Telescopic support column for gymnastic horizontal bar - has underfloor outer cylinder with pneumatic brake action

摘要

The column consists of a hollow square tube which can be moved up and down in the outer cylinder. The latter is sunk below floor level. The lower end of the column is fitted with a piston cap and a pliable sealing cap similar to those used in bicycle pumps. A rubber disc valve is fitted over air ducts passing through the piston unit. The closed lower end of the cylinder tube contains a quantity of lubricant. During lowering of the column air pressure increases and together with the lubricant acts as a shock absorber. The air can escape gradually through a small central air passage. The design eliminates counter-balancing weights and pulleys. A lock mechanism is fitted at the upper end of the cylinder tube.