Patent GB-1347013-A (GB)
Title: Mobile rail mounted machine for carrying out railway track work at intervals along the track
IPC: E01B27/16
Filed: 1970-12-17
Abstract: 1347013 Automatically controlling the operating location of a track working railway vehicle F PLASSER [trading as FRANZ PLASSER BAHNBAUMASCHINEN] 17 Dec 1970 [19 Dec 1969] 59894/70 Heading E1G In order to effect arrest of a railway vehicle which bears track-working tools at a position at which a desired operation is to be effected by the tools either on a rail fastening or in a sleeper interval or crib, a pulse generator providing a pulse for each unit length travelled is caused, when a sensor detects a chosen longitudinally repeated identifiable track element, i.e. a sleeper or a rail fastening, to operate a pulse counter system which after a chosen number of pulses produces a first command signal which causes a brake to be applied; while after a further number of pulses selected in accordance with the further distance travelled by the vehicle during braking to a stop, the counter system produces a second command signal which causes lowering of a tool to engage the rail fastening or ballast; means also being provided to reset the counters to zero after the second command signal and before restart of the movement of the vehicle or detection of the next identification track element. As shown, a magnetic inductor device or pulsor 10, forming part of an oscillating resonant circuit, on detection of a rail fastening as shown in Fig. 1a stops the circuit oscillating and so causes emission of a signal which operates an "and" gate 13 to allow pulses from a generator 12, operated by a rail-engaging measuring wheel 11, to pass to a pulse counting device including separate indicator boards 14, 15. The pre-set indicator 18 for board 14 determines the time at which the brake 8 is applied to the wheel 2 of the carriage 1, the pulse count on reaching this valve energizing the brake. Similarly the pre-set indicator 20 for board 15 determines the subsequent value at which the pulse count operates the hydraulic ram 7 to lower the tool carrier 6 and hence insert the ballast tamping tools 5 into the ballast bed and effects simultaneously operation of the lifting roller mechanism 9 for raising the track as shown in Fig. 1b. The raising of the tools 5 at the end of the tamping operation causes resumption of the carriage advance. Fig. 4, not shown, relates to a machine adapted for combined tamping and crib ballast surface consolidation, each set of tools having its own sensor and pulse counter control arrangement; while Fig. 5, also not shown, relates to a modified tamping machine having a double tamping head for packing ballast beneath two adjacent sleepers simultaneously. In the modified vehicle of Fig. 2, the pulses are counted as soon as the vehicle moves forward from the stopped position shown; the pulsor 10, measuring wheel 23 and pulse generator 24 all being mounted on the same axle located centrally of the tamping tools 5. The pulse counting control system includes an indicator 26 which has separate scales for the two rails, viz. for the right hand rail a scale 27 which is pre-set to display problem deviations from the normal sleeper interval and a scale 28 for indicating forward travel, with corresponding scales 29, 30 for the left-hand rail. Adjusting means 31, 32 set on scales 28, 30 the values of forward travel for the beginning of braking and for total travel between stops, and a summator 33 determines from all these values the correct pulse values at which the braking and tool lowering command signals are issued via relay block 34. In the embodiment of Figs. 6 to 8, not shown, the sensor comprises a wheel running along the ballast bed and engaging the leading edge of each sleeper, pulses being counted as soon as the vehicle moves, as in the Fig. 2 embodiment but only a single indication of pulse count being provided, braking and tamping tool lowering being effected at pre-selected values of the pulse count. Return of the count to zero is effected when the ballast bed engaging wheel meets the sleeper edge, a delay in this return being provided to provide time for an operator to effect an over-riding control if necessary. Reference is also made to (1) automatically forming a signal representing the average of the variation from normal of the sleeper intervals at the two rails (of Fig. 2 arrangement) and to control operation on the basis of such a signal, when optionally a visual indicator may be omitted; and (2) utilizing the pulse counting control system in a vehicle for driving in or extracting rail fastening spikes.