# US 12,759,173 B1 · Elbow assembly of a humanoid robot > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,759,173 B1 - Document ID: US12759173B1 - Status: Granted - Kind: B1 - Application number: 19/090,353 - Filed: 2025-03-25 - Granted: 2026-10-13 - Earliest claimed: 2024-03-25 - Assignees: Figure Ai Inc. - Applicants: Figure AI Inc. - Inventors: Nathan Jenest; Michael Stevens; David McCall - Web page: https://patentgrep.com/patent/US12759173B1 ## CPC - B25J 17/00: Joints - B25J: MANIPULATORS; CHAMBERS PROVIDED WITH MANIPULATION DEVICES ({manipulators specially adapted for use in surgery A61B34/70; manipulators used in cleaning hollow articles B08B9/04}; manipulators associated with rolling mills B21B39/20; manipulators associated with forging machines B21J13/10; {manipulators associated with picking-up and placing mechanisms B23P19/007}; means for holding wheels or parts thereof B60B30/00; {vehicles with ground-engaging propulsion means, e.g. walking members B62D57/02, B62D57/032; devices for picking-up and depositing articles or materials between conveyors B65G47/90, B65G47/91; manipulators with gripping or holding means for transferring packages B65H67/065}; cranes B66C; {manipulators used in the protection or supervision of pipe-line installations F17D5/00; walking equipment adapted for nuclear steam-generators F22B37/006}; manipulators specially adapted for, or associated with, nuclear reactors G21C; {apparatus used for handling wafers during manufacture or treatment of semiconductor H10P72/50}) ## Abstract A humanoid robot comprises a torso and an arm assembly with an upper arm twist actuator, lower humerus, upper forearm, and elbow actuator. The lower humerus features a humerus extender coupled to the twist actuator and an elbow actuator mating assembly with a curvilinear external surface. The upper forearm includes a coupling assembly with a U-shaped external surface in a first plane, and an extender with a U-shaped external surface in a second plane perpendicular to the first plane. The elbow actuator has one extent received within the mating assembly and another extent within the coupling assembly, with these assemblies collectively surrounding most of the elbow actuator. This configuration enables controlled arm movement while maintaining structural integrity at the elbow joint. ## Claims ### Claim 1 A humanoid robot comprising: an upper region including a torso and at least one arm assembly operably connected to the torso, and wherein when said arm assembly is in an extended state, the arm assembly includes: an upper arm twist actuator assembly with a rotational upper arm twist axis; a lower humerus with: (i) a lower humerus extender operably coupled to the upper arm twist actuator assembly and having a lower humerus center, and (ii) an elbow actuator mating assembly integrally formed with an extent of the lower humerus extender, and wherein an extent of the elbow actuator mating assembly has a curvilinear external surface; an upper forearm with: (i) an upper forearm coupling assembly that includes an external surface having a curvilinear extent that resides within a first plane, and (ii) an upper forearm extender integrally formed with an extent of the upper forearm coupling assembly and that includes an upper forearm center and an external surface having a curvilinear extent that resides within a second plane that is oriented perpendicular to the first plane; and an electric elbow actuator having: (i) an elbow axis that is offset from a plane that extends between the lower humerus center and the upper forearm center, (ii) a first extent positioned within a portion of the elbow actuator mating assembly, and (iii) a second extent positioned within a portion of the upper forearm coupling assembly, and wherein said elbow actuator mating assembly and said upper forearm coupling assembly collectively surround a majority of said electric elbow actuator. ### Claim 2 (depends on 1) The humanoid robot of claim 1, wherein a majority of the upper arm twist actuator assembly is located external to the lower humerus. ### Claim 3 (depends on 1) The humanoid robot of claim 1, wherein the arm assembly includes an energy attenuation member adapted to compress to limit movement of the upper forearm towards the lower humerus. ### Claim 4 (depends on 1) The humanoid robot of claim 1, wherein the electric elbow actuator includes a through bore opening formed through the electric elbow actuator, and wherein a wire bundle that receives electrical signals from the upper arm twist actuator assembly is positioned within said through bore opening. ### Claim 5 (depends on 1) The humanoid robot of claim 1, wherein the upper forearm coupling assembly includes a cover opening formed through an extent of said upper forearm coupling assembly, and wherein the electric elbow actuator includes an output that is coupled to the upper forearm coupling assembly by a coupling means that is accessible through the cover opening. ### Claim 6 (depends on 1) The humanoid robot of claim 1, wherein the elbow actuator mating assembly and the upper forearm coupling assembly each include a substantially circular edge configured to abut and rotate with respect to each other. ### Claim 7 (depends on 1) The humanoid robot of claim 1, wherein the electric elbow actuator comprises a rotary actuator having a strain wave gearbox and a brushless DC motor. ### Claim 8 (depends on 1) The humanoid robot of claim 1, further comprising at least one light emitting assembly positioned adjacent to the electric elbow actuator and configured to indicate an operational state of the humanoid robot arm. ### Claim 9 (depends on 1) The humanoid robot of claim 1, further comprising a rotation limiting system comprising: a limiting projection extending from an output adapter of the electric elbow actuator; and a limiting adapter coupled to the upper forearm and comprising a groove configured to receive the limiting projection, wherein the groove comprises a maximum wall and a minimum wall configured to limit rotation of the upper forearm relative to the lower humerus. ### Claim 10 (depends on 1) The humanoid robot of claim 1, wherein the lower humerus and the upper forearm are housed within a textile exterior covering. ### Claim 11 (depends on 1) The humanoid robot of claim 1, further comprising a lower arm twist actuator assembly with a rotational lower arm twist axis, and wherein the rotational lower arm twist axis is aligned in an arm plane with the rotational upper arm twist axis. ### Claim 12 (depends on 11) The humanoid robot of claim 11, wherein the elbow axis is offset from the arm plane. ### Claim 13 (depends on 12) The humanoid robot of claim 12, wherein the plane is coincident with the arm plane. ### Claim 14 (depends on 12) The humanoid robot of claim 12, wherein the elbow actuator has a center that is offset from the arm plane. ### Claim 15 A humanoid robot comprising: an upper region including a torso and at least one arm assembly operably connected to the torso, said arm assembly including: an upper arm twist actuator assembly having a projection and a rotational upper arm twist axis; a lower humerus with: (i) a lower humerus extender operably coupled to the upper arm twist actuator assembly and having a receiver configured to receive the projection of the upper arm twist actuator assembly, and (ii) an elbow actuator receiving assembly integrally formed with an extent of the lower humerus extender, and wherein an extent of the elbow actuator receiving assembly has a curvilinear external surface; an upper forearm with: (i) an upper forearm coupling assembly, and (ii) an upper forearm extender integrally formed with an extent of the upper forearm coupling assembly, and wherein an extent of the upper forearm extender has a curvilinear external surface; an elbow actuator having an output that is coupled to the upper forearm coupling assembly, and wherein a majority of said elbow actuator is positioned within an extent of the elbow actuator receiving assembly. ### Claim 16 (depends on 15) The humanoid robot of claim 15, wherein the arm assembly; does not include a single wire that traverses multiple degrees of freedom. ### Claim 17 (depends on 15) The humanoid robot of claim 15, further comprising at least one light emitting assembly positioned adjacent to the elbow actuator and configured to indicate an operational state of the humanoid robot arm. ### Claim 18 (depends on 15) The humanoid robot of claim 15, further comprising an energy attenuation member coupled to the lower humerus and configured to contact the upper forearm when the elbow actuator rotates the upper forearm towards the lower humerus. ### Claim 19 (depends on 15) The humanoid robot of claim 15, wherein the elbow actuator lacks a separate housing and is protected by the lower humerus and the upper forearm. ### Claim 20 (depends on 15) The humanoid robot of claim 15, wherein the upper forearm coupling assembly includes a curvilinear extent of an external surface residing within a first plane, and the upper forearm extender integrally formed with an extent of the upper forearm coupling assembly and that includes a curvilinear extent of the external surface residing within a second plane that is oriented perpendicular to the first plane. ### Claim 21 (depends on 15) The humanoid robot of claim 15, wherein the lower humerus and the upper forearm are housed within a textile exterior covering. ### Claim 22 (depends on 15) The humanoid robot of claim 15, further comprising a lower arm twist actuator assembly with a rotational lower arm twist axis, and wherein the rotational lower arm twist axis is aligned in an arm plane with the rotational upper arm twist axis.