CN1142830C - Apparatus for spraying liquids, and disposable containers and liners suitable for use therewith - Google Patents

Abstract

A spray gun(1)has a fluid reservoir(11)which contains a removable liner(13). The liner(13), which may be thermo/vacuum-formed from a plastics material, is a close fit within the interior of the reservoir and collapses as fluid is withdrawn from within the liner during operation of the gun. Preferably, the liner has a comparatively-rigid base and is capable of standing, unsupported, outside the reservoir. The side walls of the liner are preferably thin in comparison to the base and can be collapsed for disposal of the liner. The reservoir(11)has a removable lid(15)and is capable of standing, inverted, on its own so that it can be filled with fluid. The lid(15)also functions to secure the liner(13)in the reservoir and, at the end of a spraying operation, the lid(15)and the liner(13)are removed together from the reservoir(11)and discarded, thereby simplifying the cleaning of the spray gun.

Description

spray gun for spraying liquid

The present invention relates to containers, especially disposable containers, and to containers which can be used as liners. The invention also relates to devices for spraying liquids, such as spray guns, and in particular liquid containers or tanks for such devices.

Disposable containers have many uses in many different fields. For example, many items are packaged in disposable containers such as bags before or after purchase. When the disposable container is a plastic bag, shoppers often reuse the bag for another storage tank, such as a disposable liner for a waste hopper. In some cases, disposable liners are made specifically for use in otherwise reusable tanks: in those cases, the liner can be used to help discard the contents of the tank (such as a liner in a waste hopper conditions); protect the tank or its contents; or facilitate, or even eliminate, the cleaning of the tank.

A substance in which a substance such as glue, paint or plaster of paris is mixed or contained for use, from the point of view of facilitating the cleaning of the tank after use and of preventing the contamination of the substance in the container by residues of other substances The use of a liner in the tank is particularly advantageous. Tanks in which paint is mixed or contained for use must, for example, be cleaned to ensure that other trace substances do not alter the color or quality of the paint. As mentioned above, this is especially important when a vehicle is to be repainted to match the original paint color. To prevent contamination when mixing paint, disposable waxed paper cups are often used as mixing containers in body shops, especially when only a small amount of paint is required. Another approach proposed in US Pat. No. A-4,383,635 involves providing a disposable container which is housed in a reusable frame tank for use.

In the field of spray guns, it has been proposed for various reasons that a disposable liner should be used in the tank of this spray gun (see U.S. Patents US-A-3,211,324, 3,255,972, 4,151,929, 4,951,875 and 5,143,294 and European Patent EP- A-0678334). Generally, spray guns for spraying liquids (such as paints, garden chemicals, etc.) are familiar and usually include a storage tank containing the liquid to be treated and a dispenser through which the liquid is dispensed under pressure under the control of a trigger mechanism. of the nozzle. The liquid can be delivered by gravity from the tank, and/or it can also be carried in a stream of compressed fluid, such as air or water, fed to the spray gun from an external source.

When a user wishes to change the fluid in the reservoir of a spray gun, it is usually necessary to clean the spray gun quite thoroughly to ensure that no traces of old fluid remain in the spray gun to contaminate the new fluid. This is especially the case with paint spray guns, because any old paint remaining in a spray gun will affect the color of a fresh batch of paint to the point where it cannot be used anymore. Problems arise in body shops where it is often required that the paint being applied be strictly matched to the existing paint product. Or, if paint residue dries in the spray gun, it can flake off and contaminate the freshly mixed paint. However, cleaning the spray gun is a relatively complicated and time-consuming work. Furthermore, in the case of paint spray guns, relatively large quantities of solvents are used for cleaning, which should be disposed of carefully and discarded for environmental reasons. In this way, the cost of painting can be greatly increased. It has been suggested (eg see the above-mentioned European patent EP-A-0678334) to use a disposable liner in the oil tank of a spray gun; this simplifies cleaning of the spray gun and reduces the amount of solvent required.

The invention provides a spray gun, which comprises: a fluid tank; a detachable and foldable inner liner, whose shape is consistent with the shape of the inner wall of the tank before injecting fluid into the inner liner; fit on the inner wall of the tank; and, a nozzle for distributing fluid from the inner liner. Wherein, during operation of the spray gun, the liner folds when fluid is expelled from the liner.

The designation "collapsible" used herein with respect to the side wall of a container/liner according to the present invention indicates that the side wall can be deformed such that under the condition of being applied with moderate pressure (i.e. hand pressure), The rim of the container can be pushed towards the bottom of the container without the side walls being damaged.

The term "paint" is used herein to include all forms of paint-containing materials which can be applied to a surface using a spray gun, whether or not the materials are intended to color the surface. The designation includes, for example, primers, basecoats, varnishes and similar materials.

For purposes of illustration only, embodiments of the invention will be described below with reference to the accompanying drawings. in:

Fig. 1A and Fig. 1 B represent the perspective view of the spray gun of prior art, and wherein Fig. 1A shows the cover that is unloaded, and the cover of the spray gun shown in Fig. 1 B has been unloaded, can pour into paint inwardly;

Fig. 2 shows the parts of another form of oil tank of the spray gun of Fig. 1A and Fig. 1B in an exploded state;

Figure 3 shows the fuel tank of Figure 2 assembled, with a joint connecting the tank to a spray gun;

Fig. 4 is a longitudinal sectional view through the oil tank and joint of Fig. 3;

Figure 5 shows the tank of Figure 4 connected to a spray gun;

Fig. 6 represents the oil tank of Fig. 4 being used on a spray gun;

Figure 7 shows the parts of the oil tank of Figure 4 removed after use;

Figure 8 is similar to Figure 2 but shows a modified form of the tank;

Fig. 9 is a longitudinal sectional view of another shape of the lid of the oil tank of Figs. 2 to 4 and Fig. 8;

Figure 10 is similar to Figure 2, showing another modified oil tank;

Figure 11 is a longitudinal section through a portion of the paint can of Figure 10;

Figure 12 shows a spray gun similar to that shown in Figures 1A and 1B, but in a different form of paint can;

Figure 13 shows the spray gun shown in Figure 2 with a modified paint can;

Figure 14 shows a modification to the paint can of the spray gun of Figure 3;

Fig. 15 is similar to Fig. 3, has represented another form of paint can;

Figures 16 and 17 show two modifications of the element of Figure 15;

Figure 18 shows the use of a bracket for the paint can of Figure 15;

Figure 19 is a perspective view of a liner/container according to the present invention;

Figure 20 is a similar view showing the liner/container folded for disposal;

Fig. 21 (a) to (c) is a kind of schematic diagram of the method for making a lining for the paint can of Fig. 2 to 4 and Fig. 10;

Figure 22 represents a modification of the method of Figure 21;

Figure 23 shows a paint mixing water bottle (pitcher); and

Figure 24 shows a liner according to the present invention for use with the water bottle of Figure 23.

Figures 1A and 1B show a typical prior art paint spray gun of the gravity feed type. The spray gun 1 comprises a gun body 2, a handle 3 extending downward from the rear end of the gun body and a nozzle 4 located at the front end of the gun body. The spray gun is manually operated by a trigger 5 pivotally mounted on the side of the spray gun. A paint can or jug 6 containing paint or similar material to be discharged by the spray gun is located at the top of the gun body 2 and communicates with a compressed air channel (not visible in the figure) from a joint located at the lower end of the handle 3 7 extends to the nozzle 4 through the gun body. In use, the connector 7 is connected to a source of compressed air (not shown) so that when the user pulls the trigger 5, the compressed air is sent through the gun to the nozzle 4, carrying the air from the paint pot 6 under gravity. Paint and mist it. Then, paint just utilizes compressed air to spray from nozzle 4 like spray.

The paint that is contained in the paint pot 6 often will mix by hand (need to have an other container, as a pot for this reason), pour in the paint pot again after this. In order to ensure that there are no unwanted particles in the paint which would damage the smooth quality of the painted surface, the paint can often be poured into the paint jug 6 through a filter. The figure shows that the lid 8 of the paint pot 6 has been removed for this purpose, and that a conical filter 9 is generally located at the open end of the paint pot. The filter 9 shown is a disposable cone filter of a known type. The filter has non-porous sides and a screen portion 10 at the tip of the cone. After pouring into paint in this paint 6, take off filter 9 and it is discarded, and pot lid 8 is covered again. If the filter 9 is a reusable filter, like a spray gun, it should be thoroughly cleaned before using a different liquid (for example, a different color of paint, or a liquid with a different chemical composition). cleaning.

Figure 2 shows the components of another form of paint pot 11 that can be used in place of the paint pot 6 in the spray gun 1 shown in Figures 1A and 1B (or any similar spray gun). The assembled situation of this another form of paint pot 11 is shown in Fig. 3 and Fig. 4 (sectional view).

The paint pot 11 comprises an open container 12 which is about the same size as a prior art hand-held spray gun, has an air hole 12A in the bottom, and is provided with a disposable liner 13 . The liner 13 is shaped to correspond to (and closely fit) the inner wall of the container 12 and has a narrow lip 14 at the open end which is located on the top edge of the container. The container 12 also has a disposable lid 15 which is push fit over the open end of the liner 13 . The cover 15 has a central hole 16 (see Figure 4) from which extends a connecting tube 17, at one end of which an outward extension 18 is provided to form part of a bayonet connection. The hole 16 is covered by a filter 19 which can be pushed into the hole or formed as an integral part of the cover 15 . The lid 15 can be screwed onto the container by hand with an annular ferrule 20 pressed against the top of the lid to hold it securely in place.

The paint can 11 can be connected to the spray gun 1 by using a connection 21 shown in FIGS. 3 and (in section) FIG. 4 separate from the paint can. The joint 21 is a tubular member, forming another part of the bayonet connection inside its one end 22 to be connected to the connecting pipe 17 of the paint pot 11 . At the other end 23, the joint is shaped to match the shape of a standard connection (usually a thread) for a spray gun paint pot.

The already mentioned inner liner 13 of the paint pot 11 has a shape corresponding to the inner wall of the container 12 and has a narrow edge 14 at the top edge of the container at the open end. The liner is self-supporting, as described below, but is also collapsible, and preferably has a stiffer base 13A and thinner side walls 13B, so that when it is folded, it is formed by folding the side walls. Instead of the bottom, the fold along the longitudinal direction is achieved. Furthermore, the liner 13 has no pleats, corrugations, seams, joints or nodes, and no grooves at the internal connection of the side walls 13B to the bottom 13A. That type of liner will be described in more detail hereinafter with reference to FIGS. 19 and 20 . Further described below is the thermoforming process by which such an inner liner can be produced.

The container 12 of the paint pot 11 is made of a plastic, such as polyethylene or polypropylene, which can be made translucent (as shown in Figure 2) or opaque, and can be made into any suitable size. For use in conjunction with a paint spray, containers with a capacity of 250, 500 or 800 ml can generally be used, although other container sizes may be used if desired. The cover 15 can also be made of a plastic, such as polyethylene or polypropylene, which can be produced by an injection molding process. The cover can be translucent or opaque, and can also be tinted. Band 20 may be a molded plastic element, or a machined metal (eg aluminum) element. The joint 21 may be a frame metal element, for example made of aluminum and anodized.

To use the paint pot 11, the nipple 21 is connected (at end 23) to the spray gun in place. Then, the paint pot 11 is removed as shown in FIG. 2 , and the inner liner 13 is inserted into the container 12 . The paint is then placed in the container, the lid 15 is pushed into place and the hoop is tightened down to hold the lid in place. The top of liner 13 is sandwiched between lid 15 and container 12, and liner top edge 14 is sandwiched between the top edge of the container and collar 20 (as shown in Figure 4). Advantageously, the surface of the cap 15 is formed with a number of barbs (not visible in the figure) to fit and hold the top of the liner. Then, the spray gun 1 is turned upside down from its normal working position, so that the end of the connecting pipe 17 can be connected to the joint 21 (as shown in Figure 5), after this, the spray gun is turned back to its normal working position (as shown in Figure 5). 6), so that everything is ready to be used in the usual way. As the paint is driven from the liner 13, the side walls of the liner collapse due to the reduced pressure in the liner. The stiffer bottom of the liner retains its shape so that the liner collapses longitudinally rather than transversely, thereby reducing the possibility of paint pocketing and being left in the liner.

The user can choose to evacuate the air from the liner 13 before operating the spray gun 1, although this is not critical. However, this does increase the range of inclinations within which the spray gun will work satisfactorily since there is no risk of air entering the spray gun from the paint pot 11 . In order to evacuate the air from the liner 13, the trigger 5 of the spray gun should be activated while the spray gun is still in the position shown in FIG.

After use, when the spray gun is to be cleaned, the spray gun can be turned upside down again and the trigger briefly activated to retract the paint in the spray gun to the inner liner in the paint pot 11 . The paint pot 11 can then be removed from the spray gun by unloading the connection tube 17 from the adapter 21 (which remains on the spray gun at all times). The collar 20 is removed from the container 12, and the lid 15 is then pulled out, taking the collapsed liner 13 with it (as shown in Figure 7). The lid (including the filter 19) and liner are discarded, leaving the container 12 and hoop 20 to be cleaned and ready for reuse after a clean liner and lid are installed. Only the spray gun itself needs to be cleaned, which greatly reduces the amount of solvent used. The risk of unused paint spilling from the paint pot 11 is also reduced since the inner liner 13 has been discarded and the lid 15 is put in place. In addition, since the liner is discarded in a collapsed state, the amount of space required to collect the used liner is reduced.

As described above, since the liner 13 fits precisely to the inner wall of the container 12 and has a smooth inner surface, it is possible to mix paint within the container 12 itself without using an additional container. That way, cleaning of additional mixing vessels can be avoided, further reducing the amount of solvent to be used. When using a gravity-fed spray gun with a conventional paint pot (as shown in Figures 1A and 1B), that possibility does not exist because the paint pot is open at both ends. The possibility of being perforated or damaged by tools used for mixing paint is minimized, firstly because the liner fits precisely on the inner wall of the container 12, and secondly because the self-supporting nature of the liner (described below) means that Less likely to get dragged around inside container during paint mixing. In order to facilitate the use of the container 12 as a mixing container, scale markings 25 (as shown in FIGS. 2 and 3 ) can be made on the outside wall of the container 12 to determine the amount of content in the container. The general shape of the container 12, and especially its flat bottom and its stability when it is in the orientation shown in Figure 2, make it particularly suitable for use as a mixing container whose translucent Sex is also beneficial at this point. But, if this container 12 is opaque, can form many slits on the side wall, can see the liner 13 through these slits, so that the user of spray gun estimates the amount of the paint in the paint jug 11 at any time .

When mixing paint in the container 12, the addition of a strainer 19 to the container lid 15 prevents unwanted particles in the paint from entering the spray gun. However, this can be omitted when the paint is coarse in texture, or, if mixed in another tank and filtered when sent to the lined container 12, or if the contaminants in the paint are not important. Filter.

Although the collar 20 of the paint pot 11 as described above is a separate part, it can also be integrated with the lid 15, in which case also a disposable part. As a further variant, the cover 15 (in conjunction with the connecting tube 17 and filter screen 19) can be formed as an integral part of the liner 13, to which it can be attached with a hinge 26 as shown in FIG. In that case, the cap need not fit within the mouth of the liner to ensure that the cap and liner together can be removed from the container after use; Staying in place is required. As yet another variation, the hoop 20 may be replaced by a strap that is fastened around the top of the paint pot 11 to hold the lid 15 and liner 13 in place. The strap can be secured to the paint pot 11, and can be formed, for example, of rubber, or be part of a metal band arrangement of the kind that clamps the tops of cylinders and bottles.

If a more reliable fit is required between the lid of Figures 2 to 4 and the inner liner 13, the lid can be a snap fit with the inner liner instead of the push fit as shown. The liner can, for example, form an inner circumferential rib and be positioned to fit within a corresponding groove on the adjacent surface of the lid.

As yet another variant, the push-in lid 15 may be replaced by a lid 27 having the form shown in FIG. 9 . This cover 27 is also pushed into the inside of the liner, but it is generally conical, and the shape of its upper end 28 corresponds to the shape of the end of the connecting pipe 17 shown in Figures 2 to 4, so that it can Mates with the same connector 21. The cover 27 has an outwardly extending flange 29 seated on top of the rim 14 of the liner and a formation 29A to engage the inner surface of the liner. The shaped portion 29A is shaped to allow the cap 27 to be pushed into the mouth of the liner and is also provided with a recess 29B accessible by the edge of the liner so that the cap is securely positioned. However, the form of the forming portion shown in FIG. 9 is not exclusive and many variations are possible, including barbs as described above with reference to the lid 15 of FIG. 4, for example. The cap 27 can be held in place on the container by a threaded ferrule similar to ferrule 20 which will sit on top of the cap's flange 29 . Cover 27 may include a filter similar to filter 19 of FIGS. 2-5. Alternatively, in each case, the filter may be substantially cylindrical in shape so that it can be inserted into the tubular portion of the cap from the end adjacent to the bayonet connection. In that case the shaping of the interior of the tubular portion of the cap should ensure that the filter remains in place when the spray gun is in use.

Figure 10 shows the components of a variant of the paint pot 30. Like the paint pot 11 of FIG. 2 , the paint pot 30 includes a container 12 and an inner liner 13 . In this case, however, the filter 19 of the paint pot 11 is formed as a separate element 31 having a diameter corresponding to the diameter of the container 12 and comprising a sealing gasket 32 along the circumference. In addition, the lid 15 and collar 20 of the paint pot of FIG. 2 are replaced by a generally conical lid 33 which is threadedly fitted on the container and has a similar shape to the connecting tube 17 in FIG. 3 at its upper end. Tubular extension 34 so that it can be fitted to the same joint 21 . By pushing the liner 13 inside the container 12, then placing the filter 31 on top of the container after pouring the paint into the container, and screwing the lid down to secure the filter 31 in place, the The paint pot 30 comes assembled. The rim 14 of the liner 13 and the sealing gasket 32 of the filter 31 are then sandwiched between the lid 33 and the container 12 (as shown in Figure 11 ), so that when the paint pot is attached to a spray gun and they are turned upside down for When in use, it can prevent the paint from leaking from the paint pot 30 .

By threading the ends of the tubular parts 17, 34 of the lids of the containers 11, 30, they can be fitted directly to standard paint pot attachments on the spray gun 1, thereby eliminating the need for an adapter 21.

Fig. 12 has shown a kind of spray gun of variant design, wherein the standard paint pot 6 of spray gun 1 is retained (seeing Fig. 1A and Fig. 1B), and is provided with a liner 35 that fits inside the paint pot, and preferably It extends into the connection with the gun body 2 of the spray gun and forms a liquid-tight seal with the gun body 2 by, for example, using a flexible O-ring (not seen from the figure) between the spray gun and the liner . At this point, the liner 35 will not collapse when the paint is removed (used) from the paint pot, and the liner 35 can be made of a relatively hard material to help position it in the paint pot 6 . Once in place, the liner 35 is held in place by a cap 8 screwed down on an outwardly extending rim 36 of the open end of the liner. The paint pot 6 of Fig. 12 is additionally provided with a generally conical filter 37, which is entirely made of screen material, and it is positioned in the inner liner 35 during use. The filter 37 like the liner 35 has an outwardly extending rim 38 which sits on top of the rim 36 of the liner and is likewise held in place by the lid 8 of the paint pot 6 .

Unlike the paint pot 11 of FIG. 3 , the paint pot 12 of FIG. 12 is to be filled with paint while being connected to the spray gun 1 . Liner 35 and filter 37 are put in place, pour into paint in the paint pot, cover lid again. During this operation, there is no risk of the filter being dislodged, since the filter is entirely made of mesh material, so the user can always see the paint level when pouring paint into the paint jug. The spray gun is now ready for use. All the paint dispensed by the spray gun passes through the filter 37, so there is no need to filter the paint when it is poured into the paint jug 6. After use, the filter 37 and liner 35 can be removed by removing the cover 8 . The liner 35 is discarded, and the filter 37 can also be discarded and cleaned, depending on whether it is disposable or not. The use of the inner liner 35 reduces the amount of solvent required for cleaning the spray gun 1, which can be further reduced by using a disposable filter 37.

The filter 37 may take any suitable shape, for example may have grooved sides to increase the effective surface area of the filter.

In a modified arrangement shown in FIG. 13 , liner 35 and filter 37 are combined into one unit 39 . At this point, discard the filter and liner together.

In each arrangement shown in FIGS. 12 and 13 , the liner 35 and the filter 37 can be removed from the paint pot 6 together with the lid 8 . In that case, the conventional cover 8 can be replaced by a disposable cover, so that the cover 8, liner 35 and filter 37 are discarded together.

The disposable unit 39 shown in Figure 13 can be modified so that it can replace the paint pot 6 of the spray gun 1 without fitting inside the paint pot. In that case, as shown in Fig. 14, the unit 39 can be provided as a sealed cylinder in which paint has been previously filled. Externally, the sealing cartridge 50 is similar to the paint pot 6 and can be connected to the spray gun 1 in the same way. However, since it is sealed, it must be perforated at its outlet end 51 and provided with, for example, an air hole at its other end to allow paint to flow into the spray gun. For example, the user may perforate the outlet end 51 of the cartridge 50 before attaching the sealed cartridge (with the outlet end uppermost) to the (inverted) spray gun. Alternatively, the spray gun 1 can be modified so that the outlet port 51 is automatically perforated when the seal cartridge 50 is connected to the spray gun. A vent hole is then formed on the other end 52 of the cartridge after it has been attached to the spray gun, i.e. the end of the cartridge can be manually punched or for example attached with an additional cap 53 which can be used when the cap is put in place For drilling holes in the sealing cylinder. Alternatively, an air vent that needs to be opened when the gun is ready for use can be preformed on the seal cylinder.

After use, the cartridge 50 is removed from the spray gun and discarded. Since the cartridge 50 contains a filter, the supplier can pour the paint into the cartridge without filtering it. However, the filter in canister 50 can be omitted if the paint is pre-filtered.

FIG. 15 shows a modified version of a paint pot 40 for a spray gun 1 which is completely disposable. The paint pot 40 is roughly similar to the paint pot 30 shown in FIG. 10 , except that the container 12 is replaced by a disposable container 41 to be described below, and the inner liner 13 is omitted.

The container 41 of FIG. 15 may be any conventional disposable container suitable for containing paint and attached to the lid 42 of the paint pot. For example, the container 41 may be formed from a thin plastic, preferably translucent plastic (as shown), so that the contents of the container can be seen, and preferably have markings 43 on the side walls to identify the container's amount of content. An air hole 44 is formed on the bottom of the container, and this air hole 44 can be closed if necessary in combination with some other devices. That means can be in the form of an adhesive tape (not shown) which can be peeled off to open the hole 44 and then glued on to close the hole when required. Alternatively, a reversible closure or some simple hand operated valve mechanism could be provided. The container 41 has an external thread at its open end for connecting to a cap 42 which is substantially similar to the cap 33 of FIG. A suitable connector can be used). The material used for the lid 42 can be the same as that of the container 41, and translucent materials can also be used as shown in the figure. A flat filter 45 , also disposable, extends across the mouth of the container 41 . The net 45 may be a separate piece and held around its circumference between the lid 42 and the container 41, or it may be formed integrally with the lid.

In order to use the paint pot 40, unload the lid 42 and the filter screen 45 from the container 41, then pour paint into the container 41 (carefully make the vent 44 on the bottom of the container close). As mentioned above, it is not necessary to filter the paint as it is poured into the container 41 where it can be mixed, thereby avoiding the need for another sump for this purpose. Then, put the cover 42 and strainer 45 back into place on the container 41, the cover 42 is attached to the (inverted) spray gun 1, then turn the spray gun upside down to return to its normal position, and open the vent hole 44 on the bottom of the container. The spray gun can now be used in the usual way. After the spraying operation is completed, the vent hole 44 is closed again, and the paint pot 40 is detached from the spray gun 1 and discarded. Only the spray gun remains to be cleaned. Before the paint pot 40 is removed, the spray gun 1 can be turned upside down again, and the trigger 5 of the spray gun is operated so that the excess paint remaining in the spray gun is returned to the paint pot. In either case, if sufficient paint remains in the paint pot 40, the paint pot can be resealed (rather than discarded) and used again.

Advantageously, the container 41 of the paint pot is configured so that it collapses after use. In some cases, cover 42 can also collapse. As an alternative, the cap 42 can be a reusable element and can be cleaned together with the spray gun. With that arrangement, the disposable container 41 can be supplied in the form of a cylinder previously filled with paint and sealed, wherein the seal is closed with a lid, which is before the container is attached to the lid 42. Easy to remove. Filter screen 45 may be a disposable or reusable element. As yet another variant, the container 41 and lid 42 may be supplied together as a cartridge in which the upper end 42A of the lid closes the cartridge with a removable cap that can be removed before connecting the cartridge to the spray gun. Remove the cover. In this form, the cartridge is similar to cartridge 50 of FIG. 14 .

By suitable selection of the size of the lid 42 of the paint pot 40, a ready-to-use lid can be used in conjunction with containers 41 of different sizes. Then, in each case, the user will pick those containers that hold the most appropriate amount of paint. It is also desirable to provide a plurality of filters 45 with different mesh sizes so that the user can select the mesh size that is most suitable for the type of paint to be used. For the strainer 45, it is not important to have the form and/or position as shown in Figure 15: for example, it can have a conical shape as shown in Figure 16 and/or it can be located at the outlet of the cover 42 (as shown in Figure 17). Alternatively, the filter 45 may be omitted if the paint has been filtered before being poured into the container 41, or if the presence of contaminants in the paint is not important.

The cover 42 does not have to have the exact shape as shown in FIG. 15 , and can be replaced, for example, by a combination of a push-in cover and a screw-on collar as shown in FIG. 2 .

When container 41 (with or without lid 42) is provided in the form of a canister containing paint (or other coating material), in some cases it is desirable to house the paint/coating in a sealed container located within the canister. The foldable inner lining. If necessary, it is also desirable to keep the paints/coatings isolated from eg air or light until they are sprayed onto the surface to be painted. The vent hole 44 in the container 41 can then be kept open all the time, or it can be omitted if the container 41 itself is not airtight.

Depending on the shape of the container 41, it may be desirable to provide a bracket on which the container can be mounted to ensure that it cannot be tipped over. A suitable carrier 50 shown in FIG. 18 includes a container portion 51 which is similar in shape to container 41 but slightly larger and provided with an enlarged bottom 52 . The container 41 is placed within this container portion 51 to ensure that it remains in its upright position when being filled with paint and/or connected to the spray gun 12 .

Although the above description refers to a paint spray gun, it will be appreciated that it is applicable to other types of spray guns including, for example, spray guns that are connected to water hoses (rather than air supply lines) for spraying substances such as garden chemicals. The description also applies to suction-feed guns, where the liquid outlet from the sump is at the top of the sump when the gun is in use, by means of compressed air or other belts flowing through the gun. The action of hydraulic fluid draws liquid from the storage tank through a liquid supply pipe. In that case, when the tank is provided with a liner, the liner and/or the delivery tube should be constructed so that the liner can be folded without blocking the delivery tube. For example, a short delivery line can be used to remove all air from the liner before using the gun. Alternatively, a flexible delivery tube can be used which can be folded together with the liner. As yet another variant, a modified liner without a rigid base can be used, which is collapsed (folded) in a different way than the liner 13 of FIG. 2 . As with a gravity-feed spray gun, since the tank of a suction-feed gun is not inverted during use, vent holes in the tank can be omitted as long as there is a distance between the tank and the gun. It is sufficient that the joint allows air to enter the space between the tank and the liner.

Look back at the paint pot 11 of Fig. 2 again now, and describe in detail lining 13 and the method for making it useful. Liner 13, shown respectively in Figures 19 and 20, is preferably transparent and is thermally formed from a single piece of plastic, preferably polyethylene or polypropylene. The shape of the liner is determined by the interior shape of the container 12 . The relatively stiff bottom 13A is circular, similar to the interior of the container 12, and the liner 13 is generally cylindrical, but tapers slightly from the mouth towards the bottom 13A. Like the base, the edge portion 14 is also relatively rigid, but its side walls 13B are flexible, allowing it to be folded as described above. Nevertheless, the liner 13 can stand unsupported on the bottom 13A, while its side walls 13B are stretched and upright as shown in FIG. 19 . When the liner 13 is collapsed and folded, the relatively stiff base 13A retains its shape but moves towards the edge portion 14 of the liner due to the folding of the side walls 13B (as shown in Figure 20). The side wall 13B is folded in a manner similar to that of a plastic bag without breaking (eg, being split, torn, or shredded).

In one form, the liner has a height of about 110mm, a base diameter of about 78mm and a mouth diameter of about 86mm. The bottom has a thickness of about 400 microns, the edge portion 14 has a thickness of about 900 microns, and the side wall 13B has a thickness of about 150 microns. In another form, the liner has the same diameter as above and at its base and mouth, but has a thickness of about 300 microns at the base, about 200 microns at the edges, and about 50 to 250 microns at the sidewalls.

A method for making a liner as shown in FIG. 19 will be described below with reference to FIGS. 21(a)-(c).

A low-density polyethylene (LDPE) sheet 60 having a size of about 250 mm x 250 mm and a thickness of 0.5 mm is sandwiched around its periphery in a molding frame 61 of a vacuum forming machine. This LDPE material is commercially available, for example, from a company called Plastech Extrusions Ltd of Widnes, Cheshire, UK, and the vacuum forming machine used is from a company called C.R. Clarke and Company Limited of Ammanford, Carmarthenshire, Wales. FLB.725" type machine. However, it will be appreciated that any suitable plastic can be used and the method can be carried out using any suitable heat/vacuum forming machine.

After the thin plate 60 is put in place, a row of heaters 62 of the vacuum forming machine is moved to an upper position above the thin plate (as shown in FIG. bent state. The fact that the sheet has reached the proper temperature can be seen by its change from opalescent to transparent.

Then, the row of heaters 62 is removed and the template 63 is moved upwardly from below the sheet 60, bringing the die 64 into contact with the sheet to deform the sheet in an upward direction. At this point, the machine's vacuum pump is turned on to draw air from under the sheet 60 . The template 63 continues to move upward until it reaches the apex of its travel where it seals against the frame 61 holding the sheet 60 (as shown in Figure 21(b)). The shape of the mold 64 is consistent with the shape of the inner wall of the container 12 of the spray gun paint pot 11.

The vacuum pump continues to work, the template is sealed to the frame 61, and the pressure difference formed between the upper and lower sides of the sheet 60 causes the sheet 60 (which has been in contact with the top of the mold 64) to contact the sides of the mold 64 downwards ( See Figure 21(c)). Next, the template 63 leaves the cooled sheet 60 to leave a molded portion 65 having the desired shape of the liner 13 without folds, waves, seams, joints or nodes, or at the edges of the side walls 13B and bottom 13A. Any grooves in the connection. After the thin plate 60 comes out from the frame 61, the mouth of the molded part 65 will be trimmed to form the edge 14 of the lining 13. The position at which the sheet 60 is trimmed at this step defines the width of the edge portion 14 and can be adjusted as desired.

From the above method it is known that a molded portion 65 (and thus the liner 13) is bent, wherein that portion of the plastic sheet 60 which contacts the sides of the mold 64 during the forming process is significantly more pronounced than the portion which contacts the top of the mold. Thin. This method is different from a conventional vacuum forming process, the purpose of which is to eliminate the difference in the thickness of the molded part 65 as long as possible. For this reason, the process will include applying air pressure after step (a) of FIG. Such an additional step under the heated sheet 60 causes the template 63 to assume an arched shape before it is sealed to the frame 61: when the sheet is in contact with the mold 64 at step (c) of FIG. 21 , its thickness is relatively uniform . Generally in the process shown in Figure 21, for a given size of sheet 60, the size of the mold 64 has a greater effect on the thickness of the sides of the final lining 13 than on the bottom. In other words, if the size of the mold 64 is increased, the final liner 13 will be approximately equal in thickness at the bottom, but much thinner on both sides of the liner. On the other hand, if the size of the mold is reduced, it can be found that longitudinal creases appear on both sides of the inner liner 13 when the size of the mold is reduced to a certain value.

If it is required to further reduce the thickness of that part of the veneer 60 that is in contact with the both sides of the mold 64 in the step (c) of Fig. 21, then when the veneer 60 is clamped in the frame 61 of the forming machine, the veneer 60 can be placed Between two thin metal plates 66 (FIG. 22), each metal plate 66 is provided with a hole 67 at the position of the mold 64, the size of which is larger than the largest cross-section of the mold. The two panels 66 are also clamped in the frame 61 and the method of FIG. 21 is repeated. The effect of the plate 66 is that only the central portion of the sheet 60 is directly exposed to the heaters 62 at this time, and the sheet is pulled on the mold 64 as the mold 64 moves upwards (this time through the holes 67 on the plate 66). That way, less of the sheet 60 is used to form the mold portion 65, and the final liner 13 will have a slightly thinner bottom 13A and edge 14 and much thinner side walls 13B. A comparable result was also obtained using only the upper metal plate 66 as described in FIG. 22 .

As a modification of the method shown in FIG. 22, the plastic sheet 60 may be a disk-shaped plate whose periphery is clamped between two metal plates 66. As shown in FIG. Depending on the size of the disc, the clamped periphery can form the edge 14 of the lining 13, where no excess material has to be trimmed.

It has been found that when a liner 13 produced by a method described with reference to Figures 21 and 22 is used in the spray gun sump of Figure 2, the liner 13 will collapse as shown in Figure 20. The liner can also be collapsed when the bottom 13A of the liner 13 is pushed toward the edge 14 by hand. It has also been found that usually the liner can stand unsupported on its bottom 13A, although this feature is not very important for using the liner in the spray gun tank 11, it is also useful for storage purposes. The lining has no folds, corrugations, seams, joints or knuckles, and no grooves at the inner junction of the side walls 13B and the bottom 13A: therefore, nothing can get pinched inside the lining. Of course, the bottom 13A of the liner takes up some space at the bottom of the container 12 of the spray gun sump 11, so the positioning of the graduated markings on the wall of the container 12 takes this into account.

Although the use of the liner 13 of FIG. 19 has been described, particularly on the paint pot 11 of FIG. 2, the same or similar articles may be used in other ways (with appropriate changes in dimensions, if necessary). For example, an article as shown at 19 can also be used as a liner in many different shaped containers than a spray gun sump. It is often desirable to provide a tank with a disposable liner, for example, in order to keep it clean, to facilitate cleaning or to protect the tank or its contents. A liner as shown in Figure 19 can be used for any of the above-mentioned purposes, and is especially suitable for use on a storage tank in which materials can be mixed together, because there will be no part inside the liner where the materials will be mixed. Trapped without being mixed.

A product of the kind shown in Figure 19 could be used, for example, as a lining in a sump for mixing paint in a body shop, in which case it would give the Disposable beverage cups offer an attractive variation design. Before painting a repaired portion of a vehicle in a body shop, the repairer must mix a batch of paint of the desired color that matches the color of the surrounding portions of the vehicle. The volumes and weights of the various components used in mixing the paint lot must be accurately measured and then thoroughly mixed together in a suitable tank prior to use. Inadequate mixing, or if the sump is not absolutely clean, will affect the color/quality of the paint batch (and therefore, the quality of the repair).

To enable easy and efficient mixing of the paint, a liner as shown in FIG. 19 can be used together with a measuring container 70 as shown in FIG. 23 . The measuring container 70 is shaped like a drinking cup with a mouth 71 in a shaped rim 72 and a handle 73 . The side wall of this water cup is provided with many scale marks 74, to be able to measure the capacity of the content of this water cup. Using the method already described with reference to FIG. 21, a liner of the kind shown in FIG. 19 can be produced to precisely fit the inside wall of the cup 70. By utilizing such a liner, the components of a batch of paint can be mixed together in the water cup 70 without touching the water cup 70.

FIG. 24 shows a liner 75 suitable for use within the water cup 70 . The shape of the inner liner 75 is consistent with the shape of the inside of the water cup 70, and is generally similar to the inner liner 13 shown in Figure 19, except that the thicker outwardly extending edge portion 14 of the inner liner 13 is omitted, and the The side wall 76 of the liner 75 includes a contoured edge 77 that conforms to the rim portion 72 and the spout 71 of the cup 70 . Because the inner liner 75 is strictly fitted on the inner wall of the water cup 70, the possibility of being perforated by the mixing action when mixed in the water cup is minimized. In addition, since there is no place in the liner where debris can be trapped, it will not prevent proper mixing of all the ingredients that are measured and placed in the water cup. When the paint is mixed and poured from the cup 70 (for example, into a spray gun paint pot), the inner liner 75, which is preferably folded as shown in Figure 20, is removed and discarded, leaving the Only clean water glasses can be used again.

Since the bottom 78 of the liner 75 takes up some space at the bottom of the cup 70, this must be taken into account when positioning the scale marks 74 on the side walls of the cup. Depending on the shape of the cup 70, it may also be desirable to provide an extension at the top of the cup 75 that can be folded back over the rim 72 of the cup. Otherwise, or in addition, it is desirable that the liner 75 is sealed to the cup 70 during use, such as by some form of shaping of the liner and the cup, such that it fits closely to each other at the edges 77 and 72. together.

While it is desirable that the liner 75 of the water cup 70 should be collapsible so that it takes up less space after use, it is not absolutely necessary. Additionally, since the shape of the liner 75 is determined by the interior shape of the container to be used, there may be instances where the liner cannot stand unsupported outside the container.

As another variant, an article as shown in Figure 19 can simply be used as a container, in which case it is advantageous that although the flexibility of the wall 13B is comparable to that of a plastic bag, when the container is filled And thereafter can stand upright without support. The container can be of any suitable size and can be used to hold many different objects including, for example, powders and liquids, or simply be used as a variation of the plastic/paper bags supplied by retailers to customers. In each case, the container has the advantage that there is no place within it that can trap its contents. Depending on the contents of the container, it may be desirable to be able to close the mouth of the container, in which case some suitable form of closure can be provided. The closure may for example be an internal flange on the inside of the container around one half of the mouth and a mating groove also inside the container around the other half of the mouth into which the internal flange can be pressed to Close the container. The flexibility of the container wall 13B additionally allows the wall to be pressed down around the contents, reducing the air space within the container if required.

After use, when the container needs to be discarded, the side wall 13B is pushed toward the flange 14 to be folded with hands, so that the container (in the form shown in Figure 20 at this time) takes up less space when being discarded. few. As already mentioned, the side wall 13B can be folded in a similar manner to a plastic bag without destroying it (eg by tearing, tearing or shredding).

It will be appreciated that the article shown in Figure 19 has many other possible uses. The kind of liner of Fig. 19 can for example be used as a liner of a rubbish bin simply, at this moment, its advantage is that it can better fit the inner wall of this cylinder than a traditional bag-shaped liner, and Since it can stand upright on the bottom 13A, it is easier to handle when it is unloaded from the hopper. Some similar linings can also be used on hoppers or containers that contain materials that harden quickly (such as ash, wax or plaster): in some cases, such materials are actually mixed with a Hoppers are sold together, in which case the liner can be supplied included in the package. In some cases it may be appropriate to place a plurality of liners in place one above the other in place within a tank so that when one liner is removed the other is already in place. Furthermore, the walls of the tank need not be rigid since the container is intended to contain a liner, the container for example having the form of a frame to contain the liner.

Generally, in an article of the type shown in Figure 19, the bottom 13A will typically have a thickness of at least 25 microns, and more typically will have a thickness of at least 100 microns. Compared to the bottom 13A, the thickness of the sidewall 13B is so thin that it can be folded as described to facilitate disposal of the container/liner: typically the thickness of the sidewall 13B is less than half the thickness of the bottom 13A, and generally can be smaller than the bottom one-fifth of the thickness. Depending on the materials used and the intended use of the liner/container, the thickness of the sidewall 13A is typically less than 250 microns.

For some uses of an article such as that shown in Figure 19, the edge portion 14 is not mandatory and can be omitted (as in the case of the lining in Figure 24). If the edge portion 14 is not required, of course the thin plate 60 in Fig. 21(c) is trimmed immediately adjacent to the mouth of the molded portion 65. It has been found that the self-supporting properties of the liner/container are retained even if the edge portion 14 is omitted.

It should also be noted that the bottom 13A of the container/liner of the type shown in Figure 19 need not be circular but could take other shapes, such as rectangular or triangular. In the case of lining a tank, especially if the lining is required to fit the inner wall of the tank, the shape of the lining is defined by the shape of the tank. In some cases, the base need not be rigid.

It will be further understood that the method described in Figures 21 and 22 is not limited to the manufacture of liners in paint pots for spray guns, but may be adapted to manufacture liners/containers for other uses. It will be appreciated that this method requires the mold 64 to be slightly tapered and of the largest cross-section at its lower end (as shown in Figures 21 and 22) to allow the sheet 60 to be unloaded when the forming operation is complete. When the method is used to produce a liner which is required to fit the inner wall of a container, this requires that the container be tapered inwardly. The liner/container may be made of any suitable thermoplastic material capable of forming an impervious membrane to the material to be contained. In some cases it may be desirable to use a material in the form of a one-layer article. For some uses, such as food packaging, plastics with low air permeability are preferable. However, for most applications, polyolefins such as polyethylene and polypropylene are preferred because they are less expensive, easier to thermoform, and are inert to most aqueous and organic fluids.

Claims (12)

1. spray gun that spraying liquid is used, this spray gun comprises: a fluid slot; The one detachable and liner that can be folded, its shape is consistent with the shape of the inwall of this groove before injecting fluid to this inside liner, and it fits tightly on the inwall of this groove; And one distributes the nozzle from the fluid of this inside liner; Wherein, in this spray gun operating period, when fluid this liner when this inside liner is discharged is just folded up.

2. the spray gun that spraying liquid as claimed in claim 1 is used is characterized in that, comprises that also a setting is used for filtering the detachable filter that flows to the fluid of nozzle from inside liner.

3. the spray gun that spraying liquid as claimed in claim 2 is used is characterized in that filter bits is on storage tank.

4. the spray gun of using as each spraying liquid in above-mentioned all claims is characterized in that comprise a lid, this lid is positioned on the opening of storage tank, and at the periphery of this opening liner is fixed on storage tank.

5. the spray gun of using as the spraying liquid of claim 2 or 3 is characterized in that, comprises a lid, and this lid is positioned on the opening of storage tank, and at the periphery of this opening liner is fixed on storage tank, and wherein, filter can unload from storage tank with lid.

6. the spray gun that spraying liquid as claimed in claim 4 is used is characterized in that the outlet that flows to the fluid of nozzle from inside liner is formed on the lid.

7. the spray gun that spraying liquid as claimed in claim 4 is used is characterized in that liner can unload from storage tank with lid.

8. the spray gun that spraying liquid as claimed in claim 1 is used is characterized in that, this liner by a kind of thermoplastic through heat/vacuum forming; This liner has: a bottom and sidewall, and comparing this bottom with sidewall is hard, this sidewall is folded than Bao Bingneng compared with the bottom; And, a flat outward extending edge part, the shape of this edge part can make this edge part be located on the edge of an opening of this spray gun storage tank.

9. the spray gun that spraying liquid as claimed in claim 8 is used is characterized in that, compares with sidewall, and the edge part of this liner is hard.

10. the spray gun that spraying liquid as claimed in claim 8 is used is characterized in that, this edge part is obviously thicker compared with the sidewall of this liner.

11. the spray gun that spraying liquid as claimed in claim 8 is used is characterized in that, this liner does not stand on this bottom with having support, and its straight wall is on the spot extended.

12. the spray gun that spraying liquid as claimed in claim 8 is used is characterized in that, in this spray gun operating period, when this liner when this inside liner is discharged fluid longitudinal folding along it.

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