Fluid Swivel Valve Device

The present invention relates generally to a valve assembly used for controlling the ingress of fluid to an inflatable member. More particularly, the present invention relates to a swivel valve assembly which permits the controlled discharge of a high velocity input of fluid from a pressurized source to an inflatable member and provides sealing closure of the inflatable member upon pressure equalization between the pressurized source and the inflatable member. More specifically, the invention relates to a swivel valve assembly which may pivot as necessary during or subsequent to the introduction of high velocity fluid from a pressurized source to an attached inflatable member such as a flotation bag and sealingly closes the inflatable member once the pressure in the pressurized source and the inflatable member are equalized.

Over the years various types of fittings have been developed for use in conjunction with inflatable members such as flotation bags for helicopters. In general, it is necessary that a fluid be delivered from a high pressure, small volume source to the inflatable member on a selected basis when the system is energized. In order to provide rapid uniform inflation of such inflatable members it is common to provide a plurality of fittings on each inflatable member to permit the simultaneous introduction of fluid such as a compressed gas to a number of different areas within the inflatable member. In order to effect such distribution of fluid input through various fittings, one fitting is commonly connected to the pressurized fluid source by a conduit and additional conduits interconnect to the other fittings. Since the configuration of the inflatable member normally changes drastically from an uninflated stored configuration to the inflated operating condition, it is necessary to provide for movement of the position or orientation of the conduits or hoses as by providing swivel elements on the fittings to accommodate random repositioning of the conduits. Since the conduits may be and normally are left in position after the inflation, the possibility of further conduit or hose movements relative to the inflatable member must also be provided for to avoid undue stresses which could be deleterious to the combined fabric and elastomeric make up of such inflatable members.

Swivels of this type have normally been constructed of stainless steel or brass to accommodate high operating pressures over a brief time and corrosion resistance in a salt water environment despite cost and weight disadvantages they provide in an aircraft environment. The prior art devices have generally employed a type of poppet valve as the primary operating component of the fittings. In order to provide an effective seal after inflation, the poppet valves are commonly provided with a molded elastomeric surface to achieve an effective seal. Normally elastomers which can be molded on a valve surface have limited resistance to the distortions and pitting which can be produced by the passage of high velocity fluid.

The throttling effect produced by conventional fittings is normally predicated upon the size of a plurality of passages positioned between the poppet valve and the inflatable member. Depending upon the interconnection and spacing between the various fittings and the pressurized source of fluid it is normally necessary to have available a plurality of different fittings having different sized passages to achieve a system balance which accommodates a division of the fluid from the pressurized source to the various fittings. In employing fittings of this nature, the necessity for varying system balance, e.g., to use different pressurized fluid sources, normally requires replacement of the entire fitting. To applicant's knowledge one or more of the above outlined disadvantageous structural or operational features have accompanied prior art devices of this type.

Therefore, an object of the present invention is to provide a swivel valve assembly which can be installed and replaced in flotation bags with a minimum of difficulty and without damage to the flotation bag. Another object of the invention is to provide an inflation system made up of a plurality of such swivel valve assemblies which may be readily balanced or tuned to accommodate differing spatial relationships and interconnections of the valves and pressure source therefor by disassembly of the valve and substitution of a different size poppet element. A further object of the invention is to provide swivel valve assemblies in which the swivel seal is subjected to only low pressure fluid, thereby permitting free and easy swivel action to eliminate twisting of hoses connected to the swivel during deployment and to avoid imparting stresses to the inflatable members during changes in configuration and related movements.

Another object of the invention is to provide a swivel valve assembly which effects improved low pressure sealing by virtue of the usage of a standard configuration sealing element constructed of an optimum material to withstand attendant temperature and pressure conditions while effecting optimum sealing engagement. Yet another object of the invention is to provide a valve having a disk positioned in a bore to create a precise annular fluid throttling orifice for accurate fluid flow characteristics. Still another object of the invention is to provide such a valve in which only a limited portion of the valve interior is exposed to the high pressure discharge from the pressurized source released during deployment of the inflatable member.

Another object of the invention is to provide a swivel valve assembly which may be disassembled by removal of a single retaining ring. Yet another object of the invention is to provide such a valve wherein the sealing member is positioned to encounter only low pressure fluid flow forces and is not subjected to the high pressure fluid discharged from the pressurized source. A still further object of the invention is to provide a swivel valve assembly of this type which is constructed of a minimum of parts, which may also be constructed of lightweight material such as aluminum and which is capable of operating through repeated deployment sequences without affecting the operation of the seal or other valve components.

In general, a swivel valve assembly, according to the concepts of the present invention, for an inflatable member permitting passage of a high velocity input of fluid from a pressurized source and providing sealing closure upon pressure equalization includes a body having a connector for sealing engagement with the inflatable member, a bore in the body communicating with the pressurized source of fluid, a passage in the body communicating with the inflatable member and connecting with the bore, and a movable poppet operative with a sealing member precluding fluid flow upon pressure equalization and having a disk positioned in the bore for throttling the high velocity input of fluid before passing the sealing member.

FIG. 1 is a longitudinal cross-sectional view of a swivel valve assembly embodying the concepts of the present invention shown in operative relation to a fragment of an inflatable member.

FIG. 2 is an enlarged fragmentary view of the area depicted within the chain line circle of FIG. 1 showing the structure of the seal between the shaft and poppet elements.

A swivel valve assembly for controlling the flow of fluid to and from an inflatable member according to the concepts of the present invention is generally indicated by the numeral 10 in the attached drawing figure. The valve 10 has a fixed body member 11 and a movable body member 12 which is pivotally attached to fixed body member 11 in a manner hereinafter described. The fixed body member 11 has a projecting flange 13 which is preferably of a substantial radial dimension and may be integrally formed or attachable thereto for purposes of connection with a portion of an inflatable member M.

The inflatable member M may be a flotation bag for a helicopter or other element which is normally stored in a noninflated condition and in selected circumstances inflated to create a buoyant body or for a similar purpose. As shown fragmentally in the drawing the inflatable member M may be configured of an appropriate elastomeric material with or without fabric reinforcing and provided with an annular opening consisting of a bifurcated area having flaps 14 and 15 adapted to under and overlie the flange 13. The flaps 14 and 15 may be bonded to the flange 13 in a manner well known to persons skilled in the art to effect a fluid-tight seal between the valve 10 and the inflatable member M. The requisite ingress and egress of inflating fluid to the valve 10 is thus controlled through one or more valve assemblies, the inflatable member M being otherwise fluid impervious and sealed.

The movable body member 12 has a shaft-like portion 17 housed generally within fixed body member 11 with a reduced diameter projection 18 extending a distance outwardly of the fixed body member 11. The movable body member 12 of the valve assembly 10 has one or more nipples 20 projecting from a housing 21 which are adapted to receive hoses or other standard conduits (not shown) connected to other similar valve assemblies or to a remote source of pressurized fluid which can be controllably released. As shown, the movable body member 12 has two nipples 20 having an internal diameter 23; however, nipples 20 may be of different internal diameters for connection to two other valve assemblies 10 or for connection to the source of pressurized fluid on the one hand and to another valve assembly 10 on the other hand. Thus, different internal diameters may be selected to assist in controlling fluid pressure and flow at and between such system components.

The nipples 20 may be provided with threads 22 as is known in the art for purposes of insuring frictional retention of a hose or conduit positioned thereon during rapid movement of the movable body member 12 or the application of sudden forces to the hose and attendant movements. The housing 21 has a bore 25 for seating engagement and attachment to the projection 18 as by brazing or other known means of sealing connection.

The movable body member 12 has an entry bore 26 which communicates with the internal diameters 23 of the nipples 20. The movable body member 12 also has a valve bore 27 in the shaft-like portion 17 which communicates with the entry bore 26 and is preferably of substantially the same cross-sectional area. The valve bore 27 terminates in an end surface 28 opposite the entry bore 26 at an extremity of the movable body member 12 and is configured for positioning a sealing element as hereinafter described.

The movable body member 12 has a generally cylindrical exterior surface 31 of the shaft 17 which is adapted to receive a matingly configured interior surface 35 formed in a sleeve-like portion 36 of the fixed body member 11. As shown, the surfaces 31 and 35 are in abutting relationship to permit stabilized rotation of movable body member 12 relative to the fixed body member 11. The body members 11, 12 are detachably joined by a retaining ring 37 which may be selectively positioned in mating grooves 38 and 39 formed in the shaft 17 and the sleeve 36, respectively. The retaining ring 37 is of suitable cross-sectional area to withstand the maximum shear forces which can be effected by fluid pressure differential existing within the valve assembly 10. The retaining ring 37 is preferably accessible outwardly of sleeve 36 of fixed body member 12 in order to provide for selective removal to service the valve assembly 10, substitute a different poppet valve or to otherwise dismantle the valve assembly 10. The surfaces 31 and 35 are sealed to prevent the escape of fluid therebetween from interiorly of the valve assembly 10 by a seal 45 which may be any of a variety of conventional configurations. As shown, the seal 45 is recessed in a groove 46 formed in the fixed body member 11 such that it is compressed within the groove 46 in engagement with a portion of the surface 31 of shaft 17.

The fixed body member 11 has positioned at the base of the sleeve-like portion 36 a cylindrical recess 50 which is of slightly greater diameter than the valve bore 27 of the movable body member 12. Intercepting the cylindrical recess 50 are a plurality of outlet passages 51 extending through fixed body member 11 which are positioned interiorly of the inflatable member M and thus below the flange 13.

Positioned within the cylindrical recess 50 and the valve bore 27 is a particularly configured poppet element, generally indicated by the numeral 55. The poppet element 55 has a body portion 56 which is adapted to slidingly fit within the cylindrical recess 50. The poppet element 55 has a seating surface 57 positioned preferably substantially radially of the body 56. Since the body portion 56 is of greater diameter than valve bore 27, the poppet element 55 is precluded from moving upwardly beyond the position depicted in the drawing figure by virtue of its engagement with a portion of the end surface 28 on the shaft portion of movable body member 12, and when thus positioned, the seating surface 57 is in sealing engagement with an O-ring 60. The O-ring 60 is preferably positioned in a groove 61 in end surface 28 which may have projecting lips 62 capable of being swaged into arcuate position about O-ring 60 to provide an exposed sealing surface 63 while protecting and insuring retention of the O-ring 60.

The poppet element 55 has a projecting neck 65 extending beyond the seating surface 57 which connects to a radially projecting disk 66. The disk 66 forms with the valve bore 27 an annular throttling orifice which as is hereinafter explained, effects the predominant throttling of the fluid passing through the valve assembly 10.

The axial extremity of poppet element 55 opposite the disk 66 has a cylindrical bore 70 which houses a compression spring 71 that seats in a shallow bore 72 in the extremity of cylindrical recess 50 of fixed body member 11. The spring 71 is substantially totally housed within the bore 70 when the poppet element 55 moves downwardly in the cylindrical recess 50 to seat against the lower extremity of the cylindrical recess 50.

In operation when the inflatable member M is maintained in its normal stowage position the valve assembly 10 and inflatable member M are totally without internal pressurizing fluid. The valve assembly 10 has its elements reposing in the positions depicted in the drawing. The spring 71 in the absence of opposing pressure maintains the poppet element 55 positioned as depicted in the drawing with the O-ring 60 engaging the seating surface 57 of the poppet 55.

When the inflatable member M is to be deployed, pressure is released at the source of pressurized fluid which may typically be a tank of gas stored at approximately 3,000 p.s.i. The high pressure fluid flows at high velocities to the valve assembly 10 and is introduced through entry bore 26 and valve bore 27. The influx of high pressure fluid drives the poppet element 55 fully into the cylindrical recess 50 by overcoming the compression spring 71. The high pressure fluid thus flows by the disk 66 and is appropriately throttled at the annular orifice between disk 66 and valve bore 27. The displacement of the poppet element 55 moves the seating surface 57 away from the O-ring 60 such that inflating fluid is permitted to flow therebetween and out through the outlet passages 51. It is advantageous that portions of the valve assembly 10 are of such a relation that a greater cross-sectional area than exists at the disk 66 is provided proximate the seating surface 57 and through the outlet passages 51 during fluid flow, such that the predominant throttling action takes place in the annular throttling orifice.

Once the pressurizing fluid is rapidly converted from a small volume high pressure source to a large volume filling the inflatable member M at a pressure of approximately 3-5 p.s.i., the valve assembly 10 then provides low pressure sealing once this pressure is reached. This is accomplished by the spring 71 operating to displace the poppet element 55 such that O-ring 60 seats against seating surface 57 as shown in the drawing figure.

The rapid decompression attendant the filling of inflatable member M tends to create an extremely cold gas passing the O-ring 60 which is capable of at least instantaneously freezing the O-ring 60. Although a cold or frozen seal is less susceptible to erosion or pitting damage, it is also significant that O-ring 60 be constructed of a material which resists low temperature deterioration and is sufficiently resilient at low temperatures to effect the requisite sealing operation. It has been determined that an appropriate material for the O-ring 60 is an EPDM or other synthetic rubber and preferably a fluoroelastomer such as VITON (a registered trademark of E. I. DuPont de Nemours & Co.). In lieu of the swaged projecting lips 62, the O-ring 60 may be bonded in the groove 58 by an appropriate bonding agent dependent upon the material used. A cyanoacrylate bonding agent may be employed in conjunction with VITON or similar materials. It is also to be noted that the disposition of the groove 61 which seats O-ring 60 with respect to the fluid flow is in an area of lower velocity without direct gas impingement. It is also to be noted that the seal 45 in groove 46 is exposed only to the low pressure gases from the outlet passages 51 which have passed through the throttling area at disk 66 such that seal 45 is not exposed to the high pressure fluid introduced to valve assembly 10. It is to be appreciated that the distribution of the fluid among various valve assemblies 10 may also be controlled by having a plurality of sizes of poppet elements 55 and particularly with variations in the radial extent of disk 66 such as to selectively vary the throttling characteristics through the throttling orifice. This may be accomplished while maintaining the relative sizes and flow characteristics hereinabove set forth.

Thus, it should be evident that the valve assembly described herein carries out the various objects of the invention set forth hereinabove and otherwise constitutes an advantageous contribution to the art. As may be apparent to persons skilled in the art, modifications in the size of the valve element, the sealing member materials and other alterations could be employed without departing from the spirit of the invention, the scope of the invention being limited solely by the scope of the attached claims.