Patent GB-1454172-A (GB)
Title: Consolidating the ballast bed of a railway track
IPC: E01B27/16
Filed: 1973-10-11
Abstract: 1454172 Railway track maintenance machines FRANZ PLASSER BAHNBAUMASCHINEN-INDUSTRIE-GmbH 11 Oct 1973 [13 Oct 1972] 47522/73 Heading E1G [Also in Divisions B7 and G3] A railway track is pressed down to a desired level as determined by a reference system by applying a substantially horizontal transverse vibrating force to the rails or sleepers and simultaneously applying a local vertical loading to the rails by rams and optional vibrators. The compressing apparatus may be on an independent vehicle or may be on a vehicle, Fig. 21 (not shown), provided with conventional track lifters (141) and penetrative ballast tampers (140) arranged to raise the track above the desired level before using the compressing apparatus (16) of the invention. The compressing apparatus is automatically controlled (e.g. to vary the pressure, load time vibration frequency or vibration amplitude) by sensors detecting local deviations from a required level using a reference wire, light or laser beam. The machine of Fig. 2 comprises a chassis 1 supported on front and rear bogies 2' and carrying a track-level reference wire 5 extending between front and rear masts 3, 4 running on the rails. Means 12 are provided for effecting lateral track alignment The consolidating apparatus comprises a sub-chassis 16 suspended by rams 15 and carrying front and rear pairs of pressure rollers 14 and a central pair of V-groove rollers 17 which are vibrated horizontally by contra-rotating eccentric masses, Fig. 4 (not shown) to apply a horizontal vibratory force to the rails. The rams 15, and/or the drive to the vibrators, are controlled by sensors 7 which cooperate with the reference wire 5 to detect the local deviation of the track from the required level. Each sensor 7 rides on the wire 5 and may comprise a fork arm actuating a rotary potentiometer or a vertically-moving cam track actuating successive switches see Control Systems below. In the modification of Figs. 5 and 8 the sub-chassis 16 carrying pressure rollers 14 is pressed down by rams 15 while the grooved V-rollers 28 effecting horizontal vibrations are mounted on a cross beam 24 which incorporates contra-rotating eccentric masses and is suspended by rams 29 and links 25. Each ram 15 may, Fig. 7 (not shown), act on the sub-chassis (16) through a spring (32) and a single or multiple rotary vibrator (33). To accommodate variations in track gauge the rollers 28 rotate in displaceable blocks 27 coupled by arms 34, 35. Figs. 9-13 (not shown) illustrate modified means of accommodating variations in track gauge (a) by allowing rise and fall of V-rollers (41) on a common shaft (40); (b) by employing parallel displaceable shafts (40) for the two respective V-rollers (41); (c) by allowing hydraulicallycontrolled axial movement of one V-roller (41') on a common shaft (40'); (d) by mounting the V-rollers (41) on the lower ends of swing arms (50) whose upper ends, above vibratory pivots (51), are adjustably spaced by hydraulic or pneumatic mechanism (52); (e) by canting the V-rollers (41) by rocking their stub shafts about parallel longitudinal axes (57). In a modification, Fig. 1 (not shown), dispensing with the sub-chassis 16 there is provided for each rail a single pressure roller (8) which is actuated by a cylinder (9) on the vehicle chassis (1) and lies between front and rear vibrating V-rollers (11) lowered by cylinders (10). In a further modification, Fig. 14 (not shown), dispensing with V-rollers horizontal vibrations are applied directly to the sleepers by depending swing arms (60) hydraulically adjusted to grip the sleeper ends. Control Systems In Fig. 15 movements of a fork 71 embracing the reference wire 5 actuate a potentiometer 72 in a bridge network 70 so that a voltage representing the actual rail height is compared with a voltage 78 representing the desired height. The bridge voltage output, representing the difference, is amplified and fed through ammeter 77 to actuate a continuously-adjustable pressure limiting valve 74 controlling the cylinders 15 actuating the pressure rollers 14. In Fig. 16 (not shown) the bridge output voltage actuates a valve (80) to control the speed of hydraulic motors (82) driving the vibrators. In an all-electric modification, Fig. 17 (not shown) the bridge output voltage actuates a variable resistor 93 in the field winding of a shunt-connected motor 91 driving the vibrators. In Fig. 20 (not shown) the bridge output voltage is arranged to actuate successively first, second and third hydraulic vibrator motors (124, 125, 126) and first, second and third pressure cylinders (130, 131, 132). In Fig. 18 a vertical cam track 106 following the reference wire 5 cooperates with switches 104, 105 following the actual rail height (e.g. at the pressure roller, not shown), the switches energising respective vibrator motors 100, 101 so that excessive local spacing between the wire 5 and rails energises an additional vibrator. Fig. 19 (not shown) illustrates a modification of Fig. 18 for hydraulic vibrator motors.