A torsional vibration damper, particularly for use between the engine and
the transmission of the power train in a motor vehicle, including two
flywheels rotatable relative to each other against the opposition of a
first energy storing device employing, for example, one or more coil
springs and a second energy storing device, which is carried by one of
the flywheels, which operates in parallel with the first energy storing
device and which opposes rotation of the two flywheels relative to each
other. In order to isolate the irregularities of movement of the first
flywheel (such as vibrations which develop while the engine is in
operation) from the second flywheel, the second energy storing device
(such as a snap spring or a set of diaphragm springs) is coupled to the
flywheels in such a way that the second flywheel develops a degressive
action only when the first flywheel is caused to move through relatively
small angles (especially between 1.degree. and 10.degree.) but not when
the angles are larger (especially larger than 10.degree.).