Patent Publication Number: US-6222461-B1

Title: Emergency warning system for vehicles

Description:
BACKGROUND AND OBJECTS OF THE INVENTION 
     The present invention is generally related to the emergency warning system arts and, in particular, to a system and method to warn a motorist of an approaching train or locomotive. The system described is also useful to warn motorists of an approaching or nearby ambulance, fire truck or police vehicle. 
     As is known in the art, the number of railway crossing collisions, fatalities and injuries annually in the United States is quite startling. 
     Based upon an NBC News study for 1999, there are 160,000 public highway and rail intersections in the U.S. Of this number, 60 percent or over 96,000 lack warning gates and lights. There were over 3400 train-vehicle collisions in 1999 which resulted in 399 deaths and 1,360 persons injured. 
     As is also known in the art, the number of collisions between vehicles and ambulances, fire trucks and police cars is also very high and results in many deaths and injuries annually. 
     Accordingly, it is an object of the present invention to set forth an efficient on-board warning system to alert a vehicle driver of a potentially dangerous condition such as the approach of a train, locomotive or emergency vehicle. 
     It is also an object of the invention to demonstrate a warning system for the above purposes which may be economically mass-produced and installed for widespread commercial appeal. 
     These and other objects and advantages of the invention will be apparent to those of skill in the art from the description which follows. 
     PRIOR ART PATENTS AND DESIGNS 
     U.S. Pat. No. 5,729,213 teaches the use of a train warning system which uses a receiver/transmitter mounted to the crossbucks at a railroad crossing. While effective for the purposes described, this patent would require costly installations at each railroad crossing to achieve the desired results. 
     The present invention teaches a more efficient train warning system and also provides an on-board unit to warn of other potential hazards such as emergency or police vehicles. 
     The present invention is thus believed to be clearly patentable over all known prior art systems. 
     SUMMARY OF THE INVENTION 
     A locomotive is equipped with a transmitter device which sends a focused signal at a particular radio or radar frequency which is dedicated only to trains. 
     An on-board, in-vehicle receiver unit responds to this train frequency, Frequency A, by activating visible, audible and/or vibratory warning signals. 
     The in-vehicle unit is also designed to respond with warning signals when other frequencies(B, C, or D) are detected. These other frequencies could be dedicated to ambulance, fire or police units respectively. 
     The receiver may be portable for easy placement in any vehicle. While especially useful for buses and trucks, the overall design has utility in combination with any automotive vehicle and may be factory installed in new vehicles or used in an after-market fashion. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING FIGURES 
     FIG. 1 shows an overhead schematic of a train approaching a railroad crossing an indicates a focused signal being sent to a vehicle on a roadway. 
     FIG. 2 is a schematic view of the in-vehicle receiver which receives the train-dedicated Frequency A and is also capable of receiving other Frequencies B, C and D which may be dedicated to ambulance, fire and police units respectively. 
     FIG. 3 is an overhead schematic view of an ambulance, fire or police unit and indicates how the present invention may be effectively utilized in combination with such emergency vehicles. 
    
    
     DESCRIPTION OF A PREFERRED EMBODIMENT 
     Referring to the drawing figures, FIG. 1 shows a locomotive  10  on railway track  11  approaching a railway intersection  22 . A vehicle  20 , such as a bus or truck, is on roadway  21  and is also approaching the railway intersection  22 . 
     When the locomotive  10  is in forward motion, a motion sensor  16  serves to activate a low-power radio frequency transmitter  15  which transmits at a particular dedicated Frequency A as indicated at numeral  18 . 
     Vehicle  20  is equipped with an on-board in-vehicle receiver unit  25  which, when Frequency A is detected, serves to activate a warning light  26   a  on the dashboard of vehicle  20 . After a brief time delay, indicated at numeral  27   a , an audible warning is given as indicated at numeral  28   a . See drawing FIG.  2 . 
     The audible warning means  28   a  would preferably be a verbal caution such as “Locomotive Approaching” which is given several times. 
     The locomotive radio transmitter system  15  may also be equipped with a manual over-ride switch  17  in the event the locomotive operator wishes to activate signal  18  to warn that the locomotive is about to move forward. 
     The rear of the locomotive or the last car on a train  10   a  may be similarly equipped with a low-power radio frequency transmitter  15   a , motion sensor  16   a  and manual over-ride  17   a.    
     A signal  19  at the train-dedicated Frequency A is thus generated if the locomotive/train is moving in a reverse direction. It serves to warn any vehicles which may be approaching on a roadway behind the locomotive/train. 
     As further indicated in FIG. 2, the in-vehicle receiver  25  may also sense other dedicated frequencies such as Frequency B, Frequency C and Frequency D. 
     When Frequency B is received, for example, a warning light  26   b  which reads “AMBULANCE” is flashed on the dashboard of vehicle  20 . 
     After a brief time delay, indicated at numeral  27   b , an audible warning is given at numeral  28   b  which may verbally state “Ambulance In Area” several times. 
     The in-vehicle receiver  25  may also sense a Frequency C dedicated to fire truck vehicles and show a “FIRE TRUCK” light as indicated at numeral  26   c  and verbally state “Fire Truck” as indicated at numeral  28   c.    
     A fourth frequency(Frequency D) may also be sensed by the receiver  25 . Such could, for example, be dedicated to police vehicles and give a “POLICE” warning sign and verbal warning as indicated a numerals  26   d  and  28   d.    
     FIG. 3 is an overhead schematic view of an emergency vehicle  40  such as an ambulance, fire truck or police vehicle. A low-power radio frequency transmitter  45  is shown as generating a signal  48 . 
     The transmitter  45  may be activated by the siren or flashing light circuitry  46  of the vehicle or manually activated by switch  47 . 
     In FIG. 3, the emergency vehicle  40  is also shown to have a rear transmitter  45   a  which generates a signal  49 . Such signal is activated by a switch  47   a  at the choice of the vehicle operator. 
     For example, if a police or ambulance vehicle were at the side of a roadway to assist in an emergency, the rear warning signal  49  could be activated so that motorists approaching the scene could be alerted. 
     Such would be very helpful since many police and emergency personnel are injured or killed at the side of a roadway while rendering emergency assistance. 
     The display and verbal warning circuitry described are of types known in the electrical arts but which have not been used in the particular combination described herein. 
     While a particular system has been shown and described, it is intended in this specification to broadly cover all equivalent systems and methods which would reasonably occur to those of skill in the art. 
     Among the many advantages of the present invention, the overall system and method provides a clear warning to motorists of potentially hazardous conditions. 
     Injuries to ambulance, police and fire personnel will be reduced. The State of Indiana, for example, has recently passed legislation requiring motorists to move to a lane away from a roadside police vehicle in response to fatalities of State Troopers. The present system would aid in complying with this and other recently enacted laws. 
     It is contemplated that the system would be legislatively required for certain vehicles such as buses and hazardous material cargo trucks where any accident may be one of disastrous proportions. 
     The system described is economical to manufacture and may be designed as a portable add-on unit for easy addition to the dash or display area of any vehicle.