Foam Dispenser

Abstract

Dispenser apparatus for multicomponent products comprises a pair of containers each having its own dispensing valve. A bracket is arranged to hold the containers in fixed position and includes a manual trigger. Links are provided for connecting the trigger with the valves for actuation of the valves in unison; and the dispenser apparatus additionally includes a remote dispensing nozzle unit and tubing connecting each of the dispensing valves with the latter unit.

Description

This invention relates generally to apparatus for dispensing multicomponent products and more particularly to portable apparatus of that type.

Portable dispensers for multicomponent products, such as urethane foams, have been developed heretofore; and these devices have commonly employed a rupturable membrane for isolating the reactable ingredients of the product. However, when the membrane has been ripped or broken and the ingredients mixed, the entire contents of the device must be used or discarded at once. While this requirement for immediate and complete utilization is acceptable and desirable in instances where the contents closely approximate the volume of the product needed in a particular application, other situations exist in which a considerably smaller quantity of product is desired at periodic intervals.

Therefore, an important object of the present invention is to provide a portable dispenser for multicomponent products which can be operated intermittently with either short or long intervals between activations.

A more general object of the invention is to provide a new and improved portable device for dispensing multicomponent products.

Another object of the invention is to provide a portable dispenser for multicomponent products which incorporates a novel, disposable mixing and dispensing nozzle.

Still another object of the invention is to provide a dispenser of the type described which is capable of one-hand operation.

Yet another object of the invention is to provide a portable dispenser of the type described which is able to dispense into relatively inaccessible locations.

These and other objects and features of the invention will become more apparent from a consideration of the following descriptions.

In order that the principles of the invention may be readily understood, a single embodiment thereof, applied to the dispensing of rigid urethane foam products but to which the application is not to be restricted, is shown in the accompanying drawings wherein:

FIG. 1 is a perspective view of dispensing apparatus in accord with the invention used in a one-hand manner for calking a crack in a wall;

FIG. 2 is a perspective view illustrating two-hand use of the apparatus of FIG. 1 with the dispensing nozzle demounted for manual manipulation into a comparatively inaccessible location;

FIG. 3 is an enlarged, bottom plan view of the dispensing apparatus of FIGS. 1 and 2;

FIG. 4 is a further enlarged sectional view of the breakaway fitting, being a view taken substantially along the line 4-4 of FIG. 3;

FIG. 5 is an intermediate scale view in side elevation showing the dispensing apparatus of the invention arranged for one-hand operation, actuation of the manual trigger and corresponding movement of the dispensing valves being suggested in broken outline;

FIG. 6 is a further enlarged, sectional view taken substantially along the line 6-6 of FIG. 5 to show the pivot for the manual trigger;

FIG. 7 is a further enlarged, sectional view taken substantially along the line 7-7 of FIG. 5 to show the construction of a dispensing valve and the fitment used in connecting it to the tubing system;

FIG. 8 is an enlarged, central sectional view taken substantially along the line 8-8 of FIG. 3 to show the construction of the mixing and dispensing nozzle; and

FIG. 9 is an exploded perspective view, on a somewhat reduced scale, of the mixing and dispensing nozzle.

Referring now in detail to the drawings, specifically to FIGS. 1 and 2, portable dispensing apparatus constructed in compliance with the invention and designated generally by the reference numeral 10 comprises a pair of pressure vessels or containers 12 and 14, a support bracket or holder 16, and a dispensing nozzle unit 18. Two of the pressure vessels are employed in the apparatus 10 because the product to be dispensed, for purposes of the illustrative embodiment, is reacting urethane foam and because such foams are comprised of two basic reactants, namely an isocyanate resin and a suitable source of hydroxyl groups, such as a polyester or polyether polyol. The isocyanate component, for example, will be charged into container 12 together with a suitable quantity of a selected, liquified propellant gas, such as dichlorodifluoromethane for example. The companion container is charged with the reactable component, a polyester polyol for example, suitably formulated with catalyst material, such as organotin compounds or tertiary amines, a surfactant and a mixture comprising a suitable, liquified propellant gas and foaming agent, such as a mixture of difluorodichloromethane and trichlorofluoromethane. In compliance with the features of the present invention, a quantity of a common liquified propellant is charged into each of the containers 12 and 14 in order to have substantially the same vapor pressure in each of the containers. As a result, substantially equal volumes will be dispensed from the two vessels, thus insuring proper stoichiometry of the dispensed foam. It is also advantageous to provide a quantity of an inert, compressed but unliquified gas, such as nitrogen, in each of the containers 12 and 14 to preserve the propellant in both a liquid and gas phase so that the liquid phase thereof may serve to froth the reacting resins as they are dispensed.

In order that the dispensing apparatus 10 may be lightweight and portable and capable of one-hand operation, in the manner suggested in FIG. 1, the containers 12 and 14 are fabricated to be of thin-wall construction as well as of pressure-resistant shape whereby to contain the various pressurized contents successfully. Each of the containers 12 and 14, therefore, comprises a cylindrical body, a domed top and a concave bottom. Suitable pressure-resistant construction, as well as manufacturing economy, has been secured by selecting the containers 12 and 14 to be conventional, metal aerosol product cans. Economy of manufacture is also promoted by closing the containers 12 and 14 with a conventional foam aerosol valve 20, as is shown in FIG. 7.

Continuing with reference to FIG. 7, the foam-dispensing valve 20 includes a recessed metal cap 22 having a peripheral rim 24 that is crimped onto a rolled bead 26 surrounding the mouth of the associated pressure vessel or container. The cap 22 is centrally perforated to receive an elastomeric sealing body 28, and the sealing body 28 has a central bore which resiliently receives a rigid valve element 30. The valve element 30 is tubular and is radially apertured with dispensing ports 32 which serve to pass the contents of the pressure vessel whenever the valve element 30 is tilted. An external portion 34 of the valve element 30 is fashioned with a spiral rib or thread 36, the utility of which will be described more fully hereinafter.

Turning to FIG. 5, the container bracket or holder 16 generally comprises a reclining U-shaped part that is made up of an upper plate 38, a lower plate 40 and an interconnecting bight portion 42 which serves as a handle or grip. As is shown in FIG. 6, the upper plate 38 is fashioned with a rectangular aperture 44 which serves as a pivot point for a trigger blade 46. With reference to FIG. 3, the lower plate 40 is provided with a longitudinally extending slot 48 that acts as a guide for the trigger blade. Returning to FIG. 5, the unpivoted lower end of the trigger blade 46 extends beyond the lower plate 40 into approximately the plane of the dispensing valves 20. Each of the valves 20 is provided with a tubular fitment 50 that is forced onto the rigid valve element 34 until at least several turns of the thread 36 are buried in the fitment as is shown in FIG. 7 whereby to establish a secure connection. In addition, the fitment 50 includes a medial, circumferential flange 52 that defines a shoulder 54 for use in assembling the fitment and the valve element. A flexible tension strap 56 radiates from the fitment 50 at the flange 52 to terminate in a trigger eye 58 as is shown in FIG. 3. With reference to FIG. 5, the unpivoted lower end of trigger blade 46 is fashioned with a rearwardly opening, horizontal slot 60 for positioning and retaining the trigger eye 58. Each of the straps 56 may terminate in an individual trigger eye or the two straps may be provided with a common trigger eye as is desired. In any event, the straps 56 are arranged to be flexible and advantageously of some longitudinal resilience. Flexibility in the straps 56 is desirable to insure actuation of the valves 20 only on a pull stroke of the trigger blade 46, thus minimizing the possibility of accidental actuation and concomitant undesired dispensing action. Resiliency in the straps 56 is desirable in that it tends to insure equal tilting force on the two valve elements 34 and thereby substantially equal volumetric discharge rates from the two containers 12 and 14. Suitable radial resiliency in the fitment 50, suitable axial resiliency in the straps 56 and desired chemical inertness in the fitting 50 is achieved by fabricating these components from an olefinic resin such as polyethylene; and advantageously, the fitment 50, the strap 56 and the trigger eye 38 are fashioned as a unit by being molded integral.

In order that the valve elements of the valves 20 may be properly tiltably actuated, the pressure containers 12 and 14 must be secured in rigid relationship. For this purpose, both the upper plate 38 and the lower plate 40 of bracket 16 are fashioned with oppositely laterally opening, container-mounting notches or recesses 62 and 64, shown in FIG. 3. The recesses 62 and 64 are selected to take a circular shape corresponding with the cylindrical body of the containers 12 and 14 whereby fitably to engage the containers intermediate the ends thereof. In addition, suitable means are provided for drawing the containers 12 and 14 into radially converging relationship tightly fitting into the recesses 62 and 64. In the illustrated embodiment one or more encircling, tension straps 66 are employed for this purpose.

In compliance with the present invention, each of the valves 20 is connected individually to the dispensing nozzle 18 by a flexible conduit. More specifically and as is well illustrated in FIG. 2, the pressure vessel 12 is connected to the dispensing nozzle by a tubing unit 68, and the pressure vessel 14 is connected to the dispensing nozzle by a tubing unit 70. Each of the tubing units 68 and 70 comprises a primary length of flexible tubing 72 and a secondary length of flexible tubing 74. The lengths or sections of tubing 72 are connected to the fitments 50, the lengths or sections of tubing 74 are connected to the dispensing nozzle 18, and the respective sections 72 and 74 are joined together by a breakaway fitting 76. Referring for the moment to FIG. 7, the fitment 50 includes a stem 78 which extends beyond the flange 52, stem 78 being intended to telescope with the inlet end of tubing section 72 in a relatively secure manner. For this latter purpose, the stem 78 includes external, circumferential shoulders or ribs 80 which lock into the material to tubing section 72.

Considering FIG. 4, the breakaway fitting 76 comprises a union plate 82 and a pair of parallel coupling tubes 84 which extend axially from both sides of the plate 82 for joining each tubing section 72 with its companion tubing section 74. Associated ends of the coupling tubes 84 are fashioned with one or more external, annular ribs 86 for making relatively permanent connections when telescoped into the ends of the tubing sections 72. On the other hand, the other ends of coupling tubes, which are to be telescoped into the corresponding ends of the tubing section 74, are smooth-walled in order to facilitate separation of the tubing sections for purposes to be described more fully hereinafter.

The tubing sections 72 and 74 are selected to be flexible to facilitate manipulation of the dispensing nozzle unit 18 into comparatively inaccessible locations in the manner suggested in FIG. 2. In addition, both the tubing sections 72 and 74 and the breakaway fittings 76 are selected to be of chemically inert material. The various polyolefinic resins have proved eminently useful as materials construction for the tubing and the breakaway fitting.

Turning to FIGS. 8 and 10 for a description of the mixing and dispensing nozzle unit 18, that unit comprises a tubular cylindrical housing 88, a dispensing end cap 90, a static mixing element 92 and an inlet end cap 94. In order to promote economy and permit periodic disposal of the mixing and dispensing nozzle unit 18, the housing 88 is fabricated as an inexpensive paper tube or as an extruded plastic sleeve and the discharge end cap 90 is fabricated, for example, as a sheet metal stamping. The cap 90 is fashioned with a peripherally located, axially opening, circular groove 96 that is defined between an outer annular wall portion 98 and an inner annular wall portion 100. This groove receives the edge of one end of housing 88, and the wall portions 98 and 100 are crimped together to clamp the end of the housing, forming a secure connection. The cap 90 is also apertured for purposes of dispensing the foaming product; and in order to develop multiple streams of exiting product and thereby promote both expansion and the foamed state, the cap 90 is perforated with a plurality of discharge apertures 102.

The static mixing element 92 is advantageously fabricated from a rigid, chemically inert resin such as high density polyethylene or polypropylene and structurally comprises a solid, central stem 104 and a single, spiralled fin 106 which cooperates with the stem 104 in defining a radially outwardly opening, spiral mixing groove 108. The static mixing element 92 also includes a cylindrical base 110 whose outside diameter coincides with the outside diameter of the fin 106 and with the inside diameter of the tubular housing 88. As is shown in FIG. 8, the base 110 is provided with a conical premix chamber 112, and a radial port 114 opens from the premix chamber 112 into the spiral mixing groove 108. A segment plate 116 advantageously extends across a portion of the opening which connects port 114 and chamber 112 in order to direct the mixing materials into the spiral mixing groove. In accordance with the features of the present invention, the static mixing element 92 is shorter in length than the tubular housing 88, and the static mixing element includes a radially extending end flange 118 which abuts the edge of one end of the housing 88, as is shown in FIG. 8, in order to position the mixing element relative to the housing. This positive location of the static mixing element creates an expansion chamber 120 between the end of the static mixing element and the discharge end cap 90. It has been found that this expansion chamber promotes efficient foaming of the urethane materials packaged in the pressure vessels 12 and 14.

The inlet end cap 94 comprises a coupling cup portion 122 which telescopingly receives that end of housing 88 which encompasses the base 110 of the static mixing element 92. Furthermore, a pair of axially extending tubular inlet members 124 and 126 project from the floor of coupling cup portion 122 to receive the discharge end portions of the tubing sections 74 thereover. Each of the inlet members 124 and 126 is provided with an external, annular rib 128 which promotes and preserves the attachment to the respective tube sections 74. As will be seen in FIG. 8, the tubular inlet members 124 and 126 open through the floor of cup coupling portion 122 and into the premix chamber 112 generally adjacent the major diameter thereof.

For purposes of affording a more complete understanding of the invention, it is advantageous now to provide a functional description of the way in which the component parts operate. Assuming that the pressure vessels 12 and 14 have been properly filled with their respective ingredients and that the dispensing valves 20 have been secured in place and assuming that the filled and closured pressure vessels have been assembled with the holder 16, the tubing units 68 and 70 and the mixing and dispensing nozzle 18, it is only necessary to pivot the trigger blade 46 from the rest position shown in FIG. 5 in solid outline to the operating position illustrated in that FIG. in broken outline. This movement of the trigger blade tilts the valve elements 34 of the dispensing valves 20, opening the ports 32 to permit flow of material through the fitments 50, the tubing section 72 and 74 and into the premix chamber 112 of the dispensing nozzle unit 18. The holder 16 is arranged for use of the unit in the optimum, inverted condition of the containers 12 and 14, vertical grip portion 42 promoting this advantageous feature. When one-hand operation is desired, the mixing nozzle unit 18 will be positioned as shown in FIG. 1, i.e., resting between the containers 12 and 14 on the forward end of the upper plate 38. This type of operation is particularly convenient for sealing a crack 130 between masonry elements as is suggested in the FIG. The dispensed foam, being in an actively expanding condition, will completely fill cracks of any size and adhere to the confronting surfaces. Less accessible locations may be calked using the two-hand method suggested in FIG. 2.

When one particular task has been completed, operation of the dispensing apparatus 10 may be ceased merely by releasing the trigger blade 46. The resiliency of the sealing bodies 28 will urge the valve elements 34 into their normal nondispensing condition, terminating flow. The unit may be stored in this condition, the solidifying material in the mixing and dispensing nozzle 18 acting as an efficient seal for any ingredients remaining in the tube sections 72 and 74. When it is desired to restart and reuse the apparatus, the tube sections 74 and the nozzle unit 18 connected thereto will then be discarded and fresh components assembled at the breakaway fitting. The dispensing apparatus 10 is thus readied for a second utilization. This use procedure may be repeated until the contents of the pressure vessels 12 and 14 is exhausted, at which time the entire apparatus may be discarded.

From the foregoing descriptions, it will be appreciated that the instant invention provides conveniently used apparatus for dispensing a multicomponent product such as a curing urethane foam. It will also be appreciated that the apparatus of the present invention is readily stopped and restarted repeatedly; and while use of the dispensed foam as a calking material has been described, numerous other utilities are contemplated, for example, but not limited to, repair of refrigeration and air conditioning insulation, potting and environmental protection in the electronic industry, packaging of fragile and delicate instruments or tools or art objects, vibration or sound dampening, pipe insulation and various decorative applications.

The drawings and the foregoing descriptions are not intended to represent the only form of the invention in regard to the details of its construction and manner of operation. Changes in form and in the proportion of parts, as well as the substitution of equivalents, are contemplated as circumstances may suggest or render expedient; and although specific terms have been employed, they are intended in a generic and descriptive sense only and not for the purposes of limitation, the scope of the invention being delineated in the following claims.

Claims

We claim:

1. Dispenser apparatus comprising first and second container means, each including a foam dispensing valve mounted in the bottom end thereof, said valve including a downwardly extending, tiltably actuatable valve-and-delivery element; bracket means for holding said containers in fixed positions and including a manual grip portion and a manual trigger spaced from said valves and disposed between said valves and said grip portion, said bracket means further including spaced upper and lower container-retaining means engaging said container means for rigidly positioning said container means against actuating tension from said trigger whereby to insure uniform actuation of said valves; links connecting said trigger to said valve-and-delivery elements for actuation of said valves in unison; disposable mixing and dispensing nozzle means; and flexible tubing means, including disposable portions releasably connecting each of said valve-and-delivery elements with said mixing and dispensing nozzle means.

2. Dispenser apparatus according to claim 1 wherein each of said container means encloses a quantity of a propellant liquid, the propellant liquid in said first container means having substantially the same vapor pressure as the propellant liquid in said second container means whereby to dispense substantially equal volumes of the contents of said container means.

3. Dispenser apparatus according to claim 1 wherein each of said tubing means includes first and second lengths of tubing connected respectively to a said dispensing valve and said dispensing nozzle means and a breakaway fitting releasably interconnecting said first and second lengths of tubing.

4. Dispenser apparatus according to claim 3 wherein said breakaway fitting comprises tubular connectors telescoping into said lengths of tubing, said connectors having external rib means at said first lengths and smooth external surface portions at said second lengths.

5. Dispenser apparatus according to claim 1 wherein said dispensing nozzle means includes a tubular housing, an apertured discharge cap on one end of said housing, and a static mixing element in said housing spaced from said cap to define an expansion chamber therebetween.

6. Dispenser apparatus according to claim 5 wherein said cap has a plurality of discharge apertures therein.

7. Dispenser apparatus according to claim 5 wherein said static mixing element includes a radially extending end flange for positioning said element relative to said housing.

8. Dispenser apparatus according to claim 5 wherein said static mixing element includes a radially outwardly opening, spiral mixing groove, a conical premix chamber, and a radial port connecting said groove and said premix chamber.

9. Dispenser apparatus according to claim 8 wherein said dispensing nozzle means further includes an inlet cap on the other end of said housing, said inlet cap having axially aligned inlet members adapted to be connected to said tubing means and opening into said premix chamber.