GB2578586A

GB2578586A - Mower with switch

Info

Publication number: GB2578586A
Application number: GB1817753.5A
Authority: GB
Inventors: John Gittins
Original assignee: Allett Ltd
Current assignee: Allett Ltd
Priority date: 2018-10-31
Filing date: 2018-10-31
Publication date: 2020-05-20
Anticipated expiration: 2038-10-31
Also published as: GB2578586B; GB201817753D0

Abstract

A mower 200 has a cutter 230 for cutting grass; a drive means 120 for driving the mower 200 at a speed; a motor 110 for rotating the cutter 230 in a cutting direction; a controller 130 for controlling the motor 110; and a switch 140 communicatively coupled to the controller 130. The switch 140 signals the controller 130 to activate a back-lapping mode only when the switch 140 is activated. In the back-lapping mode, the cutter 230 rotates in a reverse direction to the cutting direction, and the cutter 230 rotates at a slower speed in the reverse direction than in the cutting direction.

Description

MOWER WITH SWITCH

FIELD OF INVENTION

The present invention relates to a mower having a switch, in particular to a switch for controlling the cutting speed and direction of a mower cutting blade.

BACKGROUND OF THE INVENTION

Mowers are used extensively, both in the home and in public spaces, to maintain lawns. For larger areas of lawn, self-propelled mowers are typically used, especially in professional sport arenas, such as football, golf, cricket, bowls and the like.

Self-propelled mowers generally have motors that act to both turn a cutting blade (or typically a rotatable cutter/cutting cylinder) and to drive a rear roller that propels the mower. The cutting blade will blunt through use.

A method of sharpening the cutting blade of a rotatable cutter, known as "backlapping", comprises applying grinding paste onto the blade and rotating the cutter in reverse. This method requires the operator to make adjustments to the relative position of the cutter throughout the procedure. The operator is also required to apply several layers of grinding paste during rotation of the cutter, to ensure that the paste is applied over the whole surface.

When performed manually (e.g. rotating the cutter with a hand drill), this can be very time consuming and laborious. However, the requirement to make adjustments to the cutter and to apply several layers means that using conventional backlapping machines carries a high level of risk. Conventional backlapping machines are freestanding, and so not only is the end user of a mower unlikely to have easy access to these machines, they also require a separate power source, which an operator has to separately control, increasing the risk that an accident may occur.

This second problem also arises with 'onboard' backlappers such as used on ride on lawnmowers. The backlapping in such mowers is typically achieved with a hydraulic transmission with a reverse value. Furthermore, the switch for controlling operation of such mowers, typically placed on a handle of the mower or by the seat cabin, is out of reach of an operator when they are in close proximity to the blades, which are rotating at sufficiently high speed to cause an injury. This is further exacerbated by conventional mowers having engines that both rotate the cutter and drive the mower, with no means to isolate either action. Instead a brake is typically relied upon to prevent the drive of the mower. As such, using a motorised backlapping machine carries a high level of risk.

The present invention aims to at least ameliorate the aforementioned disadvantages with the prior art backlapping systems.

SUMMARY OF THE INVENTION

According to a first aspect of the present invention, there is provided a mower comprising: a cutter for cutting grass; a drive means for driving the mower at a speed; a motor for rotating the cutter in a cutting direction; a controller for controlling the motor; and a switch communicatively coupled to the controller, wherein the switch signals the controller to activate a backlapping mode only when the switch is activated. In the backlapping mode, the cutter rotates in a reverse direction to the cutting direction, and at a slower speed in the reverse direction than in the cutting direction.

The present invention provides improves safety over conventional systems, by virtue of the backlapping mode being activated only when the switch is activated. The issues of accessibility to backlapping machines and time-intensiveness of manually performing the procuedure are also overcome, because motorised backlapping functionality is part of the as-sold mower. No separate power source or free-standing machine is required, and so the end user is capable of performing the backlapping themselves. This also heightens the requirement for improved safety if an inexperienced operator is performing the procedure.

The motor may also provide power for the drive means, or a separate motor may be used.

The mower may further comprise a battery coupled between the motor and controller, wherein the battery is configured to provide power to the motor as directed by the controller. Where multiple motors are provided, separate batteries to power each motor may be provided. Additionally or alternatively, multiple batteries may be used to power each or a motor. Types of battery typically include one or more batteries based on a Lithium-ion chemistry or any other battery chemistry, such as lead acid or the like. Such batteries are typically lighter than petrol engines. It can be appreciated that in such examples, reference to motors can include electric motors that provide power to drive means of the mower, and any cutter, and any other electronic functionality of the mower.

The switch may be communicatively coupled to the controller by a physical connection, and the switch may be housed in a detachable pendant. An advantage of this arrangement is that a deliberate action is required to attach the switch to the mower and so to couple the switch to the mower. This adds an additional layer of safety to the procedure by reducing the likelihood of the backlapping mode inadvertently being activated.

Alternatively, the switch may be communicatively coupled to the controller via a wireless connection. The wireless connection may be between the switch and the controller directly, or via a shared network. BluetoothTM or other such suitable wireless communication protocol may be used to form the communication link between the controller and the switch.

The switch may be a software switch on a hardware device. The hardware device may be a mobile device, with the software switch an application running on the mobile device. An advantage of this arrangement is the reduction of physical equipment involved in the process. This reduces the likelihood of the process being halted unexpectedly (i.e. the wire connecting the switch and the mower being cut).

The switch may isolate the motor and the drive means when communicatively coupled to the controller. Alternatively, it may be that the activation of the switch and therefore the backlapping mode isolates the motor and the drive means. Isolating the motor and the drive means ensures that there is no risk of the mower moving when performing the backlapping procedure.

Where a battery and one or more electric motors are used, it can be appreciated that by isolating the drive means the switch ensures that battery drain is minimum.

Additionally, any risk to the user of the drive means engaging, causing the mower to advance or move during the backlapping is eliminated.

The switch may be activated by an end user actuating the switch, and deactivated on 10 de-actuation. The switch may be a dead man switch. That is, the switch may use hold-to-run logic: thus releasing pressure on the switch will cause the switch to deactivate.

The slower speed run in the backlapping mode may be within the range of 10% to 95% of the speed in the cutting direction. More preferably the slower speed may be between 20% and 80% of the speed in the cutting direction or up to 50% of the speed in the cutting direction, or more preferably between 10% and 35%. In one embodiment the backlapping speed is 250rpm. Given a normal cylinder cutting speed is between 800-1500rpm this equates to around 16-30% of normal speed The reduced speed is a safety feature, and ensures that the grinding paste can be applied more easily than if the backlapping speed matched that of the cutting speed. However, the speed must be sufficient for the blades to be sharpened by rotation of the cutter.

The controller may comprise a reverse direction pin and a mode direction pin, with the switch configured to activate said pins on activation of the switch.

According to a second aspect of the present invention there is provided a method of operating a mower in a backlapping mode to sharpen a cutter, said mower comprising a cutter for cutting grass in a cutting direction, a motor for rotating the cutter in a cutting direction; and a controller for controlling the motor; said method comprising the steps of: communicatively coupling a pendant to the controller, said pendant comprising at least one switch; and activating said switch, wherein said switch signals the controller to activate a backlapping mode; and wherein the controller directs the motor to rotate the cutter in a reverse direction to the cutting direction, and wherein the controller directs the motor to rotate the cutter at a slower speed in the reverse direction than in the cutting direction.

In this second aspect, the switch may signal the controller to also deactivate any drive means of the mower. The switch may be physically or electrically coupled to the controller. Wireless communication protocols may also be used to couple the switch to the mower.

When operating in the backlapping mode, a user may then sharpen the cutter, for example by application of a backlapping paste or another sharpening means.

In some example embodiments the set of instructions/method steps described above are implemented as functional and software instructions embodied as a set of executable instructions which are effected on a controller, such as a computer or machine which is programmed with and controlled by said executable instructions. Such instructions are loaded for execution on a processor (such as one or more CPUs). The term processor includes microprocessors, microcontrollers, processor modules or subsystems (including one or more microprocessors or microcontrollers), or other control or computing devices. A processor can refer to a single component or to plural components.

In other examples, the set of instructions/methods illustrated herein and data and instructions associated therewith are stored in respective storage devices, which are implemented as one or more non-transient machine or computer-readable or computer-usable storage media or mediums. Such computer-readable or computer-usable storage medium or media is (are) considered to be part of an article (or article of manufacture). An article or article of manufacture can refer to any manufactured single component or multiple components. The non-transient machine or computer-usable media or mediums as defined herein excludes signals, but such media or mediums may be capable of receiving and processing information from signals and/or other transient mediums.

The skilled man will appreciate that preferred features of any one embodiment and/or aspect of the invention may be applied to all other embodiments and/or aspects of the invention.

These and other aspects of the invention will be apparent from, and elucidated with reference to, the embodiments described hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiment of the invention shall now be described in detail by way of example and with reference to the accompanying drawings in which: Figure 1 illustrates components for a mower according to a preferred embodiment of the present invention; Figure 2 illustrates a mower comprising the components of figure 1; Figure 3 shows a switch as embodied in figures 1 and 2; and Figure 4 shows a connection between a mower and the switch of figure 3.

It should be noted that the Figures are diagrammatic and not drawn to scale. Relative dimensions and proportions of parts of these Figures have been shown exaggerated or reduced in size, for the sake of clarity and convenience in the drawings. The same reference signs are generally used to refer to corresponding or similar feature in modified and different embodiments.

DETAILED DESCRIPTION OF EMBODIMENTS

In an exemplary embodiment of the present invention, as shown in figures 1 and 2 there is provided a system 100 for a mower. Figure 1 shows a broad overview of the components of the system 100. In particular, the system 100 comprises a motor 110 having drive means 120 for propelling the mower and for rotating cutting means. In the example shown a single motor is used, however it may be appreciated that multiple motors may be used, such as a separate motor to power the drive means from the motor used to power cutting means.

A controller 130 is provided, in communication with the motor for controlling the speed of the mower. Finally a switch 140 is used to provide a signal to the controller 130. The switch 140 is typically a dual switch, comprising a first switch 141 and a second switch 142. Alternatively, a single switch having dual states may be used.

Broadly, the motor 110 provides drive to both the mower and cutting means (or one motor provides drive to the mower, whilst a second motor provides drive to the cutting means). In a conventional petrol mower the motor can be a combustion engine -in this instance the motor also provides power to any electrical components on the mower. Alternatively (or potentially additionally) one or more batteries may be used to power the motor and any electronics. The advances in battery chemistry, leading to improved battery capacities and voltage output has allowed mowers to remove combustion engines in some instances. When a pure battery is used to provide power to the mower, the motor is typically an electric motor. The electric motor may be a permanent magnet synchronous motor, or the like. In the example described herein, a battery and electric motor is used.

The switch 140 in the example shown is attached to the controller 130 using a physical connection, such as a cable. However other means to communicatively couple the switch 140 to the controller 130, such as wireless communication, can be used. As noted above, the switch 140 can comprise two switches (or a bi-mode single switch) -the first switch 141 is used to select a reverse state, and the second switch 142 is used to slow down the rotation speed of the cutting means. Preferably, both switches are actuated by a single switch, such as a dead-man's switch or a hold to run style switch. Such switches must be continually depressed or activated in order to actuate the switch.

A detailed schematic of a mower 200 including the system 100 of figure 1 is shown in figure 2. A housing 210 is provided to contain the system. In figure 2, the motor 110, controller 130 and switch 140 are shown. Motor 110 is mechanically coupled to a rear drive means, in this instance a rear roller 220 to provide forward drive of the mower 200. The motor 110 is configured to supply a constant drive force to the rear roller 220 when, resulting in a normal drive speed when the mower is used as intended on flat, straight stretches of lawn or the like.

The motor 110 (or a separate motor, controlled in a similar manner by the controller) is also configured to drive rotation of a cutter 230, in the example shown in figure 2 a cylindrical drum comprising a series of cutting blades, which may be arranged in cartridges. It can be appreciated that alternative cutting means may be utilised, such as a rotary cutter depending on the style of mower.

Control of the motor 110 in relation to the drive speed of the rear roller 220 may use a throttle, which may be a thumb operated switch, pull (bail) bar, or other form of hold to actuate a switch that ensures that motor operation is tied to an action of the user. Such switch is typically mounted or part of a handle 240 and may utilise proportional control up to the normal drive speed specified by the controller 130.

Gearing (not shown) may be utilised to ensure that the cutter 230 rotates at a different speed to the rear roller and/or to allow the cutter to have a different throttle response upon actuation of the throttle such that the rotational speed of the cutter is essentially constant at all drive speeds.

In the example shown in figure 2, motor 110 is controlled by the controller 130. In use the controller 130 acts to control the speed of the motor, which in turn controls the rotational speed of the cutter mower and/or the drive speed of the mower. In general the mower is set to a normal drive speed by the controller 130, in accordance with a pre-set value, which acts to control the voltage supplied to the motor 110 by the battery 250. This control may be by changing the value of the voltage supplied and/or the timing. The controller 130 may utilise pulse width modulation to control the output of the motor 110.

As a consequence of general use, the cutting blades of the cutter 230 tend to blunt over time, resulting in the need to sharpen them. This is typically done by operating the applying a sharpening paste to the blades whilst the blades are operated in reverse. In the present embodiment, connection of the switch 140 to the controller 130 optionally acts to isolate the drive means 220 of the mower 200 to prevent forward motion of the mower. Additionally, actuation of the switch 140 closes switches 141 and 142 resulting in the motor rotating the cutter 230 in reverse and at a reduced speed. This allows application of the necessary backlapping technique and sharpening of the blades of the cutter 230. In one embodiment the backlapping speed is 250rpm. Given a normal cylinder cutting speed is between 800-1500rpm this equates to around 16-30% of normal speed.

The switch is shown in figure 3. Switch 140 typically comprises a thumb-switch 340 connected to a handle 342. Handle 342 provides a surface for the user to hold in one hand, with the thumb switch 340 placed at the end of the handle 342 to allow for easy actuation by the user. The thumb switch acts to actuate the reverse switch 141 and the speed limiter switch 142. The thumb switch 340 is configured to be a press to hold switch, such that pressure must be maintained on the switch 340 to maintain actuation. Release of pressure causes the switches to be disengaged.

The reverse switch 141 signals the controller 130 to operate the motor in a manner that causes the cutter 230 to rotate in a reverse direction to a cutting direction. This may be by gearing or the like. The speed limiter switch 142 acts in a similar manner, signalling the controller 130 to limit the speed of rotation of the cutter 230, which may be by reducing the output of the motor 110 or by gearing. It can be appreciated that a single switch could be utilised, with the signals being sent by the controller 130.

A cable 350 is used to couple the switch 340 to a housing of the mower 200 via a connector 360. In the example shown in figures 3 and 4, connector 360 is a typical screw to engage connector, configured to couple to a corresponding port 370 on a housing of the mower 200, which in turn is electrically coupled to the controller 130.

By providing a dedicated, separate electrical system for backlapping, which removes the need for the user to either manually actuate the cutter 230 or to adjust the operation of the mower 200, safety is greatly increased, along with ease.

From reading the present disclosure, other variations and modifications will be apparent to the skilled person. Such variations and modifications may involve equivalent and other features which are already known in the art of receivers and which may be used instead of, or in addition to, features already described herein.

Although the appended claims are directed to particular combinations of features, it should be understood that the scope of the disclosure of the present invention also includes any novel feature or any novel combination of features disclosed herein either explicitly or implicitly or any generalisation thereof, whether or not it relates to the same invention as presently claimed in any claim and whether or not it mitigates any or all of the same technical problems as does the present invention.

Features which are described in the context of separate embodiments may also be provided in combination in a single embodiment. Conversely, various features which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable subcombination. The applicant hereby gives notice that new claims may be formulated to such features and/or combinations of such features during the prosecution of the present application or of any further application derived therefrom.

For the sake of completeness it is also stated that the term "comprising" does not exclude other elements or steps, the term "a" or "an" does not exclude a plurality, a single processor or other unit may fulfil the functions of several means recited in the claims and reference signs in the claims shall not be construed as limiting the scope of the claims. 11.

Claims

CLAIMS1. A mower comprising: a cutter for cutting grass; a drive means for driving the mower at a speed; a motor for rotating the cutter in a cutting direction; a controller for controlling the motor; and a switch communicatively coupled to the controller; wherein the switch signals the controller to activate a backlapping mode only when the switch is activated; and wherein, in the backlapping mode, the cutter rotates in a reverse direction to the cutting direction, and the cutter rotates at a slower speed in the reverse direction than in the cutting direction.
The mower of claim 1, further comprising: a battery coupled between the motor and controller, wherein the battery is configured to provide power to the motor as directed by the controller.
The mower of claim 1 or claim 2, wherein the switch is communicatively coupled to the controller by a physical connection.
The mower of claim 3, wherein the switch is housed in a detachable pendant.
The mower of claim 1 or claim 2, wherein the switch is communicatively coupled to the controller via a wireless connection.
The mower of claim 5, wherein the switch is a software switch on a hardware device.
The mower of claim 6, wherein the software switch is an application and the hardware device is a mobile device. 2. 3. 4. 5. 6. 7.
8. The mower of any preceding claim, wherein the switch isolates the motor and/or the battery from the drive means when communicatively coupled to the controller.
9. The mower of any one of claims 1 to 7, wherein activation of the backlapping mode isolates the motor and the drive means.
10. The mower of any preceding claim, wherein the switch is activated by an end user actuating the switch, and deactivated on de-actuation.
11. The mower of claim 10, wherein the switch is a dead man switch.
12. The mower of any preceding claim, wherein the slower speed is within the range of 10% to 35% of the speed in the cutting direction.
13. The mower of any preceding claim, wherein the controller comprises a reverse direction pin and a mode direction pin and the switch is configured to activate said pins on activation of the switch.
14. A method of operating a mower in a backlapping mode to sharpen a cutter, said mower comprising a cutter for cutting grass in a cutting direction, a motor for rotating the cutter in a cutting direction; and a controller for controlling the motor; said method comprising the steps of: communicatively coupling a pendant to the controller, said pendant comprising at least one switch; and activating said switch, wherein said switch signals the controller to activate a backlapping mode; and wherein the controller directs the motor to rotate the cutter in a reverse direction to the cutting direction, and wherein the controller directs the motor to rotate the cutter at a slower speed in the reverse direction than in the cutting direction.