Variable height adjustment for camping chairs and tables - centrally operated linkage withdraws locking pins from legs for relocating

摘要

The seat has circular tubular supports, sliding in square tubular legs, joined together by wooden rails, springs biassing the seat upwards. A central rod, pivoting on a fixed stay has four sets of linkages, two being straight links at each end of the rod. The intermediate sets have links in Z formation, also pivoting on the fixed stay. A srping loaded knob in one rail moves the central rod sideways, simultaneously extracting locking pins from holes in the supports. The seat is pressed down, the knob released and the pins relocate in another set of holes.