Abstract: A main body 1 of a grinding assembly for use in a track rail joint grinding apparatus comprising a pair of grinding assemblies A, A' rotating around vertical shafts 5, 5' in mutually opposite directions so as to grind one and the other width-wise halves of a track rail R, comprises grinding blade supporting portions 3A to 3C which each constitute a recess edge 2 complementarily engaging with a head Ra of the track rail R, said grinding blade supporting portions being arranged at equiangular distances in the rotational direction of the vertical shaft 5, 5', and a suitable number of grinding blades 4a to 4h being detachably attached to grinding blade attaching portions 6a to 6h of each of the grinding blade supporting portions 3A to 3C.

Abstract: A grinding apparatus of a welded residue on a seam of a rail head portion including a rail, a machine table capable of moving forward and backward along the rail, an apparatus base erected on a distal end side of the machine table, a first support disk board mounted on the apparatus base and capable of moving vertically by electric power or an operator's hand, a second support disk board mounted on the first support disk board and capable of moving vertically by electric power or an operator's hand, a grinding drive motor mounted on a front surface of the second support disk board and capable of rotating about a horizontal axis, a cutter unit mounted on the front surface of the second support disk board and capable of rotating about the horizontal axis, the cutter unit being operatively connected to the grinding drive motor, an engaging portion formed on the cutter unit and adapted to engage a head portion of the rail, and a grinding edge disposed on the engaging portion and adapted to grind an upper surface,