Synchronous back and seat linkage device used for chair and chair

Abstract

The invention discloses a synchronous back and seat linkage device used for a chair. The device comprises a base, a bearing frame, a wane, a first connection rod and a second connection rod which aresymmetrically arranged on the two sides of the base leftward and rightward, and a crank, the two ends of the crank are respectively hinged to the upper portions of the first connection rod and the second connection rod, and the wane and the crank are connected integrally; the lower portions of the first connection rod and the second connection rod are hinged to the base separately; the lower portions of the first connection rod and the second connection rod are movably connected with the bearing frame, so that the first connection rod and the second connection rod are in linkage with the bearing frame; force is applied to and drives the wane, so that the wane contrarotates and moves forward at the same time, and the front and back portions of the bearing frame ascend at the same time; whenthe wane applied with force contrarotates, hinge points between the first and second connection rods and the crank move forward, therefore a virtual rotary shaft of the wane relative to the ground isalways located nearby the waist, the waist of the human body is regarded as a rotary axis of the upper part of the human body, that is, a back of the chair always closely fits the back of the human body, and the effect of always supporting the waist is achieved.

Description

technical field [0001] The invention relates to the technical field of swivel chairs and office chairs, in particular to a back seat synchronous linkage device for chairs and chairs. Background technique [0002] In the prior art, there is a linkage device for synchronizing the seat and the back of the chair. When the back of the chair is tilted back, the seat moves. Rod linkage and a lever to synchronize the tilt of the seat frame and back frame. The four-bar connection mechanism only includes two cranks, and the cranks are hinged between the base and the seat frame. The lever has two arms and has a fulcrum on the base. Wherein said one arm is integral with said seatback frame. Instead, the other arm acts on the rear of the seat frame and lifts or pulls the rear up or down depending on the angle and direction of inclination of the seat back. [0003] This approach makes the driving force of the back assembly opposed to the restoring force of the seat frame, so people wh...

AI Technical Summary

Problems solved by technology

But this linkage chair does not have the effect of self-adaptive gravity of DUPART patent; moreover, the hinge point of the backrest and the armrest is set on the armrest, so the armrest must ensure sufficient strength and support, which makes the armrest must exist, and it is difficult to improve its appearance

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