Shock absorbers and shock absorber struts, notably for aerodyne landing gear

A suspension shock absorber for the landing gear of an aerodyne, comprising

• a cylinder including a first chamber filled with hydraulic fluid and a second chamber containing a gas under pressure and forming a high-pressure elastic return chamber;
• said cylinder including a transverse wall separating said first and said second chambers and a sleeve extending along the axial length of said cylinder spaced from an inner wall thereof to form a free space therebetween and connected with said transverse wall;
• a separator piston mounted to slide in a leak-proof fashion in said second chamber;
• a shock absorber shaft containing a low pressure elastic return chamber and including means mounting said shaft to slide in a leak-proof fashion in the interior of said first chamber;
• said shock absorber shaft including a shaft piston at the end thereof sliding in said free space in the interior of said first chamber between said inner wall and said sleeve and guided on said sleeve;
• at least one permanent compression-throttling orifice formed in said cylinder;
• a grooved shaft connected with said separator piston passing through said transverse wall;
• means guiding said grooved shaft in the interior of said sleeve, the base of said sleeve adjacent to said transverse wall having a radial passage larger in section than that of said at least one permanent compression-throttling orifice;
• and
• groove means on said grooved shaft displaceable with said separator piston so that in the event of penetration of said shock absorber shaft into said cylinder at a rate very much higher than that for which said at least one permanent compression-throttling orifice is calibrated, said separator piston is displaced in said second chamber against said gas under pressure forming said high pressure elastic return chamber by uncovering said radial passage for the passage therethrough of the hydraulic fluid in said first chamber through said groove means and conditioned for the rate of penetration of said shaft into said cylinder.