Abstract:
A vehicle door opening warning system for a car includes a sensor for sensing the approaching of another car from behind when a person is opening the car door, a car door-opening control unit stops the car door from being opened when the sensor senses the approaching of the other car from behind, and a warning light and a buzzer are activated to give a visual warning signal and an audio warning signal when the car door is being opened.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to vehicle safety and pre-warning technology and more particularly, to a vehicle door opening warning system, which gives audio and visual warning signals when the car door is being opened, and limits the opening angle of the car door when a sensor at the car door senses the approaching of a car from behind. 
     2. Description of the Related Art 
     Following fast development of technology, many vehicle security and safety related products have been continuously created to enhance driving safety. A vehicle may be equipped with rearview monitor system for enabling the driver to view any vehicle or object approaching from behind. However, this rearview monitor system has its rearview dead angle. When a car driver or a person in a car is opening a car door of the car, the driver or person may be unaware of a car or moving object from behind, causing an accident. Even an experienced car driver may be unable to control any person sharing the car from opening the car door upon a sudden approaching of car or object from behind. Further, a vehicle may be equipped with a variety of signal lights, however, no warning light is designed to give a visual pre-warning signal when a car door is going to be opened. 
     SUMMARY OF THE INVENTION 
     The present invention has been accomplished under the circumstances in view. It is one object of the present invention to provide a vehicle door opening warning system, which gives audio and visual warning signals when the car door is being opened. It is another object of the present invention to provide a vehicle door opening warning system, which limits the opening angle of the car door when a sensor at the car door senses the approaching of a car from behind. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a circuit block diagram of a vehicle door opening warning system in accordance with the present invention. 
         FIG. 2  is a schematic drawing of a part of the present invention, illustrating the related component parts of the vehicle door opening warning system installed in a car door of a car. 
         FIG. 3  is schematic drawing a part of the present invention, illustrating one normally closed contact switch and one normally opened contact switch of the vehicle door opening warning system mounted in the car door frame of the car. 
         FIG. 4  is a schematic drawing of a part of the present invention, illustrating the positioning of the car door-opening control unit of the vehicle door opening warning system in the car door of the car. 
         FIG. 5  is an elevational view of the car door-opening control unit of the vehicle door opening warning system in accordance with the present invention. 
         FIG. 6  is a schematic side view of a part of the present invention, illustrating the stop bar moved to the first position. 
         FIG. 7  is a schematic side view of a part of the present invention, illustrating the stop bar moved to the second position. 
         FIG. 8  is a schematic side view of a part of the present invention, illustrating the stop bar moved to the third position. 
         FIG. 9  is a schematic side view of a part of the present invention, illustrating the handle of the car door in the non-operative position and the related normally closed contact switch in the closed-circuit position. 
         FIG. 10  corresponds to  FIG. 9 , illustrating the handle of the car door biased and the related normally closed contact switch in the open-circuit position. 
         FIG. 11  is a schematic side view of the car door-opening control unit of the vehicle door opening warning system in accordance with the present invention, illustrating the through hole of the linkage in alignment with the photo sensor. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to  FIGS. 1˜5 , a vehicle door opening warning system in accordance with the present invention is shown comprising a car door-opening control unit  1  installed in a linkage  51  of a car that extends out of a car door frame that is movable to open/close a car door  5  that is hinged to the car door frame, a normally closed contact switch  2  and a normally opened contact switch  21  mounted in the car door frame of the car, an approaching object sensor  3  mounted in the free end of the car door  5 , one or a series of warning lights  31  mounted in the free end of the car door  5 , a buzzer  32 , a relay  33 , a battery  34 , and a controller  4 . 
     The car door-opening control unit  1  comprises a holder frame  11  having a through hole  12  for the passing of the linkage  51 , an electromagnetic valve (solenoid)  14  mounted at a bottom side inside the holder frame  11  and operable to move a reciprocating rod  141  up and down, a stop bar  13  pivotally mounted in the holder frame  11  and having the free end  131  thereof supported on the reciprocating rod  141  and movable with the reciprocating rod  141  to one of a first position where the free end  131  of the stop bar  13  is stopped at a first stop portion  511  of the linkage  51  to prohibit the car door  5  from being opened, a second position where the free end  131  of the stop bar  13  is stopped at a second stop portion  512  of the linkage  51  to prohibit the car door  5  from being opened, and a third position where the free end  131  of the stop bar  13  is released from the linkage  51  for allowing the car door  5  to be opened. When a person is opening the car door  5 , the normally closed contact switch  2  is released from the pressure of the car door  5  for allowing the battery power supply of the battery  34  to be conducted through normally closed contact switches  162  and  53  to the controller  4  to operate the approaching object sensor  3  and the warning lights  31 , causing the approaching object sensor  3  to sense any approaching object (car) and the warning lights  31  to give a visual warning signal (to give off light or to flash). If the approaching object sensor  3  senses the approaching of an external object (car) at this time, it gives a signal to the controller  4 , causing the controller  4  to drive the buzzer  32  in giving an audio warning signal and to switch on the relay  33  in starting the electromagnetic valve  14  to that the electromagnetic valve  14  extends out the reciprocating rod  141  to lift the free end  131  of the stop bar  13  to the first position where the free end  131  of the stop bar  13  is stopped at the first stop portion  511  of the linkage  51  to prohibit the car door  5  from being opened (see  FIG. 6 ). After the external object passed and the approaching object sensor  3  senses no signal, the controller  4  receives no signal from the approaching object sensor  3  and switches off the relay  33  to cut off the battery power supply from the electromagnetic valve  14 , allowing the free end  131  of the stop bar  13  to be lowered with the reciprocating rod  141  to the third position for allowing the car door  5  to be opened. If the approaching object sensor  3  senses a signal again at this time, the controller  4  switches on the relay  33  to start the electromagnetic valve  14  again, enabling the free end  131  of the stop bar  13  to be lifted by the reciprocating rod  141  to the second position where the free end  131  of the stop bar  13  is stopped at a second stop portion  512  of the linkage  51  to prohibit the car door  5  from being opened (see  FIG. 7 ). 
     Further, the normally closed contact switch  53  is mounted in the car door  5  at an inner side relative to the handle  52  of the car door  5 . When the handle  52  is operated to open the car door  5 , a connected rod  521  of the handle  52  is forced to open the normally closed contact switch  53 , causing the controller  4  to switch off the approaching object sensor  3  and the warning lights  31  (see  FIG. 1 ,  FIG. 9  and  FIG. 10 ). When the car door  5  is closed, the normally opened contact switch  21  conducts the battery power supply to the controller  4 , driving the approaching object sensor  3  into the standby mode for further sensing operation after a next opening action of the car door  5 . 
     Further, a manual push button  16  is disposed at one side relative to the car door-opening control unit  1  operable to move a link  161  that is connected to the reciprocating rod  141  of the electromagnetic valve  14  and to open the normally closed contact switch  162 . When the manual push button  16  is pressed by a person in an emergency or car crash, the normally closed contact switch  162  is opened to cut off the battery power supply from the car door-opening control unit  1 , and the reciprocating rod  141  of the electromagnetic valve  14  is moved to lower the stop bar  13  from the linkage  51 , allowing the car door  5  to be opened by a person (see  FIG. 8 ). 
     The car door-opening control unit  1  further comprises a photo sensor  15 , which gives a signal to the controller  4  to switch off the sensor  3  when the linkage  51  is moved to open the car door  5  and to aim a through hole  513  thereof at the photo sensor  15  (see  FIG. 11 ). 
     In conclusion, the invention provides a vehicle door opening warning system, which controls the opening angle of the car door to prevent a car crash and gives audio and visual warning signals when the car door is being opened. 
     Although a particular embodiment of the invention has been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be limited except as by the appended claims.