DE29504598U1 - Device for removing protruding objects inside a pipe - Google Patents

Description

Applicant: Priority:

Mr DE, G 94 04 390.6

Helmar Haas from 16 March 1994 Schlehenweg 21

D-71686 Remseck

1729 019 F/sch 13.03.1995

Title: Device for removing protruding objects inside a pipe

DESCRIPTION

The invention relates to a device for removing objects protruding into the interior of a pipe, such as deposits, circumferential inner welding beads and the like according to the preamble of claim 1.

Such a device is known from DE 87 12 494 Ul. The cutting tools that can be moved against the inner wall of the pipe are radially aligned circular blades that can be extended in a radial direction against the resistance of a spring. However, the travel distance is quite limited, which is why the inner diameter of the pipe to be cleaned can only deviate slightly from a certain target value. In addition, due to the purely radial displacement movement

In most cases, the circular blades cannot move back when an obstacle is encountered due to a self-blockage. This makes this device very susceptible to failure.

If plastic pipes are butt-jointed using the mirror welding process, bulges are formed both on the outside and inside, with the inner bulge reducing the cross-section at that point. Solids that are carried along by the medium flowing through them also tend to settle there. Because the formation of such bulges cannot be prevented and, on the other hand, there is a desire for pipes that are smooth at least on the inside over their entire length, there is a great need for a device with which such bulges and other objects that protrude inwards, such as deposits, encrustations and the like, can be removed.

PE pipes are laid at the bottom of landfills, which are perforated along part of their circumference. Through these holes, seepage water from the landfill can enter the pipes in which it is collected and drained. No significant currents occur, which is why the internal bulges mentioned are particularly disadvantageous in this area of application. The liquids transported in the pipe are heavily enriched with solids. The latter settle

on each inner bead and thus clog the pipes more and more.

The same applies to pipes such as sewage pipes made of concrete or plastic, in which, for example, concrete deposits are present from connecting the pipe sections or in which tree roots have grown into them and thus at least partially block the free passage.

The task is therefore to further develop a device of this type in such a way that protruding objects such as deposits, ingrowths and the like can be removed flush without having to fear blockage or adjustment movement of the tool during work.

To achieve this object, the features specified in claim 1 are provided in a device of the type mentioned.

If this device is set in rotation, at least one bearing block and, in the case of several bearing blocks, all bearing blocks are simultaneously pivoted outwards with their cutting tools due to the centrifugal force. The cutting edge of the cutting tool therefore rotates on a flight circle that is larger than an imaginary circle on which this cutting edge is located when the tool is at a standstill. By taking suitable measures, it can be ensured that the

The flight circle of the rotating cutting tool is not larger than the inner diameter of the pipe to be cleaned or freed of deposits or the like. However, if the resistance becomes too great when removing weld beads, protruding projections, deposits, ingrowths and similar protruding objects, for example because the feed rate of the device is too high, the cutting tool is not sharp enough or is not suitable for removing a deposit for some other reason, these deposits, as soon as they are reached by the cutting edge of the cutting tool, press the latter inwards, which leads to a swinging back movement of the bearing block against the effect of centrifugal force. In any case, this prevents damage to both the device and the pipe, channel or the like.

A particularly preferred embodiment of the invention is characterized in that the bearing block is a one-armed lever and the cutting edge of each cutting tool is located at a radial distance from the geometric pivot axis of the bearing block. As the embodiments show, the one-armed lever does not necessarily have to be straight, but rather a bent shape, an angled shape and the like are also easily conceivable and usable. It is only important that when the bearing block is pivoted about its geometric pivot axis, the cutting edge of the

cutting tool describes a circular arc around the same geometric axis.

A further embodiment of the invention provides that the cutting edge of each cutting tool is located on a cutting steel that can be positioned and secured transversely to the longitudinal extension of the single-armed lever. In this way, the cutting steel and, via this, the cutting edge can be precisely aligned with respect to the single-armed lever. This is particularly important if the outward pivoting movement of the single-armed lever can be limited in a suitable manner.

A particularly advantageous variant of the invention is characterized in that the holder has several cutting steels or similar cutting tools, the cutting edges of which rotate in the working position on different sized flight circles. In this way, projections, deposits and the like can be removed step by step, thereby saving drive energy.

At this point, it should be noted that this device, like the generic device mentioned at the beginning, is pushed or pulled forward inside the pipe and the cutting steels are still in their inner transport position in which they do not touch the pipe wall. In the current state of the art, the movement is carried out with the help of rollers, which are also used in the

device according to the invention can be used. Instead, however, it is also possible to use runners, as one of the embodiments shows.

The cutting steels are very advantageously arranged evenly around the circumference of an essentially rotationally symmetrical holder. The axis of rotation of this device therefore coincides with the geometric axis of the pipe. Depending on the size of the pipe and the thickness as well as the strength or toughness of the materials to be removed, three or more cutting steels can be provided.

Another particularly preferred embodiment of the invention is given in claim 6. It enables a deposit or the like to be removed step by step, whereby the cutting steel that is at the front in the feed direction of the device is the first to take effect, but this only partially removes the deposit or the like. The next cutting steel further removes the bead and, in the case of three cutting steels, the third turns the inside of the pipe even more, in particular flush. The advantage of this variant is that, due to the lower removal capacity of each cutting steel, a lower drive power is required overall in comparison to a device that has to completely remove the bead in one operation. This also results in a longer service life for the cutting edges.

In a further development of the invention, the holder has two circular disks arranged at an axial distance, between which the pivoting bearing blocks, each with a cutting steel, are located. The special design of these bearing blocks depends on the shape of the cutting steel and other requirements such as space requirements, low weight, etc.

To adjust the working flight circle of each cutting steel, the device is advantageously equipped with the features of claim 8 or claim 9. The fine toothing mentioned in the latter enables a sensitive adjustment of each cutting steel relative to its bearing block. By loosening the screws, preferably a grub screw, the toothing can be loosened, so that a readjustment or even removal of the cutting steel is possible.

A further preferred variant of the invention is characterized in that a support member is located on each bearing block, the support surface of which rotates during operation on a flight circle that is equal to or larger than the flight circle of the cutting steel that is swung out the furthest. This means that under the influence of centrifugal force, the swinging out of the bearing block ends when the support member rests against the inner wall of the pipe. If the cutting edge or cutting edges or the cutting edge that protrudes the furthest is on the

the same flight circle as the support surface or edge of the support member, then in the case of a bead removal, for example, the bead is removed flush down to the inner diameter of the pipe. The same applies to the removal of incrustations, dirt, ingrowths and the like.

The support member can be variably moved and locked outwards on the bearing block so that it can be adjusted to suit the desired work result.

A further variant of the invention is characterized in that the support member forms a unit with the cutting steel that is mounted on the bearing block in a movable and lockable manner. In a further embodiment of the invention, the latter can be locked by means of a retaining plate that can be adjusted and locked on the bearing block, whereby both can be coupled via a support toothing and can therefore be finely adjusted.

Furthermore, it is very advantageous that a projection or similar rearward projection pointing away from the axis of rotation of the bearing block together with a stop fixed to the housing forms a swing-out limiting device. As a result, even with the greatest centrifugal force, the bearing blocks cannot be swung further outwards than the swing-out

limiting device, whereby an adjustment option is of course also provided in this case.

A guide on the inner wall of the pipe and thus also the working flight circle of each cutting edge can be achieved in a very expedient manner by means of the features described in claim 13.

Furthermore, the travel distance of the bearing block is advantageously adjustable and can be limited by means of fixed stops at the end points, as is implemented according to the features of one or more of claims 17 to 19. This results in deformations, pipe misalignments, and dimensional changes of neighboring pipes in the pipe run to be cleaned being easily bridged.

Further embodiments and resulting advantages as well as modes of operation emerge from the remaining subclaims and the following description of embodiments.

The drawing shows these embodiments of the invention in a partially simplified representation. Here:

Figure 1 shows schematically and partially broken away a longitudinal section through a at least two

Pipeline consisting of pipe sections with a device according to a first embodiment of the present invention in side view,

Figure 2 shows, on an enlarged scale, a partially broken away and radially sectioned front view of the device according to Figure 1 in the area of a cutting steel,

Figure 3 shows an enlarged and partially sectioned view of the front part of the device according to Figure 1 in side view,

Figure 4 shows an enlarged and partially sectioned view of the front part of the device according to Figure 1 in plan view,

Figure 5 shows a representation of the device corresponding to Figure 2, but according to a second embodiment of the present invention,

Figure 6 is a representation of the embodiment of Figure 5 corresponding to Figure 3, and

Figure 7 is a representation according to Figures 2 and 5, but according to a third embodiment of the present invention.

A pipeline consists of a number of individual pipes or pipe sections, whereby in the case of drainage pipes, these are at least partially perforated pipes. If the pipes are made of plastic, for example PE material, adjacent pipes 1 and 2 can be butt-jointed using the so-called mirror welding process. This then creates an outer bead 3 and an inner bead 4. The latter can be removed using the device according to the invention. It is supported by several, for example three, runners 6 or the like evenly distributed around the circumference on the inner wall 7 of the pipe and is transported through the pipe, for example in the direction of arrow 5. This is achieved either with the help of a traction cable connected to the front eyelet 8 and/or by means of a known nozzle pressurized water drive 9, to which the pressurized water is fed via a hose 10.

An essential element of the device according to the invention is a holder 11 with at least one cutting steel 12 protruding outwards. In all embodiments, however, three cutting steels 12 are provided, evenly offset around the circumference of the holder 11 in a manner not shown in detail. The longitudinal axes of the cutting steels 12 do not necessarily run in a radial direction but are only directed outwards and this also applies to the feed into the working position or the return to the rest or transport position. The holder 11 is by means of a

Rotary drive 14 can be rotated around the geometric axis 13 of the pipe 1, 2. In analogy to the nozzle pressurized water drive, the rotary drive is also a hydraulic drive known in itself, which can also be fed with pressurized water via the hose 10. The drive is effected by recoil, which is why these drives are equipped with nozzles 15 and 16. The holder 11 is mounted on the rest of the device by means of ball bearings in a manner not shown.

The central position of the holder 11 in the pipe 1, 2 is achieved by appropriate design of the supports 17 for the runners 6. The supports 17 can be divided into two and extendable like a telescope in a manner only indicated, so that the device can be used within specified limits in pipes with different inner diameters. In Figure 2, a smallest and a largest flight circle of the cutting edge 20 of a cutting steel 12 are shown, i.e. with regard to the cutting steels 12, adaptation to different pipe inner diameters is also possible. This will be discussed in more detail below.

According to Figures 3 and 4, the holder 11 has two parallel disks 21 and 22 held at a distance from one another, whereby these are preferably circular disks. Between them there are several, for example three, bearing blocks 23, each with a cutting steel 12. In this case, it is provided that the two disks 21 and 22 are held together by means of three

Screws 24 are held together, with spacer bolts at the corresponding points. Each bearing block 23 is mounted on a bolt 25 in the direction of the double arrow 26, which extends parallel to the connecting screws 24 and can, for example, be pressed into one of the plates. A tension spring 27 holds each bearing block 23 in its inner pivoting position, in which the cutting edges 20 are located approximately on an imaginary circle that is smaller than the smallest flight circle 18. This imaginary circle is also smaller than the inner diameter of the pipe, so that the device can be pushed or pulled forward to the work site without the cutting edges touching the pipe wall. The inner position of each bearing block 23 is secured with the aid of a stop member, a stop edge or the like of the bearing block, which interacts with a stop surface, edge or the like on one of the disks 21, 22 or a disk-fixed element between the disks. In Figure 3, the two spring ends are connected to one of the disks, e.g. disk 22, and the bearing block 23. Instead, however, it is also possible to use a common, e.g. ring-shaped spring, in particular a tension spring, which pivots all holders inwards and which is tensioned or additionally tensioned when the device is in operation. It is then guided via a support member on each bearing block.

If the device is rotated, the bearing blocks 2 3 pivot outwards under the influence of centrifugal force.

• · · · ft

The cutting edges 20 then move on the actual intended or set or otherwise specified flight circle or the actual inner contour in the case of non-round pipes. The cutting steels 12 can be moved and locked in an approximately radial direction, i.e. they are held adjustably on their bearing block 23. So that not all of the cutting edges work at the same time, the flight circle is selected to be different for each cutting steel 12. This is achieved by the three cutting steels 12 being moved outwards by different distances on their bearing block 23 and then clamped in place. The diameters of the effective flight circles can differ from one another by a few millimeters.

If all three effective flight circles were located in a common radial plane, this would of course not have the desired effect, but rather only one cutting steel, namely the one that protrudes the furthest, would work. To prevent this from happening, the three effective flight circles are slightly offset from one another in the direction of the geometric axis of rotation 29 of the device or in the working feed direction 5. This is illustrated in Figure 3 by three dash-dotted lines 30, 31 and 32. The dash-dotted line 3 2 symbolizes the plane of the flight circle that protrudes the least when working on the cutting edge 20. The dash-dotted line 30 symbolizes the plane of the flight circle of the one that protrudes the furthest outwards.

Cutting edge 20. The cutting edge of the medium-sized cutting circle rotates in between, which is symbolized by the line 31. This means that when the device rotates and is fed in the direction of the arrow 5, the inner bead 4 or similar is only slightly removed with the help of the cutting edge 20 on the cutting circle of level 3 2. The next cutting edge 20 on the cutting circle of level 31 removes the inner bead 4 somewhat more and the cutting edge 20 of level 30 then removes the inner bead 4 completely or to the extent that this is intended.

In order to limit the swinging out of the bearing blocks 2 3 due to the centrifugal force and thus also to determine the effective flight circles of the cutting edges 20, a support member 3 3 is attached to each bearing block 2 3. The support surfaces 34 of all support members, which are designed, for example, as elastic or hardened molded parts or as ball or needle bearings, rotate on a common flight circle which is determined by the inner diameter of the pipe to be cleaned or processed and is possibly as large as this. This means that none of the cutting edges 20 protrudes outwards beyond the support surface 3 4. If flush machining of an inner bead 4 or of contaminants or of protruding tree roots or the like of a pipe 1 is intended, only one of the cutting edges 20 of all cutting steels protrudes up to the flight circle of the support surface 34, while the others

16

corresponding amounts according to lines 30, 31 and are offset inwards.

The corresponding effective flight circles of the three cutting edges 20 for the smallest pipe diameter are designated 18, 18a and 18b in Figure 2. The same applies to any other pipe diameter.

In order to be able to use the device for cleaning or processing pipes with different internal diameters, the support members 33 as well as the cutting steels 12 are mounted on their bearing block 23 in a way that is movable and lockable in the direction of arrow 28 (Figure 2). For this purpose, the support members 33 have a shaft 35, indicated in Figure 2, on which there is an elongated hole through which a clamping screw or the like passes, which is screwed firmly into a thread of the bearing block 23 after the longitudinal adjustment. In the case of the adjustment device for the cutting steels 12, indicated, there is a longitudinal groove 36 closed at both ends on its cylindrical shaft 43, into which the free end of a locking screw 37 engages and presses against the bottom of the longitudinal groove 36.

Figures 3 and 4 show that a support plate 38 of each support member 3 3 overlaps one of the disks, in the embodiment the disk 21, on the outside. When the device is at a standstill, its underside rests on the cylinder jacket 39 of the

Disc 21. In this respect, the working position of the cutting steels 12 with the bearing blocks 23 pivoted out is shown in Figure 3. The contact of the underside of the support plates is achieved with the help of at least one tension spring. Thus, the inner pivoted-in position of the bearing blocks can be limited with the help of the stop device formed from the support plates 38 and the casing 39 of the disc 21. When the device rotates, the support surface 34 of each cutting steel 12 rests on the inside of the pipe.

The connecting screws 24 for holding the two disks 21 and 22 together are located on a relatively small hole circle diameter according to Figure 2. They can also be placed further outwards, for example close to the cylinder jacket, as indicated by the cross 40 (Figure 2). In this case, together with a rear extension 41 of the bearing block 23, they can form a device for limiting the maximum outward pivoting of the bearing blocks 23, which becomes effective, for example, when there is a sudden pipe expansion or similar increase in diameter inside the pipe and the support surfaces 3 4 are exposed as a result. When removing the inner bead 4 or similar elements protruding into the pipe 1, 2, internal support via the support members 3 3 is generally provided.

The design of the cutting steel 12 is according to Figures 2 and 3 such that the cutting head 44 is provided with a

Cutting plate 42 made of, for example, hard metal and is held by means of a screw or the like, so that it can be removed for regrinding or replacement.

The shaft 43 of the cutting steel 12 consists largely of round material and is slidably mounted in a circular bore 45 of the bearing block 23. It is secured against twisting by the screw 37. The head 44 of the cutting steel 12 can, as shown in the drawing, have a different shape, in particular a different cross-sectional shape. This depends, for example, on the cutting plate 42. A prismatic holder can be provided for this. The lateral displacement of the cutting edges 20 of the three cutting steels 12 is achieved, for example, by different design of the head 44. This has the advantage that both the shafts 43 of the cutting steels 12 and the mounting bores 45 on all bearing blocks 23 can be designed and arranged in the same way. However, it is also conceivable, with identical cutting steels 12, to offset the geometric axis 46 of the bore 45 by amounts corresponding to the lateral distance of the lines 30, 31, 32.

In Figure 2, the cutting edge 20 of the cutting steel 12 that protrudes furthest during operation and the support surface 34 of the support member 3 3 rotate on a common smallest flight circle 18. With this setting, the inner beads 4 or the like.

flush with the inner wall of the smallest pipe. For safety reasons, the support member 3 3 can instead be pushed a little further outwards so that it rotates on a circle that is a little larger than the circle 18 of the cutting edge 20. When the rotary drive 14 is at a standstill, the force of the spring or springs 27 takes effect so that each bearing block 23 is pivoted clockwise around the bolt 25 until the support plate 38 of the support member 33 hits the cylinder jacket 39 of the disk 21.

In the embodiment of Figures 5 and 6, the support member 33 is made in one piece with the bearing block 23. It can have two spherical support surfaces 34 lying one behind the other in the circumferential direction. Both are expediently in contact with the inner wall of the pipe at the same time. The cutting steel 12, which is mounted on the bearing block 23 in a way that is movable and lockable in the direction of the double arrow 28, carries a removable hard metal plate 42, which in this embodiment is frustoconical and has a circular cutting edge 20. When it wears out, it can simply be rotated further by a certain angle and then held in place again using a central screw.

In the embodiments of Figures 5 and 6 and Figure 7, the two disks 21, 22 are arranged in a manner analogous to the somewhat shortened representation in Figure 4 over several evenly spaced

The bolts are connected to one another by bolts arranged offset around the circumference. The bolt 25 is pressed with its end 50 on the left in Figure 6, which is reduced in diameter, into a corresponding hole in the disk 21. A corresponding bolt section 51 fits precisely into a hole in the disk 22. This is followed by a bolt end designed as a threaded bolt 52, which protrudes beyond the outer surface of the disk 22 and onto which a nut 53 is screwed. It can be secured by a split pin 54. Furthermore, according to Figure 6, for example, there are additional bolts 55, the bolt ends of which are reduced in cross-section and engage in corresponding holes in the disks 21 and 22, analogous to the bolt 25. They have the function of spacer bolts. In addition, in conjunction with the rear extension 41 according to Figures 5 and 7, they function as a housing-fixed stop for a swing-out limiting device. For an adjustable travel distance of the bearing block 2 3 outwards, the bolt 55 can be eccentric and rotatable in a manner not shown. Figure 6 also shows that the entire device is rotatably mounted on a sleeve 6 3 via suitable roller bearings 61, 62. The front eyelet 8 (Figure 1) can be attached to this. A nut 64 and an inner collar 65 of the sleeve ensure axial securing together with a cover 66.

The cutting steel 12 can be moved and locked in approximately the radial direction of the discs 21 and 22. The locking screw

37 for locking the set position of the cutting steel is selected to be relatively small in the embodiments of Figures 5 to 7 compared to the embodiment of Figure 2; in addition, a pressure piece 47 is connected between the inner end of the locking screw 37 and the square or rectangular shaft 43 of the cutting steel 12 with the cutting plate 42. Both this and the facing surface of the cutting steel 12, which is preferably rectangular in cross section, are equipped with fine teeth, which are designated 48 and 49 in Figures 5 and 7 respectively. This allows the cutting steel 12 to be adjusted very sensitively in the direction of arrow 28 and securely locked.

The pressure piece 47 can be moved and fixed perpendicular to the image plane and thus parallel to the geometric axis 29 of the device or the two circular disks 20 and 21. Cross bolts 57 on each bearing block 23 also extend in the same direction. A tension spring element, here in the form of a rubber ring 58, is guided over all of the cross bolts 57 - three in this embodiment - which consequently takes on a triangular shape (Figure 5 or 7). In the initial position, i.e. with the bearing blocks 23 pivoted back, the rubber ring is preferably slightly pre-tensioned and the bearing blocks 23 rest against inner stops 56 fixed to the housing, which serve as fixed points for setting the adjustment length of the shaft 43 of the cutting jet 12 depending on the application.

As soon as the bearing blocks are pivoted around the geometric axis 60 in the direction of the arrow 59 due to the centrifugal force, the rubber ring 58 is tensioned or even more strongly tensioned. As a result, together with the cross bolts 57, it forms a spring-elastic return device for the bearing blocks 23, which are pivoted back into the starting position (against the stops 56) in the opposite direction to the arrow 59 when the centrifugal force ceases.

The variant in Figure 7 differs from the other two primarily in that the support member 3 3 and the cutting steel 12 with the cutting or hard metal plate 42 form a unit and are provided on the square shaft 43. If the position of the support member 33 on the bearing block 23 is adjusted using the locking screw 37, the pressure piece 47 and the shaft 43, the cutting edge 20 is simultaneously adjusted or set relative to the bearing block 23. The conditions according to Figure 7 are such that the support surface 34 of the support member 3 3 and the cutting edge 20 of the cutting steel 12 or, if present, its cutting plate 42 rotate on one and the same circular path, for example 18 or 19. In no case does the cutting edge 20 rotate on a larger circular path than the support surface 34, but at most on a smaller one.

It goes without saying that instead of the three bearing blocks described, fewer or more bearing blocks can be provided depending on the pipe diameter to be processed.

Claims (19)

Protection claims 1. Device for removing objects protruding into the interior of a pipe (1), such as deposits, circumferential inner welding beads (4) and the like, with a drivable rotating tool, wherein the device can be supported centrally on the inner pipe wall (7) by means of skids (6), rollers and similar sliding or rolling devices and can be transported through the pipe (1) by means of a feed drive (15), wherein the tool is furthermore at least one cutting tool (12, 42) which can be moved under the influence of centrifugal force against the resistance of a common or a respective spring-elastic return device (27; 57, 58) from the inside to the outside, against the inner pipe wall (7), and wherein the or each cutting edge (20) is located approximately on an imaginary circle which is smaller than the inner pipe diameter (7) when the rotary drive is at a standstill, characterized in that each cutting tool (12, 42) is located on a bearing block (23) which is mounted on a holder (11) of the device so as to be at least limitedly pivotable about an axis (60) running approximately parallel to the geometric tube axis (13). 2. Device according to claim 1, characterized in that the bearing block (23) is a one-armed lever and the cutting edge (20) of each cutting tool (12, 42) is in radial Distance from the geometric pivot axis (60) of the bearing block (23). 3. Device according to claim 2, characterized in that the cutting edge (20) of each cutting tool is located on a cutting steel (12) which can be inserted and secured to the single-armed lever (23) transversely to the longitudinal extension of the latter. 4. Device according to claim 3, characterized in that the holder (11) has several cutting steels (12) or similar cutting tools, the cutting edges (20) of which rotate in the working position on different sized flight circles (e.g. 18, 18a, 18b). 5. Device according to claim 4, characterized in that the cutting steels (12) or cutting tools are arranged evenly on the circumference of a substantially rotationally symmetrical holder (11). 6. Device according to claim 5, characterized in that the different sized effective flight circles (e.g. 18, 18a, 18b) of the cutting edges (20) of the cutting tools (12, 42) are offset from each other (30, 31, 32) in the axial direction (13) of the pipe (1), the smallest effective flight circle (e.g. 18b) is located in front of the middle one (18a) and this one in front of the largest flight circle (e.g. 18). 7. Device according to at least one of claims 1 to 6, characterized in that the holder (11) has two spaced apart, in particular circular disks (20, 21), between which the pivotably mounted bearing blocks (23) are located. 8. Device according to at least one of claims 1 to 7, characterized in that it has a longitudinal groove (36) which is preferably closed at both ends and into which an actuatable clamping member (37) of the bearing block (23) engages. 9. Device according to one of claims 1 to 7, characterized in that for adjusting the working flight circle (18, 19) of each cutting steel (12) its shaft (43) has a fine toothing (49) into which a counter toothing (49) of a pressure piece (47) engages. 10. Device according to claim 9, characterized in that the shaft (43) of the cutting steel (12) simultaneously also forms an anti-twisting device for the latter. 11. Device according to at least one of claims 1 to 10, characterized in that a tension spring (27), in particular a helical tension spring, is inserted between the bearing block (23) and a holding element on one of the disks (20, 21). 12. Device according to at least one of claims 1 to 10, characterized by a common spring-elastic return device, which consists of at least one rubber ring (58) or the like, which is guided over a cross bolt (57) of each bearing block (23) or of the cutting steel (12). 13. Device according to at least one of claims 1 to 12, characterized in that on each bearing block (23) there is a support member (33) whose support surface (34) rotates during operation on a flight circle that is equal to or larger than the flight circle (e.g. 18) of the cutting steel (12) that is swung out the furthest. 14. Device according to at least one of claims 1 to 3, characterized in that the support member (33) on the bearing block (23) can be displaced and secured outwards. 15. Device according to at least one of claims 1 to 14, characterized in that the support member (33) with the Cutting steel (12) forms a unit which is mounted on the bearing block (23) and can be moved and locked. 16. Device according to claim 15, characterized in that the unit comprising the support member (33) and cutting steel (12) can be locked by means of a holding plate (47) that can be adjusted and fixed on the bearing block (23), whereby both can be coupled via a pointed toothing (48). 17. Device according to at least one of claims 1 to 16, characterized in that a projection pointing away from the axis of rotation (25 or 60) of the bearing block (23) or a similar rear extension (41) together with a stop (40, 55) fixed to the housing forms a swing-out limiting device. 18. Device according to claim 17, characterized in that the housing-fixed stop (55) is formed by a rotatable eccentric bolt. 19. Device according to at least one of claims 1 to 18, characterized in that an inner housing-fixed stop (56) is provided as a pivoting-in limiting device.