US 11,751,691 B2
Seat connecting device with adjustable backrest
Zhenlin Meng, Dipu Town (CN); Chiachi Shu, Dipu Town (CN); Bin Zheng, Dipu Town (CN); Wenyuan Pan, Dipu Town (CN); and Kun Yang, Dipu Town (CN)
Assigned to Anji Deka Office System Co., Ltd., Dipu Town (CN)
Appl. No. 17/623,044
Filed by ANJI DEKA OFFICE SYSTEM CO., LTD., Dipu Town (CN)
PCT Filed Jun. 12, 2020, PCT No. PCT/CN2020/095705
§ 371(c)(1), (2) Date Dec. 27, 2021,
PCT Pub. No. WO2021/237811, PCT Pub. Date Dec. 2, 2021.
Claims priority of application No. 202010468052.7 (CN), filed on May 28, 2020; and application No. 202020932351.7 (CN), filed on May 28, 2020.
Prior Publication US 2022/0225777 A1, Jul. 21, 2022
Int. Cl. A47C 7/44 (2006.01); A47C 3/18 (2006.01)
CPC A47C 7/443 (2013.01) [A47C 7/446 (2013.01); A47C 3/18 (2013.01)] 12 Claims
OG exemplary drawing
 
1. A seat connecting device with an adjustable backrest, comprising a tray for connecting a gas spring; and a seat connector for installing a chair cushion, the seat connector being fixedly or movably connected to the tray;
wherein:
the tray has a first hinge point and a second hinge point; the seat connecting device further comprises a seat back connector, a first end of the seat back connector is a first hinge part, and a second end of the seat back connector is a free part for installing a backrest of a chair; an upper end of a middle part of the seat back connector is further provided with a second hinge part; the first hinge part is hinged to the first hinge point of the tray, the second hinge part is hinged to the second hinge point through a link and a triangular adjuster; the link has a first end and a second end, the triangular adjuster has a first hinge site at a top part, a second hinge site at a front end of the lower part, and a third hinge site at a rear end of the lower part that are respectively distributed in a triangle shape; the second hinge part is connected to the first end of the link, the second end of the link is hinged to the first hinge site of the triangular adjuster, and the second hinge site of the triangular adjuster is hinged to the second hinge point of the tray;
the seat connecting device further comprises a seat back tightness control assembly comprising a control handle that performs control by rotation, a universal joint, a transmission rod, a first bevel gear, a second bevel gear, a lifter, a mounting seat the lifter and a tightness adjust rod;
the first bevel gear has a first bevel tooth part and a mounting part; the mounting part is fixedly connected to a first end of the transmission rod, and a second end of the transmission rod is fixedly connected to a first end of the universal joint, and a second end of the universal joint is fixedly connected to the control handle;
the second bevel gear has a second bevel tooth part and a flat tooth part; the second bevel tooth part is engaged with the first bevel tooth part;
the lifter has a gear part, a thread part and a bearing part; the flat tooth part is engaged with the gear part of the lifter; the lifter is mounted on the mounting seat in a liftable manner through the thread part of the lifter;
a first end of the tightness adjust rod is fixedly connected to a crossbar, and another end is provided in the tray; a middle part of the crossbar is carried on the bearing part, two ends of the crossbar are respectively hinged with the third hinge site of the triangular adjuster through a first hinge arm and a second hinge arm; and the crossbar is hingedly provided adjacent to the second hinge point.