Abstract:
A system and method for enabling rapid and controlled releasing of fluid pressure, as for deflating a tire. The system, in an embodiment thereof, enables rapid and controlled deflation of a tire to enable a vehicle to navigate in rough or unstable terrain.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates generally to improvements in fluid pressure releasing systems and methods. In particular, it relates to a new and improved system and method for rapidly and controllably releasing fluid pressure. 
   2. Description of the Related Art 
   The systems and methods of the present invention are particularly useful for enabling the reduction of the air pressure in a tire. 
   A variety of systems and methods have been developed over the years for deflating a tire. Rapid and controlled reduction of tire air pressure enables the tire to provide a larger contact area on a road or trail surface and/or to substantially improve traction for navigating over rough or unstable terrain. Tire deflation, for example from a common tire pressure such as 30 pounds per square inch (psi) used on paved roads, to a substantially lower tire pressure such as 12 psi or 9 psi, is desired for enabling efficient and effective vehicle navigation in rough terrain. It is utilized in the military for military vehicles when having to move from relatively smooth surfaces to rough terrain, and is also utilized in the same manner for off-roading for vehicles such as cars, trucks, and/or sport utility vehicles, and for tractors and vehicles for forestry, construction, power line and pipeline maintenance, agricultural uses, and the like. 
   The various systems and methods developed for tire deflation to reduce tire air pressure include, for example, depressing the pin head in the air valve in the tire, by hand or by use of a depression device which may be pressed, clipped, or threaded onto the valve system, allowing the air to escape. Deflation to a desired pressure in such systems relies on alternately releasing air and checking pressure with a gauge, or on an integral pressure gauge intended to stop releasing air at a preset pressure. In other such systems, the valve core may be removed or held outside the valve by a tool, the air pressure may be released, and the cap may be replaced on the valve or the valve core replaced after releasing the desired amount of air. Further, a chuck, connected through a tube to a fitting attached to the valve, or attached directly to the valve, may be activated to release air from the tire. Also, a deflator fitting may be attached to the valve, to enable tire deflation. Another device is secured to the air valve, and releases pressure as the vehicle is driven, to a preset lower pressure. 
   However, there have been problems associated with such systems and methods. They are relatively slow, with substantial deflation times required which exceed desired times for military applications where speed is essential, and also for non-military uses where speed is desirable. Further, some such systems include installed deflators that project substantially from the valve stem, creating a risk of total deflation if the deflator is snagged on trail debris and any part of the deflator or valve stem is then damaged or detached. Other such systems require resetting and recalibration of the deflator if a different final pressure is desired. Still other such systems may be unsafe, with potential pressurized projection of the valve core or fittings resulting from sudden release of air pressure, and may be subjected to damage from rocks picked up while driving through the rough terrain. 
   Therefore, the present invention provides improved systems and methods for enabling the rapid and controlled release of fluid pressure, as for metered deflation of a tire for reducing tire air pressure in a safe manner. The inventions disclosed herein satisfy these and other needs. 
   SUMMARY OF THE INVENTION 
   The present invention, in general, provides a new and improved system and method for enabling the rapid and controlled release of fluid pressure, as for reducing tire air pressure. 
   More particularly, for example, in an embodiment of the present invention, a system is provided for providing for the efficient and effective deflation of a tire. The tire deflation system is usable in connection with a tire air valve which includes a valve stem which is extendable through a wheel rim, wherein the stem includes an extendable portion which is adapted to be extendable outside and adjacent the wheel rim. The tire deflation article includes multiple openings, formed in the extendable portion of the valve stem, and an external element, which is extendable about the openings in the extendable portion of the valve stem. The external element is securable in position relative to the extendable portion of the valve stem so as to cover the openings, and is movable so as to uncover the openings for enabling deflation of the tire. The covering of the openings by the external element prevents air from being released from the tire, while the uncovering of the openings fully or partially by the external element enables the safe and effective rapid and controlled release of air from the tire for deflation, so as to reduce the air pressure therein. 
   The above objects and advantages of the present invention, as well as others, are described in greater detail in the following description, when taken in conjunction with the accompanying drawings of illustrative embodiments. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is an exploded elevational partly-fragmentary partly-sectional view of a system in accordance with an embodiment of the present invention. 
       FIG. 2  is an elevational partly-fragmentary view of the uncovering of the openings in the system in  FIG. 1  pursuant to an embodiment of the invention. 
       FIG. 3  is an elevational partly-fragmentary partly-sectional view of the system with the openings covered and the cap installed, in an embodiment of the invention. 
       FIG. 4  is a similar view of the system in  FIG. 3  with the openings uncovered and the cap removed, in the practice of the invention. 
       FIG. 5  is a top plan partly sectional view of the openings in the system, facing the centerline of the wheel, pursuant to the invention. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   The present invention is directed to an improved system and method for enabling the rapid and controlled release of fluid pressure, as for the deflation of a tire to reduce tire air pressure in an efficient and effective manner. The preferred embodiments of the improved system and method are illustrated and described herein by way of example only and not by way of limitation. 
   In the drawings, wherein like reference numerals denote like or corresponding parts throughout the drawing figures, and particularly in the preferred embodiments in accordance with the invention as shown in  FIGS. 1–5 , for example, a system  10  is provided for enabling the deflation of a tire for reducing tire air pressure. The tire deflation system  10  of the present invention is usable in a tire air valve  12 . 
   The tire air valve  12  includes a valve stem  14  comprising a valve body, which is extendable through a wheel rim  16 . The wheel rim  16  includes an outer surface  18  and an inner surface  20 . The valve stem  14  includes a flange  22 , and an extendable portion which extends from the flange  22 , wherein the flange  22  and the extendable portion  24  are extendable outside and adjacent the wheel rim  16 . The valve stem  14  also includes an outer portion  26 , which extends from the extendable portion  24 , and which is threaded on the outside thereof to receive a cap  28  threadably securable thereto. The valve stem  14  further includes an air valve  30  extending therein. 
   The valve stem  14  also includes an inner portion  32  which is extendable through the wheel rim  16  and protrudes into the volume enclosed by the tire and the wheel rim  16 . The valve stem inner portion  32  includes a threaded portion  34  for receiving a nut  36  which is threadably securable thereto, and a washer  38  extending thereabout adjacent the inner surface  20  of the wheel rim  16 , for securing the valve stem  14  to the wheel rim inner surface  20 . An enlarged bore  40  in the valve stem  14  and a funnel-shaped opening  42  in the threaded portion  34  of the valve stem  14  to enhance air flow. A grommet  44  extends about the inner portion  32  of the valve stem  14  adjacent the wheel rim outer surface  18 . The valve stem extendable portion  24  further includes a medial portion  46  from which the outer portion  26  extends. The valve stem medial portion  46  includes an upper threaded portion  48  on the outer surface thereof, and a lower portion  50  positionable adjacent the outer surface  18  of the wheel rim  16 . 
   Referring to  FIGS. 1–5 , in an embodiment pursuant to the present invention, for example, the tire deflation system  10  includes at least one opening  52 , and preferably a plurality of openings  52 , formed in the lower portion  50  of the valve stem medial portion  46 . The openings  52  may extend for example radially or at an angle in side view and/or in plan view. They are preferably spaced apart circumferentially about the valve stem medial lower portion  50 . The tire deflation system  10  further includes an external element  54 , which is extendable about the openings  52  in the valve stem medial lower portion  50 . The external element  54  is securable in position relative to the valve stem medial portion  46  so as to cover the openings  52 , and is moveable so as to partially or fully uncover the openings  52 , for enabling metered or rapid deflation of the tire. Threading the cap  28  onto the valve stem  14  assists the external element  54  in further preventing unthreading thereof and unintended release of air pressure. 
   The external element  54 , for example, includes a connecting portion  56  which has an inner upper threaded portion, for enabling the threadable securing thereof to the medial upper threaded portion  48  of the valve stem  14 . A compressible member  58  such as an O-ring is positionable between the external element  54  and the openings  52  for enabling the substantial sealing of the openings  52 . The external element  54  further includes a portion  60  for retaining the O-ring  58  in position. An angular surface  62  in the external element  54  and a step portion  64  in the flange  22  enable compression of the O-ring  58  so as to substantially seal the openings  52 . 
   As illustrated in  FIGS. 1–5 , in a method for the use of the preferred embodiment in accordance with the present invention, for example, the system  10  enables the deflation of a tire. The valve stem  14  may be mounted on the wheel rim  16  of the tire by extending the valve stem  14  through the wheel rim  16 , threading the nut  36 , with the washer  38  adjacent thereto, against the wheel rim inner surface  20 , and with the valve stem flange  22  and the grommet  44  bearing against the wheel rim outer surface  18 . The threaded connecting portion  56  of the external element  54  may be threadably secured to the medial upper threaded portion  48  of the valve stem  14 , such that the O-ring  58  and the retaining covering portion  60  of the external element  54  covers the openings  52 . The threaded connecting portion  56  of the external element  54  may be unthreaded partially or fully from the medial upper threaded portion  48  of the valve stem  14 , such that the retaining portion  60  of the external element  54  and the O-ring  58  partially or fully uncover the openings  52 , enabling air to escape from the tire, dependent upon the extent to which the openings  52  are uncovered, for rapid and controlled deflation of the tire. Air pressure is reduced rapidly by the tire deflation system herein, as contrasted with much longer periods of time with other tire deflation systems and procedures. 
   The system  10  enables the monitoring of tire pressure during deflation, with commonly available gauges. It may be implemented such that the valve stem  14  protrudes from the outer surface  18  of the wheel rim  16  no further than a standard valve system. It also is relatively lightweight, so as to reduce the need for an additional balancing weight. 
   In accordance with the present invention, the particular embodiments set forth above for the system  10  are capable of providing rapid and metered deflation of a tire. However, other forms of the system  10  may be utilized with the present invention without departing from the spirit and scope of the invention. For example, a system such as the system  10  may be utilized for enabling the rapid and controlled release of fluid pressure in other applications, as for venting compressed gas vessels. The system  10  may also be implemented as a replacement for an original equipment standard tire air valve, or as an additional air valve along with the original equipment air valve, using a pressure gauge attachable thereto or to the original equipment air valve for measuring the air pressure in the tire and the tire deflation rate. Based on the present disclosure, other constructions and applications are known to one skilled in the art. 
   In view of the above, it is apparent that the system and method of the preferred embodiments of the present invention enhances substantially the effectiveness of deflating a tire for reducing tire air pressure. 
   While the present invention has been described in connection with the specific embodiments identified herein, it will be apparent to those skilled in the art that many alternatives, modifications and variations are possible in light of the above description. Accordingly, the invention is intended to embrace all such alternatives, modifications and variations as may fall within the spirit and scope of the invention disclosed herein.