GB2573614A

GB2573614A - Safety pull cord for a conveyor

Info

Publication number: GB2573614A
Application number: GB1902982.6A
Authority: GB
Inventors: J Cressman Toby; N Marburger Andrew
Original assignee: Joy Global Underground Mining LLC
Current assignee: Joy Global Underground Mining LLC
Priority date: 2018-03-06
Filing date: 2019-03-06
Publication date: 2019-11-13
Anticipated expiration: 2039-03-06
Also published as: WO2019173502A1; CA3035866A1; GB2586730B; GB201902982D0; CA3093410A1; ZA201901396B; RU2019106293A; ZA202005983B; RU2769319C1; AU2019201543A1; GB202015636D0; AU2019231680A1; GB2573614B; GB2586730A

Abstract

A conveyor system comprising a flexible conveyor train 14, a controller 26, and a safety actuator 30 supported on the train. The conveyor train has a first and second end, a belt (22, fig 1) to transport material driven by a motor that is in communication with the motor. The safety actuator 30 comprises a cord 42 connected at one end 38 to a trip switch 94 coupled to the controller, and at a second end 34 to a retractor 46 to maintain tension in the cord 42 during flexing of the conveyor. The trip switch 94 may move between two positions designating modes that permit or inhibit the controller operating the conveyor, where force on cord 42 may shift the switch. The retractor 46 may have two modes to permit or inhibit cord 42 from being paid out, it may include a spool 54 around which the cord 42 is wrapped, where excessive spool rotation engages a clutch 62 with a pawl 70 inhibiting rotation.

Description

SAFETY PULL CORD FOR A CONVEYOR

CROSS REFERENCE TO RELATED APPLICATIONS [0001] This application claims priority to co-pending, prior-filed U.S. Provisional Patent Application No. 62/639,000, filed March 6, 2018, the entire contents of which are incorporated by reference herein.

BACKGROUND [0002] The present application relates to conveyor systems, and more particularly to a safety pull cord for a conveyor.

[0003] Mining conveyors facilitate the movement of a mined material. In order to comply with many global regulations, conveyors are required to have a safety pull cord that can be operated to shut down the conveyor in case of an emergency. However, some conveyors are flexible and move throughout a mining cycle causing conventional pull cords to accidentally shut down the conveyor. In addition, conventional pull cords provide a large amount of slack requiring a user to pull a significant amount before the conveyor shuts down.

SUMMARY [0004] In one embodiment, a conveyor system includes a flexible conveyor train configured to move along a path, a controller, and a safety actuator supported on the conveyor train. The conveyor train includes a first end, a second end, a continuous belt for transporting material along a length of the conveyor train, and at least one motor for driving the continuous belt. The controller is in communication with the motor to control operation of the conveyor train. The safety actuator includes a retractor, a trip switch electrically coupled to the controller, and a cord having a first end and a second end. The first end is coupled to the retractor, and the second end is coupled to the trip switch.

[0005] In another embodiment, a conveyor system includes a conveyor train movable upon a support surface, a controller, and a safety actuator. The conveyor train includes a plurality of movable segments coupled to one another in series, a continuous belt for transporting material along a length of the conveyor train, and at least one motor for driving the continuous belt. The controller is supported by the conveyor train and operable to control operation of the conveyor train. The safety actuator is supported on the conveyor train and includes a cord, a spool for receiving the cord, and a clutch. While a rotational speed of the spool exceeds a predetermined level, the clutch causes a pawl to engage the spool and inhibit rotation of the spool, thereby causing the controller to stop operation of the conveyor train.

[0006] In yet another embodiment, a conveyor system includes a flexible conveyor train configured for movement along an underground path, a trip switch, and a cord. The conveyor train includes a first end, a second end, a continuous belt fortransporting material along a length of the conveyor train, and at least one motor. The trip switch is selectively operable in a first mode in which operation of the motor is permitted and a second mode in which operation of the motor is inhibited. The cord is partially wrapped onto a spool and coupled to the trip switch. The spool is biased to wrap the cord onto the spool, and application of a force on the pull cord is operable to change the trip switch from the first mode to the second mode.

[0007] Other aspects will become apparent by consideration of the detailed description and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS [0008] FIG. 1A illustrates an overview of a mining roadway and mining operation.

[0009] FIG. 1B is a perspective view of a conveyor.

[0010] FIG. 2 is a front elevation view of a safety actuator.

[0011] FIG. 3A is a side view of a retractor of the safety actuator of FIG. 2 in a free position.

[0012] FIG. 3B is a side view of the retractor in a locked position.

[0013] FIG. 4A is a perspective view of the retractor in a free position, with a clutch and cam member removed.

[0014] FIG. 4B is a perspective view of the retractor in a locked position, with a clutch and cam member removed.

[0015] Before any embodiments are explained in detail, it is to be understood that the disclosure is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The disclosure is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. Use of including and “comprising” and variations thereof as used herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Use of “consisting of’ and variations thereof as used herein is meant to encompass only the items listed thereafter and equivalents thereof. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings.

[0016] In addition, it should be understood that embodiments may include hardware, software, and electronic components or modules that, for purposes of discussion, may be illustrated and described as if the majority of the components were implemented solely in hardware. However, one of ordinary skill in the art, and based on a reading of this detailed description, would recognize that, in at least one embodiment, aspects may be implemented in software (for example, stored on non-transitory computerreadable medium) executable by one or more processing units, such as a microprocessor, an application specific integrated circuits (“ASICs”), or another electronic device. As such, it should be noted that a plurality of hardware and software based devices, as well as a plurality of different structural components may be utilized to implement the invention. For example, “controllers” described in the specification may include one or more electronic processors or processing units, one or more computer-readable medium modules, one or more input/output interfaces, and various connections (for example, a system bus) connecting the components.

DETAILED DESCRIPTION [0017] Underground roadway development equipment typically includes a continuous miner and haulage equipment that transports cut material from a cutting face. As shown in FIG. 1A, a mining machine (e.g., a continuous miner 10) can be operated to create a roadway. The mining machine 10, as shown in FIGS. 1A and 1B, performs a cutting operation that includes cutting material from the cutting face and directing the cut material onto a conveyor (e.g., a flexible conveyor train or FCT) 14 to transfer the cut material to other material handling equipment (e.g., a crusher and/or feeder breaker). In the illustrated embodiment, an operator controls both the mining machine 10 and the flexible conveyor train 14 using a remote control. In other embodiments, an operator may control the mining machine 10 and the flexible conveyor train 14 from a deck on the flexible conveyor train 14.

[0018] In the illustrated embodiment, the conveyor 14 is a flexible conveyor train. The flexible conveyor train 14 follows the mining machine 10 to collect and transport mined material. As such, the flexible conveyor train 14 is capable of moving forward and backward along the underground roadway and is capable of turning. The flexible conveyor train 14 employs a plurality of segments or cars 18 coupled to one another in series. In the illustrated embodiment, the cars 18 are coupled by universal joints to allow the flexible conveyor train 14 to flex in lateral and vertical directions. The flexible conveyor train 14 includes a flexible continuous conveyor belt 22 that wraps around rollers on the cars 18 to transport mined material from the mining machine 10 to the other material handling equipment. In some embodiments, each of the cars 18 of the flexible conveyor train 14 includes a controller 26 (FIG. 1A) and a safety pull cord 30. The controllers 26 control the operation of the carts 18 and can communicate with one another and with a controller on the mining machine 10.

[0019] The flexible conveyor train 14 includes a plurality of safety actuators or pull cords 30; as mentioned above, in the illustrated embodiment each car 18 of the flexible conveyor train 14 includes a safety actuator or pull cord 30. With reference to FIG. 2, each safety actuator 30 includes a first end 34, a second end 38 opposite the first end 34, and a cord 42 extending between the first and second ends 34, 38. The first end 34 is fixed to the flexible conveyor train 14 at a position near the back of a respective car 18 (e.g., by screws, bolts, adhesives, etc.). The second end 38 is fixed to the flexible conveyor train 14 at a position adjacent a controller 26 of another respective car 18 (e.g., by screws, bolts, adhesives, etc.).

[0020] With reference to FIGS. 3A and 3B, the first end 34 of the safety pull cord 30 includes a retractor 46 positioned in a housing 50. The retractor 46 includes a spool 54, a resilient member (not shown), a centrifugal clutch 62, a cam member 66, and a pawl 70. The spool 54 is rotatably coupled to the inside of the housing 50 and includes a ratchet portion including teeth 74 positioned along an outer periphery. A first end 78 (FIG. 2) of the cord 42 is coupled to the spool 54 and slack from the cord 42 is wound about the spool 54. The resilient member biases the spool 54 to rotate in a first direction (e.g., counter-clockwise as seen in FIG. 3) to wind up any slack of the cord 42. The centrifugal clutch 62 is pivotally coupled to the spool 54 adjacent the ratchet teeth 74. For example, in the illustrated embodiment, the clutch 62 is pivotably coupled to the spool 54 about a pin 76, and is biased toward a retracted or radially inward position by a spring 80. The cam member 66 is supported adjacent the spool 54. The cam member 66 is coupled to the pawl 70 by a sliding pin 82 that slides within an aperture 86 on the pawl 70.

[0021] The retractor mechanism 46 acts to wind slack from the cord 42 around the spool 54. Slack from the cord 42 may be unwound or paid out from the retractor mechanism 46 when the spool 54 rotates in a second direction (e.g., clockwise as shown in FIGS. 3A and 3B) against the bias of the resilient member. Releasing the cord 42 allows the resilient member to act on the spool 54 rotating it in the first direction to wind up the slack of the cord 42 (FIG. 4A). However, if slack from the cord 42 is paid out rapidly, the spool 54 will increase its rotational speed. The increased rotational speed increases the rotational force on the spool 54 and causes the centrifugal clutch 62 to pivot driving an end 90 of the centrifugal clutch 62 radially outward away from the spool 54. The end 90 of the centrifugal clutch 62 engages and pushes the cam member 66 (e.g., upwardly as shown in FIG. 3B), moving the sliding pin 82 along the aperture 86. The movement of the sliding pin 82 pulls the pawl 70 into the path of the spinning ratchet teeth 74 of the spool 54 as shown in FIGS. 3B and 4B, inhibiting rotation of the spool 54 in the second direction and inhibiting payout of the cord 42. As such, the retractor mechanism 46 is operable in a first mode in which the spool 54 is allowed to pay out slack from the cord 42, and operable in a second mode in which the spool 54 is prevented from paying out slack from the cord 42.

[0022] Referring again to FIG. 2, the second end 38 of the safety actuator 30 includes a trip switch 94. The trip switch 94 includes a conductor 98 that is electrically coupled to the controller 26 of the car 18 of the flexible conveyor train 14 on which the corresponding safety pull cord 30 is positioned. The trip switch 94 is operable in a first mode in which the trip switch 94 communicates with the controller 26 to operate the flexible conveyor train 14, and in a second mode in which the trip switch 94 communicates with the controller 26 to stop operation of the flexible conveyor train 14.

[0023] The trip switch 94 further includes a latch 102, an emergency stop button 106, and a reset button 110. The latch 102 is coupled to a second end 114 of the cord 42 and is moveable between a first position and a second position. While the latch 102 is in the first position, the trip switch 94 is in the first mode to communicate with the controller 26 to operate the flexible conveyor train 14. While the latch 102 is in the second position, the trip switch 94 is in the second mode to communicate with the controller 26 to stop the motors running the flexible conveyor train 14. The emergency stop button 106 may be depressed to stop the motors of the flexible conveyor train 14 and the mining machine 10.

[0024] In an emergency, the flexible conveyor train 14 and the mining machine 10 may be stopped by either actuating the emergency stop button 106 or moving the latch 102 to the second position (e.g., by pulling the cord 42). In order to resume operation of the mining machine 10 and flexible conveyor train 14, the latch 102 must be returned to the first position and/or the emergency stop button 106 must be returned to a non-depressed position and the reset button 110 must be actuated.

[0025] With reference to FIG. 2, in some embodiments the cord 42 is a poly-coated twisted/braided cord; the cord 42 can be made from a rope material covered in a polymer resin. The cord 42 may include clips/hooks 118 at both the first and second ends 78, 114 to attach to the trip switch 94 and/or the spool 54. Eyelets 122 may be coupled to the flexible conveyor train 14 between the first and second ends 34, 38 of the safety pull cord 30 for the cord 42 to slide through and be supported.

[0026] During operation of the mining equipment, the flexible conveyor train 14 follows the mining machine 10 along the underground roadway. As the flexible conveyor train 14 moves, it traverses turns and rough terrain that requires it to flex and curve to maneuver around the underground passages. The maneuvering of the flexible conveyor train 14 will require more slack from the cord 42 in order to avoid an unintentional shut off of the mining equipment. As described above, as slack is needed (for example, when the flexible conveyor train 14 is turning), the spool 54 will rotate to pay out the cord 42 from the retractor mechanism 46. Then, after the flexible conveyor train 14 has completed the turn, the slack is no longer needed and the resilient member rotates the spool 54 in an opposite direction to wind the cord 42 onto the spool 54. While the flexible conveyor train 14 flexes or adjusts for length, the cord 42 of the safety pull cord 30 is allowed to extend and retract as needed without activating the trip switch 94. It should be noted that normal movement of the flexible conveyor train 14 is not sufficient to pull the cord 42 to lock the spool 54 and activate the trip switch 94.

[0027] If, however, during operation of the mining equipment an emergency were to occur requiring a quick shut off of the flexible conveyor train 14, an operator or a bystander may pull the cord 42 sharply to shut the flexible conveyor train 14 down. For example, if a bystander positioned near the flexible conveyor train 14 were to get their hand stuck in the flexible conveyor train 14 or the continuous conveyor belt 22, the bystander could pull the cord 42. As described above, pulling the cord 42 sharply applies an increased centrifugal force to the spool 54 that causes the end 90 of the centrifugal clutch 62 to pivot. The centrifugal clutch 62 pushes the cam member 66 moving the pawl 70 into contact with the ratchet teeth 74, thereby stopping the rotation of the spool 54. The stopping of the spool 54 discontinues payout of the cord 42 and allows the second end 114 of the cord 42 to move the latch 102 of the trip switch 94 from the first position to the second position, shutting off the motors of the mining machine 10 and the flexible conveyor train 14. Once the emergency condition is cleared, the latch 102 of the trip switch 94 can be moved back to the first position and the reset button 110 pressed to continue operation of the flexible conveyor train 14 and the mining machine 10.

[0028] Providing a flexible conveyor train 14 with a safety pull cord 30 including a centrifugal clutch 62 and a spool 54 advantageously allows the flexible conveyor train 14 to adhere to safety regulations while still permitting movement without activating a trip switch 94. The safety pull cord 30 can be pulled by an operator in an emergency to shut down the flexible conveyor train 14. In addition, providing a conveyor 14 with a safety pull cord 30 with a centrifugal clutch 62 and spool 54 manages the cord 42 to avoiding the excessive slack. Reducing slack allows a bystander or an operator to effectively pull the cord 42 to deactivate the conveyor 14 when needed.

[0029] Although various aspects have been described in detail with reference to certain embodiments, variations and modifications exist within the scope and spirit of one or more independent aspects as described. Various features and advantages are set forth in the following claims.

[0030] Attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

[0031] All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

[0032] Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

[0033] The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

1. A conveyor system comprising:

a flexible conveyor train configured to move along a path, the conveyor train including a first end, a second end, a continuous belt fortransporting material along a length of the conveyor train, and at least one motor for driving the continuous belt;

a controller in communication with the motor to control operation of the conveyor train; and a safety actuator supported on the conveyor train, the safety actuator including a retractor, a trip switch electrically coupled to the controller, and a cord having a first end and a second end, the first end coupled to the retractor, the second end coupled to the trip switch.

2. The conveyor system of claim 1, wherein the trip switch is selectively operable in a first trip mode and a second trip mode, while the trip switch is in the first trip mode the controller operates the flexible conveyor train, while the trip switch is in the second trip mode, the controller interrupts operation of the flexible conveyor train.

3. The conveyor system of claim 2, wherein the retractor is selectively operable in a first retractor mode and a second retractor mode, while the retractor is in the first retractor mode the retractor permits the cord to be paid out, while the retractor is in the second retractor mode the retractor inhibits the cord from being paid out.

4. The conveyor system of claim 3, wherein the trip switch further includes a latch movable between a first position and a second position, wherein while the latch is in the first position, the trip switch is operable in the first trip mode, and while the latch is in the second position, the trip switch is operable in the second trip mode, wherein while the retractor is in the second mode the latch is movable from the first position to the second position.

5. The conveyor system of any one of claims 2 to 4, wherein applying a predetermined force on the cord shifts the trip switch from the first trip mode to the second trip mode.

6. The conveyor system of any preceding claim, wherein the retractor includes a spool and a centrifugal clutch, at least a portion of the cord wrapped onto the spool, wherein when a rotational speed of the spool exceeds a predetermined level, the centrifugal clutch extends radially outwardly to cause a pawl to engage the spool and inhibit rotation of the spool.

7. A conveyor system comprising:

a conveyor train movable upon a support surface, the conveyor train including a plurality of movable segments coupled to one another in series, a continuous belt for transporting material along a length of the conveyor train, and at least one motor for driving the continuous belt;

a controller supported by the conveyor train and operable to control operation of the conveyor train; and a safety actuator supported on the conveyor train, the safety actuator including a cord, a spool for receiving the cord, and a clutch, while a rotational speed of the spool exceeds a predetermined level, the clutch causes a pawl to engage the spool and inhibit rotation of the spool, thereby causing the controller to stop operation of the conveyor train.

8. The conveyor system of claim 7, wherein application of a force on the cord while rotation of the spool is inhibited causes the controller to stop operation of the flexible conveyor train.

9. The conveyor system of claim 7 or 8, wherein the controller is one of a plurality of controllers, each of the controllers supported on an associated one of the movable segments, wherein the safety actuator is one of a plurality of safety actuators, each of the safety actuators supported on an associated one of the movable segments.

10. The conveyor system of any one of claims 7 to 9, wherein the safety actuator further includes a resilient member biasing the spool in a direction to wind the cord onto an outer surface of the spool.

11. The conveyor system of claims 7 to 10, wherein the clutch is a centrifugal clutch, while the rotational speed of the spool exceeds the predetermined level, the centrifugal clutch extends to cause a pawl to engage a ratchet surface.

12. The conveyor system of claims 7 to 11, further comprising a trip switch coupled to an end of the cord, wherein actuation of the trip switch causes the controller to stop operation of the conveyor train.

13. A conveyor system comprising:

a flexible conveyor train configured for movement along an underground path, the conveyor train including a first end, a second end, a continuous belt for transporting material along a length of the conveyor train, and at least one motor;

a trip switch selectively operable in a first mode in which operation of the motor is permitted and a second mode in which operation of the motor is inhibited; and a cord partially wrapped onto a spool and coupled to the trip switch, the spool biased to wrap the cord onto the spool, application of a force on the pull cord operable to change the trip switch from the first mode to the second mode.

14. The conveyor system of claim 13, wherein the flexible conveyor train includes a plurality of movable segments coupled together in series, wherein the trip switch is one of a plurality of trip switches, each of the trip switches positioned on an associated one of the movable segments.

15. The conveyor system of claim 13 or 14, wherein application of the force on the cord causes rotation of the spool, further comprising a clutch for stopping and locking the spool against rotation when the rotational speed of the spool exceeds a predetermined level.

16. The conveyor system of claim 15, wherein the clutch is a centrifugal clutch, wherein rotation of the spool causes the clutch to extend radially outwardly, while the rotational speed of the spool exceeds the predetermined level, the centrifugal clutch causes a pawl to engage a ratchet surface.

17. The conveyor system of any one of claims 13 to 16, further comprising a controller electrically coupled between the motor and the trip switch, actuation of the trip switch causing the controller to inhibit operation of the motor.