GB2227915A - Pruning machine - Google Patents

Description

1.

PRUNING MACHINE The present invention relates to a motorised cutting implement e.g. hedge- clippers and pruning machines (hereinafter "pruning machines").

A conventional pruning machine is typically arranged such that nonflexible members are provided between a pruning edge unit composed of movable and fixed edges and an operating unit for the movable edges.

When using such non-flexible members, however, it is impossible to vary the angle of the pruning edge unit independently of e.g. the body carrying the driving source. It is required that this angle of the pruning edge unit be changed, conventionally by raising or lowering the operator's hand position to adapt to varying heights of plants in the garden or of a hedge. Especially when pruning low garden plants, the gardener conventionally also has to bend his waist to manipulate the machine. Where the body of the pruning machine incorporates a driving source, in the great majority of cases the body is formed with protrusions which interfere with the raising or lowering of the hand position. In the case of motorised shears suited to prune tall branches, a long handle is provided between the operating unit and the pruning edge unit, with the result that the angle of the pruning edge unit cannot be changed simply 2.

by raising or lowering the hand position. Thus, wellpruned branches are not invariably obtained.

It is a primary object of the present invention to provide a pruning machine which at least ameliorates these problems.

other objects and advantages of the invention will become more apparent during the following discussion in conjunction with the accompanying drawings, in which:

Figure 1 is a plan view illustrating a pruning machine according to the present invention; Figure 2 is a side view thereof; Figure 3 is a cross-sectional view depicting a pipe in a case where guide members are provided; and Figure 4 is an explanatory view showing a handy type pruning machine.

The present invention will hereinafter be described with reference to Figures 1 to 4.

A driving source generally designated at 2, which is conventionally incorporated into a conventional hair- clippers type pruning machine driven by a motor, is also used in this embodiment. Fixed to a front portion of driving source 2 is a fixed plate 1, one side surface of which is provided protrusively with a multiplicity of fixed edges 3 at given intervals in a comb-like configuration in the longitudinal direction thereof. A 1 3.

flexible driving band 4 is mounted on fixed plate 1 in the longitudinal direction, the rear end of which driving band 4 is connected to a driving source 2. Movable cutting parts 6 are provided in the gaps between the fixed edges 3 and have at one end cutting edges, and at the other are fixed to the band 4. The cutting parts 6 are rotatable about a screw 11. In use, the band 4 reciprocates, being driven by the driving source 2 so that the cutting edges and the fixed edges together perform a cutting action.

The band 4 is typically formed of a thin steel sheet which exhibits a flexible strength. The band 4 may be composed of thin steel sheets laminated on each other to obtain a considerable strength or of a single steel sheet. The material of the band 4 may alternatively be aluminium, FRP or the like. Any materials having a suitable flexible strength can be employed in the present invention.

As illustrated in the Figure, the band 4 may have uniform thickness along its length. However, part(s) of the band may be replaced by a thickened length of e.g. steel, in which case the lengths are fastened together with screws or by welding. The numeral 7 represents an edge fixing screw provided in the vicinity of the top of an angular or round pipe 8 for accoarnodating and supporting the band 4, the fixing screw being positioned at a point at which the band 4 is bent. If the band 4 is too long, it is likely that the driving force given by driving source 2 is not transferred efficiently due to flexure of the band 4. Such being the case, guide members 13 for the band 4 are formed on an inner wall of the pipe 8 and are coated with low- friction resin, thereby obtaining good slidableness between the inner wall of pipe 8 and movable plate 4. The numeral 9 denotes an edge clamping screw provided in rear of edge fixing screw 7. When the edge clamping screw 9 is slackened, the pruning edge unit 12 can, as depicted by an imaginary line in Figure 2, be inclined at a desired angle by a slight force. Once the edge clamping screw 9 is re-tightened after changing the angle, the pruning edge unit 12 is kept at the desired angle.

In the thus constructed pruning machine according to the present invention, the pruning edge unit may be bent through a desired angle about a point of the edge fixing screw by slackening edge clamping screw 9. Subsequently, edge clamping screw 9 is fastened, whereby the pruning machine has a pruning edge unit with the desired angle for pruning particular garden plants.

As best seen in Figure 4, the present invention can be applied to a handy type pruning machine including a shortened driving band 4, the arrangement being such that the angle of pruning edge unit 12 can be varied, with edge fixing screw 7 serving as a fulcrum, by slackening edge clamping screw 9.

If the present invention is applied to shears (not illustrated) suited to shear tall branches which are a type of pruning machine, instead of a rod shaped in continuation from the movable edges, a band-like thin steel plate is employed; or alternatively the band-like thin steel plate is used for part of the rod, and the steel plate is connected to the rod with a screw or by welding.

In accordance with the present invention, the flexible driving member is interposed between the pruning edge unit and the operating unit, it is therefore feasible to freely change the angle of the pruning edge unit by bending the flexible member. With this arrangement, operations such as mowing of lawns and pruning of very low garden plants can be effected without bending the waist. Tall branches can also readily be pruned more easily and effectively.

Although the illustrative embodiments of the present invention have been described in greater detail with reference to the accompanying drawings, it is to be understood that the invention is not limited to those 6.

precise embodiments. Various changes or modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the invention.

7.

Claims (9)

1. CLAIMS:

   A motorised cutting implement comprising:

   body; driving source in the body; a fixed plate, at least one edge of which has protrusions with fixed cutting edges; cutting parts mounted on the fixed plate to be reciprocably driven by a driving member driven by the driving source, at least part of the driving member being flexible, there being means to allow alteration of the angle between the body and the fixed plate in the region where the driving member is flexible.
2. 2. A motorised cutting implement according to claim 1 wherein the means to allow alteration include means for holding the fixed plate at a fixed angle to the body.
3. 3. A motorised cutting implement according to claim 2 wherein the means for holding includes a clamping screw.
4. 4. A motorised cutting implement according to any one of the preceding claims wherein the driving member is a flexible band.
5. 5. A motorised cutting implement according to any one of the preceding claims wherein part of the driving member is a rigid rod.
6. 49 A motorised cutting implement according to any one of the preceding claims wherein at least one guide member is provided which guides at least part of the driving member.
7. 7. A motorised cutting implement according to claim 6 wherein at least part of the driving member runs in a pipe, the guide means being inside the pipe.
8. 8. A motorised cutting implement according to any one of the preceding claims wherein said cutting parts are rotatably mounted on the fixed plate.
9. 9. A motorised cutting implement substantially as herein described with reference to the accompanying drawings.

   Published 1990 at The Patent 051ce. State HOuse.6671 High Holborn. London WC1R4TP- Further copies maybe obtained from The PatentOffice Sales Branch, St Mary Cray. Orpington. Kent BRS 3RD Printed by Multiplex techniques ltd. St Mary Cray. Kent, Con 1'87 1