GB2221373A

GB2221373A - Rotary mower

Info

Publication number: GB2221373A
Application number: GB8917343A
Authority: GB
Inventors: Theodore William Reihhold
Original assignee: Individual
Current assignee: Individual
Priority date: 1988-08-01
Filing date: 1989-07-28
Publication date: 1990-02-07
Anticipated expiration: 2009-07-28
Also published as: GB2221373B; GB8917343D0

Abstract

A rotary mower in which the cutter housing (12) is provided with a cutout in the side wall (18) of the housing which is disposed intermediate one pair of inwardly extending front and rear wheels (14, 15) and formed in the housing substantially coincidentally with the lateral extremity of the blade tip path, and a cover assembly (25) secured to the cutter housing to cover said cutout. The cover is made from a thin wear resistant material allowing the mower to cut close up to vertical borders. <IMAGE>

Description

IMPROVEMENTS TO ROTARY MOWERS This invention relates to improvements to rotary mowers.

The basic configuration of conventional rotary mowers has remained unchanged for many years and includes a cutting blade supported on the end of the motor's vertical crank shaft and within a cutter housing. The latter supports the motor and is provided with front and rear pairs of height adjustable wheels. In order to provide stability, the wheels are spaced as far apart as possible. The lateral spacing of the wheels is limited by the requirement that the cutting blades cut as close as possible to an edge such as a garden edge beside which the mower is wheeled.

This requirement has resulted in the provision of offset pairs of wheels with the front and rear wheels at one side (called the inner side) being disposed with their outer edges substantially in line with the outer edge of the cutter housing adjacent the blades tip path, and the wheels at the opposite side being space outwardly from the blades tip path.

This enables a grass delivery chute to curve outwardly from the cutter housing to facilitate transfer of cut grass rearwardly to a grass catcher. Mowers with the wheels on at least one side set inwardly to permit mowing adjacent an upstanding surface will be referred to ; > hereinafter as "of the type described", At present1 practically all rotary mowers of the type described are provided with a cast aluminium cutter housing which has a thickness of several millimetres in order to provide the required strength and stiffness. The blades tip path extend close to the inner edge of the inner side wall of the cutter housing which is opposite the grass exit chute and in use, this inner side wall is frequently abraded by contact with exposed path edges and the like as the user tries to mow as close as possible to such adges.The housing is often damaged to an extent that it must be replaced.

Furthermore the thickness of the side wall of the cutter housing prevents the blades from approaching an edge coincident with outer face of the housing or with a line extending between the outer faces of the adjacent wheels.

This prevents such mowers from cutting up to the edges. This task is normally performed in a further operation, either manually or by using an edge trimmer.

Attempts have been made in the past to overcome this problem by truncating the side wall of the housing intermediate the adjacent supporting wheels 90 that the blade is exposed and extends outwardly beyond the cutter housing.

While this may be effective in use, it is extremely dangerous and does not confine within the housing that material thrown by the blades.

Mowers of the type described also utilise fold down handles to enable them to be carried in the boot of a car or the like. These handles ofren comprise a lower frame simply bolted to the cutter housing and a foldable top frame pivotally connected thereto. Such handle assemblies or the cutter housing frequently break at their connection due to the relatively high loads applied through the joint.

This invention also aims to alleviate the abovementioned disadvantages and to provide an improved rotary mower which will be reliable and efficient in use. Other objects and advantages of this invention will hereinafter become apparent.

With the foregoing and other objects in view, this invention in one aspect resides broadly in a rotary mower of the type described, characterised in the provision of a cutter housing provided with a side wall cutout in the side wall of the housing, said cutout being disposed intermediate one pair of inwardly extending front and rear wheels and being formed in said housing substantially coincidently with the lateral extremity of the blades tip path, and a cover assembly secured to said cutter housing to cover said cutout.

Preferably, the cover assembly is made of tougher material than the material from which the cutter housing is formed Bo that the thickness of the cover may be small compared to the cutter housing. Preferably the cover is formed from a tough, wear-resistant material whereby its thickness may be minimised and preferably the outermost face of said cover assembly is planar and is disposed in the plane containing the outermost faces of the adjacent front and rear wheels.

In the preferred form the cover assembly is formed as a hardened steel component which is adapted to be releasably secured to a cast aluminium cutter housing. The cover assembly may be in the form of a flat plate extending in the longitudinal direction of the mower and permanently secured to the cutter housing such as by being rivetted, bolted or screwed to the cutter housing. Alternatively, the cover assembly may be provided with opposed channel recesses along its forward and rear edges which engage about respective flanges provided on the cutter housing about the side wall opening whereby it may be slideably retained.on the cutter housing.

Cf course if desired, the cover assembly or wear plate may be readily detachable and may be supported on linkages or on rails for movement between an operative shielding position and an inoperative position at which it is spaced from the side wall opening. Furthermore, the cover assembly or wear plate may be adjustably secured to the cutter housing such that its lateral position may be varied to maintain a position coincident with the outer extremities of the cutting blades as the latter vary in length through ware.

In a further aspect1 this invention resides in a cutter housing having a front shielding portion and a rear arched portion which forms an outlet and the sidewalls of said arch portion being recessed to provide handle recesses which snugly accomodate the attached ends of the mowers handle.

The arched portion may be in any desired configuration such as curved or rectangular and preferably the top wall of the cutter housing rises substantially helically about the motor housing to the arched portion. Preferably the cutter is formed with a side wall opening as defined above.

In a further aspect this invention resides broadly in a mower assembly including a cutter housing having integral location means thereon for locating a handle mounting and means for securing the handle mounting to the cutter housing.

In yet another aspect, this invention resides broadly in a blade mounting for a mower, said blade mounting having a central mounting for connection to a drive shaft a pluraliy of blade mountings spaced around the blade amounting, the latter being waisted or having radially reduced sections between said blade mountings.

In order that this invention may be more readily understood and put into practical effect, reference will now be made to the accompanying drawings which illustrates a typical embodiment of the invention and wherein: Fits. 1 is a overall view of a rotary mower made according to the present invention; FIG. 2 is an enlarged plan view illustrating the relationship between the detachable cover assembly for the cutter housing and wheels; FIG. 3 is an enlarged sectional view of the cover housing mounting, and FIG. 4 illustrates the handle mounting arrangement.

FIG. 5 is a plan view of the preferred form of cutting disc, and FIG. 6 is a side view of the cutting dise illustrated in Fig. 5.

As illustrated, the mower 10 is a rotary mower of the type having a motor 11 supported on a cutter housing 12 whereby its vertically disposed crank shaft extends beneath the cutter housing and supports a rotary cutting blade indicated at 13 in Fig. 3. The cutter housing 12 is supported by front and rear wheels 14 and 15 respectively which are height adjustable to vary the cutting height of the blade 13. The wheels 14 and 15 at one side are disposed adjacent the outermost edge of the cutter housing to enable the cutting blade 13 to approach an abutment, such as a path, beside which the wheels 14 and 15 may run. The opposite side of the cutter housing includes a grass chute 16 for transferring grass cuttings rearwardly to the grass catcher 17.

According to the present invention the side face 18 of the cutter housing 12 opposite the grass chute 16 is formed with a side opening 19 which extends substantially the full height of the side wall. The side opening has opposed vertical flanges 20 and a top horizontal flange 21. The flanges 20 are contained in a plane which contains the outer faces 23 of the front and rear wheels 14 and 15 so that a cover assembly 24 in the form of a hardened steel plate 25 formed with inwardly facing channels 26 at opposite ends thereof may abut the outer feces of the flanges 20 and be secured thereto as illustrated in Fig. 3. The top edge of the cover plate 25 is also provided with an inwardly facing channel member which passes over the top flange 21 and locates the cover plate in its operative vertical position.

As shown in Fig. 3 the cutter blades 13 extend outwardly to the vertical plane containing the outer faces 23 of the wheels 14 and 15 and as the cover plate 25 is formed of hardened steel material, it may be formed of thin plate material so that the distance between the outer ends of the blades 13 and the outer face 27 of the cover plate 25 is minimal.

In use, the mower may be pushed along an abutment face such as the side edge of a path or the like with the cover plate scraping against the path so that the blades 13 can cut grass substantially to the edge of the abutment. As the cover plate is formed of hardened steel such abrasion will not significantly damage the cover plate or the cutter housing 12 as the latter is shielded by the cover plate 25.

In the preferred embodiment the cover plate 25 is secured with fastening such as rivets and the like so that it can not be readily removed. However, these fastenings can be removed to enable the cover plate 25 to be removed by a serviceman for replacement purposes when the abrasion caused through contact with abutments wares out the cover plate.

As illustrated in Fig. 4, the fixed lower part 31 of the handle assembly 30 attaches to the cutter housing 12 by through bolts 32. For this purpose, the cutter housing is formed with a rear step 33 which extends along and abutts the rear face of the flattened end portion 34 of the handle shaft 35. The step 33 curves about the lower end face of the portion 34 to form a recess 36 in which the lower end 37 of end portion is snugly located, Thus when the handle assembly 30 is pressed down to lift the front of the mower, the torque is transmitted from the handle shaft 35 to the cutter housing 12 directly through the step 33 and not throygh the bolts 32.

Thus high point loadings are minimised.

Of course the housing 12 could have continuous side walls extending along either side of the lower end 37 or the recess could be in the form of raised abutments arranged in spaced relationship around the end portions of the handle to restrain its pivotal movement with respect to the cutter housing 12.

It will also be seen that in the illustrated embodiment the lower end portions of the tubular handle are pressed with a central flat portion 38 provided with side flanges 39 which extend upwardly into the transition zone so as to provide strength at that zone.

The cutter disc 40 illustrated in Figs. 5 and 6 is of substantially square cross-sectional configuration. It includes an apertured central hub portion 41 to enable it to be connected to the mower shaft flange and square apertures 42 for connection of the cutter blades and or grass throwing blades thereto and bridge portions 43 which reinforce the square apertures 42 and provide a suitable amount for the cutting and throwing blades.

The disc is provided with medial rib 44 and is dished as shown in so that the blade mountings are angled slightly downwardly with respect to the plane extending normally to the mower shaft to which the cutter plate is mounted. If desired, the straight peripheral edge members 46 of the cutter disc 40 may be modified to further reduce the inertia of the cutter disc by recessing or scolloping the discs along these edge portions so as to reduce their radial dimensions.

It will ofcourse be realised that the above has been given only by way of illustrative example of the invention and that all such modifications and variations thereto as would be apparent to persons skilled in the art are deemed to fall within the broad scope and ambit of the invention as is defined in the appended claims.

Claims

I CLAIM:

1. A rotary mower of the type described, characterised in the provision of a cutter housing provided with a side wall cutout in the side wall of the housing, said cutout being disposed intermediate one pair of inwardly extending front and rear wheels and being formed in said housing substantially coincidently with the lateral extremity of the blades tip path, and a cover assembly secured to said cutter housing to cover said cutout.

2. A rotary mower as defined in claim 1, wherein said cover assembly assembly is substantially planar and extends substantially parallel to the mowers direction of movement.

3. A rotary mower as defined in claim 1 or claim 2, wherein said cover assembly is made of material which is toughex than the material from which said cutter housing is formed and wherein the material thickness of said cover is small compared to the material thickness of said cutter housing.

4. A rotary mower as defined in any one of the preceding claims, wherein the outermost face of said cover assembly is disposed in the plane containing the outermost faces of the adjacent front and rear wheels.

5. A rotary mower as defined in any one of the preceding claims, wherein said cover is formed from a tough, wearresistant material.

7. A rotary mower as defined in any one of the preceding claims, wherein said cutter housing is cast aluminium and said cover assembly is formed as a hardened steel component Which is releasably secured to said cutter housing.

8. A rotary mower as defined in any one of the preceding claims, wherein said cover assembly is in the form of a flat plate extending in the longitudinal direction of the mower and mechanically secured to the cutter housing.

9. A rotary mower as defined in any one of the preceding claims, wherein said cutter housing is formed with opposed mounting means along its forward and rear edges and which engage with complementary mounting means provided on the said cover assembly whereby the latter may be releasably engaged with the cutter housing.

10. A cutter housing having a front shielding portion and a rear arched portion which forms an outlet and the sidewalls of said arch portion being recessed to provide handle recesses which snugly accomodate the attached ends of the mower's handle.