Abstract:
A tire pressure monitoring system which is linked to the control unit or other control device of a vehicle which limits the operation, or completely disables the operation of, the vehicle when the pressure in one or more of the tires of the vehicle is insufficient. The operation of the vehicle may be limited so as to completely disable the operation of the engine, transmission, or a combination of both. The rotational speed of the engine may be limited, or the operation of the transmission may be limited. A combination of limitations may be placed on both the engine and transmission, to prohibit the vehicle from being operated at unsafe speeds due to the tire pressure in one or more of the tires being at an undesirable level.

Description:
FIELD OF THE INVENTION 
       [0001]    The invention relates generally to a tire pressure monitoring system, and more particularly, to a tire pressure monitoring system which limits the operation of or disables the propulsion system of a vehicle. 
       BACKGROUND OF THE INVENTION 
       [0002]    Monitoring pressure in the tires of a vehicle functions to not only ensure the safety of the driver or operator of the vehicle, but also to facilitate the vehicle having optimal fuel economy. Tire pressure monitoring systems (TPMS) are incorporated to cars, trucks, sport-utility vehicles, motorcycles, semi-trucks, tractors, and the like. A sudden or gradual loss of tire pressure presents a danger to the driver of any vehicle, and the incorporation of a TPMS provides a warning to the driver to attend to the reduced amount of pressure in one or more of the tires. 
         [0003]    In some instances, such as motorcycles, it is more difficult to sense or “feel” when the tire pressure is low, which presents a danger. It is particularly difficult to notice when the tire pressure is low when the motorcycle is travelling at high speeds, and it is more dangerous to travel at high speeds with low tire pressure. Additionally, some drivers may choose to ignore the warning provided by a TPMS, and continue to drive the vehicle in an unsafe condition. This not only presents a danger to the driver of the vehicle, but also presents the danger of an accident to other drivers of other vehicles as well. Accordingly, there exists a need for a TPMS which is incorporated into the operation of the vehicle which disallows or limits the operation of the vehicle when the vehicle is unsafe to drive. 
       SUMMARY OF THE INVENTION 
       [0004]    The present invention is a system for signaling an indication of insufficient pressure in one or more tires of a vehicle. The system includes a tire pressure monitoring system (TPMS) having a plurality of pressure sensors and a first control unit. The system also includes plurality of tires, each one of the plurality of pressure sensors mounted to a corresponding one of the plurality of tires, and the first control unit of the TPMS is in communication with each of the plurality of sensors such that the first control unit receives a signal from one or more of the plurality of pressure sensors indicating that one or more of the plurality of tires has an undesired pressure. 
         [0005]    A second control unit is in communication with the first control unit, such that the second control unit receives the signal from the first control unit that one or more of the plurality of tires has an undesired pressure. A warning device is controlled by the second control unit, to provide an indication to the driver of the vehicle that one or more of the plurality of tires has an undesired pressure. At least one light, which is capable of functioning as a hazard light, is mounted to the vehicle. A propulsion unit, such as an engine and transmission, is controlled by the second control unit, and the light is activated to operate as a hazard light by the second control unit when the one or more of the plurality of pressure sensors detects an undesired pressure level in one or more of the tires. 
         [0006]    Accordingly, it is an object of the invention to provide a tire pressure monitoring system which is linked to the control unit or other control device of a vehicle which limits the operation of or completely disables the operation of the vehicle when the pressure in one or more of the tires of the vehicle is insufficient. 
         [0007]    One type of limitation of the operation of the vehicle is to completely disable the operation of the engine, transmission, or a combination of both. The rotational speed (rpm) of the engine may be limited, or the operation of the transmission may be limited. If the transmission is a multiple gear transmission, the transmission only may be allowed to shift up to a specific gear, such as second gear. A combination of limitations may be placed on both the engine and transmission, to limit the operation of the vehicle. 
         [0008]    In one embodiment, once an undesirable amount of pressure is detected in one or more of the tires, the vehicle may be allowed to operate as normal until the vehicle comes to a stop. Once the vehicle comes to a stop, the operation of the engine, transmission, or a combination of both, may be limited to prohibit the vehicle from being operated at unsafe speeds due to the tire pressure in one or more of the tires being at an undesirable level. 
         [0009]    The system of the present invention is for use with any type of vehicle where it is necessary to monitor the tire pressure. The system may be used with vehicle such as, but not limited to, motorcycles, cars, trucks, vans, semi-trucks, tractors, all-terrain vehicles, and the like. 
         [0010]    Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein: 
           [0012]      FIG. 1  is diagram of a vehicle having a system which is used for limiting the operation of the vehicle when one or more of a plurality of tires has an undesired pressure, according to the present invention; 
           [0013]      FIG. 2  is a diagram of an instrument cluster having a warning device used with a system for limiting the operation of a vehicle when one or more of a plurality of tires has an undesired pressure, according to the present invention; and 
           [0014]      FIG. 3  is a rear view of a vehicle navigating a curve, the vehicle having a system for limiting the operation of a vehicle when one or more of a plurality of tires has an undesired pressure, according to the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0015]    The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. 
         [0016]    A system, shown generally in the Figures at  10 , according to the present invention is incorporated with the use of a vehicle  12 . The system  10  includes a tire pressure monitoring system (TPMS)  14 . The TPMS  14  includes two pressure sensors  16 , and a first control unit  18 . The control unit  18  is in wireless communication with the sensors  16 , and the sensors  16  monitor pressure in the tires. More specifically, the first sensor  16 A monitors pressure in the front tire  20 , and the second sensor  16 B monitors pressure in the rear tire  22 . 
         [0017]    In addition to a TPMS  14 , the system  10  also includes a second control unit  24 , which is the control unit  24  of the vehicle  12 , which in one embodiment may be connected to the control unit  18 , such that both control units  18 , 24  are one component. In other embodiments each control unit  18 , 24  may be a separate component, able to operate together, but not connected to one another. 
         [0018]    The vehicle  12  is a motorcycle, and also includes rear lights  26  which may function as hazard lights, brake lights, or both. The rear lights  26  may be a combination of lights that include turn signals, which may also be used as hazard lights. The vehicle  12  also includes an instrument cluster, shown generally at  28 , and best seen in  FIG. 2 , having various gauges, such as a speedometer  30 , tachometer  32 , fuel gauge  34 , temperature gauge  36 , and a warning device  38 . The warning device  38  in one embodiment may be a light or lamp which functions as a “tell tale,” and includes an alarm sound to warn the driver that the pressure in one or both of the tires  20 , 22  is low. Mounted toward the front of the vehicle  12 , in front of the instrument cluster  28 , is a set of front lights  40 , which function as hazard lights, headlights, or both, and may also be a combination of lights which include turn signals that may function as hazard lights as well. 
         [0019]    In operation, the TPMS  14  functions to monitor pressure in both tires  20 , 22 . If the pressure in one or more of the tires  20 , 22  is low, the control unit  18  receives a signal from one or both of the sensors  16 A, 16 B, and the control unit  18  of the TPMS  14  communicates with the control unit  24  of the vehicle  12  by receiving a second signal from the control unit  18  of the TPMS  14 . The control unit  24  then sends a third signal to the warning device  38  to alert the driver that one or both of the tires  20 , 22  is at a lower than desired pressure level. The warning device  38  may include one or both of a visible warning, such as a tell tale, and an alarm sound to warn the driver that the tire pressure is low. The warning device  38  may also be configured to provide an indication as to which one of the tires  20 , 22  is low in pressure. 
         [0020]    The control unit  24  also commands the rear lights  26  and the front lights  40  to act as hazard lights or warning lights to warn drivers of other vehicles that the vehicle  12  is in an emergency condition. As mentioned above, the rear lights  26  may be a combination of brake light and turn signal lights, a combination of which may be used as hazard lights, and the rear lights  26  may also be a combination of headlights and turn signal lights, a combination of which may be used as hazard lights. Furthermore, the control unit  24  also controls the propulsion system of the vehicle  12 , which in this embodiment is a combination engine/transmission  42 A,B. The engine  42 A may be gasoline powered, or electrically powered, but is still controlled by the control unit  24 . The control unit  24  limits the operation of the engine  42 A such that the vehicle  12  may only travel up to a limited speed, such as twenty miles per hour. This may be accomplished by limiting the rotational speed (rpm) of the engine  42 A. The speed the vehicle  12  is limited to may be programmed into the control unit  24  by the manufacturer, and changed depending upon the laws of the country the vehicle  12  is sold in, or specified by the manufacturer. The control unit  24  may also be programmed to limit the operation of the transmission  42 B, such as limiting the gears the transmission  42 B may be shifted to. 
         [0021]    Furthermore, the vehicle  12  may be equipped with the appropriate sensor to detect when the vehicle  12  is navigating a curve, such as shown in  FIG. 3 . If the sensor detects that the vehicle  12  is navigating a curve, than no further action by the control unit  24  is taken until the vehicle  12  resumes travelling in a straight line, upon which the control unit  24  limits or disables the operation of the engine  42 A in one of the ways previously described. 
         [0022]    In one embodiment, the control unit  24  may limit the operation of the vehicle  12 , and more specifically the engine  42 A such that the vehicle  12  is only operable for a limited amount of time to allow the driver of the vehicle  12  to reach a safe destination where one or both of the tires  20 , 22  may be repaired as necessary. Once the limited amount of time has passed, the control unit  24  disables the vehicle  12  such that it is no longer operable. 
         [0023]    In another embodiment, the control unit  24  may completely disable the engine  42 A the instant an unacceptable amount of tire pressure is in one or both of the tires  20 , 22 . In yet another embodiment, the control unit  24  permits the vehicle  12  to operate until the vehicle  12  has come to a stop, and then prohibits operation of the vehicle  12  until the proper amount of pressure is restored in each of the tires  20 , 22 . 
         [0024]    There are also conditions where one or both of the tires  20 , 22  may suffer catastrophic failure during driving. Under these conditions, if one or both of the sensors  16 A, 16 B detects a sudden and significant drop in tire pressure, indicating that one or both of the tires  20 , 22  has suffered catastrophic failure. This sudden drop in pressure is signaled to the control unit  18  by the sensors  16 A, 16 B, and the control unit  18  of the TPMS  14  communicates with the control unit  24  of the vehicle  12 , and the control unit  24  activates the hazard functions of the rear lights  26  and the front lights  40 , indicating to other drivers of other vehicles that the vehicle  12  is in a state of emergency. 
         [0025]    Some tire pressure monitoring systems also include the ability to self-inflate the tires of a vehicle while driving. The system  10  of the present invention may also include a tire pump in each of the tires  20 , 22  to inflate the tires  20 , 22  in case there is an insufficient amount of pressure in each of the tires  20 , 22 , or one or both of the tires  20 , 22  suffers from a slow leak. However, if the tire pump in one or both of the tires  20 , 22  stops working correctly, and one or both of the tires  20 , 22  continues to leak, the sensors  16 A, 16 B detect the leak, and a signal is received by the control unit  18 , which then communicates to the control unit  24  of the vehicle  12 , and the control unit  24  commands the warning device  38  to alert the drive of the vehicle  12  that one or both of the pumps inside the tires  20 , 22  have malfunctioned, or that there is insufficient pressure in one or both of the tires  20 , 22 . 
         [0026]    While the vehicle  12  has been described as a motorcycle, it is within the scope of the invention that the system  10  may be incorporated for use with other types of vehicles as well, such as, but not limited to, cars, trucks, sport utility vehicles, tractors, all-terrain vehicles, semi-trucks, and the like. 
         [0027]    The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.