US3319837A

US3319837A - Dispensing device

Info

Publication number: US3319837A
Application number: US428363A
Authority: US
Inventors: John J Mueller
Original assignee: AIR JECT CORP
Current assignee: AIR JECT CORP
Priority date: 1965-01-27
Filing date: 1965-01-27
Publication date: 1967-05-16
Anticipated expiration: 1984-05-16

Description

M y 1967 J. J. MUELLER DISPENSING DEVICE 2 Sheets-Sheet 1 Filed Jan. 27, 1965 mm TL MHM V mww J N% HW O J Afforneys May 11%, M67 J. .1. MUELLER DISPENSING DEVICE 2 Sheets-Sheet 2 Filed Jan. 27, 3.965

JNVENTOR. JOHN J. MUELLER M /j 6 dwjwf A fforneys United States Patent s,s1s,s37 DISPENSING DEVICE .iohn .l'. lt Iueller, Richmond Heights, Ghio, nssignor to Air-Ject Corporation Filed Jan. 27, 1965,5er. No. assess I8 laims. ((l'l. 222-212) This invention relates to a dispensing device, and more particularly to a dispensing device having an outer container that is both flexible and resilient.

The dispenser of the present invention is of the constant volume type; that is, the interior of the dispenser is divided into two separate zones, one zone for the ingredients to be dispensed and the other zone for air to displace the dispensed ingredients. The walls of the device are flexed to dispense the contents. The respective volumes of these two zones vary as the outer container, originally full of the ingredients to be dispensed, is emptied through use.

This invention particularly relates to such a dispensing device having a flexible diaphragm member separating the two interior zones of the container. Specifically, the flexible member is an expansi'ble and inflatable bladder or envelope within the outer container, fixed to one interior surface thereof, and sealed with respect to the interior of the outer container. Most advantageously, the bladder is stretchable and may be elastic.

The outer container of the dispensing device of the present invention includes two openings, one communicating with the interior zone containing the material to be dispensed, and the other communicating to the zone within the container defined by the expensible and inflatable bladder. A one-way valve cooperates with each of the two openings. The valve cooperating with the opening for dispensing the contents permits flow only from within the container to the outside. The one-way valve coopcrating with the opening in the bladder permits air to flow only from outside the container into the bladder. Flexing and releasing the resilient wall of the outer container dispenses the contents of the container and inflates the bladder, respectively. Thus, as the contents of the outer container are dispensed, the bladder fills with air, thereby displacing the dispensed contents and keeping the outer container, in etfect, always full.

The present invention is particularly useful for dispensing liowable materials, ranging from liquids to heavy creams or pastes. Furthermore, by providing an appropriate nozzle, a spray or stream effect may be obtained. Alternatively, multiple outlets may be used and, if desired, an applicator surface may be utilized in conjunction with the dispensing outlet.

The dispensing device of the present invention provides a convenient and inexpensive container that is, in effect, always full until empty and which may be readily and conveniently used in any position because the contents are always maintained adjacent the dispensing outlet or out lets. The construction of the dispenser effectively isolates the contents from the displacing air. Furthermore, no propellants are necessary. Thus, the size of the container is minimized and it is under no internal pressure until the wall is flexed to dispense the ingredients.

One particularly advantageous feature of the present invention is that the dispenser may be constructed to consistently dispense a substantially uniform and predetermined amount of the contents with each flexing. This is accomplished by limiting the maximum flexure of the container at a predetermined location. The container, by virtue of being always full, will dispense the same volume each time it is squeezed. This embodiment of the present invention is particularly useful for providing measured volumes of such things as cough medicine, cooking ingredients, liquid cleansers, etc.

Other attendant advantages of this invention and of the various embodiments thereof will be readily appreciated as the same become better understood by reference to the following detailed description when considered in connection with the accompanying drawings in which:

FIGURE 1 is a sectional view showing the construction of a dispenser constructed in accordance with the present invention; i

FIGURE 2 is a sectional view taken along the line 22 of FIGURE 1 and showing the manner in which the dispenser functions when squeezed to dispense a fiowable material contained therein;

FIGURE 3 is a sectional view similar to FIGURE 2 showing the manner in which the dispenser functions upon release of pressure on the outer container;

FIGURE 4 is a sectional view of another embodiment of a dispenser constructed in accordance with the present invention;

FIGURE 5 is a plurality of partial sectional views of the dispenser of FIGURE 4, FIGURE 5A showing a covering on the external surface of the dispenser have resilient tips or fingers, FIGURE 5B showing an abrasive covering, FIGURE 5C showing a covering of soft, absorbent material, and FIGURE 5D showing a brush-like covering;

FIGURE 6 is a sectional view of another embodiment of the present invention disclosing a roller dispenser applicator;

FIGURE 7 is a sectional view of another embodiment of the present invention disclosing a dispenser having a refillable reservoir and a wick for dispensing the fluid;

FIGURE 8 is a sectional view of another embodiment of the present invention showing a dispenser having an open, concave, reservoir in the external surface;

FIGURE 9 is an elevational view, partly in section, showing a spray type dispenser embodying the present invention; and

FIGURE 10 is an expanded, sectional view showing the separate components and one mode of constructing a dispenser embodying the present invention.

Referring now to the embodiment of FIGURES 1, 2 and 3, there is shown a dispensing container 15 having an outlet opening 17 and an inlet opening 18. An expansible, fluid-imprevious, envelope or bladder 16 is located within the container 15.

The container 15 is a tube or bottle formed of a flexible and resilient material such as a so called plastic material, for example, polyethylene. The container 15 is comprised of a continuous, upstanding, wall portion 20, a base portion 22 and top portion 24. The bottom opening 18 is formed in the base portion 22 and the top opening 17 is formed in the top portion 24.

The bladder 16 is attached in a fluid-tight, sealed, relationship to the inner surface of the base portion 22 of the container 15. The bladder surrounds the bottom opening 18 and isolates it from the top opening 17 and from the contents 19 within the container 15. Preferably, the expansible bladder 16 is formed of a stretchable material which may be elastic, such as synthetic or natural rubber.

Associated with the base opening 18 is a one-way valve, such as schematically shown check valve 25 that allows air to pass into the sealed envelope 16 within container 15 while preventing outward passage. Associated with top opening 17 is a one-way valve, such as schematically shown check valve 26, that allows the passage of a flowable material from container 15 through opening 17 while preventing the entrance of air or fiowable material into the container from the outside. As shown, each check valve is biased closed by a

spring

27 or 28 on the entrance side of the valve and by any pressure of a fluid trying to flow from the exit side through the valve. The

valve readily opens in response to a slight pressure increase on the entrance side of the valve relative to the exit side sufficient to overcome the bias of the spring. Suitable check valves for use with liquids and gases, as well as with more viscous flowable materials, are well known in the art. Suitable check valves include swing type check valves and ball type check valves, as well as the spring biased stern valve shown.

The embodiment of FIGURES 1-3 includes an optional stop member 30 and pressure plate 31. The pressure plate 31 is relatively rigid and is fastened to and extends across the upstanding wall 20 of the container at a generally central location. The stop member 30 is in the form of a rigid bracket fastened to the inside surface of the upstanding wall portion opposite the pressure plate 31. The stop member 30 includes

ends

32 and 33 extending inwardly of the container wall 20 and spaced a predetermined distance from the inner surface of the upstanding portion of wall 20 to which the pressure plate 31 is attached. This limits the degree of flexure to which the upstanding wall 20 of the container 15 can be subjected.

The manner in which the container 15 functions may be best understood with reference to FIGURES 2 and 3. Upon the application of pressure to the upstanding side wall 20, as indicated by the arrow in FIGURE 2, the container 15 flexes and the internal volume is reduced. The reduction in volume developes a pressure within the container 15 and, in response to this pressure, the check valve 26 in top opening 17 opens and flowable material within the container 15 is dispensed. During this time, the volume contained within the flexible, expansible, bladder 16 is maintained substantially constant by the closed check valve in the bottom opening 18. Upon the release of pressure against the upstanding side wall 20 of container 15, as shown by the arrow in FIGURE 3, the resiliency of the container wall 20 returns the wall to its original position, increasing the internal volume of the container and reducing the internal pressure. Check valve 26 in the top opening 17 is, at this time, closed by the spring 27 and the pressure external to container 15 and prevents air from entering the container through the top opening 17. At the same time, check valve 25 in the bottom opening 18 of the container opens as a result of the reduced internal pressure, and air flows from outside the container into the expansible bladder 16 to inflate the bladder and displace the dispensed material. When the pressure is approximately equalized, the spring 28 closes the valve 25. Because the bladder 16 displaces the dispensed material, the container remains full and the flowable material within the container is therefore maintained adjacent the dispensing outlet 17. Where desired, the stop member 30 and pressure plate 31 are utilized to limit the amplitude of the flexure of upstanding side wall 20 when the container is squeezed. Thus, with each application of pressure to the pressure plate 31, the volume of the container 15 is reduced a constant amount. Because the remaining flowable material within container 15 is always maintained adjacent the dispensing outlet 17, and because there is substantially no reduction in the volume enclosed by bladder 16 when the contents are dispensed, a uniform, predetermined volume is dispensed with each squeeze of the container. It will be understood that other means of limiting the flexure of the container may be used. For example, a split ring may be located within the container so as to be closed upon flexure of the walls. Alternatively, the container may be rigid except for a flexible portion or bubble that dispenses a predetermined amount when flexed to a maximum degree.

There is shown in FIGURE 4 a flexible container 35 constructed in the general configuration of a bar of soap. In the orientation of the container in FIGURE 4, there are upper and lower

major wall portions

37 and 38, respectively, and an upstanding, peripheral wall portion 39 connected thereto. A plurality of spaced dispensing openings 40 are provided in the upper and

lower wall portions

37 and 38. A check valve 42 is associated with each dispensing opening 40 to allow the outward flow -of material from within the container 35 while preventing flow into the container. A side opening 45 is provided in the upstanding, peripheral, wall portion 39 of the container 35. Within the container 35 and associated with the side opening 45 is a flexible, expansible bladder or envelope 46 surrounding the opening 45 and sealed with the side wall, isolating the opening 45 from the dispensable contents of container 35. Optionally, a covering 47 for use with the material dispensed through openings 40 may be adhered to one or both of

surfaces

37 and 38. If desired, only one of the major surfaces need have openings 40. By way of example, there is shown in FIGURE 5A a covering on wall 37 consisting of a multitude of protuberances, such as fingers 50, and in FIGURE 58 there is shown an abrasive covering 52, such as sandpaper or steel wool. These materials are capable of cooperating with a dispensed material, such as detergent soap, for purposes of scouring or otherwise abrading a work piece. In FIGURE 5C there is shown a covering of sponge-like material 54 and in FIGURE 5D a covering of a brush-like material 56 for applying the dispensed material, for example soap or shoe polish, from container 35 to a work article. In the same manner as already described in connection with the embodiment of FIGURES l-3, material is dispensed from the openings 40 of the container 35 when the flexible container is squeezed. The dispensed material is displaced, upon the release of pressure on the container walls, by the entrance of air through side opening 45 into flexible bladder 46. The bladder 46 is attached to the container about a valve containing portion of the wall and is arranged to extend generally centrally of the container 35. Hydraulic pressure exerted by the flowable material when the container is squeezed assures flow to all outlets and maintains the bladder essentially spaced from the inner wall or walls. At the same time, the material to be dispensed is maintained adjacent the openings 40.

Shown in FIGURE 6 is a combination roller dispenser and applicator 60 embodying the principles of the present invention. The roller 60 is constructed of an endless, flexible, cylindrical wall 62 having a circular end wall 63 at each end of wall 62. The roller is mounted for rotation about its central, longitudinal axis, as by a bracket 64, in a conventional manner. A plurality of dispensing outlets 66 extend through the cylindrical wall 62 at locations spaced from each other peripherally and axially of the roller. Cooperating with each dispensing outlet 66 is a check valve 67 that permits a flowable material, such as paint, contained within the cylindrical roller 60 to be dispensed. A fabric covering 69, typical of paint rollers, is provided on the external surface of the peripheral wall 62. An opening 70 is provided at a central location in one end wall 63. An expansible bladder 72 is within the roller 60 surrounding the opening 70. The bladder is sealed with respect to the end wall 63 to isolate the opening 70 from any flowable material contained within cylindrical roller 60. A check valve 71 cooperates with the opening 70 to allow air from outside the cylindrical roller 60 to enter the bladder while preventing air already within the bladder from escaping. When pressure is applied to the flexible wall 62 as the cylindrical roller 60 is passed across a surface, material, such as liquid paint, contained within the roller 60 is dispensed through outlets 66. When pressure is released, the flexible wall 62 returns to its original shape, reducing the pressure within roller 60. Air enters through opening 70 and check valve 71 and expands bladder 72 to displace the dispensed liquid. The bladder is shaped to allow it to extend centrally within the roller in a manner similar to that explained in connection with the embodiment of FIGURE 4 to maintain the material to be disizer or spray pensed adjacent the openings 66. An opening and cap (not shown) are provided in the end wall opposite end wall 63 to permit the roller to be refilled. Prior to or during refilling, the bladder 72 is deflated by mechanically opening the check valve 71.

There is shown in FIGURE 7 an embodiment of a dispenser 73 constructed basically in the manner of the embodiment of FIGURES 1-3 but including an enclosed reservoir 74 in direct communication with a dispensing outlet 75. The outlet 75 is provided through a dispenser wall 76 forming the bottom of the enclosed reservoir 75. A check valve 77 allows fluid to flow only from the dispenser 73 to the reservoir 74. A wick or other suitable component 78 extends through an opening 79 in the top of the enclosed reservoir 75. With this arrangement, the wick or component 78 is supplied with fluid from the reservoir 74 through capillary action. The reservoir 74 may be conveniently refilled through opening 75 by squeezing the flexible walls of the dispenser, without inverting the dispenser. By way of example, where a combustible fluid is contained within the reservoir 74, the wick 78 may be used to provide a flame. Where the fluid i an ink, the wick 78 may be used as a marker.

Shown in FIGURE 8 is a flexible container 80 of generally box-shaped form, having an upper wall portion 81, a base wall portion 82 and a surrounding, upstanding side wall 83. Upper wall 81 includes a recess or exposed reservoir 84. Within the recess 84 and extending through the upper wall 81 is a dispensing outlet 85. Cooperating with the outlet 85 is a check valve 8% that permits a flowable material from within the container 80 to be dispensed to the reservoir 84 while preventing inward flow. An opening 87 is provided in the base wall 82. A check valve 38 cooperates with the opening 87 to allow air to enter the container 80 from outside while preventing outward flow. A flexible, expansible, bladder 89 is within the dispenser 80. The bladder surrounds the opening 87 and is in sealed relationship with the container walls to isolate the opening 87 from the contents of the container 80 that are to be dispensed through the opening 85. When the container 88 is squeezed, as by pressing downward upon upper surface 81, flowable material within the container 88 is dispensed through opening 85 into the reservoir 84,. Upon the release of such external pressure, air enters bladder 89 through the opening 87 to displace the dispensed material.

There is shown in FIGURE 9 of the drawing an atomdispenser embodying the present invention. An outer container 90 constructed of flexible and resilient material has a base portion 91, an upstanding wall portion 92, a neck portion 93, and a nozzle 94 connected to the neck portion 93. A solid wall 95 divides the outer container 98 into two

sub-chambers

96 and 97. The wall 95 extends along neck 93 and terminates at nozzle 94. There is an opening 98 in sub-chamber 96 where the neck portion 93 connects with the nozzle 94-. Similarly, there is an opening 99 in the chamber 97 at the neck portion 93 adjacent the nozzle 94-. A one-way valve 108 and 189, respectively, is associated with each opening 98 and 99 to allow fluid to be emitted from

respective chambers

96 and 97 while preventing the flow of fluid back into the chambers. Base portion 91 include two

inlet openings

100 and 101, communicating, respectively, with

subchambers

96 and 97. A flexible and expansible bladder 102 is provided within sub-chamber 96, surrounding the opening 100 and sealed with respect to the container Walls, isolating opening 100 from opening 98 and from any fluid to be dispensed from sub-chamber 96. Subchamber 96 is adapted to contain fluid to be sprayed, and may be filled through a capped opening 103. Subchamber 97 is adapted to contain air for entraining the liquid to be sprayed in a moving stream. Each opening 108 and 181 includes a oneway valve 104 and 185, respectively, that allows air to enter the associated subchamber while preventing outward flow. In operation, the wall portion 92 is squeezed to diminish the internal volume of

sub-chambers

96 and 97, creating an increased pressure therein. This causes air contained in sub-chamber 97 and liquid contained in sub-chamber 96 to be expelled through opening 98 and 99 into nozzle 94 and out nozzle 94 as a spray of air and liquid. Upon the release of pressure to wall 92, the resilient container returns to its original shape, reducing the pressure within

sub-chambers

96 and 97. At this time, air enters subchamber 97 through opening 101 and check valve 105 and air enters opening 100 through check valve 104 into bladder 192 to replace the volume of air and liquid, respectively, displaced. The liquid in sub-chamber 96 may be replaced through capped opening 193 by deflating the bladder, as explained in connection with the embodiment of FIGURE 6.

Several alternative arrangements similar to that shown in FIGURE 9 may be constructed. For example, the spray nozzle may be replaced by a stream nozzle; the opening 1011, check valve 185, and check valve 109 may be eliminated and sub-chamber 97 may be filled with air through nozzle 94 upon release of pressure to Wall 92; or bladders may included in both sub-chambers to dispense to liquids simultaneously, either in a spray or stream, for example, two components of an epoxy resin.

One specific mode of construction and the separate components of a container embodying the inventive features of this invention is shown in FIGURE 10. A base 110 with a central opening 112 and a check valve 113 is adapted to fit in a bottom opening of a flexible resilient container 114. A bladder 115 is placed, folded or stretched over the periphery of the base 119 and the subassembly is fitted into the bottom opening of the container in fluid-tight engagement. If desired, an adhesive may be applied between the base and bladder and between the bladder and the container wall. Similarly, a valve base element 118 with a valve element 119 and spring 120 may be inserted in fluidtight engagement into an outlet opening of a container to cooperate with the container and base assembly in providing a dispenser in accordance with the present invention. It will be understood that the base 118 may, alternatively be threaded and may fit onto rather than into the container.

From the above embodiments, it will be apparent that variou flowable materials, from extremely fluid liquids, to extremely viscous pastes may be conveniently dispensed and, if desired, may be dispensed in a predetermined and measured volume. Furthermore, while it is believed to be most advantageous to utilize an expansible bladder or flexible envelope of a stretchable material, it will be understood that an initially full-sized but collapsed, expansible bladder or membrane may be used. For convenience in assembly, it may be rolled or folded so as to unroll or unfold as it expands. While hydrostatic pressure of the fluid to be dispensed will prevent entrapment of fluid by the bladder, even if the bladder should initially inflate at a location Within the container above the base portion, longitudinal grooves may be provided on the inner surface of the container to provide passageways to the outlet or outlets. It will also be apparent that, if desired, the inherent resiliency of the container need not be relied upon solely to return the container to its initial shape, but may be assisted by other means, such as an internal spring, etc. Thus, it will be evident that while in the foregoing disclosure certain preferred embodiments of the invention have been disclosed, numerous modifications or alterations may be made therein without departing from the spirit and scope of the invention as set forth in the appended claims.

What is claimed is:

1. In a dispensing device, a flexible, resilient, container; an expansible bladder within the container fixed to a surface thereof and sealed with respect to the interior of said container, a first opening through the container and communicating to the interior of said bladder, a first check valve cooperating with said first opening and constructed and arranged to allow the passage of fluid only from outside the container into the bladder, whereby the bladder may be expanded, a second opening through the container, spaced from said first opening, and communicating with a zone within the container external to the bladder, a second check valve cooperating with said second opening and constructed and arranged to allow the passage of material only from within the container to without the container.

2. The device of claim 1 including additional openings through the flexible, resilient, container, each such additional opening having a check valve constructed and arranged to allow the passage of material only from within the container to without the container and each such additional opening communicating with a zone within the container but external to said bladder.

3. The device of claim 1 including a textured outer applicator surface upon at least a portion of said container and at least one said second opening adjacent said textured surface.

4-. The device of claim 3 wherein the textured surface is soft and porous.

5. The device of claim 3 wherein the textured surface is hard and abrasive.

6. The device of claim 1 including means to limit the amplitude of fiexure of the flexible container at a predetermined location.

7. The device of claim 1 wherein the second opening communicates with a reservoir external to said container.

8. The device of claim 7 wherein said reservoir is formed by a portion of said container surface that is concave with respect to the exterior of the container.

9. The device of claim 7 including a wick in communication with said reservoir.

10. The device of claim 1 wherein the bladder is stretchable.

11. The device of claim 1 wherein the bladder is elastic, is fixed to a base portion of the outer container and expands from the base portion along the interior of the outer container toward the second opening in the container.

12. The device of claim 2 wherein the bladder is fixed to a portion of the outer container and extends centrally of the container remote from all other portions of the interior surface of the container.

.13. A container for dispensing a substantially uniform volume of material with the container in any position, including a flexible, resilient, outer wall having two spaced openings and diin'ded into two fluid impervious zones, a first of said zones constructed and arranged to contain a material to be dispensed when the outer wall of the container is flexed inwardly, and a second of said zones constructed and arranged to be expanded by the introduction of ambient atmosphere after each time material is dispensed from said first zone when the outer wall returns to an original shape, a first of said two spaced openings providing a passageway between the outside of the container and the first said zone, a second of said two spaced openings providing a passageway between the outside of the container and the second said zone, a first check valve cooperating with said first opening and constructed and arranged to permit material to flow only from within the first zone of the container to without the container, a second check valve cooperating with said second opening and constructed and arranged to permit air to flow only from outside the container into the second zone within the container and means for limiting maximum inward flexure of the container at a predetermined position on the container.

14. A dispenser comprising: a flexible, resilient container adapted to contain and dispense a flowable material; a flexible, inflatable diaphragm member within the container forming a sealed envelope with respect to the interior of the container and any flowable material within the container; an opening through the container, into the sealed envelope; means to permit passage of fluid only from outside the container through the opening and into the sealed envelope; a second opening through the container remote from the sealed envelope and adapted to directly communicate with any flowable material within the container; and means to permit passage of flowable material only from within the container through the second opening to outside the container.

15. In a liquid spray dispenser, a flexible, resilient outer container having two internal chambers; a nozzle extending from said outer container; first passageways from each of said internal chambers opening into said nozzle; check valve means cooperating with each of said passageways opening into said nozzle and constructed and arranged to permit flow only from within each chamber to without, through said nozzle; a second passageway in each chamber, each opening through a wall of the outer container; a check valve cooperating with each said second passageway and constructed and arranged to permit flow of air only from outside said outer container to within; and a flexible diaphragm dividing one of said two internal chambers into two sub-chambers, one of which is connected via one of said second passageways to without the outer container and the other of which is connected via one of said first passageways to said nozzle.

16. A liquid spray dispenser comprising a flexible, resilient outer container having two internal chambers; a nozzle; a passageway from each chamber to said nozzle; a check valve in one of said passageways constructed and arranged to permit flow only from within the associated chamber to the nozzle; [an air inlet into the chamber associated with the passageway having the check valve; a check valve cooperating with said air inlet constructed and arranged to permit flow only from outside the chamber to within; and an expansible and inflatable bladder within the chamber associated with the air inlet, fixed to one internal surface thereof, isolating the air inlet from the passageway of the chamber to the nozzle.

17. The dispenser of claim 16 wherein the bladder is elastic.

18. The dispensing device of claim 1 wherein the second check valve is constructed and arranged to be opened solely by increased internal pressure within the container.

References Cited by the Examiner UNITED STATES PATENTS 863,260 8/1907 Butterfield. 1,715,335 5/1929 Cocks 222 2,286,797 6/1942 Duerme 2l5-ll 2,560,944 7/ 1951 Garrison 51-267 2,743,038 4/ 1956 Ferries 222-95 2,766,907 10/1956 Wallace 22294 2,820,234 l/1958 Rigney 15-543 2,947,449 8/ 1960 Hernandez 22294 2,973,883 3/ 1961 Modderno 22294 3,109,190 11/1963 Nelson 15-181 3,169,670 2/1965 Hrebenak et al 222-95 3,211,348 10/1965 Greer 222386.5

FOREIGN PATENTS 1,358,483 3/ 1964 France.

158,377 3/1957 Sweden.

ROBERT B. REEVES, Primary Examiner. N. L. STACK, Assistant Examiner.

Claims

16. A LIQUID SPRAY DISPENSER COMPRISING A FLEXIBLE, RESILIENT OUTER CONTAINER HAVING TWO INTERNAL CHAMBERS; A NOZZLE; A PASSAGEWAY FROM EACH CHAMBER TO SAID NOZZLE; A CHECK VALVE IN ONE OF SAID PASSAGEWAYS CONSTRUCTED AND ARRANGED TO PERMIT FLOW ONLY FROM WITHIN THE ASSOCIATED CHAMBER TO THE NOZZLE; AN AIR INLET INTO THE CHAMBER ASSOCIATED WITH THE PASSAGEWAY HAVING THE CHECK VALVE; A CHECK VALVE COOPERATING WITH SAID AIR INLET CONSTRUCTED AND ARRANGED TO PERMIT FLOW ONLY FROM OUTSIDE THE CHAMBER TO WITHIN; AND AN EXPANSIBLE AND INFLATABLE BLADDER WITHIN THE CHAMBER ASSOCIATED WITH THE AIR INLET, FIXED TO ONE INTERNAL SURFACE THEREOF, ISOLATING THE AIR INLET FROM THE PASSAGEWAY OF THE CHAMBER TO THE NOZZLE.