# US 2019/0170493 A1 · Form measuring apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0170493 A1 - Document ID: US20190170493A1 - Status: Published application - Kind: A1 - Application number: 16/207,706 - Filed: 2018-12-03 - Published: 2019-06-06 - Earliest claimed: 2017-12-04 - Assignees: Mitutoyo Corporation - Applicants: Mitutoyo Corporation - Inventors: Atsushi SHIMAOKA; Kazuhiko HIDAKA - Web page: https://patentgrep.com/patent/US20190170493A1 ## CPC - G01B 5/201: {for measuring roundness} - G01B 5/0007: {Surface plates} - G01B 5/0009: {Guiding surfaces; Arrangements compensating for non-linearity there-of} - G01B 5/20: for measuring contours or curvatures - G01B 5/28: for measuring roughness or irregularity of surfaces - G01B 7/34: for measuring roughness or irregularity of surfaces - G01B 5/30: for measuring the deformation in a solid, e.g. mechanical strain gauge - G01B: MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS ## Abstract A form measuring apparatus includes a base; an arm capable of swinging relative to the base; a coupler coupling the base and the arm, and having a deformation region that is capable of elastic deformation between the base and the arm; and a distortion detector installed in the deformation region. In the form measuring apparatus, a stylus is mounted to the arm and can slide along a surface of a work piece. ## Claims ### Claim 1 A form measuring apparatus comprising: a base; an arm configured to swing relative to the base; a coupler that couples the base and the arm, the coupler having a deformation region that is capable of elastic deformation between the base and the arm; and a distortion detector installed in the deformation region. ### Claim 2 (depends on 1) The form measuring apparatus according to claim 1, further comprising a distance adjuster that adjusts a distance between the base and the arm, wherein the coupler is formed of an elastic material. ### Claim 3 (depends on 1) The form measuring apparatus according to claim 1, further comprising a placement adjuster that adjusts a position of the distortion detector within the deformation region in the coupling direction of the base and the arm. ### Claim 4 (depends on 2) The form measuring apparatus according to claim 2, further comprising a placement adjuster that adjusts a position of the distortion detector within the deformation region in the coupling direction of the base and the arm. ### Claim 5 (depends on 1) The form measuring apparatus according to claim 1, further comprising a limiter that constrains elastic deformation of the coupler in a portion between the base and the arm, wherein the coupler is formed of an elastic material. ### Claim 6 (depends on 1) The form measuring apparatus according to claim 1, wherein the coupler comprises at least one plate spring, a middle portion of which comprises the deformation region. ### Claim 7 (depends on 2) The form measuring apparatus according to claim 2, wherein the coupler comprises at least one plate spring, a middle portion of which comprises the deformation region. ### Claim 8 (depends on 3) The form measuring apparatus according to claim 3, wherein the coupler comprises at least one plate spring, a middle portion of which comprises the deformation region. ### Claim 9 (depends on 4) The form measuring apparatus according to claim 4, wherein the coupler comprises at least one plate spring, a middle portion of which comprises the deformation region. ### Claim 10 (depends on 5) The form measuring apparatus according to claim 5, wherein the coupler comprises at least one plate spring, a middle portion of which comprises the deformation region. ### Claim 11 (depends on 6) The form measuring apparatus according to claim 6, wherein the at least one plate spring is least one pair of plate springs that are intersectingly arranged with each other. ### Claim 12 (depends on 7) The form measuring apparatus according to claim 7, wherein the at least one plate spring is least one pair of plate springs that are intersectingly arranged with each other. ### Claim 13 (depends on 8) The form measuring apparatus according to claim 8, wherein the at least one plate spring is least one pair of plate springs that are intersectingly arranged with each other. ### Claim 14 (depends on 9) The form measuring apparatus according to claim 9, wherein the at least one plate spring is least one pair of plate springs that are intersectingly arranged with each other. ### Claim 15 (depends on 10) The form measuring apparatus according to claim 10, wherein the at least one plate spring is least one pair of plate springs that are intersectingly arranged with each other. ### Claim 16 (depends on 6) The form measuring apparatus according to claim 6, wherein the distortion detector comprises a pair of piezoelectric elements installed on opposing surfaces of the at least one plate spring such that the at least one plate spring is sandwiched between the pair of piezoelectric elements. ### Claim 17 (depends on 7) The form measuring apparatus according to claim 7, wherein the distortion detector comprises a pair of piezoelectric elements installed on opposing surfaces of the at least one plate spring such that the at least one plate spring is sandwiched between the pair of piezoelectric elements. ### Claim 18 (depends on 8) The form measuring apparatus according to claim 8, wherein the distortion detector comprises a pair of piezoelectric elements installed on opposing surfaces of the at least one plate spring such that the at least one plate spring is sandwiched between the pair of piezoelectric elements. ### Claim 19 (depends on 9) The form measuring apparatus according to claim 9, wherein the distortion detector comprises a pair of piezoelectric elements installed on opposing surfaces of the at least one plate spring such that the at least one plate spring is sandwiched between the pair of piezoelectric elements. ### Claim 20 (depends on 10) The form measuring apparatus according to claim 10, wherein the distortion detector comprises a pair of piezoelectric elements installed on opposing surfaces of the at least one plate spring such that the at least one plate spring is sandwiched between the pair of piezoelectric elements. ### Claim 21 (depends on 1) The form measuring apparatus according to claim 1, further comprising: a driver that is installed in the deformation region and that drives deformation of the coupler.