Patent GB-1209151-A (GB)
Title: Method and apparatus for grinding welded rails
Inventor: LINDMARK KARL L
IPC: B24B19/00
Filed: 1967-10-25
Abstract: 1,209,151. Grinding rails. CHEMETRON CORP. 25 Oct., 1967 [21 Nov., 1966], No. 48603/67. Heading B3D.  A method of grinding welds 22, Fig. 1, produced by welding rail sections 24 together end-to-end comprises moving a travelling abrasive surface 160 longitudinally of the rail across the weld successively from opposite sides thereof and forcing the abrasive surface into contact with the weld area during the longitudinal movement in such a manner as to increase the grinding pressure against the rail in the area of the weld and to reduce the pressure as the abrasive surface moves away from the weld area. The apparatus for carrying out the method may be mounted on the floor of a railway waggon 26 and consists of a frame 28 provided with a base 30 having wheels 32 engaging tracks 34 in the floor, one of the wheels being driven by a motor 36. The frame consists of end plates 44 between which are mounted upper and lower grinding heads 50, 52 having abrasive belts 160 for grinding the running and underside of the rail. Each end plate supports a clamping assembly 48 for holding the rail which extends through openings in the end plates. Each clamping assembly includes a lower vertically adjustable roller 64 for supporting the rail during positioning thereof relative to the frame. The rail is laterally located in each assembly 48 by an adjustably fixed roller 68, Fig. 2, and a spring- pressed roller 66. When the rail is in position it is clamped by upper and lower pads 60, 62 carried at the ends of arms 98, 100 movable about pivots 102, 122 by a fluid-operated cylinder 112. The lower grinding head 52, Fig. 1, consists of an abrasive belt 160 entrained around a backing roller 162, a fixed roller 164 and an adjustable roller 166, the rollers being mounted between a pair of spaced plates 176, 178, Fig. 7. The backing roller has a resilient outer covering 192 and is driven by belts 172 from a motor 168 adjustably mounted on one of the plates, and the roller 166 is adjustable to control the tracking of the belt and is acted on by a pneumatic cylinder 214 to tension the belt. A pair of vertical sleeves 220 is secured to the plate 176, each sleeve being slidable on a rod 226 secured to a carriage plate 232 supported for horizontal sliding movement on a pair of rods 234 carried by end plates 244 of the head. A pair of vertically disposed fluid cylinders 260 can be operated to urge the abrasive belt assembly vertically towards or away from the rail along the rods 226 and a further fluid cylinder acts to reciprocate the assembly along the rods 234 automatically under the control of a reversing valve. Maximum grinding pressure is applied at the weld and decreasing pressure each side thereof under the control of a guide roller assembly 310 consisting of a V-shaped member 316 which is mounted on a sleeve 340 disposed between the plates 176 and supports a pair of rollers 318 for engaging the under surface of the rail. The sleeve is eccentric and connected by a linkage 348, 354 to a pin 360 fixed to the plate 244 so that as the belt assembly is reciprocated along the rods 234, the eccentric sleeve is oscillated to move the guide rollers 318 vertically relative to the backing roller 162 so that the abrasive belt engages the weld 22 with greater pressure than the sections of the rail adjacent thereto. The position of the eccentric sleeve 340 can be adjusted initially by a further eccentric to determine the initial grinding pressure. The lower grinding head is supported in the frame 28 by axially aligned pins 390, Fig. 6, which are mounted on the end plates 244 and engage seatings 44b on the end plates 44 of the frame. A bolt 292 engages  a slot 244a in the plate 244 to permit angular adjustment of the lower grinding head. The upper grinding head is substantially identical to the lower grinding head but is mounted for oscillation about the longitudinal axis of the rail, to enable the arcuate profile of the running section to be ground on hubs 44b on the end plates 44 and are clamped to chains 418 which are guided over idler sprockets 420 and driven from a reversible motor 400, Fig. 1.