Cutting wheel

Abstract

The invention relates to a cutting wheel (30) for a trench wall cutter (10), said cutting wheel comprising a drum-shaped hub (32), on the outer periphery of which plate-shaped tooth holders (40) are mounted in at least one peripheral row, in which tooth holders cutting teeth (50) are detachably held for removing soil. At least one cutting tooth (50) is provided comprising a tooth head (60) extending transversely to both sides of the tooth root, the tooth head (60) having a lateral first head region (61) and a lateral second head region (62) which extend in opposite directions from one another, and at least two adjacent cutting bodies (66) being located on each head region (61, 62).

Description

The invention relates to a milling wheel for a trench cutter having a drum-shaped hub, on the outer circumference of which plate-shaped tooth holders are arranged in at least one circumferential row, in which milling teeth are releasably held for removing soil, according to the preamble of claim 1.A generic milling wheel is known, for example, from EP 2 685 007 A1. This known milling wheel has ring segment-like tooth holders along several circumferential rows, which are attached to the drum-shaped hub axially offset to each other. Each curved tooth holder has a large number of removal teeth, which are positioned differently in relation to each other. The individual removal teeth protrude to varying degrees in relation to the tooth holder, in order to cover as wide an area of the ground as possible with the cutting bodies on the individual removal teeth. This enables good soil removal to be achieved.In the milling wheel according to EP 2 685 007 A1, a total of six circumferential rows of tooth holders are provided, wherein a plurality of teeth are arranged in each case. If a soil layer with cohesive soil, such as clay or loam, is worked with a milling wheel of this type, the cohesive soil material can adhere to the curved tooth holders and attach in the spaces between the teeth. This clogs the milling wheel as a whole, which significantly reduces the removal rate during milling. In addition, a clogged milling wheel tends to deflect, so as to make it difficult to create a milling slot in the exact position.EP 1 780 375 B1 discloses a milling tooth with a tooth base for mounting in a holder of a milling wheel and with a tooth head with a main cutting element. One or more recutting elements with pin-shaped cutting edges are arranged in the region of thetooth base, offset towards the rear in the milling direction, which can also be used to process harder soil geologies.The object of the invention is to specify a milling wheel for a trench cutter that enables efficient milling even with different soil layers.According to the invention, the object is achieved by a milling wheel with the features of claim 1. Preferred embodiments of the invention are specified in the dependent claims.The milling wheel according to the invention is characterised in that at least one milling tooth is provided with a tooth head extending transversely to both sides of the tooth base, that the tooth head has a lateral first head region and a lateral second head region, which extend in opposite directions to one another, and that at least two cutting bodies lying next to one another are arranged on each head region.A basic idea of the invention is to provide a milling wheel with one or more milling teeth that are T-shaped in the circumferential direction when viewed from above and that have a transversely extending tooth head with a plurality of cutting bodies. This allows a single cutter tooth to machine material in a removing manner from a larger width of soil in situ. This in turn makes it possible to reduce the number of necessary milling teeth and thus also the number of necessary tooth holders in a circumferential row and distributed over the milling hub. This considerably increases the clearance between the milling teeth and the adjacent tooth holders, which in turn greatly reduces the possibility of cohesive soil material adhering and makes it much easier to strip off adhering soil material.The width of the tooth head can be a multiple, in particular one up to three, four or five times or more the width of the tooth base. The two head sections can be designed symmetrical or asymmetrical to each other. Preferably, at least one cutting body is arranged in the centre between the two head regions.A milling wheel according to the invention can thus be used to efficiently mill different soil layers and, in particular, also soil layers with cohesive soil material, without or at least with a significantly reduced risk of clogging of the milling wheel. This improves acontrol of the milling machine and a erecting in a precise positioning manner of the milling slot.The preferred embodiment of the invention is that all cutting bodies on the tooth head are directed forwards in a cutting direction. The cutting bodies can achieve a particularly good and even removal rate when aligned parallel to each other. In particular, the cutting bodies can be designed to be identical to each other. The cutting bodies are carbide bodies that are solder in the tooth head.According to a further embodiment of the invention, it is preferable that the head regions with the cutting bodies are offset relative to one another in the circumferential direction or arranged in a cutting line. The line can be straight or curved. Preferably, the cutting bodies are arranged in such a way that they have a same radial distance to the axis of rotation or centre axis of the hub of the milling wheel and the head regions are symmetrical to a centre plane of the milling tooth. If the two head regions are arranged offset in the circumferential direction, one head region can advance and the other head region can lag during removal.According to a further embodiment of the invention, it is expedient for the cutting head to have a sweep in the cutting direction and for the cutting bodies to form a V-shaped arrangement on the cutting head. In particular, when using a central cutting body, which is located between the two head regions in the centre of the tooth head, the subsequent cutting bodies can be arranged evenly offset towards the rear in the milling direction. With this V-shaped arrangement of the cutting bodies, in particular a good flow-off of the removed soil material past the tooth head can be achieved. This reduces frictional wear and increases the overall service life of a milling tooth.In principle, the cutting bodies can be designed differently in relation to each other. According to a further development of the invention, it is particularly advantageous that the cutting bodies have the same design and, in particular, have a cutting edge. The end faces of the cutting bodies have one or more linear cutting edges, which allow a high removal rate with both softer and harder soil layers. The use of identical cutting tools reduces production and repair costs. In particular, the cutting bodies are made of a high-strength carbide metal.In principle, any number of circumferential rows can be provided for the tooth holders on the drum-shaped hub, provided there is sufficient spacing between the circumferential rows. The axial distance between the circumferential rows is preferably between 20 cm and 50 cm. The distance between the individual tooth holders in a circumferential row in a circumferential direction is also between 20 cm and 150 cm. The number of tooth holders in a circumferential row basically depends on the size of the hub to which they are attached. Preferably, the individual tooth holders are arranged at a predetermined equal angular distance from one another, in particular 60, 90, 120 or 180 degrees.It is particularly advantageously, according to a further development of the invention, that between two and four tooth holders are arranged distributed over the circumference in a circumferential row.Furthermore, in one embodiment of the invention it is expedient that in an axial direction of the milling wheel on the hub, an outer circumferential row is arranged on a free outer side of the toothed wheel, an inner circumferential row is arranged on an inner side of the milling wheel directed towards a bearing plate and at least one centre circumferential row is arranged. The individual circumferential rows can be designed differently from one another. In particular, one or more hinged teeth, so-called folding teeth, can be mounted on the inner circumferential row, which can be pivoted into a position below a milling plate on which the milling wheel is mounted during milling operation. On the outer circumferential row on a free side of the milling wheel, which faces away from the side of the bearing plate, there may be more tooth holders than in a centre circumferential row and / or different milling teeth than in the centre circumferential row.The approximately T-shaped milling tooth or the T-shaped milling teeth are preferably arranged only in the one or more centre circumferential rows, which are positioned in the axial direction between the outer circumferential row and the inner circumferential row. In particular, L-shaped milling teeth with only one head region extending transversely to the tooth base can be provided on the outer circumferential row and / or the inner circumferential row. The head regions each extend inwards towardsthe at least one centre circumferential row. In this way, a sufficient axial distance between the individual tooth holders and the teeth to each other can be achieved while still maintaining a high removal rate with these milling teeth.In principle, the number of centre circumferential rows depends on the axial length of the drum-shaped hub and therefore on the intended milling width. A particularly expedient and easy-to-clean design of a milling wheel is that only two centre circumferential rows are arranged.Particularly large clearances can be achieved on the milling wheel according to a further development of the invention in that only two tooth holders with milling teeth are provided in the at least one centre circumferential row, which are arranged offset by 180° to one another on the circumference of the hub. In the case of a plurality of centre circumferential rows, the arrangements of the individual circumferential rows can be arranged at an offset angle to one another. With two centre circumferential rows, the offset angle to each other can be 90°, with three centre circumferential rows 60° to each other. This counteracts rattling during milling. In particular, this ensures that the plate-shaped milling holders in two adjacent circumferential rows do not lie directly next to each other in the axial direction. This further increases the spacing and thus the free spaces between the individual tooth holders, which counteracts an adherence of soil material and further improves the possibility of scraping off adhering material or cleaning off.In particular, a removal rate of a milling wheel can be improved by arranging at least one hinged milling tooth on the inner circumferential side. In milling operation, the hinged tooth can be pivoted out during rotation in a region below the bearing plate, which is located between two milling wheels and keeps them rotating, in order to remove soil material directly below the bearing plate. In principle, any number of milling teeth and tooth holders can be provided on the outer circumferential row. It is preferable that the number of milling teeth and tooth holders in the outer circumferential row is greater than the number in a centre circumferential row. It is particularly preferable that twice as many tooth holders are arranged on the outer circumferential row as in a centre circumferential row. In principle, it is also possibleto use double tooth holders on the outside. Experience has shown that the use of individual, inclined tooth holders reduce wear on the milling tooth itself and on the tooth holders.Despite an increased number of tooth holders on the outer circumferential row, due to the free end face of the milling wheel makes it easy to remove and clean off adhering soil material along the first outer circumferential row.A further milling wheel according to the invention for a trench cutter with a drumshaped hub, on the outer circumference of which plate-shaped tooth holders are arranged in at least one circumferential row, in which milling teeth are releasably held for removing soil, is characterised in that two plate-shaped tooth holders are arranged on the outer circumference of the hub adjacent to one another in the axial direction, under formation of a double tooth holder, and in that a first milling tooth is received and held in the first tooth holder and a second milling tooth is received and held in the second tooth holder. Conventional tooth holders can be used, which can absorb higher forces due to their doubling.A preferred further development is that the first milling tooth is formed as a first tooth half and the second milling tooth as a second tooth half, which together form a complete tooth. If only one tooth half is damaged, only this half needs to be replaced. This further reduces maintenance effort.Furthermore, it is preferred that the first tooth half is designed L-shaped with a tooth base for holding in the first tooth holder and a tooth head with a lateral head region that extends transversely to the tooth base away to one side, and that the second tooth half is designed L-shaped with a tooth base for holding in the second tooth holder and a tooth head with a lateral head region that extends transversely to the tooth base to an opposite side.In a further development of the invention, it is advantageous that the two L-shaped tooth halves are designed to be mirror-symmetrical to each other, at least in their head region.According to a further embodiment of the invention, it is provided that a deflector element is placed upstream in front of the two tooth holders, being adjacent to each other, in one direction of rotation of the milling wheel, through which ground material can be deflected into a side region of the tooth holders. This protects the tooth holder.The invention further comprising a milling tooth, which is characterised in that the milling tooth is formed with a tooth head extending transversely to both sides of the tooth base, that the tooth head has a lateral first head region and a lateral second head region, which extend in opposite directions to one another, and that at least two cutting bodies lying next to one another are arranged on each head region.The milling tooth according to the invention can be used, in particular in the milling wheel according to the invention described above, wherein the advantages described herein arise.A preferred further development of the milling tooth is that it has a first tooth half and a second tooth half, which are detachably connected to one another to form the milling tooth. In particular, the detachable connection can be made by at least one connecting element, in particular a connecting bolt or a screw. A detachable connection can also comprise a simple tack weld. The two-part design of the milling tooth allows, in the event if cutting elements are damaged on only one half of the tooth, only this tooth half to eplace. This can save costs for repair and maintenance.The two tooth halves are preferably mirror-symmetrical to each other. The tooth halves each have a tooth base and a head region.Furthermore, a particularly expedient embodiment of the milling tooth according to the invention is that the first tooth half is designed L-shaped with a tooth base and a tooth head with a lateral head region that extends away to one side transversely to the tooth base, and that the second tooth half is designed L-shaped with a tooth base and a tooth head with a lateral head region that extends transversely to the tooth base to an opposite side. This arrangement results in an approximately even distribution of the milling power to both tooth halves during milling operation.A further aspect of the invention relates to a hinged tooth for a milling wheel having- a pivot bearing for pivoting support on a pivot bolt on a hub of themilling wheel,- a tooth holding arm extending away from the pivot bearing, and- a control arm extending away from the pivot bearing essentially in theopposite direction to the direction of the tooth holding arm,wherein the tooth holding arm is designed plate-shaped with a tongue-shaped recess for releasably receiving and holding at least one milling tooth and a strip element for filling a dead space is attached to the tooth holding arm on at least one side of the tooth holding arm, wherein the strip element at least partially covers one side of the tongue-shaped recess. The tooth holing arm can be formed simply, wherein the strip element is subsequently attached to one side, covering the recess at the side. The strip element reduces or significantly reduces a dead space that is created in one of the two folded end positions of the hinged tooth, in particular between the hinged tooth and the milling wheel hub.It can be particularly advantageous for the milling tooth to have a tooth base for insertion into the tongue-shaped recess on the tooth holding arm and a tooth head with at least one cutting body. In particular, a conventional milling tooth can be used in the hinged tooth arrangement, which reduces the maintenance effort.A particularly simple fastening of the tooth can be achieved by the fact that the milling tooth is fastened in the tooth holding arm in the region of the tooth base via at least one transverse directed fastening bolt that extends transversely to a longitudinal direction of the tooth base, and that at least one through-hole for the fastening bolt is provided in the strip element.Another advantageous hinged tooth is that the strip element is arranged on the tooth holding arm on the side facing away from a bearing plate on which the milling wheel is mounted.Furthermore, the invention relates to a trench cutter having a milling frame, on the underside of which at least one bearing plate is arranged, wherein at least one millingwheel according to the invention is mounted on the bearing plate, so as described above. This results in the advantages described above when using a trench cutter.Furthermore, according to one embodiment variant of the invention, it is preferred that scraper elements are attached to the milling frame, which project into an intermediate space between the circumferential rows with the tooth holders with the milling teeth for scraping off adhering soil material. In particular, the scraper elements can be designed paddle-like with a wide scraper blade and a thin retaining web arranged thereon. The web is designed relatively thin and preferably has a width of between 1 cm and 3 cm.A distance between the tooth holders of two adjacent circumferential rows is determined by the size of the unsupported head region on a T-shaped tooth and the width of the retaining web of a scraper element with a slight distance between the outer edge of the milling teeth and the retaining web of an intermediate scraper element.Such a paddle-shaped arrangement of one or more scraper elements can be effected to safely and reliably scrape off adhering soil material from the drum-shaped hub and the tooth holders with the T-shaped milling teeth. Due to the relatively large free spaces between the individual tooth holders, the scraped off soil material can also be reliably discharged radially to the outside.Another advantageous embodiment of a trench cutter according to the invention is that a total of four milling wheels are provided, which are mounted in pairs on a bearing plate each. The bearing plate is located on the underside of the milling frame. The milling wheels can be driven either by a hub motor or preferably by one or more drive motors on the milling frame, wherein a torque is transmitted via a corresponding gear arrangement on the respective bearing plate.In the following, the invention is described in more detail using preferred exemplary embodiments, which are shown schematically in the drawings. In the drawings show:Fig. 1 a front view of a lower part of a trench cutter with a milling wheelaccording to the invention;Fig. 2 a side view of the lower part of a trench cutter with the milling wheel according to Fig. 1;Fig. 3 a side view of a milling wheel according to the invention;Fig. 4 a top view of the milling wheel from Fig. 3;Fig. 5 a perspective view of the milling wheel from Figures 3 and 4;Fig. 6 a side view of a milling tooth holder;Fig. 7 a front view of the milling tooth holder from Fig. 6;Fig. 8 a top view from above of the milling tooth holder according to Figures 6 and 7;Fig. 9 a perspective view of the milling tooth holder according to Figures 6 to 8;Fig. 10 a front view of a milling tooth;Fig. 11 a perspective view of the milling tooth from Fig. 10;Fig. 12 a front view of a further milling tooth made up of two milling tooth halves;Fig. 13 a side view of the milling tooth from Fig. 12;Fig. 14 a top view of the milling tooth of Figures 11 and 13;Fig. 15 a perspective view of the milling tooth according to Figures 12 to 14;Fig. 16 a side view of a hinged tooth;Fig. 17 a front view of the hinged tooth from Fig. 16;Fig. 18 a further side view of the hinged tooth from Figures 16 and 17;Fig. 19 a perspective view of the hinged tooth from Figures 16 to 18; andFig. 20 a further perspective view of the hinged tooth according to Figures 16to 19.A trench cutter 10 according to the invention is shown schematically in Figures 1 and 2, wherein only a lower part of a milling frame 12 with only a single milling wheel 30 is shown. However, a total of four milling wheels 30 are arranged on the trench cutter 10, of which in each case two are mounted as a pair of milling wheels on either side of a bearing plate 20, so as to be rotatable about a bearing axis 22.Between the two pairs of milling wheels 30, a box-like suction nozzle 14 with a plurality of suction openings 16 is arranged on an underside of the milling frame 12 for suctioning off the milled soil material with surrounding suspension. A suction pump (not shown) is mounted on a flange 18 shown in Fig. 1 for suction.The structure of a milling wheel 30 according to the invention is explained below in connection with Figures 3 to 5. The milling wheel 30 has a drum-shaped hub 32, on the outer circumference of which tooth holders 40 with milling teeth 50 are arranged in circumferential rows structured.In addition to normal tooth holders 40, pivot bearings 80 for hinged teeth 70 can be arranged on an inner circumferential row, which is directed towards the bearing plate 20. At the outer circumferential row at the other end of the hub 32, individual tooth holders 40 can be arranged with an angle of inclination relative to a radially directed plane.In the exemplary embodiment of a milling wheel 30 shown, two centre circumferential rows with a double arrangement of tooth holders 40 for receiving milling teeth 50 according to the invention with a T-shaped tooth head 60 are arranged between the inner circumferential row and the outer circumferential row. The tooth holders 40 and the milling teeth 50 are explained in more detail below.In the milling wheel 30 shown in Figures 3 to 5, two double tooth holders 40 are arranged in each of the two centre circumferential rows, which are offset by 180° in the same circumferential row. The tooth holders 40 are in turn offset by 90° from the first centre circumferential row in relation to the second centre circumferential row, so that there is a sufficient distance between the individual tooth holders 40 in the adjacent circumferential rows.A total of four inclined tooth holders 40 are arranged in the outer circumferential row with an outward inclination. On the inner circumferential row, which is directed towards the bearing plate 20, two hinged teeth 70 are arranged offset by 180° to each other. Two double tooth holders 40 are also arranged on the inner circumferential row, offset by 90°, which are also offset by 180° in relation to each other.The double tooth holder arrangement, each having two plate-shaped tooth holders 40, which are directly adjacent to one another, is preceded by bevelled deflector elements 46 in the direction of rotation of the milling wheel 30, in order to prevent soil material from penetrating into a joint between the two adjacent tooth holders 40.U-shaped recesses 41, in which the milling teeth 50 are held directly or via a U-shaped insert 42, are in each case brought in the tooth holders 40 to accommodate the milling teeth 50. The plate-shaped tooth holders 40 can thus be attached to the hub 32 of the milling wheel 30 in a single arrangement as in the outer circumferential row or in a double arrangement as in the two centre circumferential rows.The double arrangement of tooth holders 40 according to the invention is described in more detail below in connection with Figures 6 to 9. A single tooth holder 40 is designed plate-shaped and has an arcuate edge on its underside for welding to the outer circumference of the hub 32 of a milling wheel 30. Furthermore, a U-shaped recess 41 is provided, into which a tooth base 52 of a milling tooth 50 can be inserted radially in a manner known in principle, under forming a tongue and groove connection. For fastening, a fastening pin 44 can be inserted transversely through a through-hole 53 in the tooth base 52 of the cutter tooth 50, with which the inserted cutter tooth 50 is fixed in a form-fitting and force-fitting manner to the tooth holder 40. In particular, the fastening pin 44 can be designed as a slotted sleeve, which is fixed in the through-hole 53 with a certain clamping force.According to the invention, two plate-shaped tooth holders 40 are arranged directly next to each other to absorb particularly high forces. The two adjoining to one another tooth holders 40 can also be easily detachably connected to each other by means of fastening screws or spot welds. In this double arrangement of two toothholders 40, a single milling tooth 50 with two corresponding tooth bases 52 or two individual milling teeth 50 with a single tooth base can be inserted, which together can form a complete tooth.A strip-shaped deflector element 46, which is welded to the milling wheel hub 32 and / or to the tooth holders 40, is arranged upstream of the double arrangement of tooth holders 40 in the direction of rotation or in the milling direction of the milling wheel 30.The deflector element 46 prevents milled soil material from entering the joint between the two adjacent tooth holders 40, thereby increasing the stability of the double arrangement. Furthermore, the deflector element 46 can have one or more inclined deflector surfaces, with which soil material hitting the front is deflected laterally around the tooth holders 40. This further reduces the load on the tooth holders 40 and can also achieve a certain guidance of the milled soil material to the outside or to the suction openings 16 of the suction nozzle 14 of the trench cutter 10.A first milling tooth 50 according to the invention, which can also be provided as a milling tooth half 51, is shown schematically in Figures 10 and 11. The approximately L-shaped milling tooth 50 has a tongue-shaped tooth base 52 and a tooth head 60 projecting to one side with a first head region 61. Three cutting bodies 66, lying next to each other, with linear cutting edges for removing soil material are arranged next to each other on the first head region 61.An approximately V-shaped circumferential groove 54 in cross-section is formed along an outer side of the tooth base 52, which, when inserted into a U-shaped recess on a tooth holder with a corresponding tongue-like projection, provides a tongue-and-groove connection for holding the tooth 50 in the tooth holder. To fix the tooth 50 in a tooth holder, a transverse directed through-hole 53 is formed in the tooth base 52, into which a fastening pin 44 can be inserted.Figures 12 to 15 show a further milling tooth 50 according to the invention, which is formed from two tooth halves 51a and 51b by detachably connecting the two tooth halves 51a, 51b. The detachable connecting can involve screwing or tack welding, for example. A first tooth half 51a can be designed to correspond to the tooth half 51shown in Figures 10 and 11. The second tooth half 51b can be formed mirror-symmetrically to the first tooth half 51a, wherein a milling tooth 50, which is approximately T-shaped in cross-section or in front view, is formed with a tooth head 60.The tooth head 60 has a first head region 61 that extends laterally outwards towards a first side beyond the tooth base 52. Three cutting bodies 66 are arranged in a descending line on the first head region 61 of the tooth head 60. In a corresponding manner, the second head region 62 projects laterally in the opposite direction from the tooth base 52, wherein three cutting bodies 66 are also arranged in a descending line. As can be seen particularly clearly from Fig. 14, the cutting heads 66 with the arrangement sloping outwards and backwards in the milling direction, form a sweep of the entire milling tooth 50, which, together with the T-shaped contour of the head regions 61, 62 of the milling tooth 50 extending to both sides in front view, contributes to a particularly good removal rate.By forming the entire cutter tooth 50 by a first cutter tooth half 51a and a second cutter tooth half 51b that is mirror-symmetrical to it, a common double tooth base 52 with a total of two circumferential grooves 54 is created. This allows the milling tooth 50 to be mounted in a double arrangement of tooth holders 40. This results in particularly good retention and support of the milling tooth 50 on the milling wheel. As a result, large forces can be absorbed by the double tooth holder 40 even if the tooth head 60 protrudes far beyond the tooth base 52.As with the milling tooth 50 according to Figures 10 and 11, the milling tooth 50 according to Figures 12 to 15 has a through-hole 53 in its tooth base 52 extending through the entire tooth base 52, into which one or two fastening pins 44 can be inserted laterally for fixing to the tooth holder 40.The invention further relates to a hinged tooth 70, which is shown in Figures 16 to 20. The hinged tooth 70 is pivotably mounted on a pivot bearing 80 of a milling wheel 30, as is clearly illustrated in Figures 3 to 5. During one revolution of the milling wheel 30, the hinged tooth 70 can assume a folded position and an unfolded position. The hinged tooth 70 is in the unfolded position when this tooth is located outside thecircumferential region of the bearing plate 20, in order to remove soil material from underneath the bearing plate 20.If the hinged tooth 70 passes directly by the bearing plate 20 of a trench cutter 10, the hinged tooth 70 is pivoted into a folded position by a basically known slotted gate control on the bearing plate 20, in order to prevent by this way damage to the bearing plate 20.According to a basic structure, the hinged tooth 70 according to the invention has a pivoting body 71 with a downwardly directed control arm 73 and an upwardly directed tooth holding arm 74. Two bearing eyes 72 are provided between the control arm 73 and the tooth holding arm 74 to accommodate a pivot bolt of the pivot bearing 80 on the milling wheel 30. A wear plate 75 can be attached to the control arm 73, which is in contact with a slotted gate of a slotted gatecontrol on the bearing plate 20, by means of which the pivoting position of the hinged tooth 70 is predetermined.A U-shaped recess 41 is provided on the tooth holding arm 74 in a manner known in principle, into which the previously described milling tooth 50 according to Figures 10 and 11 or any other milling tooth with a corresponding tongue-shaped tooth base 52 is inserted in a known manner. A through-hole 53 on the tooth base 52 can be used to fix the position of the milling tooth 50 on the tooth holding arm 74 via a fastening pin.According to the invention, a strip element 76 is attached, in particular screwed or welded, to at least one side of the tooth holding arm 74. In particular, the strip element 76 is located on the side facing away from the bearing plate 20 on a trench cutter 10. The strip element 76 covers and fills a dead space that is basically present, which is formed function-related due to the pivoting movement of the hinged tooth 70 in a purely plate-shaped design of the tooth holding arm 74. In principle, cohesive soil material could adhere to the hinged tooth 70 in this dead space, whereby the functioning of the hinged tooth 70 can be impaired. By providing the additionally attached strip element 76, which extends essentially over the entire length of the hinged tooth 70 extending in circumferential direction, this dead space is filled, sothat no or at most only a small amount of adhesive ground material can then adhere to the hinged tooth 70.The individual aspects of the invention described can be used to create a milling wheel that is suitable, in particular, for removing also cohesive soil layers, wherein the various measures are used to prevent or at least to a great extent reduce the adhesion of soil material. The individual measures can be provided in combination with each other or also individually.

Claims

1. Milling wheel for a trench cutter (10) having a drum-shaped hub (32), on the outer circumference of which plate-shaped tooth holders (40) are arranged in at least one circumferential row, in which milling teeth (50) are releasably held for removing soil, wherein at least one milling tooth (50), which is T-shaped in the circumferential direction when viewed from above on the milling wheel, is provided with a tooth head (60) extending transversely to both sides of a tooth base (52) and with respect thereto in a multiple width, the tooth head (60) has a lateral first head region (61) and a lateral second head region (62), which extend in opposite directions from one another, and at least two adjacent cutting bodies (66) are arranged on each head region (61, 62), characterised in that the milling tooth (50) has a first tooth half (51a) and a second tooth half (51b), which are detachably connected to one another to form the milling tooth (50).

2. Milling wheel according to claim 1, characterised in that all cutting bodies (66) on the tooth head (60) are directed forwards in a cutting direction.

3. Milling wheel according to claim 1 or 2, characterised in that the head regions (61, 62) with the cutting bodies (66) are offset relative to one another in the circumferential direction or are arranged in a cutting line.

4. Milling wheel according to any one of claims 1 to 3, characterised in that the tooth head (60) has a sweep in the cutting direction and the cutting bodies (66) form a V-shaped arrangement on the tooth head (60).

5. Milling wheel according to any one of claims 1 to 4, characterised in that the cutting bodies (66) are of the same design and, in particular have a cutting edge (68).

6. Milling wheel according to any one of claims 1 to 5, characterised in that between two and four tooth holders (40) are arranged distributed over the circumference in a circumferential row.

7. Milling wheel according to any one of claims 1 to 6, characterised in that in an axial direction of the milling wheel (30) on the hub (32), an outer circumferential row is arranged on a free outer side of the milling wheel (30), an inner circumferential row is arranged on an inner side of the milling wheel (30) directed towards a bearing plate (20) and at least one centre circumferential row is arranged.

8. Milling wheel according to claim 7, characterised in that solely two or three centre circumferential rows are arranged.

9. Milling wheel according to claim 7 or 8, characterised in that solely two tooth holders (40) with milling teeth (50) are provided in the centre circumferential row or the centre circumferential rows, which are arranged offset by 180º to one another on the circumference of the hub (32).

10. Milling wheel according to any one of claims 7 to 9, characterised in that at least one hinged tooth (70) is arranged on the inner circumferential row.

11. Milling wheel according to any one of claims 7 to 10, characterised in that more tooth holders (40) are arranged on the outer circumferential row than on a centre circumferential row.

12. Milling tooth for a milling wheel (30) according to any one of claims 1 to 11, characterised in that the milling tooth (50) is formed with a tooth base (52) for receiving and holding in a tooth holder (40) on the milling wheel (30) and a tooth head (60) extending transversely to at least one side of the tooth base (52) and with respect to the tooth base (52) in a multiple width, in that at least two cutting bodies (66) lying next to one another are arranged on a head region (61, 62) of the tooth head (60), in that all cutting bodies (66) on the tooth head (60) are directed forwards in a cutting direction, and in that the milling tooth (50) has a first tooth half (51a) and a second tooth half (51b), which are detachably connected to one another to form the milling tooth (50).

13. Milling tooth according to claim 12, characterised in that the tooth head (60) has a lateral first head region (61) and a lateral second head region (62), which extend in opposite directions from one another.

14. Milling tooth according to claim 12 or 13, characterised in that the first tooth half (51a) is designed L-shaped with a tooth base (52) and a tooth head (60) with a lateral first head region (61) that extends away to one side transversely to the tooth base (52), and in that the second tooth half (51b) is designed L-shaped with a tooth base (52) and a tooth head (60) with a lateral second head region (62) that extends transversely to the tooth base (52) to an opposite side.

15. Trench cutter having a milling frame (12), on the underside of which at least one bearing plate (20) is arranged, characterised in that at least one milling wheel (30) according to any one of claims 1 to 11 is mounted on the bearing plate (20).

16. Trench cutter according to claim 15, characterised in that scraper elements (26) are attached to the milling frame (12), which project into an intermediate space between the circumferential rows with the tooth holders (40) with the milling teeth (50) for scraping off adhering soil material.