# US 11,440,770 B2 · Elevator derailment detection device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,440,770 B2 - Document ID: US11440770B2 - Status: Granted - Kind: B2 - Application number: 16/081,297 - Filed: 2016-04-18 - Published: 2019-02-07 - Granted: 2022-09-13 - Earliest claimed: 2016-04-18 - Assignees: Mitsubishi Electric Corporation - Applicants: Mitsubishi Electric Corporation - Inventors: Shinichi Sato - Web page: https://patentgrep.com/patent/US11440770B2 ## CPC - B66B 5/0031: {for safety reasons} - B66B 5/0025: {for maintenance or repair} - B66B 5/02: responsive to abnormal operating conditions - G01D 5/14: influencing the magnitude of a current or voltage - B66B: ELEVATORS; ESCALATORS OR MOVING WALKWAYS ({apparatus for raising or lowering persons on theatrical stages or the like A63J5/12} ; funicular railbound systems with rigid ground-supported tracks and cable traction, e.g. cliff railways, B61B9/00; arrangements of ammunition handlers in vessels B63G3/00; hoists, lifts, or conveyors for loading or unloading in general B65G; braking or detent devices controlling normal movements of winding drums or barrels B66D; ship-lifting devices E02C; garages for many vehicles with mechanical means for lifting vehicles E04H6/12; hoists for feeding ammunition or projectiles to launching apparatus or to loading mechanisms F41A9/00) - G01D: MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR ## Abstract Provided is an elevator derailment detection device configured to detect disengagement of a vertically movable body to be guided by guide rails to be raised and lowered from at least one of the guide rails. The elevator derailment detection device includes: a conductive wire, which is provided in a hoistway in parallel to a direction in which the vertically movable body is raised and lowered; a magnetic field measurement device, which is provided to the vertically movable body so as to measure an intensity of a magnetic field generated by a current flowing through the conductive wire, and is configured to output the measured magnetic field intensity; and a controller configured to detect the disengagement of the vertically movable body from the at least one of the guide rails when the magnetic field intensity output from the magnetic field measurement device falls above or lower than an allowable range. ## Claims ### Claim 1 An elevator derailment detection device, which is configured to detect disengagement of a vertically movable body, which is to be guided by guide rails to be raised and lowered, from at least one of the guide rails; the elevator derailment detection device comprising: a conductive wire provided in a hoist way in parallel to a direction in which the vertically movable body is to be raised and lowered; a magnetic field measurement device, which is provided to the vertically movable body so as to measure an intensity of a magnetic field generated by a current flowing through the conductive wire, and is configured to output the measured magnetic field intensity; and a controller configured to detect the disengagement of the vertically movable body from the at least one of the guide rails in response to, the magnetic field intensity output from the magnetic field measurement device falling above or lower than an allowable range. ### Claim 2 (depends on 1) The elevator derailment detection device according to claim 1, further comprising a noise attenuator configured to attenuate noise superimposed on the magnetic field intensity output from the magnetic field measurement device. ### Claim 3 (depends on 1) The elevator derailment detection device according to claim 1, wherein the controller includes: a determinator configured to determine whether the magnetic field intensity falls within the allowable range; a detector configured to detect the disengagement of the vertically movable body from the at least one of the guide rails; and a normal-signal output device configured to output a normal signal to the detector, wherein the determinator is configured to interrupt input of the normal signal from the normal-signal output device to the detector in response to the magnetic field intensity falling above or lower than the allowable range, and wherein the detector is configured to detect the disengagement of the vertically movable body from the at least one of the guide rails in response to the input of the normal signal from the normal-signal output device being interrupted. ### Claim 4 (depends on 1) The elevator derailment detection device according to claim 1, wherein the controller is configured to detect occurrence of an abnormality in the elevator derailment detection device in response to the magnetic field intensity output from the magnetic field measurement device being zero. ### Claim 5 (depends on 2) The elevator derailment detection device according to claim 2, wherein the controller includes: a determinator configured to determine whether the magnetic field intensity falls within the allowable range; a detector configured to detect the disengagement of the vertically movable body from the at least one of the guide rails; and a normal-signal output device configured to output a normal signal to the detector, wherein the determinator is configured to interrupt input of the normal signal from the normal-signal output device to the detector in response to the magnetic field intensity falling above or lower than the allowable range, and wherein the detector is configured to detect the disengagement of the vertically movable body from the at least one of the guide rails in response to the input of the normal signal from the normal-signal output device being interrupted. ### Claim 6 (depends on 2) The elevator derailment detection device according to claim 2, wherein the controller is configured to detect occurrence of an abnormality in the elevator derailment detection device in response to the magnetic field intensity output from the magnetic field measurement device being zero. ### Claim 7 (depends on 3) The elevator derailment detection device according to claim 3, wherein the controller is configured to detect occurrence of an abnormality in the elevator derailment detection device in response to the magnetic field intensity output from the magnetic field measurement device being zero.