FIELD OF THE INVENTION 
     The present invention relates to a tire pressure sensor mounting system, and more particularly to a tire pressure sensor mounting system mounted on wheel rim directly. 
     BACKGROUND OF THE INVENTION 
     Many modern cars now come with built-in tire pressure sensors as part of a tire pressure monitoring system (TPMS) that allow all four tire pressures to be read simultaneously from inside the car. TPMS can be divided into direct and indirect systems. Direct TPMS employ pressure sensors on each tire, either internal or external. The sensors physically measure the tire pressure in each tire and report it to the vehicle&#39;s instrument cluster or a corresponding monitor, sometimes also the temperature inside the tire. These systems can identify under-inflation in any combination, of one tire or all four, simultaneously. Typically, the sensor is connected to a tire valve. When the valve breaks, sensor would normally have to be replaced, which is time-consuming due to reprogramming new sensor and cost unfriendly. Therefore, it is desirable for a system with the tire pressure sensor mounted on wheel rim directly without connections to the tire valve. 
     Any feature or combination of features described herein are included within the scope of the present invention provided that the features included in any such combination are not mutually inconsistent as will be apparent from the context, this specification, and the knowledge of one of ordinary skill in the art. Additional advantages and aspects of the present invention are apparent in the following detailed description and claims. 
     SUMMARY OF THE INVENTION 
     The present invention features a tire pressure sensor mounting system. The system comprises a singular mounting piece with a rim strap and at least two side straps to securing a tire pressure sensor. The side straps are disposed along the rim strap with extension direction perpendicular to the rim strap. Both the rim strap and side straps have lock means to securely lock the tire rim and tire pressure sensor respectively. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows an isometric view of a tire pressure sensor mounting piece. 
         FIG. 2  shows a side view of a tire pressure sensor mounting system with the mounting piece mounted on a wheel rim directly. 
         FIG. 3  shows an isometric view of a tire pressure sensor mounting system with the mounting piece mounted on a wheel rim directly. 
         FIG. 4  shows a detailed view of a tire pressure sensor mounting system with the mounting piece mounted on a wheel rim directly. 
         FIG. 5  shows a cross-sectional view of a tire pressure sensor mounting system with the mounting piece mounted on a wheel rim directly. 
     
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
     Following is a list of elements corresponding to a particular element referred to herein: 
       100  tire pressure sensor mounting system 
       110  mounting piece 
       120  rim strap 
       121  first end of the rim strap 
       122  second end of the rim strap 
       123  teeth of the rim strap 
       124  first lock means 
       130  first side strap 
       131  first end of the first side strap 
       132  second end of the first side strap 
       133  teeth of the first side strap 
       134  second lock means 
       140  second side strap 
       141  first end of the second side strap 
       142  second end of the second side strap 
       143  teeth of the second side strap 
       144  third lock means 
       210  wheel rim 
       220  valve 
       310  tire pressure sensor 
     Referring now to  FIG. 1-5 , the present invention features a tire pressure sensor mounting system ( 100 ). The system comprises a wheel rim ( 210 ) with a valve ( 220 ) disposed on the wheel rim ( 210 ), a tire pressure sensor ( 310 ) without mechanical connection to the valve ( 220 ), and tire pressure sensor mounting piece ( 110 ). 
     The tire pressure sensor ( 310 ) are typically a direct tire pressure measurement sensor integrated power sources, microcontroller, A/D converter, radio frequency (RF) transmitter, and optionally a receiver. 
     The tire pressure sensor mounting piece ( 110 ) comprises a wheel rim strap ( 120 ) and at least two side strap ( 130  and  140 ) disposed on the wheel rim strap. 
     The wheel rim strap ( 120 ) has a first end ( 121 ) and a second end ( 122 ), wherein the rim strap ( 120 ) has a first lock means ( 124 ) disposed on the second end ( 122 ) to securely lock the first end ( 121 ) to tightly enclose the wheel rim ( 210 ). 
     The first side strap ( 130 ) has a first end ( 131 ) and a second end ( 132 ), wherein the first side strap ( 130 ) is disposed on the rim strap between the first end ( 121 ) and the second end ( 122 ) of the rim strap ( 120 ), wherein the first side strap ( 130 ) is perpendicular to the rim strap ( 120 ), wherein the first end ( 131 ) and second end ( 132 ) of the first strap ( 130 ) are on opposite sides of the rim strap ( 120 ), wherein the first side strap ( 120 ) has a second lock means ( 134 ) disposed on the second end ( 132 ) to form a first loop ( 135 ) and securely lock the first end ( 131 ). 
     The second side strap ( 140 ) has a first end ( 141 ) and a second end ( 142 ), wherein the second side strap ( 140 ) is disposed on the rim strap ( 120 ) and adjacent to the first side strap ( 130 ), wherein the second side strap ( 140 ) is perpendicular to the rim strap ( 120 ), wherein the first end ( 141 ) and second end ( 142 ) of the second strap ( 140 ) are on opposite sides of the rim strap ( 120 ), wherein the second side strap ( 140 ) has a third lock means ( 144 ) disposed on the second end ( 142 ) to form a second loop ( 145 ) and securely lock the first end ( 141 ). 
     The tire pressure sensor ( 310 ) is disposed on rim strap ( 120 ) and securely held by the first loop ( 135 ) of the first side strap ( 130 ) and by the second loop ( 145 ) of the second side strap ( 140 ). 
     In some embodiments, the first end ( 121 ) of the rim strap ( 120 ), the first end ( 131 ) of the first side strap ( 130 ) and the first end ( 141 ) of the second side strap ( 140 ) comprise triangular teeth that slope in one direction; wherein the first lock means ( 124 ), the second lock means ( 134 ) and the third lock means ( 144 ) are zip tie lock. Zip ties are well known to one of ordinary skill for secure locking applications. 
     In some embodiments, the first lock means ( 124 ), the second lock means ( 134 ) and the third lock means ( 144 ) are hook mechanism, button mechanism, hook-and-loop fastener or a combination thereof. 
     In some embodiments, the rim strap ( 120 ), the first side strap ( 130 ) and the second side strap ( 140 ) are made of plastics, nylon, metal or a combination thereof. 
     In some embodiments, at least part of the rim strap ( 120 ), the first side strap ( 130 ) or the second side strap ( 140 ) is elastic. Such arrangement would help the rim strap ( 120 ) further securely enclose the wheel rim and help the first side strap ( 130 ) and the second side strap ( 140 ) further securely enclose the tire pressure sensor. 
     In some embodiments, the wheel rim strap has a length enough to securely enclose a wheel rim ranging from 13 inch diameter up to 24 inch diameter. In some embodiments, at least part of the rim strap ( 120 ), the first side strap ( 130 ) and the second side strap ( 140 ) have the same width ranging from 0.5 inch to 5 inches. In some embodiments, at least part of the rim strap ( 120 ), the first side strap ( 130 ) or the second side strap ( 140 ) have different width. 
     As used herein, the term “about” refers to plus or minus 10% of the referenced number. For example, a 5″ wide strap refers as a strap with width between 4.5″ and 5.5″. 
     The disclosures of the following U.S. Patents are incorporated in their entirety by reference herein: (1) U.S. Pat. No. 2,652,858; (2) U.S. Pat. No. 3,101,529; (3) U.S. Pat. No. 6,574,853; (4) U.S. Pat. No. 7,021,133; (5) U.S. Pat. No. 7,281,421; (6) U.S. Pat. No. 7,656,281; (7) U.S. Pat. No. 8,096,175 and (8) USD 653,576. 
     Various modifications of the invention, in addition to those described herein, will be apparent to those skilled in the art from the foregoing description. Such modifications are also intended to fall within the scope of the appended claims. Each reference cited in the present application is incorporated herein by reference in its entirety. 
     Although there has been shown and described the preferred embodiment of the present invention, it will be readily apparent to those skilled in the art that modifications may be made thereto which do not exceed the scope of the appended claims. Therefore, the scope of the invention is only to be limited by the following claims. Reference numbers recited in the claims are exemplary and for ease of review by the patent office only, and are not limiting in any way. 
     The reference numbers recited in the below claims are solely for ease of examination of this patent application, and are exemplary, and are not intended in any way to limit the scope of the claims to the particular features having the corresponding reference numbers in the drawings.
The present invention features a tire pressure sensor mounting system to mount a tire pressure sensor on a wheel rim directly. The system comprises a singular mounting piece with a rim strap and at least two side straps to securing a tire pressure sensor. The side straps are disposed along the rim strap with extension direction perpendicular to the rim strap. Both the rim strap and side straps have lock means to securely lock the tire rim and tire pressure sensor respectively.