MOWER

Abstract: A mower for use in public places where the cutter is prone to damage from debris, has the cutter unit mounted (34) on a sub-frame which is completely detachable from the main frame (16) to facilitate rapid replacement in the field.

Description: MOWER This invention relates to mowers primarily but not exclusively, of the kind intended to be pedestrian controlled and for use in public spaces, such as along road-side verges, public parks and , the like. According to the invention a mower comprises a wheeled main frame carrying a drive motor, a sub-frame journalling a mowing-cutter shaft, means releasably connecting the main frame and sub-frame together", and a drive transmission between the motor and cutter shaft which is also readily releasable, whereby the sub-frame may be interchanged rapidly in the event of damage to the cutter. In one embodiment gears- are journalled on the respective frames and meshed to transmit drive. By these means, separation and reconnection of the main frame and sub-frame automatically disconnects and reconnects the drive transmission. This is particularly important if a cylinder mower construction is employed in public spaces, because the cutting cylinder is easily damaged by foreign objects which have been deposited in the grass by the public, and frequent removal for re-sharpening, repair or ether replacements is necessary. In another embodiment chain-drive is used with a tensioning sprocket which, when released, allows separation of the frames possibly even before chain removal. Two embodiments of the invention are described b Y wa Y °f example with reference to the accompanying OMPI drawings where in : - Fig. 1 shows a gear-driven embodiment, with the parts separated; Fig. 2 shows a chain-driven embodiment with the parts separated; and Fig. 3 shows the Fig. 2 construction assembled. Referring to Fig. 1 of the drawing, the chassis 10 carries a pair of ground wheels 12 and is intended to be pedestrian guided and controlled by handle bars (not shown) connected to the end 14. The chassis comprises a main frame 16 including a drive transmission from the drive-motor (not shown) via engine driven pulley 18 and main drive pulley 20 which are connected for example by a toothed belt with a tensioning roller 22 adjustable in the direction of the arrow A in conventional manner. The shaft carrying the pulley 20 also carries a drive gear 24. The structure 16 also carries a ground-engaging roller 26 which is adjustable by conventional mechanism in the direction of the arrows F. The structure 16 carries pairs of co-axially aligned pins 28 and 30 for engagement of the sub-frame. The sub-frame is shown in Figure 1 disconnected from the main frame and includes a shaft provided with a main gear 32 and a cutting cylinder 34. The cutting cylinder is associated with a conventional straight bottom blade 36 carried on the sub-frame. The sub-frame is connected to the main frame by means of slots which can be engaged with the pins 28,30, and a toggle fastener (for example) can be connected to hold the sub-frame assembled to the main frame. Conveniently the sub-frame is supported on castors 38 which may be swung to an inoperative position when mowing and arranged in the ground-engaging position as illustrated to facilitate movement of the sub-frame when separated from the main frame, or for additional support in manoeuvring the mower when not in use. The gears 24, 32 enable a greater reduction ratio to be obtained between motor and cylinder than would be possible (in a limited space) with a simple belt transmission. It is particularly useful that the gear transmission 24,30 reverses the direction of rotation', because it enables a flail mower to be driven from the pulley 20 (or from a similar pulley in the same location) or the cylinder to be driven, since cylinder mowers and flail mowers require (ideally) opposite directions of rotation. It will be appreciated that in the field a damaged cylinder unit can be replaced in a matter of moments simply by releasing any fastener, withdrawing one unit, inserting a fresh unit, and re-engaging the fastener. Turning now to Figures 2 and 3, the arrangement shown in these drawings is generally similar to that in Figure 1 except for the use of drive by an endless roller chain 40 to connect drive sprocket 42 (corresponding to the drive gear 24 on the main frame) with driven sprocket 44 (corresponding to the main gear 32 on the sub-frame in Figure 1) . The chain is tensioned by a sprocket 46 adjustable in a long slot 48. The length of the chain is sufficient, for example, to enable the chain to be engaged with the sprocket 44 when the parts are in the Figure OMPI 2 position, after which the main frame and sub- rame can be moved to the Figure 3 position and connected together by the fastener (not shown) and the slack taken up in the chain by adjustment of the sprocket 46. In this case, it will be appreciated that sprockets 42 44 run in the same direction, as compared to the opposite direction of sprockets 24 32. In this case the output from, the gear box to the sprocket 42 is arranged to give reversal of the normal direction of drive so as to bring the final drive back to the same direction. It will be appreciated from the foregoing description that variation is required according to whether the final cutting unit is a flail unit or a cylinder unit for example. OMPI

Claims: CLAIflS 1. A mower comprising a wheeled main frame carrying a drive motor, a sub-frame journalling a mowing cutter shaft, means releasably connecting the main frame and sub-frame together, and a drive transmission between the motor and cutter shaft which is also readily releasable, whereby the sub-frame may be interchanged rapidly in the event of damage to the cutter. 2. A mower as claimed in Claim 1 wherein the drive transmission comprises gear pinions on the respebtive frames which are meshed when the frames are connected. 3. Λ mower as claimed in Claim 1 wherein the drive transmission comprises an endless roller chain extending around sprockets provided on the respective frames. 4. A mower as claimed in Claim 3 wherein a tensioning sprocket is provided, and the length of the N chain and the adjustment of the tensioning sprocket,is such as to enable the main frame and sub-frame to be wholly separated before the chain is disengaged from the sprocket cn the sub-frame. 5. A ov/er substantially as described with reference to Figure 1 of the accompanying drawings. 6. A mower substantially as described with reference to Figures 2 and 3 of the accompanying drawings.

Inventors: ROBERTS EDWARD CYRIL, ROBERTS, EDWARD, CYRIL
Applicants: TURNER INT ENG, TURNER INTERNATIONAL (ENGINEERING) LIMITED
Application year: 1984
Main classification: A01D35
IPC codes: A01D34