GB2172326A - A travelling on-track machine for taking up ballast from a ballast bed under suction - Google Patents

Abstract

An on-track ballast cleaning machine has a ballast-lifting suction unit 25 mounted so that it can move horizontally in the sleeper cribs, and vertically so that it can penetrate the ballast bed. The suction head 25 may be rotatable so as to penetrate under sleepers, and may be associated with a ballast-loosening unit 44 for loosening compacted ballast. <IMAGE>

Description

SPECIFICATION Atravelling on-track machine for taking up ballast from a ballast bed under suction This invention relates to atravelling on-track machine for removing ballast by suction from a ballast bed beneath a track consisting of rails and sleepers, of which the machine frame designed to travel on the rails is provided with a suction arrangement which is connected to a compressor and which comprises at least one adjustable suction unit connected via a suction pipe and having a suction opening for the ballastto be taken up.

GB 2080858 describes a travelling on-track ballast cleaning machine in which the ballastistaken upfrom a ballast bed beneath a track consisting of rails and sleepers by an endless clearing chain arranged on the machineframeandguided aroundthetrack.Atthe same time, the continuously circulating clearing chain,which comprises pivotally interconnected shovel-like links provided with scraperfingers, removes all the ballast beneath the track over the entire width ofthe ballast bed as the machine advances continuously. The ballast taken up is then cleaned in a vibrating sieve.Travelling on-track machines such as thesefortaking up and cleaning bedding ballast which have already proved successful in practice and which, in most cases, also comprise lifting units to create easier accessibility forthe clearing chain in taking up the ballast achieve very high performance levels and, in particular, may be used fortaking up and cleaning even heavily encrusted ballast. However, when it comestotunnelsandcompulsoryzones,asfor example at platforms or the like, it is often very difficult and, in most cases, impossible for the clearing chain, which is widerthan the sleepers are long, to evade or, more particularly, to circumvent such obstacles under control. Before and after negotiating such obstacles, the clearing chain has to be disengaged and then replaced.

DE-Gbm 82 36 650.0 describes a machine fortaking up the ballast of a track consisting of rails and sleepers resting on the ballast bed underthe effect of suction.

This known machine comprises a suction arrangement in the form of a suction compressor mounted on the machine frame and a suction unit connected to the compressor by a suction pipe and formed by a rectangular or round suction nozzle. The suction pipe which is connected to the compressor substantially centrally at the top ofthe machine projects beyond one longitudinal end ofthe machineframe and is bent downwards at an angle to the track. The free end ofthe suction pipe in the form of a suction nozzle is connected to a rubber skirt which in its side has an inlet opening or rather a suction opening which is openintheworking direction in orderto slide more easily over the ballast stones and the sleepers or rather to allow them through by deflection of the skirt during the continuous advance ofthe machine.As the machine advances, the suction nozzle which moves along over the top ofthe sleepers longitudinally ofthe machine is intended to take up soil and ballast stones from or adjacent the track through this lateral suction opening. The material taken up is then sucked into a collecting container and ejected therefrom onto a vibrating deck serving as a sieve for cleaning.

Accordingly, the described arrangement is only able to take up relatively loosely piled bedding ballast and not compacted and, in particular, encrusted bedding ballast. In addition, according to the specification,the suction nozzle is only designed to move transversely of the track and vertically, although it can also be moved longitudinally ofthe track in a travel mode of the machine.Because of this, the performance of the machine and its effectiveness in taking up ballast under suction can only ever be very limited, in addition to which lateral displacement of the suction nozzletransversely ofthe longitudinal axis ofthetrack can only be obtained - according to the illustrated embodiment-- by manual pivoting ofthe suction pipe connected to the suction nozzle and leading to the compressor.

Finaily, JP-OS 41 762179 describes a travelling on-track machine fortaking up and, atthe sametime, cleaning the ballast of a railway track consisting of a rails and sleepers resting on the ballast bed. This machine comprises a machineframe designed to travel on the rails with a suction arrangement connected to a compressorwhich comprises a suction unitconnected via a suction pipe. The suction unit is formed by a beam arranged beneath the track over its width with a suction opening-open in the working direction-forthe ballastto be taken up which is fixedly connected to the machineframe. At one end, the suction pipe leads outside the track to the compressor.The suction beam is preceded in the working direction by two shovel-like clearing tools pivotal by a drive in the plane of the track beneath the track panel for the intermittent rather than continuous introduction of ballast into the region ahead of the suction beam. Accordingly, the take-up of ballast by a machine such as this, which has not yet been used in practice, can only be obtained-similarly to a clearing chain in a cleaning machine-- by advance ofthe machine itself and by previous placement ofthe suction beam beneath the track panel. This suction arrangement also cannot be used in tunnels and compulsory regions and similar obstacles becausethe suction beam is wider than the sleepers are long and the ballast cannot be cleared out in the vicinity of obstacles of the type in question.In addition, this known machine comprises a sieveforcleaning the ballast taken up in the form of a rotating drum communicating with a container in which the cleaned ballast is mixed with a water-insoluble adhesive. This mixture is distributed onto the subgrade by a chute whilethe waste spoil accumulating during cleaning is carried away. Thereafter, new in-fill ballast can be deposited onto the track from afollowingtransporting vehicle. A machine such as this does nottake up ballast as effectively as the known ballast cleaning machines using a continuously circulating chain, nor is it able at all to take up ballast in the vicinity of obstacles orthe like. In addition, it is not possibleto obtain a sufficiently strong suction effect in view ofthe fairly considerable interval separating the suction beam with its suction opening from the ballast clearing zone.

Now, the object of the present invention isto provide a travelling on-track machine ofthe type mentioned at the beginning by means ofwhich ballast can be taken up under suction from sleeper cribs and almost completely from under sleepers as the suction unit advances in steps from one sleeper crib to the next within the clearance profile, even along difficult stretches of track, in tunnels, at platforms and similar obstacles.

According to the invention, this object is achieved by a machine of the type described at the beginning in which the suction arrangement is designed both for a penetrating movement of the suction unit equipped withasuction headthroughthetrackandfora substantially horizontal movement of the suction head fr lateral penetration into the ballast bed beneath the sleepers and in which the suction unit is connected to independently operable drives, at least for vertical and lateral adjustment even beneath the sleepers. With this construction according to the invention, it is possible for the first time even to remove ballast compacted by repeated tamping from under sleepers, even in difficult, laterally confined stretches oftrack, by suction to a very considerable extent.The independent drives ofthe suction unit provide for particularly free mobility ofthe suction head so that, after penetration throughthetrack panel, the suction head can be applied directly and specifical ly to the compacted ballast by lateral penetration beneath the sleepers to obtain quick and effective removal of ballast under suction. However, the particular mobility of the suction head also enables it to be directed with precision onto areas of ballast adjacent the track situated for example immediately adjacent a tunnel sidewall. a supporting wall, a platform edge orthe like, so thatthis "marginal" ballast, which in most cases is particularly heavily soiled, can also be completely taken up under suction.

Genuine and substantially complete clearance of ballast from the subgrade is obtained in this way, even in difficult sections of track. In particular, however, the construction according to the invention provides for a penetrating movement through the optionally raised track panel with lateral penetration for almost complete removal of ballast without exceeding the clearance profile and without affecting rail traffic on the adjacent line. In addition, by virtue ofthe driveoperated vertical displacement of the suction unit, the suction unit may readily be lowered to a constant depth during the repeated penetrating movements between the sleepers, for example by the provision of travel limiting stops, to form an even subgrade.

In one particularly advantageous embodiment of the invention, the suction units at its lower ends is in the form of a suction head which extends substan tially paralleltothe planeofthetrackand of which the width is smaller and its length greaterthanthewidth of a sleeper crib for penetration into the ballast between the sleepers and for lateral penetration into the ballast beneath the track, respectively. This very simple and extremely effective construction of the suction head which involves relatively little design effort provides for safe and effective removal by suction ofthecompacted ballast between and also beneath the sleepers.By virtue ofthis practical and relatively simple form, the suction head is able to penetrate laterally to reach the compacted ballast beneath the sleepers and comes into direct contact with the ballast stones so thatfull suction can be applied. The practical arrangement of the suction head substantially parallel to the plane of the track provides for the formation of an even subgrade both in the basic position of the suction head for penetration through the track panel and also in its working position after lateral penetration.

Another advantageous embodiment ofthe invention is characterized in that the suction unit connected to the compressor by the preferably flexible suction pipe is connected to three independently operable, especially hydraulically operable, drives both for transverse and vertical displacement ofthe suction head in the sleeper crib and for lateral displacement thereof even beneath the sleepers. With a drive combination such as this and the resulting, particu la r- ly high mobility ofthe suction head, virtually any area of ballast can be treated both quickly and without difficulty, even in particularly difficult sections of track, such as for example switches or crossings. In addition, theflexibilityofthesuction pipe providesforcompletely unimpeded adjustment or rather application of the suction unit.

Another embodiment ofthe invention ischaracte- rised in that, at its lower end comprising the suction opening the suction unit is in the form of a suction head designed for iateral dispiacement and rotation beneath the sleepers and connected to a rotary drive.

This construction increases the working area ofthe suction head after penetration with its narrow side through the sleepers beneath the plane ofthetrack panel. By rotation, for example aboutthe central longitudinal axis beneath the bottom edge ofthe sleeper, the suction head is also able to penetrate simulataneously into two adjacent sleeper bearing surfaces, which provides for particularly economical operation.

According to a particularly practical aspect ofthe invention, the suction head is arranged substantially perpendicularly ofthe vertical longitudinal axis ofthe suction pipe, being connected to the suction pipe around the edge ofthe suction opening, and is no greater in heightthan the depth ofthe ballast bed. This vertical arrangement provides for simple rotation aboutthe vertical longitudinal axis ofthe suction pipe, the suction head always being stopped atthe same distancefromthe bottom sleeper edge forsafe penetration. In addition, the suction head is always substantially parallel to the track in any working position. Also,thefactthatthe height ofthe suction head is less than the height of the ballast bed enables the suction head to penetrate without difficulty beneath the track panel without damaging the subgrade.

In one particularly preferred embodiment ofthe invention, a unit for loosening or vibrating the ballast (where the ballast bed is hard or encrusted) is associated with the suction arrangement or more precisely with the suction unit, preferably being connected to the suction head.With a machine constructed in this way, even heavily encrusted ballast and ballastwhich has been seriously compacted by rail traffic in the vicinity ofthe sleeper bearing surfaces beneath the sleepers can be satisfactorily removed undersuction to a considerable extent. The ballast may be loosened for example by a such a unit useable immediately in front of the suction unit in theworking direction and thentaken upundersuctionwithout difficulty by the suction unit.However, the arrangement ofthe unit directly on the suction head is particularly advantageous because in this way the ballast stones moved and at the same time loosened by the loosening orvibrating unit can be very effectivelytaken up undersuction with immediate utilization ofthis initial movement. In addition, the unit may beformed,forexample, byavibrator arranged on the suction unit, the vibrations being transmitted to the ballast stones for loosening through their contact with the suction head. However, its also possibleforexampleto provide poking tools which project laterally beyond the suction head like fingers and which, when the suction head rotates or moves transversely beneath the sleepers, loosen the adjoining ballast stones by dislodging them.

In another practical embodiment ofthe invention, the ballast loosening unit is formed by clearing tools connected to the suction head and operable by a drive.

This embodiment is structurally simple and yet very effective because the ballast loosening unit is moved universally by the same drives used for the suction head. In addition, this clearing arrangement, for example in the form offinger-like entraining eiements orthe like, not only loosens, it also has a transporting effect for moving the loosening ballast towards the suction opening.

Another particularly preferred embodiment of the invention is characterized in that the clearing tools consist of raking tines which are preferably provided on two scraper wheels arranged on either side ofthe suction opening in the suction head in a plane parallel to the plane of the track and connected to the drive. By means of the scraperwheels, the ballastto be taken up can be loosened beneath the sleeper (even in that part of the suction head situated furthest from the suction opening) and atthe same time transported by rotation to the central suction opening situated between the two sleepers. Another advantage isthatthe raking tines are able to penetrate with relatively little resistance, the rapid clearance of the ballast stones in one plane causing the adjoining stones to be loosened as well.

In another advantageous embodiment of the invention, the two scraper wheels provided around their periphery with the raking tines are arranged in a downwardly open housing on the suction head and an intermediate geartransmission connected to the drive is provided for rotation in opposite directions in a plane parallel to the plane of the track, the raking tines projecting beyond the edge of the housing and downwards, and in that the rotary drive is designed for lateral pivoting of the suction head provided with the clearing tools through an angle of at least 904 This arrangement in the downwardly open housing with downwardly projecting raking tines provides in prac ticeforadownward and also lateral clearing or raking effect.Loosening isthmus possible both during penetration and lowering between the sleepers and also during lateral penetration ofthe suction head beneath the sleepers. With the angular range of 90 C,thefuli length of the suction head is available, through rotation beneath the track, for a suction movement transversely ofthe longitudinal axis ofthe track.

According to another aspect of the invention, the two scraper wheels with their projecting raking tines have a diameter which is smaller than about the standard sleepercribwidth,forexample 25 cm, the center-to-center distance between the two scraper wheels likewise being substantially equivalentto the standardsleepercribwidth.Throughthisarrange- ment, the raking fingers extend from the longitudinal axis of one sleeper to the axis of the opposite sleeper, displacement ofthe suction head longitudinally of the sleeper crib enabling ballast to be removed under suction over halfthe length of the sleeper bearing surface. The other half is stripped of ballast during penetration into the next sleeper crib. In this way, the next operation can be rationally carried out adjoining the first to ensure complete removal.

In another particularly advantageous embodiment of the invention, a suction arrangement comprising three suction units is provided on the machine frame, two of these suction units being intended to suck up the ballast outside the two rails and the third suction unit being intended to suck up the ballast between the two rails.With a machine constructed in this way, a significant, i.e. more than three4old, increase in performance can be obtained for the simultaneous removal of ballast under suction from the three separate sections of a sleeper crib as defined by the two rails in the longitudinal direction, because timeconsuming raising and lowering with only one suction unitfcr each rail is avoided. Thefactthatthe three suction units may be adjusted independently of one another enablesthetwo outer suction units to be simultaneously used for removing ballast along the shoulders and from other areas situated outside the track panel, for example at a supporting wall orthe like.

According to another aspect of the invention, all three suction units are mounted on a common guide frame and are designed for adjustment independently of one another both vertically and laterally and also transversely ofthe track via their respective drives.

This arrangementcreatesa supportforcommon centring over the sleeper crib. Independently of the guide frame, however, full independence and mobility is guaranteed for the suction units with their respective drives.

In a practical embodiment ofthe invention, the guide frame preferably designed to telescope transversely ofthe track, with the adjustable suction units mounted thereon, is in the form of a pole-like supporting frame adapted to travel on the track and designed for displacement longitudinally ofthetrack relative to the machine frame via a hydraulic drive.

While relieving the machine frame of load, the pole-like construction of the guide frame enables inertia forces to be directly transmitted to the track. In addition, the hydraulic drive enablesthe guideframe to be longitudinally displaced for common centring of all three suction units over a sleeper crib. Providing the longitudinal displacement path is sufficiently long, the machine is able to continue its non-stop advance whilst the guide frame with the suction units advances in steps. Thetelescopicwidth adjustment ofthe guide frame provides for easy adaptation to difficult sections of track, such as for example switches, supporting walls bordering the track, tunnels and similar confined spaces.

Another particularly preferred embodiment ofthe invention is characterized in that, for directly cleaning the ballast taken up, the suction arrangement with the compressor and with the suction units and the associated drives is arranged on a ballast cleaning machine equipped with a track-lifting unitanda vibrating sieve and with at least one pivotal ballast ejecting conveyor belt and a waste-spoil conveyor belt. In this way, the suction arrangement as a whole may be installed in a ballast cleaning machine without significant modification of an already tried and tested basic design concept.The soiled ballast sucked from the ballast bed to the vibrating sieve is separated by the sieve into ballast and waste spoil, afterwhich the cleaned ballast is deposited back on the exposed subgradethrough thetrack panel and the waste spoil is carried away. Accordingly, it is possible by this new ballast suction technology to obtain cleaned ballast before the rearmost undercarriage ofthe machine.

According to another aspect ofthe invention, the suction unit with its suction opening is designed for rotation and displacement by variation of the angle of thesuction pipeaxisfortaking uptheballastinthe region beneath the sleepers adjoining the sleeper crib.

Simply by varying the suction angle or rather by inclining the suction opening, it is also possible to remove ballast from underthe sleepers, the design of the suction unit being particularly simple.

In another embodiment ofthe invention, a sieve container connected to the following suction unit is provided on the machine frame, being connected to a sieve deck, a ballast lock and a waste-spoil lock each with a rotatable agitator. With this arrangement, the ballast or rather waste spoil may be carried from the sieve containervia the locks (without any reduction in the strength of the suction effect) onto the corresponding conveyor belts without interrupting work or disturbing the suction operation. In addition, the ballast or rather waste spoil in the lock may be transported from the receiving opening to the discharge opening by the agitator. The lock system may be integrated into various suction machines.Accordingly, work may progress or advance without having to be interrupted for emptying the sieve container.

Another embodiment ofthe invention ischaracterized in that, in the direction in which the ballast taken up is transported, the sieve deck in the sieve container is preceded by a guide deck pivotally arranged on the machine frame. In this way, it is possible where the ballast taken up is clean or only slightly soiled to let the guide deck down in front ofthe sieve deck because it is not necessaryto use the sieve deck. In addition, the ballasttaken up under suction can be collected by the guide deck and fed directly to the ballast lock for deposition onto the subgrade.

According to anotheradvantageous aspect of the invention, an operator's cabin is provided on the machine frame in front of or behind the suction unitin the working direction for direct visual observation of the suction unit. This enables all three suction units and especially the suction heads lowered through the track panel to be carefully observpj. Since in confined areasthesleepercrib is surrounded on the one hand bythetwo sleepers and the rail and on the other hand by the opposite supporting wall, platform edge or the like, this possibility of careful observation is particularly important.

Finally, according to further aspects ofthe inven tion,two on-track guideframes each with a suction arrangement comprising three suction units and their associated drives are arranged one behind the other longitudinally ofthe machine and are each connected to the machine frame by vertical displacement drives, the two guide frames each preferably being connected to a longitudinal displacement drivefor longitudinal displacement independently of one another. With a machine such as this, a considerable improvement in performance is obtained through a total of six suction units used in alternation.While the suction units ofthe rearframe are taking up ballast under suction, the front guide frame may be advanced a few sleeper cribs forwards-all while the machine continues its non-stop advance. By elimination ofthe constant and sudden starting and stopping movements, machine wear and energy consumption are reduced and the machine operator is able to work in greater comfort.

Three embodiments ofthe invention are described byway of example in the following with reference to the accompanying drawings, wherein: Figure lisa side elevation of a travelling on-track machine constructed in accordance with the invention forthe removal of bedding ballast by suction.

Figure 2 is a plan view ofthe machine shown in Figure 1 with a section through the suction arrange ment on the line Il-Il and a partial plan view ofthe front suction unit.

Figure 3 is a front elevation ofthe guide frame carrying the suction units on the line Ill-Ill in Figure 2.

Figure4isan elevation on a largerscaleofthe suction head in the region of the track panel in the direction of arrow IV in Figure 3.

Figure 5 is a plan view in the direction of arrow of the suction head situated beneath the track panel as shown on the left-hand side of Figure 3.

Figure 6 is a partial side elevation ofthe suction arrangement according to the invention of another embodiment of a travelling on-track machine forthe removal of bedding ballast by suction.

Figure 7 is a side elevation of another embodiment of a travelling on-track machine according to the invention forthe removal of bedding ballast by suction.

Figure 8 shows part ofthe sieve container illustrated in Figure7with the guide deck in its lowered position.

Figure9 is a plan view ofthe guideframeshown in Figure 7 connected to the suction units.

The machine 1 shown in Figures 1 and 2 comprises an elongate machineframe3supported by undercarriages 2 and is designed to travel along a track 7 formed by sleepers 4 and rails 5 and resting on a ballast bed 6. The power supply ofthe machine 1 is in theform of a central power supply unit 8 which is connected to a central control unit 9, to an axle drive 10 and to various drive cylinders.At either end ofthe machine frame 3, there is a driver's cabin 11 for in-transit runs, an operations cabin 12 2 being provided substantially atthecenter ofthe machineframe 3. In the working direction of the machine 1 as indicated by an arrow 13, the operations cabin 12 is immediately followed by a vibration sieve arrangement 14with an unbalanced flywheel drive 15 and an inclined sieve 16.

Beneath the sieve 16, there is a waste spoil conveyor belt 17 for carrying away the waste spoil, a ballast ejection conveyor belt 18 designed to pivot into the plane ofthetrackand a conveyor20connectedto a guide 19. A vertically and laterally adjustable track lifting unit 21 comprising lifting rollers designed to engage positively with the rails 5 is provided for taking upthetrack panel 7.

Arranged in the front half ofthe machine is a suction arrangement 23 which is connected to a compressor 22 and which is designed both for a lowering movement ofthe suction unit 25 comprising a suction head 24 through the track panel and alsofora substantially horizontal movement of the suction head 24 for lateral penetration into the ballast bed 6 beneath the sleepers 4. As shown in Figure 2, the suction arrangement 23 consists ofthree suction units 25,26 and 27, of which the two suction units 25 and 27 suck up the ballast outside the two rails 5 whilst the third suction unit 26 sucks up the ballast between the two rails 5. All three suction units 25,26 and 27 are mounted on a common guide frame 28 which is in the form of a pole-like supporting frame 29 designed to travel along the track.At its front end, the supporting frame 29 is supported by guide rollers 30 on the machine frame 3 and is designed for displacement longitudinally of the track relative to the machine frame 3 by a hydraulic drive 31. Each suction unit 25, 26,27 which is connected to the compressor 22 by a flexible suction pipe 32 is coupled to three independent, hydraulic drives, namely hydraulic cylinder-and- piston vertical displacement, transverse displacement and rotary drives 33,34 and 35 both for transverse displacement and also for vertical displacement of the suction head 24 in the sleeper crib 36 and for lateral displacement and rotation of the suction head 24 beneath the sleepers 4.

It can be seen from Figures 1 and 2 and also from Figure 3 that the bifurcate supporting frame 29 comprises two crossbeams 37 extending across the track in which two U-shaped supports 38 are mounted for transverse displacement and are each connected to a hydraulic cylinder-and-piston transverse dis piacement drive 34. Mounted centrally between the two crossbeams 37 is a guide plate 39 which is also mounted fortransverse displacement on guides connected to the crossbeams 37 and which is connected to a transverse displacement drive 34 ofwhich the piston rod is telescopically extendable, as shown in Figure 3.The suction units 25,26 and 27 are respectively mountedforvertical displacement on the two U-form supports 38 and on the central guide plates 39. This vertical displacement is imparted by the hydraulic cylinder-and-piston vertical displacement drives 33 which are arranged on either side of the suction pipe 32 and which are fixed at their cylinder end to the support38 and to the guide plate 39 and, at their piston end, to a flanged ring 40. The flanged ring 40 divides the suction pipe 32 into a flexible section connected to the compressor22 and a rigid section connected to the suction head 24. The two adjoining ends of these two sections of the suction pipe 32 are flanged and are held together by the flanged ring 40, the lower, non-flexible section of the suction pipe 32 being rotatable about its longitudinal axis.To this end, the flanged ring 40 is merely connected for rotation to the flexible section of the suction pipe 32. The horizontally arranged rotary drive 35 of each suction unit 25,26,27 is fixed at its cylinder end to a bracket 41 which in turn is connected to the fixed, non-rotatable flanged ring 40. The piston end of the rotary drive 35 is connected by a laterally projecting fixing lug to the rigid suction pipe 32 rotatable about its longitudinal axis in the flanged ring 40.

As can be seen in particular in Figures 3to 5, the suction head 24 at the lower end of each suction unit 25,26,27 extends substantially parallel to the plane of the track. The width ofthe suction head 24 is narrower than the width of a sleeper crib 36 for penetration into the ballast between the sleepers 4 (position shown in dash-dot lines in Figure 5) whilst its length is greater than the width of a sleeper crib 36 for lateral penetration into the ballast beneath the track panel 7 (working position shown in solid lines in Figure 5). The suction head 24 is connected to the suction pipe 32 at its suction opening 42 and is smaller in height than the ballast bed 6 which rests on a subgrade 43.

As shown in Figures 3and4, a unit 44 connected to the suction head 24 for loosening or vibrating the ballast (where the ballast bed 6 is hard or encrusted) is associated with each suction unit 25,26,27. This unit 44 is formed by clearing tools 46 illustrated diagram maticallyin Figure 3 which are connected to the suction head 24 and which are operable by a drive 45.

The guideframe 28 which carries all three suction units 25,26 and 27 is directly supported on the track by a supporting and guiding undercarriage 47 arranged at its rear end. The section of track in question is, for example, a switch comprising switch tongues 48.

As shown particularly clearly in Figure4,the clearing tools 46 ofthe suction units 25,26 and 27 consist of raking tines 49 which are arranged on the suction head 24 on either side of the suction opening 42 in a plane parallel to the plane ofthetrackand which are connected to scraping wheels 50 operable by the drive 45. The scraping wheels 50 are arranged in a housing 51 open underneath and are designed to be rotated in opposite directions in a plane parallel to the plane ofthe track by an intermediate transmission 52 connected to the drive 45. The raking tines 49 project beyond the edge ofthe housing 51 and downwards. The two scraperwheels 50 with their projecting scraping tines 49 have a diameter which is smallerthan the standard crib width for concrete sleepers, for example 25 cm, the center-to-center distance between the two scraper wheels 50 being substantially equivalent to the standard sleeper crib width.

The mode of operation ofthe machine 1 constructed in accordance with the invention and illustrated in Figures 1 to 5 is described in detail in the following.

On arrival at the section oftrackto be treated, the rails 5 ofthetrack7 are taken up bythetrack lifting unit 21 and the suction units 25,26and 27 are longitudinally displaced together with the guide frame 28 by operation ofthe hydraulic drive 31 until theirsuction heads 24 are centered exactly overthe sleeper crib 36.

At the same time, the suction heads 24 are aligned with their longitudinal axis parallel to the longitudinal axis ofthe sleepers 4 (position shown in dash-dot lines in Figure 5) by operation ofthe rotary drive 35. The suction units 25,26 and 27 are then lowered onto the ballast ofthe sleeper crib 36 by means ofthe vertical displacement drives 33 and the two scraperwheels 50 are set rotating by operation ofthe drive 45. In this way, the soiled and encrusted ballast is loosened and moved in front of the suction openings 42. The compressor 22 switched on in the meantime produces in all three suction units 25,26 and 27 a suction stream which sucks up the ballast particles turned up by the clearing tools 46 and ejects them onto the vibration sieve arrangement 14.The transfer is best made through a lock chamber arranged in the compressor 22 to keep the space in front ofthe compressor 22 airtight.

When the uppersurface ofthe housing 51 ofthe suction head 24 arrives beneath the bottom edge of the sleepers as a result of the continuous lowering of the suction units 25,26 and 27 to maintain contact with the ballast, the entire suction head 24 is turned through 90" by operation of the rotary drive 35 (cf.

solid-linesuctionhead in Figure 5).Thesuction units 25,26 and 27 are then moved laterally back and forth to the rail 5 by means of the associated transverse displacement drives 34. In this way, at least halfthe ballast beneath the sleepers 4 is also sucked up and a uniform, even subgrade is formed (Figure 4). The remaining half 53 of the sleeper bearing surface beneath the sleepers 4 is similarly cleared by the following suction treatmentofthe adjoining sleeper crib 36.

Since one sleeper crib 36 issimultaneouslytreated bythree suction units 25,26 and 27, ballast can be sucked up particularly quickly both between and also beneath the sleepers 4 and also along the shoulders of the ballast bed 6. The fact that the individual suction units 25,26 and 27 can be moved independently of one another also provides for close adaptation to various working conditions along various sections of track.

For example, the central suction unit 26 shown in Figure 3 can clearthe section between a switch tongue 48 and the right-hand rail 5 of the track, the suction head 24 still extending with its longitudinal axis in the longitudinal direction ofthe sleepers. To clearthe longer switch crib, the right-hand suction unit 25 is displaced further outwards by comparison with the left-hand suction unit 27. In addition, obstacles 54 adjacent the track can also be avoided by means of the transverse displacement drives 34 (Figure 2). The suction heads 24 ofthe suction arrangement 23 may still be working at different levels at the beginning of the suction process. However, after complete clearing ofthe ballast between and beneath the sleepers 4, all three suction units 25,26 and 27 work at the same level in orderto establish an even subgrade 43.To this end, each suction unit 25,26,27 may be provided with its own travel-limiting stop which automatically switches offthe vertical displacement drives 33 after a predetermined working depth has been reached.

After the ballast in the associate sleeper crib 36 has been completely sucked up by one or even more lateral reciprocations ofthe suction head 24 in its working position where its longitudinal axis extends parallel to the rails, the suction head 24 is turned back through 90" into its starting position by operation of the rotary drive 35 and raised overthe sleepers 4 by means ofthe vertical displacement drives 33. The guideframe 28 is then longitudinally displaced to centerthe suction heads 24 over the next sleeper crib 36, afterwhich the described cycle of operations for the removal of ballast between and beneath the sleepers 4 under suction begins again.The control of a suction arrangement in the vertical and horizontal directions and also in the direction of rotation may even be automated in orderto accelerate the suction process. The cleaned ballast separated from the waste spoil in the vibration sieve arrangement 14 is ejected onto the exposed subgrade 43 bythe ejection conveyor belt 18 designed to pivot into the plane ofthe track (Figure 1). The waste spoil is carried away by the wastespoil conveyor belt 17. If thetrackisto is to be lowered by removal under suction of only part ofthe ballast bed, forexample in a tunnel,the guide 19 is raised so that the ballast sucked up is immediately carried away bythe conveyor belt 20.The machine 1 may even advance continuously at lowspeed, in which case the guide frame 28 is moved in stepsfrom one sleeper crib 36 to the adjoining sleeper crib by corresponding operation ofthe hydraulic drive 31 for removal ofthe ballast by suction.

A machine 55 shown in part in Figure 6 consists essentially of an elongate machine frame 56 which is supported by undercarriages 57 on a track 58 consisting of rails and sleepers. Two on-track guide frames 59 each comprising a suction arrangement 61,62 with three suction units 60 (of which onlythe front suction unit is shown) and the associated drives are arranged one behind the other longitudinally of the machine.

The suction arrangements61,62 are connected to the machine frame 56 by vertical displacement drives 63, the two guide frames 59 each being connected to a longitudinal displacement drive 64for longitudinal displacement independently of one another. At its lower end, each suction unit 60 comprises a suction head 65 with a suction opening. The individual suction heads are connected to a compressor by flexible suction pipes 66, of whichthere arethus 6 in ali,for taking up the ballast under suction.

In operation,the machine 55 shown in Figure 6 advances continuously (non-stop) in the working direction indicated by an arrow 67, one of the two guide frames 59 with the suction units 60 arranged thereon always being in operation. While the suction units 60 on the rearguideframe 59take upthe ballast undersuction from the sleeper crib, the front guide frame 59 advances from the chain-line position into the solid-line position where it is lowered onto the track58forsucking up ballast. Afterthe suction units 60 on the rear guide frame 59 have completely sucked up the ballast both between and also beneath the sleepers in the meantime, the associated longitudinal displacement drive 64 is brought into operation to movetherearguideframe59tothenext-but-one sleeper crib (dash-dot line).The sleeper cribs passed over by the rear guide frame 59 are respectively treated by the front guideframe 59 of which the suction units 60 are likewise lowered into only every second sleeper crib.

The machine 68 shown in Figures 7 comprising a mach ine frame 69 is adapted to travel by u nderca rriages 70 on a track 73 consisting of sleepers 71 and rails72.Toenablethemachineto be used in tunnels where exhaust gases area particular problem, it is powered by a combined diesel/electric engine 74.

Accordingly, the method of propulsion may be selected according to the operational conditions. The machine 68 comprises a suction arrangement 78 consisting ofthreesuction units 75 with suction heads 76 and suction openings 77 arranged transversely of the longitudinal axis of the machine. Each suction head 76 is designed forvertical and directional adjustment. One of the suction units 75 sucks up the ballast between the rails 72, a second suction unit 75 coversthe areaform the outeredge/rail (on the land side) to the foot of the slope and the third suction unit 75, working on the track side, covers the area from the outer edge/rail to the track axis (central reservation) using a pivoting stop (Figure 9).The suction heads 76 may be switched on and off individually as required.

By varying the suction angle, ballast can also be sucked up from beneath the sleeper71 (to this end, the suction heads 76 are designed for rotation and displacement). By means of a rubberskirt, air is prevented from penetrating laterally, so that the suction power remains fully intact. The suction heads 76 are hydraulically lowered and controlled in an on-track guide frame 80 acting as a suction head guide 79. The machine operator working in an operations cabin 81 has an unobstructed view of the working parts and, by varying the suction angle, can also take up ballast from beneath the sleeper71.

Avibrator 82 for generating vibration and a pincer-like holding assembly are provided on the guide frame 80. The suction heads 76 are connected by flexible suction hoses 83 to a compressor 84 and a sieve container 85. Dust problems are solved by an integrated filter system. A sieve deck 86 and a guide deck 87 (raised in Figure 7) are arranged in the sieve container 85. Towards the bottom ofthe sieve container 85, there is an agitator-equipped waste spoil lock 88 and an agitator-equipped ballast lock 89 which are designed to be operated by the lock drive 90.

The ballast lock 89 enablesthe ballastand waste spoil (remains) to be transferred from the sieve container 85 via the locks to the corresponding belts without interrupting or disturbing the suction process and without any weakening of the suction effect. The ballast locks 89 are intheform of a cylinderwhich is three-quarters closed at its upper and lower ends. The intake opening (1/4 cutout, upper end) is situated exactly opposite the outlet opening (1/4 cutout, lower end). An enclosed agitator, which divides the cylinder into eight compartments, is continuously supplied with ballast from above through the opening.During the rotational movement,the ballast isfurther agi- tated and the partitions of the agitator, by virtue of their arrangement, continuously close offthe upper inlet opening from the lower outlet opening. The volume of ballast discharged depends onthe agitation rate and on the content of the compartments.

The lock system for ballast and waste spoil may be integrated into various suction machines. Accordingly, work is able to progress continuously without any need for interruptions to empty the sieve container.

Levelling arrangementsforestablishing asubgradeto supportthe track, which normally plough orcutout the ballast, chippings, gravel or sand ploughed upto either side ofthe track, may be constructed in such a way that some of the material is taken up by a suction system and transferred via a lock system to conveyor belts in transporting orself-unloading wagons for reuse at a later date. Beneath the waste-spoil lock 88 there is a waste-spoil conveyor belt 91 for carrying away ballast residues. Beneath the ballast lock 89, there is a pivotal ballast distributing conveyor 92 and a conveyor belt 93for ballast or sand and dirt. A pivotally mounted metering unit 94 is provided for diverting the cleaned ballast.In the working direction, the suction head guide 79 is followed by a lifting and lining unit 95 by which the track can be kept in its original position or raised ortu rned.

The machine 68 constructed in accordance with the invention affords the following possibilities: The hydraulic suction head guide 79 with its three suction heads 76 is released from its raised and locked transporting positionforoperation and lowered onto the track using the on-track suction guide frame 80 hydraulically controlled by drives 96 connected to the machine frame. The guide frame 80 is hydraulically variable i n its working width. The maximum permitted pivoting movement towards the adjacent track is defined by a limit switch. The three suction heads 76 controlled in the guide frame 80 may be vertically and directionally adjusted. On two-line tracks, therefore, ballast can be taken up under suction from the central reservation to the foot of the embankment on the land side.The ballast in this region can be sucked by varying the suction angle, i.e. by inclining the suction head 76 beneath the sleeper 71. The vibrator 82 fixed to the suction head guide frame 80 imparts vibrations to the track raised bya lifting unit 95. Encrusted and interlocked ballast beneath the sleeper 71 is thus loosened for removal by suction. A holding unit (clamp) prevents derailment of the vibrating, hydraulic suction head guide frame 80. The vibrations are transmitted to the central and two outer suction heads 76 and further by the contactwith the ballastto be taken up by suction. As a result, the ballast to be taken up by suction is shaken up slightly to an extent sufficientto open up and accelerate the suction process.

In one possiblevariant,the ballasttaken up by suction is ejected with dirt onto the vibrating sieve deck 86 on which it is separated from the dirt and delivered through the corresponding locks 88,89 onto the conveyor belts. The cleaned ballast may be used as required for partial orcomplete ballasting via the pivotal ballast distributing conveyor belt 92, for which purpose the track may be lowered or raised. Excess, cleaned ballast is collected for reuse inthe balast self-unloading wagon via the metering unit94 and the conveyor belt 93. The ballast remains (dirt) are deposited into waste-spoil wagons via the waste-spoil lock 88 and the waste-spoil conveyor belt 91.

The sieve deck 86 does not have to be used in cases where the ballastto betaken up bysuction is clean or only slightly soiled. Accordingly, a guide deck 87 is lowered ahead ofthe sieve deck 86 (Figure 8). The ballast is thus collected and delivered directly to the ballast lock 89. The ballast is emptied via the metering unit94ontotheconveyorbelt93for loading onto self-unloading ballastwagons for reuse or onto the pivotal ballast distributing conveyor belt 92 for distribution onto the track. To this end, the track may be lowered or, where the lifting unit 95 is used, even raised as requiredforsimultaneous ballasting.

During thetake-up of sand and dirt, the guide deck 87 is lowered ahead of the sieve deck 86. The material being taken up by suction is collected and passes antirely Phrough the ballast lock89 and the metering "n94ontotheconveyor93forloading onto waste spoil wagons (Figure 8).

During the suction process, the ballast is actually rjlea ed during its journey from thetake-up zoneto the c;iec.ion point. During this journey, the movement and str;4ningoftheballastparticlesagainstoneanotheris Sc '.ntense that they appear as ifthey have been trcated with a steel brush.The sole function of the save deck 86 is merely to separate the constituents.

Claims (20)

1. Atravelling on-track machine for removing icallast by suction from a ballast bed beneath a track consisting of rails and sleepers, of which the machine frame designed to travel on the rails is provided with a suction arrangementwhich is connected to a com pressor and which comprises at least one adjustable suction unit connected via a suction pipe and having a suction opening forthe ballast to be taken up, characterised in that the suction arrangement is designed both for a penetrating movement ofthe suction unit equipped with a suction head through the track and for a substantially horizontal movement of the suction head for lateral penetration into the ballast bed beneath the sleepers and in thatthe suction unit is connected to independently operable drives, at least for vertical and lateral adjustment even beneath the sleepers.

2. A machine as claimed in Claim 1, characterized in that, at its lower end, the suction unit is in the form of a suction head which extends substantially parallel to the plane ofthetrackand ofwhichthewidth is smaller and its length greaterthan the width of a sleeper crib for penetration into the ballast between the sleepers and for lateral penetration into the ballast beneath the track, respectively.

3. A machine as claimed in Claim 1 or2,characte- rized in that the suction unit connected to the compressor by the preferably flexible suction pipe is connected to three independently operable, especially hydraulically operable, drives both for transverse and vertical displacement of the suction head in the sleeper crib and for lateral displacement thereof even beneath the sleepers.

4. A mach;ne as claimed in any of Claims 1 to 3, characterized in that, at its lower end comprising the suction opening, the suction unit is in the form of a suction head designed for lateral displacement and rotation beneath the sleepers and connected to a rotary drive.

5. A machine as claimed in ar ç of Claims 1 to 4, characterized in that the suction head is arranged substantially perpendicularly ofthe vertical longitudinal axis ofthe suction pipe, being connected to the suction pipe around the edge ofthe suction opening, and is no greater in heightthanthe depth ofthe ballast bed.

6. A machine as claimed in any of Claims 1 to 5, characterized in that a unit for loosening or vibrating the ballast (where the ballast bed is hard or encrusted) is associated with the suction arrangement or more precisely with the suction unit, preferably being connected to the suction head.

7. A machine as claimed in Claim 6, characterized in that the ballast loosening unit is formed clearing tools (46) connected to the suction head and operable by a drive.

8. A machine as claimed in Claim 7, characterized in thatthe clearing tools consist raking tineswhich are preferably provided on two scraperwheels arranged on either side ofthe suction opening in the suction head in a plane parallel to the plane of the track and connected to the drive.

9. A machine as claimed in Claim 8, characterized in that the two scraper wheels provided around their periphery with the raking tines are arranged in a downwardly open housing on the suction head and an intermediate gear transmission connected to the drive is provided for rotation in opposite directions in a plane parallel to the plane of the track, the raking tines projecting beyond the edge of the housing and downwards, and in thatthe rotary drive is designed for lateral pivoting of the suction head provided with the clearing tools through an angle of atieast90 .

10. A machine as claimed in Claim 8 or 9, characterized in that the two scraperwheels with their projecting raking tines have a diameter which is smallerthan aboutthe standard sleeper crib width, for example 25 cm,the center-to-centerdistance between the two scraperwheels likewise being substantially equivalent to the standard sleeper crib width.

11. A machine as claimed in any of Claims 1 to 10, characterized in that a suction arrangement comprising three suction units is provided on the machine frame, two of these suction units being intended to suck up the ballast outside the two rails and the third suction unit being intended to suck up the ballast between the two rails.

12. A machine as claimed in Claim 11, characterized in that all three suction units are mounted on a common guideframe and are designed for adjust- ment independently of one another both vertically and laterally and also transversely ofthe track via their respective drives.

13. Amachine as claimed in Claim 11 or 12, characterized in that the guide frame preferably designed to telescope transversely ofthe track, with the adjustable suction units mounted thereon, is in the form of a pole-like supporting frame adapted to travel on the track and designed for displacement longitudinally ofthe track relative to the machine frame via a hydraulic drive.

14. A machine as claimed in any of Claims 1 to 13, characterized in that, for directly cleaning the ballast taken up, the suction arrangement with the compress- or and with the suction units and the associated drives is arranged on a ballast cleaning machine equippc i with a track-lifting unit and a vibrating sieve and with at least one pivotal ballast ejecting conveyor belt and a waste-spoil conveyor belt.

15. A machine as claimed in any of Claims 1 to 14, characterized in that the suction unit with its suction opening is designed for rotation and displacement by variation of the angle ofthe suction pipe axis for taking up the ballast in the region beneath the sleepers adjoining the sleeper crib.

16. A machine as claimed in any of Claims 1 to 15, characterized in that a sieve container connected to and following the suction unit is provided on the machine frame, being connected to a sieve deck, a ballast lock and awaste-spoil lock each with a rotatable agitator.

17. A machine as claimed in Claim 16, characterized in that, in the direction in which the ballast taken up is transported, the sieve deck in the sieve container is preceded by a guide deck pivotally arranged on the machine frame.

18. A machine as claimed in any of Claims 1 to 17, characterized in that an operator's cabin is provided on the machine frame in front of or behind the suction unit in the working direction for direct visual observation ofthe suction unit.

19. A machine as claimed in any of Claims 1 to 18, characterized in that two on-track guide frames each with a suction arrangement comprising three suction units and their associated drives are arranged one behind the other longitudinally ofthe machine and are each connected to the machine frame by vertical displacement drives, the two guideframeseach preferably being connected to a longitudinal displace ment drivefor longitudinal displacementindepen- dently of one another.

20. A machine for removing ballast, substantially as herein described with reference to Figures 1 to 5, Figure 6, or Figures 7 to 9 ofthe accompanying drawings.