GB2231249A - Flail mower - Google Patents

Abstract

A topping mower 10 is mounted on a pivotal arm 17 attached to a frame 13 carried on the lower links of the tractor lift 12. The mower comprises, within hood 28, a horizontal drum 31 carrying flails 32 and rotated by a shaft 33 from a gearbox 34 mounted on the tractor power take off shaft. The flails 32 cut the grass and rough growth below the hood, then toss the cuttings up into the hood where they are further shredded and thrashed by the flails, before being deposited behind the mower. <IMAGE>

Description

Improvements in Mowing Machines, and Mounting Arrangements Therefor.

This invention relates to improvements in mowing machines and to mounting arrangements therefor.

The invention relates in particular to a so-called 'topping mower, which is intended to remove coarse grass tussocks, seed heads and other vegetation such as thistles and docks whilst leaving an ample depth of sweeter grass for grazing. Regular topping will check the coarse species, and encourage growth of the more nutritious sweeter grasses.

A variety of cutting arrangements have been proposed, including rotary knife drums similar to those used for close cropping of lawns and playing fields, the length of grass remaining depending on the height these are carried above the ground. Such cutters are however preferred for harvesting hay or silage rather than merely topping grazing land. More often used for topping mowers are flails, a plurality, e.g.

two or three being mounted on each of two or three rotors to lie in a horizontal plane above the ground, the rotors being driven by a belt drive. Such drives are relatively inefficient, and if the flails should become clogged with cut matter, thebelt will slip rather than exert the power needed to cut through the material.

Such toppers are carried by the three point hydraulic linkages of a tractor, being trailed, partially offset or fully offset, and are raised and lowered by the tractor hydraulics. They do not however have any capability of riding over obstacles, such as rocks, and the driver has to stop, perhaps reverse, and use the tractor hydraulics to lift the mower clear of the obstacle.

Objects of the invention accordingly include the provision of a topping mower with a cutting mechanism which is driven direct from the power shaft without the intermediary of belts or chains to acheive a more efficient drive, and the provision of a mowing machine which is mounted in such a way that it can ride over obstacles without damage to the cutting mechanism and without use of the tractor hydraulics.

According to one aspect the invention provides a grass topping mower wherein a plurality of flail cutters are mounted on a horizontally extending shaft, the flails rotating in planes perpendicular to the ground, the shaft being directly connected to an input drive shaft.

From another aspect, the invention provides a mowing machine having means for mounting said machine on the three point hydraulic lift linkage of a tractor, and buffer means between the mowing machine and the linkage such as to .enable the machine to ride over an obstruction and be reset by such buffer means at the correct cutting height.

The cutters are preferrably carried below a downwardly open hood which is arched above the cutters se as to allow cut material te be tossed into the hood and thrashed by the flails to shred the cut plant material completely, so that even the coarsest grasses and plants are made edible to live stock. The hood is preferrably carried on an arm which is pivoted to the linkage or a mounting frame on the linkage.

The buffer means may be a coil spring coaxial with a ram for raising and lowering the mower between its operating and transporting positions. The spring will thus act to absorb rising movements of the mower riding over obstructions and automatically return it to the cutting position. A further suspension rod may be provided which carries the hood, taking some of the weight from the arm, and cushioned by a coiled compression spring.

A preferred embodiment of topping mower according to the invention will now be described by way of example with reference to the accompanying drawings, wherein: Fig. 1 is a partly sectional view of the mower and its mounting, as seen from behind the tractor; Fig. 2 is a plan view; and Fig. 3 is a sectional view from one side of the mower.

A topping mower 10 according to the invention is carried on the usual three point hydraulic lift 12 of the tractor.

The mounting is carried on an inverted V-shaped frame 13 carried on the lower links of the lift 12, and supporting a bracket 14 to which is pivotally connected a plate 15, in the general configuration of a bell-crank lever. A limb 16 rigidly extends down from the plate 15 and an arm 17 is pivoted to the lower end of this limb. The other end of the arm is connected to the top of a hood 28 via brackets 18.

The outer end of plate 15 is connected by a pair of levers 19, 20 to a further fixed bracket 21 carried on the frame 13. At the point of articulation 22 between levers 19, 20 is connected the piston 23 of a hydraulic ram 24, carried by the plate 15. This ram serves to swivel the whole mower between a transport position and a mowing position.

A weight bearing rod 25 extends between a bracket 26 at the top of the frame 13 to brackets 27 at the end of arm 17 where the latter connectes with hood 28. A compression spring 29 is seated between an end 30 of the rod 25 and a seat on bracket 26. This spring acts to suspend part of the weight of the mower from the bracket 26, releiving the load on the main arm.

The mower itself comprises within the hood 28, a horizontal drum or cylinder 31 carrying a plurality of sets of flails 32.

The cylinder 31 is driven for rotation by a shaft 33 from a gearbox 34 mounted- on the tractor power take off shaft. The flails 32 cut the grass and rough growth below the hood, then toss the cuttings up into the hood where they are further shredded and thrashed by the flails, before being deposited behind the mower.

The pivot axis for raising and lowering the mower is provided by the tractor power take off. The hood is raised from the cutting position shown by the action of the ram 24 which when it extends, acts via the levers 19, 20 to swing the plate 15 clbckwise in Fig. 2 and correspondingly move arm 17 to the right, thereby causing the hood 28 to be raised.

A compression spring 35 is coiled about the ram 24, with one end seated on an adjustable nut 36 on a threaded end of ram 24, and the other end on a member fixed to plate 15. This arrangement allows plate 15 to be displaced by forcing upwards of the hood 10 by an obstruction, to a limit of 30 , against the bias of spring 35, but without movement of the ram piston 23.

Variations may be made within the scope of either aspect of the invention; for example cutters of the kind described may be mounted on a simpler mounting of known construction.

Other types of cutter may be mounted using the flexible mounting described.

The spring 29 may be of 16mm. gauge wire, and the spring 35 of 20mm. gauge wire.

The mower described has a cut width of 2 metres, but other widths are possible within the scope of the invention.

Claims (8)

1. A grass topping mower wherein a plurality of flail cutters are mounted on a horizontally extending shaft, the flails rotating in planes perpendicular to the ground, the shaft being directly connected to an input drive shaft.

2. A mowing machine having means for mounting said machine on the three point hydraulic lift linkage of a tractor, and buffer means between the mowing machine and the linkage such as to enable the machine to ride over an obstruction and be reset by such buffer means at the correct cutting height.

3. A mowing machine according to Claim 1 or 2, wherein the cutters are carried below a downwardly open hood which is arched above the cutters so as to allow cut material to be tossed into the hood and thrashed by the flails to shred the cut plant material completely, whereby the coarsest grasses and plants are made edible to live stock.

4. A mowing machine according to Claim 3, wherein the hood is carried on an arm which is pivoted to the linkage or a mounting frame with the linkage.

5. A mowing machine according to Claim 2, 3, or 4 wherein the buffer means is a. coil spring coaxial with a ram for raising and lowering the mower between its operating and transporting positions.

6. A mowing machine according to Claim 3, 4 or 5, wherein a suspension rod carries the hood.

7. A mowing machine as described herein and illustrated by the drawings.

8. A grass topping mower as described herein and illustrated by the drawings.