| 摘要 |
A height adjustment mechanism for a chair armrest contains: an inner tube, an adjusting member, an outer tube, a driving block, a fixing member, and a resilient element. The inner tube includes a base, an accommodating groove, and an elongated hole. The adjusting member includes a guiding slot, two toothed racks, and a plurality of guide teeth, wherein each guide tooth has a first crown portion, a first root portion, and a first bottom face. The outer tube includes a support plate an orifice. The driving block includes a pressing portion, two flanges, and plural positioning teeth, wherein a number of the plural positioning teeth is less than that of the plurality of guide teeth. The fixing member includes a first segment and a second segment. The resilient element is fixed in the inner tube and includes a first end abutting against the driving block and the fixing member. |
| 主权项 |
1. A height adjustment mechanism for a chair armrest comprising:
an inner tube including a base disposed on a bottom end thereof, an accommodating groove longitudinally defined on a first side thereof, and an elongated hole vertically formed on a second side thereof; an adjusting member mounted in the accommodating groove of the inner tube and including a guiding slot longitudinally arranged thereon, two toothed racks formed on two sides of the guiding slot, and a plurality of guide teeth arranged on the two toothed racks, wherein each guide tooth has a first crown portion defined on a top end thereof and formed in an arc shape, a first root portion extending between the top end and a bottom end of each guide tooth, and a first bottom face arranged on the bottom end thereof, wherein the first root portion of each guide tooth has two first arcuate sections extending outwardly from two sides of a bottom end thereof, and the first crown portion of each guide tooth has two first angled faces extending on two sides thereof; an outer tube fitted on the inner tube and including a support plate fixed on a top end thereof and an orifice formed on a first side thereof; a driving block including a pressing portion secured on one end thereof and extending out of the orifice of the outer tube, two flanges extending outwardly from two sides of the pressing portion and corresponding to the two toothed racks, and plural positioning teeth disposed on the sides of the two flanges facing and engaging with the plurality of guide teeth, wherein a number of the plural positioning teeth is less than that of the plurality of guide teeth, each positioning tooth has a second crown portion, a second root portion extending between a top end and a bottom end thereof, and a second bottom face, and wherein the second root portion has two second arcuate sections extending outwardly from two sides of a bottom end thereof, the second crown portion has a top face in an arc shape, and the second crown portion has two second angled faces extending on two sides thereof; a fixing member accommodated in the inner tube and including a first segment and a second segment, wherein the first segment is inserted through the elongated hole of the inner tube to retain in a second end of the outer tube opposite to the second end of the outer tube; a resilient element fixed in the inner tube and including a first end and a second end which abut against the driving block and the fixing member, wherein between the fixing member and the driving block is defined a compressing space which is larger than or equal to a depth of each positioning tooth. |
