Key operated lock mechanism with mixed mechanical and electric control
BACKGROUND TO THE INVENTION 
     The invention relates to a key-operated vehicle lock mechanism incorporating mechanical and electric control, utilising an emitter of a coded control signal and a receiver of the said signal, the emitter being independent of the receiver. 
     STATEMENT OF PRIOR ART 
     A device of the above type is known which is utilised for the remote control of the locking and unlocking of the doors of an automobile vehicle. The use of this device for the control of the anti-theft steering lock would be very desirable to increase security against theft, but certain designers wish the key for locking the doors to be different from the anti-theft lock key. Moreover the direct utilisation of the emitter to control the anti-theft device requires numerous security precautions and the education of drivers to the handling of a new device. 
     OBJECT OF THE INVENTION 
     The present invention aims at mitigating these drawbacks and objections by means of a new bolt combining the emitter of a coded message with a traditional mechanical lock. 
     SUMMARY OF THE INVENTION 
     According to the invention there is provided a key-operated vehicle lock mechanism including a bolt movable between locking and unlocking positions and an electro-mechanical drive operatively connected to the bolt, the provision of 
     a. a stator having a bore therein, 
     b. a rotor rotatable within the bore and having a recess therein, 
     c. a plurality of pairs of pistons movable in radial openings respectively in the rotor and stator between a rotor locked position and a rotor release position, the pistons in the rotor capable of entry at their innermost ends into the recess, 
     d. a key having: 
     i. a body formed with a series of coded notches engageable by the innermost ends of the rotor pistons whereby the pistons are moved to the rotor release position; 
     ii. an emitter within the body for emitting coded signals along a predetermined axis, and 
     iii. manually operable switch means on the body to control the emitter, and 
     e. a receiver in the stator housing electrically connected to the electro-mechanical drive, the rotor being movable from a first angular position in which the receiver is not in alignment with the predetermined axis of the coded signals to a second angular position where alignment takes place, whereby on actuation of the switch the electro-mechanical drive moves the bolt to its unlocking position. 
     By means of the lock mechanism according to the invention an additional security is provided, compared with remote control alone, thanks to the mechanical bolt which permits utilisation of the emitter and the associated receiver only after mechanical actuation of this bolt. 
    
    
     BRIEF DESCRIPTION OF DRAWINGS 
     The invention will be clearly understood on reading of the following description given with reference to the accompanying drawing, wherein: 
     FIG. 1 is a cross-sectional view of an anti-theft lock bolt according to an example of embodiment of the invention; 
     FIG. 2 is a longitudinal sectional view of the bolt according to FIG. 1; and 
     FIG. 3 is a diagram of the angular positions of the rotor of the bolt according to FIGS. 1 and 2. 
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
     The bolt comprises a combination key and emitter 1 wherein the emitter can work by infra-red radiation, ultrasonics, radio waves, etc. A rotor 2 of the mechanical bolt comprises a recess or bore 2&#39; closed by an end wall for receiving the combination key and emitter 1 which comprises a rib 1&#39; equipped with a coded notching 9, similar to that of a conventional key. A boss 1&#34; serves as reference for the notching 9. The bolt likewise comprises a stator 3 and pairs of pistons 4-5, returned by springs 6, are enclosed in the bolt 2-3 by a closure plate 7 and co-operate with the notching 9 to permit rotation of the rotor 2 in the stator 3 in the usual way. 
     The combination key and emitter 1 carries a control knob 8 and an emitter diode 12 (in the case of luminous radiation) transmitting the coded message to a receiver diode 13 mounted to a casing 10 so as to be fast with the stator 3. The rotor 2 is fast with a small plate 14 equipped with a window 12&#39; and carrying movable contacts co-operating with fixed contacts 11, 11&#39; under the action of a spring 15. A window 12&#34; is provided in the end wall of the rotor 2 opposite to the window 12&#39;. 
     In the position &#34;0&#34; (FIG. 3) the combination key and emitter 1 can be introduced into the recess 1&#39;, the notching 9 co-operating with the pistons 4-5 to liberate the rotor 2. In this position the emitter diode 12 is not opposite the receiver diode 13. Thus the actuation of the control knob 8 does not permit passage of the signal from the emitter diode 12 to the receiver diode 13. 
     After rotation of the rotor 2 to the &#34;anti-theft lock&#34;position (A-T), the emitter diode 12 comes opposite the receiver diode 13 through the windows 12&#39; and 12&#34;. The actuation of the knob 8 permits the transmission of the coded message from the emitter diode 12 to the receiver diode 13. The receiver (not shown) connected to the diode 13 then orders electro-mechanical unlocking of the bolt. If the rotation of the rotor 2 is then continued, the necessary electrical contacts are obtained such as &#34;Acc&#34; (auxiliary), &#34;M&#34; (normal running), starter &#34;S&#34;. The emitter diode 12 is no longer facing the receiver diode 13 during these movements, and any action upon the knob 8 has no effect. 
     If a return is effected in the opposite direction to the position &#34;Anti-theft lock&#34;, an action upon the knob 8 commands locking of the bolt. Then the return to the position &#34;0&#34; permits withdrawal of the combination key and emitter 1.