Patent Application
20160152102
The present invention relates to a robotic tyre changing apparatus and associated hardware and methods. Embodiments of the present invention find application, though not exclusively, in the mining industry for use with the wheels and tyres of large haul trucks and dump trucks.
Any discussion of documents, acts, materials, devices, articles or the like which has been included in this specification is solely for the purpose of providing a context for the present invention. It is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present invention as it existed in Australia or elsewhere before the priority date of this application.
The removal of wheels and tyres from large mining haul trucks and dump trucks is typically achieved with the use of a mechanical wheel handler to support the wheel whilst a worker removes nuts to free the wheel from the hub. Typically this involves the worker operating hand tools or mechanised nut runners (such as pneumatic impact drivers, or the like) to loosen and remove each of the nuts whilst working within a region that is unsafe due to a risk that the tyre may fall or explode.
A partial solution to this problem is provided by the prior art arrangement disclosed in International Publication No. WO 2012/094706, which utilises a movable vehicle 42 working in conjunction with a tyre handler (as illustrated, for example, in
If it is desired to remove only a tyre (as opposed to the wheel and tyre together as discussed in the preceding two paragraphs), the tyre is firstly deflated and then a tyre handler is typically used to push the side wall of the tyre inwardly so as to reveal hardware referred to as “jewelry”, that is used to connect the tyre bead to the rim of the wheel. The jewelry typically includes a circular clip, referred to as a “lock ring”, which seats within a circumferential groove that extends around the wheel rim. The lock ring is removed from the wheel rim manually by a worker using a crow bar; with the worker being required to briskly evacuate from the area next to the wheel once the lock ring has been loosened and falls to the ground. Due to the size and weight of the lock ring, this poses a substantial risk of injury. An additional component of the jewelry is an o-ring, which also seats within a circumferential groove that extends around the wheel rim. Such o-rings are typically manually removed and subsequently inserted by a worker and this manual process exposes the worker to a risk of crushing or exposure to an explosion.
It is an object of the present invention to overcome, or substantially ameliorate, one or more of the disadvantages of the prior art, or to provide a useful alternative.
In one aspect of the present invention there is provided a tyre changing apparatus for use with a tyre disposed on a wheel, said apparatus including:
a tyre handler having two arms respectively defining distal ends adapted in use to clampingly engage the tyre; and
at least one robot disposed on said tyre handler, the at least one robot being positioned for interaction with the wheel when the tyre is clampingly engaged by said distal ends.
Preferably the two arms define respective proximal ends that are each disposed on a frame and the at least one robot is disposed at, or adjacent to, at least one of the proximal ends. In one embodiment a first robot is disposed at, or adjacent to, the proximal end of a first of the two arms and a second robot is disposed at, or adjacent to, the proximal end of a second of the two arms.
Preferably the at least one robot is a robotic arm having a proximal end disposed on said tyre handler and having a distal end from which a tool is operable. In one embodiment the tool is at least one of: a nut runner; a lock ring gap spreader, an o-ring installation device, a cleaning device, an inflation device or a deflation device.
According to a second aspect of the present invention there is provided a lock ring gap spreader for use with a lock ring defining a gap, the lock ring gap spreader including:
a circular housing sized for fitment around the lock ring; and
an automated spreader unit disposed on a periphery of the housing, the automated spreader unit acting upon a pair of projections so as to define a closed state in which the pair of projections are disposed close enough to each other so as to fit within the gap and said spreader unit defining an open state in which the pair of projections are circumferentially spaced from each other so as to spread the gap in the lock ring.
In one embodiment the automated spreader unit is hydraulic and in another embodiment it is pneumatic.
The lock ring gap spreader preferably further includes a plurality of handles disposed on the periphery of the housing, each of the handles being engagable by a robotic arm.
Preferably the circular housing is sized so as to receive the lock ring whilst the gap in the lock ring is being maintained in a spread apart state by the spreader unit to thereby stablise the lock ring against twisting.
According to a third aspect of the present invention there is provided an o-ring installation device for installing an o-ring onto a slot in a wheel rim, the o-ring installation device including:
a circular ledge sized for fitment around the wheel rim and being sized so as to retain the o-ring upon the ledge by frictional engagement of the o-ring with the ledge; and
an actuator disposed on a periphery of the ledge and being operable to displace the o-ring off the ledge such that, in use, the o-ring radially contracts onto the slot in the wheel rim.
In one embodiment of the o-ring installation device the actuator is an electromagnetic linear actuator. Preferably the actuator acts upon an elongate member disposed at an angle of between 45° and 135° with respect to the ledge.
Preferably the o-ring is installable so as to resiliently radially bear upon the ledge and so as to rest against the elongate member.
According to a fourth aspect of the present invention there is provided a method of removing a wheel from a truck including the steps of:
providing a tyre changing apparatus as described above;
using the tyre handler to clampingly engage a tyre on the wheel;
causing the robot to operate a nut runner so as to remove nuts holding the wheel onto the truck; and
using the tyre handler to remove the wheel from the truck.
According to a fifth aspect of the present invention there is provided a method of removing a lock ring from a slot in a wheel rim, the method including the steps of:
providing a tyre changing apparatus as described above;
using the tyre handler to displace a bead of the tyre away from the lock ring installed on the wheel;
causing the robot to operate a lock ring gap spreader as described above so as to remove the lock ring.
According to a sixth aspect of the present invention there is provided a method of installing a lock ring onto a slot in a wheel rim, the method including the steps of:
causing a robot to operate a lock ring gap spreader as described above in the closed state so as to position the pair of projections within a gap in the lock ring;
toggling the lock ring gap spreader into the open state so as to spread the gap and so as to house the lock ring within the housing;
causing the robot to position the lock ring gap spreader such that the housed lock ring is radially aligned with the slot; and
toggling the lock ring gap spreader into the closed state so as to install the lock ring onto the slot.
According to another aspect of the present invention there is provided a method of installing an o-ring onto a slot provided within a rim of a wheel, the method including the steps of:
providing a tyre changing apparatus as described above; and
causing the robot to operate an o-ring installation device as described above so as to install the o-ring.
The features and advantages of the present invention will become further apparent from the following detailed description of preferred embodiments, provided by way of example only, together with the accompanying drawings.
The embodiment of the tyre changing apparatus 1 as depicted for example in
The proximal ends 9 and 10 of arms 5 and 6 are each disposed on a cross member 11 to form a frame that is referred to as a “grab unit”. The frame (5, 6, 11) is disposed on a generally vertical track system 12 to allow the operator to raise and lower the frame as required. Additionally, in many embodiments of tyre handler, the distal ends 7 and 8 are rotatably mounted to the arms 5 and 6 to allow the operator to rotate the tyre and wheel, if necessary.
It has been appreciated by the inventor of the present application that the grab unit of a tyre handler can provide a stable work platform from which robots may execute tasks. Hence, a first robot 13 is disposed adjacent to the proximal end 9 of arm 5 and a second robot 14 is disposed adjacent to the proximal end 10 of the second arm 6. The illustrated preferred embodiment utilized two robots 13 and 14 so as to share the workload to increase the total operational speed. However, for applications in which operational speed is of a lesser importance, a single robot may be disposed on the frame (5, 6, 11). Additionally, if operational speed is of the essence, then more than two robots may be utilized. A robot control system is housed within a stainless steel enclosure that is disposed upon the tyre handler 4.
Each of the robots 13 and 14 is a robotic arm such as one of the IRB 4600 series of articulated robot, as marketed by ABB AB Robotics Products, which is based in Vasteras, Sweden. The particular robot utilized in the preferred embodiment is the IRB 4600-40/2.55. However, it will be appreciated that various other robots may be utilized in alternative embodiments.
The proximal ends 15 and 16 of the two robots 13 and 14 are disposed on a base plate that is bolted or otherwise connected to the frame (5, 6, 11) of the tyre handler 4. The distal ends 18 and 19 of the two robots 13 and 14 each include a tool changer unit that is capable of automatically engaging with, and operating, a selected tool. The tool changer unit includes a plug for establishing electrical connections between the robot and the selected tool, along with hydraulic and pneumatic connections, as required. This allows the robot to control the operation of the selected tool. By way of non-limiting example, as shown in
A non-limiting example of a plurality of tools being separately operated at the distal ends 18 and 19 of each the robots 13 and 14 is depicted in
One of the important functions of a tyre handler 4 is to rotate and then refit tyres so that the previous outer edge of the tyre becomes the new inner edge. This promotes even tread wear on the tyres. Hence, the robots 13 and 14 each have a rest position that provides sufficient clearance to allow for the removed tyre and wheel to be rotated within the grab unit without hitting either of the robots.
A reversal of the steps described above may be undertaken to fit a wheel onto the truck. When fitting a wheel to a truck, the robot control system is programmed to drive the robots 13 and 14 to perform the nut tightening in a sequence that aims to spread the load approximately equally across all of the nuts. Some embodiments of the nut runners provide for data logging of the final torque level to which each of the nuts has been tightened, which may be advantageous for the purposes of maintaining a safety audit trail and for quality assurance purposes.
Other examples of tools that the robots are capable of operating include an o-ring installation device, a cleaning device, a tyre inflation device and a tyre deflation device. The various tools as required for a particular job may be stored in locations on the fork truck part of the tyre handler 4.
A first embodiment of a lock ring gap spreader 20 is illustrated in
Four handles 41, 42, 43 and 44 are disposed equidistantly along the circumference of the housing 25. Each of the handles is for engagement by one of the robotic arms 13 or 14. This allows the robot to physically handle the lock ring gap spreader 20 and includes an electrical interface to enable control signals to be provided from the robot 13 or 14 to operate the lock ring gap spreader 20.
An automated spreader unit 26 is disposed on a periphery of the housing 25. It has a hydraulic or pneumatic cylinder 40 that forces a rod to radially extend or retract from the cylinder in accordance with a control signal that is provided to the cylinder by the robot control system. In an alternative embodiment a linear electric actuator takes the place of the hydraulic or pneumatic cylinder 40. The cylinder 40 is rigidly connected to left and right outer arms 28 and 29. The left outer arm 28 is hingedly connected to a minor extremity of left L-shaped member 33. The distal end of the rod 27 is rigidly connected to a boss 30. A left inner arm 31 is hingedly connected at a proximal end to the left hand side of the boss 30 and at a distal end to the apex of the left L-shaped member 33. The major extremity of the left L-shaped member 33 is hingedly attached to a left hand circumferential slider unit 35, which is rigidly connected to a left hand projection 36.
The right outer arm 29 is hingedly connected to a minor extremity of right L-shaped member 34. A right inner arm 32 is hingedly connected at a proximal end to the right hand side of the boss 30 and at a distal end to the apex of the right L-shaped member 34. The major extremity of the right L-shaped member 34 is hingedly attached to a right hand circumferential slider unit 37, which is rigidly connected to a right hand projection 38.
Each of the circumferential slider units 35 and 37 has a pair of followers 64 and 65, which track within a circumferential slot 39. The geometry of this arrangement is such that, when the rod 27 is retracted within the cylinder 40, the spreader unit 26 is in a closed state in which in the left and right projections 36 and 38 are disposed close enough to each other so as to fit within a gap 46 in the installed lock ring 23. However, as the rod 27 extends from the cylinder 40, the slider units 35 and 37 are forced by the L-shaped arms 33 and 34 to slide apart. This causes the spreader unit 26 to assume its open state whereby the left and right projections 36 and 38 are circumferentially spaced apart from each other.
The method of removing the lock ring 23 from a slot 21 in a wheel rim 22 commences with the use of the tyre handler 4 to displace the outer bead of the tyre 24 away from the lock ring 23. This provides some clearance between the lock ring 23 as installed on the wheel rim and the other jewelry that is depicted in
The control system then causes the two robots 13 and 14 to rotate the lock ring gap spreader 20 until the projections 36 and 38 are in axial alignment with the previously determined position of the gap 46. This may require the two robots to conduct a hand-to-hand shuffle of the handles 41, 42, 43 and 44 to achieve the desired alignment. The two robots 13 and 14 then displace the lock ring gap spreader 20 axially along the hub 45 until the housing 25 surrounds the installed lock ring 23, as shown for example in
Whilst the gap 46 in the lock ring 23 is spread apart, and once the lock ring is no longer seated within the slot 21 of the rim 22, there is a risk of the lock ring 23 twisting and springing off the projections, which could be potentially damaging and dangerous. For this reason, once the gap 46 is spread apart and the outer diameter of the lock ring 23 is thereby increased, the lock ring 23 is now sized to be received by, and retained within, the housing 25, which provides support to resist twisting and to stably retain the lock ring 23.
The control system then causes the two robots 13 and 14 to displace the lock ring gap spreader 20 (with the lock ring 23 housed within) axially away from the truck as shown in
Once the lock ring has been removed the tyre handler 4 may be used to break the rear bead and remove the tyre 2 from the wheel 3. It is then typically necessary to remove the used o-ring 55 from the wheel rim 22. This may be performed manually or by the robots 13 and 14. Typically the used o-ring 55 is discarded and hence it may simply be destroyed whist being removed, for example by being ripped off.
An alternative embodiment of a lock ring gap spreader 47 is shown in a closed state in
By reversing the steps outlined above, it is possible to use the lock ring gap spreader 20 or 47 to install a lock ring 23 onto the slot 21 that is provided in the wheel rim 22. More particularly, the method of installing the lock ring 23 onto the slot 21 in the wheel rim 22 commences with the robot control system sending a signal via one the robots 13 or 14 to put the lock ring gap spreader 20 or 47 into the closed state. Next the robot control system drives the robots 13 and 14 so as to position the pair of projections 36 and 38 within the gap 46. The robot control system then sends a signal to toggle the lock ring gap spreader 20 or 47 into the open state so as to spread the gap 46 and thereby expand the lock ring 23 such that it is housed within the housing 25. Next the robot control system drives the robots 13 and 14 so as to position the lock ring gap spreader 20 or 47 such that the housed lock ring 23 is radially aligned with the slot 21. The robot control system then sends a signal to toggle the lock ring gap spreader 20 or 47 into the closed state, which contracts the lock ring 23 such that it seats onto the slot 21.
In some embodiments, the robots 13 and 14 have access to dispensers, which may be operated by the robots to deliver materials and/or fluids as required during the fitment of the tyre 2. For example, in some circumstances it may be necessary to use the robots 13 and 14 to deliver a lubricant such as “rim soap” to assist in fitting the tyre onto the wheel. Alternatively, adhesives to bond the tyre bead 24 to the wheel rim 22 may be delivered. Additionally, it may be necessary to use the robots 13 and 14 to deliver fire retardant materials within the tyre 2 immediately prior to installing the tyre 2 onto the rim 22.
When fitting a tyre 2 to a wheel 3 it is typically necessary to install a fresh o-ring 55 into a slot 56 that is provided within the wheel rim 22. A cross sectional depiction of a first embodiment of an o-ring installation device 53 is shown in
An electromagnetic linear actuator 58 is disposed on a periphery of the circular ledge 57. It will be appreciated that other types of actuator, such as hydraulic or pneumatic actuators, may be used in alternative embodiments, as required. The actuator 58 has a rod 59 that is depicted in
The o-ring 55 has a diameter that is slightly smaller than the slot 21 into which it is to be installed. Given that the circular ledge is sized for fitment around the wheel rim 22, it therefore follows that the o-ring diameter is also smaller than the diameter of the circular ledge 57. To commence the o-ring installation process, the o-ring 55 is firstly loaded onto the circular ledge 57. This requires a slight stretching of the o-ring when it is manually installed onto the circular ledge 57, which retains the o-ring 55 upon the circular ledge 57 by frictional engagement of the o-ring 55 with the ledge 57 due to the resiliency of the o-ring 55. That is, the resiliency of the o-ring 55 causes it to radially bear upon the ledge and it is preferably pushed along with ledge 57 so as to rest against the elongate member 60, as shown in
Once the o-ring 55 has been loaded onto the circular ledge 57, the o-ring installation device 53 is grasped by the two robots 13 and 14 via two of the four handles in a similar manner to that described above with regard to the lock ring gap spreader 20. The control system then drives the robots 13 and 14 to position the o-ring removal device 53 into axial alignment with the wheel rim 22. The control system then drives the robots 13 and 14 to axially displace the o-ring removal device 53 toward the slot 56 until the edge of the ledge 57 is adjacent the slot 56 as shown in
As shown in
Once a tyre 2 has been loosely fitted to a wheel 3, an embodiment of the invention includes an inflation device whereby a hose is connected at a proximal end to an air compressor that is stored on the fork truck part of the tyre handler. An outlet nozzle is disposed on the distal end of the hose. In this embodiment the control system drives one of the robots 13 to manipulate the distal end of the hose such that the outlet nozzle engages the wheel's inlet valve. The control system then sends a signal to the air compressor to start the provision of pressurized air to inflate the tyre. As inflation commences the other robot 14 operates an impulse hammer so as to seat the bead 24 of the tyre 2. Inflation then proceeds until the desired inflation pressure has been achieved within the tyre 2.
Embodiments of the present invention marry the robotics with the tyre handler 4 to provide a single functional unit. This compares favourably with the disclosure of WO 2012/094706 in which the robotics is disposed on a movable vehicle 42 that is separate from the tyre handler. Importantly, when disposed on the tyre handler, the robotic arms 13 and 14 of the preferred embodiment of the present invention have good access to the wheel. This compares favourably with the disclosure of WO 2012/094706 in which the robotic arm is disposed on a moveable vehicle 42 that is located to the side of the arms of the separate tyre handler. This arrangement requires the robotic arm disclosed in WO 2012/094706 to work around the obstruction caused by the arms of the tyre handler. Additionally, the present invention allows the operator of the tyre handler to maintain an improved view of the working area, as compared to the disclosure of WO 2012/094706 in which the separate movable vehicle 42 may cause a visual obstruction. Further, the integration of robotics onto the currently used tyre handling equipment allows for minimal impact on current practices (other than to advantageously remove labour from the danger zone) and maintains the familiarity that operators have with known tyre handling equipment. It also allows the fork truck part of the tyre handler 4 to provide hydraulic, pneumatic and/or electrical services for the robotics that are disposed on the grab unit.
While a number of preferred embodiments have been described, it will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the invention without departing from the spirit or scope of the invention as broadly described. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2013902573 | Jul 2013 | AU | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/AU2014/000633 | 6/19/2014 | WO | 00 |
