# US 5,542,507 A · Position dependent variable output torque viscous damper > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,542,507 A - Document ID: US5542507A - Status: Granted - Kind: A - Application number: 08/343,114 - Filed: 1994-11-22 - Granted: 1996-08-06 - Earliest claimed: 1994-11-22 - Assignees: Vibratech, Inc. - Inventors: Mark Warchocki; Walter P. Pukalo - Web page: https://patentgrep.com/patent/US5542507A ## CPC - F16F 9/12: Devices with one or more rotary vanes turning in the fluid any throttling effect being immaterial, {i.e. damping by viscous shear effect only (F16F9/53 takes precedence; pivoting supports for apparatus or articles placed on stands or trestles F16M11/06)} - A63B 21/00069: {Setting or adjusting the resistance level; Compensating for a preload prior to use, e.g. changing length of resistance or adjusting a valve} - A63B 21/008: using hydraulic or pneumatic force-resisters - A63B 21/4049: {Rotational movement} - F16D 57/00: Liquid-resistance brakes; {Brakes using the internal friction of fluids or fluid-like media, e.g. powders (for braking drums, barrels or ropes of cranes, lift hoists or winches B66D5/026)} - A63B 22/0605: {performing a circular movement, e.g. ergometers} - A63B 23/0476: {by rotating cycling movement (arrangements on or for real bicycles A63B69/16)} - F16F: SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION - A63B: APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT (apparatus for passive exercising, massage A61H) - F16D: COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES ## Abstract A rotary viscous damper having a disc surrounded by a housing and cover, the disc rotatable with a shaft which penetrates the housing, a gap provided between opposite sides of the disc and the inside surfaces of the housing and cover for receiving viscous fluid, and triangularly shaped indentations formed on opposing surfaces of the disc and the housing and cover, the indentations on the housing and the cover arranged at selective rotational positions. Rotation of the disc aligning opposing indentations on the discs and the housing and cover to create a rotary position of minimum torque and when misaligned, a rotary position of maximum torque. The oscillating torque value creates a nominal torque associated with the damper, but can be selectively installed to present a minimum torque at a particular rotational position. The invention is particularly adapted to rotary devices where rotational position can effect the available torque for driving the shaft, such as an exercise bicycle. ## Claims ### Claim 1 A rotary viscous damper, comprising: a first member and a second member, said first member arranged to continuously rotate about an axis of rotation with respect to said second member, and said first and second members arranged having a first gap therebetween for filling with viscous fluid; wherein said first member provides at least one first indentation on a first side thereof facing said first gap and said second member also has at least one second indentation facing said first gap and said first side of said first member said first and second indentations alignable at a rotary position of said first and second members. ### Claim 2 A rotary viscous damper, comprising: a first member and a second member, said first member arranged to rotate about an axis of rotation with respect to said second member, and said first and second members arranged having a first gap therebetween for filling with viscous fluid; wherein said first member provides at least one indentation on a first side thereof facing said first gap and said second member also has at least one indentation facing said first gap and said first side of said first member; wherein said at least one indentation on said first side of said first member comprises a plurality of indentations angularly spaced around said axis of rotation of said first member. ### Claim 3 (depends on 2) The damper according to claim 2, wherein said at least one indentation of said second member comprises a plurality of indentations angularly spaced around said axis of rotation of said first member. ### Claim 4 A rotary viscous damper, comprising: a first member and a second member, said first member arranged to rotate about an axis of rotation with respect to said second member, and said first and second members arranged having a first gap therebetween for filling with viscous fluid; wherein said first member provides at least one indentation on a first side thereof facing said first gap and said second member also has at least one indentation facing said first gap and said first side of said first member; wherein said first member comprises a disc and said second member comprises a housing and a cover mounted together surrounding said disc, said at least one indentation of said first member comprising a plurality of indentations on said first side carried on said disc, and further comprising a plurality of indentations on a second side of said disc, and said at least one indentation of said second member comprises a plurality of indentations on a wall of said housing facing said first side of said disc, and said cover comprises a plurality of indentations on a wall thereof facing said second side of said disc, a second gap formed between said cover and said second side of said disc. ### Claim 5 (depends on 4) The damper according to claim 4, wherein said plurality of indentations on said wall of said housing and said plurality of indentations on said wall of said cover are angularly aligned in one-to-one correspondence. ### Claim 6 (depends on 5) The damper according to claim 5, wherein said indentations are triangularly shaped recesses expanding radially outwardly of an axis of rotation of said disc. ### Claim 7 (depends on 4) The damper according to claim 4, wherein said housing and said cover are arranged to be selectively movable toward and away from each other to vary the first and second gaps between the first and second side of said disc and said wall of said housing and said wall of said cover; and means for selectively moving said cover and said housing to vary the first and second gaps between the disc and the housing and cover. ### Claim 8 A stationary exercise device comprising: a stationary frame; opposing foot pedals mounted on a horizontal axle for rotation about an axis of said axle, said axle journaled to said frame; means for converting rotation of said foot pedals to rotation of a shaft; a first member and a second member, said first member arranged to rotate with respect to said second member, and said members arranged having a first gap therebetween and a viscous fluid filling the first gap; wherein said first member provides at least one indentation on a first side thereof facing said first gap and said second member also has at least one indentation facing said first gap and said first side of said first member; and said first member is fixedly connected to said shaft to rotate therewith, and said second member is fixed to said frame preventing rotation, said indentations on said first and second members arranged to align when said foot pedals are in vertical alignment. ### Claim 9 (depends on 8) The device according to claim 8, wherein said at least one indentation on said first side of said first member comprises a plurality of indentations angularly spaced around an axis of rotation of said first member. ### Claim 10 (depends on 9) The device according to claim 9, wherein said at least one indentation of said second member comprises a plurality of indentations angularly spaced around said axis of rotation of said first member. ### Claim 11 (depends on 8) The device according to claim 8, wherein said first member comprises a disc and said second member comprises a housing and a cover mounted together surrounding said disc, said at least one indentation of said first member comprising a plurality of indentations on said first side carried on said disc, and further comprising a plurality of indentations on a second side of said disc, and said at least one indentation of said second member comprises a plurality of indentations on a wall of said housing facing said first side of said disc and said cover comprises a plurality of indentations on a wall thereof facing said second side of said disc, a second gap defined between said cover and said second side of said disc. ### Claim 12 (depends on 11) The device according to claim 11, wherein said plurality of indentations on said wall of said housing and said plurality of indentations on said wall of said cover are rotationally aligned in one-to-one correspondence. ### Claim 13 (depends on 12) The device according to claim 12, wherein said indentations are triangularly shaped recesses expanding radially outwardly of an axis of rotation of said disc. ### Claim 14 (depends on 11) The device according to claim 11, wherein said housing and said cover are arranged to be selectively movable toward and away from each other to vary the overall gap between the first and second side of said discs and said wall of said housing and said wall of said cover; and means for selectively moving said cover and said housing to vary the overall gap between the disc and the housing and cover. ### Claim 15 A rotary viscous damper, comprising: a housing and a cover forming an enclosed space; a disc located between said housing and said cover within said space, said disc arranged to rotate about an axis of rotation and said disc and said housing arranged having a first gap therebetween and said disc and said cover arranged having a second gap therebetween for filling with viscous fluid; means arranged between said disc and said cover for reducing rotational drag by said viscous fluid on said disc at a select rotational position of said disc; wherein said housing and said cover are arranged to be selectively movable toward and away from each other to vary the first and second gaps between the disc and said housing and said cover; and means for selectively moving said cover and said housing to vary the first and second gaps between the disc and the housing and cover. ### Claim 16 A rotary viscous damper, comprising: a housing and a cover forming an enclosed space; a disc located between said housing and said cover within said space, said disc arranged to rotate about an axis of rotation and said disc and said housing arranged having a first gap therebetween and said disc and said cover arranged having a second gap therebetween for filling with viscous fluid; wherein said housing and said cover are arranged to be selectively movable toward and away from each other to vary the first and second gaps between the disc and said housing and said cover; and motive means for selectively moving said cover and said housing to vary the first and second gaps between the disc and the housing and cover. ### Claim 17 A stationary exercise device comprising: a stationary frame; opposing foot pedals mounted on a horizontal axle for rotation about an axis of said axle, said axle journaled to said frame; means for converting rotation of said foot pedals to rotation of a shaft; a first member and a second member, said first member arranged to rotate with respect to said second member, and said members arranged having a first gap therebetween and a viscous fluid filling the first gap; and said first member is fixedly connected to said shaft to rotate therewith, and said second member is fixed to said frame preventing rotation; means arranged between said first member and said second member for reducing rotational drag by said viscous fluid on said first member at select rotational position of said pedals; wherein said second member is arranged to be movable toward said first member; and motive means for selectively moving said second member with respect to said first member to vary the first and second gaps. ### Claim 18 A rotary viscous damper, comprising: a first member and a second member, said first member arranged to continuously rotate about an axis and located adjacent said second member across a gap filled with viscous fluid, said first member connected to an axially aligned output shaft; and means for adjusting a profile of said gap at a select rotary position of said first member to periodically alter the viscous drag on said first member by said viscous fluid as said first member rotates continuously about said axis. ### Claim 19 (depends on 18) The damper according to claim 18, wherein said means comprises at least one first indentation on said first member and at least one second indentation on said second member arranged to be in alignment at said selected rotary position. ### Claim 20 (depends on 18) The damper according to claim 18, wherein said means comprises a motive means for selectively changing the distance between said first and second member.