IES59885B2 - Apparatus for screening material - Google Patents

Description

This invention relates to apparatus for the screening of aggregate T material, the apparatus being of the type using vibrating screens of varying mesh size to separate the material by particle size.

A screening apparatus is known comprising a body unit housing a drive mechanism, the body unit being mounted on wheels. The apparatus is provided with an arm for attachment to a tow bar. A twoscreen screening unit is mounted on top of the body unit and may be set at an angle to the horizontal, in use. The apparatus includes a fines conveyor for removing the smallest size of graded material and can optionally include a side conveyor for removing the larger size(s) of graded material.

In use, the aforementioned apparatus is towed to the desired location, the wheels are moved to one side to allow the body to sit on the ground, the apparatus is levelled by hydraulic means and the desired screen angle is set. The material to be separated is added directly on to the screening unit. Coarse grade material, which will not pass through the upper screen, drops off the screening unit to one side of the apparatus above said upper screen. Medium grade material, which can pass through the upper screen, but not the lower screen, will also drop off the screening unit to one side of the apparatus at a point intermediate the upper and lower screens. Finally, the fine grade material, which can pass through both screens, is collected below the screening unit on the fines conveyor. The use of an optional side conveyor allows the medium grade material to be collected separately, otherwise it remixes with the course grade material which has not passed through the first screen. , The provision of integral wheels, a towing arm and a fines i conveyor adds considerably to both the overall weight and the cost of manufacture of the apparatus as described above. Also for proper separation of the aggregate material a further conveyor must be used. ο ) It is an object of the present invention to overcome the drawbacks of known apparatus and to provide a simple transportable screening apparatus.

Thus the invention provides an apparatus for the screening of aggregate material, said apparatus comprising a framework and means associated with the framework for conveying said material to a screening mechanism for screening thereof, said framework being adjustable between a first position, wherein the apparatus is engageable with a trailer for transporting the apparatus, and a second position wherein the apparatus is self-standing and clear of the trailer.

As used herein the expression aggregate material includes any of the following materials: blasted rock, crushed stone, coal and shale, landfill, refuse, sand and gravel, top soil, mineral ore or riprap.

It will be appreciated that the apparatus according to the invention has the advantages, relative to the known apparatus hereinbefore described, of being compact, easily transportable and being self-erecting on site. Also, when erected and, in use, the fine grade material can collect under the apparatus, on the ground or in a trailer or dumper placed under the apparatus. This means that an integral or optional fines conveyor is unnecessary.

Preferably, the framework is adjustable between the first and second positions by means of a plurality of adjustable legs telescopically mounted thereon.

The advantage provided by telescopically mounted, adjustable, legs is that they are easy and quick to adjust and, when retracted, provide a compact apparatus which is suitable for transportation on a trailer.

Preferably, the adjustable legs are hydraulically operated.

Further, preferably, the means for conveying said material comprises a hopper and a variable speed belt feeder.

€ The provision of a hopper and a variable speed belt feeder results in an adaptable apparatus suitable for different aggregate materials.

Advantageously, the apparatus has a flow control gate, detachably mounted to the framework between the belt feeder and the screening mechanism.

The detachably mounted, flow control gate can be removed when handling material containing large items such as tree roots, which would otherwise catch in the hopper and halt or impede the operation of the apparatus. With the flow control gate removed these items will be fed to the screening mechanism and will pass thereover and off to one side of the apparatus.

The invention will be further illustrated by the following description of embodiments thereof given by way of example only with reference to the accompanying Drawings in which: Fig. 1 is a front elevation of a first embodiment of apparatus according to the invention in a first position; Fig. 2 is a front elevation of the apparatus of Fig. 1 in a second position; Fig. 3 is an end elevation at one end of the apparatus of Fig. 1; Fig. 4 is an end elevation at one end of the apparatus of Fig. 2; I Fig. 5 is an end elevation at the other end of the apparatus of Fig. 1; Fig. 6 is an end elevation at the other end of the apparatus of Fig- 2; Fig. 7 is a front elevation of a second embodiment of apparatus according to the invention including a trailer; Fig. 8 is a plan view of the trailer of the apparatus of Fig. 7; Fig. 9 is a front elevation of a third embodiment of apparatus according to the invention in a first position; Fig. 10 is a front elevation of the apparatus of Fig. 9 in a second position; and Fig. 11 is a plan view of the apparatus of Fig. 10.

Referring to Figs. 1-6, there is shown, generally at 10, apparatus according to the invention for the screening of aggregate material, comprising a metal framework 11, a hopper shown generally at 12, having two side walls 13, 14 which may be adjusted, by adjusting 15 means (not shown) to accommodate varying widths of loader bucket. A screening mechanism 15 is flexibly mounted to the framework 11 at mounting points 16, 17, and 18 (Figs. 3 and 4) and a fourth mounting point not shown.

The screening mechanism 15 houses two screening decks 19, 20 20 (Figs. 3 and 4). The screening decks 19, 20 can be changed and this can be accomplished in about ten minutes. Screen sizes from 1 mm to 150 mm can be used and these can be of the piano wire type or be end tensioned mesh screens. Harp finger screens from 6 mm to 50 mm finger size may also be used.

The screening decks 19, 20, shown in ghost outline in Figs. 1 and 2, are set at an angle to the horizontal to allow material to run off them to one side of the apparatus 10.

Four legs 21, 22, 23, 24 are telescopically mounted to the . framework 11 for movement between a first position (Figs. 1 and 3), wherein the apparatus 10 is engageable with a trailer (not shown) for transporting the apparatus 10, and a second position (Figs. 2 and 4), wherein the apparatus 10 is free-standing and clear of the trailer. Legs 21, 23 are joined at their base by a connecting member 25 and legs 22, 24 are joined at their base by a connecting member 26. Movement of legs 21, 23, is controlled by a pair of hydraulic cylinders (not shown) housed in framework members 27, 28, respectively. Movement of legs 22, 24 is controlled by a further hydraulic cylinder 29 mounted between the framework 11 at 30 and the connecting member 26 at 31. The legs 21, 22, 23, 24 are provided with a plurality of fixing positions 32 (Fig. 2), which allow the legs 21, 22, 23, 24 to be held at a variety of extended leg lengths and, thereby, the apparatus 10 can have a variety of working heights.

A hydraulically operated belt feeder 33 is mounted between the hopper 12 and the screening mechanism 15. A diesel motor 34 provides the power for the extension and retraction of the legs 21, 22, 23, 24, the screening mechanism 15 and the belt feeder 33, all of which are controlled using the control unit 35. A tank 36 is provided for the diesel fuel.

Detachable chutes 37, 38 are suspended on chains 39, 40, respectively, from the framework 11 at 41 (see Fig. 2). The chutes 37, 38 are also attached to the screening mechanism 15 at points 42, 43, respectively and at two further points not shown.

A detachable flow control gate 44 is mounted to the framework between the hopper 12 and the screening mechanism 15.

Referring to Fig. 7, there is shown the apparatus 10 mounted on a detachable trailer shown generally at 51.

Referring to Figs. 7 and 8 the detachable trailer 51 comprises a pair of axles 52, 53 to which the wheels 54, 55, 56, 57 are attached.

The axles 52, 53 are mounted to an A-frame 58 which has a hitching point 59 at the apex thereof.

The apparatus 10 is detachably mounted to the trailer 51 at mounting points 60, 61, 62, 63. In use, the apparatus 10 is trailed to the 5 site on trailer 51. The framework 11 is released from the mounting points 60, 61, 62, 63 of the trailer 51 and the control unit 35 is operated to extend the legs 21, 22, 23, 24 to the desired working height. The trailer 51 may then be manoeuvred from under the framework 11.

The material is added to the hopper 12 and is fed to the screening mechanism 15, by the belt feeder 33. The coarse grade material passes over the upper screen deck 19 and down the chute 37. The medium grade material, which has passed through the upper screen deck 19, but not the lower screen deck 20, exits down chute 38. Finally the fine grade material, which has passed through both screen decks 19, 20, collects under the framework 11 between the legs 21, 22, 23, 24.

When it is desired to remove the apparatus 10, the trailer 51 is manoeuvred under the framework 11 and the legs 21, 22, 23, 24 are retracted so that the framework 11 sits on the trailer at mounting points 20 60, 61, 62, 63. The framework 11 is attached to the trailer 51 and apparatus 10 may be trailed to a new site.

It should be noted that when the apparatus 10 is mounted on the trailer 51 the connecting member 25 engages the lower side 64 of Aframe 58, thus providing further support for apparatus 10 on the trailer 51.

The trailer 51, is further provided with an integral braking system (not shown) and rear lights (not shown), thus allowing the apparatus 10 to be towed on public roads at speeds of up to 80 kilometres per hour.

Referring to Figs. 9, 10 and 11 there is shown generally at 65, ? apparatus according to the invention adapted for on-site trailing by a vehicle such as a tractor or dumper. Apparatus 65 is similar to $ apparatus 10 of Figs. 1-8, and like parts are denoted by the same reference numerals.

Thus, apparatus 65 is provided with a pair of on-site wheels 66, joined by an axle 67 (Fig. 11). The wheels 66 and axle 67 are mounted on brackets 68, fixed to one end of framework 11, the wheels 66 being mounted by means of a pair of axle arms 69, which can swivel about mounting points 70 to allow wheels 66 to be fixed in either a standby position (Fig. 9) or a towing position (Fig. 10).

A towing arm, shown generally at 71 is mounted at the other end of framework 11 at points 72, for movement between a standby position (Fig. 9) and a towing position (Figs. 10 and 11). The towing arm 71 is held in the standby position by a retaining rod 73 (Fig. 9) and in the towing position by retaining bolts 74, receivable in receiving means 75, on framework 11.

A pair of support legs 76 are provided for supporting the apparatus 65 while it is being hitched/unhitched to/from a suitable onsite towing vehicle. When not in use the support legs 76 can be retracted (Fig. 9).

For on-road towing of apparatus 65 the towing arm 71 and wheels 66 are placed in their respective standby positions and the support legs 76 are retracted.

The provision of the towing arm 71 and wheels 66 does not add * significantly to the overall weight of apparatus 65. ( u The invention is not limited to the embodiments described above which may be modified and/or varied without departing from the scope of the invention.

Claims (5)

1. i Claims: f I. Apparatus for the screening of aggregate material, said apparatus comprising a framework and means associated with the framework for conveying said material to a screening mechanism for 5 screening thereof, said framework being adjustable between a first position, wherein the apparatus is engageable with a trailer for transporting the apparatus, and a second position wherein the apparatus is self-standing and clear of the trailer.

2. Apparatus as claimed in Claim 1, wherein the framework 10 is adjustable between the first and second positions by means of a plurality of adjustable legs telescopically mounted thereon.

3. A combination of an apparatus as claimed in Claim 1 or 2 and a detachable trailer.

4. Apparatus as claimed in Claim 1, substantially as 15 hereinbefore described with particular reference to and as illustrated in Figs. 1-6 and Figs. 9-11 of the accompanying Drawings.

5. A combination as claimed in Claim 3, substantially as hereinbefore described with particular reference to and as illustrated in Figs. 7 and 8 of the accompanying Drawings.