AU2020256432A1 - Apparatus for aggregate and emulsion application - Google Patents

Abstract

An apparatus for forming an aggregate layer containing bitumen, the apparatus comprising a hopper for holding the aggregate, the hopper having an upper inlet to enable aggregate to be loaded into the hopper, and a plurality of outlets through which the aggregate can flow, wherein each of the plurality of outlets is associated with its own gate member which can open and close the outlet, and a plurality of spray nozzles through which emulsion can be sprayed, wherein at least one of the plurality of spray nozzles is associated with each of the plurality of outlets, and wherein the apparatus further includes ground contact wheels mounted at a lower extremity of opposed ends of the hopper.

Description

APPARATUS FOR AGGREGATE AND EMULSION APPLICATION TECHNICAL FIELD

[0001] The present invention relates to an apparatus to allow bitumen to be laid down in an easy and rapid manner. The apparatus is particularly suited for smaller jobs such as paths and driveways. The apparatus can be attached to and operated by the hydraulics on a bobcat or similar machine. The apparatus can also be used to dispense solids and liquids other than aggregate and emulsion.

BACKGROUND ART

[0002] Any references to methods, apparatus or documents of the prior art are not to be taken as constituting any evidence or admission that they formed, or form part of the common general knowledge.

[0003] Throughout the specification and claims, the terms bitumen and asphalt are used interchangeably. Also, throughout the specification and claims the term bitumen may be used to describe the mixture of aggregate and binder which forms the pathway, driveway or other desired application. More correctly, the mixture should be called bitumen or asphalt concrete which is the mixture of aggregate and bitumen/asphalt binder. However, as the term concrete is often limited to Portland cement and aggregate, the term shall not be used herein.

[0004] Building driveways and paths for houses and other relatively small-scale projects using bitumen instead of concrete, pavers or just gravel presents particular difficulties. Because of the particular difficulties, the current options for small areas are generally limited to concrete or gravel finishes. However, a bitumen finish would be attractive for many prospective clients as it is generally cheaper than concrete, is more robust, requires less maintenance than gravel, and can be used within three days of application in contrast to a concrete path or driveway which can require up to 4 weeks to cure.

[0005] However, applying a bitumen driveway or path or other relatively small scale job is difficult because existing machinery to do the job is designed for much larger applications such as roadways, large car parks and the like. These large machines cannot be used for the small-scale applications either for physical constraints or price constraints by which is meant that the cost of using such large scale machinery is far too expensive for small-scale job.

[0006] Therefore, it is generally necessary to apply a bitumen driveway/path etc using manual labour which is physically hard and time consuming and therefore quite expensive making a small-scale bitumen job generally uneconomic notwithstanding the advantages of using bitumen as opposed to concrete, pavers and gravel.

[0007] A known bitumen method is known as "cold mix" or "warm mix". In this method, aggregate is laid down and bitumen is applied over the aggregate. The bitumen is emulsified in water prior to mixing with the aggregate. While in its emulsified state, the bitumen is less viscous, and the mixture is easy to work and compact. The emulsion will break after enough water evaporates and the cold mix will take on the properties of cold "hot mixed" bitumen. Cold mix is commonly used as a patching material and on lesser trafficked service roads.

[0008] A lesser used method emulsifies the bitumen in kerosene or other light fraction of petroleum.

[0009] The water-based emulsion is a combination of three basic ingredients, asphalt/bitumen, water, and small amount of an emulsifying agent. In the same process, these components are introduced into a mechanism known as a colloid mill, which shears the asphalt into tiny droplets. The emulsifier, which is a surface-active agent, keeps the asphalt droplets in a stable suspension and controls the breaking time. The result is a liquid product with a consistency ranging from that of milk to heavy cream, which can be used in cold processes for road construction and maintenance.

[0010] Asphalt/bitumen emulsions are classified into three categories; anionic, cationic, or non-ionic. The anionic and cationic classes refer to the electrical charges surrounding the asphalt particles. The absence of the letter "C" denotes anionic emulsions. Asphalt emulsions are further classified on the basis of how quickly they coalesce i.e., revert to asphalt cement. The terms RS (Rapid Set), MS (Medium Set), SS (slow set), and QS (Quick Set) have been adopted to simplify and standardize this classification. Additionally, trailing numbers are used to delineate the relative viscosity if the emulsion and the letters "h" and "s" indicate whether a hard or soft base asphalt is used to make the asphalt emulsions. Thus, a CSS-1h is a cationic slow set emulsion with a relatively low asphalt emulsion viscosity made with a hard base asphalt.

[0011] A disadvantage with laying bitumen paths etc, is that a number of workers are required for the job. One worker applies the bitumen emulsion by spraying or pumping. Another worker lays the aggregate typically by dumping aggregate roughly in the required area. Another worker then levels the aggregate to the required thickness.

[0012] Another disadvantage is that many of the workers need to work in the sun and heat and are not able to work from a shaded or air-conditioned cabin.

[0013] Another disadvantage is the risk of injury to workers by the proximity of moving machinery and workers.

[0014] Another disadvantage is wastage and mess on the site by the need to dump aggregate on site, usually in excess, and drums of emulsion. This is a particular disadvantage for small jobs where space for aggregate dumping may not be available or may cause damage to surrounding plants, gardens and the like.

[0015] Another disadvantage with existing methods is that the equipment can usually only provide a path width of a particular size or if different size widths are required, the differences are usually quite large. For instance, existing equipment may be able to make a path having a width of 1 m or 2 m and the like but it is usually difficult if not impossible for existing equipment to enable a path to be made of smaller increment widths, or to incrementally adjust the width along the length of the path.

[0016] Another disadvantage with existing methods is that it is sometimes difficult to accurately quote for a job as it is difficult to know exactly how much material will be used and how long the job will take. One reason for this is the need to bring various workers together, to bring various pieces of separate equipment together and the like.

[0017] Another disadvantage with existing methods is that the equipment used is very specialized. That is, a separate operating machine is generally used to lay the aggregate. Another separate operating machine is used for the application of bitumen. These machines are typically self-powered, large and expensive.

[0018] Another disadvantage is that scheduling all the different pieces of equipment required for the job - usually from different service providers - and ensuring that the weather conditions are suitable is a time-consuming task. Any rescheduling can add to cost.

[0019] Smaller versatile operating machines are known. An example of one type of machine is commonly known as a bobcat. These machines are provided with hydraulics and attachment links to enable a wide range of attachments and accessories to be fitted to the machine. However, there does not appear to be any single attachment for a bobcat that can be used to conduct all the steps required to form a bitumen path/driveway etc.

[0020] Another disadvantage with a dispensing apparatus which can be attached to an operating machine is that the apparatus is usually specialized for one use only, so for a broader range of applications it may be necessary to provide a plurality of separate specialized apparatus. For example, for outdoor use a dispensing apparatus may be required to carry out a large range of specialized liquid dispensing activities such as dispensing:

1.1. Cold bitumen emulsion

1.2. Hot bitumen emulsion

1.3. Water

1 .4. Liquid fertiliser

1 .5. Degreaser

1 .6. Herbicide

1.7. Other pesticides

1.8. Dust suppression emulsions

[0021] Also, the apparatus may be required to dispense a variety of solid products such as:

1.1. Sand

1.2. Crusher dust

1.3. Stone aggregate up to 30 millimetre diameter

1.4. Any aggregate material up to 30 mm diameter

1.5. Granular fertilisers

1.6. Lime and other soil treatments

[0022] Furthermore, the apparatus may be required to be used in a variety of areas such as:

1.1. Top dressing of golf courses, parks and other lawns

1.2. Fertilising of golf courses, parks and other lawns

1.3. Weed and pest control of golf courses, parks and other lawns

1.4. Degreaser application to large concrete areas such as car parks

1.5. Dust suppression on roads, worksites and other similar areas

1.6. Site preparation requiring a water or other liquid application

[0023] Furthermore, there would be an advantage if the apparatus, as well as being able to function as a dispensing apparatus, is also able to function as a loader bucket, such as for:

1.1. Shovelling said, gravel, soil, rocks and other materials

1.2. Loading of vehicles such as utility trucks, other small/light trucks, and

trailers

1.3. Levelling of sites

1.4. Cutting and/or excavations of sites.

[0024] There would be an advantage if it were possible to provide an apparatus which can be attached to an operating machine and which could overcome at least some of the above-mentioned disadvantages or provide a useful or commercial choice.

[0025] It will be clearly understood that, if a prior art publication is referred to herein, this reference does not constitute an admission that the publication forms part of the common general knowledge in the art in Australia or in any other country.

SUMMARY OF INVENTION

[0026] The present invention is directed to an apparatus for aggregate and emulsion application, which may at least partially overcome at least one of the abovementioned disadvantages or provide the consumer with a useful or commercial choice.

[0027] According to a first broad aspect of the present invention there is provided an apparatus comprising a hopper for holding material to be dispensed, the hopper having an upper inlet to enable material to be loaded into the hopper, and at least one outlet through which the material can flow, the outlet being associated with a gate member which can open and close the outlet, and at least one spray nozzle through which a fluid can be sprayed.

[0028] According to a more particular aspect of the present invention there is provided an apparatus for forming an aggregate layer containing bitumen, the apparatus comprising a hopper for holding the aggregate, the hopper having an upper inlet to enable aggregate to be loaded into the hopper, and at least one outlet through which the aggregate can flow, the outlet being associated with a gate member which can open and close the outlet, and at least one spray nozzle through which emulsion can be sprayed.

[0029] In this manner, it is no longer necessary to have two separate machines one to lay the aggregate and a second to spray the emulsion. The apparatus according to this form of the invention contains at least one spray nozzle to enable emulsion to be sprayed onto the ground or a prepared surface, and a hopper to enable aggregate to be laid on top of the emulsion.

[0030] The apparatus includes at least one spray nozzle or other emulsion outlet to enable emulsion to be sprayed or otherwise applied onto the ground or prepared surface. Suitably, the emulsion has a sprayable consistency and therefore can be sprayed through a spray nozzle. However, if the emulsion has a thicker consistency, it may need to be pumped through other types of outlets.

[0031] In another broad form of the invention, the emulsion may be replaced with another type of binder or finish for the aggregate. This may include hot melt bitumen which can flow under regulated conditions.

[0032] Suitably a plurality of spray nozzles is provided. It is preferred that each aggregate outlet is associated with at least one spray nozzle such that emulsion can be sprayed or otherwise applied. The emulsion will usually be sprayed onto the ground or prepared surface prior to the aggregate. However, there may be circumstances where the emulsion can contact the gravel after the gravel is on the ground and/or as the gravel is falling from the outlet to the ground. Alternatively, the nozzles, rather than being associated which each outlet, may be located elsewhere on the apparatus but in such a manner that the emulsion can be sprayed onto the ground etc.

[0033] Suitably, a plurality of spray nozzles is provided, and the spray nozzles can be individually operated or operated in groups such that emulsion is only sprayed in a desired width or "zone". For instance, if only two of the four gate members on the hopper are opened, it is preferred that only some of the spray nozzles are activated these spray nozzles being located to spray emulsion onto the ground prior to application of the aggregate.

[0034] To ensure adequate contact of aggregate with the emulsion, it is expected that each outlet on the hopper will be associated with a plurality of spray nozzles and typically between 2-6 spray nozzles. As a nonlimiting example, if the hopper comprises four gate members, there may be provided about 14 or so spray nozzles.

[0035] The spray nozzles may be of any suitable shape and size or any suitable type. As mentioned previously, there may be circumstances where the spray nozzles are not used, and the emulsion or other type of binding agents can flow through other types of outlets onto the aggregate. As an example, a perforated pipe may be provided through which the emulsion/binder can flow. The perforated pipe may be associated with valve members or other devices to ensure that the emulsion only flows through parts of the perforated pipe which correspond to gate members which are in the open position. In another alternative, a plurality of perforated pipes may be provided each associated in some way with a gate member and each being separately operable.

[0036] The emulsion can be stored in a storage tank. It is preferred that the storage tank forms part of the apparatus. However, there may be circumstances where it may be more convenient for the storage tank to be supported by the operating machine. Usual conduit such as pipes or hoses may be provided to connect the storage tank to the spray nozzles. The storage tank may be of any convenient shape and size. It is anticipated that the storage tank will have a size suitable to complete the potential job thereby minimising the requirements of constantly refilling the storage tank. There may be circumstances where more than one storage tank may be provided. In this circumstance, there may be an advantage in having different types of emulsion or different types of binder in each storage tank with the operator able to select the type of emulsion/binder to use. There may be circumstances where the emulsion may be provided in a container or tank which can be used as a storage tank. In this embodiment the apparatus or the operating machine may contain some form of support for the container.

[0037] The storage tank may be associated with some form of heating means if there is an advantage or need to heat the material in the storage tank. In this instance, it will be understood that heating the material in the storage tank may assist in keeping the material fluid so that it is kept in a suitable state to flow through the pipes and nozzles. For instance, the heating means may include an electrical heating unit (such as, but not limited to, an immersion-type tank flange heater, a circulation heater, a pipe heater, or the like), a direct heating unit (such as, but not limited to, gas-fired burner, diesel-fired burner or the like), a heat exchanger or indirect heating unit (such as but not limited to a hot oil, steam coils, or the like).

[0038] It is preferred that the emulsion is pressure sprayed. Therefore, it is preferred that the storage tank can be pressurised. The pressure may be maintained by a compressor which may be provided on the apparatus or on the operating machine or somewhere else. Alternatively, some form of pump may be used to pump the material from the storage tank through the spray nozzles. There may be circumstances where a gravity feed may be used to enable the emulsion or other binder to contact the aggregate.

[0039] In another form of the invention, the apparatus as described above includes a plurality of outlets each being associated with a gate member such that a particular outlet can be separately opened or closed and more than one outlet can be open or closed. In this manner, the width of the aggregate can be varied by opening or closing more than one of the outlets.

[0040] The width of each outlet can vary. However, it is envisaged that the width of each outlet will be between 10-100 cm such that each outlet can form a strip of aggregate having a width of between 10-100 cm. Typically, each of the outlets will have a width of approximately 500mm (50 cm). It is envisaged that each outlet will have about the same width however there may be circumstances where some of the outlets can have a different width than other of the outlets.

[0041] It is envisaged that the hopper will have at least one outlet and will preferably have between 2-10 outlets and most preferably about four outlets. If each outlet is approximately 50 cm in width, a four-outlet hopper can enable a path to be laid having a width of anywhere between 50 cm up to 2 m merely by opening and closing the required number of gate members. Also, the path width can be varied along its length again by opening and closing gate members as the aggregate is laid.

[0042] The at least one outlet on the hopper will typically be adjacent the lower end of the hopper. The outlet may extend substantially along the lower end of the hopper from adjacent one side to adjacent the other side of the hopper. One or more gate members may be provided to close off all or part of the outlet to enable different widths of aggregates to be laid. Alternatively, the hopper may be provided with a plurality of separate outlets with each outlet being associated with a gate member. It is also envisaged that two or more outlets may be associated with a single gate member although it is considered more preferable that each outlet is operable by its own separate gate member.

[0043] The gate member may have varying opening positions. For instance, the gate member may enable the outlet to be fully open or only partially open. This can be used to control the rate of aggregate flow through the outlet.

[0044] The gate member may comprise any device or assembly that can open and close the outlet. The gate member may be operable in a sliding manner, a rotating manner, by a hinge mechanism and the like. The gate member may comprise a plurality of parts which operate relative to each other between an open and a closed position. It is not considered that any unnecessary limitation should be placed on the mechanism by which the at least one outlet in the hopper can be open and closed.

[0045] The hopper may have any suitable shape and size which will be determined, inter alia, by the job size and by the operating machine to which the hopper can be attached. It is envisaged that the hopper will be sized to hold between 0.5-2 cubic meters of aggregate and typically about 1 cubic meter.

[0046] The hopper will typically be tapered from a wider upper open mouth (inlet) to a narrower lower outlet area to enable smooth flow of aggregate through the hopper. The open mouth may comprise substantially the entire upper end of the hopper such that the hopper has an open top. If desired, some form of lid or other closure may be provided over the mouth.

[0047] The hopper will typically comprise a single container. However, there may be circumstances where it is desirable for the hopper to be divided into compartments, for instance, to enable aggregates of different sizes to be stored and/or to assist in laying paths of different widths.

[0048] It is preferred that the hopper can be tipped to a substantially horizontal position to enable aggregate to be loaded into the hopper. To assist this, the hopper may have an inclined front wall. This will be described in greater detail below.

[0049] The apparatus is preferably mountable to an operating machine. The operating machine may comprise a skid loader or skid-steer loader which is a small rigid frame, engine-powered machine with lift arms used to attach a wide variety of labour-saving tools or attachments. The term "bobcat" is sometimes used as a generic term for this type of operating machine.

[0050] Though sometimes equipped with tracks, skid-steer loaders are typically four-wheel vehicles with the wheels mechanically locked in synchronization on each side, and the left-side drive wheels can be driven independently of the right-side drive wheels. The conventional bucket of many skid loaders can be replaced with a variety of specialized buckets or attachments, many powered by the loader's hydraulic system. These include backhoe, hydraulic breaker, pallet forks, angle broom, sweeper, auger, mower, snow blower, stump grinder, tree spade, trencher, dumping hopper, ripper, tillers, grapple, tilt, roller, snow blade, wheel saw, cement mixer, and wood chipper machine.

[0051] Some models of skid steer also have an automatic attachment changer mechanism. This allows a driver to change between a variety of terrain handling, shaping, and leveling tools without having to leave the machine, by using a hydraulic control mechanism to latch onto the attachments. Hydraulic supply lines to powered attachments may be routed so that the couplings are located near the cab, and the driver does not need to leave the machine to connect or disconnect those supply lines.

[0052] A small version of a skid steer mini loader is known. The Dingo TM is one type of such mini loader. Some versions have a platform on the back on which the operator stands. Other versions have the operator walking behind the apparatus.

[0053] Some mini loaders are articulated about a central portion. Other apparatus can steer by turning wheels as opposed to skid steer arrangements.

[0054] Front end loaders are larger operating machines which can be articulated between the front wheels and the rear wheels for steering, or which may have wheels which can steer like car wheels. Unless otherwise indicated, no unnecessary limitation should be placed on the type of operating machine to which the apparatus can be hitched/unhitched.

[0055] The apparatus may comprise components or parts to enable the apparatus to be attached to the lift arms of the bobcat or to other parts of other operating machines.

[0056] Suitably, the apparatus includes ground wheels. The ground wheels can enable the apparatus to be pushed by the operating machine. The apparatus may comprise enough wheels or other ground traversing devices (e.g. skids) to enable the apparatus to be free standing. However, it is preferred that the apparatus is provided with a pair of wheels such that it needs support from the operating machine.

[0057] The apparatus preferably comprises a height adjustment means to adjust the height between the outlet and the ground. The height adjustment means may be associated with the wheels. For instance, the wheels may be attached to posts which can be adjustably attached to the remainder of the apparatus.

[0058] It will be realized that in one aspect of the invention there is provided the previously described apparatus in combination with a bobcat wherein tilting arms of the bobcat engage the hopper for tilting the hopper between a horizontal position, in which it may be driven into an aggregate stockpile for loading for example, and an upright position in which it may be moved over an area whilst dispensing aggregate

[0059] The invention also encompasses a method for laying an aggregate surface comprising the steps of:

coupling a wheeled hopper to tiltable arms of an excavation vehicle such as a bobcat;

operating the excavation vehicle to move the hopper over an area to be covered with the aggregate surface whilst dispensing aggregate from the hopper.

[0060] The method may include: loading the hopper with aggregate by operating the tiltable arms to tilt the hopper so that an aggregate entry of the hopper is directed toward an aggregate stockpile and driving the excavation vehicle toward said stockpile so that aggregate enters the aggregate entry; and operating the tiltable arms to return the hopper to an upright position whilst retaining the aggregate therein.

[0061] In a further broad aspect of the invention the dispensing apparatus comprises a hopper for holding material to be dispensed, the hopper having an upper inlet to enable material to be loaded into the hopper, and at least one outlet through which the material can flow, the outlet being associated with a gate member which can open and close the outlet, and at least one spray nozzle through which a fluid can be sprayed.

[0062] The material may comprise any solid flowable material or material mix. This makes the apparatus very versatile and suitable for dispensing a variety of solid products such as:

1.1. Sand

1.2. Crusher dust

1.3. Stone aggregate up to 30 millimetre diameter

1.4. Any aggregate material up to 30 mm diameter

1.5. Granular fertilisers

1.6. Lime and other soil treatments

[0063] The spray nozzle can be used to spray any suitable liquid or liquid mix. This makes the apparatus very versatile and suitable for dispensing a large range of specialized liquid dispensing activities such as dispensing:

1.1. Cold bitumen emulsion

1.2. Hot bitumen emulsion

1.3. Water

1.4. Liquid fertiliser

1.5. Degreaser

1.6. Herbicide

1.7. Other pesticides

1 .8. Dust suppression emulsions

[0064] The combination of the solids dispensing hopper and the liquid dispensing spray nozzles makes the apparatus very versatile and suitable for use in a variety of areas such as:

1.1. Top dressing of golf courses, parks and other lawns

1.2. Fertilising of golf courses, parks and other lawns

1.3. Weed and pest control of golf courses, parks and other lawns

1.4. Degreaser application to large concrete areas such as car parks

1.5. Dust suppression on roads, worksites and other similar areas

1.6. Site preparation requiring a water or other liquid application

[0065] The use of a strongly built open topped hopper makes the apparatus very versatile as the hopper can be used as a conventional bucket such as for:

1.1. Shovelling sand, gravel, soil, rocks and other materials

1.2. Loading of vehicles such as utility trucks, other small/light trucks, and

trailers

1.3. Levelling of sites

1.4. Cutting and/or excavations of sites.

[0066] Any of the features described herein can be combined in any combination with any one or more of the other features described herein within the scope of the invention.

[0067] The reference to any prior art in this specification is not, and should not be taken as an acknowledgement or any form of suggestion that the prior art forms part of the common general knowledge.

BRIEF DESCRIPTION OF DRAWINGS

[0068] Preferred features, embodiments and variations of the invention may be discerned from the following Detailed Description which provides sufficient information for those skilled in the art to perform the invention. The Detailed Description is not to be regarded as limiting the scope of the preceding Summary of the Invention in any way. The Detailed Description will make reference to a number of drawings as follows:

[0069] Figure 1. Illustrates an operating machine (Bobcat) and an attached apparatus.

[0070] Figure 2. Illustrates the ability of the operating machine to load the hopper of the apparatus with required aggregate.

[0071] Figure 3. Illustrates the ability of the operating machine to tilt the hopper such that aggregate can be scraped into the hopper.

[0072] Figure 4. Illustrates the ability of the hopper to be loaded from a truck.

[0073] Figures 5A-5D. Illustrate schematically how various widths of pathway can be sprayed with emulsion by selective operation of spray nozzles.

[0074] Figures 6A-6D. Illustrate schematically how various widths of pathway can be laid by selective operation of gate members to control the widths of aggregate passing from the hopper to the ground.

[0075] Figure 7. Illustrates an upper view of the apparatus and particularly illustrating the top of the hopper.

[0076] Figure 8. Illustrates a side view of the apparatus.

[0077] Figure 9. Illustrates a forward view of the apparatus.

[0078] Figure 10. Illustrates a rear view of the apparatus from one side.

[0079] Figure 11. Illustrates a rear view of the apparatus from the other side.

[0080] Figure 11. Illustrates a ground wheel.

[0081] Figure 12. Illustrates a support foot which replaces the ground wheel to enable the apparatus to be supported in an upright position without tipping over.

[0082] Figure 14. Illustrates an underneath view of the lower end of the hopper and particularly illustrating the spray nozzles.

[0083] Figure 15. Illustrates attachment of the Bobcat to the apparatus.

[0084] Figure 16. Illustrates another view of attachment of the Bobcat to the apparatus.

[0085] Figures 17A-17V. Illustrate various other views of the apparatus.

DESCRIPTION OF EMBODIMENTS

[0086] Referring now to the illustrations, there is illustrated in Figure 1 an apparatus 10 which can be releasably attached to the front of an operating machine in the form of a Bobcat 17 (it being appreciated that the Bobcat is only an example of a particular type of operating machine that can be used).

[0087] The apparatus has a hopper 11 designed to hold a suitable quantity of aggregate, and in the particular embodiment, it is expected that the hopper will be able to hold between 0.5-2 cubic meters of suitable aggregate. The aggregate may be in the form of stones, pebbles, sand and the like, and it is considered that a person skilled in the art would be aware of the type of aggregate that would be suitable for a particular purpose.

[0088] The hopper has an upper inlet 12 which in the preferred embodiment comprises an open mouth and into which the aggregate can be dumped. The hopper has at least one outlet 13 to allow the aggregate to flow out of the hopper. Figures 6A-6D illustrate schematically aggregate 30 flowing out of the bottom of the hopper through the at least one outlet 13. The at least one outlet in the preferred embodiment is positioned at the lowermost portion of hopper 11.

[0089] The outlet 13 is associated with a gate member 14 which functions to open and close the outlet thereby controlling flow of aggregate from the hopper onto the ground. Figure 14 illustrates an example of a gate member 14.

[0090] The apparatus further comprises at least one spray nozzle 15 through which emulsion, such as liquid tar, can be sprayed to form the bitumen pathway. Figure 14 illustrates a plurality of such spray nozzles and Figures 5A-5D illustrate schematically the spray nozzles 15.

[0091] A separate hand wand (not illustrated) can be associated with the apparatus to spray emulsion into hard to reach areas.

[0092] Referring to Figure 1, the apparatus 10 comprises an emulsion tank 20 in which to hold the emulsion. The emulsion tank is preferably pressurised, and this can be achieved by any suitable means. The emulsion tank may also be fitted with a heater to keep the emulsion, e.g. tar, fluid in colder climates so that it is kept in a suitable state to flow through the pipes and nozzles. A heater is not needed in warmer climates. Emulsion tank 20 is also illustrated at least in Figure 11. Tank 20 can hold a sufficient volume of emulsion and it is considered that the tank should hold at least 20-200 L of emulsion although this can vary to suit. The type of emulsion can vary, and it is considered that a person skilled in the art would be knowledgeable in the type of emulsion that is used to spray over aggregate to form a bitumen surface.

[0093] The lower part of the hopper 11 contains a pair of spaced apart ground wheels 18 this being illustrated in several of the figures but especially with reference to Figure 1, and any of Figures 5A-5D. These wheels are adjustable in height relative to the hopper and this can assist in determining the thickness of aggregate layer that passes from the bottom of the hopper and onto the ground. Referring to Figure 13, there is illustrated a close-up view of the lowermost part of the hopper. In this close- up view, the ground wheels have been removed and replaced by a removable supporting foot 19. There will be a foot 19 on each side of the hopper (see for instance Figure 9) and the function of the removable supporting foot 19 is to allow the hopper to be placed on the ground and be self-supporting and to not tip over. However, in use, the ground wheels replace the supporting foot 19.

[0094] Referring to Figure 11 and 12, the ground wheels 18 have temporarily been placed over the mouth of the hopper while the supporting foot 19 is attached. When the supporting foot 19 is removed, there will be left a vertical short steel box section channel 21 (see for instance Figure 13) and the corresponding post 22 (see Figure 12) on the wheel 18 is positioned in channel 21 at a desired location this providing a height adjustability of the wheel relative to the lower part of the hopper.

[0095] Another reason for attachment of the supporting foot 19 on each side of the hopper is evident in Figure 2. By enabling the apparatus to be self-supporting in an upright position, the Bobcat can be used to fill the hopper with the aggregate. The Bobcat is not required to be attached to the apparatus at this stage in order to maintain the apparatus in an upright position and therefore the Bobcat can be used for other purposes.

[0096] The versatility of the apparatus is also demonstrated in Figure 3. In this figure, the Bobcat 17 has lowered the apparatus such that the inclined front wall 16 of the hopper 11 contacts the ground. The hopper can then be used as a "bucket" and can be filled by simply pushing the hopper into a mound of aggregate as illustrated in Figure 3. Once filled, the apparatus can be raised back to the generally upright use position as illustrated in Figure 1.

[0097] Figure 4 illustrates yet another way to fill the hopper and in this embodiment, the back of a truck is tilted to drop aggregate into the hopper of the apparatus. The apparatus in Figure 4 is supported by the feet 19, but it is also envisaged that the apparatus can be attached to the Bobcat in the manner illustrated in Figure 1 and then filled from the truck.

[0098] Referring to Figures 6A-6D, the lower outlet 13 of the hopper can be associated with one or more gate members 14 which can be operated to adjust the width of aggregate that is dropped out of the bottom of the hopper. This is clearly illustrated in the figures. In an embodiment, the lower outlet 13 of the hopper may comprise a single outlet extending entirely along the bottom of the hopper and there may be provided a single gate which can be slid or otherwise progressively moved to progressively open the lower end from a small opening (Figure 6A) to a full opening (Figure 6D). Of course, it is also envisaged that the lower outlet may comprise four or more separate outlets each being associated with a gate member. Other combinations are also envisaged.

[0099] Referring to Figures 5A-5D, the lower outlet of the hopper is associated with a number of spray nozzles 15. The spray nozzles function to spray emulsion. The spray nozzles 15 can be selectively operated to ensure that the emulsion is sprayed at specified widths onto the ground. The nozzles are typically used in an initial run to spray emulsion onto the ground to act as a binder or "glue" for a second run/pass of aggregate over the emulsion and this second pass can be as described above.

[0100] Referring to Figure 7, there is illustrated an upper view of the apparatus 10. The hopper 11 is divided into two compartments 24, 25. The lower end of each compartment 24, 25 is associated with its own outlet 13. Thus, the design of this particular hopper allows a narrower pathway to be laid by operating the outlet 13 of only one of the compartments or allows a wider pathway to be laid by operating the outlet 13 of both compartments. Figure 7 also illustrates some of the components of the emulsion tank 20.

[0101] Figure 8 illustrates a side view of the apparatus and illustrates the emulsion tank 20 hopper 11 and the lower supporting feet 19.

[0102] Figure 9 illustrates a front view of the apparatus and particularly illustrates the inclined front wall 16 of the hopper 11.

[0103] Figure 10 and Figure 11 illustrate a rear view of the apparatus showing the emulsion tank and the various conduits and hoses.

[0104] Figure 12 illustrates in greater detail the lower ground wheels 18 which are temporarily placed on the mouth of the hopper because the lower feet 19 have been attached in the present embodiment. However, Figure 12 does illustrate the post 22 of the wheel. Post 22 fits into the channel 21 (see Figure 13) once the supporting foot 19 has been removed. Channel 21 contains a pin 26, and post 22 is provided with a number of through openings 27. This "pin in slot" arrangement enables the height of the wheel to be adjusted relative to the bottom of the hopper.

[0105] Referring to Figure 14, there is illustrated the underneath view of the lower end of hopper 11 and particularly illustrates the plurality of spray nozzles 15. These nozzles 15 are in linear alignment and spaced apart and can be individually controlled. An overspray skirt 28 is provided behind the nozzles.

[0106] Figures 15 and 16 illustrate how the apparatus can be coupled to the front of a Bobcat and particularly to the lift arms 29 of the Bobcat.

[0107] Figures 17A-V provide further illustrations of the parts of the apparatus 10.

[0108] There are many advantages of the preferred embodiment of the invention that has been described. For instance, it is now possible for a single operator and for one machine (e.g. Bobcat) to prepare construct and bitumen finish the entire job.

[0109] No job will now be too small because of the advantages provided by the present invention.

[0110] The apparatus can be loaded with the aggregate from an on-site stockpile (if desirable) and, for small jobs, can be transported to the site preloaded which overcomes the difficulties with dumping aggregate on site.

[0111] The apparatus can carry the appropriate ratios of aggregate and emulsion.

[0112] The operator does not have to manually handle the emulsion or the aggregate.

[0113] The apparatus can utilise the existing attachments of a Bobcat or other suitable machine. Therefore, there is no need for the apparatus itself to be provided with a motor and the like.

[0114] The apparatus is scalable to fit a range of machines sizes such as the small machines (e.g. Dingo) up to a medium-sized loader.

[0115] After initial calibration and setup, the material usage can indicate that correct application rates are being maintained.

[0116] The apparatus is easy to clean after use.

[0117] There is little or no waste material. Any leftover material can be stored in the apparatus or decanted.

[0118] The apparatus can be used as a standard bucket for spreading and moving material and for loading and unloading. The spray tank to hold emulsion can also be used as a water tank for watering driveways, house pads, for dust suppression and the like.

[0119] It is now easier and therefore more predictable to quote for a job because the application time is now more predictable as the surface area of the job will be all that is required to quote and the application rates is now more predictable to allow the operator to finish within time.

[0120] A single machine operator is now all that is required to apply both to spray emulsion and the aggregate in appropriate ratios to achieve the finished bitumen job.

[0121] The apparatus can be loaded mechanically by the operator from either a stockpile or the tip truck. It is no longer necessary to manually load aggregate into the apparatus. The entire operation is completely independent of any additional services or equipment.

[0122] The apparatus can be preloaded with the required material quantities before being transported to site, this being especially desirable for small jobs and where a stockpile is undesirable.

[0123] The "all in one" apparatus does away with the need to schedule all the different pieces of equipment required for the job - usually from different service providers. The apparatus reduces reliance on favourable weather conditions as the apparatus is a single operator and single unit apparatus.

[0124] A significant advantage of the apparatus of the present invention is that the width of the finished job is flexible and can quite easily be changed by the operator in increments - typically 50 cm increments. Other specialist widths could be achieved through minor modification during construction.

[0125] The adjustable height indicator takes the guesswork out of the operation as well as providing safety benefits to the operator and to any bystanders.

[0126] The apparatus has relatively few moving parts reducing maintenance and service requirements.

[0127] The design of the apparatus can be quite compact to allow it to be hitched and unhitched from the operating machine, e.g. an autonomous vehicle such as an excavation machine or bobcat, even when fully loaded.

[0128] In the present specification and claims (if any), the word 'comprising' and its derivatives including 'comprises' and 'comprise' include each of the stated integers but does not exclude the inclusion of one or more further integers.

[0129] Reference throughout this specification to 'one embodiment' or'an embodiment' means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearance of the phrases'in one embodiment' or'in an embodiment' in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more combinations.

[0130] In compliance with the statute, the invention has been described in language more or less specific to structural or methodical features. It is to be understood that the invention is not limited to specific features shown or described since the means herein described comprises preferred forms of putting the invention into effect. The invention is, therefore, claimed in any of its forms or modifications within the proper scope of the appended claims (if any) appropriately interpreted by those skilled in the art.

Claims (12)

1. An apparatus for forming an aggregate layer containing bitumen, the apparatus comprising a hopper for holding the aggregate, the hopper having an upper inlet to enable aggregate to be loaded into the hopper, and a plurality of outlets through which the aggregate can flow, wherein each of the plurality of outlets is associated with its own gate member which can open and close the outlet, and a plurality of spray nozzles through which emulsion can be sprayed, wherein at least one of the plurality of spray nozzles is associated with each of the plurality of outlets, and wherein the apparatus further includes ground contact wheels mounted at a lower extremity of opposed ends of the hopper.

2. An apparatus according to claim 1 wherein the hopper has a rear side formed with an attachment for coupling to an automotive vehicle.

3. An apparatus according to claim 2, wherein the hopper has a forward side that diverges upwardly and away from the rear side so that in side profile the hopper presents a triangular form.

4. An apparatus according to any one of the preceding claims wherein the hopper is formed with mounting brackets for receiving posts and wherein the contact wheels are mounted to posts received by the mounting brackets.

5. An apparatus according to any one of the preceding claims, wherein the hopper is formed with mounting brackets for receiving posts and wherein the apparatus includes wheels fitted to posts and interchangeable feet fitted to posts for reception into the mounting brackets so that the apparatus may be rolled on the wheels for dispensing aggregate or stood on the feet for loading the hopper with aggregate.

6. An apparatus according to any one of the preceding claims, including a partition dividing the hopper into two side by side portions so that the width of aggregate dispensed by the hopper is reduced in use.

7. An apparatus according to any one of the preceding claims wherein the hopper has between 3-10 outlets.

8. An apparatus according to any one of the preceding claims comprising between 6-20 spray nozzles.

9. An apparatus according to any one of the previous claims including an emulsion tank to hold emulsion for dispersal over the aggregate.

10. An apparatus according to any one of claims 1 to 9 in combination with a bobcat wherein tilting arms of the bobcat engage the hopper for tilting the hopper between a horizontal position and an upright position.

11. A method for laying an aggregate surface comprising the steps of: coupling the apparatus of any one of the preceding claims to tiltable arms of an excavation vehicle such as a bobcat; operating the excavation vehicle to move the apparatus over an area to be covered with the aggregate surface whilst dispensing aggregate from the hopper.

12. A method according to claim 11, including: loading the hopper with aggregate by operating the tiltable arms to tilt the hopper so that an aggregate entry of the hopper is directed toward an aggregate stockpile and driving the excavation vehicle toward said stockpile so that aggregate enters the aggregate entry; and operating the tiltable arms to return the hopper to an upright position whilst retaining the aggregate therein.