Abstract: The backrest adjusting mechanism includes an adjusting base, a cushion, a supporting frame, a backrest, an air pressure rod, a connecting rod and a steel wire core; the cushion is fixed to a top of the adjusting base; the supporting frame is rotationally connected to a rear end of the adjusting base; the backrest is fixed on the supporting frame; the air pressure rod is rotationally connected with the supporting frame; the rear end of the base is provided with a fixing frame; the connecting rod is rotationally connected with the fixing frame and a movable rod; the connecting rod and the fixing frame are both provided with a limiting block; when the backrest is used, two of the limiting blocks are propped against each other to fix the backrest at a specific position.

Abstract: The backrest adjusting mechanism comprises an adjusting base, a cushion, a supporting frame, a backrest, an air pressure rod, a connecting rod and a steel wire core; the cushion is fixed to a top of the adjusting base; the supporting frame is rotationally connected to a rear end of the adjusting base; the backrest is fixed on the supporting frame; the air pressure rod is rotationally connected with the supporting frame; the rear end of the base is provided with a fixing frame; the connecting rod is rotationally connected with the fixing frame and a movable rod; the connecting rod and the fixing frame are provided with a limiting block; when the backrest is used, two of the limiting block are propped against each other to fix the backrest at a specific position.

Abstract: The backrest adjusting mechanism comprises a base, a cushion, a supporting frame, a backrest, an air pressure rod, a connecting rod and a steel wire core; the cushion is fixed to a top of the adjusting base; the supporting frame is rotationally connected to a rear end of the adjusting base; the backrest is fixed on the supporting frame; the air pressure rod is rotationally connected with the supporting frame; the rear end of the base is provided with a fixing frame; the connecting rod is rotationally connected with the fixing frame and a movable rod; the connecting rod and the fixing frame are provided with a limiting block; when the backrest is used, two of the limiting block are propped against each other to fix the backrest at a specific position.

Abstract: A jointed mechanism of an electric wheelchair is disclosed. The jointed mechanism includes symmetrically arranged front caster assemblies, symmetrically arranged rear caster assemblies, drive wheel assemblies, and a main chassis assembly. The front caster assemblies are bushed to the main chassis assembly and the rear caster assemblies respectively. The rear caster assemblies are fixed to the drive wheel assemblies by pivot arm plate assemblies and bushed to the main chassis assembly and the rear caster assemblies to construct a four-bar linkage, which allows the electric wheelchair to always have contact with the ground with all wheels and to adjust the center of gravity to maintain balance automatically, even when the electric wheelchair is climbing a slope or moving on an uneven surface.

Abstract: A jointed mechanism of an electric wheelchair is disclosed. The jointed mechanism includes symmetrically arranged front caster assemblies, symmetrically arranged rear caster assemblies, drive wheel assemblies, and a main chassis assembly. The front caster assemblies are bushed to the main chassis assembly and the rear caster assemblies respectively. The rear caster assemblies are fixed to the drive wheel assemblies by pivot arm plate assemblies and bushed to the main chassis assembly and the rear caster assemblies to construct a four-bar linkage, which allows the electric wheelchair to always have contact with the ground with all wheels and to adjust the center of gravity to maintain balance automatically, even when the electric wheelchair is climbing a slope or moving on an uneven surface.