Abstract:
This apparatus and system for integration of a sensor into a wheel includes sensors for monitoring temperature, pressure or other variables inside of an inflated tire that are mounted directly to or inside of a wheel for the tire, that are in communication with conditions in the tire&#39;s interior via ducts or channels in the wheel, and/or that are held in place by and between rim portions of a two piece wheel.

Description:
BACKGROUND AND SUMMARY 
   This application claims an invention which was disclosed in a provisional application filed Nov. 14, 2006, entitled “Apparatus and Systems for Integration of a Sensor into a Wheel”. The benefit under 35 USC § 119(e) of the United States provisional application is hereby claimed, and the aforementioned application is hereby incorporated herein by reference. 
   The purpose of this invention is to integrate a sensor into a wheel. This is advantageous as various factors, including particularly tire pressure, can be more easily monitored in this fashion. The sensor of our invention may be attached to the wheel or may be integrated into the wheel. An air passageway between the tire cavity and the sensor may or may not be employed. 
     FIG. 1  shows a section of a one-piece wheel assembly  1  without sensor. The one-piece wheel assembly  1  consists of a wheel  2  with tire  3  and inflation valve  4 . The circular wheel  2  includes a rim portion  5 , formed coaxially on opposite ends thereof with outwardly flaring circumferential flange sections disposed to be engaged by the beads of a tubeless tire. A transverse wall section, disc portion  6 , extends transversely of the axis of the circular wheel  2  and its rim  5 , and includes a central opening (hub bore area  9 ) disposed coaxially on said axis. Also illustrated are drop center area  7 , valve hole  8 , and hub bore area  9 . The tire  3  and rim  5  form a tire air chamber  10  that contains a pressured fluid (usually air). 
     FIG. 2  shows a section of a two-piece wheel assembly  11  without sensor. The two-piece wheel assembly  11  includes a wheel  12  with tire  3  and inflation valve  4 . Parts of wheel  12 , as before, include a rim portion  5 , a transverse wall or disc portion  6 , and a hub bore area  9 . Also illustrated, and forming a typical part of a two-piece wheel assembly, is rim flat area  13 . The tire  3  and rim  5  form a tire air chamber  10  that, as with the one-piece wheel assembly, contain a pressured fluid (usually air). 
   Two-piece wheels  12  are usually used when a bead lock  14  or run flat device (not shown) are utilized in the two-piece wheel assembly  11 . The wall section of two-piece wheels consists of two major parts, an outer portion (or rim hall)  15  and inner portion (or rim hall)  16 . The two portions  15  and  16  are sealed with an o-ring  17  placed between confronting surfaces of the two portions  15  and  16  so as to prevent air from escaping out of tire air chamber  10  (thereby creating a sealed space including tire chamber  10 ). Studs  18  and nuts  19  bolt the two rim halves  15  and  16  together. 
   Current technology for use of sensors employs several different configurations and methodologies. First, sensors may be embedded in tire  3  where they are invisible to inspection and generally inaccessible. (This version is not illustrated). Second, as illustrated in  FIG. 3 , a sensor portion  20  may be placed with the tire interior (air chamber  10 ) connected to a valve portion  21 . The valve portion  21  goes through valve hole  8  in one-piece wheel  2 . The sensor portion  20  measures the air pressure in tire air chamber  10  and sends a signal to a monitor (not shown) in the cab portion of the vehicle. Third, as illustrated in  FIG. 4 , a sensor  22  can be employed anywhere within the tire cavity  10 . (The tire  3  and tire chamber  10  are not shown in  FIG. 4  so that sensor  22  and bracket or band  23  can be seen). Sensor  22  can be attached with a bracket or band  23  or by any other method inside the tire chamber  10 . Fourth, as illustrated in  FIG. 5 , another technology attaches a sensor  25  directly to the inflation valve  4 . Fifth, a sensor may be contained in a sensor body so that it is exterior to the tire chamber, but detects pressure therein via an air channel portion extending through the sensor body from the tire chamber to the sensor. (See, e.g., U.S. Pat. No. 7,089,147). 
   However, all of the aforesaid methods and apparatus have disadvantages. Sensors inside the tire cavity are subject to harsh environments including elevated temperatures and impact damage. In addition, such sensors are difficult to assemble when inside the tire, there is limited access in case of malfunction, and sensors can be damaged during tire assembly or tire removal. Sensors in the tire cavity may also cause wheel imbalance, may have signal interference due to the tire and or wheel structure, and are expensive to install and maintain. Sensors that attach to inflation valves are susceptible to damage from curbs, rocks or other obstructions on the road; require removal in order to inflate or deflate tires; can cause the inflation valve to leak; and are highly visible and more susceptible to theft. In addition, some sensors require the vehicle to be driven in order to be activated, many are too bulky, and some require special brackets or hardware to attach. Finally, many of the current art place sensors in locations (outwardly from the axis of the wheel) where they are subject to radical centrifugal forces. 
   Thus, as previously noted, the purpose of this invention is to avoid the disadvantages of prior art by integrating a sensor into a wheel. If the sensor is embedded in the wheel rim or disk, then numerous advantages can be realized. First, integrated sensors are well protected and less susceptible to environmental fluctuations including but not limited to, temperature, humidity, harsh chemicals, theft, and/or impact loads. Second, sensors on or in the wheel are easier to assemble and remove. If the sensor is mounted on the “weather” side of the rim (any portion of the wheel that is exposed to weather—as opposed to the tire-side of the rim) then the tire does not have to be removed to gain access to the sensor. Third, the sensor can be located closer to the wheel hub to reduce centrifugal forces and reduce wheel imbalance. Fourth, a sensor can be attached to the wheel or embedded in the wheel more securely and without excessive components/hardware. Fifth, a sensor mounted onto or into the wheel results in less weight, especially when part of the wheel material is removed in order to attach the sensor, to create a mounting void in which the sensor can be mounted, or to create an air passageway/duct to the sensor. Sixth, the placement of the sensor will result in less signal interference. Seventh, sensors in the wheel are less likely to leak air. Eighth, the sensor can be smaller due to the fact that there will often be no need for a bulky and protective sensor housing. Ninth, cost is reduced due to lack of a sensor housing or the reduction in size of such housings, lack of brackets and other mounting hardware, smaller batteries and not having to re-mount tires in order to mount/service sensors. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  provides a perspective view of a section of a one-piece wheel assembly without sensor. 
       FIG. 2  provides a perspective view of a section of a two-piece wheel assembly without sensor. 
       FIG. 3  provides a schematic cross-sectional view showing how a sensor portion may be connected to a valve portion. 
       FIG. 4  provides a perspective view of a wheel, illustrating how a sensor can be employed anywhere within a tire cavity. 
       FIG. 5  provides a schematic cross-sectional view showing how a screw-on sensor can be directly attached to an inflation valve. 
       FIG. 6  provides a schematic cross-sectional view showing how a screw-on sensor can be attached to a tank valve mounted to a two-piece wheel. 
       FIG. 7  provides a schematic cross-sectional view showing how a screw-on sensor can be attached directly to a two-piece wheel such that it does not interfere with a standard inflation valve. 
       FIG. 8  provides a schematic cross-sectional view showing how a screw-on sensor  26  can be screwed into a two-piece wheel such that there is no protrusion extended beyond the wheel surface. 
       FIG. 9  provides a schematic cross-sectional view showing how a sensor can be screwed into the wheel with threads on the outside diameter of the sensor. 
       FIG. 10  provides a schematic cross-sectional view showing how a sensor with no threads can be installed in a two-piece wheel by means of a retaining ring. 
       FIG. 11  provides a schematic cross-sectional view showing how a bolt-on sensor can be attached to a wheel by means of cap screws. 
       FIG. 12  provides a schematic cross-sectional view showing how a sensor can be located in the disc portion of a two-piece wheel. 
       FIG. 13  provides a schematic cross-sectional view showing placement of sensor in the outer portion of a two-piece wheel. 
       FIG. 14  provides a schematic cross-sectional view showing placement of sensor on the brake side of the disc portion (in contrast to the curb side of the disc portion as illustrated in  FIG. 7 ). 
       FIG. 15  provides a schematic cross-sectional view showing a sensor placed in the hub bore area of the disc portion. 
       FIGS. 16 and 17  provide schematic cross-sectional views showing placement of a sensor between two rim halves. 
       FIGS. 18 and 19  provide schematic cross-sectional views showing a sensor embedded in the rim portion. 
       FIG. 20  provides a schematic cross-sectional view showing how a sensor can be placed into or onto a one-piece wheel. 
       FIG. 21  provides a schematic cross-sectional view showing a sensor sealing off air from an internal passageway by means of a sensor O-ring. 
       FIG. 22  provides a schematic cross-sectional view showing details of operation of a sensor. 
   

   DESCRIPTION 
   Our invention might be described, in general terms, as comprehending all methods and apparatus for mounting a sensor directly onto or into a wheel and/or using internal air passageways in the wheel to communicate air pressure from the tire chamber to a sensor. (As used herein, the term “sensor” is inclusive of any housing or “body” for the sensor; however, such housings will generally be unnecessary and/or de minimis unless the sensor is mounted in an exposed external position). This inventive concept can be actualized in various way, as illustrated in the drawing figures. 
   Thus,  FIGS. 6 through 9  provide some initial examples of how screw on sensors can be used in accordance with the teachings of our invention.  FIG. 6  shows a tank valve  24  (a tank valve is a special kind of tire inflation valve) mounted to two-piece wheel  12 . In this situation, a screw-on sensor  25  with internal threads can be attached to the tank valve  24 . 
     FIG. 7  shows a version where a screw-on sensor  26  attaches directly to the two-piece wheel  12  such that it does not interfere with standard inflation valve  4  (Inflation valve  4  is shown in  FIGS. 1 and 2 ). Sensor  26  is similar to the sensor  25  shown in  FIGS. 5 and 6  except sensor  26  has a male screw threaded extension  27  with an air channel therethrough rather than internal female threads.  FIG. 8  shows a screw-on sensor  26  screwed into a two-piece wheel  12  such that it does not protrude beyond the wheel surface  28 . (A mounting void is provided of size sufficient to accommodate the sensor).  FIG. 9  shows a sensor  29  screwed into the wheel via threads on the outside diameter of the sensor. 
     FIGS. 10 and 11  show some other possibilities.  FIG. 10  shows a sensor with no threads  30  installed in a two-piece wheel  12  by means of a retaining ring  31 . And,  FIG. 11  shows a bolt-on sensor  32  attached to the wheel by means of cap screws  33  passing therethrough. However, all of the foregoing are merely exemplary, numerous other means of attachment can be employed to attach a sensor either onto or into the wheel without deviating from the spirit and scope of the invention. 
   For example, the sensor can be placed in a variety of locations on or inside a wheel assembly.  FIG. 12  shows the sensor  26  located in the disc portion  6  of a two-piece wheel  12 .  FIG. 13  shows placement of sensor  26  in the outer portion  15  of a two-piece wheel  12 .  FIG. 14  shows placement of sensor  26  on the brake side  34  of the disc portion  6  (compared to the curb side  35  of the disc portion  6  illustrated in  FIG. 7 ).  FIG. 15  shows the sensor  26  placed in a void adjacent to and opening onto the hub bore area  9  of the disc portion  6 .  FIGS. 16 and 17  show placement of the sensor  30  between the portions  15  and  16  so that it is held in place by the two portions.  FIGS. 18 and 19  shows a sensor  29  embedded in the rim portion  5 . In  FIG. 18  the sensor  29  is substantially enclosed within the rim with a flange in (and inlet to) the tire interior. In  FIG. 19 , the sensor  29  is on the exterior of the rim  5  with an inlet providing communication with the tire interior via a short passageway (or duct)  36 . Further, although two-piece wheels  12  are shown in most of these illustrations, it is obvious that a sensor  25 ,  26 ,  29 , or  30  can be placed onto or into a one-piece wheel  2  as well. (See,  FIG. 20  as an example). 
   Internal air passageways (or ducts)  36  may or may not be used. An example of an internal passageway  36  is shown in many of the figures. The internal passageways  36  are a separate object of this invention and are also comprehended with the scope of this patent. 
     FIG. 21  shows a sensor  30  sealing off air from internal passageway  36  by means of a sensor O-ring  37 . Other means of sealing the internal passageway  36  can be used without effecting the invention. A few examples are gaskets; thread sealers, tapered threads or any other means. 
   Thus, in accordance with the teachings of our invention and as best seen in  FIG. 22 , air pressure inside the tire air chamber  10  travels through the internal passageway  36  to the sensor  26 . The air can be sealed from escaping around the sensor by means of sensor O-ring  37 . The sensor  26  can detect air pressure, temperature, or any other parameter that can be included in the sensor functionality. 
   From the foregoing, it will be appreciated that various of the above-disclosed and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. Also that various presently unforeseen or unanticipated alternatives, modifications, variations or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the claims to be filed hereafter. 
   PARTS LIST 
   
       
         1 . One-piece wheel assembly 
         2 . One-piece wheel 
         3 . Tire 
         4 . Inflation valve 
         5 . Rim portion of wheel 
         6 . Disc portion of wheel 
         7 . Drop center portion of wheel 
         8 . Valve hole 
         9 . Hub bore area 
         10 . Tire air chamber 
         11 . Two-piece wheel assembly 
         12 . Two-piece wheel 
         13 . Rim flat diameter 
         14 . Bead lock 
         15 . Outer portion 
         16 . Inner portion 
         17 . O-ring 
         18 . Stud 
         19 . Nut 
         20 . Sensor portion 
         21 . Valve portion 
         22 . Sensor 
         23 . Bracket or band 
         24 . Tank valve 
         25 . Screw-on sensor (female threads) 
         26 . Screw-on sensor (male threads) 
         27 . Male threads on the sensor 
         28 . Wheel surface 
         29 . Sensor with external threads 
         30 . Sensor with no threads 
         31 . Retaining ring 
         32 . Bolt-on sensor 
         33 . Cap screws 
         34 . Brake side 
         35 . Curb side 
         36 . Internal passageway 
         37 . Sensor O-ring