An excavator

Abstract

The invention relates to an excavator comprising: a control system comprising a user interface, a first actuation system comprising a power supply, and a first motor powered by the first power supply; a transportation unit comprising a plurality of rotatable elements; an operating platform supported by the transportation unit and comprising a length and a carriage track extending along at least a portion of the length of the operating platform; a carriage movable along the carriage track between opposing first and second ends of the operating platform; and an extendable and retractable excavator arm directly or indirectly mounted on the carriage and being controllable via the control system. The rotatable elements are rotatable by the first actuation system to move the excavator between locations.

Description

[0001] AN EXCAVATOR

[0002] FIELD OF INVENTION

[0003] The present disclosure relates to an excavator comprising an operating platform that allows an excavator arm to move along the platform and above the ground surface during use. Optionally, the operating platform is extendable and / or rotatable.

[0004] BACKGROUND TO THE INVENTION

[0005] An excavator is a vehicle that can be driven to a work site and that comprises an articulated excavator arm, typically comprising a pair of moveable gripping jaws, to move objects from one place to another at the work site. For example, excavators may be used to pick up logs from a logging site and load the logs onto trucks. Excavators may also be used to pick up rubble from an area and load the rubble onto trucks or pile the rubble in a different area. Excavators comprise bulldozer tracks to move from place to place (i.e. excavators are considered to be ‘tracked’ machines).

[0006] To be sufficiently strong and robust, excavators are typically made of heavy metal components, such as steel. All components of an excavator, including the motor, add to the weight of the excavator. Consequently, as the excavator moves back and forth across the ground surface, it is common for the ground surface to become compressed and chewed up, especially where the excavator moves along rotatable tracks. At logging sites, the ground can become particularly chewed up and muddy, which makes it more difficult for the excavator and other vehicles to move across the site. Furthermore, excavators tend to cross a worksite in many different directions, not just back and forth in two directions. Changing the direction of the excavator requires the excavator to be turned until its tracks are facing the intended direction of movement. It is difficult to turn a tracked machine, especially on rough ground. As such, the turning components of the excavator are subject to considerable wear, which can increase maintenance costs. The difficulty moving and turning an excavator on rough ground also tends to increase the fuel consumption of the excavator.

[0007] It would be useful to provide an excavator that goes at least way towards addressing the foregoing problems, or that at least provides the public with a useful alternative.

[0008] Unless the context clearly requires otherwise, throughout the description and the claims, the words “comprise”, “comprising”, and the like, are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense, that is to say, in the sense of “including, but not limited to”.

[0009] Reference to any prior art in this specification is not, and should not be taken as, an acknowledgement or any form of suggestion that that prior art forms part of the common general knowledge in the field of endeavour in any country in the world. Further aspects and advantages of the present invention will become apparent from the ensuing description which is given byway of example only.

[0010] SUMMARY OF THE INVENTION

[0011] In one form, the invention provides an excavator comprising: a control system comprising a user interface, a first actuation system comprising a first power supply, and a first motor powered by the first power supply; a transportation unit comprising a plurality of rotatable elements; an operating platform supported by the transportation unit and comprising a length and a carriage track extending along at least a portion of the length of the operating platform; a carriage movable along the carriage track between opposing first and second ends of the operating platform; an extendable and retractable excavator arm directly or indirectly mounted on the carriage and being controllable via the control system; wherein the rotatable elements are rotatable by the first actuation system to move the excavator between locations.

[0012] In some forms, the control system comprises a second actuation system comprising a second power supply and a second motor, powered by the second power supply, to control independent or simultaneous movement of the carriage and the excavator arm.

[0013] In some forms, the operating platform is extendable in length and comprises a central section comprising first and second opposing ends, and at least one extension section attached to, or removably attachable to, the central section and configured to extend from at least one end of the central section.

[0014] Preferably, the at least one extension section is movably attached to the central section.

[0015] In some forms, the extension section is movable across the length of the central section to extend from either end of the central section.

[0016] Preferably, the operating platform comprises an extension actuation system operatively connected to the control system to slide the extension section between an extended position and a stowed position.

[0017] Optionally, the extension actuation system comprises a winch mechanism comprising a winch drum, and a tension member comprising a length and first and second ends, wherein a central portion of the tension member is wound around the winch drum, a first end portion of the tension member is attached to the extension section, near the first end of the extension section, and a second end portion of the tension member is attached to the extension section, near the second end of the extension section, and wherein the winch drum is rotatable in each direction by a winch motor such that rotating the drum in one direction winds the first end portion of the tension member onto the drum and unwinds the second end portion to move the extension section in a first direction, and rotating the drum in the other direction winds the second end portion onto the drum and unwinds the first end portion to move the extension section in an opposing, second direction. Preferably, rotation of the winch drum is hydraulically powered and the winch motor comprises the first or second motor.

[0018] In some forms, the carriage is movable along the carriage track by a carriage actuation system in which the carriage comprises a rotatable toothed member that is rotatable in opposing directions by a reversable motor, and the operating platform comprises an elongate carriage engagement element extending along at least a majority of the length of the operating platform, wherein the carriage engagement element comprises a plurality of apertures or recesses spaced equidistant along its length, and wherein each tooth of the rotatable toothed member is engageable with each aperture or recess of the carriage engagement element.

[0019] Optionally, the rotatable toothed member comprises a drive sprocket and the elongate carriage engagement element comprises a chain that is attached to each end of the operating platform, wherein a tension sprocket is located on each side of the drive sprocket, and wherein the chain partially wraps around one side of each tension sprocket and the opposing side of the drive sprocket to tension the chain.

[0020] Alternatively, the rotatable toothed member comprises a pinion and the elongate carriage engagement element comprises a rack that extends along at least a majority of the length of the operating platform.

[0021] In some forms, the carriage track comprises at least one guide element that engages with at least one engagement feature of the carriage. Optionally, the guide element comprises a channel and the engagement feature comprises a rail or a plurality of rollers received within the channel.

[0022] In some forms, the operating platform is rotatably attached to the transportation unit by a rotatable connection such that: the operating platform is independently rotatable relative to the transportation unit; the transportation unit is independently rotatable relative to the operating platform; or both the operating platform and transportation unit are independently rotatable relative to the other.

[0023] In some forms, the operating platform comprises a plurality of support legs that are removable support legs or that are extendable and retractable support legs. In some forms, the support legs are extendable in a deployed position to lift the transportation unit off a ground surface to enable rotation of the transportation unit relative to the operating platform.

[0024] In some forms, the excavator arm is rotatable relative to the operating platform. In some forms, an operator cab is rotatably attached to the carriage and comprises a user interface operatively connected to the control system.

[0025] In some forms, the excavator comprises a remote user interface that is operatively connected to the control system to enable remote control of the excavator.

[0026] Optionally, the second motor is an electric motor or a hybrid motor.

[0027] Also disclosed herein is an excavator comprising: a control system; a transportation unit comprising a plurality of rotatable elements, a first power supply and a first motor operatively connected to the first power supply, the control system, and the rotatable elements, the first power supply being configured to power the first motor to move the excavator between locations by rotating the rotatable elements according to one or more inputs from the control system; and an operating platform comprising a central section and at least one retractable or removable extension section. The operating platform also comprises at least one pair of retractable legs to support the operating platform above a ground surface. The operating platform is also supported by the transportation unit. In addition, the excavator comprises an extendable and retractable excavator arm mounted on the carriage or cab and being controllable via the control system; and a second power supply and a second motor operatively connected to the second power supply, the carriage, and the control system, the second power supply being configured to power the second motor and to control independent or simultaneous movement of the carriage, cab, and excavator arm. The carriage is movable along the operating platform to move the excavator arm between ends of the operating platform.

[0028] Optionally, a cab is rotatably mounted on a carriage.

[0029] In some forms, the transportation unit comprises an undercarriage and the rotatable elements comprise a pair of rotatable tracks attached to the undercarriage to supportthe undercarriage above the ground surface.

[0030] In some forms, the transportation unit comprises an undercarriage and the rotatable elements comprise four or more wheels attached to the undercarriage to supportthe undercarriage above the ground surface.

[0031] In some forms, the extension section of the operating platform is removable and locatable upon a portion of the central section in a stowed position, and, when the retractable legs are in a retracted position, the retractable legs project upwardly on opposing sides of the central section and the extension section is located between the upwardly projecting legs in the stowed position. In some forms, the central section and extension section are connected together in a telescoping arrangement in which the extension section is slidable relative to the central section to adopt a retracted, stowed position and an extended, operational position.

[0032] In some forms, the operating platform is rotatably attached to the transportation unit and is independently rotatable relative to the transportation unit.

[0033] Additionally, or alternatively, the transportation unit may be rotatably attached to the operating platform and independently rotatable relative to the operating platform.

[0034] Preferably, the operating platform is rotatably attached to an undercarriage of the transportation unit by a slew ring.

[0035] In some forms, the operating platform comprises support legs that are extendable to lift the transportation unit off a ground surface to enable rotation of the transportation unit relative to the operating platform.

[0036] BRIEF DESCRIPTION OF THE DRAWINGS

[0037] One or more embodiments of the invention will be described below by way of example only, and without intending to be limiting, with reference to the following drawings, in which:

[0038] Figure 1 is a side view of one form of excavator of the invention;

[0039] Figure 2 is another side view of the excavator of Figure 1 ;

[0040] Figure 3 is an isometric view from above of the excavator of Figure 1 ;

[0041] Figure 4 is another isometric view from above of the excavator of Figure 1 ;

[0042] Figure 5 is an isometric view from below of the excavator of Figure 1 ;

[0043] Figure 6 is an end view of one form of excavator of the invention with the boom of the excavator arm fully extended;

[0044] Figure 7 is a top view of one form of excavator of the invention with a telescopically extendable operating platform in a stowed position;

[0045] Figure 8 is a side view of the excavator of Figure 7 and in which the operating platform is in an extended position and the transportation unit is suspended above the ground;

[0046] Figure 9 is a top view of the excavator of Figure 8;

[0047] Figure 10 is a bottom view of excavator of Figure 8;

[0048] Figure 11 is an enlarged bottom view of the undercarriage and a portion of the operating platform of the excavator of Figure 10 and in which the operating platform is rotatable relative to the transportation unit of the excavator by engagement with a swivel joint comprising a slew ring provided on the undercarriage of the transportation unit;

[0049] Figure 12 is an isometric view from above of the excavator of Figure 8; Figure 13 is an isometric view from below of the excavator of Figure 8;

[0050] Figure 14 is an end view showing one form of excavator of the invention in which the operating platform comprises three guide rails and the carriage is slidably mounted on the rails of the operating platform;

[0051] Figure 15 is an enlarged end view of the operating platform and carriage of the excavator of Figure 14;

[0052] Figure 16 is an isometric view from above of one form of excavator in which the carriage, cab and excavator arm are located at one end of the operating platform;

[0053] Figure 17 is a top view of one form of carriage located centrally on one form of telescopically extendable operating platform, in a retracted, stowed position, for an excavator of the invention;

[0054] Figure 18 is an isometric view of the carriage and operating platform of Figure 17;

[0055] Figure 19 is a top view of the carriage and operating platform of Figure 17 and in which the operating platform is in an extended position;

[0056] Figure 20 is an isometric view of the carriage and operating platform of Figure 19;

[0057] Figure 21 is an isometric view of another form of carriage on a telescopically extendable operating platform 500 for an excavator of the invention;

[0058] Figure 22 is a bottom view of the carriage and operating platform of Figure 21 and in which one extension section of the operating platform is in an extended position and the other extension section is in a retracted, stowed position;

[0059] Figure 23 is a side view of the carriage of Figure 21 on a portion of the operating platform of Figure 21 ;

[0060] Figure 24 is an isometric cross-sectional view of the carriage and operating platform of Figure 21 taken through a transverse centreline of Figure 21 ;

[0061] Figure 25 is an isometric view from below of one form of carriage to be used with an excavator of the invention;

[0062] Figure 26 is a side view of the carriage of Figure 25;

[0063] Figure 27 is an isometric view of one form of excavator comprising removable and stackable extension sections, the extension sections being shown stacked on the central section between support legs in a stowed position;

[0064] Figure 27a is an isometric view of the excavator of Figure 27 in which the extension sections have been attached to the central section to extend the length of the operating platform; Figure 28 shows another form of excavator without a cab, the excavator being shown operating on the central section of the operating platform, with the extension sections in the retracted, stowed position and the transportation unit is suspended above the ground;

[0065] Figure 29 is a side view of an alternative form of excavator of the invention in which the operating platform is not extendable;

[0066] Figure 30 is a side view of yet another form of excavator of the invention, in which the operating platform is extendable, but is shown in a stowed position;

[0067] Figure 31 a is an isometric view from above of an excavator of Figure 30 in an extended position and in which support legs are deployed to stabilise the central section of the excavator;

[0068] Figure 31 b is an isometric view from below of the excavator of Figure 31a;

[0069] Figure 32 is an enlarged view of a portion of the excavator of Figure 31 b, showing a receiving portion of the central section of the extendable operating platform slidably receiving a connection portion of the extension section of the operating platform, and also showing a pulley of an extension actuation system for the operating platform;

[0070] Figure 33 is a partial schematic view from below of an excavator of the invention with an extendable operating platform in the extended position, and showing a winch mechanism of an extension actuation system, includinga winch drum, winch cables, and pulleys configured to extend and retract the extension section of the operating platform;

[0071] Figure 34 is another partial schematic view from below of an excavator of the invention with an extendable operating platform in the extended position, and showing first and second winch cables wrapped around the winch drum of the winch mechanism, one of the cable being wrapped around a pulley and the other of the cables being attached to the extension section near one end of the extension section;

[0072] Figure 35a is an isometric view from above of one form of excavator of the invention that has an extendable operating platform with a movable extension section shown in the stowed position, and in which the excavator carriage is movably attached to a carriage track located on the extension section;

[0073] Figure 35b is an enlarged isometric view of one end of the excavator of Figure 35a, showing the extension section located within a receiving portion (in this case, a pair of opposing channels) of the central section;

[0074] Figure 36 is a partial cut-away end view showing rollers between the receiving portion and connection portion of the extension section and central section of one form of extendable operating platform according to the invention; Figure 37a is an isometric view from above of a portion of one form of carriage track, a carriage that is slidably located on the carriage track, and an elongate carriage engagement element of a carriage actuation system comprising a chain attached to the operating platform at one end of the carriage track;

[0075] Figure 37b is another isometric view from above of a portion of the carriage track of Figure 37a and showing the chain attached to the operating platform at the other end of the carriage track;

[0076] Figure 37c is a partial view of a carriage track of Figure 37a from below and shows a drive sprocket of the carriage actuation system and two tension sprockets, one on each side of the drive sprocket, the chain extending along the length of the carriage track and wrapping around one side of the drive sprocket and the other side of the tension sprockets to tension the chain;

[0077] Figure 38 is a partial cross-sectional view of an excavator carriage located on a carriage track of an operating platform;

[0078] Figure 39 is a partial end view of a carriage located on a carriage track of one form of operating platform according to the invention;

[0079] Figure 40 is an isometric viewfrom above of another form of excavator of the invention in which the operating platform is extendable, and the central section of the platform is slidably received within the extension section;

[0080] Figure 41 is an isometric view from above of the excavator of Figure 40 in which the operating platform is in the extended position, the cab is located on the extension section, and support legs are deployed to support the operating platform;

[0081] Figure 42 is a side view of the excavator of Figure 41 in which the transportation unit is lifted off the ground by support legs to enable the transportation unit to be rotated independently of the operating platform;

[0082] Figure 43 is an isometric view of the excavator of the invention in which the transportation unit has been independently rotated relative to the operating platform such that the rotatable tracks of the transportation unit are substantially perpendicular to the length of the operating platform;

[0083] Figure 44a is a bottom view of an excavator of the invention in which the operating platform and transportation unit are independently rotatable relative to each other, and in which a portion of the slew ring connection between the transportation unit and operating platform is shown;

[0084] Figure 44b is a top view of the excavator of Figure 44a and in which a carriage is shown at one end of the operating platform (for clarity, the cab and excavator arm are not shown), and a portion of a slew ring connection (i.e. the rotatable connection between a rotatable cab and / or excavator arm and the carriage) is shown on the carriage. BRIEF DESCRIPTION OF PREFERRED EMBODIMENTS OFTHE INVENTION

[0085] Various embodiments of the invention and methods for use will now be described with reference to Figures 1 to 44b, byway of example only.

[0086] Features described in the context of separate aspects and embodiments of the invention may be used together and / or be interchangeable unless the context clearly indicates otherwise.

[0087] Referring to Figures 1 to 44b, the excavator 1000 of the invention is an operational vehicle that comprises an articulated excavator arm 300 to conduct various tasks, such as lifting, hauling, or digging, for example. The excavator 1000 can be driven along a ground surface from one location to another. The excavator 1000 comprises a control system, a user interface 950, and one or more actuators (such as motors) and / or actuation systems to control various components of the excavator. Preferably, the excavator control system also comprises an electronic controller 900 that is operatively connected to the user interface 950 and actuator(s) and / or actuation systems. In some forms, the excavator comprises a remote user interface that is operatively connected to the controller 900 of the control system to enable remote control of the excavator.

[0088] The excavator 1000 also comprises a transportation unit 100 comprising a plurality of rotatable elements and an operation unit 600.

[0089] The control system comprises a first actuation system comprising a first power supply and a first motor powered by the first power supply. The first actuation system is configured to control movement of the transportation unit 100 and may, in some forms, also control movement of one or more components of the of the operational unit 600. For example, the first actuation system may be operable to drive rotation of the rotatable elements. The first motor may be a fuel powered motor, an electric motor, or a hybrid (electric and fuel powered) motor. Preferably, the first motor is a fuel powered motor, such as a diesel motor. The first power supply is configured to power the first motor to move the excavator between locations by rotating the rotatable elements according to one or more inputs from the control system.

[0090] The operational unit 600 comprises an operating platform 500, carriage 400, and excavator arm 300. The operating platform is supported by the transportation unit 100, and comprises a length. A carriage track 540 extends along at least a portion of the length of the operating platform and between opposing first and second ends of the operating platform. The carriage 400 is movable along the carriage track 540. The extendable and retractable excavator arm 300 is directly or indirectly mounted on the carriage 400. The excavator arm 300 is rotatable relative to the carriage 400 and the operating platform 500. Movement of the excavator arm is controllable via the control system. In some forms, the operating platform 500 is extendable and retractable in length. The excavator may also optionally comprise a cab 200 located on the carriage 400.

[0091] The control system of the excavator 1000 may optionally comprise a second actuation system comprising a second power supply and a second motor powered by the second power supply. The second actuation system may be configured to control movement of one or more components of the operational unit 600. For example, under operation of the control system, the second power supply may power the second motor and to control independent or simultaneous movement of one or more components of the operational unit 600. The second motor may be a fuel powered motor, an electric motor, or a hybrid (electric and fuel powered) motor. The second actuation system is operatively connected to, and forms part of, the control system. In other forms, the first actuation system controls independent or simultaneous movement of one or more components of the operational unit 600 in addition to controlling movement of the transportation unit 100.

[0092] Control System

[0093] Operation of the excavator 1000 and its components is controlled by the control system, which may be a hydraulic control system, a fully electric / electronic control system, a mechanical control system, or a hybrid control system (i.e. a partially electric and partially mechanical control system, ora partially electric and partially hydraulic control system). One example of a hybrid control system comprises a hydraulic actuation system controlled by an electronic controller and / or an electric motor.

[0094] The control system comprises a user interface 950 for use by an operator. The control system may also comprise a controller 900, such as an electronic programmable controller, that is operatively connected to the user interface.

[0095] In some forms, the excavator 1000 is configured to operate with an operator onboard. In such forms, the excavator may include an operator cab 200. The user interface may be used by an operator onboard the excavator. For example, the user interface may be located within the cab 200 and may comprise various levers, switches, dials, buttons, and / or other user input controls. The user interface may be any suitable user interface, such as a mechanical user interface or an electronic user interface. The control system may be an electronic or mechanical control system or a hybrid control system.

[0096] In other forms, the excavator 1000 is configured to be operated remotely via an electronic control system or hybrid control system. In such forms, the excavator optionally comprises an operator cab 200. The remotely controlled excavator may comprise an electronic remote user interface 950 that is operatively connected to the controller 900 to enable remote control of the excavator by an operator who is remote from the excavator, as shown in Figure 3. The remote user interface transmits signals to an electronic controller onboard the excavator and operatively engaged with the actuation system(s) of the excavator. The remote user interface 950 also optionally receives signals from the controller. For example, the user interface 950 may be provided on a personal computer, smart phone, or on a dedicated control module.

[0097] Principal Actuation System

[0098] The control system of the excavator 1000 comprises at least one principal actuation system that controls movement of key components of the excavator and may control movement of one or more subsidiary actuation systems. The, or each principal actuation system may be a hydraulic actuation system, an electronic actuation system, a mechanical actuation system, or a hybrid actuation system that is at least partly electrically operated. Each principal actuation system comprises at least one motor powered by at least one power supply. The at least one motor is operatively connected to at least one moveable component of the excavator to control movement of that component.

[0099] In some forms, the excavator comprises at least one principal actuation system that comprises a hydraulic actuation system. The hydraulic actuation system comprises at least one motor, a power supply to power the motor, and a hydraulic pump operatively connected to the motor and to a valve bank comprising a plurality of valves connected to hydraulic hoses that operatively connect to one or more movable components of the excavator 1000, or to subsidiary actuation systems that are connected to one or more movable components of the excavator. The hydraulic pump is driven by the motor to pump hydraulic fluid through one or more of the hoses in order to move one or more components of the excavator according to operator inputs from the user interface. The motor may be any suitable motor for operating a hydraulic system. In some forms, the hydraulic motor may comprise a combustion engine, in which the power supply may be fuel. In otherforms, the hydraulic motor may comprise an electric motor, in which the power supply may be a battery.

[0100] In some forms, the at least one principal actuation system may be configured to drive operation of the transportation unit 100. In some forms, the principal actuation system may also be configured to actuate movement of one or more components of the operational unit 600. For example, the principal actuation system may be configured to actuate rotation of the operating platform and / or actuate the extension and retraction of the operating platform 500. In some forms, movement of the carriage and / or the optional cab and / or the excavator arm may also be actuated, at least in part, by the principal actuation system. In some forms, the at least one principal actuation system may be operatively connected with one or more subsidiary actuation systems to actuate movement of one or more moveable components of the excavator 1000, whether those components are part of the transportation unit 100 and / or the operation unit 600.

[0101] In some forms, the control system comprises a first principal actuation system to control movement and operation of the transportation unit 100.

[0102] For example, in some forms comprises a first hydraulic actuation system to control movement and operation of the transportation unit 100. As described above, the first hydraulic actuation system comprises a first hydraulic pump and a first motor to drive the first hydraulic pump. The first hydraulic control system also comprises a first power supply to power the first motor. The first motor may be any suitable motor to operate the first hydraulic pump. Where the first motor is a fuel powered motor, such as a diesel motor, the first power supply may comprise fuel, such as diesel. In other forms, the first motor may be an electric motor or a hybrid motor, in which case the first power supply may comprise a battery. The first hydraulic pump is connected to first hydraulic hoses and first valves that connect to hydraulically movable components of the excavator. For example, the transportation unit 100 may be hydraulically movable by the first hydraulic actuation system. Preferably, the first hydraulic actuation system is configured to move the excavator between locations by rotating the rotatable elements of the transportation unit 100 according to one or more operator inputs. The operating platform, when extendable and / or rotatable, may also be hydraulically movable by the first hydraulic actuation system. In some forms, the carriage and / or the optional cab and / or the excavator arm may also be hydraulically movable by the first hydraulic actuation system.

[0103] In some forms, the control system comprises a second principal actuation system to control movement and operation of one or more components of the excavator, such as components of the operational unit 600.

[0104] In some forms, the second principal actuation system comprises a second hydraulic actuation system to control movement and operation of one or more components of the excavator, such as components of the operational unit 600. As described above, the second hydraulic actuation system comprises a second hydraulic pump, a second motor to drive the second hydraulic pump, and a second power supply operatively connected to the second motor to power the second motor. The second motor may be any suitable motor to operate the second hydraulic pump. Where the second motor is a fuel powered motor, such as a diesel motor, the second power supply may comprise fuel, such as diesel. In other forms, the second motor may be an electric motor or a hybrid motor, in which case the second power supply may comprise a battery. The second hydraulic pump is connected to second hydraulic hoses and second valves that connect to hydraulically movable components of the operation unit 600.

[0105] In some forms, the second principal actuation system may be employed to control movement of the carriage 400, the optional cab 200 and the excavator arm 300 of the operational unit 600. For example, the second power supply may be operatively connected to the carriage 400 to actuate independent or simultaneous movement of the carriage and the excavator arm and optional cab. For example, the second actuation system may be configured to move the carriage 400 along the carriage track 540 of the operating platform 500, whilst simultaneously rotating the operator cab 200 and excavator arm 300, and causing the excavator arm to extend. In some forms, the second actuation system may also be employed to deploy and optionally extend one or more support legs 505 for the operating platform 500, and to retract and store the one or more support legs 505. In some forms, the second actuation system may also control extension and retraction of the operating platform 500 instead of the first actuation system. Additionally, or alternatively, the second principal actuation system may control rotation of the operating platform 500 instead of the first actuation system.

[0106] Where the principal actuation system(s) is / are electrically and mechanically powered by a hybrid system, the actuation system may comprise at least one battery power supply connected to at least one electric motor with an output that is operatively connected to one or more drive members or drive systems to move various components of the excavator. For example, an electric motor of the actuation system may be connected to a hydraulic drive system, as described above, to drive movement of one or more movable components of the excavator. Alternatively, an electric motor may be connected to a drive system comprising a drive shaft and gear system to drive rotational movement of the rotatably elements of the transportation unit 100. Alternatively, an electric motor of the actuation system may be connected to a drive system comprising a subsidiary winch actuation system (as described below) to extend and retract an extension section of the operating platform. In other forms, an electric motor of the actuation system may be connected to a drive system comprising a drive shaft and a rotatable connection to rotate the operating platform, or to rotate the excavator arm 300 and optional cab 200 simultaneously on the carriage 400. A mechanically powered principal actuation system comprises the same configuration, but uses a fuel powered motor instead of an electric motor, as would be appreciated by a person skilled in the art.

[0107] In some forms, the control system of the excavator comprises a first controller to control operation of the first principal actuation system and a second controller to control operation of the second principal actuation system. Alternatively, the control system may comprise a controller that controls operation of both the first and second principal actuation systems.

[0108] Transportation Unit

[0109] The transportation unit 100 is located at a base of the excavator. The operational unit 600 sits above the transportation unit 100 and is attached to the transportation unit 100. The operational unit 600 comprises the optional operator cab 200, the articulated excavator arm 300, the chassis / carriage 400 on which the optional cab 200 and the excavator arm 300 are located, and the operating platform 500 along which the carriage 400 can move back and forth. The operating platform 500 is mounted on the transportation unit 100. In some forms, the operating platform 500, on which the carriage 400, optional cab 200, and excavator arm 300 are located, may be rotatably mounted on / attached to the transportation unit 100 by a rotational connection, such as a typical slew ring connection 140 that is operatively connected to a slew motor to rotate the slew ring to enable the operating platform and / or the transportation unit to rotate relative to the other. In some forms, the slew motor is a typical swing drive. The slew ring and slew motor form a subsidiary actuation system that is operatively connected to a principal actuation system of the control system. For example, the operational unit 600 (comprising the operating platform, carriage, optional cab, and excavator arm) may be independently rotatable relative to the transportation unit 100 and / or the transportation unit 100 may be independently rotatable relative to the operational unit 600, or both the operating platform and the transportation unit may be independently rotatable relative to the other. Preferably, the operating platform 500 is rotatable 360° relative to the transportation unit 100 and / or the transportation unit 100 is rotatable 360° relative to the operating platform 500.

[0110] The transportation unit 100 is located beneath the operating platform 500 of the operational unit 600. The transportation unit 100 supports the operational unit 600 (i.e. the operating platform 500, carriage 400, excavator arm 300, and optional cab 200) from below so that the operating platform 500, carriage 400, excavator arm 300, and cab 200 are positioned above the ground surface.

[0111] The transportation unit 100 is the vehicular component of the excavator 1000 and is configured to drive the excavator 1000 between locations. The transportation unit 100 is motorised to allow the excavator 1000 to be driven from one location to another by an operator, such as to a work site or across a work site where excavation is required, or to a storage site or across a storage site where the excavator is stored when not in use.

[0112] To enable movement of the excavator, the transportation unit 100 may comprise an undercarriage 110 and a plurality of rotatable elements 120. The rotatable elements 120 are attached to the undercarriage 110 and support the undercarriage above the ground surface. The rotatable elements 120 are operatively connected to a principal actuation system of the excavator (such as a first hydraulic actuation system, as described above), and are rotatable to propel the excavator 1000 in the intended direction determined by the operator, such as forward or backward, left or right. Thus, the rotatable elements 120 are rotatable by a principal actuation system, such as the first principal actuation system, to move the excavator between locations. In some forms, as shown in Figures 1 to 14 and 40 to 44b for example, the set of rotatable elements 120 comprises a pair of rotatable tracks, such as bulldozer tracks, that rotate to move the excavator along the ground. In other forms, as shown in Figure 28, the set of rotatable elements 120 comprises at least four rotatable wheels that are attached to the undercarriage 110 to support the undercarriage above the ground surface and that rotate to move the excavator along the ground.

[0113] The transportation unit 100 also comprises a drive system to operate the vehicle.

[0114] In some forms, the drive system of the transportation unit may comprise a first motor that is an electric motor connected to a battery power supply to rotate the rotatable elements 120 directly (such via a mechanical drive shaft and gear system) or indirectly (such as via the hydraulic pump of the first hydraulic system).

[0115] In other forms, the drive system comprises the first hydraulic actuation system (comprising a first hydraulic pump and a first motor 130, as described above), and a first power supply. Each of the components of the first hydraulic actuation system (i.e. the first hydraulic pump, first motor and first power supply) is operatively connected to the control system and the transportation unit 100. The first motor 130 is supported by the undercarriage 110 and is operatively connected to the first power supply and the rotatable elements 120 to rotate the rotatable elements. Preferably, the first motor is attached to the undercarriage 110 from below. In some forms, the first hydraulic actuation system is operatively connected to a steering system of the transportation unit 100, such as a typical skid steer arrangement. In such forms, the first motor (and therefore the skid steer) is operable by an operator in the cab 200, or by a remote operator, via the control system, to drive rotation of the rotatable elements 120 in a forward direction or in a backward direction and straight, left, or right using a typical skid steer arrangement.

[0116] The first motor 130 is therefore powered by the first power supply, and the first power supply and the first motor are controlled by the operator via the control system to drive rotation of the rotatable elements 120 of the transportation unit 100 in order to propel the transportation unit, and therefore the excavator 1000, in the direction selected by the operator and at a speed determined by the operator. The transportation unit 100 is steerable straight, left and right and is driveable forwards and backwards. In some forms, the first power supply for the first motor 130 may be fuel powered, such as a combustion engine. In other forms, the first power supply for the first motor 130 may be a battery, so that the first motor is electrically powered. In other forms, the first motor may be a hybrid motor that is fuel powered and electrically powered by the first power supply. Preferably, the first power supply operates at approximately half the energy consumption of a standard excavator during operation. Thus, the first power supply is configured to power the first motor to move the excavator 1000 between locations by rotatingthe rotatable elements 120 accordingto one or more inputs from the user interface.

[0117] Excavator Arm

[0118] The excavator arm 300 is an extendable and retractable articulated arm that is directly or indirectly attached to / mounted on the carriage 400, and may be rotatable relative to the carriage 400 and the operating platform 500. In some forms, the excavator arm 300 is mounted on the optional cab 200. In some forms, the excavator arm 300 is rotatably mounted on the cab 200 via a rotatable connection, such as via a slew ring and slew motor / swing drive connection, so that the excavator arm is rotatable relative to the cab. In other forms, the excavator arm 300 is directly mounted on the optional cab 200, and the cab is rotatably mounted on the carriage 400 via a rotatable connection, such as via a slew ring and slew motor / swing drive connection, so that the cab 200 and excavator 300 are simultaneously rotatable relative to the carriage 400. In other forms, the excavator arm 300 may be directly mounted on the carriage, via a rotatable connection, such as via a slew ring and slew motor / swing drive connection, so that the excavator arm 300 is rotatable relative to the carriage 400. The slew ring and slew motor form a subsidiary actuation system that is operatively connected to a principal actuation system of the control system.

[0119] The excavator arm may be movable in the same way as existing excavator arms. For example, the excavator arm may extend and retract using hydraulic rams operatively connected to a hydraulic actuation system, such as to the second hydraulic actuation system (where present).

[0120] Movement of the excavator arm is controlled by the control system. Preferably, the control system comprises a second principal actuation system to control movement of the excavator arm. In some forms, the second principal actuation system comprises a second hydraulic actuation system, as described above, that operates the excavator arm hydraulically.

[0121] Operating Platform

[0122] The operating platform 500 of the excavator 1000 is attached to the transportation unit 100. Typically, the operating platform is at least partly located above the undercarriage 110 of the transportation unit 100 and is supported by the undercarriage 110. The operating platform is typically an elongate platform comprising first and second opposing ends. The excavator arm 300 and optional operator cab 200 are located on the carriage 400 that is movable along at least a portion of the length of the operating platform 500. Therefore, the excavator arm 300 and the optional cab 200 are also movable back and forth along at least a portion of the length of the platform 500 and between the first and second ends of the platform. By moving the excavator arm 300 along the elevated operating platform 500, it is possible for the excavator arm to access multiple locations on a worksite without needing to move the transportation unit 100 between those locations, which would churn up the ground and increase the power consumption of the excavator.

[0123] The operating platform 500 comprises a carriage track 540 that extends along at least a portion of the length of the operating platform, and preferably along a majority of the length, or along the whole of the length of the operating platform. The carriage 400 is located on the carriage track and is movable back and forth along the carriage track 540 to move between ends of the operating platform.

[0124] The operating platform 500 comprises a primary section / central section 510 mounted on the undercarriage 110 and located above the transportation unit 100. The operating platform 500 is supported by the transportation unit so as to extend horizontally above the ground surface. The central section 510 of the operating platform has a length and comprises first and second opposing ends. A track is provided on the central section 510 and extends at least partially along the length of the central section. Preferably, the track extends between first and second ends of the central section 510. In some forms, the track comprises the carriage track 540. In other forms, the operating platform 500 is extendable in length, and the track comprises an extension track 570 along or within which an extension section of the operating platform can move.

[0125] The operating platform 500 may be of any suitable length and typically comprises a length that extends beyond the periphery of the transportation unit 100. In some forms, the length of an extendable operating platform 500 in an extended position is between about 20m to about 30m, such as about 27m. In some forms, the non-extended length of the operating platform 500 is between about 10m and about 15m, such as about 12m. In some forms, the operating platform is about 14m in length and the carriage track extends the almost the whole length of the operating platform such that the carriage 400 is moveable about 6m (from the centre of the platform 500) in a first direction and about 6m in an opposing, second direction along the carriage track 540.

[0126] In some forms, the operating platform 500 is rotatably attached to the transportation unit by a rotatable connection, such as a slew ring actuation system, so that at least one of the operating platform and transportation unit are rotatable relative to the other. Non-extendable Operating Platform

[0127] In some forms, as shown in Figure 29, the operating platform 500 is not extendable and comprises only the central section 510 on which a carriage track 540 is provided. The carriage track 540 may extend along a portion of the central section 510, a majority of the central section, or the whole of the central section.

[0128] In some forms, the carriage track 540 comprises at least one guide element 542 for engaging with at least one engagement feature 442 of the carriage 400. The guide element 542 and engagement feature 442 may be of any suitable form to locate the carriage 400 on the carriage track 540 and enable the carriage to slide along the track 540. In some forms, the guide element may comprise a channel and the engagement feature may comprise a rail or a plurality of rollers that are received within the channel and enable the carriage to move along the carriage track 540. In other forms, the engagement feature comprises a channel and the guide element comprises a rail or a plurality of rollers that are received within the channel and enable the carriage 400 to move along the carriage track 540. In some forms, the guide element 542 and engagement feature 442 are configured to slidably interlock / engage with each other so that the carriage 400 is unable to pull upwardly and out of engagement with the operating platform 500. For example, as shown in Figure 35b, the guide element 542 may com prise a channel that comprises a rollercavity 543 that is at least partially defined by an overhang 544. The engagement feature 442 of the carriage 400 comprises a plurality of rollers that are located within the cavity 543 and are able to roll horizontally back and forth along the cavity but are prevented from moving upwards out of the cavity 543 by the overhang 542. In other forms, the engagement feature 442 of the carriage may comprise a projection, such as an L-shaped rail, that projects substantially horizontally and at least a portion of which is located within the cavity and is able to slide back and forth along the cavity but is prevented from moving upwardly out of the cavity 543 by the overhang 544.

[0129] The carriage 400 is movable along the carriage track 540 by a subsidiary carriage actuation system. In some forms, the carriage actuation system comprises a rotatable toothed member 546 that is rotatable in opposing directions by a carriage motor 549. The rotatable toothed member 546 is located on the carriage 400, preferably on the underside of the carriage. The operating platform 500 comprises an elongate carriage engagement element 506 extending along at least a portion of, and preferable along a majority of, or the whole of, the length of the operating platform. The carriage engagement element 506 comprises a plurality of apertures or recesses spaced equidistant along its length. Each tooth of the rotatable toothed member 546 is engageable with each aperture or recess of the carriage engagement element 506 to enable the carriage to move along the carriage engagement element as the rotatable toothed member rotates.

[0130] In some forms, the rotatable toothed member 546 comprises a drive sprocket and the elongate carriage engagement element 506 comprises a chain that is attached to each end of the operating platform. Optionally, a tension sprocket 547 is located on each side of the drive sprocket. The chain partially wraps around one side of each tension sprocket and the opposing side of the drive sprocket to tension the chain.

[0131] In another form, the rotatable toothed member comprises a pinion and the elongate carriage engagement element comprises a rack that extends along least a portion of, and preferably along a majority of, or the whole of, the length of the operating platform 500.

[0132] In some forms, the carriage motor is operated by the first principal actuation system. In other forms, the carriage motor is operated by the second principal actuation system. Preferably, the second principal actuation system comprises a second hydraulic actuation system, as detailed above. Actuation of the carriage motor, and therefore of the carriage, is controlled by the control system. In other forms, the carriage motor is an independent motor controlled by the control system.

[0133] Thus, the carriage motor may be a hydraulic motor of the second hydraulic actuation system, or the carriage motor may be a reversible electric motor or fuel powered motor.

[0134] By actuating the carriage motor, the rotatable toothed member 546, engaged with the carriage engagement element 506, begins to rotate and pull the carriage 400 along the carriage engagement element 506 as the next tooth engages with the next aperture or recess of the carriage engagement element during rotation of the toothed member 546.

[0135] Extendable Operating Platform

[0136] In some forms, the operating platform 500 is extendable in length between an extended position and a stowed position. In such forms, the extendable operating platform 500 comprises the central section 510 comprising first and second opposing ends, and at least one extension section 520 attached to, or removably attachable to, the central section 510 and configured to extend from one or both ends of the central section.

[0137] The, or each, extension section 520 is configured to extend from at least one end of the central section 510 to extend the operating length of the operating platform 500 when in the extended position. The, or each, extension section 520 may or may not be removably attached to the central section 510. An extension section 520 may be provided at the first end or at the second end of the central section 510, or an extension section 520 may be provided at both ends of the central section 510 to extend the length of the operating platform 500. For example, in some forms, the extendable operating platform 500 may comprise a single extension section 520 provided at one end of the central section 510. In other forms, the operating platform 500 may comprise two extension sections 520, each of the two extension sections being provided at a respective end of the central section 510. In yet other forms, the operating platform 500 may comprise an extension section 520 that is movably attached to the central section and is movable / slidable between the first and second ends of the central section 510 to extend from either end of the central section 510, as and when required. Thus, different embodiments of excavator of the invention enable the operating platform 500 to be slidingly extendable, telescopically extendable, hingedly extendable, or extendable by the removable attachment of one or more extension sections. When an extension section is in the extended / deployed position, the overall operating length of the operating platform 500, which includes the central section and extension section(s), may be increased. Preferably, the operating platform is extendable without changing the height of the carriage track.

[0138] In some forms, as shown in Figures 1 to 10, 12, 13, 15 to 22, 27a and 28, the operating platform 500 comprises at least two extension sections 520. A first extension section may be provided at the first end of the central section 510, and a second extension section may be provided at the second end of the central section, to enable the operating length of the operating platform 500 to be extended from each end of the central section 510. The, or each, extension section 520 may be extendable and retractable or removable from the respective first or second end of the central section 510.

[0139] In some forms, the, or each extension section 520 is removably attachable to the central section 510 so as to extend the length of the operating platform 500 (i.e. to reach the extended position), when attached, and is detachable from the central section 510 to reduce the length of the operating platform 500 (i.e. to reach the stowed position), when removed. In some forms, a removable extension section 520 may also be linearly extendable and retractable once attached to the central section 510.

[0140] Figures 27 and 27a show one form of extendable operating platform 500 that comprises a central section 510 and at least one removable extension section 520 that is removably attached to one end of the central section 510. Optionally, the operating platform 500 comprises a pair of removable extension sections, each extension section being removably attachable to a respective end of the central section 510. As shown in Figures 27 and 27a, the, or each, extension section 520 may be removably attached to the central section 510 with a releasable fastening arrangement. In such forms, the extension section(s) may be configured to attach to the central section 510 to extend the length of the operating platform 500, and to be detached from the operating platform 500 and stowed when not in use.

[0141] For example, the central section 510 and removable extension section(s) 520 may each comprise complementary engagement features to engage with each other and that may also disengage with each other so that the extension section(s) 520 may be detached and removed from the central section 510 in order to be stowed. Any suitable system may be employed for removably attaching an extension section 520 to the central section 510 as would be apparent to a person skilled in the art. For example, in some forms, the, or each, extension section 520 is configured to connect with the central section 510 via a hooked connection in which a first, connection end of each extension section 520 comprises at least one hook that engages with a respective aperture located at a respective, adjacent end of the central section 510 to attach the extension section 520 to the central section 510. In other forms, the first, connection end of the extension section may comprise an aperture for engaging with at least one hook provided at the respective, adjacent end of the central section to attach the extension section to the central section.

[0142] Optionally, regardless of the how the extension sections(s) attach to the central section, the first, connection end of the removable extension section 520 may comprise a tapered surface 521 that rests on an inversely tapered surface of the central section 510 when the extension section 520 is attached to the central section 510 to produce an overlap between the central section 510 and the extension section 520, as indicated in Figure 27. In some forms, at least one support leg 505 may be located beneath the overlapping central section and extension section. Optionally, a removable fastener, such as a pin or bolt, may connect the overlapping central section and extension section and may also connect with an adjacent support leg 505, when present.

[0143] In some forms, the extension section 520 is locatable upon at least a portion of the central section 510 in a stowed position. For example, the, or each, extension section 520 may be detached from the central section 510 and stacked on top of the central section 510 in a stowed position. For example, each extension section 520 may be removable (by detaching from the central section) and locatable upon a portion of the central section 510 in the stowed position. Optionally, the central section 510 comprises a pair of retractable support legs 505 that are movable between a deployed position and a retracted, stowed position. In some forms, the retractable legs 505 hinge upwardly to reach the retracted, stowed position and are held in place by any suitable locking mechanism, such as hydraulics, or a mechanical locking member that attaches one or more of the legs to the central section to hold the leg(s) in position, such as a pin in hole arrangement. In other forms, the retractable support legs 505 may slide upwardly and be held in place in the retracted, stowed position by any suitable locking mechanism, such as hydraulics, or a mechanical locking member that attaches one or more of the legs to the central section to hold the leg(s) in position, such as a pin in hole arrangement. When in the retracted position, the support legs 505 project upwardly on opposing sides of the central section 510 and a space is provided on top of the central section 510 and between the legs 505 in which at least one extension section 520 may be located in a stowed position, as indicated in Figure 27. Thus, at least one removable extension section 520 may be located on top of the central section 510 and between the upwardly projecting legs 505 in the stowed position. The retractable support legs 505 therefore support the removable extension section(s) 520 in the deployed position and act as side barriers to help retain the extension section(s) in the stowed position by preventing the extension section(s) from falling off either side of the central section 510. Optionally, the extension section(s) may be secured to the central section 510 for transportation by any suitable arrangement, such as by straps orclips forexample that attach the extension section(s) to the central section.

[0144] In other forms, an extension section 520 may be hingedly attached to the central section 510 by a hinged connection element. The hinged connection element connects the extension section to the central section, such as to an adjacent first or second end of central section to enable the extension section to hinge upwardly to a stowed position and to hinge outwardly and horizontally to an extended position. Optionally, the operating platform 500 comprises a pair of hinged extension sections 520, each of which is hingedly attached to a respective first or second end of the central section 510. In some forms, a hingedly attached extension section may be removable from the central section, such as by detaching the extension section from the connection element, or by disassembling the connection element. For example, the connection element may comprise a first part attached to the central section 510 and a second part attached to the extension section 520, the firstand second parts of the connection element being attachable to each other to form a hinged connection and being able to be detached / disassembled to detach the extension section from the central section. In other forms, the extension section 520 may be fixedly attached to the central section 510 via a hinged connection element. Optionally, at least one support leg is provided at the hinged connection between the central section 510 and the extension section 520.

[0145] In some forms, the, or each extension section 520 is movably attached to the central section 510 and may be extendable and retractable relative to the central section 510 by the control system. For example, each extension section 520 may be linearly extendable to the extended position and linearly retractable to the stowed position. In such forms, the extendable operating platform is operatively connected to the control system and comprises an extension actuation system that is controlled by the control system to move the extension section 520 between an extended position and a stowed position. The extension actuation system is a subsidiary actuation system controlled by a principal actuation system of the control system. For example, the extension actuation system may be controlled by the first or second hydraulic actuation systems described above, or by a mechanically driven or an electrically driven actuation system, or a hybrid actuation system.

[0146] Figures 7 to 13, 19 and 20 exemplify one form of extendable operating platform 500 that comprises two extension sections 520 that are movably attached to the central section 510 under operation of the control system. A first extension section 520a is provided at a first end of the central section 510 and a second extension section 520b is provided at a second end of the central section 510. Each extension section 520a, 520b may be linearly extendable to an extended / deployed position to increase the operating length of the operating platform 500, and may also be linearly retractable to a retracted, stowed position. In the retracted, stowed position, the length of the operating platform 500 may be the same as, or slightly longer than, the length of the central section 510, but is less than the length of the operating platform in the extended position.

[0147] In such forms, the, or each, extension section 520 may be slidably attached to the respective end of the central section 510 to enable each extension section to slide and retract inwardly to a stowed position and to slide and extend outwardly to an extended position under operation of the control system. In some forms, an extension section 520 may comprise extension rails that slide within extension channels provided on the central section 510. Alternatively, the extension section 520 may comprise extension channels that slide over extension rails provided on the central section 510.

[0148] In some forms, as shown in Figures 8 to 10, 12 and 13, the extendable operating platform 500 is telescopically and slidably extendable. The operating platform 500 comprises a central section 510 and at least one extension section 520 that are connected together in a slidable arrangement. In such forms, the, or each, extension section 520 may be slidable (under operation of the extension actuation system) relative to the central section 510 to adopt a retracted, stowed position and an extended, operational position. Optionally, the operating platform 500 may comprise one extension section 520 that is telescopically and slidably attached to one end of the central section 510, or the operating platform 500 may comprise two extension sections 520, each extension section being telescopically and slidably attached to a respective end of the central section 510. For example, as shown in Figures 8 to 10, 12 and 13, a first extension section 520a may be attached to a first end of the central section 510, and a second extension section 520b may be attached to a second end of the central section 510. Each end of the central section 510 comprises one of a connecting portion and a receiving portion and the, or each, extension section 520 comprises the other of the connecting portion and receiving portion. Each connecting portion is configured to be slidingly received within a respective receiving portion to enable the extension section 520 to slide relative to the central section 510 in a telescopic arrangement. In some forms, the receiving portion comprises one or more extension channels, each of which may be an elongate hollow or recess, and the connecting portion comprises one or more extension engagement elements, such as at least one projection, such as a rail, lug, or roller for example. Each extension engagement element is shaped to be slidably received in a respective one of the extension channels to enable the extension section 520 to slide along or within the extension channels of the central section 510.

[0149] In some forms, the, or each, extension section 520 comprises a connecting portion that is slidably received within a receiving portion of the central section 510. For example, the receiving portion of the central section 510 may comprise one or more extension channels, and the connecting portion of the extension section 520 may comprise at least one extension engagement element comprising an extension rail configured to be slidably received within a respective one of the extension channels of the central section 510.

[0150] Where a single extension engagement element and extension channel are employed, the extension engagement element (such as an extension rail) may be located substantially centrally between left and right sides of the extension section 520, and the extension channel may be located substantially centrally between left and right sides of the central section 510. In some forms, the extension section 520 comprises a pair of parallel extension engagement elements (such as parallel extension rails) at or nearthe left and right sides of the extension section and the central section 510 comprises a pair of parallel extension channels at or near the left and right sides of the central section for slidably receiving the extension engagement elements / rails therein. In yet other forms, a central extension engagement element (such as a central extension rail) may be provided between the pair of parallel extension elements / rails and is slidably received within a central extension channel provided between the pair of extension channels of the central section 510. Of course, it should be appreciated that the arrangement may be reversed without departing from the invention. In some forms, the central section 510 may comprise a connecting portion that is slidably received within a receiving portion of the extension section 520. For example, the extension section may comprise one or more extension channels, and the central section may comprise one or more extension engagement elements (such as extension rails) configured to be slidably received in a respective one of the extension channels. The slidable engagement between the extension element(s) / rail(s) and the extension channel(s) enable the extension section 520 to slide outwardly to extend from the central section 510, or slide inwardly to retract within the central section 510 in a telescoping arrangement. In some forms, a plurality of rollers are provided between each extension rail and the respective extension channel to encourage smooth movement of the extension rail within the extension channel.

[0151] A stop is provided at a first end of the connecting portion and abuts an abutment surface of the central section 510 when the extension section 520 is fully extended. The abutment between the stop and the abutment surface prevents the extension section 520 from separating from the central section 510.

[0152] In some forms, the, or each, extension section 520 is extendable itself. For example, as shown in Figures 7 to 10, the, or each, extension section 520 comprises a plurality of extendable subsections 525. For example, the, or each, extension section 520 may comprise a first sub-section section 525a, a second sub-section 525b, and optionally also a third sub-section 525c, or more. The, or each extension section 520 may comprise any suitable number of sub-sections 525, but preferably, to retain sufficient strength and to minimise cost, each extension section 520 comprises no more than three sub-sections. Each sub-section may be of any suitable length. In some forms, each sub-section of an extension section 520 may be between 1 m and about 3m long, such as about 2.7m long.

[0153] Each sub-section 525 of an extension section 520 may be directly or indirectly connected to the central section 510. For example, a first sub-section 525a of the extension section 520 may be connected to the central section 510 and to one adjacent second sub-section 525b, whereas the second sub-section 525b may be connected to the first sub-section 525a and optionally to a third sub-section 525c, and so on. The final sub-section is directly connected only to one adjacent subsection and, at its other end, forms the distal end of the extension section 520.

[0154] Each of the sub-sections 525 may be extendable and retractable to extend and retract the extension section 520. In some forms, each sub-section 525 is operatively connected to a hydraulic ram that is connected to a hydraulic actuation system, such as the second hydraulic actuation system, and that operates to extend in order to push each sub-section outwardly to an extended position, and to retract in order to pull each sub-section inwardly to a retracted position. Optionally, each sub-section 525 is telescopically extendable and retractable such that the sub-sections extend and retract in a telescoping arrangement. In such forms, each sub-section may comprise a connecting portion. For example, the connecting portion of the first sub-section 525a may be telescopically extendable from and retractable into a receiving portion of the central section 510, as described above. The connecting portion of the second sub-section 525b may be telescopically extendable from and retractable into a receiving portion of the first sub-section 525a. The connecting portion of an optional third sub-section 525c may be telescopically extendable from and retractable into a receiving portion of the second sub-section 525b, and so on, such that each sub-section 525 is telescopically extendable from and retractable into a receiving portion of at least one adjacent section or sub-section of the operating platform 500. In some forms, at least a portion of each subsection 525 slides within a channel, such as an elongate hollow or recess, of the adjacent, connected central section 510 or sub-section 525 and can slide outwardly to extend from the adjacent, connected central section 510 or sub-section, or slide inwardly to retract within the adjacent, connected central section 510 or sub-section 525.

[0155] A stop may be provided at a first end of each sub-section 525a, 525b, 525c and abuts an abutment surface of the adjacent central section 510 or sub-section when fully extended. The abutment between the stop and the abutment surface prevents each sub-section 525 from separating from the adjacent central section 510 or sub-section 525.

[0156] In some forms, a brace 530 is provided between each sub-section to provide additional strength, support, and rigidity to the, or each extension section 520 and sub-section 525. In some forms, a surface of each brace 530 forms an abutment surface and an opposing surface of each brace forms a stop. For example, a front surface of each brace located between subsections may form a stop and a rear surface of the same brace may form an abutment surface.

[0157] Optionally, the control system comprises both a first hydraulic actuation system to control movement of the transportation unit 100 and a second hydraulic actuation system to control movement of at least some components of the operational unit 600. In this form, the extension actuation system for the extendable operating platform 500 may be actuated by the second hydraulic actuation system. For example, the, or each, extension section 520 may be slidable between the extended position and retracted position by operating the second hydraulic actuation system according to operator inputs received by the control system. In some forms, as shown in Figures 15, 15a, and 15b, the second hydraulic actuation system comprises one or more hydraulic platform extension rams 550 that are operatively connected to the central section 510 and extension section(s) 520. Alternatively, or additionally, the second hydraulic actuation system comprises one or more hydraulic platform extension rams that are operatively connected to the central section and extension sub-section(s), or one or more hydraulic platform extension rams may be operatively connected to an extension section and sub-section(s), or between extension sub-sections. Each hydraulic ram 550 is configured to slidably extend and retract the connected extension section 520 or sub-section 525 relative to the central section 510. In some forms, at least one hydraulic platform extension ram 550 may be located within or beneath at least one guide rail 540a, 540b, 540c of the carriage track 540 and may be connected to the second hydraulic actuation system of the operational unit 600. For example, a first central platform extension ram 550 may be located within or beneath a central guide rail 540c of the carriage track 540 at the first end of the central section 510, and a second platform extension ram 550 may be located within or beneath the central guide rail 540c at the second end of the central section 510. Each platform extension ram 550 may be connected to a respective extension section 520, such as an inner end of the extension section, and is configured to push against the extension section to slidably extend the operating platform 500, or pull the extension section toward the central section 510 to slidably retract the extension section 520. For example, each platform extension ram 550 may push against a distal end of the respective extension section 520, such as againsta brace 530 located atthe distalend of the extension section, to extend the operating platform, and to pull against the respective extension section 520, such as by pulling on the same brace 530, to retract the operating platform. Where an extension section 520 comprises one or more sub-sections 525, the platform extension hydraulic ram 550 for that extension section 520 may push against each sub-section (such as against a brace for each subsection) 525 to extend each sub-section, or pull on each sub-section (such as on the same brace for each sub-section) to retract each sub-section.

[0158] In other forms, the extension actuation system comprises an extension drive motor that operates a winch system, as shown and described further below. The extension drive motor may be a hydraulic motor of the first or second hydraulic actuation system, or a reversible electric motor of a hybrid actuation system, which may comprise the reversible electric motor and one or more actuators.

[0159] The extendable operating platform 500 comprises a carriage track 540. The carriage track 540 extends along a portion of, a majority of, or the whole of, the length of the operating platform 500. The carriage track 540 comprises at least one guide element for engaging with at least one engagement feature of the carriage 400. Each carriage track 540 is configured to support and guide the carriage 400 to enable the carriage to move along the length of the track 540 and therefore along the operating platform.

[0160] In some forms, such as in the embodiments shown in Figures 1 to 28 where the extendable operating platform 500 comprises an extension section 520 that is extendable from just one end of the central section 510, then regardless of whether the, or each, extension section 520 is retractable or removable, the carriage track 540 may be provided on both the central section 510 and the extension section(s) 520. In such forms, when the extension section 520 is in the extended position, the portion of the carriage track 540 of the central section 510 substantially aligns with the portion of the carriage track 540 of the extension section(s) 520 to enable a smooth transition as the carriage moves along the carriage track. The carriage track 540 may extend along a majority of, or the whole of, the length of the operating platform 500.

[0161] In some forms, the carriage track 540 comprises a guide element comprising a single guide rail along which the carriage 400 can move. In other forms, the carriage track 540 comprises a guide element comprising a pair of parallel guide rails. In some forms, the carriage track 540 comprises a guide element comprising a pair of parallel guide rails and a third guide rail centrally located between the pair of guide rails and parallel to the pair of guide rails.

[0162] In some forms, as shown in Figures 14 and 15 and 23 to 26, the carriage track 540 may comprise a guide element comprising a central guide rail 540c and a pair of outer guide rails 540a, 540b, all lying in parallel with each other. Each of the outer rails 540a, 540b may comprise a channel 541 formed in one side of the rail 540a, 540b for receiving at least one engagement feature of the carriage 400 therein. In some forms, the at least one engagement feature comprises a plurality of rollers 410 of the carriage 400 that are received within the channels of the rails 540a, 540b. In the embodiment shown in Figures 14 and 15, channels 541 are provided on outwardly facing sides of each guide rail. In other forms, channels may be provided on inwardly facing sides of each guide rail, or on the left side and / or the right side of each guide rail. Thus, each of the central section 510 and extension section(s) 520 may comprise a carriage track 540 comprising at least one guide rail, and preferably comprising at least a pair of guide rails 540a, 540b, along which the carriage 400 can move. The carriage track 540 on each of the central section 510 and extension section 520 may also comprise a central guide rail 540c.

[0163] In some forms, the carriage 400 may comprise two or more engagement features for engaging with the carriage track 540. For example, two or more rollers 410 may be provided on opposing sides of the carriage, the rollers 410 on each side being configured to roll along a channel 541 of a respective one of the guide rails to move the carriage 400 along the length of the carriage track 540.

[0164] In some forms, the operating platform 500 may comprise a plurality of braces 530 to support the guide rail(s) of the carriage track 540 along the length of the operating platform 500 and to optionally strengthen the operating platform laterally. For example, a brace 530 may be provided at each end of the central section 510 and one or more braces 530 may optionally be provided between each end of the central section 510. A brace 530 may also be provided at the distal end of the, or each, extension section 520 and one or more braces 530 may optionally be provided between each end of each extension section 520. Where an extension section 520 comprises a plurality of extendable sub-sections, a brace 530 may be provided between each sub-section. Each brace may extend across the whole of, or a portion of, a width of the operating platform 500.

[0165] In other forms, the extendable operating platform 500 may comprise a substantially solid structure and the, or each guide element may comprise a guide rail that comprises a channel extending along a majority of, or the whole or, the length of the operating platform 500. A single, central channel may be provided, or a pair of parallel channels may be provided, or three parallel channels may be provided. Each channel may be configured to receive a plurality of engagement features, such as rollers 410, or one or more projecting elements, of the carriage 400 therein to allow the carriage 400 to move along the length of the channel, as discussed above. I n some forms, the operating platform 500 comprises a pair of parallel channels and the carriage comprises two or more rollers 410 on opposing sides 402 of the carriage 400, the rollers on each side being configured to roll along a respective one of the channels to move the carriage 400 along the length of the operating platform 500.

[0166] Typically, the carriage track 540 is located on an upper surface of the extension section 520, but optionally the carriage track may be located along or near left and right sides of the extension section.

[0167] Figures 30 to 44b, show other forms of excavator of the invention, comprising extendable operating platforms 500 that are movable between an extended position and a stowed position by operation of the control system. As shown in Figures 31 a and 31 b, the extendable operating platform 500 comprises an extension section 520 that is movably attached to the central section 510. The extendable operating platform 500 also comprises an extension actuation system that is operatively connected to the control system to move the extension section 520 between an extended position, as shown in Figures 31a and 31 b, and a stowed position, as shown in Figure 30. Under actuation by the extension actuation system, the extension section 520 is movable between the first and second ends of the central section 510 and is extendable beyond either end of the central section, depending on which end requires extending during use. Forexample, the extension section 520 may extend from the first end of the central section 510 and may then retract from the first end and move along the central section 510 to extend from the second end of the central section. In this form, a single extension section 520 enables the operating platform 500 to extend in length in a first direction and in an opposing second direction. The central section 510 therefore forms a supporting platform for the movable extension section 520. The track of the central section 510 comprises an extension track 570 along or within which the extension section 520 may move between first and second ends of the central section. The extension section 520 is therefore supported by the central section 510 and is movable back and forth along or within the extension track 570 located on the central section 510.

[0168] The moveable extension section 520 is configured to adopt an extended position; a central position, which is also a stowed position; and any position in between. In the extended position, the extension section 520 extends to its full extent beyond either the first or second end of the central section 510, as shown in Figures 31a and 31 b, for example. When the extension section 520 is in the extended position then the operating platform 500 is in the extended position. Similarly, when the extension section 520 is in the central, stowed position, the operating platform 500 is also in the retracted, stowed position. The extension section 520 is movable between the extended position at the first end of the central section 510, where the extension section extends from the first end to its full extent, and the extended position at the second end of the central section 510, where the extension section extends from the second end to its full extent. In the central position / stowed position, the extension section 520 is preferably positioned substantially centrally on the central section 510, as shown in Figure 30. Preferably, the excavator arm 300 and / or the optional cab 200 are positioned substantially centrally on the extension section 520 in the stowed position.

[0169] The extension section 520 may be substantially the same length as the central section 510, or the extension section 520 may be shorter or longer than the central section 510. Where the extension section 520 is shorter than, or of substantially equal length to, the central section 510, the extension section is unable to extend from both the first and second ends of the central section 510 simultaneously, even when the position of the extension section is centred relative to the central section. In the extended position (i.e. when the extension section 520 is fully extended beyond the first or second end of the central section 510), the extension section 520 extends the overall length of the operating platform 500 to its maximum length.

[0170] Movement of the extension section along the extension track 570 is controlled by an extension actuation system 580 controlled by the control system. In some forms, the extension actuation system may be a subsidiary actuation system controlled by a principal actuation system of the control system, such as the first or second hydraulic actuation systems. In some forms, as shown in Figures 33 and 34, the extension actuation system 580 comprises a winch mechanism comprising a rotatable winch drum 581 , and an elongate tension member, such as a cable 582 or rope. The tension member comprises a length comprising a central portion between a first end portion and a second end portion. In the embodiment shown in Figures 33 and 34, the tension member comprises a rope. The winch drum 581 is rotatably attached to the central section 510. Preferably, the winch drum 581 is attached substantially centrally along the length of the central section 510. A central portion of the tension member 582 is wound around the winch drum 581 , One end of the tension member 582 is attached to the extension section 520, at or near the first end of the extension section. The other end of the tension member 582 is attached to the extension section 520, at or near the second end of the extension section 520. In some forms, a first end portion of the tension member 582 is wound around a first pulley 583a and then passes back on itself to attach to the extension section at or near the first end of the extension section 520, as shown in Figure 33. Preferably, the first pulley 583a is attached to the central section 510 at or near the second end of the central section 510. A second end portion of the tension member 582 is wound around a second pulley 583b and then passes back on itself to attach to the extension section 520 at or near the at the second end of the extension section, as shown in Figure 33. Preferably, the second pulley 583b is attached to the central section 510 at or near the first end of the central section 510. Preferably, the winch system is hydraulically powered and is rotatable clockwise and anti-clockwise. In other forms, the winch drum 581 is operatively connected to a drive output of a reversible electric winch motor and is rotatable in each direction by the winch motor, which is powered by a winch power supply, such as a battery. When the hydraulic system or electric motor causes the winch drum 581 to rotate in one direction, the first end portion of the tension member 582 is at least partly wound onto the drum 581 whilst and the second end portion of the tension member 582 is simultaneously unwound from the drum 581 to move the extension section 520 in a first direction. By rotating the winch drum in the opposite direction, the second end portion of the tension member 582 is at least partly wound onto the drum 581 whilst the first end portion of the tension member 582 is simultaneously unwound to move the extension section 520 in an opposing, second direction. In some forms, the control system comprises a first and second hydraulic actuation system, as described above, and the winch drum 581 is operatively connected to and controlled by the second hydraulic actuation system of the control system.

[0171] In another form (not shown), the extension actuation system 580 may comprise a pair of hydraulic extension rams that are operatively connected to the first or second hydraulic actuation systems. One end of each ram is attached to the central section 510 and the other end of each ram is attached to the extension section 520. The rams are extendable in opposite directions, such that one ram is extendable in the direction of the first end of the operating platform and the other ram is extendable in the direction of the second end of the operating platform. The rams are configured so that one ram is retracted whilst the other ram is extended. The hydraulic extension rams are preferably operatively connected to the second hydraulic actuation system to cause the rams to extend and retract to move the extension section 520 across the central section 510 between the extended position and the central, stowed position.

[0172] The extension section 520 may be movable to extend from either end of the central section 510 in a sliding arrangement. In each sliding arrangement between the central section 510 and the extension section 520, at least a portion of the extension section 520 slidably engages with the central section 510 to enable the extension section to slide relative to the central section and to extend from one end of the central section 510.

[0173] In one form, the extension section 520 may be configured to engage with the central section in a telescopically sliding arrangement. In such an arrangement, the extension track 570 of the central section 510 may comprise one of a receiving portion 512 and a connection portion 522, and the extension section 520 may comprise the other of the receiving portion 512 and the connection portion 522. For example, the central section 510 may comprise a receiving portion 512 that slidably receives a connection portion 522 of the extension section 520 therein, as shown in Figures 31 a to 32. In another form, the extension section 520 may comprise a receiving portion 512 that slidably receives a connection portion 522 of the extension track 570 of the central section 510 therein, as shown in Figures 41 and 42. In either form, the receiving portion 512 partially surrounds the connection portion to prevent the connection portion 522 from pulling vertically out of the receiving portion. Instead, the connection portion can only move substantially horizontally within the receiving portion. In some forms, the receiving portion 512 may comprise one or more extension channels 522 that extend lengthwise along the central section 510 or the extension section 520, as the case may be. In some forms, the connecting portion 522 may comprise one or more extension rails that extend lengthwise along the central section 510 or the extension section 520, as the case may be. In other forms, outer side edges of the central section 510 or the extension section 520 (as the case may be) may form the connecting portion. In some forms, the receiving portion comprises a channel and a plurality of rollers may be provided along the channel between to enable smooth sliding movement of the extension section 520. A casing may extend along the channel to at least partially cover and retain the rollers in the channel. Access ports 528 may be provided in the casing to enable access to the rollers and the interior of the channel for cleaning and maintenance. Optionally, a removable outer cover is provided over the casing to close the access ports in order to reduce the ingress of dust and debris within the channel.

[0174] In the embodiment shown in Figures 31a to 32, the central section 510 comprises a receiving portion 512 comprising a pair of parallel channels that extend along left and right sides of the central section. Each channel comprises an opening that faces toward the other channel and is configured to receive a portion of the extension section 520 therein. The extension section 520 comprises a central body that extends between the side rails of the extension section. The side edges extend along left and right sides of the extension section 520 and form the connection portion 522 of the extension section. Each of the side rails is slidably received within a respective one of the extension channels. A plurality of rollers are provided between the side rails / connection portion 522 of the extension section and the extension channels / receiving portion 512. For example, a plurality of rollers, provided within each extension channel, are located above the connection portion 522 of the extension section and a plurality of rollers are located below the connection portion 522 of the extension section. In other forms, rollers may be provided between the side rails of the extension section and a side wall of the respective extension channel.

[0175] In the embodiment shown in Figures 41 and 42, the extension section 520 may comprise a receiving portion 512 comprising side channels, and the central section 510 comprises a connection portion 522 that comprises side rails or side edges of the central section. The side channels partially wrap around the outer side rails or side edges of the central section to enable the extension section to slide along the central section. A plurality of rollers are provided between the receiving portion 512 of the extension section and connection portion 522 of the central section to facilitate a smooth sliding action.

[0176] In some forms, the receiving portion 512 comprises an extension channel comprising inner and outer side walls to provide lateral support to the connection portion 522. For example, as shown in Figure 36, a cross-section of the receiving portion 512 / extension channel may be substantially hexagonally shaped with a channel opening facing toward a longitudinal centre line of the operating platform 500. An outer side wall and angled side walls at the top and bottom of the channel provides lateral support to the connection portion 522 located within the channel. The connection portion 522 may comprise a projecting element, such as a lug or extension rail, that is also substantially hexagonally shaped to be slidably received within the extension channel. Rollers 528 may be provided within the extension channel, above and below the connection portion 522 / extension rail and may at least partially extend through openings formed in the channel walls to contact the extension rail and assist the rail to slide smoothly within the receiving portion 512 / channel.

[0177] The carriage track 540 of the extendable operating platform 500, shown for example in Figures 31a, 31 b, and 35a to 36, is provided on the extension section 520 and extends between first and second ends of the extension section 520. The carriage track 540 extends along at least a portion of, a majority of, or the whole of, the length of the extension section 520. The carriage 400 is operatively connected to the control system and is moveable / slidable along the carriage track 540 in a first direction and an opposing second direction. Whether the extension section is in the extended position, the central position, or a position in between, the carriage 400 is movable back and forth along the carriage track 540 of the extension section 520. Advantageously, because the carriage 400 does not move between the central section 510 and the extension section 520, and instead remains on the extension section 520 as the extension section itself moves along the central section 510, the excavators shown in Figures 30 to 44b enable extension of the operating platform 500 without needing to carefully align the carriage track 540 for a smooth transition at the connection between the central section and extension section(s), as required in other embodiments shown in Figures 1 to 28.

[0178] In some forms, as shown in Figures 37a, 37b, and 39, the carriage track 540 comprises at least one guide element 542 for engaging with at least one engagement feature 442 of the carriage 400. In some forms, the guide element 542 may comprise a channel and the engagement feature 442 may comprise a slider, such as a rail, or a plurality of rollers, that are received within the channel and enable the carriage to move along the carriage track, as shown in Figures 37a, 37b, and 39. In other forms, the engagement feature may comprise a channel and the guide element may comprise a rail or a plurality of rollers that are received within the channel and enable the carriage to move along the carriage track. However, it should be appreciated that the guide element(s) and engagement feature(s) may be of any suitable arrangement to locate the carriage on the carriage track 540 and enable the carriage to move along the track 540.

[0179] In some forms, the guide element 542 and engagement feature 442 slidably interlock / engage with each other so that the carriage 400 is unable to pull upwardly and out of engagement with the operating platform 500. For example, as shown in Figure 37b, the guide element 542 may comprise a channel that comprises a roller cavity 543 that is at least partially defined by an overhang 544. The engagement feature 442 of the carriage 400 comprises a plurality of rollers, as shown in Figure 37a, that are located within the cavity 543 and are able to roll horizontally back and forth along the cavity but are prevented from moving upwards out of the cavity 543 by the overhang 542. The rollers enable the carriage to smoothly slide horizontally back and forth along the channel. In other forms, the engagement feature 442 of the carriage may comprise a projection, such as an L-shaped rail, that projects substantially horizontally and at least a portion of which is located within the cavity and is able to slide back and forth along the cavity but is prevented from moving upwardly out of the cavity 543 by the overhang 544. Carriage

[0180] The carriage 400 supports the excavator arm 300 and optional cab thereon. The carriage comprises a carriage actuation system that is operatively connected to, and controlled by, the control system. The carriage 400 may take any suitable form for moving along the carriage track 540 of the operating platform 500. The carriage is configured to convey the excavator arm 300 and optionally also the cab 200 along the operating platform 500 according to operator inputs via the control system.

[0181] In some forms, as shown best in Figure 25, 37a, and 39, the carriage 400 comprises a deck 405 extending between a pairof opposingdownwardly projecting side walls 402. The deck 405 comprises an upper surface and a lower surface that forms an underside of the carriage 400.

[0182] In some forms, the carriage 400 comprises at least one engagement feature 442 comprising a projecting element, such as a rail, slide, or a plurality of rollers that is / are slidably received within at least one guide element 542, such as a receiving channel, of the carriage track 540. Optionally, the carriage 400 comprises a pair of parallel rails and the carriage track comprises a pair of parallel receiving channels, each of which is shaped to slidingly receive a respective one of the rails therein.

[0183] Alternatively, the at least one guide element of the carriage track 540 comprises at least one rail that is slidably received within at least one engagement feature of the carriage, the engagement feature comprising a receiving channel. Optionally, the carriage track 540 comprises a pair of parallel rails and the carriage 400 comprises a pair of parallel receiving channels, each receiving channel being shaped to slidingly receive a respective one of the rails therein. In some forms, a plurality of rollers are provided between the guide element 542 / rail and the engagement feature 442 / channel in which the rail is located.

[0184] In some forms, as shown in Figures 17 to 26, the underside of the carriage 400 comprises a centrally located engagement feature, comprising a channel / groove 440, that receives at least a portion of a guide element, comprising a central guide rail 540c, of a carriage track 540 therein and is configured to slide along the central guide rail 540c. A plurality of rollers 410 are also provided along each side of the carriage 400 and are received within parallel channels of the carriage track 540. In some forms, the parallel channels of the carriage are outwardly facing, and the rollers 410 are located within a cavity provided in the carriage side walls 402. In some forms, the rollers 410 may be attached to the side walls 402 so that the rollers 410 of one side face inwardly toward the rollers 410 of the other side, as shown in Figures 15 and 25. In other forms, the parallel channels are inwardly facing, and the rollers may be located outside the carriage side walls 402. In some forms, the rollers may be rotationally attached to an outer surface of the carriage side walls 402 so that the rollers face away from each other. In both forms, the rollers 410 on each side of the carriage 400 are received within the adjacent respective channel 541 of the outer guide rails 540a, 540b of the carriage track 540 and are configured to move along the guide rails 540a, 540b as the rollers 410 rotate, thereby moving the carriage 400 along the length of the operating platform 500.

[0185] In some forms, the carriage 400 may be operatively connected to a hydraulic actuation system of the control system, such as the second hydraulic actuation system, that comprises the carriage actuation system. The hydraulic actuation system is operatively connected to the rollers to cause the rollers 410 to rotate in a first direction in order to move the carriage in the first direction, and to rotate in an opposing second direction to move the carriage in the second direction, depending on operator inputs at the user interface. For example, the excavator 1000 may comprise both first and second hydraulic actuation systems and the carriage actuation system may be controlled by the second hydraulic actuation system. In other forms, the carriage 400 may be operatively connected to a reversible electric carriage motor, controlled by the control system, to cause the rollers 410 to rotate in a first direction in order to move the carriage in the first direction, and to rotate in an opposing second direction to move the carriage in the second direction, depending on operator inputs at the user interface. For example, the carriage actuation system may comprise a reversible carriage motor that drives a drive shaft connected to at least one roller of the carriage to rotate the roller(s) in a select direction, causing other rollers to follow suit.

[0186] In another form, as shown in the embodiments of Figures 35a, 37a, and 39, the carriage 400 comprises an engagement feature 442 comprising a plurality of rollers 410 extending in parallel lines on each side of the carriage. The rollers 410 are configured to be received within a guide element 542, comprising channels, of the carriage track, such as those shown in Figure 37a. Preferably, the rollers 410 are located beneath an overhang 544 of the channel to engage with the channel and prevent the carriage from pulling up and away from the carriage track 540.

[0187] The carriage 400 of Figures 35a, 37a, and 39 is movable along the carriage track 540 by a carriage actuation system controlled by the control system. In some forms, as shown in Figure 37c, the carriage actuation system comprises a rotatable toothed member 546 that operatively connected to a hydraulic actuation system, such as the second hydraulic actuation system (where present) or a reversible electric carriage motor connected to an electric power supply. The rotatable toothed member 546 is rotatable in opposing directions by the connected hydraulic actuation system or the reversable electric carriage motor. The rotatable toothed member is located on the carriage 400, preferably on the underside of the carriage deck 405. The operating platform 500 comprises an elongate carriage engagement element 506 extending along at least a portion of, and preferable along a majority of, or the whole of, the length of the operating platform. The carriage engagement element 506 comprises a plurality of apertures or recesses spaced equidistant along its length. Each tooth of the rotatable toothed member 546 is engageable with each aperture or recess of the carriage engagement element 506 to enable the carriage 400 to move along the carriage engagement element as the rotatable toothed member 546 rotates.

[0188] In some forms, as shown in Figure 37c, the rotatable toothed member 546 comprises a drive sprocket and the elongate carriage engagement element 506 comprises a chain that is attached to each end of the operating platform. The chain comprises apertures between and / orwithin the chain links for engaging with the teeth of the drive sprocket. Optionally, a tension sprocket 547 is located on each side of the drive sprocket 546 and also includes teeth to engage with apertures in the chain. The chain partially wraps around one side of each tension sprocket 547 and the opposing side of the drive sprocket 546 to tension the chain.

[0189] In anotherform (not shown), the rotatable toothed member comprises a pinion and the elongate carriage engagement element comprises a rack that extends along least a portion of, and preferable along a majority of, or the whole of, the length of the operating platform.

[0190] The carriage may be moved by the carriage actuation system, according to operator inputs via the control system, by rotating the rotatable toothed member 546, which is engaged with the carriage engagement element 506. As the rotatable toothed member546 rotates, it pulls the carriage 400 along the carriage engagement element 506 as the next tooth engages with the next aperture or recess of the carriage engagement element during rotation of the toothed member 546.

[0191] In some forms, the carriage 400 comprises a scraper to remove debris from the carriage track 540 as the carriage moves along the track 540.

[0192] The excavator 1000 optionally comprises an operator cab 200 mounted on / attached to the carriage 400. Preferably, the cab 200 is rotatably attached to the carriage 400, such as via a typical slew ring and slew motor / swing drive connection controlled by the control system.

[0193] The excavator arm 300 may be rotatably attached to the carriage 400, such as via a typical slew ring and slew motor / swing drive connection 700 controlled by the control system, or the excavator arm 300 may be attached to a cab 200 that is rotatably attached to the carriage 400. Any suitable rotatable connection may be used to rotatably attach / mount the excavator arm 300 or cab 200, such as a typical slew ring and slew motor / swing drive connection, as shown in Figures 37a, 38 and 44b. Support Legs

[0194] In some forms, the operating platform 500 may be supported by one or more removable or retractable support legs 505 that may project beneath the operating platform and contact the ground in a deployed position to help stabilise the operating platform during use, and may be stowed in a stowed position when not in use. For example, the operating platform 500 may be supported at each end by at least one support leg 505 that, in the deployed position, contacts the ground surface to support the operating platform, especially the ends of the operating platform 500, above the ground. In some forms, where the operating platform comprises one or more extension sections 520, a support leg 505 may be provided at or near a distal end of the, or each, extension section (the distal end being farthest from the central section 510) to support the extension section(s). Additionally, or alternatively, a support leg 505 may be provided at, or near, the connection between the central section 510 and the extension section 520. In some forms, at least one support leg 505 is located at each end of the central section 510, or at a distal end of the, or each extension section 520. In some forms, a support leg 505 comprises a pair of struts. Optionally, the struts are splayed apart to provide better stability to support the operating platform 500.

[0195] Each support leg 505 may be removable or retractable to the stowed position when not in the deployed position. In some forms, at least one retractable or removable support leg 505 is located at each end of the central section 510 and may be deployed to support the ends of the central section 510 such that the central section remains substantially in the same, preferably horizontal, plane. When in the deployed position, each support leg 505 projects below the operating platform 500, such as below the central section 510 and / or extension section(s), to contact the ground surface and support the operating platform 500 above the ground. Optionally, each support leg 505 may be linearly extendable (such as telescopically extendable or slidingly extendable), or hinged from the operating platform 500. In some forms, each support leg 505 may also be removable from the operating platform 500.

[0196] In some forms, the support legs 505 may be extendable in length. For example, the length of each support leg 505 may be adjustable to compensate for an uneven ground surface. In some forms, the, or each, support leg 505 may be linearly extendable, such as in a telescoping arrangement. Optionally, the, or each, support leg 505 is a telescopically extending hydraulic leg, as shown in Figures 6, 8, and 12 for example. In other forms, the, or each, support leg may comprise two or more parts that are configured to be secured to each other mechanically in an extended position. For example, the, or each, leg 505 may comprise at least a pair of telescopically extending or slidably extending parts in which at least one part extends / moves away from the other to reach an extended position, and may also retract / move toward the other to reach a retracted or stowed position. Each part may comprise one or more locking features to engage with one or more complementary locking features of another part of the leg to lock the parts of the leg together in an extended position. However, it will be appreciated that the extendable and retractable support leg(s) 505 may take manydifferent configurations without departing from the invention, as will be apparent to a person skilled in the art. In some forms, the, or each, support leg 505 is a telescopically extendable and retractable hydraulically operated leg that is operatively connected to the second hydraulic system of the operational unit 600 and is extendable and retractable by extension and retraction of a support leg hydraulic ram located within a respective one of each of the support legs 505. Optionally, an extendable and retractable support leg 505 may also be attached to the operating platform 500 by a rotatable connection, such as a hinged connection, to allow the leg 505 to be linearly retracted and then rotated to a stowed position (as shown in Figures 30 and 35a), and then be rotated to an operative position before being extended to a deployed position (as shown in Figures 31a and 31 b). By adjusting the length of a support leg 505, regardless of how the support leg extends or retracts, at least a portion of the operating platform 500, such as the central section 510 and / or the optional extension section(s) 520, may be supported substantially horizontally to lie in a substantially flat plane regardless of the ground terrain. In some forms, the extendable support legs, when extended in a deployed position, allow the transportation unit to be lifted off a ground surface to enable rotation of the transportation unit relative to the operating platform.

[0197] Where the operating platform 500 comprises one or more removable support legs 505, each removable support leg may be removably attached to the operating platform 500, such as to the central section 510 and / or the optional extension section(s) 520, by any suitable means, such as by a hook and aperture type arrangement, or by being bolted or otherwise removably attached to the operating platform 500.

[0198] Where the operating platform 500 comprises one or more retractable support legs 505, each retractable support leg may be retractable by any suitable arrangement. For example, each retractable leg may comprise a hinged leg, or a telescopically retractable and extendable leg, or a combination of both. In some forms, the operating platform 500 comprises a pair of retractable support legs that, when retracted to a stowed position, project upwardly on opposing sides of the central section 510, as shown in Figure 27.

[0199] In some forms, as shown in Figures 37b and 43, in the deployed position, the removable or retractable support legs 505 may splay outwardly to one side, away from the operating platform, to provide additional lateral stability to the excavator 1000. In other forms, the support legs 505 may splay outwardly in the direction of the operating platform, as shown in Figures 41 and 42.

[0200] Preferably, at least one support leg 505, and more preferably a pair of extension support legs 505, is / are provided at a distal end of the, or each, extension section 520. Additionally, or alternatively, at least one support leg 505 is provided beneath the connection between the central section 510 and the extension section 520. Each support leg 505 may be removable or retractable. For example, each removable support leg 505 may be removably attached to the extension section 520 by any suitable means as would be apparent to a person skilled in the art, such as a hook and aperture type arrangement, or a pin and hole type arrangement. Each retractable support leg 505 may be retractable by any suitable arrangement. For example, each retractable extension support leg may com prise a hinged leg, ora telescopically retractable or extendable leg that may be extended and retracted mechanically, electrically, pneumatically, or hydraulically.

[0201] In some forms, an extendable operating platform 500 with one or more removable extension sections may comprise one or more support legs 505 that attach to and project below the extension section 520 to contact the ground surface and support the operating platform above the ground, and that hinge upwardly to extend above the operating platform and act as side barriers when stowed.

[0202] The extension section(s) 520 may therefore be removably attached, hingedly attached, or slidably attached to the central section 510 and may comprise one or more removable and / or retractable and optionally extendable support legs 505 to further support the operating platform 500. In some forms, the central section 510 of the operating platform 500 also comprises one or more removable and / or retractable and optionally extendable support legs 505, but in other forms, only the extension section(s) 520 may comprise removable and / or retractable and optionally extendable support legs, or only the central section 510 may comprise removable and / or and optionally extendable retractable support legs 505. Typically, the support legs 505 are hydraulically extendable and retractable legs.

[0203] Rotatable Operating Platform and / or Transportation Unit

[0204] In some forms, the operating platform 500 (and therefore the operation unit 600) may be rotatable relative to the undercarriage 110 of the transportation unit and the transportation unit 100 may be rotatable relative to the operating platform and operation unit 600. For example, the operating platform 500, particularly the central section 510 of the operating platform 500, may be rotatably mounted to the undercarriage 110 by a typical slew ring (sometimes called turnable bearings, ring gears, a slewing swing bearing, slew gears, or slewing rings). Rotation of the slew ring is driven by a slew motor, such as swing drive. The slew ring and slew motor form a subsidiary actuation system that is operatively connected to a principal actuation system of the control system. The slew ring comprises a bearing with gears that may be mounted to the undercarriage and attached to the operating platform to allow the operating platform to independently rotate relative to the undercarriage, and to optionally allow the undercarriage to independently rotate relative to the operating platform.

[0205] In some forms, as shown in Figure 11 , the rotatable operating platform 500 is connected to the undercarriage 110 by a slew ring 140 and slew motor / swing drive. For example, the undercarriage 110 may comprise a central annulus comprising a slew ring 140 therein. The slew ring 140 may comprise: an outer ringthat is fixed in position on the undercarriage; an inner ring, having a toothed central annulus; a set of ball bearings / rollers located between the outer ring and inner ring to allow the inner ring to rotate relative to the outer ring; and a pair of seals to prevent dust and debris building up around the ball bearings / rollers. The operating platform 500 may comprise a pinion gear that comprises a toothed head that projects downwardly beneath the platform 500 to mesh with the toothed annulus of the inner ring of the slew ring 140, as shown in Figure 11 . A swing motor, such as a swing drive, may be attached to the operating platform 500 and is operatively connected to the pinion gear and slew ring 140 to rotate the operating platform 500 relative to the undercarriage and / or rotate the undercarriage relative to the operating platform 500 according to signals received from the control system as a result of operator inputs.

[0206] The slew ring connection forms a subsidiary actuation system that is controlled by the control system. In some forms, the slew ring connection is hydraulically controlled by the first or second (where present) hydraulic actuation system of the excavator. In other forms, the slew ring may be connected to a reversible electric motor powered by an electric power supply to rotate the operating platform or transportation unit.

[0207] Preferably, the slew ring actuation system is configured to allow the operating platform 500 to rotate 360° relative to the undercarriage 110, and optionally also to allow the undercarriage to rotate 360° relative to the operating platform.

[0208] In some forms, the transportation unit 100 may be driven to a desired worksite and stopped. The operating platform 500 may then be caused to rotate relative to the transportation unit 100 by rotating the platform 500 about the slew ring 140 connection. When the operating platform 500 is located in the desired orientation, the operator causes (via the user interface and connected control system) rotation of the platform 500 to be stopped and the support legs 505 of the platform to be (optionally) extended to provide additional support to the platform 500, if needed. In some forms, the operating platform 500 may also be extended in length, if desired, by deploying one or more extension sections 520 to the extended position. Once the operating platform 500 is in the desired position, the excavator 1000 may be operated by moving the carriage 400 back and forth along the operating platform 500 and operating the excavator arm 300 as required.

[0209] Additionally, or alternatively, the excavator 1000 may be configured such that the transportation unit 100 is rotatable relative to the operating platform 500. When the excavator needs to be moved to a different site, the transportation unit typically needs to be driven across the ground and steered in the desired direction. Where that direction requires turning the transportation unit, significant energy is usually required to turn the heavy machine on the ground, especially where the ground is muddy. Turning such a heavy machine on the ground also tends to churn up the ground and make the worksite more difficult for people and vehicles to cross. Therefore, to avoid such problems, the excavator 1000 of the invention may be configured to allow the transportation unit 100 to be lifted off the ground and then rotated to a desired direction. Such an arrangement can be useful to efficiently turn the transportation unit 100 in a different direction without damaging the ground surface of the worksite. For example, as shown in Figures 8, 12, 28, and 42, support legs 505 may be extended to a deployed position. The extendable support legs 505 may be configured to extend to such a length that the legs 505 jack / lift the transportation unit 100 off the ground and above the ground surface. Optionally, the support legs 505 are hydraulically powered support legs to provide the legs with sufficient strength to liftthe transportation unit 100. The transportation unit 100 may be lifted off the ground surface during use of excavator 1000 (i.e. whilst the excavator arm 300 is operating) or afterwards. Once the transportation unit 100 is lifted off the ground, the unit 100 can be rotated relative to the operating platform 500 via the slew ring 140. When the transportation unit 100 is then facing in the desired direction, the support legs 505 may be retracted, to lower the transportation unit 100 to the ground, and optionally stowed. The excavator 1000 may then be driven across the ground surface. By rotating the transportation unit 100 to the desired direction when the unit 100 is suspended above the ground, less energy is required to rotate the transportation unit 100 and less damage is done to the ground surface.

[0210] Overview and Operation of Preferred Embodiments

[0211] An overview of preferred forms of the invention and the use of the excavator will now be described. It should be appreciated that this overview is not intended to limit the excavator to exclude any features described above.

[0212] The excavator arm 300 is an articulated hydraulic arm comprising a plurality of hydraulic rams that enable the arm to extend to reach, and curl to retract. A distal end of the excavator arm 300 may comprise a removable tool, such as gripping jaws, a bucket, a hook, or any other tool required for the particularjob. In some forms, the excavator a rm 300 may comprise a robotically controlled hydraulic arm.

[0213] The excavator 1000 comprises a control system comprising a user interface 950 and one or more actuation systems to move one or more components of the excavator. In some forms, the control system comprises an electronic controller 900, such as a programmable controller, that is operatively connected to the user interface 950 and the actuation system(s).

[0214] The user interface 950 is configured to receive operator inputs from an operator. The user interface comprises a plurality of control elements by which an operator can make operator inputs to control the operation of the excavator. In some forms, the user interface comprises control elements comprising an accelerator, a brake, and a steering means to accelerate, brake, and steer the transportation unit 100. The user interface may also comprise control elements to cause the carriage 400 to move in a first direction or a second direction along the operating platform 500 and to cause: the operating platform 500 to rotate in a first direction or a second direction relative to the transportation unit 100 and / or cause the transportation unit 100 to rotate in a first direction or a second direction relative to the operating platform and / or cause the cab 200 to rotate in a first direction or a second direction relative to the operating platform 500 and / or cause the excavator arm 300 to reach and extend or curl and retractand / or cause the excavator arm 300 to open or close jaws attached to the arm or to modify the angle of a bucket attached to the arm and / or to cause the excavator arm 300 to rotate in a first direction ora second direction relative to the transportation unit 100 (in embodiments where the arm 300 is attached to the carriage 400, but not to an operator cab 200 and therefore does not move simultaneously with the cab).

[0215] In some forms, the user interface 950 is located in the cab 200 for easy access by an operator in the cab. Additionally, or alternatively, the user interface 950 may be a remote interface (such as a transportable electronic interface), to allow a remotely located operator to operate the entire excavator remotely, as shown in Figure 3. Therefore, the excavator may be controlled by an onboard operator within the cab, or may be remotely controlled by an operator located remotely from the excavator, or the excavator may be configured for an onboard operator to select to use onboard control (i.e. control from within the cab) or remote control.

[0216] The control system comprises at least one principal actuation system that may comprise or control subsidiary actuation systems within the control system, such as an extension actuation system of the operating platform 500, or a carriage actuation system to move the carriage 400 along the carriage track. In some forms, the control system comprises a first principal actuation system, as described above, and comprising a first power supply and first motor. Where the first principal actuation system is a hydraulic system, it may also comprise a first hydraulic pump driven by the first motor and connected to movable components of the excavator via hydraulic hoses and valves. In some forms, the first principal actuation system is operatively connected to the control system, the transportation unit 100, and the operating platform 500.

[0217] The excavator 1000 may also comprise a second principal actuation system, as described above, comprising a second power supply, and a second motor that is operatively connected to the second power supply. Again, where the second principal actuation system is a hydraulic system, it may also comprise a second hydraulic pump driven by the first motor and connected to movable components of the excavator via hydraulic hoses and valves. The second principal actuation system is operatively connected to the control system, the carriage 400, the optional cab 200, and the excavator arm 300.

[0218] The first and second motors may be fuel powered, such as diesel motors, or the motors may be electrically powered.

[0219] The control system, upon receiving operator inputs from an operator, may transmit input instructions to the first and / or second principal actuation systems to control movement of the transportation unit 100, carriage 400, operating platform 500, optional cab 200, and the excavator arm 300.

[0220] For example, the first power supply may be configured to receive input instructions from the user interface, such as POWER ON and POWER OFF. When powered on, the first power supply supplies power to the first motor. When powered off, the first power supply stops supplying power to the first motor. Therefore, the first power supply is configured to power the first motor according to input instructions received as a result of operator inputs via the user interface 950. The first motor may also be configured to receive input instructions from a controller of the control system, as a result of operator inputs via the user interface. Therefore, when receiving power from the power supply, the first motor controls movement of the transportation unit 100 according to input signals received from the control system. Movement of the transportation unit 100 is controlled by controlling the speed and direction of rotation of the rotatable elements 120. The control system may cause the transportation unit 100 to move in a direction that is typical of an excavator, such as forward, backward, left, right, or straight. The control system may also cause the transportation unit 100 to accelerate, slow, and stop, as is typical of an excavator. Thus, the operator can, via the user interface and control system, control operation of the first principal actuation system to drive and steer the transportation unit 100 to move the excavator from place to place. In some forms, the control system comprises an electronic controller. In some forms, the control system may comprise a programmable controller and a non-transitory storage medium for storing operating programmes / instructions therein. Any suitable programmes / instructions may be stored in the memory to assist with operation of the excavator, such as independent and joint operation of the transportation unit 100, carriage 400, optional cab 200 and / or excavator arm 300. In some forms, the storage medium may store programmes / instructions for the remote control of the transportation unit 100. In some forms, the controller is wirelessly connected to the first principal actuation system to operate the transportation unit 100 remotely.

[0221] In some forms, the first principal actuation system may also be operatively connected to the operating platform 500 and may be configured to extend and / or rotate the operating platform 500 relative to the transportation unit 100 and / or rotate the transportation unit 100 relative to the operating platform 500 according to input signals received from the control system as a result of operator inputs via the user interface.

[0222] The control system may also be operatively connected to the second principal actuation system. The second motor of the principal actuation system is powered by the second power supply. The second principal actuation system may be configured to drive movement of the carriage 400 alongthe operating platform 500 and / or rotation of the cab 200 relative to the transportation unit 100 and / or movement of the excavator arm 300 and moveable components attached to the arm. In some forms, the second principal actuation system may be configured to extend and / or rotate the operating platform 500. In some forms, the second principal actuation system is a hydraulic system. The second hydraulic actuation system may comprise a second hydraulic pump and a plurality of hydraulic hoses connected to various movable components of the operational unit 600 (such as the carriage actuation system, optional cab, excavator arm, and optionally also the operating platform extension actuation system). In a preferred embodiment, the second power supply powers the second motor which drives the second pump to control independent or simultaneous movement of one or more components of the excavator, such as the carriage 400, optional cab 200, and excavator arm 300. For example, the excavator arm 300 may be independently controllable via the user interface, or the arm 300 may be caused to move simultaneously with movement of the cab 200 or carriage 400. The second hydraulic system may also be configured to extend and retract the excavator arm 300 and move any moveable components attached to the arm 300. In some forms, the second hydraulic system may also be used to rotate the excavator arm 300 and optional cab 200 relative to the carriage and / or to rotate the transportation unit 100 relative to the operational unit 600. In some forms, a single motor may be used to control movement of the transportation unit 100, operating platform 500, carriage 400, cab 200, and excavator arm 300. In other forms, two or more motors may be used to control movement of the transportation unit 100, operating platform 500, carriage 400, cab 200, and excavator arm 300.

[0223] In some forms, the second power supply may also configured to receive input instructions from the user interface, such as POWER ON and POWER OFF. When powered on, the second power supply supplies power to the second motor. When powered off, the second power supply stops supplying power to the second motor. Therefore, the second power supply is configured to power the second motor according to input instructions received as a result of operator inputs via the user interface. The second motor may also be configured to receive input instructions from a controller of the control system, as a result of operator inputs via the user interface. When receiving power from the power supply, the second motor may control independent or simultaneous movement of the carriage 400, optional cab 200 and excavator arm 300 according to input instructions received from the controller as a result of operator inputs via the user interface. In some forms, the second motor may also control independent or simultaneous movement of the operating platform 500.

[0224] By making various operator inputs via the user interface, the operator may cause the control system to control translational movement of the optional cab 200 and excavator arm 300 relative to the transportation unit 100 by controlling movement of the carriage 400 forward and backward along the operating platform 500, and the operator may cause the control system to rotate the operating platform 500 in a first direction or a second direction relative to the transportation unit 100 and / or cause the control system to rotate the optional cab 200 in a first direction or a second direction relative to the transportation unit 100 and / or cause the control system to manipulate the excavator arm 300 to reach and extend or curl and retract and / or cause the control system to manipulate the excavator arm 300 to open or close jaws attached to the arm or to modify the angle of a bucket attached to the arm and / or to cause the control system to rotate the excavator arm 300 in a first direction or a second direction relative to the transportation unit (in embodiments where the arm 300 is attached to the carriage 400, but not to the cab 200 and therefore does not move simultaneously with the cab).

[0225] Although in preferred forms, the excavator comprises a cab 200 to provide the option of having an operator operate the excavator onboard, in other forms, the excavator 1000 may not comprise a cab and instead the excavator may be fully remotely controlled. In such forms, the excavator arm 300 may be rotatably mounted directly to the carriage 400. Such an excavator comprises the same operational features as described above, except that the cab is not present and the user interface is a portable interface for full remote control of the excavator 1000.

[0226] The operation of one form of excavator 1000 of the invention will now be described in relation to Figu res 1 to 26 by way of exa m p le o n ly .

[0227] The excavator 1000 comprises a control system, a transportation unit 100 and an operational unit 600. The control system comprises a user interface, a programmable controller, and a non- transitory storage medium for storing operating instructions to control operation of the excavator 1000, and that may include operating instructions for remote control of the excavator, such as remote control of the transportation unit 100 and operational unit 600.

[0228] The transportation unit 100 comprises: an undercarriage 110 supported above the ground surface by a plurality of rotatable elements 120, a first power supply and a first motor operatively connected to the first power supply, the control system, and the rotatable elements. The rotatable elements 120 preferably comprise a pair of rotatable tracks attached to the undercarriage 110 to support the undercarriage above the ground, but in other forms, the rotatable elements may comprise wheels. The first power supply is configured to power the first motor to move the excavator 1000 between locations by rotating the rotatable elements 120 according to one or more operator inputs received from the control system.

[0229] The operational unit 600 comprises an operating platform 500. The operating platform may be rotatably mounted on the undercarriage 110 of the transportation unit 100 by a swivel joint or slew ring connection. The operating platform 500 comprises a central section 510. In some forms, the operating platform is extendable and comprises at least one extension section 520, such as a pair of extension sections 520a, 520b. Where the extendable operating platform comprises a pair of extension sections, the first extension section 520a may be slidably attached to a first end of the central section 510, and the second extension section 520b may be slidably attached to an opposing second end of the central section 510. Each extension section 520a, 520b optionally comprises three sub-sections 525a, 525b, 525c that are slidably connected together. A brace 530 is located between each sub-section 525, at the end of each extension section 520, and at each end of the central section 510. Each brace 530 assists to provide structural strength and rigidity to the operating platform 500.

[0230] The operating platform 500 comprises a carriage track 540.

[0231] In some forms, the operating platform comprises three guide elements that form the carriage track 540. Each guide element comprises a guide rail. In the embodiment shown, a central guide rail 540a is located between a pair of outer guide rails 520b, 540c. The three guide rails 540a, 540b, 540c are parallel to each other. A hydraulic ram 550 is located within the central guide rail 540a, at each end of the central section 510 to push against each extension section 520a, 520b to extend the operating platform 500, or pull each extension section 520a, 520b toward the central section 510 to retract the extension section 520a, 520b. Each guide rail 540a, 540b, 540c comprises opposing sides, a top and a bottom. An elongate channel 541 extends along the length of the outer sides of each of the two outer guide rails 540a, 540b.

[0232] The operational unit 600 also comprises a carriage 400, a cab 200, and an excavator arm 300. The cab 200 and excavator arm 300 are rotatably mounted on the carriage 400.

[0233] The carriage 400 comprises two opposing sides 402 and a deck 405 extending between the two sides 402 on which the optional cab 200 and the excavator arm 300 are mounted. A line of rollers 410 are located along each side of the carriage 400. The rollers 410 may face inwardly toward each other. Each line of rollers 410 is received within a respective channel 541 of the carriage track, such as outer guide rails 540a, 540b of the operating platform 500. A central groove or channel 420 may also located on the underside of the carriage 400 and positioned on top of the central guide rail 540c of the operating platform 500 to slide along the central guide rail 540c.

[0234] The excavator 1000 comprises a first principal actuation system comprisinga first power supply and first motor. The first power supply and first motor are operatively connected to the control system to control movement of the transportation unit 100 and the operating platform 500 based on operator inputs received from the user interface.

[0235] The excavator 1000 also comprises a second principal actuation system comprising a second power supply and second motor. The second power supply and second motor are operatively connected to the control system to control movement of the carriage 400, cab 200, and excavator arm 300 based on operator inputs received from the user interface.

[0236] To operate the excavator 1000, an operator may sit or stand within the cab 200 in which the user interface may be located, or for remote operation, the operator may be located remotely from the cab 200 and have access to a portable user interface. The operator may then power on the first power supply to power the first motor and begin rotating the rotatable elements, such as rotatable tracks, in the desired direction to drive the excavator to a desired work site, such as to clearing within a forest where felled logs are located, using the user interface. Where the operator drives the excavator 1000 using the user interface within the cab 200, the cab may also comprise standard operator controls, such as an accelerator, brake, and steering controls, to control the direction and speed of the transportation unit 100. Once the excavator 1000 is at the desired location, the operator may brake the excavator and may optionally stop power to the first motor by powering off the first power supply.

[0237] The operator may then make various inputs via the user interface to rotate the operating platform 500 relative to the transportation unit 100 so that the length of the operating platform aligns with the desired direction of travel of the carriage 400, such as in the direction of one or more felled logs to be retrieved and stacked by the excavator 1000. Once the platform 500 is facing in the desired direction, the operator, via the user interface, may cause the control system to extend retractable support legs 505 of the central section 510 and optionally to extend the operating platform 500, such as by causing hydraulic ram(s) 550 to push against each extension section 520 of the operating platform 500 until each extension section and any and all sub-sections 525 of each extension section are fully extended. The operating platform 500 is now fully deployed in its extended position.

[0238] The operator may then, via the user interface, cause the control system to move the carriage 400 (and therefore the excavator arm 300) toward one end of the operating platform 500, such as the forward end. The operator may then, via the user interface, cause the control system to move the excavator arm 300 to reach out and grab one or more felled logs, lift the logs off the ground, and optionally retract toward the carriage 400. The operator may then, via the user interface, cause the control system to move the carriage back along the operating platform 500, such as to the rearward end of the platform 500 where the excavator arm 300 may be caused to lower and release the logs in a stack onto a truck, for example. The movement of the carriage 400 and arm 300 can be repeated as necessary.

[0239] In some cases, the operating platform 500 may need to be rotated to face in a different direction. In such cases, the carriage 400 may be moved onto the central section 510, preferably the carriage is moved to be centrally located on the central section 510, the support legs 505 are retracted, and then the operating platform 500 is rotated to the desired position. Once in position, the support legs 505 may be extended again. In some forms, the extension sections 520 may be retracted before the operating platform 500 is rotated.

[0240] In some cases, it may be desired to change the direction in which the transportation unit is facing. In this case, the operator, via the control system, may extend the support legs sufficiently to lift the transportation unit 100 off the ground. The operator then, via the control system, rotates the transportation unit 100 about the slew ring connection. The operating platform 500 remains stationary and is supported on the ground by the support legs 505. When the transportation unit is facing in the desired direction, its rotation is stopped, and the support legs are retracted to lowerthe transportation unit to the ground. Once the support legs are fully retracted to a stowed position, the transportation unit may be driven in the desired direction by the operator.

[0241] In some forms, as shown in Figure 29, the excavator 1000 may not comprise an extension section or may be used without extending the extension section(s) 520. For example, the length of the central section 510 may be sufficient for the carriage to reach its desired location(s).

[0242] In some forms, as shown in Figures 30 to 44b, the excavator may be used with only one extension section 520 that may be extended between an extended position and a stowed position. In some forms, the excavator may operate as described above in relation to the two extension section arrangement, but the extension section is movable along or within an extension track of the central section 510 to extend from either end of the central section. The extension section 520 may be moved back and forth across the central section 510 to extend from either end of the central section according to operator inputs received by the control system.

[0243] Typically, one the excavator 1000 is in the desired position and once the operating platform is in the desired orientation, the central section 510 of the excavator 1000 may be stabilised with support legs 505. The extension section 520 may then be moved to the desired extended position (if necessary), which may be to extend from the first or second end of the central section 510. The carriage 400 may be moved back and forth along the carriage track 540.

[0244] To move / slide the extension section 520 across the central section 510, the operator may cause the winch actuation system to activate the winch motor to rotate in a first direction to rotate the winch drum 581 and pull the extension section in the desired direction. In some forms, the winch drum may continue to move the extension section until maximum extension is reached. In other forms, the operator may stop movement of the extension section 520 by stopping the winch motor when the extension section is at the desired location. In some forms, the excavator 1000 may comprise one or more position sensors that sense the position of the extension section relative to the central section and signal the electronic controller of the control system, which then determines the position of the extension section 520. The controller may be programmed to move the extension section to a desired position, such as a fully extended first position at the first end of the central section 510, a fully extended second position at the second end of the central section, and the central, stowed position. In such forms, a user may select the stowed position as an input on the user interface, for example, and the controller may actuate the winch motor to drive the winch drum in the required direction to move the extension section toward the central section 510. The one or more position sensors may signalthe controller when the extension section 520 reaches the stowed position, at which point the controller stops the winch motor. Similarly, a user may select the first extended position as an input on the user interface, for example, and the controller may cause the winch actuation system to activate the winch motor to drive the winch drum 581 in the required direction to move the extension section 520 along or within the extension track 570 in the direction of the first end of the central section 510. The one or more position sensors may signal the controller when the extension section 520 reaches the extended position, or the extension section may abut a stop at the extended position, at which point the controller stops the winch motor.

[0245] When the extension section 520 is in the desired operating position, the carriage 400 may be moved along the carriage track 540 of the extension section. The operator may control movement of the carriage (and therefore of the excavator arm 300 and optional cab 200) via the user interface of the control system and the carriage actuation system. The carriage actuation system may activate the carriage motor to rotate the rotatable toothed member 546 to engage with and move along the carriage engagement element 506 in a particular direction until the carriage 400 reaches the desired position, at which point the operator may input a STOP command to the user interface to cause the carriage actuation system to stop the carriage motor, or one or more sensors may signal to the controller that the carriage 400 has reached a predetermined position and the controller may then cause the carriage actuation system stop the carriage motor.

[0246] The operator may also control rotation of the excavator arm 300 (and optionally also the cab 200, where present) through the user interface, such as by using the second hydraulic actuation system to rotate the carriage 400 about the slew ring connection with the operating platform 500 or with the transportation unit 100.

[0247] The carriage 400 is therefore movable along the operating platform 500, in the retracted and extended positions, to move at least the excavator arm 300, and optionally a cab 200 (where present), between ends of the platform 500.

[0248] Optionally, the operating platform 500 may be rotated, relative to the transportation unit 100, to the desired orientation to enable the excavator arm 300 to access one or more other work locations without needing to move the excavator 1000 across the worksite and / or the transportation unit 100 may be rotated relative to the operating platform 500.

[0249] Therefore, the excavator 1000 of the invention enables the carriage 400 and the excavator arm 300 located on the carriage to move back and forth across the operating platform 500, which may be extendable and / or rotatable relative to the transportation unit 100. When the carriage 400 is to be moved along the carriage track 540 on the extension section, one or more support legs 505 may be deployed from the central section and / or the extension section, as described above, to contact the ground and help stabilise and support the operating platform. The ability of the movably extendable operating platform 500 of Figures 1 to 44b, and particularly the extension section 520 of the operating platform, to be adjusted between an extended position and a central position is useful at a work-site to enable the excavator arm 300 to operate at more than one work location on the work site without requiring the excavator 1000 itself to move between the work locations. Instead, the excavator 1000 may be positioned between two or more work locations and stopped in that location so that the excavator arm can move back and forth along the operating platform and between the work locations.

[0250] When the excavator is to be moved across a worksite or to a new site, the extension section 520 may first be removed or retracted to the stowed position, as shown in Figures 29, 30, 35a, and 40, for example. Any support legs 505 are also retracted and stowed when the extension section 520 is in the stowed position, as shown in Figure 35a.

[0251] The excavator of the invention may therefore be operated without moving the entire excavator 1000 back and forth across a worksite. Instead, only the excavator arm 300 or only the cab 200 and arm 300 may be moveable across the worksite by moving along the operating platform 500. Where the transportation unit is operated by a first motor and the excavator arm and optional cab are operated by a second motor, the first motor may be stopped once the excavator is in the desired position, and the second motor may solely be used to move the carriage, cab, excavator arm, and optionally also to extend and rotate the operating platform. This configuration allows the second motor to be a small, low powered motor as (unlike the first motor) the second motor does not need to be of sufficient power to move the excavator across rough terrain. As such, the general power consumption or fuel consumption of the excavator can be minimised.

[0252] Additionally, or alternatively, the optional ability of the operating platform 500 and / or the transportation unit 100 to be independently rotated relative to the other when suspended above the ground, minimises the energy required to rotate the operating platform or transportation unit and minimises damage to the ground surface.

[0253] By minimising the energy required to move and operate the excavator of the invention, it is possible for the excavator to use lower powered motors, such as electric motors, than typical excavators. Using smaller motors may be less costly and may also allow the excavator to run efficiently and more cost-effectively.

[0254] The excavator 1000 of the invention may have many different uses other than for use logging. For example, the excavator may also be useful for clearing debris after an earthquake or tsunami where it can be difficult to cross a ground surface strewn with rubble. The technology may also be said broadly to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, in any or all combinations of two or more of said parts, elements or features.

[0255] Where in the foregoing description reference has been made to integers or components having known equivalents thereof, those integers are herein incorporated as if individually set forth.

[0256] It should be noted that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications may be made without departing from the scope of the invention and without diminishing its attendant advantages. It is therefore intended that such changes and modifications be included within the present invention.

[0257] For example, although in some forms the control system may be an electronic programmable control system, it should be appreciated that in other forms, the control system may be a mechanical control system comprising a variety of operator controls, such as levers, that manipulate the motors of the excavator to drive and steer the transportation unit and / or move the carriage along the operating platform and / or extend or retract the support legs and / or manipulate the articulated arm using hydraulic systems of the excavator.

[0258] It should be appreciated also that the excavator of the invention may be used as a robotic arm, such as that used for picking products in a warehouse.

Claims

AMENDED CLAIMS received by the International Bureau on 01 May 2026 (01.05.2026)1. An excavator 1000 comprising: a control system comprising a user interface, a first actuation system comprising a first power supply, and a first motor powered by the first power supply; a transportation unit 100 comprising a plurality of rotatable elements 120; an operating platform 500 supported by the transportation unit and comprising a length and a carriage track 540 extending along at least a portion of the length of the operating platform; a carriage 400 movable along the carriage track between opposing first and second ends of the operating platform; an extendable and retractable excavator arm 300 directly or indirectly mounted on the carriage and being controllable via the control system; wherein the rotatable elements 120 are rotatable by the first actuation system to move the excavator between locations; wherein the operating platform 500 is extendable in length and comprises a primary section 510 comprising first and second opposing ends, and at least one extension section 520 attached to, or removably attachable to, the primary section 510 and configured to extend from at least one end of the primary section 510.

2. The excavator of claim 1 , wherein the control system comprises a second actuation system comprising a second power supply and a second motor, powered by the second power supply, to control independent or simultaneous movement of the carriage 400 and the excavator arm 300.

3. The excavator of claim 1 or 2, wherein the at least one extension section 520 is movably attached to the primary section 510.

4. The excavator of claim 3, wherein the extension section 520 is movable across the length of the primary section 510 to extend from either end of the primary section.

5. The excavator of claim 4, wherein the operating platform 500 comprises an extension actuation system operatively connected to the control system to slide the extension section 520 between an extended position and a stowed position.

6. The excavator of claim 6, wherein the extension actuation system comprises a winch mechanism comprising a winch drum 581 , and a tension member 582 comprising a length and firstand second ends, wherein a central portion of the tension member is wound around the winch drum581 , a first end portion of the tension member 582 is attached to the extension section, near the first end of the extension section, and a second end portion of the tension member 582 is attached to the extension section, near the second end of the extension section, and wherein the winch drum is rotatable in each direction by a winch motor such that rotating the drum in one direction winds the first end portion of the tension member onto the drum and unwinds the second end portion to move the extension section in a first direction, and rotating the drum in the other direction winds the second end portion onto the drum and unwinds the first end portion to move the extension section in an opposing, second direction.

7. The excavator of claim 6 when dependent from claim 2, wherein rotation of the winch drum581 is hydraulically powered and the winch motor comprises the first or second motor.

8. The excavator of claim any preceding claim, wherein the carriage 400 is movable along the carriage track 540 by a carriage actuation system in which the carriage comprises a rotatable toothed member 546 that is rotatable in opposing directions by a reversable motor, and the operating platform 500 comprises an elongate carriage engagement element 506 extending along at least a majority of the length of the operating platform, wherein the carriage engagement element506 comprises a plurality of apertures or recesses spaced equidistant along its length, and wherein each tooth of the rotatable toothed member 546 is engageable with each aperture or recess of the carriage engagement element.

9. The excavator of claim 8, wherein the rotatable toothed member 546 comprises a drive sprocket and the elongate carriage engagement element 506 comprises a chain that is attached to each end of the operating platform, wherein a tension sprocket 587 is located on each side of the drive sprocket, and wherein the chain partially wraps around one side of each tension sprocket and the opposing side of the drive sprocket to tension the chain.

10. The excavator of claim 8, wherein the rotatable toothed member 546 comprises a pinion and the elongate carriage engagement element 506 comprises a rack that extends along at least a majority of the length of the operating platform.

11. The excavator of any preceding claim, wherein the carriage track 540 comprises at least one guide element 542 that engages with at least one engagement feature 442 of the carriage400.

12. The excavator of claim 11 , wherein the guide element 542 comprises a channel and the engagement feature 442 comprises a rail or a plurality of rollers received within the channel.

13. The excavatorof any one of the preceding claims, wherein the operating platform 500 is rotatably attached to the transportation unit 100 by a rotatable connection such that: a. the operating platform is independently rotatable relative to the transportation unit; b. the transportation unit is independently rotatable relative to the operating platform; or c. both the operating platform and transportation unit are independently rotatable relative to the other.

14. The excavator of any one of the preceding claims, wherein the operating platform 500 comprises a plurality of support legs 505 that are removable support legs or that are extendable and retractable support legs.

15. The excavator of any one of claim 14, wherein the support legs 505 are extendable in a deployed position to lift the transportation unit 100 off a ground surface to enable rotation of the transportation unit relative to the operating platform 500.

16. The excavator of any one of the preceding claims, wherein the excavator arm 300 is rotatable relative to the operating platform 500.

17. The excavator of any one of the preceding claims, wherein an operator cab 200 is rotatably attached to the carriage 400 and comprises a user interface operatively connected to the control system.

18. The excavator of any one of the preceding claims, wherein the excavator 1000 comprises a remote user interface that is operatively connected to the control system to enable remote control of the excavator.

19. The excavator of any one of the preceding claims when dependent from claim 2, wherein the second motor is an electric motor or a hybrid motor.

20. An excavator 1000 comprising: a control system comprising a user interface, a first actuation system comprising a first power supply, and a first motor powered by the first power supply; a transportation unit 100 comprising a plurality of rotatable elements 120; and an operating unit comprising:an operating platform 500 supported by the transportation unit and comprising a length and a carriage track 540 extending along at least a portion of the length of the operating platform; a carriage 400 movable along the carriage track between opposing first and second ends of the operating platform; and an extendable and retractable excavator arm 300 directly or indirectly mounted on the carriage and being controllable via the control system; wherein the rotatable elements 120 are rotatable by the first actuation system to move the excavator between locations; and wherein the excavator comprises a second actuation system comprising a second motor powered by a second power supply, wherein the second actuation system is operable by the control system and wherein at least one of the carriage 400 and the excavator arm 300 are movable by operation of the second actuation system.

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