# US 2018/0023641 A1 · Electromagnetic-released, multi-disc enclosed safety brake > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2018/0023641 A1 - Document ID: US20180023641A1 - Status: Published application - Kind: A1 - Application number: 15/547,194 - Filed: 2016-01-28 - Published: 2018-01-25 - Earliest claimed: 2015-01-29 - Assignees: Pt Tech, LLC - Applicants: PT Tech, LLC - Inventors: Richard E. Cole, Jr.; Timothy A. Clapp; David A. Farwell - Web page: https://patentgrep.com/patent/US20180023641A1 ## CPC - F16D 55/36: Brakes with a plurality of rotating discs all lying side by side - B63B 21/16: using winches (winches per se B66D) - B63B 27/08: of winches - B66D 5/14: embodying discs - B66D 5/30: electrical - F16D 65/0006: {Noise or vibration control} - F16D 65/16: arranged in or on the brake - F16D 65/42: non-automatic - F16D 66/02: Apparatus for indicating wear - F16D 2121/22: for releasing a normally applied brake - F16D: COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES - B63B: SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING (arrangements of vessel ventilation, heating, cooling, or air-conditioning B63J2/00; floating substructures as supports of dredgers or soil-shifting machines E02F9/06) - B66D: CAPSTANS; WINCHES; TACKLES, e.g. PULLEY BLOCKS; HOISTS (winding or unwinding ropes or cables for feeding or storage purposes B65H; rope or cable winding or unwinding mechanisms for lifts B66B) ## Abstract An electromagnetic-released, multi-disc, enclosed safety brake for primary use in offshore marine winch applications includes a stationary coil housing that encompasses springs that apply pressure to an armature, a pair of separator plates, three friction plates and a stationary endplate. The multi-disc brake is released by means of a DC voltage applied to the brake coil. The excited coil generates an electromagnetic force that attracts the armature across an air-gap thus reducing the spring force applied to the disc pack. The brake is applied when the DC voltage is removed from the brake coil. Various structures and methodologies for reducing vibrations in the brake are also provided. ## Claims ### Claim 1 A multi-disc electric motor brake, comprising: a motor mounting plate; an electromagnetic coil attached to said mounting disc; an armature in operative engagement with said electromagnetic coil; a plurality of springs in axially biasing engagement with said armature; a hub received on an end of a motor shaft, said hub engaging a plurality of friction rotors; a plurality of torque reaction members attached to said mounting plate and in engagement with a plurality of separator stators interleaved with said friction rotors and forming a disc pack; and an endplate attached to said torque blocks and axially encapsulating said disc pack. ### Claim 2 (depends on 1) The multi-disc electric motor brake assembly according to claim 1, wherein said torque reaction members are parallel-sided blocks. ### Claim 3 (depends on 1) The multi-disc electric motor brake assembly according to claim 1, wherein said friction rotors and separator stators have tapered surfaces matingly engaging each other. ### Claim 4 (depends on 1) The multi-disc electric motor brake assembly according to claim 1, wherein said separator stators comprise self-contained, positive-release spring assemblies. ### Claim 5 (depends on 1) The multi-disc electric motor brake assembly according to claim 1, further comprising disc pack wear adjustment shims interposed between said endplate and said torque blocks. ### Claim 6 (depends on 5) The multi-disc electric motor brake assembly according to claim 5, further comprising an externally visible disc pack wear indicator. ### Claim 7 (depends on 6) The multi-disc electric motor brake assembly according to claim 6, wherein said wear indicator comprises a thread form to manually release the brake by overcoming said springs in axially biasing engagement with said armature. ### Claim 8 (depends on 1) The multi-disc electric motor brake assembly according to claim 1, wherein said separator stators are radially slotted. ### Claim 9 (depends on 1) The multi-disc electric motor brake assembly according to claim 1, further comprising a sealed external enclosure engaging said mounting plate. ### Claim 10 (depends on 1) The multi-disc electric motor brake assembly according to claim 1, further comprising a spring plate assembly in axial interacting engagement with said endplate. ### Claim 11 (depends on 1) The multi-disc electric motor brake assembly according to claim 1, further comprising spring-applied friction pads operative to resist motion of said separator stators in relation to said torque blocks. ### Claim 12 (depends on 1) The multi-disc electric motor brake assembly according to claim 1, further comprising a shock absorber interposed between said endplate and said armature. ### Claim 13 (depends on 1) The multi-disc electric motor brake assembly according to claim 1, further comprising a friction-damped linkage interposed between said armature and said mounting plate. ### Claim 14 (depends on 13) The multi-disc electric motor brake assembly according to claim 13, wherein said friction-damped linkage comprises a pair of arms extending between said armature and mounting plate, said arms being secured together with a friction member and spring therebetween. ### Claim 15 A safety brake for offshore marine winch applications, comprising: a stack of alternatingly interleaved separator discs and friction discs; a stationary endplate at a first end of said stack; an armature at a second end of said stack opposite said first end; a stationary coil housing having an electromagnetic coil received within a circular recess therein and a plurality of springs received by said stationary coil housing and urging against said armature; and wherein said plurality of springs urge engagement of said stack of alternatingly interleaved separator and friction plates between said armature and stationary endplate, and energization of said electromagnetic coil draws said armature to release such engagement.