GB2307163A

GB2307163A - Mulching mower

Info

Publication number: GB2307163A
Application number: GB9623595A
Authority: GB
Inventors: Juergen Dzierzewski; Hans-Josef Brenner
Original assignee: Sabo-Maschinenfabrik GmbH; SABO Maschinenfabrik GmbH
Current assignee: Sabo-Maschinenfabrik GmbH; SABO Maschinenfabrik GmbH
Priority date: 1995-11-17
Filing date: 1996-11-13
Publication date: 1997-05-21
Also published as: ITMI962317A1; SE9604187L; GB9623595D0; FR2741235A1; DE19542860A1; ITMI962317A0; SE9604187D0; IT1287141B1

Description

2307163 PATENTS ACT 1977 CMD/A9024GB/D20 Title: MULCHING MOWER

Description of Invention

This invention relates to a mulching mower having a housing movable, over a lawn surface, in a plane, a motor, and at least one mowing blade and mulchin. blade received in the housing, the mowing and the mulching blades being rotatingly drivable by the motor around a joint axis of rotation which lies generally perpendicularly to the plane in which the housing is movable, the blades being each provided at their front edges with reference to their driving direction of rotation - with a cutting edge.

Such a mulchine mower is described in DE-4202)865-C2. There is provided a mowing blade and a mulching blade. Both are firmly attached to the output shaft of the motor at a vertical distance from one another so that they rotate together in the driving direction of rotation of the output shaft of the motor. Furthermore, both blades, at their edges facing away from their cutting edges, are provided with vanes directed upwardly away from the plane of movement of the mower, for the purpose of generating a directional air flow. The mower is suitable for use as a mulching mower and also as a mower with rear or/and side ejection of cuttings. As far as its use as a mulching mower is concerned, it also applies to the abovedescri beef embodiment that the desired o mowing success is achieved only if short grass is being mowed. The frequency of mowing for looking after a lawn is correspondingly high, because only a short length of grass can be separated to achieve a clean- cut appearance.

It is the object of the invention to provide a mulching mower which is also suitable for cutting higher grass, i.e. which, as compared to the conventional mulching mower, requires a lower frequency, of rnowinu to look after the lawn surface.

In accordance with the invention, we provide a Mulching mower wherein at least one mowino blade, towards its rear edges facing away from the c BAD ORIGINAL J0 2 cutting edges, comprises means for achieving an air flow directed away at least from the plane of movement of the housing; and the driving direction of rotation of the mulching blade(s) is opposed to the driving direction of rotation of the 0 zn mowing blade(s).

The advantage of this embodiment is that the grass cut by the mowing blade(s) is superbly crushed by the mulching blade(s) rotating in the direction opposite to that of the mowing blade(s). The grass is accelerated by the mowing blade(s) upwardly and also in the direction of their rotation, i.e. towards the cuttin. edues of the mulchinc, blade. Because the separated grass is crushed to a greater extent it is possible to achieve a lower mowing frequency as compared to mulching mowers according to the state of the art. Whereas state of the art mulchinu mowers, by means of two or more blades rotating together in the same direction of rotation, i.e. at least one mowing blade and one mulching blade arranged above the mowing blade in the housing, achieve good mowing results onlY if, as compared to standard mowers with ejection facilities and a rotating cutter bar, the length of grass to be removed by mowing amounts to approximately one third of the total length of the grass, the mulching mower according to the invention can achieve good mowing results even if the length of the grass to be removed amounts to 50% or more of the total length of the grass.

Furthermore, the energy requirements for additionally driving the mulching blade(s) in the opposite driving direction of rotation are no greater than the total energy requirements of a mulching mower with two jointly driven mowin. and mulching blades.

The speed of the mulching blade(s) may correspond to, or differ from, that of the mowing blade(s).

The mowing blade(s) and the mulching blade(s) may be associated with the output shaft of the motor, either the mowing blade(s) or the mulching blade(s) being directly drivable by the output shaft and a reversing drive being provided for driving the respective other blade(s). Such a design and BAD ORIGINAL J0 3 arrangement are particularly suitable in those cases where, for reasons of space, the driving motor has to be arranged above the blades.

The reversing drive can be provided in the form of a planetary gear C1 drive, for example.

However, it is alternatively possible to provide an assembly wherein the joint axis of rotation of the blades is arranged so as to he offset relative to the axis of rotation of the output shaft of the motor. In such a case, the drive for each of the mowina and mulchina blade(s) may be a belt drive, for example, a Vbelt drive. To achieve the reversing effect, one of the two belts may be crossed or the blade to be driven in the opposite direction may be driven by a pulley loaded by the back of the belt.

The preferred embodiment comprising one mowing blade and one mulchina blade arranged thereabove may be modified in that one mowing blade may be associated with at least two mulching blades in order to accelerate the crushing process. It is alternatively possible to provide a plurality of mowing blades and mulching blades, one above the other, with a joint axis of rotation. In this way it is possible to increase performance further and especially to separate lone pieces of grass whose length is close to the grass length separated by standard cutter bar mowers.

The blades may each be in the form of an oblong leaf or lamina, or be star-shaped.

Preferred embodiments of a mulchinu mower according to the invention are diagrammatically illustrated in the accompanying drawings, wherein:Fi-ure 1 is a side elevation of an embodiment of mulching mower in accordance with the invention, including a sectional view of a housing with one C mulching blade and one mowing blade, the mulching blade being driven by a C) c reversinu drive in the form of a planetary gear drive; Fi-ure 2 shows an embodiment modified relative to Figure 1 in that the output shaft of the motor and the driveshaft of the blades are arranged " ORIGINAL %J 4 parallel relative to, and at a distance from, one another, with the drive being a belt drive; Figure 3 shows a detail of an alternative design relative to Figure 2, in plan view, of the belt drive to achieve the necessary reversing effect; Figure 4 is a diagrammatic illustration in the form of a plan view of a mowinu blade, with a further mowing blade being associated therewith; Figure 5 is a plan view of a mulching blade, with a further mulching blade being associated with the first mulching blade.

In the drawings, corresponding parts in the different embodiments are identified by the same reference numerals.

Figure 1 shows a mulching mower 1 comprising a housing 2 which is movable on wheels 4 by an operative using a guiding bar 3, in a plane of movement over lawn surfaces. The wheels 4 hold the lower edge of the housing 2 at a distance from the plane of movement 5. Said distance is adjustable. The interior of the housinu 2 contains one mowing blade 9 and, thereabove, one mulching blade 13, the blades being arranged so as to be drivable around an axis c C of rotation 8 of an output shaft 7 of a motor 6. The mowing blade 9 is driven directly by the output shaft 7 of the motor 6. The mowing blade 9 is firmly connected to the output shaft 7 of the motor 6. Furthermore, the mowing blade 9 is provided with vanes 10 to achieve an air flow directed upwardly and in the direction of rotation NI. The mulching blade 13 is also arranged so as to be driven around the axis of rotation 8, for which purpose there is provided a reversinu drive 12 which is secured to the housing 22, which is driven by the output shaft 7 of the motor 6 and which, via a sleeve 11, drives the mulching blade 13 in a direction of rotation N2 which is opposed to the direction of rotation NI and to the direction of rotation N3 of the output shaft 7 of the motor 6. The direction of rotation NI of the mowinu blade 9 is the sanic as the direction of rotation N3 of the output shaft 7 of the motor 6. The confilgu ration of the mowing blade 9 and of the mulching blade 13 will be described in greater detail with reference to Figures 4 and 5. Figure 1 also shows that the mulching blade 13 is arranged at BAD ORIGINAL 00) a vertical distance above the mowino blade 9. The rotational axis 8 extends substantially perpendicularly to the plane of movement which the housing 2 is movable over the lawn surface 5 by means of the wheels 4. The grass cuttings separated by the mowing blade 9 are guided by the airflow generated by the vanes 10 in the upward direction into the sphere of influence of the mulching blade 13 which crushes the grass further so that the grass cuttings do not have to be removed from the lawn surface; they sink into the turf where they can rot.

In the embodiment of the mulching mower 1 ' according to Figure 2, the housing 2 ' is movable by wheels 4 on the plane of movement 5, for example a lawn surface, with an operative holding the guiding bar 3. The motor output shaft 7 ' with its axis of rotation 8 ' is arranged parallel to, and offset from, a driveshaft 15 with an axis of rotation 14 which carries the mowing blade 9 and the mulching blade 13 arranged thereabove. The driveshaft 15 is supported by bearing means (not illustrated) in tile housing 2 ' and in a driving sleeve 22 respectively. The mowing blade 9 is non-rotatingly connected to the driveshaft 15 and drivable in a direction of rotation NI which corresponds to the direction of rotation N3 of the output shaft 7 ' of the motor 6. A first belt pulley 16 is provided on the output shaft 7 ' of the motor 6. A belt pulley 17 is associated with the driveshaft 15 to which the mowinu blade 9 is connected. Both belt pulleys are connected to one another by a V-belt 18, so that the output shaft 7 serves for directly driving the mowing blade 9 in the direction of rotation NI. The output shaft 7 ' of the motor 6 is further provided with a second belt pulley 19. The driving sleeve 22 is associated with a belt pulley 20. Both these pulleys are connected to one another by a crossed Vbelt 21, so that the direction of rotation of the output shaft 7 ' is reversed, which means that the mulching blade 13 is driven in a direction of rotation N2 which is opposed to the direction of rotation N3. The motor 6 may be an internal combustion enuine or an electric motor.

The housing 2 may contain two blades arranged one above the other, 0 for example a single mowing blade 9 and a single mulching blade 13. However, BAD ORIGINAL A0 6 it is alternatively possible to provide an assembly wherein there is provided one mowing blade 9 and a plurality of mulching blades 13 or a plurality of mowing blades 9 and mulching blades 13.

Figure 3 shows a detail regarding the possibility of using a belt drive to reverse the driving direction of rotation N3 of the motor 6 into the driving direction of rotation N2 for the mulchinu blade. For this purpose, the output shaft 7 ' of the motor is associated, for example, with a first belt pulley 19 ' which cooperates with the belt 21 '. The back of the belt 21 is guided over the belt pulley 20 ', thus driving the sleeve 22 and mulching blade in a direction of rotation N2 around the axis of rotation 14. To achieve the necessary arc of conduct of the belt around the belt pulley 20 ', there are provided two further belt pulleys 23, 24 which guide the belt.

Figure 4 shows a first mowing blade 9 which is in the form of an oblong lamina and which is to be rotatinaly driven in the direction of rotation NI around the axis 27. At its two front edges - with reference to the direction of rotation NI - the mowing blade 9 is provided with cutting edges 25, 25 ' which serve to sever the grass. At the rear edges of the blade, against the direction of rotation NI, there are provided vanes 10, 10 ' which extend from the cuttingedges 25, 25 ' backwards towards the rear edge, which rise towards the rear and are angled relative to the longitudinal axis of the mowing blade 9, thereby achieving an air flow which is directed upwardly and in the direction of rotation NI.

The mowing blade 9 may be associated with a further mowing blade 9 ' which is shown in dashed lines, which is identical in desiun to the mowing blade 9 but which, in the direction of rotation NI, is offset by 90' relative to t mowin blade 9. The mowinu blade 9 ' is shown as separate from the mowing 9 C blade 9, but both may be provided in one piece.

Figure 5 shows a mulching blade 13) which, in the direction of rotation N2 opposed to the direction of rotation NI of the mowing blades 9, 9 ', at its front edges, is provided with cutting edges 26, 226 ' which serve to crush the grass cuttings severed by the mowing blades 9, 9 '. The mulching blade 13 is also in the 0 c) ,BAD ORIGINAL.03) 4 7 form of an oblong lamina and at its centre is the axis of rotation 28. A second mulching blade 13 ' is shown in dashed lines and offset in the direction of rotation N2 by 90' around the axis of rotation 28. Both may be provided in one piece. Furthermore, it is possible to provide a mulching mower with a plurality of mowing blades 9, 9 ' and/or mulching blades 13, 13 The mulching blades 13, 13) ' may be provided in the form of a planar lamina, but towards its rear ed-es facing away from the cutting edges 26, 26 ', it may be provided with small vanes which serve to extend the time spent by the grass in the region of the mulching blade(s) 13, 13 The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

BAD ORIGINAL 8

Claims

A mulching mower comprising a housing movable over a lawn surface in a plane; a motor; at least one mowing blade and at least one mulching blade disposed in the housing; the mowing and mulching blades being rotatingly drivable by the motor about a common axis of rotation which lies generally perpendicular to the plane in which the housing is movable; the blades being each provided at their front edges with a cutting edge, wherein at least one mowing C & W blade, towards its rear edges facing away from the cutting edges, comprises means c for achieving an airflow directed away at least from the plane of movement of the housing; and the driving direction of rotation of the mulching blade(s) is opposed 0 to the driving direction of rotation of the mowing blade(s).
2. A mulching mower according to Claim 1 wherein the speed of the 0 mulching blade(s) is the same as that of the mowing blade(s).

0 c
3. A mulching mower according to Claim 1 wherein the speed of the 0 mulching blade(s) is different from that of the mowing blade(s).

0 0
4. A mulching mower according to any one of Claims 1 to 3 wherein the mowing blude(s) and the mulching blade(s) are associated with the output shaft 0 of the motor, either the mowing blade(s) or the mulchinu blade(s) being directly C1 drivable bv the output shaft and a reversing drive being provided for driving the 1 c c respective other blade(s).
5. A mulching mower according to Claim 4 wherein the reversing drive c comprises a planetary gear drive.

BAD ORIGINAL 9
6. A mulching mower according to any one of Claims 1 to 3 wherein the joint axis of rotation of the blades is arranged so as to be offset from the axis of rotation of the output shaft of the motor.
7. A mulching mower according to Clairn 6 wherein each of the mowing C and mulching blade(s) is driven by a belt drive, e.g. a V-belt drive.
8. A mulching mower according to any one of the preceding claims comprising one mowing blade and at least two mulching blades.

C> 0 0
9. A mulching mower according to any one of Claims 1 to 7 comprising a plurality of mowing blades and a plurality of mulching blades.
10. A mulching mower substantially as hereinbefore described with reference to the accompanying drawings.

0
11. Any novel feature or novel combination of features described herein and/or in the accompanying drawings.

BAD ORIGINAL P