Domestic cooking appliance

Abstract: A domestic appliance such as a deep fryer is provided with a lid assembly (3) that is itself configured, and interacts with a container (2) in which food is cooked and with an outer casing (1) for the container, so as to avoid the need for a seal between the lid assembly and the container. The lid assembly (3) comprises a spaced-apart inner liner (6) and external wall (5) and both are vented (7, 9) in regions overlying a central part of the container (2) so as to allow hot gases to escape from the container. The external wall (5) is further vented (10) in a region surrounding the first-mentioned vented region (9) therein, and the further vented region (10) communicates though a passage (12) with an entry (12a) for ambient air between the casing (1) and a downturned portion (4) of the lid assembly (5).

Description: This invention relates to domestic cooking appliances and finds particular, though not exclusive, application to deep fryers. It is conventional, in domestic deep fryers, to have a metallic bowl or tank in which oil or fat or some other medium is heated and into which food to be cooked can be suspended in a basket. The bowl is usually provided with a high-powered heating element, rated for example at 3kW, secured directly to the underside of its base to ensure efficient thermal transfer from the element to the oil or other cooking medium in the bowl. Typically, the bowl (and the attached heating element) is housed in an outer casing from which it can be removed for cleaning. The outer casing contains, or can have attached to it (removeably or otherwise), various electrical components, such as power supply interconnects, thermostats and thermal fuses, all of which can conveniently communicate with the bowl and/or the heating element in the manner described in our co-pending GB patent application No 9701039.1. The outer casing is closed by a lid which is preferably hinged and contains, at least over part of its area overlying the bowl, means such as louvres to permit hot gases created by the cooking process to escape to avoid the risk of a build up of pressure in the appliance. Typically, the hot gases are filtered or treated in some way as they exit the appliance through the lid, to reduce their grease and moisture content. Such a cooking appliance, as disclosed in the preamble of claim 1, is known from DE-U-9312133. It is conventional to fit a seal between the lid and the bowl for several reasons: (a) to reduce or prevent condensation, which collects on the side wall of the lid, from leaking out and running down the outside of the outer casing of the fryer, causing staining and discolouration; (b) to act as a thermal break between the top of the bowl and the lid; and (c) to resist the exit of hot gases from the body-to-lid interface. From the standpoint of economy, however, as well as convenience for the user, it is desirable to omit the aforementioned seal, and it is an object of this invention to provide an electrically-heated appliance, such as a deep fryer, with a lid assembly which performs all or at least a major part of the functions hereinbefore attributed to the seal, making such omission possible. According to the invention there is provided a domestic cooking appliance comprising a casing housing a container in which food is to be cooked, and a heater for said container, the casing having a lid overlying the container, wherein the lid comprises an external wall and an inner liner spaced therefrom, a region of said liner and a corresponding region of said external wall being vented to permit hot gases to escape from the container, characterised by the external wall of said lid being vented in a further region thereof, and by the provision of air passages allowing ambient air to enter between the casing and the lid and to exit through the further vented region of said external wall of the lid. In order that the invention may be clearly understood and readily carried into effect, one embodiment thereof will now be described, by way of example only, with reference to the accompanying drawing, the single figure of which shows a cross-sectional view through part of an appliance in accordance with one embodiment of the invention. Referring now to the drawing, part of the outer casing, or main body, of the appliance is shown at 1. The casing is conveniently formed of plastics material and will, of course, be configured as desired in accordance with the overall external appearance of the appliance. Part of the metal bowl is shown at 2, and a portion of the lid assembly which surmounts the appliance is shown generally at 3. The lid assembly 3 includes an outer component, of plastics material, which includes side wall portions such as that shown at 4, and a top face, forming the major part of the lid surface as shown in part at 5. The lid assembly contains a metallic liner 6 which, over the central region thereof (i.e. that overlying the central area of the bowl 2) is louvred or otherwise vented as shown at 7 to enable hot gases from the bowl to exit the appliance through a filter medium (not shown) retained in the area 8 and filter area vents, such as those shown at 9, in the top surface 5 of the lid assembly 3. Surrounding the filter area vents such as 9 are, in accordance with this embodiment of the invention, flue vents such as 10; a partitioning rib 11 separating the filter venting region from the flue venting region. It is highly preferable, for reasons that will be explained hereinafter, that the flue vents such as 10 are located closely proximate to the partitioning rib 11 and thus to the outermost of the filter vents 9. It will be seen that there is no seal between the bowl 2 and the liner 6 of the lid assembly 3. However, in order to address the issues identified as (a), (b), and (c) above, the lid assembly 3 is constructed so that there is an air passage 12 allowing cool air from outside of the appliance to be drawn into the appliance and mix with some of the hot gases generated therein. The passage 12 comprises a portion 12a between the sidewall 4 of the lid assembly 3 and the top region of the body part 1, a portion 12b between the outer periphery of the bowl 2 and the sidewall 4, and a portion 12c which constitutes a mixing region for the cool air from outside the appliance with hot gases passing between the top of the bowl 2 and the underside of the lid liner 6. The mixed air and hot gases then flow, optionally being diverted through a tortuous path by a rib member 13 (which can be omitted if desired), across the undersurface of the plastic lid part 5 to exit the appliance via the flue vent 10. The construction described ensures that, in at least the peripheral area of the lid assembly, which is that part likely to be grasped by a user of the appliance to open or close the lid, the undersurface thereof is not exposed to hot gases directly exiting the bowl 2. The gases which flow in that peripheral region have been cooled by their interaction with ambient air entering the appliance via passage 12 and thus the appliance exhibits so-called "cool wall" attributes in those areas of the lid which are likely to be touched by the user in normal operation of the appliance. The central part of the outer surface of the lid assembly, i.e. that containing the filter vents 9, will run hotter since the presence of the partitioning rib 11 prevents the cooler gases from mixing in that area, but there is no incentive for a user to touch or grasp the central region of the lid assembly, so this is of little consequence. It will be understood that the closer the flue vent 10 is located to the partitioning rib 11, the broader is the area of the lid assembly which is cooled by the flow of gases that have mixed with ambient air. Thus the flue vent 10 is, as mentioned previously, placed as close as convenient to the rib 11, and the latter is positioned as close as is convenient to the outermost of the filter vents 9. As mentioned previously, the outer rib 13 may be omitted altogether, or it may be made shorter and/or apertured or vented so as to cause some of the mixed gas and air to follow a less tortuous path than that indicated in the drawing. The primary function of the rib 13 is to prevent ingress of debris to the cavity between the lid and its metallic liner. The filter medium utilised in areas 8 can be of any convenient form, such as a mesh, active carbon or a slit plate designed to extract most of the moisture and oil in suspension. The construction and configuration of the appliance shown and described herein is such that there is no direct communication between the gases exiting via the flue vents 10 and those exiting via the filter vents 9 other than that which occurs within the bowl 2 and whatever communication may occur after venting from the appliance. A "curtain" of cooler gases from vents 10 thus surrounds the hotter gases exiting from vents 9.

Claims: A domestic cooking appliance comprising a casing (1) housing a container (2) in which food is to be cooked, and a heater for said container, the casing having a lid (3) overlying the container, wherein the lid comprises an external wall (5) and an inner liner (6) spaced therefrom, a region of said liner and a corresponding region of said external wall being vented (7,9) to permit hot gases to escape from the container, characterised by the external wall (5) of said lid (3) being vented in a further region thereof (10), and by the provision of air passages (12) allowing ambient air to enter between the casing (1) and the lid (3) and to exit through the further vented region (10) of said external wall (5) of the lid. An appliance according to Claim 1 characterised in that the vented region (7) of the liner (6) and the first mentioned vented region (9) of the external wall (5) of the lid (3) are disposed to overlie a central region of said container (2). An appliance according to Claim 2 characterised in that the further vented region (10) of said external wall (5) surrounds the first-mentioned vented region (9) of said external wall (5). An appliance according to any preceding claim characterised by the provision of a partitioning rib (11) extending across the space between said external wall (5) of the lid (3) and the inner liner (6) thereof and separating said further vented region (10) from the first-mentioned vented region (9) of said external wall (5). An appliance according to any preceding claim characterised in that filter material is disposed in a space (8) between the vented region (7) in said liner (6) and the first-mentioned vented region (9) of the external wall (5) of the lid (3). An appliance according to any preceding claim characterised in that the passage (12) comprises a first portion (12a) disposed between the casing (1) and a down-turned portion (4) of the lid (3) and a second portion (12b) disposed between the periphery of the container (2) and said down-turned lid portion (4). An appliance according to Claim 6 characterised in that said path (12) further includes a third portion (12c) providing a mixing region in which said ambient air can mix with hot gases exiting transversely into the passage (12) from the container (2) beneath the outer part of the inner lining (6). An appliance according to any preceding claim characterised by the provision of a further rib member (13) on the lid (3) and in the path from said passage (12) to the further vented region (10) of the external wall (5) of said lid (3). An appliance according to any preceding claim constituting a domestic deep fryer.

Inventors: GURNEY RUSSELL JOHN, TONG PAUL CHARLES, GURNEY, RUSSELL JOHN, TONG, PAUL CHARLES
Applicants: KENWOOD MARKS LTD, KENWOOD MARKS LIMITED
Application year: 1998
Main classification: A47J37
IPC codes: A47J37, A47J36