GB2317320A

GB2317320A - Rotary mower

Info

Publication number: GB2317320A
Application number: GB9619841A
Authority: GB
Inventors: Bell Christopher O'neil
Original assignee: NEIL BELL CHRISTOPHER O
Current assignee: NEIL BELL CHRISTOPHER O
Priority date: 1996-09-24
Filing date: 1996-09-24
Publication date: 1998-03-25
Anticipated expiration: 2016-09-24
Also published as: GB2317320B; GB9619841D0

Abstract

A rotary lawn mower, has a grass alignment device 9 fitted towards the back of the mover, relative to the direction of travel, and protruding below the main body of the mower 1 to align the cut grass 10 with the direction of travel 11 of the mower. The purpose of the device 9 is to provide the same striped effect on a lawn as a more expensive cylinder mower.

Description

GRASS ALIGNMENT DEVICE This invention relates to a grass alignment device for use on all rotary type mowers.

Two general types of lawn mower exist. These can be described according to the type of cutting blade used, which are either rotary or cylinder arrangements. In order to clarify the difference between these two types of cutting arrangements Figure 2 has been constructed.

This is a two dimensional representation of the three possible dimensions of axial movement.

The figure has indicated on it a cylindrical cutting type device which is fixed axially on the ' axis and set to revolve about the 'X' axis and, when cutting, traverse in the direction shown on the 'Z' axis. By comparison, the rotary blade is shown positioned on the 'Y' axis and rotating about the 'Y' axis. The direction of travel, when cutting, is along the 'Z' axis as indicated.

Numerous different types of grass cutting rotary mowers exist. By way of example Figure 1 shows such a machine where the main body of the mower 1 is the support structure for many of the machine components. These may often include an electric or internal combustion engine 2 to power the rotary cutting blade and possibly rear drive roller 8. For guidance and to improve mobility a set of front wheels 3 may be included. The forward speed of the mower may be controlled by a separate lever 5 supported on a handle 6 with an additional clutch lever 7. When in operation the mower will normally travel in a forward direction 11.

By further way of example Figure 3 shows the under side of a typical cylinder mower. The mower is propelled by a rear roller 8 which is driven by a pulley wheel 14 which is interconnected to the cylindrical cutting blade 12 via an additional pulley wheel 15. As the cylindrical blade 12 rotates grass is drawn against the striker plate 13 and cut. In front ofthe cylindrical cutting blade 12 a roller 16 is positioned. As the mower moves forward as indicated 11 the grass is collected in a grass collection box 4. This produces a uni-directional cutting action across the width ofthe blade 12. When the mower is turned through 180 degrees to perform each successive cut a characteristic stripe effect is formed on the lawn.

By further way of example Figures 4, 5, 6, 7 and 8 all show the under side of different types of rotary mower. Figure 4 is a basic type hover mower using a single cutting blade 16 with 2 sharpened edges 17 locked in position and connected to a drive unit at 18 and rotating as indicated at 20. A down draught, generated within the main body of the mower 1, is created by an impeller 19 and used to lift the mower.

Figure 5 shows a basic 'push' rotary mower. In this machine the main body of the mower 1 is supported on wheels 3 removing the necessity for an impeller for the generation of a down draught. This mower can more easily be directed along a linear path 11.

Figure 6 shows a basic push rotary mower as in Figure 4 with an impeller 19 included to help disperse grass cuttings.

Figure 7 shows the under side of a rotary mower. This is similar to Figure 6 with the replacement of two rear wheels with a single rear drive roller 8 connected to an electric or internal combustion engine via a drive pulley 14 and used to propel the mower in the direction shown 11.

Figure 8 shows a further improvement over Figure 6 with the inclusion of a grass outlet shute 22 and grass collection box 4.

Despite the use of a large rear roller, as shown in Figures 7 and 8, this does not give a major improvement in alignment of the grass to give the appearance it has been cut by a cylinder mower. Figure 9 indicates why. If the angle of the cut grass 26 is acute as indicated at 27 in Figure 9A the grass will be pushed forward as the roller rotates in direction 25 and moved forward in direction 11. This will give the result shown in Figure 9B. If however, the angle of the grass is large, as shown at 27 in Figure 9C, then the tip of the grass will be nearing an angle of 180 degrees with respect to the surface of the roller 8. As the roller moves forward 11 and rotates 25 the direction the grass moves will be uncertain, but is more likely to be pulled backwards by the frictional force of the roller as shown in Figure 9D.

Cylinder mowers offer the benefit of producing a clean striped effect on a lawn after it has been cut. None of the rotary mowers shown in Figures 1, 3, 4, 5, 6, 7, and 8 can replicate this feature due to the different cutting and rotating arrangement of the blade, as indicated in Figure 10. By way of explanation of Figure 10, the locus of the centre point of the rotary blade is shown at 23, small arrows indicating the finished direction of the grass after cutting are shown at 24 and the direction of rotation of the blade is shown at 20.

However, because rotary mowers are considerably less complex they are easier to manufacture and consequently less expensive. This makes them very attractive to purchasers despite the poorer finish achieved.

According to the present invention there is provided a strip of material which when fitted to a rotary mower has the effect of substantially re-aligning the mowed grass to give the appearance it has been cut by a cylinder mower. The strip may be formed from either a man made or naturally occurring material provided it presses down on to the grass due to its own resilience or the application of sprung assistance. A strip manufactured from rubber has been used to very good effect for such a purpose. The process of re-alignment will occur due to a combination of the frictional force between the grass and the alignment strip which will be in the direction of travel of the mower as a result of its forward movement and downward pressure of the strip. Alternatively the strip may be sub-divided in to a multitude of smaller strips to aid in guiding the grass in to a substantially uni-directional alignment with the direction of forward movement of the mower.

To make the strip effective a substantial proportion should be situated at a position behind the central point of the central blade fixing position as indicated in Figures 1,3, 4, 5, 6, 7 and 8 at position 18. And should preferably, but not necessarily, extend to cover the same width as the rotary blade. One skilled in the art would appreciate that to obtain the desired stripe effect on a mowed lawn a multitude of strips could be employed, or a combination of segmented, or continuous and segmented strips. Additionally, one skilled in the art would appreciate that a suitable strip could be incorporated in to the design of the mower to become an integral part of the mower casing 1 identified in Figures 1, 3, 4, 5, 6, 7 and 8.

A specific embodiment of the alignment strip will now be described by way of example with reference to Figure 11.

Figure 11 shows two elevations of a rotary lawn mower with a grass alignment device fitted.

The bottom elevation shows a grass alignment device 9 fitted towards the back of the mower casing 1 via a support/fixing member 26, and at 90 degrees relative to the direction of travel 11 of the mower, for the purpose of providing the same striped effect on a lawn as a more expensive cylinder mower. In this example the device has been placed in front of the rear roller 8 and perpendicular to the two side walls of the case 1. Other characteristics of the bottom elevation include known features, these are, the grass outlet shute 22 as part of the mower main frame 1 and leading to the grass collection box 4 which is supported off the handle 6. This in turn incorporates a forward motion speed control lever 5 and clutch control 7. The cutting action is provided by a blade 16 with two sharpened edges 17 rotating about the central fixing point 18 in the direction shown 20. An impeller 19 is included to aid the removal of grass through the grass outlet shute 22. The rear roller 8 is connected to the motor drive unit via a pulley wheel 14 and drives the mower forward 11.

The side elevation of the mower shows many of the features previously identified on the bottom elevation and described previously. Additional features include the motor drive unit 2 which is connected to the pulley wheel 14, shown on the bottom elevation, and a cut away section 27 of the mower main frame 1 to reveal the support/fixing member 26 and alignment device 9 pressing against and aligning the grass 10.

By way of further example Figures 12 to 22 show additional alignment strips or methods of fixing, and positioning, the strip to the mower casing.

Figure 12 shows a curved alignment strip 9 fixed directly to the casing of a hover mower and held in position with a support/fixing member 26 by means mechanical, adhesive or cast-in.

When the alignment strip is fitted to the rear of a hover mower, or rotary mower without the benefit of grass collection, it has the added advantage that the operator is substantially shielded from contamination with grass cuttings.

Figure 13 shows a grass alignment strip 9 supported by a support/fixing member 26 and connected to the outside of a push along mower casing 1 via mounting brackets 27 by means mechanical, adhesive or cast-in.

Figure 14 shows a motor powered rotary mower with a semi-circular grass alignment strip 9 fitted to the inside of the mower casing 1 and supported by a support fixing member 26 by means mechanical, adhesive or cast-in.

Figure 15 shows a plain grass alignment strip which could typically be manufactured from a man made or naturally occurring material that possessed the required amount of resilience, frictional properties and stiffness to produce alignment.

Figure 16 shows a partially segmented grass alignment strip which could typically be manufactured from a man made or naturally occurring material that possessed the required amount of resilience, frictional properties and stiffness to produce alignment.

Figure 17 shows a fully segmented grass alignment strip which could typically be manufactured from a man made or naturally occurring material that possessed the required amount of resilience, frictional properties and stiffness to produce alignment.

Figure 18 shows a castellated grass alignment strip which could typically be manufactured from a man made or naturally occurring material that possessed the required amount of resilience, frictional properties and stiffness to produce alignment.

Figure 19 shows a tapered grass alignment strip which could typically be manufactured from a man made or naturally occurring material that possessed the required amount of resilience, frictional properties and stiffness to produce alignment. One skilled in the art would appreciate that the change in sectional thickness need not be restricted to tapering but could be any sectional change to obtain the required mechanical properties from said strip.

Figure 20 shows a plurality of plain grass alignment strips which may have different frictional, stiffness and resilience properties, which could typically be manufactured from man made or naturally occurring materials that possess the required amount of resilience, frictional and stiffness to produce alignment.

Figure 21 shows a plurality of grass alignment strips of different sizes and geometric form which could typically be manufactured from different combinations of man made or naturally occurring materials that possess the required amount of resilience, frictional properties and stiffness to produce alignment.

Figure 22 shows a rigid or semi rigid grass alignment strip which could typically be manufactured from a man made or naturally occurring material. In order to gain the required amount of pressure to result in smoothing and alignment of the grass a secondary spring or spring mechanism will have to be included in the design (not shown).

It should also be appreciated that, although not shown, additional features such as height adjustment to the strip could be included in any designs to provide pressure variations between the strip and grass thereby changing the visual appearance of the stripes.

Claims

1 A single or multi-bladed rotary lawn mower fitted with a strip of man made or naturally occurring material which, when it comes in to contact with the grass, and by virtue of the forward movement of the mower, frictional properties and downwards pressure of the strip re-aligns the grass after it has been cut to give a stripe effect to the lawn characteristic of the finish a cylinder lawn mower produces.

2 A strip of material as claimed in 1 wherein the strip is fitted by direct or indirect means to the internal surface of the mower casing.

3 A strip of material as claimed in 1 wherein the strip is fitted directly to, or forms an integral part, of the mower casino

4 A strip of material as claimed in 1 wherein the strip is fitted by direct or indirect means to the outside of the mower casing.

5 A strip of material as claimed in any of the preceding claims wherein the strip is of plain, partially segmented, fully segmented,is castellated or has a change in sectional thickness or any other such form that may be used to produce a similar effect on a lawn.

6 A strip of material as claimed in any of the preceding claims wherein the strip is straight, curved or a combination of straight and or curved sections.

7 A composite strip of material manufactured from a plurality of individual strips having similar or different geometric forms.

8 A strip of material as claimed in any of the preceding claims wherein the strip displays the required combination of flexibility, resilience and frictional properties when pressed against and moved over grass to promote alignment of the grass.

9 A strip of material as claimed in any preceding claims wherein the total width of the stripe formed by the strip after re-alignment of the grass is equal to the width of the mower casino

10 A strip of material as claimed in Claims 1 to 8 wherein the total width of the stripe formed by the strip after re-alignment of the grass is greater than the width of the mower casing.

11 A strip of material as claimed in Claims 1 to 8 wherein the total width of the stripe formed by the strip after re-alignment of the grass is less than the width of the mower casing.

12 A strip of material as claimed in any of the preceding claims wherein the strip is provided to, or performs the function of, protecting the operator from contamination with grass cuttings.

13 A strip as claimed in any of the preceding claims that is held in position on the mower by a fixing or support member, mechanical, adhesive, cast or moulded-in or by other such means.

14 A strip as claimed in any of the preceding claims that is held in position on the mower by a fixing or support member and or the use of additional distancing or spacing features.

15 A strip of material as claimed in any of the preceding claims wherein the strip is pivoted and makes the required contact with the cut grass by means sprung attachments connecting the strip to mower or parts thereof.

16 A strip of material as claimed in any of the preceding claims wherein said strip is fitted or encorrporated in to the mower at the time of manufacture of said mower.

17 A strip of material as claimed in Claims 1 to 15 wherein said strip is added to to the mower after manufacture of said mower.

18 A rotary mower fitted with a strip of material as described herein with reference to Figures 1, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 and 22.

18 A strip of material as claimed in any of the preceding claims wherein the height and position of the strip relative to the cut grass is adjustable.

19 A rotary mower fitted with a strip of material as described herein with reference to Figures 1, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 and 22.

Amendments to the claims have been filed as follows A A single or multi-bladed rotary lawn mower fitted with a strip of man made or naturally occurring material which, when it comes in to contact with the grass, and by virtue of the forward movement of the mower, frictional properties and downwards pressure of the strip re-aligns the grass after it has been cut to give a stripe effect to the lawn characteristic of the finish a cylinder lawn mower produces.

2 A single or multi-bladed rotary lawn mower as claimed in 1 wherein the strip is fitted by direct or indirect means to the internal surface ofthe mower casing.

3 A single or multi-bladed rotary lawn mower as claimed in 1 wherein the strip is fitted directly to, or forms an integral part, of the mower casing.

4 A single or multi-bladed rotary lawn mower as claimed in 1 wherein the strip is fitted by direct or indirect means to the outside of the mower casing.

5 A single or multi-bladed rotary lawn mower as claimed in any of the preceding claims wherein the strip is of plain, partially segmented, fully segmented, is castellated or has a change in sectional thickness or any other such form that may be used to produce a similar effect on a lawn.

6 A single or multi-bladed rotary lawn mower as claimed in any of the preceding claims wherein the strip is straight, curved or a combination of straight and or curved sections.

7 A single or multi-bladed rotary lawn mower as claimed in any of the preceding claims wherein the strip displays the required combination of flexibility, resilience and frictional properties when pressed against and moved over grass to promote alignment of the grass.

8 A single or multi-bladed rotary lawn mower as claimed in any preceding claims wherein the total width of the stripe formed by the strip after re-alignment of the grass is equal to the width of the mower casing.

9 A single or multi-bladed rotary lawn mower as claimed in Claims 1 to 7 wherein the total width of the stripe formed by the strip after re-alignment of the grass is greater than the width of the mower casing.

10 A single or multi-bladed rotary lawn mower as claimed in Claims 1 to 7 wherein the total width of the stripe formed by the strip after re-alignment of the grass is less than the width of the mower casing.

I I A single or multi-bladed rotary lawn mower as claimed in any of the preceding claims wherein the strip is provided to, or performs the function of protecting the operator from contamination with grass cuttings.

12 A single or multi-bladed rotary lawn mower as claimed in any of the preceding claims wherein the strip is held in position on the mower by a fixing or support member, mechanical, adhesive, cast or moulded-in or by other such means.

13 A single or multi-bladed rotary lawn mower as claimed in any of the preceding claims wherein the strip is held in position on the mower by a fixing or support member and or the use of additional distancing or spacing features.

14 A single or multi-bladed rotary lawn mower as claimed in any of the preceding claims wherein the strip is pivoted and makes the required contact with the cut grass by means sprung attachments connecting the strip to mower or parts thereof.

15 A single or multi-bladed rotary lawn mower as claimed in any of the preceding claims wherein said strip is fitted or incorporated in to the mower at the time of manufacture of said mower.

16 A single or multi-bladed rotary lawn mower as claimed in Claims 1 to 15 wherein said strip is added to the mower after manufacture of said mower.

17 A single or multi-bladed rotary lawn mower as claimed in any of the preceding claims wherein the height and position of the strip relative to the cut grass is adjustable.