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Title:
HAZARD SHIELD SAFETY LATCH
Document Type and Number:
WIPO Patent Application WO/2019/150226
Kind Code:
A1
Abstract:
There is disclosed a shield (3) for isolating hazardous components of a machine (1) characterised in that the shield is provided with at least one electromagnetic lock (maglock, 17, 19) operable to lock the shield in place and/or release the shield so that the shield may be opened. Various triggers for activating and deactivating the maglock are disclosed.

Inventors:
REGIER, Bernard Dean (420 W Lincoln Boulevard, Hesston, Kansas, 67062-0969, US)
SPARE, Andrew (AGCO Corporation, 420 W Lincoln BlvdHesston, Kansas, 67062, US)
Application Number:
IB2019/050518
Publication Date:
August 08, 2019
Filing Date:
January 22, 2019
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
AGCO CORPORATION (4205 RIVER GREEN PARKWAY, DULUTH, Georgia, 30096, US)
International Classes:
B60R25/01; A01D75/20; E05B47/00; E05B83/24; E05B83/42; E05C19/16; F16P3/08; F16P3/14
Domestic Patent References:
WO2015086333A12015-06-18
WO2015103363A22015-07-09
Foreign References:
FR696676A1931-01-06
US20160281396A12016-09-29
GB2306573A1997-05-07
EP2228269A22010-09-15
DE4309668A11994-09-29
Other References:
None
Download PDF:
Claims:
CLAIMS

1 . A shield for isolating hazardous components of a machine, characterised in that the shield is provided with at least one electromagnetic lock operable to lock the shield in place and/or release the shield so that the shield may be opened.

2. A shield as claimed in claim 1 , wherein said electromagnetic lock is operable to lock the shield in place when the hazardous components are in an operating state.

3. A shield as claimed in claim 1 , wherein said electromagnetic lock is operable to lock the shield in place when the machine is in an on state.

4. A shield as claimed in claim 1 , wherein said electromagnetic lock is operable to lock the shield in place when the machine transitions from an initial mode to a subsequent mode.

5. A shield as claimed in claim 4 wherein the machine is supplied with a key and a first control panel, and the transition from an initial mode to a subsequent mode is any one or more of:

A transition from a key outside mode, where the key is remote from the control panel of the machine, to a zeroth mode where the key is in close proximity to the control panel;

A transition from the key outside mode or the zeroth mode to a first off mode where the key is engaged with an ignition slot in the control panel;

A transition from the key outside, the zeroth or the first off mode to a second standby mode where components of the machine, other than the hazardous components or ancillaries to the hazardous components, are operating or active;

A transition from the key outside, the zeroth, the first off or the second standby mode to a third active mode where ancillaries of the hazardous components are operating or active;

A transition from the key outside, the zeroth, the first off, the second standby or the third active mode to a fourth ignition mode where the hazardous components become operational or active.

6. A shield as claimed in any of claims 1 , wherein the electromagnetic lock is operable such that it releases the shield when the machine is off or if the hazardous components are in a non-operative state.

7. A shield as claimed in any of claims 1 , wherein the electromagnetic lock is operable to release the shield when the machine transitions from a mode to a different mode.

8. A shield as claimed in claim 7, wherein the machine is supplied with a key and a first control panel, and the transition from a mode to a different mode is any one or more of:

A transition from an ignition mode where the hazardous components are operational to a third active mode where ancillaries of the hazardous components are operating or active;

A transition from the ignition mode or the third active mode to a second standby mode where components of the machine, other than the hazardous components or ancillaries therefor, are operating or active;

A transition from the ignition mode, the third active mode or the second standby mode to a first off mode where the key is engaged with an ignition slot in the control panel;

A transition from the ignition mode, the third active mode, the second standby mode or the first mode to a zeroth mode where the key is in close proximity to the control panel;

A transition from the ignition mode, the third active mode, the second standby mode, the first mode or the zeroth mode to a key outside mode where the key is remote from the control panel of the machine.

9. A shield as claimed in claim 1 , wherein the electromagnetic lock is operable to release the shield when the key or a special tool are engaged with or proximate to a second control panel that is remote from the first control panel.

10. A shield as claimed in claim 1 wherein the shield is further provided with at least one additional mechanical latch or fastener operable to lock the shield in place and/or release the shield.

1 1. A shield as claimed in claim 10 wherein the machine is supplied with a key and wherein the additional latch or fastener requires the key or a special tool to operate.

12. A shield as claimed in claim 1 1 wherein the special tool and the key are a unitary item.

13. A shield as claimed in claim 1 , further comprising a sensor arrangement for detecting that the shield is in place, wherein the hazardous components can only become operational when the sensor detects that the shield is in place.

14. A machine comprising a removable shield as claimed in claim 1.

15. A machine as claimed in claim 14 wherein the machine is a vehicle.

16. A machine as claimed in claim 14 wherein the machine is an agricultural machine or vehicle.

Description:
HAZARD SHIELD SAFETY LATCH

Field of Invention

The present invention relates to a safety latching system for a hazard shield. In particular, the invention relates to an electromagnetic lock for use with a hazard shield. Such a hazard shield may typically be found in a number of applications, such as, for example, agricultural vehicles and equipment, construction industry vehicles and equipment, military vehicles and equipment, vehicles in general, or indeed any situation where hazardous machinery or equipment must be isolated from operators, other workers or the general public by a physical barrier.

Background of invention

Hazardous elements, systems or components of equipment and vehicles (generally ‘machines’, which may include for example electrical or electronic devices) are commonly provided with shielding to prevent, among other things, contact with personnel of the hazardous components. The hazardous components may be mechanical components, such as parts of an engine; pneumatic or hydraulic components; hi-voltage electrical or electronic components; may be items that generate or reach very hot or cold temperatures, or may be optically dangerous. Such shielding may be removable, either in part or in whole, or openable, to allow access to the hazardous elements for purposes of, for example, adjustment or maintenance. Such shielding may take a number of forms, such as for example, a hatch, a door, a bonnet or hood, an inspection plate or hatch, or a casing. In some circumstances and for some equipment, such shielding should not be opened or removed when the hazardous elements are in operation, and operator’s manuals in such cases stipulate that equipment or vehicles must be shut down before shielding is opened or removed.

In some jurisdictions, there are relevant regulations or legislation stipulating that shielding must require a special tool in order to be removed or opened, which may necessitate use of the tool at a point on the vehicle or machine which is away from the main controls, so that the hazardous components may not be easily be activated by a user at the same time as they perform an action to allow opening or removal of the shielding. However, where an operator is either ignorant of, or determined to ignore, the manual and/or associated safety warnings, it is often possible to open such shielding and access the hazardous components whilst the hazardous elements are still in operation or in a state where they may be readily operated or activated.

A solution to these problems would be desirable.

Summary of Invention

Accordingly there is provided in an aspect a shield for isolating hazardous components of a machine, characterised in that the shield is provided with at least one electromagnetic lock operable to lock the shield in place and/or release the shield so that the shield may be opened. In this context,‘opened’ will be understood to cover embodiments where a shield remains physically attached to a machine, such as by a hinge or a strap (as for example in the case of a bonnet or hood), as well as embodiments where the shield may be totally removed. The shield may be describable as a hazard shield or an openable or removable shield or an openable or removable hazard shield. It is understood that the term‘hazardous components’ may cover components, elements or systems and generally refers to parts, or collections of parts, of a machine that may be dangerous when in operation.

In an embodiment, the electromagnetic lock operates to lock the shield in place when the hazardous components are in an operative state. That is, whenever the hazardous components are operating, the maglock is locked and the shield is thus locked in place.

In an embodiment, the electromagnetic lock (maglock) operates to lock the shield in place when the machine is in an‘on’ state. In the case of some machines, they may be‘on’ albeit without the hazardous components active or in use - however, the hazardous components may readily activate or be used. For example, vehicles with so-called‘auto stop-start’ systems have engines which automatically cease running when the vehicle is at a standstill but the ignition is‘on’. If the engine is considered the hazardous component, the vehicle may be‘on’ and the engine not running, but the engine is readily able to re-start should the driver press the clutch or accelerator. Accordingly, the shield (bonnet or hood) should stay closed even though the engine is not running, because the vehicle is still‘on’ and the engine may re-start at any time. It will also be recognised that a machine may be in any one of a number of‘on’ modes corresponding to various levels of activity, or preparedness for activity, of any number of components or systems, including hazardous components or systems.

The advantage of these arrangements is that the shield may be arranged so as not to be removable when the hazardous components of the machine, or indeed the machine itself, are in operation, or at least in an‘on’ state whereby they may come into operation readily, so that they may only be accessed by a user when the hazardous components are not in operation and are therefore considered relatively safe.

An electromagnetic lock is also known as a magnetic lock or a‘maglock’ and is an item of equipment generally known in the prior art as commonly being applied to doors, mainly to security-type doors in buildings, such as offices or other places of work, at entry points or where certain areas are restricted, and as such can only be accessed by keypad or card or other authorising means, such as fingerprint, retina, or other bio-marker recognising means. Such locks typically comprise an electromagnet and an armature plate. They can be either‘fail safe’ or‘fail secure’ - a fail-secure locking device remains locked when power is lost; a fail-safe device is unlocked when de-energised.

In embodiments, the maglock may be arranged such that it operates to release the shield, or effectively deactivates or turns off, when the machine is off or if the hazardous components are in a non-operative state. In this embodiment, the maglock is essentially arranged in a‘fail-safe’ manner, such that when the machine is off (and the hazardous components are therefore not going to be in operation), or if the hazardous components are not in operation (whether the machine is on or off), the shield can be opened or removed.

By way of example, if the machine is a vehicle with an Internal Combustion Engine (ICE) as a power source, the shield may be a bonnet or hood or other panel or hatch which allows access to the ICE. The maglock is arranged to be able to‘lock’ the shield in place. The vehicle may be provided with a key or button or switch or other device which allows the vehicle to be switched between:

an‘off or first mode - when all or nearly all systems in the vehicle are deactivated; an ‘on’ or ‘key on’ or ‘standby’ or second mode - when systems such as instrumentation, lighting, air conditioning, infotainment and/or service systems (such as a tailgate lift, scoop, digger arm or other mechanical or hydraulic system, depending on vehicle type) are available, powered by (for example) a battery, but with the ICE inactive, and;

an‘engine on’ or‘active’ or third mode when, in addition to the systems in the‘key on’ mode, the ICE is operating. In embodiments, the machine may need to briefly be put into a fourth‘ignition’ mode in order to actually activate the ICE - it then reverts to the third‘active’ mode.

Clearly it will be recognised that similar alternative or analogous arrangements may be in place for different types of machine or vehicle where the ICE is some other hazardous component, and the third mode is ‘hazardous component active’ in alternative to‘engine on’. In that respect, the first, second and third modes may generally be described as‘off,‘standby’ and‘active’ modes in relation to a general machine.

As such, in some embodiments, turning the machine or vehicle‘on’ (or putting it in ‘standby’) does not necessarily immediately put the hazardous components in an active or operating state, and a further action is required to put them in an operating state with the machine in‘active’ mode.

In embodiments, the maglock may be arranged to lock in response to a number of potential triggers even before a key is put in a lock; for example, the key may be a fob with an IR sensor or near-field sensor or other arrangement known in the art, as present in so-called ‘keyless entry’ and/or ‘keyless start’ systems common in vehicles. The maglock may be arranged to lock when the key enters the vehicle (cabin or cockpit), or may be arranged to lock when the key is put in proximity to a dashboard or steering column, or may be arranged to lock when the key is put into a slot or otherwise engaged with the dashboard or steering column. Such a dashboard or steering column or similar such arrangement may be generally termed a‘control panel’. As such, similar arrangements may be operable for other types of machine, particularly where a key of some kind is required to be used to operate the machine. In one arrangement, the maglock may be arranged to lock when the vehicle is switched into the second‘on’ or‘standby’ mode from the first‘of mode.

In another arrangement, the maglock may be arranged to lock when the vehicle is switched into the‘engine on’/’active’ or third mode from the second‘on’/’standby’ mode; or when the vehicle is switched into a fourth‘ignition’ mode, where present. Having been locked, the maglock may then unlock when the vehicle is switched into the second‘on’ mode from the third‘engine on’ mode - or may only unlock when the vehicle is switched into the first‘off mode from the second‘on’ mode.

In an alternative arrangement, the maglock may only unlock when a further action, beyond switching‘off is initiated. This may be the removal of a key from a keyhole, where present (or similar alternative, such as a keycard from a keycard slot, or a key ‘fob’ from a‘fob’ slot - for the avoidance of doubt, the use of the word‘key’ herein is generally envisaged as encompassing such readily available and well-known alternatives), or the removal of a key or alternative equivalent device from an internal cabin space or an area in close proximity to a dashboard area of a vehicle (or control panel of a machine), or the removal of a key from the immediate vicinity of the vehicle (or other type of machine) itself.

The advantage of this is that it requires the vehicle/machine to not only be definitively ‘off, but also in a state whereby it cannot easily be switched to either‘on/standby’ or ‘active’ states wherein the ICE (or other hazardous component) might be readily made operational. This reduces the possibility of activating the hazardous component once a shield has been removed, as well as ensuring the shield cannot be removed with the hazardous component in an active state.

In an alternative arrangement, the further action may be the use of a special tool to deactivate the maglock. The special tool may be required to be used at a location on the vehicle or machine that is remote from the normal operating position (ie: dashboard of a vehicle or control panel of a machine) of the user. The special tool may be a further, second key, or may, particularly where the special tool is required to be used at a remote position as described above, actually be the vehicle or machine key. In an alternative, the special tool may be attached to the vehicle key. The advantage of this is that an operator has to first turn the machine to‘off, then must leave the control panel (such as a dashboard) and move to a different location on the machine, and then use the special tool to unlock the shield. In embodiments, the machine key must, in addition, be removed as noted hereinbefore.

By way of example, the machine may be a vehicle with an ICE, having a key which fits into a key slot (the‘ignition’ slot) situated by a steering wheel in a cabin. Initially, the key is outside the cabin of the vehicle. This may be considered a‘key remote’ mode. The key is then brought into the cabin; the vehicle is‘off and the key is not in the key slot. This may be considered a‘key out’ or‘zeroth’ mode. The key is inserted into the slot, and the vehicle is then in the first‘off mode with the key in a first position. The key may then be turned a number of degrees, for example 20degrees, to a second position which puts the vehicle into a standby/on second mode wherein dashboard instruments, air conditioning, infotainment and lighting equipment are activated but the ICE is not activated. Having the key in second position and the vehicle having been put in standby/on mode, the maglock is activated and an openable engine cover of the vehicle is locked. A further 20degree turn of the key to a third position turns the ICE ancillaries, such as the fuel pump on, so the vehicle is in a third,‘active’ mode. A yet further 20-degree turn of the key to a fourth position (‘ignition’ mode) actually starts the ICE, after which the key automatically reverts back to the third position, and so the vehicle is in the‘active’ third mode and may be driven.

When the vehicle is at its destination, the operator turns the key back to the second position, which turns the ICE and its ancillaries off, and puts the vehicle into the standby/on second mode. The operator may then turn the key back to the first,‘off position, which also deactivates instrumentation and infotainment, etc. The operator then wishes to open the bonnet (UK) or hood (US) of the vehicle.

In the present example, in a safest arrangement, because the key has been turned to at least the second position, the maglock is on and now remains on until actively deactivated. To do this, the operator must first remove the key from the ignition slot (putting the vehicle in‘zeroth’ mode again). The operator must then use the key to open the boot (UK) or trunk (US) of the vehicle, wherein there is a further ‘deactivation’ key slot. The key must be inserted into this slot and turned, whereupon the maglock is deactivated. Finally, in an embodiment, the key must be retrieved fro the deactivation key slot and taken to the bonnet/hood in order to unlock a further mechanical lock, whereupon the bonnet/hood may be opened. The addition of the further mechanical lock openable by the vehicle key is another means by which the opportunity to operate the hazardous components (in this case, the ICE) without shielding is minimised by ensuring the key is out of the vehicle cabin when the shield is unlocked. Further, it is advantageous to have mechanical means as well as the maglock(s) available to keep shielding in place in case of maglock failure or to provide further resistance to any attempt to‘force’ the shielding open.

Accordingly, it can be seen from the prior example that the maglock may be activated at any one of the following stages:

Entry of key into the cabin/cockpit/dashboard area (from ‘key outside’ mode to ‘zeroth’ mode, where key is in cabin but out of slot);

Entry of key into‘ignition’ key slot (vehicle from‘zeroth’ to first‘off mode, with key in first position);

Key turning from first position to second position (vehicle from‘off to‘on/standby’ mode with vehicle non-ICE systems available);

Key turning from second position to third position (vehicle from‘on/standby’ to‘active’ mode with ICE ancillaries running);

Key turning from third position to fourth position (vehicle from ‘active’ to‘ignition’ mode and ICE activating); Any of which may be deemed appropriate for the design of vehicle and its function. It will be recognised that locking of the shield when the key first enters the vicinity of the ‘ignition’ key slot would tend to be the safest option, and current ‘keyless’ entry/ignition systems could be readily adapted to this option by one skilled in the art.

Likewise, once the maglock is activated, deactivation may occur at any one of the following potential steps:

Key turning from third position to second position (turning engine off, vehicle from ‘active’ to‘on/standby’ mode);

Key turning from second position to first position (vehicle from‘on/standby’ to‘off mode;

Removal of key from key slot (‘off to‘zeroth’ mode);

Removal of key from cabin/cockpit/dashboard area (‘zeroth’ to‘key outside’ mode) as noted above, one skilled in the art of so-called‘keyless’ entry/ignition systems will readily be able to supply a key with well-known means for achieving this);

Use of the key (insertion, or insertion and turning) to deactivate the maglock in a second ‘deactivation’ key slot, which is separate from the ‘ignition’ key slot - in embodiments, this deactivation slot being situated elsewhere on the vehicle, outside of the cabin/cockpit/dashboard area.

Specific Description

The invention will now be described in more detail by reference to the attached Figures.

Figure 1 shows a diagrammatic picture of an agricultural machine - a tractor - arranged in accordance with aspects and embodiments of the present application. Figure 1 a shows a close up view of a dashboard portion of the tractor of Figure 1 and a key for use with the tractor.

Figure 2 shows a diagrammatic picture of a generator for producing electricity which is powered by an ICE.

Figure 2a shows a close up view of a control panel portion of Figure 2 and a key for use with the generator.

Figure 1 shows a tractor (1 ) having a bonnet (3) which is capable of being opened (open position shown as dotted line 3a) to allow access to an ICE (5).

The tractor has a cab 7 with a steering column 9 having a dashboard 9a, on the side of which is an ignition key slot 1 1 a for the receipt of key 1 1 k (seen in Figure 1 a). As seen in Figure 1 a, the key slot 1 1 a has markings I, II, III and IV (13a, 13b, 13c, 13d) representing four positions for the key 1 1 k once inserted into the slot 1 1 a.

The key 1 1 k is also equipped with elements of an RFID system including a transmitter 15b. The dashboard is equipped with elements of an RFID system including a receiver 15a.

The bonnet has an integrated armature plate 17 which, when the bonnet is closed, is in contact with electromagnet 19 which is attached to chassis 21 of the tractor 1. Electromagnet 19 is controlled by ECU 23 which is an ECU of the tractor 1. The ECU is connected to the ICE 5, the electromagnet 19, a second control panel 9r and dashboard 9a. Second control panel 9r is equipped with a key slot 1 1 b.

The bonnet is also supplied with a lock 25 with a key slot 1 1c, which engages with catch 27 to provide a mechanical lock for the bonnet 3/3a.

In use, the key 1 1 k is initially outside the cabin 7 of the tractor 1. This may be considered the‘key remote’ mode.

The key 1 1 k is then brought into the cabin 7; the vehicle is‘off and the key is not in the key slot, although the RFID system 15a/15b is able to recognise the key is in the cabin 7. This may be considered a‘key out’ or‘zeroth’ mode.

The key is inserted into the slot, and the vehicle is then in the first‘off mode with the key in a first position 13a, as indicated with marking I.

The key is then turned to the second position 13b with marking II. This puts the vehicle into a standby/on second mode wherein the dashboard instruments, air conditioning, infotainment and lighting equipment are activated but the ICE is not activated.

A further turn of the key to the third position 13c with marking III turns the ICE ancillaries, such as the fuel pump (not shown) on, so the vehicle is in a third,‘active’ mode, with the ICE not yet running but primed to do so.

A yet further turn of the key to fourth position 13d with marking IV (‘ignition’ mode) actually starts the ICE, after which the key automatically reverts back to the third position 13c, with the vehicle in the‘active’ third mode with the ICE running and able to be driven.

In some embodiments, the tractor may also be supplied with sensor arrangement 29/29a, where the proximity of magnet 29a which is attached to bonnet 3 is detected by sensor 29. This sensor 29 is also in contact with ECU 23. ECU 23 is in contact with (or is part of) the control ECU for ICE 5, and even with the key in position 13d (‘ignition’ mode, marked IV on the dashboard), the ICE will only start when a signal from sensor 29 indicates that the bonnet 3 is shut (and magnet 29a is next to sensor 29). The skilled person will recognise alternative arrangements which will give a like result, which adds to the operational safety of the tractor.

As described hereinbefore, the electromagnet 19 may become operational, and activated by ECU 23, so as to attract armature 17 and thus to lock the bonnet 3 into a closed position, in response to any one of a number of possible triggers, as determined by programming of the ECU 23. This may be when the key 1 1 k enters cabin 7 or comes into close proximity with the dashboard 9a as sensed by the RFID system 15a/15b. This may be when the key 1 1 k is inserted into the slot 1 1 a. This may be any of the possible movements of the key 1 1 k, once inserted into slot 1 1 a, from position I to II, II to III, or III to IV, thus changing the mode of the tractor. Any of these triggers may further be contingent on a signal from sensor 29 that the bonnet 3 is closed.

In order to release the armature 17, electromagnet 19 must be deactivated. The electromagnet may be deactivated in response to any of the following triggers, again as determined by programming of the ECU 23.

These may be;

any time the ICE is inactive;

when the key is turned from position IV to III, from III to II, or from II to I;

when the key is removed from key slot 1 1 a;

when the key is distal from the dashboard 9a, column 9 or outside of cabin 7, as determined by the RFID system.

In one arrangement, the key 1 1 k (and/or any copy of key 1 1 k) must be absent from cabin 7, and key 1 1 k must also be inserted into key slot 1 1 b in second control panel 9r. Once the electromagnet 19 is activated in response to any activation trigger as detailed in the ICE start sequence noted above, the ECU 23 will then only deactivate the electromagnet 19 in response to a chosen set of circumstances as proscribed by the programming of the ECU 23. In this arrangement, ECU 23 only deactivates electromagnet 19 (and thus releases the bonnet 5) only when the key 1 1 k is absent from cabin 7 and then presented into slot 1 1 b.

In the absence of power from the ICE 5 of the tractor, power for the ECU 23 and the electromagnet 19 is supplied by battery 31 , to which ECU 23 is connected. The battery 31 may be the or a main battery of the tractor 1 , an auxiliary battery, or may be a separate battery specifically included for the purpose of powering the maglock system. In an arrangement, the electromagnet 19 may be deactivated, but bonnet 3 still requires the release of mechanical lock 25 in order to open. Mechanical lock 25 requires the insertion and turning of key 1 1 k in key slot 1 1 c of lock 25. In this way, key 1 1 k must have been removed from ignition slot 1 1 a, removed from cabin 7, inserted into second panel 9r key slot 1 1 b to deactivate the electromagnet 19, and then removed again from slot 1 1 b and inserted into and turned in slot 1 1c before the bonnet 5 will open. This ensures the safety of the operator by not allowing access to ICE 5 unless it is inactive and not in a position to easily re-start, especially if sensor 29 is also in place which does not allow re-start of ICE 5 unless bonnet 5 is closed as indicated by the proximity of magnet 29a.

Figure 2 shows a generator 101. Elements of the generator 101 as shown in Figure 2 are equivalents of the elements of the tractor 1 shown in Figure 1.

Generator 101 is fitted with an ICE and electrical components for generating electricity, shown as unit 105. Inspection panel 103 is held in place with two maglocks comprising electromagnets 1 19 and armatures 1 17. Also, panel 103 is held in place with a mechanical lock 125 with a key slot 1 1 1c. Control panel 109a of generator 101 has an ignition slot 1 1 1 a for insertion of key 1 1 1 k as shown in Figure 2a. Figure 2a is a close up of panel 109a showing that key 1 1 1 k when inserted into slot 1 1 1 a may be in an initial first mode‘off position 1 13a, a third mode‘active’ 1 13c, or a fourth mode‘ignition’ 1 13d. In this embodiment, there is no equivalent second ‘standby’ mode as with the Tractor 1 of Figure 1. Panel 109a is also supplied with a sensor 129 for detecting if the panel is in place by the presence of magnet 129a, and a second control panel 109r in the form of a key slot 1 1 1 b. Processor 123 controls magnets 1 19 and unit 105 in response to inputs from panel 109a, sensor 129 and second control panel/key slot 109r/1 1 1 b.

To start the generator, key 1 1 1 k must be put in slot 1 1 1 a and turned from position 1 13a‘off, through position 1 13c‘active’, and to position 1 13d‘ignition’. Processor 123 will then start the ICE of unit 105 provided a signal is received from sensor 129 that the panel is in place, and will simultaneously activate magnets 1 19 to lock the panel 103 in place.

In order to unlock the panel 103, key 1 1 1 k must be turned back to position 1 13a and removed from slot 1 1 1 a, so that unit 105 is inactive. Processor 123 keeps magnets 1 19 on, however, using power from battery unit 131 which is charged up whenever unit 105 is active. Key 1 1 1 a must then be inserted into slot 1 1 1 b, which provides a signal to processor 123, which then releases/deactivates the magnets 1 19. The panel 103 is no longer electromagnetically locked. To remove the panel 103, however, key 1 1 1 k must then be removed from slot 1 1 1 b and used to unlock mechanical lock 125 by insertion into and turning of key slot 1 1 1c. The unit 105 may then be accessed.

The invention may be further understood by reference to the following paragraphs:

Para 1. A shield for isolating hazardous components of a machine, characterised in that the shield is provided with at least one electromagnetic lock operable to lock the shield in place and/or release the shield so that the shield may be opened.

Para 2. A shield as described in para 1 , wherein said electromagnetic lock is operable to lock the shield in place when the hazardous components are in an operating state.

Para 3. A shield as described in para 1 or 2, wherein said electromagnetic lock is operable to lock the shield in place when the machine is in an on state.

Para 4. A shield as described in any of paras 1 , 2 or 3, wherein said electromagnetic lock is operable to lock the shield in place when the machine transitions from an initial mode to a subsequent mode.

Para 5. A shield as described in para 4, wherein the machine is supplied with a key and a first control panel, and the transition from an initial mode to a subsequent mode is any one or more of:

A transition from a key outside mode, where the key is remote from the control panel of the machine, to a zeroth mode where the key is in close proximity to the control panel;

A transition from the key outside mode or the zeroth mode to a first off mode where the key is engaged with an ignition slot in the control panel;

A transition from the key outside, the zeroth or the first off mode to a second standby mode where components of the machine, other than the hazardous components or ancillaries to the hazardous components, are operating or active;

A transition from the key outside, the zeroth, the first off or the second standby mode to a third active mode where ancillaries of the hazardous components are operating or active;

A transition from the key outside, the zeroth, the first off, the second standby or the third active mode to a fourth ignition mode where the hazardous components become operational or active. Para 6. A shield as described in any of paras 1 to 3, wherein the electromagnetic lock is operable such that it releases the shield when the machine is off or if the hazardous components are in a non-operative removable state.

Para 7. A shield as described in any of paras 1 to 5, wherein the electromagnetic lock is operable to release the shield when the machine transitions from a mode to a different mode.

Para 8. A shield as described in para 7, wherein the machine is supplied with a key and a first control panel, and the transition from a mode to a different mode is any one or more of:

A transition from an ignition mode where the hazardous components are operational to a third active mode where ancillaries of the hazardous components are operating or active;

A transition from the ignition mode or the third active mode to a second standby mode where components of the machine, other than the hazardous components or ancillaries therefor, are operating or active;

A transition from the ignition mode, the third active mode or the second standby mode to a first off mode where the key is engaged with an ignition slot in the control panel;

A transition from the ignition mode, the third active mode, the second standby mode or the first mode to a zeroth mode where the key is in close proximity to the control panel;

A transition from the ignition mode, the third active mode, the second standby mode, the first mode or the zeroth mode to a key outside mode where the key is remote from the control panel of the machine.

Para 9. A shield as described in any of paras 1 to 5 wherein the electromagnetic lock is operable to release the shield when the key or a special tool are engaged with or proximate to a second control panel that is remote from the first control panel.

Para 10. A shield as described in any previous para wherein the shield is further provided with at least one additional mechanical latch or fastener operable to lock the shield in place and/or release the shield. Para 1 1 . A shield as described in para 10 wherein the additional latch or fastener requires the key or the special tool to operate.

Para 12. A shield as described in para 1 1 wherein the special tool and the key are a unitary item.

Para 13. A machine comprising a shield as described in any of paras 1 to 12.

Para 14. A machine as described in para 13 wherein the machine is a vehicle.

Para 15. A machine as described in either of paras 13 or 14 wherein the machine or vehicle is an agricultural machine or vehicle.

Clearly the skilled person will recognise that various aspects, embodiments and elements of the present application, including as illustrated in the figures, may be arranged in differing combinations, any and all of which may be considered to fall within the ambit of the inventive concept. The invention will be defined by the following claims.