Screening bucket assembly

Abstract

The present invention in one aspect is broadly directed to a screening bucket assembly (10) comprising: 1. a support structure (12) adapted for mounting to a loader (9); 2. a screening bucket (14) mounted to the support structure (12) for rotation about a rotational axis (16) of the screening bucket (14); 3. a linear actuator (18) connected to the support structure (12) and operatively coupled to the screening bucket (14) for actuation in: (a) a supplementary collection mode wherein the linear actuator (18) drives the screening bucket (14) in an upward tilting motion about the rotational axis (16) enhancing collection of solid material within the bucket (14); (b) a screening mode wherein the linear actuator (18) drives the screening bucket (14) in rotation about the rotational axis (16) for screening of the solid material collected within the bucket (14).

Description

SCREENING BUCKET ASSEMBLYTechnical Field

[0001] The present invention is broadly directed to a screening bucket assembly. The invention is also broadly directed to a method of screening solid material.Background of Invention

[0002] Figure 1 illustrates a conventional vehicle V carrying the initial applicant’s screening device SD in place of a conventional excavator bucket. The screening device SD comprises a bucket B and a support structure SS by which the bucket is connected to the vehicle V. The support structure SS takes the form of a yoke and the bucket B is rotatable between arms of the yoke about a horizontal transverse axis. The bucket B is shown in a collecting orientation in which the vehicle V is advanceable to drive the bucket B into a pile P of material to collect material in the bucket B. The bucket B comprises an inlet edge IE and a wall arrangement WA that extends rearwardly from the inlet edge and upwardly around the axis about which the bucket B rotates. The wall arrangement WA comprises a screen portion SP.

[0003] After collecting material, the vehicle is moved to a site at which the fines are to be deposited. The bucket B is then rotated in one direction to cause the fines to fall through the screen portion SP whilst retaining the coarser material in the bucket B. The vehicle can then be moved to another site before rotating the bucket in the opposite direction to dump the coarser material. This known screening device SD is the subject of the applicant’s International patent publication No. WO 03 / 101597.

[0004] It is to be understood that this admission of prior art is not to be taken as an acknowledgement or concession that this prior art forms part of the common general knowledge in Australia or elsewhere.Summary of Invention

[0001] According to a first aspect of the present invention there is provided a screening bucket assembly comprising:a support structure adapted for mounting to a loader;a screening bucket mounted to the support structure for rotation about a rotational axis of the screening bucket;a linear actuator connected to the support structure and operatively coupled to the screening bucket for actuation in:(a) a supplementary collection mode wherein the linear actuator drives the screening bucket in an upward tilting motion about the rotational axis enhancing collection of solid material within said bucket;(b) a screening mode wherein the linear actuator drives the screening bucket in rotation about the rotational axis for screening of the solid material collected within said bucket.

[0002] Preferably the linear actuator includes one of a pair of hydraulically actuated cylinders operatively coupled to the screening bucket at respective of opposing ends of the screening bucket. More preferably each of said hydraulic cylinders is double acting and connected to the screening bucket via a crank arrangement enabling complete rotation of said bucket during actuation of the hydraulic cylinders in a reciprocating action in the screening mode. Even more preferably each of said hydraulic cylinders in either the supplementary collection mode or the dumping mode is actuated for movement in an outward or inward direction only corresponding to tilting of the screening bucket in respective of the upward or downward tilting motions.

[0003] Preferably the screening bucket includes a digging part of a solid construct, and a screening part connected to the digging part and including screening apertures for screening of solid material collected in the screening bucket via the digging part. More preferably the digging part includes a forward-most edge configured for digging of the solid material in a primary collection mode, said forward-most edge at least in part defining a bucket opening for entry of the solid material into the screening bucket. Even more preferably the screening part is shaped in the form of a partly enclosed barrel having an opposing pair of end wall panels. Still more preferably the screening bucket includes a throat part formed between the digging part and an opposing surface of the screening part, said throat part formed as a continuation of the bucket opening and configured for admission of the collected solid material within the screening bucket.

[0004] According to a second aspect of the invention there is provided a screening bucket assembly comprising:a support structure adapted for mounting to a loader;a screening bucket mounted to the support structure for rotation about a rotational axis of the screening bucket;a linear actuator connected to the support structure and operatively coupled to the screening bucket for actuation in a supplementary collection mode wherein the linear actuator drives the screening bucket in an upward tilting motion about the rotational axis enhancing collection of solid material within said bucket;a rotational actuator connected to the support structure and operatively coupled to the screening bucket for actuation in a screening mode wherein said rotational actuator drives the screening bucket in rotation about the rotational axis for screening of the solid material collected within said bucket.

[0005] Preferably the linear actuator includes a hydraulically actuated ram at one end connected to the support structure and at an opposite end arranged to cooperate for releasable contact with the screening bucket to drive it in the upward tilting motion in the supplementary collection mode. More preferably the screening bucket includes a rigid contact configured for abutment with a corresponding rigid contact associated with the opposite end of the hydraulic ram wherein said mutual abutment effects the upward tilting motion in the supplementary collection mode. Even more preferably the linear actuator includes an alignment arrangement configured to (i) align the rigid contacts for tilting of the screening bucket in the supplementary collection mode, and (ii) displace the rigid contact associated with the hydraulically actuated ram relative to the corresponding contact of the bucket thereby permitting rotation of the screening bucket in the screening mode and downward tilting of said bucket in the dumping mode. Still more preferably the alignment arrangement includes a hydraulically-actuated alignment cylinder at one end operatively coupled to the support structure, and at an opposite end coupled to the rigid contact associated with the hydraulically actuated ram.

[0006] Preferably the rotational actuator includes a rotational drive mounted to the support structure at one or both ends of the screening bucket for rotation of said bucket. More preferably the rotational drive includes a hydraulic motor coupled to ashaft of the screening bucket aligned with its rotational axis and configured for rotation of said bucket in the screening mode. Even more preferably in a dumping mode the rotational actuator drives the screening bucket in a downward tilting motion thereby discharging retained solid material from the screening bucket. Still more preferably the rotational actuator is configured wherein the rotation in the screening mode is in an opposite direction to the downward tilting motion in the dumping mode.

[0007] According to a third aspect of the invention there is provided a method of screening solid material, said method comprising:providing a screening bucket assembly including:(a) a support structure adapted for mounting to a loader,(b) a screening bucket mounted to the support structure for rotation about a rotational axis of the screening bucket,(c) a linear actuator connected to the support structure and operatively coupled to the screening bucket;in a supplementary collection mode, actuating the linear actuator thereby driving the screening bucket in an upward tilting motion about the rotational axis enhancing collection of solid material within said bucket;in a screening mode, driving the screening bucket in rotation about the rotational axis for screening of the solid material collected within said bucket.

[0008] Preferably in a primary collection mode the screening bucket is configured to remain stationary relative to the support structure without actuation of the linear actuator whilst the screening bucket is moved in a forward motion via the loader for collection of solid material within the screening bucket. More preferably in the supplementary collection mode the screening bucket is upon actuation of the linear actuator configured to be driven in the upward tilting motion thereby enhancing collection of the solid material within said bucket. Even more preferably the screening bucket is advanced in a forward motion via the loader to promote collection of solid material whilst the linear actuator drives the screening bucket in the upward tilting motion.

[0009] Preferably in a dumping mode the linear actuator drives the screening bucket in a downward tilting motion thereby discharging retained solid material fromthe screening bucket via the throat part and associated bucket opening. More preferably in the supplementary screening mode the linear actuator is configured wherein the upward tilting motion in the supplementary collection mode is in the same direction as the rotation of the screening bucket in the screening mode.Brief Description of Drawings

[0010] In order to achieve a better understanding of the nature of the present invention a preferred embodiment of a screening bucket assembly according to both aspects of the invention will now be described, by way of example only, with reference to the accompanying drawings in which:Figure 1 is a schematic illustration of a prior art screening device and conventional vehicle;Figure 2 is a perspective view of an embodiment of a screening bucket assembly according to a first aspect of the invention shown together with a loader;Figures 3a to 3g are schematic illustrations of operation of the screening bucket assembly of all aspects of the invention in primary and supplementary collection modes together with screening and dumping modes;Figure 4 is a side elevational view of the screening bucket assembly of the embodiment of figure 2 of the first aspect shown without the loader;Figure 5 is a perspective view of an embodiment of a screening bucket assembly according to a second aspect of the invention shown together with a loader;Figure 6 is a side elevational view of the screening bucket assembly of the embodiment of figure 5 of the second aspect shown without the loader;Figure 7 is a side elevational view of part of the screening bucket assembly of the embodiment of figures 5 and 6 of the second aspect;Figure 8 is an enlarged side elevational view of the linear actuator of the screening bucket assembly of the embodiment of figures 5 to 7 of the second aspect;Figure 9 is a perspective view of the screening bucket assembly of the embodiment of figures 5 to 8 of the second aspect depicting the linear actuator in operation in the supplementary collection mode;Figure 10 is a perspective view of the screening bucket assembly of the embodiment of figures 5 to 9 of the second aspect showing the rotational actuator in operation in the screening mode with displacement of the linear actuator.Detailed Description

[0011] As seen in figures 2 and 3, there is an embodiment of a screening bucket assembly 10 of a first aspect of the invention. In this embodiment the screening bucket assembly 10 broadly comprises:1. a support structure 12 adapted for mounting to a loader 9;2. a screening bucket 14 mounted to the support structure 12 for rotation about a rotational axis 16 of the screening bucket 14;3. a linear actuator 18 connected to the support structure 12 and operatively coupled to the screening bucket 14 for actuation in:(a) a supplementary collection mode wherein the linear actuator 18 drives the screening bucket 14 in an upward tilting motion about the rotational axis 16 enhancing collection of solid material within the bucket 14;(b) a screening mode wherein the linear actuator 18 drives the screening bucket 14 in rotation about the rotational axis 16 for screening of the solid material collected within the bucket 14.

[0012] Figure 3 is intended to schematically illustrate the various modes of operation of the screening bucket assembly 10 and its associated linear actuator 18. It is to be understood that the linear actuator 18 operates in the following modes: 1. the supplementary collection mode where the screening bucket 14 is driven via the linear actuator 18 in an upward tilting motion counterclockwise about the rotational axis 16 (see figures 3a and 3b);2. a screening mode where the linear actuator 18 drives the screening bucket 14 in rotation counterclockwise about the rotational axis 16 for screening of thesolid material 3 collected within the bucket 14 to provide undersize solid material 5 (see figures 3c to 3f);3. a dumping mode where the linear actuator 18 drives the screening bucket in a downward tilting motion in a clockwise direction thereby discharging oversize solid material 7 from the screening bucket 14 (see figure 4g).

[0013] In this embodiment the screening bucket 14 includes a digging part 20 of a solid construct, and a screening part depicted generally at 22 connected to the digging part 20. The screening part 22 includes screening apertures such as 24a and 24b for screening of solid material collected in the screening bucket 14 via the digging part 20. The digging part 20 includes a forward-most edge 26 having teeth such as 28a of a conventional construct configured for digging of the solid material in a primary collection mode, see for example figure 3a.

[0014] It is to be understood that in the primary collection mode the screening bucket 14 is configured to remain stationary relative to the support structure 12 without actuation of the linear actuator 18. The screen bucket 14 is moved in a forward motion via the loader 9 for collection of solid material within the screening bucket 14. In this embodiment the forward-most edge 26 of the digging part 20 at least in part defines a bucket opening 30 for entry of the solid material into the screening bucket 14. The screening part 22 is shaped in the form of a partly enclosed barrel having an opposing pair of end wall panels 32a and 32b. The screening bucket 14 also includes a throat part 34 formed between the digging part 20 and an opposing surface of the screening part 22. The throat part 34 is formed as a continuation of the bucket opening 30 and configured for admission of the collected solid material within the screening bucket 14.

[0015] Importantly in the supplementary collection mode the screening bucket 14 is upon actuation of the linear actuator 18 configured to be driven in the upward tilting motion. This action enhances or increases collection of the solid material already collected within the bucket in its primary collection mode. Generally, the screening bucket 14 is advanced in the forward motion via the loader 9 to promote collection of solid material whilst the linear actuator 18 drives the screening bucket 14 in the upward tilting motion. This is schematically represented in figures 3a and 3b.

[0016] The screening bucket 14 in the supplementary collection mode is typically tilted upward from between 30° to 60° relative to its initial horizontal disposition in the primary collection mode. It must be appreciated that this tilting motion is about the rotational axis 16 of the bucket 14 and is independent of any change in the angle of attack of the bucket 14 which is effected by the loader 9 tilting the support structure 12 and in turn the bucket 14 using existing articulating structures and hydraulic rams / cylinders coupled between the loader 9 and the support structure 16. It should be noted that the tilting motion required in the supplementary mode demands materially greater forces and torques be applied to the screening bucket 14 via the linear actuator 18 as compared to any conventional change in the angle of attack via existing articulating structures and hydraulic rams / cylinders.

[0017] In this embodiment the linear actuator 18 in a dumping mode drives the screening bucket 14 in the downward tilting motion. As seen in figure 3g this action is effective in discharging retained and oversize solid material 7from the screening bucket 14 via the throat part 34 and the associated bucket opening 30. In this embodiment the downward tilting motion in the dumping mode is clockwise and in an opposite direction to the upward tilting motion in the supplementary and screening modes.

[0018] As best seen in figure 4, the linear actuator 18 is in the form of a hydraulically-actuated cylinder at one end mounted to the support structure 12and at an opposite end operatively coupled to the screening bucket 14. In this construct the hydraulically-actuated cylinder 18 is one of a pair of cylinders located at respective of opposing ends of the screening bucket 14. Each of the hydraulic cylinders such as 18 is double acting and connected to the screening bucket 14 via a crank arrangement 36. The crank arrangement 36 enables rotation of the bucket 14 during actuation of the hydraulic cylinders such as 18 in a reciprocating action in the screening mode. Although not illustrated, it is to be understood that the crank arrangements such as 36 are angularly offset relative to one another wherein the reciprocating action of the hydraulic cylinders together ensures complete rotation of the screening bucket 14.

[0019] In this embodiment either or both of the hydraulic cylinders such as 18 is in the supplementary collection mode actuated for movement in an outward direction fortilting of the screening bucket in the upward tilting motion. It will be understood that the pair of hydraulic cylinders 18 are actuated in concert to effect this tilting motion. In the dumping mode the hydraulic cylinders 18alone or together are actuated for movement in an inward direction corresponding to tilting of the screening bucket 14 in the upward tilting motion. It is to be appreciated that depending on the orientation of the crank arrangement 36, upward tilting may likewise be effected by actuation of the hydraulic cylinder 18 in an inward direction whereas actuation of the hydraulic cylinder 18 in the outward direction provides downward tilting.

[0020] Figures 5 to 10 illustrate an embodiment of a screening bucket assembly 100 according to a second aspect of the invention. For ease of reference and in order to avoid repetition, like components of the embodiments of the first and second aspects will be designated with corresponding reference numerals wherein the second aspect has an additional “0”. For example, the screening bucket assembly of the second aspect is designated as 100 and its screening bucket as 140.

[0021] In this embodiment the screening bucket assembly 100 of the second aspect broadly comprises:1. a support structure 120 adapted for mounting to a loader 90;2. a screening bucket 140 mounted to the support structure 120 for rotation about a rotational axis 160 of the screening bucket 140;3. a linear actuator 180 connected to the support structure 120 and operatively coupled to the screening bucket 140 for actuation in a supplementary collection mode wherein the linear actuator 180 drives the screening bucket 140 in an upward tilting motion about the rotational axis 160 enhancing collection of solid material within the bucket 140;4. a rotational actuator depicted generally at 190 connected to the support structure 120 and operatively coupled to the screening bucket 140 for actuation in a screening mode wherein the rotational actuator 190 drives the screening bucket 140 in rotation about the rotational axis 160 for screening of the solid material collected within the bucket 140.

[0022] As best seen in figures 7 to 10, the linear actuator 180 of this embodiment of the second aspect includes a hydraulically actuated ram 195 at one end connectedto the support structure 120 and at an opposite end arranged to cooperate for releasable contact with the screening bucket 140. The screening bucket 140 includes a rigid contact 210 configured for abutment with a corresponding rigid contact 230 operatively coupled to the opposite end of the hydraulic ram 195. In this embodiment the rigid contact 210 is one of a pair of rigid contacts mounted to respective of the pair of side walls 320a and 320b of the screening bucket 14. It will be understood that actuation of the hydraulic ram 195 effects mutual abutment between the rigid contacts 210 and 230 wherein the screening bucket 140 is driven in the upward tilting motion in the supplementary collection mode. In this embodiment the linear actuator 180 includes an alignment arrangement 250 configured to (i) align the rigid contacts 210 / 230 for tilting of the screening bucket 140 in the supplementary collection mode (see figure 9), and (ii) displace the rigid contact 230 associated with the hydraulic ram 190 relative to the corresponding contact 210 of the bucket 140 (see figure 10). It will be understood that this relative displacement of the rigid contacts 210 / 230 permits rotation of the screening bucket 140 in the screening and downward tilting modes.

[0023] In this embodiment the alignment arrangement 250 includes a hydraulically-actuated alignment cylinder 270 at one end operatively coupled to the support structure 120, and at a opposite end operatively coupled to the rigid contact 230 of the hydraulic ram 190 via alignment actuating arm 290. The hydraulic alignment cylinder 270 is double acting wherein it effects pulling or pushing of the hydraulic ram contact 230 out of or into alignment with the bucket contact 210. As seen in figure 8, the rigid contact 210 of the screening bucket 140 includes a ramped surface 310 configured to deflect the rigid contact 230 from the rotating screening bucket 140 should the alignment arrangement 250 alone be ineffective in displacing the rigid contacts 210 / 230 from one another.

[0024] In this embodiment the hydraulic ram 195 incorporates or is supplemented by a hydraulic intensifier. The ram 195 in this form may include an intrascopic hydraulic cylinder having a hydraulic intensifier, see for example the applicant’s International publication No. WO2019 / 227146 the contents of which are incorporated herein by reference.

[0025] In this embodiment the rotational actuator 190 includes a rotational drive 330 mounted to the support structure 120 at both ends of the screening bucket 140 for rotation of the bucket 140. The rotational drive 330 is in the form of a hydraulic motor coupled to a shaft (not shown) of the screening bucket 140 aligned with its rotational axis 160. The rotational drive or hydraulic motor 330 is configured to rotate the screening bucket 140 in one direction in part or complete rotations in the screening mode. The hydraulic motor 330 is configured in a dumping mode to drive the screening bucket 140 in a downward tilting motion thereby discharging retained solid material from the screening bucket 140. It is to be understood that the downward tilting motion in the dumping mode is in the opposite direction to the rotation of the screening bucket 140 in the screening mode. Figure 3 although depicted in the context of the embodiment of the first aspect likewise extends or is applicable to this embodiment of the screening bucket assembly 100 in the second aspect where:1. the screening bucket 140 is driven into solid material for collection in the primary collection mode (see figure 3a);2. the screening bucket 140 is tilted in the upward motion via the linear actuator 180 in a counterclockwise direction in the supplementary collection mode (see figure 3b);3. the screening bucket 140 is rotated via the rotational drive 330 in the counterclockwise direction in the screening mode (see figures 3c to 3f);4. the screening bucket 140 is via the rotational drive 330 tilted downward in the clockwise direction discharging retained solid material in the dumping mode (see figure 3g).

[0026] In an embodiment of the third aspect of the invention there is a method of screening solid material. In the context of the embodiments of the first and second aspects of the invention, the method of this embodiment of the third aspect broadly comprises:1. providing a screening bucket assembly 10 or 100 including:(a) a support structure 12 or 120 adapted for mounting to a loader 90,(b) a screening bucket 14 or 140 mounted to the support structure 12 or 120 for rotation about a rotational axis 16 or 160 of the screening bucket 14 or 140,(c) a linear actuator 18 or 180 connected to the support structure 12 or 120 and operatively coupled to the screening bucket 14 or 140;2. actuating the linear actuator 18 or 180 thereby driving the screening bucket 14 or 140 in an upward tilting motion about the rotational axis 16 or 160 enhancing collection of solid material within the bucket 14 or 140;3. driving the screening bucket 14 or 140 in rotation about the rotational axis 16 or 160 for screening of the solid material collected within the bucket 14 or 140.

[0027] In all aspects of the invention it will be appreciated that the method and screening bucket assembly are typically deployed in collecting solid material from a stockpile of said material or unexcavated ground. In the primary mode of collection, the loader is conventionally driven forward wherein the bucket 14 or 140 traverses into the material until the loader runs out of power and / or traction. In the supplementary collection mode, the linear actuator 18 or 180 is actuated to drive the screening bucket 14 or 140 in the upward tilting motion to crowd or scoop additional material into the bucket 14 or 140. The screening bucket 14 or 140 whilst tilting upward in the supplementary mode may, where possible, be advanced forward by continued transversing movement of the loader 9 or 90. This action is effective in extra filling of the screening bucket 14 or 140 prior to screening of the collected material.

[0028] Now that embodiments of the various aspects of the screening bucket assembly and method of screening solid material have been described it will be apparent to those skilled in the art that they present the following advantages:1. the linear actuator is effective in providing adequate torque to effect the upward tilting motion of the screening bucket in its supplementary collection mode; 2. the linear actuator can be replicated at both ends of the screening bucket balancing forces and reducing torsional loads whilst it is tilted upward in the supplementary collection mode;3. in the first aspect the linear actuator and offset crank arrangements ensure complete rotation of the screening bucket in the screening mode;4. in the second aspect the linear actuator required to generate relatively high torques in the supplementary collection mode is designed and operated independent of the rotational drive requiring less demanding torques in at least the screening mode;5. the screening bucket assemblies and methods of screening under the additional influence of the linear actuator in the supplementary collection mode increase the volume of solid material collected.

[0029] Those skilled in the art will appreciate that the invention as described herein is susceptible to variations and modifications other than those specifically described. For example, the linear actuator in the first aspect may be limited to a single double-acting hydraulic cylinder associated with a crank arrangement at one end of the screening bucket only. In the first aspect the linear actuator in the screening mode may oscillate the screening bucket in a back and forth motion rather than the rotation in one direction of the preferred embodiment In the second aspect the linear actuator may be configured to cooperate with the screening bucket to effect its downward tilting motion in the dumping mode. The linear actuator of the second aspect may be biased wherein mutual contact of the rigid contacts is promoted without reliance on an alignment arrangement where instead the mutually abutting rigid contacts are shaped to permit rotation in the opposite direction in the form of a ratchet.

[0030] All such variations and modifications are to be considered within the scope of the present invention the nature of which is to be determined from the foregoing description.

Claims

CLAIMS1. A screening bucket assembly comprising:a support structure adapted for mounting to a loader;a screening bucket mounted to the support structure for rotation about a rotational axis of the screening bucket;a linear actuator connected to the support structure and operatively coupled to the screening bucket for actuation in:a supplementary collection mode wherein the linear actuator drives the screening bucket in an upward tilting motion about the rotational axis enhancing collection of solid material within said bucket;a screening mode wherein the linear actuator drives the screening bucket in rotation about the rotational axis for screening of the solid material collected within said bucket.

2. A screening bucket assembly as claimed in claim 1 wherein the linear actuator includes one of a pair of hydraulically actuated cylinders operatively coupled to the screening bucket at respective of opposing ends of the screening bucket.

3. A screening bucket assembly as claimed in claim 2 wherein each of said hydraulic cylinders is double acting and connected to the screening bucket via a crank arrangement enabling complete rotation of said bucket during actuation of the hydraulic cylinders in a reciprocating action in the screening mode.

4. A screening bucket assembly as claimed in either of claims 2 or 3 wherein each of said hydraulic cylinders in either the supplementary collection mode or the dumping mode is actuated for movement in an outward or inward direction only corresponding to tilting of the screening bucket in respective of the upward or downward tilting motions.

5. A screening bucket assembly as claimed in any one of the preceding claims wherein the screening bucket includes a digging part of a solid construct, and a screening part connected to the digging part and including screening apertures for screening of solid material collected in the screening bucket via the digging part.

6. A screening bucket assembly as claimed in claim 5 wherein the digging part includes a forward-most edge configured for digging of the solid material in a primary collection mode, said forward-most edge at least in part defining a bucket opening for entry of the solid material into the screening bucket.

7. A screening bucket assembly as claimed in claim 6 wherein the screening part is shaped in the form of a partly enclosed barrel having an opposing pair of end wall panels.

8. A screening bucket assembly as claimed in claim 7 wherein the screening bucket includes a throat part formed between the digging part and an opposing surface of the screening part, said throat part formed as a continuation of the bucket opening and configured for admission of the collected solid material within the screening bucket.

9. A screening bucket assembly comprising:a support structure adapted for mounting to a loader;a screening bucket mounted to the support structure for rotation about a rotational axis of the screening bucket;a linear actuator connected to the support structure and operatively coupled to the screening bucket for actuation in a supplementary collection mode wherein the linear actuator drives the screening bucket in an upward tilting motion about the rotational axis enhancing collection of solid material within said bucket;a rotational actuator connected to the support structure and operatively coupled to the screening bucket for actuation in a screening mode wherein said rotational actuator drives the screening bucket in rotation about the rotational axis for screening of the solid material collected within said bucket.

10. A screening bucket assembly as claimed in claim 9 wherein the linear actuator includes a hydraulically actuated ram at one end connected to the support structure and at an opposite end arranged to cooperate for releasable contact with the screening bucket to drive it in the upward tilting motion in the supplementary collection mode.

11. A screening bucket assembly as claimed in claim 10 wherein the screening bucket includes a rigid contact configured for abutment with a corresponding rigid contact associated with the opposite end of the hydraulic ram wherein said mutual abutment effects the upward tilting motion in the supplementary collection mode.

12. A screening bucket assembly as claimed in claim 11 wherein the linear actuator includes an alignment arrangement configured to (i) align the rigid contacts for tilting of the screening bucket in the supplementary collection mode, and (ii) displace the rigid contact associated with the hydraulically actuated ram relative to the corresponding contact of the bucket thereby permitting rotation of the screening bucket in the screening mode and downward tilting of said bucket in the dumping mode.

13. A screening bucket assembly as claimed in claim 12 wherein the alignment arrangement includes a hydraulically-actuated alignment cylinder at one end operatively coupled to the support structure, and at an opposite end coupled to the rigid contact associated with the hydraulically actuated ram.

14. A screening bucket assembly as claimed in any one of the preceding claims wherein the rotational actuator includes a rotational drive mounted to the support structure at one or both ends of the screening bucket for rotation of said bucket.

15. A screening bucket assembly as claimed in claim 14 wherein the rotational drive includes a hydraulic motor coupled to a shaft of the screening bucket aligned with its rotational axis and configured for rotation of said bucket in the screening mode.

16. A screening bucket assembly as claimed in either of claims 14 or 15 where in a dumping mode the rotational actuator drives the screening bucket in a downward tilting motion thereby discharging retained solid material from the screening bucket.

17. A screening bucket assembly as claimed in claim 16 wherein the rotational actuator is configured wherein the rotation in the screening mode is in an opposite direction to the downward tilting motion in the dumping mode.

18. A method of screening solid material, said method comprising:providing a screening bucket assembly including:(a) a support structure adapted for mounting to a loader,(b) a screening bucket mounted to the support structure for rotation about a rotational axis of the screening bucket,(c) a linear actuator connected to the support structure and operatively coupled to the screening bucket;in a supplementary collection mode, actuating the linear actuator thereby driving the screening bucket in an upward tilting motion about the rotational axis enhancing collection of solid material within said bucket;in a screening mode, driving the screening bucket in rotation about the rotational axis for screening of the solid material collected within said bucket.

19. A method as claimed in claim 18 where in a primary collection mode the screening bucket is configured to remain stationary relative to the support structure without actuation of the linear actuator whilst the screening bucket is moved in a forward motion via the loader for collection of solid material within the screening bucket.

20. A method as claimed in claim 19 where in the supplementary screening mode, the screening bucket is advanced in a forward motion via the loader to promote collection of solid material whilst the linear actuator drives the screening bucket in the upward tilting motion.

21. A method as claimed in any one of claims 18 to 20 where in a dumping mode the linear actuator drives the screening bucket in a downward tilting motion thereby discharging retained solid material from the screening bucket.

22. A method as claimed in claim 21 wherein the linear actuator is configured wherein the downward tilting motion in the dumping mode is in an opposite direction to the upward tilting motion in the supplementary collection mode.

23. A method as claimed in any one of claims 18 to 22 where the linear actuator is configured where in the upward tilting motion in the supplementary collection mode is in the same direction as the rotation of the screening bucket in the screening mode.

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