Mixing And Dispensing Gun Having A Replaceable Nozzle

Abstract

A dispensing gun for fluids such as urethane foam and the like is provided in which separate fluid components are individually led to the gun and are mixed within a replaceable mixing and dispensing nozzle member. After gun use, the used nozzle member can be removed for cleaning or replacement with a fresh nozzle, thereby obviating difficulties encountered in cleaning and purging the entire gun. Also disclosed are inexpensive and effective component fluid flow control valves, which are opened by a gun trigger. Each valve is positively closed into a fluid-tight seal by pressure of the controlled fluid against a sealing resilient ball member, and is opened by the action of a plunger against the ball member.

Description

BACKGROUND OF THE INVENTION

This invention relates generally to portable apparatus for mixing and dispensing multi-component foam or like fluid products having several fluid components, and relates more particularly to spray guns for urethane foam.

Recently, the use of sprayed urethane foams in the construction of buildings and vehicles has rapidly expanded. Urethane foam is currently used as a wall insulation for buildings ranging in size from domestic houses to large skyscrapers. This relatively inexpensive material is also finding wide acceptance as an insulation for vans, trucks, and other vehicles used to move produce, flowers and like products requiring constant temperatures.

Urethane foam has proved to be a highly valuable insulating and construction material for a number of reasons. It is an excellent insulation, having extremely low heat-transmitting properties. It does not deteriorate rapidly, thus providing a long service life. Relatively extreme temperatures do not greatly affect it. It adheres to virtually all building materials. Its high compressive strength and its excellent dimensional stability permit it to be used not only as insulation but also as a supplemental support material in the construction of walls, partitions and the like.

Another reason for the increasingly wide acceptance of urethane foam as a construction and insulation material is the ease with which it can be applied or installed. The several fluid components of urethane foam can be separately stored, and can be easily mixed on the job site to create the foaming product. This foaming product can then be discharged or sprayed into a desired area. The sprayed foam product adheres to the target material and then hardens into a light insulation so strong that previously used auxiliary bracing materials are sometimes rendered unnecessary.

One foam mixing and dispensing device which has met with great commercial success is described and claimed in U.S. Pat. No. 3,633,795. As that patent explains, several portable, pressurized vessels are provided, each containing one of the basic reactants of the foam product. Each container vessel is connected by an individual tube to a dispensing gun. Actuation of a gun trigger permits the fluid components to flow into the gun, where they are intermixed. The mixed foaming product is discharged against a wall surface or other target area. After the spray application, the foam hardens into the finished strong and effective insulation material.

General experience with the mixing and spraying of urethane foam components and discharging the product upon the intended target surface has shown that, after mixing, the components of the urethane foam can be desirably selected so as to harden relatively quickly. While most of the material is sprayed on the target area before solidification begins, some residue remains within the dispensing gun after spraying has been completed. This residue tends to harden inside those parts of the gun where the fluid components have been mixed. Solidified foam within the gun makes the task of cleaning the gun and readying it for subsequent use extremely difficult.

Several attempts have been made to solve the problem of foam solidification within gun mechanism. Some guns have been designed to permit the entire mechanism to be cleaned or purged. Other guns, such as those shown in U.S. Pat. No. 3,575,319 and in U.S. Pat. No. 3,633,795 have been provided with replaceable dispensing nozzles or other parts which can be removed. After removal, the parts can be readily replaced with new parts.

Some mechanisms have operated satisfactorily, but have been expensive to manufacture, and cleaning or purging the entire gun has often been found to be expensive and time-consuming. In other mechanisms, loosely connected parts make the accidental disconnection of the nozzle or other members a continuous possibility. Accidental dislodgement of the dispensing nozzle from other gun parts during spraying operations can lead to discharge of unmixed fluid components onto the target area, injury to the surprised operator, damage to previously sprayed areas, or other undesirable results.

It is therefore a broad object of the present invention to provide a dispensing gun for mixing and discharging fluids such as urethane foam wherein the problem of foam solidification within the gun is obviated at low cost.

More specifically, it is an object of the present invention to provide a dispensing gun for urethane foam fluid components and like liquids wherein the fluid components are kept separate from one another until their introduction into a mixing and discharge member. During gun use, this mixing and discharge member is securely attached and made a part of the gun. After use, this member can be easily removed from the remaining gun parts, as for replacement with a fresh member.

It is another object of the invention to provide the described fluid discharge gun with fluid control valves which are inexpensive to manufacture, and which are highly effective in controlling the flow of the fluid components.

It is yet another object of the invention to provide a fluid discharge gun which is inexpensive in initial cost, and which may be easily and effectively operated by even inexperienced personnel.

Other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings. Throughout the drawings, like reference numerals refer to like parts.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an overall perspective view showing the discharge gun of the present invention and related apparatus being used to apply urethane foam or a like product to a typical target area;

FIG. 2 is an enlarged, perspective view of the discharge gun of FIG. 1, removal of the nozzle being suggested in broken ouline;

FIG. 3 is a further enlarged, sectional view taken substantially in the plane of line 3--3 in FIG. 2 showing in further detail the mixing and discharge gun nozzle, ejector apparatus, trigger, and related structure;

FIG. 4 is a sectional view taken substantially in the plane of line 4--4 in FIG. 3 showing in further detail the novel fluid control valve mechanism of the present invention;

FIG. 5 is a sectional view taken substantially in the plane of line 5--5 in FIG. 4 showing in yet further detail the novel fluid control valve mechanism;

FIG. 6 is a sectional view taken substantially in the plane of line 6--6 in FIG. 4 showing structure by which the fluid mixing and discharge nozzle is attached to the discharge gun housing;

FIG. 7 is a perspective view showing the novel fluid mixing and discharge spray nozzle member; and

FIG. 8 is a fragmentary sectional view similar to FIG. 6 but showing the discharge spray gun with the nozzle member removed.

DESCRIPTION OF THE INVENTION

While the invention will be described in connection with a preferred embodiment, it will be understood that it is not intended to limit the invention to that embodiment. On the contrary, it is intended to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention.

Turning first to FIG. 1, there is shown a typical embodiment of the present invention in use. An operator 10 is shown spraying a wall surface 11 with a urethane foam product 12 by means of a spray gun 14 embodying the present invention. The fluid components of the urethane foam are separately stored in individual pressurized vessels 16 and 17, which, in turn, may be located for convenience within a portable carrier 18. The urethane foam components are separately led to the spray gun 14 by individual connector hoses 19 and 20 where the components are mixed and are then discharged against the wall 11 as urethane foam 12.

In general, the mixing and discharge spray gun 14 includes, as may be seen in FIGS. 2-5, a housing 22, a handle 23 affixed thereto for grasping and aiming the gun, a plurality of valves 25 and 26 for controlling the flow of the fluid components to the gun, a manually operable trigger 27 for controlling the valves 25 and 26, and a mixing and a dispensing nozzle 29. The respective fluid components which are stored in the separate tanks 16 and 17 are received at spaced apart locations, as at plug connectors 31 and 32, and are delivered to the nozzle 29 in an unmixed condition, thereby confining all the fluid component mixing to the interior of the nozzle 29 which is advantageously fabricated from chemically inert material. When the operator squeezes the trigger mechanism 27, a fluid pathway is established between the fluid containers 16 and 17 and the mixing and discharge nozzle 29. As may be best seen in FIG. 4, each fluid component passes through the respective hose 19 or 20, and through the connector 31 or 32 to the respective control valves 25 and 26. After passing through these valves, each fluid component then flows down individual bores 37 and 38 to intersecting ports 39 and 40 formed within the housing 22, and thence into communicating nipple ports 41 and 42 formed in the the nozzle member 29 and having a series of sealing rings 43 fashioned on the external surface thereof.

The interior of the nozzle member 29, as illustrated in FIGS. 3 and 4, is internally configured to promote the mixing of the separately received fluid components. To that end, a single, helically configured mixing guide 45 is mounted on a solid, central cylindrical stem 46 within the nozzle housing. A discharge opening 47 permits the mixed foaming components to be sprayed from the nozzle 29 on the target area. As illustrated in FIGS. 2, 3 and 7, this opening 47 is a diametrically extending slot which forms a fan-shaped discharge flow in a pre-determined direction. It will be understood, however, that one or more substantially round discharge openings could likewise be provided to discharge the mixed urethane foam components in a stream of circular cross-section.

In accordance with the invention, the mixing and discharge nozzle member 29 is rigidly securable to the gun housing 22, and yet can be easily removed from the housing 22 as for replacement with a fresh nozzle. By providing a removable and replaceable nozzle 29, the problem of foam solidification within the gun is obviated. To this end, in the illustrated embodiment, the gun housing 22 is provided with a relatively deep seat recess 50 for receiving a base portion 51 of the detachable nozzle 29 and orienting it in a pre-determined discharge position. A rigid and secure seating action between the nozzle 29 and the housing 22 is provided by forming the seat recess 50 within encompassing walls 52 extending from the housing 22 itself.

In further accordance with the invention, the removable nozzle 29 is selectively but positively retained upon the gun 14 by a latch mechanism 54 mounted on the housing 22. In the illustrated embodiment, the latch mechanism 54 includes a latch lever 55 pivotally mounted, by a transverse pin 56 of other convenient means, upon the housing 22. At its fore-end, the latch lever 55 is provided with a retaining finger 57 oriented to engage an annular front step 58 formed upon the nozzle base 51. As may be envisioned by reference to FIG. 3, depression of a thumb-lever portion 59 of the latch lever 55 will rotate the latch lever 55 about its pivot pin 56 from the position illustrated in solid lines to that illustrated in phantom lines. When the lever 55 is thus depressed, the latch finger 57 is removed from the base step 58, thus freeing the nozzle 29 for ejection.

It is another feature of the invention that the latch mechanism 54 operates to positively eject the used nozzle 29. For this purpose, a nozzle ejector lever 60 is formed upon the latch lever 55 and is positioned for engagement with a rear surface 61 of the nozzle 29. Depression of the thumb-lever portion 59 of the lever 55 positively urges the nozzle 29 out of its seat 50. Normally, however, the latch lever 55 is biased into its retaining position rather than its ejecting position, as by a coil spring 63.

It is another feature of the invention that the replacement nozzle can be easily and quickly oriented for insertion into the spray gun housing 22. To this end, the housing is provided with a guide, and the nozzle 29 is provided with a mating guide follower. In the embodiment, illustrated in FIGS. 6, 7 and 8, the housing guide takes the form of a keyway slot 65 and the nozzle guide follower takes the form of a key 66. By sliding the guide-following key 66 into the keyway slot 65, the protuding nipple ports 41 and 42 of the nozzle 29 are automatically aligned for correct insertion into their mating bores within the housing 22.

In accordance with another aspect of the invention, fluid flow through the discharge gun 14 is controlled by inexpensive but highly effective fluid valves located within the gun. As illustrated in FIGS. 4 and 5, these valves 25 and 26 include valve seats 68 and 69 respectively, which may be conical in configuration. Spherical valve balls 71 and 72, which may be formed of a resilient substance, are provided for deformably engaging the seats 68 and 69 to form a fluid-tight seal and halt fluid flow from the tubes 19 and 20 to the valve outlet bores 37 and 38.

To unseat the balls and permit fluid flow, individual plungers 74 and 75 are mounted slidably within the housing 22 by antifriction sleeves for engaging the balls as illustrated. As illustrated herein, the plungers 74 and 75 are connected to the trigger 27 by expanded heads 77 and 78, which engage slots 79 and 80 formed in the substantially upright side frame members of the trigger 27, thus forming scotch gearing mechanisms.

As best seen in FIG. 5, the trigger means 27 is pivotably mounted, as by the latch mounting pin 56 on the housing 22. Squeezing action by the gun operator on the pendant portion of trigger 27 causes the engaged plungers 74 and 75 to slide into the housing 22, thus unseating the balls 71 and 72, and permitting fluid flow. Normally, the trigger 27 is urged generally away from the housing 22 by a biasing member such as a wire spring 85. In this position, the plungers 74 and 75 are pulled away from the housing 22 by a biasing member such as a wire spring 85. In this position, the plungers 74 and 75 are pulled away from the respective ball members 71 and 72, thereby permitting the balls 71 and 72 to be seated on the respective valve seats 68 and 69 by fluid pressure against the upstream ball sides.

Accidental manipulation of the trigger 27 and consequent fluid flow through the discharge gun 14 can be prevented by a trigger safety mechanism 87. In the illustrated embodiment of the invention, the safety mechanism 87 takes the form of an invented U-shaped plate rotatably mounted upon a lower surface portion of the gun handle 23. When the safety is selectively rotated from the position shown in FIG. 3 to trigger-engaging position shown in broken outline in FIG. 5, motion of the trigger 27 is positively prevented. If desired, a small bias member 88, as for example a compression spring can be provided to urge the safety into frictional engagement with the housing 22, thereby preventing unwanted or accidental rotation of the safety member 87.

Claims

What is claimed is:

1. In a dispensing gun for mixing and discharging multi-component fluids, the gun comprising housing means, handle means affixed to the housing means for grasping the gun and aiming the discharge thereof, a plurality of valve means carried by the housing means for controlling the flow of the multi-component fluid through the gun, a plurality of connections adapted for cooperating in establishing a fluid pathway between said valve means and remote supply container means, and manually operable trigger means mounted on the housing means for controlling the valve means, the improvement comprising detachable mixing and dispensing nozzle means adapted for communication with each of the valve means for receiving all the components of the multicomponent fluid, the nozzle means being internally configured to promote the mixing of the received fluid components, and having nozzle exit means to discharge the mixed fluid in a pre-determined direction, nozzle seating means for orienting the nozzle means in a pre-determined discharge position, and nozzle latch means mounted on the housing means for selectively retaining the detachable nozzle means in a rigidly seated position relative to the housing and alternatively releasing the detachable nozzle means for removal from the nozzle seating means, said nozzle means including a plurality of spaced apart ports for receiving each fluid component of the multi-component fluid at separated locations and delivering each component to the interior of the nozzle means in an unmixed condition, thereby confining all the fluid component mixing activity to the nozzle means interior.

2. A dispensing gun according to claim 1 wherein said latch means includes nozzle ejector means for positively urging said nozzle means out of said nozzle seating means when the latch means is actuated for releasing the nozzle means from the gun.

3. A dispensing gun according to claim 2 wherein said ejector means comprises a nozzle ejector member oriented for engagement with the nozzle means.

4. In a dispensing gun for mixing and discharging multi-component fluids, the gun comprising housing means, handle means affixed to the housing means for grasping the gun and aiming the discharge thereof, a plurality of connectors adapted for cooperating in establishing a fluid pathway between said gun and remote supply container means, nozzle means affixed to the housing means for mixing the fluid components and discharging the mixed fluid in a predetermined direction and trigger means for selectively starting and stopping fluid flow through the dispensing gun, the improvement comprising valve means for starting and stopping fluid flow through the dispensing gun in response to actuation of the trigger means, the valve means including valve seat means communicating with said connectors, ball means engageable with said seat means to form a fluid-tight seal for stopping fluid flow through the gun, plunger means connected to the trigger means for unseating the ball means and permitting fluid flow when the ball means is unseated, biasing means urging the plunger means away from the ball means thereby permitting the ball means to be normally seated on the valve seat means and the valve means to be normally closed, and valve outlet means connecting said valve seat means with said nozzle means for establishing a fluid pathway between said valve means and said nozzle means when the ball means is unseated and fluid flow is permitted, said biasing means engaging the housing means and the trigger means and normally urging the trigger means into an inoperative position, thereby pulling the connected plunger means away from the ball means and permitting the ball means to be normally seated with a fluid-tight seal on the valve seat means.

5. Apparatus for mixing and discharging multicomponent products comprising: supply containers for the respective components of a multi-component product; fluid component materials in said containers; a dispensing gun; and hose means connecting said gun with each of said supply containers, said gun including a housing, a handle affixed to the housing for grasping the gun and aiming the discharge thereof, valves carried by the housing for controlling the flow of the individual components of the multi-component product through the gun, a manually operable trigger mounted on the housing for controlling the valves, and detachable mixing and dispensing nozzle means adapted for communication with each of said valves to receive all of the component materials, said nozzle means being configured to promote the mixing of said component materials and having nozzle exit means for discharging the mixed product in a predetermined direction, said gun having nozzle seating means in the housing for orienting the nozzle means in a pre-determined discharge position and nozzle latch means mounted on the housing for selectively retaining the nozzle means in a rigidly seated position in said seating means and alternatively releasing said nozzle means for removal thereof, said nozzle means including fluid guide means for promoting the mixing of said component materials and a plurality of spaced ports for receiving each of said component materials at separated locations and delivering each component material to said fluid guide in an unmixed condition whereby to confine mixing action to said nozzle means.