876,453. Grinding welded rails. RAILTRACK EQUIPMENT CORPORATION S.A. Jan. 8, 1960 [Jan. 19, 1959], No. 714/60. Class 60. A machine for grinding excess weld metal from a butt-welded joint between aligned railroad rails comprises a base structure, a pair of upstanding pedestals in longitudinal alignment with and at opposite ends of said base structure for guiding and supporting said welded rails, first grinding means disposed on said base structure between said pedestals, means for vertically translating said first grinding means into engagement with the bottom surface of said welded rails, second grinding means disposed on said base structure between said pedestals, means for vertically and horizontally translating said second grinding means into engagement with the sides of said supported rail, and carriage means mounting said grinding means and translating means therefore and movable on said base structure between said pedestals, thereby to longitudinally traverse said surfaces of said rail with said grinding means. The base comprises a pair of longitudinal foundation members 2 on each of which is mounted a channel member 6. Cross members 12 extending between the ends of the channels 6 each support a pair of pedestals 14 carrying a flanged roller 18 on which rests the rail 20 having the butt-welded joint to be ground. The base may be mounted on a railroad flat car. A carriage comprises longitudinal channel members 28 connected by cross channel members 30 and top and bottom plates 32, 34. Axles 24 extending through the channels 28 carry pairs of flanged wheels 22 running on tracks 10 mounted on the channels 6. The axles have hand wheels 26 by rotation of which the carriage is moved longitudinally. A unit for grinding the bottom of the rail base flange comprises a grinding wheel 40 on the upper end of the vertical shaft of an electric motor 36 adjustable vertically in a housing 44 by a screw-and-nut mechanism operated, through chain and sprocket and bevel gearing, by a handwheel 48. Guide rollers 45 bear against the bottom surface of the rail 20 thereby helping to guide and position the grinding unit. Each guide roller 45 is mounted within a housing 47 which seats on the upper end of a spring-locked guide 46, an interposed ball 49 allowing tilting if the base flange of the rail is twisted or irregular. The housing 44 is supported between the housings 47. The rollers 45 are insulated from the housings 44, 47 by non-conductive bushings and washers 51. The spring loaded guides 46 are mounted on the top plate 32 of the carriage. A rail web grinding unit comprises two grinding wheels 64 on vertical shafts 66 belt-driven by a motor 77, the peripheral surface of each grinding wheel being contoured to the lower head portion and upper base portion of the rail 20 and cylindrical where it meets the web portion. The shafts 66 are mounted in housings 70 which support housings 68 partially enclosing the grinding wheels. The housings 70 are fixed to a frame 72 pivotally mounted by pin 74 on a support 76. A double-acting hydraulic cylinder 84 is mounted in the upper end of a column 86 having its base secured to the top late 32 of the carriage. The piston rod ends 88 are located within sleeves 85 on opposite sides of the column 86, and urged against recesses 90 in the frame 72 by springs 92, thus centering the grinding wheels. Hydraulic actuation of the piston 87 swings the frame 72 about the first 74 so as to move the grinding wheels alternately into contact with the rail. The motor 77 is mounted pivotally by support member 96 on adjacent axle 24 so that the entire grinding unit may be pivoted in a vertical plane to grind the sides of the base flange, the pivoting being effected by a doubleacting hydraulic cylinder 102 carried on supports 104 by the carriage. Movement of the grinding wheels 64 towards the rail is limited by bumper elements 106 fastened to arms 110 slidably adjustable on the grinding wheel housings 68.