# US 5,351,042 A · Lock, key and combination of lock and key > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,351,042 A - Document ID: US5351042A - Status: Granted - Kind: A - Application number: 07/851,565 - Filed: 1992-03-16 - Granted: 1994-09-27 - Earliest claimed: 1991-03-19 - Assignees: Yale Security Products Limited - Inventors: Walter J. Aston - Web page: https://patentgrep.com/patent/US5351042A ## CPC - E05B 47/063: {with a rectilinearly moveable blocking element} - G07C 9/00309: {operated with bidirectional data transmission between data carrier and locks} - E05B 47/0002: {with electromagnets} - E05B 47/0009: {with thermo-electric actuators, e.g. heated bimetals} - G07C 2009/00634: {Power supply for the lock} - G07C 2009/00777: {by induction} - Y10T 70/7079: Key rotated [e.g., Eurocylinder] - Y10T 70/713: Dogging manual operator - E05B: LOCKS; ACCESSORIES THEREFOR; HANDCUFFS - G07C: TIME OR ATTENDANCE REGISTERS; REGISTERING OR INDICATING THE WORKING OF MACHINES; GENERATING RANDOM NUMBERS; VOTING OR LOTTERY APPARATUS; ARRANGEMENTS, SYSTEMS OR APPARATUS FOR CHECKING NOT PROVIDED FOR ELSEWHERE - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A battery-less electronic cylinder lock comprises an electromagnet or other electrical release mechanism controlled by an electronic circuit. A cooperating key comprises a battery and a code producing circuit. When the key is inserted in the lock, power for the lock is supplied from the battery to the electronic circuit and the electromagnet by means of a transformer coupling arrangement with a primary portion in the key and a secondary portion in the lock. Alternatively, power may be supplied via electrical contacts on the key and on the lock. ## Claims ### Claim 1 A batteryless electronic lock comprising: a cylindrical body having a bore disposed therein; a barrel rotatably disposed in the bore of the cylindrical body, the barrel having a recess with a central cam portion disposed therein; a key slot disposed in the barrel, the key slot usable for receiving a blade of a coacting key; a locking element disposed in the cylindrical body wherein the locking element may enter the recess and limit rotation of the barrel relative to the cylindrical body; electromagnetic release means for controlling the locking element in response to an identification signal, the identification signal provided by the coacting key when the blade of the coacting key is disposed in the key slot wherein the central cam portion retains the locking element in a rest position in which an air gap between the locking element and the electromagnetic release means is minimized and wherein rotation of the barrel in either direction when the electromagnetic release means is not energized will cause the locking element to enter the recess and prevent further rotation of the barrel relative to the cylindrical body; means for acquiring electrical power for the electromagnetic release means from the coacting key. ### Claim 2 (depends on 1) The lock as claimed in claim 1, wherein the means for acquiring electrical power comprises a secondary portion of a transformer. ### Claim 3 (depends on 1) The lock as claimed in claim 1, wherein the means for acquiring electrical power comprises an electrical contact for receiving current from a corresponding electrical contact of the coacting key. ### Claim 4 (depends on 2) The lock as claimed in claim 2, further comprising rectifying means connected between the means for acquiring electrical power and the electromagnetic release means. ### Claim 5 (depends on 1) The lock as claimed in claim 1, further comprising a frequency shift keying demodulator connected to the means for acquiring electrical power wherein the frequency shift keying demodulator receives frequency shift keyed signals from the coacting key. ### Claim 6 (depends on 5) The lock as claimed in claim 5, further comprising a decoder connected to the frequency shift keying demodulator. ### Claim 7 (depends on 6) The lock as claimed in claim 6, further comprising timing means for actuating the electromagnetic release means for a predetermined time in response to the decoder. ### Claim 8 A combination of a battery-less lock and a coacting key, the combination comprising: a cylindrical body having a bore disposed therein; a barrel rotatably disposed in the bore of the cylindrical body, the barrel having a recess with a central cam portion disposed therein; a key slot disposed in the barrel, the key slot usable for receiving a blade of the coacting key; a locking element disposed in the cylindrical body, wherein the locking element may enter the recess and limit rotation of the barrel relative to the cylindrical body; electromagnetic release means for controlling the locking element in response to an identification signal, the identification signal provided by the coacting key when the blade of the coacting key is disposed in the key slot, wherein the central cam portion retains the locking element in a rest position in which an air gap between the locking element and the electromagnetic release means is minimized and wherein rotation of the barrel in either direction when the electromagnetic release means is not energized will cause the locking element to enter the recess and prevent further rotation of the barrel relative to the cylindrical body; means for acquiring electrical power for the electromagnetic release means from the coacting key, wherein the means for acquiring electrical power is disposed on the cylindrical body; and a circuit for producing an encoded signal for unlocking the locking element, a battery, and supplying means for supplying electrical power from said battery to said acquiring means, wherein the coacting key comprises the circuit, the battery, and the supplying means. ### Claim 9 A batteryless electronic lock comprising: a cylindrical body having a bore disposed therein; a barrel rotatably disposed in the bore of the cylindrical body, the barrel having a recess with a central cam portion disposed therein; a key slot disposed in the barrel, the key slot usable for receiving a blade of a coacting key; a locking element disposed in the cylindrical body wherein the locking element may enter the recess and limit rotation of the barrel relative to the cylindrical body; electromagnetic release means for controlling the locking element in response to an identification signal, the identification signal provided by the coacting key when the blade of the coacting key is disposed in the key slot wherein the central cam portion retains the locking element in a rest position in which an air gap between the locking element and the electromagnetic release means is minimized and wherein rotation of the barrel in either direction when the electromagnetic release means is not energized will cause the locking element to enter the recess and prevent further rotation of the barrel relative to the cylindrical body; means for acquiring electrical power for the electromagnetic release means from the coacting key wherein the means for acquiring electrical power is disposed in the cylindrical body off an axis of the barrel. ### Claim 10 (depends on 9) The lock as claimed in claim 9, further comprising interlock means for allowing the coacting key to be removed from the key slot only when the barrel is in its locking position.