Fluid sprinkling – spraying – and diffusing – Including supply holder for material – Fluid pressure discharge means
Reexamination Certificate
1999-11-02
2002-09-03
Morris, Lesley D. (Department: 3752)
Fluid sprinkling, spraying, and diffusing
Including supply holder for material
Fluid pressure discharge means
C239S302000
Reexamination Certificate
active
06443371
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a device for automatic spray application of paint through a spray nozzle. The device comprises a container containing paint and arranged in the immediate proximity of the spray nozzle. The container is connected to the spray nozzle through a conduit for supplying paint thereto for spray application. The device further includes pressing means adapted to press the paint out of the container and through the conduit to the nozzle through a pressurized medium.
Such a device may have different fields of use, but for illustrating, but not in any way restricting the invention, the use of such a device for painting objects, such as vehicle bodies, through a spray painting robot will hereinafter primarily be discussed. Notwithstanding, the invention also comprises devices in the form of so called painting machines. “Paint” is here to be given a broad meaning and comprises all types of paints suited for spray application.
It is often desired to place such a container containing paint in spray application robots close to the spray nozzle to avoid long conduits between the source of paint and the spray nozzle. This is done primarily to avoid a great waste of paint when color is changed, but also to facilitate cleaning of such conduits and avoid having long conduits impede the ability to move the robot or otherwise constitute obstacles. However, a problem arises when the container is arranged close to the spray nozzle, if the container and the robot arm carrying the spray nozzle are moved so that the container is turned or tilted. The paint present in the container will, upon such movements of the container, assume a new position in the container through gravitation and may perhaps not be reachable by the conduit in this position, so that it will not be possible to spray paint out through the spray nozzle in certain positions of the robot arm, and thereby the container. Similarly, it may not be possible to efficiently discharge all the paint from the container should this be desired. Rather, the problem of supplying the spray nozzle with paint will instead increase with a decreasing content of paint in the container.
A solution to this problem is presented in FR 2 635 990, which consists of arranging a member for mechanically dividing the container inside the container for separating the paint and the pressurized medium, such as compressed air, in which this member is formed by a piston or a flexible membrane. However, an arrangement of such a membrane or piston in the container requires control means that are unnecessarily complicated and makes the construction of the container unnecessarily costly.
SUMMARY OF THE INVENTION
The object of the present invention is to provide a device of the type mentioned in the introduction, which solves the problem discussed above in a simpler, more advantageous and less costly way than has been achieved through the device according to the French publication mentioned above.
This object is obtained, according to the invention, by arranging the container to be rotatable and providing the device with members adapted to drive the container to rotate, for pressing paint contained therein outwardly towards a region of the periphery thereof. Further, the conduit has an opening in the peripheral region, and that the pressing means are adapted to establish an overpressure of the pressurized medium in the container for pressing paint out through the opening to the spray nozzle.
Thus, regardless of its positioning in the interior of the container, it may always be ensured that paint contained in the container is present where the conduit terminates in the container. Thus, paint may be supplied to the spray nozzle as long as there is any paint left in the container. This is achieved completely without any requirement of any membrane or piston inside the container. It is a matter of course that the driving member has to drive the container to rotate with such a speed that “the centrifugal force” keeps the paint against the periphery of the container. It is also within the scope of the invention that the driving member does not have to drive the container to rotate continuously, but this capability is present and utilized when needed. Thus, when spray is applied, for example, on any object with the spray nozzle and the container is in a fixed position during at least a period, rotating the container may be omitted should the container be positioned with the peripheral region at the lowest point, so that the gravitation keeps the paint close to the opening of the conduit. Furthermore, it is emphasized that “the pressing means are adapted to establish an overpressure of the pressurized medium in the container” is to be broadly interpreted and intended to comprise the case in which no real supply of pressurized medium to the container is provided. Rather, for example, the container may initially be filled by so much pressurized medium and pressurized medium of such a high pressure, besides the paint, that this pressurized medium is sufficient for obtaining pressing of all the paint out of the container during a pressure decrease, while maintaining an overpressure in the container when all the paint has been removed.
According to a preferred embodiment of the invention the opening of the conduit is located in the peripheral region at an inner wall of the container, so as to enable discharging of substantially all the paint contained in the container through the opening. A capability of completely emptying the container, with an optimum utilization of the volume thereof, is obtained due to such an arrangement of the opening of the conduit in combination with rotation of the container.
According to another preferred embodiment of the invention the peripheral region extends over a limited part of the extension of the container in a direction substantially in parallel with the axis for the rotation of the container. The opening does not thereby have to be given a disproportionately large extension in this direction so as to achieve an optimum emptying of paint to “the very last drop”.
According to another preferred embodiment of the invention, which constitutes a further development of the embodiment last mentioned, the peripheral region is formed by a valley-like design of the container which is circumferential with respect to the axis of rotation of the container, and having a valley bottom with a maximum distance to the axis of rotation of the container, and wherein the opening is located in the valley bottom. A very well defined point for collection of the paint is obtained in this way, since the extension in the axial direction will be small due to this design, and the paint will move in the valley in a circumferential path and thereby be caught at a point by, or more exactly be pressed out through, the opening.
According to another preferred embodiment of the invention the container is substantially symmetrical with respect to the axis of rotation thereof. Such a design of the container is advantageous, since the paint thereby may be smoothly pressed outwardly towards the periphery of the container by the “centrifugal” force without any substantial formation of swirls or exerting shearing forces on the paint, which may degrade it. At the same time, a capability of even discharging of the paint from of the container is ensured.
According to another preferred embodiment of the invention the pressing means are adapted to press the paint out of the container through compressed air, which in most cases is to be preferred due to the ease of access to this pressurized medium.
According to another preferred embodiment of the invention the pressing means are adapted to supply the pressurized medium to a container in the region of the axis of rotation thereof. This is advantageous since the pressurized medium is then introduced into the space being free from paint at the rotation of the container, which improves the efficiency of the device, as well as because it is easier to fix the means with respect to rotation should thi
ABB Flexible Automation A/S
Connolly Bove & Lodge & Hutz LLP
Kim Christopher
Morris Lesley D.
LandOfFree
Device for automatic spray application of paint does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Device for automatic spray application of paint, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Device for automatic spray application of paint will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2897962