Patent Publication Number: US-6661349-B1

Title: Automatic door warning system

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to warning systems and, more particularly, to an automatic door warning system. 
     2. Description of the Related Art 
     With the increased use of public transportation in our society, there has been a corresponding increase in accidents that occur to public transportation passengers. Perhaps the most traumatic of these accidents occur when a passenger tries to board a vehicle in which the doors are closing or are about to close and thus becomes trapped. This action often results in bodily injury, trauma, physical disability or even death. Further compounding this problem is the fact that most forms of public transportation including trains, trams, trolleys, buses, subway trains, and elevators do not have an operator in close physical proximity to the door. This fact often results in an increased response time to door trapped victims increasing injuries and causing mental trauma to fellow passengers. 
     While most people would never knowingly subject themselves to direct physical harm, sometimes carelessness and a preoccupation with boarding a vehicle leads to distraction from the dangers. Often the first indication a passenger has that a vehicle is about to move is when the vehicle doors begin to close. At this point the passenger must either rapidly move out of the way, perhaps also causing injury, or rely on numerous prior art door safety devices, which may or may not be operational, to avoid injury. 
     Numerous attempts have been made to correct for the foregoing problems. For instance, U.S. Pat. No. 5,142,152, issued in the name of Boiucaner, discloses a sliding door sensor. However, a sliding door sensor made in accordance with this reference is associated with several drawbacks. For example, this invention controls the operation of sliding doors so that the doors remain in an open position until the pedestrian traffic clears the door threshold. This action would not be acceptable in many situations such as subway trains where a strict schedule must be adhered to. Moreover, this is invention does not address the problem of pre-warning the passenger that the doors are about to close. 
     Several other attempts have been made at providing an automatic door warning system. For example, U.S. Pat. Nos. 4,967,083 and U.S. Pat. No. 4,698,937, issued in the name of Kornbrekke et. al., discloses an invention which utilizes multiple sensor modules either mounted above or on the door itself. Once again, any devices made according to either of the Kornbrekke disclosures only provide for the detection of movement within the door threshold or door swing area and do not address the problem of pre-warning the passenger that the doors are about to close. 
     Finally, U.S. Pat. No. 4,821,024, issued in the name of Bayha, discloses a door operator pre-warning system and proposes solutions which involve an advance warning system. However, the preferred embodiment disclosure in the Bayha reference only addresses the advance warning problem as would be found on a residential overhead garage door and associated radio frequency link and does not address the problem as would be found on various forms of public transportation. 
     Consequently, a need has been felt for providing an apparatus and method which provides clear and distinct advance warning messages that automatic doors on various forms of public transportation are about to close. 
     SUMMARY OF THE INVENTION 
     It is therefore an object of the present invention to provide an improved automatic door warning system. 
     It is another object of the present invention to provide an automatic door warning system which allows for the visual warning of imminent automatic door closure aboard public transportation vehicles. 
     It is yet another object of the present invention to provide an automatic door warning system which allows for the audible warning of imminent automatic door closure aboard public transportation vehicles. 
     It is another object of the present invention to provide an automatic door warning system which allows for retro-fitting and ease of installation into existing public transportation vehicles. 
     It is therefore a feature of the present invention to utilize existing warning light technologies to allow for visual warning of imminent automatic door closure aboard public transportation vehicles. 
     It is another feature of the present invention to utilize existing message display technologies to allow for visual warning of imminent automatic door closure aboard public transportation vehicles. 
     It is yet another feature of the present invention to utilize existing audible warning alarm technologies to allow for audible warning of imminent automatic door closure aboard public transportation vehicles. 
     It is another feature of the present invention to utilize existing electronic voice reproduction technologies to allow for audible warning of imminent automatic door closure aboard public transportation vehicles. 
     In accordance with a preferred embodiment, an apparatus is provided for the pre-warning of passengers of public transportation vehicles that automatic doors are about to close. Comprised of a panel mounted above the automatic door, consisting of an alarm light, a message display area, and a speaker capable of producing audible alarm warnings as well as audible verbal warning messages, it is capable of warning incoming passengers that automatic door closure is imminent. When a door close signal is received from existing door control circuitry, the apparatus is activated and produces the audible and visual warning messages. After an appropriate delay period the audible and visual warning devices are deactivated and a door close signal is issued to the existing automatic doors and associated door safety guard circuitry. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The advantages and features of the present invention will become better understood with reference to the following more detailed description and claims taken in conjunction with the accompanying drawings, in which like elements are identified with like symbols, and in which: 
     FIG. 1 is a pictorial illustration of an automatic door warning system according to a preferred embodiment of the present invention; 
     FIG. 2 is a rear view of an automatic door warning system as seen along a line I—I in FIG. 1.; 
     FIG. 3 is a one-point perspective illustration of an automatic door warning system in use on a public transportation system according to a preferred embodiment of the present invention; and 
     FIG. 4 is a functional block diagram of an automatic door warning system according to a preferred embodiment of the present invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     1. Detailed Description of the FIGURES 
     Referring now to FIG. 1, an automatic door warning system  5  is shown, according to a preferred embodiment of the present invention. A front panel  10 , contains a speaker  15 , a message display area  20 , and a visual warning means  25 . The front panel  10  is provided with first circular openings  30  for installation using an attachment means  35 , such as a screw or rivet. 
     Referring to FIG. 2, the automatic door warning system  5  is shown from a rear view. A rear housing  40  is shown in direct and firm mechanical contact with the front panel  10 . A second circular opening  45  is provided in the rear housing  40  for a power and control wiring harness  47 , which will be described in greater detail below. The rear housing  40  and the front panel  10  in conjunction with the first circular openings  30  provide for recessed mounting of the automatic door warning system  5  in a manner that is well known to those skilled in the art. 
     FIG. 3 shows the automatic door warning system  5  installed on a public transportation vehicle  50 . The automatic door warning system  5  is installed directly above and in close physical proximity to an automatic door  55  of the public transportation vehicle  50 . The rear housing  40  (shown in FIG. 2) and the power and control wiring  47  (shown in FIG. 2) are located in a recessed and concealed manner within the public transportation vehicle  50 . 
     FIG. 4 is a functional block diagram of an automatic door warning system according to a preferred embodiment of the present invention. A door close is signal  60  is received from existing door control circuitry and an electrical signal  62  enables an automatic door warning circuit  64 . An instantaneous output signal  68  and a delay output signal  70  is generated from the automatic door warning circuit  64 . The delay output signal  70  energizes a door actuator  72  which is part of the existing automatic door mechanism. The instantaneous output signal  68  energizes an audible/verbal alarm module  75 , the message display area  20  and the visual warning means  25 . The audible/verbal alarm module  75  produces audible output in the speaker  15  through an analog waveform  78 . The electrical signal  62  and the delay output signal  70  is contained within the power and control wiring harness  47  (shown in FIG.  2 ). 
     The message display area  20  is preferably an electronic display panel capable of being programmed with different messages, but may also consist of one message capable of being backlit at the appropriate time. The visual warning means  25  is preferably a flashing red strobe light, but may consist of many other different visual warning indicators familiar to those skilled in the art. The audible/verbal alarm module  75  is preferably an electronic voice storage module capable of being programmed with different messages and/or warning sounds, but may also consist of a mechanical tape playback unit or an audible alarm module only. 
     2. Operation of the Preferred Embodiment 
     In operation, the present invention provides an additional level of accident avoidance to the everyday user of public transportation in a clear and concise manner without any input or training on the part of the user. The operation of the present invention with its preferred embodiment can best be described in conjunction with the functional block diagram of an automatic door warning system as shown in FIG.  4 . 
     Referring to FIG. 4, the door close signal  60  is received from existing door control circuitry, which is either an automatic signal as would be found on passenger elevators or an operator produced signal as would be found on transit buses. The door close signal  60 , is utilized by automatic door warning circuit  64  to produce either the instantaneous output signal  68  or the delay output signal  70 . The instantaneous output signal  68  is utilized to produce both audible and visual warnings that automatic door closure is imminent. These warnings are produced by the audible/verbal alarm module  75  and its associated speaker  15 , the message display area  20  and the visual warning means  25 . The audible/verbal alarm module  75  produces audible voice messages to warn of imminent door closure, alarm warning sounds to warn of imminent door closure, or a combination of both. After a suitable period of time on the order of three to five seconds, the audible and visual warnings cease and the delay output signal  70  energizes a door actuator  72  which is part of the existing automatic door mechanism. The automatic door warning system is intended as an additional safety element for public transportation passengers and would supplement any existing door safety systems such as limit switches, electric photocells, infra-red motion detectors and the like which would remain in place and operational. 
     The foregoing description of the preferred embodiment of the present invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the present invention to the precise form disclosed, and obviously many modifications and variations are possible in light of the above teachings. 
     The preferred embodiment was chosen and described in order to best explain the principles of the present invention and its practical application to those persons skilled in the art, and thereby to enable those persons skilled in the art to best utilize the present invention in various embodiments and with various modifications as are suited to the particular use contemplated. It is intended that the scope of the present invention be broadly defined by the claims which follow.