DE2529558A1 - DEVICE FOR MIXING AND DISPENSING COATING MATERIAL - Google Patents

Description

Patent attorneys Dipl. - Ing.F. W ^ ickmann, 7529558

DiPL.- ^T N (; H. Weickmann, Dipl.-Phys. Dr. K. Fincke Dipl.-Ing.FA ¥ eickmann, Dipl.-Chem. B. Huber

SAHA 8 MUNICH 86, DEN

POST BOX 860 820 MÖHLSTRASSE 22, CALL NUMBER 98 3921/22

HERBERT WILLIAM VOLKER, 463 Church Street, Kohler,

Wisconsin, V.St.A.

Device for mixing and dispensing coating material

The invention relates to a device for mixing and dispensing coating materials, for example for spraying, pouring or foaming such materials.

There are already dispensers for applying different coating materials, such as different plastics, which consist of rapidly reacting chemical components are known. Conventional devices, such as the usual one Spray guns, are not suitable for applying plastic coatings, their chemical components in the mixture react quickly. While the individual components are generally stable, when mixed in the correct proportions they react immediately to form the final product and quickly bind or begin to solidify. Therefore Care must be taken to mix the components in the correct proportions and dispense the mixture immediately. It Attempts have already been made to modify conventional paint spray guns for dispensing such plastics. In general for this purpose, a mixing chamber has been provided in the gun, into which the components are fed through separate feed lines are introduced in the correct mixing ratio to form the desired coating. Most of the so far on this Purpose-designed devices do not work satisfactorily, mainly because the device is inadequate

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Measure is kept pure, so that the control valves and ducts for the constituents of the plastic components that solidify in them and make the device unusable become clogged. A previously developed device for the stated purpose, which is described in US Pat. No. 5,504,855, has proven to be very efficient in use. The practical use of this device and other devices however, of this general nature, there has been a desire for a simplified spray gun construction which the aspired puncture is met with sufficient efficiency and can be produced at a lower cost.

The invention is based on the object of creating a device of the type mentioned at the outset that is relatively simple Construction is appropriate and ensures that the materials to be dispensed are kept at the correct temperature and the control valves and ducts are cleaned so that the device is always ready for operation, and that in production is sufficiently rational that it can compete with more complex devices.

The invention solves this problem by providing an improved valve assembly of relatively simple construction provides which controls the flow of the discrete components through the gun so that the valves are kept free of materials that could clog the valves and can easily be washed out with a solvent without to do this, the pistol must be dismantled so that it is always ready for use. According to the invention, valves are provided which control the flow of materials from the supply lines into a mixing chamber and which are mounted in such a way that they can be easily removed for cleaning or repair. How the device according to the invention is constructed, emerges from the characterizing part of the first claim.

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7529558

Further details of the invention emerge from the following Description of an exemplary embodiment based on the attached drawings. Show in it:

Pig.1 is a side view of a spray gun with the features the invention;

Pig.2 is a front view of the Pig.1 spray gun, which is the Deduction side is;

Pig. 3 is a rear view that is opposite to the trigger Side of the gun illustrated;

Pig.4 a vertical section along the line 4-4 of Pig.2;

Pig.5 is a sectional view along line 5-5 of Pig.4j

Pig.6 is a sectional view along line 6-6 of Pig.4;

Pig.7 is a sectional view along line 7-7 of Pig.4;

Pig.8 is a fragmentary sectional view along the line 8-8 of Pig.4 on an enlarged scale, which shows one selector valve in the "ON" position, and

Pig.9 is a fragmentary sectional view after the same Line like Pig.8, but with the selector valve in the "OFF" position shows.

In the pig. is a dispenser in the form of a spray gun shown, which is particularly suitable for the output of coating materials, such as foams, for example made of an isocyanate resin and a polyol resin can be composed, with a suitable solvent being provided and compressed air as the propellant serves. In the example shown, the gun is intended for spraying. With a minor adjustment or modification it can also be used for pouring or foaming the foam. The illustrated spray gun has a body of approximately circular cross-section which forms a head 10 and a handle 11. The handle 11 is fastened with its upper end to the head 10 in a suitable manner. The head 10 has a nozzle 12, which with-

tele of a connector 13 connected to the head 10 and is pushed telescopically onto a drill bit 14 which forms a mixing chamber 15. The pipe section 14 abuts to an impact chamber 18 which is received in a recess 16, welohe the inner or front end of a bore 17 forms which extends through the upper part of the head extends. The end of the connecting piece 13 is screwed into the front end of the recess 16. The hole 17 is widened in its rear part and an air valve 20 is received in the widened part. This is a bushing 21 with an external thread is screwed into an internal thread at the rear end of the bore 17.

The air valve 20, which is used to control any suitable gaseous propellant, has a drum 22, which is displaceable in the axial direction in an axial bore 23, which is located at the rear end of a valve housing opens, which forms an air chamber. The valve housing 24 has at the front end a narrower part 25, which extends into the rear Part of the tubular impingement chamber 18 extends. The cross section of the bore 23 increases towards the front end gradually and the front end serves as a nozzle with a longer channel 26 of relatively small cross-section. The valve drum 22 is traversed in the axial direction by an air duct 27 with one running to the side Channel at the front end which is axially spaced from the tapered inner end portion 28. The end portion 28 of the The valve drum is intended to rest against a step 30 which forms a valve seat in the bore 23 when the valve closes. A nut 32 for operating the valve has at one end inside a shoulder that when turned with a stationary shoulder on socket 21 comes into contact; at the other end the nut is in screw connection with one Head part 33 on the axially displaceable valve drum 22, so that the valve is opened and closed by turning the nut can be. To secure the valve drum against

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rotation about its axis is provided a pin 34 which into an axial slot in the outer wall of the valve drum engages. The end 25 of the valve housing 24 ends shortly before two radial slots 35 and 35 '(FIG. 6) in the wall of the impact chamber 18 (Fig. 4 and 6), through which the plastics via channels 36 and 36 · of control valves 40 and 40 ', which are from the trigger are actuated, are fed into the mixing chamber 15.

The materials that must be mixed to provide the desired coating are fed to the gun through feed lines 42 and 42 (Figures 4 and 7) which, by means of suitable couplings or nipples 43 and 43 ', are inserted into threaded bores at the rear end of Feed channels 44 and 44 * are connected, pull the selector valves 45 and 45 'through in the axial direction. The selector valves are arranged in parallel bores 46 and 46 'which are arranged in a transverse section in triangle with the upper parallel bore 17 in the body 10 of the gun in which the air valve 20 is housed. Outer return lines 47 and 47 'are assigned to the inner feed lines 42 and 42' for the material, the inner diameter of which is greater than the outer diameter of the inner feed lines 42 and 42 'and which surround the latter. The outer return lines 47 and 47 'are connected by means of intermediate pieces 48 and 48' to the outer ends of housing parts 50 and 50 'of the selector valves 45 and 45', with which the inner supply lines 42 and 42 'are also connected so that they are connected to return flow channels 52 and 52 'are in communication, which run substantially parallel to the corresponding supply channels 44, 44' and lead to substantially radially or laterally directed openings near the front ends of the valve housing parts 50 and 50 '. The valve housing parts 50 and 50 'have conically tapered front ends which are embedded ^{in sleeves 53 and 53 1.} The sleeves 53 and 53 * are in turn received in the parallel bores 46 and 46 * that they cannot rotate. The rear ends of the sleeves 53 and 53 'are internally threaded, in

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that an external thread is screwed on the end of nuts 54 and 54 '. In this way, the nuts hold the valve housings in the sleeves 53 and 53 'by abutment on an outer shoulder of the valve housing, but allow the valve housing parts 50 and 50' to rotate about their longitudinal axes. On the rear ends of the housings 50 and 50 *, hexagonal rings 55 and 55 'are attached, on which the valve housings can be rotated by hand. The connected material supply lines rotate with the valve housings when the selector valves are rotated. As can be seen from FIGS. 4 and 7, the front ends of the valve housings 50 and 50 · are spaced from the front ends of the bores 46 and 46 · and the sleeves 53 and 53 'are provided with axial slots 56 and 56 * (Pig. 4, 8 and 9) which, as shown in Pig. 4, allow the fluids flowing in from the feed channels 44 and 44 'to pass into the small chamber 57 at the end of the valve housing. Axially running channels 58 and 58 'at the ends of the valve housings adjoin essentially radial channels 60 and 60' which open into one end of slots 62 and 62 'running in the circumferential direction in the sleeves 53 and 53'. The slots 62 and 62 · extending over approximately a quarter of the circumference, so that ^"w in a position of the valve housings 50 and 50 · (Pig.4, 7 and 8) the Pluid through the channels 58 and 58 ·, the slots 62 and 62 · can flow into the return flow channels 52 and 52 · in order to return through the outer return lines. The rotation of the valve housings 50 and 50 · is restricted to about 90 ° by means of a grub screw 64. One end of the grub screw engages in a Groove in the outer wall of the valve housing 50 and 50 '. When the valve housing 50 and 50' are turned into their other position, namely "OFF", (Pig.9), the fluid flows directly from the supply channels 44 and 44 'into the Slots 62 and 62 · and from there into the return flow ducts 52 and 52 ·. In the "ON" position, the ducts 58 and 58 * can be opened by actuating the control valves 40 and 40 · (FIGS. 4 and 7) with the aid of a Trigger 65 to be closed.

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The control valves 40 and 40 * (Pig.2 and 4-7) are received in a recess 67 at the front end of the head 10, the rear ends being in parallel bores 68 and 68 ^f , which are axial with the bores 46 and 46 ^f are aligned, in which the selector valves 45 and 45 'are located. The bores 68 and 68 'have a smaller diameter than the bores 46 and 46 ·. The control valves 40 and 40 ^f have cylindrical valve housings 70 and 70 'which sit immovably in the bores 68 and 68', with outer sealing rings being provided, as well as pistons 72 and 72 · which are axially displaceable in the valve housings 70 and 70 · are. The valve pistons 72 and 72 'each have an internally widened head 73 and 73' with a forwardly conical part 74 and 74 'which extends to a much narrower neck 75 and 75'. In this way, at the end of the valve housing 70 and 70 ', a relatively small cylindrical chamber 76 or 76 ^f , which is closed at its inner end by the contact of the head 73 or 73' on a complementary conical edge surface at the end of the valve housing . The valve housings 70 and 70 'have larger diameter portions 77 and 77 * at their forward, outer ends which are received in the inner ends of surrounding ears 78 and 78', respectively. Compression springs 80 and 80 'are housed in the front ends of the tubes. The compression springs 80 and 80 surround parts 82 and 82 'of the valve pistons 72 and 72' and are supported with their one ends on the ends of the valve housings 70 and 70 'and with their other ends on the inner surfaces of the heads of caps 83 and 83 ', which are fastened in the ends of the valve pistons 72 and 72 ·. In this way, the heads 73 and 73 'of the valve pistons are normally held in the valve-closing position and the ends of the chambers 76 and 76' can be opened by axially displacing the valve pistons 72 and 72 'so that the spray material from the chambers 57 and 57 'into the chambers 76 and 76' and through openings 84 and 84 'in the walls of the valve housings 70 and 70 · into the channels 36 and 36' which

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lead to mixing chamber 15. These housing walls have diametrically opposed openings 85 and 85 * (Pig.4 and 6) for the Supply of solvent from a flush valve 86 for the solvent, which is a push button valve which is in a Transverse bore 87 is arranged directly below the two control valve housings 70 and 70 *, as can best be seen in Fig. 6.

The housings 70 and 70 'of the control valves 40 and 40 are opposite A displacement in the axial direction is secured by a pull-out locking pin 90 which is inserted in a transverse bore 92 is displaceable in the head 10. The transverse bore 92 has such a position in relation to the depression 67 (see Pig. 5) that parts 93 and 95 'of the full diameter locking pin 90 into the Countersink 67 protrude when the locking pin 90 is fully inserted into the transverse bore 92, and in transverse Grooves 94 and 94 * of pipes 78 and 78 * and the valve housing Embed 70 and 70 '. The locking pin 90 is provided with axially spaced apart thick parts 93 and 93 ', the one allow partial axial movement to unlock control valves 40 and 40 * so that they are as units can be removed for replacement or repair. The locking pin 90 is in the transverse bore 92 through a spring locking screw 95 (Fig. 4) held

The control valves 40 and 40 'are pivoted of trigger 65 operated. The trigger 65 carries a transverse pin 96 (Fig.2, 4 and 7), which with its two ends through axial slots 97 and 97 * in opposite wall parts of the tubes 78 and 78 'of the control valves and the valve housing 70 and 70 · occurs and is pivotally attached to the valve piston 72 and 72 *. The trigger has 65 at the top an extension 98 which protrudes into a downwardly open recess 100 in the upper wall of the recess 67 and a forms a loose pivot point for the trigger. The cross pin 86 sits in an upwardly open cross slot 101 on the trigger

and is detachably retained therein by a spring locking screw. The compression springs 80 and 80 normally hold the trigger 65 in the inoperative position. When the trigger 65 is pushed towards the handle 11 of the pistol, the control valves for the plastic feed are opened. The heads 73, 73 'of the valve pistons are moved inwardly to rest against the front ends of the selector valves 50 and 50', whereby the channels 58 and 58 'are closed and the plastics from the chambers 57 and 57' through the control valves 40 and 40 · can flow. By shifting the valve pistons 72 and 72 ^f to the rear, the openings 85 and 85 * are closed so that no solvent can flow in, regardless of the position of the flush valve 86.

The flush valve 86 for the solvent (Fig. 6) is a push button valve, an elongated, cylindrical housing

105, the size of which is dimensioned such that it fits into the transverse bore 87. A control slide is located in the housing

106 movable. The housing 105 has grooves 107 and 108 on its outside, which form channels which connect with the openings 85 and 85 'in the valve housings 70 and 70' in connection stand. A transverse bore 110 in the housing 105 connects the grooves 107 and 108 to the inside of the housing 105 at one Place where this connection from the head 112 of the spool valve is closed in one position and in the other Position is opened. The flush valve is normally held closed by a compression spring 113, which is connected to a End rests against the head 112 and at its other end is supported on a grub screw 114 in the end of the housing 105. The control slide 106 has a shaft with a threaded end on which a push button is screwed, the manual Actuation of the control slide is used. The flush valve 86 receives solvent through a channel 115 (Pig. 3 and 4) which is connected in a suitable manner to a solvent feed line. The channel 115 connects to an opening 116 into the interior of the valve housing 105 at the same point

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like the outflow slots formed by the transverse bore 110 are ·

In the use of the described embodiment for a typical spraying on of a coating using foams, the two synthetic resin components that are to be mixed and expelled from the nozzle 12 by a propellant are supplied from a storage tank through the supply lines 42 and 42, the material being supplied to heated to the correct temperature for the desired mixture. The manually adjustable selector valves 45 and 45 'can be adjusted so that the resin components flow back through the storage tanks without flowing through the control valves 40 and 40', as shown in FIGS. If the gun is to be used for spraying the mixed synthetic resins, the selector valves 45 and 45 'are first turned into the position shown in FIGS. When the trigger 65 is in its normal inoperative position, shown in solid lines in Figure 4, the valves 40 and 40 remain in the position of Figures 4 and 7 and the synthetic resin components flow back through the selector valves 45 and 45 *, as shown. This corresponds to the normal "OFF ^H" position of the control valves 40 and 40 ^1. In this position of the control valves, the solvent supply line is open so that solvent passes through the valves into the mixing chamber 15 in order to wash it out when the flushing valve 86 is actuated.

When the trigger 65 is pivoted towards the handle 11 to the full "Ellf position, the control valves 40 and 40 * the dashed position in Fig.7 and the valve ends are at the ends of the selector valves 45 and 45 * connected so that the plastics through the selector valves 45 and 45 'and through the control valves 40 and 40 'to the mixing chamber 15 flow. In this position of the control valves 40 and 40 are the solvent openings 85 and 85 · blocked by the valve pistons 72 and 72 ·.

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The selector valves 45 and 45 'can be turned through 90 ° into the position shown in Pig. 9, which prevents plastic materials from flowing into the chambers 57 and 57', but allows the plastic materials to flow back through the return flow channels 52 and 52 *, while the control valves 40 and 40 ^! can be opened so far that the flushing valve 36 can be switched to wash out the channels and the mixing chamber. The control valve 20 for the compressed air or the other propellant can be opened and closed by hand as desired.

The control valves 40 and 40 'are both held in the bores 68 and 68 by the locking pin 90. The trigger 65 can are released from the cross pin 96 and removed, whereupon the control valves 40 and 40 'by pulling out the locking pin 90 can be conveniently removed as complete units from the bores 68 and 68 'for the purpose of cleaning or the replacement of parts. The selector valves 45 and 45 'become natural brought into the position shown in Pig. 9 if the control valves 40 and 40 'are to be removed to prevent that plastic components in the bores 68 and 68 flow, and to allow the backflow of the plastic into the storage tanks.

The device according to the invention has been described using the example of a spray gun, but its use is not limited to spraying. Rather, it can also be used for pouring or foaming. Purely the pouring function it is necessary to remove the nozzle and replace it with a piece of tubing (not shown) with a full orifice, a motor-driven one for mixing the plastic components May contain stirrer. Another mixing head, a spiral coil, is used for the foaming function to dispense the foam.

Within the scope of the invention, materials that differ from those described and equivalent construction details can be used be used.

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Claims (1)

Expectations Device for mixing and dispensing coating materials, characterized by a head (10) in which a mixing chamber (15) is formed and from which a nozzle (12) extends and through which parallel bores (46, 68; 46 ', 68') extend, of which one channel (36, 36) each leads to the mixing chamber (15), a control valve (40, 40 ·) in one end of each bore and a selector valve (45, 45 ') in each bore which is aligned with the control valve of the relevant bore and is adjustably held in the bore, a pivotably mounted trigger (65), which is a connection with each control valve (40, 40 ') and in its one position opens the control valves so that coating material through the channels (36, 36) to the mixing chamber (15) can flow, and in its other position closes the control valves, each selector valve (45, 45 ') has an axial supply channel (44, 44 *) to which an inner supply line (42, 42') is connected, and a parallel return flow channel (52, 52 ') to which an outer return line (47, 47 ') is connected, which surrounds the inner supply line (42, 42'), and each selector valve (45, 45 *) is arranged in its associated bore in such a way that between its inner end and the facing inner end of the associated control valve (40, 40 '), a small chamber (57, 57') is formed, and is constructed in such a way that it can be adjusted into a position in which it connects the feed channel (44, 44 ') with the chamber (57, 57 '), and in another position in which it blocks the connection with the chamber and connects the supply channel (44, 44 *) with the return flow channel (52, 52 »), and finally each control valve (40, 40' ) is designed and arranged in its bore that in its open position coating material from the chamber (57, 57 ^f ) d flows through the control valve. 6 (19808/0683 2. Apparatus according to claim 1, characterized in that the parallel and axial supply and Rüekströmkanäle (44, 44 ^f »52, 52 ') of each selector valve are provided at its inner end with substantially radially directed outlets and this inner end in a Sleeve (53 »53 ') is rotatably received, which is fixed in the bore (46, 46 *) in which the selector valve in question is mounted and with an axial slot (56, 56') and a circumferential slot (62, 62 '), which are arranged in such a way that in one rotary position of the selector valve they connect the supply channel to the return flow channel via the chamber (57, 57') located between the selector valve and the associated control valve and in the other rotary position the connection via the Block chamber (57, 57 '), but maintain a connection between the supply and return flow channels. 3. Apparatus according to claim 2, characterized in that the radial Outlets are spaced about 90 ° from one another on a circumference and that in the one rotational position the axial Slots (56, 56) the feed channel with the chamber (57, 57 ') connect and in the other rotational position the circumferential slots (62, 62 ') on the inner surface of the sleeve connect the feed channel directly to the return channel. 4. Apparatus according to one of the preceding claims, characterized in that two parallel bores (46, 68; 46 ·, 68 ^f ) are arranged side by side, in each of which there are a control valve and a selector valve, and that a third bore (17) is provided in the head (10), in one end of which the mixing chamber (15) is located and in the other end of which there is a propellant valve (20) for controlling the inflow of a propellant from a connected feed line. 5. Apparatus according to claim 4, characterized in that the channels (36, 36 *) from a central region of each bore lead to the mixing chamber. B0980 8/0683 -H- 6. Device according to one of the preceding claims, characterized in that that the control valves (40, 40 ') can be actuated by a conveniently removable trigger (65) and as units are removable from the bores (68, 68 *) in the axial direction and that they are normally in the bores by means of a locking pin (90) are locked which is pulled out in a transverse bore (92) which is under the Control valves (40, 40 ') whose bores is arranged spanning, and which has parts (93, 93') which are in grooves (94, 94 ') of the control valves engage when the locking pin is inserted into the transverse bore (92). 7. Device according to one of the preceding claims, characterized in that that the trigger (65) has a connection (96) with the control valves (40, 40 ') such that it is of the connection can be released and the connection is made ineffective, so that the control valves can be removed are. 8. Device according to one of the preceding claims, characterized in that that the head (10) channels (85, 85 ', 115) for Has connection to a supply line for a solvent, which are connected to each control valve (40, 40 '), so that Solvent can flow through the control valves and into the mixing chamber when the control valves are in one position take in. 9. Apparatus according to claim 8, characterized in that in the solvent channels (85, 85 ', 115) a manually operable Solvent valve (86) is arranged, in one position, the flow of solvent to the control valves locks. 10. Apparatus according to claim 9, characterized in that the solvent valve (86) lies in a transverse bore (87) which defines the bores (68, 68 ¹ ) in which the control valves un- 9806/0 6 83 are housed, spanned, and that connecting channels (85, 85 ') connect the cross hole with the control valves. 11. Device according to one of the preceding claims, characterized in that that each control valve (40, 40 ') is provided with an axially displaceable piston (72, 72'), the the valve opens and closes, and that the suction (65) has an end part (98) which can pivot in a recess (100) is received in the head (10), and a cross pin (96) carries the piston (72, 72 ') with its tiiden ends, so that the piston moves in the axial direction when the trigger is pivoted. 12. Device according to one of the preceding claims, characterized in that that each control valve (40, 40 ') is provided with a piston (72, 72') displaceable in the axial direction is, which is so constructed and arranged relative to the associated selector valve (45 »45 ') that in his one position the control valve and the selector valve is open, and the coating material to be mixed by both Valves to the mixing chamber flows, while in another position both valves are closed and the material flow is locked. 15. Apparatus according to claim 2 and 3, characterized in that each tfahl-irentil Lsrt rotatable through about? 0 ° ^{in its sleeve (53.53 T),} fi Π 9 8 0 B / Π B 8 3 away Blank page