GB2304266A

GB2304266A - Vegetation cutter

Info

Publication number: GB2304266A
Application number: GB9604152A
Authority: GB
Inventors: Godfrey Henry Grima
Original assignee: Individual
Current assignee: Individual
Priority date: 1995-08-21
Filing date: 1996-02-27
Publication date: 1997-03-19
Also published as: AU6875496A; WO1997006665A1; GB9604152D0

Abstract

A vegetation cutter has a drive shaft (10), a motor for driving the drive shaft (10) to rotate, and a rotation head (1) mounted on the drive shaft (10) and carrying a plurality of flexible strand or filament cutting members (3), wherein ```the rotation head (1) is a one-piece rotation head having ```a mounting portion (1a), mounting the rotation head on the drive shaft, which portion (1a) is attached directly to the end of the drive shaft (10) with no additional fixing or attachment means, and ```a skirt portion (1b), extending from and formed in one piece with the mounting portion (1a), which skirt portion (1b) has slots or holes (2) through it, at uniform intervals around the periphery thereof, in which respective flexible strand or filament cutting members (3) of the plurality are received, and wherein ```the outer diameter of the skirt portion (1b) is no more than 6cm, and ```the wall thickness of the skirt portion (1b) is no more than 6mm.

Description

Vegetation Cutters The present invention relates to vegetation cutters.

Various kinds of vegetation cutter are known, for example those generally designated as lawn or grass mowers and those generally designated as lawn or grass trimmers.

Conventional vegetation trimmers, such as lawn trimmers or strimmers, have one or two - or perhaps three - flexible strands or filaments extending radially outwardly from a rotation head. The rotation head and hence the filaments are driven to rotate by a shaft, which is in turn driven by an electric or petrol motor, to provide a cutting or trimming action within the radius of rotation of the filaments.

In some trimmers, the flexible strand or filament is wound up on a spool mechanism at the rotation head. Only a relatively short length of the strand or filament is drawn off the spool so as to extend radially outwardly from the rotation head and act as the cutting or trimming member.

The flexible strand or filament cutting member is subject to more or less rapid wear in use, and is also subject to breakage. At intervals, the trimmer must be stopped and a new length of strand drawn off the spool to provide a new, useable cutting or trimming member.

This process of renewal of the cutting member by drawing off a fresh length of filament from the spool mechanism can be problematic and frustrating for the user.

Many proposals have been made for improving the spool mechanism, and proposals have been made to provide for automatic feed or draw-off of filament from the mechanism, so that the cutting member is automatically renewed as wear or breakage takes place.

Proposals have also been made for trimmers which avoid any spool mechanism, thereby to avoid with certainty the problems associated with such mechanisms.

In such trimmers the rotation head generally carries individual, relatively short lengths of filament. The individual lengths are replaced when worn or when broken.

An example of such a trimmer is described in US-A-4 571 831 (TORO). Here, the rotation head is in the form of an inverted bowl having a wide radially extending flange or lip around the mouth of the bowl. At two opposite locations on the flange or lip, at a distance from the axis of rotation, structures are provided which afford slots into which ends of strands or lengths of filament can be mounted in a way preventing the strands flying off radially when the head is rotated. Mounting is effected in that one end of a strand or length of filament is first fitted with an eyelet, and then the eyelet is pressed into one of the slots. The rotation head is mounted on the shaft by means of a countersunk opening in the base of the bowl through which, apparently, a bolt passes to attach the head to the shaft.

Another example of such a trimmer is described in GB-A-1 514 604 (KIORITZ 1). Here, the rotation head is generally discal in shape. It has an upper (towards the shaft) hub part with a hole through which a bolt can pass for fastening the head to the shaft. It also has generally disc-like lower part which is radially considerably wider than the hub part, with a central recess and a thick wall around the central recess. Bores pass radially through the thick wall. A length of filament having a cylindrical fastening member at one end can be inserted into a bore from the central recess. The cylindrical fastening member is located in the central recess and engages behind the inlet end of the bore, to prevent the strand flying off radially when the head is rotated.

GB-A-1 507 438 (KIORITZ 2) discloses a rotation head of more complicated structure. The upper part of the head (towards the shaft) has a hole through which a bolt can pass for fastening the head to the shaft. It has generally disc-like lower part which is radially considerably wider than the upper part, with a central recess and a thick wall around the central recess. Bores pass radially through the thick wall. A strand or length of filament can be inserted into a bore from the central recess and its inner end clamped in the central recess to prevent the strand flying off radially when the head is rotated.

All the prior proposals suffer problems which render them unsatisfactory in terms of practicality of use, effectiveness in use and commercial viability.

According to the present invention there is provided a vegetation cutter having a drive shaft, a motor for driving the drive shaft to rotate, and a rotation head mounted on the drive shaft and carrying a plurality of flexible strand or filament cutting members, wherein the rotation head is a one-piece rotation head having a mounting portion, for mounting the rotation head on the drive shaft, which portion is attached directly to the end of the drive shaft with no additional fixing or attachment means, and a skirt portion, extending from and formed in one piece with the mounting portion, which skirt portion has slots or holes through it, at uniform intervals around the periphery thereof, in which respective flexible strand or filament cutting members of the plurality are received, and wherein the outer diameter of the skirt portion is no more than 6cm, and the wall thickness of the skirt portion is no more than 6mm.

As will become clear from the following, with the present invention, significant advantages can be achieved, and problems associated with prior proposals such as TORO, KIORITZ 1 and KIORITZ 2 overcome.

The one-piece or integral structure of the rotation head offers clear advantages in terms of robustness and reliability, and in the fact that component parts of the head cannot be inadvertently omitted or lost, which represents a real practical advantage to the user.

The provision of a mounting portion of the head which attaches directly to the drive shaft with no additional fixing or attachment means likewise has the advantage that there is no possibility of loss of any fixing or attachment means such as the fastening bolts of the TORO, KIORITZ 1 and KIORITZ 2 prior art proposals mentioned above, which are there used to attach the rotation head to the drive shaft. This has considerable practical benefits. Further, the direct attachment of the mounting portion of the head offers more secure fixing with reduced risk of inadvertent detachment of the head as a result of incorrect or incomplete assembly by user. This is an advantage in terms of safety.

Preferably, the direct attachment of the mounting portion of the head to the shaft in accordance with the invention is afforded by means of a threaded recess in the mounting portion, into which the shaft can be screwed with a corresponding external thread on the shaft. With appropriately directed thread, the attachment is selftightening when the cutter is operated and the head rotated. The risk of inadvertent detachment is thus minimised and safety improved.

Alternatively, the mounting portion of the head may for example be press fit onto the end of the shaft.

The configuration of the skirt portion of the rotation head in accordance with the present invention also affords profound advantages over the prior art proposals.

In the prior art proposals TORO, KIORITZ 1 and KIORITZ 2, the most radially inward part of a strand or filament which can effect a cutting action is at a considerable distance from the axis of rotation (the drive shaft). This means that, around the drive shaft, there is an extensive zone in which cutting does not take place. Further, as a result, of the fact that the radially inwardmost part of a strand or filament which can effect cutting is at a considerable distance from the axis of rotation, this part of the strand is, in operation, moving around the axis of rotation at a considerable linear velocity. This imposes high stresses on this inwardmost part of the strand, which is disadvantageous in terms of its effect on the strand and on the relevant part of the rotation head.

In contrast, in embodiments of the present invention, the most radially inwardmost part of a strand or filament which can effect a cutting action is at a short distance from the axis of rotation (the drive shaft) - 3cm or preferably less. This means that the "no cutting" zone around the shaft is reduced in size, thus increasing efficiency. This also means that the linear velocity of the strand around the axis of rotation at this inwardmost part is low, and correspondingly lower stresses are imposed on this part of the strand. At the same time, the whiplash effect of the strands, when the rotation head is being rotated and the strands are striking and cutting vegetation, is improved and hence the cutting effect is enhanced.

Furthermore, in embodiments of the present invention, the small wall thickness of the skirt - 6mm at most - is highly beneficial in terms of the durability and cutting effectiveness of the strand or filament cutting members.

The fact that only a minor portion of the overall length of each strand or filament cutting member is held or restrained in a hole or slot in the skirt portion of the rotation head not only means that a greater proportion of any given strand length is available for actual cutting work, but has proved also to mean that the strand is less susceptible to breakage near its inward end. The short length of strand restrained, together with the fact that the fit of the strand in the hole or slot is relatively loose (i.e. such as to permit insertion of the strand through the hole or into the slot) means that stress on the strand at its point of exit from the hole or slot is less and breakage less likely to occur.

In contrast to this, in KIORITZ 1 for example, a considerably greater length of strand is in practice restrained in the bores (e.g. 2cm length of strand is restrained in the bores), and the point of exit of a strand from a mounting bore is, as indicated above, at a considerable distance from the axis of rotation.

In KIORITZ 2 also a considerable length of strand is restrained in a bore in the rotation head and the point of exit of a strand from a mounting bore is again at a considerable distance from the axis of rotation. Here, however, an attempt is apparently made to reduce the shearing force on the strands whilst in service by the provision of curved surfaces at the radially outer mouths of the bores through which the strands pass. Such a measure, involving more intricate or complicated configuration of the rotation head, with consequent increased costs, may not be effective. Such a measure is not needed in embodiments of the present invention.

Also in TORO the point of exit of a strand from a mounting eyelet is at a considerable distance from the axis of rotation. Again, an attempt is apparently made to reduce the shearing force on the strands whilst in service by the provision of curved surfaces at the radially outer mouths of the eyelets in which the strands are held. Although only a short length of strand is apparently restrained in its eyelet and the mounting structure associated with the eyelet, that length of strand is clearly very firmly held by the crimping of the eyelet to the strand and press fitting of the eyelet into the mounting structure.

The small diameter of the skirt portion - 6cm at most - in accordance with the invention is also highly beneficial for other reasons. Not only is the linear velocity of the strands, where they exit from the holes or slots in the skirt portion, relatively low as explained above, but the small diameter and corresponding low weight of the head enable the head to be rotated at high speed with consequently enhanced cutting efficiency.

In accordance with the present invention, the rotation head may be of metal, such a steel or preferably aluminium, or of plastics material such as ABS or high impact nylon.

In accordance with the present invention a greater number of cutting members can be provided at the rotation head, very simply through the provision of an appropriate number of slots or holes in the skirt portion. The provision of a greater number of cutting members, for example four or preferably six or twelve, in an embodiment of the present invention increases cutting efficiency. It also greatly extends the time for which the cutter can be used before the operator must stop the cutter and renew any individual one or all of the cutting members.

In embodiments of the present invention, the flexible strands or filaments are simply inserted through the holes in the skirt portion of the rotation head from the radially inward side. Where slots are provided instead of holes, the flexible strands of filaments are simply placed into the open mouths of the slots, at the hem of the skirt portion, and drawn or pulled down to the closed ends of the slots. At their radially inner ends, the strands or filaments have integral nodules or thickenings, of the strand material, which cannot pass through the holes or radially exit the slots. No other particular fastening means are needed. The strands or filaments can be easily withdrawn through the holes or from the slots for replacement when worn or broken in use.This provides for further advantages over the prior art, where in general additional fastening or mounting means are needed for the strand or filaments.

In embodiments of the present invention the thickness of a strand may vary along the length of the strand. In particular, a strand may be made which increases in thickness away from the end which is to be mounted in a hole or slot. In embodiments in which slots are provided in the skirt portion of the rotation head, for mounting the strands, the thicker ends of the strands - away from the slots - can have a diameter or thickness greater than the width of the slots into which the strands are inserted.

This increased thickness of the strands increases their working lives.

In summary, embodiments of the present invention provide vegetation cutters which are of refined structure extremely well adapted to the purpose of the cutter but which nonetheless are simple, compact, user-friendly, economic and highly reliable in structure and which have advantages in terms of its cutting action and for the lifetime of the strand or filament cutting members used. The rotation head is a one piece or integral structure which mounts directly on the drive shaft and on which the strands themselves are directly mounted, with no other mounting or fastening means. The structure is of inherent simplicity and safety in use. Dimensioned in accordance with the invention, the rotation head is of a configuration which is compact and light, enabling higher speeds of rotation to be achieved to provide more efficient cutting operation.At the same time the configuration is such that the strands themselves are more reliably protected from breakage and are better able, in operation, to effect a whiplash action favourable to efficient cutting of vegetation.

In embodiments of the invention, the wall of the skirt portion has a thickness in the range up to 6mm, preferably at least 2.Omm, and more preferably in the range 2.Smm to 5mm. Tests have shown that thicknesses in this latter range, in particular lower thicknesses in this range such as 2.5mm, afford particularly desirable operation.

In embodiments of the invention, the outer diameter of the skirt portion is in the range up to 6cm, preferably at least 2cm, and more preferably in the range 3cm to 5cm, for example 4cm or 5cm. Tests have shown that a diameter of around 4cm may be optimal in terms of cutting action. A lesser diameter may be advantageous in some cases, where lighter cutting is adequate, to reduce weight and to allow lighter motors to be exploited.

Most preferably, the skirt wall thickness is 2.5mm and the skirt outer diameter 4cm. In tests, best results have been achieved with this configuration.

The axial length of the rotational head should generally be as small as possible consistent with secure attachment of the mounting portion to the shaft, considering the loads which might be encountered, and consistent with the provision of the holes or slots for receiving the strand or filament cutting members. Typically, the axial length may be 2cm to 6cm, or more if appropriate.

The invention also provides a special configuration of strand or filament for use with a vegetation cutter in accordance with the invention. This strand configuration is such that the strand of filament cutting member is thicker or of greater diameter away from the strand end which is to be mounted at the rotation head, either in a hole or in a slot. This increased thickness provides for improved cutting action and enhanced durability of the strand in use. In particular in a case in which the rotation head is provided, in the skirt portion, with slots for receiving the strands or filaments, the strand or filaments may at their outer ends be thicker or of greater diameter than the width of the slots.

Reference is made, by way of example, to the accompanying drawings, in which: Fig. 1 schematically illustrates main parts of a trimmer embodying the present invention, in particular a rotation head and flexible strand or filament cutting members thereof, in a perspective view, Fig. 2 schematically illustrates the trimmer of Fig. 1, in a sectional view, Fig. 3 schematically illustrates in particular the rotation head of another trimmer embodying the present invention, configured for carrying more flexible cutting members than that of Figs. 1 and 2, in a sectional view, Fig. 4 schematically illustrates a radial section through the skirt portion of the rotation head of Fig. 3, Fig. 5 schematically illustrates main parts of a further trimmer embodying the present invention, in particular a rotation head and flexible strand or filament cutting members thereof, in a perspective view, Figs.

6 and 7 schematically illustrate flexible filament or strand cutting members in accordance with embodiments of the present invention, Fig. 8 schematically illustrates details of flexible strand or filament cutting members, and the mounting thereof on the rotation head, in accordance with an embodiment of the present invention, in perspective and sectional views, and Fig. 9 schematically illustrates main parts of another trimmer embodying the present invention, in particular the rotation head thereof, in perspective views.

Figs. 1 and 2 schematically illustrate the cutting head end of a trimmer embodying the present invention.

Figs. 3 and 4 schematically illustrate a trimmer which differs from that of Figures 1 and 2 only in that it mounts a greater number of strands or filaments.

The handle or shaft by means of which the trimmer is held or manipulated by the user is not illustrated in detail.

Similarly, the motor by which the trimmer is driven and which may be an electrical, petrol or any other suitable motor, is not shown. Neither is the drive transferring the rotation of the motor to the cutting head illustrated in detail. These non-illustrated components may be of conventional form or of any other suitable form.

The cutting head end comprises a rotation head 1 which can be rotated by the motor (not shown) of the trimmer via a drive shaft mechanism schematically indicated at 10. The rotation head is formed in one piece and has a mounting portion la and a skirt portion lb.

The rotation head may be of metal, for example steel or preferably aluminium, or of plastics material, for example ABS or high impact nylon.

The mounting portion la of the rotation head 1 has an aperture with an internal thread and is screwed directly onto the threaded end of a final drive shaft 10, as illustrated in Fig. 2 or 3. No other mounting or attachment means are employed for fixing the rotation head to the shaft.

As alternative to screw mounting of the rotation head on the shaft, press fitting of the head onto the shaft may be employed.

The skirt portion lb of the rotation head 1 has a cylindrical wall and is open at its end away from the shaft 10. Apertures or holes 2 penetrate the cylindrical wall of the skirt portion lb. In the embodiment of Figures 1 and 2, six apertures or holes are provided, whilst in the embodiment of Figures 3 and 4 twelve apertures or holes are provided. Lengths of flexible strand or filament 3 extend from the skirt portion 1b of the rotation head 1 and provide the cutting members of the trimmer.

The wall of the skirt portion lb need not be cylindrical in all cases. It may alternatively be, for example, hexagonal or octagonal, or of other rotationally symmetric shape.

The wall of the skirt portion lb has a thickness in the range up to 6mm, preferably at least 2.Omm, and more preferably in the range 2.5mm to 5mm, for example 2.5mm or Smm. The lesser the wall thickness, the lesser the weight of the skirt portion lb and of the overall rotation head.

The diameter of the skirt portion lb is in the range up to 6cm, preferably at least 2cm, and more preferably in the range 3cm to 5cm, for example 4cm or 5cm. The lesser the diameter, the lesser the weight of the skirt portion lb and of the overall rotation head.

Most preferably, the skirt wall thickness is 2.5mm and the skirt diameter 4cm. In tests, best results have been achieved with this configuration.

With a rotation head of aluminium, a skirt wall thickness of 5mm and a skirt diameter of 5cm (and with suitably proportioned mounting portion la) an overall weight of the rotation head of about 75gm can be achieved. With a wall thickness of 3mm and a diameter of 4cm (and with suitably proportioned mounting portion la) this weight can be reduced by about two thirds, to around 25gm.

Figure 9 illustrates a further embodiment of the present invention generally similar to the embodiments of Figures 1 to 4 but in which the skirt portion 1b of the rotation head is a simple extension of the mounting portion la, with the same diameter as the mounting portion. In this case even greater weight savings can be achieved, but at some cost in cutting performance.

In the embodiments described above each cutting member is provided by a strand or filament 3 of predetermined length.

By way of example only, each strand or filament cutting member may have a length in the range 10cm to 40cm.

In the embodiments described above, the strand or filament cutting members 3 are simply inserted through the apertures or holes 2, from the open end of the skirt portion lb of the rotation head 1. To facilitate this insertion, the apertures or holes 2 may be inclined inwardly towards the open end of the rotation head 1, as best seen in Fig. 2 or Fig 3.

Figure 5 illustrates a further embodiment of the present invention in which slots 2a are provided in place of holes 2 but otherwise similar to that of Figs. 1 and 2. These slots are open at the lower hem of the skirt portion lb.

When slots 2a are provided, rather than inserting the cutting members 3 through the holes, the cutting members are inserted into the open ends of the slots 2a, then drawn, pushed or pulled down to the closed ends of the slots.

As shown in Figure 5, the slots 2a are preferably angled, inclined or curved so that cutting members cannot simply drop out of then slots when the rotation head is vertical.

At their radially inner ends, the strand or filament cutting members 3 employed in embodiments of the present invention have nodules or thickenings 3A which cannot pass radially through the apertures 2 or radially out of the slots 2a. The nodules or thickenings 3A are integral with the remainder of the strands or filaments 3.

In practice, no additional fastening of the strands or filaments is needed. The nodules or thickenings 3A prevent the strands 3 flying off radially outwardly when the trimmer is in use, and in practice the strands 3 do not drop radially inwardly out of the apertures or holes 2 or slots 2a, and do not fall axially downwardly out of the slots 2a, provided there is a reasonable match between the thickness of the strands in the apertures or holes or slots and the sizes of the apertures or holes or slots. The relatively small diameter of the rotation head 1 assists in hindering radially inward drop-out of strands.

When a strand is worn or broken, it is an extremely simple operation for the user to withdraw any remaining strand portion from the rotation head 1 and to replace it with a new strand 3.

The flexible strand or filament cutting members 3 may be of any suitable material, for example of plastics such as nylon, or of carbon fibre based material, or of metal wire or metal filaments, and each may be single thread or may have multiple threads. A superior quality strand is provided when a co-polyamide raw material is used. PA6 is more generally used.

Although Figs. 1, 2 and 5 show six strand or filament cutting members 3, and Figures 3 and 4 show twelve strand or filament cutting members 3, embodiments of the present invention may employ a lesser number or a greater number of cutting members 3. Particularly for trimmers which will be subjected to heavy duty use, or for mowers, a large number of cutting members, e.g. twelve, is desirable to increase the intervals between strand replacement operations by ensuring that cutting efficiency remains acceptably high even if one or some strands are worn or broken. Fewer strands may be provided in light-use trimmers or mowers.

For example, four strands may be provided.

In cross-section, the flexible strand or filament cutting members 3 may be rounded or may be shaped to provide corners. For example, a square cross-section provides four corners. The corners of the cross-section afford relatively sharp cutting edges along the length of the cutting member, which edges increase the efficiency with which vegetation is cut or trimmed or mowed. This is illustrated schematically in Fig. 6.

The flexible strand or filament cutting members 3 may have cross-sections which vary along their length. For example, the flexible cutting members 3 may become thicker from a portion nearer the rotation head 1 towards the end remote from the rotation head. This is illustrated schematically in Fig. 7. Because wear is heavier towards the end remote from the rotation head 1, such thickening compensates for this factor and extends the period of time for which the cutting members 3 can be used before they need to be replaced.

In the case of a rotation head having slots 2a for mounting the cutting members 3, for example as illustrated in Figure 5, the thickness of the cutting members 3 away from the rotation head may be greater than the width of the slots 2a. The cutting members 3 can be mounted in the slots 2a by passing their thinner sections down the slots.

Fig. 8 illustrates a cutting member 3 which is thicker away from its mounting end and which has at its mounting end a disc-shaped or hemispherical, or flattened hemispherical head or nodule 3A. As also illustrated, the end of the slot 2a in the skirt portion lb, into which slot the head 3A is located when the cutting member is mounted, has a recess into which the head 3A fits. This kind of arrangement, of matching or complementary head or nodule 3A on the strand 3 and receiving recess in the skirt portion lb, may be employed in any embodiment of the invention to further hinder any potential drop out of the cutting member 3.

The flexible strand or filament cutting members 3 may be manufactured and/or sold individually, as relatively short lengths of strand or filament. Alternatively, the cutting members may be manufactured and/or sold as extended lengths of strand or filament from which appropriate portions can be cut or broken off. The extended length of strand or filament may be formed and profiled repetitively along that length, with break or snap-off points provided, so that a cutting member can simply be cut or broken off as needed.

For heavy duty use, the strands or filaments may be up to 3mm or more in diameter or thickness. For lighter or domestic use, diameters of the order of lmm may be sufficient.

Cutters in accordance with embodiments of the invention may be trimmers, or mowers or any other kind of vegetation cutter.

Thus, it will be appreciated that in accordance with the invention there can be provided vegetation cutters which are of refined structure extremely well adapted to their purpose but which nonetheless are simple, compact, userfriendly, economic and robust and highly reliable in structure and which have advantages in terms of cutting action and for the lifetime of the strand or filament cutting members used.

Claims

1. A vegetation cutter having a drive shaft (10), a motor for driving the drive shaft (10) to rotate, and a rotation head (1) mounted on the drive shaft (10) and carrying a plurality of flexible strand or filament cutting members (3), wherein the rotation head (1) is a one-piece rotation head having a mounting portion (la), mounting the rotation head on the drive shaft, which portion (la) is attached directly to the end of the drive shaft (10) with no additional fixing or attachment means, and a skirt portion (lib), extending from and formed in one piece with the mounting portion (la), which skirt portion (lib) has holes (2) or slots (2a) through it, at uniform intervals around the periphery thereof, in which respective flexible strand or filament cutting members (3) of the plurality are received, and wherein the outer diameter of the skirt portion (lob) is no more than 6cm, and the wall thickness of the skirt portion (lb) is no more than 6mm.

2. A vegetation cutter as claimed in claim 1, wherein the outer diameter of the skirt portion (lib) is at least 2cm.

3. A vegetation cutter as claimed in claim 1 or 2, wherein the outer diameter of the skirt portion (lib) is in the range 3cm to 5cm.

4. A vegetation cutter as claimed in claim 1, 2 or 3, wherein the wall thickness of the skirt portion (lob) is at least 2.Omm.

5. A vegetation cutter as claimed in any preceding claim, wherein the wall thickness of the skirt portion (lb) is in the range 2.5mm to 5mm.

6. A vegetation cutter as claimed in any preceding claim, wherein the outer diameter of the skirt portion (lb) is 4cm and the wall thickness of the skirt portion (lb) is 2.5mm.

7. A vegetation cutter as claimed in any preceding claim, wherein the length of the rotation head (1), along the axis of rotation of the head, is 2cm to 6cm.

8. A vegetation cutter as claimed in any preceding claim, wherein the skirt portion (lib) has slots (2a) through it, at uniform intervals around the periphery thereof, in which respective strand or filament cutting members (3) of the plurality are received1 which slots (2a) are open at the lower hem of the skirt portion (lb) and are angled, inclined or curved so that cutting members (3) cannot drop out of the slots (2b) when the rotation head is vertical.

9. A vegetation cutter as claimed in any preceding claim, wherein the rotation head (1) is of metal, for example steel or preferably aluminium, or of plastics material, for example ABS or high impact nylon.

10. A vegetation cutter as claimed in any preceding claim, wherein there are at least four and preferably six or twelve holes (2) or slots (2a) in the skirt portion (lb) receiving the cutting members (3).

11. A vegetation cutter as claimed in any preceding claim, wherein the or each flexible strand or filament cutting member (3) has at its radially inner end, inside the aperture or hole (2) through which it passes, an integral nodule or thickening (3A) preventing it flying radially away from the rotation member (1) when the cutter is in use.

12. A vegetation cutter as claimed in claim 11, wherein the or each strand or filament cutting member (3) thickens from a portion thereof proximate the rotation head (1) towards its end remote from the rotation head (1).

13. A vegetation cutter substantially as described in relation to and shown in Figures 1 and 2, or Figures 3 and 4, or Figure 5, or Figure 8 or Figure 9 of the accompanying drawings.

14. A rotation head of a vegetation cutter as claimed in any preceding claim.

15. A rotation head of a vegetation cutter, substantially as described in relation to and shown in Figures 1 and 2, or Figures 3 and 4, or Figure 5, or Figure 9 of the accompanying drawings.

16. A flexible strand or filament cutting member for a vegetation cutter as claimed in any preceding claim, having an integral nodule (3A) at one end thereof, and then the body of the strand or filament, extending from the nodule, increasing in diameter or thickness towards the end away from the nodule (3A).

17. A cutting member for a vegetation cutter, substantially as described in relation to and shown in Figure 7 or Figure 8 of the accompanying drawings.