GB2029188A - Mowers - Google Patents

Abstract

A two wheeled walk-type tractor supports a mowing mechanism in which the mowing bar is mounted, for movement about an axis extending in the direction of travel, on a triangular plate 13 pivoted on a pin 14 passing into a connecting arm 15 the opposite end of which is mounted on a transverse plate 22 connected to the tractor by a fixing parallel plate 23, resilient buffers 24 being provided between the two plates. The mowing bar is reciprocated by a crank, mounted on a pulley pivoted on the triangular plate and driven by a belt from the tractor, the tension on the belt maintaining the end of the connecting arm in contact with the triangular plate. <IMAGE>

Description

SPECIFICATION Improvements in means for mounting a mowing mechanism on a two wheeled motor tractor The invention relates to improvements in means for mounting a mowing mechanism on a two wheeled tractor of the kind described in German Application No. 2631186 laid open to public inspection. In the known embodiment there is provided on a fixed plate on a tractor a tube connection member which extends in the direction of a supporting arm and in which the supporting arm engages leaving a space on all sides filled with a rubber body so that a so-called oscillating metal element results and the supporting arm is mounted movably on a plate fixed on the tractor. In a similar manner a pin projecting from the fixing piece for the mowing bar engages in the other end of the supporting arm and is mounted thereover a rubber element.

In spite of the support of the mowing bar being effected completely via rubber buffers, with the known embodiments too many oscillations are transmitted from the mowing bar carrying out an oscillating movement, to the supporting arm and the tractor, which is especially noticable with twowheeled tractors, the mass of which compared with the mass of the mowing bar is not so much greater and which therefore is easily subjected to oscillations. This leads to very inconvenient vibrations-in the control handles of the two-wheeled tractor.

From the German Gebrauchsmuster 7503214 another embodiment is known in which the supporting arm consists of two parallel webs which are firmly disposed on the plate mounted on the tractor.

The pin of the connecting member to the mowing bar engages between the webs and is connected thereto by means of laterally fixed rubber buffers.

The rubber buffers supportthe pin mainly with a movement clamped in the plane of the legs of the supporting arm. Because of the firm application of the supporting arm on the tractor the embodiment could give advantages because even the supporting arm itself cannot oscillate but practice has shown that considerable oscillations are transmitted to the tractor.

The disadvantage in both embodiments is the fact that the mowing bar can only adapt itself to the ground by deformation of the elastic supporting elements.

The invention has the problem of improving an arrangement of the type based on the aforesaid arrangements so that the transmission of oscillations is reduced. The solution of this problem according to the invention consists in that the mowing bar is mounted freely rotatable on the supporting arm about its longitudinal axis and the end of the supporting arm adjacent the tractor carries a transverse plate which is connected to a parallel plate by damping elements, the latter plate being affixed to the tractor.

It has surprisingly been found that due to the free movement of the supporting arm in conjunction with the damping connection between the two plates substantially less oscillations are transmitted to the tractor than with the known embodiments.

The rotary oscillations can no longer be transmitted from the mowing bar to the supporting arm. The damping between the plates permits of a distribution of the damping forces over a relatively large surface so that the damping can be made effective and nevertheless sufficiently great forces can be transmitted. Due to the free movement of the mowing bar about the supporting arm the mowing bar can be adapted to unevenness of the ground without any reaction on the supporting arm taking place.

In the preferred embodiment a pin rigidly connected to the mowing bar is provided which pin is mounted to rotate freely in the supporting arm about its longitudinal axis.

It is preferable to provide a stop for limiting the rotary movement of the mowing bar about the supporting arm.

In operation only oscillations in a limited angle range come into cinsideration. The provision of the stop prevents too great a pivoting of the mowing bar during transport.

The transverse plate and the connecting plate may be inclined to a vertical plane passing through the axis of the supporting arm.

The plate may thus be fixed at a height approximately vertically on the tractor so that the supporting arm is inclined downwards towards the mowing bar. The forces initiated through the supporting arm represent a combination of compression and shear forces which are taken up by the damping arrangement between the plates.

The damping elements may be formed as resilient buffer blocks distributed over the face of the connecting plate and the transverse plate. The provision of individual damping elements separated from one another has practical advantages because such elements are available in the trade cheaply and advantageously suppress the transmission of oscillation because the elements can be deformed independently of one another.

Astop should also be provided to prevent the transverse plate from becoming too close to the connecting plate.

This is of importance when, for example, the mowing bar comes against an obstruction; which might otherwise cause damage to the driving ofthetrans- mission bar.

In an embodiment in which the drive of the mowing bar is effected through a belt drive one belt pulley of which is mounted near the upper end of the supporting arm on the tractor and the other belt pulley is mounted on the mowing bar is of an advantage for the mowing bar to be held under the tension of the belt in contact on the supporting arm.

A pin on the mowing bar is inserted into the end of the supporting arm and the connecting arm is kept in contact with the mowing bar by the belt tension.

Upon wear of the contact face an automatic adjustmenttakes place.

The invention will be described with reference to the accompanying drawings showing one embodiment of the invention: Fig. 1 shows a perspective front view of a twowheeled tractor; Fig. 2 shows a view of the lower part of the supporting arm and of the centre area of the additional mowing mechanism; Fig. shows a side view of the supporting arm; Fig. 4 shows a view corresponding to Fig. 3 in which the driving belt is also indicated.

The two-wheeled tractor of Fig. 1 indicated in its entirety by 10 comprises an internal combustion engine 1 which is supported on an axle and driven by rubbertyred wheels 2. To the engine 1 a steering column 3 is connected which at the upper end carried a forked steering handle bar 4 which contains on the handles 5 and 6the controls for the engine 1. The steering column 3 and the steering handle bar4 extend back behind the engine so that the tractor 10 can be steered with the hands in engagement on the handles 5, 6 so that the engine 1 is in front of the operator.

The engine 1 drives the wheels 2 and the mowing bar designated in its entirety by 7 which mowing bar is connected to the two-wheeled tractor 10 via a fixing means concealed under the cover 8 in Fig. 1. The mowing bar 7 comprises a blade carrier 9 with triangular blades 11 which operate in a longitudinal direction of the mowing bar 7 and thus cut the grass or other material to be mown. The driven of the mowing bar with which the parts carrying the blades 11 and the under blades 12 are reciprocated in a longitudinal direction is derived from a corresponding top connection on the two-wheeled tractor 10.

In Fig. 2 the fixing area of the mowing bar with the cover8 removed is shown drawn in full lines. The mowing bar7 is screwed to an approximately isosceles triangular connecting plate 13 located with its base on the blade bar carrier 9. At the apex of the triangular plate 13 is located a pin which engages freely in a supporting arm 15 formed as a tube and the plate 13 may therefore swing freely aboutthe supporting arm 15 on the pin 14. In order to limit the swinging movement over the area required in operation and prevent the mowing bar 7, for example, during transport from falling down too far there is provided adjacent to the pin 14 a transverse pin 16 which is guided in a slot 17 in the supporting arm 15.

As shown in Fig. 3 there is mounted on the plate 13 a belt pulley 18 which carries a crank pin 19. This crank pin 19 operates in a manner not shown but knownforthe driving of the lower blades 12 of the blade bar 9. The drive is as can be seen from Fig. 4 driven from a further belt pulley 21 via a V-belt 20 which belt pulley 21 is located on the two-wheeled tractor 10 and is driven bythe engine 1.

The carrying arm 15 extends with its lower end placed in the vicinity of the ground in the direction of travel obliquely upwards to an anchorage on the two-wheeled tractor 10. On the upper end there is fixed on the supporting arm 15 a transvere plate 22 which is inclined to a vertical plane passing through the axis of the supporting arm as shown in Fig. 3.

The transverse plate 22 may therefore be mounted vertically on the two-wheeled tractor 10 so that the supporting arm is directed forwardly and downwardly.

Parallel with the transvere plate 22 there is a plate 23 of equal size spaced apart therefrom and affixed to the two-wheeled tractor 10. The anchorage may be effected in any way and is not shown in Figs. 3 and 4.

It depends on the construction of the two-wheeled tractor 10. The plate 23 may, for example, be screwed to a fixing face of the two-wheeled tractor 10 or carry fixing members welded onto the rear side.

The plates 22, 23 are connected to one another by resilient damping elements in the form of rubber buffers. As shown in the drawing there are provided three spaced apart rubber buffers 24 arranged around the supporting arm 15 which is mounted in the centre of the plate 22. Thus with the lateral arrangement of the driving pulley 21 shown in Fig.4 the supporting arm 15 is not drawn obliquely out of line and it is recommended to employ somewhat harder rubber buffers on the side adjacent driving pulley 21. In orderto provide, for example, if the mowing bar7 should strike against an obstruction a corresponding deflection of the supporting arm 15 and deformation of the rubber buffers 24 takes place without too great a displacement of the transverse plate 22 relatively to the plate 23 a stop screw 25 is provided which normally is not located in contact with the plate 23 but prevents an excessive approach. In this way a displacement of the belt 20 from the belt pulley 21 is prevented. The other screw 25 is located on the side of the plate 22.

As the pin 14 is freely movable in the end of the supporting arm 15 the plate 13 and thus the mowing bar7 is held in contactfree of play againstthe end face 26 of the supporting arm 15 by means of the tension of the belt 20.

Claims (10)

1. Meansforthe mounting of a mowing mechanism on a two-wheeled tractor having a mowing bar disposed transversely of the direction of travel with blades moving to and fro with a supporting arm extending substantially in the direction of travel and transversely of the mowing bar which is affixed to the tractor by means of resilient damping elements and at its free end the mowing bar is allowed a restricted movement, characterised in that the mowing bar (7) is freely mounted on the supporting arm (15) about its longitudinal axis and the supporting arm (15) at its end facing the tractor (10) carries a transverse plate (22) which is connected through resilient damping elements (24) to a parallel plate (23) mounted on the tractor (10).

2. Means according to Claim 1, characterised in that a pin (14) passes through the mowing bar (7) which is freely mounted about its longitudinal axis in the supporting arm (15).

3. Means according to Claims 1 or 2, characterised in that a pin (16, 17) in a slot is provided for limitation of the rotary movement of the mowing bar (7) about the supporting arm (15).

4. Means according to any one of Claim 1 to 3, characterised in that the transverse plate (22) and the plate (23) are inclined to a vertical plane passing through the axis of the supporting arm (15).

5. Means according to any one of Claim 1 to 4, characterised in that the damping elements (24) are formed as resilient buffer blocks arranged between the surfaces of the plate (23) and the transverse plate (22).

6. Means according to any one of Claims 1 to 5, characterised in that a stop (25) is provided which to prevent the transverse plate 22 approaching closely to the plate (23).

7. Means according to any one of Claims 1 to 6, in which a mowing bar is driven by a tractor through a belt drive one belt pulley of which is mounted on the tractor near the upper end of the carrying arm and the other belt pulley of which is mounted adjacent the carrying arm on the mowing bar, characterised in that the mowing bar (7) is held in contact on the carrying arm (15) by the tension in the belt (20).

8. Means according to Claim 7, characterised in that there is provided on the mowing bar end of the supporting arm (15) an intermediate plate (13) which is connected to the mowing bar (7) and to the carrying arm (15) and on which the belt pulley (18) is mounted.

9. Means according to Claims 2 and 8, characterised in that the pin (14) is mounted in the triangular plate (13).

10. Means for mounting mowing mechanism on a two-wheeled motor tractor substantially as described with reference to the accompanying drawings.