Abstract: For relieving the impact force of a collision and insuring passenger safety by building an easily destructible structure into a railroad car underframe, two transversally extending cross or end sills 21, 23 are disposed in parallel and longitudinally spaced apart relation at the front end of a railroad car underframe 1 and energy absorbing sills 61 adapted to absorb shock energy by undergoing wall buckling when subjected to a shock load exceeding a predetermined value from the front of the car is disposed between the cross beams.

Abstract: The car under-frame of the invention comprises a planar coupling member 2 projecting from a first car C toward a second car B, a bearing inner ring 3 positioned on the upper side of planar coupling member 2 and secured rigidly thereto, a bearing outer ring 6 disposed on the outer peripheral side of bearing inner ring 3 through balls, a bearing step 5 positioned on the upper side of bearing outer ring 6 and to which the bearing outer ring is rigidly secured, and an articular coupling member 7 projecting from the second car B toward the first car C to grip a mounting arm 5b of bearing step 5. The mounting arm 5b of bearing step 5 is integral with a generally discoid body segment 5a and disposed below the top end face of body segment 5a and extending radially outwardly from either side of body segment 5a. In accordance with the invention there can be provided a under-frame structure which makes it possible to lower the car floor level without interfering with strength and coupler performance.

Abstract: A pin plug comprises a plug cover made of a substantially cylindrical body of a metal and having a front end divided into several branches and a pin made of a substantially tubular body of a metal and arranged inside of said plug cover coaxially therewith, two conductors of an electric wire being connected to said plug cover and pin, respectively by soldering or clamping. The pin plug further comprises a molded body of electrically insulating synthetic resin which covers the rear ends of said plug cover and pin and that end of the electric wire which is connected to said plug cover and pin, so that the plug cover and pin are fixed in position without using an electrically insulating plate.