Abstract:
A coupling assembly for attachment of an air line to a tire comprising, a first conduit associable with an axle about which a tire rotates, a second conduit associable with a hub of a tire, and means for compensating misalignment of the first conduit relative to the second conduit, to, in turn, accommodate sealed fluid communication of the first conduit and the second conduit.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates in general to a coupling assembly, and more particularly, to a coupling assembly for use in association with an air line of a tire inflation system. 
     2. Background Art 
     Tire inflation systems and components associated therewith have been known in the art for years and are the subject of numerous patents including: U.S. Pat. No. 5,769,979; U.S. Pat. No. 5,584,949; U.S. Pat. No. 4,883,106; U.S. Pat. No. 4,685,501; U.S. Pat. No. 4,387,931; and U.S. Pat. No. 3,276,503. While tire inflation systems have become commercially available for use in association with vehicles, the cost, reliability, and longevity of these tire inflation systems remains largely problematic. 
     It is therefore an object of the present invention to provide a low-cost, reliable coupling assembly for use in association with a tire inflation system which remedies the detriments and/or complications associated with conventional tire inflation systems. 
     These and other objects of the present invention will become apparent in light of the present specification, claims, and drawings. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to a coupling assembly for attachment of an air line to a tire comprising: (a) a first conduit associable with an axle about which a tire rotates; (b) a second conduit associable with a hub of a tire; and (c) means for compensating misalignment of the first conduit relative to the second conduit, to, in turn, accommodate sealed fluid communication of the first conduit and the second conduit. 
     In a preferred embodiment of the invention, the misalignment compensating means comprises means for flexibly mounting the first conduit to the axle. In this embodiment, the means for flexibly mounting the first conduit to the axle comprises a flexible mount which facilitates sealed pivoting of the first conduit about a first end thereof. 
     In another preferred embodiment of the invention, the misalignment compensating means comprises means for flexibly connecting the first conduit to the second conduit. In this embodiment, the means for flexibly connecting comprises a flexible conduit having a greater flexibility than at least of portion of each the first and second conduits. The flexible conduit may optionally include a bulge region. 
     In yet another preferred embodiment of the invention, the flexible conduit is attached to at least one of the outside and/or the inside surfaces of the first conduit and/or the second conduit. Preferably, the first conduit and the second conduit comprise a substantially circular cross-section. The flexible conduit may additionally comprise a substantially circular cross-section. 
     In accordance with the present invention, the misalignment compensating means may comprise: (a) means for flexibly mounting the first conduit to an axle; and (b) means for flexibly connecting the first conduit to the second conduit. 
     The present invention is also directed to a coupling assembly for attachment of an air line to a tire comprising: (a) a conduit having a first end attachable to an air line so as to be in fluid communication therewith, and a second end positionable so as to extend at least partially through an opening in a hub of the pneumatic tire; (b) at least one seal positioned between the conduit and the opening in the hub to, in turn, define at least one volume therebetween; and (c) means for venting the volume in fluid communication to surrounding ambient conditions. 
     In a preferred embodiment of the invention, the venting means extends through one of the hub and the at least one seal. Such seal(s) may comprise lip seals and/or mechanical seals. Alternatively, the venting means may comprise a conduit extending through the hub. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will now be described with reference to the drawings wherein: 
     FIG. 1 of the drawings is a cross-sectional view of a coupling assembly in accordance with the present invention; 
     FIG. 2 of the drawings is a side-elevational view of an coupling assembly in a pneumatic tire environment; 
     FIG. 3 of the drawings is a side-elevational view of an embodiment of a flexible connector in accordance with the present invention; and 
     FIG. 4 of the drawings is a cross-sectional view of an embodiment of flexible connecting means in accordance with the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     While this invention is susceptible of embodiment in many different forms, there is shown in the drawings and described herein in detail several specific embodiments with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the invention to the embodiments illustrated. 
     Referring now to the drawings and to FIG. 1 in particular, a cross-sectional schematic representation of coupling assembly  10  is shown, which generally comprises first conduit  12 , second conduit  14 , misalignment compensating means  16 , and rotary union  18 . It will be understood that FIG. 1 is merely a schematic representation of coupling assembly  10 . As such, some of the components have been distorted from their actual scale for pictorial clarity. As is shown in FIG. 2, coupling assembly  10  is primarily intended for use in association with a pneumatic tire inflation system which is adaptable to a vehicle (car, truck, tractor, trailer, etc.) to couple air line  100 , extending through axle  110 , to hose  120 , and, in turn, to a tire which is mounted on hub  130 . 
     Referring again to FIG. 1, first conduit  12  includes first end  20 A, second end  20 B, outer surface  22  and inner surface  24 . First end  20 A of first conduit  12  includes retaining lip  26  which is associated with axle  110 . First conduit  12  generally comprises a seamless tubular material that is preferably substantially resistant to corrosion. However, the conduit is not limited to such a material, and other materials, such as other metals and alloys as well as composites and plastics are contemplated for use. Such a material may comprise a substantially circular seamless stainless steel tubing having a particular inner diameter and a particular wall thickness. While not limited thereto, the inner diameter of the air lines and the conduits are on the order of {fraction (3/16)} of an inch. 
     As is shown in FIG. 1, second conduit  14  generally comprises first end  30 A, second end  30 B, outer surface  32  and inner surface  34 . First end  30 A of second conduit  14  is associated with hub  130 . As can be further seen in FIG. 1, second end  30 B of second conduit  14  is associated with second end  20 B of first conduit  12 , such that the longitudinal axis of each of first conduit  12 , second conduit  14  and the axle  110  are substantially co-linear. It will be understood that second conduit  14  can be fabricated from the same or similar materials as that of first conduit  12 . 
     Misalignment compensating means  16  comprises flexible mounting means  40  for flexibly associating first conduit  12  to axle  110  and flexible connecting means  50  for flexibly associating first conduit  12  to second conduit  14 , either directly or indirectly. Due to tolerances and variations in the manufacturing process, the longitudinal axis of each of first conduit  12 , second conduit  14 , and axle  110  are not generally perfectly aligned in a co-linear configuration. Accordingly, misalignment compensating means  16  compensates for these variations and tolerances to, in turn, insure the integrity of the conduit. 
     As is shown in FIG. 1, flexible mounting means  40  generally comprises a flexible mount  42  extending between first end  20 A of first conduit  12  and axle  110  which is, in turn, associated with air line  100  (See FIG.  2 ). Flexible mount  42  permits the first conduit to pivot substantially transversely about first end  20 A, while maintaining an effective seal between axle  110  and the same. Flexible mount  42  comprises rubberized material  44  and stability rim  46 . Stability rim  46  provides integrity to rubberized material  44  and provides a means by which to attach flexible mount  42  to axle  110 . Of course, other configurations are likewise contemplated for use. For example, flexible mount  42  may comprise a rubberized material that does not include a rubberized rim. In other embodiments, the flexible mount may comprise a boot which extends over each of axles  110  and first  12  conduit. In addition, it will be understood that other variations that would be known to those having ordinary skill in the art are likewise contemplated for use. 
     Preferably, flexible connecting means  50  comprises flexible conduit  52  which connects second end  20 B of first conduit  12  to second end  30 B of second conduit  14  in a substantially fluid tight connection. Specifically, flexible conduit  52  comprises a material having a portion which is more flexible than either of the first and second conduits, such as molded rubber compounds, natural and synthetic resins and/or composites. In certain embodiments the material may comprise a composite which includes reinforcement means, such as, for example, woven or non-woven mesh. As is best shown in FIG. 1, flexible conduit  52  may be dimensionally configured so as to comprise a substantially uniform cross-section. 
     Alternatively, as is shown in FIG. 3, flexible conduit  52  may include bulge region  54  which is of a larger cross-sectional area than the general remainder of the flexible conduit. Such a configuration compensates for misalignment of first conduit  12  and/or second conduit  14 , even in situations where the magnitude of misalignment may be larger than is observed during normal operation of an associated vehicle. 
     As can be seen in FIG. 1, flexible conduit  52  is generally positioned so as to overlie outer surface  22  of first conduit  12  and outer surface  32  of second conduit  14 . In another embodiment, flexible conduit  52  may be positioned on inner surface  24  of first conduit  12  and inner surface  34  of second conduit  14 . In further embodiments, the flexible conduit may be positioned on the inside and/or outside of first conduit  12  and/or second conduit  14 , respectively. 
     Alternatively, and as is shown in FIG. 4, flexible connecting means  50  may comprise ball joint  60 , which may or may not be covered by a rubber boot, such as boot  62 . In other embodiments, multiple components can be utilized to attach the first conduit to the second conduit so as to compensate for the misalignment thereof. 
     Referring now back to FIG. 1, rotary union  18  generally comprises first seal  70 , second seal  72  and venting means  74 . First seal  70  and second seal  72  are positioned toward first end  30 A of second conduit  14  to provide a fluid tight seal between outer surface  32  of second conduit  14  and hub  130 . The first and second seals are distally spaced apart so as to define volume  80  therebetween. The seals generally comprise lip seals which permit rotation of second conduit  14  relative to hub  130  while retaining the integrity of the seal. The lip seals may comprise various rubbers and other natural and synthetic resins and/or composites which are capable of providing an effective seal over millions of rotative cycles. While two seals have been shown, for illustrative purposes only, it will be understood that a single seal or multiple seals (i.e. more than two) can be utilized. Additionally, other seals, such as mechanical (carbon) seals are contemplated for use in accordance with the present invention. 
     Venting means  74  provides fluid communication between volume  80  and ambient/external conditions. In the embodiment illustrated, venting means  74  comprises a conduit which extends from hub opening  76  through hub  130  to the outside surface of the hub. In other embodiments, the venting means may comprise a small conduit which extends through one of the lip seals. It will be understood that if more than two seals are used, the volume between any two seals can be vented. 
     As will be explained, if one of the first and second seals  70  and  72 , respectively, undesirably degrades, it is possible for moisture and contaminants to enter volume  80 , and subsequently air line  100  (See FIG.  2 ). Entry of these contaminants and moisture into an associated tire (not shown) can materially reduce the life of the tire and lead to premature failure thereof. Venting means facilitates the release of moisture and/or other contaminants that may enter into volume  80 , so that these contaminants are removed into the ambient/external environment so as to reduce the risk that any contaminants enter into the tire. As will be understood the rotating coupling, and the venting means are likewise applicable to embodiments that do not include any flexible coupling means. 
     To install coupling assembly  10 , the operator first attaches first conduit  12  to flexible mounting means  40 . Next, flexible mounting means  40  is attached to axle  110  (which has already been associated with air line  100 ). More specifically, first end  20 A of first flexible conduit  12  is attached to flexible mount  42  so that lip  26  abuts the outer surface thereof. As was previously explained, flexible mounting means  40  allows for a certain amount of pivoting of first conduit  12  about its first end. 
     After first conduit  12  is operatively positioned, flexible connecting means  50  is attached to second end  20 B of first conduit  12 . Subsequently, lip seals  70  and  72  are positioned in the desired locations in hub  130 . Once positioned, second conduit  14  is slid into position so as to extend through hub  130  and into flexible connecting means  50 . Once fully positioned, a tire (not shown) is placed in fluid communication with first end  30 A of second conduit  14  by way of a rotatably coupled air line  100  (See FIG.  2 ). Of course, the conduit is not limited to the use of any particular air line. 
     In operation, air line  100  is capable of providing air at a desired pressure (i.e. 100 psi) through coupling assembly  10  to a tire mounted on hub  130 . Air line  100  and the flow therethrough can be manually controlled by the user in the cab of a vehicle, or alternatively, controlled by an automated system. Various control systems for controlling the flow of air into the tire are known in the art, and the system is not limited to any one particular method or control system. 
     As the hub and the tire rotate, due to variations and tolerances, the axis of rotation of each of the hub, the axle, and the first and second conduits may be misaligned so that they are not perfectly co-linear. The flexible connector and the flexible rubber mount compensate for the misalignment of the various components and maintain the integrity of the coupling—essentially compensating for the variations in the respective longitudinal axis of rotation. 
     The foregoing description merely explains and illustrates the invention and the invention is not limited thereto except insofar as the appended claims are so limited, as those skilled in the art who have the disclosure before them will be able to make modifications without departing from the scope of the invention.