JPS598222B2 - System for mixing and distributing product fluids - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates generally to apparatus for mixing and dispensing multicomponent foams or similar fluid products, and more particularly to:
Concerning a cleanable spray gun for urethane foam.

The use of sprayed polyurethane foam is rapidly expanding in the construction, insulation and packaging industries.

This relatively inexpensive product has been recognized as a valuable insulating and packaging material for a number of reasons. Due to its elasticity, high compressive strength and good dimensional stability, this product makes an excellent packaging material for transporting relatively fragile items in cartons that may experience rough handling. There is. The product has very low heat transfer properties, making it an excellent thermal insulation material. Relatively extreme temperatures do not significantly affect the product, which does not deteriorate rapidly and has a long service life. Additionally, urethane foams are readily available and can be used in an almost unlimited variety of desired locations.

Some fluid components of urethane foam are often
Stored separately and mixed at the job site to obtain a foamed product. This mixed foam product is discharged or sprayed onto the desired target area. After application, the foam cures into a light, strong, protective insulating coating.
A device that has been used with success for mixing and applying urethane foams is disclosed in BrOOks U.S. Pat. No. 355,989.
No. 0 and No. 3,633,795. Experience has determined that the components of the urethane foam can be selected to provide a relatively rapidly curing product fluid.

After the material is sprayed onto the target area, the foam product begins to harden. This curing occurs not only in the desired target area, but also in any residual product that may remain in the dispensing gun after spraying has stopped. Residual foam products that harden inside each gun make cleaning and subsequent use of the gun difficult. This problem can be solved, for example, by B
rOOks U.S. Patent Nos. 3,633,795 and 3
This problem has been addressed with great success by a foam distribution gun such as that shown in No. 784110. In these devices, the foam gun has a nozzle inside through which the foam product components are mixed, thereby dispensing the mixed foam product. After using the gun, the nozzle can be removed and a new nozzle installed. Recently, the use of urethane foam as an insulating and packaging material has found increased advantages in its use to provide target areas of limited size and shape.

When an operator is working with such a restricted target area, the operator is often required to spray the foam in an intermittent manner. For example, after a layer of foam is initially applied to a limited target area, spraying of the foam is interrupted to allow an operator to inspect the target area, and then additional layers of foam are applied. In other cases, the operator is forced to interrupt spraying the foam while the operator or co-workers place the item in a carton or other container for shipping. After stowing the article, the forming operation is resumed. Once the container is filled, the spraying operation will necessarily be stopped again while the finished packaging operation is inspected. Next, close the carton and put it away.
A new empty carton is placed in the working position for spraying and packaging. Under such circumstances, it may be inconvenient to remove and reinstall the spray gun nozzle after each short spraying operation.

A large number of short spray operations are required during a single packaging or insulation operation and repeated nozzle reinstallation would further increase costs and slow production. The relatively short elapsed time between each spray operation can, under some circumstances, cause foam hardening and gun blockage? Although acceptable without scrubbing, longer periods of time can cause the fluid components to solidify completely or partially within parts of the gun, partially or completely clogging the gun.

Poor gun operation, insulation, or packaging practices result in inferior quality. Operator irritation and hurried work also results, indirectly resulting in a finished product that is not of the highest quality. This problem of partial gun clogging during intermittent spraying operations can be minimized by cleaning those parts of the gun, where the fluid components are mixed with a non-reactive cleaning fluid and evacuated. .

This conventional type of gun is shown in US Pat. No. 2,991,015 to Standllck. Additionally, gun cleaning allows the use of fluid components that create relatively fast-setting products that cannot be practically achieved with other types of guns or dispensing devices. It is an object of the present invention to provide an improved dispensing gun for mixing and dispensing fluids such as urethane foam.

Another object is to provide a fluid mixing and dispensing gun in which the problem of fluid solidification inside the gun is economically reduced or eliminated when the gun is used intermittently over short intervals of time. It is.

Yet another object is to provide a spray gun that allows cleaning of curable product fluid components from critical gun areas. Yet another object of the present invention is to provide a dispensing-spray gun for polyurethane foam and the like in which relatively thorough cleaning of both the nozzle and relatively upstream gun sections is ensured.

For more specific purposes, fluid components and products may be
It is an object of the present invention to provide a dispensing gun for fluids such as urethane foam that can be easily and quickly removed from mixing nozzles and other parts, thereby eliminating blockages. Yet another object of the invention is to provide a nozzle member that can be easily cleaned when the gun is used for intermittent spraying, and that can be easily removed and quickly reinstalled after the completion of an extended spraying operation. To provide potash for mixing and spraying fluids such as polyurethane.

Yet another object is to provide a potash as described above which is not expensive to manufacture and which can be easily and effectively operated even by unskilled workers.

Another object of the present invention is to provide a mixing and dispensing gun for products such as polyurethanes that ensures that the interaction of each component is limited to disposable or reconfigurable nozzles.

The present invention will now be described in more detail with reference to the accompanying drawings.

The same reference numerals are used throughout the drawings to refer to the same parts. FIG. 1 shows a typical embodiment of the invention in use.

An operator 10 is spraying a wall 11 with a urethane foam product 12 by means of a spray gun 14 according to the invention. Each fluid component of the urethane foam is stored separately in separate pressurized containers 16 and 17, which may be located within carrier 18 for convenience. Each urethane foam component has an individual connecting hose 19,
20 to the spray gun 14 where they are mixed and then sprayed as urethane foam 12 onto the wall 11. In accordance with the present invention, after use of the gun, a relatively inert fluid is pumped through each section of the gun to clean the mixed product foam fluid.

This cleaning fluid is also conveniently stored in a pressurized container 21 which may be mounted within the carrier 18 and is led separately to the gun 14 by a connecting hose 22. As shown in Figures 2 and 6, the mixer-discharge spray gun 14 has a housing 25 extending from the housing 25 to a handle 2 shaped to facilitate handling of the gun.
6 is down.

Hoses 19 and 20 conducting product fluid components are connected to gun housing 25 by mutual fittings 27 and 28, respectively.
It is securely installed. In the illustrated example, these fittings 27 and 28 are formed with reduced diameter grooves 29 and 30, respectively. These grooves 29 and 30
fittings 27, 28 and hose 19, against axial movement or accidental disconnection from gun 14 by engaging housing locking screws 31 and 32, respectively.
Tighten 20.

A seal, which is a known member such as an O-ring, is provided to prevent fluid leakage. To control the flow of each product fluid component through the gun, a plurality of primary valves 37 and 38 block and selectively inhibit fluid flow or allow fluid flow.

In the illustrated example, the valves include ball members 39 and 40, respectively, adapted for fluid-tight engagement with seats 41 and 42, respectively, formed in housing 25. Normally, these ball members 39 and 40 are biased to a fluid flow inhibiting position. This biasing action is achieved by valve coil springs 43, 44 interposed between the fittings 27, 28 and the ball members 39, 40.
Simultaneous actuation of 7 and 38 and subsequent flow of product fluid components is provided by a tricar mechanism 50 as shown in FIGS. 2 and 3.

Tricker member 51 conveniently pivoted to housing 25
are adapted to engage thrust pins 53 and 54 that are slidably mounted within housing 25. The rear ends 56, 57 of these pins 53, 54 are connected to the ball member 3.
9 and 40 to move them from the closed seated position shown in FIG. 4 to the open unseated position of FIG. When the pressure on trigger 51 is released, biasing members, such as compression coil springs 58, 59, retract pins 53, 54 from ball members 39, 40, causing balls 39, 40 to move into seats 41, 42. Allows for relocation. Guide collars 60, 61 may be provided to ensure smooth spring, trigger and valve operation.
As shown in FIG. 2, if desired, a tricker retaining member 62 may be provided to move the tricker and associated valve either in a closed position to restrict fluid flow as shown, or in an open position to allow fluid flow. , can be held to. This is done by providing recesses 63, 64 in the gun handle 26. The leg portion 65 of the holding member 62 is arranged in either of these recesses 63, 44 to hold the tricker mechanism 51 in the corresponding position. Downstream of the valves 37, 38 are primary passages 67, 68.

These passageways formed in housing 25 establish a separate fluid path between each primary valve 37, 38 and mixer-discharge nozzle member 70 (FIG. 3). A helical baffle member 71 is provided within the nozzle member 70 to promote thorough mixing of separately received product fluid components. Mixing of the components and positive discharge of the product fluid is further facilitated by the nozzle orifice 72. The nozzle orifice 72 is dimensioned to allow free (ie, easy) flow of product fluid through the nozzle at a sufficient velocity to create an easily directed flow of relatively good morphology. A feature of the present invention is that the nozzle member 70 can be quickly removed from the gun and a new replacement nozzle easily installed, if desired.

For this purpose, the illustrated nozzle 70 is provided with a somewhat enlarged bayonet base 74 adapted to fit into a bayonet recess 75 formed in the housing 25 . The nozzle extensions 76, 77 are connected to the receiving parts 78, 7.
9 to form a fluid-tight connection therebetween. Thus, each product fluid component flowing from valves 37, 38 passes through primary passages 67, 68 through flow extensions 76, 77 and mixes within nozzle member 70. The reliable mixing action of the components is achieved by the spiral diagonal member 7.
1 and the mixed foaming fluid is discharged through the nozzle orifice 72 to the target area. In order to securely hold the nozzle member 70 and facilitate its replacement if desired, a nozzle ejector-retainer lever mechanism 80 is provided as shown in FIG.

The lever mechanism 80 has a first extension 81 terminating in a hook 82 adapted to engage an annular collar 80 partially defining an enlarged bayonet base 74 of the nozzle 70. There is. The interengagement of hook 82 and collar 84 prevents accidental ejection of the nozzle from the gun when nozzle removal is not desired. The second lever extension 85 is adapted to engage the rear portion of the nozzle member 70 as shown in FIGS. 2 and 3. Ejector-holding member lever 8 from the position shown by the solid line in FIG.
Pivoting to the position shown in phantom at 0 moves the second lever extension 85 forward, forcing the nozzle 70 out of the gun housing 25. Lever 80 is normally held in the nozzle retaining position by biasing means, such as a coil spring 87 conveniently mounted on the top of gun housing 25. In accordance with the present invention, at least a portion of the primary passages 67, 68 and nozzle 70 are adapted to be purged of component fluids and mixed product fluids.

To this end, a secondary valve 90 is provided to control the flow of cleaning fluid into the gun, and secondary passages 91, 92 provide a cleaning fluid path between the secondary valve and each primary passage. Establish.
This arrangement allows cleaning fluid to flow through at least a portion of each primary passageway 67, 68 and nozzle 70 when cleaning the gun.
flow through to facilitate extensive, reliable cleaning. The cleaning fluid is preferably compressed air, nitrogen, or other inert fluid that does not react with the product fluid, product fluid components, or parts of the gun. A feature of the invention is that secondary passages 91, 92 intersect primary passages 67, 68 at respective locations 93, 94 near primary valves 37, 38.

The cleaning fluid thus passes through the primary valves 37, 38 and prevents the valves from clogging and consequent gun malfunction. The formation of both the primary passages 67, 68 and the secondary passages 91, 92 may be conveniently accomplished by drilling through the working recess 95. After passage formation is achieved, these recesses 95 can be closed by cap screws 96. It is a feature of the present invention that the secondary or cleaning fluid valve 90 is adapted to be controlled independently of the gun trigger, even when the operator holds the gun handle 26 and trigger mechanism 21 in one hand. .

To this end, the illustrated valve 90 has a hollow kill member 97 adapted to be connected to the cleaning fluid hose 22 . As shown in FIGS. 3 and 4, this hose-kill interconnection is accomplished by providing a hose fitting 98 with a reduced diameter groove 99. kill 97
A locking screw 101 is provided in the enlarged portion 100 of the groove 99.
are intersecting and engaged. one or more 0-
Ring 102 provides a fluid tight connection between kill 97 and fitting 98.

The enlarged kill section 100 is knurled to facilitate rotation of the kill and operation of the secondary valve. The kill 97 and kill receiving housing tube 107 have threads 108,10
9 is provided.

When the kill 97 is rotated relative to the housing 25 about its axis, insertion of the kill into or partial withdrawal of the kill from the housing 25 occurs. Kill member 97 is also provided with holes 111, as shown in FIG. 4, through which cleaning fluid can flow.

Near the end face 112 of the kill, a plurality of radially oriented passageways 113 direct a flow of cleaning fluid out of the kill member 97;
The flow is directed to an annular chamber 114 between the reduced diameter kill tip 115 and the housing tube 107. An O-ring 117 prevents backflow of cleaning fluid from the housing through the kill member. At the bottom 118 of the housing cylinder 107,
One or more orifices 120, 121 are located in the chamber 114, as indicated by arrow A in FIG.
to the secondary passages 91 and 92.

However, when the kill member 97 is fully inserted into the housing tube, the bottom 118 of the tube as shown in FIG.
The sealing abutment of kill surface 112 against prevents flow through orifice 120 and into the gun. By opening the kill 97 to an appropriate degree, cleaning fluid can flow freely through the gun and into the nozzle 7 behind the distribution orifice 72.
Displaces the cleaned material without creating pressures higher than a relatively low back pressure of zero. A feature of the invention is that the bottom part 11 of the cylinder
8 is inhibited and cleaning fluid flow is facilitated by the washer member 130 adapted to be retained on the barrel bottom 118. The washer member 130 is provided with orifices 131, 132 adapted to align with the secondary passage orifices 120, 121 of the housing to allow cleaning fluid to kill and pass from the tube to the secondary passages 91, 92. do. The washer 130 is retained within the housing barrel 118 in its orifice aligned position by one or more alignment pins 135, which are located in a pin receiving recess 136 in the housing 25 and in a pin receiving recess 137 in the washer 130 itself. It has been extended between. To extend the service life of the gun 14, the washer 130 is constructed from a polytetrafluoroethylene material that is inert with respect to the cleaning fluid and product fluid components.

The described structure of the spray gun is easy to use even by an inexperienced person.

Each product fluid component is directed to the gun in a separate product fluid component flow path by individual hoses 19 and 20. The flow of each product fluid component is restricted by a valve 37 or 38. Each fluid component passing through a valve 37 or 38 flows from a separate primary passageway 67 or 68 to a common mixing and dispensing nozzle chamber 70. The nozzle and gun itself are adapted to precisely direct the mixed foam product onto the target area. After use of the gun, if the gun is not used for a short period of time, the secondary valve is opened by rotating the knurled portion 100 of the kill 97. The cleaning fluid is passed through the secondary passage 9
1,92, passes through the primary valves 37,38, and enters the primary passages 67,68, forcing the product fluid components out of the primary passages and out of the nozzle itself so that a relatively fast-hardening product foam is absorbed by the fluid components. Clean the gun even when it forms. Since the gun will not be used for a relatively long period of time, the nozzle 70
can be removed from the gun, eliminating the possibility of backflow of uncleaned foam product upstream of the gun. When it is desired to use the gun again, a new nozzle can be installed. Although specific embodiments of the invention have been described above, it will be understood that the invention is not limited to the embodiments described, as many modifications are possible.

Therefore, for a better understanding of the invention, modifications of the invention are shown in FIGS. 7-9. The specific examples in Figures 7 to 9 are as follows:
Since many of the parts used in the embodiments of Figures 1-6 are included, the same reference numerals and suffix A have been used for the same parts to refer to the embodiments of Figures 7-9. Common parts are now distinguished. In the specific example of FIGS. 7 to 9, the nozzle 7
Characterized by the installation of a restriction valve in 0A, which is used to selectively introduce fluid product components into the mixing chamber section 138 of nozzle 70A and, more importantly, to prevent backflow. be done. The installation of check valves of the type described below positively limits the physical and chemical interaction of product components to separate nozzle members that may be discarded or reconditioned. The check valve thus prevents clogging of gun 14A by preventing one product component from leaking across the nozzle and into the other product component. If this were not done, there would be blockage of gun A, which would be encountered, for example, upon a decrease in pressure in only one component tube or a lack of smoothness variation when pulling the trigger. Thus, although it is not possible to visually inspect the gun system, the check valve arrangement described is susceptible to problems resulting from defective parts and the interaction of components into the nozzle, which can be removed to resolve the problem. limit. The described check valve arrangement allows for different pressures to be used in the various product component pipes while maintaining a preselected stoichiometric ratio of each component itself.

Variations in the viscosity of the product components can also be achieved by appropriate design of the check valve of the present invention. With particular reference to FIG. 7, and also FIGS. 8 and 9, the nozzle 70A includes a helical coil disposed within the mixing chamber 138 spaced apart to form a flow path downstream of a pair of tubes 140. Stationary mixing member 71A
Contains.

The tube 140 is adapted to snugly engage the holes 78A, 79A and is provided with a plurality of sealing ribs 1 for this purpose.
42 is clearly shown in FIG.
Each of the tubes 140 is provided with a conical tapering tip 144 to facilitate insertion of the tube into the appropriate hole in the gun housing. The tip 144 of each tube 140 is centrally bored by a cylindrical bore 146 to form an inlet for the product fluid component, and the bore 146 opens into an internal bore 148 . The hole 148 has a tapered conical shape and widens outward in the direction of the mixing chamber 138 so that the check valve device 1
50 to form a valve seat. It should be appreciated that an important feature of the present invention is the installation of the check valve device 150 as an integral part of the nozzle 70A, and in addition to the valve seat defined by the conical taper bore 148. Each check valve device has a valve ball 152 disposed between a valve seat and a coil bias spring 154.

The strength of the spring 154 is selected to force the valve ball 152 into a position in the conical valve seat of the bore 148 that would normally close communication with the corresponding tube 140;
additionally selects a valve ball in response to fluid pressure within the pipe;
The tube is positioned to selectively open the tube to product component flow. To establish a preselected positional relationship between the valve ball 152 and the biasing spring 154 relative to the valve seat defined by the hole 148, the nozzle 70A has the eighth and ninth
As shown in the figure, it has a holding member 156.

An integral cylindrical, centrally located, upstream-oriented stem 158 extends from the body of the retaining member 156 into a mating hole 160 in the nozzle base to secure the retaining member in place. There is. If desired, a film of adhesive may be placed between the stem and hole 160 to maintain the assembled relationship. Outside the stem 158, a pair of parallel
A tubular stem member 162 extends toward and in axial alignment with tube 140. The members 162 communicate with each other by a cylindrical aperture 164 formed therein.
4, each product component is passed through the holding member into the mixing chamber 13.
Proceed to within 8. Member 162 also includes radial hole 1
66 is provided to provide additional means for exit of fluid product components. Locating ears 168 are additionally provided on the retaining member 156 to additionally facilitate mounting and positioning of the retaining member. It should be appreciated that each check valve 150 operates independently of each other and in response to the pressure of each bias spring and product component.

As shown in FIG. 9, one of the valve balls 152 accidentally
may be seated to close the corresponding tube 140, while the other valve ball is forced by the pressure of the product fluid from the seated position shown in dashed lines at reference numeral 170 to the position shown in solid lines to correspond. The tubes are opened to allow the corresponding fluid product components to enter the mixing chamber 138. In such a state, the closed check valve closes the hole 78A to the hole 79.
Prevent leakage of ingredients to A. Product component interaction is thus limited with respect to nozzle 70A. The nozzle base advantageously includes an axial locating rib 172 that fits into a groove 174 in the gun housing to align tube 140 with holes 78A and 79A.

Although the present invention has been described above with reference to specific embodiments, the invention is not limited to the embodiments shown in the drawings and described in detail herein.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram illustrating a typical use of the new dispensing gun. FIG. 2 is a side view showing further details of the new dispensing gun. FIG. 3 is a cross-sectional view taken substantially along line 2--2 of FIG. 2 showing further detail of the dispensing gun where the gun is discharging a multicomponent product fluid; be. FIG. 4 is a partial view similar to FIG. 3, showing portions of the gun as cleaning fluid passes through the interior of the gun.
FIG. 5 is an exploded view showing further details of the cleaning fluid regulation mechanism. FIG. 6 is a front view of the gun. FIG. 7 is a central sectional view similar to FIG. 3, but illustrating a modification of the invention, in which interaction of the fluid components is positively restricted to the nozzle. FIG. 8 is an enlarged cross-sectional view taken along line 8--8 of FIG. 7 showing the check valve retaining member.
FIG. 9 is a view similar to FIG. 7, but showing one of the check valves in the open position that would occur if the mating tube became clogged. 12... Urethane foam product, 1
4,14A...Spray gun, 26...
・Handle, 27, 28... Mutual fixture, 31, 3
2... Housing locking screw, 37, 38...
...Primary valve, 50...Triker mechanism, 51.
...Trigger member, 53,54...Thrust pin, 60,61...Guide collar, 67,
68...Primary passage, 70,70A...
Mixing-discharge nozzle member, 72... Nozzle orifice, 80... Nozzle ejector-holding member lever mechanism, 82... Hook, 90...
Secondary valve, 97... Kill member, 92...
Cleaning fluid hose, 107... Kill receiving housing tube, 138... Mixing chamber, 150...
... Check valve device, 156 ... Holding member.

Claims (1)

[Claims] 1 In a system for mixing-dispensing of product fluids: a container for separately stored components; a gun housing with a passageway connected to the container; a product component flow path and in the gun housing. including a primary valve, the primary valve being capable of controlling the flow of a component through the passageway; actuator means within the housing selectively operating the primary valve to control the flow of a corresponding fluid product component; a mixing chamber having a dispensing orifice; and a reinstallable nozzle element mounted within the gun housing for receiving and mixing each product component and dispensing the resulting mixed product; a pair of product component tubes having connecting elements that individually open into the chamber remote from the orifice and are connected to corresponding product component flow passages in the gun housing; mounted on the nozzle element to form a fluid flow path between the tube and the mixing chamber for selectively introducing corresponding fluid product components into the chamber to produce any mixture into the gun housing; The nozzle element, together with the check valve, can be removed as a unit, independent of the primary valve, for repair, replacement and cleaning of the nozzle element. A system for mixing and dispensing said product fluids.