GB2287304A

GB2287304A - Control systems for land-drive lawnmowers

Info

Publication number: GB2287304A
Application number: GB9402060A
Authority: GB
Inventors: Arland Shawe-Taylor; Alan Edward Roberts
Original assignee: ATCO QUALCAST Ltd
Current assignee: ATCO QUALCAST Ltd
Priority date: 1994-02-03
Filing date: 1994-02-03
Publication date: 1995-09-13
Also published as: GB9402060D0; DE19503356A1

Description

2287304 1 CONTROL SYSTEMS FOR LAbl)-MIVE LAWNMOWERS This invention relates

to a control system for operating a land-drive lawnmower.

Many attempts have been made to devise an operating system which meets the safety regulations but which is at the same time convenient to use.

In one known system, a bale bar pivotally secured to a lawnmower handle controls a blade or engine brake mechanism, while an actuating lever for the land-drive is separately operable to engage the land-drive when moved to an engaged position. The land-drive lever remains latched in this position only if the bale bar has been actuated to release the blade brake. If the bale bar is then released slightly, the latch is released and the land-drive lever springs back to disengage the land- drive. Thereafter the land-drive can be re-engaged only by manually returning the actuating lever to its engaged position.

Such a system is generally inconvenient, and it would be preferable to provide a system in which the bale bar controls the land-drive while at the same time ensuring that the blade is braked whenever the bale bar is released.

According to the present invention there is provided a control system f or operati ng a 1 and-dri ve 1 awnmower i n whi ch a f i rst manual 1 y operabl e member is movable from a first position to a second position to engage the land-drive, and in which first latch means responsive to movement of a second manually operable member in a first direction when the first member is in its second position latches the first member to the second member for subsequent movement therewith, the arrangement being such that partial return movement of the second member in the opposite direction is permitted without releasing the first latch means whereby the second member is able to at least partially disengage and re-engage the land drive without returning the first member to its first position.

1 - W 2 In a preferred embodiment of the invention, a second latch means responsive to movement of the second manually operable member in the first direction latches a mc4L--r brake release actuator in an operative position with the brake released, the second latch being released to re-apply the brake only when the partial return movement of the second member in the opposite direction exceeds a predetermined limit. In this case, the first latch is preferably released at about the same time or just before the return movement reaches the predetermined limit.

The brake actuator may comprise a lever which is manually operable to release the blade brake, or it may comprise an over-centre toggle link responsive to movement of the second manually operable member such that the initial movement of the second member in the first direction urges the toggle link to its over-centre position and releases the brake. Further movement of the second operating member when latched to the first operating member and controlling the land-drive is then permitted without disturbing the toggle link.

The second operating member preferably comprises a bale bar pivotally mounted between the opposed side rails of a lawnmower pram handle.

One example of the invention is illustrated in the accompanying drawings in which:

Fig. 1 illustrates a rotary lawnmower fitted with a land-drive control system embodying the invention.

Fig. 2 diagrammatically illustrates the components of the control 30 system, the components being shown in their rest positions with the brake engaged and the land-drive disengaged, and Figs. 3-5 show subsequent stages in the operation of the control shown in Fig. 2.

j k 3 - IF Referring to the drawings, a control mechanism 30 for a land-drive lawnmower 31 includes a land-drive cable 11 which controls a jockey pulley (not shown) that clutches a belt drive between the power take off from the internal combustion engine 32 and a rear roller (not visible in the drawings). This is a well-known form of drive transmission for a lawnmower and will not be described further. The mower is also supported on front wheels 33.

The control mechanism 30 further includes a brake cable 12 which controls a conventional braking system 34. This may either comprise a mechanism on the engine which controls both an ignition cut-out and a motor brake (normal 1 y act i ng on a f 1 ywheel), or i t may compri se a bl ade brake clutch mounted on the engine shaft. With a blade brake clutch, the blade is detached from the engine drive shaft and braked when the clutch is disengaged, and the brake is then released when the clutch engages. Both types of braking system are well-known for a lawnmower, and will not be described further.

The land-drive cable 11 is attached to a land-drive plate 10, and the plate 10 has a slot 13 for receiving a latch pin 14 of a manually operable actuating lever 15. In Fig. 2 the lever 15 is retained in its rest position and prevented from moving by the engagement of the latch pin 14 with a cam 36 forming part of a control link 21 secured to a bale bar 22.

Accordingly, the land-drive is engaged by first displacing the bale bar 22 to move the control link 21 from its Fig. 2 position to its Fig. 3 position, and then manually rotating the lever 15 about its pivot pin 16 such that the latch pin 14 bears against the side of the slot 13.

The plate 10 is thus rotated about its axis 17 to tension the land- drive cable 11 and engage the belt drive to the rear roller.

The brake release cable 12 is attached to a boss 23 at one end of a toggle link 18, the other end of the link 18 having a pin 19 located within a slot 20 in the control link 21 secured to the bale bar 22.

1 -IF 4 The boss 23 abuts one side of a trapezium-shaped opening 24 in the control link 21 so that as the bale bar 22 is rotated from the fully released position shown -in Fig. 2 to its operative position shown in Fig. 3, the control link 21 carries the toggle link 18 to its overcentre position shown in Fig. 3 and at the same time releases the blade brake by tensioning the brake cable 12.

The bale bar 22 has two opposed side arms 22a, 22b pivotally secured between opposed side rails 27a, 27b of a lawnmower pram handle. In Fig. 2 the side arm 22b of the bale bar is angularly displaced from the side rail 27b of the handle. To release the blade brake (and allow starting of the engine), the bale bar is rotated upwards until the side arms 22a, 22b lie substantially parallel with the side rails 27a, 27b as shown in Fig. 3, and the bale bar is positioned adjacent the handle 35. In this position, the user can grasp the bale bar 22 and handle 35 with one hand.

In operation, the bale bar 22 is first operated to release the brake, and the actuating lever 15 is then moved from its inoperative position shown in Figs. 2 and 3 to its operative position shown in Fig. 4 to engage the land-drive. During this movement of lever 15, the latch pin 14 of the lever rides over the crest of the cam 26 formed along the upper edge 25 of the control link 21 so that the pin 14 moves to the bottom of slot 13 and is latched in the Fig. 4 position.

In effect, the bale bar 22 is now latched to the actuating lever 15 and can therefore be used to control the land-drive. In particular, the bale bar can be partially released as shown in Fig. 5 to progressively disengage the landdrive by rotating the actuating lever 15 back toward its rest position. During the first part of this partial release movement, the drive to the rear roller starts to slip as the jockey pulley comes off the belt drive. Further movement of the bale bar toward the Fig. 5 position then disengages the drive completely. At any point during this movement the bale bar can be pulled back up to its Fig. 4 position to fully reengage the land-drive. However, the 0 Ir opening 24 in the control link 21 allows this partial release and return movement of the bale bar without disturbing the toggle link 18 which remains in its over-centre position. Accordingly, the user can use the bale bar to repeatedly engage and disengage or "feather" the land-drive when manoeuvring in confined spaces but without braking the motor. On the other hand, if the bale bar is released just beyond its Fig. 5 position, the land-drive latch drops out and the toggle link 18 is forced back from its over-centre position to release the brake cable 12 and stop the motor.

If desired, a light torsion return spring could be attached to the landdrive lever 15 so that the land-drive drops out automatically before the bale bar reaches its limit position (just beyond Fig. 5).

6 -1010,

Claims

1. A control system for operating a land-drive lawnmower, the system comprising a first manua",y operable member movable from a f-rst position to a second position to engage the land-drive, and first latch means responsive to movement of a second manually operable member in a first direction and to subsequent movement of the first member into its second position to latch the first member directly or indirectly to the second member for subsequent movement therewith, the arrangement being such that partial return movement of the second member in the opposite direction is permitted without releasing the first latch means whereby the second member is able to at least partially disengage and re-engage the land drive without returning the first member to its first position.

2. A control system according to claim 1 further comprising second latch means responsive to movement of the second manually operable member in the first direction for latching a motor or blade brake release actuator in an operative position with the brake released, the second latch means being released to re-apply the brake only when the return movement of the second member in the opposite direction exceeds a predetermined limit.

3. A control system according to claim 2 wherein the first latch means is released at about the same time or just before the return movement reaches the predetermined limit.

4. A control system according to claim 2 or claim 3 in which the second latch means comprises an over-centre toggle link so arranged that the initial movement of the second manually operable member in the first direction urges the toggle link to its over-centre position to latch the brake release actuator in its operative position.

5. A control system according to claim 4 in which further movement of the second manually operable member when latched to the first manually operable member and controlling the land-drive is permitted 7 -W with the toggle link remaining in its over-centre position.

6. A control system according to any one of the preceding claims wherein the first manually operable member comprises a lever pivotally mounted on a handle of the lawnmower.

7. A control system according to any one of the preceding claims wherein the second manually operable member comprises a bale bar.

8. A motor or blade brake control system for a lawnmower, the system comprising latch means responsive to movement of a manually operable member in a first direction for latching a motor or blade brake release actuator in an operative position with the brake released, the latch means permitting partial return movement of the manually operable member in the opposite direction with the brake release actuator remaining in its operative position whereby the latch means is released to re-apply the brake only when return movement of the manually operable member in the opposite direction exceeds a predetermined limit.

9. A control system according to claim 8 in which the latch means comprises an over-centre toggle link so arranged that the initial movement of the manually operable member in the first direction urges the toggle link to its over-centre position to latch the brake release actuator in its operative position.