Abstract: The vertical vibration isolation system of the present invention includes a bearing base, a guide rail assembly and a plurality of buckling elements. The bearing base has an upper platform that can move along a vertical direction. The guide rail assembly surrounds the bearing base and has a plurality of arc-shaped sliding channels. The top portion of each buckling element can move with the upper platform, while the bottom portion of each buckling element is slidably connected to the corresponding arc-shaped sliding channel. The vertical displacement of the upper platform would cause different degrees of buckling of the buckling elements and also induces sliding motion of the bottom portion of the buckling elements along the arc-shaped sliding channels. Accordingly, the vertical vibration isolation system can provide nonlinear restoring force by buckling and sliding mechanisms so as to exhibit vertical vibration isolation effect.

Abstract: A railcar end unit is operable to be mounted in a center sill between buff and draft sill stops. The buff and draft end bodies are configured to be shiftably mounted relative to the center sill to engage the respective sill stops and to shift axially relative to one another along a unit axis. The end unit includes a buff spring pack operably mounted between the end bodies and compressible along the unit axis from a neutral condition to a compressed condition.