Automatically adjustable roller assemblies

Abstract

A roller assembly (10) comprising a mounting frame (12) and a substructure (16) which is pivotably mounted to the mounting frame (12) by means of a main pivot (18). The roller assembly (10) is operatively mounted to a conveyor frame by means of the mounting frame (12). A set of rollers (20) is supported by the substructure (16). A linear adjustment mechanism (300) is incorporated in the main pivot (18) to allow linear adjustment of the substructure (16) relative to the mounting frame (12). In some cases, the linear adjustment mechanism (300) comprises an automated linear adjustment mechanism.

Description

[0001] AUTOMATICALLY ADJUSTABLE ROLLER ASSEMBLIES

[0002] BACKGROUND TO THE INVENTION

[0003] This invention relates to conveyors. More particularly, the present invention relates to roller assemblies used with conveyors, the roller assemblies characterised by having automatic adjustment mechanisms.

[0004] The roller assemblies referred to here may typically, but not exclusively, relate to roller assemblies of trough conveyors. Such roller assemblies may form part of steering, alignment or tracking mechanisms or return roller mechanisms.

[0005] Conventional steering, alignment or tracking mechanisms typically have a central roller or rollers, and wing rollers on either side of the central roller which are angled upwards from the horizontal so as to match the profile or troughing angle of the belt.

[0006] Trough shaped conveyor belts tend to be difficult to guide or steer because the alignment or steering mechanism, in particular the wing rollers, tend to push into the belt as the mechanism seeks to align the belt. Also, trough configurations of different belts are not standard and, in particular, the troughing angle can vary from conveyor to conveyor.

[0007] Accordingly, known trough conveyor alignment mechanisms are often provided with pivotably adjustable wing rollers. The range of adjustment of these known alignment mechanisms is very limited, and the range is typically only a few degrees. Furthermore, known alignment mechanisms tend to butt out sideways from the side of the alignment mechanism, and often protrude beyond or stand proud of the conveyor frame and into maintenance walkways running along sides of the conveyor.

[0008] This may pose potential safety concerns and may inhibit the use of hoods or other covers typically employed over conveyors of this nature. Such hoods, therefore, often have to be customized in areas where alignment mechanisms are installed, which adds complexity to the installation and maintenance of the conveyor.

[0009] It is furthermore believed that the bulky construction of prior art alignment mechanisms may negatively impact the efficiency of the alignment mechanism.

[0010] Since loads experienced by the belt running over the roller assemblies vary dynamically (because of uneven loads carried by the belt, accelerations and jerks experienced when starting up or slowing down or when the belt does not carry a load) tension within the belt may vary and forces exerted by the belt on the roller assemblies, and vice versa, may vary. This may negatively affect the interaction between the belt and the roller assemblies, and, for example, the efficiency of the steering or alignment mechanisms. It is accordingly an object of the invention to provide an automatically adjustable roller assembly that will, at least partially, address the above disadvantages.

[0011] It is also an object of the invention to provide an automatically adjustable roller assembly which will be useful alternatives to existing or known assemblies.

[0012] SUMMARY OF THE INVENTION

[0013] In accordance with a first aspect of the invention there is provided a roller assembly, comprising:

[0014] - a mounting frame for operatively mounting the roller assembly to a conveyor frame;

[0015] - a substructure, pivotably mounted to the mounting frame by means of a main pivot;

[0016] - a set of rollers supported by the substructure; and

[0017] - a linear adjustment mechanism incorporated in the main pivot to allow linear adjustment of the substructure relative to the mounting frame.

[0018] The linear adjustment mechanism may comprise an automated linear adjustment mechanism, such as a mechanical actuator, a mechatronic actuator, a hydraulic actuator, a pneumatic actuator, or a linear electric actuator.

[0019] The mechanical actuator may comprise a power screw arrangement, driven by a motor to adjust the substructure linearly relative to the mounting frame. The power screw arrangement may comprise:

[0020] - a main body;

[0021] - a threaded shaft which is driven by the motor and supported relative to the main body;

[0022] - a threaded sleeve received on the threaded shaft, the threaded sleeve supported by the main body and comprising a slot through which a pin from the main body extends, interaction between the pin and the slot inhibiting rotation of the sleeve relative to the main body;

[0023] - an outer sleeve pivotably supported by the threaded sleeve, wherein the substructure forms part or is supported by the outer sleeve.

[0024] Further according to the first aspect of the invention, the set of rollers may comprise at least a first and second steering rollers. At least a distal portion of each of the first and second steering rollers may be tapered.

[0025] In accordance with a second aspect of the invention there is provided a roller assembly, comprising:

[0026] - a mounting frame for operatively mounting the roller assembly to a conveyor frame;

[0027] - a substructure, pivotably mounted to the mounting frame by means of a main pivot; - a set of rollers supported by the substructure, the set of rollers comprising at least a first and second steering rollers, wherein each steering roller is mounted to the substructure by means of an angle adjustment mechanism such that each steering roller is pivotably adjustable relative to the substructure, the angle adjustment mechanism comprising an automated linear actuator.

[0028] Each angle adjustment mechanism may comprise a tubular bracket with a bore within which a shaft of the respective steering roller may operatively be received and retained in cantilever fashion. The shaft of the respective steering roller may be fixed relative to the tubular bracket by means of at least a first, but typically also a second grub screw.

[0029] Towards a first end thereof, the tubular bracket may be pivotably mounted to the substructure by means of a first pivot.

[0030] The automated linear actuator may extend between a second end of the tubular bracket and the substructure. The automated linear actuator may be pivotably fixed to both the tubular bracket and the substructure by means of a second and third pivot, respectively.

[0031] An effective length of the automated linear actuator may be adjustable, to pivot the tubular bracket about the first pivot to adjust an angle of the tubular bracket relative to substructure.

[0032] The automated linear actuator may take the form of a linear hydraulic actuator, comprising a piston and cylinder arrangement, a linear pneumatic actuator, comprising a piston and cylinder arrangement or a power screw arrangement.

[0033] Each steering roller may be adjustable between about 0 degrees and 65 degrees relative to a plane in which the central rollers are arranged.

[0034] At least a distal portion of each of the first and second steering rollers may be tapered.

[0035] The set of rollers may comprise at least a first, but typically two, central rollers. The central rollers may be arranged on opposite sides of the main pivot.

[0036] Each steering roller may be configured to be pivotably adjustable in a plane substantially perpendicular to a plane in which the substructure is pivotable about the main pivot.

[0037] A linear adjustment mechanism may be incorporated in the main pivot to allow linear adjustment of the substructure relative to the mounting frame. The linear adjustment mechanism may comprise an automated linear adjustment mechanism in the form of a mechanical actuator, a mechatronic actuator, a hydraulic actuator, a pneumatic actuator or a linear electric actuator.

[0038] The mechanical actuator may comprise a power screw arrangement, driven by a motor to adjust the substructure linearly relative to the mounting frame. The power screw arrangement may comprise:

[0039] - a main body;

[0040] - a threaded shaft which is driven by the motor and supported relative to the main body; - a threaded sleeve received on the threaded shaft, the threaded sleeve supported by the main body and comprising a slot through which a pin from the main body extends, interaction between the pin and the slot inhibiting rotation of the sleeve relative to the main body;

[0041] - an outer sleeve pivotably supported by the threaded sleeve, wherein the substructure forms part or is supported by the outer sleeve.

[0042] In accordance with a third aspect of the invention there is provided a conveyor, comprising:

[0043] - a main conveyor frame;

[0044] - a roller assembly according to any one of the first and second aspects of the invention mounted to the main conveyor frame; and

[0045] - a belt supported at least partially on the conveyor alignment mechanism.

[0046] In accordance with a fourth aspect of the invention, there is provided a roller assembly, comprising:

[0047] - a mounting frame for operatively mounting the roller assembly to a conveyor frame;

[0048] - a substructure, pivotably mounted to the mounting frame by means of a main pivot; and

[0049] - a set of rollers supported by the substructure, the set of rollers comprising at least a first and second steering rollers, wherein each steering roller is mounted to the substructure by means of an angle adjustment mechanism such that each steering roller is pivotably adjustable relative to the substructure, each angle adjustment mechanism associated with an adjustable link mechanism which extends between said angle adjustment mechanism and the substructure, to pivotably adjust the respective steering roller, wherein, the adjustable link mechanism comprises: o an inner and outer body arranged in telescopically adjustable fashion; o a threaded shaft extending within the outer body, the threaded shaft comprising, towards a second end thereof, a driving head, which driving head protrudes from the second body; and o a lead nut which is fixed to the inner body and arranged on the threaded shaft.

[0050] The roller assembly may further comprise a first pivot arrangement located towards a first end of the inner body, and a second pivot arrangement located on the outer body.

[0051] An endcap with a central opening may be received over a second end of the outer body and may be fixed thereto. The endcap may be configured for retaining the driving head and therefore central shaft in position within the telescopic bodies.

[0052] The roller assembly may further comprise a linear adjustment mechanism incorporated in the main pivot to allow linear adjustment of the substructure relative to the mounting frame. In accordance with a fifth aspect of the invention, there is provided an adjustable link mechanism comprising:

[0053] - an inner and outer body arranged in telescopically adjustable fashion;

[0054] - a threaded shaft extending within the outer body, the threaded shaft comprising, towards a second end thereof, a driving head, which driving head protrudes from the second body; and

[0055] - a lead nut which is fixed to the inner body and arranged on the threaded shaft.

[0056] The adjustable link mechanism may further comprise a first pivot arrangement located towards a first end of the inner body, and a second pivot arrangement located on the outer body.

[0057] An endcap with a central opening may be received over a second end of the outer body and may be fixed thereto. The endcap may be configured for retaining the driving head and therefore central shaft in position within the telescopic bodies.

[0058] BRIEF DESCRIPTION OF THE DRAWINGS

[0059] The invention will now be described in more detail, by way of example only, with reference to the accompanying drawings in which:

[0060] Figure 1 shows a perspective view of a roller assembly in accordance with the invention;

[0061] Figure 2 shows a front view of the roller assembly of Figure 1 ;

[0062] Figure 3 shows a top view of the roller assembly of Figure 1 ;

[0063] Figure 4 shows a side view of the roller assembly of Figure 1 ;

[0064] Figure 5 shows a sectioned side view of the roller assembly of Figure 1

[0065] Figure 6 shows a sectioned front view of the roller assembly of Figure 1 , in which rollers are lowered relative to a conveyor belt frame structure;

[0066] Figure 7 shows a sectioned front view of the roller assembly of Figure 1 , in which rollers are raised relative to a conveyor belt frame structure;

[0067] Figure 8 shows a detailed sectioned front view of a linear adjustment mechanism forming part of the roller assembly of Figure 1 ;

[0068] Figure 9 shows a perspective view of an example embodiment of a subframe used with, for example, the roller assembly of Figure 1 , subframe fitted with various components, including an adjustable link mechanism as shown in Figure 11 ;

[0069] Figure 10 shows a front view of the subframe of Figure 9;

[0070] Figure 11 shows a perspective view of an adjustable link mechanism used with roller assemblies having adjustable wing rollers;

[0071] Figure 12 shows a front view of the adjustable link mechanism of Figure 11 ; Figure 13 shows a side view of the adjustable link mechanism of Figure 11 ; and

[0072] Figure 14 shows a sectioned side view of the adjustable link mechanism of Figure 11.

[0073] DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

[0074] Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in several ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of "including," "comprising," or "having" and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms "mounted", "connected", "engaged" and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings and are thus intended to include direct connections between two members without any other members interposed therebetween and indirect connections between members in which one or more other members are interposed therebetween. Further, "connected" and "engaged" are not restricted to physical or mechanical connections or couplings. Additionally, the words "lower", "upper", "upward", "down" and "downward" designate directions in the drawings to which reference is made. The terminology includes the words specifically mentioned above, derivatives thereof, and words or similar import. It is noted that, as used in this specification and the appended claims, the singular forms "a," "an," and "the," and any singular use of any word, include plural referents unless expressly and unequivocally limited to one referent. As used herein, the term “include” and its grammatical variants are intended to be non-limiting, such that recitation of items in a list is not to the exclusion of other like items that can be substituted or added to the listed items.

[0075] Referring to the figures, in which like numerals indicate like features, a non-limiting example of a roller assembly in accordance with the invention is generally indicated by reference numeral 10. It will be appreciated that the roller assembly 10 may take different forms, for example, in the form of alignment or steering mechanisms for trough conveyors, return rollers and the like.

[0076] The alignment mechanisms detailed herein are of a type having outer or wing rollers configured as steering rollers. Central rollers (if present) typically do not play an active or fundamental role in the steering or alignment of the belt. In some implementations, the roller assemblies may comprise alignment mechanisms in which side rollers play a role as "activation rollers” and in which case a central roller plays an active or primary role in steering or alignment of the belt. The roller assembly 10 comprises a mounting frame 12 with end mounting brackets 14 which, in use, mount to a conveyor belt frame structure (not shown). In some cases, the mounting frame 12 is telescopically adjustable (in width) to facilitate use with various conveyor belt frame structure configurations.

[0077] The roller assembly 10 also comprises a substructure in the form of a subframe 16, which is pivotably mounted to the mounting frame 12 by means of a main pivot (or pivot post) 18.

[0078] A set of rollers (collectively referred to by reference numeral 20) is supported by the subframe 16. The set of rollers 20 operatively support a conveyor belt.

[0079] In the example shown in figures where the roller assembly 10 comprises a trough conveyor alignment mechanism, the set of rollers 20 typically comprises at least one, but preferably a pair of central rollers 24 and a pair of tapered steering or wing rollers 26. In some embodiments, only lateral portions of the steering rollers are tapered, while main body parts of the steering rollers are cylindrical. The wing rollers 26 are configured as steering rollers, as discussed more fully below. The central rollers 24 are arranged to the front and rear (in a direction of travel of the belt 22) of the main pivot 18. The wing rollers 26 are arranged on either side of the pair of central rollers 24. The wing rollers 26 are arranged at an angle 28 relative to the central rollers 24 such that a troughing angle 30 is defined (the troughing angle 30 is slightly smaller than the wing roller angle 28, due to the taper of the wing rollers 26). Edge portions of the belt 22 are carried and supported by the wing rollers 26. Since the set of rollers 20 is wholly supported by the subframe 16, the complete set 20 is therefore pivotable about the main pivot 18. As is known in the art, if the belt 22 becomes misaligned in use, one edge of the belt 22 will ride up one of the wing rollers 26 and the other edge of the belt 22 will ride down the opposite wing roller 26. Since the wing rollers 26 are tapered, this puts an uneven force on the two wing rollers 26 which causes a moment about the main pivot 18, causing the subframe 16 to pivot or swing on the main pivot 18. This, in turn, causes the roller assembly 10 (and in particular, the steering or wing rollers 26) to steer the belt 22 back to a central position in which the forces on the wing rollers 26 are substantially equalised and the subframe 16 is substantially perpendicular to the length or direction of travel of the belt 22.

[0080] The roller assembly 10 further comprises a linear adjustment mechanism 300 which is incorporated in the main pivot 18, which therefore allows linear displacement of the subframe 16 relative to the mounting frame 12 while allowing the subframe 16 still to pivot relative to the mounting frame 12 about the main pivot 18. More particularly, though not necessarily exclusively, the linear adjustment mechanism 300 comprises an automated or automatic linear adjustment mechanism (in other words, not actuated by hand). The automated linear adjustment mechanism typically takes the form of a mechanical actuator, a mechatronic actuator, a hydraulic actuator, a pneumatic actuator or a linear electric actuator.

[0081] The embodiment shown in the figures comprises a mechanical actuator in the form of a power screw arrangement 302, driven by a motor 304, such as an electric, hydraulic or pneumatic motor.

[0082] The power screw arrangement 302 comprises a main body 306 which is fixed to, or which extends from, the mounting frame 12. A substantially vertically extending threaded shaft 308 is (directly or indirectly) supported by the main body 306 and driven by the motor 304. The threaded shaft 308 is inhibited from being displaced linearly relative to the main body 306.

[0083] A threaded sleeve 310 is received on the threaded shaft 308. The threaded sleeve 310 is also supported by the main body. The threaded sleeve 310 has a linearly extending slot 312 through an outer surface thereof. A pin 314 which is fixed to the main body extends into the slot 312. Interaction between the slot 312 and the pin 314, allows the sleeve to be displaced linearly relative to the main body 306, but inhibits it from rotating relative to the main body 306. In this way, when the threaded shaft 308 is driven, the sleeve 310 is displaced linearly (upwards or downwards, depending on the direction in which the threaded shaft 308 is driven).

[0084] An outer sleeve 316 is supported on the threaded sleeve 310 by means of a bearing 318, which allows the outer sleeve 316 to pivot relative to the threaded sleeve 310. The outer sleeve 316 and threaded sleeve 310 therefore define between them, the main pivot 18.

[0085] The outer sleeve 316 may therefore form part of or be directly fixed to the subframe 16.

[0086] Use of the automated linear adjustment mechanism allows real time height adjustments of the roller assembly 10. This may, advantageously, occur while the conveyor is operation. The automated linear adjustment mechanism may typically be controlled by a remote (wired or wireless) controller, such as a control panel, tablet computer, or the like. In some cases, input, for example relating to tension in the belt or a load on the roller assembly 10 may be used to make adjustments to the vertical position of the roller assembly 10.

[0087] It will be appreciated that the linear adjustment mechanism 300 as detailed herein may be incorporated with return roller assemblies (not shown) without deviating from the spirit and scope hereof.

[0088] In the embodiment shown in the figures, each wing roller 26 is mounted proximally relative to the subframe 16 (therefore towards a centre of the alignment mechanism or towards the main pivot 18) in outward-facing cantilevered fashion. Therefore, an outside-facing end (distal end) 32 of each wing roller 26 is unsupported and therefore, the wing rollers 26 are only supported relative to the subframe 16 at their lower or proximal ends 34. It will readily be appreciated that arranging the wing rollers in cantilevered fashion: i. reduces an overall footprint of the subframe 16, which makes fitting of hoods and other structures relative to the conveyor structure more viable, whilst reducing the probability of contact with, catching or pinching of persons or equipment proximate the conveyor structure; ii. potentially reduces the overall mass of the subframe 16 (due the removal of outer support structures provided for supporting the outside-facing ends 32 of the wing rollers 26); iii. removes heavy and outwardly projecting support and adjustment mechanisms thereby making the distal ends of subframe 16 and / or wing rollers 26 lighter (the weight distribution of the alignment mechanism is therefore shifted towards the axis of rotation [the main pivot 18]); and iv. reduces a rotational inertia of the subframe 16 and set 20.

[0089] The present inventor has found that a reduction in rotational inertia as aforementioned improves the ability of the roller assembly 10 to steer the belt when compared to prior art alignment mechanisms 10 not utilising such cantilevered arrangements. More particularly, a reduced rotational inertia facilitates a quicker pivoting response of the roller assembly 10 through its alignment arc. This results in a more responsive, quicker and more accurate reaction to misalignments (even slight misalignments) of the belt 22, which enhances steering and trackability. Put differently, a lower rotational inertia requires a lower moment about the main pivot 18 (caused by the unbalanced forces transferred to the wing rollers 26 as aforementioned) to steer the belt back to a substantially central position.

[0090] As discussed in more detail below, the embodiments shown in the figures have wing rollers 26 which are pivotably adjustable relative to the subframe 16. That said, it will be appreciated that the present disclosure is not limited to alignment mechanisms 10 with such pivotably adjustable wing rollers 26, and therefore also extends to configurations in which the wing rollers 26 are fixed in position relative to the subframe 16. Such a configuration is not shown in the figures nor discussed in more detail herein.

[0091] The pivotable adjustment of the wing rollers 26 is provided for, since not all trough conveyors or belts have the same configuration - that is - troughing angles 30 of different conveyor arrangements may differ. An angle adjustment mechanism 36 is incorporated into the support structure with which the wing roller 26 is supported in cantilevered fashion relative to the subframe, 16 for this purpose. The angle adjustment mechanism 36 therefore allows adjustment of the wing roller angle 28 which, in turn, results in an adjustment of the troughing angle 30. The angle adjustment mechanism 36 therefore facilitates adjustment of the wing rollers 26 in the direction of the arrow 38. The angle adjustment mechanism 36 comprises a tubular bracket 40 with a central bore within which a proximal portion of a shaft 44 of the wing roller 26 is received. At least one, but typically two grub screws 46 are used to fix the shaft 44 relative to the tubular bracket 40. The fit between the central bore and the shaft 44 is relatively fine or tight.

[0092] The tubular bracket 40 is mounted relative to the subframe 16 by means of a first pivot 48. More particularly, the first pivot 48 is located towards a first end 50, that is, a distal or top end, of the tubular bracket 40. The first pivot 48 attaches to a plate which forms part of the subframe 16. The tubular bracket 40 may therefore pivot about the first pivot 48 relative to the subframe 16.

[0093] The angle adjustment mechanism 36 furthermore comprises an adjustable link mechanism 54, which is pivotably fixed towards a second end 56, that is a proximal or lower end, of the tubular bracket 40 by means of a second pivot 58. The adjustable link mechanism 54 is furthermore supported relative to the subframe 16 (and more particularly, the plate) by means of a third pivot 60. The adjustable link mechanism 54 therefore extends between the second end 56 of the tubular bracket 40 and the subframe 16. The adjustable link mechanism 54 can adjust a distance between the second and third pivots (58, 60). An “effective length” of the adjustable link mechanism 54 defined between the second and third pivots (58, 60) is therefore adjustable. Since the relative locations of the first and third pivots (48, 60) are fixed (both are fixed relative to the subframe 16), adjusting the effective length causes the tubular bracket 40, and therefore the wing roller 26, to pivot about the first pivot 48.

[0094] In some example embodiments, the adjustable link mechanism 54 takes the form of an automated linear actuator. The automated linear actuator may take the form of a linear hydraulic actuator, comprising a piston and cylinder arrangement (as shown), a linear pneumatic actuator, comprising a piston and cylinder arrangement or a power screw arrangement. A drive circuit (not shown) is provided for controlling the automated linear actuator, causing the linear actuator to become actuated, thereby to adjust the adjustable link mechanism and in turn, the wing rollers 26.

[0095] Due to the configuration of the angle adjustment mechanism 36, the wing roller angle 28 can be adjusted between about zero degrees and about 65 degrees and may therefore be adjusted to any angle between (and including) those extremities. It will be appreciated that this represents a relatively large range of angular adjustment (compared to ranges of adjustment of some prior art alignment mechanisms). This large range of angular adjustments and the ability to make fine or minor angular adjustments within said range provide important benefits and lend functionality to the roller assembly 10: i. by being adjustable to about 0 degrees, the roller assembly 10 can be packaged very compactly, which eases transportability; ii. a wide range of troughing angles 30 are now achievable with a single roller assembly 10, which removes the need to provide different roller assembly 10 models for different ranges of troughing angle, removes the need to custom-manufacture alignment mechanisms 10 to order and enables end-users to keep fewer stock or spare items; iii. fine adjustments (in the order of one or two degrees) are sometimes required to enhance the functionality and effectiveness of the alignment mechanism.

[0096] Furthermore, the automatic adjustability of the adjustable link mechanism 54 enables remote adjustment of the wing rollers 26, without the need for an artisan or mechanic physically to make any adjustments. As a result, adjustment of the wing rollers 26 may be done while the conveyor is in use. This also means that incremental and fine adjustments may be made continuously to ensure proper interaction between the rollers and the belt. Data received from hardware such as load cells or belt tension monitors may serve as inputs to the automatically adjustable linear actuators.

[0097] It will be appreciated that the wing rollers 26 are arranged to pivot in a plane which is substantially perpendicular to a plane in which the subframe 16 is allowed to pivot about the main pivot 18. The wing rollers 26 are arranged to pivot in a plane which is substantially perpendicular or vertical relative to the surface on which the conveyor is supported, whereas the subframe pivots in a plane which is substantially horizontal relative to the surface on which the conveyor is supported (assuming the belt extends substantially vertically).

[0098] In some cases, the automatic adjustable link mechanism 54 may include a manual override function with which the adjustable link mechanism 54 may be adjusted manually. This may be useful in cases where power supply to the automatic adjustable link mechanism 54 falls away or is interrupted, or when an actuator of the automatic adjustable link mechanism 54 fails.

[0099] Reference is now made to figures 11 to 14, which show an example embodiment of an adjustable link mechanism 400. In this example, the adjustable link mechanism 400 is manually adjusted. However, it will be appreciated that the adjustable link mechanism 400 can easily be adapted to be automatically adjustable.

[0100] The adjustable link mechanism 400 comprises an outer body 402 and a telescopic inner body 404. The second pivot 58 is located towards a first end 406 of the inner body 404, while the third pivot 60 is located on the outer body 402. In use, the telescopic inner and outer bodies (402, 404) are inhibited from rotating relative to each other, for example, due to them being fixed to external components. The adjustable link mechanism 400 also comprises a threaded central shaft 410 which, towards a second end 408 thereof, and relative to a second end 418 of the outer body 402, comprises a driving head 412. The central shaft 410 and driving head 412 operatively rotate together, and relative to the telescopic inner and outer bodies (402, 404). A lead nut 414 is fixed to a second end 416 of the inner body 404 and has in inner thread which cooperates with thread of the shaft 410. The lead nut 414 is therefore received on the central shaft 410, and operatively located within the telescopic bodies (402, 404). Since the lead nut 414 is fixed to the inner body 404, it too, does not operatively rotate. When the driving head 412 is driven to rotate, the central shaft 410 therefore rotates relative to the lead nut, causing same to be displaced along the central shaft 410. This, in turn, causes the inner body 404 to be displaced relative to the outer body 402. An endcap 420 with a central opening is received over the second end 416 of the outer body 402 and fixed thereto. The endcap 420 retains the driving head 412 and therefore central shaft 410 in position within the telescopic bodies (402, 404).

[0101] It will be appreciated that the inner body 404 may be received within the outer body 402 with a close tolerance, which may inhibit ingress of debris there in between. Furthermore, the endcap 420 may inhibit ingress of debris from the second end of the outer body 402. An enclosure is therefore formed around the threaded components of the adjustable link mechanism 400 which protects the threaded components from dust and debris buildup that could impede smooth operation. The design also allows for adjustment using a wrench on the driving head 412, enabling precise angular adjustments of the wing rolls. It will be appreciated that the adjustable link mechanism 400 may be used with a roller assembly 10 having a linear adjustment mechanism 300, or with other roller assemblies without such linear adjustment mechanisms. The adjustable link mechanism 400 may also form a standalone aspect of the invention.

[0102] Figures 9 and 10 show a subframe 16 specifically adapted for use with the adjustable link mechanism 400.

[0103] It will be appreciated that the above description only provides one preferred example embodiment of the conveyor roller assembly 10 and that there may be many variations without departing from the spirit and / or the scope of the invention.

[0104] In some implementations, a single central roller rather than two central rollers may be provided. In alternative implementations, the one or more central rollers may be replaced all together with one or more bearing plate(s) manufactured from a low-friction material (such as a polished metal or a low-friction polymer) (here it should again be noted that the central rollers in this type of alignment mechanism do not play an instrumental role in the steering of the belt).

[0105] A configuration where the central roller(s) 24 is not pivotable relative to the mounting frame 12 or about the main pivot 18 could also theoretically be possible (especially, given that the central roller 24 is not configured as a steering roller).

[0106] Examples where no central rollers are present are also provided for.

[0107] Furthermore, different belt widths, conveyor speeds and load weights will determine the physical characteristics and strength required of the various components, including the angle adjustment mechanism. The invention is not therefore limited to the embodiments depicted in the drawings.

[0108] It will be appreciated that each of the alignment mechanisms discussed above, the steering or wing rollers are arranged in-line with the main pivot 18. As a result, the tracking mechanisms may be used to align a belt travelling in a forwards or reverse direction.

[0109] It will be appreciated that the above description only provides example embodiments of particular aspects of the invention and that there may be many variations without departing from the spirit and / or the scope of the invention.

[0110] It will be easily understood from the present description that the particular features of the present invention, as generally described and illustrated in the figures, can be arranged and designed according to a wide variety of different configurations. In this way, the description of the present invention and the related figures are not provided to limit the scope of the invention but simply represent selected embodiments.

[0111] The skilled person will understand that the technical characteristics of a given embodiment can in fact be combined with characteristics of another embodiment, unless otherwise expressed or it is evident that these characteristics are incompatible. Also, the technical characteristics described one embodiment can be isolated from the other characteristics of this embodiment unless otherwise expressed.

Claims

CLAIMS1. A roller assembly, comprising: a mounting frame for operatively mounting the roller assembly to a conveyor frame; a substructure, pivotably mounted to the mounting frame by means of a main pivot; a set of rollers supported by the substructure; and a linear adjustment mechanism incorporated in the main pivot to allow linear adjustment of the substructure relative to the mounting frame.

2. The roller assembly according to any one of the preceding claims, wherein the linear adjustment mechanism comprises an automated linear adjustment mechanism.

3. The roller assembly according to claim 2, wherein the automated linear adjustment mechanism comprises one of: i) a mechanical actuator; ii) a mechatronic actuator; iii) a hydraulic actuator; iv) a pneumatic actuator; and v) a linear electric actuator.

4. The roller assembly according to claim 3, wherein the mechanical actuator comprises a power screw arrangement, driven by a motor to adjust the substructure linearly relative to the mounting frame.

5. The roller assembly according to claim 4, wherein the power screw arrangement comprises: a main body; a threaded shaft which is driven by the motor and supported relative to the main body; a threaded sleeve received on the threaded shaft, the threaded sleeve supported by the main body and comprising a slot through which a pin from the main body extends, with operative interaction between the pin and the slot inhibiting rotation of the sleeve relative to the main body; an outer sleeve pivotably supported by the threaded sleeve, wherein the substructure forms part or is supported by the outer sleeve.

6. The roller assembly according to claim 1 , wherein the set of rollers comprises at least a first and second steering rollers.

7. The roller assembly according to claim 6, wherein at least a distal portion of each of the first and second steering rollers is tapered.

8. A roller assembly, comprising: a mounting frame for operatively mounting the roller assembly to a conveyor frame; a substructure, pivotably mounted to the mounting frame by means of a main pivot; a set of rollers supported by the substructure, the set of rollers comprising at least a first and second steering rollers, wherein each steering roller is mounted to the substructure by means of an angle adjustment mechanism such that each steering roller is pivotablyadjustable relative to the substructure, the angle adjustment mechanism comprising an automated linear actuator.

9. The roller assembly according to claim 8, wherein each angle adjustment mechanism comprises a tubular bracket with a bore within which a shaft of the respective steering roller is operatively received and retained in cantilever fashion.

10. The roller assembly according to claim 9, wherein the shaft of the respective steering roller is fixed relative to the tubular bracket by means of at least a first grub screw.

11. The roller assembly according to claim 9, wherein, towards a first end thereof, the tubular bracket is pivotably mounted to the substructure by means of a first pivot.

12. The roller assembly according to claim 11 , wherein the automated linear actuator extends between a second end of the tubular bracket and the substructure, wherein the automated linear actuator is pivotably fixed to both the tubular bracket and the substructure by means of a second and third pivot, respectively.

13. The roller assembly according to claim 12, wherein an effective length of the automated linear actuator is adjustable, to pivot the tubular bracket about the first pivot to adjust an angle of the tubular bracket relative to substructure.

14. The roller assembly according to claim 12, wherein the automated linear actuator is selected from the list comprising: i) a linear hydraulic actuator, comprising a piston and cylinder arrangement; ii) a linear pneumatic actuator, comprising a piston and cylinder arrangement; iii) a power screw arrangement.

15. The roller assembly according to claim 8, wherein each steering roller is adjustable between about 0 degrees and 65 degrees relative to a plane in which the central rollers are arranged.

16. The roller assembly according to claim 8, wherein at least a distal portion of each of the first and second steering rollers is tapered.

17. The roller assembly according to claim 8, wherein each steering roller is configured to be pivotably adjustable in a plane substantially perpendicular to a plane in which the substructure is pivotable about the main pivot.

18. The roller assembly according to claim 8, further comprising a linear adjustment mechanism incorporated in the main pivot to allow linear adjustment of the substructure relative to the mounting frame.

19. The roller assembly according to claim 18, wherein the linear adjustment mechanism comprises an automated linear adjustment mechanism, selected from the list comprising: i) a mechanical actuator; ii) a mechatronic actuator; iii) a hydraulic actuator; iv) a pneumatic actuator; and v) a linear electric actuator.

20. The roller assembly according to claim 19, wherein the mechanical actuator comprises a power screw arrangement, driven by a motor to adjust the substructure linearly relative to the mounting frame, the power screw arrangement comprising: a main body; a threaded shaft which is driven by the motor and supported relative to the main body; a threaded sleeve received on the threaded shaft, the threaded sleeve supported by the main body and comprising a slot through which a pin from the main body extends, interaction between the pin and the slot inhibiting rotation of the sleeve relative to the main body; and an outer sleeve pivotably supported by the threaded sleeve, wherein the substructure forms part or is supported by the outer sleeve.

21. The roller assembly according to claim 1 or claim 8, wherein the set of rollers includes at least a first central roller.

22. The conveyor alignment mechanism according to claim 21 , comprising a first and a second central roller arranged on opposite sides of the main pivot.

23. A conveyor, comprising: a main conveyor frame; a roller assembly according to claim 1 or 8 mounted to the main conveyor frame; and a belt supported at least partially on the conveyor alignment mechanism.

24. A roller assembly, comprising: a mounting frame for operatively mounting the roller assembly to a conveyor frame; a substructure, pivotably mounted to the mounting frame by means of a main pivot; and a set of rollers supported by the substructure, the set of rollers comprising at least a first and second steering rollers, wherein each steering roller is mounted to the substructure by means of an angle adjustment mechanism such that each steering roller is pivotably adjustable relative to the substructure, each angle adjustment mechanism associated with an adjustable link mechanism which extends between said angle adjustment mechanism and the substructure, to pivotably adjust the respective steering roller, wherein, the adjustable link mechanism comprises: an inner and outer body arranged in telescopically adjustable fashion; a threaded shaft extending within the outer body, the threaded shaft comprising, towards a second end thereof, a driving head, which driving head protrudes from the second body; and a lead nut which is fixed to the inner body and arranged on the threaded shaft.

25. The roller assembly according to claim 24, further comprising a first pivot arrangement located towards a first end of the inner body, and a second pivot arrangement located on the outer body.

26. The roller assembly according to claim 24, wherein an endcap with a central opening is received over a second end of the outer body and fixed thereto, the endcap configured for retaining the driving head and central shaft in position relative to the telescopic bodies.

27. The roller assembly according to claim 24, further comprising a linear adjustment mechanism incorporated in the main pivot to allow linear adjustment of the substructure relative to the mounting frame.

28. An adjustable link mechanism comprising: an inner and outer body arranged in telescopically adjustable fashion; a threaded shaft extending within the outer body, the threaded shaft comprising, towards a second end thereof, a driving head, which driving head protrudes from the second body; and a lead nut which is fixed to the inner body and arranged on the threaded shaft.

29. The adjustable link mechanism according to claim 28, further comprising a first pivot arrangement located towards a first end of the inner body, and a second pivot arrangement located on the outer body.

30. The adjustable link mechanism according to claim 28, wherein an endcap with a central opening is received over a second end of the outer body and fixed thereto, the endcap configured for retaining the driving head and central shaft in position relative the telescopic bodies.

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