GB2324019A

GB2324019A - Lawn trimmer

Info

Publication number: GB2324019A
Application number: GB9807375A
Authority: GB
Inventors: Klaus Hager
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 1997-04-12
Filing date: 1998-04-06
Publication date: 1998-10-14
Anticipated expiration: 2018-04-06
Also published as: GB9807375D0; GB2324019B; DE19715240A1

Abstract

A lawn-trimmer (14) having at least one cutting filament (4) and a motor mounted in a housing (1) for the purpose of driving the cutting filament (4) has, on that side of the housing (1) on which the cutting filament (4) is situated, supporting members which are disposed outside the housing (1). The supporting members are constructed as spherical bodies (11, 12) which slide on the ground (15) when the lawn-trimmer (14) is being held and guided. This makes it possible both to operate and maintain the lawn-trimmer (14) more conveniently and also to design it more simply.

Description

2324019 1 Lawn-trimme

Prior art

The invention relates to a lawn-trimmer of the type in claim 1, particularly a lawntriminer having at least one cutting filament.

DE 44 30 788 AI has already made known a filament-type mower in which a housing surrounding a motor is carried by a rotatably mounted roller and a runner is provided as a stop guard for a filament drum. The runner and roller are attached to the housing, essentially parallel with the underside of the said housing. Instead of the roller, use may also be made of wheels. Since the roller or wheels permit unhindered movement of the mower, parallel to the ground, only M one direction, propulsion of a filament-type mower of this kind in all directions is inconvenient. Movements of the mower which are not directed at right angles to the axis of rotation of the roller or wheels require tilting and lifting movements of the entire filament-type mower and can therefore be performed only with increased effort. In addition, the use of rotating parts with corresponding bearings entails outlay and expense. Finally, pieces which have been mown become lodged between the rotating parts and their bearings, and these pieces make it more difficult to move the filamenttype mower and are hard to remove.

Advantages of the invention The filament-type mower according to the invention having the characterising feature of claim 1 avoids rotating parts and the disadvantages they entail in the prior wl, namely the inhibition of movement and the cleaning problems. It is less expensive to manufacture and can be handled more easily and with less 2 expenditure of force. Furthermore, the setting of the cutting height requires no interruption of the mowing operation, but can be successfully regulated by greater or lesser pressure on the handle of the filament- type mower, if the spherical bodies are resiliently mounted. To this end, spring bars or leaf springs are advantageously attached laterally to the filament-type mower in such a way that they are directed essentially obliquely to the filament side of the housing, and project beyond the said housing in this direction. Since leaf springs have greater stability M the lateral direction than in the vertical direction, they are generally to be preferred. The spherical bodies are attached to the free ends of the resilient components, which are clamped on the housing by their other ends and preferably have a curved shape. In a similar manner, the spherical bodies can be attached to the filairnent side of the housing peripherally to the filament spool. Adjustable stops are advantageously provided for the purpose of limiting the range of oscillation of the resilient members and for height-setting purposes. The height of the spherical bodies can also be set by adjusting the clamping points of the resilient components. For providing protection against external influences and for improving the aesthetic impression, the resilient components are provided with a plastic coating. Advantageous attachment of the spherical bodies is obtained if they are disposed symmetrically to a plane which is determined by the axis of rotation of the filament spool and the geometrical axis of the handle. As a result of the invention, the filament-type mower can easily be slidingly displaced m all directions. The spherical bodies themselves can be constructed as complete spheres or hemispheres or as cups. They are likewise not restricted to a surface which is always curved in a precise manner; what is important is that they should have"good sliding properties.

Drawings 3 An exemplified embodiment with variants will be described m greater detail below with the aid of the diagrammatic drawings, in which:

figure 1 shows a side view of a filament-type mower according to the invention, figure 2 shows a plan view of the filament-type mower according to figure 1, figure 3 shows an adjustable clamping point for the resilient component, figure 4 shows a section along the line A-A in figure 3, and figure 5 shows a view of an ad. ustable stop for the resilient component.

Description of the exemplified embodiments

In figures I and 2, there is disposed a lawn-trimmer 14 with a housing I With an electric motor which is not represented but to the drive shaft 2 of which, which is perpendicular in figure 1, there is detachably fastened a filament spool 3 with a protective cap 13 for at least one cutting filament 4. Also provided on the housing I is an attached piece 5 to which a handle 6 is fixedly connected.

The cutting filament 4 rotates, with the drive shaft 2, about an axis X-X which intersects the prolongation of the geometrical axis S-S of the handle 6 and determines a plane E-E which, in figure 2, is directed at right angles to the plane of the drawing. Fastened to the housing 1, symmetrically to the plane E-E, are two carrying elements 7, 8 into each of which there is clamped, by one end, a curved leaf spring 9, 10 which is provided with a plastic coat and of which the other, free end faces towards the handle 6 and is provided with a sphere 11 and 12 respectively. In addition, the free end of the spring 9 or 10 respectively, is curved towards that side of the housing 1 on which the filament spool 3 is situated, in such a way that the spheres 11, 12 project, when the lawntrimnier 14 is in the normal position, beyond the filament spool 3 in the direction of the ground 15 by an amount which can'be set. On the housing 1 there are provided, above the leaf 4 springs 9, 10, stops 16, 17 which limit the deflections of the said leaf springs 9, 10 and, in doing so, prevent the protective cap 13, which rotates with the filament spool 3, from resting on the ground 15.

In figures 3 and 4, the carrying element 8 is fastened, With the leaf spring 10, on a sliding piece 18 which is adjustable in a dovetail guide 19 between guide stops 20, 21 and can be immobilised with the aid of a set-screw 22. The carrying element 7 has the same system of attachment. The height of the lawn-trinuner 14 above the ground 15, and therefore the cutting height of the filament 4, can be set by adjusting the sliding pieces 18 in the dovetail guides 19.

In figure 5, the stop 17 for the leaf springs 10 is fastened on a sliding piece 23 which is able to slide m a dovetail guide 24 between two guide stops 26 and 27 and can be locked with a set-screw 25. The stop 16 has the same system of attachment. For limiting the deflection of the leaf springs and for setting the cutting height of the cutting filament 4, the sliding piece 23 is brought into the desired position with the set-screw 25 loosened and is locked in the said position by means of the said setscrew 25.

When the lawn-trimmer 14 according to the invention is being used, the cutting height of the cutting filament 4 is first of all set by adjusting the carrying elements 7, 8 and/or the stops 16, 17, after which the mowing operation is carried out by guiding, for example swivelling, pushing or pulling, the filament-type mower 14 with the aid of the handle 6. If, during the mowing operation, the cutting height is to be changed on a more or less temporary basis, this can be achieved by a suitable manual change in pressure on the handle 6 approximately parallel to the axis X-X.

The invention is not restricted to the forms of embodiment of a filamenttype mower or light lawn-mower which have been represented. For example, the springs 9, 10 may also be spiral springs or bar springs in a suitable arrangement. Instead of the spheres 11, 12, use may also be made of other bodies provided with an essentially curved surface, all of which have been designated here as spherical bodies. It is also possible to dispose the carrying elements 7, 8 on the housing 1 on the same side as the handle attachment system, so that the free ends of the springs 9, 10 with the spherical bodies 11, 12 extend m that direction of advance of the filament-type mower which is indicated by an arrow 29. Provided that no collision with the cutting tool, which consists, for example, of one or two cutting filaments, is to be anticipated, the spheres 11, 12 or the like can also be disposed, preferably resiliently, on that front face of the housing 1 through which the drive shaft 2 of the electric motor or internal-combustion engine is routed and which has been designated above as the filament side of the housing 1. There is also the possibility of using more than two spherical bodies for supporting the lawntrimmer 14 on the ground 15, including a grass surface, in a sliding manner. Finally, the handle attachment system may be designed to be pivotable, and the handle length to be variable, so that they can be easily adapted to local, ergonomic and individual conditions.

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Claims

1. Lawn-triminer (14) having a cutting element (4), particularly having at least one cutting filament, a motor which drives the cutting element (4) and is mounted in a housing (1) which has, on its outside, particularly on opposite sides, and outside the working range of the cutting element (4), supporting members (11, 12) for supporting the lawn-trimmer (14) on a lawn or the like to be trimmed, and also having a handle (6), which is fastened to the housing (1), for holding and guiding the lawn-ti-immer (14), characterised in that the supporting members are constructed as spherical bodies (11, 12).

Lawn-trimmer according to claim 1, characterised in that the spherical bodies (11, 12) are disposed on the housing (1) m a resilient manner.

3. Lawn-trimmer according to claim 1 or 2, characterised m that the spherical bodies (11, 12) are disposed on the housing (1) in a manner such that they can be set.

Lawn-trimmer according to claim 3, characterised in that each spherical body (11, 12) is fastened to the free end of a resilient leaf-shaped or barshaped component (9, 10) which is clamped by its other end into a carrying element (7, 8) which is fastened laterally to the housing (1).

5. Lawn-trimmer according to claim 4, characterised in that the carrying elements (7, 8) are disposed in an essentially vertically adjustable manner.

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6.

Lawn-trimmer according to claim 4, characterised in that a stop ( 16, 17) is provided on the housing (1) for each resilient component (9, 10).

7. Lawn-trimnier according to claim 6, characterised in that tile stops (16, 17) are disposed in an adjustable manner.

8. Lawn-trimmer according to claims 4 and 7, characterised m that the stops (16, 17) are adjustably disposed between the ends of the leafshaped or bar shaped components (9, 10), above the said components and transversely to the said components.

9. Lawn-trimmer according to claim 1, characterised in that the two spherical bodies (11, 12) are disposed essentially symmetrically to that plane E - E which is determined by the axis of rotation X - X of the cutting element (4) and the geometrical axis (S - S) of the handle (6).

10. Lawn-trimmer according to claim 4, characterised in that the leaf shaped or bar-shaped components (9, 10) have a plastic covering.

11. A lawn er substantially as herein described with reference to the accompanying drawings.