Folding conveyor

Abstract

A folding endless conveyor (100, Fig 3), possibly associated with and mounted on the side of a bulk material screening / sieving apparatus (M, Fig 1) comprising fixed tail (50), mid-section (10), linear actuator 30 comprising hydraulic cylinder (31), head section (20) and linkages (40, Fig 2), Conveyor 100 is adjustable between an extended / in-line working position (Fig 1) and a bent / folded storage position (Fig 2) and has a lower section mounted to a frame or chassis (C). Mid-section 10 is raised by linear actuator 30, causing end (11) to move about pivot (15) util section 10 is parallel to the side of apparatus (M). During this action, actuator 30 also raises linkages (40) about pivot connections 45, 46, positioning the head section 20 extends over top of / up and over apparatus (M), with middle section to be parallel to the frame when in a stored position. When unfolded, using hydraulic cylinders 30, mid-section 10 rotates relative to apparatus (M) via pivot (15) until section 10 extends from the frame by 15-30 degrees. Apparatus (M) may comprise a screen box (S) above the extendable conveyor when in use.

Description

The present invention relates to improvements in and relating to a folding conveyor for material processing apparatus, in particular to an up-and-over folding conveyor for screening machinery. Background to the Invention Folding conveyors comprise two or more sections which pivot with respect to each other such that the conveyor may be folded for storage and, when unfolded, are arranged to receive bulk material, e.g., screened material, at one end and to discharge such material from the other end so as to convey the material from one location to another, for example along an elevating path from a low position adjacent a tail section of the conveyor, to a higher position adjacent a head section of the conveyor. Such conveyors play a crucial role in any mining, aggregates or industrial operation and are often provided on both static apparatus and apparatus intended to be transported from one site to another. For example, it is usual to have at least one discharge conveyor which can be adjusted between a working position in which it projects to one side of the apparatus and a transport or storage position in which the conveyor is folded over the top of the apparatus to reduce the overall envelope of the apparatus in size. Such conveyors are often referred to as up-and-over conveyors. Conventional up-and-over conveyors use a plurality of hydraulic processes involving multiple rams and require the conveyor to be folded and unfolded in a particular sequence to avoid damage to the conveyor. They are also heavy and costly to manufacture. It is a therefore an object of the present invention to provide a folding conveyor which overcomes the drawbacks of known solutions or at least provides a suitable alternative. Summary of the Invention The present invention addresses the problem of ease of adjustment of a discharge conveyor of a static or mobile material screening apparatus between a storage or transport position and a working position. This problem is solved by reducing the number of rams and linkages used in typical up-and-over conveyors, i.e., reducing the number of hydraulic processes typically required. The present invention is primarily concerned with an improved folding mechanism which is operative to adjust a discharge conveyor of a static or mobile material screening apparatus between a storage or transport position and a working position. However, it should be understood that the improved folding mechanism of the invention has general application to a conveyor for use in other suitable apparatus. The present invention thus relates to a folding conveyor for a screening machine, the conveyor having a tail section, a mid-section, a head section and a folding mechanism. The folding mechanism is configured to fold the head section over the top of the machine and has a linear actuator to raise and lower the mid-section of the conveyor and a linking mechanism for mounting, folding and supporting the head section. The invention is set out in the claims. Accordingly, a first aspect of the present invention is a conveyor which is adjustable between an in-line working position and a bent storage position, the conveyor comprising: a fixed lower conveyor part adapted to be mounted on the frame of a material handling apparatus; an adjustable mid-section connected at a first end on the lower conveyor part via a pivot connection for movement between a working position in which the mid-section forms a prolongation of the lower conveyor part and extends laterally from the apparatus and a storage position in which the mid-section is generally parallel to the side of the apparatus; an upper conveyor part adjustably mounted at a first end on an opposite second end of the mid-section for movement between a working position in which the upper conveyor part forms a prolongation of the mid-section and so that the opposite second end of the upper conveyor part forms a discharge end of the conveyor, and a storage position in which the mid-section and upper conveyor part are substantially perpendicular to each other with the upper conveyor part extending over the top of the apparatus; the conveyor further comprising a folding mechanism comprising a pair of linkages either side of the upper conveyor part which connect the upper conveyor part to the frame via respective pivot connections and a linear actuator associated with the mid-section and having a first end adapted to be mounted on or below the lower conveyor part and a second end mounted to the mid-section, the linear actuator being operable to rotate the first end of the mid-section about the pivot connection wherein the folding mechanism, under the action of the single linear actuator, can adjust the mid-section and upper conveyor part between the in-line working position and the bent transport position. Advantageously, the folding mechanism results in ease of adjustment of the conveyor. Further advantageously the linkages of the folding mechanism are operable to support the conveyor when in the working position, resulting in the need for fewer components. This further reduces the overall weight of the conveyor. The conveyor according to the invention is particularly suitable for use as a discharge conveyor, and more particularly a side conveyor mounted below a screening plant on a mobile screening apparatus, in which space is available above the screening plant which can be occupied by a portion of the side conveyor when folded to its transport position. Each linkage independently has a first end adapted to be pivotally mounted on the frame of the material handling apparatus above the first end of the mid-section and a second end pivotally mounted on the first end of the upper conveyor part. Each linkage independently is preferably adjustable in length to facilitate building tolerances, e.g., by way of a threaded bar, telescoping section or the like. Upon folding and unfolding the conveyor, the lower conveyor part remains fixed and both the mid-section and the upper conveyor part move. The lower conveyor part is preferably mounted to a material processing apparatus at an upwardly inclined angle. When in the working position, the conveyor extends laterally from an apparatus to which it is mounted. To fold the conveyor from the working position into the storage position with the folding mechanism, the mid-section is raised by the linear actuator such that the first end of the mid-section is rotated relative to the lower conveyor part via the pivot connection until the mid-section is generally parallel to the side of the apparatus. The upper conveyor part is adjustably mounted to the mid-section and the linkages connect the upper part to the apparatus. Thus, as well as raising the mid-section, the linear actuator also raises the linkages and the first ends of the linkages are rotated relative to the frame of apparatus via respective pivot connections, preferably through approximately 90 degrees relative to the frame, which results in the second ends of the linkages being rotated about respective pivot connections to the first end of the upper conveyor part, preferably through approximately 45 degrees, and the first end of the upper conveyor part pivots such that the upper conveyor part is substantially perpendicular to the mid-section and extends over the top of the apparatus. Upon unfolding the conveyor from the storage position, the mid-section is lowered by the linear actuator such that the first end of the mid-section is rotated relative to the lower conveyor part via the pivot connection until the mid-section extends laterally from the machine at a desired angle, preferably until the mid-section extends laterally from the machine at an angle in the range of from about 15 degrees to about 30 degrees. This movement of the mid-section lowers the linkages such that the first ends of the linkages are rotated relative to the lower conveyor part via respective pivot connections and the second ends of the folding mechanism linkages are rotated about respective pivot connections to the first end of the upper conveyor part until the upper conveyor part and mid-section are in-line. The linear actuator is preferably operable to rotate the first end of the mid-section through an angle in the range of from approximately 15 degrees to approximately 90 degrees about the pivot connection. The linear actuator preferably comprises a piston cylinder device, particularly preferably a hydraulically operated device. Additionally, or alternatively, the linear actuator comprises a motor driven actuator unit. In a particularly preferred embodiment, the linear actuator requires only one piston cylinder device. However, this is not to be considered limiting and a linear actuator having two or more piston cylinder devices is also contemplated within the scope of the invention. For example, for heavier conveyors the linear actuator may comprise two parallel piston cylinder devices. Alternatively, or additionally, the linear actuator comprises a transverse member fixedly mounted across the width of the mid-section, preferably wherein the transverse member is fixedly mounted midway between the first and second end of the mid-section. In a preferred embodiment, the conveyor is an endless conveyor. An endless conveyor has an upper conveyor run and a lower conveyor run, and it is usual to provide guide or transfer rollers which facilitate the movement of the belt along an endless path. In another aspect, the invention provides a mobile processing apparatus comprising one or more conveyors as described herein. In a preferred embodiment, the invention provides a mobile screening apparatus comprising a wheeled or tracked chassis, a frame and a screen mounted on the frame, wherein a conveyor as described herein is mounted below the screen on one side of the apparatus. In this embodiment, when the conveyor is in the storage position, the mid-section is located adjacent the screen and the upper conveyor part folds over the screen. The skilled person will understand that where the same feature has been referenced in different aspects of the invention, this feature comprises the same parts and operates in the same way unless otherwise stated. Brief Description of the drawings Certain preferred embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings in which: Figure 1 is a perspective view of a screening apparatus provided with preferred folding conveyor according to the invention in the folded, i.e., storage, position; Figure 2 is a side view of the screening apparatus of Figure 1; Figure 3 is a perspective view of a screening apparatus provided with preferred folding conveyor according to the invention in the unfolded, i.e., working, position; Figure 4 is a side view of the screening apparatus of Figure 3; Figures 5, 7 and 9 are perspective views of a screening apparatus provided with preferred folding conveyor according to the invention being folded; and Figures 6, 8 and 10 are side views of the screening apparatus of Figures 5, 7 and 9, respectively. Detailed Description In overview, a folding conveyor with a fixed tail section is provided, the conveyor comprising a folding mechanism having a linear actuator, preferably a single ram, to raise and lower the mid-section of the conveyor and a linking mechanism for mounting, folding and supporting the head section such that the conveyor may be unfolded for use and folded for storage or for transport of an apparatus to which it is attached. Various embodiments of the present invention will be described in detail with reference to the drawings, where like reference numerals represent like parts and assemblies throughout the several views. It will be appreciated that the invention should not be construed to be limited to the examples, which are now described; rather, the invention is construed to include any and all applications provided herein and all equivalent variations within the skill of the ordinary artisan. Referring to the drawings, there is shown a folding endless conveyor according to the invention, generally referred to herein by reference numeral 100, and mounted to the side of material handling apparatus M, conveyor 100 comprising fixed tail 50, mid-section 10, head section 20, linear actuator 30 and a pair of linkages 40. Tail 50 is mounted to the frame of material handling apparatus M. Mid-section 10 is mounted at end 11 on tail 50 via pivot connection 15 and at opposite end 12 is connected to end 21 of head section 20 via pivot connection 16. Linear actuator 30 comprises single hydraulic cylinder 31 and fixed transverse member 32. Hydraulic cylinder 31 is mounted on frame of apparatus M beneath end 11 of mid-section 10 and transverse member 32 is fixedly mounted across the width of mid-section 10 midway between ends 11 and 12. Linear actuator 30 is operable to rotate end 11 of mid-section 10 through an angle in the range of from approximately 15 degrees to approximately 90 degrees about pivot connection 15. Linkages 40 are located either side of head section 20 to connect head section 20 to the frame of apparatus M via respective pivot connections 45 and to adjust mid-section 10 and head section 20 between the in-line working position shown in Figures 3 and 4 and the bent transport position shown in Figures 1 and 2. Linkages 40 comprise an elongate box section 43 with an adjustable treaded bar 44 at end 42 connecting linkage 40 to pivot connection 46 on head section 20. Threaded bar 44 enables linkage 40 to be adjustable in length to facilitate building tolerances. As shown in the Figures, apparatus M is a screener and has chassis C on which a frame is mounted for supporting power unit P, screen deck S, conveyor 100 and a tail conveyor T. However, it should be understood that the improved folding mechanism of the invention has general application to a conveyor for use in other suitable apparatus. As shown in Figures 1 and 2, in the storage position, conveyor parts 10, 20 are substantially perpendicular to each other with head section 20 extending over the top of apparatus M and mid-section 10 extending upwards from the chassis such that it is generally parallel to the side of the apparatus M. As shown in Figures 3 and 4, in the working position, mid-section 10 extends laterally from apparatus M and head section 20 forms a prolongation of tail 50 and mid-section 10 with end 22 of head section 20 forming a discharge end of conveyor 100. Tail 50 includes the feed end of the conveyor. When mounted to a material handling apparatus and in the deployed state, the conveyor discharge end is raised with respect to said feed end. As shown in the Figures, conveyor 100 may be unfolded for use and folded, for example for storage or for transport of an apparatus (not shown) to which it is attached, from the unfolded position shown in Figures 3 and 4 via the bent positions of Figures 5 to 10 to the folded position shown in Figures 1 and 2. This folding action may be driven by hydraulic cylinder 30. To fold conveyor 100 into the storage position, mid-section 10 is raised by linear actuator 30 such that end 11 is relative to the frame of apparatus M via pivot connection 15 until midsection 10 is generally parallel to the side of apparatus M. On raising mid-section 10, linear actuator 30 also raises linkages 40 and ends 41 of linkages 40 are rotated relative to the frame of apparatus M via respective pivot connections 45 which results in ends 42 of linkages 40 being rotated about respective pivot connections 46 to end 21 of head section 20 and end 21 of head section 20 pivots such that head section 20 is substantially perpendicular to midsection 10 and extends over the top of apparatus M. Upon unfolding conveyor 100 from the storage position, mid-section 10 is lowered by hydraulic cylinder 30 such that end 11 of mid-section 10 is rotated relative to the frame of apparatus M via pivot connection 15 until mid-section 10 extends laterally from machine M at an angle of about 15 to 30 degrees. This movement of mid-section 10 lowers linkages 40 such that ends 5 41 of linkages 40 are rotated relative to the frame of apparatus M via respective pivot connections 45 and ends 42 are rotated about respective pivot connections 46 to end 21 of head section 20 until head section 20 and mid-section 10 are in-line. It is to be understood that the invention is not limited to the specific details described herein which are given by way of example only and that various modifications and additions are 10 possible without departing from the scope of the invention as defined in the appended claims.

Claims

1. A folding conveyor adjustable between an in-line working position and a bent storage position, the conveyor comprising:a lower conveyor part adapted to be mounted on the frame of a material handling apparatus;a mid-section adapted to be mounted at a first end on the lower conveyor part via a pivot connection for movement between a working position in which the mid-section extends laterally from the apparatus and a storage position in which the mid-section is generally parallel to the side of the apparatus;an upper conveyor part adjustably mounted at a first end on an opposite second end of the mid-section for movement between a working position in which the upper conveyor part forms a prolongation of the mid-section and so that the opposite second end of the upper conveyor part forms a discharge end of the conveyor, and a storage position in which the mid-section and upper conveyor part are substantially perpendicular to each other with the upper conveyor part extending over the top of the apparatus; anda folding mechanism comprising:a pair of linkages either side of the upper conveyor part which connect the upper conveyor part to the frame via respective pivot connections; anda linear actuator associated with the mid-section and having a first end adapted to be mounted on or below the lower conveyor part and a second end mounted to the mid-section, the linear actuator being operable to rotate the first end of the mid-section about the pivot connection,wherein the folding mechanism, under the action of the linear actuator, can adjust the midsection and the upper conveyor part between the in-line working position and the bent transport position.

2. The folding conveyor as claimed in claim 1, wherein the linear actuator comprises a hydraulic cylinder, preferably a single hydraulic cylinder.

3. The folding conveyor as claimed in claim 1 or claim 2, wherein the linear actuator comprises a transverse member fixedly mounted across the width of the mid-section, preferably midway between the first and second end of the mid-section.

4. Material processing apparatus comprising one or more conveyors as claimed in any 5 one of claims 1 to 3.

5. The material processing apparatus as claimed in claim 4, further comprising a screen box, wherein the conveyor is mounted on the apparatus below the screen box such that when the conveyor is in the folded position, the mid-section is located adjacent the screen box and the upper conveyor part is located above the screen box.11

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