Abstract:
A tire assembly is disclosed, wherein the tire has a tread portion and a pair of sidewalls extending radially inward from the tread portion to join with a respective bead; a supporting carcass for the tread portion and sidewalls; and a pump passageway positioned within a bending region of the tire. The pump passageway is operative to open and close as the tire rotates. The tire assembly further includes a valve assembly in fluid communication with the pump passageway. The tire further includes a filter assembly mounted in the tire. The filter assembly is formed of a housing having an interior cavity for receiving the filter media, the interior cavity having an inlet in fluid communication with the outside air and an outlet in fluid communication with the inlet port of the valve assembly. The housing further includes a second cavity, wherein the second cavity is in fluid communication with the pump inlet and the valve assembly outlet.

Description:
FIELD OF THE INVENTION 
       [0001]    The invention relates generally to tires and more specifically, to an air maintenance assembly for a tire. 
       BACKGROUND OF THE INVENTION 
       [0002]    Normal air diffusion reduces tire pressure over time. The natural state of tires is under inflated. Accordingly, drivers must repeatedly act to maintain tire pressures or they will see reduced fuel economy, tire life and reduced vehicle braking and handling performance. Tire Pressure Monitoring Systems have been proposed to warn drivers when tire pressure is significantly low. Such systems, however, remain dependent upon the driver taking remedial action when warned to re-inflate a tire to recommended pressure. It is a desirable, therefore, to incorporate an air maintenance feature within a tire that will maintain correct air pressure within the tire without a need for driver intervention to compensate for any reduction in tire pressure over time. It is useful to incorporate a filter in the design of an air maintenance tire system, so that the outside air is filtered before entering the system. The filter must be secured to the tire, and be able to sustain rotational forces. The filter must also be designed in such a way to minimize the stresses in the tire and allow for ease of assembly. 
       SUMMARY OF THE INVENTION 
       [0003]    The invention provides in a first aspect a tire assembly including a tire having a tread portion and a pair of sidewalls extending radially inward from the tread portion to join with a respective bead; a supporting carcass for the tread portion and sidewalls. A pump passageway is positioned within a bending region of the tire, the pump passageway being operative to open and close as the tire rotates, and having an inlet end and an outlet end, wherein the outlet end is in fluid communication with the tire cavity and a valve assembly is in fluid communication with the inlet end of the pump passageway. A filter conduit is mounted in the tire, the filter conduit having a first end in air flow communication with the outside air and a second end connected to the valve assembly inlet port, wherein the filter conduit further includes filter media. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0004]    The invention will be described by way of example and with reference to the accompanying drawings in which: 
           [0005]      FIG. 1  is an exploded view of a tire and rim assembly shown with a pump, valve and filter assembly. 
           [0006]      FIG. 2  is a front view of the tire and rim assembly of  FIG. 1 ; 
           [0007]      FIG. 3  is a perspective view of the pump tube assembly showing the inlet and outlet ends connected to the T fitting; 
           [0008]      FIG. 4  is a cross-sectional view of the tire showing the filter assembly and valve assembly in the tire bead area; 
           [0009]      FIG. 5   a  is an exploded side view of the filter and valve assembly and the connectors in the bead area of the tire; 
           [0010]      FIG. 5   b  is a side view of the filter and valve assembly shown assembled to the tire bead area; 
           [0011]      FIG. 6  is a side cross-sectional view of the filter and valve assembly shown assembled to the tire bead area; 
           [0000]    assembly in the pocket of the tire bead area; 
           [0012]      FIG. 7A  is a front view of the filter and valve assembly; 
           [0013]      FIG. 7B  is an exploded view of the filter and valve assembly; 
           [0014]      FIG. 7C  is a side cross-sectional view of the filter and valve assembly; 
           [0015]      FIG. 8A  is a front view of a second embodiment of a filter and valve assembly; 
           [0016]      FIG. 8B  is a side cross-sectional view of the second embodiment of the filter and valve assembly of  FIG. 8A ; 
           [0017]      FIG. 8C  is an exploded view of the second embodiment of the filter and valve assembly of  FIG. 8A ; 
           [0018]      FIG. 9A  is a top cross-sectional view of the second embodiment of the filter and valve assembly of  FIG. 8A  in the direction  9 A; 
           [0019]      FIG. 9B  is a side cross-sectional view of the second embodiment of the filter and valve assembly of  FIG. 8A  in the direction  9 B; 
           [0020]      FIG. 9C  is a close up side cross-sectional view of the valve assembly. 
           [0021]      FIG. 10A  is a front view of a third embodiment of a filter and valve assembly; 
           [0022]      FIG. 10B  is a side cross-sectional view of the third embodiment of the filter and valve assembly of  FIG. 10A ; 
           [0023]      FIG. 11A  is a top cross-sectional view of the third embodiment of the filter and valve assembly of  FIG. 10A  in the direction  11 A; 
           [0024]      FIG. 11B  is a side cross-sectional view of the third embodiment of the filter and valve assembly of  FIG. 11A  in the direction  11 B; 
           [0025]      FIG. 12A  is a perspective view of a fourth embodiment of a filter and valve assembly; 
           [0026]      FIG. 12B  is a side cross-sectional view of the fourth embodiment of the filter and valve assembly of  FIG. 12A ; 
           [0027]      FIG. 13A  is a cross-sectional view of the fourth embodiment of the filter and valve assembly of  FIG. 12A  in the direction  13 A; 
           [0028]      FIG. 13B  is a view of the fourth embodiment of the filter and valve assembly of  FIG. 12A  in the direction  13 B; 
           [0029]      FIG. 13C  is a cross-sectional view of the fourth embodiment of the filter and valve assembly of  FIG. 12A  in the direction  13 C; 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0030]    Referring to  FIGS. 1 and 2 , a tire assembly  10  includes a tire  12  and a pump assembly  14 . The tire mounts in a conventional fashion to a wheel  16  having outer rim flanges  22 . An annular rim body  28  joins the rim flanges  22  and supports the tire assembly as shown. The tire is of conventional construction, having a pair of sidewalls  32  extending from opposite bead areas  34  to a crown or tire tread region  38 . The tire and rim enclose an interior tire cavity  40  which is filled with air. 
         [0031]    As shown in  FIGS. 1 and 3 , the tire assembly includes a pump  14  formed of a pump passageway  42  that is mounted or located in the tire in a channel  44 , preferably near the bead region  34  of the sidewall. The pump passageway  42  may be formed of a discrete tube (as shown) made of a resilient, flexible material such as plastic, elastomer or rubber compounds, and is capable of withstanding repeated deformation cycles when the tube is deformed into a flattened condition subject to external force and, upon removal of such force, returns to an original condition. The tube is of a diameter sufficient to operatively pass a volume of air sufficient for the purposes described herein and allowing a positioning of the tube in an operable location within the tire assembly as will be described. Preferably, the tube has an elliptical cross-sectional shape, although other shapes such as round may be utilized. 
         [0032]    The pump passageway  42  itself may also be integrally formed or molded into the sidewall of the tire during vulcanization, eliminating the need for an inserted tube. An integrally formed pump passageway is preferably made by building into a selected green tire component such as a chafer, a removable strip made of wire or silicone. The component is built into the tire and cured. The removable strip is then removed post cure to form a molded in or integrally formed pump air passageway. 
         [0033]    Hereinafter, the term “pump passageway” refers either to installed tubes or an integrally molded in passageway. The location selected for the pump passageway within the tire may be within a tire component residing within a high flex region of the tire, sufficient to progressively collapse the internal hollow air passageway as the tire rotates under load thereby conveying air along the air passageway from the inlet to the pump outlet. 
         [0034]    The pump air passageway  42  has two inlet ends  42   a,    42   b  joined together by a valve system  200 , as shown in  FIGS. 1 ,  6 . The valve system functions to regulate the amount of air supplied to the pump. Examples of pressure regulators or valve systems suitable for use with the invention are disclosed in application Ser. Nos. 13/221,231, 13/221,433, 13,221,506 and hereby incorporated by reference. The pump air passageway has two outlet ends  44   a,    44   b  that are in fluid communication with the tire cavity. As shown in this particular example, there are two 180 degree pumps, so that the inlet ends  42   a,    44   a  and the outlet ends  42   a,    44   a  are spaced apart approximately 180 degrees. However, the inlet and outlet ends may also be spaced apart 90 degrees, 180 degrees. To modify the system for a 360 degree or greater, the pump only has one inlet and one outlet, wherein the outlet is located next to the inlet, and is in fluid communication with the tire cavity. 
         [0035]    The valve assembly  200  is preferably affixed to the inside of the tire, near the bead area. The valve assembly  200  has an inlet port  202  and an outlet port  206 . The valve assembly  200  is operable to control the amount of inlet air to the pump system  42 . If the tire cavity pressure  40  falls below a set trigger pressure, the valve assembly allows air to enter through the filter conduit  204 , and then through to the pump passageway  42 . The valve assembly  200  may allow airflow into the pump system through an air inlet port  210 . The valve assembly  200  also may control the flow of air from the pump into the tire cavity, as well as prevent cavity air from back flowing into the pump passageways. 
         [0036]    A filter conduit  204  is shown in  FIG. 4 , and is a flexible tube or passageway that extends from the tire sidewall to the inlet port  202  of the valve assembly  200 . An optional gasket  205  is received about the filter conduit to seal the inlet port  202 . The filter conduit  204  is preferably made of high strength polyurethane. The inlet end  208  has an enlarged opening that is positioned on the tire sidewall area, typically in the bead area. The inlet end  208  preferably has one or more barbs  210 , which lock or secure the filter conduit  204  in the sidewall of the tire. 
         [0037]    A filter  230  is received in the inlet end  208  of the filter conduit. The filter  230  is comprised of layers of filter media such as a woven or nonwoven fiber, foam, spun fiberglass, charcoal, or other materials known to those skilled in the art. Alternatively, a membrane filter such as PTFE, GoreTex may be used, alone or in combination with the filter media. 
         [0038]    An outlet conduit  300  has a first end  302  that is connected to the outlet port  206  of the valve assembly  200 . An optional gasket  306  is provided about the outlet conduit  300  to seal the outlet port  206 . The outlet conduit  300  has an a second T shaped end  310  having outlet ends  312 ,  314  that are connected to the pump tube ends  42   a,    42   b.    
         [0039]      FIGS. 8-9  illustrate a second embodiment of a filter assembly  400  of the present invention. As shown in  FIG. 8C , the filter assembly  400  has a housing  410  having a removable cover  412 . As shown in  FIGS. 8B and 9B , the housing  410  has an interior cavity  414  that is in fluid communication with the outlet of the valve assembly  200 . The valve assembly as shown in  FIG. 8B  regulates the inlet flow to the pump inlet. As shown in  FIG. 9C  the valve assembly may include a spring  203  which biases a sealing member  207  in an open position relative to the inlet  202  of a valve assembly. A holder  209  has a first end which supports the sealing member  207 , and a second end positioned against a flexible disk  211  that is in fluid communication with the tire cavity pressure, and responsive thereto. As shown in  FIG. 9B , a valve conduit  420  has a first end  422  connected to the outlet port  206  of the valve assembly, and a second end  424  connected to an inlet port  426  of the housing  400 . The valve conduit  420  communicates fluid from the valve assembly  200  to the interior cavity  414  of the filter housing, and then to the pump via outlet ends  430 . 
         [0040]    As shown in  FIG. 8A , the filter housing  400  further includes a filter pocket  440  for receiving one or more layers of filter media  450 . The filter pocket  440  and filter media  450  are in fluid communication with the outside air, and is preferably positioned on the outside surface of the tire, typically near the pump. As shown in  FIG. 8C and 9A , the filter pocket  440  has an outlet  442  connected to an inlet end  444  of a filter conduit  448 . The filter conduit  448  has an outlet end  446  connected to the inlet port  202  of the valve assembly  200 . 
         [0041]      FIGS. 10-11  illustrate a third embodiment of a filter assembly  500 . As shown in  FIG. 10B , the filter assembly has an external housing  502  which houses a first and second cavity  504 ,  506 . The first cavity  504  has a single inlet opening  508  that is connected to a first end  510  of a valve conduit  512 . The valve conduit  512  has a second end  514  that is connected to the outlet port  202  of the valve assembly  200 . The first cavity  504  receives filtered air from the valve assembly  200  through the valve conduit  512  and into the first cavity. The first cavity  504  has two outlet ends  507 ,  509  connected to the pump ends  42   a,    42   b.  The valve assembly is shown in a generic manner, and can control the flow to the valve conduit  512  and or the inlet flow from the filter conduit. The second cavity  506  houses the filter media  503  and/or filter membrane  505  and has an outlet port  520  connected to first end  522  of a filter conduit  530 . The filter conduit  530  has a second end  532  connected to an inlet port  202  of the valve assembly, for providing filtered ambient air to the valve assembly. 
         [0042]      FIGS. 12-13  illustrate a fourth embodiment of a filter assembly  600 . As shown in  FIG. 12B , the filter assembly has an external housing  602  which houses a single cavity  604 . The filter cavity  604  has an outlet opening  608  that is connected to a first end  610  of a valve conduit  612 . The valve conduit  612  has a second end  614  that is connected to the inlet port  202  of the valve assembly  200 . The filter cavity  604  has filter media  605  and an optional filter membrane  607  received in the single cavity. The filter cavity  604  is positioned to be in fluid communication with the outside air, typically on the sidewall of the tire. Thus ambient air enters the housing through an opening  603  of the filter cavity  604 , and passes through the filter media  605  and optional filter membrane  607  to the inlet  202  of the valve assembly  200 . If the tire needs air, the valve assembly opens and allows the filtered air to travel through the valve cavity  209  and into the valve conduit  620 . The valve conduit  620  connects to a T  623  with two outlet end  625 ,  630  that are connected to a respective pump ends  42   a,    42   b.    
         [0043]    Variations in the present invention are possible in light of the description of it provided herein. While certain representative embodiments and details have been shown for the purpose of illustrating the subject invention, it will be apparent to those skilled in this art that various changes and modifications can be made therein without departing from the scope of the subject invention. It is, therefore, to be understood that changes can be made in the particular embodiments described which will be within the full intended scope of the invention as defined by the following appended claims.