WO2000065897A1

WO2000065897A1 - Tool rotor for garden combination machine

Info

Publication number: WO2000065897A1
Application number: PCT/SE1999/000699
Authority: WO
Inventors: Ingvar BJÖRKMAN
Original assignee: Combita Garden Tools, Ingvar Björkman
Priority date: 1999-04-28
Filing date: 1999-04-28
Publication date: 2000-11-09

Abstract

Tool rotor (4) for a combination machine for different types of garden care activities like lawn cutting, earth cultivation, moss removal, sweeping, snow blowing etc. comprising a chassis mounted on wheels and in which a drive engine of a suitable type is mounted, for instance an electric motor or an internal combustion engine, and in which the tool rotor (4) is rotatably mounted on a drive shaft (7) and is driven by the engine/motor over a transmission, and in which the tool rotor (4) is arranged to carry different types of tools (9) on two or more, preferably three tool shafts (10), and in which said tool shafts (10) are fixed mounted between two end plates (8) and with their shaft centers spaced from the drive shaft (7) of the tool rotor (4) by a distance which is less than radius of rotation of the tool (9) on the tool shaft (10), and in which the tools (9) are mounted rotatable a limited angle on the tool shaft (10) from a normal position which is radially or nearly radially directed out from the drive shaft (7), and such limited rotation is accomplished against the action of a spring means (16) in case the tool (7) is strongly meeting a hard resistance, and in which said spring means resets the tool to its normal position as soon as said hard resistance is ceased.

Description

TOOL ROTOR FOR GARDEN COMBINATION MACHINE

The present invention generally relates to a combination machine for different types of garden care like grass cutting, earth cultivating, sweeping, snow blowing etc whereby only tools are substituted in a tool rotor, or eventually a new rotor having other tools is mounted in the machine The machine is of the type which is shown in the Swedish patent publication SE 505 261 and which comprises a chassis which is supported on wheels and in which a drive engine of a suitable type is mounted, which engine may be an internal combustion engine, an electric motor connected to the mains or a battery driven motor, and on which a tool rotor is mounted, whereby the engine drives the tool rotor over a transmission, and in which the tool rotor is arranged to carry different types of tools As conventional the tool rotor co-operates with an ejection channel which, for some purposes like grass cutting, moss removing etc , if desired, in turn can be connected to a collecting device The tool rotor is formed with two or more, preferably three shafts, on which tools are arranged for being mounted

In the above mentioned known garden combination machine the tools are formed as separate units, for instance grass cutting knives, brush pieces, wings for snow blowing, which units can easily be removed, and which can be mounted onto the tool shafts especially by a spring clamp action A large number of tool units are mounted aside of each other on one and the same shaft The tools are actuated by centrifugal action during the rotation of the rotor and are generally set themselves radially outwards for executing their action This involves the advantage that the tools yield and turn aside in case the tool hits a hard object on the ground like a stone or a tree root, whereby it is possible to avoid damages on the tools

A problem with saiα priorly known apparatus is that the tool units must be capable of rotating a full turn on its tool shaft in order to avoid that the tool gets stuck to any part of the machine It is necessary that the tool can rotate freely past the main shaft, and this involves the disadvantage that the rotor pack becomes relatively voluminous It may also happen that the tool units which are only loosely clamped on the tool shaft, slide in the transversal direction and that some tools thereby become positioned too close to each other, other tools too far from each other. This can impair the result of the work performed by the machine. Further the work with mounting of the many separate tool units is time consuming, and it may be necessary to frequently check that no tool units have become loosened, or that the tool units have slid sideways on their tool shafts.

SOLUTION OF THE PROBLEM

The basis of the invention therefore has been the problem of providing a modified type of garden combination care machine which is formed with a new type of tool rotor comprising two or more tool shafts which are preferably provided evenly distributed round the drive shaft of the tool rotor, and on which tool shafts a number of tools are mounted with a moving possibility restricted by a spring action, and in which the tool shaft is mounted much closer to the main shaft of the rotor than in the said previously known apparatus, whereby the entire system of tool units gets reduced dimensions in the cross rotary plane.

According to the invention the utensil tools are pre-mounted in a resilient way on a tool shaft which is arranged for being mounted, for instance welded between two end plates of the machine chassis. The tools are mounted on the tool shaft so that they can not be displaced in the transversal direction thereon. The tool rotor with the pre-mounted tools preferably is formed as a separate unit which can easily be substituted by another unit for a different type of work.

In a first embodiment of the invention the parts of the tool implement shaft, where the tools are to be mounted are oval, for instance elliptic, and the tools are mounted thereon by means of resilient, oval mounting pieces with the tools preferably directed radially out from the rotor shaft, and so that each separate tool can rotate over a certain angle, for instance up to 30°, at least in a direction which is opposed to the direction of rotation of the tool rotor for the case that the tool should hit any hard object on the ground, and so that the tool immediately after having passed said hard object regains its position radially our from the rotor shaft depending on the spring action.

In an alternative embodiment of the invention the tools are mounted rotatable but not displaceable on the tool shaft over a carrier plate which is at least slightly rotatable together with the tool against the action of a spring, so that the tool can be rotated slightly and can thereafter regain its original position, preferably radially out from the drive shaft of the tool rotor, in the same way as in the above mentioned first embodiment of the invention.

The apparatus of the invention is formed with fan wings for providing a blowing out of grass cuts, moss, leaves, snow etc., and according to the invention said fan wings are fixedly mounted between the end plates of the tool rotor and are hidden and protected against damage behind the tools.

Further advantages and characteristics of the invention will be evident from the following detailed specification in which reference is made to the accompanying drawings. In the drawings figure 1 diagrammatically and in a perspective view shows a garden care combination machine comprising the new details according to the invention. Figure 2 shown, in a comparative cross section a tool rotor according to the prior art technics, shown to the left in the figure, and a tool rotor according to the invention, shown to the right. Figure 3 is a vertical cross section view through a tool rotor according to a first embodiment of the invention, and figure 4 shows a cross section view along line IV-IV of figure 3. Figure 5 shows, like in figure 3, a vertical cross section view through a tool rotor according to a second embodiment of the invention, and figure 6 shows a cross section view along line VI-Vl of figure 5. The combination garden care machine which is diagrammatically shown in figure 1 comprises a machine chassis 1 which, in the illustrated case, is carried on four wheels 2 and can, as convention, be steered and controlled from a handle. As conventional the machine comprises an engine (not shown in the drawings), which may be an internal combustion engine, an electric motor connected to the mains, or eventually a battery driven electric motor. The engine/motor is by a transmission 3, preferably a V-belt, connected to a tool rotor 4 arranged to perform the intended work such as lawn cutting, moss scratching, earth cultivating, sweeping, snow blowing etc., whereby different types of tool units are mounted on the tool rotor. Between the engine 3 and the tool rotor 4 there may exist a release clutch of known type. It is, of course, also possible to provide the power transmission from the engine to the tool rotor using some type of known hydrostatic transmission. An ejector 5 extends from the tool rotor 4, over which ejector a collector device 6 can be placed if desired.

Figure 2 is a comparative view of a tool rotor of known type (to the left) and a tool rotor 4 according to the invention.

In both cases the tool rotor is formed with a drive shaft 7 which is mounted between two end plates 8 and which is rotated by the engine 1. In the illustrated case the tool rotor is formed with three sets of tools 9a (prior art) and 9b (new art), respectively, each of which is mounted on a tool shaft 10 which is mounted between the end plates 8 and rotate together with same as an integral unit. Each tool shaft 10 can carry a large number of tools 9b, for instance mounted spaced from each other by 3-10 cm. Between the end plates 8 also fan wings 11 are mounted for creating an air flow adapted to divert grass cuts, moss, snow etc. through the ejector 5.

PRIOR ART

It is evident from figure 2 that the tools 9a are mounted so on the tool shaft 10 that said tools 9a can rotate freely thereof. In this case it is necessary that the tools 9a can rotate a complete turn without hitting the drive shaft 7 or any other part of the machine. The known structure thereby gets a relative large diameter, and the fan wings 11 are correspondingly relatively long and may run the risk of becoming damaged if hitting some hard objects on the ground, especially since the tools, while being rotated on the tool shaft 10 may uncover the fan wings 11. THE INVENTION

In the right hand half of figure 2 there is shown an apparatus according to the invention in which he tools 9b are at least the same long as the tools 9a of the prior art structure, but in which the operation diameter of the new embodiment of the tool rotor is substantially reduced. This has been made possible in that tool shafts 10 have been mounted closer to the drive shaft 7, and in that the tools 9b have been mounted with only limited possibility to rotate, namely over an angle of, for instance, 30° in the clockwise direction as shown in the figures, or ±30° from their oridinary positions radially out from the centre of the drive shaft 7. A further advantage with said new arrangement is that the fan wings 11 are mounted protected at the rear side of the tools 9b, whereby there is practically no risk that the fan wings become damaged if hitting hard objects on the ground.

In figures 3 and 4 is shown a first embodiment of a tool rotor according to the invention. As described above the tool shafts 10 are mounted between end plates 8, for instance in that said shafts are welded between said end plates. Also the fan wings 11 are secured, for instance welded between the end plates 8, whereby said end plates with the tool shafts 10 and the fan wings 11 provide a well interconnected integral unit. The end plates preferably are profile pressed plates as indicated in figure 4. In figure 3 is shown that the tool shafts 10 are formed with a series of oval indentations 12 each intended for fixed connection of a tool, which in the illustrated case is formed as a twin layer tool part 13 that has, in the outer end thereof, a functional cutting tool end 14, a clamp 15 which can be clamp connected to the tool part 13 and which is kept clamed to the tool part 13 by means of two spring biassed screws 16. Adjacent its outer end the layers of the twin layer tool parts 13 are kept together by a screw and at the inner end by a screw/nut connection 17.

In the illustrated case the tool rotor 4 is a triplet rotor consisting of three units of tools and intermediate fan wings arranged with spacings of 120°. It is obvious that the rotor, if desired or for special purposes, can be formed with only two units of tools, or with more than three units

The rotor rotates following the arrow 18, whereby the cutting edges 14 of the tools perform their activities, for instance cutting of grass, removal of moss, blowing out snow etc , which material is thereby ejected upwards-outwards along the ejector 5 If any of the tools 9 should happen to hit a hard object on the ground, for instance a stone, a root or another hard object the tool 9 is rotated in the clockwise relative direction on the oval shaft part 12 in that the tool part 13 and the clamp 15 are slightly separated from each other by spring action while the springs of the spring screws are compressed The rotation can be for instance 30° at most As soon as the tool has passed the hard object it is automatically rotated back to its normal position directed radially outwards

In figures 5 and 6 is shown an alternative embodiment of a tool rotor 4 according to the invention In the illustrated case the tool 9, comprising the tool part 13 and the cutting edge 14, is fixedly mounted on a carrier disc 19 which can be rotated slightly on the shaft 10 in common with the tool 9 In this case the shaft 10 is circular cyhndric The carrier disc 19 is formed so that it can be rotated over an angle of for instance 30° in the clockwise direction on the shaft 10, in common with the tool 9 In its normal position the carrier disc engages, with a part thereof, a guide ring 20 thereby keeping the tool 13 in radial direction The carrier disc 19 is kept in said normal position by a spring 21 which is connected to the adjacent carrier disc 19, as seen in counter clockwise direction

In figure 6 is shown that the transmission between the engine/motor of the apparatus and the tool rotor 4, as one out or several possible embodiments, comprises a V-belt 22 and a belt pulley 23 which is fixed on the drive shaft 7, and in which the unit comprising end plates 8 and tools 9 which are fixed to the drive shaft 7 by means of split pins 24 As mentioned above there may be a release clutch between the engine/motor and the tool rotor 4 REFERENCE NUMERALS

1 chassis 13 tool part

2 wheels 14 tool end, cutting edge

3 engine 15 clamp

4 tool rotor 16 screw

5 ejector 17 screw/nut connection

6 collector device 18 arrow

7 drive shaft 19 carrier disc

8 end plate 20 guide ring

9 tool (a, b) 21 spring 0 tool shaft 22 V-belt 1 fan wing 23 belt pulley 2 indentation 24 split pin

Claims

C L A I M S

1 Tool rotor (4) for combination machines for different types of garden care activities like lawn cutting, earth cultivation, moss removal, sweeping, snow blowing etc , and comprising a chassis (1) carried on wheels (2), in which chassis a drive engine/motor of suitable type is mounted, like an electric motor or an internal combustion engine, and in which the tool rotor (4) is mounted rotatable on a drive shaft (7) and is driven by the engine/motor over a transmission (3), and in which the tool rotor (4) is arranged to carry different types of tools on two or more, preferably three tool shafts (10) on which tools (9) are arranged for being mounted, characterized in

- that the tool shafts (10) are fixed mounted between two end plates (8) with the shaft center on a distance from the drive shaft (7) of the tool rotor (4) which is less than rotation radius of the tool (9) on the tool shaft (10), - that the tools (9) are mounted on the tool shaft (10) for being rotated a limited angle from a normal position which is a position with the tools directed radially or nearly radially out from the drive shaft (7),

- and that such limited rotation is made against the action of a spring means (16, 21) and occurs when the tool (9) is acted on by a strong resistance, and whereby said spring means resets the tool to its normal position as soon as said strong resistance is ceased

2 Tool rotor according to claim 1 , characterized in that the tools (9) are mounted for being rotated a limited angle on the fixed mounted tool shaft (10) and without giving the tools a possibility of being laterally displaced on the tool shaft (10)

3 Tool rotor according to claim 2 characterized in that the tool shaft (10) is formed with several indentations (12) having an oval or elliptic cross section shape and preferably being evenly distributed along the tool shaft (10), on which indentations a spring actuated, correspondingly oval carrier for the tool (9) is mounted, which carrier under spring (16) action allows a certain rotation, against the action of the spring (16) of the tool (9) on the oval indentation of the tools shaft (10).

4. Tool rotor according to claim 2, characterized in that the tool shaft (10) is formed with circular cylindric indentations which allow a rotation of the tool (9) together with its tool connection means (13) on the tool shaft (10), and in which the tool is fixed mounted in the transversal direction and is mounted on a carrier disc (19) which in normal position is locked so that the tool takes a position radially out from the drive shaft (7) but allows a rotation against the action of a spring (21 ) which is connected to the carrier disc (19).

5. Tool rotor according to any of the preceding claims, characterized in that the tool (9) is mounted so that it can be rotated up to about 30° in a direction which is opposed to direction of the rotor (4) rotation [figure 3] from a normal position, in which the tool is directed radially out from the rotor shaft (10).

6. Tool rotor according to any of the preceding claims, characterized in that it is formed with fan wings (11) mounted between the tools (9) and which fan wings (11) thereby are mounted in protected positions.