Gas spring for tables and chairs with outer cylinder

摘要

Gas spring for adjusting the height of chairs, tables etc. has a housing defined by an outer cylinder (3) contg. a piston displaceable along its longitudinal axis (21) and fixed to a piston rod projecting beyond one end of the cylinder. A valve is provided for adjustment of the length of the gas spring. The improvement is that a thin, hard outer nitrided layer (43) is formed on the outside of the cylinder and a substantially softer core layer (44) includes the inside surface of the cylinder.