A damping apparatus for damping vibrations in a vibrating system including
a piston which is reciprocally movable in a hydraulic fluid filled damper
chamber, piston movement in either direction of movement being resisted
by fluid pressure in the damper chamber behind the piston, which
resistance provides damping forces which act to oppose piston movement,
the piston being connected to one component of the vibrating system and
the damping chamber being connected to a second component of the
vibrating system, characterised in that the fluid at at least a first
side of the piston acts on a movable part which is movable in response to
changing fluid pressure in the damper chamber at the first side of the
piston as the piston moves, the movable member providing a relief volume
for the fluid into which and from which fluid may flow from and towards
the first side of the piston without passing to an opposite second side
of the piston.