GB2337324A - Cooker - Google Patents

Abstract

A cooker comprises heat storage means (4) in thermal communication with at least one oven (preferably two, 6 and 8) and an electrically powered heater for supplying heat to the heat storage means (4). The ovens are intended to be maintained at a raised temperature, even when not in use. The oven temperatures are regulated by insulation material (10a and 10b) between the respective ovens and the heat storage means. The cooker may also include for each oven, a slidable liner (58) comprising a base plate (60), back plate and side plates (62). Each side plate includes a step (64) resting on rollers. Each oven door is downwardly-openable by means of two support rods (66).

Description

2337324 1 COOKER This invention relates to a cooker and more particularly

to a cooker suitable for cooking foodstuff.

Food cookers are widely used in both industrial and domestic kitchens. A conventional type of cooker includes one or more ovens which can be maintained substantially at a selected constant temperature by burning gas or by passing electric current through a resistive element.

Cookers of this type have several disadvantages. For is both electric and gas cookers of the type described above, when the oven (s) is/are not in use it is not economic to maintain them at a raised temperature.

Thus when it is desired to use one of the ovens, it is first necessary to raise its temperature up to the desired or required value. A significant amount of energy is needed, and essentially wasted, to provide this rise in temperature, with associated cost and 2 environmental implications. Furthermore, the time delay involved in this temperature rise can often be frustrating.

Another type of known cooker is the range cooker, for example an I'Aga 'm" or a 11Rayburn 1. In this type of cooker the heat source takes the form of fuel (e.g.

gas, oil or solid fuel such as coal or wood) which is burnt, with the hot exhaust gases from this combustion process being used to heat the various cooking components - typically two or more ovens and one or more hot-plates. Unlike the conventional cookers described above, the cooking components of a ranCre cooker are maintained at a raised temperature even when is they are not in use. This may be achieved by continuous combustion of the fuel or, in the case of oil or gas fired range cookers, the operation of the burner(s) may be intermittent and controlled by a thermostat.

Although this type of cooker does not suffer from the disadvantages associated with the required initial pre- 3 heating of the above described conventional cookers it does have several equally undesirable disadvantages. In particular, as the range cooker is continuously maintained at a raised temperature, the cost of running it is relatively high. The amount of fuel consumed by this continuous operation is also perceived as wasteful by some consumers and such cookers are generally not therefore seen as being environmentally friendly.

Another disadvantage of known types of cookers is that the oven (s) is/are usually positioned at an inconvenient height. For example, if the oven is situated at ground level, the cook has to crouch down to gain access to the oven, and then stand up to reach the working surface which is typically situated at waist level. Any hot items retrieved from the oven have to be lifted from ground level up to the work surface higher up which can be awkward, especially for the taller or less agile cook. If a hot item removed from the oven has to be put down very quickly, for example because it is too hot to hold, then this usually means that it is put on the floor which, unless 4 it is heat resistant, may be damaged. Ovens situated high up present the problem that hot items are removed from the oven at head/eye level which may be awkward and possibly dangerous due to, for example, spitting fat from cooking food being brought close to the cook's eyes.

The present invention aims to overcome or ameliorate at least some of the above identified problems by providing an electrically powered cooker having an oven which is intended to be maintained at a raised temperature even when not in use, yet which cooker is relatively economical to operate.

Accordingly, the present invention provides a cooker including at least one oven and a heat source for supplying heat to the oven(s), wherein the heat source includes heat storage means in thermal communication with the oven(s) and an electrically powered heater for supplying heat to the heat storage means, and wherein at least one oven is located, in use, above the heat storage means.

This configuration of the cooker allows more efficient thermal communication from the heat storage means upwards to the oven(s) compared with other possible configurations. Preferably all ovens are located directly above the heat storage means.

The location of the oven above the heat storage means additionally affords a particular ergonomical advantage over many conventional cookers (the ovens of which are usually near floor level), namely that the cook does not have to crouch down to floor level to access the oven. The heat storage means and oven can be arranged for the oven to be at any convenient height, typically with its base about twenty inches above floor level.

is Preferably, thermally insulating material is interposed between the oven(s) and the heat storage means, more preferably in the form of one or more layer(s) The insulation material is used to regulate the temperature of the respective oven(s) and desirably, where at least two ovens are present, to pr ovide that the ovens are at respectively different temperatures.

6 Most advantageously, the insulating material and/or its thickness and/or position is selected so as to achieve in use a desired temperature of the oven (s) In embodiments in which the invention includes more than one oven, the insulating material between each oven and the heat storage means may be different and/or of different thickness so that the operating temperatures of the ovens may differ.

Preferably, the temperature of the heat storage means is raised in use to a predetermined level which is selected in relation to the desired rate of heat supply to the oven(s).

is The invention encompasses cookers in which a thermostat control system is used to regulate the electrically powered heater to supply heat to the heat storage means so as to raise the temperature of the heat storage means to a predetermined temperature. The thermostat may, for example, measure the temperature of the heat storage means and/or the oven(s).

7 Any suitable electrically powered heater, for example those known in the context of electrical storage heaters, may be used to supply heat to the heat storage means.

The power of the electrically powered heater is preferably selected such that the heater is capable of supplying the desired amount of heat to the heat storage means, during the time period or periods for which mains electricity is supplied at a reduced cost.

is The heat storage means is capable of receiving heat for a first time period (e.g. for one part of the day or night) and subsequently discharging that heat over a second time period (e.g. later in the day or night).

In use, the heat storage means of a cooker according to the invention can preferably be heated up during offpeak charging periods (e.g. overnight) by the electrically powered heater, thus taking advantage of the lower rate of charging for electricity consumed during that period. The heat storage means 8 subsequently gradually releases this stored heat (e.g.

during the following day) so as to continuously maintain the oven(s) at a raised temperature.

Consequently, the oven(s) do not require pre-heating prior to use, thereby avoiding the associated energy wastage and time delay. Additionally, since the cooker can operate using electricity consumed during a period of reduced charge, the cost of running it is potentially low as compared with many conventional cookers.

The heat storage means is preferably also capable of simultaneously receiving and discharging heat, without substantially affecting the temperature of the oven(s) Consequently the heat storage means can for example receive heat while the cooker is in use, with no substantial adverse effect on the -temperature of the oven(s).

In some practical embodiments of the cooker of the invention, the heat storage means may be storage heater-type blocks or bricks or any other suitable heat 9 storage medium or device, examples of which are used in electric storage heaters.

The physical properties of the heat storage means, such as its heat capacity, its surface area adjacent the ovens and its heat transfer properties can all be selected in relation to the desired rate of heat supply to the oven(s).

Preferably, the cooker of the present invention includes a plurality of ovens (preferably two), which may be located side by side. Advantageously, each oven is maintained at a different temperature by providing layers of insulating material having e.g. different is levels of thermal conductivity or thickness between each oven and the heat storage means. In such cookers, the temperatures of adjacent ovens may be maintained substantially independent of each other by interposing therebetween a water filled container (a "water jacket,'), which is desirably connected to a cold water supply.

The oven(s) may contain a sliding liner. The liner includes at least a base portion for supporting food/articles in the oven and may also include side and back portions. Preferably, the liner is fabricated from thermally conductive material.

The liner is slidable relative to the oven interior and may be provided with means coupling it to the oven door so that by opening the oven door the liner is drawn at least part-way out of the oven. This feature means that the user can e.g. retrieve food from the oven without placing his hands in the oven. Preferably means are provided for restraining the liner from sliding entirely out of the oven. The coupling means is preferably act so that by closing the door the liner is pushed back into the oven.

Means for coupling the liner to the oven door may include an elongate element attached at one end to the door and at its other end to the liner. Preferred points of attachment are near an edge of the door and to a side plate of the liner. The elongate element is 11 preferably pivotally attached to both the liner and the door respectively.

The oven doors may be attached to the cooker by conventional hinges. Preferably, however, the oven door is borne on at least one support member, which is attached at one end to the cooker near an edge of the oven opening (preferably the bottom edge), and attached at its other end to the door near the opposite edge (i.e. preferably the top edge). Viewed in profile, the front face of the cooker, the support member and the door can be considered to the support member being the cooker and the door is left uprights of the "N" be arranged in an "N" shape, the diagonal, and the front of respectively being right and The support member is pivotable about the attachments, so that the door can swing away from the oven opening with the "outer" surface (i.e. the surface which faces outwards from the cooker when the door is closed) remaining facing generally outwards. Effectively the "N" shape is straightened out, by opening up the angle 12 at each end of the diagonal. This feature reduces the likelihood of a user being burned by contact with the inner surf ace of an open oven door.

is For stability, the door is preferably attached to the oven by means of two parallel support members, e.g. one at each side of the door.

With swinging doors as described above, means may be provided for ensuring that the free edge of the door (i.e. the edge opposite that near which the support members are attached) is securely closable. Such means may include a flexible tie (e.g. a metal rope) attached at one end to the door, preferably near the free edge, and at the other to the liner. Thus as the door is closed and the liner returns to the oven, tension is generated in the tie, thereby closing the free edge of the door against the cooker. Preferably two ties are provided, one at each end of the free edge.

Preferred cookers of the present invention also include an electric hob or hobs. These are preferably heated 13 independently from the ovens, by separate electric elements. More preferably, at least two hobs are provided, which when supplied with electric current are heated to different fixed temperatures, e.g. for gentle warming and rapid heating of pans placed thereupon.

A particularly preferred embodiment of the cooker of the present invention will now be described in detail, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 is a part sectioned perspective view of an embodiment of a cooker according to the present invention showing the rear of the cooker; Figure 2 is a perspective view of the cooker of Figure 1 showing the front of the cooker; Figure 3 is a top view of the cooker of Figures 1 and 2.

A practical embodiment of a cooker according to the present invention is illustrated in Figure 1. The 14 cooker 1 includes a housing 2 which contains a heat source comprising a stack of heat storage bricks 4 which can be heated up by a thermostatically controlled, electrically powered heater (not shown), which is disposed within the stack of bricks 4. The heater includes electric elements of the type used in conventional electric storage heaters.

Advantageously, the stack of heat storage bricks 4 can be heated up by the electrically powered heater during off-peak charging periods (e.g. overnight), thus taking advantage of any lower rate of charging for electricity consumed during that period. The heat content of the bricks can be boosted if required (e.g. during the day is between overnight off-peak charging periods), preferably during daytime off-peak charging periods if available, with no adverse affect on the temperature of ovens 6, 8. The heat storage bricks 4 gradually release this stored heat, so as to continuously maintain each oven of the cooker 1 at a raised temperature.

is The cooker 1 includes a first, baking, oven 6 and a second, roasting, oven 8, the interiors of both of which can be accessed via respective doors 52 in the ovens 6 and 8. The doors are insulated (shown at 56).

is As shown in Figure 2, inside each oven is a lining member 58 (termed a plunging liner) which includes a base plate 60 attached to a back plate (not shown) and side plates 62. Between the base plate and each side plate is a step 64, which provides a downwardly-facing surface 63, set higher than the remainder of the base plate 60. This surface may rest on rollers (not shown) set in the sides or base of the oven, to allow the liner to slide in and out of the oven. A back stop (not shown) may be provided to prevent the liner from sliding entirely out of the oven.

Each oven door is attached to the cooker by means of two support rods 66, each pivotally attached to the door near a top corner and to the cooker near a corresponding bottom corner of the oven opening. The door opens by swinging downwards on these support rods, 16 with the bottom edge of the door dropping away from the oven opening and with the handle 68 remaining facing generally outwards from the front of the cooker.

Coupling bars 70 link each oven door 52 to its corresponding liner 58. Each coupling bar is pivotally attached at one end to the door near a top corner and at the other to the liner near the rear end of a corresponding side plate 62. Thus, as a door is opened and swings downwards on the support rods 66, the coupling bars 70 pull the liner outwards from the oven, and vice versa for door closure.

A flexible tie 72 (e.g. a metal rope) runs between a is point near the bottom edge of the door and a point on or near the bottom of the base plate of the liner. The tie is of a suitable length so that when the door is closed, tension in the cable draws the bottom of the door securely against the front of the oven.

Optionally, two such ties may be provided, one at each bottom corner of the door.

17 When the oven door is opened and the liner slides out, at least part of the liner is stably supported (for example at the inner end of the liner) so that the liner as a whole provides a stable element on which foodstuffs/crockery may be supported.

Returning now to Figure 1, the ovens 6, 8 are disposed above the stack of heat storage bricks 4, from which they are partially insulated by a layer of insulating material 10. The thickness of the insulating material 10a interposed between the heat storage bricks 4 and the baking oven 6 is greater than that lob interposed between the heat storage bricks 4 and the roasting oven 8. In this way, when the cooker 2 is operating, less heat is conducted from the heat storage bricks 4 to the baking oven 6 than to the roasting oven 8, which is therefore maintained at a higher temperature than the baking oven 6. The two ovens 6 and 8 are thermally insulated from each other by a water-filled container 12 (or "water jacket,') interposed between the two ovens. This limits the heat transfer from one oven to the other so the temperature of each oven is maintained 18 substantially independent of the temperature of the other. The water jacket could be supplied with cold water from e.g. a mains water supply.

Shown in Figure 3, the top 80 of the cooker is provided with hobs 82, 83, which when switched on are heated by electric elements (not shown) to different set temperatures. Hob 83 is split into two portions 84, 86, each set to a different temperature.

Accordingly, the temperature at which a foodstuff is cooked (e.g. in a pan) can be controlled by placing the pan on the appropriate hob.

is The above embodiments of the present invention have been described by way of example only and various alternative features or modifications from what has been described can be made within the scope of the invention, as will be readily apparent to persons skilled in the art.

1,1

Claims (8)

CLAIMS:

1. A cooker including at least one oven and a heat source for supplying heat to the oven, wherein the heat source includes heat storage means in thermal communication with the oven and an electrically powered heater for supplying heat to the heat storage means, and wherein the oven is located in use above the heat storage means.

2. A cooker according to claim 1 in which the heat storage means is capable of receiving heat over a first time period and subsequently discharging the heat over is a second time period.

3. A cooker according to either-one of the preceding claims in which the heat storage means are storage heater-type blocks. 71

4. A cooker according to any one of the above claims in which the temperature of a first oven is set at a 2C lower value than a second oven by providing a thicker layer of insulating material interposed between the first oven and the heat storage means than is interposed between the second oven and the heat storage means.

5. A cooker according to any of the above claims wherein at least one oven has a liner slidable in and out of the oven.

6. A cooker according to claim 5 wherein the liner has a base portion, and forms and enclosure with side and back walls.

7. A cooker according to claim 5 or claim 6 wherein the liner is connected or connectable to a door of the oven so as in use to slide outwards from the oven when the door is opened.

8. A cooker substantially as any one embodiment herein described, with reference to, and as illustrated in, any of the accompanying drawings.