Patent ID: 7004079

Claim:
A truck for a railroad freight car comprising: wheelsets, a pair of first and second sideframes mounted to said wheelsets, and a bolster mounted cross-wise between said sideframes; said sideframes being free of unsprung lateral connection interconnecting the sideframes; wherein, the lateral connection of which said side frame are being free is chosen from the set consisting of a transom, cross brace members, and lateral extending rods; said bolster having a first end borne by a lower region of said first sideframe, and a second end borne by a lower region of said second sideframe; a first group of friction dampers being mounted between said first end of said bolster and said first sideframe; a second group of friction dampers being mounted between said second end of said bolster and said second sideframe; said first group of dampers including a first friction damper and a second friction damper, said first and second friction dampers being independently sprung, and said first friction damper being located more laterally inboard than said second friction damper; said sideframes having upper regions having pedestal fittings; said wheelsets having bearing adapters mounted thereto, said bearing adapters being mounted in said pedestal fittings; said bearing adapters and said pedestal fittings engaging each other at pairs of first and second surfaces that mate in rocking engagement to permit lateral swinging motion of said sideframes such that when said lower region of said first sideframe swings laterally outboard, said upper regions of said first sideframe rock laterally inboard; said first surface having a first radius of curvature of less than 25 inches; and said second surface having a second radius of curvature lying in the range of ¼ to ¾ of said first radius of curvature.