Patent GB-975483-A (GB)
Title: Improvements in or relating to apparatus for grinding rails
IPC: E01B31/17
Filed: 1963-02-27
Abstract: 975,483. Grinding rails in situ. H. SCHNYDER. Feb. 27, 1963 [Feb. 27, 1962], No. 7920/63. Heading B3D. Apparatus for grinding rails comprises a slide mounted on a frame and arranged to be displaced along a rail, and a grinding unit carried by the slide and arranged to trace a template controlling the vertical adjustment of the grinding unit relative to the slide. Two frame members 2 each comprise two curved pipes 4 connected by square bar 5, the vertical parts 6 of the pipes being clamped, in vertically adjusted position, in bushes 7 mounted on a rail 8 secured by clamping plates 9 to the track rail 1 to be ground. Members 2 are connected by two parallel rails 13 adjustably clamped in supports 14 pivotally carried by sleeves 16 adjustably clamped on square bars 5. Rails 13 each comprise sheet-iron channel 23 within which is secured by webs 24 tubular hardened steel guide 25 for slide 26 supporting grinding unit 28 and also constituting an oil tank for the hydraulic control system. Slide 26 comprises arm 30 and two cross-arms 29 having sleeves 31 slidable on the guides 25 and slotted at 32 for webs 24. One cross-arm 29 carries an electric motor 33 and a pump 34 for the hydraulic system. An hydraulic motor 97 mounted on arm 30 has its piston-rod attached to arm 41 connected to two rods 39 vertically displaceable in slide 26. Each rod 39 carries a plate 44 having links 45, 46 connected to a link 47 to which is pivoted electric motor 35 with grinding-wheel 36. These are swivelled through 90 degrees, for grinding half the outer contour of the profile of track rail 1, by hydraulic motor 51 carried by one plate 44. To compensate for wear of the grinding wheel, the rotor of motor 35 is axially adjustable by handcrank 27; alternatively, a pin 119 fixed to motor 35 is adjustable in a slot in plate 120. A threaded spindle 57 pivoted to link 46 is in threaded engagement with shaft 58 having external thread 59 and hand crank 60. Shaft 58 has collar 61 and carries nut 79. Shaft 58 has displaceable thereon sleeve 62 of toggle linkage 63, spring 64 being interposed between sleeve 62 and collar 61. Leg 67 of the toggle linkage is pivoted to arm 56 of plate 44, and leg 65 is pivoted to rod 66 vertically movable on arm 56 and carrying actuators 68, 69 operating valve 73 controlling operation of motor 51. The curve length ground by wheel 36 is determined by the distance between collar 61 and nut 79. The position of the curve length is set by screwing shaft 58 on threaded spindle. Motor 51 can be stopped at any point by closing valve 124. Height adjustment of the grinding unit for chamfering frog noses and grinding wing rails is controlled by template 80 comprising exchangeable T-shaped pieces inserted in a T- groove of a part 88 vertically adjustable on support 14. Two rods 82 are rotatably mounted in lugs 81 on arm 41. Each rod carries a rocker arm 84 carrying roller 85. Spring 86 connecting arms 84 urge rollers 85 into contact with template 80. The roller centres are spaced apart a distance equal to the diameter of grinding-wheel 36. Each rod also carries a cam 83. As slide 26 is moved along guides 25, rollers 85 travel along template 80 whereby cams 83 are rocked to actuate, through levers 90, valves 91-94 controlling motor 97. Valves 92, 93 are connected in parallel and valves 91, 94 in series. If slide 26 is moved until one roller 85 runs on to part 105 of template 80, Fig. 14, either valve 91 or 94 will be actuated according to the direction of movement, but no control will be effected. On further movement of slide 26 a distance equal to the diameter of grinding wheel 36, the other roller 85 will also run on to part 105, and other valve 91 or 94 will also be actuated. With both valves 91, 94 actuated, the lower side of motor 97 is put to exhaust, and grinding-wheel 36 is lowered to grind portion 106. If slide 26 is moved until one roller 85 runs on to part 108 of template 80, Fig. 15, valve 92 or 93 will be actuated according to the direction of movement, putting the lower side of motor 97 to pressure and grinding-wheel 36 is raised to grind portion 111. If the spacing of rollers 85 is greater than the diameter of the grinding-wheel, the cut will be as shown at 125. One side of the rail 1 is ground first and then the grinding unit is turned round, either by changing over the whole apparatus or turning the slide. A plastic-bonded flat grinding-wheel with woven insert may be used, having a diameter of 230 mm. and rotated at 6000 r.p.m. For grinding a frog nose, a wheel of 80 mm. diameter is used, and the spacing of rollers 85 is adjusted accordingly. Slide 26 may be moved by power means, e.g. a motor on the slide driving a pinion meshing with a rack on channel 23.