| 摘要 |
<p>An electronic lock is constructed to resemble the appearance and functionality of a conventional cylinder lock. Its key (22) has a bit (24) in which is mounted an integrated circuit chip (27) storing the key code and including a transmission coil for inductive coupling with reading means of the lock. The latter includes a coil (33) for generating a high frequency alternating magnetic field across a localised region of the keyway (12) concentrated via a toroidal ferrite core structure which defines a gap spanning the keyway through which the chip (27) passes when the key bit (24) is inserted. This core structure includes a U-shaped part (31) in the stationary lock housing (30) around which the coil (33) is wound, and two parts (35) mounted in the barrel, one to either side of the keyway (12), which register with the part (31) in the housing when the barrel is in the key-reading position. Further ferrite pads (28) may be mounted to either side of the coil in the key itself, to register with the ferrite parts (35) in the barrel. By this means, optimum flux coupling between the lock and key may be achieved, thereby minimising power consumption. <IMAGE> <IMAGE></p> |
