WO 2013/131140 PCT/AU2013/000220 EARTH-DISPLACING APPARATUS The present invention relates to an improved apparatus for displacing earth. The invention has advantageous, though not exclusive, application to scraper train apparatuses, including 5 articulated dump truck (ADT) scraper apparatuses and tractor-scraper apparatuses. Tractor-scraper apparatuses are commonly used in civil engineering applications for the purposes of removing, adding, smoothing or levelling ground. Typically, such an apparatus comprises a powered vehicle, such as an ADT or tractor, and one or more 10 scraper units towed by the vehicle. Shown in Figure IA is a typical scraper apparatus A, which comprises a driver-operated powered vehicle V (such as an ADT or tractor) at a forward position of the apparatus and a train TS of scraper units SI, S2, S3 (generally designated "S") which are coupled in 15 end-to-end relation, the train TS being coupled at its forward end to vehicle V to be towed thereby. Each of the scraper units S comprises a payload carrier P (a hopper) and a ground-engaging implement or tool T, in the form of a knife or blade, which is 20 hydraulically actuatable so as to be moveable between an extended or operating position (as shown for unit S3), in which it penetrates the ground G, thus causing ground material to be collected in the payload carrier P, and a retracted or stowed condition (as shown for units S1 and S2), in which it is clear of the ground surface, permitting haulage of the material M by the apparatus A. Each of the units S further includes an apron or gate GA 25 which is hydraulically actuatable so as to be moveable between an open position, in which it is clear of an opening into the hopper P to pennit earth to be drawn (via operation of the tool T) into -the hopper P, and a closed position, in which it covers the opening to prevent escape of the payload material M therethrough (e.g. during haulage of the material M). Each of the units S further comprises an ejector, in the form of a hydraulically actuatable 30 pusher blade B, which, when the gate GA of the unit is in an open position, can be urged forwardly to effect discharge of material M through the opening and thus unloading (e.g. to WO 2013/131140 PCT/AU2013/000220 -2 dump and/or distribute the material on the ground). The front scraper unit SI is provided with a gooseneck N via which a forward end thereof is coupled to a rear part of the vehicle V, such that unit Sl and vehicle V can articulate. 5 Scraper unit S2, in turn, is provided with a gooseneck N via which a forward end thereof is coupled to a rear end of scraper unit S1, such that the units SI and S2 can articulate. Scraper unit S3, similarly, is provided with a gooseneck N via which a forward end thereof is coupled to a rear end of scraper unit S2, such that the units S2 and S3 can articulate. 10 The wheels W of the units S are unpowered, so that the only means of locomotion in the apparatus A are driven wheels of the vehicle V. A problem commonly encountered with apparatuses such as this is that the locomotion provided by the vehicle V is insufficient to overcome adequately the resistance to forward motion by the scraper train TS when one or more of the tools T are in their operating conditions. With reference to Figure 1B, the 15 problem can be remedied by operating a further powered vehicle V', such as a track-type tractor, to push against the rear end of the train TS, whereby driving force is imparted to the train TS at both its leading and trailing ends (possibly, but not necessarily, then permitting more a plurality of tools T to be invoked at the same time (as shown in Figure IB) instead of only the single tool T being shown in Figure 1A). This requires not 20 only a separate item of equipment (in vehicle V) but also a further operator (to operate the vehicle V'), increasing complexity and reducing efficiency, thereby increasing expense. In particular, apparatus A often must stop to await engagement therewith by the vehicle V', which vehicle will often end up providing most of the locomotive power to the apparatus A. 25 According to the present invention, there is provided an apparatus for displacing earth, comprising: a driver-operable powered vehicle at a forward position of the apparatus; one or more ground-displacing units coupled to the vehicle to be pulled thereby, the 30 or each ground-displacing unit including a ground-engageable implement; and a powered dolly coupled to the unit(s) so as to provide to the apparatus locomotion WO 2013/131140 PCT/AU2013/000220 -3 which supplements that provided by the vehicle, Preferably, the apparatus comprises a plurality of said ground-displacing units coupled in end-to-end relation. 5 In a preferred embodiment of the invention, the dolly is coupled to a rear of the unit(s). The dolly may, in this embodiment, be arranged so as to push the unit(s). In an alternative embodiment of the invention, the unit(s) may be coupled to the vehicle 10 via the dolly. In the latter embodiment, the dolly may be arranged to pull the unit(s), and is preferably coupled to a front of the unit(s). Preferably, the or each unit includes traction means from which the or each earth-engageable implement of that unit is supported. The traction means may comprise 15 tracks and/or wheels. In a preferred embodiment of the invention, the apparatus further comprises one or more further ground-displacing units coupled to ,the dolly to be pulled thereby, the or each further ground-displacing unit including a ground-engageable implement. The apparatus 20 may comprises a plurality of said further ground-displacing units coupled in end-to-end relation. Preferably, the or each further unit includes traction means from which the or each earth-engageable implement of that unit is supported. The traction means may comprise 25 tracks and/or wheels. In a preferred embodiment of the invention, the apparatus further comprises a further powered dolly coupled to the further ground-displacing unit(s) to so as to provide to the apparatus locomotion which supplements that provided by the vehicle and said dolly. 30 Preferably, the further dolly is coupled to a rear of the further ground-displacing unit(s). Said further dolly may be arranged so as to push the further ground-displacing unit(s).
WO 2013/131140 PCT/AU2013/000220 -4 Preferably, the apparatus according to such an embodiment further comprises one or more additional ground-displacing units coupled to the further dolly to be pulled thereby. The apparatus may comprise a plurality of additional ground-displacing units coupled in end to-end relation. The apparatus of such an embodiment may further comprise an additional 5 powered dolly coupled to the additional ground-displacing unit(s) to so as to provide to the apparatus locomotion which supplements that provided by the vehicle and said dollies. Preferably, said additional powered dolly is coupled to a rear of the additional ground-displacing unit(s). Said additional powered dolly may be arranged so as to push the additional ground-displacing unit(s). 10 In the preferred embodiments of the invention, the or each dolly comprises brakes, in addition to an engine and a transmission via which the engine drives traction means of the dolly, which traction means may comprise wheels and/or tracks. Preferably, the or each dolly is steerable. 15 In one preferred embodiment of the invention, the driver-operable powered vehicle comprises ground-engaging tracks and the traction means of the dolly comprises tracks. In another preferred embodiment of the invention, the driver-operable powered vehicle comprises ground-engaging wheels and the traction means of the dolly comprises wheels. 20 In preferred embodiments of the, invention, the apparatus includes a communication system via which the or each dolly and vehicle are operatively linked, such that operation of the vehicle and the.or each dolly is synchronised. Preferably, at least throttling and braking of the vehicle and the or each dolly are synchronised. Preferably, steering of the vehicle and 25 the or each dolly are additionally synchronized. The communication system may comprise any suitable communication means, such as, for example, communication cabling and/or wireless linkage(s), between the vehicle and dolly or dollies. The communication means/cabling may be releasably connected to the vehicle and/or the or each dolly. 30 Preferably, the or each dolly is coupled to at least one said unit, either directly or indirectly, in articulated relation, Preferably, the or each dolly is so coupled such that WO 2013/131140 PCT/AU2013/000220 relative pivotal movement between the dolly and unit(s) is possible in both vertical and horizontal planes which extend parallel to a direction of travel of the apparatus. In a preferred embodiment of the invention, at least one said, and preferably each, 5 ground-engageable implement comprises a scraper. In a preferred embodiment of the invention, at least one said, and preferably each, ground-engageable implement comprises a plough. 10 In a preferred embodiment of the invention, at least one said, and preferably each, ground-engageable implement comprises a ripper. In a preferred embodiment of the invention, at least one said, and preferably each, ground-engageable implement comprises a grader blade, 15 In a preferred embodiment of the invention, the apparatus is configured such that operation of the units is sequenced. To this end, the apparatus may included a programmed computer or other suitable electronic means (which may form part of said communication system), to effect sequenced operation of the units. For example, the apparatus may be 20 configured such that an implement of one, or each of more than one, of the units is in a ground-engaging condition while an implement of the or each other unit is in a non-ground engaging, or retracted/stowed, condition. Where the units comprise scraper units, loading and/or unloading of the units is preferably sequenced, 25 Apparatuses embodying the invention may be configured for on-board driver-operation and/or remote driver-operation. In the case of the latter, the driver of the vehicle may be a person controlling the vehicle remotely, e.g. from off-site. The present invention will now be described, by way of non-limiting example only, with 30 reference to the accompanying drawings, in which: Figures IA and 1B depict operation of a typical scraper train apparatus as already WO 2013/131140 PCT/AU2013/000220 -6 described; Figure 2 shows a scraper train apparatus according to a first preferred embodiment of the present invention; Figure 3 shows a scraper train apparatus according to a second preferred 5 embodiment of the present invention; and Figure 4 indicates how varying numbers of scrapers and dollies can be arranged in a scraper train apparatus in accordance with preferred embodiments of the present invention. 10 A scraper train apparatus 1 according to a first preferred embodiment of the present invention is shown in Figure 2. In the description of this and subsequent embodiments, the same reference indicia as have been used in respect of the embodiment illustrated in Figures 1A and IB will be used to designate the same or corresponding features. 15 The apparatus I is substantially the same as the apparatus A except that it additionally comprises a powered dolly D interposed between adjacent ones of the scraper units S, and, more particularly, units S2 and S3, and a communication line L which extends from the vehicle V to the dolly D, via which the dolly D is operatively linked to the vehicle V. The dolly D comprises a chassis C, ground-engaging wheels WD, an engine (not shown), a 20 transmission (also not shown), via which the engine drives the wheels WD, and brakes (also not shown). The dolly D is formed with a gooseneck ND via which it connects in an articulated manner to a rear part of scraper unit S2 (whereby the dolly D and unit S2 are coupled for relative pivotal movement in planes which are horizontal and vertical when the apparatus is on level ground), and a connector, rearward of the gooseneck end ND, to 25 which the gooseneck N of scraper unit S3 connects in an articulated manner (whereby the dolly D and unit S3 are also coupled for relative pivotal movement in planes which are horizontal and vertical when the apparatus is on level ground). The dolly D, in addition to towing scraper unit S3, pushes, from behind, the scraper units SI and S2 which are towed by vehicle V, thereby providing to the apparatus I locomotion which supplements that 30 provided by the vehicle V, whereby there is sufficient overall locomotion to drive the apparatus 1 forwardly.
WO 2013/131140 PCT/AU2013/000220 -7 The line L forms part of a communication system via which control of the dolly D, including in particular acceleration and braking, and optionally also steering, thereof, is synchronised with the control of the vehicle V effected by the driver. The line L connects 5 to each of the vehicle and dolly via a respective releasable multiple pin plug-and-socket interconnection, and is appropriately supported by the scraper units SI and S2. The supplementary driving force provided by the dolly D may, for example, enable the apparatus 1 to operate with all of the tools T in their operating conditions, as shown in 10 Figure 2. This being said, the apparatus 1, consistent with conventional apparatuses, is configured such that actuation of the ejectors 13, gates GA and tools T, and thus loading and unloading of the units S, can be sequenced, and the apparatus I may include a programmed computer or other suitable electronic means (which may form part of the communication system) whereby it is so configured. For example, the apparatus I may be 15 configured such that one of the units S loads or unloads while the others do not, and/or such that when loading or unloading of one of the units S is almost complete, loading of another of the units S commences (with closing of the gate GA of the first-mentioned unit S being effected shortly thereafter). Owing to the supplementary drive provided by the dolly D, it may be that the sequencing can be such that more than one unit S is being 26 loaded at a given time. A scraper train apparatus V according to a second preferred embodiment of the present invention, illustrated in Figure 3, is the same as% the apparatus I but includes additional scraper units S4, S5, the former being coupled in an articulated manner to the rear of 25 scraper units S3 via its gooseneck N (for relative pivotal movement in perpendicular planes, as previously outlined), and an additional dolly DI interposed between units S4 and S5 and coupled thereto in the same manner as the dolly D is coupled to units 82 and S3, as well as an additional communication line L' (also forming part of the communication system) which operatively links the further dolly D' with the vehicle V in 30 the same manner as the line L operatively links the vehicle V and dolly D. It will, of course, be appreciated that, in this embodiment, sequencing of operation, as described WO 2013/131140 PCT/AU2013/000220 -8 above, applies to all of the units S (and it may thus be that typical operation of the apparatus ' would not involve all of the units S loading, despite this being shown in Figure 3). 5 In a variant of the second embodiment, without departure from the invention, scraper units Sl and S2 are not directly coupled but rather are coupled via an interposing unpowered (preferably single-axld) dolly, and scraper units S3 and S4, similarly, are not directly coupled but rather are coupled via an interposing unpowered (also preferably single-axle) dolly, these interposing dollies thus providing weight-bearing support to the front ends of 10 the units S2 and S4 respectively, instead of the units Sl and S3 respectively doing so, whereby there is significantly less loading on the axles and wheels of the units Si and S3. It will be appreciated that the number of dollies and scraper units in an apparatus embodying the invention can vary considerably. Shown in Figure 4, an apparatus 1" 15' embodying the invention comprises X scraper units interposed between the vehicle V and a first dolly Di, Y scraper units S interposed between dolly DI and a dolly D2, and Z scraper units coupled to dolly D2 to be towed thereby, where each of X, Y and Z is greater than or equal to one. There may, of course, be only one dolly (consistent with the first embodiment) or more than two dollies. It will, again, be appreciated here that, in this 20 embodiment, sequencing of operation, as described above, applies to all of the units S and it may again be that typical operation of the apparatus ' would not involve all of the units S loading, despite this being shown in Figure 4. Adjacent scraper units in the scraper train apparatuses described above with reference to 25 the drawings may, instead of being coupled together via a gooseneck hitch, be coupled together via a drawbar-type hitch, as will be known to a person skilled in the art, without departure from the invention. The latter may be preferable where the powered towing vehicle is a tractor. 30 Apparatuses embodying the invention may be used to displace, for example, soil, coal, shale, oil sands, overburden and/or sand. An apparatus embodying the invention can have WO 2013/131140 PCT/AU2013/000220 -9 numerous applications. One such application is in mining, where the apparatus may be used to clear mines, e.g. coal mines, to remove overburden, to dig partings and/or to reclaim mine sites. 5 Although the illustrated embodiments of the invention are scraper train apparatuses or towed scraper apparatuses, in which each unit includes a scraper tool or blade, the invention can be embodied in other earth-displacing apparatuses, including such apparatuses in which each earth-displacing unit includes, for example, a plough, ripper or grader blade. 10 In an alternative embodiment of the invention, a powered dolly may couple a front of the the towed unit(s) to a rear of the vehicle, the unit(s) thus being pulled by both the vehicle and that dolly. 15 While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example only, and not by way of limitation. It will be apparent to a person skilled in the relevant art that various changes in form and detail can be made therein without departing from the spirit and scope of the invention. Thus, the present invention should not be limited by any of the above described 20 exemplary embodiments. Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" and "comprising", will be understood to imply the inclusion of a stated integer or step or group of integers or steps 25 but not the exclusion of any other integer or step or group of integers or steps. The reference in this specification to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as an acknowledgment or admission or any form of suggestion that that prior publication (or information derived 30 from it) or known matter forms part of the common general knowledge in the field of endeavour to which this specification relates.