# US 8,770,768 B2 · Spherical mechanical linkage and multi-axis trackers > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,770,768 B2 - Document ID: US8770768B2 - Status: Granted - Kind: B2 - Application number: 14/034,267 - Filed: 2013-09-23 - Published: 2014-02-13 - Granted: 2014-07-08 - Earliest claimed: 2012-06-28 - Applicants: Donald E. Hultberg - Inventors: Donald E. Hultberg - Web page: https://patentgrep.com/patent/US8770768B2 ## CPC - F16H 21/52: for interconverting rotary motion and oscillating motion - G01S 3/7861: {Solar tracking systems} - G02B 5/08: Mirrors {(vehicle mirrors involving special optical features B60R1/08)} - G02B 7/183: specially adapted for very large mirrors, e.g. for astronomy, {or solar concentrators} - Y10T 74/18248: Crank and slide - F16H: GEARING - G01S: RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract Spherical mechanical linkages may include a yoke defining a first axis and a second axis, a crank rotatably coupled to the yoke about the first axis; a deflecting member that defines a plane and that is coupled to the crank along a third axis, and a rocking frame slideably coupled to the yoke in the plane defined by the deflecting member and rotatably coupled to the yoke about the second axis. Such spherical mechanical linkages may further include a stub shaft coupled to the deflecting member and rotatably coupled to the crank along a fourth axis. One or more components of the spherical mechanical linkage may be symmetric about an axis. A payload, such as a mirror or a camera, can be mounted on the linkage as part of a multi-axis tracker. ## Claims ### Claim 1 A spherical mechanical linkage comprising: a yoke comprising an annular section and one or more yoke bearing points, the yoke defining a first intersecting axis and a second intersecting axis perpendicular to the first intersecting axis, the one or more yoke bearing points being disposed on the yoke on the second intersecting axis; a crank comprising a crank bearing, the crank being rotatably coupled to the yoke about the first intersecting axis, the crank having a symmetry about the first intersecting axis; a rocking frame comprising an annular section rotatably coupled to the yoke about the second intersecting axis at the one or more yoke bearing points, the rocking frame defining a plane; a deflecting member slideably coupled at one or more bearing points to the rocking frame along a third intersecting axis; and a stub shaft coupled to the deflecting member and rotatably coupled to the crank along a fourth axis. ### Claim 2 (depends on 1) The spherical mechanical linkage of claim 1, wherein the third intersecting axis intersects with the first intersecting axis at an angle substantially equal to a planet's angle of obliquity. ### Claim 3 (depends on 1) The spherical mechanical linkage of claim 1, wherein the deflecting member comprises an annular section. ### Claim 4 (depends on 1) The spherical mechanical linkage of claim 1, wherein the first intersecting axis, the second intersecting axis, and the third intersecting axis intersect at an intersection point in the plane. ### Claim 5 (depends on 4) The spherical mechanical linkage of claim 4, wherein the intersection point and the plane define a payload axis normal to the plane and passing through the intersection point. ### Claim 6 A multi-axis tracking system comprising: a base; a spherical mechanical linkage mounted on the base, the spherical mechanical linkage comprising: a yoke comprising an annular section, the yoke defining a first intersecting axis and a second intersecting axis perpendicular to the first intersecting axis; a crank rotatably coupled to the yoke about the first intersecting axis, the crank having a symmetry with respect to the first intersecting axis; a rocking frame comprising an annular section rotatably coupled to the yoke about the second intersecting axis, the rocking frame defining a plane; a deflecting member slideably coupled at one or more bearing points to the rocking frame along a third intersecting axis; and a stub shaft coupled to the deflecting member and rotatably coupled to the crank along a fourth axis; a yoke driver configured to drive the yoke about the first intersecting axis; and a crank driver configured to drive the crank about the first intersecting axis. ### Claim 7 (depends on 6) The multi-axis tracking system of claim 6, wherein the first intersecting axis, the second intersecting axis, and the third intersecting axis intersect at an intersection point in the plane. ### Claim 8 (depends on 7) The multi-axis tracking system of claim 7, wherein the intersection point and the plane define a payload axis normal to the plane and passing through the intersection point. ### Claim 9 (depends on 6) The multi-axis tracking system of claim 6 further comprising a payload mounted on the rocking frame. ### Claim 10 (depends on 6) The multi-axis tracking system of claim 6, wherein the first intersecting axis is substantially parallel to a planet's axis of rotation. ### Claim 11 (depends on 10) The multi-axis tracking system of claim 10, wherein the third intersecting axis intersects with the first intersecting axis at an angle substantially equal to the planet's angle of obliquity. ### Claim 12 (depends on 11) The multi-axis tracking system of claim 11, wherein: the yoke driver drives the yoke about the first intersecting axis at a rate of about 360 degrees per mean solar day; and the crank driver drives the crank about the first intersecting axis at a rate of about 360 degrees per sidereal day. ### Claim 13 (depends on 12) The multi-axis tracking system of claim 12 further comprising an equation-of-time correction mechanism coupled to the yoke driver. ### Claim 14 (depends on 13) The multi-axis tracking system of claim 13, wherein the payload comprises a mirror. ### Claim 15 (depends on 14) The multi-axis tracking system of claim 14, wherein the mirror comprises a substantially paraboloidal portion. ### Claim 16 (depends on 15) The multi-axis tracking system of claim 15, wherein the substantially paraboloidal portion of the mirror defines a focal point along the payload axis. ### Claim 17 (depends on 16) The multi-axis tracking system of claim 16 further comprising an energy receiver disposed at the focal point. ### Claim 18 (depends on 17) The multi-axis tracking system of claim 17 further comprising an energy conduit configured to transmit energy received by the energy receiver. ### Claim 19 (depends on 16) The multi-axis tracking system of claim 16, wherein the first intersecting axis, the second intersecting axis, and the third intersecting axis intersect at an intersection point in the plane and wherein the focal point and the intersection point are identical. ### Claim 20 (depends on 14) The multi-axis tracking system of claim 14, wherein the mirror comprises a substantially planar portion.