IE83537B1 - A material processing device - Google Patents

Description

A MATERIAL PROCESSING DEVICE The invention relates to a material processing device and more particularly to a mobile aggregate processing plant for use in quarries, mines or recycling plants to treat aggregate material.

For the purposes of this specification, the term aggregate is taken to include materials such as sand, loam, stone, crushed stone, rock, brick, coal or recyclable materials such as glass, plastics or wood chips.

Aggregate material delivered to the plant is processed by crushing, washing and grading, or similar processing techniques, to quickly and effectively deliver processed material for collection and distribution. In large scale processing facilities, the necessary throughput of processed material is achieved with bespoke items of plant designed for and assembled, on a specific site. Such solutions are only possible where the scale and anticipated duration of processing make such assemblies economically viable. Where there is a lesser Volume of material or ad hoc processing is required, mobile items of plant are used. The design and construction of such mobile equipment is critical in that there is always a trade off between processing capacity and portability. This is particularly so in that it is often necessary to deliver the mobile aggregate processing plant to a remote site. Thus, the plant must be capable of being transported along minor roads and across soft terrain. The obvious objective for a designer therefore, is to provide this portability, by minimising overall weight, height and width while maximising processing capacity.

A variety of mobile aggregate processing plants are known. British Patent Specification No. GB-2223963 (McDonald) describes an arrangement whereby conveyors are separated from the mobile plant and are then lifted by a loader onto upper support brackets mounted above the plant. These brackets significantly increase the height of the plant limiting access in certain areas. Furthermore, carrying separated conveyor sections on such brackets represents a potential safety hazard as well as being time-consuming and awkward.

PCT Patent Specification No. W0 85/03652 (Powerscreen) describes a mobile screening apparatus in which there is a pair of opposed lateral conveyors extending on opposite sides of the plant. Even though the conveyors are mounted on pivots the device must be of sufficient length to avoid a situation where they project longitudinally beyond the plant.

This overall length requirement again limits the site applicability of the device.

British Patent Specification No. GB 1,480,688 (Machines & Structures) also describes a mobile screening plant with lateral conveyors. Again these conveyors are pivotable about a vertical axis for delivery of separated material to different stockpiles. Similar length restrictions apply as described above and the overall structure is too heavy for many applications.

Thus, while a wide variety of mobile aggregate processing plants have been used in the past, there are still many practical problems in the, size versus capacity trade-off. These problems can be Very important where the plant is frequently moved from site to site and where the plant must be transported over large distances from the place of manufacture.

There is therefore a need for a road-hauled aggregate material processing plant which is physically smaller and lighter than known devices but which does not compromise processing capacity.

Accordingly, there is provided a mobile aggregate material processing device comprising: - a wheel mounted chassis for allowing the device to be moved between processing locations; a plant support frame carried on the chassis; a raw material delivery means mounted on the plant support frame; a material processing means mounted on the plant support frame and fed from the raw material delivery means and having an outlet; and processed material delivery means mounted on the plant support frame and fed from the material processing means, characterised in that the wheel-mounted chassis and the plant support frame are integrally fonned as a support chassis combining the operative functions of both the support chassis is movable between an operative position and a transport position and the operative position and transport positions are separated by a relative operating angle of between 15° and 25° and wherein one end of the support chassis has a wheel pin for connection to a truck for moving the device, the end of the support chassis being kinked relative to the remainder of the support chassis.

By the relatively simple expedient of combining the functions of the chassis and the plant support frame the overall weight of the unit is significantly reduced without compromising processing capacity. The support chassis operates as a trailer base for the device during transport and as a plant superstructure when in position on site. This weight reduction allows the device to be transported to a greater number of sites previously limited by road access and or surrounding terrain. Additionally, the reduction allows the device to be transported using much lighter and therefore less costly haulage equipment. The production cost for a device in accordance with the invention is greatly reduced as the need for a separate chassis is obviated. The compact nature of the assembly allows the unit to be configured to process four grades of material while remaining light and mobile.

Ideally, the operating angle is 18°.

In one embodiment, the support chassis is movable between the operative position and the transport position using a plurality of hydraulic rams carried on the support chassis. In this way plates on the rams provide the required support for the device and no pressure is exerted on the chassis wheels, as was previously the case. Known devices of this type spread the load on both wheels and stabilising rams, greatly reducing the length of service possible from expensive tyres. As the provision of stabilising rams was always required this too represents a significant improvement over known devices.

According to another aspect of the invention, the plant support frame supports a screening plant having three overlapping screening beds, each screening bed having a mesh for processing of aggregate material and a receptacle having an opening for supporting the mesh screen wherein the mesh is contoured to the receptacle opening and wherein each of three screening beds is individually tensionable in an end wise direction. ldeally, the mesh is convex.

Prior art screening beds comprise an open screen box having a base, a pair of spaced apart side walls carried on the base and a pair of end walls, each end wall being connected to the side walls and forming a mesh junction with the base. Thus, when aggregate is delivered to the box it tends to gather at either end of the mesh at the mesh junction. This creates a wear point on the box end walls and at the edge of the mesh reducing component life.

Meshes and boxes need to be replaced more often or manufactured from more durable materials, both of which increase costs. The arrangement of the current invention prevents unnecessary gathering of material at the ends of the receptacle and the wear associated therewith.

According to a further aspect of the invention there is provided a mobile aggregate material processing device comprising: - a wheel mounted chassis for allowing the device to be moved between processing locations; a plant support frame carried on the chassis; a raw material delivery means mounted on the plant support frame; a material processing means mounted on the plant support frame and fed from the raw material delivery means and having an outlet; and processed material delivery means mounted on the plant support frame and fed from the material processing means, wherein the wheel-mounted chassis and the plant support frame are integrally fonned as a support chassis and wherein the screening plant has three overlapping screening beds, each screening bed having a dished mesh for processing of aggregate material contoured to a receptacle opening on which the mesh is canied and into which processed material is passed and wherein each of the three screening beds is individually tensionable in an end wise direction.

The invention will be more clearly understood from the following description of an embodiment thereof given by way of example only with reference to the accompanying drawings in which:- Fig. 1 is a diagrammatic side view showing a mobile aggregate material-processing device of the invention in an operating position; Fig. 2 is a diagrammatic side view of the device of Fig. 1 in a transport position; Fig. 3 is a side view of portion of a prior art screening plant; Fig. 4 is a side view of portion of a screening plant forming part of the current invention; and Fig. 5 is a side portion of a three-deck vibrating screen assembly forming part of the current invention.

Referring to the drawings, and initially to Figs. 1 and 2 there is shown a mobile aggregate material processing device of the invention, indicated generally by the reference numeral 1.

The plant 1 is in this embodiment has a material processing means provided by a screening assembly indicated generally at 100, for screening and grading of aggregate materials such as stone, rubble, loam, or mined minerals.

The device 1 comprises a support chassis 2 having a pair of longitudinal beams 3 mounted on wheels 4 and supported on hydraulic rams 5. The support chassis 2, when in the operating position (as shown in Fig. l) performs the fimction of a plant support frame. As already mentioned, the plant supported in this case is a screening assembly 100, which will be described in more detail below, but may be any other appropriate item of aggregate material processing equipment. When the support chassis 2 is in the transport position (as shown in Fig. 2), the chassis 2 operates as a trailer bed with a towing point 6 and wheel pin 7 for moving the device between sites and for transport on site. This represents an important feature of the invention in that by combining the functions of the chassis and the plant support frame the overall weight of the unit is significantly reduced. This is achieved without compromising processing capacity for the device and allows for the provision of a greater screening area on the device. The reduced weight of the device facilitates transportation to previously inaccessible sites by lighter haulage equipment. The reductions in materials required to produce the device also greatly reduce manufacturing costs.

The device 1 further incorporates a raw material delivery means provided by an input hopper 10, mounted over an input feed conveyor 11. The input hopper lO communicates with the screening assembly 100 by way of the input feed conveyor 11 to deliver material to be processed. In more detail and referring, in addition, to Figs. 4 and 5, the assembly 100 incorporates a three—deck vibrating screen assembly giving four sizes of processed aggregate material. Each deck has three screening beds 400 for grading and sorting the material. This material is delivered for collection and distribution through three processed material out-feed delivery chutes 12 and fine discharge conveyor 13, fed from the assembly 100.

In operation, with the device in an operating position as shown in Fig. 1 material is delivered by a conveyor, into the input hopper 10. The material to be graded is passed onto the input feed conveyor 11. The conveyor 11 delivers the material to be graded onto the assembly 100 to the top end of the screening beds 400. Each screening bed 400 is inclined as the support chassis 2 is raised on the hydraulic rams 5 to 18° to 20°. Material is then screened for grading and delivery to the chutes. The vibratory actions of the screening beds and the sequence of screening beds does not form part of the current invention and this therefore not described to prevent unnecessary misunderstanding. It is important to note however that the weight reduction by the combined functions described allows additional decks to be added without increasing weight.

When it is desired to move the device 1 the hydraulic rams 5 are activated to lower the device onto the wheels 4. The device can then be moved using truck connected to the towing point 6.

To facilitate understanding of one aspect of the current invention, a prior art screening bed, fonning part of a screening assembly is now described with particular reference to Fig. 3 and identified generally by the reference numeral 300. The screening bed 300 has an open screen box with a base 301, a pair of spaced apart side walls 302 carried on the base 301 and a pair of end walls 303. Each of the end walls 303 are connected to the side walls 302 and form a mesh junction 304 with the base 301 at either end of the box. A convex mesh 305 is mounted in the box such that the mesh 305 extends up from the junction 304 at one end toward the middle of the box and down again to the junction 304 at the other end.

Prior art beds of this type have problems associated with durability and cost. As aggregate is delivered to the box it tends to gather at either end of the mesh at the mesh junctions.

This creates a wear point on the box end walls and at the edge of the mesh reducing To overcome the need for meshes and boxes to be replaced more component life. expensive durable materials are often required.

Referring now in particular to Fig. 4, a screening bed in accordance with the invention is shown, indicated generally by the reference numeral 400. The screening bed 400 has a convex mesh 401 for processing of aggregate material mounted across a receptacle 402 having an opening for supporting the mesh 401. The mesh 401 is contoured to the opening to prevent material being processed from coming into contact with an wall of the receptacle as described with reference to Fig. 3. The bed arrangement of the current invention prevents unnecessary gathering of material at the ends of the receptacle and the wear associated such gathering of material.

Fig. 5 shows three screening beds 400 arranged in a deck indicated generally by the reference numeral 500. The overlapping arrangement of the beds 400 allows the plant to present an increased screen area ever known decks. Furthermore the deck with three individually tensioned is more durable and efficient.

The device may be a mobile mining or crushing plant or any other aggregate material processing plant instead of a screening device. The device may be provided as a combination of any of the above, for example, the screening device described may incorporate a crusher or draw bar for a mobile crusher.

It will of course be understood that the invention is not limited to the specific details as herein described, which are given by way of example only, and that various alterations and modifications are possible without departing from the scope of the invention.

Claims (2)

CLAIMS:

1. A mobile aggregate material processing device comprising: - a wheel mounted chassis for allowing the device to be moved between processing locations; a plant support frame carried on the chassis; a raw material delivery means mounted on the plant support frame; a material processing means mounted on the plant support frame and fed from the raw material delivery means and having an outlet; and processed material delivery means mounted on the plant support frame and fed from the material processing means, wherein the wheel-mounted chassis and the plant support frame are integrally formed as a support chassis, the support chassis is movable between an operative position and a transport position and the operative position and transport positions are separated by a relative operating angle of between 15° and 25° and wherein one end of the support chassis has a wheel pin for connection to a truck for moving the device, the end of the support chassis being kinked relative to the remainder of the support chassis.

2. A mobile aggregate material processing device comprising: - a wheel mounted chassis for allowing the device to be moved between processing locations; 10 a plant support frame carried on the chassis; a raw material delivery means mounted on the plant support frame; a material processing means mounted on the plant support frame and fed from the raw material delivery means and having an outlet; and processed material delivery means mounted on the plant support frame and fed from the material processing means, wherein the wheel-mounted chassis and the plant support frame are integrally formed as a support chassis and wherein the screening plant has three overlapping screening beds, each screening bed having a dished mesh for processing of aggregate material contoured to a receptacle opening on which the mesh is carried and into which processed material is passed and wherein each of the three screening beds is individually tensionable in an end wise direction. . A mobile aggregate material processing device substantially as herein described with reference to and as shown in the accompanying drawings. . A processed material whenever produced by a mobile aggregate material processing device substantially as herein described with reference to and as shown in the accompanying drawings. MACLACHLAN & DONALDSON Applicants’ Agents 47 Merrion Square