B61F—RAIL VEHICLE SUSPENSIONS, e.g. UNDERFRAMES, BOGIES OR ARRANGEMENTS OF WHEEL AXLES; RAIL VEHICLES FOR USE ON TRACKS OF DIFFERENT WIDTH; PREVENTING DERAILING OF RAIL VEHICLES; WHEEL GUARDS, OBSTRUCTION REMOVERS OR THE LIKE FOR RAIL VEHICLES
B61F5/00—Constructional details of bogies; Connections between bogies and vehicle underframes; Arrangements or devices for adjusting or allowing self-adjustment of wheel axles or bogies when rounding curves
B61F5/26—Mounting or securing axle-boxes in vehicle or bogie underframes
B61F5/30—Axle-boxes mounted for movement under spring control in vehicle or bogie underframes
B61F5/301—Axle-boxes mounted for movement under spring control in vehicle or bogie underframes incorporating metal springs