Rail car suspension damping

摘要

A freight rail car suspension has independent but co-operating springs; a first spring is load carrying and has a variable damping function and a second control spring operates on a friction shoe to apply a constant damping component. A practical embodiment has a friction shoe engaged for vertical displacement by the first spring which is mounted on a side frame and the second spring is obliquely arranged between the bolster of the bogie and the friction shoe, which has guides to cause it to move into greater frictional engagement upon load being applied through the spring. This arrangement provides a dual damping characteristic involving both constant damping and variable damping forces.