AU2316388A - Chisel bit arrangement - Google Patents

Description

VERIIED TRANSLATION 23% 8 CHISEL ARRANGEMENT The invention is directed to a chisel arrangement for a plowing mining device in underground mining according to the features in the preamble of claim 1. Such a chisel arrangement is considered as prior art on the basis of DE-PS 12 91 708. It comprises a receptacle body which can be provided in a multiple arrangement, one on top of the other, on the coal face side of a planing body. The receptacle bodies are preferably welded on. A bearing pocket for a planing chisel is constructed in every receptacle body, the bearing pocket being open toward the working face. Two undercuts are formed in the interior of the bearing pocket, the undercut located in front in the cutting direction comprising an opening. Two nose-like projections which are adapted to the undercuts of the bearing pocket and serve to fasten the planing chisel in the receptacle body are provided at the planing chisel. The length of the projection located at the rear in the cutting direction on the one hand, as well as the smallest longitudinal extension of the planing chisel in the cutting direction in relation to the length of the inserting opening of the bearing pocket, are constructed in such a way that the planing chisel can be swiveled into the bearing pocket on the working face side for the purpose of assembly and can be swiveled out in the opposite direction for the purpose of disassembly. The locking of the planing chisel in the bearing pocket is effected by means of a filling piece which is inserted between the nose-like projection located in front in the cutting direction and the wall of the bearing pocket defining the undercut located in front in the cutting direction after the insertion of the planing chisel in the bearing pocket and after the nose-like projection at the rear in the cutting direction engages in the corresponding undercut. The filling piece and accordingly the planing chisel are secured in position subsequently by means of a VERIED TRANSLATION OF -2 clamping pin which is driven into coaxial bore holes of the filling piece and of the chisel projection located adjacent to the latter. A substantial disadvantage of the known chisel arrangement consists in the necessity of adapting the planing chisel to the bearing pocket very accurately with respect to contour in order to be able to limit, from the beginning, bearing clearance and accordingly wear and deformation stresses to a minimum. That is, since the wall portion defining the inserting opening of the bearing pocket at the end located in the rear in the cutting direction is loaded to an extremely great degree by means of the engagement of the planing chisel in the working face during operational use, a greater play can occur in this area between the planing chisel and the bearing pocket comparatively quickly, with the result that even small forces acting on the planing chisel subsequent to this can press the planing chisel out of the bearing pocket. Since the loss of a planing chisel is not always noticed immediately during the winning operation and since a replacement chisel is not always immediately installed even when it is determined that a planing chisel was lost, since the winning process must be interrupted for this purpose, the bearing pocket can fill with small coal very quickly and the latter can cake together in the bearing pocket subsequently. It is then compulsory to clean the bearing pocket in order to install a new planing chisel. However, this involves great difficulties chiefly in the lower vertical area, since the bearing pocket is accessible only from the working face side. As a rule, there is only a small space available for manipulation in this area between the working face and the side of the receptacle body facing the latter. The manual removal of caked on coal from the bearing pocket is therefore very cumbersome and, in addition, must be carried out in a -3 longwall area which offers the miner inadequate protection against rock or coal which may possibly cave in. The miner must also work under extremely poor lighting conditions in this area. The disassembly of a worn or damaged planing chisel involves considerable problems. When disassembling, it is first necessary to drive the clamping pin far enough into the centering projection of the planing chisel so that the filling piece can be removed. But this driving-in often fails because the clamping pin has been upset on the striking side during assembly. Even if successful, the clamping pin can only be driven into the centering projection by expending high forces. But these forces must be applied purely manually by the miner, wherein it must be taken into consideration that he must apply these forces - as already indicated above - under very cramped conditions in poor light and with increased risk of a cave-in of rock or coal. In particular cases, the clamping pin must even be drilled out. Even if the miner succeeds in driving the clamping pin out of the filling piece into the bore hole of the chisel projection, he must subsequently also remove the filling piece in addition and then drive the planing chisel out of the bearing pocket, which planing chisel is often very tightly secured. For this purpose, only one area of application is available which is formed by means of the opening of the undercut of the bearing pocket located in front in the cutting direction. This area of application is therefore very small and only allows the use of hand tools. Moreover, another disadvantage in the known chisel arrangement is that the filling pieces and the clamping pins are very small structural component parts which can be lost easily as a result and can accordingly form a permanent annoyance for the miner when exchanging the planing chisel.

-4 Finally, another disadvantage in the known case consists in that the clamping length of a planing chisel, which clamping length lies transversely relative to the cutting direction, is dimensioned so as to be short, particularly in comparison to the freely projecting length of the planing chisel when the latter engages above or below a rock inclusion located in the working face. The relatively long free lever arm of the planing chisel then leads to higher stresses, particularly in the area of contact of the planing chisel with the receptacle body in the wall area of the inserting opening located in the rear in the cutting direction. This fact also often contributes to the play between the planing chisel and the bearing pocket increasing in scope already after a comparatively short time by means of wear and deformation stresses, which can lead very quickly to a loss of the chisel. The invention is based on the task of improving the chisel arrangement described in the preamble of claim 1 in such a way that the assembly and disassembly of a chisel is facilitated on the one hand and its service life is increased on the other hand. According to the invention, the solution to this task consists in the features indicated in the characterizing part of claim 1. A significant advantage of the invention consists first in that the bearing pocket opens in a continuous manner in a sector which is directed in the cutting direction as well as toward the working face. A chisel to be newly inserted into a bearing pocket can accordingly first be inserted in the bearing pocket opposite the cutting direction. Only after this is it necessary to shift it in the direction of the timbering and walling so that the inserting end remote of the working face can be introduced into the end portion of the bearing pocket remote of the chisel cutting-edge and the shoulder can be introduced into the sector of the bearing -5 pocket which is open in the cutting direction. This inserting possibility involves a considerable facilitation of labor in practice. The miner need no longer carry out the assembly exclusively from the side of the working face. Another advantage is the fact that the chisel is now supported at the pocket base on the one hand and at the nose like projection on the other hand with a considerable longitudinal area of its rear surface. The specific surface area pressure during the engagement of the chisel in the working face is accordingly perceptibly reduced. Consequently, there is less frictional wear and the stresses directed to deformation are substantially reduced. The torque caused by means of the engagement of the chisel in the working face is absorbed in an unobjectionable manner by means of the secure position of the inserting end in the bearing pocket. The large supporting surface of the chisel at the base of the bearing pocket and at the projection also no longer leads to problems with relatively long, freely projecting chisels such as are necessary e.g. above and below rock inclusions. The surface pressures caused by the greater torque are then also absorbed in an unobjectionable manner and without deformations. The risk that the chisel can press out of the bearing pocket by means of wear and/or deformations already after a brief period of time is eliminated. The chisel is additionally secured in position in the receptacle body first in that the chisel engages in a positive-locking manner in the open sector of the bearing pocket by means of the shoulder which projects forward in the cutting direction. In addition, a defined working position for the chisel is accordingly ensured in the receptacle body which obtains its relative importance precisely in underground mine operations because of the special requirements there. In particular, the insertion of the clamping pin after the chisel assembly is considerably facilitated.

-6 The tangential position of the clamping pin relative to the chisel has the advantage that the clamping pin need no longer absorb any stresses which are brought about by means of the engagement of the chisel in the working face. Such stresses are transmitted exclusively by the chisel directly to the receptacle body over a large surface area. In addition, the receptacle trough for the clamping pin located on top can always be produced at a defined distance relative to the underside of the chisel. This means that after driving in the clamping pin, which is generally formed by a clamping sleeve, the clamping pin can exert an additional bracing effect for the chisel accompanied by support at the receptacle body, regardless of the manufacturing tolerances. This bracing effect contributes to the securing of the operating position of the chisel in the receptacle body even over a longer period of use and to the prevention of the development of play with a loose fit of the chisel, which is brought about by means of this. Also, this clamping pin can be constructed so as to be relatively long and stable, so that it can be easily handled by the miner. In addition, its position is also advantageous with respect to assembly and disassembly, since the opening of the recess, which extends partly in the chisel and partly in the receptacle body, is arranged approximately in the longitudinal direction of the longwall. Therefore, it can be reached easily, so that the miner need no longer work in the area between the working face and the receptacle body. The chisel does not undergo any hindrances during the loosening process, since the width of the nose-like projection is adapted to the thickness of the chisel. The inserting end of the chisel, according to the features of claim 2, is preferably a stable rectangular construction. The length can be dimensioned so as to be approximately equal to its width, since the chisel is first -7 inserted into the bearing pocket opposite the cutting direction and need no longer be swiveled in exclusively from the working face side as in the known case. In addition, the accessibility of the pocket end portion from the conveyor side can be improved by means of a corresponding construction of the planing body in order to facilitate the disassembly of the chisel. The features of claim 3 improve the chisel assembly as well as the working position of the chisel during winning. The features of claim 4 ensure an extensively unimpeded flow of the won mineral. Consequently, when applying the features of claim 5, the areas of the receptacle body located between two chisels located one above the other can also participate, at least to a limited extent, in the loosening process. The features of claim 6 produce their advantageous characteristics particularly in the disassembly of the clamping pin. Consequently, the latter need not be driven through a fit bore-hole along the entire width of the chisel and the receptacle body. The fit bore-hole extends substantially only along a portion of the chisel as well as along the wall portion of the receptacle body located in front in the cutting direction. When the features of claim 7 are used, allowances can also be made for greater tolerances between the chisel and the receptacle body. With the embodiment form corresponding to the features of claim 8, there is the advantage that even extremely tightly secured chisels can be loosened comparatively easily in that the miner applies a pick hammer to the chisel and can accordingly drive it out of the bearing pocket. Moreover, the miner has an optimal possibility for monitoring the correct inserting position of the chisel in the receptacle body, even -8 under the poor conditions of visibility in underground operations. The trapezoidal construction of the receptacle body according to the features of claim 9 is adapted to the given conditions of plowing and the transportation in the conveyor of the won material which is accordingly loosened. Thus, as a whole, a chisel arrangement has been provided in the framework of the invention which optimally takes into account to a particularly great extent the underground conditions in plowing mining on the one hand and the necessity of disassembling and installing chisels in the longwall on the other hand. The wear and deformation stresses of a chisel and the receptacle body holding the latter are reduced to a minimum as a result of large contact surfaces, and the assembly and disassembly of a chisel is considerably facilitated substantially in that necessary manipulations are shifted from the area between the working face and the receptacle body to the area in front of the receptacle body, specifically as seen in the cutting direction. Because of this, the risk to the miner when exchanging chisels is reduced to a considerable extent, since the time during which the miner must be active in the area of the working face in a relatively unprotected manner is considerably reduced. The invention is explained in more detail in the following by means of an embodiment example shown in the drawings. Figure 1 shows a view of the chisel arrangement of a coal plane or plow as seen opposite the cutting direction; and Figure 2 shows a horizontal section through Figure 1 along line II-II.

-9 In Fig. 1 the construction of a coal plane or plow, not otherwise illustrated in more detail, is designated by 1 and is positively guided at a conveyor for transporting coal in order to loosen the coal occurring in the working face 2, the conveyor being placed in the longitudinal direction of the longwall 3. A plurality of housing-like receptacle bodies 4 are fastened on above the other, particularly in a step-like manner, at the planing construction 1 corresponding to the respective geological conditions. The fastening is effected, as a rule, by means of welding. However, the receptacle bodies 4 can also be articulated at the planing construction 1 so as to be swivelable individually or by groups. The receptacle bodies 4 serve for the support of planing chisels 5 (see Figures 1 and 2) which are provided with hard metal cutting-edges 6 so as to increase their service life. The free length of the planing chisels 5 projecting forward toward the working face 2 relative to the receptacle bodies 4 varies as a function of the state of the working face 2, e.g. depending on whether or not there are strip-like rock inclusions in the working face 2. In this case, the planing chisels 5, arranged e.g. above and below such rock inclusions, are provided with a greater free length than those planing chisels located in the vertical area of the rock inclusions. As can be seen further in Figures 1 and 2, each planing chisel 5 is shaped in the manner of a plate. Its thickness D is dimensioned so as to be uniform. The planing chisel 5 has the approximate shape of a parallelogram as seen from the top, so that it has a free-cutting face 7 behind the hard-metal cutting-edge 6 and a surface 8 for diverting the won material into the conveyor in the cutting direction SR. The front side 8 (diverting surface 8) and rear surface 9 of the planing chisel 5 extend parallel to one another to a great extent (Figure 2).

-10 The inserting end 10 of the planing chisel 5 is adapted in a positive-locking manner to a bearing pocket 11 which is open in a continuous manner in the cutting direction SR as well as toward the working face 2. The end portion 12 of the bearing pocket 11 remote of the chisel cutting-edge 6 is constructed so as to be open on the side 13 of the receptacle body 4 remote of the working face 2. Otherwise, the bearing pocket 11 extends so as to be extensively parallel to the front side 14 of the receptacle body 4 extending at an angle relative to the cutting direction SR. The rear surface 9 of the planing chisel 5 is supported at the base 15 of the bearing pocket 11, as well as at a nose like projection 16 provided in a lengthening of the base 15 of the bearing pocket 11, with a width adapted to the thickness D of the chisel 5. A large contact surface is accordingly formed between the planing chisel 5 and the receptacle body 4. The torque brought about by means of the engagement of the planing chisel 5 in the working face 2 is likewise absorbed over a large surface area by means of the engagement of the inserting end 10 in the bearing pocket 11. The rear surface 17 of the nose-like projection 16 located in the rear in the cutting direction SR extends approximately parallel to the front side 14 of the receptacle body 4. As can be seen in particular from Figure 2, the front side 8 of the planing chisel 5 projects forward relative to the front side 14 of the receptacle body 4. Accordingly, a force P can easily be applied to the shoulder 18 of the planing chisel 5 for loosening the planing chisel 5, e.g. by means of a pick hammer. The wall portions 20 of the receptacle body 4 laterally defining the area 19 of the bearing pocket 11, which is open in the cutting direction SR, come to a point in the manner of a chisel and are constructed so as to be resistant to wear, at least with respect to the edges 28.

-11 A clamping sleeve 21 serves to secure the planing chisel 5 in position in the receptacle body 4 and is formed out in a bore hole 22 in the plane of the upper expansion joint 23 between a planing chisel 5 and the receptacle body 4, which bore hole 22 is formed out partly in the planing chisel 5, partly in the receptacle body 4 and partly in the projection 16. The longitudinal axis 24 of the bore hole 22 extends vertically relative to the front side 14 of the receptacle body 4. The bore hole 22 is enlarged in diameter in a step like manner proceeding from the front side 14, so that the clamping sleeve 21 need only be driven into the longitudinal portion 25 of the bore hole 22 having the greater diameter in order to disengage the planing chisel 5. However, the clamping sleeve 21 is also accessible from the rear side 26 of the substantially trapezoidal receptacle body 4 and the nose like projection 16. Figure 1 also shows, at the lower chisel 5, that the portion 27 of the recess 22 formed out in the chisel 5 can also be constructed in the shape of a trough, wherein the width B is dimensioned so as to be greater than the diameter of the clamping pin 21.

Claims (9)

1. Chisel arrangement for a plowing mining device in underground mining comprising a plate-like chisel with a hard metal cutting edge, wherein the chisel can be inserted into a bearing pocket of a receptacle body transversely relative to the cutting direction of the mining device, can be centered with an inserting end in an end portion of the bearing pocket remote of the chisel cutting-edge and can be fastened by means of a clamping pin in the receptacle body, characterized in that the chisel (5) is supported at the receptacle body (4), with its rear surface (9) remote of the cutting direction (SR), at the base (15) of the bearing pocket (11), which opens in a continuous manner in the cutting direction (SR) and toward the working face (2), as well as at a nose-like projection (16) provided in a lengthening of the base (15) of the bearing pocket (11) with a width adapted to the thickness (D) of the chisel (5), and the clamping pin (21) transversely penetrates the upper expansion joint (23) between the chisel (5) and the bearing pocket (11) approximately in the center of the supporting area of the rear surface (9) of the chisel (5) with the pocket base (15) and with the projection (16), respectively, wherein the chisel (5) engages in a positive locking manner in the area (19) of the bearing pocket (11) which is open in the cutting direction (SR) with a shoulder (18) projecting forward relative to the inserting end (10).

2. Chisel arrangement according to claim 1, characterized in that the pocket end portion (12) filled by the inserting end (10) of the chisel (5) is constructed so as to be open on the side (13) of the receptacle body (4) remote of the working face (2), -13

3. Chisel arrangement according to at least one of claims 1 or 2, characterized in that the bearing pocket (11) extends extensively parallel to the front side (14) of the receptacle body (4) extending at an angle relative to the cutting direction (SR).

4. Chisel arrangement according to claim 1, characterized in that the rear surface (17) of the nose-like projection (16) located in the rear in the cutting direction (SR) extends approximately parallel to the front side (14) of the receptacle body (4).

5. Chisel arrangement according to at least one of claims 1 to 4, characterized in that the wall portions (20) of the receptacle body (4) laterally defining the area (19) of the bearing pocket (11) which is open in the cutting direction (SR) come to a point in a chisel-like manner and are constructed so as to be resistant to wear.

6. Chisel arrangement according to claim 1, characterized in that the bore hole (22) for the clamping pin (21), which bore hole (22) is formed out partly in the chisel (5), partly in the receptacle body (4) and partly in the nose-like projection (16), is constructed so as to have a larger diameter in its rear longitudinal portion (25) remote of the cutting direction (SR), at least in the receptacle body (4) or in the nose-like projection (16).

7. Chisel arrangement according to claim 1, characterized in that the portion (27) of the recess (22) for the clamping pin (21), which portion is formed out in the chisel (5), is shaped in the manner of a trough, whose width (B) is dimensioned so as to be greater than the diameter of the clamping pin (21). -14

8. Chisel arrangement according to claim 1, characterized in that the shoulder (18) of the chisel (5) projects forward in the cutting direction (SR) relative to the front side (14) of the receptacle body (4).

9. Chisel arrangement according to at least one of claims 1 to 8, characterized in that the receptacle body (4) is constructed in a trapezoidal manner.