Patent Application
20140050532
The present invention relates to the mining arts and, more particularly, to a mesh handling apparatus for an underground mining machine, such as a roof bolter.
Anchors or “bolts” provide primary support for one or more of the faces of a passage in an underground mine, such as the roof or overburden. In connection with the installation of these bolts, it is often necessary or desired to install a reticulated mesh or grid material along the corresponding face(s). The main role of mesh is to provide passive confinement, especially in locations where poor ground conditions prevail, preventing fragments of rock and coal from falling from the roof and ribs in the spacing between reinforcing bolts.
Under the current approach, this supplemental protection afforded by the grid or mesh is separately applied to the roof and ribs of the mine passage, and oftentimes completed manually as part of the bolting operation. Past proposals have been made in an effort to facilitate the application of grid or mesh through semi-automated approaches, such as by having a roll of mesh or grid in flexible form carried by a mining machine and applied during the advance to form the mine passage.
Despite such advances, any manual approach suffers from being relatively complex in nature, and generally do not obviate the continued need for significant operator involvement. Specifically, an operator must still be involved to a significant extent in helping to initially support and tension the grid material or mesh during installation, and must also take measures to ensure that the proper amount of tension is provided throughout the operation. These requirements for frequent manual intervention increase the man hours and thus limit the practical effectiveness and efficiency of the limited automation provided.
Accordingly, a need is identified for an improved arrangement for use in applying a flexible grid material, or mesh, to a face of a mine passage. As compared with past approaches, the arrangement would be relatively simple in construction and inexpensive to implement. Yet, it would bring a significant level of advancement in terms of the savings in time and cost realized from its use. The result that follows from use of the system would be an overall increase in the efficiency of the mining operation.
An apparatus for applying mesh from a roll to a face of a mine passage is disclosed. The apparatus comprises a spindle adapted for supporting the roll of mesh. An arm connected to the spindle extends in a generally vertical direction and adapted for rotation about an axis aligned with a direction of elongation of the mine passage such that the spindle traverses a path for applying the mesh from the roll to the face. A mast carries a drill head for drilling into the face of the mine passage, and the arm is independently movable relative to the mast.
The apparatus may further include a rotary actuator for rotating the arm about the path, as well as a boom for supporting the arm. The spindle (which may be mounted to the arm on one end and include a free end for receiving the roll of mesh) provides an axis of rotation for the roll of mesh, and the axis of rotation of the roll of mesh may be generally aligned with the axis of rotation of the arm. The boom may include a longitudinal axis generally in alignment with the axis of rotation of the arm and the axis of rotation of the roll about the spindle. The boom may support the mast, which may be connected to the boom in a manner that permits the arm to move independently of the mast. An automated temporary support extendable in the vertical direction may also be for contacting a roof of the mine passage.
A further aspect of this disclosure relates to an apparatus for providing support for a face of a mine passage by placing mesh from a roll along the face. The apparatus comprises a boom including a mast supporting a drill for drilling into the face of the mine passage. A support is provided for supporting the roll of mesh, and is mounted to the boom for movement independent of the mast to allow the support to traverse a path through the mine passage for applying the mesh from the roll to the face.
In one embodiment, the support comprises an extendable arm. The support may further comprise a spindle for supporting the mesh roll. The mast may be adapted for extending toward and away from the face of the mine passage. A rotary actuator may also be provided for rotating the support.
The disclosure also relates to an apparatus for providing support for a face of a mine passage including a longitudinal direction by placing mesh from a roll along the face. The apparatus comprises a spindle for supporting the roll of mesh. The apparatus further includes means for rotating the arm relative to the mast about an axis aligned with the longitudinal direction while applying the mesh onto the face.
Also disclosed are methods, such as a method of applying mesh carried by a rotatable arm for anchoring using a mast to a face of a mine passage having a longitudinal direction, a vertical direction, and a transverse direction. The method comprises, rotating the arm relative to the mast about an axis aligned with the longitudinal direction while applying the mesh to the face. The method may further include the step of extending or retracting the arm in one of the vertical direction or the transverse direction during the rotating step.
In one possible version, the method further comprises positioning the arm at a location for dispensing mesh from the roll onto the face and, during the rotating step, extending or retracting a first portion of the arm relative to a second portion of the arm to maintain the roll adjacent to the face. The method also includes using the mast to anchor the dispensed mesh to the face.
The method may also include the step of actuating the mast independent of the arm. The rotating step may comprise moving a point on the arm through an arcuate path. The rotating step may also comprise moving a point on the arm from a lower position to a higher position.
Referring now to
In the depicted embodiment, the path P is generally transverse to a direction of elongation of an associated boom 16 supporting the apparatus 10, or transverse to a direction of elongation of the associated mine passageway (which typically corresponds to and is aligned with a direction of travel of the machine). Thus, as shown in
Optionally, the arm 14 may be adapted for being lengthened or extended relative to the point O about which it pivots to follow the path P (or, stated, differently, in the radial direction), including during the dispensing of the mesh from the roll R. For example, the arm 14 may comprise a base portion 14a and an extendable portion 14b connected to and adapted to move relative to the base portion. The extendable portion 14b may carry the spindle 12 supporting the roll R at the distal end, and may be extended using type of linear actuator (such as an electric motor, hydraulic cylinder, a ball screw, or the like). Together, the portions 14a, 14b forming the extendable arm 14 and the actuator are considered means for lengthening the arm during the application or dispensing of the mesh.
Accordingly, as shown in
It is also noted that the support, such as arm 14, is provided independent of the mast M, which may include anchoring means, such as a drill or drill head used to form boreholes and install fasteners (such as bolts) into one or more of these surfaces in connection with the application of the mesh. Optionally, this mast M may also be rotatably mounted to the boom 16 by an actuator 22 that allows the mast to pivot in different directions transverse to the direction of elongation of the passage (and independent of the rotation of the arm 14 about the longitudinal direction or the extension of the arm in the transverse (width) or vertical (height) direction) in order to secure the mesh once dispensed in position. As can be appreciated from
The foregoing descriptions of various embodiments are provided for purposes of illustration, and are not intended to be exhaustive or limiting. Modifications or variations are also possible in light of the above teachings. For example, the portions 14a, 14b of the arm may be nested or telescoping to provide the desired extension for the roll R. The term “generally” is used to connote a possible variance from an exact value (such as, for example, up to about 10%). The embodiments described above were chosen to provide the best application to thereby enable one of ordinary skill in the art to utilize the disclosed inventions in various embodiments and with various modifications as are suited to the particular use contemplated. All such modifications and variations (including the combination of any or all of the embodiments disclosed into a single apparatus) are within the scope of the invention.
This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/684,423, the disclosure of which is incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 61684423 | Aug 2012 | US |
