Patent Application
20210199008
The present disclosure generally relates to a jack for installing a mine stopping.
Mine stoppings can be installed in the passageway of a mine to block the flow of air through the passageway. As described in, for example, U.S. Pat. Nos. 2,729,064, 4,483,642, 4,695,035, and 7,438,506, each of which is hereby expressly incorporated by reference in its entirety, mine stoppings comprise a plurality of extendible mine stopping panels arranged in side-by-side relation across a mine passageway. To seal the passageway, each of the panels is extended longitudinally until a seal member at one end of the panel is crushed against a wall of the passageway. After extending the panels, a panel securing system (e.g., a system of clamps as described in U.S. Pat. No. 7,438,506, a system of ties as described in U.S. Pat. No. 4,483,642, or a system of brackets as described in U.S. Pat. No. 2,729,064) is installed to yieldably hold the panels in the extended positions while allowing the panels to contract in the event of mine convergence.
Various jacks have been used to extend the extendible panel of a mine stopping. For example, U.S. Pat. No. 4,483,642 describes a ratcheting jack that telescopically extends the jack to extend an upper telescoping panel member with respect to a lower panel member. The ratcheting jack incrementally extends the panel with each throw of the jack lever. U.S. Pat. No. 4,695,035 describes a bottle jack that uses a lever-actuated pressurized cylinder to telescopically extend the jack. The bottle jack likewise incrementally extends the panel with each throw of the lever. U.S. Pat. No. 7,438,506 describes a jack comprising a gripping system that causes a lever actuator to grip an extendible shaft when the lever is pivoted in a first direction and release the extendible shaft when the lever is pivoted in an opposite direction. Thus, the gripping system is operative to incrementally extend the jack, and thereby incrementally extend the panel, with each throw of the lever.
In one aspect, a jack for installing a mine stopping panel in a mine passageway comprises a first stopping panel support configured to engage a first portion of the mine stopping panel to press the first portion against a first surface of the mine passageway. The jack includes a second stopping panel support configured to engage a second portion of the mine stopping panel to move the second portion away from the first portion to press the second portion against a second surface of the mine passageway. An extendible post has a length and comprises a first post segment connected to the first stopping panel support and second post segment connected to the second stopping panel support. The first post segment is movable relative to the second post segment to adjust the length of the extendible post. The jack includes a press configured to move the first post segment relative to the second post segment such that the first stopping panel support moves away from the second stopping panel support to press the first portion of the mine stopping panel against the first surface of the mine passageway. The press includes a lever movable relative to the extendible post to a non-actuated position and to an actuated position. The press is connected to the first and second post segments such that movement of the lever toward the actuated position moves the first post segment relative to the second post segment to extend the length of the extendible post and movement of the lever toward the non-actuated position moves the first post segment relative to the second post segment to retract the length of the extendible post.
In another aspect, a jack for installing a mine stopping panel in a mine passageway comprises a column including a first stopping panel support, a second stopping panel support, an extendible post, and a press. The first stopping panel support is configured to engage a first portion of the mine stopping panel to press the first portion of the mine stopping panel against a first surface of the mine passageway. The second stopping panel support is configured to move a second portion of the mine stopping panel away from the first portion to press the second portion of the mine stopping panel against a second surface of the mine passageway. The extendible post has a length and comprises a first post segment connected to the first stopping panel support and a second post segment connected to the second stopping panel support. The first post segment is movable relative to the second post segment to adjust the length of the extendible post. The press is connected to the first and second post segments and configured to move the first post segment relative to the second post segment such that the first stopping panel support moves away from the second stopping panel support to press the first portion of the mine stopping panel against the first surface of the mine passageway. The column is configured to yield in response to a compression force on the extendible post resulting from the first stopping panel support pressing the first portion of the mine stopping panel against the first surface of the mine passageway. The column is configured to bias the first stopping panel support away from the second stopping panel support after yielding in response to the compression force.
In another aspect, a jack for installing a mine stopping panel in a mine passageway comprises a first stopping panel support configured to engage a first portion of the mine stopping panel to press the first portion of the mine stopping panel against a first surface of the mine passageway. A second stopping panel support is configured to press a second portion of the mine stopping panel away from the first portion to press the second portion of the mine stopping panel against a second surface of the mine passageway. An extendible post has a length and comprises a first post segment connected to the first stopping panel support and second post segment connected to the second stopping panel support. The first post segment is movable relative to the second post segment to adjust the length of the extendible post. A press comprises a connecting linkage. The connecting linkage includes a first link and a second link. The first link is configured to be connected to the first post segment for rotation with respect to the first post segment about a first pivot axis. The second link is connected to the second post segment for rotation with respect to the second post segment about a second pivot axis. The first link is connected to the second link for rotation with respect to the second link about a connecting pivot axis. The connecting linkage is movable through a range of motion from a first configuration to a second configuration, and the press is configured to extend the length of the extendible post as the connecting linkage moves in the range of motion from the first configuration toward the second configuration. At least one retainer connected to the first link is configured to connect the first link to the first post segment. The first post segment has a first post segment length and a plurality of retainer receivers spaced from each other along the first post segment length. Each retainer receiver is configured to receive the retainer to connect the first link and the first post segment.
Other objects and features will be in part apparent and in part pointed out hereinafter.
Corresponding reference characters indicate corresponding parts throughout the drawings.
Referring to
Referring to
As shown in
Having described an exemplary embodiment of a mine stopping 1, reference is now made to
The illustrated jack 101 further comprises a press, generally indicated at 113. The press is configured for adjusting the length L of the extendible post 107. As will be described in further detail below, the illustrated press 113 is configured to be selectively actuated to extend the length of the post 107 by an extension distance ED. In one or more embodiments, the press 113 comprises a linkage, generally indicated at 115, connected to the upper and lower post segments 109, 111. The linkage 115 is movable to selectively extend and retract the upper post segment 109 relative to the lower post segment 111, as will be described in further detail below.
The illustrated linkage 115 comprises a lever 117 (broadly, a first link) pivotally connected to the lower post segment 111 and a connecting link 119 (broadly, a second link) pivotally connected to the lever and upper post segment 109.
The press 113 is configured to be selectively connected to the extendible post 107 at a plurality of spaced apart locations along the length of at least one of the upper and lower post segments 109, 111 to adjust a non-actuated length L of the post independent of actuation of the press. For purposes of this disclosure, the “non-actuated length” of the post 107 refers to the length L of the post when the press is in a non-actuated configuration (e.g., when the lever is in the non-actuated position). In this disclosure, the reference character ‘L’ designates the length of the post generally, whether the press 113 is actuated, non-actuated, or partially actuated. In the illustrated embodiment, a lower post segment mount 121 comprising a collar 123 and a pivot bracket 125 connects the press 113 to the lower post segment 111 at a fixed location along the length of the lower post segment. Stops 126 against which the lever 117 rest in the actuated position extend from opposite sides of the pivot bracket 125. In one or more embodiments, the collar 123 is fixedly mounted on the top end portion of the lower post segment 111, the pivot bracket 125 is mounted on the collar, and the lever 117 is rotatably connected to the pivot bracket. In contrast, an upper post segment connector 131 is configured to selectively connect the press 113 to the upper post segment 109 at a plurality of spaced apart locations along the length of the upper post segment to adjust the non-actuated length L of the post (e.g., coarse adjustment). Suitably, the press 113 is configured such that the extension distance ED achievable by the press is about the same at any non-actuated length of the post 107 (e.g., when the connector 131 is connected to the upper post segment 109 at any location along the length of the upper post).
Any suitable connector for selectively connecting the press 113 to one of the post segments at spaced apart locations along the length of the post segment can be used without departing from the scope of the present disclosure. In the illustrated embodiment, the upper post segment 109 comprises a plurality of openings 133 (broadly, “retainer receivers”) extending diametrically through the shaft member at spaced apart locations along the post segment length. Referring to
Referring to
As introduced above, the illustrated press 113 comprises a connecting linkage 115 including the lever 117 and the connecting link 119. In the illustrated embodiment, the connecting linkage 115 comprises a toggle linkage. Each of the lever 117 and the connecting link 119 has a respective length extending between respective opposite first and second end portions. As explained below, the first end portion of the lever 117 includes a free handle, and the first end portion of the connecting link is connected to the upper post connector 131. The second end portions of the lever 117 and the connecting link are pivotally connected to each other.
Referring to
Referring to
When the upper post connector 131 is locked in a desired position with respect to the upper post segment 109, the press 113 is connected to the post 107 such that movement of the lever 117 toward the actuated position (e.g., in the counterclockwise direction RD1 in
As shown in
The toggle linkage 115 is configured so that the distance between lever axis PA1 and the upper pivot axis PA2 is greatest when the included angle α is 180°. When the upper post connector 131 is locked in the desired position with respect to the upper post segment 109, the pivot axes PA1, PA3 have fixed positions with respect to the lower post segment 111 and the upper post segment, respectively. Thus, when the included angle α is 180° and the distance between the pivot axis PA1, PA2 is greatest, the press 131 extends the post 107 by the maximum amount. As the lever 117 moves in the stroke toward the actuated position, the linkage 115 provides increased leverage and applies increased force extending the stopping panel until the angle α is 180°. In the actuated position, the lever 117 positions the toggle linkage 115 such that the included angle α is slightly greater than 180° so that the post must be extended slightly to rotate the lever away from the actuated position toward the non-actuated position. As will be explained further below, during use of the jack 101, this mechanically inhibits the post 107 from retracting after it is extended until such time as an installer has finished securing the stopping panel 3 in the extended configuration (e.g., by installing suitable ties or brackets on the panel). Accordingly, the illustrated toggle linkage 115 comprises an over-center linkage that has an over-center configuration in the actuated position of the lever 117. Because the toggle linkage 115 passes over the centered position as the lever 117 moves from the non-actuated position to the actuated position, the press 113 is configured to mechanically inhibit movement of the lever away from the actuated position.
Referring to
A compression spring 165 (broadly, a yieldable biaser) is located between the extendible post 107 and the post support 161. In the illustrated embodiment, the spring 165 is received in the interior of the post support body 161A and comprises a bottom end engaged with a bottom of the jack 101 (e.g., a portion of the lower stopping panel support 105) and a top end engaged with the bottom end portion of the post. The spring 165 is configured to yield in response to a compression force that urges the extendible post 107 toward the mine floor F when the press 113 is actuated to press the head 37 of the mine stopping panel 3 against the roof R of the mine. Suitably, the spring 165 is configured to yield when the compression force exceeds the force required to operably crush the seal 39 of the mine stopping panel 3 against the roof R of the mine. Thus, compression of the spring 165 and movement of the extendible post 107 downward in the post support 161 provide an indication that the seal 39 has been crushed to form a resilient and/or elastic anchorage of the stopping panel to the mine roof. Moreover, the spring 165 prevents an excessive crushing force from being applied to the seal 39 because the spring yields and thereby relieves the seal before the crushing force becomes excessive. After the spring 165 is compressed, it imparts a biasing force that biases the post 107 and the upper stopping panel support 103 upward away from the post support 161 and the lower stopping panel support 105. The spring 165 thus biases the upper stopping panel support 103 away from the lower stopping panel support 105 and thereby maintains engagement of the upper stopping panel support with the head 37 of the panel 3 and the lower stopping panel support 105 with the foot 41, and cooperates with the over-center arrangement to maintain the lever in the actuated position, after the press is actuated. It will be appreciated that a user must partially compress the spring to move the lever back over center to move the lever back to the non-actuated position. It is contemplated that, in other embodiments, a jack comprising a yieldable biaser 165, which yields to relieve an excessive crushing force on a stopping seal and/or imparts a biasing force to maintain engagement of a jack with an extended stopping panel, can have another type of press (e.g., a press that extends the jack incrementally with each throw of a lever).
Referring to
Subsequently, the installer uses the press 113 to operably crush the seal 39 against the roof R. Before actuating the press, 113 the user rotates the pins 139 and rings 145 of the press connector 131 to the non-retaining orientations to return the pins to the locked positions. The pins 139 extend into a respective pair of openings 133 of the upper post segment 109 to mechanically connect the press to the upper post segment and establish the desired non-actuated length of the post 107. The installer then moves the lever 117 from the non-actuated position to the actuated position. As explained above, the connecting end portion of the lever 117 forces the connecting member 119 and the upper post segment 109 to move upward relative to the lower post segment. The length L of the post 107 is extended by the extension distance ED. Initially, the extension of the post 107 moves the upper panel 13 upward with respect to the lower panel 11 to crush the seal 39. But when the seal is crushed a sufficient amount to create an elastic and/or resilient anchorage of the panel 3 to the mine roof R, the spring 165 yields in compression to prevent further crushing of the seal. As the spring 165 yields, the extendible post 107 moves downward in the post support 161 while maintaining a crushing force on the seal 39.
As the lever 117 is rotated to the actuated position, the included angle α increases to an angle of slightly greater than 180°. Thus, as explained above, after the press 113 is actuated, the post 107 must be extended slightly before it can be retracted. Together, the spring 165 and the seal 29 impart a compressive force on the post that strongly inhibits the lever from inadvertently moving back over center and prevents the post from being inadvertently retracted. Accordingly, after moving the lever 117 to its actuated position, the installer can release the lever. After the lever is released, the over-center mechanism of the toggle linkage 115 maintains the lever in the actuated position and maintains the post 107 in the extended configuration, and the spring 165 urges the post and the upper stopping panel support 103 upward to maintain an operative crushing force on the seal 39. The installer can then secure the panel 3 in the extended configuration using the clamps 7 as disclosed in U.S. Pat. No. 7,438,506 or another type of panel securing system, such as a system disclosed in U.S. Pat. No. 2,729,064, 4,483,642, or 4,695,035.
After the first panel is secured in place, the installer moves the lever 117 from the actuated position to the non-actuated position to retract the post 107 by the extension distance ED and release the upper stopping panel support 103 from the panel head 37. The process is then repeated with a second panel 3. The second panel is installed in side-by-side relation to the first panel. After the second panel is extended using the jack 101, additional clamping devices 7 or another securement mechanism can be used to secure the upper and lower panel members 11, 13 in their extended position and to secure the first and second panels 3 together in the aforesaid side-by-side relation. The above process is repeated for the third and following panels until a wall of panels 3 is formed across the passage, as shown in
The resulting wall is strong, lightweight, resistant to leakage, and functions as an integral load-bearing unit capable of resisting larger loads due to pressure differentials across the wall, concussive forces within the mine due to blasting, roof raising or collapse, etc. Nevertheless, in the event of a mine convergence between the roof and floor of the mine passage, the panels 3 will yield in the vertical direction to inhibit damage to the stopping. During this convergence, one of the upper and lower panel members 11, 13 of each telescoping panel will slide relative to the other panel and relative to the clamping device(s) 7.
As can be seen, in one or more embodiments, the jack 101 of the present disclosure is operative to extend a stopping panel 3 and crush the stopping seal 39 by a single throw of the lever 117. The single-throw toggle linkage 115 is very robust and is capable of reliable, repeatable operation in the often harsh environments of a mine. In certain embodiments, after a single downward stroke of the lever 117, the illustrated jack 101 is automatically positioned to securely hold the panel in the extended position, allowing a single installer to extend the jack and immediately begin securing the extended panel 3. Further, in some embodiments, the jack 101 has a built in mechanism (e.g., the spring 165) that prevents over-extension of the panel 3 and excessive crushing of the seal 39.
It will be apparent that modifications and variations are possible without departing from the scope of the invention defined in the appended claims.
As various changes could be made in the above constructions and methods without departing from the scope of the invention, it is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.
