GB2181534A - Improvements in or relating to hobs - Google Patents

Abstract

A hob having a lid includes a safety switch/valve 11 operable by the lid to terminate the supply of gas/electricity to the hob taps/switches (13) as the lid is closed and, provided that all of the hob taps/switches are in the "OFF" position, to restore that supply when the lid is opened. In the event that at least one hob tap/switch 13 is not in its "OFF" position when the lid is closed, the safety valve/switch 11 is latched by a latching mechanism and held closed when the lid is next opened. To restore the supply, all the hob taps/switches must be returned to the "OFF" position. That action releases the latching mechanism and allows the safety valve/switch to restore the supply when the lid is open. The hob may be a separate unit or it may be part of a cooker. <IMAGE>

Description

SPECIFICATION Improvements in or relating to cookers and hobs This invention relates to cookers and hobs which may be gas or electric. The hob may be an independent unit for mounting in a work surface or it may be part of a cooker.

It is known to fit such hobs and cookers with lids thatopentogiveaccesstothegasburnerand/or electric hot plates or rings. When closed, the lid covers the burners, hot plates or rings thereby protecting the latter and providing a "clean" iineto the surface ofthe hoborcooker.

To allow a user to close the lid when a burner is alightorwhen a hot plate or ring is energised is extremely dangerous. The heat from the burner, hot plate or ring will damagethe lid and, ifthe latter isof glass, maywell shatterthe lid. Closure of the lid may result in extinguishment ofthe burnerflame andthe consequent escape of gas, or alternatively if the flame is not extinguished, poor combustion ofthe gas and damage to the lid.

Safety measures have been proposed which ensure that the supply of gas and/or electricity is automatically cut-offto all the hob burners and/or hot plates and rings when the lid is closed but such measures are not entirely satisfactory.

Accordingly, it is an object ofthe present invention to provide measures which give a greater certainty of safety than has been available hitherto.

According to the present invention, a hob has one or more gas burners and/or electric rings/hot plates and a lid movable between a fully opened position giving access two the burners and/or electric rings/hot plates and a closed position in which the lid covers the burner/burners/rings/hot plates and having hob taps and/orswitches controlling theflow of gas/electricity thereto, the hob also comprising a safetyvalve/switch controlling the supply of gas/electricitytothe hobtaps/switchesand operatively connected to the lid in a manner such that movement of the lid into its closed position operates thesafetyvalve/switch to terminate the supply of gas/electricitytothe hob taps, switches, means being provided for preventing the restoration ofthe supply to the hob taps/switches on movement of the lid into its fully opened position unless all the hob taps/switches are "OFF".

In an embodimentofthe invention, the means is operable to prevent the restoration of the supply by the safety valve/switch on movement of the lid into itsfullyopenedposition unlessallthehob taps/switches are "OFF".

The means may comprise a latching mechanism that inhibits response of the safety valve/switch to lid movement unless all hob taps/switchs are "OFF".

The latching mechanism may operate to render ineffective the operative connection between the lid and the safety valve/switch on movement ofthe lid from its closed to its fully opened position unless all hob taps/switches are "OFF".

The operative connection between the lid and the safetyvalve/switch may comprise an actuator linked to the lid and to the safety valve/tap for operating the latter on lid movement, and in which the latching mechanism holds the actuator against response to lid movement unless all hob taps/switches are "OFF".

The actuator may be joined to the lid via a linkage including an elementthattransmitsopening and closing movement of the lid to the actuator if all hob taps/switches are "OFF" and that does not transmit lid opening movement in the event that at least one hobtap/switch is not "OFF".

The element may be a spring.

The actuator may include a push rod.

The latching mechanism may be coupled to the hobtaps/switches in a manner such that it is rendered ineffective only when all hobtaps/switches are "OFF".

The latching mechanism may be coupled to the hobtaps/switches buy a component movable in response to operation of a hob tap/switch from its "OFF" position.

The component may be a plate slidable by cam surfaces associated with the hob taps/switches.

Eachtap mayhaveasensorforsensingwhenthe tap/switch is in an "OFF" position, the sensors being operatively connected to the latching mechanism.

The sensor may be a pressure sensor.

Alternatively, the means may comprise one or more thermally responsive devices, the or each of which is associated with one of the burners/electric rings/hot plates and isreponsiveto heat emitted by the associated burner/electric ring/hot plate when in use.

The hob may further include warning means which provide a warning in the event that the lid is moved from its fully open position when at least one hob tap/switch is not "OFF".

The warning may be visual or audible.

Means may be provided for counterbalancing the closing weight of the lid.

Where counterbalancing means is provided, the push rod referred to above may be actuable by a movable part ofthe counterbalancing means.

Each hob tap/switch may include a niting arrangement.

The hob may be part of a cooker.

By way of example only, embodiments of the invention will now be described in greater detail with reference to the accompanying drawings of which Figure 1 is a perspective view of part of a gas hob embodying the invention, Figure2 is a perspective view in exploded form of a safety mechanism forthe hob of Figure 1, Figure 3 is an explanatory view of parts of the safety mechanism of Figure 2, Figure 4is a perspective view of part of a gas cooker embodying the invention, Figure 5is a perspective view in exploded form of a safety mechanism for the cooker of Figure 3, and Figure 6and 7 are explanatory views of parts ofthe safety mechanism of Figure4.

The hob shown in perspective view in Figure 1 comprises a hollow, box-like structure 1 which accommodates four gas burners shown schematically at2, 3, 4, 5, a pan support 6, a gas supply rail with gas taps operated by control knobs 7 above a control panel 8,fuel supply passages (not shown) forconveying a gas/air mixtureto the burners, and a gas ignition mechanism (not shown) controlled by an ignition button 9.

Hinged about a horizontal axis at the rear ofthe structure lisa lid 10. In Figure 1,the lid loins shown in itsfullyopened position giving access to the burners and the control panel. The lid 10 is movable by a user to a closed position in which it conceals and covers the burners and the control panel.

Also located in the structure lisa counterbalance mechanism operatively connected to the lid 10for counterbalancing, in a desired manner, the closing weightofthe lid.

Further details of the general construction ofthe hob are found in U.K. PatentApplication No.

2,109,919A. That Application also describes a lid operated safety valve for cutting off the gas supply to the gas rail as the lid is moved into its closed position.

In the embodiment shown in Figure 2, that safety valve is contained in a housing 11 and it controls gas flowfrom a mains supply conduit (not shown) to a gas rail 12 on which gas taps 13 are mounted.The taps 13 control the flow of gas from a supply passage in the gas rail to injectors 14. From the injectors, gas passes into the gas/air supply passage referred to above.

The housing 11 is mounted on the gas rail and is generally similar in form and construction to the housing 22 described in U.K. PatentApplication No.

2,144,845 and itcontains a valve similarto valve 28 described in the Application just mentioned and which is open against the action of a valve spring by the enlarged head 15 of a push rod 16 slidably mounted in a bore in the housing 11 similar two the bore 34 ofthe housing 22 described in the Application. In the present embodiment, the gas rail 12 has a single internal gas passageway flow of gas to which is controlled by the valve in housing 11.

The push rod 16 is coupledto an actuator 17 by means of a stiff torsion spring 18 having one arm 19 in contact with the actuator 17 and a second arm 20 with a cranked end in contact with the enlarged head 15 ofthe push rod 16. The spring 18 is pivotally mounted upon the upper surface ofthe block 11 by means of a screw 21.

The actuator 17 is operatively connected to the lid 10 in a manner such that closing movementofthe lid causes the actuatorto move towards the housing 11 and exert pressure on the arm 19 ofthe spring 18. As the lid is opened,the actuator moves away from the housing 11 and the pressure on the arm 19 is relaxed.

Also mounted upon the housing 11 but in a side wall thereof is a latch 22 pivotable about a horizontal axis on a screw 23 and having a cut-away 24 that is biassed by spring 25 towardsthe push rod 16 adjacentto but out ofalignmentwith a peripheral groove 26 in the rod.

Supported in some manner (not shown) above the taps 13 is an elongate cam plate 27. The plate 27 is so supported that it is slidable backwards and forwards as indicated byarrow28.

The plate 27 has, along its length, a series of spacedapertures29to provideclearancesforthe operating spindles 30 ofthetaps 13. In addition, the plate 27 has, at one end, a short right-angled extension 31. The extension 31 rests upon the upper surface of the housing shown. Connected to the other end of the plate 27 is a helical spring 32 which biasses the plate to the right as seen in Figure 2.

The taps 13 are operated by control knobs 7 carried bythe spindles 30. Only one such knob is shown in Figure 2. On its rearface each knob has a cam surface 34 which, in the "OFF" position of the associated tap, contacts an adjacent edge of the aperture 29 through which the spindle 30 carrying the knob passes and holds the plate 27 to the right as viewed in Figures 2 and 3. In that position, the extension 31 ofthe plate 27 engages the upper end of the latch 22 and holds it away from the push rod 16.

In use, with all thetaps 13 in the "OFF" position, closureofthe lid 10 results in movementofthe actuator 17 towards housing 11 and pressure is exerted on arm 19 of the torsion spring 18. The spring 18 pivots about screw 21 in a clockwise direction and arm 20 acting through the enlarged head 15 moves rod 16 and closes the safetyvalve against its spring thereby shutting off the supply of gas to the gas rail 12. Movement ofthe rod 16 brings the groove 26 into alignment with the cut away 24. Spring 25 attempts to pivot latch 22 in a clockwise direction but this is prevented because the extension 31 prevents such pivotal movement.

If the lid is now opened, actuator 17 moves away from arm 19 relaxing pressure on the latter allowing the spring 18 to pivot in an anti-clockwise direction underthe action ofthe spring of the safety valve and the latter opens and the supply of gas to the gas rail 12 is restored.

If, whilst the lid is closed, a userturns any ofthe taps 13 to its "ON" position, no gas will emerge from the associated burner because the safety valve is closed and the gas supplyto the gas rail 12 is cutoff.

To use a burner,the user mustfirstopenthe lid.

The user can operate any ofthe taps 13 to its "ON" position by rotating the knob to a required position.

Preferably, however, the taps 13 incorporate a niting mechanism which requires a knob to be depressed inwardly with respect to the tap before the knob can be rotated.

As the knob is rotated, cam 34 moves into contact with the adjacent side edge of the associated aperture 29 and moves the cam plate27totheleftas viewed in Figure 2 against the action of spring 32.

That movement of the cam plate 27 results in extension 31 moving away from latch 22 by an amount sufficient to allow the latter to pivot and move into contact with the surface of the rod 16. The cam 34 is so contoured thatthefull movement ofthe cam plate 27 is effected during the initial part ofthe rotary movement of the knob 7.

If now the user closes the lid having inadvertently left at least one ofthetaps 12,13 in an "ON" or partially "ON" position, the resultant movement of the push rod 16 not only closes the safety valve, thereby terminating the supply of gas to the gas rail 12, but also brings grooves 26 into alignmentwith the cut away 24. The latch 22 moves slightly and the edge ofthe cut away 24 enters the groove 26 and holds the push rod 16 againstfurther movement, the safety valve is thus held in its closed position.

On opening the lid, the push rod 16 is held bythe latch 22 despite the relaxation of pressure by the actuator on the arm 19 which merely resumes its previous position, the spring 18 being prevented from pivoting becausethe otherarm 20 is held against movement. The safety valve is held closed and no gas will flowtothe gas rail orto any burner despite the factthat at least one of the taps 13 is in an "ON" or partially "ON" position.

Before any ofthe burners 2,3,4 or 5 can be brought into use, the user must move to its "OFF" position anytap not in that position. If only one tap is not in its "OFF" position, rotation of the knob to bring the tap into that position allows spring 32 to move the cam plate 27to the right. Movementtothe rightofthe extension 31 of the cam plate pivots the latch 22 to an extension 31 of the cam plate pivots the latch 22 to an extent sufficient to disengage the edge of the cut away from the groove 26. The spring in the safety valve opens the lattertherebyrestoring gas supply to the gas rail and permitting the burners to be brought into use.

If more than one ofthetaps 13 is in an "ON" or partially "ON" position, it will beappreciatedthatall such taps are holding the cam plate 27 in its left-ward position and that the movement to the right ofthe cam plate 27 will occuronly as the last of such taps is moved to its "OFF" position and not before.

In that way, closure ofthe lid results in the extinguishment of any lit burner flame so that damage to the lid is avoided. Moreover, no escape of gas from a burner can occur.

The hob be part of a cooker as is shown, in part, in Figure 4. Top burners indicated schematically at 35 and located above a spiilage tray 36 are controlled by taps 37 mounted upon a gas rail that is arranged transversely across the front of the cooker behind a control panel. Also located on the control panel are two furthertaps 38, 39 that control the gassupplyto an oven burner (not shown) and a grill burner (not shown) respectively. Tap 38 incorporates a thermostatic control. A pan support is shown diagrammatically at40.

The cooker has a lid 41 pivotally mounted atthe rear of the spillage plate 36 on a horizontal axis so as to be movable between a fully opened position shown in Figure 4 and a closed position in which the lid covers the top burners 35. The closing weight of the lid is counterbalanced and in Figure 4 part ofthe counterbalance mechanism is shown at 42.

An example of a counterbalance mechanism is given in U.K. PatentApplication No. 2,144,845A which also describes a form of a gas rail suitable for the embodiment ofthe present invention shown in Figures 4 7.

In thBconstruction described in Application No.

2,144,845A, the counterbalance mechanism also operates a push rod that moves a safety valve against a restoring spring to a closed position when the lid closes and thereby cuts off the supply of gas to the taps controlling the top bu rners but not to the taps controlling the oven and grill burners.

One of the forms of gas rail described in Application No.2,1 44,845A- that shown in Figure 2 ofthe drawings ofthatApplication - is incorporated in the embodiment ofthe present invention shown in Figures 4... .7 as is the safety valve shown in Figures 3,4 and 5 of that Application.

In the accompanying Figure 5, the gas rail is shown at 43 and comprises two independent gas supply passages (not shown). One ofthose passageways supplies taps 37 and the other passageway supplies taps 38,39. The safety valve controls the supply of gas to the one passageway only.

The safety valve is contained in a housing 44 into which extends a push rod 45 movable to and fro, as indicated by the arrow 46, by the counterbalance mechanism 42 as is explained in Application No.

2,144,845A. The push rod 45 extends through the housing 44 and its outer end has an enlarged head 47. Movement to the left (as viewed in Figure 4) ofthe push rod 45 occurs against the action of a helical spring 48 that encircles the rod between the housing 44 and a flange 49 fixed to the rod.

Located in the housng 44 is the safety valve (not shown). The safety valve has an extension 50 that projects from the housing adjacentthe head 47 enabling the latter to move the extension inwardly with respecttothe housing 44 and so close the safety valve as will be explained below in more detail.

Mounted in some suitable manner in front of the gas rail 43 is an elongate cam plate 51. The mounting ofthe plate 51 is such that the plate is able to moveto and fro in front of the rail 43 as indicated by the arrow 52.

The plate 51 has a series of apertures spaced along its length in position corresponding with the taps 37, 38 and 39. Two of those apertures, referenced 53 are longerthan the remaining apertures 54 and correspond in position with taps 38 and 39. The apertures provide clearance for the spindles 55 ofthe taps. Mounted upon the spindle 55 are control knobs of which one only is shown in Figure 5 and is referenced 56 At its rear, the knob 56 carries a cam 57 which locates in the respective one ofthe apertures 54. The control knobs oftaps 38 and 39 do not have cams.

Adjacent its right-hand (as viewed in Figure 5) end, the cam plate 51 has an elongate hole 58 that has an upstanding flange 59 at one end. The flange 59 forms one anchorforone end of a helical spring 60that locates in the hole and is anchored at its other end on a peg 61 projecting from the housing 44. The spring 60 biasses the cam plate 51 to the right as seen in Figure 5.

Pivotally mounted by means of a screw 62 on the housing 44 on that side of the rod 45 remote from the extension 50 is a latch 63. The latch has a cut-away 64 and an angled extension 65 at its lower (as seen in Figure 5) end adjacent the cut-away 64. A spring 66 biassesthe latch in an anti-clockwise direction about its pivotal axis. In a certain angular position ofthe latch 63, the edge ofthe cut-away 64 engages a peripheral groove 67 in the push rod 45.

In the fully open position of the lid 41, the push rod 45 has been moved to its extreme left-hand position (as seen in Figure 5), the head 47 having moved away from the housing 44 thereby allowing the spring of the safety valve to open the latter. Gas can thus flow into the one passageway in the gas rail 43.

A userwishing to use one or other of the top burners 35 does so by turning its tap by rotating the associated control knob 56. That rotation bringsthe cam 57 from the position shown in Figure 6to that shown in Figure 7. As its rotates, the cam 47 bears on the adjacent edge of the associated aperture 54 and moves the cam plate 51 to the left (as viewed in Figure 7) againstthe action of spring 60. The plate 51 moves from the position shown in dotted lines to that shown by the full line. Such movement of the plate 51 allows spring 66to pivotthe latch memberfrom its position shown in dotted lines in Figure 7 to that shown in full lines. In the latter position, the edge of the cut-away 64 bears on the surface ofthe push rod 45.

In the eventthatthe user brings additional top burners into use, rotation oftheircontrol knobs and cams does not result in any movement of the cam plate 51.

If the user now closes the lid 41, having inadvertently left one or more of the taps in an "ON" or partially "ON" position, closing movement ofthe lid is transmitted to the push rod 45 which moves to the right (as seen in Figure 5). The head 47 moves backtowards the housing 44 and in so doing contacts the end of the extension 50 and closes the safety valve against its restoring spring and thereby cutting offthe supply of gastothe one passageway. Atthe same time, the edge of the cut-away 64 enters the groove 67 on the push rod 45 and holds the latter against further movement thus maintaining the safety valve closed.

In that manner, the flame of any top burner left "ON" is extinguished and damage to the lid is avoided.

On opening the lid again,the push rod 45 remains latched and the safety valve closed and escape of gas from any burner left "ON" is prevented.

If, having opened the lid, a user wishes to bring into operation any ofthe top burners 35, any ofthe taps 37 not in the "OFF" position must first be returned to that position.

If there is only ofthe taps 37 not in the "OFF" position, rotation ofthe control knob 56 of that tap to bring the latter into its "OFF" position, rotates the associated cam 57 and allows the cam plate to return to the position indicated in dotted lines in Figure7 underthe action of spring 60. That movement ofthe cam plate brings the right-hand (as seen in Figure 7) edge thereof into engagement with the angled extension 65 of the latch 63 and the latter moves awayfrom the push rod 45 and the edge ofthe cut-away 64 disengages from the groove 67 thereby allowing the safety valve to be opened under the action of its restoring spring.

It will be understood that if more than one ofthe taps 37 is in an "ON" or partially "ON" position, all such taps are holding the cam plate 51 in its extreme left-wards position and that the movementofthe cam plate 51 and latch 63 just described will take place only as the least of the taps is moved to its "OFF" position.

It will be appreciated that, even when the lid is closed, it is possible to bring the oven burner and/or the grill burner into use because the gas supply to the other passageway in the gas rail 43 feeding the taps 38 and 39 is not controlled by the safety valve.

Furthermore, operation of the safety valve is not dependent upon either of those taps being in their "OFF" positions as is the case with taps 37.

It will be appreciated that the condition of a hob tap, i.e. whetherthe tap is in an "OFF" position or an "ON " or partially "ON" position may be sensed in other ways than that using the cam plate referred to above.

For example, each hob tap may incorporate an individual sensor for sensing when the tap is in the "OFF" condition and which latches the safety valve in its closed condition and holds it latched when the lid is next opened with one or more hob taps notfully "OFF". The sensor may be a pressure sensorthat is actuated when the tap is "OFF" or it may be a mechanical device that is actuated in the "OFF" position ofthetap.

The latch is released only when all hob taps are "OFF" thereby enabling the safety valve to restore the supply.

In a further alternative embodiment, each hob burner may have associated with it a flame sensor responsive to the presence of a flame at the burner.

Each sensor is linked to the latch mechanism in a manner such that if the lid is closed with one or more hob burners alight, the safety valve which will be closed by the lid as the latter closes will be latched and held latched. The latch will be released only when all hob taps are in the "OFF" position.

The flame sensor may be a bimetal element or a phial containing an expansible fluid or it may be a thermocouple that operates in conjunction with an electromagnet.

The gas taps may be of the form described in U.K.

PatentApplication No.2,1 29,097A or No.84.24903.

The lid counterbalance mechanism may take the form described in U.K. Patent Applications No.

2,109,919A, or in No.2,1 44,845A, orthat described in No.84.24904 or some other suitable form.

Alternatively, the counterbalance may be omitted.

In that case, the push rod 45 of the embodiment described above with reference to Figure 5 is coupled to the lid 41 in some other waxy than that shown in Application No. 2,144,845A.

If desired, a warning device may be fitted to the hob or cooker to provide an audible or visual warning in the event that a user closes the lid 41 with one or more of the hob burners ortop burner taps not in its "OFF" position. The warning may continue until each such tap is in its "OFF" position or warning may end when the lid is in its closed position.

Alternatively, the warning may be given when a user next opens the lid if one or more hob taps are not "OFF".

Furthermore, the invention is not limited to use with gas hobs and cookers. It may also be used with electric hobs and cookers and with hobs and cookers with both gas burners and electric rings and/or hot plates. The supply of electricity is, of course, controlled by suitable switches and a switch performing the function ofthe safety valve described above is also provided in the cooker embodiments.

Claims (22)

1. A hob having one or more gas burners and/or electric rings/hot plates and a lid movable between a fully opened position giving access to the burners and/or electric rings/hot plates and a closed position in which the lid covers the burner/burners/rings.hot plates and having hob taps and/or switches controlling the flow of gas/electricity thereto, the hob also comprising a safety valve/switch controlling the supply of gas/electricity to the hob taps/switches and operatively connected to the lid in the manner such that movement ofthe lid into its closed position operates the safety valve/switch to terminate the supply of gas/electricity to the hobstaps/switches, means being provided for preventing the restoration of the supply to the hob taps/switches on movement ofthe lid into its fully opened position unless all the hob taps/switches are "OFF".

2. A hob as claimed in claim 1, in which the means is operable to prevent the restoration of the supply by the safety valve/switch on movement of the lid into its fully opened position unless all the hob taps/switches are "OFF".

3. A hob as claimed in claim 2, in which the means comprises a latching mechanism that inhibits response ofthe safety valve/switch to lid movement unless all hob taps/switches are "OFF".

4. A hob as claimed in claim 3, in which the latching mechanism operates to render ineffective the operative connection between the lid and the safety valve/switch on movement ofthe lid from its closed to itsfullyopened position unless all hob taps/switches are "OFF".

5. A hob as claimed in claim 4, in which the operative connection between the lid and the safety valve/switch comprises an actuator linked to the lid and to the safety valve/tap for operating the latter on lid movement, and in which the latching mechanism holds the actuator against response to lid movement unless all hob taps/switches are "OFF".

6. A hob as claimed in claim 5, in which the actuatorisjoined to the lid via a linkage including an elementthattransmits opening and closing movement ofthe lid to the actuator if all hob taps/switches are "OFF" and that does not transmit lid opening movementintheeventthatatleastone hobtap/switch is not "OFF".

7. A hob as claimed in claim 6, in which the element is a spring.

8. A hob as claimed in claim 5,6 or7, in which the actuator includes a push rod.

9. Ahob as claimed in anyoneofclaims 5to 8, in which the latching mechanism is coupled to the hob taps/switches in a manner such that it is rendered ineffective only when all hob taps/switches are "OFF".

10. A hob as claimed in claim 9, in which the latching mechanism is coupled to the hob taps/switches by a component movable in response to operation of a hob tap/switch from its "OFF" position.

11. A hob as claimed in claim 10, in which the component is a plate slidable by cam surfaces associated with the hobtaps/switches.

12. A hob as claimed in claim 9, in which each hob tap/switch comprises a sensor for sensing when the tap/switch is in an "OFF" position, the sensors being operatively connected to the latching mechanism.

13. A hob as claimed in claim 12, in which the sensor is a pressure sensor.

14. A hob as claimed in any one of claims 1 to 8, in which the means comprises one or more thermally responsive devices, the or each of which is associated with one of the burners/electric rings/hot plates and is responsive to heat emitted by the associated burner/electric ring/hot plate when in use.

15. A hob as claimed in any one ofthe preceding claims and further including warning meanswhich provide a warning in the event that the lid is moved from its fully open position when at least one hob tap/switch is not "OFF".

16. A hob as claimed in claim 15, in which the warning is visual or audible.

17. A hob as claimed in any one ofthe preceding claims in which means are provided for counterbalancing the closing weight ofthe lid.

18. A hob as claimed in claim 17 when appended to claim 8, and in which the push rod is actuable buy a movable part ofthe counterbalancing means.

19. A hob as claimed in anyone ofthe preceding claims in which each hob tap/switch includes a niting arrangement.

20. A cooker including a hob as claimed in any one of the preceding claims.

21. A hob substantially as described herein with reference to and as illustrated by Figures 1,2 and 3 of the accompanying drawings.

22. Acookersubstantially as described herein with reference to and as illustrated by Figures 4,5,6 and 7 ofthe accompanying drawings.