating with said buttress threads on handle in fluid communication with said paint said container; spray head for controlling the flow of paint to said a paint spray head mounted on said handle for receivpaint spray head; 0 ing paint and pressurized air from said container a first conduit extending from said aerosol valve and for mixing the paint and pressurized air to prothrough the interior of said handle into said conduce a paint spray; tainer for supplying paint from said container to a manually operable aerosol valve mounted on said said aerosol valve; handle in fluid communication with said paint a second conduit connected to said paint spray head spray head for controlling the flow of paint to said and to the interior of said handle for supplying paint spray head; pressurized air from said container to said paint a first conduit extending from said aerosol valve spray head; and through the interior of said handle into said conmeans for supplying pressurized air to said container tainer for supplying paint from said container to to cause paint to flow under pressure from said said aerosol valve; container through said first conduit to said paint a second conduit connected to said paint spray head spray head upon manual operation of said aerosol and to the interior of said handle for supplying valve and pressurized air to flow from said conpressurized air from said container to said paint tainer through said handle and second conduit to spray head; and said paint spray head to be mixed by said paint means for supplying pressurized air to said container spray head to produce a paint spray. to cause paint to flow under pressure from said 8. A paint spray apparatus operable by pressurized container through said first conduit to said paint air, comprising: spray head upon manual operation of said aerosol a container for holding paint and pressurized air,said valve and pressurized air to flow from said concontainer comprising a one-piece cylindrical plas- 3 tainer through said handle and second conduit to tie canister having an open top and a closed bottom said paint spray head to be mixed by said paint end. said canister including buttress threads spray head to produce a paint spray. formed on the external surface thereof adjacent

Claims

1. A paint spray apparatus, including: a container for holding paint and pressurized air, said container comprising a canister-like base including an open end for receiving the paint and a cover for closing said open end of said canister-like base; said cover including an air inlet for receiving pressurized air to be supplied to said canister-like base and an integral handle extending upward from said cover to enable the paint spray apparatus to be manually gripped, said handle having a hollow interior in fluid communication with said canister-like base; a paint spray head mounted at the top of said handle for receiving paint and pressurized air from said container and for mixing the paint and air to produce a paint spray; first conduit means extending downwardly from said paint spray head through the interior of said handle into said canisterlike base to permit paint to flow from said canister-like base to said paint spray head; and second conduit means for connecting said paint spray head to the interior of said handle to permit pressurized air to flow from said canister-like base through said handle to said paint spray head.

3. A paint spray apparatus as claimed in claim 1 wherein said container comprises a one-piece, plastic, molded canister having buttress threads formed on an external surface thereof and wherein said cover includes internal buttress threads for cooperation therewith.

4. A paint spray apparatus operable by pressurized air, comprising: a container for holding paint and pressurized air; a handle projecting from said container to permit the paint spray apparatus to be manually gripped, said handle having a hollow interior in fluid communication with said container; a paint spray head mounted on said handle for receiving paint and pressurized air from said container and for mixing the paint and pressurized air to produce a paint spray; a manually operable aerosol valve mounted on said handle in fluid communication with said paint spray head for controlling the flow of paint to said paint spray head; a first conduit extending from said aerosol valve through the interior of said handle into said container for supplying paint from said container to said aerosol valve; a second conduit connected to said paint spray head and to the interior of said handle for supplying pressurized air from said container to said paint spray head; and means for supplying pressurized air to said container to cause paint to flow under pressure from said container through said first conduit to said paint spray head upon manual operation of said aerosol valve and pressurized air to flow from said container through said handle and second conduit to said paint spray head to be mixed by said paint spray head to produce a paint spray.

6. A paint spray apparatus, including: a container for holding paint and pressurized air, said container comprising a canister-like base including an open end for receiving the paint and a cover for closing said open end of said canister-like base, said base including a closed bottom end having an elliptical contour to resist forces generated by pressurized air; said cover including an air inlet for receiving pressurized air to be supplied to said canister-like base and an integral handle extending upward from said cover to enable the paint spray apparatus to be manually gripped, said handle having a hollow interior in fluid communication with said canister-like base; a paint spray head mounted at the top of said handle for receiving paint and pressurized air from said container and for mixing the paint and air to produce a paint spray; first conduit means extending downwardly from said paint spray head through the interior of said handle into said canister-like base to permit paint to flow from said canister-like base to said paint spray head; and second conduit means for connecting said paint spray head to the interior of said handle to permit pressurized air to flow from said canister-like base through said handle to said paint spray head.

7. A paint spray apparatus operable by pressurized air, comprising: a container for holding paint and pressurized air, said container including a closed bottom end having an elliptical contour to resist forces generated by pressurized air; a handle projecting from said container to permit the paint spray apparatus to be manually gripped, said handle having a hollow interior in fluid communication with said container; a paint spray head mounted on said handle for receiving paint and pressurized air from said container and for mixing the paint and pressurized air to produce a paint spray; a manually operable aerosol valve mounted on said handle in fluid communication with said paint spray head for controlling the flow of paint to said paint spray head; a first conduit extending from said aerosol valve through the interior of said handle into said container for supplying paint from said container to said aerosol valve; a second conduit connected to said paint spray head and to the interior of said handle for supplying pressurized air from said container to said paint spray head; and means for supplying pressurized air to said container to cAuse paint to flow under pressure from said container through said first conduit to said paint spray head upon manual operation of said aerosol valve and pressurized air to flow from said container through said handle and second conduit to said paint spray head to be mixed by said paint spray head to produce a paint spray.

8. A paint spray apparatus operable by pressurized air, comprising: a container for holding paint and pressurized air, said container comprising a one-piece cylindrical plastic canister having an open top and a closed bottom end, said canister including buttress threads formed on the external surface thereof adjacent said top; a handle projecting from said container to permit the paint spray apparatus to be manually gripped, said handle having a hollow interior in fluid communication with said container, said handle including buttress threads formed on an internal surface thereof for mating with said buttress threads on said container; a paint spray head mounted on said handle for receiving paint and pressurized air from said container and for mixing the paint and pressurized air to produce a paint spray; a manually operable aerosol valve mounted on said handle in fluid communication with said paint spray head for controlling the flow of paint to said paint spray head; a first conduit extending from said aerosol valve through the interior of said handle into said container for supplying paint from said container to said aerosol valve; a second conduit connected to said paint spray head and to the interior of said handle for supplying pressurized air from said container to said paint spray head; and means for supplying pressurized air to said container to cause paint to flow under pressure from said container through said first conduit to said paint spray head upon manual operation of said aerosol valve and pressurized air to flow from said container through said handle and second conduit to said paint spray head to be mixed by said paint spray head to produce a paint spray.