Patent Application
20130062430
The invention relates to a portable paint spraying system and to a method for processing quantities of paint or coating materials or varnishes to be sprayed.
The processing of quantities of paint by spraying technology is well known from the prior art. Due to the legal requirement imposed on paint manufacturers to produce paints having as few solvents as possible, or even to completely omit certain types of solvents, the problem arises both for the paint industry and for the paint-processing industry that quantities of paint having a lower solvent content or having alternative solvents, for example, paints on the basis of water, have to be processed, wherein the surface which is to be produced and is intended to be obtained with the paint, as before, must not permit any step back in terms of processing quality.
One possibility of improving the application of paint to a surface and of achieving an increased surface coating quality without appropriate solvents, which frequently are highly volatile and also are irritating or even poisonous, additionally having to be admixed with the paint, consists in reducing the viscosity of the quantity of paint to be processed by the latter, for example, being heated and being applied in a heated state onto the surface.
The prior art, for example U.S. Pat. No. 2,148,986, discloses paint spray guns with heating devices, in which a conventional paint spray gun is placed together with the paint container thereof onto a heating plate and the quantity of paint which is located in the paint container is thereby heated.
However, a heating plate which is therefore used as heating means for the quantity of paint to be processed does not constitute a particularly convenient solution for workmen processing the paint, since a further apparatus for processing a quantity of paint is required.
It is therefore the object of the invention to provide the possibility of processing heated quantities of paint without inconvenient additional apparatuses having to be transported and handled.
The invention relates to a portable paint spraying system which comprises a base station with a blower, paint spraying means, in particular a paint spray gun, at least one tube for connecting the base station and the paint spraying means, and at least one paint container for receiving a quantity of paint. Furthermore, the portable paint spraying system according to the invention comprises a device for transmitting power to the paint container, wherein the quantity of paint in the paint container is heated by said transmitted power. According to the invention, the device for transmitting power is arranged in the base station and partially in the paint container of the portable paint spraying system according to the invention.
Paint spraying systems, in particular those which make use of HVLP technology, generally comprise a blower which is used to provide the required conveying air for conveying a quantity of paint out of a spray nozzle. Said blower is arranged in an apparatus part which, in the present case, is referred to as the base station, since it is not absolutely necessary to arrange the blower directly on the paint spraying means, for example a paint spray gun. By integration of a device for transmitting energy, with which a quantity of paint in a paint container is heated, in the apparatus body of the base station, a compact and uniform apparatus version of a portable paint spraying system is provided without the paint spraying means which are to be handled and are constantly moved by the workmen having to be changed and without said paint spraying means, for example, increasing in weight because of the device for transmitting power.
In a development of the portable paint spraying system according to the invention, a stirrer is additionally provided, wherein the stirrer is submerged into the quantity of paint at least during the transmission of power to the paint container and therefore during the heating of the quantity of paint, and, in the process, the quantity of paint is moved by the stirrer.
This provides uniform heating of the quantity of paint and any scorching or local overheating in the power transmission region is avoided.
In an expedient refinement of the portable paint spraying system, the device for transmitting power is formed by electric contacts in the base station and corresponding mating contacts on the paint container, said contacts transmitting electric power to at least one heating device in the paint container.
Resistance heating elements which are integrated in the paint container are thereby formed by electric contact points, for example by contacts interengaging in an interlocking manner. By means of the electric contact connection, a current can flow through, for example, a heating element in the paint container and can transmit the generated heat to the quantity of paint to be heated.
In a further expedient refinement, the device for transmitting power is formed by an inductive and/or thermal coupling in the base station. The inductive and/or thermal power is then transmitted by the base station to an inductively and/or thermally operating heating device in the paint container such that the quantity of paint contained therein is heated. For example, metal plates or other types of heat store, which can be correspondingly coupled on, can be used for this purpose.
Inductive and/or thermal couplings to a device for transmitting power may be expedient in an individual case if, for example, paint containers made of non-conductive materials are present, or if locally different quantities of power are intended to be transmitted to the paint container.
In a development of the portable paint spraying system according to the invention, it is provided that the device for transmitting power and the paint container have means for producing an interlocking connection in at least one plane, wherein the means are preferably formed in the form of rotationally symmetrical or concentric and interengaging structures.
Corresponding means for producing an interlocking connection in a plane help to predetermine the position of the paint container in the region of the power transmission device, in which said paint container can be placed. This achieves an optimized and reproducible coupling of the paint container to the device for transmitting power. Furthermore, paint containers of this type are customarily designed as rotationally symmetrical bodies, for example as paint canisters or paint buckets, which, although they have to be positioned exactly with respect to the central axis thereof, can be arranged in a manner rotated as desired about the axis of symmetry thereof to the corresponding position on the device for transmitting power.
A further refinement according to the invention of the portable paint spraying system is characterized in that the paint container comprises a leadthrough for a drive shaft for a stirrer, wherein the drive shaft which is guided through the leadthrough preferably comprises, on one side, a star-shaped bushing for receiving an output shaft of a motor and, on another side, a star-shaped shaft section for receiving a stirring element, in particular a propeller.
By a stirring element being introduced into the quantity of paint to be heated, said quantity of paint can be moved during the heating, thus resulting in uniform heating. However, a problem frequently encountered in this case is the cleaning, since stirring elements of this type customarily have undercuts and inaccessible locations when said stirring elements are mounted fixedly in a paint container. The preferred refinement of the drive shaft for a stirrer with star couplings present on both sides affords the possibility both of separating the paint container from the base station and of dismantling the stirrer in the paint container and, for example, of removing the stirring element for cleaning purposes.
In a furthermore expedient refinement of the portable paint spraying system according to the invention, the paint container is fastenable to, preferably screwable on, the paint spraying means, wherein the paint is conveyed by a rising tube from the paint container to a spray nozzle on the paint spraying means.
One possibility of the spraying processing of the quantity of paint consists in screwing a paint container directly on a paint spraying means, for example a paint spray gun, such that the quantity of paint has to be moved during the processing with the paint spraying means. Care should be taken in this connection to ensure that the quantity of paint heated according to the invention and the paint container have a sufficient heat capacity so that, during the processing, i.e. while the paint container is not located on the device for transmitting power, the quantity of paint does not cool too greatly and therefore the desired processing temperature or the desired processing temperature range is departed from.
The paint container may also be heat insulated, for example, by means of a double-walled container or a suitable insulating layer on the container wall.
In a further expedient refinement of the portable paint spraying system according to the invention, it is provided that the paint container is formed on the surface of the base station or partially in the base station or completely in the base station, but preferably so as to be separable from the base station.
The base station may have a receiving space for a quantity of paint or may provide a receptacle for a paint container which is arranged partially in the base station or completely in the base station during the operation of processing the quantity of paint at the base station. In this case, the quantity of paint to be processed is conveyed via a paint conveying tube from the base station to the paint spraying means by means of a pump, wherein, in this case, the paint spraying means may advantageously be designed to be lightweight and compact, and therefore processing, in particular of relatively large quantities of paint, is possible without interruption, since paint does not have to be refilled into a container on the paint spraying means.
In this connection, the paint conveying tube may be heat insulated and/or the heating element may also be provided in or on the tube.
Furthermore, the invention comprises a method for processing quantities of paint to be sprayed, wherein, in an interchangeable paint container, a quantity of paint is heated to a temperature above an ambient temperature by a device for transmitting power. Furthermore, the heated quantity of paint is transported by a rising tube or by a paint tube to a paint spraying means, in particular to a paint spray gun, wherein, according to the invention, during the transmission of power to the paint container and the resultant heating of the quantity of paint, the latter is stirred by means of a stirrer.
The method according to the invention advantageously provides a quantity of paint for processing, in which the viscosity can be reduced to a sufficient extent in order to bring about an improved surface coating.
In a development of the method according to the invention, the quantity of paint is heated to a temperature of between 20° and 70°, preferably between 30° and 50° C.
In particular, it may be expedient for the user or apparatus manufacturer to predetermine two exact temperatures for processing two different paint categories, which temperatures may also be formed, for example, by the boundary ranges of the above-mentioned temperature ranges.
In a moreover expedient development of the method according to the invention, it is provided that the stirrer is operated at a rotational speed of 100 rpm to 300 rpm in an operating state during the transmission of power to a quantity of paint, and, preferably after the transmission of energy is ended, i.e. after the desired temperature for the quantity of paint is reached, still runs on for some time. In particular, the stirrer according to the method according to the invention may furthermore have a second operating state which serves for cleaning the paint container, and is operated at a rotational speed of 200 rpm to 500 rpm.
In order to circulate heated quantities of paint so that heating within the quantity of paint may be uniform, a low rotational speed generally suffices. However, it may be expedient for the stirrer still to run on even after the end of the heating of the quantity of paint, i.e., for example, after a desired processing temperature is reached, despite the device for transmitting heat energy being switched off, so that scorching or local overheating of the paint due to residual heat being present at the device for transmitting heat energy is avoided.
Expediently, a cleaning mode may also be provided according to the method according to the invention, said cleaning mode being characterized, for example, in a cleaning rotational speed, which is increased in relation to the heating rotational speed, at the stirrer. This considerably facilitates the cleaning of the paint container, since a manual movement of a cleaning fluid in the paint container is required only to a limited extent, if at all.
In a further development of the method according to the invention, the latter is characterized in that the device for transmitting power is controlled, in particular regulated, via temperature detection means in or on the paint container and/or via temperature detection means in the quantity of paint.
Temperature detection means may supply a control or regulating variable for the device for transmitting power from the temperature of the quantity of paint or the temperature of the paint container such that either the device for transmitting power can be controlled by the latter being switched on and off or the device for transmitting power is regulated in accordance with a predetermined parameter via a regulating device for regulating the power thereof.
In this manner, preferred heating curves or retaining parameters for determining a temperature to be maintained of a quantity of paint to be processed can be set.
A refinement according to the invention of a portable paint spraying system is illustrated in the exemplary embodiment below.
However, the invention is not restricted to the exemplary embodiment illustrated, but rather comprises all refinements which make use of the concept which is essential to the invention.
In detail,
The surface of the base station 1 furthermore has end switches 10, of which, in the present illustration, only the end switch 10 on the right-hand side can be seen. A correspondingly opposite end switch and an end switch in the handle region of the paint spray gun are provided. The end switch 10 serves to detect the presence of a paint container and accordingly only switches the device for transmitting power to an active state if a paint container which is to be heated is present.
The housing 3 of the base station 1 furthermore has operating elements 12 and displays 11 which describe the various operating states of the system according to the invention. Furthermore, a temperature selection switch 13 for a paint temperature of 30° C. or 50° C. is provided.
The paint spray gun 21a comprises a paint container 23 which is screwed onto the paint spray gun 21a from below. The quantity of paint contained in the paint container 23 is heated during regular operation by the device for transmitting power 4 from the base station 1.
In the case of the paint spraying system 30 according to the invention, a paint spray gun 31a, to the lower side of which a paint container 32 is fastened, is used as the paint spraying means 31. The spray gun has an air connection 33, by means of which the working air is conveyed by the blower out of the base station via a tube S. For handling purposes, the paint spray gun 31a has a handle 34 at which said paint spray gun is held in order to carry out painting work. A rising tube 35 is provided in the interior of the paint container 32, said rising tube connecting a quantity of paint 36 in the paint container 32 to a spray nozzle 37 such that the paint can be discharged from the spray nozzle 37. For clarity reasons, metering means, for example a needle valve, etc., are not illustrated.
The lower side of the paint container 32 according to the invention has a leadthrough D for a drive shaft 40 which has been led through a base of the paint container 32. The upper end of the drive shaft 40 has a coupling 41, which is designed as a star coupling 41a, for receiving a stirring element 42a of a stirrer 42. The stirring element 42a is easily separable from the shaft 40 for cleaning purposes by means of the star coupling 41a which is present. The lower side of the shaft 40 has a further coupling 43 which is designed as a star coupling 43 and via which the output shaft 44a of a motor/transmission unit 44 can act on the shaft 40 and therefore drives the stirring element 42a.
The end switches 10, 10′, 10″ release the conductor or the neutral conductor depending on the orientation by which the mains plugs have been plugged in.
A heating region 60 of the paint container 32 contains at least one resistance heater, in the present case two illustrated resistance heaters 61, 62, which are supplied with power by the device for transmitting power by the base station via corresponding heating contacts 63, 64. A heating device H therefore comprises at least one resistance heater 61 and/or 62. The heating contacts 63, 64 may be formed, for example, by the centering grooves 5 (illustrated in
In a further embodiment (not illustrated), it would also be conceivable to store the paint container in a depression of the housing 3 of the base station 1 and, for example, to pivot the stirrer from above into the paint container in order to omit the leadthrough of the shaft on the lower side. Furthermore, a termination by means of a cover on the top side of such a configuration would likewise be conceivable, thus producing a closed portable paint spraying system, in which a paint container does not need to be arranged on a spray gun, which considerably reduces the handleability and the weight to be moved during the processing of paint to be sprayed.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2010 012 538.5 | Mar 2010 | DE | national |
This application is a continuation of International Application No. PCT/EP2011/001441 filed Mar. 23, 2011, which designated the United States, and claims the benefit under 35 USC §119(a)-(d) of German Application No. 10 2010 012 538.5 filed Mar. 23, 2010, the entireties of which are incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/EP2011/001441 | Mar 2011 | US |
| Child | 13621438 | US |
