Abstract:
A bus safety system for reminding a driver to search a bus for passengers comprising a receiver module incorporating a microprocessor, the receiver module programmed to control an alarm based on at least one selected time interval following activation; a wire harness attachable between the receiver module and an electrical system of the bus; and a transmitter incorporating an alarm deactivation switch and adapted to send RF signals; wherein the receiver module is adapted to receive the RF signals from the transmitter.

Description:
[0001]    This application is a continuation-in-part of application Ser. No. 09/877,393 filed Jun. 8, 2001. 
     
    
     
         [0002]    This invention relates to a safety device for buses, and specifically, to a child safety device particularly applicable to school buses.  
         BACKGROUND OF THE INVENTION  
         [0003]    There are several alarm systems currently available for ensuring that no children are left on a bus after the last scheduled stop. These systems require the driver to walk to the back of the bus to deactivate an alarm that will otherwise sound after a predetermined interval. In some cases, the driver can perform the check and deactivate the alarm while the ignition is on, for example, after the last stop but before returning to the bus yard. Examples of such alarm systems may be found in U.S. Pat. Nos. 6,107,915; 5,874,891; 5,243,323 and 5,128,651.  
           [0004]    In each case, the alarm system is connected to the existing electrical system in the bus, and alarm components at the front and rear of the bus are hard wired. There remains a need for a safety alarm system that is simpler and less costly to install, and that provides bus drivers with greater flexibility with respect to the use and operation of the alarm system, but which does not permit the system to be circumvented.  
         BRIEF SUMMARY OF THE INVENTION  
         [0005]    This invention provides a microprocessor-controlled wireless system for ensuring that the bus driver checks the bus for children after the last stop, and after the ignition has been turned off. In one embodiment, the system includes a self-contained battery operated transmitter located at the rear of the bus, and a self-contained receiver module located at the front of the bus. Utilization of radio frequency (RF) signals eliminates the need for hard wiring between the receiver module and the transmitter.  
           [0006]    The receiver module at the front of the bus includes a microprocessor and a “plug-in” wire harness that is easily connected to the bus electrical system. In its simplest form, the receiver module need be connected only to the bus battery positive cable or terminal, the chassis ground, and the ignition “on” switch positive wire. Built-in circuitry is provided, however, for pre-alarm warning, pre-alarm and full alarm features, that may include the bus horn, parking lights, optional siren or any combination thereof. An optional plug-in LED provides visual indication of the alarm status. Momentary and service related override switches may also be included.  
           [0007]    The battery operated transmitter located at the rear of the bus includes a deactivation button and a 9-volt battery compartment, but in an alternative arrangement, the transmitter may be powered by the bus battery.  
           [0008]    In an exemplary configuration, when the driver effects a “triggering event,” e.g., when he turns the ignition off, the receiver module is programmed to beep intermittently for a predetermined time period (a pre-alarm warning). Thus, the driver has a relatively short but sufficient time to inspect the bus. During this initial time period, the transmitter is active but ignored by the receiver, so that it will not stop the further alarm sequence even if the deactivation button is pushed, i.e., the full initial time period must expire before the alarm deactivation button on the transmitter is effective.  
           [0009]    After the first or initial time period, the intermittent beeping in the receiver module becomes a continuous beep (i.e., a pre-alarm) to remind the driver that he/she has an additional period of time (preferably shorter than the first period) to finish checking the bus and to press the deactivation button on the transmitter to thereby preclude a full alarm from sounding. The full alarm will sound after these two time intervals (from ignition shut-off) if not deactivated.  
           [0010]    The receiver module also includes two built-in relays that both begin to cycle after the second time period expires. One stops the horn sound after, for example, 3 minutes in the full alarm state, while the other continues the full alarm indefinitely, with the additional alarm elements, i.e., lights and/or siren.  
           [0011]    The system may be deactivated at any time by turning the ignition key to the ignition “on” position, or the ignition “accessory” position; by using the optional momentary override switch; or by pressing the transmitter deactivation button after the initial pre-alarm warning. Additional installation details are provided further herein.  
           [0012]    The invention described herein is not limited to wireless RF arrangements. The programmable receiver module and the specific pre-alarm and alarm sequences may be implemented with other wireless systems including, for example, infrared, acoustic, or with hard wired systems.  
           [0013]    In addition, a motion sensor may be incorporated into the alarm system. This serves as an effective “double check” on the driver&#39;s search of the bus, particularly if the driver is careless in the search, or if the driver simply deactivates the switch without searching at all. The motion sensor would include a built-in time delay, so as to leave sufficient time for the driver to leave the bus. Another delay could also be incorporated so as to delay the alarm after motion is detected, thus allowing a driver time to deactivate the system upon re-entering the bus.  
           [0014]    This additional feature also provides a measure of deterrence to vandalism, and may be supplemented by vibration and/or glass break detectors.  
           [0015]    Accordingly, in one aspect, the invention relates to a bus comprising a chassis; an electrical system including a horn and parking lights; an ignition switch; and a safety system for reminding a driver to search the bus for passengers, the safety system comprising a receiver module incorporating a microprocessor, the receiver module programmed to control an alarm having one or more alarm components including a motion sensor; means for electrically connecting the receiver module and the electrical system of the bus such that the alarm is activated upon a triggering event in the electrical system; and a transmitter incorporating an alarm deactivation switch and adapted to send signals to the receiver module to deactivate the alarm.  
           [0016]    In another aspect, the invention relates to a bus safety system for reminding a driver to search a bus for passengers comprising an alarm including one or more alarm components; a receiver module incorporating a microprocessor, the receiver module programmed to control the one or more alarm components based on at least one selected time interval following activation; means for establishing electrical connection between the receiver module and an electrical system of the bus; a transmitter located remote from the receiver module, incorporating an alarm deactivation switch and adapted to communicate with the receiver module; and a motion sensor operatively connected to the receiver module and adapted to activate the one or more alarm components upon detection of motion in the bus.  
           [0017]    In still another aspect, the invention relates to a bus comprising a chassis; an electrical system including an ignition switch; and a safety system for reminding a driver to search the bus for passengers, the safety system comprising a receiver module incorporating a microprocessor, the receiver module programmed to control an alarm having one or more alarm components; means for electrically connecting the receiver module and the electrical system of the bus such that the alarm is activated upon a triggering event in the electric system; and a transmitter incorporating an alarm deactivation switch and adapted to send infrared, acoustic or RF signals to the receiver module to deactivate the alarm.  
           [0018]    Objects and advantages not expressly mentioned above will become apparent from the detailed description that follows. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0019]    [0019]FIG. 1 is a simplified perspective of a bus chassis, indicating the location of the wireless RF components of the invention; and  
         [0020]    [0020]FIG. 2 is a simplified wiring diagram, illustrating the receiver module wiring harness connections to the bus electrical system. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0021]    With reference to FIGS. 1 and 2, a typical bus  10  includes a chassis generally indicated at  12 . A receiver module  14  in accordance with the invention is shown at the forward end of the chassis, in proximity to the bus driver  18 , e.g., on the dashboard. A transmitter  16  is located at the rear of the bus, preferably in an out-of-the-way position, relatively inaccessible to passengers in the bus. The receiver module  14  is intended to work with the existing wiring of the bus, and to receive wireless radio frequency (RF), acoustic or infrared signals from the transmitter  16 . Thus, no hard wiring is required between the receiver/controller and the transmitter. This arrangement is particularly recited for retrofit applications, but hard wiring may be utilized particularly if installed during production of the bus.  
         [0022]    The transmitter  16  is a self-contained battery operated transmitter with a single one-button transmitter switch  20  (representing the deactivation button). The transmitter is powered by a single nine volt battery  22  with an approximate three year life, but the battery is located in an easily accessible compartment for replacement. Alternatively, the transmitter may be wired so as to be powered by the bus battery  23  as shown in phantom in FIG. 2.  
         [0023]    As indicated above, the transmitter  16  is preferably mounted inside the bus at the rear end thereof, in an up and out of the way location so as not to invite access by bus passengers. The transmitter may be attached by one or more screws (or other suitable fasteners) to a desired mounting location, and preferably incorporates a cover that permits access to the battery compartment.  
         [0024]    The receiver module  14  is located at the driver end of the bus, preferably on or under the dashboard, keeping in mind the need to make a connection to the ignition switch, power supply and relay control panel already existing in the bus.  
         [0025]    The receiver module  14  is also preferably mounted using one or more screws or other suitable fasteners. It is important that the antenna wire (not shown) of the receiver module  14  not be covered by any metal bus chassis parts so as not to impede its range.  
         [0026]    The receiver module  14  incorporates a microprocessor  24  (or equivalent circuitry) programmed to sequence the alarm conditions as further described herein. A main wiring harness  26 , with a plug-in connector  28  adapted for connection with the receiver module, enables a series of electrical inputs to, and outputs from, the receiver module  14 , and is used to connect the receiver module to the bus electrical system without modification of the latter. On the input side, wire  30  is connected to the twelve volt bus battery and wire  32  is connected to a chassis ground. Wire  34  is connected to the main ignition switch wire, while wire  36  is connected to the ignition switch “accessory” position wire. An optional momentary override switch  38  may be mounted at a location (remote or proximate to the receiver module), for programming and emergency override situations. The override switch  38  is connected to the receiver module via wire  40 . A keyed override switch  42  may be in a hidden location, available for service technicians only.  
         [0027]    On the output side, wire  44  is connected to the buses&#39; flashing parking lights  46  (see FIG. 1), and wire  48  is connected to the horn. Relays in the receiver module  14  are programmed to limit the horn sounds in full alarm to 3 minutes as described further below. An input wire  50  for the timed output is also connected to the horn. An alarm status indicator (an LED device)  52  is connected to the receiver module via wire  54  and an optional siren is connected via wire  56 . An optional data logger for monitoring system activity may be connected to the receiver module via harness wire  58 . It will be appreciated that the described harness  26  is exemplary only, and other harness configurations may be provided, depending on the particular application.  
         [0028]    It is also a feature of the invention to include a motion sensor  60  that may be wire connected to the wiring harness  28  or directly to the receiver module  14  via wire  62 . The motion sensor may be of the microwave type but other conventional motion sensors may be employed. The motion sensor may be located as desired within the bus, preferably optimally arranged to detect any motion inside the bus. Activation of the sensor and/or commencement of the alarm sequence after motion detection, may be delayed for a short period of time as further described below. The programming of the microprocessor  24  and/or related circuitry to implement the delays are well within the skill of the art.  
         [0029]    Operation of the wireless safety system in an exemplary configuration is as follows. Once the bus driver ends his/her run, and the ignition switch is turned “off,” a microprocessor-controlled beeping sound of 90 second duration prompts the driver to check for children remaining in the bus. Thus, the driver will have 90 seconds to check around and under each seat, as he progresses to the rear of the bus. During this initial 90 seconds of pre-alarm warning, the deactivation button on the transmitter  16  (for closing the switch  20 ) mounted at the back of the bus remains active but the receiver is programmed to ignore the transmitter during the 90 second pre-alarm warning. Therefore, the pre-alarm warning must expire before the transmitter  16  is recognized. After 90 seconds, the intermittent beeping is programmed to become continuous, so as to remind the driver that he or she has an additional 30 seconds to finish checking the bus and to press the deactivation button on the transmitter  16  to close the switch  20  and prevent the full alarm from sounding. This additional 30 seconds is also referred to as the pre-alarm stage. The specific time durations mentioned herein are exemplary only, and the receiver module may be programmed for different time periods as desired.  
         [0030]    The full alarm will sound after two minutes (the 90 second pre-alarm warning and 30 second pre-alarm) if the transmitter button is not pushed. The full alarm may consist of flashing of the parking lights  46 , intermittent sounding of the horn  50 , and/or the optional siren  58  in any combination. Horn sounds in the full alarm state are controlled by a relay (not shown) in the receiver and limited to three minutes if not deactivated. However, a second relay (not shown) may continue the full alarm with flashing parking lights (with or without siren). The duration of the various sounds and/or lights in the full alarm state can be programmed as desired, and are oftentimes dictated by local ordinances.  
         [0031]    The alarm system may be deactivated at any time by turning the ignition switch  36  to the “on” or “accessory” position, by activating the override switch  36 , or by pushing the transmitter button after the 90 second pre-alarm has expired.  
         [0032]    The inclusion of parking lights  46  in the alarm is especially helpful, particularly in instances where there are numerous school buses parked in a lot, and in the full alarm state, the school bus can be easily detected via the flashing lights, enabling the alarm to be turned off more quickly. In addition, using the optional override switch  38  prevents the alarm system from sounding on a momentary or temporary basis, while the keyed override switch  42  is available for service requirements by technicians. Upon completion of any maintenance, the system must be activated and a 90 second wait completed before activating the system in a normal manner.  
         [0033]    The mounting override switch  38  is designed to connect to the ignition switch “accessory” position, dome light or door switch. Thus, the override switch will disarm all alarm conditions while picking up children, or in stop and go situations when the engine must be turned off. For example, local requirements may dictate maximum engine idle time, after which the engine must be turned off.  
         [0034]    In the event the driver deactivates the alarm system by engaging the transmitter switch  20  at the back of the bus, the motion sensor  56  now comes into play. Activation of the sensor per se is preferably delayed for a short period of time, e.g., 1-2 minutes, so that the driver has time to exit the bus without detection by the sensor. Upon expiration of the delay, the sensor is activated and senses any motion inside the bus. The sensor may be configured to activate any alarm or sequence of alarms, e.g., horn, flashing lights or alarm sounds individually or in any combination. Thus, in the event a driver did not perform a careful search during the allotted time, the motion sensor would trigger the chosen alarm elements that would, in turn, cause a research of the bus for a child not previously discovered by the driver.  
         [0035]    It will be appreciated by those skilled in the art that the motion sensor will also detect intruders entering the bus, activate the alarm, and either scare off the intruders, or at least alert others to their presence.  
         [0036]    A suitable delay in the alarm could also be incorporated into the motion sensor configuration, allowing the bus driver to re-enter and deactivate the alarm sequence. In other words, the sensor would detect motion but the alarm elements would only be activated after a short time delay. This is useful if the driver must exit the bus for a short period of time, but intends to re-enter the bus, or to give a driver entering the bus at the beginning of a scheduled run sufficient time to deactivate and re-set the system.  
         [0037]    The receiver module  14  utilizes ultra low idle current when the ignition is “off” and the alarm deactivated. Thus, there is no significant drain on the vehicle battery  24  when the system is inactive. In addition, the receiver module  14  and transmitter  16  are individually coded to prevent bus-to-bus interference and the receiver can learn new transmitter codes. This allows either of the transmitter or receiver module to be replaced individually in the case of failure.  
         [0038]    While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.