Spray gun for liquid compositions

Abstract

The present invention relates to a spray gun suitable for applying a liquid composition, such as an uncured or unhardened plaster composition, to a surface.

Description

[0001] Spray gun for liquid compositions

[0002] Technical field of the invention

[0003] The present invention relates to a device for applying liquid compositions to a surface.

[0004] Background of the invention

[0005] The application of a plaster material to a surface, including walls, can be hard and time-consuming work, since it is often necessary to use tools, such as filling knives, to ensure a homogenous distribution and an even thickness of the material. Plaster compositions are difficult to apply and often require some form of post processing before paint or wall coverings, such as wallpaper or the like, can be applied.

[0006] W02020020996 discloses a spray gun suitable for applying uncured or unhardened plaster composition to a surface. The spray gun comprises an inlet for reception of a plaster material, an outlet for delivery of the plaster material, at least one compressed-air inlet, and a first and a second compressed-gas nozzle. The outlet is designed as an elongated slot, and the first and second compressed-gas nozzles are arranged above and below the elongated slot. The first and second compressed-gas nozzles aid in directing and lifting the plaster material away from the elongated slot. However, this configuration has certain limitations when it comes to properly distributing the material over large surfaces and is only constructed to handle specific plaster compositions.

[0007] Description of the invention

[0008] It is one object of the present invention to provide a solution that solves the above-mentioned problem.

[0009] The inventor of the present invention has built a spray gun where the upper and lower air nozzles are equipped with multiple channels, each arranged in a preferable linear row. These rows of channels are aligned along the width of a first elongate outlet, which consists of a wide (the gap is broader than its height) gap for dispensing liquid material, preferably dense liquid material, such as an uncured or unhardened plaster composition, a waterproofing membrane composition, or a slurry coating composition.

[0010] The wide-gap nozzle serves as the main outlet for the liquid material, ensuring a uniform and consistent flow across a broad area. The rows of air channels on the upper and lower nozzles are strategically positioned to direct air streams along the edges and across the width of the gap. This arrangement ensures that the air envelops the plaster flow evenly, improving atomization and aiding in precise, wide-surface coverage.

[0011] The inventor of the present invention has also built a spray gun where the outlet can be adjustably directed relative to the shaft and towards a surface such that the user at all times can use and hold the spray gun in an ergonomically favorable position.

[0012] The spray gun can feed the liquid material in a direction away from the spray gun and at the same time provide an air lift for the liquid material, such as an uncured or unhardened plaster composition. The liquid composition may also be a waterproofing membrane composition, such as a wet-room waterproofing membrane composition.

[0013] One aspect relates to a spray gun adapted for applying a liquid composition to a surface, the spray gun comprising:

[0014] - a hollow shaft part with a first inlet adapted for reception of a liquid composition, preferably an uncured or unhardened plaster composition;

[0015] - a housing in liquid communication with said shaft part and with a first elongate outlet adapted for delivery of the liquid composition to a surface;

[0016] - a first gas channel in gas communication with a first gas nozzle comprising an outlet at its tip, said first gas nozzle positioned at, such as above, a first side face of said housing; and

[0017] - a second gas channel in gas communication with a second gas nozzle comprising an outlet at its tip, said second gas nozzle positioned / arranged at, such as below, a second side face of said housing, opposite to said first side face.

[0018] Another aspect relates to a spray gun adapted for applying a liquid composition to a surface, said spray gun comprising:

[0019] - a hollow shaft part with a first inlet adapted for reception of a liquid composition, preferably an uncured or unhardened plaster composition, or a slurry coating composition, preferably a slurry mortar;

[0020] - a housing in liquid communication with said shaft part and with a first elongate outlet extending along the width of the housing and adapted for delivery of the liquid composition to a surface;

[0021] - a first gas channel in gas communication with a first gas nozzle comprising an outlet at its tip, said first gas nozzle positioned at a first side face of said housing; and

[0022] - a second gas channel in gas communication with a second gas nozzle comprising an outlet at its tip, said second gas nozzle positioned at a second side face of said housing, opposite to said first side face; wherein the first and the second gas nozzles are, respectively, arranged above and below the first outlet, wherein at least one of said first and second gas nozzles comprises a plurality of channels running along the length of the housing, said channels arranged side by side along the width of the first outlet and each with an outlet which opens into the tip of the respective gas nozzle. The term “spray gun” refers to a tool suitable for spraying / delivering a liquid uncured or unhardened plaster composition. In the present context, the term “uncured or unhardened plaster composition” refers to a mixture consisting of plaster, adhesive, and preferably water or other liquid acting as catalyst, curing agent, or solvent. The uncured or unhardened plaster composition preferably has a viscosity suitable for application with a spray gun according to the present invention. After application to a surface, e.g., after 15 minutes to 24 hours, the uncured or unhardened plaster composition will cure or harden and thereby become hard.

[0023] A surface may be a wall, e.g., a wall covered by insulation, such as stone wool, where it is desired to cover said stone wool with a plaster material. The plaster composition may thus be an alternative to mounting of molded plasterboards, which can be very hard work and often results in considerable waste material.

[0024] In one or more embodiments, at least one of said first or second gas nozzles are configured to be displaceable, such as slidable, and / or tiltable relative to the housing, or vice versa.

[0025] In one or more embodiments, at least one of said first or second gas nozzles are configured to be displaceable, such as slidable relative to the housing, or vice versa.

[0026] In one or more embodiments, at least one of said first or second gas nozzles are configured to be tiltable relative to the housing, or vice versa.

[0027] In one or more embodiments, the first and second gas nozzles are configured to be displaceable, such as slidable, and / or tiltable relative to the housing, or vice versa. In one or more embodiments, the first and second gas nozzles are configured to be displaceable, such as slidable, relative to the housing, or vice versa.

[0028] In one or more embodiments, the first and second gas nozzles are configured to be tiltable relative to the housing, or vice versa.

[0029] In one or more embodiments, at least one of said first or second gas nozzles comprises a plurality of channels each with an outlet which opens into the tip of the respective gas nozzle. In one or more embodiments, the plurality of channels each are of a length within the range of 5-100 mm, such as within the range of 10-90 mm, e.g., within the range of 15-80 mm, such as within the range of 20-70 mm, e.g., within the range of 25-60 mm, preferably within the range of 10-50 mm. The specific length of the channels makes the gas flow passing therethrough better directed than when the channels are e.g., 1 mm, i.e. , when only an outlet is present, which causes more disturbance of the gas flow. The channel’s outlet may have a width or diameter within the range of 0.1 -4 mm, such as 0.2-3 mm, e.g., 0.3-2 mm, such as 0.4-1.9 mm, e.g., 0.5-1.8 mm, such as 0.6-1.7 mm, e.g., 0.7-1 .6 mm, such as 0.8-1 .5 mm, e.g., 0.9-1 .4 mm, such as 1 .0-1 .3 mm, e.g., 1 .1 -1 .2 mm. In one or more embodiments, the gas nozzle comprises at least one channel per 5 mm length of the first outlet, such as 1 -25 channels per 5 mm length of the first outlet, e.g., 2-20 channels per 5 mm length of the first outlet, such as 3-15 channels per 5 mm length of the first outlet, e.g., 4-10 channels per 5 mm length of the first outlet.

[0030] Preferably, each first and second gas nozzle comprises outlets with a width within the range of 0.1 -4 mm, such as 0.2-3 mm, e.g., 0.3-2 mm, such as 0.4-1 .9 mm, e.g., 0.5-1 .8 mm, such as 0.6-1 .7 mm, e.g., 0.7-1 .6 mm, such as 0.8-1 .5 mm, e.g., 0.9-1 .4 mm, such as 1.0-1.3 mm, e.g., 1.1 -1.2 mm.

[0031] In one or more embodiments, at least one of said first or second gas nozzles are releasably fastened to the housing. In one or more embodiments, the spray gun further comprises a pair of brackets adapted for flanking the housing and for functioning as a support for at least one of said first or second gas nozzles.

[0032] In one or more embodiments, each bracket comprises a guide recess adapted for slidably receiving a part of the housing, thereby allowing the housing to be displaceable relative to at least one of said first or second gas nozzles.

[0033] In one or more embodiments, each bracket comprises a guide recess adapted for slidably receiving a part of one of said first or second gas nozzles, thereby allowing at least one of said first or second gas nozzles to be displaceable relative to the housing.

[0034] In one or more embodiments, at least one of said first or second gas nozzles comprises a rear end configured as a tubular construct spanning from one side to the other, said tubular construct comprising a first end and an opposite second end, and wherein each bracket is adapted for rotatably supporting one of said ends, thereby allowing said gas nozzle(s) to be tiltable relative to the housing.

[0035] In one or more embodiments, an end, such as the rear end, of said first or second gas nozzles further comprises a handle adapted for aiding in rotating the tubular construct within said brackets, thereby allowing said gas nozzle(s) to be tiltable relative to the housing.

[0036] In one or more embodiments, the spray gun further comprises a pivoting coupler, either connected to the shaft part, or positioned between the shaft part and the housing, said pivoting coupler being in liquid communication with said shaft part and said housing, thereby being able to direct a liquid composition, e.g., uncured, or unhardened plaster, there between. Preferably, the pivoting coupler is releasably fastened to either the shaft part or to the housing, more preferably to both. In the present context, the term “pivoting coupler” is to be understood as a coupling between the shaft part and the housing that functions as a pivot joint, but at the same time also serves to direct liquid uncured or unhardened plaster composition from the shaft part to the housing.

[0037] In one or more embodiments, the pivoting coupler comprises:

[0038] - a base part coupled to said shaft part;

[0039] - a moving part coupled to said housing and rotatably mounted to said base part; and

[0040] - a locking mechanism adapted for releasably fastening said moving part at a given position relative to said base part.

[0041] In one or more embodiments, the spray gun further comprises a pivoting coupler positioned between said shaft part and said housing, or positioned between two parts of the shaft part, said pivoting coupler being in liquid communication with said shaft part and said housing, thereby being able to direct a liquid composition there between.

[0042] In one or more embodiments, the pivoting coupler comprises:

[0043] - a base part coupled to said shaft part, or to a part of said shaft part;

[0044] - a moving part coupled to said housing, or to a part of said shaft part, and rotatably mounted to said base part; and

[0045] - a locking mechanism adapted for releasably fastening said moving part at a given position relative to said base part.

[0046] In one or more embodiments, the locking mechanism comprises:

[0047] - a plurality of cavities positioned at predetermined distances from one another; and

[0048] - a lock pin, roller, or ball adapted for partly fitting into each cavity, thereby making it at least more difficult for a user to rotate said moving part away from a given position relative to said base part; wherein said cavities are formed in said base part, and wherein said lock pin, roller, or ball is mounted on said moving part, or vice versa. When the lock pin is used, the user will need to pull the pin out of the cavity in order to turn the moving part relative to the base part, while when the roller or ball is used, the roller or ball will roll out of the cavity if sufficient force is applied by the user. Preferably, the lock pin, roller, or ball is spring activated, e.g., such that the spring will act on the lock pin or ball to force them into a cavity.

[0049] In one or more embodiments, the first and second gas channels are configured as flexible tubes, such as plastic tubes, adapted for bending in response to said housing being tilted relative to said shaft part.

[0050] In one or more embodiments, the spray gun further comprises a hollow extension shaft, wherein said shaft part is adapted for engagement with said extension shaft, and wherein said extension shaft is in liquid communication with said shaft part. As its name implies, the extension shaft serves to extend the shaft part. The length of the extension shaft may vary, but could preferably be from 10-500 cm. It could in some embodiments be telescopic.

[0051] In one or more embodiments, the first and second air channels are configured with airflow adjustment means, such as rotary valves, thereby being able to regulate the airflow through said first and second gas nozzles.

[0052] In one or more embodiments, the shaft part is configured with liquid composition flow adjustment means, such as rotary valves, thereby being able to regulate the flow of liquid composition through said first outlet.

[0053] In one or more embodiments, the extension shaft is configured with liquid composition flow adjustment means, such as rotary valves, thereby being able to regulate the flow of liquid composition through said first outlet. The spray gun may comprise activating, regulating, and / or deactivating means, e.g., configured as electronics with turn knobs or push buttons, that are configured to control the machine that delivers the liquid (uncured or unhardened) plaster composition to the spray gun. Such means may regulate the rate of delivery of the liquid plaster composition to the spray gun by sending a signal (wired or wireless) to the machine about a wanted rate of delivery. Another signal may be a standby signal (e.g., be ready but do not deliver) or a signal to turn off the machine. Similar activating, regulating, and / or deactivating means may be present on the spray gun to activate, regulate, and / or deactivate the compressed air delivery to the first and / or second air channel.

[0054] The size of the spray gun is not as such limited but may be adjusted to its specific use. E.g., a handheld spray gun may be smaller than a spray gun held by a robotic arm or a chassis. The different parts of the spray gun may therefore be sized accordingly.

[0055] In one or more embodiments, the first outlet has a length of at least 5 cm, such as at least 10 cm, e.g., at least 15 cm, such as at least 20 cm, e.g., at least 25 cm, such as at least 30 cm, e.g., at least 35 cm, such as at least 40 cm, e.g., at least 45 cm. The longer the first outlet is, the larger the treatment area. The width is also important to be able to provide an even flow of uncured or unhardened plaster composition. If too narrow, filler material may clot the first outlet, and if too wide, the amount of uncured or unhardened plaster composition will be too large to be carried by the air stream from the gas nozzles. Preferably, the first outlet has a width of at least 2 mm, such as within the range of 2-20 mm, e.g., at least 3 mm, such as within the range of 3-19 mm, e.g., at least 4 mm, such as within the range of 4-18 mm, e.g., at least 5 mm, such as within the range of 5-17 mm, e.g., at least 6 mm, such as within the range of 6-16 mm, e.g., at least 7 mm, such as within the range of 7-15 mm, e.g., at least 8 mm, such as within the range of 8-14 mm, e.g., at least 9 mm, such as within the range of 9-13 mm, e.g., at least 10 mm, such as within the range of 10-12 mm, preferably within the range of 3-15 mm. The upper range may be dependent on the size of spray gun.

[0056] In one or more embodiments, the first outlet has a length of at least 5 cm, and a width within the range of 2-20 mm, preferably within the range of 3-15 mm.

[0057] It is preferred that the cross-sectional area of the first outlet is identical to the cross-sectional area of the first inlet in order to avoid accumulation of the liquid composition in the housing of the spray gun. The cross-section of the inlet can be e.g., circle shaped, which will make it easy to attach to a hose.

[0058] In one or more embodiments, the first and the second gas nozzles are arranged in parallel above and under the first outlet and are preferably substantially smaller than the first outlet. The first gas nozzle may be configured as a single gas nozzle. In this situation, it is preferred that the width of the first gas nozzle is substantially the same as the width of the first outlet. The height of the first gas nozzle in this configuration is preferably narrower than the height of the first outlet, such as within the range of 0.1-4 mm, such as 0.2-3 mm, e.g., 0.3-2 mm, such as 0.4-1 .9 mm, e.g., 0.5-1 .8 mm, such as 0.6-1 .7 mm, e.g., 0.7-1 .6 mm, such as 0.8-1 .5 mm, e.g., 0.9-1 .4 mm, such as 1 .0-1 .3 mm, e.g., 1 .1-1 .2 mm. The second gas nozzle may be configured as a single gas nozzle. In this situation, it is preferred that the width of the second gas nozzle is substantially the same as the first outlet. The height of the second gas nozzle in this configuration is preferably narrower than the height of the first outlet, such as within the range of 0.1-4 mm, such as 0.2-3 mm, e.g., 0.3-2 mm, such as 0.4-1 .9 mm, e.g., 0.5-1 .8 mm, such as 0.6-1 .7 mm, e.g., 0.7-1 .6 mm, such as 0.8-1 .5 mm, e.g., 0.9-1 .4 mm, such as 1 .0-1 .3 mm, e.g., 1 .1-1 .2 mm. Preferably, both the first and second gas nozzles comprises a plurality of outlets, but the combination of a first gas nozzle with a single outlet may be combined with a second gas nozzles with a plurality of outlets, and vice versa. The distance between the gas nozzles and the first outlet may vary, but the first and second gas nozzles, respectively, are preferably positioned in line to provide a homogenous air flow. The first gas nozzle may be positioned at a different distance from the first outlet than the second gas nozzle. In one or more embodiments, the spray gun is configured to vary the distance between the first outlet and the gas nozzles. The parts of the spray gun holding the gas nozzles may, e.g., be moved relative to the part holding the first outlet.

[0059] In one or more embodiments, the gas nozzle comprises at least one outlet per 5 mm length of the first outlet, such as 1-25 outlets per 5 mm length of the first outlet, e.g., 2-20 outlets per 5 mm length of the first outlet, such as 3-15 outlets per 5 mm length of the first outlet, e.g., 4-10 outlets per 5 mm length of the first outlet. The number of outlets depends on their diameter or width. Preferably, each outlet has a diameter or width within the range of 0.1-4 mm, such as 0.2-3 mm, e.g., 0.3-2 mm, such as 0.4-1.9 mm, e.g., 0.5-1.8 mm, such as 0.6-1.7 mm, e.g., 0.7-1 .6 mm, such as 0.8-1.5 mm, e.g., 0.9-1 .4 mm, such as 1.0-1.3 mm, e.g., 1.1-1.2 mm.

[0060] Preferably, each first and second gas nozzle comprises outlets with a width within the range of 0.1-4 mm, such as 0.2-3 mm, e.g., 0.3-2 mm, such as 0.4-1 .9 mm, e.g., 0.5-1 .8 mm, such as 0.6-1 .7 mm, e.g., 0.7-1 .6 mm, such as 0.8-1 .5 mm, e.g., 0.9-1 .4 mm, such as 1.0-1.3 mm, e.g., 1.1 -1.2 mm.

[0061] In one or more embodiments, each first and second gas nozzle is positioned 2- 20 mm from the first outlet, such as 3-19 mm, e.g., 4-18 mm, such as 5-17 mm, e.g., 6-16 mm, such as 7-15 mm, e.g., 8-14 mm, such as 9-13 mm, e.g., 10-12 mm from the first outlet.

[0062] In this way, a spray gun is provided, which is suitable for application of an uncured or unhardened plaster composition to a surface, e.g., a wall, where the uncured or unhardened plaster composition may be sprayed onto this surface homogeneously. The homogeneous distribution of the uncured or unhardened plaster composition is secured by the elongated first outlet, which constitutes the outlet of the plaster material, and the first and second gas nozzles. Providing the spray gun with first and second gas nozzles enables it to manipulate the mentioned uncured or unhardened plaster composition. In a typical use situation, the user of the spray gun will make sure that the slot is horizontal, such that gravity will cause the uncured or unhardened plaster composition (without supply of compressed air) to fall like a waterfall out of the first outlet. By arranging the first gas nozzle under the first outlet (i.e. , in parallel to the first outlet in a use situation, where the elongate first outlet is horizontal), the compressed air supplied from said gas nozzle will cause the uncured or unhardened plaster composition to be lifted in such a way that it doesn’t just drop straight down after leaving the first outlet. In other words, the compressed air is delivered homogeneously along the first outlet. Furthermore, by providing the spray gun with a second gas nozzle arranged above the first outlet (under the same conditions as mentioned earlier), the said second gas nozzle will cause the uncured or unhardened plaster composition to be delivered with a certain power and speed such that the user may be able to position himself at a certain distance from (e.g., 1 m) the surface, which is to be covered by uncured or unhardened plaster composition. By adjusting the pressure of the compressed air, it is possible to adjust the thickness of the uncured or unhardened plaster composition being applied to the surface.

[0063] The described use of a spray gun provides an easy and economical way of applying a plaster material, thereby resulting in great saving of working time compared to know methods. Due to the homogeneous distribution of the uncured or unhardened plaster composition on the surface, the subsequently hardened plaster composition is suitable for further processing, e.g., application of paint or wall coverings.

[0064] In one or more embodiments, the first and second gas nozzles are angled towards each other.

[0065] In one or more embodiments, the first and the second gas nozzles’ outlets are angled towards each other, thereby ensuring that the streams of gas converge in front of the first outlet.

[0066] In one or more embodiments, the first and the second gas nozzles’ outlets are aligned with the first outlet.

[0067] In one or more embodiments, the first outlet has a lateral span that is substantially greater than its vertical height.

[0068] In one or more embodiments, the width of the first outlet is within the range of 3- 12 cm, preferably within the range of 4-8 cm. Here, the term “width” is to be considered equal to the lateral span of the outlet, as opposed to its vertical height.

[0069] In one or more embodiments, the first and / or the second gas nozzle comprises an antechamber, preferably funnel-shaped, leading to, e.g., opening into, a plurality of channels, each with an outlet which opens into the tip of the respective gas nozzle. The dimensions of the channels and outlets may be as discussed above.

[0070] In one or more embodiments, the antechamber is funnel-shaped, and tapers to its broadest point at the transition to the plurality of channels. These channels extend from the antechamber and terminate in individual outlets at the tip of the nozzle. The broadest section of the antechamber at the transition ensures optimal distribution of gas into the channels, maintaining consistent and controlled flow through each outlet. The broader transition point allows the antechamber to handle higher flow rates while ensuring consistent delivery across all channels. The gradual convergence of the gas flow and the broad transition may help minimize localized stress and turbulence, potentially increasing the lifespan of the nozzle. Another aspect relates to a system for applying a liquid composition, e.g., an uncured or unhardened plaster composition, to a surface, comprising:

[0071] - a spray gun according to the present invention; and

[0072] - a guide rail adapted for guiding the spray gun across a surface.

[0073] The guide rail is especially suitable for relatively large spray guns or at least for relatively large surfaces. The guide rail may be configured for releasably fastening to the ground and extending upwards relative to the ground.

[0074] Alternatively, or additionally, the guide rail may be releasably fastened to a ceiling.

[0075] In one or more embodiments, the spray gun is releasably fastened to a bracket being slidably connected to the guide rail.

[0076] In one or more embodiments, the guide rail comprises two elongate rods, and wherein the spray gun is directly or indirectly (e.g., through a bracket) connected thereto. The elongate rods may in one end be configured for releasably fastening to the ground and extend upwards relative to the ground. Alternatively, or additionally, the elongate rods may at another end be configured for releasably fastening to a ceiling. The pressure from the applied uncured or unhardened plaster composition released from the first outlet may be enough to slide the spray gun up the elongate rods. Alternatively, the bracket may be motorized and configured for crawling or sliding up and down the two elongate rods. Obviously, the hose delivering the uncured or unhardened plaster composition to the spray gun needs to be of a length suitable for the spray gun being able to slide up and down the two elongate rods.

[0077] In one or more embodiments, the elongate rods are telescopic. Alternatively, the elongate rods may be configured for connection to extension rods.

[0078] Another aspect relates to a system for applying a liquid composition, e.g., an uncured or unhardened plaster composition, to a surface, comprising:

[0079] - a spray gun according to the present invention; and

[0080] - a robotic arm adapted for guiding the spray gun across a surface.

[0081] Yet another aspect relates to a system for applying a liquid composition, e.g., an uncured or unhardened plaster composition, to a surface, comprising:

[0082] - a spray gun according to the present invention; and

[0083] - an apparatus for delivering a liquid composition, e.g., an uncured or unhardened plaster composition, to said spray gun, said apparatus comprising an outlet shaped as a tube part, said tube part being in liquid communication with said spray gun, wherein apparatus further comprises a pump means operably connected to said outlet and adapted for pumping liquid uncured or unhardened plaster composition through said outlet.

[0084] An apparatus for delivering liquid uncured or unhardened plaster composition to said spray gun may be of the type generally used within the art i.e. , comprising a mixing chamber, a pump, and an outlet. Slight modifications may be necessary to allow for mixing with adhesive, such as a pump, e.g., a dosage pump, adapted for pumping a dosage of adhesive into the mixing chamber of the apparatus, where water is normally also added / introduced to a plaster composition in powder form. The plaster composition in powder form may be mixed with an adhesive selected from the group consisting of: adhesives comprising an anionic copolymer dispersion of acrylic acid ester and styrene, polyvinyl acetate adhesives, polyvinyl alcohol adhesives, polyurethane adhesives, phenolic resin adhesives, cyanoacrylate adhesives, adhesives comprising an ethylene / vinyl acetate copolymer, adhesives comprising an ethylene-vinyl acetate-vinyl chloride emulsion, and mixtures thereof. The formed plaster composition may, e.g., comprise 6-15% by dry matter weight adhesive.

[0085] Another aspect relates to a system for applying an uncured or unhardened plaster composition to a surface, the system comprising: - a hose with a first end, and a second opposite end, said hose adapted for receiving and transporting an uncured or unhardened spray plaster composition;

[0086] - a plastering machine operatively coupled to the first end of said hose, and adapted for pumping an uncured or unhardened spray plaster composition through said hose;

[0087] - a spray gun according to the present invention and operatively coupled to the second end of said hose.

[0088] Yet another aspect relates to a method for applying an uncured or unhardened plaster composition to a surface, the method comprising:

[0089] - providing a plastering machine adapted for pumping an uncured or unhardened spray plaster composition through a hose operatively coupled thereto at a first end;

[0090] - operatively coupling a spray gun according to the present invention to a second end of the hose; and

[0091] - applying an uncured or unhardened plaster composition to a surface by activating the spray gun.

[0092] Still another aspect relates to the use of a spray gun according to the present invention for applying an uncured or unhardened plaster composition to a surface.

[0093] Yet another aspect relates to a system for applying a slurry coating composition, preferably a slurry mortar, to a surface, the system comprising:

[0094] - a hose with a first end, and a second opposite end, said hose adapted for receiving and transporting a slurry coating composition, preferably a slurry mortar;

[0095] - a plastering machine operatively coupled to the first end of said hose, and adapted for pumping a slurry coating composition, preferably a slurry mortar, through said hose;

[0096] - a spray gun according to the present invention and operatively coupled to the second end of said hose.

[0097] Another aspect relates to a method for applying a slurry coating composition, preferably a slurry mortar, to a surface, the method comprising:

[0098] - providing a machine adapted for pumping a slurry coating composition through a hose operatively coupled thereto at a first end;

[0099] - operatively coupling a spray gun according to the present invention to a second end of the hose; and

[0100] - applying a slurry coating composition to a surface by activating the spray gun.

[0101] Yet another aspect relates to the use of a spray gun according to the present invention for applying a slurry coating composition, preferably a slurry mortar, to a surface.

[0102] As used in the specification and the appended claims, the singular forms "a", "an", and "the" include plural referents unless the context clearly dictates otherwise. Ranges may be expressed herein as from "about" or "approximately" one particular value and / or to "about" or "approximately" another particular value. When such a range is expressed, another embodiment includes from the one particular value and / or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent "about", it will be understood that the particular value forms another embodiment.

[0103] It should be noted that embodiments and features described in the context of one of the aspects of the present invention also apply to the other aspects of the invention.

[0104] Brief description of the figures

[0105] Figure 1 illustrates a top view of the spray gun according to the invention. Figure 2 illustrates a bottom view of a part of a spray gun according to the invention.

[0106] Figure 3 illustrates a side view of the spray gun according to the invention.

[0107] Figure 4 illustrates a rear view of the spray gun according to the invention.

[0108] Figure 5 illustrates a schematic view of the spray gun according to the invention, where the shaft part is shown in two different positions relative to the housing.

[0109] Figure 6 illustrates a pivoting coupler for releasably coupling the shaft part and the housing according to the invention.

[0110] Figure 7 illustrates a transparent view of the first and second gas nozzles according to the invention, where the plurality of channels may be seen at their tip.

[0111] Detailed description of the invention

[0112] In the following, the invention will be described in detail by embodiments, which are not to be construed as limiting for the scope of the invention.

[0113] Figure 1 illustrates a spray gun 100 in a top perspective view. The spray gun comprises a hollow shaft part 104 with a first inlet 102 for the reception of an uncured or unhardened plaster composition. The shaft part 104 is connected to a hollow housing with a first outlet 103 for delivery of said uncured or unhardened plaster composition, i.e., the shaft part 104 and the housing 101 are in liquid communication. Furthermore, the spray gun 100 comprises a first gas / air inlet 111 and a second gas / air inlet 112. Each gas inlet 111 , 112 having substantially the same width as the first outlet 103, and a height that is narrower than the height of the first outlet 103 (the latter is shown in Figure 2). The mentioned gas inlets 111 ,112 lead the compressed gas into each first 120 and second 130 gas nozzles. Thereby, the gas pressure may be individually regulated through the first 120 and second 130 gas nozzle, preferably further regulated by turn valves (not shown). The gas nozzles 120,130 are arranged in parallel to the outlet 103, which is best illustrated in Figure 2. The first outlet 103 is, and may in general be, configured as an elongated slot, which is also best illustrated in Figure 2. The function of the spray gun 100 is to lead the uncured or unhardened plaster composition from the first inlet 102 through the housing 101 , and further on out of the first outlet 103. The first 120 and the second 130 gas nozzles are arranged above and under a part of the housing 101 , respectively, in order for the compressed air to flank the first outlet 103. In other words, a part of the housing 101 , especially the part near the first outlet 103, is placed between the first 120 and the second 130 gas nozzles. In this configuration, the gas nozzles 120, 130 are each configured with multiple outlets. The two gas nozzles 120,130 are independent of each other, which allows for manipulation of the functions of the spray gun 100. In the present embodiment, the two gas nozzles 120,130 are each configured with an antechamber (defined by the oblique side faces / edges of the gas nozzle, having an inverted funnel shape) leading into multiple straight channels (defined by the straight side faces / edges of the gas nozzle) that ultimately terminate in each outlet.

[0114] The first 120 and second 130 gas nozzles allow the uncured or unhardened plaster composition leaving the first outlet 103 to be lifted and carried forward (accelerated), thereby allowing the spray gun to apply the uncured or unhardened plaster composition from a certain distance and more efficiently. Accelerating the plaster material allows it to be spread over a larger area. Especially the second gas nozzle 130 contributes to a lift (opposing gravity), while the first gas nozzle 120 carries forward and / or accelerates the uncured or unhardened plaster composition in order for the uncured or unhardened plaster composition to be distributed in the most homogenous manner on a surface.

[0115] The opening / aperture (diameter, height, and / or width) 126, 136 of the gas nozzles’ 120,130 outlets may in some embodiments be mechanically varied, e.g., by means adapted to block a part of the opening, thereby allowing for an adjustment of the operation. As disclosed above, the first 111 and second 112 air channels may, alternatively or in combination, be configured with airflow adjustment means, such as rotary valves (not shown), thereby allowing for regulation of the airflow through the gas nozzles 120,130.

[0116] In the embodiments shown in Figures 1-4, the gas nozzles 120, 130 are configured to be displaceable and tiltable relative to the housing 101 to allow for regulation of acceleration of the uncured or unhardened plaster composition as well as the liftablity of the uncured or unhardened plaster composition. The airflow (gas flow) may be varied by regulating the distance of the gas nozzles’ 120,130 outlets 126, 136 from the housing’s 101 first outlet 103. In Figures 1 and 2, the front end 124, 134 of the gas nozzles 120,130 are shown in an extended configuration, and in Figure 3, the front end 124, 134 of the gas nozzles 120,130 are shown in a retracted configuration, relative to the housing’s 101 first outlet 103. The spray gun further comprises a pair of brackets 140A, 1406 adapted for flanking the housing 101 and for functioning as a support for both the first 120 and the second 130 gas nozzles. The gas nozzles 120, 130 comprises a rear end 122, 132 configured as a tubular, here cylindrical, construct 122, 132 spanning from one side of the spray gun to the other. The tubular construct comprises a first end and an opposite second end. One of the ends are in gas communication with the first 111 or second 112 air channel. Each bracket 140A, 1406 is adapted for rotatably supporting each end of the tubular construct 122, 132, thereby allowing the gas nozzles 120, 130 to be tiltable relative to the housing 101. The rear end (here, the tubular construct 122, 132) of the gas nozzles 120, 130 comprises a handle 128, 138 adapted for aiding in rotating the tubular construct within said brackets 140A, 1408, thereby allowing the gas nozzle(s) 120, 130 to be tiltable relative to the housing 101. This configuration allows for an adjustment of the direction of flow of liquid composition away from the first outlet 103.

[0117] Furthermore, each bracket 140A, 1406 comprises a guide recess 142, 144 adapted for slidably receiving each end of the tubular construct 122, 132, thereby allowing the first 120 and second 130 gas nozzles to be displaceable relative to the housing 101 . The airflow (gas flow) may thereby be varied by adjusting the distance of the gas nozzles’ 120,130 outlets 126, 136 from the housing’s 101 first outlet 103. The guide recess 142, 144 also acts as support for each end of the tubular construct 122, 132, and is here configured such that the ends can be rotated therein. The guide recess 142, 144 is here shown holding a spring 146 adapted for resiliently supporting the end of the tubular construct 122, 132 within the guide recess 142, 144. Furthermore, a turn knob 150 (more generally, a displacement means) is operatively mounted into the guide recess 142, 144, such that the position of the end within the guide recess 142, 144 can be altered by turning the turn knob 150 back and forth. This configuration also keeps the specific rotation of the ends in place.

[0118] Both the gas nozzles 120, 130 are here shown releasably fastened to the housing 101 by means of a screw bolt and a recess formed in the brackets 140A, 1406. Hence, the gas nozzles 120, 130 are indirectly mounted to the housing 101 via the brackets 140A, 1406.

[0119] The housing 101 may in some embodiments be tiltably adjustable relative to a part 104B of the shaft part 104, or relative to an extension shaft (not shown). In Figure 5, it is illustrated how a part 104B of the shaft part 104 may be placed in two different positions relative to the housing 101 , here shown by the aid of a pivoting coupler 105 positioned between two parts 104A, 104B of the shaft part 104 and the housing 101. The gas nozzles 120, 130 are shown configured according to a different embodiment than shown in Figures 1-4, but both embodiments are suitable for use in connection with the pivoting coupler 105.

[0120] The other shaft part 104A is directly coupled to the housing 101 .

[0121] Figure 6 illustrates an exemplary pivoting coupler 105 for releasably coupling two shaft parts 104A, 104B (not shown). The pivoting coupler 105 is in liquid communication with the shaft parts 104A, 104B. This makes it capable of directing liquid uncured or unhardened plaster composition there between. The disclosed pivoting coupler 105 comprises a base part 106, and a moving part 107. The base part 106 is adapted for being coupled to one shaft part 104A, and the moving part 107 is adapted for being coupled to the other shaft part 104B. In principle, this could also be done the other way around, but the present configuration makes it easier to grasp the housing 101 to rotate it relative to the shaft part 104. Obviously, the moving part 107 is rotatably mounted to the base part 106. The joint between the two may preferably be sealed against leakage of liquid uncured or unhardened plaster composition by a rotary sealing member (not shown). A locking mechanism 108,109 is present to releasably fasten the moving part 107 at a given position relative to the base part 106. The locking mechanism comprises a plurality of cavities 108 (here eight are visible) positioned along an arc-shaped line at predetermined distances from one another. Furthermore, the locking mechanism comprises a ball housing 109 comprising a ball (not shown) adapted for partly fitting into each cavity 108, thereby making it difficult for a user to rotate the moving part 107 away from a given position relative to the base part 106. This embodiment allows the user to operate the spray gun without worrying that the moving part 107, and hence the housing 101 , will dislocate from its position during use. At the same time, the locking mechanism allows the user to turn the moving part 107 relative to the base part 106 when needed with the use of appropriate force, thereby letting the ball enter into another one of the cavities 108. This operation may be eased if the ball is spring activated.

[0122] Figure 7 illustrates a transparent view of the first and second gas nozzles according to the invention, where the plurality of channels may be seen at their tip. The multiple channels are arranged in a linear row. These rows of channels are aligned along the width of the first elongate outlet (not shown).

[0123] References

[0124] 100 Spray gun

[0125] 101 Housing

[0126] 102 First inlet

[0127] 103 First outlet

[0128] 104 Shaft part

[0129] 105 Pivoting coupler

[0130] 106 Base part

[0131] 107 Moving part

[0132] 108 Cavity

[0133] 109 Ball housing

[0134] 111 First air inlet

[0135] 112 Second air inlet

[0136] 120 First gas nozzle

[0137] 122 Rear end

[0138] 124 Front end

[0139] 126 Outlet

[0140] 128 Handle

[0141] 130 Second gas nozzle

[0142] 132 Rear end

[0143] 134 Front end

[0144] 136 Outlet

[0145] 138 Handle

[0146] 140 Bracket

[0147] 142 Guide recess Guide recess Spring Turn knob Extension shaft, straight / angled

Claims

Claims1 . A spray gun (100) adapted for applying a liquid composition to a surface, said spray gun (100) comprising:- a hollow shaft part (104) with a first inlet (102) adapted for reception of a liquid composition, preferably an uncured or unhardened plaster composition, or a slurry coating composition, preferably a slurry mortar;- a housing (101 ) in liquid communication with said shaft part (104) and with a first elongate outlet (103) extending along the width of the housing (101 ) and adapted for delivery of the liquid composition to a surface;- a first gas channel (111 ) in gas communication with a first gas nozzle (120) comprising an outlet at its tip, said first gas nozzle (120) positioned at a first side face of said housing (101 ); and- a second gas channel (112) in gas communication with a second gas nozzle (130) comprising an outlet at its tip, said second gas nozzle (130) positioned at a second side face of said housing (101 ), opposite to said first side face; characterized in that the first (120) and the second (130) gas nozzles are, respectively, arranged above and below the first outlet (103), wherein at least one of said first (120) and second (130) gas nozzles comprises a plurality of channels running along the length of the housing (101 ), said channels arranged side by side along the width of the first outlet (103) and each with an outlet (126, 136) which opens into the tip of the respective gas nozzle (120, 130).

2. The spray gun according to claim 1 , wherein the first (120) and the second (130) gas nozzles’ outlets are angled towards each other, thereby ensuring that the streams of gas converge in front of the first outlet (103).

3. The spray gun according to any one of the claims 1-2, wherein the first (120) and the second (130) gas nozzles’ outlets are aligned with the first outlet (103).

4. The spray gun according to any one of the claims 1-3, wherein the first outlet (103) has a lateral span that is substantially greater than its vertical height.

5. The spray gun according to any one of the claims 1-4, wherein the width of the first outlet (103) is within the range of 3-12 cm, preferably within the range of 4-8 cm.

6. The spray gun according to any one of the claims 1-5, wherein at least one of said first (120) or second (130) gas nozzles are configured to be tiltable relative to the housing (101 ).

7. The spray gun according to any one of the claims 1-6, wherein at least one of said first (120) or second (130) gas nozzles are releasably fastened to the housing (101 ).

8. The spray gun according to any one of the claims 1-7, further comprising a pair of brackets (140A, 1406) adapted for flanking the housing (101 ) and for functioning as a support for the first (120) and second (130) gas nozzles.

9. The spray gun according to claim 8, wherein each bracket (140A, 1406) comprises a guide recess adapted for slidably receiving a part of the housing (101 ), thereby allowing the housing (101 ) to be releasably fastened to said first (120) and second (130) gas nozzles.

10. The spray gun according to any one of the claims 1-9, wherein the plurality of channels each with an outlet (126, 136) which opens into the tip of the respective gas nozzle (120, 130) each are of a length within the range of 5-100 mm, preferably within the range of 10-50 mm.11 . The spray gun according to any one of the claims 1 -10, further comprising a pivoting coupler (105) positioned between said shaft part (104) and said housing (101 ), or positioned between two parts of the shaft part (104), said pivoting coupler (105) being in liquid communication with said shaft part (104) and saidhousing (101 ), thereby being able to direct a liquid composition there between.

12. The spray gun according to claim 11 , wherein said pivoting coupler (105) comprises:- a base part (106) coupled to said shaft part (104), or to a part (104A, 104B) of said shaft part (104);- a moving part (107) coupled to said housing (101 ) , or to a part (104A, 104B) of said shaft part (104), and rotatably mounted to said base part (106); and- a locking mechanism adapted for releasably fastening said moving part (107) at a given position relative to said base part (106).

13. A system for applying an uncured or unhardened plaster composition to a surface, the system comprising:- a hose with a first end, and a second opposite end, said hose adapted for receiving and transporting an uncured or unhardened spray plaster composition;- a plastering machine operatively coupled to the first end of said hose, and adapted for pumping an uncured or unhardened spray plaster composition through said hose;- a spray gun according to any one of the claims 1-12 operatively coupled to the second end of said hose.

14. A method for applying an uncured or unhardened plaster composition to a surface, the method comprising:- providing a plastering machine adapted for pumping an uncured or unhardened spray plaster composition through a hose operatively coupled thereto at a first end;- operatively coupling a spray gun according to any one of the claims 1-12 to a second end of the hose; and- applying an uncured or unhardened plaster composition to a surface by activating the spray gun.

15. Use of a spray gun according to any one of the claims 1 -12 for applying an uncured or unhardened plaster composition to a surface.

16. A system for applying a slurry coating composition, preferably a slurry mortar, to a surface, the system comprising:- a hose with a first end, and a second opposite end, said hose adapted for receiving and transporting a slurry coating composition, preferably a slurry mortar;- a plastering machine operatively coupled to the first end of said hose, and adapted for pumping a slurry coating composition, preferably a slurry mortar, through said hose;- a spray gun according to any one of the claims 1 -12 operatively coupled to the second end of said hose.

17. A method for applying a slurry coating composition, preferably a slurry mortar, to a surface, the method comprising:- providing a machine adapted for pumping a slurry coating composition through a hose operatively coupled thereto at a first end;- operatively coupling a spray gun according to any one of the claims 1-12 to a second end of the hose; and- applying a slurry coating composition to a surface by activating the spray gun.

18. Use of a spray gun according to any one of the claims 1 -12 for applying a slurry coating composition, preferably a slurry mortar, to a surface.

Images