Abstract:
An accessible pedestrian signal system to assist visually impaired persons to cross a signal controlled intersection. The signal system has a push button which is pressed by the pedestrian. Circuitry is provided to vibrate the push button when the signal system is programmed to send a signal that it is time to cross the intersection. Preferably, the push button is mounted on a flexible diaphragm and a vibrating movement is transmitted to the inner surface of the diaphragm when it is desired to vibrate the push button. Preferably, the pressing of the button flexes a piezo-electric member which has an output to the circuitry of the signal system.

Description:
BACKGROUND OF THE INVENTION 
     The field of the invention is pedestrian signal indicators and the invention relates more particularly to pedestrian signal indicators which are provided with a tactile output so that a person of limited vision can determine when it is time to cross the signal controlled intersection. 
     The most metropolitan areas in the United States have intersections controlled by traffic lights. These intersections are also equipped with walk/don&#39;t walk signals to make it safe for pedestrians to cross the street. Such walk/don&#39;t walk signals are invariably equipped to provide a visual walk/don&#39;t walk signal. For persons of limited vision, such lighted signals are often of no value. For this reason various pedestrian signal systems have been developed which provide an audible or tactile signal that persons of impaired vision can use. 
     One such system is shown in U.S. Pat. No. 2,461,448. A button  14  either projects or is flush with the casing, depending on whether the traffic lights are red or green. This provides a tactile indication to a blind person as to whether the light is red or green. Two alternate versions show a pair of push buttons so that a blind person feeling for a signal can always obtain a positive indication and avoid the danger of feeling the top of the casing and assuming that the button is depressed, whereas he may not be feeling the correct spot. A third version causes the button to extend if the power goes out, thereby indicating an unsafe condition. An audible buzzer is also shown. 
     U.S. Pat. No. 4,590,474 shows a street crossing signal which includes a pair of handrails which are oriented in the direction of the crossing so that the blind person can orient himself in a desired direction for crossing the street. A vibrator is included in the handrail so, when the lights at the crosswalk are in a designation inviting pedestrian crossing, the vibration means in the handrail is activated. 
     In U.S. Pat. No. 4,851,836, the pedestrian crossing system includes a tactile tone generator. The tone is generated in an area located immediately above the push button switch. U.S. Pat. No. 5,103,223 utilizes a street crossing signal which includes means for vibrating a direction arrow extending through the panel  23 . The depressing of a push button  24  initiates the crossing signal sequence. 
     While the above-described systems assist a visually impaired pedestrian, further simplification, which makes it easier for the pedestrian to become informed when the walk indicator is active, is needed. 
     BRIEF SUMMARY OF THE INVENTION 
     It is the object of the present invention to provide an accessible signal system to assist visually impaired persons to cross a signal controlled intersection which system is intuitively simple to use and highly reliable and provides information currently not provided by other devices on the market. 
     The present invention is for an accessible pedestrian signal system which includes a push button station, which includes means for generating a tactile signal and also audible information. The system has a push button frame mounted at or near each crosswalk at the intersection. A flexible diaphragm is mounted on the frame and supports a push button which is used to initiate a pedestrian crossing signaling sequence. Means are provided for vibrating the push button so that a pedestrian may receive a tactile response while touching the push button to convey a cross/don&#39;t cross indication. Preferably, the pressing of the push button flexes a piezo-electric switch to transmit a signal to the control circuit for the intersection. Also preferably, a coil causes a plunger to vibrate and the movement of the plunger is transmitted to the push button. Also preferably, the push button is mounted on a flexible diaphragm over an opening in the frame. The diaphragm allows limited movement of the button and a backing plate holds the diaphragm and the button together. The backing plate is designed to contact the frame as a hand stop when the button is impacted, thus protecting the internal mechanism of the device. The use of the diaphragm and the limited movement provides a push button assembly with a high degree of vandal resistance yet allows the button to both move and vibrate to indicate a walk cycle. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a front view of the accessible pedestrian signal system of the present invention. 
     FIG. 2 is an exploded perspective view thereof. 
     FIG. 3 is a cross-sectional view thereof. 
     FIG. 4 is an enlarged cross-sectional view of the push button portion of the system of FIG.  1 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The accessible pedestrian signal system of the present invention is shown in front view in FIG.  1  and indicated generally by reference character  10 . The system has a push button station indicated generally by reference character  11  which is mounted on a push button frame  12 . A pedestrian sign or panel  13  provides notice that the intersection is controlled by a pedestrian crossing signal system. Panel  13  also provides a protective cover for an outdoor speaker  14  shown in FIG.  2 . Speaker  14  can provide a locating tone as well as audible information about the intersection as well as the status of the walk or don&#39;t walk signals. 
     Accessible pedestrian signal system  10  includes a push button  15  which is a circular aluminum piece with a chamfered edge  16  and a raised arrow  17 . A central depression  18  assists the user to hold his finger in the middle of the push button  15  to await a tactile signal. Push button  15  is mounted on a flexible diaphragm  19 . An aluminum ring  20  holds the flexible diaphragm  19  and, thus, the push button  15  to frame  12 . Flexible lot diaphragm  19  is shown in FIG.  2  and can be seen to have four tabs  21  which permit the push button  15  to be oriented in four different positions, depending upon the location of the crosswalk. Flexible diaphragm  19  is preferably fabricated from stainless steel having a thickness of about 0.008 inches. This provides a combination of flexibility and strength which permits the easy pushing of push button  15 , while still providing the vandal resistant closure to the components in opening  29 . The provision of various steps in opening  29  provide an especially durable land maintenance-free assembly. 
     Once push button  15  is depressed, indicator light  22  turns on to inform the non-visually impaired pedestrian that the button has been pushed. A control unit  23  is diagrammatically indicated and is electronically connected to the accessible pedestrian signal system  10  in a conventional manner. Once push button  15  is depressed and the presence of a pedestrian call is signaled to control unit  23 , the control unit can initiate a voice-on-location option. The control unit can provide that if the push button  15  is held for an extended period of time, such as at least about three seconds, a message will play announcing the intersection and the street being crossed. In this way, a person with impaired vision can be assured that he or she is in the correct location. Also, by delaying the initiation of the message for three seconds or longer, the message announcing location will not be aimlessly repeated. The system  10  can also include a locating tone to assist a blind person to find the push button. The control unit can provide various jumper settings for different verbal messages or walk sounds. The unit is preferably equipped with means for raising the volume of the audible sounds, depending upon traffic noise. The message process operates by inputting information in electronic circuitry capable of emitting an audible output in the pedestrian signal system. The audible output includes announcement of the particular intersection at which the pedestrian signal system is located. 
     When the push button is pressed it will provide a timed output. A timing circuit is provided to detect the presence of said timed output and the timing circuit. A signal is transmitted to said electronic circuitry capable of emitting an audible output in the pedestrian signal system providing the announcement of the particular intersection at which the pedestrian signal system is located when said push button is depressed for at least about three seconds. The timing circuit does not provide an announcement when the push button is depressed for less than about three seconds. 
     Once push button  15  has been depressed, the walk/don&#39;t walk information cycle is initiated. A visually impaired person would maintain his finger on push button  15  and when the “walk” time has arrived, the push button  15  will vibrate, telling the pedestrian that the walk signal is on. The details of how this vibration is accomplished are set forth below. 
     The individual parts used in accessible pedestrian signal system  10  are shown in exploded perspective view in FIG.  2 . Frame  12  has a circular push button portion which includes a circular groove  23  which holds an o-ring  24  shown in FIG.  4 . O-ring  24  serves the following functions. First, it rests against the inwardly facing surface  25  of flexible diaphragm  19  and provides a water-proof intersection between the diaphragm and the frame  12 . Also, as shown best in FIG. 4, it raises the flexible diaphragm  19  above support surface  26 . Thus, when push button  15  is depressed, flexible diaphragm  19  moves inwardly slightly as viewed in FIG. 4, but the inward movement is limited by the contact between a rigid (e.g. Nylon or aluminum) back plate  30  held against undersurface  25  of flexible diaphragm  19  which bottoms onto the upper surface of floor  31 . Preferably, the outer peripheral edge  27  of push button  15  extends past the edge  28  of opening or recess  29  for strength and vandal protection. As shown best in FIG. 4, back plate  30  is held by screws through diaphragm  19  to push button  15 . Back plate  30  has an outwardly facing surface which contacts the inwardly facing surface  25  of diaphragm  19 . Back plate  30  also has an inwardly facing surface  32 . Inwardly facing surface  32  is contacted by a vibration transmitting pin  33 . Pin  33  is guided by bushing  34  supported in guide plate  35 . Guide plate  35  is secured on step  36  by screws  37 . Back plate  30  is preferably fabricated from machined aluminum that is hard nickel plated or hard anodized. Alternately, it may be fabricated from Nylon or other impact resistant polymer. With this construction it is almost completely impervious to damage by impact. 
     The push button  15  is caused to vibrate by a solenoid. The solenoid consists of a coil  38 , and a steel enclosure consisting of a steel top plate  35 , a steel ring  57 , and a steel bottom plate  43 . The coil is positioned inside the steel enclosure. The coil surrounds a ferro-magnetic vibrating member  39 . The solenoid assembly rests on step  44  (FIG. 4) of inside opening  29 . The steel enclosure around the coil forms an efficient magnetic path for the field produced by the coil which, when energized, causes the vibrating member  39  to move. 
     Pin  33  is adhered to vibrating member  39  so that it moves with vibrating member  39  and transmits the vibration to the inwardly facing side of back plate  30  and, thus, to push button  15 . Vibrating member  39  also has a second recess to which rubber pin  40  is adhered. Rubber pin  40  transmits the depressed movement of push button  15  to piezo-electric element  42 . The piezo-electric element  42  is connected via two wires to the switch circuit on OCB assembly  59  located in cavity  58  on frame  12 . Two 5 position terminal blocks on PCB assembly  59  facilitate connections via eight wires to control unit  23  to initiate the various functions involved in the operation of the signal. The control unit  23  can be located either in the pedestrian signal corresponding to the push button station, or in the intersection control cabinet. Piezo-electric element  42  rests on step  45  which is just above the bottom  46  of opening  29 . This base provides sufficient room for the slight deflexion of piezo-electric element  42 . 
     Returning to FIG. 2, it can also be seen that frame  12  includes a speaker recess  47 . A wall has an upper surface  48  which supports speaker mounting plate  49 . Speaker  14  is screwed into the tapped holes in plate  49 . 
     A pair of U-shaped perforated stainless steel covers are looped over squared posts  51  and help protect the speaker against vandalism while still permitting sound to traverse the covers. An upper compartment  52  and lower compartment  53  provide access to mounting holes in frame  12  for mounting the unit to a pole or surface. Compartment  53  also provides for wires to route from the speaker to terminal blocks on switch circuit PCB assembly  59  located in cavity  58 . 
     The frame is preferably cast from aluminum and the front panel  13  and the back panel  54  are secured to the frame by vandal-resistant fasteners. 
     While a piezo-electric element has been shown and is the preferred method of initiating a signal, other switch means can, of course, be used. Because of the presence of a speaker, numerous audible instructions and information can be heard from the unit. The combination of the activating push button with the tactile vibration simplifies the construction and permits a compact and attractive unit. 
     The present embodiments of this invention are thus to be considered in all respects as illustrative and not restrictive; the scope of the invention being indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are intended to be embraced therein.