Patent Application
20190353035
This invention is related to mining, and more particularly to an apparatus and method for protecting one or more persons from falling rock and debris during longwall mining.
During longwall mining, a drum of a longwall shear advances along a wall of coal, shearing off a layer of coal for collection. Mine roof supports, such as shield canopies of mine roof support systems, contact the mine roof during the shearing operation to prevent roof collapse. The shield canopies may not be positioned over the drum to avoid interference, but may instead be positioned just behind the drum. Therefore, the portion of the mine roof directly above the drum may be exposed. As the shear operation advances the mine face, some shield canopies have extensions that can rotate up from, or extend from within, those shield canopies to correspondingly extend the roof supports so they continue to be positioned just behind the drum.
Periodically, a technician services the longwall shear, such as by changing the cutting bits on the drum. Though the exposed mine roof area directly above the drum may not be in danger of collapse, a danger of falling rock or debris still exists.
However, extending a roof support extension directly over the drum to protect the technician when he or she is positioned at the drum has drawbacks. For example, a hinged, rotatable extension on a shield canopy may swing into place via hydraulic cylinders mounted to the underside of that extension. Absent a significant clearance, the rotating of that extension may interfere with the drum. Further, the cylinders may interfere with the drum as they increase the thickness of the extension machinery below the shield canopy. Similarly, an extension that extends from within a shield canopy causes the shield canopy to be thicker, as the shield canopy has layers on either side of the extension. Such a configuration also leaves less space for the drum underneath. Roof support extensions such as those above may assume too much space to protect against falling rock and debris when used in, for example, thin coal seams, such as those in the eastern United States, or in other mining operations with space constraints.
There may therefore be a need for an extension on a shield canopy that by configuration and movement lessens the chance of interference with the drum when extended overhead of the drum, such as when used on thin coal seams or in other mining operations where space is limited. There may also be a need for an extension on a shield canopy to protect a technician from falling debris or rock when the technician is servicing a longwall shear, but which may not contact a mine roof as support against collapse.
The accompanying drawings, wherein like reference numerals are employed to designate like components, are included to provide a further understanding of apparatuses and methods for protecting a person servicing a longwall shear, are incorporated in and constitute a part of this specification, and show embodiments of those apparatuses and methods that together with the description serve to explain those apparatuses and methods.
Various other objects, features and advantages of the invention will be readily apparent according to the following description exemplified by the drawings, which are shown by way of example only, wherein:
In an embodiment, an apparatus for protecting a person servicing a longwall shear includes: a base plate to be secured to an underside of a shield canopy, the base plate comprising an underside and two sides, each of the two sides comprising a plurality of guides; and a slide plate to be movably secured to the underside of the base plate, the slide plate including a front end and a back end, the slide plate slidable along the plurality of guides of the base plate between positions out from, and back under, the underside of the shield canopy.
In another embodiment, a method of protecting a person servicing a longwall shear includes: sliding a slide plate out from under an underside of a shield canopy toward a face of coal such that the slide plate positions over shearing equipment without contacting a roof adjacent to the face of coal; holding the slide plate over the shearing equipment while maintenance is performed on the shearing equipment; and sliding the slide plate back under the underside of the shield canopy after the maintenance on the shearing equipment has been performed.
Other embodiments, which may include one or more parts of the aforementioned apparatus and method or other parts, are also contemplated, and may thus have a broader or different scope than the aforementioned apparatus and method. Thus, the embodiments in this Summary of the Invention are mere examples, and are not intended to limit or define the scope of the invention or claims.
Reference will now be made to embodiments of apparatuses and methods for protecting a person servicing a longwall shear, examples of which are shown in the accompanying drawings. Details, features, and advantages of apparatuses and methods for protecting a person servicing a longwall shear will become further apparent in the following detailed description of embodiments thereof.
Any reference in the specification to “one embodiment,” “a certain embodiment,” or a similar reference to an embodiment is intended to indicate that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of such terms in various places in the specification do not necessarily all refer to the same embodiment. References to “or” are furthermore intended as inclusive, so “or” may indicate one or another of the ored terms or more than one ored term.
In the embodiments shown in
Referring to
In an embodiment, the guides 22 and 32 of the base plate 10 may be L-shaped members whose bottom part of the “L” extends at least partially around the slide plate 100 to the underside 102 of the slide plate. Those L-shaped members may be slender relative to the length of the sides 120 and 130 of the slide plate 100. Those L-shaped members may be relatively slender because they are supporting a slide plate 100 that is for rock and debris deflection, and may not contact the mine roof 300 to provide roof support. In other embodiments, the guides 22 and 32 may be otherwise shaped to extend at least partially around and to the underside 102 of the slide plate 100.
The base plate 10 may be secured to the shield canopy 200 with a plurality of connectors of the base plate 10 that each extend into a different one of a plurality of holes 210 and 222 of the shield canopy 220. Holes 210 and 222 are shown in
In an embodiment, the plurality of connectors of the base plate 10 include a plurality of hooks 40, such as four hooks 40 (two hooks 40 can be seen in
The slide plate 100 may include a front end 110, a back end 112, and two sides 120 and 130. As introduced above, the slide plate 100 may slide along the guides 22 and 32 of the base plate 10. For example, the slide plate 100 may slide its underside 102, by way of the actuator 150 described herein, along the guides 22 and 32 of the base plate 10. The slide plate 100 may slide out from under the underside 202 of the shield canopy 200 toward a face of coal 302, and slide back under the underside 202 of the shield canopy 200,
The slide plate 100 may have a void 140 defined by its periphery 142. The void 140 may be cut into the back end 112 of the slide plate 100. An actuator 150, which may include one or more devices for moving the slide plate 100, may be secured to the slide plate 100. In an embodiment, the actuator 150 is one hydraulic cylinder. The hydraulic cylinder may have fittings for connecting hoses and a check valve mounted to its ring (retract port). The hydraulic cylinder may be operated with a 2-function control valve that has a restrictor, such as a one mm restrictor, to slow the movement of the slide plate 100 during operation of the apparatus 1. The hydraulic cylinder may have a 25″ stroke. The hydraulic cylinder may have other specifications as desired.
The actuator 150 may be activated to slide the slide plate 100, as described herein, out from, and back under, the underside 12 of the base plate 10, and thus out from, and back under, the underside 202 of the shield canopy 200. The actuator 150, in an embodiment, may be secured to the slide plate 100 adjacent to, such as at or near, the periphery 142 of the void 140. As so secured or otherwise secured, the actuator 150 may be disposed at least partially within the void 140. In that position at least partially within the void 140, the actuator 150 may assume less space below the underside 102 of the slide plate 100 than if the actuator 150 were disposed under a solid portion of the underside 102 of the slide plate 100. Such a configuration provides more space underneath for a longwall shear (not shown) or part thereof, such as a drum (not shown). Such extra space may allow the slide plate 100, without interference, to slide overhead of the longwall shear drum in mining operations where space is limited, such as for thin coal seams in the eastern United States. A technician may then service the drum while being shielded by the slide plate 100 from falling rock or other debris from the mine roof 300.
In an embodiment, the hydraulic cylinder or other actuator 150 may further be secured to the base plate 10. In this configuration, the actuator 150 may not only be disposed partially within the void 140 of the slide plate 100, but may run at a small angle or parallel to the underside 102 of the slide plate 100. That positioning may limit space the actuator 150 takes under the underside of the 102 of the slide plate 100, providing extra space underneath for mining operations where space is limited, such as described herein.
In an embodiment, and as discussed herein, the slide plate 100 may not be for mine roof 300 support, but merely to protect a technician or other person from falling rock or other debris. For example, a drum of a longwall shear (not shown) may not be covered by the shield canopy 200, and thus may be exposed to the mine roof 300. Periodically, the bits on the drum are replaced or otherwise serviced. Though there may not be a danger of mine roof 300 collapse above the drum in certain mining operations, there may be a danger of falling rock or debris. Thus, a slide plate 100 that can extend to provide cover against the falling rock or other debris, but does not contact the mine roof 300, may not need to be as sturdy as a shield canopy extension that contacts a mine roof to provide support against collapse.
Embodiments of the apparatus 1 described herein may be space-efficient. For example, embodiments of the apparatus 1 do not pivot into position and thus do not swing down when moving into operational position, and so do not require significant clearance between the drum and other longwall shear equipment. Also, embodiments of the apparatus 1 do not swing or otherwise move up to contact the mine roof 300 as the apparatus 1 is not for supporting the mine roof 300, again limiting the vertical space the apparatus 1 assumes. Additionally, the base plate 10 and slide plate 100 of the apparatus 1 may not be thick for providing mine roof 300 support and are not positioned within a shield canopy. Rather, the base plate 10 and slide plate 100 may be exposed on the underside 202 of the shield canopy 200 without another shield canopy 200 layer underneath the slide plate 100, providing more space-efficiency.
The void 140 of the slide plate 100 also lessens the space and weight of the apparatus 1. In an embodiment, the void 140 of the slide plate 100 may extend, in a direction toward the front end 110 of the slide plate 100, at least halfway to the front end 110. The void 140 may be sized as such to further limit space and weight of the slide plate 100 and apparatus 1 while still allowing the slide plate 100 to sufficiently function to catch falling rock and debris from the mine roof 300.
In an embodiment, the void 140 of the slide plate 100 narrows as it extends from the back end 112 towards the front end 110 of the slide plate 100. In an embodiment, the void 140 may be shaped, at least in part, as a triangle. This configuration may limit space while remaining sufficiently sturdy to withstand falling rock and other debris when the slide plate 100 is in the extended position of
In an embodiment, the slide plate 100 includes a framework 160. The framework 160 may be a network of reinforcing supports for the slide plate 100. The framework 160 may be disposed on the underside 102 of the slide plate 100. The framework 160 may strengthen the slide plate 100 with limited material to limit the weight increase of the slide plate 100. Limiting the slide plate 100 weight provides for energy and cost efficiency, allowing for a more easily moveable slide plate 100. A limited weight slide plate 100 may, for example in an embodiment, be moveable with an actuator 150 that is a single hydraulic cylinder as opposed to multiple hydraulic cylinders. Use of one hydraulic cylinder as opposed to multiple ones also limits the space apparatus 1 assumes.
In an embodiment in which the framework 160 is included, the two sides 120 and 130 of the slide plate 100 may each include a track 122 and 132, respectively. The tracks 122 and 132 may be formed by portions of the underside 102 of the slide plate 100 adjacent to its sides 120 and 130 plus the part of the framework 160 that runs adjacent to and along the sides 120 and 130. The guides 22 and 32 of the base plate 10, in this embodiment, may extend around and to the underside 102 of the slide plate 100 such that guides 22 and 32 slide along the tracks 122 and 132, respectively.
As described above, the shield canopy 200 may be a part of the apparatus 1 for protecting a person servicing a longwall shear during a longwall mining operation, or may not be part of the apparatus 1. The shield canopy 200 may be made of steel, stainless steel, aluminum or another desired material.
At 404, the slide plate 100 is held over the shearing equipment while a technician or other person performs maintenance on the shearing equipment.
For example, at 304 a technician may move to and then change the cutting bits on a drum in which the slide plate 100 has been advanced out from under the shield canopy and over the drum. The slide plate 100 may deflect rock or other debris that falls overhead from the mine roof 300, thus protecting the technician's hands, for example, from being hit with the debris.
At 406, after the technician has performed the maintenance on the drum or other shearing equipment, such as replacing bits on the drum, the technician moves away from the drum and then the slide plate 100 is slid back under the underside 202 of the shield canopy 200. As described above, in an embodiment, that retraction may be by way of the actuator 150 sliding the slide plate 100 by its underside 102 over the guides 22 and 32, respectively, of the base plate 10.
In one embodiment of the method 400 at 402 and 406, having the slide plate 100 move along the underside 202 of the shield canopy 200 as opposed to, for example, moving between layers of a shield canopy with one layer underneath a roof support extension, may be space-efficient. The slide plate 100 may be considered herein to move along the underside 202 of the shield canopy 200 as it is positioned under the underside 202, notwithstanding that the slide plate 100 may be directly attached to the base plate 10 and thus the slide plate 100 may or may not directly contact the underside 202. Thus, the slide plate 100 may, at 402 and 406, respectively slide out from and slide back under the underside 202 of the shield canopy 200 by so sliding along the base plate 10 that is secured, such as described above, to the underside 202 of the shield canopy 200.
In an embodiment in which the slide plate 100 includes the framework 160, the framework 160 may form tracks 122 and 132 as described herein. In this embodiment, in the method 400 at 402 and 406, the sliding of the slide plate 100 out from under, and back under, the underside 202 of the shield canopy 200 may be by way of the tracks 122 and 132 of the slide plate 100 sliding along the guides 22 and 32 of the base plate.
In an embodiment of the method 400 at 402 and 406, the actuator 150 that causes the slide plate 100 to advance out from, and retract back under, the shield canopy 200 may be disposed at least partially within a void 140 cut into the back end of the slide plate 100. As described above, having the actuator 150 disposed at least partially within the void 140 may decrease the space the apparatus 1 assumes, which may decrease interference between the slide plate 100 and shearing equipment. In this embodiment at 402 and 406, the actuator 150 may be attached to the slide plate 100 at a periphery 142 of the void 140, such as discussed above. In this embodiment, at 402 the slide plate 100 may be slid out from the under the underside 202 of the shield canopy 200 such that no part of the void 140 in the back end of the slide plate 100 extends past the shield canopy 200. This is shown, for example, in
The embodiments described herein of the apparatus 1 and method 400 for protecting a person servicing a longwall shear, such as from falling rock or other debris from a mine roof overhead, provide for a space and weight-efficient solution. Such space efficiency allows for less material to be used, lowering the cost of the apparatus 1 and corresponding method 400, and such weight efficiency allows for less power to be used for sliding the slide plate 100. Less power may, in turn, allow for use of an actuator 150, to slide the slide plate 100, that is in one embodiment a single hydraulic cylinder as opposed to multiple hydraulic cylinders, further limiting the space used by the apparatus 1 and method 400.
While specific embodiments of the invention have been described in detail, it should be appreciated by those skilled in the art that various modifications and alternations and applications could be developed in light of the overall teachings of the disclosure. Accordingly, the particular arrangements, apparatuses, and methods disclosed are meant to be illustrative only and not limiting as to the scope of the invention.
