Device for retracting seat leg at angle, seat support, and seat unit

A seat support, comprising a seat frame mount, a seat linkage assembly, a driving connecting member, and device for retracting seat leg at angle, wherein the device for retracting seat leg at angle comprises a leg assembly hinged to a front end of a seat frame mount of a seat, the seat linkage assembly is rotatably connected below the seat frame mount, and the driving connecting member is connected to an end of the seat linkage assembly distal to the device for retracting seat leg at angle;

• the leg assembly comprises a footrest driving link, a footrest driven link, a first footrest link, a second footrest link, and a footrest member, wherein the footrest driving link and the footrest driven link are hinged to a front end of the seat frame mount respectively, an end of the first footrest link is hinged to the footrest driving link, an opposite end of the first footrest link is hinged to an end of the footrest member, an end of the second footrest link is hinged to the footrest driven link, and an opposite end of the second footrest link is hinged to a middle of the footrest member;
• the footrest member comprises a footrest plate mounting surface used to mount a footrest plate, wherein the footrest plate mounting surface is configured to be retracted below the seat frame mount and is configured to be oblique with respect to a horizontal plane upon the leg assembly being retracted to a limit position;
• wherein an included angle between the footrest plate mounting surface and a horizontal plane is configured to be 20°-26° upon the leg assembly being retracted to a limit position;
• wherein a distance from a connecting point between the second footrest link and the footrest member to the footrest plate mounting surface is less than a distance from a connecting point between the first footrest link and the footrest member to the footrest plate mounting surface;
• an interior side of the seat frame mount is provided with a mounting platform, wherein a height of the mounting platform is lower than an upper edge of the seat frame mount, and a plane where the mounting platform is positioned is a seat frame mounting surface;
• and
• a vertical distance H1 between a highest point where the seat frame mount is positioned on the seat frame mounting surface and a lowest point of the driving connecting member is not greater than 270 mm.

A seat unit, comprising a seat frame mount, a seat linkage assembly, a driving connecting member, a device for retracting seat leg at angle, and a backrest assembly, wherein the device for retracting seat leg at angle comprises a leg assembly hinged to a front end of a seat frame mount of a seat, the seat linkage assembly is rotatably connected below the seat frame mount, the driving connecting member is connected to an end of the seat linkage assembly distal to the device for retracting seat leg at angle, the backrest assembly comprises a backrest mounting member, and the backrest mounting member is used to connect and adjust a seat backrest;

• the leg assembly comprises a footrest driving link, a footrest driven link, a first footrest link, a second footrest link, and a footrest member, wherein the footrest driving link and the footrest driven link are hinged to a front end of the seat frame mount respectively, an end of the first footrest link is hinged to the footrest driving link, an opposite end of the first footrest link is hinged to an end of the footrest member, an end of the second footrest link is hinged to the footrest driven link, an opposite end of the second footrest link is hinged to a middle of the footrest member, and the footrest member comprises a footrest plate mounting surface used to mount a footrest plate;
• upon the seat unit being in a seated position, the leg assembly is configured to be retracted to a limit position, the footrest plate mounting surface is configured to be retracted below the seat frame mount and is configured to be oblique with respect to a horizontal plane;
• and
• a highest point of the seat frame mount is configured to be higher than a highest point of the backrest mounting member upon the seat unit being in a lying position.