Apparatus for cushioning shock forces acting on the underframe of a railway car

A cushion underframe for railway cars comprising:

• a pair of spaced bolsters extending laterally of the car and having aligned openings;
• a fixed sill extending lengthwise of the car through said aligned bolster openings;
• a movable sill disposed within said fixed sill and extending lengthwise of the car through said aligned bolster openings, said movable sill being movable relative to said fixed sill lengthwise of said car;
• cushion means disposed substantially adjacent each end of said sill for absorbing shocks generated during buff operating condition;
• low reaction cushion element affixed to said movable sill and operable during initial increments of the sill's movement to cushion longitudinal shock forces applied to said sill;
• stop means including a first plate attached to said movable sill on one side of a bolster and a second plate attached to the sill on the other side of the bolster equidistant from the first plate for limiting maximum lengthwise travel of said sill relative to said bolster;
• additional cushion means attached to said movable sill and located at approximately the longitudinal center thereof;
• means defining a pair of elongated slots formed in the movable sill on either side of said additional cushion means;
• and
• first and second follower members affixed to said fixed sill, with a first follower member extending within one of said slots and a second follower member extending within the other of said slots, the distance between said follower members and said cushion element being less than the distance between the stop means plates and bolster, with engagement between one of said follower members and said additional cushion means cushioning the impact force between said stop means and said bolster.