WO1992016097A1

WO1992016097A1 - Reels for combing, raking, or vertical cutting of grassed or other ground

Info

Publication number: WO1992016097A1
Application number: PCT/AU1992/000118
Authority: WO
Inventors: Walter Oechsle
Original assignee: Walter Oechsle
Priority date: 1991-03-22
Filing date: 1992-03-20
Publication date: 1992-10-01
Also published as: DE4290710C1

Abstract

Reels for a machine for working grassed or other ground comprise a dethatching and combing reel with spring tines (4), a knife reel with blades (52) and a flail blade wheel with blades (84). The tines (4) and blades (52, 84) are mounted on shafts of the respective reels in such a manner as to permit replacement without removal of the reel from the machine. Each spring tine (4) is formed with a hooked mounting portion (8) to permit the tines to be mounted on the shaft by a bolt without the need to tap the shaft. The knife blades (52) and flail blades (84) are bolted to mounting plates (54, 82) carried by the respective shafts and are reversible in position on the mounting plates to present a different section of the blade as the working part of the blade in order to prolong the working life of the blade.

Description

"REELS FOR COMBING, RAKING, OR VERTICAL CUTTING OF GRASSED OR OTHER GROUND"

The present invention relates to working reels for incorporation into a machine for removing thatch from the ground or for combing grass or other vegetation or for vertically cutting ground.

So-called power rakes for dethatching and combing grass have been available for a number of years. Conventional machines comprise a reel which carries a series of flail blades which on rotation of the reel provide a dethatching/combing action. The action is non-selective and causes damage to healthy grass and also to equipment installed at ground level, such as sprinkler heads. The reel is driven at relatively high speed and has a high power requirement. In some existing machines an optional knife reel is provided with a series of vertical blades operative to form vertical slits or cuts in the ground. These are sometimes known as verticutters or slicers. Conventional arrangements of knife blades also have high power requirements. Conventionally, flail blades and vertical knife blades are arranged in rectilinear groups parallel to the axis of the reel with the result that substantial vibrational forces are generated as each group meets the ground.

There have been proposed dethatching and combing reels comprising spring tines which operate at relatively low speed and which provide a more selective combing and dethatching action which is similar to that provided by a manual rake. Previous proposals for arrangements of spring tines have proven rather expensive to manufacture. In addition they have resulted in large space requirements to accommodate the diameter of the reel within the machine, and the tines themselves have been prone to wear within spring coils of the tines. There has also been a general prejudice against spring tines due to fear of damage arising to the tines, especially during transportation, and as a result spring tines have not met with widespread acceptance. According to one aspect of the present invention there is provided a dethatching and combing reel for use on grassed or other ground, comprising a shaft, and a series of spring tines spaced along the length of the shaft for rotation with the shaft, each tine having a tip portion adapted to scrape the ground during rotation of the shaft and a mounting portion by which the tine is releasably mounted on the shaft, the tine being resilient between the mounting portion and the tip portion to permit deflection of the tip portion relative to the shaft, said mounting portion being of a hook-like shape to extend partially around the circumference of the shaft whereby parts of the mounting portion will lie at diametrically-opposed portions of the shaft such that a single bolt passing through the shaft can clamp both parts to the shaft, the tine being removable from the shaft by releasing the bolt and manoeuvring the mounting portion away from the bolt and out of engagement with the shaft.

According to another aspect of the invention there is provided a spring tine for mounting on a reel for dethatching and combing, comprising a mounting portion for attachment to a shaft of the reel, a first rectilinear section extending from the mounting portion, a second rectilinear section carrying a working tip, and a helically wound portion between the first and second rectilinear sections, the first and second rectilinear sections being inclined one relative to the other by an included angle of between approximately 90 ° and 150 °.

According to another aspect of the invention there is provided a knife reel for use on grassed or other ground, comprising a shaft, and a plurality of blade assemblies mounted along the length of the shaft so as to form cuts at right angles to the plane of the shaft during rotation, each blade assembly comprising a mounting member mounted for rotation with the shaft, and a plate-like blade removably attached to the mounting member, the blade being of substantially rectangular form positioned on the mounting member such that the blade lies in a plane substantially as right angles to the axis of the shaft, with an axis of the plate being substantially parallel to but spaced from a line extending radially of the shaft axis whereby to provide an offset mounting for the blade such that a leading corner portion of the blade in the direction of rotation of the shaft constitutes a cutting edge of the blade, said blade being removable from the mounting member without removal of the shaft from the machine.

According to yet another aspect of the invention there is provided a flail blade reel for use on grassed or other ground comprising a shaft, and a plurality of flail blade assemblies mounted for rotation with the shaft at spaced positions along the length of the shaft, each flail blade assembly comprising a mounting member mounted for rotation with the shaft, and a flail blade pivotally mounted to the mounting member for rotation about an axis parallel to the axis of the shaft, wherein each flail blade is of plate-like form of a non right-angled parallelogram shape so disposed on the mounting member that a leading corner portion of the blade forms a working tip of the blade during rotation of the shaft, the flail blade being removable from the mounting member without removal of the reel from the machine.

The invention also provides a machine having any one of the reels defined above. The reel may be removably mounted in the machine to be replaced by either one of the other two reels defined above.

Embodiments of the invention will now be described by way of example only with reference to the accompanying drawings in which:-

Figure 1 is a perspective view of a dethatching and combing reel in accordance with a preferred embodiment of the invention;

Figure 2 is a section through the reel of Figure 1;

Figure 3 is a perspective view showing a single spring tine of the reel of Figure 1; Figure 4 is an exploded perspective view of a knife reel in accordance with a preferred embodiment of the invention;

Figure 5 is a section through the knife reel of Figure 4;

Figure 6 is a fragmentary plan view of a flail blade reel in accordance with a preferred embodiment of the invention; and

Figure 7 is a section through the reel of Figure 6.

With initial reference to Figure 1 there is shown a dethatching and combing reel 2 comprising spring tines 4 for selective dethatching and combing at low to medium operating speeds, for example working tip speeds of the order of 2.5 to 7.00 m/s. The reel 2 comprises a shaft 6 with pairs of spring tines 4 arranged along the axis of the shaft 6. As shown in Figures 2 and 3, each tine -4 comprises a mounting portion 8 which will be described in greater detail hereinafter, by which that tine 4 is attached to the shaft 6 by means of a bolt 10 which is common to the pair of tines. The tine 4 is fabricated from wire or rod of spring steel which is corrosion resistant in order to prevent fatigue due to the effects of corrosion. Beyond the mounting portion 8, an inner rectilinear portion 12 of the tine extends substantially tangentially outwardly from the shaft 6 and is then wound helically through a number of turns, typically two or three turns, to extend to an outer rectilinear portion 14 which is deformed at its end to form the working tip 16. The helical winding of the tine shown at 18 forms a torsion spring which will absorb the deflection of the outer rectilinear portion 14 and working tip 16 as the latter moves along the ground with a scraping motion.. As shown, the outer rectilinear portion 14 extends approximately at right angles to the inner rectilinear portion 12 and this minimises the overall deflection of the tine while enabling the working tip 16 to remain in contact with the ground over a relatively large distance during the rotation of the reel. Although as illustrated the outer rectilinear portion 14 extends approximately at right angles to the inner rectilinear portion 12, the included angle between these portions can be selected to be between approximately 90 ° and 15C ^c. As the included angle increases, the deflection of the working tip reduces and when higher operating speeds are used, a higher included angle is required in order to reduce the stress on the tine. The variation in included angle permits the tine configuration to be optimised for the required working conditions.

The mounting portion 8 of the tine 4 is of a hooked shape and comprises a semi-circular hooking part 22 which passes around the side of the shaft opposite to that on which the major part of the tine 4 lies and which terminates in a hook portion 26 which engages around the shank of the bolt 10. In the configuration shown, the hooked terminal portion 26 and the part of the inner rectilinear portion 12 immediately adjacent the semi-circular hooking part 22 will be clamped at opposite sides of the shaft between the shaft and a captive washer 28 at the head end or tail end of the bolt 10. The nut 30 of the bolt 10 is a locking nut and the washers 28 may be locking washers or U-shaped captive washers. It will be seen from Figure 2 that a single bolt 10 is used to mount each spring tine 4 of the pair, with the mounting portions 8 of the two spring tines 4 being at opposite sides of the shaft 6 and also at opposite sides of the bolt and the two hooked terminal portions 26 also being at opposite sides of the shaft 6. This configuration enables individual tines 4 to be replaced without removing the reel as a whole. All that is required is for the anchoring bolt 10 to be loosened whereby a damaged tine 4 can be slid out of engagement from the bolt 10 and replaced by a new tine.

It is to be noted from Figure 1 that each pair of tines 4 is angularly offset from the pair of tines 4 adjacent thereto so that the tines 4 are arranged in two rows which follow helical paths on opposite sides of the shaft 6. The arrangement of the tines in helical rows provides for progressive contact of the tines 4 with the ground as the machine advances along the ground resulting in reduced vibration. Preferably, the shaft 6 carries at least one disc 32 having a radius larger than the outside radius of the helical winding 18 which serves to limit excessive deformation of the tines 4 whereby to prevent damage, especially during transportation.

The dethatching/combing reel described above is relatively inexpensive to manufacture. The shaft 6 is drilled with a series of plain holes along its length to accept the mounting bolts 10, with the holes being angularly offset to provide the required helical configuration of the tines 4, no tapping of the holes being required. The tines themselves can readily be fabricated by bending wire or rod to the required shape.

A knife reel 48, suitable f r medium to high speed operation, for example above about 6 m/s working tip speed, is shown in Figures 4 and 5. The knife reel comprises a shaft 50 carrying opposed pairs of blades 52 at intervals along the length of the shaft 50. Each pair of blades 52 is mounted on a common mounting plate 54 carried by the shaft. Each blade 52 of the pair is substantially of rectangular plate-like form and is attached to the mounting plate 54 at an opposite side of the axis of the shaft 50, with the plane of the blade 52 lying in a plane at right angles to the axis of the shaft 50. The longitudinal axis 56 of the blade 52 lies eccentrically with respect to the shaft axis and as a result of this, only the leading lower corner portion 58 of the blade 52 cuts through the ground during rotation. This can be seen from the schematic illustration in Figure 5. It will also be noted from Figure 5 that the lower trailing corner portion^* 60 does not itself cut through the ground. The relatively small leading corner portion 58 of the blade 52 which performs the cutting action not only leads to reduced power requirements but also results in absence of wear of the trailing corner portion 58 during cutting. As a result of this, when the leading corner portion 58 becomes worn after use, the blade 52 can be removed from the mounting plate 54 and reversed (by

180 ° rotation about its longitudinal axis) so that the other lower corner portion now forms the leading corner portion. After wear of that corner portion, the blade may be again removed from its mounting and reversed (by 180 ° rotation about its transverse axis) so that the upper two corner portions can be used selectively as the alternative cutting corner portions. The rectangular blade 52 is bolted to the mounting plate 54 and the bolt holes 62 in the blade are positioned symmetrically to permit the mounting of the blade 52 in any one of the four alternative configurations as discussed above. As will be appreciated, the configuration of bolt holes 62 may be different from that shown and any configuration can be used which will provide the four-way reversible mounting for the blade 52 on the mounting plate 54.

As the blades 52 do not extend to the shaft 50, they do not need to be fabricated from as heavy a gauge of metal sheet as does the mounting plate 54 which carries a greater force due to the driving torque. This enables optimisation of the blades 52 for cutting.

It will of course be appreciated that the construction described permits individual blades 52 to be replaced without the necessity of removing the shaft 50 from the machine.

Each pair of blades 52 is mounted on the shaft 50 with an angular offset relative to the pairs of blades 52 adjacent thereto so that the reel carries two rows of blades 52 arranged in a helical formation along the length of the shaft 50 in order to provide a progressive cutting action as the machine advances along the ground, and thereby to produce a smoother action with reduced vibration.

The mounting plates 54 may be welded or otherwise attached directly to the shaft 50 in the appropriate angular orientation. Alternatively, and as shown, the mounting plates 54 may be welded to sleeves 64 mounted on the shaft 50 and clamped to the shaft 50 by friction so as to normally rotate with the shaft 50 but to permit rotation relative to the shaft 50 if one or more of the blades 52 happens to strike a rigid object during rotation. In one assembly of this type, mounting plates 54 are welded to opposite ends of a spacer sleeve 64, the two mounting plates 54 on the same sleeve 64 being angularly offset. The adjacent mounting plates 54 at the ends of two adjacent sleeves 64 are spaced by a spacer washer 66 and the pair of blades 52 is bolted between the adjacent pair of mounting plates 54 of the two sleeves 64. There is thus formed an assembly of sleeves 64 and mounting plates 54, with the blades 52 being bolted between the pairs of adjacent mounting plates 54 and being positioned at the required angular offset by means of the angular offset between the two mounting plates 54 on each sleeve 64. The assembly of sleeves 64 carrying the mounting plates 64 and blades 52 is friction-clamped to the shaft 50 by being forced against an abutment 68 at one end portion of the shaft 50 by means of a clamping nut 70 screwed onto the other end portion of the shaft 50 which is threaded for this purpose. Alternatively, single mounting plates 54 may be friction-clamped between spacer sleeves mounted on the shaft 50 and held in axial compression between the abutment 68 and clamping nut 70 as discussed above.

With reference to Figures 6 and 7 a flail blade reel comprises a shaft 80 carrying flail-blade mounting plates 82 at intervals along the shaft 80. Each mounting plate 82 carries two pairs of flail blades 84, the two pairs being on opposite sides of the shaft 80. The two flail blades 84 of each pair are mounted on a common bolt 86 carried by the mounting plate 82, with a spacer 88 being interposed between each side of the mounting plate 82 and the adjacent flail blade 84. The two flail blades are mounted between the respective spacers 88 and a washer 90 adjacent to the bolt head or nut so that the blades 84 have freedom to swing about the axis of the bolt 86 which is parallel to the axis of the shaft 80. During rotation of the shaft 80, the flail blades 84 provide a non-selective dethatching and combing action.

Each flail blade 84 is of a non right-angled parallelogram shape, with the bolt hole 92 in the blade being positioned forwardly of the longitudinal centreline of the blade as considered in the direction of rotation of the shaft 80. This configuration causes the blade 84 to assume the orientation shown in Figure 7 during dethatching and combing whereby the action is provided by the leading corner portion 94 of the blade 84, with the trailing corner portion 96 being above the ground and not subject to wear. The flail blade 84 is provided with a second bolt hole 98 adjacent to the lower trailing corner portion 96 of the blade 84 to enable the blade 84 to be remounted on the bolt 86 to present a fresh leading corner portion after wear has occurred. As will be apparent, individual flail blades 84 can be reversed and replaced without the need to remove the shaft 80 from the machine.

An angular offset is provided between each adjacent set of flail blades 84 whereby two helical rows of flail blades 84 will be provided to provide a smooth action as the machine advances along the ground. However, as will be apparent, there is not in this case an angular offset between each blade 84 in the row, but rather between each adjacent pair of blades 84 in the row. The individual blades 84 of each pair, being mounted on the same bolt, are in angular alignment and will engage the ground at substantially the same time.

The blade mounting plates 82 may be mounted on the shaft 80 either by being welded to the shaft 80, or by being friction clamped to the shaft 80 in the manner described in relation to the mounting plates 54 for the cutting blades 52.

Although in each of the working reels particularly described there are two helical rows of spring tines, cutting blades or flail blades, in other embodiments there may be only a single such row, or more than two rows, for example 3 or 4 rows, according to requirements.

A machine incorporating any of the working reels described above may be constructed as a single-purpose machine specific to the reel in question or alternatively may be constructed as a multi-purpose machine having the facility to easily change the reels. The construction of the reels as described reduces the power requirements and also the vibration whereby the machine can be of lighter construction with a smaller driving motor. The individual tines or blades can be replaced without the need to remove the reel and the blades themselves are capable of reversal one or more times in order to maximise the working life of each blade. The machine will comprise a body or chassis within which the reel is mounted and ground-engaging wheels or rollers. A suitable transmission is incorporated between the driving motor and the shaft of the reel, and the motor might also drive the wheels or rollers or alternatively the machine may be moved along the ground by the working reel which itself provides propulsion for the machinery assisted and controlled by the operator as required.

Although the embodiments have been particularly described in relation to dethatching, combing and vertically cutting grassed ground, the working reels described are., not exclusively intended for use on grassed ground. For example dethatching and combing of the ground can be of use with other forms of vegetation, and vertical cutting or slitting of the ground can be of use either with bare ground or with ground having other forms of vegetation.

The embodiments have been described by way of example only and modifications are possible within the scope of the invention.

Claims

CLAIMS:-

1. A dethatching and combing reel for use on grassed or other ground, comprising a shaft, and a series of spring tines spaced along the length of the shaft for rotation with the shaft, each tine having a tip portion adapted to scrape the ground during rotation of the shaft and a mounting portion by which the tine is releasably mounted on the shaft, the tine being resilient between the mounting portion and the tip portion to permit deflection of the tip portion relative to the shaft, said mounting portion being of a hook-like shape to extend partially around the circumference of the shaft whereby parts of the mounting portion will lie at diametrically-opposed portions of the shaft such that a single bolt passing through the shaft can clamp both parts to the shaft, the tine being removable from the shaft by releasing the bolt and manoeuvring the mounting portion away from the bolt and out of engagement with the shaft.

2. A reel according to claim 1, wherein the mounting portion has a first hook portion which extends around part of the circumference of the shaft, and a second hook portion at the end of the first hook portion and which engages around part of the shank of the bolt.

3. A reel according to claim 2, wherein the bolt mounts a pair of said tines, the working tips of the respective tines of the pair being on opposite sides of the shaft, the respective first hook portions of the two tines extending around opposite sides of the shaft, and the respective second hook portions of the two tines being at opposite sides of the shaft.

4. A reel according to any one of claims 1 to 3, wherein the tine is wound helically between the mounting portion and the working tip to form a torsion spring which permits deflection of the working tip during use.

5. A reel according to claim 4, wherein the helically-wound portion is connected to the mounting portion by a first rectilinear section extending substantially tangentially from the shaft, and the helically-wound portion is connected to the working tip by a second rectilinear section which is inclined to the first rectilinear section.

6. A reel according to claim 5, wherein the first and second rectilinear sections are inclined by an included angle of between about 90 ° and 150 °.

7. A reel according to any one of claims 1 to 6, wherein adjacent tines along the length of the shaft are angularly offset to define a helical formation of tines.

8. A reel according to any one of claims 4 to 6, further comprising at least one disc mounted on the shaft and having a radius greater than the maximum distance of the helically wound portions from the shaft whereby to protect the tines against damage.

9. A spring tine for mounting on a reel for dethatching and combing, comprising a mounting portion for attachment to a shaft of the reel, a first rectilinear section extending from the mounting portion, a second rectilinear section carrying a working tip, and a helically wound portion between the first and second rectilinear sections, the first and second rectilinear sections being inclined one relative to the other by an included angle of between approximately 90 ° and 150 °.

10. A knife reel for use on grassed or other ground comprising a shaft, and a plurality of blade assemblies mounted along the length of the shaft so as to form cuts at right angles to the plane of the shaft during rotation, each blade assembly comprising a mounting member mounted for rotation with the shaft, and a plate-like blade removably attached to the mounting member, the blade being of substantially rectangular form positioned on the mounting member such that the blade lies in a plane substantially as right angles to the axis of the shaft, with an axis of the plate being substantially parallel to but spaced from a line extending radi Jly of the shaft axis whereby to provide an offset mounting for the blade such that a leading corner portion of the blade in the direction of rotation of the shaft constitutes a cutting edge of the blade, the blade being removable from the mounting member without removal of the shaft from the machine.

11. A reel according to claim 10, wherein the mounting of the blade to the mounting member is such that the blade can be orientated in a position such that any one of the four corner portions is able selectively to form the cutting edge of the blade.

12. A reel according to claim 11, wherein the blade is bolted to the mounting member and the blade includes a plurality of sets of bolt holes which can be used selectively to mount the blade in the selected orientation.

13. A reel according to any one of claims 10 to 12, wherein each mounting member removably mounts a second said blade which extends on the opposite side of the shaft to the first mentioned blade.

14. A reel according to any one of claims 10 to 13, wherein adjacent blades along the axis of the shaft are angularly offset whereby to form a row of blades disposed in a helical formation to provide progressive contact as the machine advances over the ground.

15. A reel according to any one of claims 10 to 14, wherein each mounting member is rigidly secured to the shaft.

16. A reel according to any one of claims 10 to 15, wherein the mounting members are clamped by frictional force for rotation with the shaft, the friction clamping permitting the shaft to rotate relative to the or each mounting member if a said blade is obstructed against rotation.

17. A flail blade reel for use on grassed or other ground comprising a shaft, and a plurality of flail blade assemblies mounted for rotation with the shaft at spaced positions along the length of the shaft, each flail blade assembly comprising a mounting member mounted for rotation with the shaft, and a flail blade pivotally mounted to the mounting member for rotation about an axis parallel to the axis of the shaft, wherein each flail blade is of plate-like form of a non right-angled parallelogram shape so disposed on the mounting member that a leading corner portion of the blade forms a working tip of the blade during rotation of the shaft, the flail blade being removable from the mounting member without removal of the reel from the machine.

18. A reel according to claim 17, wherein each flail blade assembly comprises a pair of said flail blades removably mounted on the mounting member by a single bolt which provides the pivotal mounting for the blades, the bolt carrying spacer means to hold the two flail blades at a predetermined axial spacing.

19. A reel according to claim 7 or 18, wherein the blade is reversible in position on the mounting member to present a different corner portion as the leading corner portion.

20. A reel according to any one of claims 17 to 19, wherein each blade assembly comprises at least one further said blade mounted on the mounting member at the opposite side of the shaft axis to the first mentioned blade.

21. A reel according to any one of claims 17 to 20, wherein adjacent blade assemblies along the axis of the shaft are angularly offset so that the successive adjacent blade assemblies follow a generally helical path to provide for progressive contact of the flail blades as the machine moves along the ground.

22. A reel according to any one of claims 17 to 21, wherein each mounting member is rigidly mounted to the shaft for rotation therewith.

23. A reel according to any one of claims 17 to 22, wherein the mounting members are clamped by frictional force for rotation with the shaft, the friction clamping permitting the shaft to rotate relative to the or each mounting member if a said blade is obstructed against rotation.

24. A combing and dethatching reel comprising a shaft to which is mounted at least one row of tines according to claim 9.

25. A machine comprising a reel according to any one of claims 1 to 8 or 10 to 24, and means for driving the reel.

26. A machine in combination with reels according to claims 1, 10, and 17, each of the reels being selectively mountable within the machine to provide the required mode of operation, said machine including means for driving the reel.