GB2191545A - Improvements in or relating to inflators - Google Patents

Abstract

An inflator comprises a resilient hollow body member (12) having an input (20) and an output (22). Check valves (24) and (26) are provided in the input (20) and output (22) respectively to prevent fluid flow out of the hollow body member (12) via the input (20) and to prevent fluid flow into the hollow body member (12) via the output (22). By squeezing and releasing the hollow body member (12) fluid in the hollow body member (12) is forced out of the output (22) only and fluid is drawn into the hollow body member (12) via input (20) only. The hollow body member may be formed of two injection molded halves joined together and the inflator is useful both for inflating and deflating life rafts, sphygmomanometer cuffs and the like. To assist in positively deflating articles, the input end (20) may be provided with an adaptor sleeve (38) to fit certain commonly used valves. <IMAGE>

Description

SPECIFICATION Improvements in or Relating to Inflators Background of the Invention Field of the Invention This invention relates to inflators. More particularly, this invention relates to bulb shaped inflators operable to inflate an inflatable or to pressurize a tank or other container.

Description of the Background Art Presently, there exist many types of inflators designed to inflate an inflatable or to pressurize a tank or other container. The uses for such inflators to inflate inflatables vary widely from inflating cuffs of a sphygmomanometer to inflating personal flotation devices, rafts, and the like. The most predominent type of inflator comprises a mechanical device utilizing an air cylinder having a reciprocating piston which is pumped by hand or by foot to inflate the inflatable. Other types of inflators comprise basically a bulb shaped design which, when combined with a check valve and pumped by hand, inflates the inflatable. One particular type of bulb shaped inflator is that of a sphygmomanometer used to inflate the inflatable cuff about the patient's arm causing restriction of the blood flow in the arm.

Bulb shaped inflators are typically manufactured by a dip method in which a bulb shaped mandrel is dipped into a tank of liquid elastomeric, resilient material. After removal of the mandral from the tank and curing the elastomeric material, the thin coat of cured elastomeric material on the mandrel is peeled from the mandrel in what is commonly referred to as "stripping". Since dip methods also produce unwanted material along the neck of the mandrel, such material must be trimmed from the cured material after stripping. Consequently, bulb shaped inflators produced by a dip method are relatively costly.

Another disadvantage with presently availabie bulb shaped inflators is that they function to simply inflate the inflatable. Indeed, in some applications, it may be desirable to completely deflate the inflatable after use so that the deflated inflatable can be properly folded and stored in a compact manner. Moreover, deflation of an inflatable prior to storage will, to a large degree, remove the ambient moisture from within the inflatable, thereby decreasing the degradation of the inflatable from improper storage in an internally moist condition.

Therefore, it is an object of this invention to provide an apparatus which overcomes the aforementioned inadequacies of the prior art devices and provides an improvement which is a significant contribution to the advancement of the inflator art.

Another object of this invention is to provide a bulb shaped inflator operable to inflate an inflatable or to pressurize a tank or other container with a fluid such as air.

Another object of this invention is to provide a bulb shaped inflator having capabilities to not only inflate the inflatable, but to also deflate the inflatable allowing the deflated inflatable to be safely stored in its original container or the like.

Another object of this invention is to provide an economical method for producing a bulb shaped inflator and deflator device without using conventional dip methods of manufacture.

Another object of this invention is to provide a bulb shaped inflator and deflator which can be economically manufactured and assembled.

The foregoing has outlined some of the more pertinent objects of the invention. These objects should be construed to be merely illustrative of some of the more prominent features and applications of the intended invention. Many other beneficial results can be obtained by applying the disclosed invention in a different manner or modifying the invention within the scope of the disclosure.

Accordingly, other objects and a fuller understanding of the invention may be had by referring to the summary of the invention and the detailed description of the preferred embodiment in addition to the scope of the invention defined by the claims taken in conjunction with the accompanying drawings.

Summary of the Invention The invention is defined by the appended claims with a specific embodiment shown in the attached drawings. For the purpose of summarizing the invention, the invention comprises a bulb shaped inflator and deflator and method for manufacture of the same. More particularly, the bulb shaped inflator and deflator of the invention comprises a bulb shaped body member composed of an elastomeric, resilient material and having an input and an output at two opposing ends. Both the input and output are tapered to a substantially cylindrical configuration.

A one-way check valve is positioned in the input and the output in such a manner that the check valve positioned in the input allows air to flow only into the bulb while preventing the air contained in the bulb to flow outward through the input. Conversely, the check valve positioned in the output allows the air contained within the bulb to flow outwardly via the output while preventing air from outside the bulb from flowing into the bulb. Consequently, upon squeezing the bulb, the air contained therein is forced out of the bulb only through the output and upon release of the bulb allowing it to return to its nondeformed state only allows air to flow into the bulb via the input. Thus, repeated squeezing and releasing of the bulb produces a pumping action with air flowing into the bulb via its input and air flowing outwardly therefrom via its output.This double action effect of the inflator and deflator allows the inflator and deflator device to inflate an inflatable connected to its output or, alternatively, completely deflate an inflatable connected to its input.

It is noted that the device of the invention may optionally include an adapter collar connected about its input and its output thereby allowing the inflator and deflator device to be readily connected to conventional valves commonly found on inflatables. Further, a similar adapter may be fitted to the output of the inflator and deflator device allowing a conventional inflator needle to be fitted to the output allowing the inflator and deflator device to inflate a inflatable having a needle valve.

In view of the foregoing, it should readily be appreciated that the inflator and deflator device of the invention may be conveniently used to inflate an inflatable such as a personal flotation device, life raft, cuff of a sphygmomanometer and related articles. Alternatively, the inflator and deflator device invention can be easily adapted to completely deflate such inflatables, particularly personal flotation devices, so that the inflatable can be compactly folded and stored for later use. Moreover, it is noted that complete deflation of the inflatable has the inherent advantage of removing humid air from within the inflatable thereby preventing the degradation of the material constituting the inflatable from continued exposure to humid internal conditions.

The method of the invention for producing the bulb of the inflator and deflator device comprises injection moulding a pair of flanged half sections of a suitable resilient material such as 78 durometer polyvinylchloride. Each half section is then positioned within a cylindrical electrode with a flange seated upon the face of the electrode. The electrodes are positioned facing one another such that the flange of each half section are forced together. Radio frequency (RF) electrical current is flowed through the electrodes causing the mated flanges to become heated and weld (melt) together. The electrical power is then removed and after an appropriate cooling period, the electrodes are separated and the newly formed mated half sections are removed. Finally, the mated welded flanges are then trimmed of excess material.

Since the input and output of the newly formed bulb were precisely manufactured by injection molding techniques, the newly formed bulb is now ready to receive the check valves at its input and output. Thus, greater degree of control and uniformity is obtained at a significant cost savings when compared with conventional dip methods of manufacture.

The foregoing has outlined rather broadly the more pertinent and important features of the present invention in order that the detailed description of the invention that follows may be better understood so that the present contribution to the art can be more fully appreciated. Additional features of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the artthatthe conception and the specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims.

Brief Description of the Drawings For a fuller understanding of the nature and objects of the present invention, reference should be had to the following detailed description taken in conjunction with the accompanying drawings in which: Fig. 1 is an end view of the output of the inflator and deflator device of the invention; Fig. 2 is a cross sectional view of Fig. 1 along lines 2-2; Fig. 2A is a side view of the inflator and deflator device of the invention having a flow control valve incorporated in its output; Fig. 3 is a cross sectional view of an injection mold illustrating the manner in which the bulb half sections are injection molded; Fig. 4 is a diagrammatic view, partially in section, illustrating the manner in which the flanged half sections are RF welded together; and Fig. 5 is a diagrammatic view illustrating the manner in which the excess material of the welded flanges is trimmed from the newly formed bulb.

Similar reference characters refer to similar parts throughout the several views of the drawings.

Detailed Description ofthe Preferred Embodiment Referring to Figs. 1 and 2, the inflator and defiator device 10 of the invention comprises a hollow, resilient bulb shaped body 12 composed of two identical resilient half sections 12A and 12B each connected together at flange 14 by the method of the invention discussed below. Each half section 1 2A and 1 2B comprises a tapered end 16A and 16B having a substantially cylindrical passageway 18A and 18B formed therein, respectively. One fluid passageway 1 8A functions as an input 20 whereas the other fluid passageway 1 8B functions as an output 22.

An input check valve 24 is positioned with the input passageway 1 8A to allow fluid to flow exteriorly from the device 10 into the bulb shaped body 12 while precluding the flow of a fluid from within the bulb shaped body 12 to flow outward through the input fluid passageway 18A. In a similar and opposite'fashion, an output check valve 26 is positioned within the output fluid passageway 18B allowing a fluid contained within the body 12 to flow outwardly through the output fluid passageway 1 8B while precluding outside fluid from flowing into the body 12. As a result, upon squeezing of the bulb shaped body 12, the air contained in the body 12 flows outwardly therefrom only through the output fluid passageway 18B.Upon release of the body 12 allowing the inherent resiliency of the material to return to its "memory" position, outside air is diawn into the body 12 only through input fluid passageway 18A.

The check valves 24 and 26 may comprise various types of check valves without departing from the spirit and scope of this invention. However, one type of check valve which is particularly suited in this application comprises those "catheter" check valves sold by the assignee of this application. Basically, a catheter check valve of that type comprises a generally cylindrical valve element 28 having a forwardly converging frusto-conical seat 30 reciprocatedly positioned within a generally cylindrical housing 32 having a mating forwardly converging frustro-conical seat 34. The valve element 28 is retained within housing 32 by folding in the ends of the output of the housing 32 at crimp 36.More complete disclosures of catheter valves of this nature are contained in U.S. Patent 3,831,629, in U.S. Patent 4,602,655, issued on July 29, 1986 entitled "Flow Control Valve", and in U.S. Patent Application entitled "Check Valve with Preset Cracking Pressure" filed concurrently herewith and assigned to the assignee of this application, the disclosure of each of which is hereby incorporated by reference herein. However, most preferably, catheter check valves 24 and 26 have zero cracking pressure to operate as a check valve in the common sense of the term.

As discussed earlier, the inflator and deflator device 10 of the invention functions as an inflator to inflate an inflatable such as a personal flotation device, life raft, cuff of a sphygmomanometer, or a basketball.

Indeed, the output 22 of the inflator device 10 may be easily fitted with a hose or other adapter to facilitate inflation of the inflatable. For example, output 22 may be fitted with a conventional inflation needle designed to inflate, via a needle valve, a basketball or other sport related inflatable.

In a similar fashion, the input 20 of the inflator and deflator device 10 of the invention may be used to draw a fluid, such as air, from the above described or related inflatables. Indeed, complete deflation of inflatables, particularly, personal flotation devices, functions to remove the moist air contained therein, thereby allowing the inflatable to be compactly folded and stored in an internally dry environment.

Degradation of the inner surface of the material constituting the inflatable is, therefore, substantially eliminated. As illustrated in Fig. 2, the input 20 of the inflator and deflator device 10 may be provided with a substantially cylindrical adapter collar 38 allowing the input 20 to be readily connected to conventional valves found on marine related inflatables such as personal flotation devices.

Referring to Fig. 2A, the flow control valve 27 disclosed in the U.S. Patent Application entitled "Flow Control Valve" filed concurrently herewith and assigned to the assignee of this application, may be fitted to the output 22 of the inflator and deflator device 10, in lieu of output check valve 26, to produce a hand pump with integral bleed control. Such an arrangement is particularly suitable for inflating a cuff of a sphygmomanometer wherein it is desirous to inflate the cuff positioned about a patient's arm to constrict blood flow therethrough, and then slowly bleed air from the cuff to gradually deflate the same to reduce constriction about the patient's arm.

In referring to Figs. 3--5, the method of the invention basically comprises injection molding the two half sections 1 2A and 1 2B, RF welding the flanges 1 4A and 1 4B thereof together in a mating relationship, and then trimming excess material from the flanges 14A and 14B.

More particularly, as shown in Fig. 3, a mold 40, composed of a female portion 40F and a male portion 40M, are mated together to define a cavity 42 therebetween of the desired configuration of the half section 12 of the bulb shaped body 12. Liquid synthetic material, such as 78 durometer polyvinylchloride (PVC) is injected into cavity 42 via input 44. The mold 40 is then cooled by means of a cooling fluid flowing through conduits (not shown) in the mold 40. Upon curing of the PVC, the two mating sections of the mold 40 are separated and the half section 12 is removed.

Fig. 4 illustrates the manner in which the flange 14 of one half section 12 is RFwelded to the flange 14 of the other half section 12. Specifically, the two half sections 1 2A and 1 2B are each positioned within a cylindrical electrode fixture 46A and 46B having an inner diameter approximately equal to the outer diameter of the bulb shaped body 12 immediately below the flange 14. Thus, flanges 1 4A and 1 4B rest upon the faces 48A and 48B of the electrode fixtures 46A and 46B. Two electrode fixtures 46, each having a half section 12 fitted therein, are then positioned in a facing relationship as shown in Fig. 4. The mated electrode fixtures 46A and 46B are then positioned between a pair of platens 50A and 50B of a RF welding press.

Electrical RF current is caused to flow through the electrode fixtures 46 from one platen 50A to the other 50B to heat the mated flanges 14A and 14B positioned between the mating faces 48A and 48B of the electrode fixtures 46A and 46B, respectively. During this welding (heating), the mated flanges 14Aand 14B become sufficiently heated to nearly a liquid state thereby melting together and forming a homogenous seal between the two half sections 1 2A and 1 2B. After a cooling period, the platens 40A and 50B are moved away from each other releasing the electrode fixture 46A and 46B from therebetween. The fixtures 46A and 46B are separated to release the newly formed bulb shaped body 12.

More specifically, the above described steps of the method of the invention is best illustrated by the data contained in the chart below with reference to Fig. 4.

Thickness of Flange: 0.045 inch Outer Diameter of Flange: 2.00 inch Inner Diameter of Flange: 1.51 inch Applied Pressure 40to 120 P.S.I.

Power Output 3 kw Power (Dial Graduation) 35 to 95 Frequency 27.12 MHz Grid Current 0.2 to 0.65 milliamp Grid Voltage 3 kv Distance between face of electrodes 0.060 to 0.150 inch Welding (heating) time 5 to 10 sec.

Cooling time 10 to 15 sec.

Where: Power=0.555x Freqx(RF. Volts) 2xe' xta and ta=loss factor e'=dielectric of 78 Duro PVC 1 Referring now to Fig. 5, the excess material of the welded flanges 14A and 14B is trimmed from the bulb shaped body 12 by positioning the bulb shaped body 12 in a cylindrical fixture 52 with the welded flanges 14A and 14B positioned on the face 54 of the fixture. A cylindrical cutting element 56 is then concentrically moved over the bulb shaped body 12 to trim all of the excess material from the welded flanges 14A and 14B in a single operation. The bulb shaped body 12 is now fully formed and trimmed for receiving the check valves 24 and 26 in its input 20 and output 22, respectively.

It is noted that in lieu of the cutting element 56, the electrodes 46A and 46B may be designed to not only RF seal the two half sections 1 2A and 12B together, but also to form a tear seal (not shown) about the periphery of the welded flanges 14A and 14B. Thus, the excess material of the welded flanges 14A and 14B may be simply torn from the half sections 1 2A and 1 2B thereby obviating a need for the trimming operation via the cutting element 56.

The present disclosure includes that contained In the appended claims, as well as that of the foregoing description. Although this invention has been described in its preferred form with a certain degree of particularity, it is understood that the present disclosure of the preferred form has been made only by way of example and that numerous changes in the details of construction and the combination and arrangement of parts may be restored to without departing from the spirit of the invention.

Now that the invention has been described, what is claimed is:

Claims (13)

1. A bulb shaped inflator and deflator, comprising in combination: a bulb shaped, hollow body member composed of a resilient material and having an input and an output; input check valve means positioned in said input for preventing fluid flow from flowing outwardly therethrough; output check valve means positioned within said output to prevent fluid flow from flowing inwardly therethrough, whereby upon squeezing said body member, the fluid contained therein is forced outwardly therefrom only via said output and, upon releasing of said body member, said body member returns to its nondeformed state by drawing fluid therein only through said input.

2. The inflator and deflator device as set forth in Claim 1, wherein said output check valve means comprises a fluid flow valve having an internal check valve means and adjustable bleed means.

3. The inflator and deflator device as set forth in Claim 1, wherein said body member comprises two flanged half sections welded together to produce an airtight seal therebetween.

4. The inflator and deflator device as set forth in Claim 1, wherein each said check valve means comprises a valve element reciprocatingly positioned within a housing, said valve element and said housing each including a forwardly converging frustro-conical valve seat which are sealingly forced together upon exertion of back pressure on said valve element.

5. The inflator and deflator device as set forth in Claim 1, further including an adapter collar positioned about said input allowing said input to be connected to a valve of an inflatable to withdraw a fluid contained in the inflatable upon repeated squeezing of said body member.

6. The inflator and deflator device as set forth in Claim 1, wherein said resilient material comprises 78 durometer polyvinylchloride.

7. The inflator and deflator device as set forth in Claim 1, wherein said input and said output are positioned at opposing ends of said body member.

8. The inflator and deflator device as set forth in Claim 1, wherein said body member comprises two injection molded half sections joined together at a seam.

9. The inflator and deflator device as set forth in Claim 1, wherein said input and said output include a cylindrical cross-section.

10. A method for producing a body member of an inflator and deflator device, comprising the steps of: injection molding a pair of flanged half sections of a resilient material; positioning the flanges of the two half sections in mating relationship with one another; applying heat to the mated flanges until the mated flanges melt together to produce the body member; and trimming the mated flanges of excess material.

11. The method as set forth in Claim 10, wherein the step of heating the mated flanges comprises positioning each half section in an electrode with the flange thereof being seated upon the face of the electrode, positioning the electrodes in facing relationship with one another such that the flange of each half section is mated together with the other, and then flowing an electrical current through the electrodes causing the mated flanges to become heated and melt together.

12. The method as set forth in Claim 10, wherein the step of trimming the mated flanges of excess material comprises positioning the body member in a fixture with the welded flanges being seated upon the face thereof, and then moving a cutting element against the face of the fixture to trim the excess material around the entire periphery of the body member.

13. The method as set forth in Claim 11,further including the step of allowing the mated flanges to cool prior to withdrawing the body member from the electrodes.