GB2124891A - Water-boiling vessel with cooking insert - Google Patents

Abstract

An electrically heated water boiling vessel (1) is provided with an automatically-operating steam- sensitive element switch-off unit for switching-off the supply of electrical power to the heating element of the vessel in response to the generation of steam in the vessel when its contents boil, the interior of the vessel communicating with the said unit via a steam vent (6), and the vessel (1) has associated therewith a basket (3) which can be inserted into the vessel for cooking food, the basket (3) having an integral steam duct (9) which extends from the vent (6) downwardly into the vessel (1) to a predetermined distance from the bottom of the vessel. Tho basket (3) prevents steam generated in the vessel from reaching the vent (6) until the water level boils down to below the bottom end of the duct (9). Markings (15) in the basket (3) correspond to cooking times associated with different water levels in the vessel, the respective cooking times representing the time required to boil down the water level to the level of the bottom end of the duct. <IMAGE>

Description

SPECIFICATION Improvements relating to vessels provided with electrical heating elements This invention concerns improvements in or relating to vessels provided with electrical heating elements for heating the contents of the vessel. Examples of such vessels comprise kettles, pots, pans, jugs and urns adapted particularly though not exclusively for heating and boiling of waterorotherliquid.

Electrically heated vessels are known in which a vent, tube or duct is provided for directing steam, generated when water heated in the vessel boils, onto a thermally responsive switch or switch-actuating element so as to disconnect or reduce the supply of electrical powertothe heating element when the water in the vessel is raised in temperature to boiling; automatically switching-off electricjugs and kettles operating on this principle are known for example from British Patent Specification 2 045 588A(corresponds to Australian Patent Application No. 56698/60 assigned to us).Alternative electrically heated vessels also are known which do not incorporate such an automatic switch-off facility, such vessels being intended for use for example in the cooking of eggs or vegetables or the like and simply comprising a relatively low powered heating element adapted to maintain a generally predetermined amount ofwater at a simmering temperature without generation of excessive turbulence in the water.

It is considered that a requirement exists for a dual purpose electrically heated vessel which is operable selectively either as a steam-sensing, automatically switching-off vessel or alternatively as a continuously boiling vessel adapted for cooking vegetables or the like. It will be appreciatedthatthe known steam sensing, automatically switching-off vessel is not suited for this purpose since it will switch off automaticallyassoon as its contents boil.

According to the present invention an electrically heated vessel provided with a steam-sensitive, automatic element switch-off unit communicating with the interior of the vessel byway of a vent,tube or duct has associated therewith a liquid pervious basketortray adapted to be fitted within the vessel and retained in a predetermined position therein when the vessel is to be used in a continuous boiling mode, said basket or tray being arranged to co-operate with the vessel such that when the basket or tray is properly fitted within the vessel the said vent, tube or duct is obstructed and steam generated within the vessel cannot cause operation ofsaid elementswitch-offunit.

The invention thus provides the means whereby either automatic switch-off or continuous boiling can be selected as required by either omitting or flitting the basket or tray. The basket or tray might for example be formed with a tapered peg adapted to fit into and substantially seal the top end of a steam pipe or duct provided in or on the vessel when the basket or tray is fitted into the vessel, or alternatively where the vessel is simply provided with a vent in a side wall leading via a tube or duct to the element switch-off unit the basket ortray might simply have a portion adapted to close offsaid vent so as substantially to prevent the access of steam to the element switch-off unit.

In a presently preferred embodiment of the inven tionthe basketortray itself incorporates a steam duct designed so that when the basket or tray is in position in the vessel, the steam duct in the basket extends from a position in close proximity to the inlet end of the steam vent, tube or duct by means of which the element switch-off unit communicates with the vessel interior downwardly of the vessel to an open end spaced a predetermined distance above the bottom of the vessel. With such an arrangement and with water in the vessel to a level above the level of the bottom end ofthe steam duct in the basket ortray, the water in the vessel can itself prevent the access of steam to the steam duct in the basket ortray and thus in turn to the steam vent, tube or duct in the vessel leading to the automatic element switch-off unit.However, as the water level in the vessel falls with the escape of steam from the vessel as the water in the vessel boils, the bottom end ofthe steam duct in the basket ortraywill in time become open forthe access of steam so that the vessel element will automatically switch off. Fitted with such a basket ortray, the vessel could be used for cooking appropriate foods without risk ofthe vessel boiling dry and spoiling the food. Furthermore, the operation of the steam sensitive switch to prevent boiling dry of the vessel and consequent overheating ofthe vessel is valuable, particularly in the case where the body ofthe vessel is formed of synthetic plastics material, in avoiding the stressing ofthe element and vessel body which is associated with overheating.

Since the amount of water in the vessel will determine more or less precisely how long it will take to boil offsufficientwaterto uncoverthe bottom end oftheduct provided inthe basketortray, aform of cooking timer is obtained if water levels are marked on the basket or on the vessel so as to be visible to the user.Having filled the vessel to a selected level representative of a selected cooking time, either without the basket in the vessel in the case where the water levels are marked on the inside ofthe vessel or with the basket in the vessel in the case where the water levels are marked on the inside of the basket, the food to be cooked would be introduced; by means of this sequence of operations, the volume of the food would not affect the length oftimetaken for the water level to boil down to such an extent as to expose the bottom end ofthe duct in the basket.

The present invention will best be understood from consideration ofthefollowing description ofthe abovementioned presently preferred embodiment given with reference to the accompanying drawings wherein: Figure lisa schematic cross-sectional representation of water boiling vessel embodying the present invention; and Figure 2 is an exploded perspective view showing the vessel of Figure 1 with the basket and vessel lid shown separately.

Referring firstly to Figure 1, the vessel comprises a moulded plastics jug 1 fitted with a lid 2 and with an internal basket 3, the lid 2 and basket 3 also being formed for example of moulded plastics material. For illustration, food to be cooked is shown in the basket.

The electrically powered heating element of the jug is not illustrated in the drawings, but it will be seen that an aperture4 is provided fairly low down in the side wall of the vessel to receive a conventional element in conventional manner. The automatic steam-sensing element switch-off unit ofthe vessel is not shown either, but such units are well known in the art and it is considered to be beyond the ambit of this specification to describe such a unit. The unit could for example be in the form of the unit described in British Patent Specification 2 045 588A aforementioned and might be associated with an element protector unit, also well known in the art, designed to switch offthe supply of electrical power to the element in an overheating situation caused for example by switching on the vessel when empty.Such an element protector unit is described also in British Patent Specification No.

2 045 588A. The automatic steam-sensing element switch-off unit and its associated element protector unit could be accommodated in a housing 5 schemati cally represented in Figure 1, with steam arranged to be vented from the vessel interior through the vent 6 into the hollowjug handle 7 and thence obtain access to the steam-sensitive switch unit located in the housing 5, or alternatively the steam-sensitive switch unit could be housed in the recess 8 at the top of the handle 7.

Figure 2 shows the basket moulding 3 in more detail and as can be seen it is formed with an integral steam duct 9 which projects a certain distance beneath the bottom of the basket, is open at its bottom end, and has an orifice 10 at its top end arranged to register with the vent 6 in the rim ofthe jug. To ensure that the basket can be properlyfitted into the jug in one orientation only, a cut-out 11 in a skirt 12 depending from the base of the basket is arranged to locate with a support rib 13 formed in the jug 1.Afurthersupport rib 14 is provided opposite the rib 13 but its upper surface is at a lower level than that of the rib 13; if the basket 3 were to be inserted back to front, the lid 2 could not be properly fitted. Markings 15 within the basket 3 are intended to indicate approximate cooking times.

The jug is usable without the basketsimplyfor boiling water and will switch off automatically when the water boils. With the basket 3 properly inserted, the duct 9 formed in the basket effectively constitutes an extension ofthe steam duct provided in the jug for venting steam generated within the jug to the automatic steam-sensing element switch-off unit.

With water boiling in the jug art a level above the bottom end of the duct 9, the water itself serves to prevent steam from within the jug accessing the steam-sensing switch unit. When the water level in the jugfallsbelowthebottom end of the basket duct 9, steam will access the duct and thence will access the steam-sensitive switch unit so as to switch-off the heating element.

The bottom end of the duct 9 desirably should be arranged to locate above a relatively cool part ofthe element, for example above the element head, in orderto avoid the possibility of nuisance tripping of an overly sensitive steam-sensitive switch unit by a small amount of steam which might develop within the duct 9 were the bottom end of the duct 9 to be located closely above a relatively hot part of the element.

As previously mentioned herein, with the basket3 in the jug 1 the markings 15 provide a rough indication of cooking times, since the level to which the jug is filled will determine the time taken to boil down the water level to the level ofthe bottom end of the basket duct 9.

The food to be cooked, e.g. eggs, vegetables, cook-inthe-bag foods etc. should be introduced afterthejug has been filled to the desired level so thatthe volume ofthefood does notaffectthe cooking time.

The jug may if desired be provided with a manually operable switch operable for selecting either a highheat boiling operation ora lower-heatsimmeropera- tion.

Claims (5)

1. An electrically heated vessel provided with a steam-sensitive automatically-operating element switch-off unit communicating with the interior of the vessel by way of a vent, tube or duct for conveying steam generated within the vessel to the said unit for switching-off the vessel when water boils therewithin, the vessel furthermore having associated therewith a liquid pervious basket ortray adapted to be fitted within the vessel and retained in a predetermined position therein when the vessel is to be used in a continuous boiling mode, the said basket or tray being arranged to cooperate with the vessel in use thereof such thatwhenthe basketortray is properlyfitted within the vessel the said vent, tube or duct is obstructed and steam generated within the vessel cannot cause operation of said element switch-off unit.

2. Avessel according to claim 1 wherein the basket or tray itself incorporates a steam duct arranged so that when the basket or tray is in position in the vessel the steam duct in the basket extends from a position in close proximityto the steam inlet end of the said vent, tube or duct of the vessel downwardly of the vessel to an open end spaced a predetermined distance above the bottom of the vessel.

3. Avessel according to claim 2 wherein markings are provided in the basket ortray and/or in the vessel for indicating cooking times related to the time required to boil down the water level in the vessel from respective ones of said markings to the bottom end of the steam duct provided in the basket or tray.

4. Avessel according to any of the preceding claims which furthermore incorporates a unit designed to switch off the supply of electrical power to the heating element in the event of the element overheating for example on account ofthe vessel being switched on when empty.

5. An electrically heated vessel substantially as herein described with reference to the accompanying drawings.