GB2130626A - Track levelling and tamping machine with tamping and stabilising means - Google Patents

Abstract

A track tamping, levelling and lining machine has a main chassis 6 with spaced undercarriages, and a tool support frame 16 with its own track wheels and universally articulated to the main chassis, carrying a tamping unit 13 and a lifting and lining unit 14. The machine also carries a track stabiliser 36 for applying lateral vibrations to the track. <IMAGE>

Description

SPECIFICATION Track levelling and tamping machine with tamping and stabilising means This invention relates to a travelling tracktamping, levelling and lining machine comprising a chassis mounted on undercarriagesspaced apart from one another and at leastonetamping unit which compris estamping toolsdesigned to be lowered into the ballast bed and to be closed towards one another in pairs and vibrated by squeezing and vibration drives, said tamping tools being mounted on a tool support vertically displaceable by a drive, and further comprising a track-lifting and lining unit provided with lifting and lining drives and preceding thetamping unit and also at least one trackstabilising unit which is designed to be brought into form-locking engagement with both rails ofthe track th rough its own wheel-andaxle assemblies designed to travel on the track and which is arranged on the chassis behind thetamping unit in the working direction and ofwhich the tool frame is designed to be vibrated substantially horizontally byvibrators and to be subjected to substantially vertical loads th rough cylinder-and-piston assemblies connected to the chassis, and further comprising a tool control system and at least one levelling and, optionally, lining reference system.

In one already known tamping, levelling and lining machine comprising a chassis mounted on undercarriages spaced apartfrom one another (U.K. Patent Specn. 2094378), the tamping, track-lifting and lining units are arranged between these two undercarriages on the chassis. Each tam ping unit comprisestamping tools which are mounted on a tool support vertically displaceable by a drive, being designed to penetrate into the ballast bed and to be closed towards one another in pairs and vibrated by squeezing and vibration drives. The track-lifting and lining unit equipped with lifting and lining drives which precedes the tamping unit and is arranged separately therefrom on the chassis is connected to a tool control system and to a levelling and lining reference system.The tamping unit is followed in the working direction buy a trackstabilising unit mounted on the chassis which is designedto be brought intoform-locking engagement with both rails of the trackthrough its own on-track wheel-and-axle assemblies and of which the tool frame is adapted to be vibrated substantially horizontally byvibrators and to be subjected to substantially vertical loads by cylinder-and-piston drives connected to the chassis.This known tracktamping, levelling and lining machine in conjunction with the track stabilising unitfollowing the tamping units provides an advantageous, consecutive arrangement of tamping tools and horizontally vibrated and vertically loaded tools forstabilising the position ofthetrack, as a result of which the areas of activity ofthese toolscompletely overlap one another to the benefit of the effectiveness of both operations.

Another known tracktamping machine equipped with lifting and lining tools (U.K. Patent Specn.

2077821 ) comprises a tool support in the form of a centre-pole assemblywithtoolsfor lifting and lining the track. The tool support ofthe tamping unit and the tool supportforthetrack lifting and liningtools are mounted separatelyfrom one another on the chassis.

This pole-like tool support is pivotally connected to the chassis at one free end through a universal joint and at its other end through lifting drives. That end ofthetool support opposite the universal joint is guided on the track by a pair offlanged wheels arranged on a common axle between the two pairs of lifting tools.

This pair of flanged wheels also acts as a lining tool and is connected to a lining drive. This known machine has proved to be effective for holding the track safely and firmly and for automatically centring the track lifting and lining tools, particularly around curves in the track.

Now, the object of the present invention is to provide a travelling tracktamping, levelling and lining machine of the type described at the beginning, in conjunction with a track stabilising unitfor consolidat- ing the ballast bed of a railwaytrack, which has an even more favourable construction and enables all the tools to be better associated with the lateral and vertical trend of the track.

According to the invention, this object is achieved in thatthetamping and track-lifting and lining units are arranged with the associated drives as a working assembly on a common tool support frame which, at one end, is adapted to be supported on the track by a supporting and guiding single wheel-and-axle assembly in the form of a free steering axle and, at its other end, is pivotally connected for supportto the chassis, the track stabilising unit being arranged between the working assembly and the next machine undercarriagefollowing it in the working direction.

In operation, a tracktamping, levelling and lining machine such as this combined with a trackstabilising unit not only enables the areas of activity ofthe tamping and trackstabilising units to be advantageously brought into coincidence with one another, it also makes it possible-through the arrangement of thetamping,track-lifting and lining units as a single working assembly on a common tool supportframeforthese units or ratherthetools arranged thereon independently and preciselyto followthe vertical and lateral, in particularprescribed,trend ofthetrack.

Since in addition from fourto sixteen and even as many as thirty-two tamping tines pertamping unit have to be aligned simultaneously or substantially simultaneouslywith the associated rail, this automatic centring of the units is of considerabl advantage for efficient interference-free operation.

Another advantageous embodiment ofthe inven- tion is distinguished by the fact that, with the track stabilising units and the machine designed to advance continuously, the common tool support frame ofthe working assembly is connected to a hydraulic linear displacement drive, pivotally mounted on the chassis, for step-by-step advance longitudinally ofthe machine. A machine embodying these features may be used in particularforstep-by-steptamping and continuous stabilisation, enabling in particular an accurate track position and uniform consolidation of the ballast bed to be obtained.In addition, the continuous advanceofthe machine-avoiding numerous energy-consuming starts and stopsenables the machine operatorto concentrate in greater comfort solely on the continuing step-by-step advance ofthe working assembly, i.e. the tool support frame with the tamping, tracklifting and lining unit.

Another embodiment ofthe invention is characte rised in that the common tool supportframe of the working assembly is in the form of a centre-pole assembly which, at its end situated nearerthe tam ping unit, comprises the single wheel-and-axle assembly preferably comprising a pair of flanged wheels and, between its other end and the tamping unit, comprises a beam-like longitudinal girder for longitudinally displaceable mounting at its point of support on the chassis, the tool supportframe being connected to the chassis for universal pivoting by the hydrauliodis- placement drive.This embodiment provides for a structurally particularly simple and compactarrange- ment ofthe tamping, track-lifting and lining unit relative to the main machine frame whilst allowing the tool supportframe considerable freedom of movement both longitudinally and also transversely ofthe machine.

Another advantageous embodiment of the invention is characterised in that the beam-like longitudinal girder has a rectanguiaror I-shaped profile crosssection for the displaceable mounting ofthe working assembly on a guide formed by rollers orthe like and arranged on the chassis. This simple and yet robust construction is advantageous in particularforcon- tinuousoperation.

According to another aspect of the invention,the tool frame-likewise in the form of a centre-pole assembly-ofthetrack-lifting and lining unit guided on the track by flanged lining rollers is connected to the tool supportframe of the working assembly through the track-lifting and lining drives and, at its beam-like end, is pivotally connected to the longitudinal girder of the common tool support frame.This construction of a track-lifting and lining unit as a centre-pole assembly, which has already provedto be very effective in standard tracktamping machines is particularly advantageous to a machine according to the invention because it enables the space available beneath the longitudinal girder ofthetool support frame ofthe working assembly to be fully utilised for accommodating the track-lifting and lining unit, no additional lateral space being needed.

Another embodiment ofthe invention isdisting- uished by the fact thatthetrackstabilisiing unit follows the working assembly at an interval in the working direction and the displacement path ofthe hydraulic displacementdrivefor simple step-by-step advance ofthe working assembly from onetamping position to the next-with the machine advancing continuously with its chassis and the track stabilising unit-amountsto at leasttwicethe sleeper interval. In operation, this arrangement ofthe track stabilising unit at an interval behind the working assembly provides for particularly exact coincidence ofthe areas of activity ofthe tamping and track stabilising units.It also ensures that the continuous advance of the machine does not have to be interrupted even when a tamping operation takes slightiy more time than usual, for example on account of heavily encrusted ballast. By virtue ofthis ample distance allowedforthe displacement path,thetamping operation may be properly completed, for example even when the tamping tools penetrate twice into the ballast bed, after which the tool support frame with the working assembly may be moved forwards, for example at high speed, to the nexttamping position bythe displacementdrive.A machinethus equipped satisfies almost all the requirements imposed in practice on a high-performance, easy-to-operate track tamping, levelling and lining machine combined with a track stabilising unit and suitable for uninterrupted continuous operation by non-stop advance.

In another advantageous embodiment of the invention, the piston movement ofthe displacement drive in the form of a double-acting hydraulic cylinder-andpiston arrangement is controllablethrough a valve assembly or the like synchronously and oppositely to the continuous advance of the machine or rather its chassis with the track stabilising unit. Various-some known - elements or rather means which have proved entirely satisfactory in practice are available for implementing this hydraulic control ofthe relative movement between the main machine frame and the tool supportframe of the working assembly.

In one particularly preferred embodiment ofthe invention, the working assembly comprising the tamping, lifting and lining units and the track stabilis- ing unitfollowing the working assembly in the working direction are arranged between two machine undercarriages spaced apartfrom one another. This intermediate arrangement of the tamping, lifting and lining units between two machine undercarriages spaced apartfrom one anotherwhich overthe last ten to fifteen years has been a dominant feature of hitherto known,travelling tracktamping, levelling and lining machines has proved to be very effective in practice and is also of particular advantage to the accuracy and performance ofthe machine according to the invention where this new working assembly is used in combination withthetrackstabilising unit.

According to another aspect of the invention, the vibration drives ofthe tamping units and the vibrators ofthetrackstabilising unitare designed for an in-phase vibratory movement ofthe tamping tools and ofthetool frame ofthetrack-stabilising unit. This construction by virtue of which the ballast is vibrated in-phase in the overlapping areas of activity of the tamping and stabilising tools provides for afurther increase in the intensity and uniformity of consolidation over the entire area of ballast being treated, pa rticularly where the machine is advancing continuously, i.e. without stopping.

Finally, according to another aspect of the invention, the cylinder-and-piston drives for applying the vertical load and/orthe vibrators ofthetrack stabilising unitarecontrollable bythecontrol system, in particularwith the aid of a levelling reference system, which is also associated with the working assembly and, in particular, with the track-lifting and/or lining unit.By virtue of this construction, the extent to which thetrackis lowered bythestabilising operation may be regulated according to the difference between the actual and prescribed levels ofthetrack, as determined with the aid ofthe levelling reference system in the tamping zone, in such a waythatthe level ofthe track completed bytheworking assembly and the track stabilising unit corresponds even moreaccurate- ly to the prescribed level. In cases where a levelling reference system common to the track-lifting and the stabilising tools is used, co-ordination and also preadjustmentofthe necessary degree of lift of the track may be carried out particularly easily using a control and regulating system associated with the reference system.

Two embodiments ofthe invention are described by way of example in the following with reference to the accompanying drawings, wherein: Figure lisa diagrammatic side elevation of a single-sleepertracktamping, levelling and lining machine according to the invention comprising a track-stabilising unit.

Figure 2 is a diagrammatic plan view of the machine shown in Figure 1.

Figure 3 is a diagrammatic side elevation of part of a 2-sleepertracktamping, levelling and lining machine comprising a track-stabilising unit.

Thetracktamping, levelling and lining machine 1 shown in Figures 1 and 2 comprises a chassis 6 designed to travel on a track consisting of rails 4 and sleepers 5 by means of two machine undercarriages 2, 3. The working direction ofthe machine 1 is indicated by an arrow 7. A drive and power supply system 8 is provided for power supply purposes and a control system 9 for control purposes.

The machine 1 is equipped with a levelling reference system 10 comprising- per rail - a stretched wire 11 of which the front end is guided on the uncorrected track by the undercarriage 3 whilst its rear end is guided on the corrected track by a feeler member 12. The working units each consisting of a tamping unit 13 and atrack-lifting and lining unit 14form aworking assembly 15with the associated drives and are mounted on a common tool supportframe 16. This tool support frame is in the form of a centre-pole assembly which, at one end, is supported on the track bya supporting and guiding single wheel-and-axle assembly 17 in the form of a free steering axle and, at its other end, is pivotally connected for supportto the chassis 6.The end connected to the chassis 6 is in the form of a beam-like longitudinal girder 18 and is supported by a bearing assembly 19 on the chassis 6.

The bearing assembly 19 is intheform of a roller guide comprising two rollers 20 applied to the underneath and anothertwo rollers 20 applied to the top ofthe longitudinal girder 18, these rollers 20 being provided on both sides with guideflangesand being mounted for rotation on the chassis 6. The roller guide has a rectangular or I-shaped profile cross-section. A lateral clearance between the longitudinal girder 18 and the guide flanges of the rollers 20 enables the tool support frame 16 to pivot laterally to a limited extent about the bearing assembly 19. Thetool support frame 16 and the chassis 6 are pivotally interconnected by a hydraulic linearadjustmentdrive 21 intheformofa double-acting cylinder-and-piston assembly arranged above the longitudinal girder.Each tamping unit 13 comprises tamping tools 22 which are designed to penetrate into the ballast bed and to be vibrated parallel to the longitudinal axis ofthe rails by known hydraulic eccentric vibration drives. However, a vibration drive 23 rotatable about a shaft extending longitudinally of the rails is also designed to be brought into operation so that the tamping tools 22 can be vibrated transversely ofthe longitudinal axis of the rails. An inductive pickup 24 co-operating with the rail fastenings, for example screws, is arranged on the tool support frame 16 substantially at the longitudinal centre ofthetamping unit 13.

The track lifting and lining unit 14 ofthe machine 1 comprises a tool frame 27 in the form of a centre-pole assembly which is guided on the track by flanged lining rollers 25 and which is equipped with lifting rollers 26 designed to be swung in beneath the railhead, being pivotally connected at its front beam like end 28to the longitudinal girder 18 ofthe tool supportframe 16. In addition, the tool frame 27 is pivotally connected to the tool support frame 16 through track lifting drives 29 and lining drives 30 of the track-lifting and lining unit 14.Atamping unit 13 designed to be raised and lowered by a vertical adjustment drive 31 is arranged on the tool support frame 16for each ofthe rails 4.In order notto impede the vertical adjustment drives 31, the chassis 6 comprising two upwardly recessed girders 32 has a longitudinally extending recess 33 indicated by chain lines in each girder. A measuring wheel 34 applied firmlytothetrack is provided between the tamping units 13 and the track-lifting and lining unit 14. For each rail, a measuring sensor 35 formed for example by a rotary potentiometer is connected to the measuring wheel 34, co-operating with the corresponding stretched wire 11 of the levelling reference system 10 for determining the difference between the actual and prescribed levels of the track.

Between the working assembly 15 and the next machine undercarriage 2 following it in the working direction of the machine 1, a track stabilising unit 36 is connectedtothechassis6through cylinder-and- piston drives 37. The track stabilising unit 36 has its own flanged guide rollers 38 designed to travel on the track and also gripper rollers 39 which are designed to pivot up and down transversely ofthe longitudinal axis of the track and to be brought into form-locking engagement with the underneath ofthe railhead on the outside ofthe associated rail 4. Vibrators 40 are provided for generating substantially horizontal vibrations directed transversely of the longitudinal axis of the track.The vibrations and also the loading force designed to be applied by the cylinder-and-piston drives 37 to the track stabilising unit 36 in the direction ofthe arrow 41 are transmitted to the track through the guide and gripper rollers 38,39 brought into formlocking engagement with the rails 4.

The machine 1 is provided with various items of additional equipment for automatically controlling the various functions performed during the continuous advance ofthe machine with its chassis 6 and during the step-by-step advance of the tool support frame 16 with the tamping unit 13from one tamping position to the next. These additional items of equipmentcom- prise a control unit9 and a valve assembly 42 th rough which pressure can be admitted to the hydraulic linear displacement drive 21 to move it in either direction.

The valve assembly 42 is connected for control purposes to three different accessories. One of these accessories is a distance measuring instrument43 integrated with the feeler member 12 which, for every unitofdistancetravelled bythe machine, releases a control pulse to the valve assembly 42 which regulates the flow of pressure medium to the right-hand cylinder chamber ofthe hydraulic linear displacement drive 21 synchronously and oppositely to the direction of advance of the machine so thatthe tool support frame 16withthetamping units 13 remains centred relative to the sleeper below which the ballast is to be tamped until thetamping operation is complete.

When the tamping units 13 are raised, the valve assembly42 is reversed and pressure is admitted to the left-hand cylinder chamber of the hydraulic linear displacement drive 21 and the tool support frame 16 is moved forwards at high speed until thetamping units I3arecentred overthe nextsleeperbelowwhichthe ballast is to be tamped. When the tamping units 13 are lowered, the distance measuring instrument 43 is resetto zero and a new working cycle begins.

A similar sequence of movements takes place in cases where a cable potentiometer 44 attached laterallyofthetoolsupportframe 16to a beam 32 of the chassis 6 is used for determining the relative displacement between the tool supportframe 16 and the chassis 6. In this case, the piston movement of the hydraulic linear displacement drive 21 is controlled proportionallytothe displacement of a rod connected to the tool supportframe 16 and to the cable potentiometer or rather proportionallyto the output voltage- delivered as an analogue signal-ofthe cable potentiometer 44.

In addition, an inductive pickup 24 co-operating with the railfastenings is provided for controlling the valve assembly 42. This pickup 24 behaves neutrally for as long as it remains centred in relation to the particular rail-fastening screw. If it moves out of its centred position, the inductive pickup 24 releases a control signal to the valve assembly42, altering the flow of pressure medium to the hydraulic linear displacement drive 21. Accordingly, the tamping unit 13 remains centred in relation to the sleeper below which the ballast is to be tamped until the tamping operation is complete.The tracktamping, levelling and lining machine 1 equipped with the track stabilising unit 36 and with the working assembly 15 consisting - per rail -of the associated tamping unit 13 and the track-lifting and lining unit 14 is thus able to advance continuously or in steps-commensuratewith the sleeper interval with thetamping, track-lifting and lining unit displaceable relative to the machine.

In Figure 2, the dash-dot circle 45 indicates the area in which the ballast is vibrated and consolidated by the vibratory movements ofthe vibrators 40 of the track stabilising unit 36. The vibratory movement directed transversely of the longitudinal axis of the track is indicated by double arrows in the vicinity ofthe gripper rollers 39. The vibration drive vibrates the tamping tools 22, which are mounted to make a squeezing movement, parallel to the longitudinal axis of the rails overthe area indicated by a chain-line circle surrounding the particulartamping unit 13. As can be seen,the areas of activity ofthe track stabilising unit 36 and the two tamping units 13 overlap even in the outermost right-hand position ofthetamping units.

Ultimately, the areas of activity ofthe track stabilising unit 36 and the tamping tools 13 totally coincide in the left-hand end position (shown in chain lines) ofthe tamping units 13. When the vibration drive 23 is brought into operation, an in-phase vibratory movement can be obtained with the tamping tools 22 vibrating transversely ofthe longitudinal axis of the rails and the tool frame of the track stabilising unit 36.

The track tamping, levelling and lining machine 46 shown in part only in Figure 3 corresponds in all main features- exceptthetamping unit and the related structural dimensions-to the machine already described with referenceto Figures 1 and 2. This machine comprises a chassis 49 designed to travel on a track 48 by means of two machine undercarriages 47 spaced apartfrom one another.In the working direction of the machine 46, as indicated by the arrow 50, the rear machine undercarriage 47 is preceded by a trackstabilising unit 51 designed to be vibrated substantially horizontally by vibrators and a working assembly 55 consisting of a tool support frame 52 with a vertically displaceable double tamping unit 53 for simultaneouslytamping the ballast beneath two adjacent sleepers and a track-lifting and lining unit 54.

This working assembly 55 which at one end is supported on thetrackand at its otherend on the machine 46 is displaceable longitudinally ofthe machine by a hydraulic linear displacement drive 56 pivotally connected to the chassis 49 in conjunction with a control unit communicating therewith through a line. The stepwise advance (arrows 58) of the working assembly 55 by two adjacentsleeperinter- vals per step on completion ofthetamping operation, coupled with the partial lifting of the double tamping unit 53 as the machine 46 advances continuously, substantially corresponds to between three and four times the sleeper interval so that an even more significant increase in performance can be obtained through the more rapid advance ofthe machine 46.

The control unit 57 is designed to be influenced by an inductive pickup 59 attached to the tool supportframe 52, a cable potentiometer 60 arranged on the chassis 49 and a distance-measuring unit 62 combined with a feeler member 61 forthe step-by-step advance of the working assembly 55. The front position ofthe working assembly 55-afterastep forward -with the tamping tools ofthe doubletamping unit 53 lowered into the ballast bed is diagrammatically illustrated in chain lines.

Claims (11)

1. Atravelling tracktamping, levelling and lining machine comprising a chassis mounted on undercarriages spaced apartfrom one another and at least one tamping unitwhich comprises tamping tools designed to be lowered into the ballast bed and to be closed towards one another in pairs and vibrated by squeezing and vibration drives, said tamping tools being mounted on a tool supportvertically displaceable by a drive, and further comprising a track-lifting and lining unit provided with lifting and lining drives and preceding thetamping unit and also at least one trackstabilising unit which is designed to be brought into form-locking engagementwith both railsofthe trackthrough its own wheel-and-axle assemblies designed to travel on the track and which is arranged on the chassis behind thetamping unit in theworking direction and of which thetool frame is designed to be vibrated substantially horizontally by vibrators and to be subjected to substantiallyvertical loads through cylinder-and-piston assemblies connected to the chassis, and further comprising a tool control system and atleastone levelling and, optionally, lining reference system, characterised in thatthe tamping and track-lifting and lining units are arranged with the associated drives as a working assembly on a common tool supportframe which, at one end, is adapted to be supported on the track by a supporting and guiding single wheel-and-axle assemblyinthe form of a free steering axle and, at its other end, is pivotally connected for support to the chassis, the trackstabilising unit being arranged between the working assemblyandthenextmachineundercar- riagefollowing itin theworking direction.

2. A machine as claimed in Claim 1, characterised in that, with the trackstabilising unit and the machine designedto advance continuously, the commontool support frame ofthe working assembly is connected to a hydraulic linear displacement drive, pivotally mounted on the chassis, for step-by-step advance longitudinally ofthe machine.

3. A machine as claimed in Claim 1 or 2, characterised in thatthe common tool supportframe ofthe working assembly is in the form of a centre-pole assembly which, at its end situated nearerthetamping unit, comprises the single wheel-and-axle assembly preferably comprising a pair offlanged wheels and, between its other end andthetamping unit, comprises a beam-like longitudinal girderforlongitudinally displaceable mounting at its point of support on the chassis, the tool supportframe being connected to the chassis for universal pivoting by the hydraulic dis- placement drive.

4. A machine as claimed in Claim 3, characterised in thatthe beam-like longitudinal girder has a rectangular or I-shaped profile cross-section forthe displaceable mounting of the working assembly on a guideformed by rollers orthe like and arranged on the chassis.

5. A machine as claimed in any of Claims 1 to 4, characterised in thatthe tool frame- likewise in the form of a centre-pole assembly- of the track-lifting and lining unit guided on thetrack by flanged lining rollers is connected tothetool support frame ofthe working assembly th rough the track-lifting and lining drives and, a its beam-like end, is pivotally connected to the longitudinal girder (18) of the common tool supportframe.

6. A machine as claimed in any of Claims 1 to 5, characterised in that the track stabilising unit follows the working assembly at an interval in the working direction and the displacement path ofthe hydraulic displacement drive for simple step-by-step advance of the working assembly from onetamping position to the next-with the machine advancing continuously with its chassis and thetrackstabilising unit amountsto at leasttwicethe sleeper interval.

7. A machine as claimed in Claim 6, characterised in thatthe piston movement ofthe displacement drive intheform of a double-acting hydraulic cylinder-and- piston arrangement is controllable through a valve assembly or the like synchronously and oppositelyto the continuous advance ofthe machine or rather its chassis with thetrackstabilising unit.

8. A machine as claimed in any of Claims 1 to 7, characterised inthattheworking assemblycompris- ing the tamping, lifting and lining units and the track stabilising unitfollowingtheworking assembly in the working direction are arranged between two machine undercarriages spaced apartfrom one another.

9. A machine as claimed in any of Claims 1 to 8, characterisedinthatthevibration drives of the tamping units andthe vibrators ofthetrack-stabilising unitare designedfor an in-phasevibratory movement ofthetampingtools and of thetool frame of the track-stabilising unit.

10. A machine as claimed in any of Claims 1 to 9, characterised in thatthe cylinder-and-piston drives for applyingthevertical load and/orthevibratorsofthe track stabilising unit are controllable bythe control system, in particularwith the aid of a levelling reference system, which is also associated with the working assembly and, in particular, with the tracklifting and/or lining unit.

11. A railwaytrack maintenance machine incorporating a track-stabilising unit, substantially as herein described with referenceto Figures 1 and 2 or Figures 3 ofthe accompanying drawings.