Backrest Rotation Mechanism

Abstract

This invention relates to a backrest rotation mechanism, which mainly consists of a rotation mechanism between the backrest and the chair back tube. The backrest has a mounting base with a rotating groove, and a main seat is assembled on the chair back tube to correspondingly embed into the rotating groove. Two corresponding elastic fasteners are provided between the main seat and the mounting base. These fasteners can be engaged with the main seat to position the backrest, or disengaged from the main seat by a pressing action of a pressing unit, thereby driving the backrest to rotate. This allows users of different heights to rotate and adjust the backrest support height according to their needs. Besides adjusting the backrest support comfort, it also allows the backrest to be lowered to reduce packaging volume, increase the number of containers that can be packed, and achieve the effect of convenient transportation.

Claims

1. A backrest rotation mechanism, mainly provided between the backrest and the chair back tube, the rotation mechanism comprising: a mounting base, attached to one end of the backrest, the mounting base having a protrusion in the center and a rotating channel formed around it, a pivot hole in the center of the protrusion, and at least two insertion holes around the pivot hole, in which an elastic element and a fastener are sequentially inserted; a main seat, correspondingly attached to the chair back tube, the main seat having a concave space in the center corresponding to the protrusion, and an annular edge around it that can be embedded in the rotating channel, a fixed shaft hole in the main seat corresponding to the pivot hole, and a through hole corresponding to the at least two insertion holes; and a shaft rod, correspondingly inserted through the fixed shaft hole of the main seat and the pivot hole of the mounting base, so as to rotatably mount the backrest to the chair back tube. A pressing unit comprises a first section and a second section with different outer diameters, and a protruding ring is provided between the two sections. The first section is embedded in the through hole. A cover is provided with a slot that can accommodate the protruding ring of the pressing unit, and a through hole is provided in the slot for the second section of the pressing unit to pass through. The cover is correspondingly locked on the main seat to cover and position the pressing unit.

2. The backrest rotation mechanism as described in claim 1, wherein a bushing is further provided in the fixed shaft hole of the main seat and the rotating shaft hole of the mounting seat, the bushing being for the shaft to pass through and be fixed.

3. The backrest rotation mechanism as claimed in claim 1 or 2, wherein the backrest system has a first end and a second end with different curvatures or different shapes.

Images