# US 12,009,721 B2 · Eddy current brake configurations > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,009,721 B2 - Document ID: US12009721B2 - Status: Granted - Kind: B2 - Application number: 17/393,791 - Filed: 2021-08-04 - Published: 2021-11-25 - Granted: 2024-06-11 - Earliest claimed: 2014-12-04 - Assignees: Eddy Current Limited Partnership - Applicants: Eddy Current Limited Partnership - Inventors: Christopher James Allington; Andrew Karl Diehl; Kevin A. Wright; Weston Hill; Dave Walters - Web page: https://patentgrep.com/patent/US12009721B2 ## CPC - H02K 49/046: {with an axial airgap} - A62B 1/08: with brake mechanisms for the winches or pulleys - B60L 7/28: Eddy-current braking - F16D 59/02: spring-loaded and adapted to be released by mechanical, fluid, or electromagnetic means - H02K 7/116: with gears - H02K 7/12: with auxiliary limited movement of stators, rotors or core parts, e.g. rotors axially movable for the purpose of clutching or braking - A63B 69/0048: {for mountaineering, e.g. climbing-walls, grip elements for climbing-walls} - F16D 2121/20: using electromagnets - Y02T 10/64: Electric machine technologies in electromobility - H02K: DYNAMO-ELECTRIC MACHINES (dynamo-electric relays H01H53/00; conversion of DC or AC input power into surge output power {H03K3/53}) - A62B: DEVICES, APPARATUS OR METHODS FOR LIFE-SAVING (valves specially adapted for medical use A61M39/00; life-saving devices, apparatus or methods specially adapted for use in water B63C9/00; divers' equipment B63C11/00; specially adopted for use with aircraft, e.g. parachutes, ejector seats, {B64D17/00, B64D25/10}; rescue devices peculiar to mining E21F11/00) - B60L: PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES (arrangements or mounting of electrical propulsion units or of plural diverse prime-movers for mutual or common propulsion in vehicles B60K1/00, B60K6/20; arrangements or mounting of electrical gearing in vehicles B60K17/12, B60K17/14; preventing wheel slip by reducing power in rail vehicles B61C15/08; dynamo-electric machines H02K; control or regulation of electric motors H02P); SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES (electric coupling devices combined with mechanical couplings of vehicles B60D1/64; electric heating for vehicles B60H1/00); ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL (control or regulation of electric motors H02P); MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES - F16D: COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES - A63B: APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT (apparatus for passive exercising, massage A61H) - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract Described herein are eddy current brakes and associated methods of their use, particularly configurations that have a kinematic relationship with at least two rotational degrees of freedom used to tune operation of the brake or apparatus in which the brake is located. ## Claims ### Claim 1 An eddy current brake, comprising: a shaft with a first rotation axis; and two opposed electrical conductor members, each electrical conductor member being linked to the shaft via a respective link and a respective spring, the electrical conductor members, links and springs rotating with the shaft about the first rotation axis when the shaft rotates about the first rotation axis; wherein the electrical conductor members interact with an adjacent magnetic field and, when relative movement between the electrical conductor members and magnetic field occurs, eddy current drag forces are induced slowing relative movement between the electrical conductor members and magnetic field; wherein a respective attachment point of each link to the shaft defines a second rotation axis for each respective link, wherein the second rotation axis is not parallel to the first rotation axis; wherein, when no shaft rotation about the first rotation axis occurs, each of the electrical conductor members is biased by the respective spring to rotate about the respective second rotation axis away from the magnetic field, and, when shaft rotation about the first rotation axis occurs, each of the electrical conductor members is urged by centrifugal forces to rotate about the respective second rotation axis against the bias of the respective spring toward the magnetic field thereby causing an eddy current brake force to be induced. ### Claim 2 (depends on 1) The eddy current brake as claimed in claim 1, wherein at least one of the electrical conductor members is located at least partially within the magnetic field when the shaft is not rotating about the first rotation axis. ### Claim 3 (depends on 1) The eddy current brake as claimed in claim 1, wherein at least one of the electrical conductor members is located outside the magnetic field when the shaft is not rotating about the first rotation axis. ### Claim 4 (depends on 1) An autobelay device incorporating the eddy current brake as claimed in claim 1. ### Claim 5 (depends on 1) A self-retracting lifeline (SRL) device incorporating the eddy current brake as claimed in claim 1. ### Claim 6 (depends on 1) The eddy current brake as claimed in claim 1, wherein the first axis of rotation is orthogonal to each second axis of rotation. ### Claim 7 (depends on 1) The eddy current brake as claimed in claim 1, wherein the first axis of rotation and the second axes of rotation intersect. ### Claim 8 (depends on 1) The eddy current brake as claimed in claim 1, wherein a first one of the second axes of rotation is coaxial with the other of the second axes of rotation. ### Claim 9 (depends on 1) The eddy current brake as claimed in claim 1, wherein each of the electrical conductor members is located at least partially within the magnetic field when the shaft is not rotating about the first rotation axis. ### Claim 10 (depends on 1) The eddy current brake as claimed in claim 1, wherein each of the electrical conductor members is located outside the magnetic field when the shaft is not rotating about the first rotation axis. ### Claim 11 (depends on 1) The eddy current brake as claimed in claim 1, wherein the magnetic field within which the electrical conductor moves is formed by one or more magnets situated on a housing or external element. ### Claim 12 (depends on 11) The eddy current brake as claimed in claim 11, wherein the housing or external element defines a cavity inside which the shaft and electrical conductors move.