# US 2017/0291311 A1 · Robot arm mechanism and linear extension and retraction mechanism > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2017/0291311 A1 - Document ID: US20170291311A1 - Status: Published application - Kind: A1 - Application number: 15/634,483 - Filed: 2017-06-27 - Published: 2017-10-12 - Earliest claimed: 2014-12-27 - Assignees: Life Robotics Inc. - Applicants: Life Robotics Inc. - Inventors: Woo-Keun YOON - Web page: https://patentgrep.com/patent/US20170291311A1 ## CPC - B25J 18/04: rotatable - B25J 9/102: {Gears specially adapted therefor, e.g. reduction gears (gearings in general F16H)} - B25J 17/00: Joints - B25J 18/02: extensible - F16G 13/20: stiff; Push-pull chains - F16H 19/02: for interconverting rotary {or oscillating} motion and reciprocating motion - F16H 19/04: comprising a rack - F16H 19/0636: {the flexible member being a non-buckling chain} - F16H 2019/0613: {the flexible member being a toothed belt or chain engaging a rack} - 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}) - F16G: BELTS, CABLES, OR ROPES, PREDOMINANTLY USED FOR DRIVING PURPOSES; CHAINS; FITTINGS PREDOMINANTLY USED THEREFOR - F16H: GEARING ## Abstract A purpose is to improve movement characteristics of a linear extension and retraction mechanism. A robot arm mechanism includes a revolute joint and a linear extension and retraction joint. The linear extension and retraction joint includes a plurality of first connection pieces coupled together bendably on a bottom plate side and provided with a U-shaped cross section, and a plurality of second connection pieces coupled together bendably and each shaped like a flat plate. A foremost one of the plurality of second connection pieces is connected with a foremost one of the plurality of first connection pieces. The first and second connection pieces, when overlapped each other, form a columnar body by being constrained from bending. The columnar body is relaxed when the first and second connection pieces are separated from each other. An ejection section forms the columnar body by joining together the first and second connection pieces and supports the columnar body. A linear gear is formed on a surface of a bottom plate of each of the first connection pieces. A drive gear is engaged with the linear gears of the first connection pieces overlapped to the second connection pieces in the ejection section. ## Claims ### Claim 1 A robot arm mechanism comprising a revolute joint and a linear extension and retraction joint, wherein: the linear extension and retraction joint includes a plurality of first connection pieces coupled together bendably on a bottom plate side and provided with a U-shaped cross section; a plurality of second connection pieces coupled together bendably and each shaped like a flat plate, a foremost one of the plurality of second connection pieces is connected with a foremost one of the plurality of first connection pieces, the first and second connection pieces forming a columnar body when overlapped each other, the columnar body being relaxed when the first connection pieces and the second connection pieces are separated from each other; an ejection section adapted to form the columnar body by joining together the first and second connection pieces and support the columnar body; and a movement section adapted to move the first and second connection pieces in an ejection direction; wherein a linear gear is formed on a surface of a bottom plate of each of the first connection pieces; the movement section includes a drive gear engaged with the linear gears of the first connection pieces overlapped to the second connection pieces in the ejection section. ### Claim 2 (depends on 1) The robot arm mechanism according to claim 1, wherein: another linear gear is provided on a back face of each of the second connection pieces; and the movement section includes another drive gear engaged with the other linear gears of the second connection pieces separated from the first connection pieces outside the ejection section. ### Claim 3 A robot arm mechanism comprising a revolute joint and a linear extension and retraction joint, wherein: the linear extension and retraction joint includes a plurality of first connection pieces coupled together bendably on a bottom plate side and provided with a U-shaped cross section; a plurality of second connection pieces coupled together bendably and each shaped like a flat plate, a foremost one of the plurality of second connection pieces being connected with a foremost one of the plurality of first connection pieces, the first and second connection pieces forming a columnar body when overlapped each other, the columnar body being relaxed when the first connection pieces and the second connection pieces are separated from each other; an ejection section adapted to form the columnar body by joining together the first and second connection pieces and support the columnar body, and a movement section adapted to move the first and second connection pieces in an ejection direction; wherein a linear gear is formed on a lateral surface of each of the first connection pieces; and the movement section includes a drive gear engaged with the linear gears of the first connection pieces overlapped to the second connection pieces in the ejection section. ### Claim 4 A robot arm mechanism comprising a revolute joint and a linear extension and retraction joint, wherein: the linear extension and retraction joint includes a plurality of first connection pieces coupled together bendably on a bottom plate side and provided with a U-shaped cross section; a plurality of second connection pieces coupled together bendably and each shaped like a flat plate, a foremost one of the plurality of second connection pieces being connected with a foremost one of the plurality of first connection pieces, the first and second connection pieces forming a columnar body when overlapped each other, the columnar body being relaxed when the first connection pieces and the second connection pieces are separated from each other; an ejection section adapted to form the columnar body by joining together the first and second connection pieces and support the columnar body, and a movement section adapted to move the first and second connection pieces in an ejection direction, wherein respective linear gears are formed on opposite lateral surfaces of each of the first connection pieces; and the movement section includes a pair of drive gears engaged with the linear gears of the first connection pieces overlapped to the second connection pieces in the ejection section. ### Claim 5 A linear extension and retraction mechanism comprising: a plurality of first connection pieces coupled together bendably on a bottom plate side and provided with a U-shaped cross section; a plurality of second connection pieces coupled together bendably and each shaped like a flat plate, a foremost one of the plurality of second connection pieces is connected with a foremost one of the plurality of first connection pieces, the first and second connection pieces, when overlapped each other, form a columnar body by being constrained from bending, the columnar body is relaxed when the first connection pieces and the second connection pieces are separated from each other; an ejection section adapted to form the columnar body by joining together the first and second connection pieces and support the columnar body; and a movement section adapted to move the first and second connection pieces in an ejection direction, wherein a linear gear is formed on a surface of a bottom plate of each of the first connection pieces, and the movement section includes a drive gear engaged with the linear gears of the first connection pieces overlapped to the second connection pieces in the ejection section. ### Claim 6 (depends on 5) The linear extension and retraction mechanism according to claim 5, wherein: another linear gear is provided on a back face of each of the second connection pieces; and the movement section includes another drive gear engaged with the other linear gears of the second connection pieces separated from the first connection pieces outside the ejection section. ### Claim 7 A linear extension and retraction mechanism comprising: a plurality of first connection pieces coupled together bendably on a bottom plate side and provided with a U-shaped cross section; a plurality of second connection pieces coupled together bendably and each shaped like a flat plate, wherein a foremost one of the plurality of second connection pieces being connected with a foremost one of the plurality of first connection pieces, the first and second connection pieces forming a columnar body when overlapped each other, the columnar body being relaxed when the first connection pieces and the second connection pieces are separated from each other; an ejection section adapted to form the columnar body by joining together the first and second connection pieces and support the columnar body; and a movement section adapted to move the first and second connection pieces in an ejection direction, wherein a linear gear is formed on a lateral surface of each of the first connection pieces, and the movement section includes a drive gear engaged with the linear gears of the first connection pieces overlapped to the second connection pieces in the ejection section. ### Claim 8 A linear extension and retraction mechanism comprising: a plurality of first connection pieces coupled together bendably on a bottom plate side and provided with a U-shaped cross section; a plurality of second connection pieces coupled together bendably and each shaped like a flat plate, a foremost one of the plurality of second connection pieces being connected with a foremost one of the plurality of first connection pieces, the first and second connection pieces forming a columnar body when overlapped each other, the columnar body being relaxed when the first connection pieces and the second connection pieces are separated from each other; an ejection section adapted to form the columnar body by joining together the first and second connection pieces and support the columnar body; and a movement section adapted to move the first and second connection pieces in an ejection direction, wherein respective linear gears are formed on opposite lateral surfaces of each of the first connection pieces, and the movement section includes a pair of drive gears engaged with the linear gears of the first connection pieces overlapped to the second connection pieces in the ejection section.