ES2364320T3 - SPRAY GUN WITH FAST COUPLING CONNECTOR INCORPORATED FOR PAINT TANK. - Google Patents

Abstract

A liquid spray apparatus comprising a spray gun and a reservoir for a liquid to be sprayed, the tank having an outlet that can be connected to the spray gun to allow, in use, liquid to be removed from the tank and having the spray gun a solid bushing (621) arranged for non-threaded application with cooperating connecting means (880; 980) thanks to which the reservoir is detachably secured to the spray gun, characterized in that the cooperating connecting means of the reservoir comprise a tubular coupling member (880; 980) which is pressure mounted on the bushing (621), the coupling member (880; 980) having a first part (880a; 980a) that provides a tight connection between the coupling member (880; 980) and the bushing (621), and a second part (887; 987) that can be made to cooperate with the spray gun outside the bushing (621) to inhibit rotation of the coupling member (880; 980) in the bushing (621) without restricting the relative axial movement between the coupling member (880; 980) and the bushing (621) to apply / de-apply the coupling member (880; 980).

Description

This invention relates to improvements in or relating to liquid spray apparatus such as a spray gun. More especially, the invention relates to the connection between the spray gun and a reservoir containing the liquid to be sprayed. The invention finds particular application, although not exclusively, in a releasable connection for detachably mounting the reservoir in the spray gun and in a spray gun intended for such connection.

Spray guns are widely used in vehicle body shops, when a vehicle that has been repaired after an accident is repainted. In known spray guns, the liquid is contained in a tank attached to the gun, from where it is fed to a spray nozzle. Upon exiting the spray nozzle, the liquid is atomized and forms a spray with compressed air supplied to the nozzle. The liquid can be fed by gravity or by suction or, more recently, fed under pressure by means of an air purge line for the reservoir from the compressed air line for the spray gun.

Traditionally, the liquid is contained in a rigid canister mounted on the spray gun by application of complementary threads in the canister and in the gun. In this way, the canister can be removed to clean or replace it. Typically. The canister is secured to the empty gun and has a removable lid through which liquid can be added to the canister while it is attached to the gun. When spraying is complete, the canister can be removed and the gun and canister can be cleaned for reuse.

With this arrangement, the threads of the gun and the can can be damaged due to improper use, for example if an attempt is made to secure a can with a different thread. Likewise, when spraying is completed, careful cleaning is necessary in order to remove any trace of liquid from the threads to prevent them from becoming blocked, for example with dry paint and to avoid cross contamination with the next liquid that is spray

Damaged or blocked threads can render the gun useless, it being necessary to buy a new gun. This increases costs and is inconvenient if working time is lost because a spare gun is not available to continue spraying. In addition, cleaning the threads usually requires the use of solvents that are also used to clean the gun and the canister. The use of solvents is not desirable for health and safety reasons and causes problems when disposing of the solvent after use.

Recently, we have developed a system in which the tank can be discarded after use, thus reducing the extent of the cleaning required after finishing spraying. Thanks to this system, the tank can be filled with the liquid to be sprayed before attaching it to the gun. The traditional threaded connection requires that the tank be rotated several times, typically five five turns, to fully apply the threads and securely secure the tank. This takes time and requires considerable care and skill on the part of the user to avoid spills when the tank is full of liquid.

In order to reduce these problems, we have proposed a system to connect the tank to the spray gun by means of an adapter that is threaded into the spray gun and that provides a quick-release, releasable connection for the tank. For example, the reservoir and the adapter may be provided with bayonet type formations that can be coupled by a torsional and thrust action that requires less than a full turn of the reservoir to connect the reservoir to the gun.

This arrangement makes it possible for the tank to be attached to the gun and separated from it in a simple and efficient way, which reduces the risk of spillage when the tank contains liquid and requires less dexterity from the user.

The provision of the adapter allows converting existing guns, with screw connection for use with a usual rigid boat, for use with our system using a disposable tank. This entails numerous advantages for the user, in particular because the extent of the cleaning required when spraying is completed is reduced. However, problems may arise if an adapter that has a thread that matches the thread of the gun is not available, for example, if the adapter is removed for cleaning and lost. The gun cannot then be used with the disposable tank and work time must be lost if the user does not have a spare adapter or a rigid canister that can be screwed into the spray gun without the adapter. Also, the threaded connection between the gun and the adapter is likely to break down due to misuse, just as the connection between the gun and the can can result in the gun becoming unusable.

WO 02/072276 describes a liquid spray apparatus according to the preamble of claim 1.

The present invention has been developed from the consideration of the aforementioned problems and the disadvantages of the existing arrangements for securing a deposit to a spray gun.

More particularly, at least some embodiments of the present invention provide an improved connection between a spray gun and a reservoir, which allows the reservoir to be attached to the gun and separated from it in a simple manner, which reduces the risk of damaging the gun. .

In addition, at least one embodiment of the present invention provides a spray gun intended to quickly and releasably connect to a reservoir, which allows the reservoir to be connected when it is filled with liquid with less risk of spillage and does not require great dexterity. part of the user when connecting / disconnecting the tank.

In addition, at least one embodiment of the present invention provides an insert for converting a non-threaded, integral threaded connector bushing of a spray gun, to mount a reservoir having a connector that is not attachable with the connector bushing and that is compatible with the insert .

Thus, according to the present invention, a liquid spraying apparatus according to claim 1 is provided. Preferred features of the liquid spraying apparatus are the subject of dependent claims 2 to 17.

As used herein, the term "liquid" refers to any form of flowable material that can be applied using a spray gun (whether or not intended to apply color to the surface) including (but not limited to) paints, primers, base coatings, lacquers, varnishes and paint-like materials, as well as other materials such as adhesives, sealing agents, fillers, putties, powder coatings, shot blasting powders, abrasive sludge, mold release agents and lubricants for casting, which can be applied in atomized or non-atomized form, depending on the properties and / or the projected application of the material and the term "liquid" has to be considered accordingly.

As used herein, the term "non-threaded application" refers to all forms of releasable connection between two connectors that can mutually engage / disengage through a relative axial movement.

According to the invention, the spray gun has an integral bushing intended to be connected to an outlet of the tank. The bushing provides a through bore leading to an inlet of the spray gun and the outlet of the tank communicates with the inlet tightly when the tank is connected to the spray gun to, in use, deliver liquid to the spray gun.

The bushing may be lowered in the body of the spray gun.

The deposit can be reusable. For example, the reservoir may comprise a rigid canister that can be removed from the spray gun and cleaned upon spraying. Typically, the canister has a vent that can be opened at the far end of the connection to the spray gun in order to allow air to enter as, in use, liquid is removed from the canister.

More preferably, the reservoir is disposable. For example, the reservoir can comprise an outer container and an inner liner, the liner being able to be crushed as liquid is removed from the reservoir, and separated from the outer container so that the liner can be removed and discarded after use. Typically, the outer container has a vent at the far end of the connection with the spray gun to allow air to enter as, in use, liquid is removed from the liner.

The spray gun bushing is provided with an insert to convert the bushing for connection with a tank that has a non-attachable connector. In this way, the spray gun can be adapted, simply and efficiently, to mount tanks provided with different connectors. A set of interchangeable inserts can be provided that allow the assembly of any one of the inserts in order to provide the socket with any desired connector formation. Preferably, the inserts are molded plastic parts, but other materials, including metals, can be used. Typically, inserts are molded pieces of nylon.

In one arrangement, the spray gun is provided with an integral retaining formation outside the bushing, such that a reservoir provided with an attachable retaining formation can be installed and secured in the spray gun by means of a push-torsion action, which requires less than a complete turn of the tank relative to the spray gun, and the inserts make it possible for the spray gun to be adapted for the connection of tanks provided with usual threaded connectors or other types of connector that are not attachable with the integral retaining formation of the spray gun

The inserts may be arranged to block or save the integral retaining formation of the spray gun so that it does not interfere with the connection to the reservoir. For example, the insert may be provided with a recessed part in which the retaining formation of the spray gun is received by pressure mounting the insert in the bushing. The recessed portion may be provided on a flange that is arranged to extend to either side of the retaining formation in order to limit the rotation of the insert in relation to the spray gun. In this arrangement, the insert is preferably mounted with interference fit on the bushing to reduce the risk of inadvertent or accidental separation of the insert (and the bonded tank) from the bushing.

Preferably, the spray gun and the tank define a geometric connection axis when the tank is secured to the spray gun. The attachable connectors can be applied / unapplied thanks to a relative axial movement substantially parallel to the connecting geometric axis.

Other features, benefits and advantages of the invention will be apparent from the following detailed description of illustrative embodiments of the invention, with reference to the accompanying drawings. Figure 1 is a perspective view of a liquid spray apparatus that does not incorporate the present invention; Figure 2 is a perspective view of the reservoir shown in Figure 1, separated from the spray gun; Figure 3 is a longitudinal section given through the reservoir shown in Figure 2;

Figure 4 is a perspective view of the spray gun illustrated in Figure 1, separated from the reservoir; Figure 5 is an exploded perspective view, showing a detail of the connection between the gun sprayer and reservoir shown in figures 1 to 4;

Figure 6 is an end view of the connecting boss of the spray gun of Figure 5 with

parts removed for reasons of clarity; Figure 7 is a section through an inlet port of the body of a spray gun with gravity feed, provided with an external retaining formation;

Figure 8 is a perspective view of an insert adapter not according to the invention, for the port input shown in figure 7; Figure 9 is a plan view of the insert adapter shown in Figure 8; Figure 10 is a side view of the insert adapter shown in Figure 8;

Figure 11 is a sectional view of the insert adapter illustrated in Figure 8; Figure 12 shows the insert adapter of Figures 8 to 11 mounted on the inlet port of the body of the spray gun shown in figure 7;

Figure 13 is a perspective view of an alternative insert adapter not in accordance with the invention for entrance port illustrated in figure 7; Figure 14 is a plan view of the insert adapter shown in Figure 13; Figure 15 is a side view of the insert adapter shown in Figure 13;

Figure 16 is a sectional view of the insert adapter shown in Figure 13; Fig. 17 is a perspective view of an insert adapter according to the invention for the port of entrance shown in figure 7;

Figure 18 is a plan view of the insert adapter shown in Figure 17; Figure 19 is a side view of the insert adapter in the direction of arrow A shown in Figure 18; Figure 20 is a sectional view of the insert adapter shown in Figure 17; Figure 21 is a sectional view showing the insert adapter of Figures 17 to 20 mounted on the lum

inlet of the spray gun body shown in figure 7; Figure 22 is a perspective view of another insert adapter according to the invention for the port of entry shown in figure 7;

Figure 23 is a plan view of the insert adapter shown in Figure 22; Figure 24 is a side view of the insert adapter in the direction of arrow B shown in Figure 23; Figure 25 is a side view of the insert adapter in the direction of arrow C shown in Figure 23; Figure 26 is a sectional view of the insert adapter shown in Figure 22; Figure 27 is a perspective view of another insert adapter according to the invention for the port of

entry shown in figure 7; Figure 28 is a plan view of the insert adapter shown in Figure 27; Figure 29 is a side view of the insert adapter in the direction of arrow D shown in Figure 28; Figure 30 is a side view of the insert adapter in the direction of arrow E shown in Figure 28; Figure 31 is a sectional view of the insert adapter shown in Figure 27; Figure 32 is a perspective view of a tank with a full spout peak not according to the invention,

intended to be connected with the spray gun of figure 7; Figure 33 is a side view of the reservoir shown in Figure 32; Figure 34 is a longitudinal sectional view of the reservoir shown in Figure 32; Figure 35 is a perspective view of a tank lid with integral spout, not in accordance with the

invention, intended to be connected with the spray gun of Figure 7; Figure 36 is a side view of the tank cover shown in Figure 35; Figure 37 is a longitudinal sectional view of the tank cover shown in Figure 35; Figure 38 is a side view showing a modification of the insert of Figures 8 to 11; Y Figure 39 is a side view showing a modification of the insert of Figures 13 to 16. Referring first to Figure 1 of the accompanying drawings, there is shown a spray apparatus

of liquid that does not incorporate the present invention, comprising a spray gun 1 with feed by

gravity and a reservoir 2 detachably connected to the spray gun 1. The gun 1 comprises a body 3, a handle 4 extending downward from the rear end of the body, and a spray nozzle 5 at the front end of the body. The gun 1 is operated manually by a trigger 6 which is pivotally mounted on the sides of the gun.

The tank 2, which contains paint (or similar material) to be unloaded by the gun, is located in the upper body 3 and communicates with an internal (not visible) passage that extends through the gun to the nozzle 5.

In use, the gun 1 is connected by a connector 7 at the lower end of the handle 4, with a source of compressed air (not shown) so that when the user pulls the trigger 6, compressed air is delivered through from the gun, to the nozzle 5. As a result, the paint delivered by gravity from the reservoir 2 to the nozzle 5 It is atomized when leaving the nozzle 5 and forms a spray with the compressed air leaving the nozzle 5.

Referring now to figures 2 and 3 of the drawings, the tank 2 includes an outer container 8, a liner disposable 9, a disposable lid 10 and a collar 11. The liner 9 has a shape that corresponds to the inside of the container 8 (and fits tightly in it) and has a narrow flange 12 at the open end that sits on the upper edge of the container 8.

The cover 10 is conical in shape and has a skirt 13 directed downwards that starts from the peripheral edge. The skirt 13 press fit on the open end of the liner 9 to position the peripheral edge of the lid 10 over the flange 12 of the liner 9. The lid / liner assembly is secured in place by the annular collar 11, which threads into the container 8, above the lid 10.

The lid 10 has a central opening 14 at its apex, which leads to a connecting tube 15 that provides an outlet

of fluid and a pair of hook members 16, 17 located on each side of the connecting tube 15. The hook members 16, 17 are arranged to detachably secure the reservoir 2 to the spray gun 1 and the tube 15 is formed with outer annular ribs 18 to provide a tight seal with the spray gun 1, as described below.

A mesh filter 19 is pressure mounted inside the skirt 13 and removes the particulate material from the paint delivered, in use, through the tube 15 to the spray gun 1. Alternatively, the filter 19 can be pressure mounted in the tube 15 or may be an integral part of the lid 10.

Referring now to FIGS. 4 to 6, the spray gun 1, which is not part of the invention, is provided with an integral connecting protrusion 20 in the upper part of the body 3. The protuberance 20 extends upwardly from the body 3 and It has a bushing 21 shaped to receive the connecting tube 15 of the lid 10 of the tank 2. The bushing 21 ends in an internal shoulder 33 leading to a bore 34 that extends from the bushing 21 and provides an entrance for the delivery of paint from reservoir 2 to spray gun 1.

In this embodiment, the protuberance 20 is formed in one piece with the body 3 of the gun 1, for example the body 3 can be a cast piece of light metal or a light alloy. Alternatively, the protuberance 20 can be formed separately and permanently secured to the body 3, for example by welding, in order to form an integral part of the gun 1.

The outer ribs 18 of the connecting tube 15 provide a tight seal with the bushing 21 and the protuberance 20 has an external flange 22 at the distal end to cooperate with the hook members 16, 17 in order to loosely secure the reservoir 2 to the spray gun 1. In an alternative arrangement (not shown), a tight seal can be achieved by one or more seals, for example o-rings, located in one or more throats of the connecting tube 15 or in the wall of the bushing 21.

The flange 22 comprises four arcuate recesses 23, 24, 25, 26 (Figure 6) uniformly spaced in a circumferential direction around the periphery, such that the recesses 23, 25 are facing each other and the recesses 24, 26 are one in front of another.

Each recess 23, 24, 25, 26 carries, clockwise (as seen in Figure 6) through a cam lobe 23a, 24a, 25a, 26a at the end of recess 23, 24 , 25, 26, to a plane 27, 28, 29, 30 that ends in a support 27th, 28th, 29th, 30th.

Each hook member 16, 17 comprises an enlarged head 31, 32 at the distal end, which has a chamfer face 31a, 32a leading to a recessed locking rib 31b, 32b, to cooperate with the flange 22.

To secure the reservoir 2 to the spray gun 1, the hook members 16, 17 are aligned with a pair of opposite recesses 23, 25 or 24, 26 of the flange 22. The connecting tube 15 is then pushed into the bushing 21 of so that the enlarged heads 31, 32 of the hook members 16, 17, pass through the aligned recesses 23, 25 or 24, 26.

The tank 2 is then rotated in relation to the spray gun 1 to make the hook members 16, 17 run on the cam lobes 23a, 25a or 24a, 26a and place the locking ribs 31b, 32b behind the planes 27, 29 or 28, 30. The rotation of the tank 2 is limited by the application of the hook members 16, 17 with the supports 27a, 29a or 28a, 30a.

In this way, the tank 2 can be secured to the spray gun 1 by performing a thrust-torsion action that requires less than a full turn of the tank 2 in relation to the spray gun 1 around a geometric connection axis defined by the application of the connector tube 15 in the bushing 21. In this embodiment the tank can be rotated in approximately a quarter turn or less to secure the tank to the spray gun.

The tank 2 can be removed from the spray gun 1 by performing a reverse operation in which the tank 2 is rotated, first, to align the enlarged heads 31, 32 of the hook members 16, 17 with the opposite recesses 23, 25 or 24, 26. Then, the tank 2 is pulled to remove the connector tube 15 from the bushing 21.

The hook members 16, 17 are deflected out by application with the cam lobes 23a, 25a or 24a, 26a and spring elastically back when passing through the cam lobes when the tank 2 is rotated relative to the spray gun 1, both for joining and separating the tank 2. Thus, when attached to the spray gun 1, the tank 2 is positively held in position when the spray gun 1 is maneuvered to apply paint to a surface.

The tank 2 can also be mounted on the spray gun 1 by a simple pressurized push, first aligning the hook members 16, 17 with a pair of opposite planes 27, 29 or 28, 30 of the flange 22. The tank is then pushed 2 towards the spray gun 1 to make the chamfer faces 31a, 32a be applied with the flange 22. The enlarged heads 31, 32 are deflected out due to the elasticity of the hook members 16, 17 to run on the flange 22 and jump elastically backwards after exceeding the flange 22 to place the locking ribs 31b, 32b behind the planes 27, 29 or 28, 30. In this way, the tank 2 is secured to the spray gun 1. It can be It is possible to remove the tank 2 by performing a reverse operation if enough force is applied to release the locking ribs 31b, 32b.

In use, the reservoir 2 is filled with paint (or with another liquid to be sprayed) before mounting it on the spray gun 1. To do this, the liner 9 is pushed into the container 8. Then, paint is placed on the liner 9 and , if necessary, mixed with other dyes, hardeners and solvents. The cover 10 is then pushed into place and the collar 11 is screwed tightly to hold the cover 10 in position.

The spray gun 1 is then inverted from its normal operating position, illustrated in Figure 1, so that the reservoir 2 can be presented to the spray gun 1 in an upright position to prevent paint spillage. Then, the reservoir 2 is secured to the spray gun 1 by a push-torsion or push-only action, as described above.

Then, the spray gun 1 can be returned to its normal operating position for use in the usual manner. As paint is removed from the reservoir, the liner 9 is crushed in an axial direction from the base end 9a to the lid 10. A vent hole 8a at the base end of the container 8 allows air to enter the custom container 8 the liner 9 is crushed. The side wall 9b of the liner 9 folds inwardly, uncontrollably, as the liner 9 is crushed.

After use, when the spray gun 1 is to be cleaned, the spray gun 1 can be reverted from its operating position shown in Figure 1. The air line is disconnected and the trigger 6 is briefly operated to allow the paint inside the spray gun 1 drains back to the liner 9 in the tank 2. Then, the tank 2 of the spray gun 1 is removed in the manner described above.

As will be appreciated, the integral formations of the gun 1 and the tank 2 allow the tank 2 to be attached to the gun 1 and separated from it thanks to a simple action. In this way, the device can be assembled and disassembled quickly and easily with minimal manual dexterity by the user. Likewise, the risk of spillage is reduced when the tank 2 containing the paint is connected to the gun 1. In addition, the tank 2 can be detachably secured to the gun 1 without the need for a separate adapter and without application of the threads, which they can be damaged due to misuse or blocked with paint deposits leaving gun 1 unusable.

The tank 2 can be disassembled, when disconnected from the spray gun 1 by removing the collar 11 and pulling the cover 10 to carry with it the crushed liner 9. Any remaining paint in the liner 9 can be stored for a short period of time by closing the connecting tube 15, for example by means of a removable closure cap (not shown). The cover / liner assembly can then be reassembled with the container 8 and the collar 11 and attached again to the spray gun 1 to use the remaining paint.

When removed from the container 8, the lid / liner assembly is relatively fragile and susceptible to the liner 9 and the lid 10 being separated if improperly handled. Consequently, it is only practical, in general, to store unused paint for a few hours, and any unused paint should be decanted into another container if it has to be stored for a long time.

When all the paint has been used or if the remaining paint is no longer necessary, the lid 10 (including the filter 19) and the crushed liner 9 can be discarded leaving the container 8 and collar 11 clean and ready for new use with a liner 9 and a new cover 10. In this way, you only have to clean the spray gun itself 1. Consequently, it is possible to reduce the amount of solvent used for cleaning.

Referring now to Figures 7 to 39 of the accompanying drawings, several arrangements are shown therein to secure a deposit to a spray gun. Other details of the construction and operation of the tank and the spray gun are similar to those of the previously described embodiment and will not be described or illustrated in greater detail. When appropriate in the following description, similar reference numbers are used, in the 600, 700, 800, 900, 1000 and 1100 series to indicate corresponding parts as well as parts similar to parts of the previous embodiment.

Referring first to Figure 7, there is shown a bushing 621 not threaded in the body 603 of a gravity-fed spray gun. The bushing 621 has a cylindrical outer bore part 621a and a cylindrical inner bore part 621b, connected by an internal annular shoulder 621c. The inner bore part 621b has a smaller diameter than that of the outer bore part 621a. At the bottom of the bushing 621 there is a sealing face 621d whose purpose will be described later.

Spaced above the bushing 612 there is an integral radial pin 686 with the body 603 of the gun. Pin 686 extends partly from the circumference of bushing 621 and is delayed with respect to the marginal edge of outer bore part 621a.

Referring now to Figures 8 to 11, there is shown an insert 680 of molded plastic not according to the invention, for example a nylon insert 680, for mounting on the bushing 621 in order to convert the bushing 621 so that can receive a threaded connector (not shown) to attach a paint reservoir. The threaded connector can be an integral part of the tank or be a separate part to which the tank is connected in a disconnectable manner.

The insert 680 is a molded plastic part, for example a nylon piece, and has a tubular body provided with an external hexagonal flange 687 at one end for application with a wrench or similar tool. The insert 680 has a cylindrical upper body part 680a directed downward from the flange 687 and connected to a cylindrical lower body part 680b of reduced diameter by an external annular shoulder 680c.

The lower body part 680b is sized to be mounted with interference fit on the inner bore part 621b so as to provide a tight seal inside the bushing 621. The upper body part 680a can be sized to be mounted with interference fit on the part. 621 of upper bore but, preferably, is mounted with pressure adjustment to facilitate the introduction of the insert 680 into the bushing 621, as described below.

The upper body part 680a is provided with upper and lower radial projections, 680d, 680e of trapezoid-shaped section, which extend approximately 180 ° around the circumference of the upper body part 680a. As shown, the upper projection 680d also has a helical shape while the lower projection 680e is completely parallel to the projection 680c. In this embodiment, the projection 680d has a step of approximately 3 mm, but it will be understood that this is not essential and that the passage can be altered to suit any given application.

The insert 680 has a through bore 688 with a threaded upper part 688a connected to an unthreaded lower part 688b of reduced diameter by an internal shoulder 688c. The shoulder 688c provides an internal stop to limit the application of a threaded connector with the upper bore portion 688a in order to ensure a paint deposit.

In use, the insert 680 is located in the socket 621, first orienting the insert so that the space 689 extending approximately 180 degrees around the circumference of the upper body part 680a, between the two ends of the projections 680d, 680e, be aligned with the radial pin 686 of the gun body 603. The insert 680 can then be pushed into the bushing 621 until the end of the upper projection 680d furthest from the flange 687 is positioned below the pin 686.

Then, the insert 680 can be rotated to apply the upper projection 680d with the lower side of the pin 686, as shown in Figure 25, for example, by applying a wrench to the flange 687. The helical shape of the upper projection 680d provides a ramp face that can be made to cooperate with pin 686 when the insert 680 is rotated.

As a result, the insert 680 is displaced further into the sleeve 621, until the lower projection 680e is applied with the gun body 603 around the perimeter of the sleeve 621. This requires less than a full turn of the insert 680. lower side of the pin 686 may have a helical shape, with a passage similar to that of the projection 680d, to facilitate axial displacement of the insert 680 by application of the projection 680d with the lower side of the pin 686.

At this point, the interference fit of the lower body part 680b in the inner bore part 621b is ensured to provide a tight seal between the body 603 of the gun and the insert 680 inside the bushing.

621

The insert 680 is also locked in position and prevented from being axially removed from the bushing 621 until it is rotated in the opposite direction to realign the pin 686 with the circumferential space 689 between the ends of the projections 680d, 680e.

With the insert 680 located and secured in place, the paint reservoir can be secured to the spray gun by means of a threaded connection with the threaded bore portion 688a of the insert 680. If desired, the insert 680 can be retained in position while the paint reservoir is attached to the spray gun or removed from it, taking the flange 687 with a wrench or other suitable tool. The threaded connection can be provided as an integral part of the reservoir or by means of a separate adapter to which the reservoir can be disconnectedly connected.

As will be appreciated, the lower projection 680e provides a stop to limit the displacement of the insert 680 in the socket 621 and prevents the insert 680 from being damaged by a rotation greater than that required to secure the insert 680 and provide an effective closure within the socket 621. In addition, the insert 680 is prevented from rotating when the connector is screwed into the bore 688a by application of the projections 680d, 680e with the pin 686 and the body 603 of the gun, respectively.

In a modification shown in Figure 38, an axial support 680h is provided at the upper end of the helical projection 680d. The support 680h provides an end stop that can be made to cooperate with the pin 686 to limit the rotation of the insert 680 relative to the pin 686 and avoid excessive tightening when the insert 680 in the bushing 621 is secured.

In another modification (not shown), the pin 686 may extend further around the circumference of the sleeve 621, with a corresponding reduction in the length of the projections 680d, 680e at the insert 680, so that the pin 686 can pass through the space that exists between the ends of the projections.

In another modification (not shown), the projection 680e may be positioned above the projection 680d so that the pin 686 is received between the projections 680e, 680d, the projection 680e acting again as a stop to limit the axial movement of the insert 680 inside bushing 621 by application with pin 686. Alternatively or additionally, helical projection 680d may be provided with an end stop, as described above, to limit rotation of insert 680 relative to pin 686 Alternatively, the space between the upper and lower surfaces of the projections 680d, 680e can be reduced sufficiently to limit the rotation of the insert 680 relative to pin 686.

Referring now to Figures 13 to 16, there is shown another insert 780 of molded plastic not according to the invention, similar in general to the insert 680 described above.

As shown, the insert 780 has an annular flange 787 at one end and a helical projection 780d in the upper body part 780a to cooperate with the radial pin 686 of the body 603 of the gun, as described above. The lower projection 780e has been omitted and the lower body part 780b has an increased length and closely adjusts, instead of adjusting with interference, in the inner bore part 621b, to facilitate the introduction of the insert 780 into the socket 621.

In use, the insert 780 is inserted into the bushing 621 by aligning the pin 686 with the circumferential space 789 between the ends of the projection 780d and it is rotated to position the projection 780d under the pin 686 of the body 603 of the gun, as is described above The insert 780 can then be rotated by applying a suitable tool to the flange 787 or by screwing the connector for the paint tank (not shown) into the insert 780.

When rotated, the insert 780 is displaced axially inside the sleeve 621 by application of the projection 780d with the lower side of the pin 686, until the closing face 780f of the inner end of the insert 780 comes into contact with the closing face 621d (figure 7) at the bottom of socket 621.

The closing face 780f can be provided by the insert itself, for example as a molded one-piece lip with the insert 780, of the same plastic or of a softer plastic or by means of a gasket located on the end wall of the insert, for example a rubber o-ring (not shown). Likewise, the closing face 621d can be provided by the gun body 603 itself, for example as an internal supporting shoulder or as a joint located at the bottom of the bushing 621, for example, a gasket or a nylon washer.

In one modification (Figure 39), there is an axial support 780h provided at the upper end of the helical projection 780d that provides an end stop that can be made to cooperate with the pin 686 to limit the rotation of the insert 780 relative to the pin 686 and avoid excessive tightening of the insert 780. In another modification (not shown), the lower body part 780b can be adjusted with interference in the inner bore part 688b, to provide a tight seal without application of the closing face 621d in the bottom of the cap 621.

In the embodiments described above, the helical projection 680d, 780d has a pitch of 3 mm and the cooperating surface of pin 686 has a similar pitch. However, it will be understood that this is not essential and that any suitable step can be employed. In addition, while the helical projections 680d, 780d and, when provided, the abutment projection 680e, extend approximately 180 degrees, to leave a space 689 of approximately 180 degrees in the circumferential direction for the passage of the pin 686. It will be understood that this is also not essential and that the circumferential extent of the projections 680d, 680e, 780d can be altered provided that the resulting space 689 is of sufficient size for the pin 686 to pass through it

Referring now to Figures 17 to 21, there is shown an insert of molded plastic 880 according to the invention, which can be used to convert the bushing 621 for application of a threaded connector in order to secure the paint deposit.

As shown, the insert 880 has an annular flange 887 at one end, which is provided with a cutout 887a of suitable size and shape to receive the pin 686 in the body 603 of the gun. The helical projection and the stop projection of the previous embodiments have been omitted from the upper body part 880a, and the lower body part 880b is sized to fit with interference in the inner bore part 621b in order to provide a tight seal .

In use, the insert 880 is positioned with the cutout 887a aligned with the pin 686 in the body 603 of the gun. The insert 880 is then introduced axially in the bushing 621 until the flange 887 sits in the body 603 of the gun around the bushing 621 and the pin 686 is received in the cutout 887a as shown in Figure 21. It is thus prevented , then, that the insert 880 can be rotated relative to the body 603 of the gun when the threaded connector is screwed into the insert 880 to secure the deposit, by application of pin 686 in the cutout 887a.

As will be appreciated, unlike previous embodiments, insert 880 is not axially retained by application with pin 686 and the base for achieving closure and retaining insert 880 in a sealed manner is the interference fit of insert 880 in the bushing 621. The interference fit can be improved by forming the insert 880 so that the upper body part 880a expands when the threaded connector is screwed into place to secure the reservoir.

Referring now to Figures 22 to 26, there is shown another molded plastic insert 980 according to the invention, which can be used to convert the bushing 621 for application of a threaded connector to secure the paint deposit.

The flange 987 is provided with a cutout 987a and, also, is formed with opposite planes 987b. The cutout 987a is larger, in the circumferential direction, than the pin 686. Consequently, the insert 980 can be rotated to a limited extent when it is inserted into the bushing 621 and the planes 987b allow the insert 980 to be retained with a tool. to prevent insert 980 from rotating when the threaded connector to secure the tank is screwed into insert 980.

Again, the insert 980 is not axially retained by application with the pin 686 and is based on the interference fit of the insert 980 in the bushing 621 to join them in sealing relationship and retain the insert 980 in a sealed manner. The interference fit can also be improved by forming the insert 980 so that the upper body part 980a will expand when the threaded connector is screwed into place to secure the reservoir.

Referring now to Figures 27 to 31, there is shown a modification of the insert 980 in which the lower body part 980b is provided with a pair of axially spaced annular closing ribs 980d, 980e. The ribs 980d, 980e are continuous in the circumferential direction and provide a tight seal with the inner bore part 621b when the insert 980 is located in the sleeve 621.

It will be appreciated that the number and arrangement of the closing ribs 980d, 980e can be altered with respect to those represented and that any of the inserts 680, 780, 880, 980 described in this document may be provided with one or more closing ribs to connect the insert in the socket 621 in sealing relationship.

As will now be apparent, each of the inserts 680, 780, 880, 980, described above, converts the unthreaded bushing 621 of the gun body 603 to receive a threaded connector to ensure a separate paint reservoir. However, it will be understood that the spout spout of the reservoir could be similarly adapted to each of the inserts to allow the reservoir to be connected directly to the gun body bushing.

The spout and reservoir could be formed separately and secured together, for example by welding, or they could be formed in one piece, for example by molding. Figures 32 to 34 show a molded plastic container 1002 not according to the invention, provided with a full spout 1015 at one end for connection with the bushing 621 and a removable cover 1090 at the opposite end to add liquid to the reservoir. 1002. The cover 1090 is provided with an annular gasket 1091 and a ventilation 1092 closed by a removable plug 1093.

As shown, the spout 1015 has a cylindrical part 1080a provided with a helical projection 1080d to cooperate with the pin 686 of the body 603 of the gun. The cylindrical part 1080a leads to an externally threaded part 1080g, which adjusts with interference in the outer bore part 621a of the bushing 621 and which, in turn, leads to a cylindrical part 1080b which is received in the inner bore part 621b of the 621 socket.

The tank 1002 is secured to the gun body 603 in a manner similar to the insert 780 described above by introducing the spout peak 1015 into the bushing 621 with the pin 686 aligned with a gap 1089 between the ends of the helical projection 1080d. The tank 1002 is then rotated to apply the helical projection 1080d with the lower side of the pin 686 causing the spout peak 1015 to enter the socket 621 until a closing face 1080f of the inner end comes into contact with a face of Opposite closure of bushing 621 and form a tight seal with it.

In a modification (not shown), the cylindrical part 1080b adjusts with interference within the inner bore part 621b to provide a tight seal similar to the insert 680. Alternatively, the cylindrical part 1080b may be provided with one or more ribs closure to provide a tight seal with the inner bore part 621b similar to insert 980.

The cylindrical part 1080a may be provided with a second projection similar to the insert 680, which provides a stop to limit the insertion of the pouring spout 1015 in the bushing 621. Alternatively or additionally, there may be an axial support provided at the upper end of the helical projection 1080d, to provide an end stop to limit the rotation of the insert relative to pin 686.

The threaded part 1080g allows the reservoir 1002 to be connected to a spray gun provided with a threaded bushing in the gun body or in an adapter mounted in the gun body. It will be understood that the threaded part 1080g can be omitted.

In another arrangement, the reservoir could be provided with a separate detachable part such as a lid and the spout and the lid could be formed separately and secured together, or they could be formed in one piece. Figures 35 to 37 show a molded plastic lid 1110 not in accordance with the invention for a tank (not shown) of the type previously described with reference to Figures 1 to 6.

As shown, the cover 1110 is provided with an integral spout peak 1115 for connection with the socket 621. The spout peak 1115 is similar to the full spout peak 1015 of the tank 1002 described above and the construction and operation may be comprised of from the previous description of the spout peak 1015.

It will be appreciated that the embodiments described by way of example herein are intended to illustrate the various range and scope of the invention and that the features of the embodiments may be employed separately or in combination with any other features thereof or of Different embodiments In addition, although it is believed that the illustrative embodiments described and shown represent the best means that the applicant is currently aware of, it will be understood that the invention is not limited thereto and that, within the scope of the invention defined in the attached claims, various modifications and improvements can be made.

For example, when the pouring spout is intended to be connected directly to the bushing, a valve system can be incorporated in the connection, such that, when connecting the pouring spout, a closing device is opened to facilitate the flow of liquid from the tank to the spray gun.

It will also be understood that each of the inserts could be adapted to convert the bushing to mount the tank using any other connection system in order to secure the tank to the insert. For example, the insert and the reservoir could be provided with interchangeable bayonet formations.

The reservoir can have any construction to contain paint to be delivered to the spray gun. For example, the reservoir may contain the paint in a collapsible container which, as described, is discarded at the end of spraying. Alternatively, the reservoir may contain the paint in a reusable paint canister that is cleaned after spraying.

The tank may be constructed to allow the addition of paint to the tank while it is attached to the spray gun. In this way, the reservoir can be refilled without separating the reservoir from the spray gun in order to allow spraying over areas that require a larger volume of paint than the reservoir can contain. As a result, the reservoir can have a compact size and a shape that facilitates the handling of the spray gun. In particular, by using a refillable tank, of small volume, the balance, stability and maneuverability of the spray gun can be improved.

The tank may have been previously filled with the paint to be sprayed. Alternatively, the tank can be supplied empty and can be filled by the end user. Pre-filling can be advantageous when spraying standard color paints that do not require special color adaptation, for example, primers, base coatings, etc.

The spray gun may be of the gravity fed type, described herein. Alternatively, the spray gun can be of the suction-fed type or the pressure-fed type. The type of pressure feed may employ a purge line of the compressed air supply to the gun to facilitate delivery of the paint from the reservoir to the spray gun. The invention also finds application in other types of spray gun constructions for spraying liquids as defined herein.

Other modifications and improvements will be apparent to those skilled in the art and are intended to be within the scope of the invention, defined by the appended claims.

Claims (17)

one.

 A liquid spray apparatus comprising a spray gun and a reservoir for a liquid to be sprayed, the tank having an outlet that can be connected to the spray gun to allow, in use, liquid to be removed from the tank and having the spray gun a solid bushing (621) arranged for non-threaded application with cooperating connecting means (880; 980) thanks to which the reservoir is detachably secured to the spray gun, characterized in that the cooperating connecting means of the reservoir comprise a tubular coupling member (880; 980) which is pressure mounted on the bushing (621), the coupling member (880; 980) having a first part (880a; 980a) that provides a tight connection between the coupling member (880; 980) and the bushing (621), and a second part (887; 987) that can be made to cooperate with the spray gun outside the bushing (621) to inhibit rotation of the coupling member (880; 980) in the bushing (621) without restricting the relative axial movement between the coupling member (880; 980) and the bushing (621) to apply / de-apply the coupling member (880; 980).

2.

The apparatus according to claim 1, wherein the coupling member (880; 980) has a through bore (888; 988) leading to an inlet of the spray gun and, when the reservoir is connected to the spray gun , the outlet of the tank communicates with the entrance through the through bore (888; 988) to, in use, deliver liquid to the spray gun.

3.

 The apparatus according to claim 1 or claim 2, wherein the spray gun has a body (603) and the bushing (621) is recessed in the body (603) of the spray gun.

Four.

The apparatus according to any one of the preceding claims, wherein the first part (880a, b; 980a, b) of the coupling member (880; 980) and the bushing (621) are narrowed so that the first part (880a, b; 980a, b) adjustment with friction interference in the bushing (621) to retain the reservoir in the spray gun.

5.

 The apparatus according to any one of the preceding claims, wherein the bushing (621) and / or the coupling member (880; 980) are provided with one or more sealing gaskets, for example o-rings, arranged to provide a tight seal.

6.

The apparatus according to any one of claims 1 to 4, wherein the first part (980b) of the coupling member (980) is provided with one or more circumferentially extending ribs (980d, e), which form a Watertight closure with the bushing (621).

7.

The apparatus according to any one of the preceding claims, wherein the coupling member (880; 980) is an insert (880; 980) separate from the reservoir and the reservoir can be connected with the insert (880; 980).

8.

The apparatus according to claim 7, wherein the insert (880; 980) is arranged to convert the bushing (621) for threaded connection with the outlet of the reservoir.

9.

The apparatus according to claim 8, wherein the tank outlet is connected to an internally threaded part (888a; 988a) of the insert (880; 980).

10.

 The apparatus according to claim 7 or claim 8 or claim 9, wherein the insert is a plastic molded part such as a nylon molded part.

eleven.

The apparatus according to any one of claims 7 to 10, wherein a set of interchangeable inserts (880; 980) are provided that allow the assembly of any one of the inserts (890; 980) selected to provide the bushing ( 621) of any desired connection formation.

12.

 The apparatus according to any one of claims 7 to 11, wherein the second part (887; 987) of the insert (880; 980) is provided with a cut-out part (887a; 987a) and the spray gun has a formation (686) externally to the bushing (621), which is received in the clipped part to inhibit the rotation of the insert (880; 980) in the bushing (621).

13.

The apparatus according to any one of claims 1 to 6, wherein the coupling member (880; 980) is integral with the outlet of the reservoir.

14.

 The apparatus according to any one of the preceding claims, wherein the reservoir is provided with a disposable container that can be discarded after use.

fifteen.

 The apparatus according to claim 14, wherein the reservoir comprises an outer container and an inner container, the inner container can be crushed as liquid is removed from the tank, and separated from the outer container so that the inner container can be removed and discarded after use.

16.

 The apparatus according to claim 15, wherein the outer container has a vent at the far end of the connection with the spray gun, to allow air to enter as, in use, liquid is removed from the inner container.

17.

 The apparatus according to any one of the preceding claims, wherein the spray gun consists of any one of a spray gun with gravity feed, with suction feed or with pressure feed.