GB2146374A - A continuous-motion (non-stop) track tamping levelling and lining machine - Google Patents

Abstract

A track tamping, lifting and lining machine combines a continuously moving main vehicle frame 2 which carries the operators and reference means 36, 49, and an intermittently advancing secondary frame 20 which is coupled to the main frame and carries the tamping, lifting and lining units. At least one dynamic track stabilising unit 28 travels with the main frame following the tool frame 20, with at least one undercarriage 3 of the main frame between the stabilising units and the tool frame. The main frame 2 of the machine is articulated, the front section 6 carrying the intermittently advancing tool frame while the rear section 5 carries the stabilising units. <IMAGE>

Description

SPECIFICATION A Continuous-motion (Non-stop) Track Tamping, Levelling and Lining Machine This invention relates to a continuous-motion (non-stop) track tamping, levelling and lining machine comprising a main frame mounted on undercarriages and a tool frame advancing step-bystep which is connected to the main frame for longitudinal displacement and pivoting and on which tamping, lifting and lining units are arranged together with their drives.

The development of continuous-motion (nonstop) track tamping machines is based primarily on efforts to overcome or alleviate the undesirable secondary effects accompanying the step-by-step advance of tamping tools designed for penetration into the sleeper cribs, more particularly the heavy stressing of important parts of the machine and also the serious physical strain to which the machine operators are subjected by the constant starting and stopping of the machine. Although numerous proposals following different fundamental principles have already been put forward for the construction of continuous-motion track machines, they have not yet been put into practice on account of the persistence of certain problems which as yet have not been satisfactorily solved. Thus, G.B.

Patent No. 1320205 proposes a continuous-motion (non-stop) track tamping machine of which the tamping units are each mounted on a tool frame displaceable relative to, and along a guide arranged on, the chassis under the power of a piston-andcylinder drive. This known machine is also equipped with track lifting tools which precede the tamping units and which are connected to the chassis of the machine.During the continuous (non-stop) advance of the chassis together with the lifting tools, the tool frames together with the tam ping units have to remain stationary until the tamping operation is over and then accelerated in the working direction along their guides by means of the cylinder-andpiston drives until the tamping tools are centered over the next sleepers to betamped. By lowering the tamping units, a new working cycle is initiated.

This proposal is a solution in principle to the problem of providing a continuous-motion track tamping machine which enables various standard constructions oftamping units to be used. In addition to the loads applied by the weight of the tamping units together with the tool frames and guides, the solid and robust chassis of this machine also has to absorb the working forces (tamping, lifting and vibration forces) of the tamping units and of the lifting units. A machine based on this proposal has never been constructed.

In addition, it is already known (cf. GB Patent No.

2003961) that an additional continuous motion control and monitoring vehicle having its own axle drive can be associated with a track maintenance machine advancing step-by-step, for example a standard track tamping, levelling and lining machine with its own levelling and lining reference systems, being connected to that machine through a distance monitoring system and a long-range transmission system and being equipped with a control and monitoring system of the type also present on board the machine itself.Accordingly, when the machine is remote-controlled from the additional control and monitoring vehicle, the operator of that vehicle is able to work in greater comfort by virtue of the continuous, vibration and jolt-free advance of the monitoring vehicle, whereas the chassis carrying the drive, brake and power supply systems of the working machine advancing in steps continues to be subjected to the jolting, shaking and vibration emanating from the working forces and the drives of the tamping, lifting and lining units.In view of the additional cost of the control and monitoring vehicle and the accessories required for the remote-control and monitoring of the machine, this known track maintenance machine arrangement can only be economically used for major track works, particularly along new track or high-speed track where the uniformity of the sleeper position, particularly the sleeper interval, and the uniform condition of the ballast bed enable the advance of the machine and the control of the working tools to be extensively automated.

Accordingly, the operator is essentially left with only a monitoring function to perform which he is able to carry out on his own, i.e. without having to rely on the assistance of an operator on board the machine itself with the aid of the teievision image displayed in the control and monitoring vehicle of the working area of the tamping, lifting and lining tools. This machine has also proved very successful in practice.

In addition, an advertisement in the Journal "Der Eisenbahningenieur", No. 6, June, 1983, refers to a prototype built by Applicants of a continuousmotion (non-stop) track tamping, levelling and lining machine of the type in question which corresponds to British Patent Applications Nos.

8311413 and 8311414 (not yet published).

Accordingly, Applicants were the first to build a machine of this type which solves the problems discussed in the foregoing in regard to the development of continuous-motion (non-stop) track machines which fully satisfy practical requirements.

This prototype of a continuous-motion (non-stop) tracktamping, levelling and lining machine, which is currently on trial in Austria, comprises an undercarriage-mounted chassis carrying the drive, brake, power supply and control systems and a tool frame which is connected for longitudinal displacement to the chassis and on which the tamping, lifting and lining units along with their drives are arranged together between the bogietype under-carriages arranged at a distance apart from one another. This prototype is equipped with an arrangement for the common step-by-step advance of the tamping, lifting and lining units and with levelling and lining reference systems associated with the tools.At its rear end adjacent the tamping unit, the tool frame equipped with the tamping, lifting and lining units is supported on the track by a supporting and guiding undercarriage.

Accordingly, a considerable proportion of the weight and working forces of the tamping, lifting and lining units is transmitted during travel to the track via the supporting and guiding undercarriage so that the chassis of the machine which advances continuously in contrast to the step-by-step advance of the tool frame is subjected to considerably less static and dynamic stressing by comparison with the known proposals for continuous-motion track tamping machines comprising tamping units arranged for displacement on longitudinal guides of the chassis. Since, therefore, shuddering and vibration are also kept away from the operator's cabin of the machine, considerably improved working conditions are obtained for the machine operator.This prototype of a fully operational, continuous-motion (non-stop) track tamping, levelling and lining machine opens up numerous, favorabie development possibilities, particularly in relation to the state-of-the-art track tamping, levelling and lining machines advancing in steps, with a fresh knowledge on the subject of track maintenance.

In addition it is known from Applicant's GB Patent No. 1545574 that travelling track maintenance machines can be equipped with track stabilizing units between their undercarriages. Machines such as these are coupled onto the track tam ping, levelling and lining machines advancing in steps and are used after the track has been treated with those machines to bring the track into a deeper position and to consolidate the ballast to an even greater extent. This anticipates the initial settlement of the track which occurs under the weight of rail trafficaftertamping and, in particular, increases the transverse shift resistance of the sleepers relative to the ballast bed.Track stabilizing units of the type in question comprise a tool support which is guided on the track by flanged rollers designed to pressed firmly onto the inner shoulders of both rails by spreading drives, on which gripping rollers designed to be swung in beneath the rail head from the rail outsides by pivoting drives are arranged and which is designed to receive vibrations directed transversely of the longitudinal axis of the rails from vibrators and a force directed vertically downwards from loading drives pivotally connected to the tool support and to the machine frame. In this way, the vibrating and vertically loaded track is so to speak rubbed into the ballast which, as a result, is fluidized, the ballast particles being rearranged into a closer mutual position.The intensifies consolidation of the ballast beneath and at the ends of the sleepers previously tamped by means of vibratable tamping tools and brings the track into the deeper position corresponding to the reduction in volume of the ballast. These travelling machines equipped with track stabilizing units have proved very successful in practice.

Finally, Applicant's G.B. Patent No. 2094378 describes a tracktamping, levelling and lining machine advancing in steps which comprises a track stabilizing unit designed to travel with the machine frame between the tamping units and the rear bogie-type undercarriage. In this way, the effective ranges of the stabilizing unit and the tamping units overlap one another. This overlap applies in particular to the vibrations which are imparted by the stabilizing unit to the track and through the track to the ballast bed and of which the effective range extends deep into the tamping zone. Accordingly, the consolidating effect which thus begins in the actual tamping zone intensifies the consolidating effect of the self-vibrated tamping tools.

Now, the object of the present invention is to provide a continuous-motion (non-stop) track tamping, levelling and lining machine of the type described at the beginning with which it is possible to obtain even greaterdurablity and stability of the track position.

According to the invention, this object is achieved in that at least one track stabilizing unit advancing continuously (i.e. without stopping) together with the main frame is arranged between the two undercarriages of the main frame which are arranged immediately behind one another at a considerable distance apart, at least one undercarriage of the main frame being provided between said track stabilizing units and the tool frame advancing in steps with the tramping, lifting and lining units.

Accordingly, the present invention provides a machine which is surprisingly simple both in structure and in its mode of operation by comparison with previous proposals. In addition, this provides for integrated work which, technologically, is advantageous in terms of time and location in regard to the different modes of operation and correcting movements of the tools of the four machine units. The accuracy and durability of the track position to be established is increased along with the performance and in-machine comfort of the operating personnel.

A combination machine constructed in this way with a total of four types of working units, namely lifting, lining, tamping and stabilizing units, has the advantage that all these units are advantageously arranged not only in regard to the operational requirements of each of them but also in regard to their mutual association-on the one hand on the tool frame advancing in steps and, on the other hand, on the continuous-motion (non-stop) main frame. Accordingly, it is possible with a machine such as this to achieve an extremely high standard of work, i.e. extremely high stability of the corrected and consolidated track position.This is attributable interalia to the fact that the track already corrected in its position by the tamping, lifting and lining units in the course of the step-by-step advance of the tool frame is subjected to a uniformly progressing load by the immediately following, relatively heavily loaded undercarriage of the main frame which advances continuously (i.e. without stopping) therewith, under the effect of which the track is fixed more firmly in its corrected position and pressed onto the newly created sleeper bearing surface. In the region between this undercarriage and the immediately following undercarriage of the main frame, the corrected and already preconsolidated track may then be lowered by the track stabilizing unit advancing continuously with the main frame and hence operated in its most appropriate and track-preserving mode and, so to speak, rubbed into the preconsolidated ballast bed. In this connection, the undercarriages of the main frame which are spaced far apart from one another and between which the stabilizing unit is situated form two relatively fixed track loading points which advance continuously together (i.e. without stopping) and between which the track is able to swing out freely sideways by a distance commensurate with the amplitude of the vibration imparted to it by the vibration drive of the stabilizing unit.The tamping, lifting and lining units arranged on the tool frame advancing in steps have the same favourable arrangement and mode of operation as in the known, tried and tested track tamping, levelling and lining machines advancing in steps, although the main frame is kept free or substantially free from the weight and working forces of those units so that the personnel responsible for operating the machine are given more comfortable working conditions and, so to speak, labour and materials are spared to the greatest possible extent. At the same time, the performance and useful life of the treated track are surprisingly increased.

In one preferred embodiment of the invention, the drive, power supply and control systems of the track stabilizing, tamping, lifting and lining units and of the axle drive for the continuous (non-stop) advance of the machine are arranged on the main frame equipped with brake systems and the tamping, lifting and lining units with theirtools controllable through at least one levelling and lining reference system arranged between two undercarriages spaced far apart from one another are provided together with their drives on the tool frame connected to the main frame both for longitudinal displacement and for pivoting, the tool frame being provided at least at its rear end, for separate guiding on the track, with its own undercarriage which is designed to advance in steps and which is arranged ahead of the front undercarriage of the two undercarriages immediately following one another of the main frame of the machine. Since, therefore, all the equipment required for the operation and manipulation of the four different working units and for the propulsion of the machine is arranged on the main frame of the machine which advances continuously (i.e. without stopping), the continuous advance of the machine requires only relatively moderate propulsive power despite the considerable overall weight of the main frame carrying that equipment. In addition, the equipment in question, some of which is sensitive to impact and vibration, is protected against damage by permanent alternating stresses caused by starting and stopping.In this connection, it is possible by appropriately arranging and distributing the various pieces of equipment on the main frame on the one hand to obtain the required axle load distribution between the main undercarriages and on the other hand to keep the necessary connecting lines between the power supply and control systems and the individual working units and tool drives as short as possible. In this connection, both the undercarriages of the main frame and also the separate undercarriage advancing in steps may be of identical construction and may all be provided with a brake system.

One particularly advantageous embodiment of the invention is characterized in that the main frame of the machine designed to advance continuously (i.e. without stopping) is in two parts and comprises a rear frame section which is supported by two successive undercarriages and which, in particular, comprises two track stabilizing units arranged one behind the other longitudinally of the machine and an elongate front frame section which, at its rear end, is rotatably and pivotally supported on said rear frame section and which, at its front end, is supported by another undercarriage designed for continous (non-stop) advance which is arranged at a distance in front of the tool frame advancing in steps and carrying the tamping, lifting and lining units.

This embodiment of the machine with its pivotally divided main frame is particularly advantageous for several reasons. Thus, on the one hand, the basic structure of the already tried and tested, independent track stabilizing machines may be used virtually without modification for the rear frame section with the stabilizing units arranged thereon.

On the other hand, the pivotal support of the front frame section on the rear frame section enables the machine to negotiate curves without difficulty, even where they are of relatively small diameter. Finally, the rear frame section is also subjected to an additional weight load by the front frame section supported thereon, so that relatively powerful lowering and consolidating forces can be applied to the track through the stabilizing units and their loading drives.

Another variant of the embodiment just described of the machine according to the invention is characterized in that the tool frame carrying the tamping, lifting and lining units, which is in the form of an elongate daughter vehicle with its own two undercarriages designed to advance in steps, is spanned longitudinally of the machine by the front frame section, the daughter vehicle being linearly displaceable between the preceding and following continuous-motion (non-stop) undercarriages of the main frame by a distance substantially corresponding to the length of each step and an additional distance substantially corresponding to the interval between two successive sleepers via a coupling connected to the main frame both for longitudinal displacement and for pivoting.This variant makes a major contribution to the uninterrupted operation and simplified control of the machine as a whole because now, in addition to the track stabilizing units, the tramping, lifting and lining units are also separately guided on the track by means of the two undercarraiges of the tool frame or daughter vehicle, so that even around curved sections of track the tamping units are situated at least approximately in the correct lateral central position over the associated rails. In addition, the construction of the tool frame as an independently moving daughter vehicle enables the main frame to be completely isolated from the weight and working forces of the tamping, lifting and lining units.

In another advantageous embodiment of the machine according to the invention, the bearing by which the front frame section is rotatably and pivotally supported on the rear frame section carrying the track stabilizing unit is arranged midway along the rear frame section substantially over the track stabilizing unit. This type of mounting substantially corresponds to the support of the front frame section on a bogie with a relatively wide interval between its two axles, i.e. to an arrangement which is extremely beneficial to the riding characteristics of the machine, particularly at high speeds.In addition, that proportion of the weight of the front frame section which is supported by the bearing is transmitted to the rear frame section at precisely that point at which the loading drives of the track stabilizing unit act, producing a very favourable, direct flow of the lowering and consolidating forces acting on the track.

In another advantageous embodiment of the invention, the drive and power supply systems at least for the tamping, lifting and lining units are arranged on the continuous-motion (non-stop) main frame or mother vehicle in the front longitudinal region between the lifting and lining unit and the leading undercarriage of the main frame.This arrangement of the drive and power supply systems which has already been tried and tested in track tamping machines advancing in steps is particularly appropriate in a continuous-motion machine constructed in accordance with the invention because, in view of the necessary linear displaceability of the tool frame relative to the main frame between the lifting and lining unit and the leading undercarriage of the machine, a very considerable longitudinal space is available for conveniently accommodating the numerous units and components of the drive and power supply systems.

In another advantageous embodiment of the invention, the drive and power supply systems at least for the track stabilizing unit are arranged on the main frame or mother vehicle in the rear longitudinal region between the two immediately successive undercarriages, preceding and following the track stabilizing unit, of the main frame or mother vehicle. This embodiment provides not only for a considerable reduction in the length of the connecting and control lines leading to track stabilizing unit, but also for a desired increase in that proportion of the weight of the front frame section which is applied via the bearing to the rear frame section.

Another particularly advantageous embodiment of the invention is characterized in that the drive, power supply and control systems both for the track stabilizing unit and also for an axle drive acting on at least one of the undercarriages immediately preceding and following the stabilizing unitforthe continuous (non-stop) advance are arranged on the rear frame section of the main frame or mother vehicle.This constructional variant makes it possible as and when required or in the event of fairly prolonged maintenance work affecting only the front frame section of the machine to separate from one another and two sections of the main frame or mother vehicle joined together solely by the pivotal bearing and to use the rear frame section provided with two undercarriages and with the track stabilizing unit and with all the equipment for the motion and function control of the machine as an independently mobile track stabilizing machine, for example in conjunction with a preceding track tamping, levelling and lining machine of conventional construction.

In another advantageous embodiment of the machine according to the invention, a central operator's cabin projecting beyond the front undercarraige and the end of the rear frame section with an unobstructed view of the tamping, lifting and lining units arranged on the tool frame advancing in steps and, optionally, of the track stabilizing unit advancing continuously (i.e. without stopping) is arranged on the front frame section between the track stabilizing unit and the tamping, lifting and lining units. The various tool drives and also the step-by-step advance of the tool frame can be monitored particularly easily and conveniently from this central operator's cabin which is arranged on the continuous-motion main frame and, hence, isolated from vibration by the working forces of the tamping, lifting and lining units.

According to another advantageous embodiment of the invention, a common levelling reference system advancing continuously (i.e. without stopping) with the main frame is associated with the track stabilizing unit advancing continuously (i.e.

without stopping) and thetrack lifting and lining unit advancing in steps, extending at least from the front undercarriage to the rear undercarriage of the main frame, a vertical sensor, for example in the form of a rotary potentiometer, guided on the track by means of a feeler member advancing in steps or continuously (i.e. without stopping) being associated-per rail-with said levelling reference system in the region of the lifting and lining unit and of the track stabilizing unit.Since, therefore, the lifting of the track ahead of the tamping units and the controlled lowering of the track in the vicinity of the stabilizing unit are carried out with reference to the common levelling reference system which extends over virtually the entire length of the machine and which is isolated from the vibration caused by the working forces and the step-by-step advance of the tamping, lifting and lining units, the corrected and stabilized track is characterized by an extremely accurate level of both rails of the track largely corresponding to the required level.

In another advantageous embodiment of the machine according to the invention, preferably only one track stabilizing unit is arranged on a main frame in the form of a continuous-motion (non-stop) mother vehicle which is supported by only the two successive undercarriages and which carries the drive, power supply and control systems and an operator's cabin projecting far beyond its front undercarriage and in that the tool frame which is in the form of a daughter vehicle advancing in steps on its own two undercarriages and which carries the tamping, lifting and lining units is arranged immediately ahead of the mother vehicle and partly below the operator's cabin thereof.This variant is distinguished by a reduced overall length of the machine and by the fact that not only the working units arranged on the daughter vehicle, but also the section of track lying ahead are clearly visible from the operator's cabin. It is also possible in this embodiment of the machine, as and when required, to separate the daughter vehicle from the mother vehicle and to use the mother vehicle as an independent track stabilizing machine.

The two undercarriages, immediately preceding and following the track stabilizing unit, of the continuous-motion (non-stop) main frame or mother vehicle advantageously have substantially the same inter-axle distance as the two undercarriages immediately preceding and following the tamping, lifting and lining units, this inter-axle distance preferably amounting to at least 8 m. This inter-axle distance, which is the same for both vehicles, corresponds on the one hand to the distance between the two undercarriages of the daughter vehicle which is required for adequate lifting of the track without overstressing the rails and, on the other hand, to the distance between the undercarriages of the mother vehicle which is required for the horizontal vibration of the track transversely of its axis in the region of the stabilizing unit.

In one preferred embodiment of the invention, the track stabilizing unit arranged on the continuous motion (non-stop) main frame or mother vehicle is equipped in the usual way with a tool support guided on the track by flanged rollers designed to be pressed firmly against the inner shoulders of both rails by spreading drives, with gripping rollers arranged on the tool support and designed to be swung in beneath the railhead from the rail outside by pivoting drives, with a vibration drive designed to impart to the flanged and gripping rollers substantially horizontal vibrations directed transversely of the track and with loading drives pivotally connected both to the tool support and to the main frame and designed to apply to the flanged rollers a force directed vertically downwards.

Accordingly, the advantages of this functionally reliable and robust construction of the stabilizing units are fully brought to bear for the first time in a continuous-motion (non-stop) combination machine constructed in accordance with the invention. In addition, major advantages are created for the machine manufacturer in regard to production and storage of the stabilizing units which may be used both for independent machines and also for combination machines.

The tamping units arranged on the tool frame or daughter vehicle designed to advance in steps are best conventionally equipped with tamping tools vertically adjustable by drives and designed to be moved towards one another in pairs longitudinally of the machine and to be vibrated for penetration into the ballast bed. Since standard tamping units such as these are always available in various forms and for various purposes, the particular required tooling of the machine does not involve any additional development work.

According to the invention, similar advantages are afforded by the fact that the track lifting and lining units arranged on the tool frame or daughter vehicle designed to advance in steps is conventionally equipped with a tool support guided on the track and, arranged thereon, lifting and lining tools, such as roller pincers, gripping hooks, flanged lining rollers, etc., designed to be manipulated by lifting and lining drives in conjunction with the levelling and lining reference systems. Here, too, a whole range of tried and tested track lifting and lining units with different tooling for working on switches and/or plain track is available.All in all, therefore, the combination machine according to the invention may be individually equipped without any need for additional development work with whatever are the most suitable working units optimally co-ordinated with one another in their function.

In another advantageous embodiment of the invention, sleeper-end consolidators in the form of optionally vibratable beam or roller assemblies designed to be pressed onto the ballast through drives at the ends of the sleepers are arranged on the continuous-motion (non-stop) main frame or mother vehicle behind the track stabilizing unit and/or on the tool frame or daughter vehicle advancing in steps in the region of the tamping units on both track outsides of the particular frame or vehicle. This additional equipping of the machine with sleeper-end consolidators increases the solidity of the stabilized track position even further and, in particular, considerably increases the resistance of the sleepers to transverse shifting in the consolidated ballast bed.In addition, the sleeper-end consolidators acting along the outsiders of the ballast bed and, optionally, along the shoulders of the ballast bed prevent the vibrated ballast from flowing off to the outsides of the track.

According to another advantageous aspect of the invention, all the drives of the track stabilizing, tamping, lifting and lining units and of the sleeper end consolidators are in the form of hydraulic drives and are connected to a common hydraulic pressure source of the drive and power supply system provided on the main frame. This standardization of all the tool drives provides for a simpler structure of the control systems using identical hydraulic control and regulating elements.

Another advantageous embodiment of the invention is characterized in that-in addition to a central operator's cabin with an unobstructed view of the working units-further operator's cabins with a clear view of the track are respectively arranged at the front and rear ends of the continuous-motion (non-stop) main frame or mother vehicle, accommodating at least the controls for the axle drive and brake systems of the machine. In this way, the track is always clearly visible during in-transit runs of the machine under its own power, even in cases where the machine is exceptionally long, for example where it is equipped with a multi-sleeper tamping unit.At the same time, the tools of the track stabilizing unit can be checked or monitored in conjunction with the levelling reference system from the other operator's cabin arranged at the rear end of the continuous-motion (non-stop) main frame, which is another advantage afforded by the invention.

Finally, in another advantageous embodiment of the invention, the propulsion or axle drives of the main frame are designed both for continuous (nonstop) in-transit runs and for continuous (non-stop) working runs whilst the axle drive and/or the coupling in the form a cylindrical-and-piston drive is designed for advance in steps to obtain a coordinated speed-advance function.

Preferred embodiments of the invention are described by way of example in the following with reference to the accompanying drawings, wherein: Figure lisa side elevation of a continuous-motion (non-stop) tracktamping, levelling, lining and stabilizing machine according to the invention.

Figure 2 is a highly simplified diagrammatic plan view of the machine illustrated in Figure 1, the main frame of the machine being shown in chain lines in the interests of clarity.

Figure 3 is a view on a larger scale of the track stabilizing unit of the machine taken along the line Ill-Ill in Figure 1.

Figure 4 is a view on the same enlarged scale of a tamping unit of the machine taken along the line IV--IV in Figure 1.

Figure 5 is a view on the same enlarged scale of the track lifting and lining unit of the machine taken along the line V-V in Figure 1.

Figure 6 is a side elevation of a second embodiment of a continuous-motion (non-stop) combination machine according to the invention.

Figure 7 is a highly simplified diagrammatic plan view of the machine illustrated in Figure 6, the main frame again being shown in chain lines to enable the invention to be better understood.

Figure 8 is a side elevation of a third embodiment of a continuous-motion (non-stop) track tamping, levelling, lining and stabilizing machine according to the invention.

Figure 9 is a diagrammatic plan view of the machine illustrated in Figure 8, the main frame again being shown in chain lines in the interests of clarity, i.e. to bring the tool frame more clearly into the foreground.

The continuous-motion (non-stop) track tamping, levelling, lining and stabilizing machine 1 shown in Figures 1 to 5 comprises a two-part main frame 2 which consists of a rear frame section 5 supported on two undercarriages 3,4 immediately following one another and of an elongate, front frame section 6 which is pivotally supported at its rear end on the rearframe section 5 and which, at its front end, is supported on the track consisting of rails 8 and sleepers 9 by another undercarriage 7. Each of the undercarriages 3,4 and 7 has its own axle drive 10 for the continuous advance of the main frame 2 in the direction of the arrow 11. The undercarriages mentioned are also equipped with brakes which, in the drawing, are symbolized by brake blocks 12.

At the front end of the main frame 2 or rather the frame section 6, there is an operator's cabin 13 from which at least the axle drive 10 and the brake systems of the undercarriages 3,4 and 7 can be controlled. The leading undercarriage 7 is preceded bya measuring wheel assembly 14 for measuring the distance travelled by the machine 1. The drive and power supply systems 15 of the machine 1 are accommodated on the front frame section 6 behind the undercarriage 7. Another, central operator's cabin 16 is arranged on the front frame section 6 above the undercarriage 3, projecting beyond the undercarriage 3 and accommodating a central motion and function control console 17, a brake pedal 18 and a control system 19.

Between the undercarriages 3 and 7 of the main frame 2, there is a tool frame 20 which, at its rear end, is supported on the track via a supporting and guiding undercarriage 22 provided with an axle drive 21 and which, at its front end formed by two parallel longitudinal beams 23, is pivotally supported for longitudinal displacement on the front frame section 6 via roller guides 24. The tool frame 20 and the front frame section 6 are pivotally interconnected by a coupling 25 in the form of a double acting hydraulic cylinder-and-piston assembly.

A vertically adjustable tamping unit 26 which will be described in more detail hereinafter is arranged for each rail 8 on the tool frame 20 immediately in front of the undercarriage 22, being preceded by a track lifting and lining unit 27 to be described in detail hereinafter associated with both rails 8 of the track.

The machine 1 is equipped with two track stabilizing units 28 which will be described in more detail hereinafter and which are arranged midway between the undercarriages 3 and 4 of the rear frame section 5, being pivotally connected to that frame section on the one hand by loading drives 29 and, on the other hand, by drag rods 30. In addition, separate drive and power supply systems 31 are arranged on the rear frame section 5, being followed by another operator's cabin 32 which accommodates control systems 33 for the track stabilizing units 28 and at least one of the axle drives 10 of the undercarriages 3,4 and their brake systems. Similar control systems 34 for the axle drive 10 and brake systems at least of the leading undercarriage 7 are also accommodated in the operator's cabin 13.

A separate levelling reference system 35,36 is associated with each of the two frame sections 5,6.

The levelling reference system 35 of the rear frame section 5 consists of two wire chords 37 each associated with one of the two rails 8 and vertically guided on the track at their front and rear ends by means of rods supported on the axle bearing 38 of the undercarriages 3 and 4. Between the two stabilizing units 28, there is a feeler member 40 which is guided on the track and which, for each rail 8, carries a contact plate 41 cooperating with the associated wire chord 37 as a cut-out. The levelling reference system 36 of the front frame section 6 similarly consists of two wire chords 42 which are each associated with one of the two rails 8 and which are their front ends are each fixed to a tension roller 43 of a pilot trolley 45 which precedes the machine 1 at a distance and which is pivotally connected to the front frame section 6 by a linkage 44.The rear ends of the wire chords 42 are connected to a feeler member 46 guided on the track immediately ahead of the undercarriage 3. Another feeler member 47 guided on the track and arranged on the tool frame 20 between the tamping units 26 and the track lifting and lining unit 27 carries-per rail 8--a vertical sensor 48, for example in the form of a rotary pentiometer, cooperating with the associated wire chord 42.

The machine is further equipped with a lining reference system 49 formed by a wire chord 50 which extends from the pilot trolley 45 to the rear undercarriage 4 of the machine 1. A versine sensor 51 which is connected to the feeler member 47 and, accordingly, is laterally guided on the track cooperates with the wire chord 50.

In Figure 1, the tool frame 20 with the tamping unit 26 and the track lifting and lining unit 27 is shown in solid lines in its front end position relative to the continuous-motion (non-stop) main frame 2.

The chain-line illustration of the supporting and guiding undercarriage 22 corresponds to the rear end position of the tool frame 20 relative to the main frame 2. The step-by-step advance movement (each step corresponding to a sleeper interval) which is imparted to the tool frame 20 through the variable length coupling 25 and/or through its own axle drive 21 is symbolized by the arrows 52 in Figure 1.

Figure 3 shows the construction of the track stabilizing units 28. They comprise a tool support 53 which is guided on the track by flanged guide rollers 55 designed to be pressed firmly against the inner shoulders of both rails 8 by spreading drives 54 and to which the loading drives 29 are designed to apply a lowering force directed vertically downwards via the flanged guide rollers 55 onto the associated rail 8 and the sleepers 9. Gripping rollers 60 designed to be swung in beneath the railheads from the outside of the associated rail about pivot pins 59 through pivoting drives 56 and intermediate levers 57, 58 are mounted on both track outsides of the tool support 53.Arranged in the middle of the tool support 53 are diagrammatically illustrated vibration drives 61 in the form of eccentric vibrators through which the tool support 53 and the rails 8 (together with the sleepers 9) clamped pincer-fashion between the flanged guide rollers 55 and the gripping roller 60 are designed to be vibrated substantially horizontally and transversely of the rails 8. Figure 3 also shows the construction of the bearing 62 through which the front frame section 6 is supported for universal pivoting on the rear frame section 5 above the stabilizing units 28. In addition, the lines connecting the loading drives 29, spreading drives 54, pivoting drives 56 and vibration drives 61 to the drive and power supply systems 31 are shown diagrammatically in chain lines.

Figure 4 shows one of the tamping units 26 in its lowered position corresponding to Figure 1. This tamping unit 26, which is of substantially standard construction, comprises a tool support 55 designed to be raised and lowered along two vertical guide posts 63 under the power of a vertical displacement drive 64 and to be arranged substantially centrally over the associated rail 8. The tool support 65 comprises two lateral arms 66 on each of which two tamping tools 67 resembling pivoting levers and each comprising two tamping tines 68 arranged adjacent one another and designed to penetrate into the ballast bed on one side of the rail 8 on the opposite longitudinal sides of a sleeper 9 are mounted to pivot about horizontal journals 69 extending transversely of the rail 8.The upper ends of the tamping tools 67 of which there are four in all and of which Figure 4 shows only those two facing the viewer are pivotally connected to a vibration drive 70 in the form of an eccentric shaft arrangement mounted on the tool support 65 via a squeezing drive 71 in the form of a hydraulic cylinder-and-piston assembly. The lines connecting the vertical adjustment, vibration and squeezing drives 64,70 and 71 all in the form of hydraulic drives to the drive and power supply systems 15 arranged on the front frame section 6 are also schematized in Figure 4. The feeler member 47 preceding the tamping unit 26 and the vertical sensor 48 connected thereto and cooperating with the wire cord 42 are also shown in chain lines.

Figure 5 shows the construction of the substantially standard track lifting and lining unit 27 of the machine 1. For each rail 8, the track lifting and lining unit 27 comprises a tool support 73 which is designed to be raised and lowered by a lifting drive 72 and of which the lower frame section 75, pivotal about the shaft 74, is guided on the associated rail 8 by two flanged lining rollers 76 spaced apart from another longitudinally of the rail. Two lifting rollers 77 facing one another in pairs relative to the rail 8 are mounted to pivot about shafts 78 extending longitudinally of the rail at the front end and rear end of the frame section 75 (as seen longitudinally of the rail). The bearings 79 of the lifting rollers 77 facing one another in pairs are pivotally interconnected by a closing drive 80 in the form of a hydraulic cylinder-and-piston assembly.By means of this closing drive 80, the two lifting rollers 77 can be swung in beneath the railhead of the associated rail 8 from the outsides thereof. A lateral lining drive 81 in the form of a hydraulic cylinder-and-piston assembly is associated with each tool support 73, being mounted at one end on the frame section 75 to pivot universally about a pin 82 and, at its other end, on a bracket 83 of a central longitudinal beam 84 of the tool frame 20 to pivot universally about a pin 85. Two upwardly projecting bearing plates 86, on which the coupling 25 formed by a hydraulic cylinder-and-piston assembly is mounted for universal pivoting, are joined, for example by welding, to the longitudinal beam 84. The lines connecting the lifting, closing and lateral lining drives 72,80 and 81, all in the form of hydraulic drives, and also the coupling 25 to the drive and power supply systems 15 are shown in chain lines.

The machine shown in Figure 1 to 5 operates as follows: With the tool frame 20 in its front end position, the machine 1 is advanced in the direction of the arrow 11 by means of the axle drives 10 until thetamping units 26 are situated centrally over the first sleeper 9 to be tamped. After the vibration drives 70 have been switched on and pressure released from the coupling 25 from the motion and function control console 17, the lifting and lateral lining drives 72,81 are activated in accordance with the vertical and lateral track position errors as determined by means ofthe reference systems 36, 49 and the track is moved first into a provisional predetermined vertical position and into its final predetermined lateral position.At the same time, the tamping units 26 are lowered by means of the vertical displacement drives 64, as a result of which the tamping tools 67 penetrate into the ballast on both sides of the sleeper 9 and on both sides of the associated rails 8. In the meantime, the main frame 2 of the machine continues its non-stop advance under the power of the axle drives 10. When the tamping units 26 are lowered, the squeezing drives 71 are activated so that the tamping tools 67 facing one another in pairs make a pincer-like closing movement towards the sleeper 9 to be tamped.On completion of the tamping operation, i.e. afterthe required predeterminable tamping pressure or degree of ballast consolidation has been reached, the tamping units 26 are raised by means of the vertical displacement drives 64 and, at the same time, the coupling 25 and/orthe axle drive 21 is activated to accelerate the tool frame 20 forwards in a step-by-step movement until the tamping units 26 are situated centrally over the next sleeper 9 to be tamped.In order to prevent the tool frame 20 in its rear end position determined by the coupling 25 from beginning its forward movement in the event of a delay in the tamping operation, the distance travelled by the machine 1 since the last stoppage of the tool frame 20 is measured by the measuring wheel assembly 14, transmitted in the form of an analog or digital signal to the control system 19 and compared therein with the maximum permitted travel. When this value is reached, the axle drives 10 are automatically switched off and all the undercarriages 3,4 and 7 of the main frame 2 are fully braked.

As the machine continues its working run, the undercarriage 3 moves into the already corrected and tamped section of track. The continuously advancing load applied to the track by the undercarriage 3 produces an initial consolidation of the new track position. The vibration drives 61 of the track stabilizing units 28 are then switched on and, at the same time, pressure is also admitted to the loading drives 29. Underthe combined effect ofthe horizontal transverse vibrations imparted to the track through the flanged rollers 55 and the gripping rollers 60 and the vertical load applied by the drives 29, the ballast beneath and in the area around the sleepers 9 is, as it were, fluidized and, through rearrangement of the ballast particles, is compressed and consolidated into a compact mutual position.Due to the reduction in volume and to the vertically applied loads, the track is thus lowered to a final predetermined level situated beneath the provisional predetermined level in the region between the two undercarriages 3 and 4. The stabilizing operation has no effect on the already corrected lateral position of the track because the vibration drives 61 impart to the track reciprocating vibrations equal in amplitude in either direction. The particular degree of depression of the track required in the region of the stabilizing units 28 may be controlled as follows with the aid of the levelling reference system 35 associated therewith: The two wire chords 37 of the reference system 35 embody the level of the two rails 8 between the front and rear undercarriages 3, 4 of the frame section 5.

As long as one of the two contact plates 41 of the feeler member 40 remains in contact with the associated wire chord 37, the loading drives 29 arranged on the associated side of the machine remain under pressure. With further lowering of the track and hence of the contact plates 41, the circuits hitherto closed by the wire chords 37 are opened and pressure is released from the associated loading drives 29 through a control circuit formed, for example, by relay-controlled electrovalves. In order, therefore, to adjust the required degree of lowering of the track, the contact plates 41 merely have to be vertically adjusted to the required extent relative to the feeler member 40.

The other embodiment of a continuous-motion (non-stop) tracktamping, levelling, lining and stabilizing machine 87 which is shown in Figures 6 and 7 differs from the embodiment described in the foregoing essentially in the construction of its tool frame 90 carrying the tamping units 88 and also the track lifting and lining unit 89. This tool frame 90 which is intended for step-by-step advance in the direction of the arrows 91 is in the form of an elongate daughter vehicle 94 which is designed to travel independently along the track by means of two undercarriages 92, 93 and which is connected to the front frame section 95 of the main frame 96, again in two parts, solely by a connecting rod 98 pivotally connected to the variable-length coupling 97.In the region between the front and middle undercarriages 99, 100 of the main frame 96, the daughter vehicle 94 is linearly displaceable between the front end position shown in solid lines in Figure 6 and the rear end position shown in chain lines.

Two track stabilizing units 103 shown diagrammatically in simplified form and largely corresponding in structure to the embodiment illustrated in Figures 1 to 5 are provided on the rear frame section 102 supported by the undercarriage 100 and by another undercarriage 101 immediately following it. Three operator's cabins 104,105 and 106 and also the drive and power supply systems 107 are arranged on the main frame 96 of the machine 87, the drive and power supply systems 107 being situated behind the central operator's cabin 105 on the front frame section 95, the front frame section 95 again being supported for universal pivoting substantially centrally on the rear frame section 102.

The machine 87 is equipped with a levelling reference system 108 which is sheared by the track lifting and lining units 89 and the stabilizing units 103 and which extends from a front feeler member 109via the undercarriage 100 to the rear undercarriage 101 of the machine. Contact plates 110 guided on the track by feeler members 111 and 112 cooperate with the reference system 108 in the manner already described. The machine comprises a lining reference system 113 which extends from the front feeler member 109 to the rear undercarriage 101 and with which a versine sensor 114 connected to the feeler member 111 cooperates.

The working direction of the continuous-motion (non-stop) machine 87 is indicated by the arrow 115.

The mode of operation of this machine is based on the same sequence of individual operations described in the foregoing in reference to Figures 1 to 5.

Figures 8 and 9 show another embodiment of a continuous-motion (non-stop) track tamping, levelling, lining and stabilizing machine 116 according to the invention. In this case, the onepiece main frame 119 supported solely by the undercarriages 117 and 118 forms with only one track stabilizing unit 120 arranged between these two undercarriages and an axle drive 121 acting on the rear undercarriage 118a mothervehicle 123 which advances continuously (i.e. without stopping) in the direction of the arrow 122 and which is immediately preceded by the tool frame 126 supported by its own two undercarriages 124,125 as a daughter vehicle 127. The mother and daughter vehicles 123, 127 are connected to one another for longitudinal displacement and for pivoting by the coupling 128.The mother vehicle 123 comprises a front operator's cabin 129 projecting far beyond the undercarriage 117 and a rear operator's cabin 130 between which the drive and power supply systems 131 of the machine 116 are arranged. Tamping units 133 and, ahead of them, a track and lifting and lining unit 134 are arranged on the tool frame 126 of the daughter vehicle 127 advancing step-by-step in the direction of the arrows 132. The mother vehicle 123 has its own levelling reference system 135 which extends between the undercarriages 117 and 118 and with which-per rail-a contact plate 136 carried by the stabilizing unit 120 cooperates in the manner already explained.

As shown in Figures 6 and 7, sleeper-end consolidators 137 each formed by a roller assembly are provided at the rear end of the main frame 119 of the mother vehicle 123, being connected to the main frame 119 by vertical loading drives 138. The daughter vehicle 127 has an optical levelling reference system 139 which consists-per rail-of a light beam emitter 140 supported on the undercarriage 124 and of a receiver 142 supported on the undercarriage 125 and responding to the associated light beam 141. A feeler member 143 guided on the track between the tamping units 133 and the track lifting and lining unit 134 carries-per rail-a shadow board 144 which cooperates with the associated light beam 141 of the levelling reference system 139 in the manner of a vertical sensor.

Sleeper-end consolidators 146 in the form of plates designed for application by loading drives 145 to the outer peripheral regions of the ballast bed are arranged on the track outsides of the tool frame 126 in the vicinity of the tamping units 133. These sleeper-end consolidators 146 which may optionally be vibrated by vibration drives come into operation during the tamping process, i.e. while the daughter vehicle 127 is stationary over the tamping zone. By contrast, the sleeper end consolidators 137 which move together with the continuously advancing mother vehicle 123 remain in contact with the peripheral zones of the ballast bed throughout the entire working run.All other operations follow the sequence already described in reference to Figures 1 to 5 except that, for the step-by-step advance of the daughter vehicle 127, the coupling 128 in the form of a hydraulic cylinder-and-piston assembly is activated in the opposite direction by the admission of pressure to the rear cylinder chamber 147. The machine 116 also comprises a lining reference system 148 which extends from the leading undercarriage 124 to beyond the rear end of the machine and with which a versine sensor 149 connected to the feeler member 143 cooperates. In this embodiment, too, it can be of advantage to equip at least the undercarriage 125 with a brake system and, optionally, with its own axle drive, as described with reference to Figure 1.

In addition to the embodiments described in the foregoing, many other advantageous combinations are possible within the scope of the invention, particularly in regard to the arrangement and number of undercarriages and brake systems and axle drives, taking into account the basic arrangement according to the invention of the units and drives on the one hand and of the drive and power supply sources on the other hand.

Modifications may also be made to the cabin arrangements, particularly in regard to boarding of the machine and connecting passages, in order to find whatever is the most favorable solution for the particular construction of this four-component combination according to the invention of the units advancing continuously (i.e. without stopping) and in steps at one and the same time.

Claims (20)

1. A continuous-motion (non-stop) track tamping, levelling and lining machine comprising a main frame supported by undercarriages and, connected to the main frame both for longitudinal displacement and for pivoting, a tool frame advancing in steps with tamping, lifting and lining units arranged thereon together with their respective drives, characterized in that at least one track stabilizing unit advancing continuously (i.e.

without stopping) together with the main frame is arranged between two undercarriages of the main frame which are arranged immediately behind one another at a considerable distance apart, at least one undercarriage of the main frame being provided between said track stabilizing units and the tool frame which advances in steps with the tamping, lifting and lining units.

2. A machine as claimed in Claim 1, characterized in that the drive, power supply and control systems of the track stabilizing, tamping, lifting and lining units and of the axle drive for the continuous (non-stop) advance of the machine are arranged on the main frame equipped with brake systems and the tamping, lifting and lining units with their tools controllablethrough at least one levelling and lining reference system arranged between two undercarriages spaced far apart from one another are provided together with their drives on the tool frame connected to the main frame both for longitudinal displacement and for pivoting, the tool frame being provided at least at its rear end, for separate guiding on the track, with its own undercarriage which is designed to advance in steps and which is arranged ahead of the front undercarriage of the two undercarriages immediately following one another of the main frame of the machine.

3. A machine as claimed in Claim 1 or 2, characterized in that the main frame of the machine designed to advance continuously (without stopping) is in two parts and comprises a rear frame section which is supported by the two successive undercarriages and which, in particular, comprises two track stabilizing units arranged one behind the other longitudinally of the machine and an elongate front frame section (6;95) which, at its rear end, is rotatably and pivotally supported on said rear frame section and which, at its front end, is supported by another undercarriage designed for continuous (non-stop) advance which is arranged at a distance in front of the tool frame advancing in steps and carrying the tamping, lifting and lining units.

4. A machine as claimed in Claim 3, characterized in that the tool frame carrying the tamping, lifting and lining units which is in the form of an elongate daughter vehicle with its own two undercarriages designed to advance in steps is spanned longitudinally of the machine by the front frame section, the daughter vehicle being linearly displaceable between the preceding and following continuous-motion (non-stop) undercarriages of the main frame by a distance substantially corresponding to the length of each step and an additional distance substantially corresponding to the inverval between two successive sleepers via a coupling connected to the main frame both for longitudinal displacement and for pivoting.

5. A machine as claimed in Claim 3 or 4, characterized in that the bearing by which the front frame section is rotatably and pivotally supported on the rear frame section carrying the track stabilizing unit (28; 103) is arranged midway along the rear frame section substantially over the track stabilizing unit.

6. A machine as claimed in any of Claims 1 to 5, characterized in that the drive and power supply systems at least for the tamping, lifting and lining units are arranged on the continuous-motion (nonstop) main frame or mother vehicle in the front longitudinal region between the lifting and lining unit and the leading undercarriage of the main frame.

7. A machine as claimed in any of Claims 1 to 6, characterized in that the drive and power supply systems at least for the track stabilizing unit are arranged on the main frame or mother vehicle in the rear longitudinal region between the two immediately successive undercarriages preceding and following the track stabilizing unit, of the main frame or mother vehicie.

8. A machine as claimed in any of Claims 3 to 7, characterized in that the drive, power supply and control systems both for the track stabilizing unit and also for an axle drive acting on at least one of the undercarriages immediately preceding and following the stabilizing unit for the continuous (non-stop) advance are arranged on the rear frame section of the main frame or mother vehicle.

9. A machine as claimed in any of Claims 3 to 8, characterized in that a central operator's cabin projecting beyond the front undercarriage and the end of the rear frame section with an unobstructed view of the tamping, lifting and lining units arranged on the tool frame advancing in steps and, optionally, of the track stabilizing unit advancing continuously (i.e. without stopping) is arranged on the front frame section between the track stabilizing unit and the tamping, lifting and lining units.

10. A machine as claimed in any of Claims 3 to 9, characterized in that a common levelling reference system advancing continuously (i.e. without stopping) with the main frame is associated with the track stabilizing unit advancing continuously (i.e.

without stopping) and the track lifting and lining unit advancing in steps, extending at least from the front undercarriage to the rear undercarriage of the main frame, a vertical sensor, for example in the form of a rotary potentiometer, guided on the track by means of a feeler member advancing in steps or continuously (i.e. without stopping) being associated-per rail-with said levelling referece system in the region of the lifting and lining unit and of the track stabilizing unit.

11. A machine as claimed in Claim 1 or 2, characterized in that, preferably, only one track stabilizing unit is arranged on a main frame in the form of a continuous-motion (non-stop) mother vehicle which is supported by only the two successive undercarriages and which carries the drive, power supply and control systems and an operator's cabin projecting far beyond its front undercarriage and in that the tool frame which is in the form of a daughter vehicle advancing in steps on its own two undercarriages and which carries the tamping, lifting and lining units is arranged immediately ahead of the mother vehicle and partly below the operator's cabin thereof.

12. A machine as claimed in any of Claims 1 to 11, characterized in that the two undercarriages, immediately preceding and following the track stabilizing unit, of the continuous-motion (non-stop) main frame or mother vehicle have substantially the same inter-axle distance as the two undercarriages immediately preceding and following the tamping, lifting and lining units, this interaxle distance preferably amounting to at least approximately 8 m.

13. A machine as claimed in any of Claims 1 to 12, characterized in that the track stabilizing unit arranged on the continuous-motion (non-stop) main frame or mother vehicle is equipped in the usual way with a tool support guided on the track by flanged rollers designed to be pressed firmly against the inner shoulders of both rails by spreading drives, with gripping rollers arranged on the tool support and designed to be swung in beneath the rail head from the rail outsides by pivoting drives, with a vibration drive (61) designed to impart to the flanged and gripping rollers substantially horizontal vibrations directed transversely of the track and with loading drives pivotally connected both to the tool support and to the main frame and designed to apply to the flanged rollers a force directed vertically downwards.

14. A machine as claimed in any of Claims 1 to 13, characterized in that the tamping units arranged on the tool frame or daughter vehicle designed to advance in steps are conventionally equipped with tamping tools vertically adjustable by drives and designed to be moved towards one another in parts longitudinally of the machine and to be vibrated for penetration into the ballast bed.

15. A machine as claimed in any of Claims 1 to 14, characterized in that the track lifting and lining unit arranged on the tool frame or daughter vehicle designed to advance in steps is conventionally equipped with a tool support guided on the track and, arranged thereon, lifting and lining tools, such as roller pincers, gripping hooks, flanged lining rollers etc., designed to be manipulated by lifting and lining drives in conjunction with the levelling and lining reference systems.

16. A machine as claimed in any of Claims 1 to 15, characterized in that sleeper-end consolidators in the form of optionally vibratable beam or roller assemblies designed to be pressed onto the ballast through drives at the ends of the sleepers are arranged on the continuous-motion (non-stop) main frame or mother vehicle behind the track stabilizing unit and/or on the tool frame (126) or daughter vehicle advancing in steps in the region of the tamping units on both track outsides of the particular frame or vehicle.

17. A machine as claimed in Claims 11 to 16, characterized in that all the drives of the track stabilizing, tamping, lifting and lining units and of the sieeper-end consolidators are in the form of hydraulic drives and are connected to a common hydraulic pressure source of the drive and power supply System provided on the main frame.

18. A machine as claimed in any of Claims 1 to 10 and 12 to 17, characterized in that-in addition to a central operator's cabin with an unobstructed view pf the working units-further operator's cabins with a clear view of the track are respectively arranged at the front and rear ends of the continuous-motion (non-stop) main frame or mother vehicle, accommodating at least the controls for the axle drive and brake systems of the machine.

19. A machine as claimed in any of claims 1 to 18, characterized in that the propulsion or axle drives of the main frame are designed both for continuous (non-stop) in-transit runs and for continuous (nonstop) working runs whilst the axle drive and/or the coupling in the form of a cylinder-and-piston drive is designed for step-by-step advance to obtain a coordinated speed-advance function.

20. A railway track maintenance machine substantially as herein described with reference to Figures 1 to 5, Figures 6 and 7 or Figures 8 and 9 of the accompanying drawings.