Embodiments of the present disclosure relate to mine roof supports. More particularly, embodiments of the present disclosure relate to a telescoping mine roof support, a pre-installation assembly for the support, and a method of installation.
Mine roof supports of various types are well known. One very successful mine roof support is disclosed in U.S. Pat. No. 5,308,196 and marketed as THE CAN® support, by Burrell Mining Products, Inc. of New Kensington, Pa. This support comprises a one-piece outer metal housing filled with a compressible load-bearing material, such as grout.
Other mine roof supports include telescoping assemblies of several cylindrical tubular sections which are extended between a mine floor and roof. Some such supports may be filled with a material such as grout, which hardens into a solid, load-bearing, compressible material. Examples of such a support are disclosed and claimed in U.S. Pat. No. 8,851,805, assigned to the assignee of the present application, and the disclosure of which is hereby incorporated herein in its entirety by this reference.
In some embodiments, a mine roof support comprises two or more frusto-conical, tubular sections, the sections each flared outwardly from an upper end to a lower end thereof, a skirt portion of a section being received and secured within a neck portion of a section below in a frictional fit to define a volume within the secured sections. A solid, compressible, load-bearing material is located within the volume.
In other embodiments, a method of installing a mine roof support comprises placing a mine roof support comprising at least two sections in an installation location, each of the at least two sections of frusto-conical configuration and flared outwardly from an upper end to a lower end thereof, at least one of the at least two sections being nested within at least one other of the two or more sections. An innermost section of the at least two sections is pulled upwardly within a next adjacent section until an outer surface of the lower end contacts and frictionally engages with an inner surface of the next adjacent section to secure the innermost section to the next adjacent section.
In further embodiments, a pre-installation assembly for a mine roof support comprises three tubular, frusto-conical sections in a nested arrangement, a skirt portion of each section defining a larger diameter than a neck portion of a next outer adjacent section, wherein each section is flared outwardly from an upper end to a lower end thereof at substantially the same angle α of departure to a longitudinal axis of the section of between about 0.01° and about 3°.
The illustrations presented herein are not actual views of any particular mine roof support or method of installation, but are merely idealized representations that are employed to describe embodiments of the present disclosure.
Drawings presented herein are for illustrative purposes only, and are not meant to be actual views of any particular material, component, structure, device, or system. Variations from the shapes depicted in the drawings as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, embodiments described herein are not to be construed as being limited to the particular shapes or regions as illustrated, but include deviations in shapes that result, for example, from manufacturing. For example, a region illustrated or described as box-shaped may have rough and/or nonlinear features, and a region illustrated or described as round may include some rough and/or linear features. Moreover, sharp angles between surfaces that are illustrated may be rounded, and vice versa. Thus, the regions illustrated in the figures are schematic in nature, and their shapes are not intended to illustrate the precise shape of a region and do not limit the scope of the present claims. The drawings are not necessarily to scale.
As used herein, the terms “comprising,” “including,” “containing,” “characterized by,” and grammatical equivalents thereof are inclusive or open-ended terms that do not exclude additional, unrecited elements or method acts, but also include the more restrictive terms “consisting of” and “consisting essentially of” and grammatical equivalents thereof. As used herein, the term “may” with respect to a material, structure, feature or method act indicates that such is contemplated for use in implementation of an embodiment of the disclosure and such term is used in preference to the more restrictive term “is” so as to avoid any implication that other, compatible materials, structures, features and methods usable in combination therewith should or must be, excluded.
As used herein, the terms “longitudinal,” “vertical,” “lateral,” and “horizontal” are in reference to a major plane of a substrate (e.g., base material, base structure, base construction, etc.) in or on which one or more structures and/or features are formed and are not necessarily defined by earth's gravitational field. A “lateral” or “horizontal” direction is a direction that is substantially parallel to the major plane of the substrate, while a “longitudinal” or “vertical” direction is a direction that is substantially perpendicular to the major plane of the substrate. The major plane of the substrate is defined by a surface of the substrate having a relatively large area compared to other surfaces of the substrate.
As used herein, spatially relative terms, such as “beneath,” “below,” “lower,” “bottom,” “above,” “over,” “upper,” “top,” “front,” “rear,” “left,” “right,” and the like, may be used for ease of description to describe one element's or feature's relationship to another element(s) or feature(s) as illustrated in the figures. Unless otherwise specified, the spatially relative terms are intended to encompass different orientations of the materials in addition to the orientation depicted in the figures. For example, if materials in the figures are inverted, elements described as “over” or “above” or “on” or “on top of” other elements or features would then be oriented “below” or “beneath” or “under” or “on bottom of” the other elements or features. Thus, the term “over” can encompass both an orientation of above and below, depending on the context in which the term is used, which will be evident to one of ordinary skill in the art. The materials may be otherwise oriented (e.g., rotated 90 degrees, inverted, flipped) and the spatially relative descriptors used herein interpreted accordingly.
As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise.
As used herein, the terms “configured” and “configuration” refer to a size, shape, material composition, orientation, and arrangement of one or more of at least one structure and at least one apparatus facilitating operation of one or more of the structure and the apparatus in a predetermined way.
As used herein, the term “substantially” in reference to a given parameter, property, or condition means and includes to a degree that one of ordinary skill in the art would understand that the given parameter, property, or condition is met with a degree of variance, such as within acceptable manufacturing tolerances. By way of example, depending on the particular parameter, property, or condition that is substantially met, the parameter, property, or condition may be at least 90.0% met, at least 95.0% met, at least 99.0% met, or even at least 99.9% met.
As used herein, the term “about” in reference to a given parameter is inclusive of the stated value and has the meaning dictated by the context (e.g., it includes the degree of error associated with measurement of the given parameter).
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Mine roof supports according to embodiments of the disclosure may be designed to carry an average load of at least between about 100,000 lbs. and about 350,000 lbs, depending upon the size of the support. An aerated cementitious material such as, for example, foamed concrete having a density between about 40 to 60 ft.3 may be employed as a filler material. The mine roof support will yield longitudinally when subjected to a longitudinal load during subsidence of a mine roof. Yielding is effected by compression of the foamed grout filler material, collapsing air pockets in the foam, in combination with one or more of the frusto-conical sections 102 of mine roof support 100 folding upon itself in multiple folds as the filler material compresses.
Each mine roof support tested yielded in a predictable manner while supporting a load, and yielded only a short distance before substantial load bearing capacity was reached. As shown in
The mine roof support of the disclosure, in various embodiments, is also believed by the inventors herein to accommodate some relative lateral shifting between a roof and a floor of a mine room in which the mine roof support is placed without significant loss in load bearing capacity.
The mine roof support of embodiments of the disclosure provides a short, lightweight, compact, easy-to-transport pre-installation assembly which can be more easily placed in a room of an underground mine than many existing supports which, as transported and placed in a mine, must approximate the height of the roof above the mine floor. In addition, the telescoping nature of the assembly, when unfilled with grout or another load-bearing, compressible medium, enables accommodation of some variation of distance between the mine floor and roof without the use of wooden cribbing or other spacing materials. Further, the frusto-conical configuration and mutual frictional engagement of the mine roof support sections enables a substantially fluid-tight seal between the sections of the support without the use of sealing elements of any type.
While particular embodiments of the disclosure have been shown and described, numerous variations and alternative embodiments are contemplated by the inventors herein and will be recognized by those of ordinary skill in the art. Accordingly, the scope of the invention is only limited by the appended claims and their legal equivalents.
This application claims the benefit under 35 U.S.C. § 119(e) of U.S. Provisional Patent Application Ser. No. 62/611,094 filed Dec. 28, 2017, the disclosure of which is hereby incorporated herein in its entirety by this reference.
Number | Date | Country | |
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62611094 | Dec 2017 | US |