DE1621857A1 - Spray gun - Google Patents

Description

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THE DeVILBISS COMPANY, 300 Phillips Avenue, Toledo, Ohio,

UNITED STATES.

Spray gun

The invention relates to a high-pressure spray gun of the air-free type "in which the very small outlet opening shows signs of clogging easily, whereby the spray jet and the throughput rate are greatly changed.
A slide plate is provided which can be dismantled and exchanged in the direction transverse to the axis of the spray gun, so that the contaminated opening can be cleaned by the material flow in the opposite direction. This sliding plate can also be adjusted transversely in order to have several different outlet openings in its
To bring an action. A "hydraulically operated" seal prevents leakage in the space between the

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Slide plate and the guides in which it moves.

With these air-free spray guns for applying a Shift, the working pressure often exceeds a level of

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70 kg / cm, and frequent cleaning of the very small outlet opening The spray gun is required and this makes it difficult to have a complete seal for the There must be a removable outlet opening in the gun must, so that a leak at these high pressures is prevented. Self-cleaning spray guns of this type are already known, see the USA patents 511 728, 949 089 and 3 116 882, whereby the sealing ring, the a rotary movement of the elements is permitted, is required, and the seal achievable thereby has been found to be not sufficiently reliable at the high pressures mentioned proven. It has also been found that a removable and replaceable outlet on a spray gun can be created by having a transverse sliding. Mechanism by which the high Pressure is used to press a flat seal against the sliding plate to prevent a leak around the Outlet opening around is prevented. A device for quickly reducing the high load on the seal Pressure allows the sliding plate with the outlet opening to be replaced for the purpose of cleaning a dirty one or partially clogged opening by redirecting the

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Current in the opposite direction. In this sliding plate, several outlet openings with different Sizes can be arranged optionally by one movement the sliding washer in a Riphtung transverse to the direction of movement of the material to be sprayed or the axis of the Spray gun can be used in their action.

The invention provides an arrangement that is used on these known air-free spray guns with an m

Sealing piston can be attached so that a smaller one Movement path in the axial direction of the spray gun between the first layer away from the transversely guided sliding plate and a second layer in contact with the slide plate is enabled. The slide plate with the outlet opening is received by guides in the housing, either in a forward position to the normal Syringes or in a back position, in the one blocked outlet openings can be cleaned. Here can the sliding plate in this guide file / in one of these layers ™ be positioned to any of several AusIaIS openings to bring in their "wrongdoings. i '/ em my position of with the opening provided sliding plate has been selected and the sealing piston is with the pressure of the spray material applied, the sliding plate moves from a first in a second position in which its outer end is sealed with one side of the plate standing and the other side

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the plate is pressed into the guides mentioned.

When the trigger-operated valve of the spray gun is closed, the pressure on the sealing piston is released and the plate can be dismantled and turned over for cleaning. If the outlet opening is completely blocked or clogged and the valve prevents it from being completely closed, the arrangement between the holder and the spray gun itself can be loosened in order to increase the volume of the trapped liquid above the fluff available in the valve so that the Pressure is lowered so that a . ■■ · the valve closes quickly and the pressure on the sliding plate is reduced accordingly in order to dismantle the plate.

Further advantages and details of the invention result from the following description of an exemplary embodiment with reference to the drawing. In this show:

Fig. 1 is a partially sectioned side view;

2 shows a section through the sliding plate with the outlet openings;

Fig. 3 is a front view of the sliding plate and the Spray gun as a section along line 3-3 of Fig. 2

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with the representation of the position of the openings of the Sliding plate j '

Fig. 4 is a section along the line 4-4 of Pig, 3 with removed sliding plate and.

Pig. 5 shows a view of the sliding plate with the outlet openings without the holding device.

In Pig. 1, the reversible tip on a conventional airless spray gun is illustrated and generally designated by the numeral 10. The material to be sprayed is supplied through the line 11, which is connected to an auxiliary duct 12 in which a switching valve 13 is arranged. This switching valve 13 closes a valve seat 14 which is arranged in one end of a tubular part 15 and forms the end part of the axial fluid channel 12 in the spray gun housing 10. The valve 13 is lifted from its seat 14 by manual actuation of the pusher 16 and is biased into its generally closed or seated position by a known spring or the like, the known spring not being illustrated. '.

The switchable tip assembly of the present invention is screwed onto an outer flange 17 of the housing 10.

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This device shows a part 18 which, as best can be seen in Figures 2 and 4, a conical tubular part 19 and a transverse guide 20 for the Tip holder 10, which is firmly connected to the outer end of part 19. A nut 22 with an internal thread shows a conical passage which conforms to the outer surface of the part 19 and onto the flange 17 of the housing 10 is screwed to the body 18 a To give bracket. .., · "" ■

A sealing piston 23 is arranged coaxially in part 19. It shows a flange 24 which is connected to a counter shoulder 25 cooperates on the inner surface of the part 19 so that inadvertent dismantling of the sealing piston 23 is prevented. A plug 26 is in the tubular part arranged at the rear of the sealing piston 23, as can be seen from FIGS. 1, 2 and 4. A retaining ring 27, which in a recess is held in the part 19, limits the movement of the plug 26 to the rear. Between the Stopper 26 and sealing piston 23 has an O-ring 28 attached to it. arranged the one throttle part of the plug 26 surrounds, so that a leak in the material to be sprayed after behind the plug 26 is prevented. An axial one Fluid channel 29 extends through plug 23 and an off-axis channel 30 penetrates plug 26, thus the middle part of the back surface of the plug

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with the tree 31 between the plug 26 and the sealing piston 23 is related, see Fig. 2. The non-axial Channel 30 is used; part of the energy of the Liquid flow of a very high speed shows destroy *

According to Figures 1, 2 * 3 and 4 is the tip holder. guide generally transversely to the axial passage 1 2, so that a slot or a guide path with a rear surface 32 near the front sealing part of the sealing piston and a front surface is formed by the two flanges on both sides of the ^ retaining guide 20 with the reference numerals 33 and 34 are shown.

The sliding plate according to the invention with the openings shows a half fitting to one another, see FIG. As can best be seen in the Pig * f 2 ·. the sliding plate 37 has one or more internally arranged indentations * to accommodate the throttling discharge openings 38 or 39, and a handle 42 "is provided at one end * The two sliding plate halves can be dismantled separately from each other by removing the screws and: 36 solves. -. -: I r '_} ^-:' ■ '_ ^-..': _ '

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When the sliding plate 37 'with the openings in the holding guide 20 is inserted in its normal operative position, see FIG. 1, the material to be sprayed will flow through the opening 38 or 39 in one direction, and when the plate 37 in of the guide 20 is switched, see, FIG. 2, then the material to be sprayed will flow in the opposite direction through an opening 38 or 39. It will now be understood that the slide plate 37 can optionally be positioned so that one or the other of the openings 3 and 39 is aligned with the axial passage 29 above the piston 23 so that the operator can selectively one or the other other of the openings 38 or 39 can be used in spraying, as illustrated by the broken and solid lines in Wig. T. A spring-loaded stop 43 and spaced recesses 44 on the slide plate can be provided to adjust the position of the plate 37 and openings 38 and 39 to be checked.

As has already been mentioned, 'iesrt; the hohd Drtiök of the - ~ spray gun to seal the plate 37 with the sealing surface of the sealing piston 23 frictionally with one another. When sliding plate is in its in Fig. 1 illustrated position _f 37 so that an opening such as the opening 38 * is in its operative position ait *

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the axial passage 29 is located in the sealing piston 23, the conical nut 22 being screwed tightly onto the flange 17 so that the end of the tubular part 15 presses against the face of the plug 26, the pressurized liquid fills via the channel 30 Space 31 between the plug 26 and the sealing piston 23 ,. whereby the sealing piston 23 is pressed forwards and the plug 26 is pressed backwards. The narrower end of the piston 23 is acted upon with great force against the surface of the sliding plate 37, which in turn presses against the front surfaces 33 and 34 of the guide 20. A very reliable seal is thus formed between the rear surface of the slide plate 37 and the narrow end part of the piston 23 under high pressure. As long as this high pressure

is maintained, the plate 37 becomes rigid; held in their position, the inner surface, in the vicinity of the effective outflow opening with the surface of the sealing piston 23 seals. Leakage behind the radially outer surface of the piston 23 and on the opposite inner surface of the tubular member 19 can be prevented in any suitable manner, for example by placing a suitable "movable seal" between the surfaces or including a pressure actuated seal a conical recess 49 provides _- as illustrated in Fig. 2, the negative pressure allows an expansion of part of the.Ko Ibens 23.

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by the parts outside of the recess 40 are pressed against the neighboring wall.

When the valve 13 is closed on its valve seat 14, the force that actuates the piston 23 against the inner surface of the plate 37 decreases and the pressure decreases. The plate 37 is free to be moved manually into a different position or turned over and the like. A general malfunction of these air-free .Spritzgistolen is that a complete clogging or blocking of the effective outlet opening 38 takes place. When the effective opening 38 closes completely, the pressure in the space 31 between the piston 23 and the plunger 26, which holds the piston against the plate 37, cannot be released, even if the valve 13 is against its seat 14 can be closed * In this case it is difficult for the operator ">..-" to remove the plate 37 by hand because the high pressure presses the plate 37 against the surfaces 33 and 34. In such a case, the high pressure can be reduced by loosening the screwing of the conical nut 22 by screwing the nut around a hjiruchteileinör tinä-reüag ^: g & ~ so that the surface of the plug 26 is clear of the tip of the tubular part 15, 15. The volume in the channels 30 and 29 as well as in the space 31 is increased, see FIG. 2, and the pressure becomes fast

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lowered to the external pressure. After this pressure reduction, the valve 13 _r . if it is not yet closed, quickly move to its valve seat 14 and prevent further pressure on the sealing piston 23. Since the sealing piston 23 is now relieved of the high pressure, the dl & plate 37 can easily be dismantled from its guide 20 and turned over or reattached in some other way . ". _: ." ■ ".. .. ■" - .. - ■■ - "-.; ■ ^.: - _. -. ■ '" ..

The invention thus provides a switchable tip for use with known airless spray guns created that the replacement of several throttle orifices / © crLe & chtertf regardless of the ruling class Differential pressure and also regardless of whether the opening is completely blocked or not. It should be made clear that further modifications and changes of the embodiment described can be made by those skilled in the art know * 'without the mentioned basic idea of the invention deviate.

All of the details described and illustrated are relevant to the invention.

Pat entansp rheehe;

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Claims (5)

Claims: '1 1. Air-free high-pressure spray gun with a barrel, .der has an outlet opening for the material to be sprayed and a pusher for actuating a flow-controlling valve, thereby ge ke η η ζ eich η et that a body (18) with a passage For the liquid to be sprayed there is a guide (20) for the removable mounting of the body in the barrel of the spray gun that a sliding plate (37) is movable in the guide (20) with at least one insert with a throttling outflow opening (38 , 39) is arranged, this .. sliding plate is completely removable and rotatable with respect to the body, whereby the plate can be removed and reinstalled in two ways, so that the opening is flown through in the opposite direction for cleaning. 2. Spray gun according to claim 1, characterized in that the body (18) has a stepped central bore, a first the to be sprayed "material directing element (14) in the bore with a through the valve (13) controlled passage, wherein a pierced sealing piston (23) is movable disposed in the axial bore of the body and wherein 009831/0529 - 13 - a hydraulically operated seal- (27) on the periphery is provided, which is brought into sealing engagement with the sliding plate (37) by the hydraulic pressure, when the valve (13) is in its open position. ■ 3. Spray gun according to claim 2, characterized ge ke η η ■ - ■ ζ eich η et that a device for temporarily increasing the volume of the passages for the material to be sprayed in the body (18) is provided when the outlet opening (38) is completely clogged so that the pressure acting on the slide plate against the guides is reduced. 4. Spray gun according to claim T, characterized η GEK en - ζ § i without t, that the slide plates (37) having a plurality of individually replaceable inserts with throttle openings, optionally different by a transverse movement of the plate (37) in the guide (20) in Layers can be brought. 5. A spray gun according to claim 2, characterized geke η η - ζ ei ,, ch.net that the controlled through the valve in the first element (26) through (30) of the sealing piston (23) outside the center axis of the bore. 0 0 9 8 31/0 52 9 bad ORIGINAL Blank page