MXPA99009697A - Spray gun - Google Patents

Abstract

Spray gun for mixing and spraying of two media, and of the type incorporating a valve for one medium each. The two valves are provided one inside the other one and designed to be axially displaceable in a housing and relative to each other to and from one valve seat each against the action of a spring. The valves are together influenceable by an external force.

Description

SPRAY GUN The present invention relates to a rolling gun for mixing and spraying two media, and of the kind that incorporates a valve for each of the means. Background and problem of the invention. Rolling guns of the kind mentioned above are already known, which have two separate valves for each of the means and are positioned at a distance from one another and a common mixing chamber. A disadvantage with these is that when the two media react with one another, the valve orifices will clog and to prevent this, careful cleaning is necessary at each interruption of the spraying operation. Another disadvantage is that the rolling gun will become bulky, is more difficult to handle, has many movable components and therefore needs more maintenance and is more expensive to manufacture than rolling guns for only one medium. Purpose of the invention and solution of the problem. The purpose of the invention is to provide a rolling gun that:. be easy to clean with a damp cloth. prevent contamination of valve orifices for a large extension,. be as easy to handle as rolling guns for a medium only,. have few movable components,. require a minimum of maintenance,. its price is worth it. These tasks have been solved since the two valves are provided one inside the other and are designed axially displaceable in a box and in relation to one another and from a valve each sits against the action of a spring, and that the valves are actuable together by an external force. Description of the drawings Hereinafter, the invention will be further described as an embodiment with reference to the accompanying drawings. Figure 1 shows a section through a spray gun according to the invention in closed, passive position. Figure 2 shows on a larger scale a section through the intermediate portion of the spray gun, with the valves in the open, active position. Figure 2a is a partial elongation of the encircled portion 2a from Figure 2. Figure 2b. is a partial elongation of the surrounded portion 2b from Figure 2.

DESCRIPTION OF THE EMBODIMENT The spray gun according to the invention consists of a central box 11, which is equipped on its front "with" a spray nozzle 12 and at its rear end portion with a servomechanism. The central box 11 incorporates two valves 14 and 15, the inner 15 is provided inside the other, the external valve 14. The box also incorporates a handle 16 and on the front of this a trigger 17 in the form of a lever armed in two, which is pivotable towards an axle 18. In the upper part of the box there is also provided a valve distribution 19 for controlling the servomechanism 13. The outer valve 14, which is axially displaceable in the box 11 consists of a hose 20 , which passes inside a coaxial tube 21, which extends into the spray nozzle 12. A nozzle bearing 22 is threaded on the tube 21, and the front conical end 23 which cooperates with a valve-seat 24 in the box 11. At the front end of the tube a check valve 25 is provided, which opens at a pressure inside the tube. The nozzle bearing 22 is surrounded by an annular channel 30, which communicates with a supply conduit 31 for a first medium, for example, polyester. In the transition between the tube 21 and the hose 20 a valve seat 26 is provided in the latter, which cooperates with the final surface of the valve body 27 of the inner valve 15. This is constituted by a tube 28 , the front end being closed, but provided with side openings 29, communicating with a second annular channel 32, which can be put into communication with the inner channel 33 of the tube 21, when the body of the valve 27 is displaced in a direction away from its seat 26 and the opening of the channel 33 is exposed. The internal valve 15, which is axially displaceable in the hose 20 of the outer valve 14, passes over with its tubular valve body 28 inside a bearing 34, which is guided inside the hose 20. The inner channel 36 from the "tube 28 opens in this nozzle bearing, and a supply conduit 37 for a second means, for example, a hardening agent, is connected to this channel .. A piston rod 39 of a piston 40, which forms part of the servomechanism 13 and is subject to loading by a pressure spring 38 is also added to the nozzle bearing 34. A conduit 35 for pressurized air is also connectable to the housing 11, and which supplies pressurized air to a valve stem 41 equipped with two valve bodies 42 and 43, one of which always closes against one valve seat, while the other is open.The position of the valve stem is controlled by trigger mechanisms 17. When the fired r is subjected, the valve body 42 opens the passage to an air duct 44, which guides the pressurized air to the front side of the piston 40. The piston rod 39 by means of this will be subject to a tension force that acts against the action of the spring 38. The tension force is transferred to the nozzle bearing 34, wherein the entire valve package consisting of the external and internal valves 14 and 15 is displaced against a stop 46, as shown in Figures 2 and 2a. In this step the two valves 14 and 15 form an interconnected unit, due to the fact that the second means contained in the annular groove 32 and the channel 36 is under pressure. In this position the passage below the seat of the valve 24 is open, in this way the first means can flow from the supply conduit 31 to the connection channel 45 of the spray nozzle 12. This channel is designed as a mixing chamber or mixer channel equipped with, for example, screw-shaped mixing members, not shown. In the continuous supply of pressurized air to the piston 40 the passage below the seat of the valve 26 will be opened, in this way the second means can flow from the annular groove 32 to the inner channel 33 of the tube 21 and further to the valve of retention 25, which by means of this is open. By means of this the second means will reach the mixing chamber 45 and an intimate mixing of the two media can be carried out. While the outlet opening for the second medium in the 25 is positioned in some way in front of the outlet openings in the 24 for the first medium and the first medium is always discharged first, there will be no contamination in these outlet openings 24 The cleaning can then be limited to passing a wet cloth on the check valve 25, after the spray nozzle 12 has been unscrewed. List of reference numbers 11 _- - - box 12 spray nozzle 13 servomechanism 14 external valve 15 internal valve 16 handle 17 trigger / lever 18 shaft 19 valve distribution 20 hose 21 tube 22 nozzle bearing 23 tapered end 24 seat valve 25 check valve 26 valve seat 27 valve body 28 pipe 29 opening 30 ler annular channel 31 supply duct 32 2nd annular channel 33 interior duct 34 nozzle bearing 35 duct for pressurized air 36 internal duct 37 duct supply 38 pressure spring 39 piston rod 40 piston 41 valve stem 42 valve body 43 valve body 44 air duct 45 connection channel / mixing chamber 46 bumper

Claims (8)

1. Claims 1. A spray gun for mixing and spraying two means, and of the kind that incorporates a valve (14, 15) for each of the means, characterized therein, that the two valves (14, 15) are provided one inside of the other and are designed axially displaceable in a box (11) and have relation with each other to and from a valve seat (24, 26) each, against the action of the spring (38), and that the valves together are influenced by an external force.
2. 2. A spray gun according to claim 1, characterized in that, the valve seat (15) is provided in the outer valve (14), the valve seat (24) which is provided in the box (ll)
3. 3. A spray gun according to claim 1, characterized therein, that the internal and external valves _ (14, 15) during the initial displacement movement are hydraulically interconnected, with the body of the valve (27) of the valve interior (15) in closed position.
4. 4. A spray gun according to claim 1, characterized therein, that the external force is constituted by a pneumatically actuatable piston (40), the piston rod (39) which is connected to the valve body (27, 28) of the inner valve (15), which is displaceable in the external valve, and that the axial displaceability of the external valve (14) is limited by a stop (46) in the box (11) and that the body of the valve (27, 28) of the internal valve (15) is displaceable a little below the opening of the internal valve.
5. 5. A spray gun according to claim 1, characterized therein, that a check valve (25), which can be opened by the medium, is provided in the orifice of the internal valve (15).
6. 6. A spray gun according to claim 1, characterized in that the orifice of one of the valves is axially separated from the orifice of the other valve.
7. A spray gun according to claim 1, characterized in that the holes of both valves are arranged in order to open in a common mixer chamber / channel (45).
8. 8. A spray gun according to claim 1, characterized in that the movement of the pneumatic piston (40) is controlled by a valve rod. (41) actuatable by a trigger (17) of the spray gun, and which is adapted in one of its final positions to close the supply of air to the pneumatic piston and simultaneously open a venting opening and vice versa.