| 主权项 |
1. A height adjustment assembly comprising:
a joint having:
a through hole defined therethrough;a tube inserted through the through hole;at least one clamping plate comprising a distal end, a free end, and a midsection therebetween, wherein:
the distal end is pivotally connected to the joint on a first side of the tube,the midsection is configured to matingly engage with an outer periphery of the tube; andthe free end is aligned with, and biased towards, a second side of the tube opposite the first side; and an adjustment handle connected to the joint rotatably about an axis substantially perpendicular to and intersecting the through hole, and having:
at least one annular ear integrally formed with the adjustment handle to enclose therein the free end of the clamping plate, anda non-circular block formed inside the at least one annular ear and rotatable about the axis such that an outer periphery of the block engages with the free end of the clamping plate; wherein rotation of the adjustment handle moves the joint between:
a locked condition, wherein the block is positioned such that the free end of the clamping plate rests against the block at a first radius from the axis, such that the midsection is lockingly engaged with the outer periphery of the tube, andan unlocked condition, wherein the block is positioned such that the free end of the clamping plate rests against the block at a second radius, larger than the first radius, such that the midsection is disengaged from the outer periphery of the tube. |
