GB2177790A - Cookers and hobs - Google Patents

Abstract

A hob having a lid is fitted with a safety mechanism (18, 23, 26) for turning to its "OFF" position and tap/switch (12) not in its "OFF" position when the lid is moved from its fully opened to its closed position. The mechanism is such that once the lid is in its closed position, a user cannot turn any tap/switch to an "ON" position. The hob may be a separate unit or it may be part of a cooker. The mechanism can be incorporated in both gas and electric or mixed hobs/cookers. <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 that open to give access to the gas burner and/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" line to the surface of the hob or cooker.

To allow a user to close the lid when a burner is alight or when a hot plate or ring is energised is extremely dangerous. The heat from the burner, hot plate or ring will damage the lid and, if the latter is of glass, may well shatter the lid. In the case of a gas burner, closure of the lid may result in extinguishment of the burner flame and the consequent escape of gas or alternatively, if the flame is not extinguished, poor combustion of the gas and damage to the lid.

Safety measures have been proposed and whilst some of these ensure that the supply of gas and/or electricity is automatically cutoff to all the burners and/or hot plates and rings when the lid is closed, in most cases that supply is restored as soon as the lid is re-opened and in these cases hazardous conditions may arise.

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

According to the present invention a hob has a body portion accommodating one or more gas burners and/or electric rings/hot plates; a lid movable between a fully open position giving access to the body portion and a closed position in which the lid covers the body portion; taps and/or switches controlling the gas supply and/or electricity supply to the burners and/or electric rings/hot plates, and means for operatively connecting the taps and/or switches to the lid in a manner such that on movement of the lid into its closed position any tap or switch not in its "OFF" position is operated into that position.

The said means may be such that each tap and/or switch is held in its "OFF" position whilst the lid remains in its closed position.

Each tap and/or switch may require a rotary action to operate it and, in this case, the said means may include a linkage means associated with each tap and/or switch to rotate it to an "OFF" position if not in that position when the lid moves to its closed position.

In embodiments of the invention described herein, the said means also includes an operating member movable in response to movement of the lid and engageable with the linkage means of any tap/switch not in its "OFF" position when the lid is being closed to rotate that tap/switch to the "OFF" position. Each linkage means is movable relative to the operating member during rotation of the respective tap/switch when the lid is open, rotation of any tap/switch out of the "OFF" position causing movement of the linkage means into a position in which it is engageable by the operating member to be moved therewith when the lid is being closed.

In another embodiment, the operating member is movable, in response to rotation of any tap out of the "OFF" position, into a position in which it is movable in response to closing movement of the lid.

In these embodiments, the operating member is movable relative to the linkage means of any tap/switch which is in the "OFF" position and, when the lid is closed, the operating member engages the linkage means to prevent rotation of any tap/switch.

Each linkage means may include a rack and pinion drive, the pinion being rotatable with the tap/switch and the rack being arranged to be movable by the operating member. In one embodiment, the operating member comprises a plate. In another embodiment, each linkage also includes a respective connector member coupling the rack to the operating member and the operating member comprises a lever to which the connector members are coupled.

Warning means may be included which operate to give a user an audible or visual warning in the event that the lid is moved from its open to its closed position when at least one tap/switch is not in its "OFF" position.

Each tap/switch may be biassed into its "OFF" position, the bias being inhibited except when the lid is moved from its fully opened to its closed position and when the lid is in the latter position.

The bias may be provided by a spring or other resilient means.

The bias may be inhibited by a friction or latch plate operatively connected to the lid in a manner such that the inhibition is removed when the lid is moved from its fully opened to its closed position and when the lid is in the latter position.

The closing weight of the lid may be counter-balanced or uncounterbalanced. Examples of suitable counterbalance mechanisms are found in UK Patent Applications Nos.

2,109,919A, 2,144,845A and 2,165,350A.

The taps/switches may be operated via the counterbalance.

When the taps are used, they may be of the construction described in UK Patent Applications Nos. 2,129,097A or 2,166,221A.

By way of example only, embodiments of the invention will now be described with reference to the accompanying drawings, of which: Fig. 1 is a schematic perspective view, from one side, of a gas cooker embodying the invention; Fig. 2 is a perspective view, from the other side, of part of the gas cooker from which some parts have been removed to show a safety system of the cooker and in which other parts are shown in exploded form; Fig. 2A is a scrap view showing part of Fig.

2 in an alternative position; Fig. 3 is an end view of the gas rail of the cooker of Figs. 1 and 2; Fig. 4 is a view of the front fixed plate of the safety system of the cooker of Figs. 1 and 2; Fig. 5 is an end view in the direction of the arrow V of Fig. 4; Fig. 6 is a front view of the movable plate of the safety system of the cooker of Figs.

1 and 2; Fig. 7 is a section on the line VII-VII of Fig.

6; Fig. 8 is a side view of a rack member of the safety system of the cooker; Fig. 9 is an end view in the direction of the arrow IX of Fig. 8; Fig. 10 is a view from above of a push-rod of the safety system of the cooker; Figs. 11 and 12 are explanatory drawings of the operation of the safety system of the cooker; Fig. 13 is a view from above of a support forming part of the safety system of the cooker; Figs. 14 to 16 are, respectively, rear, side and front views of the support in the directions of the arrows XIV, XV and XVI respectively of Fig. 13; Fig. 1 7 shows the same view as Fig. 13 but including a gas supply conduit of the cooker; Figs. 1 8 to 20 are, respectively, a side view, a view from above and a front view of a tap of the cooker; Fig. 21 shows, in exploded schematic form, another safety system for a gas cooker;; Figs. 21A and 21B are explanatory drawings of the operation of the system of Fig. 21; Fig. 22 shows, in exploded schematic form, a safety system similar to that of Fig. 21 but suitable for a gas hob; Fig. 23 is a schematic perspective view of a gas hob incorporating the safety system of Fig. 22; Fig. 24 shows, in exploded schematic form, another safety system for a gas hob; Figs. 25 and 26 are explanatory drawings of the operation of the system of Fig. 24, and Fig. 27 shows, in exploded schematic form, a safety system similar to that of Fig. 24 but suitable for a gas cooker.

Fig. 1 shows, in perspective, a gas cooker embodying the invention.

Top burners indicated schematically at 1 and located above a spillage plate 2 are controlled by taps 3 located on a control panel 4.

Also located on the control panel 4 are two further taps 5, 6 that control the gas supply to an oven burner (not shown) and a grill burner (not shown) respectively, together with an ignition button 4A which controls a gas ignition mechanism (not shown). The taps 3, 5, 6 are all mounted upon a gas rail (not visible in Fig. 1) that is arranged transversely across the front of the cooker behind the control panel.

Each tap is fitted with a niting arrangement which ensures axial outward movement of the tap spindle when the "OFF" position is reached, thereby holding the tap against rotation when in the "OFF" position.

The cooker has a lid 7 pivotally mounted at the rear of the spillage plate on a horizontal axis so as to be movable between a fully open position shown in Fig. 1 and a closed position in which the lid covers the top burners 1. The closing weight of the lid is counterbalanced and in Fig. 1 a shaft forming part of the counterbalance mechanism is indicated at 8.

An example of a counterbalance mechanism is given in UK Patent Application No.

2,1 44,845A.

In the construction described in Application No. 2,144,845A, the counterbalance mechanism also operates a push rod that moves a safety valve to a closed position when the lid closes thereby cutting off the supply of gas to taps controlling the top burners. In the embodiment of the present invention shown in Figs. 1 to 20, the safety valve is replaced by a safety system shown in more detail in Fig.

2 and indicated generally at 9.

Fig. 2 shows the gas rail 10 on which are mounted the taps 3 controlling the top burners 1, and the taps 5 and 6 controlling the oven and grill burners respectively. Tap 5 incorporates a thermostat part of which is shown at 11. Each tap 3, 5, 6 has a forwardly-extending control spindle 12 on which a control knob is located, one such knob being shown at 13. The gas rail 10 is mounted on the upper ends of brackets 14 which extend upwardly behind the control panel (not shown) from the frame of the cooker and, at one end, the rail is joined to a gas supply conduit 15 leading from a gas main. The supply conduit 15 is also shown in Fig. 17 and an end view of the rail showing the gas supply passage 10A within the rail is shown in Fig. 3.

The safety system 9 that cuts off the supply of gas to the top burners 1 when the lid 7 closes is mounted on the front of the brackets 14, behind the control panel of the cooker. It comprises two fixed elongated plates 16, 17, secured together along the longer edges and shaped to enclose a movable elongated plate 18. The front fixed plate 17 is shown in Figs. 4 and 5 and the rear plate 16 is similar. The plate 17 has aperturesl9 through which the control spindles 12 of the taps 3, 5, 6 can pass and, for each of the top burner taps 3 only, a slot 20 below the aperture 19. The purpose of the slots 20 will be described below. At the end adjacent the supply conduit 15, the plate is formed with an open-ended slot 21 (Fig. 2).

Both of the fixed plates 16, 17 have a series of inwardly-extending dimples 16A formed in them, these dimples serving to centre the movable plate 18 between the fixed plates. In addition, each of the fixed plates is formed with a ported aperture beneath two of the slots 20, arranged to register with a plain aperture on the other plate to support, and provide a bearing surface for, the lower edge of themovable plate 18: in Fig. 4, the two ported apertures are indicated at 1 7A and the plain apertures at 17B.

The movable plate 18 is shown in Figs. 6 and 7: it has a series of holes 22, 23 along its length, through which the control spindles 12 of five of the taps pass, the control spindle of the sixth (left-hand) tap passing to the left-hand side of the plate. Associated with each of the top burner taps 3 is a rack member 24 located between the fixed plates 16, 17. The rack member 24 of the left-hand tap is located on the left-hand side of the movable plate 18, as shown in Fig. 6, but the rack members of the other three top burner taps are located in the holes 23 adjacent the lower edge. The rack members are shorter than the holes 23 and each has projections 25 on its front and back faces (see Figs. 8 and 9).These projections 25 extend through the respective slots 20 in the fixed plates 16, 1 7 to support the rack member 24, and each rack member 24 engages a pinion 26 (Fig. 2) on the respective tap spindle 12.

The movable plate 18 also has a semi-circular recess 27 in its right-hand edge, within the region of the open-ended slot 21 in the fixed plates 16, 17. The purpose of this recess will be described below.

Fig. 2 also shows a push rod 28 which corresponds with the push rod 35 described in UK Patent Application No. 2,144,845A except that in this case, the push rod 28 is coupled to the counterbalance mechanism 8 of the lid only for forwards movement as the lid 7 of the cooker is closed. Unlike the push rod 35 of Application No 2,144,845A, the rod 28 does not move backwards automatically as the lid 7 is opened but moves only in response to operation of one of the top burner taps 3 as will be described below. Moreover, in this case, the forward movement of rod 28 is arranged to operate the safety system 9 rather than a safety valve as described in Application No 2,144,845A.

At its forward end, push rod 28 is slidably located in a support 30 secured to the fixed plates 16, 1 7 of the safety system 9. The support 30 is shown in Figs. 13 to 16 and will be described in greater detail below.

The front end portion 31 of the rod 28 is bent as shown in Fig. 10, to provide an inclined portion 32 which, in Fig. 2 is shown located in the semi-circular recess 27 in the movable plate 18. The end 33 of the rod bears against a surface 34 of the support 30, as shown in Fig. 2.

Figs. 12 and 2 show the positions of the movable plate 18 of the safety system 9 and of the rod 28 when the lid 7 of the cooker is closed. The plate 18 has been moved to the left-hand limit of its travel, and the rod 28 has been moved into, and is held in, its forward position by the shaft 8 of the counterbalance mechanism. In this position, the inclined end portion 32 of the rod engages in the recess 27 of the plate 18 and holds the latter against movement to the right. All of the rack members 24 engage the right-hand edges of the holes 23 (or, in the case of the left-hand rack member, the lefthand end of the plate 18). If the lid 7 of the cooker is now opened, the shaft 8 of the counterbalance mechanism moves out of engagement with the rod 28.

The latter, however, does not move but.remains, with the plate 18, in the position shown in Figs. 12 and 2 until any one of the top burner taps 3 is moved into an "ON" position. Suppose, for example, that the righthand tap 3 shown in Figs. 12 and 2 is moved into the "ON" position: rotation of the associated pinion 26 moves the rack member 24 to the right and this, in turn, pushes the plate 1 8 to the right (on the bearing surfaces provided by the ported apertures 1 7A in plates 1 6, 17) for a distance depending on the extent to which the tap has been turned.The plate 18, in turn, acts on the inclined portion 32 of the rod 28 and pushes the latter backwards for a distance which also depends on the extent to which the tap 3 has been turned: if the tap has been turned into its fully "ON" position, the rear end 28A of the rod 28 will be moved into engagement with the shaft 8 of the counterbalance mechanism but if the tap has been turned only into a partially "ON" position, the end of the rod 28 will not engage the shaft although it will be in a position in which it can be engaged by the shaft when the lid 7 of the cooker is subsequently closed. During the movement of the plate 18 to the right, the rack member 24 of any tap which is still in the "OFF" position is held by the niting arrangement of the tap so that the plate 18 moves relative to such a rack member.

Figs. 11 and 2A show the positions of the movable plate 18 and the rod 28 when the lid 7 of the cooker is open and the right-hand tap 3 has been turned fully "ON". The plate 18 has been moved to the right, andthe rod 28 has been moved rearwardly and is in engagement with the shaft 8 of the counterbalance mechanism as already described. The two lefthand taps 3 are still in the "OFF" position and the associated rack members 24, which have been held by the niting arrangements of the taps, are now spaced apart, in one case, from the right-hand edge of the hole 23 in which the rack member is located and, in the other case, from the left-hand end of the plate 18.The rack member 24 of the right-hand tap 3, on the other hand, which is in its fully "ON" position and brought about the movement of the plate 18 and rod 28, still abuts the right-hand edge of the hole 23 in which the rack member is located.

If now, the user closes the lid 7 of the cooker, the shaft 8 of the lid counterbalance mechanism moves the rod 28 forwards into the position shown in Fig. 2. The inclined end portion 32 of the rod, bearing against the surface 34 of the support 30 and engaging in the recess 27 of the plate 18, moves the latter to the left as indicated by the arrow 36 in Fig.

11. During this movement of the plate 18, the rack members 24 of the left-hand taps 3 are held fixed by the niting arrangement of the taps, which (because the taps are in the "OFF" position) prevents rotation of the tap spindles 12 and, hence, of the pinions 26 which engage the rack members. However, the rack member 24 of the right-hand tap 3 is free to move and is pulled to the left by the right-hand edge of the hole 23 (as seen in Fig.

11): this rotates the associated pinion 26 and the tap spindle 12 on which it is mounted and brings the tap into its "OFF" position where it is held by the niting arrangement.

The positions of the various components in the "lidclosed" situation are now again as shown in Fig. 12. All of the rack members 24 now engage the right-hand edges of the holes 23 or, in the case of the extreme left-hand rack member, the edge of the plate 18 and as long as the lid remains closed (preventing movement of the plate 18) this engagement prevents rotation of any of the top burner taps 3 into an "ON" position.

If the right-hand tap 3 had been turned only into a partially "ON" position (rather than the fully "ON" position) then the same sequence of operations would have taken place except that an initial closing movement of the cooker lid 7 would have been required before the shaft 8 of the counterbalance mechanism engaged the push rod 28.

The support 30 which guides the movement of the rod 28 and provides the bearing surface 34 for the end of rod 28 is shown in Figs. 13 to 16. The support 30 also serves to locate the end of the gas supply conduit 15 and the end of the gas rail 10, as will be described below with reference to Fig. 17.

The support 30 is formed from a flat plate which is shaped and bent to provide a vertical side portion 37, a vertical rear portion 38, a horizontal upper portion 39 and two front lugs 40. In addition, a portion 41 of the vertical side 37 is pressed out to form a slightly in clined ledge.

The front lugs 40 of the support 30 are secured by screws to the end of the fixed plates 16, 17 of the safety system 9. The gas supply conduit 15 passes through a hole 42 in the rear wall 38 of the support and then bends upwards so that the conduit terminates at a hole 43 in the upper horizontal portion 39 of the support, as shown in Fig. 17. The end of the gas rail 10 sits on the top of the horizontal portion 39 and is secured to the support 30 by screws for which holes 44 are provided. Communication between the conduit 15 and the passage 11A within the rail is then provided by the hole 43 in the support and a corresponding hole in the floor of the rail. The rod 28 controlling operation of the safety system 9 also passes through the rear wall 38 of the support, via an aperture 45, and rests on the ledge 41, over which it slides as the cooker lid 7 is opened or closed.

The end 33 of the rod 28, as already mentioned, bears against the surface 34 provided by the vertical side wall 37 of the support.

One of the taps 3 controlling operation of the top burners is shown in Figs. 18 to 20.

The tap comprises a housing 46 of generally tubular form, the top 47 of which is flattened to enable the tap to be mounted on the undersurface of the gas rail 10. A gaseous fuel inlet 48 is formed in the top surface 47 ofthe housing and communicates with the supply passage 15A in the gas rail. The housing 46 has a central, through-passageway containing a flow control member (not visible) which is rotatably movable within the passageway. The tap spindle 12 is used to rotate the flow control member but is also axially movable relative thereto. The spindle extends from one end of the housing 46 and has one "flat" 49 for receiving the pinion 26 and a second "flat" 50 for receiving the control knob 13.

At the other end of the housing 46, the end of the through-passageway forms the gaseous fuel outlet of the tap (not shown) and rotation of the flow control member within the through-passageway controls the flow of fuel from the inlet 48 to this outlet. To ensure that the spindle 12 is locked against rotation when in the "OFF" position, a niting groove 51 is formed in the housing 46 and contains the head of a pin 52 which is secured in the spindle. The groove 51 has a longitudinallyextending portion and then a portion (not shown) that extends circumferentially around the housing 46 whereby, before the spindle 12 can be rotated to rotate the flow control member, it must be pushed into the housing 46 to move the pin 52 to the end of the longitudinally-extending portion of the niting groove.

An alternative arrangement which functions in a similar manner to that of Fig. 2 is shown diagrammatically in Fig. 21. Corresponding components carry the same reference numerals in both Figures. In this alternative arrange ment, the push rod is always coupled to the shaft 8 of the lid counterbalance mechanism and moves forwards and backwards as the lid 7 of the cooker is opened and closed as described in UK Patent Application No 2,144,845A. In addition, the forward end of the rod 28 is not shaped as in Fig. 2 but is simply supported in a mounting block 53.

Spring 54 encircling part of the rod 28 adjacent the block 53 biasses the rod rearwardly as seen in fig. 21, ie away from the block 53.

In addition, the movable plate 18 in this arrangement is resilientiy-biased by a spring 35 towards the left as seen in Fig. 21.

Pivoted about a vertical axis 55 adjacent the block 53 is a lever 56 formed at one end with an upstanding, U-shaped extension 57 which locates in a groove 58 in the rod 28, the limbs of the U straddling the rod.

Alternatively, the push rod 28 may be directly connected to the lever 56, the latter providing the support for the forward end of the push rod. The connection may be effected by a clevis for example.

Lever 56 engages a hole 59 in the movable plate 18 of the safety system 9 so that backwards and forwards movement of rod 28, as the cooker lid 7 is opened and closed, results in pivotal movement of the lever about axis 55 and moves the plate 18 to and fro.

This arrangement also differs from that shown in Fig. 2 in that there is a hole 23 in the plate 18 for each of the top burner taps and in that the rack members associated with those taps are mounted to slide on the upper edges of the holes. One rack member is shown at 79 and differs from that shown in Figs. 8 and 9 in that it has a slotted base 80 which fits over the upper edge of the hole 23 and allows the rack member to slide along the edge. The opposite edge of the hole 23 supports a bearing strip 81 which ensures that the pinion 82 on the gas tap spindle 74 is held in mesh with the rack 79. It will be noted that, in this embodiment, the pinion 82 is formed as part of the control knob 75 of the gas tap and it will be understood that the control knobs (not shown) of the oven and grill taps 5, 6 would not incorporate pinions but would be of conventional form.

Fig. 21A shows the position of the movable plate 18 of the safety system 9 when the lid 7 of the cooker is open. The rod 28 has been moved rearwardly and the plate 18 has moved to the left under the resilient bias of the spring 35. The right-hand tap 3 is in its "OFF" position and the associated rack member 24 abuts the right-hand edge of the hole 23 in which the rack member is mounted. The left-hand tap 3, on the other hand, is in its fully "ON" position and the associated rack member 24 abuts the left-hand edge of the hole 23 in which the rack member is mounted.

If now, the user closes the lid 7 of the cooker, the rod 28 moves forwards into the position shown in Fig. 2 and the plate 18 moves to the right under the action of the lever 56 and against the action of spring 35, as indicated by the arrow 36 in Fig. 21A.

During this movement of the plate 18, the rack member 24 of the right-hand tap 3 is held fixed by the niting arrangement of the tap, which (because the tap is in the "OFF" position) prevents rotation of the tap spindle 12 and, hence, of the pinion 26 which engages the rack member. However, the rack member 24 of the left-hand tap 3 is free to move and is pulled to the right by the lefthand edge of the hole 23 (as seen in Fig. 21A): this rotates the associated pinion 26 and the tap spindle 12 on which it is mounted and brings the tap into its "OFF" position where it is held by the niting arrangement.

The positions of the various components in the "lid-closed" situation is shown in Fig.

21B. All of the rack members 24 now engage the left-hand edges of the holes 23 and it will be observed that, as long as the lid remains closed, this engagement prevents rotation of any of the top burner taps 3 into an "ON" position.

If the cooker lid 7 is now opened again, the plate 18 moves back to the left under the action of the spring 35. During this movement, all of the rack members 24 are held fixed by the tap niting arrangements and, when the plate 18 has completed its movement to the right, each rack member 24 will be in engagement with the right-hand edge of the hole 23 in which it is mounted. This is the situation shown for the righthand tap 3 in Fig.

21A and, thereafter, any of the taps can be moved into the "ON" position while the cooker lid 7 remains open. If a.tap is moved into the fully "ON" position, rotation of the pinion 26 on the tap spindle 12 will move the associated rack member 24 into engagement with the left-hand edge of the hole 23 in which it is mounted (as shown for the lefthand tap in Fig. 21A) whereas movement of the tap into a partially "ON" position will bring the rack member into an intermediate position: in the latter case, there will be some movement of the plate 18 when the lid is closed before the left-hand edge of the hole 23 engages the rack member 24 to move the tap back into the "OFF" position.

Fig. 22 shows an arrangement similar to that of Fig. 21 but suitable for use in a gas hob of the type shown in Fig. 23. The hob comprises a hollow box-like structure 61 which accommodates four gas burners shown schematically at 62, 63, 64 and 65, a pan support structure 66 (also shown schematically), a gas supply rail with gas taps operated by control knobs 67 above a control panel 68, fuel supply passages (not shown) for conveying a gas/air mixture to the burners, and a gas ignition mechanism (not shown) controlled by an ignition button 69.

Hinged about a horizontal axis at the rear of the structure 61 is a lid 70 shown in Fig.23 in its fully opened position but which is movable by a user to a closed position in which it conceals the burners 62 to 65 and the control panel 68. When closed, the lid 70 may lie flush with adjacent surfaces.

Also located in the structure 61 is a counterbalance mechanism operatively connected to the lid 70 for counterbalancing, in a desired manner, the closing weight of the lid.

Further details of the general construction of the hob are found in UK Patent Application No. 2,109,919A. The hob described in that Application includes a lid-operated safety cutoff valve which, in the present embodiment, is replaced by the mechanism shown in Fig. 22.

Fig. 22 shows part of the structure 61 as accommodating a gas rail 71 on which are mounted gas taps 72 that control the supply of gas from a gas supply passage inside the rail to injectors 73 which, in turn, feed into the gaseous fuel supply passages, referred to above, of the burners 62, 65. The gas rail 71 extends to the rear of the structure 61 and is there joined to a gas supply conduit (not shown) leading from a gas main.

The rail 71 may be mounted in structure 61 in any suitable manner and in Fig. 22 it is shown as mounted upon the side wall of the structure 61.

Each gas tap 72 has an upwardly extending control spindle 74 on which a control knob is located. One such knob is shown at 75 and it can be seen that part of the knob is formed as the pinion 82 of the safety system.

Mounted upon the gas rail 71 and secured thereto so as to extend over the upper ends of the gas taps 72 is an elongate plate 76 apertured at spaced positions 76A along its length to permit passage of the spindles 74.

Resting upon the upper surface of the plate 76 and movable along that surface is a spring plate 77. The spring plate 77 has a series of rectangular holes 78 spaced along its length.

On one of the longer edges of each hole is positioned the rack member 79 whose base is slotted as at 80 to fit over that edge and allow the rack member to slide along the edge. The length of the rack 79 is less than that of the edge on which it is mounted. The opposite edge of each hole supports the bearing strip 81 which holds pinion 82 of the control knob 75 in mesh with the rack.

Spring plate 77 is biassed to the right as viewed in Fig. 22 by a spring 83.

The upstanding end of a lever 85 engages in a hole 86 in the end of the plate 77 at the rear of the hob. Lever 85 is accommodated in a rear corner of the structure 61, this corner being separated from the interior of the structure by a partition 88. As can be seen, the lever 85 extends through a hole 89 in the upper surface of the partition 88 to allow it to be connected to the plate 77.

The lever 85 is linked to the lid 70 in a manner such that, as the lid moves into its closed position, the projecting end of the lever 85 moves to the left as seen in Fig. 22 and as indicated by arrow 90. The operation of the arrangement is then exactly the same as that shown in Fig. 21.

It is not essential to employ a common connection (ie the plate 77 of Fig. 22) between the rack members 79 and the lid 70. Fig. 24 shows, diagrammatically an arrangement similar to that of Fig. 22 but employing individual connections for the rack members. Corresponding components in the two Figures carry the same reference numerals. In this case, each rack member consists of a rectangular plate 91 with a central rectangular hole 92 one of the longer sides of which is formed as a rack 93. The outer side of the plate 91 adjacent the rack 93 has spaced transverse channels 94 in it.

When in position on the plate 76, each rack member 91 is associated with one of the taps 72 whose spindle 74 passes through the hole 92 as is indicated in Fig. 24 for the extreme right-hand tap.

The racks 93 co-act, as already described, with the pinions 82 which form part of the control knobs 75 of the taps 72. The width of the holes 92 ensures that the pinions 82 are held in engagement with the racks 93.

Each pinion 82 may be an integral part of the respective knob or it may be made as a separate component and then secured to the knob.

Alternatively, the pinion may be part of the spindle 14 or, as already described with reference to Figs. 18 to 20, may simply be secured to the latter.

Each rack member 91 is linked to the end of an arm 95 (corresponding to lever 85 of Fig. 22) by a stiff pull rod 96. Each rod is cranked at one end to provide sections 97 that locate firmly in the channels 94. Each rod 96 is also cranked at its other end as indicated at 98, that end passing through one of a series of holes 100 in the upper end of the arm 95 so that the crank 98 lies on that side of the arm 95 remote from the rack members 91.

The arm 95 is linked to the lid 70 in a manner such that, as the lid moves into its closed position, the projecting end of the arm moves to the left as seen in Fig. 24 and as indicated by arrow 90.

With lid 70 open and all taps in the "OFF" position, the relative positions of each of the pinions 82 and associated rack 93 and crank 98 and the arm 95 are as shown schematically in Fig. 25. It will be observed that there is clearance between the arm 95 and the crank 98 and that the pinion 82 is at the right-hand end of the rack 93.

If now, the user closes the lid 70, arm 95 moves to the left as seen in Fig. 25, the movement being accommodated by the initial clearance between the arm and the crank 98 with the result that there is no movement of the rack and the tap remains in its "OFF" position. When the lid is fully closed, the arm 95 abuts the crank 26.

Fig. 26 shows schematically the relative positions of the same components in the case of a tap that has been turned to its fully "ON" position. It will be observed that the arm 95 abuts the crank 98 and that the pinion 82 is in contact with the left-hand end of the rack member 91.

If now a user closes the lid 70 without first turning the tap to its "OFF" position, movement to the left of arm 95 that occurs as a result of the closure of the lid, pulls the rod 96 and the rack member 91 to the left with the result that pinion 82is rotated and turns the tap to its "OFF" position.

If a tap is not in its fully "ON" position when the lid is closed, there will be some movement of the arm 95 before the latter contacts crank 98. Thereafter, the continued movement of the arm 95 will result in movement of the tap to its "OFF" position as before.

The safety system also ensures that no tap can be turned to its "ON" position whilst the lid is closed, because rotation of the tap spindle is prevented by the engagement of the arm 95 with the crank 98, which prevents rotation of the pinion 82.

Preferably, the taps are fitted with a niting arrangement which ensures axial outward movement of the tap spindle when the "OFF" position is reached thereby holding the tap in its "OFF" position.

Fig. 27 shows an arrangement similar to that of Fig. 24 but incorporated in a gas cooker. The arrangement employs a lever 56 which corresponds to that of Fig. 21 but which has an additional upstanding extension 101 with a series of holes 102 in it, arranged in a vertical line.

Located in the holes 102 are the ends of four stiff push rods of which one is shown in Fig. 27 and referenced 103. Adjacent those ends, the rods 103 are cranked as indicated at 104. At its other end, each rod 103 has closely spaced cranks 105 that locate in transverse recesses 106 in a rack member 107. The configuration of the rack members 107 is identical with that of the rack members 91 described above, the racks of the members 107 meshing with pinions 108 on control knobs 109 of the taps 110 of the top burners of the cooker. The knobs (not shown) of the taps 111 and 112 of the grill and oven burners are conventional and do not incorporate pinions and do not have rack members associated with them.

The safety system shown in Fig. 27 operates in a manner generally similar to that shown in Fig. 24 and described above. As the cooker lid is closed, lever 56 pivots in an anti-clockwise direction as already described with reference to Fig. 21. The cranked end 104 of the rod 103 of any of the top burner taps 110 that is in an "ON" position (either fully or partially) is engaged by the extension 101 of the lever 56 and the tap is moved to its "OFF" position.

As before, each of the taps 110, 111, 112 incorporates a niting arrangement which prevents rotation of the tap spindle when in the "OFF" position. Also, none of the top burner taps 110 can be turned to its "ON" position as long as the lid is closed because each tap spindle is locked against rotation by the engagement of lever 56 with the cranked end 104 of the associated rod 103.

It will be appreciated that other arrangements than those described above can be used to link the taps to the hob/cooker lid.

Thus operation to "OFF" of the taps can be effected by means of cables attached directly at one end to the control knob of a tap so as to rotate the knob into a closed position when a pull is exerted on the cable. The other ends of the cables are secured to a lever movable with the lid to apply a pull to the cables as the lid closes. it will be understood that the cables of taps already in an "OFF" position will be slack when the lid is in its open position and it is simply the slack that is taken up as the lid is closed. When the lid is in its closed position, tension in the cables prevents a user rotating any tap from its "OFF" position.

Alternatively, each tap (except those controlling the oven and grill burners) can incorporate a spring or other resilient means which biasses the tap into its "OFF" position, together with means for inhibiting the action of the spring whilst the lid is open to allow a user to operate a tap. However, during closure of the lid, the inhibition is released and the relevant spring is allowed to move, into its "OFF" position, any tap not in that position.

The inhibition is then reapplied and maintained whilst the lid is in its closed position so that the taps cannot be turned "ON" whilst the lid is in that position.

The inhibiting means may comprise a friction plate which, unless released, offers sufficient resistance to the spring action to prevent the latter moving the tap to its "OFF" position.

During closure of the lid, the plate is released allowing the spring action to come into effect.

The taps need not be of the form shown in Figs. 18 to 20 but could, for example, be of the form described in UK Patent Application Nos 2,129,097A or 2,166,221A.

The lid counterbalance mechanism may, as already described, take the form described in UK Patent Application No. 2,109,919A or that described in UK Patent Application No.

2,144,845A. However it can, alternatively, take the form described in UK Patent Applica tion No. 2,165,350A or some other suitable form, for example, some form of friction joint.

It is also possible to counterbalance the lid using the springs associated with-the tap closing mechanism described above.

Whilst a lid counterbalance is desirable, it is not essential and the closing weight of the lid may be unbalanced.

As an additional indication to a user, a visual or audible warning may be given in the case where a user closes the lid with at least one tap not in its fully "OFF" position. The warning may commence as the lid moves from its fully open position and may terminate when the lid reaches its closed position. Alternatively, the warning may remain operative until the user ensures that all taps are in the "OFF" position.

Furthermore, the invention is not limited to use with gas hobs and cookers. It can be used with electric hob and cookers and with hob and cookers having both top burners and electric rings or hot plates.

Claims (30)

1. A hob having a body portion accommodating one or more gas burners and/or electric rings/hot plates; a lid movable between a fully open position giving access to the body portion and a closed position in which the lid covers the body portion; taps and/or switches controlling the gas supply and/or electricity supply to the burner and/or electric rings/hot plates, and means for operatively connecting the taps and/or switches to the lid in a manner such that on movement of the lid into its closed position any tap or switch not in its "OFF" position is operated into that position.

2. A hob as claimed in claim 1, in which the said means is such that each tap and/or switch is held in its "OFF" position whilst the lid remains in its closed position.

3. A hob as claimed in claim 1 or 2, in which the taps and/or switches require a rotary action to operate them and in which the said means includes a respective linkage means associated with each tap and/or switch to rotate it to an "OFF" position if not in that position when the lid moves to its closed position.

4. A hob as claimed in claim 3, in which the said means also includes an operating member movable at least in response to closing movement of the lid and engageable with the linkage means of any tap/switch not in its "OFF" position when the lid is being closed to rotate that tap/switch to the "OFF" position.

5. A hob as claimed in claim 4, in which the operating member is also movable in response to an opening movement of the lid and each linkage means is movable relative to the operating member during rotation of the respective tap/switch when the lid is open, rotation of any tap/switch out of the "OFF" position causing movement of the linkage means into a position in which it is engageable by the operating member to be moved therewith when the lid is being closed.

6. A hob as claimed in claim 4, in which the operating member is movable in response to rotation of any tap out of the "OFF" position into a position in which it is movable in response to closing movement of the lid.

7. A hob as claimed in any one of claims 4 to 6, in which the operating member is movable relative to the linkage means of any tap/switch which is in the "OFF" position.

8. A hob as claimed in any one of claims 4 to 7, in which the operating member engages the linkage means when the lid is closed to prevent rotation of any tap/switch.

9. A hob as claimed in any one of claims 4 to 8, in which each linkage means includes a rack and pinion drive.

10. A hob as claimed in claim 9, in which the pinion is rotatable with the tap/switch and the rack is arranged to be movable by the operating member.

11. A hob as claimed in claim 10, in which the operating member comprises a plate.

12. A hob as claimed in claim 10 when appended to claim 5, in which each linkage means also includes a respective connector member coupling the rack to the operating member.

13. A hob as claimed in claim 12, in which the operating member comprises a lever to which the connector members are coupled.

14. A hob as claimed in claim 5, in which the operating member is coupled to a push rod associated with the lid, to be moved by the push rod in one direction during movement of the lid into its closed position.

15. A hob as claimed in claim 14, in which the operating member is resiliently biased in the other direction.

16. A hob as claimed in claim 15, in which movement of the push rod as the lid is opened permits movement of the operating member in the said other direction.

17. A hob as claimed in claim 6, in which the operating member is movable, in response to rotation of any tap out of the "OFF" position, into a position in which it is movable by closing movement of the lid via a push rod associated with the lid.

18. A hob as claimed in claim 17, in which movement of the lid into the open position releases the operating member for movement in response to rotation of any tap out of the "OFF" position.

19. A hob as claimed in any one of the preceding claims and further including warning means operable in the event that the lid is moved from its fully open position when at least one tap/switch is not in its "OFF" position.

20. A hob as claimed in claim 19, in which the warning means is operable to provide a visual or audible warning.

21. A hob as claimed in claim 1 or 2, in which each tap/switch is biased into its "OFF" position, the bias being inhibited except when the lid is moved from its fully opened to its closed position and when the lid is in the latter position.

22. A hob as claimed in claim 21, in which the bias is inhibited by a friction or latch plate operatively connected to the lid in a manner such that the inhibition is removed when the lid is moved from its fully open to its closed position and when the lid is in the latter position.

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

24. A hob as claimed in claim 23 when appended to any one of claims 14 to 18, in which the push rod is associated with the lid via the counterbalancing mechanism.

25. A hob as claimed in any one of the preceding claims, in which the taps and/or switches include a niting arrangement.

26. A hob as claimed in claim 3, in which each tap/switch includes a niting arrangement which prevents rotation of the tap/switch when in the "OFF" position.

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

28. A cooker as claimed in claim 27, including at least one gas burner/electric heating element which is not accommodated in the hob, and in which there is no operative connection between the lid and the tap/switch of that burner/element.

29. A hob substantially as herein described with reference to and as illustrated by Figs.

22 and 23 or Fig. 24 of the accompanying drawings.

30. A cooker substantially as herein described with reference to and as illustrated by Figs. 1 to 20 or Fig. 21 or Fig. 27 of the accompanying drawings.