Railroad brake shoe

A tread brake shoe for a railroad car wheel having a wheel tread and a wheel flange, which brake shoe is mountable on a brake head and, at a reference position, is engageable with said wheel tread to brake and retard a railroad car, said brake shoe comprising:

• a metal backing with a generally longitudinal axis, a radius of curvature, an upper surface and a lower surface;
• a shoe body having a first subassembly and a second subassembly,
• each of said first and second subassemblies having a core, a second longitudinal axis, a first end, a second end, a first lateral sidewall and a second lateral sidewall,
• said first and second subassemblies secured to said metal backing lower surface with general alignment of said first and second subassembly second longitudinal axes, said aligned second axes generally aligned with said metal-backing longitudinal axis, and,
• at least one lateral member for each of said first and second subassemblies, said lateral member mounted on said respective subassembly lateral sidewall;
• each of said first and second subassembly cores being a first composition material with a first dynamic coefficient of friction,
• each said core having a tread-engaging surface, a bonding surface, a first lateral sidewall and a second lateral sidewall, which first and second lateral sidewalls of each said core are generally parallel,
• one of said first subassembly first and second lateral sidewalls generally aligned with one of said second subassembly first and second lateral sidewalls, and the other of said first subassembly sidewalls generally aligned with the other of said second subassembly first and second sidewalls,
• said first and second subassembly tread-engaging surfaces having a second radius of curvature about concentric with said metal-backing radius of curvature, said tread-engaging surfaces generally aligned along said second radius of curvature;
• each of said first and second subassemblies having a cross-section approximately transverse to said second longitudinal axis with said at least one lateral member is of a second composition material with a second dynamic coefficient of friction less than said first dynamic coefficient of friction,
• said at least one lateral member of each of said first and second subassembly secured to the respective aligned and parallel sidewalls of the first and second subassemblies, which aligned and parallel said at least on lateral member on said first and second subassemblies provide a wearing side to said brake shoe;
• said core and said lateral member of each of said first and second subassembly cooperating to define a first laminate arrangement in a first cross-sectional core direction;
• means for bonding secured to said metal-backing lower surface,
• each said first and second subassembly secured to said means for bonding at the respective bonding surface, said means for bonding cooperating with said core to define a second laminate arrangement in a second core cross-sectional direction approximately normal to said core first cross-sectional direction,
• said first composition material operable to contact and grip said railroad car wheel tread to brake and retard said railroad car, and said at least one lateral member of said second composition material operable to engage said wheel flange and inhibit flange contact with said first composition material to reduce flange temperature increases at engagement of said brake shoe body with said flange at lateral displacement of said brake-shoe body from said reference position in alignment with said wheel tread to said flange engagement at a brake-shoe overriding position.