GB2214048A

GB2214048A - Cutting device for a mower

Info

Publication number: GB2214048A
Application number: GB8901128A
Authority: GB
Inventors: Peter John Jefferis
Original assignee: ALLEN POWER EQUIPMENT Ltd
Current assignee: ALLEN POWER EQUIPMENT Ltd
Priority date: 1988-01-22
Filing date: 1989-01-19
Publication date: 1989-08-31
Also published as: GB8901128D0

Abstract

A mower, such as a hover mower or a wheeled mower, has a cutting device which is constituted by a plastics blade 10 adapted for mounting on the vertical driving shaft of the mower and mounted at or adjacent its periphery a flexible cutting element 21, preferably a nylon cutting line, extending, in use at least, radially outwardly of the plastics body. Such a cutting device is safer in use than the conventional metal cutting blade. <IMAGE>

Description

IMPROVEMENTS IN OR RELATING TO MOWERS This invention relates to mowers.

Mowers, such as hover mowers or wheeled mowers have a cutting blade of metal rotatable about a centrally-disposed vertical axis, the blade being secured to a vertical shaft driven electrically or by a petrol engine mounted on top of the mower casing or housing which is open-bottomed. The latter encloses the metal cutting blade, above and peripherally, but despite this enclosure accidents, due usually to careless or inexperienced handling of the mower, occur.

It is an object of the present invention to provide such a mower which is safer in use than existing mowers.

The above object is achieved, according to this invention, by providing a cutting device for a mower which is constituted by a plastics body adapted for mounting on the vertical driving shaft of the mower and mounting at or adjacent its periphery a flexible cutting element extending, in use at least, radially outwardly of the plastics body.

Preferably the flexible cutting element is formed of nylon or other plastics material having suitable physical characteristics (hereinafter and in the claims for convenience simply referred to as 'nylon1).

Preferably, the plastics body is in the form of a blade at each end of which is secured a nylon cutting line.

Preferably, the nylon cutting lines are removably secured to the ends of the plastics blade to facilitate replacement thereof when required.

Preferably, a recess is formed adjacent but spaced inwardly of each end of the plastics blade with a pair of side-by-side holes communicating with the recess and the respective end face of the plastics blade for mounting the nylon cutting line.

Preferably the nylon cutting line is formed double the required length, or substantially so, and is fitted in U-loop configuration to the blade end through the recess and holes free ends leading.

Preferably the nylon cutting line is of circular, triangular or other suitable crosssectional shape.

Also according to the present invention there is provided a mower incorporating a cutting device as defined in one or more of the immediately preceding seven paragraphs.

An embodiment of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which: Fig. 1 is an underneath plan view, partly in section of a cutting device for a hover or wheeled mower; Fig. 2 is a corresponding top plan view of the cutting device; Fig. 3 is a side elevation, partly in section and corresponding to Fig. 1, of the cutting device; and Fig. 4 is an end elevation corresponding to Fig.

2 with the nylon cutting line omitted.

The cutting device is suitable for fitting to any type of hover or rotary or wheeled mower, and is secured to the driven vertical shaft of, for example, an engine-powered hover mower in the same way as a conventional metal cutting blade is now secured.

The cutting device comprises a plastics blade 10 having a central hole 11 to receive the mower vertical shaft (not shown).

The plastics blade 10 is of elongate construction tapering outwardly from the central hole 11 to each end.

Each side face of the plastics blade 10 has a vertical length 12 merging through a radiussed length 13 with a chamfered length 14.

When the cutting device is fitted onto the vertical shaft of a hover mower the chamfered faces 14 are inclined outwardly and downwardly thereby providing an aerodynamic configuration at each side of the plastics blade 10, which enhances the air flow produced during use and assists in holding the hover mower adjacent the grass to be cut.

In use, the lower edges 15 of the chamfered faces 14 of the plastics blade sides perform, to a greater or lesser degree, a cutting action but this is secondary to the aerodynamic action of these chamfered faces 14.

The elongate recesses indicated at 16 in Fig. 2 are simply provided to facilitate tooling of the moulded plastics blade 10.

At each end, the plastics blade 10 is formed with a recess 17 open to the bottom surface of plastics blade 10 when fitted onto the vertical shaft of the mower. This recess 17 is adjacent to but inboard of the adjacent end face 18 of the plastics blade 10. The recess 17 gradually increases in depth the nearer it is to the end face 18 as can be seen in Fig. 3. The recess 17 communicates with the end face 18 via two holes 19 which, considering the end face 18 (see Fig. 4) are transversely and vertically spaced. The diameter of the holes 19 flare outwardly as indicated at 20 (see Fig. 1 especially).

The actual cutting elements of the cutting device are a pair of nylon cutting lines (flexible elements) indicated at 21. Each cutting line 21 is of triangular or other suitable cross-section and is in the form of a U-loop. Each cutting line 21 is fitted to a respective end of the plastics blade 10 by being inserted via the recess 17 into the holes 19, the limbs 22 of the U-loop 21 being pulled through the holes 19 until the closed end 23 of the U-loop 21 abuts the end wall 24 of the recess 17.

The lengths of the limbs 22 of the nylon cutting line 21, when fitted to the plastics blade 10 are equal, or substantially so.

It will be manifest that replacement of a cutting line 21 is simple, the cutting line 21 to be replaced simply being extracted via the recess 17 and a fresh cutting line 21 threaded into position as aforesaid.

The cutting device consisting of the plastics blade 10 and nylon cutting lines 21 is substantially safer in use compared with the customary metal blade especially when used in heavy duty operations. Also, replacement of one or both nylon cutting lines 21 is easier and speedier than replacement of a damaged metal blade and is also more economic.

Claims

1. A cutting device for a mower which is constituted by a plastics body adapted for mounting on the vertical driving shaft of the mower and mounting at or adjacent its periphery a flexible cutting element extending, in use at least, radially outwardly of the plastics body.

2. A cutting device as claimed in claim 1 in which the flexible cutting element is formed of nylon.

3. A cutting device as claimed in claim 2, in which the plastics body is in the form of a blade at each end of which is secured a nylon cutting line.

4. A cutting device as claimed in claim 3, in which the nylon cutting lines are removably secured to the ends of the plastics blade to facilitate replacement thereof when required.

5. A cutting device as claimed in claim 3 or 4, in which a recess is formed adjacent but spaced inwardly of each end of the plastics blade with a pair of side-by-side holes communicating with the recess and the respective end face of the plastics blade for mounting the nylon cutting line.

6. A cutting device as claimed in claim 5, in which the nylon cutting line is formed double the required length, or substantially so, and is fitted in U-loop configuration to the blade end through the recess and holes free ends leading.

7. A cutting device as claimed in any one of claims 1 to 6, in which the nylon cutting line is of circular, triangular or other suitable crosssectional shape.

8. A cutting device for a mower, substantially as hereinbefore described with reference to the accompanying drawings.

9. A mower incorporating a cutting device as claimed in any one of claims 1 to 8.