This patent disclosure relates generally to a machine configured for cutting operations and the like and, more particularly, to a system and method for positioning the machine to perform a cutting operation.
Mobile machines may be configured for aboveground or underground operation to perform excavating, tunneling, or underground mining by cutting and removing material from a wall or surface. Such machines may have a low profile design and include an undercarriage with continuous tracks or similar propulsion devices to transport the machine about the worksite. To perform a cutting or milling operation, a rotary cutter head is disposed on a tool support and positioning assembly supported by the undercarriage. The cutter head can be a circular, drum-like structure that supports a plurality of cutting tools about its circular periphery. The cutting tools themselves may be forcibly rotated with respect to the periphery of the cutter head and include bits made of tungsten carbide, synthetic diamond, or similar hard substances to dislodge and chip material away from the cutting surface or wall. The tool support and positioning assembly can be configured to move the cutter head in multiple directions to make passes or sweeps with respect to the cutting surface removing successive layers of material from the cutting surface. When one layer of material has been removed, the cutter head can be fed further into the cutting surface and the process can be repeated to remove another layer of material.
A machine of the foregoing type is described in U.S. Publication No. 2015/0204190 (“the '190 publication”). The '190 publication describes a milling or cutting cycle for the machine in which the cutter head is maneuvered through distinct motions to make a number of passes or sweeps with respect to the cutting surface to complete a cutting profile to remove material from the surface. It had been proposed that these maneuvers can be automated to increase efficiency and reduce operator burden. The current disclosure is therefore directed to a machine configured with a maneuverable cutter head and to processes for automating the cutting cycle with provisions directed to reducing unintended or accidental occurrences during the during the cutting process.
The disclosure describes, in one aspect, a machine for removing material that includes an undercarriage supported on a plurality of propulsion devices to position the machine proximate to a cutting surface. To remove material from the cutting surface, a cutter head is disposed on a cutter boom of a tool support and positioning assembly which is slidably moveable with respect to the undercarriage between an extended position and a retracted position. An electronic control system may be configured to conduct a predetermined set of operations including the steps of moving the cutter head toward the cutting surface wall by extending the cutter boom, moving the cutter head with respect to the cutting surface to remove material, and retracting the cutter head from the cutting surface by retracting the cutter boom upon completion of the predetermined set of operations.
In another aspect, the disclosure describes a method for cutting material that includes the steps of positioning a machine supported on a plurality of continuous tracks proximate to a cutting surface. Once positioned, the machine may perform a predetermined set of operations to remove material from the cutting surface by feeding a cutter head disposed on a cutter boom toward the cutting surface and moving the cutter head with respect to the cutting surface. At the conclusion of the predetermined set of operations, the cutter head is automatically retracted from the cutting surface.
In yet another aspect, the disclosure describes a machine that also includes an undercarriage supported on a plurality of propulsion devices to position the machine proximate to a cutting surface. To remove material from the cutting surface, the machine includes a cutter head disposed on a tool support and positioning assembly that has a cutter boom slidably moveable with respect to the undercarriage assembly between an extended position and a retracted position. The machine also includes an electronic control system configured to communicate with the tool support and positioning assembly to maneuver the cutter head. The electronic control system can be selectively switched to operate in an automatic mode utilizing a predetermined set of operations and a manual mode to perform manual operations. The electronic control system is further configured to retract the cutter boom prior to enabling operation of the propulsion devices.
Now referring to the drawings, wherein like reference numbers refer to like elements, there is illustrated in
To cut or mill material from the cutting surface 108, the machine 100 includes a cutter head 110 having a plurality of cutting tools 112 disposed about its radial periphery. The cutter head 110 can include a drum structure 114 that can be made to forcibly rotate about a cutter head axis 116, thereby revolving the cutting tools 112 with respect to the cutting surface 108. The cutting tools 112 can be supported in corresponding sockets disposed in the drum structure 114 and, in an embodiment, can be made to forcibly rotate or spin within the drum structure 114 for increased cutting action. To impact and dislodge material from the cutting surface 108, a plurality of bits 118 can be disposed about the exterior surface of the cutting tools 112. The bits 118 can be made of tungsten carbide, polysynthetic diamond, or a similar material having good hardness characteristics. As the bits 118 wear down, the cutting tools 112 may be removed from the cutter head 110 and replaced.
To support cutter head 110 and to move it in passes or sweeps with respect to the cutting surface 108, the cutter head 110 can be supported on a tool support and positioning assembly 120 that is configured to move or pivot in multiple directions or about various axes. In particular, the tool support and positioning assembly 120 suspends the cutter head 110 proximately over the front end 122 of the machine 100 and includes various systems and structures that are disposed over the undercarriage 120 extending toward the rear end 123 of the machine 100. For example, to feed the cutter head 110 into the cutting surface 108 or to retract the cutter head 110 from the cutter surface 108, the tool positioning and support assembly 120 includes a cutter boom 124 that is slidably disposed on the undercarriage 102 to laterally translate in the forward and rearward directions along a boom axis 126 indicted by the double-headed arrow. The cutter boom 124 can be generally supported over the continuous tracks 104 on rails or the like to enable translation with respect to the undercarriage 102. To cause the cutter boom 124 to translate along the forward and rearward directions along the boom axis 126, the cutter boom 124 can be operatively associated with one or more hydraulic actuators, specifically a boom actuator 128. The boom actuator 128 can be located on the rear end 123 of the machine 100 and arranged to slide the cutter boom 124 toward and from the front end 122 to feed and retract the cutter head 110. In an embodiment, the travel distance of the cutter boom 124 between a fully extended position toward the front end 122 of the machine 100 and a fully retracted position toward the rear end 123 may be about a meter or more.
To cause the cutter head 110 to sweep in a side-to-side motion, the tool support and positioning assembly 120 can include a swing platform 130 such as a pivot table or the like supported on the cutter boom 122 that pivots the cutter head 110 with respect to the undercarriage 102. Actuation of the swing platform 130 moves the cutter head 110 horizontally in an arc about the vertically orientated swing axis 132. To actuate the swing platform 130, the swing platform 130 can be operatively associated with hydraulic actuators or swing actuators 134 that are connected to either side of the swing platform 130 and to the cutter boom 122. Extension of one swing actuator 134 and retraction of the other will rotate the swing platform 130 though a horizontal plane about the swing axis 132.
To vertically raise and lower the cutter head 110 with respect to the tunnel floor 106 and cutting surface 108, the tool support and positioning assembly 120 can include a cantilevered lift arm 140 disposed on the swing platform 130. The cantilevered lift arm 140 can move the cutter head 110 along the horizontally extending tilt axis 142 that may be parallel with the cutter head axis 116. In particular, the cantilevered lift arm 140 extends over the front end 122 of the machine 100 and has a hinge or pivot joint 144 that articulates the forward part of the cantilevered lift arm 140 in an up-and-down motion. To actuate the cantilevered lift arm 140, another hydraulic actuator or lift actuator 146 can be operatively arranged on the cantilevered lift arm 140 to articulate the pivot joint 144. In a further possible embodiment, to twist or roll the cutter head 110, the distal end of the cantilevered lift arm 140 can be configured as a roll joint 148 that rolls or rotates the cutter head axis 116 with respect to the rest of the machine 100.
Because the cutter head 110 is disposed over the front end 122 of the machine 100, the material it removes from the cutting surface 108 will gather in front of the machine 100 and can hinder further cutting operations. To remove the gathered material, the front end 122 of the machine 100 can be equipped with a gathering head or gathering frame 150 that extends across the width of the machine 100 below the cutter head 110 proximate to the tunnel floor 106. The gathering frame 150 can be configured to scoop the material from the tunnel floor 106 and may be designed to adjustably span the width of the tunnel floor 106 between opposing gathering wings 152 that can adjustably extend outwards from the sides of the machine 100.
To remove the material collected by the gathering frame 150, a conveyer 154 in the form of a translating belt is disposed through the machine 100 that passes the material from the front end 122 through to the rear end 123 of the machine 100. The conveyer entrance 156 can be an opening centrally disposed in the skirt of the gathering frame 150 with the conveyer 150 extending lengthwise through the machine 100 above the undercarriage 102 to the conveyer exit 158 located at the rear end 123 of the machine 100. To direct the material to the conveyer 154, the gathering frame 150 can include gathering arms 159 that pivotally sweep across the surface of the gathering frame 150 toward the conveyer entrance 156. Referring to
To power the machine 100 and movement of the cutter head 110 on the tool support and positioning assembly 120, the machine 100 can be equipped with one or more electric motors 170 that advantageously utilize electricity and avoid generating exhaust fumes if the machine is used in an underground worksite. A remote power source, such as a generator, can provide three-phase electrical power to the electric motors 170 via cables. In the embodiments in which the continuous tracks 104 and hydraulic actuators of the tool support and positioning system 120 are hydraulically operated, a hydraulic system 172 including a hydraulic pump and a hydraulic fluid reservoir can be operatively associated with the electrical motors 170 to generate fluid pressure for operation.
To further facilitate the milling or cutting operation, the machine 100 can be equipped with one or more hydraulically extendable and retractable ground-engaging devices that are operatively associated with the hydraulic system 172. For example, to stabilize the machine 100 during a cutting or milling operation, the machine 100 can be equipped with a plurality of stabilizers 180 that can be disposed about the corners of the undercarriage 102. The stabilizers 180 can include a stabilizer actuator 182 that can extend and retract a ground pad 184 with respect to the tunnel floor 106. During a milling or cutting operation, the stabilizer actuator 182 extends the ground pad 184 to engage the tunnel floor 106 and brace and support the machine 100 with respect to vibrations and oscillations generated by cutting into the cutting surface 108. To enable the machine 100 to move about the worksite, the stabilizer actuator 182 retracts the ground pad 184 adjacent to the undercarriage 102. The hydraulic actuators that serve as the boom actuator 128, swing actuator 134, lift actuator 146, and stabilizer actuator 184 can be configured as double acting hydraulic cylinders with telescoping pistons that extend and retract from the cylinder body. However, in other embodiments of the machine 100, one or more of the hydraulic actuators may be replaced with other hydraulic devices or with electric motors or the like.
To regulate and control operation of the machine 100, an electronic control system 190 can be included as shown in
In an embodiment, the machine 100 may be remotely operated through the electronic control system 190. As illustrated in
As indicated, the cutter head 110 and the tool support and positioning system 120 can be maneuvered through a plurality of distinct positions to remove material from the cutting surface 108 during a cutting or milling operation. Examples of some of these maneuvers and positions are illustrated in
The cutter head 110 can be also be raised and lowered, or tilted, with respect to the cutting surface 108 by appropriate actuation of the cantilevered lift arm 140. For example, referring to
For purposes of the disclosure, each horizontal or vertical milling or cutting operation may be referred to as an operation or pass. A plurality of horizontal and vertical operations or passes that remove a layer of material may be referred to as a cutting cycle. A plurality of cutting cycles sequentially removing a plurality of layers of material may be differentiated by different in-depth feeds into the material surface and may be referred to as a cutting set. The cutting sets including the individual passes and operations may be carried out by the operator through the electronic control system 190 on the cutting machine 100 using the remote control 192, however, in an embodiment, the cutting sets may be an automated process conducted by the electronic control system 190 with little operator intervention. In a further embodiment, the cutting cycles can be arranged in predetermined patterns or profiles that are stored as executable programs in the electronic control system 190 and that are configured to facilitate removal of successive layers of material from the cutting surface.
For example, referring to
To make a vertical cut, the cantilevered lift arm 140 is lowered to move the cutter head 110 in a second cutting pass 218 toward a third position proximate the lower edge 220 of the
In addition to the embodiment described in
At the conclusion of the cutting cycle resulting in removal of a layer of material from the cutting surface 108, the cutter boom 124 can be extended toward the front end 122 of the machine 100 to feed the cutter head 110 further into the cutting surface 108 to conduct another cycle and remove another layer of material. The distance the cutter boom 124 is fed into the cutting surface 108 may be based on the physical characteristics and capabilities of the machine 100, such as the depth-of-cut the cutter head 110 can make without stalling. In an embodiment, especially where the milling or cutting sets are automated, the feed distance of the cutter boom 124 may be a predetermined value such as 100 millimeters. Further, the cutter boom 124 can be extended with respect to the undercarriage 102 a distance of 600 millimeters so the machine 100 is capable of conducting six consecutive and sequential cutting cycles per set. However, after the cutter boom 124 has been fully extended, the machine 100 needs to be repositioned with respect to the cutting surface 108 to perform the next set. The process of repositioning the machine 100 with respect to the cutting surface 108 between successive sets may be referred to as tramming the machine 100.
Because the tool support and positioning system 120 including the cutter boom 124 are movable with respect to, and may be fed into or extracted from, a cutting surface 108, the disclosure provides various possible processes to ensure the cutter boom 124 is appropriately set before positioning or tramming the machine 100 with respect to the cutting surface 108. It should be appreciated the precise and detailed processes described herein are exemplary for the purposes of the disclosure, and aspects of the processes may be used in various operating modes or in various combinations. Referring to
The execution of the process 300 can be affected by the operating mode of the machine 100 and according the process 300 can include an operating mode selection step 304 during which automatic mode 306 or manual mode 308 may be selected. If automatic mode 306 is selected, the process 300 may be directed to operate using any one of a plurality of predetermined cutting sets 310 to maneuver the cutter head 110 with respect to the cutting surface 108. The predetermined cutting sets 310 can be embodied as software instructions that can be stored in and executable by the electronic control system 190 to direct the tool support and positioning assembly 120 to maneuver the cutter head 110. The predetermined cutting sets 310 can include information regarding the underlying cutting cycles including the distance, number and direction of the horizontal cutting passes 312 and the vertical cutting passes 314 that the electronic control system 190 should perform. In addition, the predetermined sets 310 may include a preset feed depth 316 regarding how far the cutter boom 124 should extend to feed the cutter head 110 into the cutting surface 108. The preset feed depth 316 may be a portion or fraction of the overall travel distance of the cutter boom 124 between the extended and retracted positions. The predetermined set 310 can be selected during a selection step 318, using button or the like associated with the electronic control system 190 or the remote control 192.
The electronic control system 190 executes the predetermined set 310 by extending the cutter boom 124 over the preset feed depth 316 to feed the cutter head 110 into the cutting surface 108 the desired distance. The electronic control system 190 then executes a first cutting cycle 320 with horizontal cutting passes 312 and vertical cutting passes 314 through automatic maneuvering of the swing platform 130 and the cantilevered lift arm 140. Once the first cutting cycle 320 is conducted, thereby removing a layer of material from the cutting surface 108, the electronic control system 190 again extends the cutter boom 124 over the preset feed depth 316 in a feed cutter head step 322 to further feed the cutter head into the cutting surface 108 and conducts a second cutting cycle 324. To compete the predetermined set 310, the electronic control system 190 can conduct repeated cutting cycles and extend the cutter boom 124 between cycles to intermittently feed the cutter head 110 until the cutter boom 124 is in its full-extended position. By way of example, six cutting cycles each removing a layer of material from the cutting surface may be performed, with a preset feed depth 316 of about 100 millimeters occurring between each cycle such that the cutter boom 124 is extended about 600 millimeters overall during the predetermined cutting set.
To enable the machine to move or tram to a new position or a trammed position 330, the electronic control system 190 can automatically retract the cutter boom 124 back to its retracted position so that the cutter head 110 is disengaged and removed from the cutting surface 108. If the cutter boom 110 is not retracted, tramming the machine 100 could drive or clip the cutter head 110 against the cutting surface 108. Accordingly, the electronic control system 190 may issue a retract command 332 upon completion of the predetermined set 310 to correspondingly actuate the boom actuators 128 to move the cutter boom 124 toward the rear end 123 of the machine 100 into the retracted position. The retract command 332 thereby directs the cutter boom 124 to retract after the final cutting cycle in the predetermined set 310. The retract command 332 may be automatically generated and communicated by the electronic control system 190 at the conclusion of the predetermined set without operator interaction to ensure the cutter boom 124 is retracted before tramming of the machine 100 can occur.
In an aspect, the process 300 may verify that the cutter boom 124 is retracted before enable the machine 100 to be repositioned or trammed. For example, in an embodiment, one or more boom position sensors 334 may be disposed on the undercarriage 102 to monitor positioning of the cutter boom 124 and to verify whether it is in the retracted position. In an embodiment, the boom position sensors 334 can be a limit switch or limit switches that may be triggered when the cutter boom 124 is fully slid toward the rear end 123 to the retracted position or has otherwise been sufficiently retracted with respect to the cutting surface 108. In another embodiment, the boom position sensors 334 may be optical sensors such as an infrared sensor or the like that optically measures the position of the cutter boom 124. Similarly, radio frequency receivers and transponders may be disposed on the undercarriage 102 and the cutter boom 124 to function as proximity sensors. In a further embodiment, an electrical sensor including exposed trip wires may be placed over the rail or similar structure that the cutter boom 124 is configured to slide over to register passing of the cutter boom 124 with respect to the undercarriage 102. As an alternative to directly monitoring the position of the cutter boom 124, the boom position sensors 334 may be operatively associated with the boom actuators 128 to indirectly monitor its position, for example, by sensing hydraulic pressure in the boom actuators 128 or displacement of the pistons and rods internal to the boom actuators 128.
In a sensor monitoring step 336, the electronic control system 100 can monitor the boom sensor 334 to determine if the cutter boom 124 is retracted. If the cutter boom 124 is not in the retracted position or has not been sufficiently retracted with respect to the cutting surface 108, the electronic control system 190 can issue a track deactivation command 338 to de-active or preclude operation of the continuous tracks 104. In addition, the sensor monitoring step 336 may issues a swing deactivation command 339 to deactivate the swing platform 130 and prevent the cutter head 110 from rotating with respect to the cutting surface 108. The track deactivation command 338 and swing deactivation command 339 may remain effective until the boom position sensors 334 register that the cutter boom 124 is in its fully retracted position.
In another embodiment, the process 300 may coordinate retraction of the cutter boom 124 with the timing or duration of operation of the boom actuators 128. This embodiment may be particularly useful where the machine 100 is relatively large and the travel distance of the cutter boom 124 may be approximately one or more meters in length. For example, the retract command 332 may be associated with a counter or a preset time duration 340, for example, 30 seconds which under normal circumstances would be sufficient to retract the cutter boom 124 to its fully retracted position. If the boom position sensors 334 fail to register the cutter boom 124 in its fully retracted position or that it is otherwise sufficiently retracted with respect to the cutting surface 108 within the preset time duration 340, the process 300 may recognize that occurrence as indicting a failure with the cutter boom 124 or with the boom actuator 128. For instance, the cutter head 110 may be caught in the cutting surface 108 or the boom actuators 128 may be experiencing a hydraulic or electrical failure. If the preset time duration 340 expires prior to retraction of the cutter boom 124 to the full retracted position, the sensor monitoring step 336 may issue a machine deactivation command 342 to deactivate operation of the machine 100, for example, by deactivating the continuous tracks 104 or swing platform 130, to avoid any further damage. The machine deactivation command 342 may be tied with an operator alarm 344 or diagnostic signal to indicate to the operator a possible fault with the machine 100.
If, however, during the operating mode selection step 304 the operator selects manual mode 308, the operator may manually conduct manual milling or cutting operations 350 by independently directing cutting sets including the horizontal cutting passes 312, the vertical cutting passes 314, and the preset feed depth 316 through the electronic control system 190 and the remote control 192. During manual milling or cutting operations 350, the operator may be able to selectively reposition or tram the machine 100 during the set by selecting or activating a tram command 352 to operate the continuous tracks 104. In an embodiment, to avoid unintentionally colliding the cutter head 110 with the cutting surface 108, the tram command 352 may be tied or associated with a retract command 354 to concurrently retract the cutter boom 124. If the electronic control system 190 receives the tram command 352, it can responsively issue the retract command 354. The retract command 354 may be communicated to the boom actuator 128 prior to enabling operation of the continuous tracts 104 pursuant to the tram command 352. Furthermore, utilizing the boom position sensor 334 described above, the manual mode 308 may also conduct a sensor monitoring operation 358 to verify the cutter boom 124 is in the fully retracted position or otherwise sufficiently retracted prior to enabling the operator to operate the continuous tracks 104 or the swing platform 130.
In yet a further embodiment, the process 300 can be configured to retract the cutter boom 124 in the event the milling or cutting operation becomes problematic. For example, the cutter head 110 and/or the tool positioning and support assembly 120 may be operatively associated with a vibration sensor 360 that sense vibrations generated during the operation. The machine 100 can also be equipped with a hydraulic system sensor 362 to monitor parameters regarding the hydraulic system 170, for example, the hydraulic pressure, flow rate or fluid temperature in the hydraulic system. The process 300 may conduct a machine monitoring step 364 to monitor the vibration sensors 360, hydraulic system sensor 362, and/or other systems associated with the machine. If the machine monitoring step 364 determines the vibrations measured by the vibration sensor 360 are excessive, or if the machine monitoring step 364 determines that operation of the hydraulic system 172 is unacceptably strained, the machine monitoring step 364 may issue another machine deactivation command 366 to deactivate the machine 100, e.g., by deactivating the continuous tracks or swing platform, to avoid damage to either the machine 100 or the worksite. The machine monitoring step 364 may utilize empirically or theoretically determined threshold values regarding vibrations or hydraulic pressure to indicate if those parameters are unacceptable, for example, if they indicate imminent damage to the machine or its systems. Again, the machine deactivation command 366 may be accompanied by an alarm 368 or other signal to the operator indicating the possible fault with the milling or cutting operation.
It should be appreciated that well-known variations or modifications to the foregoing process 300 will be apparent to those of skill in the art and fall within the scope of the disclosure. The process 300 may be continuous and repeated during the course of operation of the machine 100.
It will be appreciated that the foregoing description provides examples of the disclosed system and technique. However, it is contemplated that other implementations of the disclosure may differ in detail from the foregoing examples. All references to the disclosure or examples thereof are intended to reference the particular example being discussed at that point and are not intended to imply any limitation as to the scope of the disclosure more generally. All language of distinction and disparagement with respect to certain features is intended to indicate a lack of preference for those features, but not to exclude such from the scope of the disclosure entirely unless otherwise indicated.
Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context.
The use of the terms “a” and “an” and “the” and “at least one” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The use of the term “at least one” followed by a list of one or more items (for example, “at least one of A and B”) is to be construed to mean one item selected from the listed items (A or B) or any combination of two or more of the listed items (A and B), unless otherwise indicated herein or clearly contradicted by context.
Accordingly, this disclosure includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the disclosure unless otherwise indicated herein or otherwise clearly contradicted by context.