AU2012357654B2 - Dust collecting device - Google Patents

Abstract

A dust collector device (10) receives dust (72), conveyed in the airflovv F into a diffuser (70) and out through a diffuser mouth (74) wherein it is spayed into the upper regions of an internal space (62) and settles under gravity by falling down the sides of the internal space (62) along settling pathway G. As more dust (72) is blown out through the mouth (74), the dust settles into the tray (20) in a fairly even spread of dust (76). Once the tray (20) is full of settled dust (76), a dust separator device (80) may be switched off whereby the bag (50) naturally deflates due to termination of the inflating pressure created by a transverse blower (88). The bag (50) may be folded and/or tied down about or over bars (64) ready for transport of the dust (76).

Description

DUST COLLECTING DEVICE

PRIORITY CLAIM

This application claims priority from four applications, namely Australian Provisional Patent Application No. 2011905411 and US Provisional Utility Patent Application No. 61/580106 both filed on 23 December 2011, Australian Provisional Patent Application No. 2012901932 filed on 11 May 2012 and Australian Provisional Patent Application No. 2012902246 filed on 30 May 2012.

FIELD OF INVENTION

This invention relates to a dust collecting device. More particularly, this invention relates to a dust collecting device for collecting, storing and transporting dust collected from particulate material. Still more particularly, but not exclusively, this invention relates to a dust collector for use in the grain industry.

BACKGROUND ART

The following references to and descriptions of prior proposals or products are not intended to be, and are not to be construed as, statements or admissions of common general knowledge in the art. In particular, the following prior art discussion does not relate to what is commonly or well known by the person skilled in the art, but assists in the understanding of the inventive step of the present invention of which the identification of pertinent prior art proposals is but one part.

Dust, particularly fine dust particles, create significant health problems if allowed to become airborne and humans are exposed. Inhaling the hazardous dust may cause immediate breathing problems or, if inhaled over a long period, lung diseases such as lung cancer.

Known dust collectors include an arrangement with a long flexible sock of 3-6 metres in length and an expandable diameter of 1-2 meters. The sock is designed to lie on its side on the ground as large volumes of air and dust are pumped into the internal spaces of the sock.

Whilst the sock is initially in a collapsed state prior to filling with air/dust, it expands as air/dust is pumped into its internal spaces until it is expanded to its full extent. Once the bag is fiili of dust, which may contain a very large weight of between 200 and 1000 kilograms, it must be hauled onto a truck for transport and disposal. Obvious health and safety

considerations apply in respect of the workers required to lift the awkward, large and heavy bag. Otherwise, expensive and dedicated lifting and haulage requirement may be required to load the bag onto a vehicle for transport and disposal of the dust.

An object of the present invention is to ameliorate the aforementioned disadvantages of the prior art or to at least provide a useful alternative thereto.

STATEMENT OF INVENTION The invention according to one or more aspects is as defined in the independent claims. Some optional and/or preferred features of the invention are defined in the dependent claims.

Accordingly, in one aspect of the invention there is provided:

A bulk dust collecting device for collecting dust separated from particulate material comprising:

a collapsible bag defining the whole or part of a container for receiving the dust, the collapsible bag adapted to assume an elongate upright shape when inflated;

an aperture at or near the base of the container; and

a diffuser connected to the aperture and extending upwardly from the base and terminating in an outlet mouth from which airborne dust may be blown into the container.

In another aspect, the invention provides:

A method of collecting dust in bulk using a bulk dust collecting device as described herein, the method steps including:

.connecting the inlet of a powered dust separator device to a source of particulate matter from which dust is desired to be separated;

connecting the outlet of the dust separator device to the aperture;

filling the container which airborne dust from the dust separator device whereby to inflate the bag so that it assumes an elongate upright shape;

collapsing the bag once sufficient dust has been collected; and

removing the connection of the dust separator device from the aperture and sealing the aperture.

In another aspect of the invention, there is provided:

A portable bulk dust collecting apparatus connectable to a dust separating device, the dust collecting apparatus operable to collect dust separated by the dust separating device from particulate material having grain or particle sizes substantially greater than the dust collected, the dust collecting apparatus comprising a collapsible bag defining the whole or part of a container for receiving the dust, the collapsible bag adapted to inflate to form an inner space into which the dust particles may be delivered, wherein the container includes a rigid base mounted for portability.

In still another aspect of the invention, there is provided:

A pressure release valve for a bulk dust collecting device operably connected to a dust separating device, the dust collecting device, the dust separating device and the pressure release valve forming part or all of a dust collecting system, the pressure release valve adapted to provide an airtight seal during the operation of the dust collector device,

wherein, when the pressure in the dust collecting system reaches a critical level, the pressure release valve releases and the collapsible container deflates.

In another aspect, the invention provides:

A pressure release valve for a bulk dust collecting device, the valve comprising:

a mouth sealable by a closure member in a closed position;

a release member adapted to secure the closure member in sealed relationship with the mouth in the closed position by engaging a retaining member;

force regulation device to set the internal pressure bearing against an inside surface of the closure that is required to disengage the release member from the retaining member to open closure member.

COLLAPSIBLE BAG

The collapsible bag may be inflatable to create a large contained volume into which the airborne dust may be blown. The collapsible bag preferably inflates to assume an elongate, upright shape. The collapsible bag may be made from any variety of flexible materials, including woven natural and synthetic fibres, non-woven synthetic materials. Preferably, the bag comprises a woven polyester material. The material is preferably fully washable, for easy care and longevity. Preferably, the bag material permits a minimal leakage of air whilst trapping fine and super-fine dust particles, the egress of air particles being rmnimised to ensure that the bag can be inflated and maintained in an inflated state whilst the dust collecting device is collecting dust. The bag may be made up of lengths of material seamed, sewn, glued, stapled, buttoned, rivetted or otherwise joined together. The joined material may form a tall, dome-like structure when fully inflated, The seams or joins may be achieved by double folds of the edges of material in which the edge web is interlocked and seamed with one or more lines of seams.

The fully inflated bag is advantageously substantially parabolic in side elevation, although the invention includes within its scope a sock-like tube defining a substantially cylindrical section, capped with a dome-like, or flat and folded (when not inflated), pper portion.

The lower most edges of the bag are preferably hermetically sealed, or at least sealed to the extent that dust cannot escape at the join. The join may be made using a suitable high performance adhesive, such as Araldite™, Other fastening means may be used, such as screws, rivets, hooks/eyelets, sonic welding, any. combination of one or more of the foregoing, or other adherence means known to skilled persons in the bulk waste dust handling industry.

The bag may be semi-permeable whereby to allow a slow and generalised leakage of air particies, but completely trap dust particles, including super fine particles. Alternatively, the bag material may be hermetically sealable whereby to provide a completely airtight barrier. If the bag material is completely hermetically sealable, a small outlet may be provided in the bag material to permit egress of air. The outlet preferably has a replaceable or cleanable filter whereby to prevent the escape of dust particles with the egress of air. The outlet is preferably located in the upper section or cap of the bag to limit the amount of dust that may collect in the region of the outlet. There may be more than one outlet. The outlets may be completely hermetically sealable at the option of the operator, for example, by providing a screw-on clip on-cap or other sealable cover. The outlets may be useful where large volumes of air bearing the dust particles are blown into a completely inflated bag to limit the tensile stress on the joins i the seams or to other parts of the container.

The inflated container may be supported by upwardly extending poles. The poles may be telescopically extendable. The poles may be freely extendable and contractable with the inflation or deflation of the collapsible bag. The poles may be fixable at a particular height to structurally support the collapsible bag at an adjustable height. The poles may be attached to the exterior surface of the collapsible bag by a flexible strap, tether or chain to permit some tolerance and relative movement of each pole relative to the collapsible bag. The poles may be removable from the tray structure. The tray may comprise pole holders oriented vertically when the tray is lying flat or untilted. The holders may be in the form of tubes attached to the walls or other structure of the trailer.

BLOWER AND CONNECTION

The aperture is preferably an airtight sealable aperture. The aperture may receive a pipe connection that is external to the container and that is in fluid communication with the dust separating device. The dust separating device generally comprises a chamber containing agitation means to separate lighter particles, such as dust and chaff, from the particulate material, such as grains, polymer pellets and other particulate material in respect of which it is desirable to separate and remove dust and finer particles therefrom.

The bag may also be provided with an opening near the base to allow an operator to inspect the interior of the bag or to gain access to the internal spaces of the container. The opening may comprise a zip opener or hook and loop sealable flap.

The tray may have access means, such as a sealable wing, door, flap or panel to provide access to the container. The access means may be at the rear of the vehicle. The access means may comprise a drop down door or tailgate as is standard to trailers. Alternatively, the access means may be hinged at its upper edge whereby to swing upwardly to open. The opening may be at an end of the vehicle remote from the access means, so that an operator can gain access to the internal spaces of the container from either end of the vehicle The aperture may be a sealable hole in a wall of the access means. The aperture may alternatively (or additionally where more than one aperture is provided) be located in a side or front wall of the vehicle.

The dust separating device may be connected to the dust collecting apparatus via a pipe, including a wholly or partially flexible hose, tube or pipe, optionally having one or more rigid sections, such as the section of the pipe comprising a valve that is described in the cross- referenced applications. The pipe connects to the container through an aperture. The aperture may be formed in a wall of the tray. The valve section of the pipe may connect directly to the aperture and form a secure seal. The valve section and aperture connection may be permanent, save for maintenance, replacement or repair.

The dust separating device may include a transverse blower that is adapted to blow lighter particles in a different direction to that of the prevailing direction of travel of the larger, more dense, or heavier particulate material. For example, the dust separating device may involve the transfer of particulate material at high speed through a chamber , across which a transverse blower blows a transverse current of air to remove the lighter particles of dust and/or chaff. The transverse blower may be situated on the downstream side of the chamber to provide a negative pressure whereby to induce the dust particles by suction towards the aperture.

Alternatively, the transverse blower is situated on the upstream side of the chamber to force the dust particles by positive pressure towards the aperture. The airborne dust travelling through the external pipe under the impetus of the transverse blower travels through the aperture and into the diffuser,

VALVE

In apreferred form, the valve is a flap valve. The valve may be biased to the closed position. The valve may include a bias. The bias may include at least one weight whereby the weight is located on the flap or a counterweight portion. The closed position may correspond to a downward position towards a valve seat. The valve may be hinged to one side of the seat or a structure associated with the seat. The bias may include a spring The valve may be manually manipulatable. The valve may include a handle adapted to act against the bias. The handle may be pivotable against the bias. The handle may be associated with a cam mechanism. The cam may permit the opening of the valve against the bias.

The valve may be located at the downstream side of the pipe. The valve may be located close to the aperture. The valve may be adapted to operate to relivce the pressure in the container via the aperture. The valve may be mounted to a pipe attached to and in communication with the aperture.

The valve may be include a control motor. The control motor may open the valve, to a variable extent, depending on a computer control. The computer control may respond to feedback parameters determined by sensors. The feedback parameter values may be provided by one or sensors. The sensors may include a pressure sensor in the container. The sensors may include a fill sensor to detect when the container has reached its maximum capacity of dust collection, The fill sensor may communicate with the computer to operate a kill switch to turn off the dust separator device and any other equipment drawing particulate matter to the collection device.

Once the pressure release valve is actuated and the collapsible container deflates, the operation of the dust collecting system may be automatically terminated. On the collapsible container deflating, the dust separating device may be turned off manually or automatically. The pressure release valve release valve preferably includes a kill switch operably connected to the dust separating device to switch off the dust separating device. The immediate termination of the operation of the dust separating device is desirable to mitigate against dust escaping from the system and becoming airborne. Therefore, preferably the system includes a kill switch for the dust separating device which is activated on actuation of the pressure release valve so that dust is not emitted into the surrounding environment. As a safety device, the valve may include an internal filter device to permit expression of air from the system but to retard egress of solid particles. The filter device may include a filter screen which may be made of metal wire or plastic mesh that is sufficiently strong in its mounting and physical integrity to withstand a sudden rush of air through a mouth of the valve.

The pressure release valve may be located at any suitable location in the system, noting that the components of the system are in fluid communication with one another. The pressure differentials throughout the system may therefore be subject to constant equilibration. The pressure release valve may be located on the dust collecting device, including in a wall of the collapsible container. The pressure release valve may be located on or around the dust separating device. Most preferably, the pressure release valve is positioned between the dust · collecting device and a dust separating device. Still more preferably, the pressure release valve is positioned in-line between the dust collecting device and a dust separating device. The line may be a pipe or tube. The line may include a concertinaed section to enable flexibility of tire line, including thick walled pipe or wire or rigid rib-reinforced wall tube to ensure that internal positive pressure can be contained without distortions, for example in weak sections of the pipe or tube. However, the line is preferably made of rigid polymeric or metal material Given the typical agricultural environment in which the invention might be used, preferably the hue will comprise metal pipes of rigid construction. Preferably, pipe connections and comer joins are joined by welding, rivets, bolts or the like to ensure a strong and durable structure. The line internal width may be large relative to the capacity volume of the collapsible container.

The valve may comprise a valve pipe section extending traverse to the general axis of the valve mouth. The valve pipe section may extend normal to the line and terminate in an aperture mouth.

As the pressure release valve releases and the collapsible container deflates, the deflation may be rapid. Substantial deflation of the collapsible container may occur within about 10 - 20 seconds of the valve being actuated. The valve may include an outlet with an aperture. The aperture may be sealed by a closure. The aperture may be a large aperture. The aperture may be circular, ovaloid, rectangular or otherwise polygonal. The aperture may lie in a single plane. The aperture may be significant in size relative to the capacity volume of the collapsible container, such that rapid deflation is possible once the valve is actuated. The aperture may be 50 to 400mm in diameter. Preferably, the aperture is about 150 - 250mm, and still more preferably about 200mni, in diameter. The pressure release valve may be actuated by the opening of the closure. When the system is in operation, the closure may sealably cover the aperture in an airtight seal. The closure may comprise one or more lids, panels or flaps. For example, the closure may comprise a pop-off lid. or one or more hinged panels or flaps. The closure may comprise a single lid. The lid may be planar, but preferably is dome shaped and internally shallowly concave to better distribute force from the internally pressurised space in the pressure release valve in operation. The aperture may be defined by a rim or the mouth of the valve. The rim may bear the air tight seal. The seal may be made of a resiliency deformable material such as polymeric materia] or natural or synthetic rubber that cooperates with an underside rim of the lid closure to effect the seal. The underside peripheral edge of the closure may include a downwardly facing shallow groove. The groove may be an annular groove configured to seat on the aperture rim seal. The lid may be hinged or otherwise movably connected at one edge. The lid may be hinged and rotatable about a single axis. The lid may be releasably secured at one or more locations civcumferentially spaced from the hinge. Preferably the lid is releasably secured at a location diametrically opposed to the binge.

The pressure release valve may include a pressure release securing device. The securing device may include frangible means. The frangible means may be designed to fail and effect the actuation of the valve when the pressure on the closure reaches a threshold level. The frangible means may be a weakened join. The frangible means may be a consumable that needs to be replaced when the valve is actuated.

Preferably the securing means includes a permanent release member. The release member may be deflectable. Preferably the release member engages a retaining member. The release member may be located on the closure. The retaining member may be located on a wall of the valve pipe section. The positioning of the release member and the retaining member may be interchangeable.

Preferably, once the closure member is opened, an operator may manually reset the release member to be in engagement with the retaining member whereby to put tire closure in the closed position. The rapid deflation of the collapsible container of the dust collecting device is advantageous to compel the operator to clean out or replace the collapsible container before the operation of the system can be resumed.

The retaining member may be a catch, hook, loop or other type of rigid detent against which the release member may engage. Preferably, the retaining member is a rigid member that is stationary relative to its mounting point on the valve. Preferably the retaining member includes a bar about, under or against which the release member may abut or otherwise engage.

The release member is preferably deflectable and may include a hinged or otherwise deflectable member. The deflectable member may be hinged to a post mounted on the outer side of the closure. The deflectable member may rotatably pivot or rock from an engagement (closed) position to a disengagement (open) position. Preferably, the release member cannot accidentally or automatically re-engage with the retaining member after moving to the open position.

The force regulation device may be a tensioning device. The tensioning device may include a spring member, which may be a tension, compression or leaf spring or another resiliently deformable member. Preferably the spring member is a tension spring. The tensioning device may include an adjustment device. The adjustment device may be adapted to increase or reduce the tension applied to the release member. The adjustment device may be adapted to lengthen or shorten the length of a tension spring in the closed position. The adjustment device may be a turnbuckle. The adjustment device may be a threaded bolt. The bolt shaft may include an eyelet or other means to engage with an end of the tension spring.

The closure may include a hinge having a rotation limiter. Rotation limiter may include a stub or bar adapted to abut another portion of the valve to prevent the closure from rotating beyond a certain arc.

BASE

The rigid base may comprise a tray. The tray may form part of a trailer, the tray mounted on wheels. The trailer may be a box trailer. The trailer may include a draw bar and hinged tailgate.

The tray may be tiltable relative to the- draw bar. The tilting mechanism may include a variety of different means, such as an inflatable bag under one end of the tray, or a lifting device, such as a telescopic arm, a hydraulic or pneumatic ram mechanism, heavy duty solenoid, jack or worm drive mechanism. A hydraulic ram is preferred. The telescopic arm may be mounted at or near the draw bar. The draw bar may be a typical arrangement having a pair of converging arms. The lifting device may be adapted to lift the draw bar, and therefore the tray, relative to the ground surface, for example rotating the tray about the wheel axle, Alternatively and preferably, the lifting device is mounted on the draw bar and is adapted to lift a front end of the tray relative to the draw bar. The draw mar may include a cross member in the form of a beam or plate on which the lifting device is mounted, noting that the cross member must be rated to support the weight of the lifting device, the tray, the container and its contents.

The tray may include a tailgate hinged at the bottom or top edge to facilitate the removal of dust collected in the container. The tray may form the base of the container. The container may be sealed against inadvertent egress of dust from the container in use, including airtight sealing of the join of the container to the tray. The edges of the tailgate may comprise seal lining. The seal hiring may comprise rubber (or rubber-like synthetic material) seal strips. Preferably, the tailgate is hinged to a top rear cross bar of the tray. The tailgate's side or lower edges may be released from engagement to the tray walls or floor, so that, when the tray is tilted from the front upwardly, tailgate may hang freely from its hinges and open the tailgate to allow access to the tray. The tray may be mounted on a base frame, The base frame may be contiguous with the draw bar. The tray may be hingedly mounted to the rear of the base frame. When the tray is tilted it may pivot about the tray hinges on the base frame.

The tray may comprise a floor and side walls. The floor and wall joins may be curved or smoothed to facilitate the cleaning process. The joins may be concave in profile.

The tray may comprise the side walls, and end panels, including a front end panel and the tailgate. The side walls and end panels may include upper extension panels that extend the height of the side walls and end panels. The upper extension panels may extend the height of the tray sides and ends about the same height again as standard box trailer walls. The extension panels may extend the height of the tray sides and ends to about 500mm to 700mm, and more preferably to about 600mm to 650mm. The extended sides and ends provide a manufacturing advantage in that the modifications to a standard box trailer required to perform the invention are minimised. For example, the aperture may be formed in an extended panel and attached permanently to the front panel of an existing trailer.

However, preferably the trailer is manufactured using mostly dedicated components. The tub of the trailer comprising the floor and sides may be formed from a single sheet, worked to form the curved corner joins. The front panel may be a single sheet welded or bolted to the front end of the tub. A square frame comprising channel or hollow steel beams may be affixed to the upper edges of the tub to give it rigidity. The tailgate may be hinged to the rear beam of the square frame. The tub may be mounted to the base frame by welding, fasteners such as nuts and bolts, or a combination of affixing means.

The collapsible container may be mounted on a portable trailer. The trailer may comprise a tray that has a size of between 1.8 - 3 m in length and 1.2 - 2.5 m in width. The collapsible container may be 2 - 10 m in height. The capacity volume of the container is the volume of the collapsible container when it is fully inflated. A smaller collapsible container may have a capacity volume of 10 - 16 m³. A larger container may have a capacity volume of 20 - 60 m³, preferably 30 - 35 m³, for example when using a trailer tray having the dimensions of about 2.4 x 2.4m and a collapsible container height of about 6m.

Preferably, the container is mounted, or forms part of, a vehicle and is portable. The vehicle may support the bag. The container may be made up of the bag and the vehicle combining to form the container. The vehicle may include a tray which forms part of the container. The vehicle may be a trailer towable by a prime mover. The prime mover may provide power to the dust separating device, for example, by connecting the power take off (PTO) to a hydraulic drive to power the dust separating device, or by connecting the electric power supply available to the trailer of a towing prime mover vehicle, such as a standard automobile or tractor.

The base of the container may comprise the tray of the vehicle. The tray may have rounded corners and floor to wall joins to facilitate easy cleaning of the tray after use. In this regard it will be appreciated that fine dust tends to cake along crevices and surfaces. However, dry dust will tend to fall away easily from smooth, broad metal surfaces, for example by tapping the walls of the tray with a rubber mallet or the like to cause the dust to fall away onto the floor of the tray, ready for easy removal and disposal. The rounded corners may be formed by rolling sheet metal used to form the tray. The rounded corners and edges of the tray may be 5 effected by providing false surfaces in, for example, a metal tray, or by providing a blow

moulded plastic tray or. tray insert.

SUPPORT AND DIFFUSER

Prior to initiating the blowing of dust into the internal spaces of the container, it is desirable to have a pre-existing hollow into which the dust materia] may be initially blown. Accordingly, o the dust collecting device may further include at least one support that minimises the extent to whicli the bag can collapse so that the container has a minimum volume greater than it would if the bag were to be completely collapsed into the tray. The support may extend into the container from the tray. The support may be mounted on or in the tray. The support may be one or more pillars extending up from the tray. Preferably, the support is bow shaped and extends from an up-right tray wall. The support may be a rod, bar or beam extending across the tray. The support may include multiple bow shaped rods extending across the tray to create a dome-shaped or partial cylindrical wall shaped space above the tray or tray floor,

The space may be defined by the tray and a skeletal frame of bars affixed above the tray. The bar s may be mounted to tine upper edges of the side walls.

The dust collecting apparatus may include a diffuser as described in the cross-referenced applications. The diffuser may extend internally from the aperture into the space defined by the container. The diffuser may extend horizontally into the space. The diffuser may extend into a central zone of the space when viewed in plan. The diffuser may terminate in an upturned section in the central zone. The upturned section may be a short section relative to the length of the diffuser. The upturned section of the diffuser may follow a continuous curve from the substantially horizontal section to the upturned section. The upturned section may taper towards its upper end.

The diffuser may be formed from sheet metal, plastic or cloth material, forming a cylinder or duct with a rounded upper end corresponding to the upturned section. The diffuser may be perforated to facilitate and promote even delivery of the dust from the diffuser to the space in the container. The diffuser may be uniformly perforated. The perforations may be smaller and/or less concentrated in terms of total perforation area per total surface area of diffuser closer to the aperture. The concentration or size of the perforations may increase towards the upturned section. Preferably, however, the perforations are formed substantially uniformly in the diffuser wall thioughout its length. The diffuser may include slotted holes in its walls. The slots may be additional to the perforations. The slots may be formed at the tip of the upturned section facilitate dispersal of the dust in an upwardly direction into the space of an inflated container. The support may support the diffuser above the tray. The support may suspend the diffuser above the tray. The support may be a beam extending between opposed side or end walls of the tray and a suspension device may depend from the beam to hold the diffuser in place, that is extending from the aperture through to a position where its mouth is positioned in the interior of the container. The mouth may be positioned centrally within the container or may be positioned such that the airborne dust is blown centrally into the container. The mouth may face upwardly, so that the exhausted airborne dust blows upwardly into the interstitial spaces of the container. The diffuser may be a length of cylindrical pipe. The diffuser may be a curved pipe, or may comprise a shallow elbow to vary the direction of the travel of the airborne dust blowing through the diffuser. The diffuser may be of constant cross section and diameter throughout its length. Alternatively, the diffuser may be fjrusto-conical in shape along its length. The diffuser may be horn shaped, so that it is curved and has an inlet wider in size than that of the mouth, The diffuser may be made of rigid material, such as PVC plumbing piping, tin, aluminium, galvanized iron or steel. The diffuser is preferably made from steel punched mesh. Preferably, the diffuser directs the flow of airborne dust directly upwards in a plume towards the upper internal spaces of the bag. The dust may settle under the effect of gravity in the inflated bag, so that the dust collects at tire base of the container in the tray.

The effect of the upward, generated spray of dust has the affect of allowing the dust to settle evenly in the tray.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention may be better understood from the following non-limiting description of preferred embodiments, in which:

Figure 1 is a schematic end view of a dust collection device according to one embodiment and a dust separator device, showing the bag (partial representation) in an inflated condition;

Figure 2 is a schematic side view of the embodiment shown in Figure 1, but with the bag in a deflated condition;

Figure 3 is a side view of the embodiment shown in Figure 1 with the bag in an inflated condition;

Figure 4 is a side view of a dust collection device according to a second embodiment with a pressure release valve fitted thereto;

Figure 5a is a front end elevation of a dust collecting apparatus according to a preferred embodiment of the invention;

Figure 5b is a side elevation of the apparatus shown in Fig. 5a in a tilted position;

Figure 5c is a side elevation and magnified view of the lifting device shown in Fig 5b;

Figure 5d is an end rear elevation of the apparatus shown in Fig. 5a; Figure 5e is a side elevation of the assembly shown in Figure 5a;

Figure 5f is a magnified side elevation of the pressure release valve and the diffuser shown in Fig. 5e;

Figure 5g is a top plan view of the apparatus shown in Fig. 5a;

Figure 6a shows an inlet duct of the pressure release valve shown in Fig, 5f;

Figure 6b is a side elevation of the pipe of the pressure release valve shown in Fig. 5f;

Figure 6c is a front elevation of the pipe shown in Fig. 6b;

Figure 6d is a side elevation of a cammed pressure relief catch plate of the pressure release valve shown in Fig. 5f;

Figure 6e is a bolt-spring tensioning member of a lid of the pressure release valve shown in Fig. 5f;

Figures 6f - 6g are top and side elevations, respectively, of a brace plate of the lid of the pressure release valve shown in Fig. 5f;

Figures 6h - 6j are top, side and front elevations of a latch hook of the pressure release valve shown in Fig. 5f

Figui es 7a - 7b top and side elevations of the hinged cap, capped lug, brace plate, bolt-spring tensioning member, latch hook, catch plate and flange shown in Figs. 6a - j, all being components of the pressure release valve shown in Fig. 5f;

Figure 8a is a front end elevation of the diffuser shown in Fig. 5f;

Figure 8b is a top plan view of the diffuser shown in Fig. 8a;

Figure 8c is a side elevation of the diffuser shown in Figs. 8a - 8b;

Figure 9a is a schematic side elevation of a pressure release valve according to one embodiment of the invention, shown in a closed position;

Figure 9b is a schematic side elevation of the valve shown in Fig. 9a, but in an open position;

Figure 10 is a side elevation of a pressure release valve according to another embodiment of the invention;

Figure 11 a is a perspective view of the valve shown in Fig. 10;

Figure 11 b is a top plan view of the valve shown in Figs. 10 and 11 a;

Figure 1 lc is a front elevation of the valve shown in Figs. 10 to 1 lb;

Figure 1 Id is a side view of the release member of the embodiment shown in Figs. 10 - 1 lc;

Figure 1 le is a side view of the hinge arrangement of the embodiment shown in Figs. 10 - 11c;

Figure 11 f is a sectional view of the upper rim of the valve mouth and the outer rim of the closure of the embodiment shown in Figs. 10 - 1 lc. Figure 12a is an end elevation of the tray or tub of the embodiment shown in Fig. 5a;

Figure 12b is a side view of the tray shown in Fig. 12a;

Figure 12c is a top plan view of an pper rectangular frame of the embodiment shown in Fig. 5a;

Figure 1 d is a front end elevation of the front panel of the tray shown in Fig. 1 a;

Figure 12e is a top plan view of the tray frame of the tray shown in Fig. 12a;

Figs. 12f - 12h show detail of a tail light cover of the tray shown in Fig. 12a;

Figure 13a is a front elevation of a pole storage tube on the tray shown in Fig. 12a;

Figure 13b is a top plan view of the pole storage tube shown in Fig. 13 a;

Figure 13c is a side elevation of the pole storage tube shown in Fig. 13a;

Figure 14a is a front elevation of the telescopic pole assembly of the dust collecting apparatus shown in Fig. 5a;

Figure 14b is a side elevation of the telescopic pole assembly shown in Fig. 14a with a chain link shown dangling;

Figure 14c is a top plan view of the telescopic pole assembly shown in Fig. 14a with the chain link shown dangling;

Figure 15a is a top elevation of a hoop frame assembly of the dust collecting apparatus shown in Fig. 5a;

Figure 15b is a front elevation of the hoop frame assembly shown i Fig. 15a:

Figure 15c is a side elevation of the hoop frame assembly shown in Fig. 15a;

Figure 15d is a magnified view of a mounting a plate of the hoop frame assembly shown in Fig. 15c;

Figure 16a is a sectional profile or side view of a portion of a tailgate shown in Fig. 16b and forming part of the dust collecting apparatus shown in Fig. 5a;

Figure 16b is a sectional profile or side view of a tailgate forming part of the dust collecting apparatus shown in Fig. 5a;

Figure 16c is an end elevation of a preformed plate of the tailgate shown in Figure 16b;

Figure 16d is a top plan view of the tailgate shown in Fig, 16b;

Figure 16e is an end view of the tailgate shown in Fig. 1 b;

Figure 17a is a to plan view of a mounting plate for a hydraulic pump forming part of the dust collectin 'apparatus shown in Fig. 5a;

Figure 17b is an end elevation of the mounting plate shown in Fig. 17a;

Figure 17c is a side elevation of the mounting plate shown in Fig. 17a; Figure 17d is a top plan view of a mounting block for a hydraulic pump forming part of the dust collecting apparatus shown in Fig. 5 a;

Figure Z7e is an end elevation of the mounting block shown in Fig. 17d;

Figure 18a is a top plan view of a trailer chassis fonning part of the dust collecting apparatus shown in Fig. 5a;

Figure 18b is a side elevation of the trailer chassis shown in Fig. 18a;

Figure 18c is a front end elevation of the trailer chassis shown in Fig. 18a;

Figure 19a is a top plan view of a tow hitch mounting plate forming part of the dust collecting apparatus shown in Fig. 5a;

Figure 19b is a side elevation of a mounting plate for a hydraulic cylinder forming part of the dust collecting apparatus shown in Fig. 5a;

Figure 20a is a front elevation of a lower frame of the dust collecting apparatus shown in Fig. 5a;

Figure 20b is a top plan view of the lower frame shown in Fig. 20a;

Figure 20c is a side elevation of the lower frame shown in Fig. 20a;

Figuie 21a is a top plan view of an upper trailer chassis of the dust collecting apparatus shown in Fig. 5a;

Figuie 21b is a front elevation of the upper trailer chassis shown in Fig. 21 a; and

Figure 21c is a side elevation of the upper trailer chassis shown in Fig. 21a;

DETAILED DESCRIPTION OF THE DRAWINGS

Preferred features of the present invention will now be described with particular reference to the accompanying drawings. However, it is to be understood that the features illustrated in and described with reference to the drawings are not to be construed as limiting on the scope of the invention.

Referring to Figure 1 , there is shown a dust collecting device 10 and dust separation device 80. The dust collection device 10 comprises a vehicle in the form of a trailer 20 and collapsible bag 50.

The trailer 20 comprises the standard trailer chassis combined with a draw bar made up of channel sections or tube lengths of steel welded to form the chassis frame 22, including a draw bar 24 at the front of the trailer 20. The trailer 20 has a single axle 26 and coaxial wheels 28 in accordance with standard practice. Mounted on the chassis 22 is a box tray 30 having high side walls 32, a front panel 34 and a rear, hinged door 36. The door 36 may be hinged at its upper edge whereby to swing up to open, or may be hinged along its lower edge as shown. The tray 30, further includes an upper peripheral rim 38, 46 of tube or channel steel lengths to provide a broad upper surface for safety and structural strength for the upper edge of the tray 30. The lower corners 31 of the tray are rounded with either false corner edging 31 which are welded to the wall panels 32, 34, or the floor 35 and side walls 32 are formed from a single sheet of metal which is worked, such as by rolling, to provide the rounded corners 33. In any case, the rounded comers and joins present a smooth surface to facilitate the cleaning out of the tray 30 after or between uses.

The rear door or tail gate 36 is hinged by standard hinge 41 to a rear transverse lower beam of tube steel 42 extending along and welded to the rear edge of the tray floor 35. The door 36 is held upright and in closed position by clips 43. The clips 43 may be substituted with door catches, slide bolts or rotating flanges commonly used to secure a tail gate against the rear end edges of side walls of a trailer. The lining of the door 36 includes seals to eliminate gaps between the door or tail gate 36 and the surfaces that it abuts with, being the floor 35, side wall rear edges 32 and an upper lateral beam 46. The door catches 43 engage with slots caused by shaped metal brackets bolted, riveted or welded to the upper beam 46 to secure the door 3 in a closed position.

The tail gate or door 3 further includes a large aperture 47. The aperture 47 may be various shapes, such as circular, oval, rectangular or polygonal, but is preferably round or oval shaped to receive round piping or ducting. The aperture 47 receives the outlet of an external concertinaed duct 82 connecting the tray 20 with the dust separator device 80.

The dust separator device 80 includes an inlet duct 84 represented with interrupted lines and, a chamber 86 containing a transverse direction blower 88. The dust separator device 80 further includes a grain outlet port 90 and a grain outlet pipe 92. The primary product, such as grain or some other desired particulate material, is impelled through the chamber 86 from the grain inlet duct 84 at speed and out through the grain outlet duct 92. As the agitated grain particles travel through the chamber 86 the stream of grains encounters a transverse current of air generated by the transverse blower 88 to deflect light weight particles, such as dust and chaff into the concertinaed outlet duct 82 whilst permitting the primaiy product particles to continue on a direct path into grain outlet pipe 92, The transverse air flow into the outlet duct 82 may be a negative pressure or suction created by an impeller on the down-stream side of the dust separator device 80. The dust separator device 80 may be powered by hydraulic PTO or by mains electricity. Alternatively, the dust separator device 80 may be powered by a portable generator, the power lead 94 connecting the dust separator device 80 to the power source. Conveniently, the dust separator device may be powered by the DC battery and electrical system of the prime mover (not shown) to which the tow bar 24 is attached, so that a standard automobile may be used for this purpose. To provide impetus for the main direction of the flow represented by the streams, the dust separator device 80 may be provided with additional impeller means, or a separate grain flow pump (may be used in the grain inlet duct 84 line).

The tray 20 and collapsible bag 50 combine to form a container 60 defining an expandable internal space 62. The internal space 62 has a minimum volume defined by the provision of collapse-rninimising bars 64 extending laterally across the upper region of the tray 20. The bars 64 are bow shaped and mounted at either end to the side rims 38 by fastening or welding the flat portions at each of the bars 64 ends. The bars 64 create a dome space 1 even when the bag 50 is completely collapsed, as shown in Figure 2. The central bar- 64b has, suspended from it in a central position, a support bracket 69.

At the front end of the bag 50, near its base attached to the rim 38, is a zip opener 68 that permits an operator access to the collapsed space 61 for maintenance, cleaning or inspection.

Extending between the aperture 47 and central bar 64b is a curved pipe performing the function of a diffuser 70. The diffuser 70 is sealably attached to the aperture 47 and has a wider inlet diameter I than its outlet diameter E, with a gradual reduction of diameter throughout the diffuser's length. The curved pathway C defined by the diffuser 70, combined with the concentrating effect of gradually reducing the diameter of the diffuser pipe 70, increases the pressure, turbulence and speed of the airborne dust whereby to better disperse the dust particles 72 on their exit from the diffuser 70 through the diffuser mouth 74. This is important to facilitate high flow speed F of the dust 72 in the outlet duct 82 to facilitate separation of the dust 72 from the main grain stream S. The positioning of the diffuser 70 whereby the mouth 74 directs airborne dust 72 upwards, preferably directly upwards, assists to both quickly inflate the bag 50 and create the large volume of internal space 62 into which the dust 72 may be pumped to facilitate effective flow of the dust 72 and facilitate an even distribution of the dust 72 as it settles into the tray 30 at the base of the container 60.

Turning to Figure 3, the dust collector device 10 is shown in operation in which the dust 72 is conveyed in the airflow F into the diffuser 70 and out through the mouth 74, wherein it is sprayed into the upper regions of the internal space 62 and settles under gravity by falling down the sides of the internal space 62 as shown by the settling pathway G, As more dust 72 is blown out through the mouth 74, the dust settles into the tray 30 in a fairly even spread of dust 76. Once the tray 30 is full of settled dust 76, the dust separator device 80 may be switched off whereby the bag 50 naturally deflates due to termination of the inflating pressure created by the transverse blower 88. The bag 50 may be folded and/or tied down about or over the bars 64 ready for transport of the dust 76.

The diffuser 70 is preferable made from steel punched mesh. The collapsible bag 50 is preferably made from a polyester woven material. The round cornered edges 31, 33 of the tray are preferably formed by rolling the edges to minimise caking and sticking of the dust to the tray base, including the floor 35 and walls 32, 34, 36. The capacity of the small box trailer 20 (1800mm x 1200mm or 2200mm x 1500mm) can typically have a settled dust 76 carrying capacity of about 200-600kg, but it will be appreciated that the present invention is not limited to the size of the tray 30 and a wide variety of different sizes of tray 30 are within the scope of the present invention. The collapsible bag 50 may extend to 2-6 meters above the rim 38 in fully inflated condition as shown in Figure 3. The bag 50 may be made from lengths of polyester weave sown along the edges to form, a large bag or sock of elongate, generally cylindrical, form in the fully inflated condition. The bag 50 is collapsible down to the bars 64 that ensure that there is a minimum internal space 61 to permit the initiation of inflation of the bag 50 when starting up and commencing the dust separation process.

5 The tray may be formed from rolled steel or aluminium. However, the tray may also be blow moulded to form a plastic tray tub that is mountable on the trailer chassis 22.

In Fig A, there is shown a dust collector device 10a mounted on a trailer 20a. The device 10a includes a valve 110 comprising an upstanding cylinder 111 sealably welded to an inlet pipe 180 that is in communication with the inlet duct 82 at an outer end and to an aperture 147 at o the toe-end or drawbar 124 end of a trailer 20a. The cylinder 111 is weldably connected to the inlet pipe 180 by means of a collar 112 that follows the cylindrical wall of the inlet pipe 180 and forms a circular base on which the cylinder is weldably mounted.

The device 10a includes a similar bag portion 150 to that of the first embodiment 10. The bag 150, when inflated, defines a substantially round-cornered rectangular shape at its base and its form is held throughout its length as it extends upwardly by a set of 4 telescopically extendable poles located in the comers of the trailer 20a. The ends 152 of the poles 151 are linked b y a flexible connection 152, such as a length of chain or cord 153 to a tab 154 sewn into a horizontal seam 155. The poles 151 collapse down to a level of lateral bars 64 in storage mode.

The seam 155 extends fully around an upper dome 156 of the bag 150 and the bag 150 shape in cross-section transitions through its length from a rectangle at the base 157 of the trailer 20a, to a round cornered rectangle intermediate its length, to a substantially cylindrical shape at the seam 155. The dome 156 is formed from four substantially triangular quarters 158 seamed together by upwardly extending seams 159 in the inflated condition.

The section of the bag 150 between the base 157 and the dome 156 is further formed by one or more lengths of material 160,161 seamed together at intermediate seam 162. Each length 160,161 forms a loop that is seamed at their respective ends 163,164.

Figure 5a is a front end elevation of a dust collecting apparatus 300 according to a preferred embodiment of the invention The apparatus 300 comprises a trailer 301 having a frame base 310, a tray 330 that forms part of a container 350. The apparatus a lifting device 370 and collapsible bag supports 390. A wheel, suspension and axle assembly 13 is shown. The base frame 310 is mounted on the axle assembly 13 and, in turn, the tray 330 is mounted on the base frame 310.

Figures 5e and 5b are side elevations of the assembly 300 shown in Figure 5a. The trailer 300 includes the standard features of a tow hitch 10, jockey wheel assembly 11 and tray 330, The wheels 311 may be releasably secured in position by a wheel stray or cable 312. In Fig. 5b. the trailer is show in the tilted position with the hydraulic iani actuated to its full extent so that the tray 330 is set on a significant angle (about 30 degrees to the horizontal). The tailgate 70 is securable to side catches on the ends of the side walls of the tray or tub 330 by clamps 72. When the clamps are engaged to close the tailgate 70, the tailgate is sealed by seal means to prevent egress of dust through the interstitial spaces between the joins of the tailgate 70 and s the tub 330. On release of the clamps 72, the tailgate may swing from hinges 71 that suspend the tailgate from a rear upper cross beam 63 forming part of an upper rectangular frame 346 to allow access to a space 385 in the container.

The lifting device 370 comprises a hydraulic ram 101 pivotally mounted to a cylinder mounting plate 11 li that is fin shaped and welded to the frame base 310. The base frame 310 o comprises a lower frame 111 of the trailer chassis and a top frame of the trailer chassis and a top frame 112 as best shown in Figure 5b.

The assembly 300 further comprises a pressure release valve 20 that may be bolted to an aperture 332 formed in a front panel 333 of the tray 330. Extending in to the space defined by the tray 330 and a curved hoop frame 50 defining an internal space 385 under the flip frame 5 50 is a diffuser 27.

The diffuser 27 is best shown in Figure 5f which is a side elevation of the pressure release valve 20 and tire diffuser 27. The pressure release valve 20 is described in detail, particularly with regard to a preferred embodiment described with reference to Figs. 6a - 7b and 9a -1 If. The pressure release valve 20 is bolted to the aperture 332 formed in the wall of the panel 330 at a flange 26 defining the aperture 332 in an airtight seal.

The diffuser 27 is fabricated from mild steel sheeting and formed in to a cylinder 334 shape, The cylinder 334 is tapered towards a terminal rounded end 335. The diffuser walls are perforated by holes 33 to facilitate generalised dispersal of dust from the internal spaces of the diffuser 27 into the space 385. It is noted that the collapsible bag is described herein in detail with reference to Figs. 1 - 4. The cylinder 334 is supported by suspension from a hoop frame 50 by a downwardly depending rod or strap 337 that is bolted to the hoop assembly 50 and affixed to the upper surface of the cylinder 334 by one of a variety of attachment means, such as fasteners or welding at attachment point 338. Alternatively, and as shown in Fig, 8c, the rod or strap 337 is attached at the attachment point 338 by an annular strap extending around the circumference of the cylinder 334.

Figure 5d is an end rear elevation of the apparatus 300 and shows the tailgate assembly 70 and the support poles 40 uprightly supported in pole holders 31 attached to the tub 330 side walls. Detail of the pole holders 31 is shown in Figs. 13a - c. The pole holders 31 are attached by a hinge plate A and therefore can be rotated about fixed pin hinge 62 for flexibility and storage purposes,

The lifting device 370 is shown in Figure 5c and comprises a hydraulic pump 100 mounted on a mounting block 91 (see Figs. 17d-e). The hydraulic pump 100 is protected against the weather by a cover 90 that is bingedly mounted to a cross beam 372. A second cross beam is welded across the draw bars 113. The hydraulic pump assembly is mounted on the pair of cross beams 372, 373 in turn mounted astride the draw bars 113. The cross beams 372, 373 ar e also used to mount the downwardly depending ram mounting bracket 11 li.

Figure 5g is a top plan view of the apparatus 300,

Figures 6a-c are representations of the inlet duct of the pressure release valve 20.

Figures 6d - j are representations of various components , including a brace plate C, bolt- spring tensioner 22, latch hook 25 and catch plate 24, all being components of the pressure release valve 21.

Figures 7a and 7b show a hinged pressure relief lid 21.

Figure 8a is a front end elevation of the diffuser 27 showing the flange 26 and suspension rod 337.

Figure 8b is a top plan view of the diffuser 27, showing that the suspension strap or rod 337 may be secured by a ring band 340 extending around the cylinder 334 to distribute the weight of the diffuser 27 over a wider load spread, rather than concentrating the load on the attachment point 338, which may be problematic, depending on the weight of the diffuser 27, the thickness and strength of the diffuser 27 wall, and the size and concentration of the perforations 336. The diffuser 27 preferably includes multiple slots 341 at the upper end 335 to facilitate dispersal of file dust upwardly into the inflated collapsible bag (not shown).

Figure 8c is a side elevation of the diffuser 27 and shows the slight tapering of the diffuser cylinder 334 as it extends into the curved Upturned end section 335.

Turning to Figs. 9a and 9b, the valve 110 is shown in detail. The valve 110 includes a flap valve lid 113. The lid is shaped in the form of a shallow dome for strength. The lid 113 is seated on a compressible seal 114 of foam or rubber extending around the top edge of the cylinder 111 and in the closed position shown in Fig. 4 forms an airtight seal with the lid 113 and the cylinder 111.

The lid 113 is hingcdly mounted at one edge to the cylinder 111 wall by a bracket and hinge arrangement 120 that is riveted or welded in place by fasteners 115. The hinge arrangement 120 is formed from channel sectioned galvanised tube or similar and pivots about a hinge pin 116. The hinge pin 116 supports the lid flap valve 113 by a rotatable arm 117 welded to the top surface of the lid 113. The arm 117 is shaped to follow the contour of the dome lid 113 and extends to a point close to the center of the dome lid 113.

Welded to the arm 117 is an upstanding bracket or plate 118 that bears a female threaded bore such as a nut 119 that is axially aligned with the hinged arm 117. Extending through the bore is a threaded bolt or shaft 121 having a head 122 able to be rotated by a tool such as a spanner, the remote end including an eyelet 123 through which is engaged an end of a tension spring 124. The other end of the tension spring 124 is attached to an aperture 125 formed in a rotatable handle body 126. The handle body 126 is hinged mounted to a bracket 127 welded to the upper surface of the lid valve 113 and includes a cam surface 128 that is adapted to ride over a bearing surface in the form of a small plate 29 also welded to the lid 113. The handle body 126 includes and upwardly extending handle 131 adapted for manipulation by an operator whereby to manually pivot the handle body 126 upwardly against the bias of the spring 124. The handle body further includes a downwardly extending hook arm 132 that engages a loop catch 133 attached to the cylinder 111 wall at a position opposed to the hinge body 120.

Accordingly, the pressure within the cylinder 111 and inlet pipe 180 can be relieved by the handle body 126 rotating outwardly and upwardly against the bias of the spring 124 to lift the valve flap 113 from the seat seal 114 and allowing air to vent from the otherwise closed system as shown in Fig. 5 where the lid 113 is raised slightly above the seal 114 in an open position. As soon as the pressure diminishes in the cylinder 111 or the handle 131 is released, the lid 113 returned to its closed position. This valve arrangement 110 reduces the stress on the flexible bag 150 so that unsustainable pressure does not build up and allows an operator to check the flow and pressure within the system.

The dust collection system 10 shown in Fig. 1 may be fitted with a pressure release valve 210 as shown in Figs. 10 - l ie. The valve 210 may be positioned between a dust collecting device 60 and a dust separating device 80 in the same manner as the valve 110 shown in Fig. 4.

The valve 210 is fitted inline between the dust collecting device 60 and the dust separating device 80 and includes an inline pipe section 280 providing a fluid communication pipe line between a dust separating device outlet duct 82 and a port 147 in the walls 32, front panel 34 or tailgate 36 of a trailer 20 onto which a collapsible bag 50 is mounted. One end of the pipe 280 terminates with an annular flange 286 that is bolted on to the trailer 20 with a gasket or seal interposed at the join to seal ably secure the join in an airtight engagement of the flange 286 with the trailer 20 port 147. The opposed end of the pipe 280 is sealably engaged in-line with the outlet duct 82. Straddling the pipe 280 is a valve unit comprising a collar 212, upright cylinder 211 and closure 213.

The cylinder 211 terminates at its upper end in a mouth 244. The mouth 244 defines an aperture that is sealed by the closure 213. The mouth has a peripheral outwardly turned flange on which is secured an annular rubber seal 214. The seal 214 provides a seat onto which a shallow annular groove 248 in the closure's 213 underside rim 249 may be seated to achieve an airtight seal. The closure 213 further includes a domed panel 215 that is shallowly convex from the outside.

On one side of the cylinder wall 211 towards its upper end is mounted a retaining member. The retaining member at least provides a substantially horizontal bar 234 against that a release member 230 may engage. Preferably, the retaining member is in the form of a loop catch 233 having two spaced substantially vertical support posts 235 with the horizontal bar 234 bridging across the spaced posts 235. The loop catch 233 is welded or otherwise fastened to the wall 211 outer surface.

The retaining member 233 preferably comprises a single continuous rod bent into a loop shape, the tail ends of which are welded to the side Wall 211 , From the tail ends, a pair of spaced, inclined intermediate sections 236 each respectively join one of the substantially vertical posts 235 with the horizontal bar 234 extending therebetween. The horizontal bar 234 is spaced radially from the upper edge of the cylindrical wall 211 by virtue of the pair of spaced, inclined intermediate sections 236 so that an outer rim 249 of the closure 213 is cleared and the retaining mcriiber 233 does not interfere with the rotating travel or arcuate pathway of the hinged closure 213 when disengaged.

The substantially vertical- osts 235 position the substantially horizontal bar 234 above the closure rim 249 in the engaged position. The horizontal bar 234 may not be strictly horizontal and may be curved to facilitate centering of the release means 230 when engaged. The horizontal bar 234 may be circular, solid, tubular, flat bar-shaped or polygonal in cross section. Preferably, the horizontal bar 234 is circular or cam-shaped in cross section to facilitate the engagement or disengagement of the release member 230 with the retaining member 233. The retaining member 233 is preferably a length of steel rod worked into a loop or U-shaped member and attached, preferably by being welded, to the side of the cylinder wall 211.

The release member 230 is mounted to the closure's 213 outer and upper surface 247 by means of an elongate mounting structure 217. The mounting structure 217 extends wholly or partially the breadth of the upper surface 247, optionally following the contour thereof, which surface 247 may be convex.

As best seen in Figure 1 la, the mounting structure 217 includes a pair of spaced, parallel, vertically-aligned rib plates or structures 225a,b. The plates or structures 225 may form the arms of an inverted channel section that provides a central channel to locate the working parts and structures of the release member 230. The plates 225 may taper from the release member 230 end to the hinged 220 end. The height of the plates 225 at the release member 230 end may be elevated to provide sufficient space for there to be a clear passageway for an arcuate travel path of the release member 230, whilst providing hinged support for the release member 230.

At the hinged 220 end of the upper surface 247, the plates 225a,b are undercut to

accommodate an inverted elongate T-section 226 having lower lateral flanges 227. The lower flanges 227 are welded to both the upper surface 247 and to the mounting structure 217. Other forms of fastening and attachment are envisaged, such by as riveting or bolts, but welding may present the most cost effective means in terms of time and cost. The spacing of the rib plates 225a,b allow for the accommodation of a vertical ridge 228 forming part of the T-section 226 at the hinged 220 end and the hingedly mounted release member 230 at the retaining member 233 end. Integrally formed or welded there above the upper surface of the rib plates 225a, b is a threaded post or stand 218 that is aligned traverse to the ribs 225a, b and straddles the space there between.

The stand 218 is located intermediate the breadth of the closure 213, but could be located in a variety of positions as long as it provides support for a force regulating device such as a tension spring attached to the release member 230. An alternative support to the stand might comprise an extension of the rib plates 225 optionally wi th a bridge interposed therebetween. In any case, the support 218 provides a fixed support for a force regulating device spaced from a point on the release member 230 at which the force regulating device may be attached at its opposed end.

The stand 218 may include a bore for attaching the force regulating device. The bore may be threaded or have associated therewith or adjacent thereto a threaded nut attached in registration with the bore. Threadably engaged in a threaded bore of the post 218 may be a threaded bolt 222. The bolt 222 may be axially displaceable within the bore. The bolt 222 may include attachment means for attaching an end of the force regulation device. The force regulating device may be in the form of a tension spring 224. The attachment means may be an eyelet formed in the end of the bolt 222 shaft. The bolt 222 may hold the tension spring 224 at an end opposed to an end attached to the release member 230. The bolt 222 allows the tension of the tension spring 224 to be adjusted by axially displacing the eyelet 223 by rotating the bolt 222 clockwise or counter-clockwise in the threaded bore of the post 218. The distance between the eyelet 223 and the release member may be varied depending on the application, but in the particularly preferred embodiment shown in Figs. 10 to 1 lc is between 30 mm and 150mm, and most preferably about 125mm. This allows for a sufficient gap in which to place a tension spring 224 that permits adjustment of the tension force applied to the release member 230 by the axially threaded bolt 222 or he like.

The T-section comprises an elbow 229 that contiguously, continuously or integrally extends the T-section 226 downwardly in the form of a hinge arm 253, The hinge arm 253 has its base attached, preferably welded, to the cylinder wall 211. The hinge arm 253 extends outwardly from the rim 248 to enable the closure 213 to rotate about the hinge 220. The hinge 220 comprises a hinge block or housing 254 welded to the hinge 220 side of the cylinder wall 211. Continuously or integrally formed with the hinged arm 253 is a rotation limiter 252, being a short butt extending angularly, almost normal relative to the hinge arm 253. As shown in Figure 10, the rotation limiter 252 extends angularly from the hinge arm 253 such that it will limit the rotation of the hinge 220. The rotation limiter protects the mounting structure 217 and its components so that they are not damaged, or alternatively, other components of the device 210 axe not damaged, by a more extensive rotation of the closure 213 about the hinge 220.

The T-section 226 shape makes the hinge arm 253 very strong and its integrated

accommodation into the mounting structure 217 provides a structurally strong arrangement for the closure 213. A fairly robust design and components for the closure 213 is important, noting that disengagement of the release means 230 from the retaining member 233 will generally involve rapid rotation of the closure 213 about the hinge 220 as the pressure within the pipe 280 reaches a threshold upper level. In terms of the forces involved in a typical arrangement embodying the invention, it is envisaged that the tension forces applied by the tension spring 224 to maintain the closure 213 in the closed position would be equivalent to a weight of 5 - 0 kg on the closure 213, and preferably 7 - 9 kg, and most preferably about 8.25kg, or about SON. In terms of pressure, atypical threshold pressure setting would be in the range of about 1500 - 3000Pa, more preferably 2300 - 2700Pa, and most preferably about 2500 - 2600Pa, to preserve collapsible bag integrity and the sealed integrity of the overall system 10, 200.

The release member 230 rotates about a release hinge 237. The release hinge 237 is positioned between the ribs 225 at their high end of their wedge shape. The release member 233 is adapted to rotate through an arcuate path partially extending in the channel between the ribs 225. The release member comprises a horizontally aligned slot or mouth 270 at its outer extremity in the engaged position. The slot or mouth 270 is defined by a pair of upper and lower beak like extensions 271, 272. The horizontally aligned slot 270 receives the horizontal bar 234 when the release member 230 is in the engaged position and, together with the action of the tension on the release member 230, the retaining member 233 holds the release member 230 in the engaged position against the pressure that may build up under the closure 213, up until a threshold pressure level is reached.

A handle 231 may be used to enable an operator to manually re-engage the release member 230 with the retaining member 233 by pulling the release member 230 against the tension of the tension spring 224 to rotate the release member 230 clockwise Rm so that the release member 230 is reset in the engage position as shown in Figure 11 d. The handle 231 extends at an angle rearwardly from the retaining member 233 end of the closure 213 and provides an arm giving an operator sufficient leverage to rotate the release member 230 against the force of the tension spring 224. The lower most surface of the handle 231 is contiguous, continuous or integral with a generally triangular body 273 of the release member 230, the lower most corner 274 of the release member 230 providing a curved surface to permit rotation of the release member 230 without interference from the mounting structure 217 or the closure lid 213 itself.

In use, as a force Fl (for example between 50 - 100N) bears upwardly on an inside surface 245 of the closure 213, the force Fl being sufficient to overcome the tension force applied by the tension spring 224, the force Fl is transferred through the release hinge 237 to the release member 230 that is held in place by the retaining member 233 and, most particularly, the horizontal bar 234. As the force Fl urges the hinge 237 upwardly, the release member 230 rotates clockwise (as shown in Figure 1 Id) through an arc Rm, As the release member 230 rotates about the release hinge 237 and inner surface of the slot or mouth 270 slides against the horizontal bar 234, the beak 272 inner surface defining the slot 270 slides in a cam-like transition over the horizontal bar 234 until the horizontal bar 234 exits the mouth 270 and the release member 230 is fully released from the retaining member 233 resulting in the closure flinging open to release the pressure in the valve 210.

As the closure 213 is released from the retaining member 233, the closure 213 rotates in a counter-clockwise arc A (as shown in Figure l ie) about the closure hinge 220, the hinge 220 being secured by a hinge pin 216 in a bore of the hinge box 254. The arc A is limited in range by the rotation limiter 252 that permits a rotation of the hinge 220 through an arc of about 100' -130", and preferably about i 15°. The sectional shape of the butt 252 is consistent with the T-section shape of the hinge arm 253 and the T-section 226, so that the whole continuous or integral structure of the butt 252. hinge arm 253 and T-section 226 is very strong and able to withstand the force from the impact of the closure 213 flying open so that the hinge butt 252 impacts on the hinge box 254 to limit the extent of rotation of the closure 21 in the open position.

In Figure 1 If, there is shown a sectional view of the upper rim 287 of the valve mouth 244. The upper rim 287 comprises an annular outwardly curved flange 288. A rubber or synthetic rubber annular seal 289 is attached to the rim 287, having a moulded cross-sectional shape that wraps around the rim 287 profile. In the closed position, the shallow groove in the closure underside rim 248 is sealably seated on the rubber seal 288 for an air tight closure.

Figure 12a is an end elevation view of the tray or tub 330. This view clearly shows the curved join of the floor 342 and the side walls 343 at joins 344.

Figure 12b is a side elevation of the tub assembly 30.

Figure 12c is a top plan view of the upper square frame 346 showing apertures 347 adapted to rivet, button, stud or otherwise fasten the collapsible bag (not shown) sealably to the upper square frame 346 of the tub assembly 30;

Figure 12d is a front end elevation of the front panel 333, showing the upper frame section 346 and the aperture 332.

Figure 12e is a top plan view of the tub frame 310, showing that it is a rectangular frame 33 comprising a pair of central longitudinal beams 314 extending between front lateral beam 315 and rear lateral beam 16, and strengthened by frontward lateral beam 317. The longitudinal beams 314 are parallel and spaced and support an axle mount G.

Figs: 12f- show detail of a tail light cover 32,

Figures 13a-c show details of the pole storage tube 31, including front, plan and side views, respectively, and Fig. 15d shows a hinge plate A. The tube 31 includes a toggle clamp 60 that enables the telescopic pole 40 securable at a selectable length by applying a releasable screw clamp CI to secure the axially slidable pole sections. The pole 40 is to be secured in the pole storage tube 31 for storage.

In Figure 14a«c, the telescopic pole assembly 40 is shown in detail. In 16a, a clamp screw CI is shown that enables the telescopic pole 40 to be fixed at an adjustable height. As shown in Figure 14b, the telescopic pole 40 assembly comprises three separate sub-poles, including an outer tube A, a middle tube B and inner tube C, the inner tube's C terminal end having an eyelet D to engage a chain Di that is connectable to the collapsible bag (not shown). The various tubes A-C are telescopically slideable with respect to each other whereby to vary the length of the pole assembly 40 and screw clamps CI are threadably engaged through the walls of the outer and intermediate tubes A,B to secure the pole at a desired height or length..

Figures 15a-d show detail of the hoop assembly 50, including top plan, end elevation, side elevation and attachment details, respectively. Figure 15a shows that the hoop assembly 50 comprises four lateral curved arching members or hoops 392, equally spaced and joined by two central linear longitudinal members 3 3. The lateral hoops 392 are secure at their ends by attachment to the upper framed section 346 at mounting plates P best shown in Figs. 15 c and 15d. The purpose of the hoop frame 50 is to limit the extent to which the collapsible bag can collapse whereby a minimum defined space 385 is provided under the hoop frame 50 and between the tub 330 floor, walls and ends. This facilitates inflation of the collapsible bag in the first instance and makes cleaning of the container easier, as well.

Figures 16a-e shows the tailgate in detail. Figure 16c shows a planar panel 70 from which the tailgate is fabricated by folding peripheral extension tabs 321 to form the edge-reinforced panel 70, having folded edges 322, The folding of the edges 322 provides a reinforced edge and allows a lighter gauge panel 70 to be used whilst retaining strengt Most of the panels of the tray can be formed in this way to keep the overall weight of the trailer down for improved transportation.

Figures 17a-e show detail of the hydraulic pump mounting plate 92and the hydraulic pump mounting block 91. The mounting plate 92 is trapezoid, or truncated triangular, in shape and is formed as a flat sheet of metal. The mounting plate 92 is mounted on the mounting block 91, a rigid and solid thick rectangular plate by receiving a pair of mounting bolts that extend through bores 93.

Figure 18a is a top plan view of the trailer chassis 110. The trailer chassis 110 comprises a lower frame including the drawbars 111, top frame including the rectangular frame 112, and lateral beams 372, 373 to support the hydraulic pump 90.

Figure 18b is a side elevation of the trailer chassis 110 showing the drawbar lower frame 111, rectangular upper frame 112 and the hydraulic ram mounting bracket 11 li.

Figure 18c is a front end elevation of the trailer chassis 110. The hydraulic pump 90 is mounted at the front of, and close to, the tray 330, the lower bracket 11 li which permits a ram 101 to lift the tray 330, pivoting against rear hinges at the rear of the base frame 111. Accordingly, the tray 330 comprises a separate frame or monococal shell so that it can be moved and hold its integrity independent of the base frame 111.

Figures 19a shows the detail of a tow-hitch mounting plate A.

Figures 19b show greater detail of the mounting plate 111 i for the hydraulic member 101. The mounting plate Π li comprises a "keel'Or fin - like shape with an aperture F by which an hydraulic ram 101 can be rotatably or hingedly mounted, whilst providing good clearance and strength to the bracket as the aperture is located on the tip of the bracket extending from a strong and broad rearward-extending bracket body B.

Figures 20a-c show the lower frame 111 in greater detail, including the converging drawbars 113 joined at the tow hitch A, and the cross beams 372,373 adapted to support the hydraulic pump 100. The lower frame 111 provides a strong base from which the tray 330 may be lifted by the operation of the ram 101.

Figures 21a-c show the upper trailer chassis frame 112 in greater detail, including guide plates A on either side of the upper frame 112 that provide the centering means for the tub or tray 330 as it is lowered back into a horizontal position.

Throughout the specification and claims the word "comprise" and its derivatives are intended to have an inclusive rather than exclusive meaning unless the contrary is expressly stated or the context requires otherwise. That is, the word "comprise" and its derivatives will be taken to indicate the inclusion of not only the listed components, steps or features that it directly references, but also other components, steps or features not specifically listed, unless the contrary is expressly stated or the context requires otherwise,

Orientational terms used in the specification and claims such as vertical, horizontal, top, bottom, upper and lower are to be interpreted as relational and are based on the premise that the component, item, article, apparatus, device or instrument will usually be considered in a particular orientation, typically with the bars 64 uppermost.

It will be appreciated by those skilled in the art that many modifications and variations may be made to the methods of the invention described herein without departing from the spirit and scope of the invention,

Claims (1)

1. Claims:

   1. Λ bulk dust collecting device for collecting dust separated from particulate material comprising:

   a collapsible bag defining the whole or part of a container for receiving the dust;

   an aperture at or near the base of the container;

   a diffuser connected to the aperture and extending upwardly from the base and terminating in an open mouth from which airborne dust may be blown into the container.

   2. A bulk dust collecting device as claimed in claim 1, comprising a pressure release valve connected to a dust separating device, the dust collecting device, the dust separating devic and the pressure release valve forming part or all of a dust collecting system, the pressure release valve adapted to provide an airtight seal during the operation of the dust collector device,

   wherein, when the pressure in the dust collecting system reaches a critical level, the pressure release valve releases and the collapsible container deflates.

   3. A bulk dust collecting device as claimed in claim 2, wherein the valve comprises: a mouth scalable by a closure member in a closed position;

   a release member adapted to secure the closure member in sealed relationship vvith the mouth in the closed position by engaging a retaining member;

   force regulation device to set the internal pressure bearing against an inside surface of the closure that is required to disengage the release member from the retaining member to open closure member.

   4. A bulk dust collecting device according to claim Ϊ, wherein the container is mounted on a vehicle and is portable and the collapsible bag is inflatable to create a large contained volume into which the airborne dust may be blown.

   5. A bulk dust collecting device according to claim 1, wherein the aperture is an air tight sealable aperture for receiving a pipe connection external to the container that is in fluid communication with a dust separating device.

   6. A bulk dust collecting device according to claim 4, wherein the vehicle supports the bag and the container is made up of the bag and the vehicle combining to form the container.

   7. A bulk dust collecting device according to claim 6, wherein the vehicle is a trailer towable by a prime mover, the prime mover providing power to a dust separating device that is in fluid communication with the aperture.

   8. A bulk dust collecting device according to claim 2, wherein the bag is inflatable to form an elongate, upstanding and hollow structure.

   9. A bulk dust collecting device according to claim 8, wherein the diffuser blows the airborne dust upwardly into the container so that it settles at the base of the container.

   10. A bulk dust collecting device according to claim 9, wherein the base of the container comprises the tray of a vehicle.

   1 1. A bulk dust collecting device according to claim 10, wherein the tray has rounded corners and floor to wall joins to facilitate easy cleaning of the tray after use.

   12. A bulk dust collecting device according to claim 10, wherein the vehicle is a trailer towable by a prime mover such as a tractor or automobile.

   13. A bulk dust collecting device according to^" claim 10, wherein the fray has aii access means, such as a sealable wing, door, flap or panel, to provide access to the container.

   1 . A bulk dust collecting device according to claim 13, wherein the aperture is a sealable hole in a wall of the access means.

   15. A bulk dust collecting device according to claim 10, further including at least one support that minimises the extent to which the bag can collapse so that the container has a minimum volume greater than it would if the bag were to be completely collapsed.

   16. A bulk dust collecting device according to claim 15, wherein the support extends into the container from the tray.

   17. A bulk dust collecting device according to claim 15, wherein the support is bow shaped and extends from an upright tray ail.

   18. A bulk dust collecting device according to claim 15, wherein the support supports the diffuser above the tray.

   19. A bulk dust collecting device according to claim 17, wherein the support is a beam extending between opposed side walls and a suspension device depends from the beam to hold the diffuser in place.

   20. A bulk dust collecting device according to claim 10, wherein the bag is made from leagtiis of flexible material seamed to achieve an effective seal between the bag and the tray, and between the edges of the lengths of flexible material.

   21. A method οί collecting dust in bulk using a device as claimed in any one of claims 1 to 20, the method steps including:

   connecting the inlet of a powered dust sepai ator device to a source of particulate matter from which dust is desired to be separated;

   connecting the outlet of the dust separator device to the aperture;

   filling the container with airborne dust from the dust sepaiator device whereby to inflate the bag;

   collapsing the bag once sufficient dust has been collected;

   removing the connection of the dust separator device from the aperture; and

   sealing the aperture.