Patent Application
20050062284
The present invention relates to a pressure relief valve incorporated in a connector assembly, more preferably a low profile connector assembly, for connecting a source of inflation fluid, e.g., air or liquid, to a flexible inflatable article such as an inflatable garment, an air mattress, a flexible canteen, or other similar-in-principle construction.
Inflatable articles which are relatively flexible in use exist for a wide range of applications from air inflatable garments, mattresses, sleeping bags, and the like, to liquid inflatable canteens, bladders, heating/cooling pads, and other similar-in-principle constructions. As used herein, the term inflatable is intended to refer to the ability to create some pressure gradient between the interior and exterior of an article. In certain instances the inflation pressure may be significant (e.g., pressure gradients of 1.0 psi or above); however, in other instances only a slight pressure gradient may exist, and the article may be designed to permit air or liquid leakage above some pressure gradient. The term flexible is intended to refer to materials having a flexural rigidity, as described in more detail herein, of 50,000 N*m or less, preferably 1000 N*m or less, and most preferably 200 N*m or less.
Inflatable articles, for example, air mattresses, are generally provided with an inflation valve. Such valves can be simple plastic tubes affixed to a wall of the inflatable article and having a stop cock affixed thereto. Opening the stop cock allows for deflation of the inflatable article or for inflation through the tube by manual means such as by a person blowing air through the tube and into the inflatable article. Alternatively, various types of pumps are available and have been employed to force air into such inflatable articles. Especially suited for inflatable garments and the like is a bellows pump disclosed in U.S. patent application Ser. No. 10/230,889, which is commonly assigned. The term air is used for convenience herein; however, it should be appreciated that other suitable gases may be used depending on the specific application of the article.
In the case of liquid inflatable articles, collapsible or other suitably flexible canteens and bladders exist typically incorporating screw-on or snap-on fill ports affixed to the collapsible container and extending substantially perpendicular therefrom.
Pressure relief valves incorporated into inflatable articles, such as garments and the like have been taught. U.S. Patent Application Publication No. 2003-0106141 is directed to an inflatable, breathable module having one or more inflatable cavities in the module and which further incorporates a pressure relief means for reducing pressure in the inflated portion(s) should the module be subjected to sudden or excessive stress.
A need has existed for an improved assembly for a flexible inflatable article which provides ease of connection and disassembly from an external inflation source, is relatively simple to incorporate in a continuous manufacturing operation, presents a low profile during manufacturing and in use when affixedto a flexible inflatable article, and which further incorporates a pressure relief means. The present invention provides such an assembly. Other advantages of the connector assembly of the invention will become apparent from the following specification.
A low-profile connector assembly for connecting a flexible inflatable article to a source of inflation fluid, e.g., air or liquid, and which further incorporates a pressure relief means is provided. The assembly includes a semi-rigid, hollow connector housing having a first, generally tubular, insertable section, insertable through an opening in a flexible wall of the inflatable article. A second external section extends oppositely from the insertable section and outwardly from the flexible wall upon insertion. The external section and the insertable section are connected and oriented generally at an angle with respect to each other (i.e., less than 180 degrees), more preferably at a substantially right angle. The two sections provide a continuous air or liquid passageway therethrough into the inflatable article upon insertion therein, the passageway extending from an external opening in the external section, which is removably connectable thereat to a source of inflation air or liquid. The passageway extends through the connector assembly and into the inflatable article.
The insertable section has an external circumferential groove therearound which, upon insertion into and through the flexible wall opening, is secured thereat by an elastic washer positioned immediately adjacent to and concentric with the wall opening. By positioned it is meant that the washer may be held against the wall by compression between the wall and the insertable section, or affixed by means of some bond (e.g., adhesive, heat-bonded, etc.) between the wall and the washer, or even integrated with the flexible wall (e.g., molded in, etc.).
The washer is press-fit into the groove, thereby providing a seal at the wall opening and sealing off leakage of air to or from the inflatable article and the atmosphere and confining air or liquid passage to and through the passageway. When assembled, a low-profile pathway for fluid communication from an external source into the flexible inflatable article through an opening in a flexible wall thereof is provided.
The connector assembly preferably further includes a valve which controls flow of air or liquid therethrough. The valve may be a one-way check valve, a two-way check valve, a pinch valve, or similar valve construction.
In one preferred embodiment for air inflation of an inflatable article, the connector assembly can be designed to provide a pressure gradient of at least 0.5 psi, preferably effective to a pressure gradient of at least 1.0 psi.
In one preferred embodiment for providing pressure relief under desired conditions, the external section of the connector assembly can further incorporate a pressure relief means such as a valve which functions to release air or liquid from the inflatable article when the internal pressure exceeds the pressure required to open the valve. For example, in a preferred embodiment, the pressure relief valve comprises an opening, such as a round hole, a slit, or other suitable opening. In use, the pressure relief valve in the external section is covered by an appropriate valve material which covers, or otherwise closes, the opening and allows the inflatable article to be inflated to a desired extent. The materials used, the size of the opening, and the location of the pressure relief opening in the external section can be tailored to provide the desired pressure required to open the pressure relief valve depending on the given application. A suitable pressure range for engaging the relief valve is 30-500 mbar. In one embodiment for a garment construction, a suitable pressure for engaging the relief valve is about 70 mbar. In an alternative embodiment, the pressure for engaging the relief valve is about 200 mbar. One particularly preferred construction of a pressure relief valve of this invention includes a pressure relief opening comprising a hole oriented in the external section, which is then covered by a valve material which comprises the fill tube for the connector assembly. In this embodiment, if the desired pressure required to open the pressure relief valve is reached, the valve material covering the opening is lifted by the air pressure in such a way that at least one air channel is created. The air channel allows air to pass through to the outside until the desired internal air pressure is reached, then the valve material repositions to close the air channel. Such pressure relief valves have a number of advantages, including ease of construction without the need for additional mechanical pieces or loose parts, and a simple construction which provides wear-resistance and soil-resistance, is economical to manufacture and is simple to replace. Furthermore, such valve constructions are safe for children and for users who desire minimal moving parts (e.g., airplane pilots, etc).
The assembly housing and insertable section preferably are integrally formed into a unitary construction, but the insertable section may be formed as a hollow tubular component having a rim slidably mounted externally thereover, with the rim having an external circumferential groove therearound.
In a further preferred embodiment, the elastic washer is affixed to the flexible wall, preferably adhesively, but it may be affixed under heat and pressure or other suitable means. Further, the washer may be affixed by integrally molding it to the flexible wall material. The washer is preferably an elastomer, either a natural elastomer or a synthetic elastomer such as a polyurethane elastomer or a silicone elastomer.
The connector assembly may be used to connect inflatable articles such as garments, including a vest, a jacket, a pant, a coat and similar constructions, a mattress, a sleeping bag, or other flexible articles to a source of inflation air. Additionally, such as connector assembly may be used to connect inflatable articles such as collapsible canteens, bladders, heating/cooling pads and other flexible devices to a source of inflation liquid. The connector assembly provides advantages in, for example, ease of assembly, ease in use and relatively low profile of the connector in the finished article relative to prior art devices.
In the accompanying drawings:
a to 12c show top perspective views of one embodiment of the connector housing with alternative valve opening geometries.
a shows a perspective view of one embodiment of the pressure relief valve comprising a hole and with a tube as valve material.
b and 13c are cross-sectional views of two embodiments of the pressure relief valve.
a is a cross-sectional view of one embodiment of the pressure relief valve during the release of air or liquid.
b is a cross-sectional view of a further embodiment of the pressure relief valve of the present invention.
c shows a perspective view of the embodiment of
a and 15b are cross-sectional views of one embodiment of the pressure relief valve comprising a pressure relief opening with a rounded edge.
A low profile connector assembly is provided for connecting a flexible inflatable article such as an inflatable garment, air mattress or collapsible canteen to a source of inflation air or liquid. The connector includes a semi-rigid, hollow connector housing having a first, generally tubular, insertable section, insertable through an opening in a flexible wall of the inflatable article. A second external section extends oppositely from the insertable section and outwardly from the flexible wall upon insertion, the external section and the insertable section are connected and oriented generally at an angle with respect to each other to create a low profile relative to the article, most preferably the sections are oriented at right angles with respect to each other. The two sections provide a continuous air or liquid passageway therethrough into the inflatable article upon insertion therein. The passageway extends from an external opening in the external section, and is removably connectable thereat to a source of inflation air or liquid. The insertable section has an external circumferential groove therearound which, upon insertion into and through the opening in the flexible wall, is secured thereat by an elastic washer positioned immediately adjacent to and concentric with the wall opening. The washer is press-fit into the groove, providing a seal at the wall opening.
A detailed description of the invention and preferred embodiments is best provided with reference to the accompanying drawings wherein
The connector housing 14 is shown in detail in
One embodiment of the complete connector assembly 10 according to this invention is depicted in cross-section in
When the washer 18 is press-fit onto the insert section 12, the washer 18 must deform to allow the insert section to be inserted. After deforming, the washer must recover to seat into the groove 13. Washer 18 must have the ability to recover after such deformation, i.e., it must be elastic, in order to effect a seal when seated in groove 13.
A washer which is 100% elastic will seek to recover to its original, pre-deformed inside diameter (ID). If the outside diameter of the insert is larger than the ID of the washer, a compression seal will result.
If the washer 18 is constructed of an elastic material with a high durometer, it will strongly resist initial deformation, making it harder to install. However, a stronger seal will result upon installation.
If the washer 18 is made from a material which plastically deforms during installation, it will not fully recover to its original ID. So long as the amount of plastic deformation is small enough to allow for interference stress to be present after installation, a seal will be formed, albeit a weaker seal.
Some materials which are initially elastic will “stress relax” over time. For those, a seal may be formed initially to an acceptable level, but, after time, the seal will weaken to a point where there is no effective seal at pressure. The washer material must therefore be chosen to maintain an acceptable seal over its expected lifetime. Elastomer materials are particularly suitable materials for the elastic washer of the invention, in the form of either a natural elastomer such as natural rubber or a synthetic elastomer such as a polyurethane elastomer or a silicone elastomer. Cross-linked elastomer materials are most preferred for longest lifetime performance of the assembly.
In the connector assembly of the invention, the housing body 14 must be more rigid than the washer 18. A thick wall of the insertion section 12 will require more force to deform. Taking into account both the material properties of the housing and the washer (durometer, plasticity, stress relaxation) and the geometry of these components, one is able to tailor a connection to meet sealing requirements over a range of differential pressures and duration of effective seals over time.
Preferred materials of construction for the connector housing 14 will possess a durometer (Shore A) in the range of 50 Shore A or greater, more preferably in the range of 75 to 95 Shore A. The washer 18 may comprise any elastomer, preferably one having a durometer of 30 to 70 Shore A, more preferably 50 to 60 Shore A.
The elastic washer 18, when properly seated in groove 13, is in circumferential tension, resulting in a radially inwardly directed compression force which forms a seal capable of withstanding a pressure gradient. The washer 18 can be a separate component part, as shown and discussed above, or it may be constructed as an integral reinforcement around opening 16 comprising a thicker ring of elastic material surrounding the opening 16.
Preferably, the elastic washer 18 is a flat ring washer, which presents a low profile in use, and is made of an elastomer such as block copolymers, polyurethanes, silicones, and natural rubbers, more preferably comprising a polyurethane, and is adhesively bonded to the flexible wall 22 by any suitable adhesive, such as an epoxy, a polyurethane or a silicone. For example, a particularly preferred elastic washer/adhesive combination would be a crosslinked polyurethane washer with a reactive polyurethane adhesive. These low profile and flexible features of the washer allow for ease of packaging and handling of the flexible inflatable construction with the washer installed thereon.
The connector assembly of the invention provides a relatively low cost, simple, flexible and low profile design added to the flexible article for use in such inflatable systems as garments, air mattresses, disposables, collapsible canteens, and other wearable/packable products. Seals capable of withstanding applied pressures of greater than 0.5 psi, and exceeding 1.0 psi, are readily achievable. However, it should be recognized that in certain applications lower applied pressures may exist in the final article.
As shown in
One possible alternative embodiment 100 of the connector assembly on the invention is shown in
In the construction of the connector assembly of the invention, the housing is preferably constructed of a polyurethane, more preferably a thermoplastic polyurethane. Where the external housing and insertion tube are constructed as separate components, both are preferably made of polyurethane, more preferably thermoplastic polyurethane. It should be appreciated, however, that other suitable materials may be used in the connector assembly, depending on the requirements of the specific application.
The check valve shown schematically in
The effectiveness of the seal formed when the elastic washer is seated within the groove of the insertion section is dependent upon the geometry and relative elasticity of the component parts. As an example, a washer of elastomeric urethane having a center opening inside diameter (ID) of 0.36 inch, an outside diameter (OD) of 1.25 inch, and a thickness of 0.125 inch, when press-fit into a groove of OD 0.46 inch of a thermoplastic polyurethane insertion section provided a seal to a pressure gradient exceeding 1.0 psi between the interior of an inflatable and the atmosphere. One skilled in this art will readily appreciate that effective seals may be achieved over a wide range of pressure gradients using the principles of the invention set forth herein.
Certain assemblies described above include adhesive bonds between components. A preferred adhesive is reactive polyurethane, although other adhesives may be suitable for particular application, and specific adhesives should not limit the scope of the invention in any way.
Elastic washers useful in the invention may be composed of natural rubbers, synthetic elastomers such as polyurethanes, silicones, etc., and others. Cross-linked forms of these materials often provide desirable advantages such as durability and other expected features of these cross-linked materials which are desirable in the articles of this invention. All such suitably elastic washers are within the scope of the invention.
The connector assembly of the invention may be used with many types of inflatable flexible articles, including air mattresses as discussed, garments such as jackets, vests, pants, coats and other similar items, and sleeping bags, to name a few. In addition, inflatable flexible articles which are inflated with liquid, such as canteens and the like, can be fabricated using the connector assemblies of this invention.
a shows a view of the connector assembly with a pressure relief opening 50 and a valve material which covers the opening and allows the pressure relief valve to be actuated under a desired pressure. The valve material is preferably the connection 36 in the form of a tube. The tube is put over the inlet 26 and is therefore covering the pressure relief opening in an airtight manner. In another embodiment, the valve material may be in the form of a narrow tube just covering the opening. The valve material must have the ability to deform sufficiently to allow the formation of an air channel by a desired pressure. After deforming, the valve material must recover to cover in an airtight manner the pressure relief opening 50. The valve material must have the ability to recover after such deformation, i.e., it must be elastic, in order to effect a seal when covering the opening. The valve material may, for example, be made from elastomer materials like silicone, polyurethane, rubber, PVC, and the like. Preferred materials for the tube will possess a durometer (Shore A) in the range of 30 to 90 Shore A. In one preferred embodiment, the tube connection is made of siliocone having a durometer of around 50 Shore A.
b is a cross-sectional view of the connector with the pressure relief opening 50, and the valve material 36 according to
a shows a cross-sectional view of another embodiment of the pressure relief valve according to the invention. The pressure relief valve is shown in an open status in which air is allowed to extend through the pressure relief opening 50 to the outside. The valve material is usually covering the opening in an airtight manner as described in
b and
a and
The material used, the size of the opening, and the location of the pressure relief opening in the external section can be tailored to provide the desired pressure required to open the pressure relief valve depending on the given application. In a preferred embodiment, the relation between the material used, the size of the opening and the desired pressure is as follow:
F/A=p
Suitable flexible materials for at least the portion of the article wall to which the connector assembly is affixed are those materials having a flexural rigidity, as described in more detail herein, of 50,000 N*m or less, preferably 1000 N*m or less, and most preferably 200 N*m or less. Non-limiting examples of materials having these flexibilities include a wide range of fabrics, including wovens and non-wovens, resin impregnated fabrics, elastomeric sheets and other rubber-like materials. The flexible articles of the present may comprise some regions containing materials of higher stiffness; however, the inflatable regions of the articles wherein the low profile connector assembly will typically comprise flexible materials.
Embodiments of the present invention will now be described by way of example only with reference to the following examples.
Test
Flexibility/Flexural Rigidity
The flexibility, or flexural rigidity, of suitable articles to which the connector assemblies of the present invention are attached can be determined using the “Standard Test Method for Stiffness of Nonwoven Fabrics Using the Cantilever Test”, Method Number ASTM D5732-95 (Reapproved 2001).
This test method requires a 1″ wide by 8″ long sample. The sample is slid across a horizontal surface at a controlled rate so that one end overhangs the support platform. As the sample slides across the support platform and the overhang length increases, the cantilevered sample bends downward. When the downward bend angle reaches 0.785 radians (41.50), the overhang length is measured. The overhang length, sample mass, and sample dimensions are then used to calculate the bending length and the flexural rigidity.
The results for several flexible wall materials useful for atachment of the connector assembly of this invention are given in Table 1 below. The more flexible the material, the lower the bending length and the lower the flexural rigidity.
The flexible connector system of this invention is suitable for use in any article constructed, at least in the region where the connector assembly is to be affixed, of a material having a flexural regidity less than 50,000 N*m, more preferably less than 1000 N*m, and most preferably less than 200 N*m.
An inflatable jacket was manufactured substantially in accordance with the teachings of Example 1 of U.S. patent application Ser. No. 10/230,889, except that the inflation/deflation construct was fabricated in accordance with
The pressure relief valve is preferably constructed during the construction of the connector assembly, preferably by injection molding, and having a geometry such as described with respect to Example 2. The pressure relief opening is formed either during the injection molding process or by drilling a hole into the inlet.
During the installation of the connector assembly, the valve material in form of the connection tube 36 is arranged over the hole and held or fixed as described.
While the invention has been disclosed herein in connection with certain embodiments and detailed descriptions, it will be clear to one skilled in the art that modifications or variations of such details can be made without deviating from the gist of this invention, and such modifications or variations are considered to be within the scope of the claims hereinbelow.
The present application is a continuation-in-part application of U.S. patent application Ser. No. 10/742,615, filed Dec. 18, 2003, and having a priority date of Aug. 25, 2003.
| Number | Date | Country | |
|---|---|---|---|
| 60497899 | Aug 2003 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 10742615 | Dec 2003 | US |
| Child | 10776001 | Feb 2004 | US |
