Patent Application
20170114638
Present disclosure relates to an automated temporary roof support of an underground mining machine. In particular, present disclosure relates to a mounting assembly for a cross bar of an automated temporary roof support.
Roof bolter machines are generally used in mining industry for securing mine roofs to be self-supportive. Generally, there may be two types of operations that the roof bolters perform, namely, drilling operations and bolting operations. The drilling operations include drilling the roof and the bolting operations include inserting bolts such as cable bolts, or resin roof bolts, etc., and subsequently tightening the inserted bolts.
A mining machine includes an Automatic Temporary Roof Support (ATRS) for supporting the roof of a mine during roof bolting and other mining operations. In order to support the roof of the mine, the ATRS is raised and held proximate or against the roof of the mine
An ATRS may include a temporary roof support for the roof inside a mine. Generally a cross bar extending on either side of a base of the ATRS provides for temporary support to the roof. During movement of the machine, the cross bar may hit the roof surface or any other surface inside the mine. Such impact on the cross bar is transmitted to the base and may damage the base, the cross bar or mounting arrangement for the cross bar.
U.S. Pat. No. 5,983,376 discloses mounting a temporary roof support apparatus on a base. The bottom arms are mounted on the base using a bottom pin that permits the bottom arms to pivot vertically relative to the base. In the event of a side impact on the bottom arms, the impact forces are transmitted to the base, which may cause damage. An operator is required to inspect the temporary roof support apparatus for damage after each impact.
A mounting assembly for mounting a cross bar to a base, the mounting assembly including a hinge pin, the hinge pin configured to be vertically mounted on the base and pivotally support a cross bar, and a bracket for attachment to the base, the bracket having a first damper and a second damper arranged on either side of the hinge pin. The first damper and the second damper configured for compression by the pivoting of the cross bar on the hinge pin.
An automated temporary roof structure for a machine system including a base, a cross bar pivotally mounted on the base, a hinge pin, the hinge pin configured to be vertically mounted on the base and pivotally support the cross bar and a bracket for attachment to the base, the bracket having a first damper and a second damper arranged on either side of the hinge pin. The first damper and the second damper configured for compression by the pivoting of the cross bar on the hinge pin.
A method of mounting a cross bar to a base, the method including damping movement of the cross bar up to a threshold pivot angle of the cross bar by a damper provided on a bracket of the base and pivoting the bracket along with the cross bar for a pivot angle of the cross bar greater than the threshold pivot angle.
Referring to
The machine 100 includes a frame or a chassis 102. An enclosure 104 may be provided on the frame 102. The enclosure 104 houses a power source (not shown). The power source may be any conventional or non-conventional power source including, but not limited to, an internal combustion engine, power storage devices like batteries, electric motor and the like. The power source is configured to provide power to the machine 100 for mobility and/or other operational needs. The enclosure 104 may also house various other components required for operational control of the machine 100 including, but not limited to, electrical and/or electronic components, hydraulic and/or pneumatic components. Further, ground engaging members 106 such as wheels or tracks are provided on the machine 100 for the purpose of mobility. A drivetrain (not shown) is coupled to the power source and the ground engaging members 106. The drivetrain may include any one or a combination of, but not limited to, gearing, differentials, drive shafts and hydraulic and/or pneumatic circuits including valves, lines, distribution manifolds, electric drive machine, and the like. The drivetrain is configured to transmit power from the power source to the ground engaging members 106.
The machine 100 may be provided with a drill boom assembly 108. The drill boom assembly 108 may be pivotally coupled to the frame 102 of the machine 100. The drill boom assembly 108 may include an arm 110 in order to pivotally couple the drill boom assembly 108 to the frame 102 of the machine 100. The drill boom assembly 108 may include a drill assembly 112. The drill boom assembly 108 may be arranged to swing outwards, extend, contract, raise and lower by means of actuators. The drill assembly 112 may be configured to perform the rock bolting operation using suitable rock drilling and bolting tools. The drill boom assembly 108 may also include an operator platform 114. The operator platform 114 may be provided with various controls which may be used by an operator to control the drill boom assembly 108 and/or the machine 100. It should be noted that the drill boom assembly 108 may be replaced by any other implement such as, for example, a bucket, as per operational requirements.
Further, a horizontal boom 116 is provided on the machine 100. A rear end 118 of the horizontal boom 116 may be pivotally coupled to the frame 102 of the machine 100. An Automatic Temporary Roof Support (ATRS) 120, is provided on a front end 122 of the horizontal boom 116. The horizontal boom 116 may be configured as a telescopic boom having an extendable length in order to allow raising or lowering any implement mounted on the horizontal boom 116. In the embodiment shown in
The ATRS 120 includes a base 124 coupled to a cross bar 126 provided with support pads 128. The base 124 may be configured as a telescopic column having an extendable length in order to raise or lower the cross bar 126 with respect to the machine 100. The base 124 includes an enclosure 125 that encases other components of the base 124, for example a multi-stage hydraulic cylinder.
Referring to
Referring to
The cross bar 126 is coupled to the base 124 using a mounting assembly 200. The bottom plate 220 is coupled to the base plate 210 using a hinge pin 215. The hinge pin 215 is vertically mounted on the base 124 and allows for rotation of the cross bar 126 relative to the base 124 along a longitudinal hinge pin axis 218. A spacer 216 may be placed between the hinge pin 215 and the base plate 210. The spacer 216 may be configured to damp any relative movement between the base plate 210 and the bottom plate 220.
The mounting assembly 200 further includes a bracket 230 mounted on the base plate 210. The bracket 230 may be of ‘L’ shape and have vertical plate 232 and a horizontal plate 234. The bracket 230 is mounted on the base plate 210 using a mounting pin 235 received in an opening 236 in the horizontal plate 234 and the base plate 210. Further, the horizontal plate 234 defines a shear pin opening 239 and the base plate 210 defines a corresponding base plate opening 219 such that a shear pin 238 may be inserted in the shear pin opening 239 and the base plate opening 219 to restrict pivoting of the bracket 230 relative to the base plate 210 about the mounting pin axis 237. The mounting pin 235 allows the bracket 230 to pivot relative to the base plate 210 along the axis of the vertically oriented mounting pin 235 when the shear pin 238 is broken or removed. Further, the base plate 210 may be provided with two stoppers 214. The stopper 214 is configured to restrict the pivotal movement of the bracket 230 beyond a predetermined angle by blocking the movement of the horizontal plate 234. The angle at which the stopper 214 restricts the pivotal movement of the cross bar 126 is the bracket pivot angle. The bracket pivot angle may be an angle suitable to minimize the impact force transferred to the base 124.
Further, referring to
Referring to
The bracket 230 along with the dampers 242, 244 are mounted on the base plate 210 such that the two dampers 242, 244 are positioned proximate to the side surface 130 of the cross bar 126 on each side of the hinge pin 215. When the cross bar 126 is oriented in the normal position, the flanges 247 may abut the side surface 130 of the cross bar 126 such that any pivotal movement in the cross bar 126 about the hinge pin 215 will result in pushing of one of the flanges 247 and in turn compression of the springs 248. In alternate embodiments, the flanges 247 may be positioned at a distance from the cross bar 126. The springs 248 absorb any pivoting movement of the cross bar 126 till the flanges 247 abut the covers 252. This arrangement permits pivoting movement of the cross bar 126 along the hinge pin axis 218 upto a threshold angle without any damage. Any further pivoting movement in the cross bar 126 is transmitted to the bracket 230 that is prevented from movement by the shear pin 238. A threshold force acting on the bracket 230 may break the shear pin 238 and allow the bracket 230 to pivot on the mounting pin axis 237.
The spring 248 may get compressed up to a point where the flanges 247 abut the covers 252. Movement in the cross bar 126 beyond the angle B results in the cross bar 126 pushing against the bracket 230 and hence transferring the force of the impact 201 on the bracket 230. The shear pin 238 restricts the pivotal movement in the bracket 230 along the mounting pin axis 237. The shear pin 238 is configured to shear upon exposure to a shearing force greater than or equal to a threshold force. As shown in
During operation or movement of the ATRS 120, the cross bar 126 of ATRS 120 may hit a roof surface, side walls or any other surface in the mine. Such impact on the cross bar 126 may be transmitted to the base 124 and the ATRS 120 may get damaged. Present disclosure provides for a mounting assembly 200 for mounting a cross bar 126 to a base 124. Mounting the cross bar 126 in accordance with the present disclosure provides for a damping system for damping an impact 201 on the cross bar 126. The mounting assembly 200 damps the impact 201 and prevents any damage to the base 124 on account of transmittal of impact forces.
Further present disclosure provides for a method 400 of mounting a cross bar 126 to a base 124. As illustrated in
The step 404 includes pivoting the bracket 230 along with the cross bar 126 for a pivot angle of the cross bar 126 greater than the threshold pivot angle.
In an embodiment, the method 400 further includes pivoting the bracket 230 by breaking a shear pin 238 connecting the bracket 230 to the base 124. Movement in the cross bar 126 beyond the first angle B results in the cross bar 126 pushing against the bracket 230 and hence transferring the force of the impact 201 on the bracket 230. Under the force of the impact 201, the shear pin 238 is configured to shear upon exposure to a shearing force greater than or equal to a threshold force. After the shear pin 238 breaks, the bracket 230 pivots about the mounting pin 235. Thus, the movement of the cross bar 126 beyond the first angle B is allowed by breaking of shear pin 238 and the force of the impact is prevented from being transferred to the base 124. This way the base 124 or the cross bar 126 may be protected from any damage occurring due to the impact 201.
In an embodiment, the method 400 further includes restoring the cross bar 126 by replacing the shear pin 238 for a pivot angle of the cross bar 126 greater than the threshold pivot angle. The cross bar 126 may be restored to its normal operating position by aligning the base plate opening 219 with the shear pin opening 239 and replacing the shear pin 238 to reorient the bracket 230 and the cross bar 126. As the ATRS 120 can be put back into operation by replacement of a shear pin 238, present disclosure provides for a cost effective solution for averting damage in the ATRS 120 due to horizontal impacts on the cross bar 126. In another embodiment, the method 400 further includes stopping pivoting of the bracket 230 at a bracket pivot angle C.
While aspects of the present disclosure have been particularly shown and described with reference to the embodiments above, it will be understood by those skilled in the art that various additional embodiments may be contemplated by the modification of the disclosed machines, systems and methods without departing from the spirit and scope of what is disclosed. Such embodiments should be understood to fall within the scope of the present disclosure as determined based upon the claims and any equivalents thereof.
