211240 PSL/MPN

ROTARY CYLINDRICAL BRUSH

TECHNICAL FIELD

The invention relates to a rotary cylindrical brush and an arrangement for mounting brush segments in such as brush.

BACKGROUND ART

Rotary cylindrical brushes are commonly used in road sweeping machines, attached to the front or rear of truck or tractor, or as a part of a specialized road sweeping machine comprising a combination of side brushes and at least one cylindrical brush. Rotary brushes can also be used in industrial power sweepers or be mounted on a front loader.

A common problem for rotary brushes, in particular for heavy duty brushes, is that the bristles must be replaced with regular intervals. A rotary cylindrical brush usually comprises a number of bristle units mounted axially on the outer periphery of a cylindrical frame. In order to replace one or more bristle units, the operator is required to remove an end plate, replace each old bristle unit with a new bristle unit, and replace the end plate. In order to perform this operation, it is usually required to remove the entire rotary brush from the machine to access the bristle units. An arrangement of the type is described in US 3 085 274.

The object of the invention is to provide an improved rotary cylindrical brush that solves the above problem and which simplifies the replacement worn or defective of brush segments.

DISCLOSURE OF INVENTION

The above problems have been solved by a method and an arrangement according to the appended claims.

According to a preferred embodiment, the invention relates to a holder with a rotary brush. The holder comprises a pair of opposed end supports arranged to support each end of a cylindrical frame structure to be mounted for rotation about a predetermined axis, in this case the central axis of the cylindrical frame. The said holder further comprises drive means mounted on at least one end support and connected to an internal portion of the frame structure. The drive means may comprise a suitable electric or hydraulic motor attached to a core portion of the frame structure and arranged to drive the rotary brush. An example of a suitable holder and drive means for this purpose is described in the international application WO 2004/063477. A drive means being arranged to drive the rotary brush may be provided of one or both ends of the cylindrical frame, depending on the area of use and the power requirement for driving the rotary brush. The frame structure comprises a plurality of bristle segments arranged to be mounted to the frame structure at circularly spaced locations, each of said bristle segments comprising a carrier strip extending along the frame structure. A plurality of guide means are mounted fixed on the frame structure, each guide means arranged to receive one of said carrier strips. Each carrier strip may have a cross- sectional shape arranged to cooperate with a guide means having a corresponding cross-section. The guide means are arranged to be open at one or both ends, in order to allow carrier strips to be mounted by sliding them into the guide means.

The holder comprises a fixed annular guide mounted adjacent at least one end of the frame structure. The radial extension of the annular guide is preferably equal to or greater than the radial extension of the guide means retaining the carrier strips. The annular guide may be located adjacent the open ends of said guide means, with an axial spacing of 0,5-3 cm between an inner surface of the annular guide and the end of an adjacent guide means. The annular guide may have an opening or gap exposing the open end of at least one guide means and being arranged to prevent relative

displacement between said carrier strips and said guide means. In order to replace a bristle segment, the desired guide means is indexed opposite the opening. The carrier strip is then displaced to slide out of the guide means through the opening, and a new carrier strip can be pushed into the guide means. During normal operation, the friction between the carrier strip and the guide means is sufficient to hold the brush segment in position.

By providing an annular guide at both ends of a frame structure having guide means open at both ends, the carrier strips may be replaced from either end of the holder. Alternatively an annular guide is provided on one side only. In the latter case the guide means open the same end of the frame structure as the annular guide. A fixed stop is then provided in the guide means at the opposite end of frame structure

According to one example, the annular guide comprises a flat guide surface with an opening in the form of a cut-out segment. The circumferential width of the segment is preferably equal to the width of one guide means. According to an alternative example, the circumferential width of the segment may be equal to the width of up to three guide means. The circumferential width is dependent on the expected maximum transverse loading on the brush. Hence, a heavy duty rotary brush would have an opening equal to the width of one guide means.

At least one section of the annular guide adjacent the opening is angled away from the end of the cylindrical frame structure. The angled section of the annular guide adjacent the opening is located facing the direction of rotation of the rotary brush. By providing an angled section of the annular guide adjacent both sides of the opening, the rotary brush may be rotated in both directions. The angled section of the annular guide may be arranged at an angle up to 15° from a radial plane through the annular guide, preferably at an angle of 5-10° from said radial plane. According to one example, the annular guide may be a flat guide plate provided with opposing and angled free end sections on either side of an opening in the guide plate.

The function of the annular guide is to retain the carrier strips in their respective guide means during rotation of the rotary brush. During rotation of the rotary brush, the bristles on a carrier strip may be subjected to an unexpected axial force, causing the carrier strip to be displaced axially relative to its guide means. The carrier strip will then come into contact with the fixed annular guide mounted on the holder. This is normally sufficient for preventing further displacement. However, should the carrier strip be subjected to an additional axial displacement, the end of the carrier strip will come into contact with the angled section of the annular guide. When this occurs the carrier strip will be pushed back towards or into its guide means. The same displacement will occur if a carrier strip has not been pushed all the way into its guide means, or in the case of a guide means open at both ends, if a carrier strip has been pushed too far into its guide means. In this way, neither the guide means nor the carrier strips will require individual fastening means to hold the carriers strips in position on the frame stricture. The distance between the outer end of the end of one guide means and the inner surface of the annular guide must be sufficient to allow rotation of the rotary brush. The maximum distance may be selected depending on length, diameter, rotational speed, number of guide means and expected loading on the rotary brush. For instance, a brush rotating at a relatively high speed may require a smaller distance in order to avoid imbalance caused by a displaced brush segment. Depending on the above factors, the distance may be selected up to about 3 cm, preferably between 0,5 and 2 cm.

The invention also relates to a rotary brush for use with a holder as described above. The rotary brush comprises a cylindrical frame structure to be mounted for rotation about a predetermined axis. A plurality of bristle segments are arranged to be mounted to the frame structure at circularly spaced locations, each of said bristle segments comprising a carrier strip extending along the frame structure. A plurality of guide means are fixed to the frame structure, wherein each guide means is arranged to receive one of said carrier strips. Each carrier strip comprises a series of bristles

attached to said strip and projecting generally radially outwardly from the cylindrical frame. The at least one guide means is arranged to be open in a direction parallel to the axis of the rotary brush at at least one end of the frame structure.

Depending on the type of holder carrying the rotary brush and the type of brush used, the guide means may either be arranged to be open at both ends of the frame structure, or to be open at one end of the frame structure and closed at the opposite end thereof.

According to one example, the carrier strips may be arranged to extend axially and in parallel along the frame structure. According to an alternative example, the carrier strips may be arranged to extend helically and equispaced along the frame structure. In the case of helical carrier strips, the pitch of the guide means may be selected up to 5 °, depending on the length of the frame structure. Preferably the relative circumferential angle between the ends of one guide means should not exceed 90°. As stated above, the frame structure may be provided with guide means being open at both ends. In this case, the holder is provided with an annular guide at both its supporting ends and the carrier strips may be replaced from either end of the rotary brush.

According to an alternative example, the frame structure may be provided with guide means being open at one end only. In this case, the holder may be provided with an annular guide at one supporting end, although a holder with two annular guides may also be used. Consequently the carrier strips may only be replaced from one end of the rotary brush, as the guide means are provided with a stop at one end. Also, if the rotary brush is to be rotated in one direction only, or if it has a main direction of rotation, the stops may be arranged in that end of the guide means towards which the guide strips is likely to be displaced by the centrifugal forces acting on the guide strips. The annular guide will operate as

intended according to the invention if the direction of rotation is reversed, or when the carrier strips are to be removed due to wear of the brush.

Finally, the invention relates to a vehicle provided with a holder with and rotary brush as described above.

BRIEF DESCRIPTION OF DRAWINGS

The invention will be described in detail with reference to the attached figures. It is to be understood that the drawings are designed solely for the purpose of illustration and are not intended as a definition of the limits of the invention, for which reference should be made to the appended claims. It should be further understood that the drawings are not necessarily drawn to scale and that, unless otherwise indicated, they are merely intended to schematically illustrate the structures and procedures described herein.

Figure 1 shows a schematic illustration of a vehicle carrying a rotary brush mounted in a holder according to a first embodiment of the invention;

Figure 2 shows a rotary brush mounted in a holder according to a first embodiment of the invention;

Figure 3 shows a rotary brush according to a first embodiment of the invention

Figure 4 shows a rotary brush according to Figure 3, with a bristle segment partially removed;

Figure 5 shows an end view of a rotary brush according to Figure 4;

Figure 6 shows an end section of a frame structure of a rotary brush according to Figure 3;

Figure 7 shows an a plan view of the frame structure of Figure 6;

EMBODIMENTS OF THE INVENTION

Figure 1 shows a schematic illustration of a rotary brush 1 and a holder according to a first embodiment of the invention attached to a work vehicle such as a front loader 2. The rotary brush 1 is provided with a standard attachment device 3, comprising a pair of adjustable attachment hooks 4. A suitable attachment device for this purpose is described in the international application WO 2004/063477. The hooks 4 are mounted to a tool carrier 5 using shackles 6 that allow the hooks 4 to be replaced to adapt the attachment device for a carrier 7 on the vehicle in question. The hooks 4 are hooked over corresponding holders 8 on an upper portion of the carrier 7, whereby a first support 9 at a lower portion of the attachment device 3 cooperates with a second support 10 at a lower portion of the carrier 7 on the vehicle. The tool carrier 5 is provided with a transverse beam 11 that can be positioned in a neutral position substantially at right angles to the longitudinal axis of the vehicle. The transverse beam 11 can be angled relative to the tool carrier 5 about a vertical axis X by means of a hydraulic cylinder 12.

The transverse beam 11 carries a rotary brush 1 , 13 via a load carrying first strut 14 and a torque transmitting second strut 15, which struts form a quadrilateral mechanism in the shape of a parallelogram. The first and second struts 14 and 15 can be pivoted about a first and a second pivot joint 16 and 17, respectively, located at the outer ends of the transverse beam 11. The first pivot joint 15 is located substantially vertically below the second pivot joint 16, wherein the pivot axes of both pivot joints are parallel to the longitudinal axis of the transverse beam 11. The ends of the respective first and second struts 14 and 15 facing away from the ends of the transverse beam 11 are attached to a first holder 20 at the outer end of the rotary brush via a third and a fourth pivot joint 18 and 19 respectively. The struts at each side of the ends of the rotary brush can be pivoted individually about their respective pivot axes. As described for the first and a second pivot joint 16 and 17, the third pivot joint 18 is located

substantially vertically below the fourth pivot joint 19. Said third pivot joint 18 is mounted in a bearing 21 relative to the holder 20, while the fourth pivot joint 19 is mounted with a relatively large play on an axle 22 on the holder 20. This arrangement allows the holder 20 to be angled relative to the first and second struts 14, 15, which in turn allows the longitudinal axis of the rotary brush to be angled in order to follow the transverse inclination of the ground. The rotary brush 13 is driven by a direct drive hydraulic motor mounted fixed relative to the holder 20 between the third and fourth pivot joints 18, 19 of the first and second struts 14, 15. In this case, a hydraulic motor is provided at each end of the rotary brush .

When the vehicle is placed on a flat, horizontal surface the attachment device 3, the tool carrier 5 and the transverse beam 11 are located in substantially the same plane. In this non-loaded position the third and fourth pivot joints 18, 19 of the first and second struts 14, 15 are substantially parallel to the longitudinal axis of the transverse beam 11. Any forces applied to the rotary brush during operation can then be transmitted through the struts 14, 15 directly rearwards to the tool carrier 5. Advantageously, the first and second struts 14, 15 can be angled slightly upwards in a direction away from the vehicle, in order to facilitate an upward displacement of the rotary brush if it should strike an edge or a similar obstacle.

The load carrying first strut 14 is provided with a torsion spring 24 arranged to balance the combined weight of the brush, the struts and the motors. This torsion spring 24 is preferably an adjustable coil spring. By adjusting the spring it is possible to set a desired contact pressure with the surface and/or to adjust for wear of the rotary brush. The load carrying first strut 14 is also provided with a folding support 25, against which the rotary brush 13 and its holder 20 may be rested when not mounted on a vehicle.

As shown in Figure 1 , the transverse beam 11 is also used for attaching a protective cover 26 mounted around part of the outer circumference of the rotary brush 13. The transverse beam 11 is provided with stops 27 at its

outer ends. The stops 27 are located above each load carrying first strut 14 in order to prevent the strut from contacting the protective cover 26 should the rotary brush be displaced upwards by an obstacle. The stops 27 can be resilient to brake any undesired movement of the said first strut 14. The holder 20 comprises a fixed annular guide 28 mounted on the holder adjacent at least one end of the rotary brush 13. The radial extension of the annular guide from the central holder 20 is preferably equal to or greater than the radial extension of a number of carrier strips for brush segments making up the rotary brush 13. The mounting of said carrier strips and their cooperating guide means will be described in further detail below. The annular guide 28 is provided adjacent the open ends of said guide means. The annular guide 28 has an opening 29 exposing the open end of a guide means and is arranged to prevent relative displacement between said carrier strips and said guide means. In order to replace a bristle segment, the rotary brush is turned to index the guide means for the desired bristle segment opposite the opening 29. The carrier strip is then displaced to slide out of the guide means through the opening, and a new carrier strip can be pushed into the guide means.

Figure 2 shows a rotary brush 13 mounted in a holder 30 according to an alternative embodiment of the invention. In this embodiment, the holder 30 comprises a single load carrying strut 32 mounted between each end of the transverse beam 11. A brush carrier 33 is located at each end of the rotary brush, at the centre axis thereof, and extends a predetermined distance into the core of the rotary brush. The transverse beam 11 and the holder 30 can be angled relative to the load carrying strut 32 about a vertical axis X by means of a hydraulic cylinder 12, similar to the arrangement in Figure 1. The arrangement also allows the holder 30 to be angled relative to each load carrying strut 32 at either end of the rotary brush 13, which in turn allows the longitudinal axis of the rotary brush 13 to be angled in order to follow the transverse inclination of the ground. The rotary brush 13 is driven by a direct drive hydraulic motor 34 mounted fixed relative to the load carrying strut 32.

The hydraulic motor 34 is connected to one of the brush carriers 33 located at each end of the rotary brush. The opposite end of the brush is rotatably mounted in a bearing relative to the holder 30. As described in connection with Figure 1 , the holder 30 comprises a fixed annular guide 28 mounted on the holder adjacent at least one end of the rotary brush 13.

Figure 3 shows a rotary brush according to a first example. The figure shows a rotary brush 13 that can be used with a holder 20, 30 as described in relation to Figures 1 and 2 above. The rotary brush 13 comprises a cylindrical frame structure 35 to be mounted for rotation about a central longitudinal axis. The frame structure comprises a plurality of identical guide means 36 fixed to a number of carrier plates 37a, 37b, 37c at circularly spaced locations. In the example shown in Figure 3 three carrier plates are used, but the number may vary depending on the length and/or diameter of the cylindrical frame structure 35. Each carrier plate 37a, 37b, 37c comprises a circular plate provided with regularly spaced cut-outs in the outer periphery. The guide means 36 are located in the cut-outs and are welded to the carrier plates 37a, 37b, 37c. In Figure 3 the frame structure 35 comprises fourteen guide means 36 mounted helically along the length thereof.

A plurality of bristle segments 38 are arranged to be mounted to the frame structure in the guide means 36. Each bristle segment 38 comprises a carrier strip 39 extending along the frame structure 35. Each carrier strip 39 comprises a series of bristles attached to said carrier strip, which bristles projects radially outwards from the cylindrical frame structure 35. Each guide means 36 is arranged to receive at least one carrier strip 39 associated with a bristle segment 38. In the example shown in Figure 3, four bristle segments are to be mounted in-line in each guide means 36. Depending on the length of the rotary brush and the weight of the bristle segments, one or more bristle segments may be used. The guide means 36 shown in Figure 3 is arranged to be open in a direction parallel to the axis

of the rotary brush at one end of the frame structure 35. Depending on the type of holder carrying the rotary brush, the guide means may either be arranged to be open at both ends of the frame structure, or to be open at one end of the frame structure and closed at the opposite end thereof. When mounted correctly, the end of the carrier strip 39 is flush with the end of the guide means 36. The example in Figure 3 shows guide means open at one end only.

A fixed annular guide 40 is mounted on a holder (not shown; see Fig.2)) adjacent the end of the rotary brush 13. The radial extension of the annular guide 40 from the holder is preferably equal to or greater than the radial extension of the carrier strips 39 for each brush segment 38 making up the rotary brush 13. The annular guide 40 is provided adjacent the open ends of the guide means 36. The annular guide 40 has an opening 41 exposing the open end of one guide means 36 and is arranged to prevent relative displacement between said carrier strips 39 and said guide means 36. The distance between the outer end of the end of one guide means 36 and the inner surface of the annular guide 40 must be sufficient to allow rotation of the rotary brush 13. In the example shown in Figure 7, the distance is approximately 1 cm.

Each section 42, 43 of the annular guide 40 adjacent the opening 41 is angled away from the end of the cylindrical frame structure 35. The angled sections 42, 43 of the annular guide 40 adjacent the opening are located facing the direction of rotation of the rotary brush. If a bristle segment 38 should be axially displaced out of the guide means 36 during rotation of the rotary brush 13, its carrier strip 39 will eventually contact the annular guide 40. Further displacement will cause the carrier strip 39 to strike one of the angled sections 42, 43 and be pushed back into the guide means 36. By providing an angled section 42, 43 of the annular guide 40 adjacent both sides of the opening 41 , the rotary brush 13 may be rotated in both directions. The angled sections of the annular guide may be arranged at an

angle up to 15° from a radial plane through the annular guide. In the example shown, the sections are located at an angle of 10° from said radial plane. According to the example in Figure 3, the annular guide 40 is a flat guide plate mounted on one of the holders for the rotary brush (see Fig.2).

Figure 4 shows a rotary brush 13 according to Figure 3, with a bristle segment 38 partially removed. In order to replace a worn bristle segment 38, the desired guide means 36 is indexed opposite the opening 41 . The carrier strip 39 is then displaced to slide out of the guide means 36 through the opening 41 , and a new carrier strip can be pushed into the guide means. During normal operation, the friction between the carrier strip 39 and the guide means 36 is sufficient to hold the brush segment 38 in position.

Figure 5 shows an end view of a rotary brush according to Figure 4. As can be seen from the figure, the guide means 36 is substantially C-shaped and the carrier strip 39 has a cross-section cooperating with said guide means. The carrier strip 39 is arranged to contact the guide means 36 to ensure sufficient friction to maintain the bristle segment 38 in position during rotation of the rotary brush, but at the same time allow manual withdrawal of the carrier strip 39 during replacement of the bristle segment 38.

Figure 6 shows an end section of a frame structure 35 of a rotary brush according to Figure 3, with the bristle segments removed. The end carrier plate 37a comprises a circular plate provided with regularly spaced cutouts in the outer periphery. Each pair of cut-outs is separated by a finger 44 extending radially outwards between each pair of guide means 36 and being bent at its outer end substantially parallel to the longitudinal direction of the adjacent guide means 36. The C-shaped guide means 36 are positioned with their open section facing radially outwards in the cutouts and are welded to the carrier plate 37a. In Figure 6 the frame structure 35 comprises fourteen guide means 36 mounted helically along the length thereof.

Figure 7 shows an a plan view of the frame structure of Figure 6. As indicated in Figure 7, each section 42, 43 of the annular guide 40 adjacent the opening 41 is angled away from the end of the cylindrical frame structure 35. The angled sections 42, 43 of the annular guide 40 adjacent the opening are located facing the direction of rotation of the rotary brush. If a bristle segment 38 should be axially displaced out of the guide means 36 during rotation of the rotary brush 13, its carrier strip 39 will eventually contact the annular guide 40. Figure 7 shows a carrier strip 39 displaced into this position. Further displacement will cause the carrier strip 39 to strike one of the angled sections 42, 43, depending on the direction of rotation, and be pushed back into the guide means 36. By providing an angled section 42, 43 of the annular guide 40 adjacent both sides of the opening 41 , the rotary brush 13 may be rotated in both directions. The angled sections of the annular guide may be arranged at an angle α up to 15° from a radial plane through the annular guide. In the example shown, the sections are located at an angle α of 10° from said radial plane.

The invention is not limited to the above examples, but may be varied freely within the scope of the appended claims. For instance, in an example described above, the carrier strips are arranged to extend helically and equispaced along the frame structure. According to an alternative example, the carrier strips may be arranged to extend axially and in parallel along the frame structure. In addition, the above examples describe an annular guide having a single opening and a width equal to one guide means for a bristle segment. It is, however possible to provide an annular guide having more than one opening and/or an opening having a width equal to more than one guide means. Also, the above figures only describe one end of a rotary brush. As indicated above, the annular guide means may be provided at one end or at both ends of a rotary brush. In the first- mentioned case, a stop having the same or similar cross-section as the guide strip is attached inside the end of each guide means at the end of the frame structure located remote from the annular guide.