Fluid actuated friction damper

Abstract

The fluid actuated friction damper comprises a cylinder and an expandable piston assembly made up of a piston having two spaced apart parallel end walls which form an annular chamber, and two spaced apart side walls which project toward one another and terminate in two spaced apart parallel edges. These edges define a curved opening for the chamber which fronts upon the inside of the cylinder. A curved friction member is located between these edges in this opening, and is pressed against the inside of the cylinder by an underlying flexible actuator ring. This ring has a width greater than the spacing between the side wall edges and is located inside of the side walls so that the ring simultaneously self-seals against the side walls and bulges outwardly through the opening, thereby pressing the friction member against the inside of the cylinder when the chamber is pressurized. The friction member is contained in a fixed position with respect to the piston between the side wall edges, the inside of the cylinder and the flexible actuator ring. The frictional damping force obtained is controllable in relation to the direction of movement of the piston assembly within the cylinder, either by control of the fluid pressure applied to the chamber, or by control of the surface area of the actuator ring exposed to a single fluid pressure, using fluid pressure less than 35 psi.