Abstract:
A vehicle brake having a brake monitoring and sensor system attached to a brake shoe of a brake assembly for monitoring of temperature and wear of a brake shoe lining of a vehicle. The vehicle brake monitoring and sensor system includes a brake assembly for frictional braking of a vehicle. The brake assembly includes a brake shoe lining having a brake shoe and a brake pad for frictional engagement with the brake assembly; and the brake shoe lining has first rivet openings with rivets therein, and has second rivet openings with no rivets therein. The vehicle brake monitoring system also includes a sensor system having a first sensing element and a second sensing element each connected to the brake shoe; the first sensing element is embedded in one or more of the first rivet openings with the rivets therein; and the second sensing element is embedded in one or more of the second rivet openings having no rivets therein. The first sensing element is for generating a first electrical signal in response to sensing changes in the temperature of the brake shoe generated by heat in the brake shoe and transmitted to one or more rivets in the first rivet openings. The second sensing element is for generating a second electrical signal in response to sensing a predetermined depth of wear of the brake pad. The vehicle brake monitoring and sensor system further includes a monitoring unit for processing the first and second electrical signals generated by the first and second sensing elements.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates to a vehicle brake monitoring and sensor system for a braking assembly. More particularly, the vehicle brake monitoring and sensor system senses temperature and wear of the brake lining of the vehicle.  
       BACKGROUND OF THE INVENTION  
       [0002]     Brake lining wear detection systems are well known in the prior art. Further, temperture measurement systems are also well known in the prior art. However, present systems do not have the capability of detecting brake wear while detecting the operating temperature of the brake lining of a vehicle.  
         [0003]     Drum brakes are widely used in vehicle braking systems. In a typical drum brake, two arcuate brake shoe assemblies are located inside a rotating cylindrical brake drum. Each brake shoe assembly includes a backing plate which carries brake lining friction material presenting a wear surface. A brake actuator moves the brake shoe assemblies toward the rotating brake drum such that the wear surface of the brake lining friction material contacts the inner surface of the drum, thus retarding the rotation of the drum. Over a period of time, the contact between the lining and the drum causes the lining to wear. If the lining becomes too thin, ineffective braking can occur. Thus, it is desirable to provide an indication when brake lining thickness is such that the brake shoes should be changed.  
         [0004]     Several problems arise when trying to determine whether the brake linings have sufficiently worn such that they need to be changed. Often the wheel and the brake drum have to be removed from the vehicle for the brake lining thickness to be measured. This is cumbersome and time consuming. Visual brake lining wear indicators, such as notches in the lining or color coded layers in the lining, have been used more effectively to determine when the linings should be changed. When a visual wear indicator is used, an inspector can visually examine each brake lining to determine whether it needs to be changed without having to physically measure the thickness. However, the use of these visual wear indicators can also be cumbersome and time consuming because they require the inspector to visually check each lining while the vehicle is stationary. Thus, it is desirable to have an efficient way to continuously monitor the brake lining thickness during the operation of the vehicle to determine whether the brake linings need to be replaced without having to visually inspect each brake lining.  
         [0005]     As larger-type of wheeled vehicles such as 8, 10 or 12 wheeled trucks have increased in size, weight and load carrying capacity it has become increasingly important for the truck driver to have an ongoing knowledge of the effectiveness of the braking system during the braking process. Additionally, the truck driver has a need for ongoing information/data on the state of readiness of all of the braking components/parts, particularly in terms of temperature and wear at all times during truck operation.  
         [0006]     In a typical vehicle braking system, some type of function element such as a brake shoe in a drum system or a brake pad in a disc brake system is adapted to be moved against a rotating brake drum or disc brake rotor. Thus, there remains a need for a reliable method and device for measuring brake wear and monitoring brake temperature in either of the foregoing brake systems using simple temperature sensors and a simple monitoring/controller unit. It should be noted that the present invention is equally applicable to either drum brake systems or the disc brake systems.  
         [0007]     Some prior art systems have monitored brake lining thickness on vehicles by using a single thermistor sensor in the lining which changes its electrical resistance based on temperature. Brake lining wear for this system is calculated based on changes in measured resistance of the thermistor. Such systems can often be ineffective and produce inaccurate results. Other systems have monitored the temperature of the brake linings to compare these temperatures to electronically stored standard characteristics for the brake lining. These systems are complicated and vary from lining to lining due to varying characteristics in lining materials and configurations. Other prior art monitoring systems have the wear sensors embedded and inserted within the brake pad, and as the brake pad wears out these wear sensors are destroyed in the process.  
         [0008]     Thus, it is desirable to have a sensor system having a simple temperature indicator and lining wear indicator which can be used universally on all brake linings and which calculates accurately the remaining useful thickness of brake lining material.  
       DESCRIPTION OF THE PRIOR ART  
       [0009]     The use of different types of brake monitoring devices having various designs, configurations, structures and materials of construction are well known in the prior art. For example, U.S. Pat. No. 5,559,286 to WHITE et al. discloses a vehicle friction material condition measurement system. This system includes a sensor which responds to both changes in working length and temperature is embedded in a friction lining to provide a signal indicative of both wear and temperature to an electronic control unit which interprets long term averaged change in the sensor resistance measured when the vehicle is stationary as lining wear and short term changes in sensor resistance as representative of lining temperature. This prior art patent does not disclose or teach the brake monitoring and sensor system of the present invention.  
         [0010]     U.S. Pat. No. 5,637,794 to HANISK discloses a resistive brake lining wear and temperature sensing system. This system includes a brake lining temperature and wear sensor having a plurality of serially connected wire loops and a resistive temperature sensor having a lower range of resistance than any one resistor mounted in a cavity formed in the brake lining where a plurality of resistors are connected one to each wire loop to be sequentially connected to a sensor circuit as the brake lining wears and breaks each wire loop. A control unit provides an electrical current to the sensor circuit and monitors the electrical potential across the plurality of wire loops and the resistive temperature sensor and then generating an output signal representing the temperature and wear of the brake lining. This prior art patent does not disclose or teach the brake monitoring and sensor system of the present invention.  
         [0011]     U.S. Pat. No. 5,939,978 to KYRTSOS discloses a temperature sensing brake lining wear indicator. The brake lining wear indicator utilizes a temperature sensor assembly embedded in a brake lining of a drum brake assembly. The temperature sensor assembly includes two temperature sensors with a first temperature sensor located at a first distance X from the wear surface of the brake lining and a second temperature sensor located at a second distance X+d from the wear surface. A timing device measures the time period for the first temperature sensor to reach a first predetermined temperature and measures the time period for the second temperature sensor to reach a second predetermined temperature. Thus, the wear indicator provides a time-temperature based determination of when the brake linings should be replaced. This prior art patent does not disclose or teach the brake monitoring and sensor system of the present invention.  
         [0012]     U.S. Pat. No. 4,824,260 to NOVOTNY et al. discloses a brake block temperature and wear measuring device. The device uses a thermocouple with a brake block having a frictional element with a friction face adapted to be moved into contact with the braking face of a brake drum which outputs a signal indicative alternatively of the steady state temperature of the brake block friction element and of the transient temperature of the friction element brake drum interface. This prior art patent does not disclose or teach the brake monitoring and sensor system of the present invention.  
         [0013]     European Patent Number EP 1 081 404 A2 to RANCOURT discloses temperature sensors that provide temperature data with respect to the heat generated in the disc brake assembly (near the disc). For example, the sensor will measure the temperature of the housing wall next to the brake lining near the disc brake. The temperature sensors are used to measure the increase in temperature and also brake fading (breakdown in the brake pads/lining). This prior art reference does not disclose or teach the brake monitoring and sensor system of the present invention.  
         [0014]     International Publication Number WO84/00406 to MICHAEL discloses a heat sensor mounted close to a disc in a disc brake assembly. The heat sensor will give a warning when the wheels are overheating. The heat sensor is used for measuring an increase in temperature for the disc brake. This prior art reference does not disclose or teach the brake monitoring and sensor system of the present invention.  
         [0015]     None of these prior art patents teach or disclose the structure, design and configuration of a vehicle brake monitoring and sensor system that has a plurality of temperature and wear detector elements for the continuous monitoring of the temperature and wear of the brake shoe lining of the vehicle during operation as shown in the present invention.  
         [0016]     Accordingly, it is an object of the present invention to provide a vehicle brake monitoring and sensor system for the monitoring of temperature and wear of the brake shoe lining of the vehicle using one or more thermal sensor elements and one or more wear sensor detector elements being detachably connected to the brake shoe lining of the brake drum system for each wheel of the vehicle.  
         [0017]     Another object of the present invention is to provide a vehicle brake monitoring and sensor system that is easily serviceable having a low cost of installation for the vehicle and being easy to install for new or old vehicles, such as tractor trailers.  
         [0018]     Another object of the present invention is to provide a sensor system having no moving parts and each sensor element can be easily maintained; and replaced as needed by the operator.  
         [0019]     Another object of the present invention is to provide a vehicle brake monitoring and sensor system that gives more accurate heat readings as the thermal sensor elements are reading the heat generated on the rivet and brake shoe rather than on the brake pad of the brake drum system. This is because the brake pad is designed to dissipate the heat in the brake pad as soon as possible as the brake pad is in a cooling process and the thermal sensor elements receive a more accurate reading because the brake shoe takes longer to cool down than the brake pad. Also, the rivet is not thick and thus heats up quickly.  
         [0020]     Another object of the present invention is to provide a vehicle brake monitoring and sensor system that has no inaccurate temperature and wear readings and has minimal maintenance problems when in operational use thereof.  
         [0021]     Another object of the present invention is to provide a vehicle brake monitoring and sensor system having a control monitoring panel with a plurality of digital brake temperature gauges having a memory read-out that gives the highest temperature of operation during the vehicle trip.  
         [0022]     Another object of the present invention is to provide a control monitoring panel that has a buzzer and wear indicator light indicating when the brake pad of the brake shoe lining has worn a predetermined distance and is sensed by the wear sensor detector elements of a given wheel.  
         [0023]     A further object of the present invention is to provide a vehicle monitoring and sensor system that can be mass produced in an automated and economical manner and is readily affordable by the vehicle operator.  
       SUMMARY OF THE INVENTION  
       [0024]     In accordance with the present invention, there is provided a vehicle brake having a brake monitoring and sensor system attached to a brake shoe of a brake assembly for monitoring of temperature and wear of a brake shoe lining of a vehicle. The vehicle brake monitoring and sensor system includes a brake assembly for frictional braking of a vehicle. The brake assembly includes a brake shoe lining having a brake shoe and a brake pad for frictional engagement with the brake assembly; and the brake shoe lining has first rivet openings with rivets therein, and has second rivet openings with no rivets therein. The vehicle brake monitoring system also includes a sensor system having a first sensing element and a second sensing element each connected to the brake shoe; the first sensing element is embedded in one or more of the first rivet openings with the rivets therein; and the second sensing element is embedded in one or more of the second rivet openings having no rivets therein. The first sensing element is for generating a first electrical signal in response to sensing changes in the temperature of the brake shoe generated by heat in the brake shoe which is transmitted to one or more rivets in the first rivet openings. The second sensing element is for generating a second electrical signal in response to sensing a predetermined depth of wear of the brake pad. The vehicle brake monitoring and sensor system further includes a monitoring unit for processing the first and second electrical signals generated by the first and second sensing elements. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0025]     Further objects, features and advantages of the present invention will become apparent upon the consideration of the following detailed description of the presently-preferred embodiment when taken in conjunction with the accompanying drawings, wherein:  
         [0026]      FIG. 1  is a perspective view of a brake monitoring and sensor system of the preferred embodiment of the present invention showing a thermal sensor element and a wear sensor detector element attached to a brake shoe of a brake drum system;  
         [0027]      FIG. 2  is a perspective view of the brake monitoring and sensor system of the present invention showing a thermal sensor element;  
         [0028]      FIG. 3  is an exploded perspective view of the brake monitoring and sensor system of the present invention showing the thermal sensor element being received within an opening of a sensor housing member;  
         [0029]      FIG. 3A  is a bottom perspective view of the brake monitoring and sensor system of the present invention showing the thermal sensor element disposed within the opening of the sensor housing member;  
         [0030]      FIG. 4  is a cross-sectional view of the brake monitoring and sensor system of the present invention taken along lines  4 - 4  of  FIG. 1  in the direction of the arrows showing the thermal sensor element attached to the rivet of a lower brake shoe;  
         [0031]      FIG. 5  is an exploded perspective view of the brake monitoring and sensor system of the present invention showing the major component parts of the brake shoe of the brake drum system having the sensor elements attached thereto;  
         [0032]      FIG. 6  is a perspective view of the brake monitoring and sensor system of the present invention showing an air can assembly of the brake drum system;  
         [0033]      FIG. 7  is a perspective view of the brake monitoring and sensor system of the present invention showing the wear sensor detector element having a brass contact member and a pair of contact points thereon;  
         [0034]      FIG. 8  is a cross-sectional view of the brake monitoring and sensor system of the present invention taken along lines  8 - 8  of  FIG. 1  in the direction of the arrows showing the major component parts of the wear sensor detector element;  
         [0035]      FIG. 9  is a schematic representation of the brake monitoring and sensor system of the present invention showing the placement of the sensor elements on each set of paired wheels of a tractor trailer being connected to a control monitor panel;  
         [0036]      FIG. 10  is a schematic representation of the brake monitoring and sensor system of the present invention showing the control monitor panel having a plurality of digital brake temperature gauges; and a plurality of wear indicator buzzers and wear sensor indicator lights thereon; and  
         [0037]      FIG. 11  is schematic representation of the brake monitoring and sensor system of the present invention showing the sensor elements connected to a plurality of rivets of the brake shoe and sensor connections attached to the dashboard monitor. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0038]     The brake monitoring and sensor system  10  and its component parts of the preferred embodiment of the present invention are represented in detail by  FIGS. 1 through 11  of the patent drawings. The brake monitoring and sensor system  10  is used for the monitoring of temperature T and wear W of a brake shoe lining  22  of a brake drum system  20 , as shown in  FIGS. 1, 4 ,  5  and  11  of the drawings. The monitoring and sensor system  10  includes a control monitoring panel  100  on a dashboard  12  of a cab section  14  of a tractor trailer  16  and a trailer section  16   t  having a plurality of sets of paired wheels  18   a ,  18   b ,  18   c ,  18   d ,  18   e ,  18   f ,  18   g  and  18   h  on the trailer section  16   t  and a pair of standard wheels  18   i  and  18   j  on the cab section  14  of the tractor trailer  16 . The monitoring and sensor system  10  also includes a sensor system assembly  120  having at least one or more thermal sensor elements  122  detachably connected to the brake shoe lining  22  of the brake drum system  20  and having at least one or more wear sensor detector elements  152  detachably connected to the brake shoe lining  22  of the brake drum system.  
         [0039]     As shown in  FIG. 9 , the monitoring and sensor system  10  depicts the placement of the thermal sensor elements  122  and the wear sensor detector elements  152  on each set of paired wheels  18   a  to  18   h  of the trailer section  16   t  of the tractor trailer  16  as well as on the wheels  18   i  and  18   j  of the cab section  14  of the tractor trailer  16 . The thermal sensor elements  122 , as well as the wear sensor detector elements  152 , are electronically connected to the control monitoring panel  100  on the dash board  12  of cab section  14  of tractor trailer  16 , as shown in  FIGS. 10 and 11  of the drawings. The control monitoring panel  100  includes a plurality of digital brake temperature gauges  102   a ,  102   b ,  102   c ,  102   d ,  102   e ,  102   f ,  102   g ,  102   h ,  102   i  and  102   j . Each of the brake temperature gauges  102   a  to  102   j  includes a digital readout panel  103   a ,  103   b ,  103   c ,  103   d ,  103   e ,  103   f ,  103   g ,  103   h ,  103   i  and  103   j  and a reset button  104   a ,  104   b ,  104   c ,  104   d ,  104   e ,  104   f ,  104   g ,  104   h ,  104   i  and  104   j  thereon. The control monitoring panel  100  further includes a wear indicator light  106   a ,  106   b ,  106   c ,  106   d ,  106   e ,  106   f ,  106   g ,  106   h ,  106   i  and  106   j  for indicating brake wear on a particular set of paired wheels  18   a  to  18   h  of the trailer section  16   t  and/or on the wheels  18   i  and  18   j  of the cab section  14  of the tractor trailer  16 . The control monitoring panel  100  additionally includes a wear indicator buzzer  108   a ,  108   b ,  108   c ,  108   d ,  108   e ,  108   f ,  108   g ,  108   h ,  108   i  and  108   j  for indicating brake wear also on a particular set of paired wheels  18   a  to  18   h  of the trailer section  16   t  and/or on the wheels  18   i  and  18   j  of the cab section  14  of the tractor trailer  16 . Each of the brake temperature gauges  102   a  to  102   h  are electrically connected to a thermal sensor element  122  via an electrical wire  144 , as shown in  FIG. 11  of the drawings. Each of the wear indicator lights  106   a  to  106   j  and wear indicator buzzers  108   a  to  108   j  are electrically connected (in series) to a wear sensor detector element  152  via an electrical wire  194 , as shown in  FIG. 11  of the drawings, for giving a visual and auditory alarm to an operator when the brake shoe lining  22  of the brake drum assembly  20  has worn and is failing.  
         [0040]     As shown in  FIGS. 1 and 5 , the standard brake drum system  20  includes a brake shoe lining  22  having an upper brake pad  24  attached to an upper brake shoe  26  having an inner brake shoe surface  27  by a plurality of rivets  28  within rivet openings  30 , and having a lower brake pad  34  attached to a lower brake shoe  36  having an inner brake shoe surface  37  by the plurality of rivets  28  within rivet openings  40 . The brake drum system  20  also includes a pair of mounting springs  42   a  and  42   b  for holding each of the upper and lower brake shoes  26  and  36  together, a return spring  44 , a spline shaft  46  for an S-cam  48 , an S-cam roller  50  and a spider housing  52 . The brake drum system  20  further includes a dust cover  54 , a mounting bracket  56  for an air can  58 , a slack adjuster  60  and a slack adjuster clevis pin  62 . Each of the rivets  28  include a rivet head  64  and a rivet stem  66  having a rivet end  68 . As shown in  FIG. 6 , the standard brake drum system  20 , additionally includes an air can assembly  70  having an air can housing  72  with mounting studs  74  attached thereto. The air can assembly  70  further includes an inner spring  76 , an outer spring  78 , an air can shaft  80  having a slack adjuster clevis pin  82  attached thereto and inner and outer diaphragm members  84  and  86  within the air can housing  72 .  
         [0041]     As shown in  FIGS. 1, 4 ,  5  and  11 , the thermal sensor element  122  of sensor system assembly  120  includes a sensor housing member  124  having a bottom wall  126  at one end  127 , and a sensor mounting opening  128  at the other end  129  thereof for receiving a threaded sensor sleeve  130  therein. The threaded sensor sleeve  130 , as shown in  FIGS. 2 and 3 , includes a hollow sensor compartment  132  for receiving thermal sensor oil  134  therein and having a flat end tip  136  thereon. The threaded sensor sleeve  130  also includes a proximal end  138  and a distal end  140 . The proximal end  138  of thermal sensor sleeve  130  includes an attachment section  142  for receiving an electrical wire  144  and a circular stop tab  146  thereon. The threaded sensor sleeve  130  further includes an integrally attached adjustment hex nut  148  for adjusting the flat end tip  136  of the thermal sensor member  134  to be in contact with the rivet end  68  of the rivet stem  66  of rivet  28  within the rivet opening  40  of the lower brake shoe  36  of brake shoe lining  22 , as depicted in  FIGS. 1 and 4  of the drawings. Additionally, the bottom wall  126  of housing member  124  is fixedly attached to the inner brake shoe surface  27  and/or  37  of the brake shoe  26  and/or  36  via welding, laser welding or the like.  
         [0042]     As shown in  FIGS. 7, 8  and  11 , the wear sensor detector element  152  of sensor system assembly  120  includes a wear sensor housing member  154  having a mounting head  156  and a threaded shaft  158  with a shaft opening  160  therein. Mounting head  156  includes an outer wall surface  157 . Shaft opening  160  includes a proximal end  162  and a distal end  164 . The shaft opening  160  is used for receiving a compressible spring  166  having a first end  168  and a second end  170  and a sensor tip ball  172  in contact and adjacent to the first end  168  of compressible spring  166 . The distal end  164  of shaft opening  160  of threaded shaft  158  is for slidably receiving the sensor tip ball  172  therein, as shown in  FIGS. 7 and 8  of the drawings. The proximal end  162  of shaft opening  160  is for receiving a contact pad  174  and a switch member  176  therein. One side  173  of contact pad  174  is in contact with and adjacent to the second end  170  of compressible spring  166  and the other side  175  of contact pad  174  is in contact with and adjacent to switch member  176 . Switch member  176  includes a pair of electrical leads  178   a  and  178   b  attached to an upper wall surface  180  of switch member  176 , as shown in  FIG. 8  of the drawings. The outer wall surface  157  of mounting head  156  includes an electrical contact member  182  having a contact base section  184 , and a contact pad section  186  with a pair of spaced-apart electrical contact holding lead elements  188   a  and  188   b  thereon. Each of the holding lead element  188   a  and  188   b  include a threaded stem  190   a  and  190   b  and a hex nut  192   a  and  192   b , respectively, thereon, as depicted in  FIGS. 7 and 8  of the drawings. The threaded shaft  158  of the wear sensor detector element  152  is received within (tapped in) rivet opening  30  or  40  of the upper or lower brake pads  24  or  34 , respectively, as depicted in  FIG. 11  of the drawings. Each of the threaded stems  190   a  and  190   b  of the holding lead elements  188   a  and  188   b  include a first electrical wire  194  and a second electrical wire  196 , respectively, thereon. The first electrical wires  194  connect the wear indicator lights and buzzers  106   a  to  106   j  and  108   a  to  108   j  (in series) of the wear sensor detector elements  152  to the control monitoring panel  100 , as depicted in  FIG. 11 . The second electrical wires  196  are electrically connected to a 12 volt power source  110  for powering of the wear sensor detector elements  152 , as shown in  FIG. 11 . The threaded shaft  158  of the wear sensor housing member  154  of wear sensor detector element  152  also includes a detachable spacer  198  having a spacer opening  200  for receiving the threaded shaft  158  therethrough. Spacer  198  is in contact with and adjacent to the mounting head  156  and the inner brake shoe surfaces  27  and  37  of brake shoes  26  and  36 , respectively, as shown in  FIGS. 1 and 11  of the drawings, for adjusting the wear sensor detector elements  152  to a predetermined depth of wear for brake pads  24  or  34 , respectively.  
       Operation of the Present Invention  
       [0043]     Upon installation of the thermal and wear sensor elements  122  and  152  on the brake shoe lining  22  of the brake drum system  20 , as previously described above, the brake monitoring and sensor system  10  operates in the following manner, as shown in  FIGS. 1, 4 , and  9  through  11  of the patent drawings. As a driver operates a moving vehicle, such as a tractor trailer  16  as depicted in  FIG. 9 , a control monitoring panel  100  on the dashboard  12  of the cab section  14  of the tractor trailer  16  is constantly monitoring the temperature T and wear W of a brake shoe lining  22  of a brake drum system  20  for any one of the paired sets of wheels  18   a  to  18   h  on the trailer section  16   t  and/or on the wheels  18   i  and  18   j  on the cab section  14  of the tractor trailer  16 , respectively.  
         [0044]     As a particular brake pad  24  or  34  of a brake shoe  26  or  36  wears in the operation of tractor trailer  16 , the control monitoring panel  100  via the thermal sensor element  122  and the wear sensor detector element  152  of sensor system  120  give the operator a visual, as well as a sound (buzzer) readings of temperature T and wear W by the use of the digital brake temperature gauges  102   a  to  102   j  and by the use of the indicator lights or buzzer indicators  106   a  to  106   j  and  108   a  to  108   j , respectively, for detecting abnormal temperature T or wear W of a particular brake pad  24  or  34  of brake shoe  26  or  36  on a particular paired wheel set  18   a  to  18   h  or wheel  18   i  and  18   j , respectively.  
         [0045]     When the digital brake temperature gauge  102   a  to  102   j  reaches a temperature range of at least 350 to 400° F. for a particular set of wheels  18   a  to  18   j , then the vehicle operator knows to check that brake drum assembly  20  for that wheel  18   a  to  18   j  for damage, problems and the like. At ambient temperature an ambient reference electrical signal is generated. If the brake drum assembly  20  is not in electrical contact with the brake pad  24  and/or  34 , then the electrical signal S TE  generated does not increase above the ambient reference electrical signal. Thus, if there is no heat reading (lack of heat) being generated by the one or more thermal sensor elements  122  for a particular set of wheels  18   a  to  18   h  or on wheels  18   i  and  18   j  on the control monitoring panel  100 , this means that the brake drum assembly  20  is inoperative and not working. Such problems and/or damage to the brake drum assembly  20  includes the following components: air valves to the air cans  58 , air cans  58 , broken air lines, diaphragms  84  or  86 , drum shaft  80 , springs  76  or  78 , slack adjuster  60 , slack adjuster clevis pin  82 , mounting bracket  56  for the air can  58 , S-can  48 , S-can roller  50 , spline shaft  56  for the S-can  48 , return spring  44 , as well as the brake shoe lining  22 , as shown in  FIGS. 5 and 6  of the drawings. Thus, the digital brake temperature gauges  102   a  to  102   j  give the vehicle operator a “heads-up” when a problem/damage occurs to the brake drum assembly  20  by giving an accurate temperature reading T for that paired set of wheels  18   a  to  18   h  or wheels  18   i  and  18   j . In the course of operation of the tractor trailer  16 , the digital brake temperature gauges  102   a  to  102   j  have a memory read-out function that gives the vehicle operator the highest operating temperature T during the vehicle trip for each of the wheels  18   a  to  18   j  of the tractor trailer  16 , as shown in  FIGS. 9 and 10  of the drawings.  
         [0046]     In the course of operating the tractor trailer  16 , the brake shoe lining  22  of brake drum assembly  20  eventually wears for a particular pair set of wheels  18   a  to  18   h  for the trailer section  18   t  and/or for the wheels  18   i  and  18   j  for the cab section  14  of the tractor trailer  16 , such that the control monitoring panel  100  gives both a visual and a sound warning that a particular brake shoe lining  22  is failing via the wear indicator lights and buzzers  106  to  106   j  and  108   a  to  108   j , respectively. As the brake pad  24  and/or  34  of the brake shoe  26  and/or  36  is worn down, the wear sensor detector elements  152  within the empty rivet openings  30   a  and/or  40   a  are actuated as the sensor tip ball  172  has been contacted. Then the compressible spring  166  makes contact with the contact pad  174  and switch member  176 . Switch member  176  then sends an electrical signal SWE via the electrical lead line  194  which in turn lights the indicator lights  106   a  to  106   j , as well as buzzes the wear indicator buzzers  108   a  to  108   j  of a worn brake shoe lining  22  for a particular set of wheels  18   a  to  18   h  or wheels  18   i  and  18   j  for the tractor trailer  16 , as shown in  FIGS. 9 through 11  of the drawings.  
       Advantages of the Present Invention  
       [0047]     Accordingly, an advantage of the present invention is that it provides for a vehicle monitoring and sensor system for the monitoring of temperature and wear of the brake shoe lining of the vehicle using one or more thermal sensor elements and one or more wear sensor detector elements being detachably connected to the brake shoe lining of the brake drum system for each wheel of the vehicle.  
         [0048]     Another advantage of the present invention is that it provides for a vehicle monitoring and sensor system that is easily serviceable having a low cost of installation for the vehicle and being easy to install for new or old vehicles, such as tractor trailers.  
         [0049]     Another advantage of the present invention is that it provides for a sensor system having no moving parts and can be easily maintained; replaced as needed by the operator.  
         [0050]     Another advantage of the present invention is that it provides for a vehicle monitoring and sensor system that gives more accurate heat readings as the thermal sensor elements are reading the heat generated on the rivet and brake shoe rather than on the brake pad of the brake drum system. This is because the brake pad is designed to dissipate the heat in the brake pad as soon as possible as the brake pad is in a cooling process and the thermal sensor elements receive a more accurate reading because the brake shoe takes longer to cool down than the brake pad. Also, the rivet is not thick and heats up quickly.  
         [0051]     Another advantage of the present invention is that it provides for a vehicle monitoring and sensor system that has no inaccurate temperature and wear readings and has minimal maintenance problems when in operational use thereof.  
         [0052]     Another advantage of the present invention is that it provides for a vehicle monitoring and sensor system having a control monitoring panel with a plurality of digital brake temperature gauges having a memory read-out that gives the highest temperature of operation during the vehicle trip.  
         [0053]     Another advantage of the present invention is that it provides for a control monitoring panel that has a buzzer and wear indicator light indicating when the brake pad of the brake shoe lining has worn a predetermined distance and is sensed by the wear sensor detector elements of a given wheel.  
         [0054]     Another advantage of the present invention is that it provides for a control monitoring panel to indicate a worn brake pad prior to the driving of the vehicle, such that the operator can arrange for the repair of the brake pad.  
         [0055]     A further advantage of the present invention is that it provides for a vehicle monitoring and sensor system that can be mass produced in an automated and economical manner and is readily affordable by the vehicle operator.  
         [0056]     A latitude of modification, change, and substitution is intended in the foregoing disclosure, and in some instances, some features of the invention will be employed without a corresponding use of other features. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the spirit and scope of the invention herein.