Patent Publication Number: US-2015084396-A1

Title: Mining plow

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a National Stage of International Patent Application No. PCT/EP2013/000804, filed Mar. 15, 2013, which claims priority to foreign German Patent Application No. 20 2012 101 169.7, filed Mar. 30, 2012, the contents of which are incorporated herein by reference in their entirety. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates to a mining plow, in particular a coal mining plow, having a plow base which is guidable on a reversible conveyor. 
     BACKGROUND 
     Coal mining plows with extraction cutting bits fastened to pivotable cutting bit carriers, which are connected in a direction-independent manner via a connecting rod or a catch that is connected to the plow chain for the mining plow, are known, for example, from DE 201 18 259 U1 or DE 196 37 789 A1. In order to be able to excavate different thicknesses (seam heights) with the same plow, the height of the mining plow can be adjusted to the actual desired working height, in which the height of the mining plow is increased using attachment members. In DE 196 37 789 A1, the height increase is achieved using an attachment member, which is supported via a supporting portal on the goaf side on a guide rail provided on the conveyor for this purpose, whereby even with mining plows having an especially high structure, and optionally provided with a plurality of set-on attachment members, a reliable stabilization of the plow can be achieved with effective removal of the forces on the plow guide. 
     In underground mining, there is an increasing need for mining plows, in particular coal mining plows, with which even small seam thicknesses (heights) can be mined as variably as possible and with short re-tooling times. Furthermore, DE 20 2010 000 457 U1 discloses a mining plow, which includes an attachment member and ancillary cutting bit columns that are disposable on the attachment member. 
     SUMMARY OF THE DISCLOSURE 
     According to an aspect of the present disclosure, a mining plow, in particular a coal mining plow, may comprise a plow base constructed to be guided on a reversible conveyor and having a pivot pin on an inclined supporting surface for pivotably supporting a cutting bit carrier in each direction of plow travel, two cutting bit carriers pivotably supported on a respective pivot pin, including extraction cutting bits, and being pivotable in a travel-direction-dependent manner, a roof cutting bit carrier attached to the plow base in a height-adjustable manner, and including roof cutting bit columns. The roof cutting bit carrier may be removably anchorable at different heights to an attachment surface formed between the inclined supporting surfaces. The disclosed mining plow may further comprise an attachment member settable on the plow base and elongating the attachment surface for the roof cutting bit carrier to increase the working height of the mining plow. The attachment member may include ancillary cutting bit columns provided with extraction cutting bits and attached to the attachment member. Each ancillary cutting bit column may be respectively positioned in its extraction position for a plow trip above a cutting bit carrier, and an intermediate member may be disposed between the attachment member and each ancillary cutting bit column. The intermediate member may be foldable attached to the attachment member and may be folded away into an installation position, in which the corresponding cutting bit carrier may be removable while the attachment member and the intermediate part remain installed. 
     Other features and aspects of this disclosure will be apparent from the following description and the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a view of the front side of a mining plow according the present teachings, the front side facing towards the mining face during operation. 
         FIG. 2  shows a plan view of the mining plow according to  FIG. 1 , in which a left-side ancillary cutting bit column is detached and an intermediate part is folded upward. 
         FIG. 3  shows a cross-sectional view of the mining plow of  FIG. 1  along in III-III in  FIG. 1 . 
         FIG. 4  shows a plan view of an attachment member for the mining plow according to the present disclosure. 
         FIG. 5  shows a side view of the attachment member of  FIG. 4 . 
         FIG. 6  shows a perspective view of the front side of the attachment member of  FIG. 4 . 
         FIG. 7  shows a perspective plan view of the attachment member of  FIG. 4 , in which a left-side ancillary cutting bit column is detached and an intermediate part is folded upward. 
         FIG. 8  shows a perspective view of the rear side of the attachment member of  FIG. 7 . 
     
    
    
     DETAILED DESCRIPTION 
     The following is a detailed description of exemplary embodiments of the present disclosure. The exemplary embodiments described therein and illustrated in the drawings are intended to teach the principles of the present disclosure, enabling those of ordinary skill in the art to implement and use the present disclosure in many different environments and for many different applications. Therefore, the exemplary embodiments are not intended to be, and should not be considered as, a limiting description of the scope of patent protection. Rather, the scope of patent protection shall be defined by the appended claims. 
     The present disclosure may be based in part on the realization that providing a mining plow having a plow base with the lowest possible design may offer a high variability for the mining of different seam thicknesses of the to-be-excavated mineral layer, in particular coal, may be easy to assemble and may have an improved mining behavior even in the face end region as well as the longwall tunnel itself when confined spaces are present due to the work situation or a narrow roadway. 
     The present disclosure may be further based in part on the realization that the extraction cutting bits of the disclosed mining plow may lie on the ancillary cutting bit column above or in extension of the line of the extraction cutting bits of the associated cutting bit carrier, such that by adding the ancillary cutting bit columns, which are disposed substantially farther forward in the direction of travel, may improve mining behavior, in particular in the face end region as well as in the longwall tunnel. Thus, an upper bank or a concrete pack, with which a tunnel support structure may be optionally backfilled, can be removed in the tunnel. 
     A mining plow according to the present disclosure is indicated overall with reference number  1  in  FIGS. 1 to 3 . The mining plow  1  can be moved using a plow chain  2  (only shown in part) along plow guides (not shown) during underground mining operations. The plow guides are part of a conveyor apparatus, which is laid along the mining face over lengths of generally 200 m to 400 m for extracting minerals such as, for instance, coal, and may be automatically advanced forwarding the direction of the mining face using suitable advancing devices as the mining progresses. 
     In  FIG. 3  a guide shoe  5  and a guide recess  6  on the rear side of a base  4  of the mining plow  1  can be seen, with which the mining plow  1  is guided on guide bars, which are part of the plow guide. The plow chain  2  is connected to a pull-sled serving as a catch, which is disposed in a recess on the underside of the plow base  4  and moves the mining plow  1  in the pulling direction of the plow chain  2  along the plow guide, as is known from the prior art. 
     The mining plow  1  is provided with a cutting bit carrier  7  for both plow travel directions, which are indicated with F and F′, respectively, in  FIG. 1 . The cutting bit carrier  7  is pivotably supported on the plow base  4  about a pivot pin  8  that is visible in  FIGS. 2 and 3 , and rests with its weight on an oblique supporting surface  9  of the plow base  4 . As can be easily seen in  FIG. 1 , both cutting bit carriers  7  are provided with a row of extraction cutting bits  11  disposed one above another. The extraction cutting bits  11  extend over the entire height of the plow base  4  and over the height of the material to be mined by the mining plow  1  with the cutting bit carrier  7 , which means the material that lies forward of the mining plow  1  in the direction of travel F or F′. 
     Through the pivotability of the two cutting bit carriers  7 , which are here rigidly coupled by a connecting rod  62  between the two cutting bit carriers  7 , it may be achieved that the cutting bit carrier  7  disposed forward in the direction of travel rearwardly displaces the cutting bit carrier  7  disposed rearward in the direction of travel. Therefore, the extraction cutting bits  11  disposed rearward in the direction of travel may not contact the coal mining face. Moreover, when the plow travel direction F is reversed to the reverse direction F′, extraction work is now performed by the extraction cutting bits  11  on the other cutting bit carrier  7 . That is, the other cutting bit carrier is caused to pivot by the extraction forces opposite of the direction of travel and accordingly shifts back the cutting bit carrier  7  that is now disposed rearward in the direction of travel, as is also known to the person of skill in the art. 
     The mining plow  1  is further provided in a conventional manner with a roof cutting bit carrier  12  having two roof cutting bit columns  13  equipped with extraction cutting bits  14 . The roof cutting bit carrier  12  is fastened to the plow base  4  in a height-adjustable manner, and can be displaced along groove guides  15  in the height direction which means vertically, in order to be anchored at different height positions. 
     The mining plow  1  is further provided in a known manner with an attachment member  20 , with which the height, and thus the extraction height, of the mining plow  1  can be increased. An ancillary cutting bit column  21 , which is equipped with additional extraction cutting bits  22 , is disposed on the attachment member  20  for each direction of travel, in order to additionally excavate minerals or rock on the coal mining face along the height of the attachment member  20 . 
     Groove guides  26  (see  FIGS. 5 to 7 ) are disposed in the center of the attachment member  20  on its front surface. The groove guides  26  extend the groove guides  15  on the plow base  4 , in order to be able to move the roof cutting bit carrier  12  upwards in such a manner that material can be excavated in the roof area by the roof cutting bit carrier  12  also when the attachment member  20  is attached. Both the roof cutting bit columns  13  and the ancillary cutting bit columns  21  are pivotable, so that only the roof cutting bit column  13  and ancillary cutting bit column  21  disposed forward in the travel direction F or F′ perform extraction work. 
     In the mining plow  1  according to the present disclosure, both ancillary cutting bit columns  21  are positioned on the mining plow  1  in such a way that the extraction cutting bits  22  of the ancillary cutting bit columns  21  are located above the respective cutting bit carriers  7  and in an arc-like extension of the extraction cutting bits  11 . A correspondingly far-forwardmost positioning of the ancillary cutting bit column  21  in the direction of travel is achieved in the mining plow  1  by arranging an intermediate part  30  between the attachment member  20  and each ancillary cutting bit column  21 . 
     As shown in  FIG. 2 , the left-side intermediate part  30  has been folded away into an installation position, whereas the right-side intermediate part  30  is shown in the extraction position (or operational position) for the right-side ancillary cutting bit column  21 . In the installation position, neither the intermediate part  30  nor an optional ancillary cutting bit column  21  fastened to the intermediate part  30  is disposed over the underlying cutting bit carrier  7  in such a way that accessibility of the pivot pin  8  would be hindered and/or the cutting bit carrier  7  could not be removed and lifted off of the pivot pin  8 . 
     Therefore, in order to uninstall (remove) the cutting bit holder  7 , it is sufficient in the present mining plow  1  to release a lock holding the respective intermediate part  30 , and fold it back into the installation position as shown at the left of  FIG. 2 . Optionally, the associated ancillary cutting bit column  21  may be removed before the intermediate part  30  is folded back. The attachment member  20 , which is usually very heavy, can remain on the plow base  4  during installation/removal of the cutting bit carrier  7 . 
     Certain aspects of the structure of the attachment member  20 , the intermediate part  30  and the ancillary cutting bit columns  21  will now be explained in further detail with reference to  FIGS. 4 to 8 . 
     As shown in  FIG. 5 , the underside of the attachment  20  may be attachment member  20  to the plow base  4 . The latch pins  23  sit in corresponding latch recesses (not shown) on the plow base  4 , and thus fix the attachment member  20  to the plow base  4  in an interference-fit manner and parallel to the direction of travel. 
     In order to prevent vertical movement between the attachment member  20  and the plow base  4 , wedge-jaws  24  are provided and can be moved relative to each other using turnbuckles  25  (see  FIG. 6 ) in such a way that the jaws of the wedge-jaws  24  extend beyond the attachment member  20  and grasp the plow base  4 , thereby clamping the attachment member  20  onto the plow base  4 . The wedge-jaws  24  are disposed on either side of the groove guides  26 , which are removably anchored to the attachment member  20 , for example, screw-fastened in this embodiment. 
     As shown in  FIG. 6 , a fork receptacle  29  is disposed on each end of the attachment member  20  and is open towards the front side. Spaced-apart bolt receptacles  27  define a gap for receiving a bolt eye  31  of the intermediate part  30 . The bolt receptacles  27  and the bolt eye  31  are connected using a pivot bolt  45 . The pivot axis of the pivot bolt  45  extends parallel to the groove guides  26  and connects the bolt receptacles  27  and the bolt eye  31 , and thus the intermediate part  30  and the attachment member  20 , to one another. The bolt receptacles  27  and the bolt eye  31  are designed to be suitably strong, so that the entire weight of the intermediate part  30  and the connected additional column  21  can be retained in a pivotable manner. 
     As shown in  FIG. 7 , the intermediate part  30  has a middle part  32  that is integrally connected with the bolt eye  31 . A strong pressure plate  33  is formed on the rear side of the middle part  32 , as can be seen on the left side in  FIG. 7 . In the extraction (mining or operational) position, as shown in the right-side intermediate part  30  in  FIG. 7 , a beveled rear end face  34  abuts in an form-fit manner on an abutment surface  28  of the attachment member  20 . The abutment surface  28  also extends obliquely to the direction of travel, in order to direct all of the forces arising on the ancillary cutting bit columns  21  during the extraction movement to the attachment member  20  via the pressure plate  33 . 
     As shown on the left side of  FIG. 7 , the middle part  32  is further provided with pin receptacles  35  opposite the bolt eye  31 . As shown on the right side of  FIG. 7 , a supporting body  41  of the ancillary cutting bit column  21  is insertable into the pin receptacles  35 , preferably only in a certain relative position between the ancillary cutting bit column  21  and the intermediate part  30 . The supporting body  41  of the ancillary cutting bit column  21  can or must then be pivoted into a position, relative to the intermediate part  30 , in which the supporting body  41  of the ancillary support column  21  is fixedly held between an arm pair  36  on the intermediate part  30 . The arm pair  36  lies opposite the pin receptacles  35  at a short distance. The ancillary support column  21  is consequently supported in the extraction (mining or operational) position on the intermediate part  30  on the one hand via the pin receptacles  35  and on the other hand between the arm pair  36 . 
     The ancillary cutting bit column  21  can be installed or uninstalled only in a certain pivot position, however not in the extraction (mining or operational) position, which is shown on the right side of  FIG. 7 . The pivot pin connection between the ancillary cutting bit column  21  and the intermediate part  30  can be effected using pin stumps which are integrally formed on the supporting body  41  of the ancillary cutting bit column  21 . 
     As shown in  FIG. 8 , the intermediate part  30  is further provided with a supporting projection  37  directly adjacent to the bolt eye  31 . The supporting projection  37  is cantilevered laterally beyond the bolt eye  31 . In the extraction (mining or operation) position the supporting projection  37  abuts on an abutment surface located in a step-shaped recess  42  defined on the rear side of the attachment member  20 . Receiving bores  38  and  43  are respectively formed in the supporting projection  37  and on the bottom of the step-shaped recess  42 . Locking screws  44  can be screwed into the bores  38 ,  43  in order to secure the intermediate part  30  and prevent unintentional pivoting-back in the extraction position. Because the forces arising in mining operation press the end face  34  of pressure plate  33  against the abutment surface  28 , the locking screws  44  need not receive any transverse forces. 
     In order to be able to easily reach the locking screws  44 , the pressure plate  33  is provided with a recess  39 . The pivot axis formed by the pin projections and pin receptacles  35  and the pivot axis formed by the pivot bolts  45  lie parallel to one another and parallel to the groove guides  26 . 
     As shown in  FIG. 6 , the front side of the supporting body  41  of the ancillary cutting bit columns  21  and the intermediate part  30  are each provided with hook projections  48 ,  49 , which lie opposite one another in the mining position and are surrounded by a chain link, which permits a limited pivoting of the supporting body  41  of the ancillary cutting bit columns  21  relative to the intermediate part  30 , which is fastened on the attachment member  20  so as to prevent movement, and is secured against falling out using a cotter pin or the like. 
     INDUSTRIAL APPLICABILITY 
     The roof cutting bit carrier may be fastened to the base in different ways. Under certain circumstances, the roof cutting bit carrier may also allow itself to be moved into a position in which the ancillary cutting bit columns may remain on the intermediate parts, if these are pivoted out for an installation/removal of the cutting bit carrier. The same could also be achieved through a different design of the supporting body for the ancillary cutting bit columns. 
     In some embodiments, instead of pin projections, pivot bolts may also be used, which could be secured in various ways. Different mining lines between the extraction cutting bits on the cutting bit carriers and the extraction cutting bits on the ancillary cutting bit carriers could be achieved through the choice of different intermediate parts. 
     If one of the cutting bit carriers which may be pivotably mounted on the base body may be replaced, the attachment member can remain on the base body, despite the ancillary cutting bit column still being positioned in a cantilevered forward manner, and it is only required to fold or pivot the intermediate part back into an installation position, optionally after removing the ancillary cutting bit column and releasing the associated locking means. In the installation position it may be possible to lift off the cutting bit carrier from the base body without the intermediate part disturbing the installation or removal of the cutting bit carrier. 
     For extraction work using the mining plow, it may be advantageous if the ancillary cutting bit columns may be fastened to the intermediate part so as to be partially-pivotable about an axis, so that when the plow may travel in the reverse direction they may swing into a position in which they may have no contact with the face. In some embodiments, the ancillary cutting bit columns may be pivotably fastened to the intermediate part about pin stubs, which may be integrally formed on the ancillary cutting bit column and which may be only insertable into edge-open pin receptacles when the ancillary cutting bit column is located at a defined pivot position relative to the intermediate part. By pivoting the ancillary cutting bit column to the extraction position, it can then be achieved that all forces may be absorbed in an interference-fit manner between the intermediate part and the ancillary cutting bit column. 
     In order to prevent a moving away from this position with a limited degree of freedom, in some embodiments the ancillary cutting bit column and the intermediate part may be provided with hook projections, which may lie opposite one another in the extraction position. In particular with corresponding hook projections, but also with other designs, the ancillary cutting bit columns may in each case be locked against pivoting back into the pivot position for uninstalling using a chain-link-like securing element on the associated intermediate part, wherein the eyelet length of the chain link may determine the degree of freedom of pivoting. 
     The attachment member may be provided with latch pins on its underside, which in the installation state may sit in latch recesses on the plow base, and/or the attachment member may be clampable or clamped onto the plow base using wedge-jaws that may be movable using turnbuckles. 
     In some embodiments, the intermediate part and the ancillary cutting bit column may be movable about mutually parallel axes. 
     Further, the fastening surface on the plow base may be laterally bounded by groove guides, and the attachment member may be provided with groove guides on its front surface, wherein the ancillary cutting bit columns may be disposed on both sides of the groove guides. The axes may then preferably extend parallel to the grooves on the fastening surface for the roof cutting bit carrier. 
     In some embodiments, since significant forces act on the ancillary cutting bit columns and the intermediate part during extraction travel (movement), the rear side of the intermediate part may be provided with a pressure plate, which may abut on the attachment member when the ancillary cutting bit column may be in the extraction position. In some embodiments, in view of force dissipation, it may be preferable that an end face of the pressure plate may abut on an abutment surface on the attachment member in the extraction position in the direction of travel. For this purpose the end face and the abutment surface may extend obliquely to the direction of travel, in order to achieve as large as possible a contact surface between the parts with a small width of the pressure plate. 
     In some embodiments, in order to be able to install locking means even when subjected to confined space conditions, the pressure plate may be provided with an opening. Receiving bores for locking screws may be respectively provided in the attachment member and in the intermediate part, with which the attachment member may be fixable to prevent folding back when disposed in the extraction position. In some embodiments, the receiving bores may be formed in the intermediate part in the region of the opening. 
     The height adjustment and support of the roof cutting bit carrier could also be effected in a way other than via groove guides. 
     Although the preferred embodiments of this invention have been described herein, improvements and modifications may be incorporated without departing from the scope of the following claims.