Abstract: A support includes a base frame, a rotatable frame, an adjusting knob assembly and a spring element. Each leg of the base frame has a through hole formed with a protrusion and an L-shaped sliding groove. The rotatable frame pivotedly coupled to the base frame through a first shaft, which is rotatably inserted into the through hole and formed with a plurality of inner teeth. The adjusting knob has a guiding rib and a plurality of outer teeth respective to the inner teeth, and the guiding rib is slidable in and along the guiding groove portion and engagable in the engaging groove portion. The spring element surrounds the second shaft of the adjusting knob, as compressed between the protrusion and the insertion portion. Through operating the adjusting knob, the relative angle of the base frame and the rotatable frame switches between adjustable and fixed.

Abstract: A support includes a base frame, a rotatable frame, an adjusting knob assembly and a spring element. Each leg of the base frame has a through hole formed with a protrusion and an L-shaped sliding groove. The rotatable frame pivotedly coupled to the base frame through a first shaft, which is rotatably inserted into the through hole and formed with a plurality of inner teeth. The adjusting knob has a guiding rib and a plurality of outer teeth respective to the inner teeth, and the guiding rib is slidable in and along the guiding groove portion and engagable in the engaging groove portion. The spring element surrounds the second shaft of the adjusting knob, as compressed between the protrusion and the insertion portion. Through operating the adjusting knob, the relative angle of the base frame and the rotatable frame switches between adjustable and fixed.