Abstract:
The invention comprises a tire pressure monitoring system. One system comprises a tire pressure monitor that signals to a user with audio alarm and visual alarm. Another component is the use of a tire air pressure balancing device with a safety trigger to ensure that dual tire systems share air but that stop sharing air in the case of rapid air pressure drop as in cases of tire blow out.

Description:
PRIORITY APPLICATIONS 
       [0001]    This application claims priority to PCT application number PCT/US12/29575 filed Mar. 18, 2012 and to U.S. provisional patent application No. 61/454,483 filed on Mar. 18, 2011, the contents of which are incorporated herein. 
     
    
     FIELD OF INVENTION 
       [0002]    The present invention relates to tire pressure monitoring systems TPMS and devices for trucks and heavy vehicles. 
       BACKGROUND OF THE INVENTION 
       [0003]    The present invention relates particularly to tire pressure measuring devices for trucks and heavy vehicles such as tractors for hauling semi-trailers. One of the biggest operating expenses for trucks is the cost of tires. With underinflated tires, the wear of tires is excessive, the fuel consumption increases, the handling characteristics of the vehicle are affected in a negative manner and the risk for catastrophic tire failure increases, and the road safety is jeopardized. With under inflation the tires get hot and the risk for thread separation increases especially in re-threaded tires. 
         [0004]    While the U.S. government has ruled mandatory on all new cars and light trucks to have an incorporated Tire Pressure Monitoring Systems TPMS on the vehicles there is no current law for the heavy vehicles. Therefore only a small percentage of trucks have TPMS installed as original equipment. Although truck drivers are typically aware of the importance of having the right tire pressure, the amount of time and effort needed to properly inspect the tire pressure in all the tires often makes the driver neglect the inspection assuming that the pressure is correct. In addition to being time consuming on the typical dual wheel rear axles it is also inconvenient since it is often necessary to be down on your knees on the ground to locate valve stems to be able to check the pressure. A study, conducted by the United States Government, showed that 56% of all truck on the road in USA had one or more tire underinflated. U.S. Dept. of Commerce, National Technical Information Service, pub #PB2005100013, “Commercial Vehicle Tire Condition Sensors.” Research performed by Booz Allen Hamilton, Inc., McLean, Va. 
         [0005]    Many of the aftermarket TPMS are difficult to use for the end user and to market for the distributors due to several reasons:
       Tire location programming. Since most TPMS display only which tire is underinflated on the screen of the receiver, there is a need to program the system to read which transmitter is on which wheel. This is a time consuming and often confusing procedure for the common user and even for the vehicle maintenance personnel. Some TPMS have the transmitters preprogrammed at the factory which means a broken transmitter needs to be replaced with the right preprogrammed unit from the factory, and no spare units will be available required in inventory for the fleet.   Preset pressure ranges. Often the pressure warning threshold has been preset by the system manufacturer which means that for a fleet to purchase these devices they need to order units with the right warning threshold for each vehicle since the pressure differs from vehicle to vehicle and often differs depending on the axle the tire is mounted to. These systems make it difficult for the distributor to provide his customer with all the right pressure ranges in advance. However, many systems can be programmed for the warning threshold but by an often rather complicated series of inputs to the system.   Very few systems allow several monitors and a capability to cross monitor several vehicles which make those systems useless for maintenance and service personnel.   No systems are capable of monitoring a series of trailers waiting to be picked up by a tow vehicle such as a tractor.       
 
         [0010]    The intent with the present invention is to address inconvenience factors in checking the tire pressure and the shortcoming of other systems. 
       BRIEF SUMMARY OF THE INVENTION 
       [0011]    An object of the present invention is to provide a highly visible warning device, located at the wheel in addition to a receiver with both visible and audible warning inside the vehicle or maintenance personnel possession, which would alert of low tire pressure. 
         [0012]    Yet another object of the invention is to provide a warning device, which can be easily individually calibrated according to the desired tire pressure. 
         [0013]    Yet another object of the invention is to provide a TPMS which is capable of monitoring any tire pressure range used in truck, tractor, or trailer tires. 
         [0014]    Yet another object of the invention is to provide a warning device which does not need programming to be able to identify which tire is low. 
         [0015]    Yet another object for the invention is to provide the driver with an eye-catching warning both at the tire and inside the cab. 
         [0016]    Yet another object for the invention is to provide the driver with an audible warning inside the cab. 
         [0017]    Yet another object for the invention is to provide the maintenance personnel with an eye-catching warning with a remote receiver. 
         [0018]    Yet another object for the invention is to provide the maintenance personnel with an audible warning with a remote receiver. 
         [0019]    Yet another object for the invention is to be able to monitor the tire pressure of trailers without a tow vehicle hooked up. 
         [0020]    Yet another object for the invention is to provide a gate guard for a fleet of trucks with an eye-catching warning with a remote receiver to be able to monitor all vehicles passing by. 
         [0021]    Yet another object for the invention is to provide the gate guard with an audible warning with a remote receiver to be able to monitor all vehicles passing by. 
         [0022]    Yet another object of this invention is providing a system which does not give false alarms due to changes in ambient temperature. 
         [0023]    Yet another objet for this invention is to provide a system where one tow vehicle tractor can be hooked up with an unlimited number of different trailers without any reprogramming of transmitter or receiver and still have the system monitoring all wheels of both tow vehicle and trailer. 
         [0024]    Yet another objet for this invention is to provide a system where there is no limitation how many tires can be monitored simultaneously. 
         [0025]    Yet another object of this invention is providing a system where neither the sensor nor the transmitter uses any electricity when the tire pressure is correct. 
         [0026]    Yet another object of this invention is providing a system which has a low battery warning for both transmitter and receiver. 
         [0027]    Yet another object of this invention is providing a system which will monitor the tire pressure while vehicle is either moving or parked. 
         [0028]    Yet another object for this invention is to relocate the filling point of the tire to a location more convenient and accessible. 
         [0029]    Yet another object for this invention is to be able to check the tire pressure with the system in place without removing any parts. 
         [0030]    Yet another object for the invention is to provide a silent warning by the tire to eliminate any disturbance to the surroundings. 
         [0031]    Yet another object for the invention is to provide a simple method of testing the functionality and battery conditions of the warning device. 
         [0032]    Yet another object of the invention is to provide a TPMS which is easily installed by service personnel without special tooling or training. 
         [0033]    Yet another object of the invention is to provide a TPMS which has negligible or no effect on tire balancing. 
         [0034]    Yet another object of the invention is to provide a TPMS which does not need to be removed to change batteries in the Sensor/Transmitter Unit. 
         [0035]    Yet another object of the invention is to provide a TPMS where the batteries can be changed without deflating the tire or affecting the tire pressure. 
         [0036]    Yet another object of the invention is to provide a TPMS which uses standard off the shelf batteries which can easily be changed by service personnel without special tools or training. 
         [0037]    Yet another object of the invention is to provide a TPMS which has a long battery life. 
         [0038]    Yet another object of the invention is to provide a TPMS which does not need to be removed when tires are replaced, except for disconnecting hoses. 
         [0039]    Yet another object of the invention is to provide a TPMS which does not need to be re-programmed when tires are replaced. 
         [0040]    Yet another object is to provide a system of low tire pressure monitoring and warning, which is easy to install and maintain at low cost for OEM and aftermarket applications. 
         [0041]    Yet another object is to provide a system for maintaining even tire pressure between two linked tires to increase tire life. 
         [0042]    Yet another object is to provide a safety mechanism when even tire pressure between two tires is linked and one tire is damaged by subsequently shutting off the air flow between the linked tires so that the air pressure in the undamaged tire is maintained in a drivable condition. 
         [0043]    The present invention achieves its objects by providing a sensor and transmitter unit located on a bracket in the center of rear wheels or attached to the rim on the front wheels. The sensor/transmitter has a transparent cap with a bright light emitting diode LED and Radio Frequency RF antenna and circuitry for the LED flashing and the RF sending mounted on a small printed circuit board PCB. The LED start flashing and the RF signal will be transmitted if the tire pressure drops from a set pressure differential, preferably about 8 psi pounds per square inch from set pressure. Under the PCB there is a pressure reference chamber. One wall of the pressure chamber is a membrane, which purpose is to measure the pressure-difference between the Pressure Chamber and the tire pressure. If the tire pressure in the tire drops 8 psi or more the membrane of the reference chamber will be activated and make contact with the support contact washer which will activate the circuitry on the PCB for the flashing of the LED and the transmission of the RF signal indicating that the tire pressure has dropped to a warning level. Inside the body there are batteries which will power the circuitry on the PCB. The LED can visually be seen at the sensor/transmitter unit and an LED seen and beeper or alarm heard by a remote receiver inside the driver&#39;s cabin or in the possession of maintenance personnel. 
         [0044]    The manners in which the invention achieves its objects and other objects which are inherent in the invention will become more readily apparent when reference is made to the accompanying drawings wherein like numbers indicate corresponding parts throughout. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0045]      FIG. 1  is a perspective view of a preferred embodiment with a portion of the view magnified to illustrate the placement of the invention relative to a pair of wheels. 
           [0046]      FIG. 2  is a perspective view of a preferred embodiment separated from a wheel. 
           [0047]      FIG. 3A  is an exploded view of a top portion of a preferred embodiment. 
           [0048]      FIG. 3B  is an exploded view of a bottom portion of a preferred embodiment. 
           [0049]      FIG. 4  is a cross section view of a preferred embodiment. 
           [0050]      FIG. 5  is a cross section view of a preferred embodiment. 
           [0051]      FIG. 6  is a cross section view of a preferred embodiment. 
           [0052]      FIG. 7  is a cross section view of a preferred embodiment. 
           [0053]      FIG. 8  is a perspective view of an alternative preferred embodiment with a portion of the view magnified to illustrate the placement of the invention relative to a pair of wheels. 
           [0054]      FIG. 9  is a perspective view of a preferred embodiment separated from a wheel. 
           [0055]      FIG. 10A  is an exploded view of a top portion of an alternative preferred embodiment. 
           [0056]      FIG. 10B  is an exploded view of a bottom portion of an alternative preferred embodiment. 
           [0057]      FIG. 11  is a cross section view of an alternative preferred embodiment. 
           [0058]      FIG. 12  is a cross section view of an alternative preferred embodiment. 
           [0059]      FIG. 13  is a cross section view of an alternative preferred embodiment. 
           [0060]      FIG. 14  is a cross section view of an alternative preferred embodiment. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0061]    The body  1  should be machined from brass with pressure area  60  for the tire pressure and pressure channels  61  to channel the pressure into the right areas. Body  1  also has a battery cavity  62  and a test button cavity  63 . Pressure area  60 , valve stem  24 , inlet adapter comprised of  23 A,  23 B,  23 C and test button cavity  63  are all connected through pressure channels  61  in the body  1 . The batteries  13  have a positive end  13 A in contact with the battery center pin  15  and a negative end  13 B completes a circuit and allows current to flow when a battery spring  16  is in contact with a battery end cap screw  14  to make the body  1  a negative conductor. The positive side is connected from the battery center pin  15  via the connector screw  37  to the connector strip  36  to the pressure chamber closing pin  10  to the pressure chamber contact spring  11  to the pressure Chamber  9  which has the membrane  7  soldered to it. If the pressure in the pressure chamber  9  is greater than the pressure in the pressurized area  60  the membrane  7  will be activated and move enough to touch the support contact washer  4  which is in direct contact with the PC board complete with radio  3  and provide the positive power to the PC board complete with radio  3 . The negative side of the PC board complete with radio  3  will be in constant contact with the chamber threads  6  which are in direct contact with the negatively charged body  1 . 
         [0062]    The sensor/transmitting unit  100  also achieves its objects by having a mechanical sensor, membrane  7 , for the pressure drop. The membrane  7  on the pressure chamber  9  is a mechanical device and requires no electricity. When the reference pressure in the pressure chamber  9  exceeds the tire pressure by 8 psi the membrane  7  will move and contact the support contact washer  4  and the PCB circuitry will be energized. The monitoring is using no battery energy since the batteries are totally disconnected until the tire pressure has dropped 8 psi. This maximizes the battery life. 
         [0063]    Alternative Pressure Sensor 
         [0064]    Instead of using the mechanical sensing system with a pressure chamber with a membrane, the sensing system can be replaced by mechanical spring loaded or an electronic sensing device 
         [0065]    After installing the sensor/transmitting unit  100  on its mounting bracket  27  and the flex hoses  39  are connected to the tire valve stems  24  the sensor/transmitting unit  100  can be calibrated. The calibration is done by turning the lens  2  counter-clockwise about one turn until it stops. The lens  2  turns the chamber threads  6  which in turn pushes the pressure chamber  9  towards the pressure chamber closing pin  10  which with the help of the O-Ring for chamber pin  32  seal the pressure chamber  9 . The pressure chamber  9  is located inside the pressurized area  60  and will now therefore have trapped reference pressure  9 A which is the same pressure inside the pressure chamber  9  as inside the pressurized area  60 . The lens  2  then seals the pressure chamber  9  when it is rotated back to its original position. In a preferred embodiment, if the tire pressure drops 8 psi or more from being in direct connection with the pressurized area  60  through the pressure channels  61  the pressure in the pressurized area  60  will also drop the equal amount. The pressure chamber  9  will therefore have the 8 psi more pressure than the pressurized area  60  which will activate the membrane  7  which will touch the support contact washer  4  which completes the electrical circuit and activates electrical circuitry on the PC board complete with radio  3  which start flashing an LED on the PC board complete with radio  3  and sending out an RF signal to be picked up by a receiver unit (not shown). To stop the PC board complete with radio  3  from flashing and transmitting RF signal the tire pressure has to be brought back to the original pressure where the reference pressure was set or the sensor/transmitting unit  100  needs to be re-calibrated. The RF signal can be pre-programmed to have three quick signals then a two second long pause, and then repeat the cycle to keep energy output from the batteries  13  efficient. 
         [0066]    The sensor/transmitting unit  100  also achieves its objects by being capable of being calibrated to any tire pressure range used on trucks or heavy vehicles. The system is based on the pressure differential between the pressure chamber  9  and the tire pressure and can therefore adapt to any pressure. The membrane  7  can be designed to move at pressures other than 8 psi, for example if a higher degree of control were wanted the membrane  7  could be designed to move at lower pressure differentials, even down to 1 psi or lower. 
         [0067]    A preferred embodiment of the sensor/transmitting unit  100  uses the same frequency and protocol for all units because service personnel could easily monitor vehicles as they returned to a maintenance or storage facility. The range of the sensor/transmitting unit  100  to the receiver is a distance of approximately 60 feet. However, it is possible to create sets of sensor/transmitting units  100  and receiver with different frequencies to reduce the possibility of triggering false readings from nearby vehicles. 
         [0068]    The sensor/transmitting units  100  is robust in air pressure measurement and is insensitive to changes in ambient air temperature because when ambient temperature drops both the reference pressure in the pressure chamber  9  and the tire pressure will drop equally. 
         [0069]    An additional benefit of the sensor/transmitting unit  10  is mounted on a bracket at the end of the rear axles for dual wheels or “super singles.” This position allows easy accessibility so when filling tires with air personnel do not have to get on their knees. 
         [0070]    Functionality Check 
         [0071]    The functionality of the sensor/transmitting unit  100  and condition of the batteries  13  can easily be verified by depressing the test button pin  20 . Test button pin  20  presses down the valve stem core  22  which will perform two tasks simultaneously. First, the O-ring for test button  30  located at the bottom of the valve stem core  22  will close the pressure channel  60  leading to the valve stem  24  where the pressure supply from the tire is provided to the pressurized area  60 . Second, to relive the pressure in the pressurized area  60 , because the pressurized area  60  is now unpressurized, the pressure chamber  9  has more pressure than the surrounding area and the membrane  7  will be activated and give contact to the membrane  7  which will touch the support contact washer  4  which will activate the circuitry on the PC board complete with radio  3  which start flashing and sending out RF signal(s) to be picked up by a receiver unit  200 . When the test button pin  20  is released, the pressure will return to the pressurized area  60  and the membrane  7  will return to its standby position where there is no electrical contact and the flashing and sending out of RF signal will immediately stop. 
         [0072]    Receiver 
         [0073]    A receiver unit could be installed in the cab of a vehicle which has an audible signal which will beep when it receives the RF signal from the sensor/transmitting unit  100 . The audible signal could be turned on or off. The receiver could also have an LED or other light indicator to turn on when it receives the RF signal from the sensor/transmitting unit  100 . The visible signal could be turned on or off. The receiver could be wired to receive power from the vehicle battery or have its own battery. A receiver could also be portable, for example, for service or maintenance personnel. A portable receiver could have rechargeable batteries. 
       ALTERNATIVE PREFERRED EMBODIMENT 
       [0074]    In an alternative preferred embodiment the body  101  is configured with additional features to allow the sharing of air between two linked tires but at the same time have a safety feature that allow air flow to be cut off automatically in the event of a catastrophic failure of one of the tires, even if the balancing valve would manually left open  FIGS. 8-14 . There are two modes described, the first is where a balancing valve lever  142  is in the vertical position. When the balancing valve lever  142  is in the vertical position the balancing valve plunger  144  is in the open position that allows air to flow freely between air channel from ( 163  to  165 )  168 . When the balancing valve lever  142  is in the horizontal position the balancing valve plunger  144  is in the closed position that stops air from flowing freely between air channels from ( 163  to  165 )  168 . There is an automatic balancing valve plunger  147  with a spring  149  that has a preset tension and can be fine tuned by twisting the adjustment screw  151  so that for example the air pressure in one or both tires drops below 80 PSI (eighty pound per square inch) the balancing valve plunger  147  is automatically closed, thus isolating the air between the tires. 
         [0075]    Also, in the alternative preferred embodiment a inlet adapter  123  can be substituted for a more durable connection between air lines such as at flex hose  139 , compare to the inlet adapter  23 A, 23 B, 23 C in the first preferred embodiment disclosed above. 
         [0000]    
       
         
               
             
               
               
               
             
               
               
               
             
           
               
                   
               
               
                 PART LIST 
               
             
          
           
               
                   
                 Part name 
                 Part Number 
               
               
                   
                   
               
             
          
           
               
                   
                 Body 
                 1 
               
               
                   
                 Lens 
                 2 
               
               
                   
                 PC Board complete with Radio 
                 3 
               
               
                   
                 Support Contact Washer 
                 4 
               
               
                   
                 Isolation Housing 
                 5 
               
               
                   
                 Chamber Threads 
                 6 
               
               
                   
                 Membrane 
                 7 
               
               
                   
                 Membrane liner 
                 8 
               
               
                   
                 Pressure Chamber 
                 9 
               
               
                   
                 Pressure Chamber Closing Pin 
                 10 
               
               
                   
                 Pressure Chamber Contact Spring 
                 11 
               
               
                   
                 Pressure Chamber Housing Nut 
                 12 
               
               
                   
                 Batteries 
                 13 
               
               
                   
                 Battery End Cap Screw 
                 14 
               
               
                   
                 Battery Center Pin 
                 15 
               
               
                   
                 Battery Spring 
                 16 
               
               
                   
                 Battery Plastic Middle Part 
                 17 
               
               
                   
                 Test Button Threads 
                 18 
               
               
                   
                 Test Button spring 
                 19 
               
               
                   
                 Test Button Pin 
                 20 
               
               
                   
                 Test Button Housing 
                 21 
               
               
                   
                 Test Button/Valve Stem Valve Core 
                 22 
               
               
                   
                 Inlet Adapter 
                 23A, 23B, 23C 
               
               
                   
                 Valve Stem 
                 24 
               
               
                   
                 Set Screws 
                 25 
               
               
                   
                 Mounting Bolts 
                 26 
               
               
                   
                 Mounting Bracket 
                 27 
               
               
                   
                 O-Ring for Lens 
                 28 
               
               
                   
                 O-Ring for Test Button Upper 
                 29 
               
               
                   
                 O-Ring for Test Button Lower 
                 30 
               
               
                   
                 O-Ring under Inlet Adapter/Valve stem 
                 31 
               
               
                   
                 O-Ring for Chamber Pin 
                 32 
               
               
                   
                 O-Ring for Chamber Nut 
                 33 
               
               
                   
                 O-Ring for Chamber Closing Pin 
                 34 
               
               
                   
                 Bottom 
               
               
                   
                 O-Ring inside inlet adapter 
                 35 
               
               
                   
                 Connector Strip 
                 36 
               
               
                   
                 Connector Screws 
                 37 
               
               
                   
                 Bottom Sticker/Insulator 
                 38 
               
               
                   
                 Flex Hose 
                 39 
               
               
                   
                 Body 
                 101 
               
               
                   
                 Lens 
                 102 
               
               
                   
                 PC Board Complete with Radio 
                 103 
               
               
                   
                 Transmitter 
               
               
                   
                 Support Contact Washer 
                 104 
               
               
                   
                 Isolation Housing 
                 105 
               
               
                   
                 Chamber Threads 
                 106 
               
               
                   
                 Membrane 
                 107 
               
               
                   
                 Membrane liner 
                 108 
               
               
                   
                 Pressure Chamber 
                 109 
               
               
                   
                 Pressure Chamber Closing Pin 
                 110 
               
               
                   
                 Pressure Chamber Contact Spring 
                 111 
               
               
                   
                 Pressure Chamber Housing Nut 
                 112 
               
               
                   
                 Batteries 
                 113 
               
               
                   
                 Battery End Cap Screw 
                 114 
               
               
                   
                 Battery Contact Pin 
                 115 
               
               
                   
                 Battery Spring 
                 116 
               
               
                   
                 Battery Contact Pin Insulation 
                 153 
               
               
                   
                 Test Button Threads Inner 
                 118 
               
               
                   
                 Test Button Cap 
                 119 
               
               
                   
                 Test Button Pin 
                 120 
               
               
                   
                 Test Button Housing 
                 121 
               
               
                   
                 Valve Stem Valve Core 
                 122 
               
               
                   
                 Inlet Adapter 
                 123 
               
               
                   
                 Valve Stem 
                 124 
               
               
                   
                 Set Screws 
                 125 
               
               
                   
                 Mounting Bolts 
                 126 
               
               
                   
                 Mounting Bracket 
                 127 
               
               
                   
                 O-Ring for Lens 
                 128 
               
               
                   
                 O-Ring for Test Button Lower 
                 130 
               
               
                   
                 O-Ring under Inlet Adapter/Valve 
                 131 
               
               
                   
                 stem/Test Button 
               
               
                   
                 O-Ring for Chamber Pin 
                 132 
               
               
                   
                 O-Ring for Chamber Nut 
                 133 
               
               
                   
                 O-Ring for Chamber Closing Pin 
                 134 
               
               
                   
                 Bottom 
               
               
                   
                 Connector Strip 
                 136 
               
               
                   
                 Connector Screws 
                 137 
               
               
                   
                 Bottom Sticker/Insulator 
                 138 
               
               
                   
                 Flex Hose 1 
                 139 
               
               
                   
                 Pressure Chamber Housing 
                 140 
               
               
                   
                 Optional Locking Sleeve for Lens 
                 141 
               
               
                   
                 Balancing Valve Lever 
                 142 
               
               
                   
                 Balancing Valve Housing 
                 143 
               
               
                   
                 Balancing Valve Plunger 
                 144 
               
               
                   
                 Balancing Valve Plunger Seal 
                 145 
               
               
                   
                 Balancing Valve Plunger Spring 
                 146 
               
               
                   
                 Automatic Shut Off Valve Plunger 
                 147 
               
               
                   
                 Automatic Shut Off Valve Plunger Seal 
                 148 
               
               
                   
                 Automatic Shut Off Valve Spring 
                 149 
               
               
                   
                 Automatic Shut Off Valve O-ring 
                 150 
               
               
                   
                 Automatic Shut Off Valve Adjustment 
                 151 
               
               
                   
                 Screw 
               
               
                   
                 Balancing Valve Lever Pin 
                 152 
               
               
                   
                 Battery Contact Pin Insulation 
                 153 
               
               
                   
                 Air Pressure Area for Sensor 
                 160 
               
               
                   
                 O-Ring Cavity 
                 161 
               
               
                   
                 Air Pressure Area for Test Button 
                 162 
               
               
                   
                 Air pressure Area for Inlet Adapter and 
                 163 
               
               
                   
                 Valve Stem 
               
               
                   
                 Pressure Chamber 
                 164 
               
               
                   
                 Balacing Air Channel 
                 165 
               
               
                   
                 Air Channel from 163 to 162 
                 166 
               
               
                   
                 Air Channel from 162 to 160 
                 167 
               
               
                   
                 Air Channel from 163 to 165 
                 168 
               
               
                   
                 Air Channel from/to 
                 169 
               
               
                   
                   
               
             
          
         
       
     
         [0076]    It will be understood that various modifications can be made to the various embodiments of the present invention herein disclosed without departing from the spirit and scope thereof. For example, various devices are contemplated as well as various types of construction materials. Also, various modifications may be made in the configuration of the parts and their interaction. Therefore, the above description should not be construed as limiting the invention, but merely as an exemplification of preferred embodiments thereof. Those of skill in the art will envision other modifications within the scope and spirit of the present invention as defined by the claims appended hereto.