GB2165040A - Improvements relating to gas control in cookers - Google Patents

Abstract

The present specification discloses a cut-off gas control assembly for use in controlling the gas supply line to a gas hob which can be covered by a pivotable lid. Whilst it is known to provide a cut-off valve in the gas supply line, the valve being automatically closed when the lid is lowered, there is the danger that if the normal gas controls are not subsequently returned to a closed position, the lid may be raised to release unignited gas into the atmosphere. The present invention provides a cut-off gas control assembly comprising a valve (15) located in the gas supply line, with a first member (9) mounted so as to pivot to close the valve (15) as the lid (1) is hinged downwardly to cover the hob, a second member (17) being arranged to subsequently maintain the valve (15) closed until said second member (17) is manually moved. The second member (17) holds the cut-off valve (15) closed until it is manually moved by depressing push button 23, irrespective of the position of the lid (1). <IMAGE>

Description

SPECIFICATION Improvements relating to gas control in cookers The present invention relates to the control of the gas supply to a cooker.

In particular the present invention relates to the control of the gas supply to the hob of a gas cooker, the gas cooker being of the type which has a hinged lid which can be hinged downwardly to cover the hob when the hob is not in use. Such known hinged lids are usually made of a ceramic material, glass or metal.

To protect against damage in the event that the hinged lid is hinged downwardly whilst one or more gas burners of the hob are lit, a cut-out valve is provided in the gas supply line to the hob, the cut-out valve being operated by the movement of the lid downwardly. This is perfectly satisfactory assuming that the usual gas control for the hob on the cooker, is subsequently closed. However there is the danger that the lid may be hinged downwardly to cut off the gas supply to previously ignited burners, and then hinged upwardly before the gas control is closed, thus allowing the gas to pass into the atmosphere. The danger is twofold explosion and/or asphyxiation.

The aim of the present invention is to provide a cutoff gas control assembly which overcomes the above problem.

According to the present invention there is provided a cooker having a gas hob which can be covered by a pivotable lid, the cooker further having a cutoff gas control assembly for use in controlling the gas supply line to the gas hob, the assembly comprising a valve located in the gas supply line, a first member mounted so as to pivot to close the valve as the lid is hinged downwardly to cover the hob when ignited, and a second member arranged to subsequently maintain the valve closed until said second member is manually moved.

In one embodiment of the present invention the cutoff valve is opened by the depression of a push button of the valve. With this embodiment the said first member is freely pivotally located on the hinge pin of the lid and has a stop which can be engaged by a drive member which is fixed to the hinge pin and thus pivotable with said lid. Alternatively, if the hinge pin did not move with the lid, the drive member would be secured for movement with the lid. Said second member has a lateral extension which extends over the push button so that axial movement of said second member can depress the push button and open the valve, said second member being spring biassed to an axial position wherein the valve is closed.

In operation, when the lid is pivotted upwardly, said first member is allowed, by virtue of the movement of the drive member with the lid, to pivot to a position near the vertical where it engages against said lateral extension of the said second member; said second member being spring biassed to the valve closed position. By then manually moving said second member axially to depress the push button and open the valve, the said lateral extension is moved out of the way of the said first member, allowing the first member to pivot to a vertical position under the action of its own weight, wherein the first member traps the second member and the push button in the valve open position.If and when the lid is pivotted downwards the drive member engages the stop on the first member and pivots the first member to release the second member and the push button, and allow the valve to close; thus shutting off the gas supply to the hob. As will be appreciated, the valve will remain closed even if the lid is subsequently raised; it being necessary to then positively move the said second member to open the valve.

In another embodiment of the present invention the cutoff valve is closed by the depression of a push button of the valve. With this embodiment the first member has a cam profile and is fixed on the hinge pin of the lid, to thus rotate with the hinge pin as the lid is hinged upwardly or downwardly. The main intention is that the first member moves with the lid even if the hinge pin does not rotate. When the lid is in the horizontal position covering the hob, the first member engages and cams the push button down to close the valve.

When the lid is raised the first member releases the push button. Freely pivotally mounted on the hinge pin in said second member which also has a cam profile. This second member is connected by a mechanical linkage to a spring loaded push button, so that when the spring loaded push button is in its rest position, the second member is in a vertical position wherein it engages and holds the push button of the valve depressed. Thus, with the second member in this position, the lid can be hinged upwardly moving the first member away from the push button of the valve, the second member holding the valve closed. By depressing the spring loaded push button the second member is pivoted to allow the valve to open.With the valve open the spring bias of the spring loaded push button holds the second member against the side of the valve push button so that when the lid is lowered the first member depresses the valve push button allowing the second member to return under the spring bias, to the vertical rest position.

Thus the valve remains closed irrespective of movement of the lid, until the spring loaded push button is depressed subsequent to the lid having been raised.

The present invention will now be further described, by way of example, with reference to the accompanying drawings, in which: Figures 1, 2 and 3 schematically illustrate three operational positions of one embodiment of the present invention; and Figures 4, 5 and 6 schematically illustrate three operational positions of another embodiment of the present invention.

The embodiment of the present invention illustrated in Figures 1,2 and 3 of the accompanying drawings comprises a lid (1) which is pivoted about the axis of hinge pin (3) between the horizontai position shown in Figure 1, in which the lid covers the hob (not shown) and the vertical position shown in Figures 2 and 3, in which the hob is exposed. Fixed relative to the hinge pin (3) and lid (1) is a drive member (5) this drive member (5) being arranged to contact a stop (7) provided on first member (9), when the lid (1) is in the horizontal position of Figure 1. The first member (9) is freely pivotably mounted on hinge pin (3) and has a counterweighted free end region (11) which biasses the first member (9) towards the generally vertical position of Figure 3.

Mounted directly below the first member (9) and the axis of hinge pin (3), is the push button (13) of gas control valve (15). Depression of the push button (13) opens the valve (15) to allow gas to flow to the hob. Adjacent to the hinge pin (3) and the valve (15), a second member (17) is movably located. This second member (17) is elongate with a lateral extension (19) which engages over push button (13). The second member (17) is mounted in the frame (21) at the rear of the cooker and is provided at one end with a push button (23) which projects out of the frame (21). At the other end of said second member (17) an axial extension (25) retains a spring (27) and engages in a slot (27) of the frame (21). Thus depressions of the push button (23) moves the second member axially against the spring (27) so that lateral extension (19) can depress push button (13) and open the valve (15).

When the hob is switched off with the lid (1) in the horizontal position of Figure 1, the drive member (5) is engaging the stop (7) and holding the first member (9) in the pivotted position of Figure 1, with the push button (13) extended and the cutoff valve (15) switched off; spring (27) holding the second member (17) also clear of push button (13).

When the hob is to be used, the lid (1) is raised to the vertical position of Figure 2, so that drive member (5) allows first member (9) to pivot under its own weight to the position illustrated in Figure 2, where counterweight (11) engages against the side of extension (19). Thus the valve (15) is still closed and gas cannot flow to the hob even if the normal controls (not illustrated), usually positioned on the front of the cooker, are operated. To open valve (15), push button (23) must be depressed so that lateral extension (19) moves downwards depressing push button (13). As the lateral extension (19) clears the counterweighted end region (11) of first member (9), first member (9) pivots under the action of its own weight to the vertical position of Figure 3, wherein the second member (17) and push button (13) are prevented from return movement by said first member (9).Thus the valve (15) is maintained open and the gas supply to the hob can be controlled by the previously mentioned normal controls.

When the lid (1) is hinged downwardly, whether or not the hob is lit, the drive member (5) engages stop (7) and pivots first member (9) from above lateral extension (19) and push button (23), so that the second member (17) is moved by spring (27), releasing push button (23) and closing the valve (15). Thus the gas supply is switched off and even if the lid (1) is lifted before the normal controls are turned to the "off" position, the valve (15) is maintained closed until the push button (23) has been depressed.

Another embodiment of the present invention is illustrated in Figures 4, 5 and 6 of the accompanying drawings. This embodiment includes a lid (29) which is pivotable about the axis of hinge pin (31) between the horizontal position illustrated in Figure 4, where the lid (29) covers the hob (33), and the vertical position illustrated in Figures 5 and 6, where the hob (33) is exposed. The hinge pin (31) is located across the rear of the cooker within a frame (35) and fixedly mounted on the hinge pin (31) in a first member (37) having a cam profile (39). Said first member (37) is so positioned that when the lid (29) is in the horizontal position of Figure 4, the tip of the cam profile (39) presses a spring loaded plate (41) downwards, thereby depressing a push button (43) to close gas control valve (45).In this position the gas supply to hob (33) is switched off, even if the normal gas supply controls (not illustrated), usually positioned on the front of the cooker, are operated.

Also in the position illustrated in Figure 4, a second elongate member (47), freely pivotally mounted at one end region thereof, on the hinge pin (31), is positioned vertically with its tip (49) engaging the spring loaded plate (41). Said second member (47) is held in this position by a mechanical linkage (51) and a spring loaded push button (53). With said second member (47) in this vertical position, the lid (29) can be hinged upwardly, moving said first member (37) out of contact with the spring loaded plate (41), and said second member will continue to hold the valve (45) closed (see Figure 5). Only when push button (53) is depressed (see Figure 6), moving the second member (47) away from the spring loaded plate (41), can the push button (43) and plate (41), rise to open the valve (45).When the push button (53) is released it returns under the action of its spring (not shown) drawing second member (47) against the side of plate (41). The valve (45) thus remains open and the gas supply to the hob (33) is controlled by the normal controls previously referred to. When the lid (29) is hinged down, the first member (37) engages and cams the spring loaded plate (41) downwards, closing the valve (45). As the spring loaded plate (41) moves down so the second member (47) is pulled to the vertical position of Figure 4 by the spring loaded push button (53). The valve (45) can then not be opened irrespective of the position of the lid until the push button (53) has been depressed.

If required the linkage (51) can be extended through the cooker so that the push button (53) can be positioned with the other usual controls on the front of the cooker.

The present invention thus provides a gas control for cookers, which provides for the gas supply to the cooker hob to be switched off should the lid for the hob be lowered, thus preventing damage to the lid should the hob have been lit. The gas control also prevents the subsequent escape of gas should the lid be raised before the normal cooker hob controls have been switched off, by maintaining a gas supply valve closed until it is manually reset.

Claims (7)

1. A cut-off gas control assembly for use in controlling the gas supply line to the or each burner of a gas hob, which hob can be covered by a pivotable lid, the assembly comprising a valve located in the gas supply line, a first member mounted so as to pivot to close the valve as the lid is hinged downwardly to cover the hob, and a second member arranged to subsequently maintain the valve closed until said second member is manually moved.

2. An assembly as claimed in claim 1, in which said first member is freely pivotally located on a hinge pin of the lid, which hinge pin is fixed to move with the lid, said first member having a stop which can be engaged by a drive member which is also fixed to the hinge pin and which is thus pivotable with said lid.

3. An assembly as claimed in claim 1, in which the lid is pivotable about a hinge pin on which said first member is also freely pivotable, a drive member being mounted on the hinge pin so as to be pivotal with said lid.

4. An assembly as claimed in claim 2 or claim 3, in which said second member is arranged to be axially movable against a spring, to engage and depress a push button control of the valve to thus open the valve, said first member being then allowed, when the lid is raised, to pivot to a position wherein said first member holds the valve open.

5. An assembly as claimed in claim 1, in which the first member has a cam profile and is mounted on a hinge pin on which the lid is mounted, for rotation about the axis of the hinge pin as the lid is raised and lowered, the first member being arranged to depress a push button control of the valve to close the valve, when the lid is in a lowered horizontal position, and to release the push button control when the lid is raised.

6. An assembly as claimed in claim 5, in which the second member also has a cam profile and is freely pivotally mounted on the hinge pin, a linkage connecting the second member to a manually operable push button which is spring biassed to a rest position in which said second member holds the push button control of the valve in the depressed, valve closed position.

7. A cut-off gas control assembly for use in controlling the gas supply line to a gas hob which can be covered by a pivotable lid, said assembly being constructed and arranged substantially as hereinbefore described with reference to and as illustrated in Figures 1, 2 and 3, or Figures 4, 5 and 6 of the accompanying drawings.