Patent ID: 7442115

Claim:
A rail frog grinding system comprising: (A) a frame that is capable of being secured to a railway in situ at locations that flank opposed ends of a frog of a railway, said frame defining a reference path for grinding the frog and including: (1) first and second longitudinally spaced transverse supports, each of which is configured to be supported on at least two spaced rails of the railway; (2) first and second clamp assemblies, each of which is configured to releasably clamp a respective one of said supports to rails of said railway; and (3) at least one longitudinal guide rail that extends between and is supported on said transverse supports, a reference path being determined by the position of said guide rail, wherein said guide rail is sufficiently long to prevent the reference path from being influenced by the geometry of the frog; and (B) a grinding machine including a chuck and a rotating grinding tool that is supported on said chuck, said chuck being supported on the guide rail so as to have at least four degrees of freedom with respect thereto, thereby permitting said grinding tool to move relative to said guide rail to grind the frog.