Abstract:
Two embodiments of very simple by highly effective antitheft devices for use in small vehicles such as motor scooters, personal watercraft or other forms of watercraft. Each system employs a removable component which also functions as a display and which disables the operation of the prime mover of the vehicle. The removed component can be carried by the user and reinserted when he desires to again operate the vehicle.

Description:
BACKGROUND OF INVENTION  
         [0001]    This invention relates to an antitheft device for vehicles and more particularly to an improved and simplified antitheft device particularly useable with small vehicles that are more prone to unauthorized use.  
           [0002]    Automobiles are provided with very complex security systems so as to insure against unauthorized use by undesired persons. However, a wide variety of other types of vehicles such as motorcycles, motor scooters, personal watercraft and other forms of watercraft do not have nor can they accommodate such complicated sophisticated antitheft systems. Therefore, it has been mainly the practice to equip these vehicles with key operated locks which are intended to prevent unauthorized use. However, because of the very nature of these vehicles, it is very easy to disable the locking mechanism and commit theft.  
           [0003]    It is, therefore, a principal object to this invention to provide an improved and simplified system for preventing unauthorized use of these smaller type vehicles.  
           [0004]    It is a further object to this invention to provide an improved and simplified antitheft system for such vehicles which can be easily carried by the user to protect the vehicle from unauthorized use.  
         SUMMARY OF INVENTION  
         [0005]    This invention is adapted to be embodied in a vehicle and antitheft system therefore. The vehicle has a body defining a rider&#39;s area for accommodating at least one rider. A propulsion device is carried by the body for propelling the vehicle along a terrain. A prime mover for driving the propulsion device is carried by the body. A control system for operating the prime mover is also carried by the body. A main switch carried by the body enables the operation of the prime mover. A vehicle antitheft device is provided in the connection between the main switch and the control system. The vehicle antitheft device is removably supported on the body so that a rider may disable the operation of the prime mover by removing the antitheft device from the vehicle body. 
       
    
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0006]    [0006]FIG. 1 is a side elevational view of a vehicle equipped with an antitheft system constructed in accordance with a first embodiment of the invention and showing how the antitheft system can be removed from the vehicle in phantom line view.  
         [0007]    [0007]FIG. 2 is a partially schematic view showing how the antitheft device is associated with the vehicle body.  
         [0008]    [0008]FIG. 3 is a schematic view, in part similar to FIG. 2, but shows the details of the ignition circuit.  
         [0009]    [0009]FIG. 4 is a side elevational view, in part similar to FIG. 1, and shows a second embodiment of the invention.  
         [0010]    [0010]FIG. 5 is a schematic diagram, in part similar to FIG. 2, but shows the details of this second embodiment of the invention. 
     
    
     DETAILED DESCRIPTION  
       [0011]    Referring now in details to the drawings and initially to FIG. 1, a small type of vehicle of the type which can benefit from the use of the invention is identified generally by the reference numeral  11 . In the illustrated embodiment, the vehicle  11  is a motor scooter but, from the foregoing description, it should be readily apparent to those skilled in the art that the invention can be equally as well used with other types of small vehicles such as motorcycles, personal watercraft and other watercraft that are especially prone to unauthorized use.  
         [0012]    The motor scooter  11  is provided with a main body assembly  12  which includes an outer body member  13  which can be supported on any suitable type of frame. This frame journals a front wheel  14  on a fork assembly  15  that is dirigibly supported by the vehicle body  12  and which is steered by a handle bar assembly  16  positioned at its upper end. The upper portion of the handle bar assembly  16  may be enclosed preferably by a handle bar cover  17  of any suitable configuration.  
         [0013]    The body  13  has a floor board  18  on which a rider seated on a seat  19  at the rear of the motor scooter may place his feet. The rider obviously steers the vehicle  11  by the handle bar assembly  16 .  
         [0014]    Positioned beneath the seat  19  in the body assembly  12  and concealed by the main body member  13 , is a prime mover in the form of a single cylinder, spark ignited, internal combustion engine. This engine is indicated generally by the reference numeral  21 . Although this particular type of prime mover is described as being exemplary, it will be readily apparent to those skilled in the art how the invention can be utilized with other types of prime movers that may be utilized with these types of vehicles.  
         [0015]    The engine  12  is supported in the frame assembly and drives a rear wheel  22  through a transmission  23  of a suitable type. The manner of suspending the engine  21  and driving the rear wheel  22  may of any type known in this art.  
         [0016]    The engine  21  includes a cylinder block cylinder head assembly  24  in which an ignition plug  25  is provided for firing a charge which is delivered to the combustion chamber of the engine by a suitable system for engine operation. Again, those skilled in the art will readily understand how the invention can be utilized with various types of engine controls. Since the details of the engine  21  other than its control form no part of the invention, further description is unnecessary to permit those skilled in the art to practice the invention.  
         [0017]    Mounted on the body assembly  12  and concealed within the outer body member  13  is an engine ignition control, indicated generally by the reference numeral  26 , and which has a construction will be described shortly by reference to FIG. 3. This engine control system  26  is provided in a circuit, shown schematically at  30 , with the ignition plug  25  certain sensors, as will be described shortly, and an antitheft device that includes a vehicle display, indicated generally by the reference numeral  27 . This antitheft device  27  is, in accordance with the invention, mounted detachably within a receptor box  28  carried by the handle bar cover  17 . This connection is established through a quick disconnect connector, indicated by the reference numeral  29  and which makes a number of connections as will described shortly.  
         [0018]    Mounted on the handle bar cover  17  in proximity to the antitheft device  27  is a main switch  31  which is operated by a key in a manner well known in the art.  
         [0019]    The vehicle  11  is also provided with turn signal flashers  32  and  33  at the front and rear of the vehicle  11  and on opposite sides thereof. These are operated by a rider controlled switch, as is well known in the art. Except for the detachability of the antitheft device  27 , which includes a meter, to be described, the construction as thus far described many be considered to be conventional.  
         [0020]    Referring now primarily to FIG. 2, the antitheft device  27  will be described in more detail by reference to this schematic view. Shown in this view is the electrical power source for the vehicle  11  namely a battery  34  which is mounted in a suitable manner. The battery is also grounded in a suitable manner to the vehicle frame and which has a power connection  35  that goes directly to the main switch  31 .  
         [0021]    When switched on the main switch  31 , electrical power is delivered from the battery  34  to the ignition circuit  26  through a line indicated at  30  which is included in the corresponding power line  30  in FIG. 1. In addition, one of the quick connectors  29  connects the main switch  31  to a power supply circuit  36  which is positioned within the antitheft device  27 .  
         [0022]    This power supply circuit  36  controls the supply of power to a CPU  37  which processes other signals and delivers them to an ignition control interface  38  which connects to the ignition circuit  26  through another quick disconnect connector  29 .  
         [0023]    Various sensors and switches are provided for controlling not only the operation of the engine  21  but also to display certain information to the rider of the vehicle  11 . Such sensors are indicated at  39  and  41  in FIG. 2 and these may be sensors of such things as the crank angle of the engine for engine timing, and a sensor  41  for sensing vehicle speed. Also the switching of the flasher lights  32  and  33  is controlled through the CPU  37 .  
         [0024]    These signals are transmitted through suitable conductors including quick disconnect connections  29  through an input interface, indicated at  42 , which processes the signals and sends them to the CPU  37 . Having processed this information, the CPU  37  outputs control signals including a control signal through a conductor  43  to the ignition control for controlling the firing of the spark plug  25 . In addition, the CPU  37  outputs data to things such as the flasher lights  32 ,  33  through a flasher control  44 . As noted, a suitable directional signal switch (not shown) provides an additional input to the CPU  37  through the interface  42 .  
         [0025]    In addition and as already noted, the antitheft device  27  includes a meter display  45  that will displays visual information to the rider of the vehicle. This can include vehicle speed as determined from the information from the sensor  41  and also the operation of the flashers  32  and  33 . Additional information may also be displayed.  
         [0026]    Referring now additionally to FIG. 3, the connection to the ignition circuit  26  and the details of the ignition circuit  26  will be described in more detail. The ignition circuit  26  includes a communication interface  45  that receives the ignition control signal from CPU  37  through the ignition control interface  38 . In addition a power supply circuit  46  receives power directly from the battery line  30 . Both the ignition control interface  38  and the power supply circuit  46  transmit their signals and power to a CPU  47 . There is also provided an electrical storage unit  48  in the ignition circuit  26  for a purpose to be described.  
         [0027]    The output from the CPU  47  is transmitted through a conductor  49  to a spark coil for firing the spark plug  25  at the desired timing for the detected running conditions. Any desired type of control strategy can be employed for this purpose.  
         [0028]    From the foregoing description, it should be apparent that there are a number of disconnectable connections between various components and the antitheft control unit  27 . These connections are shown separately in FIGS. 2 and 3 for simplicity. In actual practice, they will be bundled together in wire harnesses with only one or two connectors at their ends.  
         [0029]    In addition to these electrical connections that can be ready disconnected, some form of mechanical interlock can be provided between the antitheft device  27  including the meter  45  and its mounting housing  28  so as to facilitate removal of the antitheft device  27  when the operator leaves the vehicle unattended. Thus, it should be readily apparent that when the operator removes the antitheft unit  27  from the vehicle  11 , it cannot be operated. In addition to preventing operation of the engine  21 , operation of such things as the gauges and flashers is also disabled.  
         [0030]    For further protection against unauthorized use, an EPROM memory unit in the form of another storage device, indicated by the reference numeral  51  is provided in the antitheft device  27 . This communicates with the device  48  of the ignition circuit and each is coded so as to recognize an appropriate or registered relationship so that someone with a meter and antitheft device from another vehicle can not operate a vehicle other than that vehicle it was intended for. That is, the storage devices  48  and  51  must provide cooperating and recognized signals with each other before permitting operation of the CPUs  37  and  47 . This provides additional assurance against unauthorized se.  
         [0031]    Referring now in detail to the embodiment of FIGS. 4 and 5, a vehicle constructed in accordance with this embodiment is identified generally by the reference numeral  71 . In many regards, the vehicle  71  is the same or substantially the same as that embodiment as thus far described. Where that is the case, components which are the same or substantially the same have been identified by the same reference numerals and will be described again only in so far as is necessary to permit those skilled in the art to practice this embodiment of the invention.  
         [0032]    In this embodiment, the antitheft device, indicated generally by the reference numeral  72 , incorporates the ignition circuit  26  in addition to the components previously described. Thus, the overall external wiring is substantially simplified as may be seen by comparing FIGS. 2 and 3 with FIG. 5.  
         [0033]    When the antitheft device  72  is completely removed from the vehicle  71 , it is impossible to operate the engine  21  because there is no ignition circuit for firing the spark plug  25 . Also, all of the auxiliaries will be inoperative because of the removal of the circuits going to them, as aforenoted.  
         [0034]    Thus, from the foregoing description it should be readily apparent that the described embodiments of the invention provide a very effective antitheft device for small vehicles which permits the operator to insure that the vehicle cannot be operated by unauthorized persons. Of course, the foregoing description is that of preferred embodiments of the invention and various changes and modifications can be made without departing from the spirit and scope of the invention, as defined by the appended claims.