Patent GB-1400093-A (GB)
Title: Methods of and apparatus for grinding rails
IPC: B24B27/00
Filed: 1973-05-22
Abstract: 1400093 Grinding rails in situ SPENO INTERNATIONAL SA and FRANK SPENO RAILROAD BALLAST CLEANING CO Inc 22 May 1973 [8 June 1972] 24479/73 Heading B3D A method of truing a rail 1, Figs. 1 and 2, by grinding comprises mounting a grinding machine on a rail, the machine having at least three rail following means, at least one of which is a grinding means thereby making the corresponding rail contacting zone a grinding zone, and adjusting the zone spacing longitudinally of the rail direction to an optimum position dependent on the irregularities of the rail. In apparatus for carrying out the method, a frame 4 of inverted U-shape is supported by flanged wheels 2, 3 on the rail, the contact between the wheels and rail providing the two point contact of the reference base. A pair of shoes 13, 14 are movable along the arms of the frame by hydraulic jacks 15 pivoted to the frame and shoes, and each shoe has a pivot 9, 10 engaged in a cross-piece 7, 8 welded to stringers 5, 6 of a movable frame, bolts 11, 12 locking the crosspieces to the pivots. As described, three rotary grinders in the form of cup wheels 21, 22, 23 are carried by the movable frame. Each grinding wheel is mounted on a vertical shaft 24 which extends through a tube 26 to a motor 25. The tube has journals 27, 28 which extend into bores in I-shaped plates 29, 30, bolts 40, 41 locking the journals to the plates. The flanges of the plates 29, 30 embrace the stringers 5, 6 and have bolts 32 ... 39 engaging the stringers for positioning the grinding wheels heightwise relation to the rail and longitudinally of the moving frame. The longitudinal adjustment permits the spacing between the grinding zones of the wheels to be such as not to coincide with the wavelength of undulations in the rail and it is usually sufficient to adjust only the central grinding wheel 22. The adjustment may be effected by slackening only the lower bolts 36 1  .... 38 1  moving the grinder and then retightening so that heightwise adjustment is not effected. The grinder may be adjusted to positions determined by switches on a stringer 6 engaged by a detent on the grinder. In another embodiment, two grinders are coupled together for adjustment in opposite directions by an endless cable. The lateral face of the rail 1 may be ground by a grinding wheel 22<SP>1</SP>, Fig. 6, carried by a grinding wheel 22<SP>1</SP>, Fig. 6, carried by a shaft 24<SP>1</SP> extending through a tube 53 which is formed with a piston 49 urged by fluid pressure in a chamber 53 of a cylinder 51 against a spring 50 to press the wheel against the rail. The cylider is carried by a pivot 56 on an arm 58 mounted on a further pivot of a shaft 60 having journals 27<SP>1</SP>, 28<SP>1</SP> for engaging the plates 29, 30 mounted on the stringers 5, 6. Three such assemblies may be mounted on the stringers for grinding the lateral face of the rail. One of the assemblies may be adjusted so that its peripheral surface guides the top face of the rail (Fig. 7, not shown). In another arrangement, a grinding wheel is rotated about a horizontal axis and supported by two feelers engaging the rail, the grinding wheel being nearer the rearward feeler with respect to the movement of the arrangement along the rail. In a further embodiment, the grinding wheel has two zones 1, 2, Fig. 9, one of the zones acting as a feeler in co-operation with a feeler A. In yet a further embodiment, the grinding wheels are arranged symmetrically about a centre, the distance between the extreme grinding wheels and adjacent grinding wheels being determined by the irregularities in the rails.