| 摘要 |
<p>A base plate of a chair whose lifting and leaning force is adjustable pertains to the technical field of chair components. It includes a middle plate (2) and a big plate (1). The rear part of the big plate (1) can swing downwards relative to the middle plate (2) around a rotation shaft. A knob (4) with a cavity is disposed under the front part of the middle plate (2). A mounting plate (5) fixed with the knob (4) is arranged in the cavity of said knob (4), and a worm gear (6) that is rotatable relative to the knob (4) around its own shaft is disposed inside the knob (4) under the mounting plate (5). A worm (7) meshing with the worm gear (6) is disposed inside the knob (4) corresponding to the worm gear (6). One end of the handle (14) projects into the knob (4) from the outside of the knob (4) and connects with said worm (7) to transmit power. After passing through the big plate (1), the middle plate (2) and the mounting plate (5) inside the knob (4) from above down in turn, the adjusting bolt (18) is connected to said worm gear (6) via its own threads. Said adjusting bolt (18) is coaxially arranged with the worm gear (6). A coil spring (20) is disposed around the part of the adjusting bolt (18) which is below the middle plate (2) and above the mounting plate (5).</p> |
