Patent Publication Number: US-2017361668-A1

Title: Air maintenance tire system component protector

Description:
FIELD OF THE INVENTION 
     The invention relates to air maintenance tire systems, which are systems that maintain appropriate air pressure within a pneumatic tire. More specifically, the invention relates to a protector for components of a valve stem-based air maintenance tire system. 
     BACKGROUND OF THE INVENTION 
     Conventional pneumatic tires are designed to perform for relatively long periods of time. In many cases, automobile tires are now expected to have a useful service life of 30,000, 50,000, or 70,000 miles. However, even long-life pneumatic tires are subject to air pressure losses due to puncture by nails and other sharp objects, temperature changes, and/or diffusion of air through the tire itself. 
     Since air diffusion reduces tire pressure over time, the pneumatic tires may repeatedly become underinflated. Accordingly, drivers must in turn repeatedly act to maintain recommended air pressures in the vehicle tires to avoid reduced fuel economy, tire life, and/or vehicle braking and handling performance. Tire pressure monitoring systems (TPMS) are automated systems that have been proposed to warn drivers when the air pressure in the vehicle tires is significantly low. Such systems, however, remain dependent upon a driver taking remedial action, when warned, to re-inflate a tire to the recommended pressure. It had thus been desirable in the prior art to incorporate an air maintenance feature within a pneumatic tire that would maintain a predetermined or recommended air pressure without requiring driver intervention. 
     To this end, air maintenance tire (AMT) systems have been developed. An AMT system typically includes one or more pumps or pumping assemblies that act to increase the air pressure in the vehicle tires as needed. An example of one such system is a valve stem-based air maintenance tire system described in U.S. patent application Ser. No. 15/065,134, which is owned by the same Assignee as the present invention, that is, The Goodyear Tire &amp; Rubber Company. 
     In such air maintenance tire systems, and particularly valve stem-based air maintenance tire systems, certain components of the systems may be exposed to road debris and environmental conditions. For example, a valve stem-based air maintenance tire system may employ air tubes that extend between a valve housing and a peristaltic pump tube. Such air tubes may be disposed on the outboard surface of the wheel rim and/or tire, where they are exposed to road debris and environmental conditions. 
     It is therefore desirable to provide a protector that shields and protects such components of a valve stem-based air maintenance tire system from potential damage. 
     SUMMARY OF THE INVENTION 
     According to an aspect of an exemplary embodiment of the invention, an air maintenance tire system includes at least one connecting tube extending between and being in fluid communication with an annular air tube and a valve housing. The protector includes a first end disposed proximate the connection of the at least one connecting tube to the annular tube, and a second end disposed proximate the valve housing. A mid-portion of the protector is disposed between the first and second ends, in which the protector covers an outboard surface of the at least one connecting tube. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be described by way of example and with reference to the accompanying drawings, in which: 
         FIG. 1  is a fragmentary elevational view of an outboard side of a tire including components of a valve stem-based air maintenance tire system; 
         FIG. 2  is a fragmentary elevational view of an outboard side of a tire including components of a valve stem-based air maintenance tire system and an exemplary embodiment of an air maintenance tire system component protector of the present invention; 
         FIG. 3  is a perspective view of the air maintenance tire system component protector shown in  FIG. 2 ; 
         FIG. 4  is a fragmentary perspective view of a portion of the air maintenance tire system component protector shown in  FIG. 2 ; and 
         FIG. 5  is a fragmentary perspective view of another portion of the air maintenance tire system component protector shown in  FIG. 2 . 
     
    
    
     Similar numerals refer to similar parts throughout the drawings. 
     DETAILED DESCRIPTION OF THE INVENTION 
     It is to be understood that the term inboard is referred to herein as a direction corresponding to the axially inner surface or side of a tire, and the term outboard is referred to herein as a direction corresponding to the axially outer surface or side of a tire. The term axially inwardly refers to an axial direction that is toward the center plane of a tire, and the term axially outwardly refers to an axial direction that is away from the center plane of a tire. The term radially inwardly refers to a radial direction that is toward the central axis of rotation of a tire, and the term radially outwardly refers to a radial direction that is away from the central axis of rotation of a tire. 
     Turning to  FIG. 1 , a tire  12  is mounted on a rim  14  in a conventional manner as known to those skilled in the art and defines a cavity (not shown). An exemplary air maintenance tire system, such as a valve stem-based air maintenance tire system, is indicated at  16 . The air maintenance tire system  16  includes a peristaltic pump assembly  18 . The peristaltic pump assembly  18  includes an annular air tube  20  that is received in an annular groove  38  formed in the tire  12  and/or rim  14 , and in turn encloses an annular passageway (not shown). 
     A first connecting tube  22  attaches to a first end  24  of the annular air tube  20  and fluidly connects the first end of the annular air tube to a valve housing  26  of the pump assembly  18 . A second connecting tube  28  attaches to a second end  30  of the annular air tube  20  and fluidly connects the second end of the annular air tube to the valve housing  26 . 
     When the tire  12  rotates under load along a ground surface, the annular air tube  20  is sequentially flattened or squeezed at the tire footprint. The sequential flattening of the annular air tube  20  and its passageway, segment by segment, directs air to the valve housing  26 . A tire valve stem (not shown), including a check valve, is fluidly connected to the valve housing  26 . When the air pressure is sufficient against the check valve and the air pressure within the tire cavity is below a set pressure level, air passes into the tire cavity. When the air pressure level within the tire cavity is at or above the set pressure, the check valve closes and air from the pump assembly  18  is vented by a relief valve in the valve housing  26  to atmosphere. 
     As seen in  FIG. 1 , the valve housing  26  of the pump assembly  18  is disposed within the rim  14 . The connecting tubes  22 ,  28  pass through an opening  36  formed in the rim  14  and extend to a fairly rigid elastomer or polymer mounting member  32 , which is referred to as a dome. The dome  32  is secured to a sidewall  34  of the tire  12 , and facilitates the fluid connection of the first connecting tube  22  to the first end  24  of the annular air tube  20  via a first fitting  72  and the fluid connection of the second connecting tube  28  to the second end  30  of the annular air tube via a second fitting  74 . The first and second connecting tubes  22  and  28  thus are disposed on the outboard surface of the tire  12  and the rim  14 , where they are exposed to potentially damaging road debris and environmental conditions. 
     With reference now to  FIGS. 2 through 5 , an exemplary embodiment of an air maintenance tire system component protector of the present invention is indicated generally at  10 . The protector  10  extends radially from the valve housing  26  to the dome  32  to engage and cover the connecting tubes  22  and  28  to protect them. The connecting tubes  22  and  28  typically are formed of a polymer, such as a flexible plastic, to enable the tubes to flex as the tire  12  undergoes cyclic deflection during rotation. As will be described in greater detail below, the protector  10  thus includes a structure that enables it to flex, while remaining stable to provide secure protection for the tubes  22  and  28 . 
     The protector  10  includes a first end  40 , a second end  42  and a mid-portion  44  disposed between the first and second ends. The first end  40  of the protector  10  provides rigid support and a secure connection of the protector to the dome  32 . More particularly, the first end  40  is curved axially inboardly relative to the remainder of the protector  10  to provide a stable mounting platform against the dome  40 . Preferably, the first end  40  is secured to the dome  32  by a mechanical fastener, such as a screw  46 . For example, an opening  48  may be formed in the first end  40  of the protector  10 , which aligns with the dome  32  in between the connecting tubes  22  and  28 , thereby enabling the screw  46  to be secured to a solid area of the dome without adversely affecting the fluid connection of each respective connecting tube to the annular tube  20 . 
     The first end  40  of the protector  10  also preferably includes a boot  50 . The boot  50  is formed of an elastomeric material, and covers the connection of each connecting tube  22  and  28  to the respective fittings  72  and  74  at the dome  32 , which reinforces these connections. In addition, the boot  50  optionally contacts and seats on the dome  32  to enable the protector  10  to be supported by the dome. The first end  40  of the protector  10  also includes a pair of slots  52  that are formed in a radially inward surface  54  of the protector first end. Preferably, each of the connecting tubes  22  and  28  snap into a respective one of the slots  52 , enabling the first end  40  of the protector  10  to support the connecting tubes adjacent the dome  32 . Such support enables the protector  10  to maintain a straight connection of each connecting tube  22  and  28  to the dome  32  to reduce any potential stress in the tubes, reduce abrasion of the tubes with other components such as connecting screws and improve the fatigue behavior of the tubes, all which desirably increase the life of the tubes. 
     The second end  42  of the protector  10  provides rigid support and a secure connection of the protector to the valve housing  26 . More particularly, the valve housing  26  typically includes a nut  56  on its outboard surface that threads onto a bolt  58  of the valve housing. An opening  60  is formed in the second end  42  of the protector  10 , which enables the bolt  58  to pass through the protector  10 . A lip  62  is formed on the inner circumference of the opening  60 , and the nut  56  engages the lip to secure the second end  42  of the protector  10  to the outboard surface of the valve housing  26 . The second end  42  of the protector  10  preferably is also formed with a rounded edge  64  that curves axially inboardly to surround the radially inward perimeter edge of the outboard surface of the valve housing  26 , thereby providing increased protection of the valve housing. 
     The protector  10  is formed with a taper extending from the first end  40  to the mid-portion  44 , and with a taper extending from the second end  42  to the mid-portion  44 . As a result, the mid-portion  44  preferably is thinner than the first end  40  and the second end  42 . The mid-portion includes a flexible member  66 , such as a bellows. The bellows  66  may be a discrete member formed of a flexible material such as an elastomer, or it may be an integrated flexible feature formed in the mid-portion  44  of the connector  10 . 
     The flexible member  66  enables the protector  10  to flex along three planes of motion. Specifically, if the valve housing  26  has shifted circumferentially relative to the dome  32  and the valve housing and dome are thus misaligned, the flexible member  66  still enables a secure connection of the protector first end  40  to the dome and the second end  42  to the valve housing. If the valve housing  26  has shifted axially inboardly or axially outboardly relative to the dome  32 , the flexible member  66  again enables a secure connection of the protector first end  40  to the dome and the second end  42  to the valve housing. Finally, as the tire  12  rotates and experiences cyclic deflection, the radial distance between the dome  32  and the valve housing  26  may change by up to about five (5) or six (6) millimeters. The flexible member  66  readily absorbs and thus accommodates such a change in radial distance, thereby maintaining a secure connection of the protector first end  40  to the dome  32  and the second end  42  to the valve housing  26 . 
     The protector  10  includes one or more pairs of connectors or clips  70  that are attached to an axially inboard surface  68  of the protector. The connectors or clips  70  snap onto and engage the connecting tubes  22  and  28  to retain the tubes adjacent the inboard surface  68  of the protector  10 . The connectors  70  thus keep the connecting tubes  22  and  28  in a protected location, and by anchoring them to the protector  10 , reduce undesirable vibration of the tubing as the tire  12  rotates. 
     Preferably, the protector  10  is formed of a light weight, yet stable, material. For example, the protector  10  may be formed of rigid nylon polymer, which provides a weight between about ten (10) and fifteen (15) grams for the protector  10 . The protector  10  is easily installed after the air maintenance tire system  16  has been assembled, requiring no special steps or specialized tools. Likewise, the protector  10  is easy to remove and/or replace, if needed. Advantageously, the protector  10  interfaces with existing components of the air maintenance tire system  16 , so that no additional components or adaptations are needed to employ the protector. 
     The air maintenance tire system component protector  10  of the present invention thus provides protection of the connecting tubes  22  and  28  and the valve housing  26  from debris impacts. In addition, the protector  10  retains the position of the connecting tubes  22  and  28  so that the tubes do not touch other components of the vehicle. By anchoring the connecting tubes  22  and  28  to a streamlined structure that also covers the outboard surface of the valve housing  26 , the protector also improves the aesthetic appearance of the connecting tubes and the valve housing. 
     By covering the connecting tubes  22  and  28 , the protector  10  desirably provides protection of the tubes, which may be formed from a polymer, from potentially degrading ultraviolet light. By being light, yet stable, the protector  10  supports the connection of the flexible connecting tubes  22  and  28  to the dome  32 , improving the ability of the connecting tubes to withstand the stress created by the cyclic deflection of the tire  12  during rotation. The protector  10  also provides a stable anchor for the connecting tubes  22  and  28  to reduce the vibration of the tubes as the tire  12  rotates. Moreover, by supporting the connecting tubes  22  and  28 , the protector  10  desirably increases the life of the connecting tubes, as it reduces potential stress in the tubes, improves the fatigue performance of the tubes and reduces abrasion on the tubes at or near their respective connections to the dome  32  and the valve housing  26 . 
     The present invention also includes a method of protecting components of an air maintenance tire system. The method includes steps in accordance with the description that is presented above and shown in  FIGS. 2 through 5 . 
     It is to be understood that the structure of the above-described air maintenance tire system component protector may be altered or rearranged, or components known to those skilled in the art omitted or added, without affecting the overall concept or operation of the invention. For example, the protector  10  may be of a one-piece or a multi-piece construction, and/or may be formed of one material or multiple materials. As an additional example, the flexible member  66  may be formed of a different material than the rest of the protector  10 , or from the same material as the rest of the protector. 
     The invention has been described with reference to a preferred embodiment. Potential modifications and alterations will occur to others upon a reading and understanding of this description. It is to be understood that all such modifications and alterations are included in the scope of the invention as set forth in the appended claims, or the equivalents thereof.