GB2137062A

GB2137062A - Lawn Treating Machines

Info

Publication number: GB2137062A
Application number: GB08408119A
Authority: GB
Inventors: Berjinder S Sehmbi; Anthony Stanley; Brian P Onufryk; John H Upton
Original assignee: BIRMID QUALCAST
Current assignee: BIRMID QUALCAST
Priority date: 1983-03-30
Filing date: 1984-03-29
Publication date: 1984-10-03
Also published as: GB8408119D0; GB2137062B

Abstract

A cylinder lawnmower has a cutting cylinder (10) mounted for rotation between opposed bearing support members (20). The mounting means is splittable into a first component (17) journalled in a bearing (19) carried by one of the support members (20a), and a second component (11) releasably coupled to the first component (17) and journalled in a bearing (29) carried by the other support member (20b). The second component (11) carries the cutting cylinder (10) and is axially movable away from the first component (17) to permit removal and replacement of the cutting cylinder from between the bearings when the coupling is released. <IMAGE>

Description

SPECIFICATION Lawn Treating Machines This invention relates to lawn treating machines, particularly cylinder lawnmowers.

The cutting cylinder of a cylinder lawnmower normally consists of helical blades disposed about a central shaft such that when the shaft is rotated about its axis the blades describe a cutting cylinder The central shaft is mounted for rotation in opposed bearings carried by respective side plates of the mower housing. It is generally necessary to construct the housing so that it can be dismantled to permit removal of the cutting cylinder. This would normally be done only by a specialist repairer and can therefore inhibit DIY repairs.

An object of the present invention is to provide a cylinder lawnmower or similar lawn treating machine in which the cutting cylinder or other treating element is more easiiy removed and replaced in the machine housing.

In accordance with the present invention there is provided a lawn treating machine comprising means mounting a lawn treating element for rotation about a generally horizontal axis between opposed bearing support members, the mounting means being splittable into a first component journalled in a bearing carried by one of the support members and a second component releasably coupled to the first component and journalled in a bearing carried by the other support member, the second component carrying the treating element and being axially movable away from the first component to permit removal and replacement of the treating element from between the bearings when the coupling is released.

Further means are preferably provided for axially and radially aligning the two components with one another. The aligning means may comprise, for example, a concentric locating surface disposed about the axis of one of the components and a seating surface disposed about the axis of the other component for seating the locating surface.

The coupling between the two components is preferably a threaded coupling. For example, the axially fixed component may comprise a sleeve journalled in the bearing with a mounting pin slidably received in the sleeve, a threaded portion of the pin projecting beyond the sleeve and engaging a threaded bore in the other component.

The drive to the treating element is then imparted through the pin in a direction tending to tighten the threaded coupling, and the two components are decoupled simply by relatively rotating the pin and the cylinder in opposite directions.

In a preferred embodiment of the invention, the lawn treating element comprises a cutting cylinder for a cylinder lawnmower.

By way of example only, one embodiment of the invention is illustrated in the accompanying drawing in which the sole Figure is a sectional view through a portion of a cylinder lawnmower showing the mounting arrangement for the cutting cylinder.

Referring to this drawing, a cutting cylinder 10 consists of helical blades 32 disposed about a central spindle 11. When the spindle is rotated about its axis the blades describe a cutting cylinder. In use the rotating cylinder cooperates with a fixed bottom blade (not shown) to perform a shear cutting action in a well known manner.

In the illustrated example, one end of the spindle 11 (the right hand end as viewed in the Figure ) has a turned-down stub 28 journalled for rotation in a self-aligning bearing 29 retained within a bearing housing 20b located in a side piate 21 b of the mower frame. At the other end (the left hand end as viewed in the Figure) the spindle is provided with a threaded bore 1 5 which receives a threaded end portion 1 6 of a mounting pin 17. The pin 17 is received within a cylindrical sleeve 1 8 rotatably mounted in a bearing assembly 1 9 supported in a bearing housing 20a carried by the opposed side plate 21 a of the mower housing.

The pin 17 has a square head 22 received in a corresponding recess in the outer face 23 of a driven pulley 24 mounted on the sleeve 18.

Accordingly, when the pulley is driven, a rotary drive is transmitted to the pin 17 through the head 22 and via the threaded coupling to the spindle 11. The arrangement is such that the threaded coupling between pin 17 and spindle 11 will tend to tighten should the cutting cylinder meet substantial resistance to its rotation.

Should it be desired to remove the cutting cylinder, this can be done simply by holding the cylinder against rotation and rotating the pin 1 7 in a reverse sense to disengage the threaded coupling.

With the pin 1 7 withdrawn, the spindle 11 can be moved to the right until it clears a frustoconical lip 33 at the inner end of the sleeve 18.

This movement is possible inner end of the sleeve 1 8. This movement is possible because, as shown in the Figure, the end face 34 of the spindle is spaced from the inside face 35 of a bearing retainer 30 located in the bearing housing 20b at the opposite end of the spindle. The self-aligning bearing 29 then permits a swivelling movement of the stub 28 in any direction to allow removal of the cylinder from between the bearings.

The frusto-conical lip 33 of sleeve 1 8 provides a locating surface 26 which seats in a corresponding countersunk recess 27 forming the entrance to the threaded bore 1 5. This ensures precise axial and radial alignment is maintained between the sleeve 18 and the spindle 11, especially following removal and replacement of the cutting cylinder.

It will be appreciated that the clearance between the fixed bottom blade and the rotating cutting cylinder is normally adjusted to lie within fine tolerances, and that, since the clearance betwee the pin 1 7 and sleeve 18 will be of the same order, seating of the locating surface 26 in the recess 27 to ensure precise alignment of the spindle 11 with the sleeve 18 is an important feature of the design.

The frusto-conical lip 33 of the sleeve 1 8 not only provides a locating surface 26 for axially and radially aligning the two components of the mounting assembly, but also provides a retaining shoulder 36 which abuts bearing 1 9 and prevents axial movement of the sleeve 1 8.

Although the invention has been described with particular reference to a cylinder lawnmower, a similar mounting arrangement could be used advantageously in other lawn treating machines in which the treating element comprises, for example, a rotary rake, scarifier, brush, slitter or roller.

Claims

1. A lawn treating machine comprising means mounting a lawn treating element for rotation about a generally horizontal axis between opposed bearing support members, the mounting means being splittable into a first component journalled in a bearing carried by one of the support members and a second component releasably coupled to the first component and journalled in a bearing carried by the other support member, the second component carrying the treating element and being axially movable away from the first component to permit removal and replacement of the treating element from between the bearings when the coupling is released.

2. A cylinder lawnmower comprising means mounting a cutting cylinder for rotation between opposed bearing support members, the mounting means being splittable into a first component journalled in a bearing carried by one of the support members and a second component releasably coupled to the first component and journalled in a bearing carried by the other support member, the second component carrying the cutting cylinder and being axially movable away from the first component to permit removal and replacement of the cylinder from between the bearings when the coupling is released.

3. A lawnmower according to Claim 2 in which the first component of the mounting means is retained against axial movement and in which drive is transmitted to the first component to rotate the cylinder.

4. A lawnmower according to Claim 2 or Claim 3 in which the bearing journalling the second component is a self-aligning bearing to provide swivelling movement of the second component into and out of its operative position when the coupling is released.

5. A lawnmower according to Claim 4 further comprising means for axially and radially locating the two components with respect to one another.

6. A lawnmower according to Claim 5 in which the locating means comprises a locating surface disposed concentrically about the axis of one component, and a cooperating seating surface disposed concentrically about the axis of the other component.

7. A lawnmower according to Claim 5 in which the locating surface is frusto-conical.

8. A lawnmower according to any one of the preceding Claims 2 to 7 in which the coupling is a threaded coupling.

9. A lawnmower according to Claim 8 in which the first component comprises a sleeve journalled in the respective bearing and a pin slidably received in the sleeve, a threaded portion of the pin projecting beyond the sleeve and engaging a threaded bore in the second component.

10. A lawnmower according to Claim 9 further comprising means for imparting drive to the pin in a direction tending to tighten the threaded coupling whenever the cutting cylinder meets substantial resistance to rotation.

11. A lawnmower according to any one of the Claims 8 to 10 in which the two components are decoupled by relatively rotating the two components in opposite directions.

12. A cylinder lawnmower substantially as herein described with reference to the accompanying drawing.