# US 8,782,917 B2 · Disc brake for a tape measure > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,782,917 B2 - Document ID: US8782917B2 - Status: Granted - Kind: B2 - Application number: 13/381,353 - Filed: 2010-06-29 - Published: 2012-05-31 - Granted: 2014-07-22 - Earliest claimed: 2009-06-29 - Assignees: Rob Nielson - Applicants: Matthew Hunsberger; Rob Nielson - Inventors: Matthew Hunsberger; Rob Nielson - Web page: https://patentgrep.com/patent/US8782917B2 ## CPC - G01B 3/1005: Means for controlling winding or unwinding of tapes - F16D 2121/14: Mechanical - F16D 2125/38: with plural cam or ball-ramp mechanisms arranged concentrically with the brake rotor axis - G01B: MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS - F16D: COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES ## Abstract A tape measure comprises a housing having a tape reel rotatably mounted therein. A measuring tape is at least partially coiled about the tape reel. The measuring tape is movable between an extended position and a retracted position. In the extended position at least a portion of the measuring tape extends outwardly of the housing. In the retracted position the measuring tape is substantially coiled about the tape reel and disposed within the housing. A spring mechanism biases the tape reel to rotate so as move the measuring tape from the extended position to the retracted position. A disc brake mechanism applies a frictional force to the tape reel to control rotation of the tape reel. ## Claims ### Claim 1 A tape measure comprising: a housing; a tape reel rotatably mounted within the housing; a measuring tape at least partially coiled about the tape reel, the measuring tape being movable between an extended position in which at least a portion of the measuring tape extends outwardly of the housing and a retracted position in which the measuring tape is substantially coiled completely about the tape reel and disposed within the housing; a spring mechanism for biasing the tape reel to rotate so as to move the measuring tape from the extended position towards the retracted position; a disc brake mechanism for applying a frictional force to the tape reel to control rotation of the tape reel, the disc brake mechanism including a disc rotatably mounted within the housing, a first side of the disc functioning as a brake pad to engage the tape reel so as to apply the frictional force to the tape reel, and a second side of the disc having a plurality of inclined cam surfaces arranged in annular formation which interact with a plurality of corresponding inclined cam surfaces arranged in annular formation on an inner wall of the housing; and wherein rotation of the disc in a first direction causes the brake pad to move towards the tape reel and rotation of the disc in a second direction causes the brake pad to move away from the tape reel. ### Claim 2 (depends on 1) The tape measure as claimed in claim 1 wherein the spring mechanism includes a coiled flat spring. ### Claim 3 (depends on 1) The tape measure as claimed in claim 1 further including a lever for rotating the disc. ### Claim 4 (depends on 1) The tape measure as claimed in claim 1 further including a biasing spring for biasing the disc to rotate in the first direction. ### Claim 5 (depends on 1) The tape measure as claimed in claim 1 further including a biasing spring for biasing the disc to rotate in the second direction. ### Claim 6 (depends on 1) The tape measure as claimed in claim 1 wherein on the second side of the disc there are eight inclined cam surfaces each of which is inclined 40 degrees, and on the inner wall of the housing there are eight corresponding cam surfaces each of which is inclined 40 degrees. ### Claim 7 A tape measure comprising: a housing; a tape reel rotatably mounted within the housing; a measuring tape at least partially coiled about the tape reel, the measuring tape being movable between an extended position in which at least a portion of the measuring tape extends outwardly of the housing and a retracted position in which the measuring tape is substantially coiled completely about the tape reel and disposed within the housing; a spring mechanism for biasing the tape reel to rotate so as to move the measuring tape from the extended position towards the retracted position; a disc brake mechanism for applying a frictional force to the tape reel to control rotation of the tape reel and movement of the measuring tape from the extended position towards the retracted position, the disc brake mechanism including a disc rotatably mounted within the housing and a biasing spring for biasing the disc, a first side of the disc functioning as a brake pad to engage the tape reel so as to apply the frictional force to the tape reel, and a second side of the disc having a plurality of inclined cam surfaces arranged in annular formation which interact with a plurality of corresponding inclined cam surfaces arranged in annular formation on an inner wall of the housing; and wherein rotation of the disc in a first direction causes the brake pad to move towards the tape reel and rotation of the disc in a second direction causes the brake pad to move away from the tape reel, and the biasing spring biases the disc to rotate in the first direction. ### Claim 8 (depends on 7) The tape measure as claimed in claim 7 wherein the spring mechanism includes a coiled flat spring. ### Claim 9 (depends on 7) The tape measure as claimed in claim 7 further including a lever for rotating the disc. ### Claim 10 (depends on 7) The tape measure as claimed in claim 7 wherein on the second side of the disc there are eight inclined cam surfaces each of which is inclined 40 degrees, and on the inner wall of the housing there are eight corresponding cam surfaces each of which is inclined 40 degrees. ### Claim 11 A tape measure comprising: a housing; a tape reel rotatably mounted within the housing; a measuring tape at least partially coiled about the tape reel, the measuring tape being movable between an extended position in which at least a portion of the measuring tape extends outwardly of the housing and a retracted position in which the measuring tape is substantially coiled about the tape reel and disposed within the housing; a spring mechanism for biasing the tape reel to rotate so as to move the measuring tape from the extended position towards the retracted position; a disc brake mechanism for applying a frictional force to the tape reel to control rotation of the tape reel and movement of the measuring tape from the extended position towards the retracted position, the disc brake mechanism including a disc rotatably mounted within the housing and a biasing spring for biasing the disc, a first side of the disc functioning as a brake pad to engage the tape reel so as to apply the frictional force to the tape reel, and a second side of the disc having a plurality of inclined cam surfaces arranged in annular formation which interact with a plurality of corresponding inclined cam surfaces arranged in annular formation on an inner wall of the housing; and wherein rotation of the disc in a first direction causes the brake pad to move towards the tape reel and rotation of the disc in a second direction causes the brake pad to move away from the tape reel, and the biasing spring biases the disc to rotate in the second direction. ### Claim 12 (depends on 11) The tape measure as claimed in claim 11 wherein the spring mechanism includes a coiled flat spring. ### Claim 13 (depends on 11) The tape measure as claimed in claim 11 further including a lever for rotating the disc. ### Claim 14 (depends on 11) The tape measure as claimed in claim 11 wherein on the second side of the disc there are eight inclined cam surfaces each of which is inclined 40 degrees, and on the inner wall of the housing there are eight corresponding cam surfaces each of which is inclined 40 degrees.