Electronic lock that can learn to recognize any ordinary key

• US 6,318,137 B1
• Filed: 04/06/1999
• Issued: 11/20/2001
• Est. Priority Date: 04/08/1998
• Status: Expired due to Fees

• Current Assignee: David Chaum
• Original Assignee: David Chaum
• Inventors: Chaum, David
• Primary Examiner(s): JAYNE, DARNELL M
• Application Number:
  US09/286,980
• Time in Patent Office: 959 Days
• Field of Search: 702/782, 702/783, 702/781, 702/787, 702/831, 340/825.31, 340/5.67, 340/5.2
• US Class Current: 70/278.3
• CPC Class Codes: E05B 47/0009 with thermo-electric actuators, e.g. heated bimetals
• CPC Class Codes: E05B 49/002 Keys with mechanical characteristics, e.g. notches, perforations, opaque marks
• CPC Class Codes: G05B 19/00 Programme-control systems
• CPC Class Codes: G07C 2009/00849 programming by learning
• CPC Class Codes: G07C 2009/00992 mechanical key
• CPC Class Codes: G07C 9/00817 where the code of the lock can be programmed
• CPC Class Codes: G07C 9/00944 Details of construction or manufacture
• CPC Class Codes: Y10T 70/7068 Actuated after correct combination recognized [e.g., numerical, alphabetical, or magnet[s] pattern]
• CPC Class Codes: Y10T 70/7073 Including use of a key
• CPC Class Codes: Y10T 70/7079 Key rotated [e.g., Eurocylinder]
• CPC Class Codes: Y10T 70/7136 Key initiated actuation of device

Abstract

An electronic lock that can be pre-programmed or trained in the field to recognize ordinary flat metal keys by sensing their shape and comparing to a database is disclosed. The lock can be contained in standard configurations for door locks, communicates with external systems, provides control logic for querying and amending its database of allowed keys and rules, provides controlled access to logs of selected data, allows convenient but protected access to replacement batteries, can have all its electronics in the rotatable plug, can communicate and obtain power from devices in the adjacent door jam, can recognize special series key-blanks, can receive coded information entered using an unknown key that makes it useable, can be operated without a key to gain access with a code, can resist manipulation of the latching mechanism can unlatch with very low power requirements, and provides for integration of almost all mechanism in silicon.

Claims

1. An electronic lock system for use with flat rigid cylinder-lock type keys, the electronic lock system comprising:

a keyway channel configured to accept one at a time, a plurality of purely mechanical, flat rigid cylinder-lock type keys, each of said keys having a keyway portion configured to be inserted into a corresponding keyway channel of a different purely mechanical lock, said keyway portion having a length dimension, a height dimension, and a thickness dimension, said length dimension, said thickness dimension, and said height dimension being mutually orthogonal and descending in size, said keyway portion having bitting cuts intended to position corresponding lock tumblers at corresponding heights, said bitting cuts perpendicular to said length dimension and said height dimension, each of said bitting cuts reducing at least a portion of a height of said keyway portion to form a bitting profile shape, said thickness dimension equal or less than approximately 0.1 inches, said keyway portions having different warding grooves parallel with the length dimension, the plurality of keys intended for use with the corresponding different purely mechanical locks, wherein the different purely mechanical locks have independent and incompatible warding and tumbler spacings and the plurality of keys have not been modified to be used with the electronic lock system;

a memory configured to store corresponding shape related information of said bitting profile shapes;

a sensor configured to sense at least a portion of the bitting profile shapes of flat rigid cylinder-lock type keys inserted into said keyway channel of the electronic locking system;

a comparator coupled to the memory and the sensor, the comparator configured to compare a sensed bitting profile shape with the stored shape related information stored in said memory; and

an actuator configured to unlock the electronic locking system at least partially in response to the comparator determining that the sensed bitting profile shape corresponds to at least the portion of the stored shape related information.

2. The electronic lock system as defined in claim 1, wherein the sensor includes an inductive sensor having at least a first coil oriented so that a key inserted into the keyway is positioned at least near the coil, and wherein the inductive sensor provides information related to changes in inductance induced by the key.

3. The electronic lock system as defined in claim 1, wherein the sensor is configured to dynamically sense the key shape portion as the key is being inserted into the keyway.

4. The electronic lock system as defined in claim 1, wherein the sensor is configured to statically sense the key shape portion when the key insertion is complete.

5. The electronic lock system as defined in claim 1, further comprising a second sensor configured to sense at least a second key shape portion.

6. The electronic lock system as defined in claim 1, wherein the sensor includes a stylus positioned to trace at least a portion of a key bitting profile as the key is inserted into the keyway.

7. The electronic lock system as defined in claim 1, wherein the sensor includes at least two axially oriented coils configured to be driven from an AC source.

8. The electronic lock system as defined in claim 1, wherein the sensor senses an electromagnetic shadow of the portion of the key.

9. The electronic lock system as defined in claim 1, wherein the actuator allows the key to be rotated when unlocked.

10. The electronic lock system as defined in claim 1, wherein a rule set associated with a first of the plurality of stored key shape related information for a first of the plurality of mechanical keys limits the unlocking of the locking mechanism to a specified sequencing of key insertions.

11. The electronic lock system as defined in claim 1, wherein shape related information for a first key is stored in the memory in response to a user inserting the first key into the keyway and the user entering a code.

12. An electronic key-sensing system, comprising:

a locking mechanism, including a channel configured to accept one at a time at least a first flat rigid key and a second flat rigid key having keyway portions of different widths, and configured independent of the electronic key-sensing system, the first key and the second key being purely mechanical, cylinder-lock type keys having differently spaced bitting cuts on the corresponding keyway portions, the bitting cuts intended to position corresponding lock tumblers at corresponding heights, the first key and the second key having different warding patterns, wherein the first key and the second key are intended for use with corresponding different purely mechanical locking mechanisms having different respective incompatible keyway wardings and the first key and the second key have not been specially modified so as to operate the electronic key sensing system;

a programmable memory configured to store at least a first template for the first key and a second template for the second key;

a sensor configured to sense at least a portion of a shape of a key, including at least the bitting cuts, being used in an attempt to unlock the locking mechanism, the sensor configured to generate corresponding sensed shape information; and

an analysis circuit coupled to the memory and the sensor, the analysis circuit configured to determine if the sensed shape information corresponds with one of the stored first template and second template and to cause the unlocking of the locking mechanism at least partly in response to determining that the sensed shape information does correspond to one of the first stored template and the second stored template.

13. The electronic key sensing system as defined in claim 12, where the analysis circuit is located remotely from the keyway and sensor.

14. The method as defined in claim 12, wherein the sensed key portion includes a warding pattern.

15. An electronic lock system, comprising:

a non-warded keyway channel configured to accept one at a time a plurality of cylinder-lock type, purely mechanical keys having corresponding different bitting profiles and dimensions, including having keyway portions of corresponding different widths, wherein the keyway portions are intended to be inserted into keyway channels of corresponding different mechanical locks having different keyway wardings and different tumbler positions, the plurality of keys configured independent of the electronic lock system, wherein the plurality of purely mechanical keys are not altered in order to be used with the electronic lock system;

a memory configured to store corresponding shape related information for at least a portion of the plurality of mechanical keys;

a sensor configured to sense key shape information, including at least the bitting profile, of keys inserted into the keyway channel;

a comparator coupled to the memory and the sensor, the comparator configured to compare a sensed key shape portion with the stored shape related information; and

an unlocking mechanism configured to bring the electronic lock system into an unlocked state at least partially in response to the comparator determining that a sensed bitting profile shape inserted into the keyway channel substantially corresponds to at least a part of the stored shape related information.