# US 5,341,688 A · Force transducer > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,341,688 A - Document ID: US5341688A - Status: Granted - Kind: A - Application number: 07/995,826 - Filed: 1992-12-23 - Granted: 1994-08-30 - Earliest claimed: 1991-12-26 - Assignees: Kabushiki Kaisha Toyota Chuo Kenkyusho - Inventors: Takeshi Morikawa; Kouji Tsukada; Yutaka Nonomura; Yoshiteru Omura - Web page: https://patentgrep.com/patent/US5341688A ## CPC - G01L 1/18: using properties of piezo-resistive materials, i.e. materials of which the ohmic resistance varies according to changes in magnitude or direction of force applied to the material - G01L: MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE (weighing G01G) ## Abstract A force transducer comprises: an N-type silicon single crystal having a crystal face of (110) on which a force is applied; a pair of first electrodes and a pair of second electrodes mounted on the crystal face of (110) of the N-type silicon single crystal, the first electrodes facing in a direction angularly spaced by 135 degrees from a direction of <001> of the crystal, and the second electrodes being angularly spaced by 90 degrees from the first electrodes, one of the pairs of first and second electrodes being adapted to serve as input electrodes and the other being adapted to serve as output electrodes; a force transmission block connected to the crystal face of (110) of the N-type silicon single crystal for transmitting the force perpendicularly to the crystal face; and a support bed supporting the N-type silicon single crystal and connected to the N-type silicon single crystal at a face opposite to the crystal face to which the force transmission block is connected, the support bed being in the form of a planar structure having a horizontal cross-sectional shape with a short axis and a long axis. ## Claims ### Claim 1 A force transducer comprising: (a) an N-type silicon single crystal having a crystal face of (110) on which a force is to applied; (b) a pair of first electrodes and a pair of second electrodes mounted on the crystal face of (110) of said N-type silicon single crystal, said first electrodes facing in a direction angularly spaced by 135 degrees from a direction of <001> of the crystal, and said second electrodes being angularly spaced by 90 degrees from said first electrodes, one of said pairs of first and second electrodes being adapted to serve as input electrodes and the other being adapted to serve as output electrodes; (c) a force transmission block connected to the crystal face of (110) of said N-type silicon single crystal for transmitting the force perpendicularly to the crystal face; and (d) a support bed supporting said N-type silicon single crystal and connected to said N-type silicon single crystal at a face opposite to the crystal face to which said force transmission block is connected, said support bed being in the form of a planar body having a horizontal cross-sectional shape with a short axis and a long axis which are different in length. ### Claim 2 (depends on 1) A force transducer according to claim 1, wherein the horizontal cross-sectional shape of said support bed is such that the ratio of the short axis to the long axis (long axis/short axis) is in the range of 1.0 to 4.0. ### Claim 3 (depends on 2) A force transducer according to claim 2, wherein the horizontal cross-sectional shape of said support bed is such that the ratio of the short axis to the long axis is in the range of 1.5 to 4.0. ### Claim 4 (depends on 1) A force transducer according to claim 1, wherein the horizontal cross-sectional shape of said support bed is rectangular. ### Claim 5 (depends on 1) A force transducer according to claim 1, wherein the horizontal cross-sectional shape of said support bed is an ellipse, a rhombus or a parallelogram. ### Claim 6 (depends on 1) A force transducer according to claim 1, wherein said input electrodes are angularly spaced by 135 degrees from the direction of <001> of said N-type silicon single crystal and said output electrodes are angularly spaced by 90 degrees from said input electrodes. ### Claim 7 (depends on 6) A force transducer according to claim 6, wherein the long axis of said support bed is at an angle ranging between about +35 degrees and about -35 degrees with respect to the direction of <1-10> of said N-type silicon single crystal. ### Claim 8 (depends on 7) A force transducer according to claim 7, wherein the long axis of said support bed is at an angle ranging between about +30 degrees and about -30 degrees with respect to the direction of <1-10> of said N-type silicon single crystal. ### Claim 9 (depends on 8) A force transducer according to claim 8, wherein the long axis of said support bed is aligned with the direction of <1-10> of said N-type silicon single crystal. ### Claim 10 (depends on 1) A force transducer according to claim 1, wherein said output electrodes are angularly spaced by 135 degrees from the direction of <001> of said N-type silicon single crystal and said input electrodes are angularly spaced by 90 degrees from said output electrodes. ### Claim 11 (depends on 10) A force transducer according to claim 10, wherein the long axis of said support bed is at an angle ranging between about +35 degrees and about -35 degrees with respect to the direction of <001> of said N-type silicon single crystal. ### Claim 12 (depends on 11) A force transducer according to claim 11, wherein the long axis of said support bed is at an angle ranging between about +30 degrees and about -30 degrees with respect to the direction of <001> of said N-type silicon single crystal. ### Claim 13 (depends on 12) A force transducer according to claim 12, wherein the long axis of said support bed is aligned with the direction of <001> of said N-type silicon single crystal. ### Claim 14 (depends on 1) A force transducer according to claim 1, wherein said N-type silicon single crystal is of a rectangular parallelepiped. ### Claim 15 (depends on 1) A force transducer according to claim 1, wherein said N-type silicon single crystal is smaller than said support bed as viewed in plan. ### Claim 16 (depends on 1) A force transducer according to claim 1, wherein said electrodes are mounted on an upper surface of said N-type silicon single crystal. ### Claim 17 (depends on 1) A force transducer according to claim 1, wherein a top surface of said N-type silicon single crystal has a shape which is identical with a shape of a top surface of said force transmission block, wherein the top surfaces of said N-type silicon single crystal and said force transmission block are a same size so that N-type silicon single crystal is completely superimposed on the force transmission block, and wherein said electrodes are mounted on a side surface of said N-type silicon single crystal. ### Claim 18 (depends on 1) A force transducer according to claim 1, wherein said N-type silicon single crystal is formed by diffusing impurities such as phosphorus or arsenic into a P-type silicon single crystal. ### Claim 19 (depends on 18) A force transducer according to claim 18, wherein said N-type silicon single crystal is formed on a part of said P-type silicon single crystal, and wherein said electrodes are mounted around said N-type silicon crystal. ### Claim 20 (depends on 1) A force transducer according to claim 1, wherein said support bed is made of a high-rigidity material such as crystalline glass or fiber reinforced resin.