Patent Grant
7721816
The present invention relates to the drilling art and, more particularly, to a drilling or bolting machine including a control system having a manual operator input device for controlling at least one aspect of the drilling or bolting operation.
Drills using rotatable bits for penetrating into the earth are in widespread use. One application of such drills is in conjunction with a machine known in the vernacular as a “roof bolter” capable of both forming boreholes in the faces of the passageways of underground mines and then installing roof anchors or “bolts” in the boreholes. As is well-known in the art, the bolts once installed provide support for the adjacent portion of the mine face (typically the roof and ribs), thereby reducing the incidence of catastrophic cave-ins.
In the typical bolting operation, once the borehole is created using the drill, a resin cartridge is inserted. The drill head is then used to insert a roof bolt into the borehole to rupture the resin cartridge. Once ruptured, the bolt is rotated using the drill head to mix the resin, which is designed to quickly set and form a secure bond with the material surrounding the borehole.
Oftentimes, a manual operator input device, such as a joystick, is used to control the operation of the drill head, both during the drilling and bolting cycles of the operation. A single joystick may be associated with a manual control valve such that movement in a first direction (i.e., forward) results in drill head feed, rotation, or both. Alternatively, two independent joysticks may be used: one for controlling feed and the other, rotation. Using a manual control valve also allows the speed and direction of rotation or feed to be easily controlled by simply pivoting the joystick. However, electronic, solenoid-operated proportional control valves may also be used, if desired.
While an input device such as a joystick provides an intuitive and easy-to-use interface for controlling the drilling and bolt insertion operations, it has been discovered that the operator sometimes inadvertently moves the input device (joystick) for causing rotation when only feed is desired. Likewise, the operator may desire to rotate the chuck at a slow speed to assist in coupling the bolt head with a wrench or socket in a drill “pot,” but inadvertently move the joystick to a position such that a higher rotational speed results. Both of these occurrences essentially require the operator to repeat the procedure and, consequently, decrease the efficiency of the operation.
Accordingly, a need is identified for a manual input device or system for use in controlling a drilling operation, such as during the forming boreholes in one or more faces of a passageway in an underground mine. The input device would be simple to operate using only one hand, yet would prevent inadvertent actuation of the drill head (feed, rotation, or both). The input device would provide failsafe operation and would be tamper-resistant to prevent operator override. The input device would also be easily retrofitted onto existing drilling machines. The use of a neutral switch to prevent movement (tramming) of a drilling machine on power up is also disclosed.
In accordance with a first aspect of the invention, a system for controlling a drilling or bolting operation is disclosed. The system comprises an input device for manually controlling at least one aspect of the drilling or bolting operation, a controller associated with at least one neutral switch, and an actuator for actuating the drilling or bolting operation. The actuator includes a valve associated with the input device and the neutral switch. The input device is operative for controlling the drilling or bolting operation only when the valve is in a neutral position according to the neutral switch.
In one embodiment, the manual input device includes an enable switch associated with the controller. Preferably, the manual input device is operative for controlling the drilling or bolting operation only when the valve is in the neutral position and the enable switch is closed. However, it is also possible that the manual input device is operative for controlling the drilling or bolting operation only when the enable switch is closed before the valve is moved from the neutral position. In either case, the enable switch may be opened once the valve is moved from the neutral position with the enable switch closed without rendering the manual input device inoperative.
In another embodiment, the controller includes a circuit for evaluating whether the enable switch is open or closed at predetermined intervals. Using this circuit, the input device is rendered inoperative for controlling the drilling or bolting operation if the controller determines that the enable switch is closed for a predetermined number of intervals.
The manual input device is preferably a joystick associated with the valve and the enable switch is closed by a trigger associated with the joystick. The actuator preferably includes a valve package for selectively permitting a fluid flow to reach the valve once the controller determines that: (1) an enable switch associated with the input device is closed; and (2) the neutral switch is closed. In a more particular embodiment, the actuator includes at least one fluid-operated motor for controlling a feed or a rotation of either: (1) a drill bit for performing the drilling operation; or (2) a roof bolt used in the bolting operation.
In accordance with a second aspect of the invention, a manual input device for a drilling or bolting machine is disclosed. The device is designed for use by a single hand of an operator having a palm and fingers. The device comprises a support, a head associated with the support and including an upper portion and a lower portion defining an interface, and a low-profile trigger positioned adjacent the interface. The trigger includes a body having a generally semi-circular face for engagement by at least one of the operator's fingers when the palm is positioned on or generally adjacent the upper portion of the head. A switch for controlling some aspect of the drilling or bolting machine or its operation is also associated with the trigger.
In one embodiment, the upper portion of the head is hemispherical, the lower portion is frusto-conical, and the two portions are secured together using fasteners recessed in the upper portion. The face of the trigger is rounded from a top edge to a bottom edge of the body. A slot is defined at the interface and a portion of the trigger body projects through the slot in a home position and when the switch is in an open condition. A spring biases the trigger toward the home position, and the support is an elongated shaft pivotally mounted to a stable support structure.
In accordance with a third aspect of the invention, a different manual input device for use by a single hand of an operator having a palm and fingers is disclosed. The device comprises a support, a head associated with the support and including first and second separable portions defining an interface. A trigger is pivotally mounted adjacent the interface, and includes a magnet and a face for engagement by at least one of the operator's fingers when the palm is positioned on or generally adjacent the head. A magnetically-actuated switch is associated with the head and the magnet of the trigger in an actuated position. Accordingly, the presence of dust or water adjacent the head does not impair actuation of the switch by the trigger.
In accordance with a fourth aspect of the invention, a system for controlling a machine for use in performing a drilling or bolting operation is disclosed. The system comprises a fluid-operated motive device for moving the machine; a valve for controlling fluid flow to the motive device; an input device for manually controlling the position of the valve; and a neutral switch associated with the valve. The motive device is capable of moving the machine only when the valve is in a neutral position according to the neutral switch. In one embodiment, the input device includes an enable switch, and the motive device is capable of moving the machine only when the enable switch is closed before the neutral switch is closed.
In accordance with a fifth aspect of the invention, an input device for controlling a position of first and second valve spools is disclosed. The input device comprises a lever, a first ball joint supporting the lever, a first linkage connecting the lever to the first spool, and a second linkage connecting the lever to the second spool. Movement of the lever to and fro in a first direction results in corresponding movement of the first spool and movement in a second direction results in corresponding movement of the second spool.
In one embodiment, movement in the first direction and the movement in the second direction occur simultaneously. In another, movement in the first direction occurs before the movement in the second direction. Preferably, the first and second directions are generally perpendicular, but the first and second spools move generally parallel.
a is a top view of the input device of
a-3d present various views of a neutral switch for intended use in the control system of
a-4d present various views of another embodiment of an operator input device;
a-6e present different views of yet another operator input device.
Reference is now made to
The system 10 further includes a controller 14 and an actuator 16 for actuating the drilling and/or bolting operation based on the manual input received, such as by rotating and feeding either a drill steel and bit into the earth to form a borehole or a roof bolt into the borehole once formed. In the illustrated embodiment, the actuator 16 includes separate fluid-operated motive devices or motors 18, 20 for providing the feed and rotational forces to the drill head (not shown). The fluid flow to the motors 18, 20 may be regulated or controlled by a valve package 21 (see
A switch 24 is associated with the feed and rotation control sections 22a, 22b of the valve 22 and the controller 14. When open, the switch 24 indicates that the valve 22 (or, more specifically, the spool 23) is in the neutral position. These “neutral” switches 24 may be conventional position or proximity switches, various types of which are well known in the art, and may be positioned adjacent to the valve 22. An exemplary neutral switch 24 including a detent ball 24a seated in a circumferential groove 23a formed in the valve spool 23 of a single valve section 22a is shown in
The preferred embodiment of the input device 12 in the form of a joystick 30 is shown in
The joystick 30 includes an elongated body or shaft 32 that supports an oversized head 34. The head 34 includes a generally rounded or hemispherical upper portion 34a adapted for being comfortably received in the cupped hand of the operator, generally in engagement with the palm. A generally tapered or frusto-conical lower portion 34b of the head 34 provides support for the upper portion 34a and serves as the interface with the shaft 32. As a result of the frusto-conical shape, the lower portion 34b provides a flat, slightly recessed resting place for the tips of the operator's fingers when the corresponding hand is positioned adjacent to the joystick 30, such as during manual engagement. The upper and lower portions may be secured together via fasteners F. As shown in
In accordance with one aspect of the invention, the input device 12 includes an enable switch 36 for preventing inadvertent actuation of the actuator 16 (i.e., the motors 18, 20). In the most preferred embodiment, as shown in
The button 38 serving as the trigger is preferably biased toward a non-engaged or home position by a spring or like biasing means (not shown) positioned within the head 34. As is the case with the joystick 30, the biasing force supplied should be low enough that it is easily overcome by finger action. However, it should not be sufficiently high to prevent inadvertent actuation, such as by being bumped or jarred by the operator or contacted by a falling object.
a-4d show an alternate embodiment of a head 40 for the joystick 30. This head 40 is comprised of two mating halves 40a, 40b secured together by a fastener F. The mated halves 40a, 40b form a receiver 42 for a shaft (not shown) carrying a torsion spring 44. These halves 40a, 40b also provide support for a pivot pin 46 carrying a trigger in the form of a button 48. The button 48 is normally biased outwardly by the spring 44, and carries a magnet 48a. An adjacent magnetically activated switch 49 (preferably zero volume) actuates upon engaging the magnet 48a when the button 48 is pressed (in which case a signal propagates along line L). The button 48 in this embodiment thus associates with the enable switch 36. The use of a magnetically actuated switch is preferable, since it is resistant to the effects of water and dust.
As briefly noted above, movement of the joystick 30 from a neutral or home position results in the opening of the control valve 22 and the closing of one or both of the neutral switches 24. However, unless the enable switch 36 is closed (such as by depressing the button 38 or 48) before the joystick 30 is moved from the neutral position (as determined by the closing of the neutral switch(es) 24), the controller 14 does not actuate (energize) the valve package 21. Consequently, no flow to the valve 22 results. In other words, if the joystick 30 moves from the neutral position before the enable switch 36 is closed (i.e., before the button 38 is engaged), the controller 14 does not signal the valve package 21 to allow additional fluid flow to reach the corresponding valve 22 (which means that the feed or rotation motors 18, 20 do not actuate).
Likewise, if the enable switch 36 is closed while the joystick 30 is moved from the neutral position, no actuation occurs even if the joystick is returned to the neutral position with the enable switch closed and then moved from the neutral position again with the switch closed. However, the logic arrangement in the controller 14 may be such that, once the joystick 30 is moved from the neutral position with the enable switch 36 closed, it thereafter may be opened (such as by releasing the button 38 or 48) without incident.
To prevent the operator from defeating the function provided by the enable switch 36 (such as by jamming the button 38 or 48 in the engaged position), the system 10 may include a “watchdog” circuit 50 (see
In accordance with a second aspect of the invention, and as shown in
As also shown in
a-6e illustrate an alternative input device 12 in the form of a lever 30 that may be used to control simultaneously two distinct valve sections 22a, 22b. The lever 30 includes a first linkage 70 extending between a body or shaft 32 and a valve spool 23a associated with a first valve section 22a. A second, generally transverse linkage 72 extends between the body 32 and a post 74. A pivotally mounted connector 76 connects the post 74 to a second valve spool 23b associated with a second valve section 22b. Both the post 74 and lever 30 are mounted using ball joints 78 to permit movement along at least two different axes in the same plane.
As should be appreciated, the input device 12 of this embodiment allows for simultaneous control of two different valve spools 23a, 23b using the same input device 30 (lever). More specifically, the second linkage 72 is rotatable about the shaft 32 such that it moves to and fro when the lever 30 is manipulated (pivoted) in a first direction (D1 in
Movement of the lever 30 to the left (that is, in a second direction D2 perpendicular to the first direction) causes the connector body 76 to pivot about a pivot point P defined by a clevis 78 connected to a support structure 80 (see action arrow A in
As should be appreciated, by associating the first valve spool 23a with drill head rotation and the second valve spool 23b with feed, it is possible to commence the former without the latter. However, both feed and rotation may result by pulling the lever 30 back and then moving it to the left. Likewise, rotation and feed can be simultaneously reversed by moving the lever forward and to the right. Other combinations are of course possible in light of the foregoing description. By using neutral switches and providing an enable switch on the input device, this arrangement may also be used in conjunction with the controller 14 to create a lockout condition unless the switches are actuated in a certain sequence, as outlined in detail in the foregoing description.
As should be appreciated, any of the above manual operator input devices may be retrofitted onto an existing drilling or bolting machine to replace the existing input device. Any adjustments necessary to provide a corresponding controller can also be made to implement the overall control systems disclosed.
The foregoing descriptions of various embodiments of the invention 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, other manual input devices, such as those including simple proximity switches for detecting the presence of the operator near the controller (see, e.g., U.S. Pat. No. 6,501,198, the disclosure of which is incorporated herein by reference) may be used instead of those described. 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 are within the scope of the invention as determined by the appended claims when interpreted in accordance with the breadth to which they are fairly, legally and equitably entitled.
This application claims the benefit of U.S. Provisional Application Ser. No. 60/485,566, filed Jul. 8, 2003, the disclosure of which is incorporated herein by reference.
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| Number | Date | Country | |
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| 60485566 | Jul 2003 | US |
