Abstract:
A duckbill pod ( 100 ) having an ejector mechanism, the duckbill pod ( 100 ) comprising a tray ( 10 ) for providing a transport surface for goods or material, a pusher plate ( 50 ) arranged substantially perpendicular to the tray ( 10 ), a drive arrangement for actuating the pusher plate ( 50 ) and reciprocate same between a mouth and a rear end of the duckbill pod ( 100 ), and a lifting plate ( 20 ) secured to the tray ( 10 ) for attaching the duckbill pod ( 100 ) to a loader.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to duckbill pods, also referred to as duckbills or ducksbills, of the type used with loaders, most typically on mining sites as a general purpose carrying device in conjunction with load-haul-dump (LHD) loaders. 
       BACKGROUND OF THE INVENTION 
       [0002]    There exist a multitude of accessories for loaders, bulldozers and the like that fulfil various purposes. A variety of simple buckets, scoops and so on are used in various contexts for moving materials, such as dirt, gravel and the like. 
         [0003]    The mining industry in particular has developed a broad range of specialised loader accessories that are used above and below ground as required. These accessories are adapted for tasks required underground, which include not only lifting and transport of raw materials, but also transport and storage of equipment. 
         [0004]    Due to the challenges of working underground, especially on low seam heights, low profile wheel loaders are favoured and built to purpose. As an example, the Eimco brand of wheel loaders is widely used in Australia and elsewhere. 
         [0005]    Duckbills are one of the various fabricated loader accessories available, and are favoured for transport of general purpose goods. A duckbill generally consists of a tray of relatively extensive dimensions (for example, 2.5 m by 2.5 m), side walls, and a back wall in the form of a lifting plate, fitted with QDS (Quick Detach System) or RAS fixtures for fitting the duckbill to a loader. The loader arms or horns engage with the QDS or similar fixtures formed on the lifting plate to removably secure the duckbill to the loader. 
         [0006]    Duckbills have proved useful in general service and their use has been favoured in many contexts beyond which their original design was envisaged. 
         [0007]    There accordingly exists a need for improvements to duckbills that at least attempt to improve their utility for certain tasks, or at least provide a useful alternative to existing constructions. 
       SUMMARY OF THE INVENTION 
       [0008]    The inventive concept resides in a duckbill ejector, namely a duckbill pod having an ejector mechanism, the duckbill pod comprising a tray for providing a transport surface for goods or material, a pusher plate arranged substantially perpendicular to the tray, a drive arrangement for actuating the pusher plate and reciprocate same between a mouth and a rear end of the duckbill pod, and a lifting plate secured to the tray for attaching the duckbill pod to a loader. 
         [0009]    The drive arrangement can be selectively actuated to drive the pusher plate along the tray, thereby to eject goods or materials from the duckbill pod or draw such goods into the duckbill pod. 
         [0010]    The drive arrangement is preferably chain-driven and hydraulically-actuated, and features an hydraulic motor which engages dual driving sprockets, which drive dual chains. The dual chains in turn drive idler sprockets mounted on a pusher housing, to which the pusher plate is secured. The pusher housing slidingly engages adjacent parallel rods that pass through the pusher housing and which in effect align and direct the pusher plate across the tray via the pusher housing. 
         [0011]    Further features of the invention are become apparent from the following description of preferred embodiments. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0012]      FIG. 1  is a perspective drawing of a duckbill in accordance with a preferred embodiment of the present invention from above, loaded with stacked pallets. 
           [0013]      FIG. 2  is a perspective drawing of the duckbill of  FIG. 1 , depicted without the stacked pallets. 
           [0014]      FIG. 3  is a perspective drawing of the duckbill of  FIG. 1  from its rear. 
           [0015]      FIG. 4  is a perspective drawing of the duckbill from below, indicating details A and B. 
           [0016]      FIG. 4A  is a fragmentary perspective drawing of the detail A indicated in  FIG. 4 . 
           [0017]      FIG. 4B  is a fragmentary perspective drawing of the detail B indicated in  FIG. 4 . 
           [0018]      FIG. 5  is a perspective drawing of a pusher plate forming part of the duckbill of  FIGS. 1 to 4 . 
           [0019]      FIG. 6  is a perspective drawing of a left hand pusher plate assembly. 
           [0020]      FIG. 7  is a perspective drawing of the left hand pusher plate assembly of  FIG. 6 , from behind. 
           [0021]      FIG. 8  is a perspective drawing of a right hand pusher plate assembly. 
           [0022]      FIG. 9  is a perspective drawing of the right hand pusher plate assembly of  FIG. 8  from behind. 
           [0023]      FIG. 10  is a perspective drawing of a pusher housing used in the pusher plate assembly as shown in  FIGS. 6 to 9 . 
           [0024]      FIG. 11  is a side elevation of the duckbill of  FIGS. 1 to 4 . 
           [0025]      FIG. 12  is a rear elevation of the duckbill of  FIGS. 1 to 4 . 
       
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0026]      FIGS. 1 to 4  illustrate in perspective view from various angles a duckbill having an ejector mechanism, referred to herein as a duckbill ejector  100 . The duckbill ejector  100  has a tray  10 , which is bounded on three sides by a lifting plate  20  and sidewalls  30 . 
         [0027]    The tray  10  is rectangular in extent, and is approximately square is shape, and provides a surface for general purpose use, which may typically include resting, storing or transporting any suitable goods or materials. The duckbill ejector  100  is intended for general use on mining sites, above and below ground, for moving goods and material. 
         [0028]    The lifting plate  20  is fixed securely along one side or edge of the tray  10 , referred to as the rear edge, with adjacent side edges of the tray  10  having the side walls  30  extending upwardly from the tray  10 . The side walls  30  are fixed securely to the tray  10  and lifting plate  20 , but in other embodiments may be removably secured to the tray  10 , or completely absent. 
         [0029]    The duckbill ejector  100  as described is rectangular in extent, and the tray  10  has bounded dimensions inside the lifting plate  20  and sidewalls  30  which are approximately 2.5 m by 2.5 m. These dimensions are sufficient to accommodate four standard-sized pallets laid in a 2×2 arrangement, as illustrated in  FIG. 1 . The pallets, as illustrated in  FIG. 1 , each carry two stacks of goods or material. 
         [0030]    The duckbill ejector  100  is engineered to carry approximately 5000 kg, owing the structural strength of the tray  10 , and lifting plate  20 . The duckbill ejector is fabricated using grade 350 steel plates of suitable dimension, and joined using suitable structural welding techniques. While goods or materials can be carried within weight and volume limitations, stacked pallets are a typical payload. The tray  10  of the duckbill ejector  100  may in alternative embodiments be provided with an optional divider which can be removably positioned between the pusher plates  50 , running the length of the tray along its middle, provided to avoid adjacent pallets from catching upon each other during loading or unloading. 
         [0031]      FIG. 2  most clearly shows pusher plates  50  arranged in their typical resting position at the rear of the tray  10 , positioned adjacently and parallel to the lifting plate  20 . The pusher plates  50  can be actuated selectively and independently such that they move forwards and backwards between the rear edge and front edge of the tray  10 . 
         [0032]      FIG. 3  shows the rear of the duckbill ejector  100  and more particularly the lifting plate  20 . The lifting plate  20  includes a plate  21 , strengthened by ribs  22 , which extend from the side edges of the lifting plate  20  to bracing plates  23 , which are arranged vertically in spaced arrangement around the middle of the lifting plate  20 . The bracing plates  23  define edges of the QDS. Extending between the bracing plates is a flanged pin  24 , an angled plate  25  and a securing plate  26 . The bracing plates  23 , flanged pin  24 , angled plate  25  and securing plate  26  are arranged and dimensions to allow a QDS connection with a loader equipped to allow this type of connection. 
         [0033]    On the loader (not shown), controllable engaging arms extend under the flanged pin  24 , between the flanged pin  24  and the angled plate  25 , and an engaging member is hydraulically actuated into engagement with the void in the securing plate  26 . The duckbill ejector  100  is thus firmly secured and can be carried by the loader using the QDS connection. 
         [0034]    As depicted in  FIG. 3 , the underside of the tray  10  incorporates voids  12  for accepting lifting tines, such as forklift tines. These voids  12  are formed of square-tubed members and are oriented lengthwise along the tray  10 , allowing the duckbill ejector  100  to be lifted and carried by means other than a loader. 
         [0035]    As is apparent from  FIG. 1 , which shows the duckbill ejector  100  loaded with four pallets, the pallets can be selectively ejected from the duckbill ejector  100 , by actuating the pusher plates  50 . Driving the left pusher plate  50  halfway from the rear of the tray  10  to the front of the tray  10  will suffice to eject the front most pallet in the left side of the duckbill ejector  100 . The front right pallet can be ejected in the same manner by driving the right pusher plate  50  forward. The top surface of the tray  10  is approximately 150 mm from the bottom surface of the duckbill ejector  100 . Accordingly, this is the distance the pallet traverses before hitting the ground, assuming that the duckbill ejector  100  is in fact resting on the ground. 
         [0036]    After ejecting the front pallets, the rear pallets are now positioned adjacent the front edge of the tray  10 . These remaining pallets can be subsequently ejected from the tray  10  by driving the pusher plates  50  forward to push the pallets from the duckbill ejector  100 . The ejected pallets are in the interim removed from where they have been unloaded, or the loader moved backwards to provide adequate clearance for ejecting the remaining pallets. 
         [0037]      FIG. 5  is an isolated perspective view of the pusher plate  50  which forms part of the duckbill ejector  100 , and which is seen most clearly in  FIG. 2  when installed on the duckbill ejector  100 . The pusher plate  50  is constructed of a vertical plate  51 , secured to a t-shaped plate  52  along the bottom edge of the vertical plate  51 . Exposed corners of the t-shaped plate  52  are bevelled, as depicted, but may in other embodiments be rounded, for example. The structural integrity of plates  51  and  52  is supported by ribs  53  which extend vertically from the t-shaped plate  52 , and taper as they extend upwardly along the surface of the vertical plate  51 . The central projecting portion of the t-shaped plate  52  has boltholes  54  formed therein for securing the pusher plate  50 , as described in further detail below. 
         [0038]      FIGS. 6 to 9  depicted the pusher plate  50  as part of a greater assembly formed for directing movement of the pusher plate  50  across the tray  10 . The assembly illustrated in  FIGS. 6 to 9  is depicted for the pusher plate  50  on the left hand side of the tray  10 , both from the rear and the front ( FIGS. 6 and 7 ), and correspondingly for the right hand pusher plate  50  ( FIGS. 8 and 9 ). The front facing surface of the vertical plate  51  of the pusher plate  50  has secured thereto a rud link  55  which can be used to pull or drag an item onto the duckbill  100 , or move it deeper into the tray  10 , when retracting the pusher plate  50 . 
         [0039]    The assemblies depicted both have a pusher plate  50  secured via fasteners secured in its boltholes  54  to a pusher housing  60 . The pusher housing slides around rods  62 , which act as rails to direct movement of the pusher plates  50 . The rods  62  are terminated at their ends by a rod holder  64  located when installed towards the rear of the tray  10 , and a chain tensioner bracket  66 , located when installed towards the front of the tray  10 . The pusher plate  50  and pusher housing  60  can slide along the rods  62 , and in use are driven along the rods  62 . 
         [0040]      FIGS. 4A and 4B  are fragmentary details of the portions A and B indicated in  FIG. 4 .  FIG. 4  depict elements of the driving arrangement that drives the pusher plate  50  across the tray  10  during use. As is apparent from  FIGS. 4 , the pusher plate assembly is secured to the underside of the tray, with the rod holder  64  secured at the rear edge of the underside of the tray  10 , and the chain tensioner bracket  66  secured at the front edge of the underside of the duckbill ejector  100 . The tray  10  has formed therein slots that allow the pusher plate  50  to extend upwardly from the tray  10 , and travel across the tray  10  in a linear trajectory defined by the rods  62 . 
         [0041]    The pusher plate  50  is driven via the pusher housing  60 . Drive sprockets  71  engages dual chains  72 , which act on the pusher housing  60 . The chains  72  extend the length of the tray parallel and adjacent to the rods  62 . The chains  72  loop around idler sprockets (not shown) located at the front edge of the tray and housed in an idler sprocket tension unit  75 , which is secured at the front edge of the tray  10 . The idler sprocket tension unit  75  can be adjusted to loosen or tighten the chains  72  via an adjustment bolt assembly  76 , depicted adjacent the front edge of the tray  10 . 
         [0042]      FIG. 10  is a perspective view of a pusher housing  60  used to secure the pusher plate  50 , and slide over the rods  62 . 
         [0043]      FIGS. 11 and 12  illustrate side and rear elevations of the duckbill ejector  100 . The drive sprockets  71  are driven by drive shafts (not shown) originating in hydraulic motors  77 . The motors  77  are supplied at both sides of the tray  10 , located at the rear of the tray  10 , and housed adjacent the lifting plate  20 . The motors  77  are suitable make and model suitable for industrial use. The motors are in the preferred embodiment used in conjunction with a gearbox 5:1 to provide a suitable speed and torque output. The motors controlled via a valve bank assembly  79 , which accepts a source of hydraulic pressure via input hoses, and using valve switches, directs the flow of hydraulic pressure via output hoses to the motors  77 . 
         [0044]    The abovementioned voids  12  depicted in  FIG. 12  are oriented lengthwise along the tray  10 , in parallel with the rods  62 . This orientation differs from the typically orientation on existing duckbills, and is adopted to avoid interference with the rods  62 , while minimising the height of the tray  10 . 
         [0045]    With reference to  FIG. 3 , the lower ribs  22  formed against the vertical plate  21  of the lifting plate has a recess formed therein to accommodate the motors  77  of either side of the QDS fixture, which are not shown in  FIG. 3 . 
         [0046]    The valve bank assembly  79  can be configured to direct full pressure to either of the motors  77 , or to direct the hydraulic pressure to be shared between the motors  77 . The input hoses are operatively connected to a controllable source of hydraulic pressure, which is in preferred embodiments such a source originating from the loader to which the duckbill ejector  100  is attached. This is conveniently provided by a hydraulic PTO (power take off) supplied via mechanical engine power from the loader, transferred to hydraulic power by a hydraulic pump on the loader. The hydraulic power delivered to the duckbill ejector  100  can be controlled by an adjustable lever which delivers variable positive or negative pressure to the duckbill ejector  100 , which consequently drives one or both of the pusher plates  50 , as selected at the valve bank assembly  79 . 
         [0047]    When the duckbill ejector  100  is secured to the loader, the hoses from the loader are also connected manually to hose inlets at the valve bank assembly  79 . One or both of the pusher plates  50  is selected at the duckbill ejector  100  manipulation of the valve bank assembly. The movement of the selected one or both pusher plates  50 —in both push and pull directions—is thus controlled from the loader via the abovementioned lever capable of delivering variable pressure to the duckbill ejector  100 . The lever may use any suitable arrangement to control the hydraulic pump, such as via cable, rod, or electronic control. 
         [0048]    Various alternative embodiments are possible, as would be apparent to one skilled in the art. As an example, various alternative forms of drive arrangement could be used to control the pusher plates  50 , such as a direct-drive hydraulic rods acting directly on the pusher housings. Also, the arrangement (and number) of pusher plates  50  used to eject or draw goods or material from or onto the duckbill ejector  100  can assume various alternative forms. As an example, side ejection may be used, in which the pusher plates  50  are oriented to move across the tray  10  from side to side rather than from rear to front. 
         [0049]    Furthermore, an electric or hydraulically actuated winch may be secured on the duckbill ejector  100  for general purpose use, and may be used to assist loading the tray  10  when required.