Patent ID: 6010119
Filing Date: 2000-01-04
Classification: F16F

Abstract:
An adjustable pneumatically operated cylinder for use on exercise equipment or chairs, comprising an external tube, a core shaft, a piston, an upper fixing seat, a sealing ring, a lower fixing mount, an adjustment bolt, an adjustable piston, an adjustment base, a rubber washer, a pair of O-shaped rings and a nut; said piston secured to a narrowed bottom end of said core shaft by means of said nut along with a washer and being movable in said external tube; on a top side of said piston being also disposed a washer engaged with the core shaft; on an intermediate periphery of said piston being disposed a groove for housing said O-shaped ring; said piston being placed in the upper portion of said external tube and the lower fixing mount with the sealing ring as well as the upper fixing seat being integrally mounted onto the core shaft and limited in position at the upper end of the external tube; said cylinder being characterized by that said adjustment base being secured to a bottom end opposite to said upper fixing seat of said external tube; the center of said adjustment base being provided with a threaded hole so as to permit said threaded adjustment bolt to be adjustably engaged with said adjustment base with part thereof sticking into said external tube and threadedly secured to said adjustable piston at its top end; said adjustment bolt being provided with a turning knob at its bottom end so as to render said adjustment bolt with said adjustable piston to rotational move forward or backward to vary the size of air chamber defined between said movable piston and said adjustable piston in said external tube whereby the air pressure in said air chamber can be varied as a result of the change of the volume of said air chamber; said adjustment base has a downward extension protecting out of said external tube; and extension having a central through innerly threaded hole is provided with outer threads so as to permit a universal joint to be removably engaged therewith and said adjustment bolt to be adjustably housed therein; said adjustment bolt has an upper end engaged with said adjustable piston and a lower end provided with a hexagon-shaped cavity for effecting adjustment of the position of said adjustable piston in said external tube; said core shaft connected to said piston is also provided with a universal joint.