Temperature Friendly Kitchen Products

TECHNICAL FIELD

The present invention relates to kitchen products, for example plates, saucers, cups, mugs, baking trays and the like that are easy and safe to handle even when containing hot or cold foods or drinks.

By 'kitchen products', it is intended to include 'cookware', 'tableware', and 'dinnerware', and so forth.

In particular, the prior invention relates to such utensils that are temperature-controlled so that they are hand-friendly when their contents are hot.

These types of utensils are especially useful for vulnerable users including children and persons having, for example, disabilities such as impaired sight. Hot consumables can be potentially very dangerous for these users.

BACKGROUMD ART

It is known to make such utensils of plastics material, for example, styrene. An example of this type of container, a microwaveable saucer, is described in JP-A-07- 204088 as published in 1995. Whilst plastics utensils are safer than china ones, because they have relatively thermoinsulating characteristics, they are not aesthetically as pleasing to handle and they tend not to be thermally resilient enough for oven-ready baking purposes.

It is also known to use even more rigid materials, such as ceramics, metals or metals coated in ceramics, which may be ovenproof. Typically, however, oven gloves have to be used for removing them from traditional or microwave ovens. Thus, importantly, most such utensils do not enable hot contents to remain hot for significant durations, whilst concurrently permitting their handlable surfaces to be touched or held without protection.

It is therefore one aim of the present invention to provide kitchenware that can contain heated foods/drinks whilst at the same time being easy to hold and carry, and that is capable of maintaining the temperature of the heated contents for prolonged periods.

DISCLOSURE OF INVENTION

Thus, according to one aspect, the present invention provides a container for holding food/drink according to claim one.

The container's wall(s) have an outer section that can be easily handled despite the temperature of the contents.

The inner section of the wall(s), however, is able to contain and maintain the thermal nature of the contents.

As such, the inner section is constructed in layers of composite material, each layer having a different and specific composition compared to that the other layer(s).

The layering arrangement of the inner section provides a functionally graded (or gradient) material (FGM). As such, the principles for manufacturing different types of FGMs have recently (particularly since about 2002) become better understood and has been applied to specified materials in the fields of, for example, turbine engines, ballistics, space and air craft, and medicine.

In essence, FGMs allow the different beneficial properties of their individual constituent materials to be expressed together in the resultant products that are formed.

In one embodiment, the present invention provides a user-friendly plate having walls with sections containing varying amounts of ceramic material in combination with increasing levels of other materials, such as stainless steel. In this way the advantages of heat resistance, physical strength and varying thermoinsulating /conducting properties attributable to each constituent material can be combined in a synergistic manner.

The layering principle for such composite layers also reduces the likelihood of fracturing of the wall(s) and separation of individual layers from one another. This would otherwise tend to occur due to the relative extremes of heat conditions experienced by the product during and after cooking.

The differentiated and graded nature of the thermal properties of the materials helps to distribute heat in a more uniform gradient across the width of the walls.

Depending upon the precise temperatures used, such a plate can contain heated food for extended lengths of time, for example up to 45 minutes or so, before the plate becomes too hot to handle. At the same time the top layers of the plate get hot quickly, to help cook the contents, and cool down slowly, so as to keep the contents hotter for longer, without risk to the user.

Further advantageous features of the product of the invention are mentioned in the accompanying subsidiary claims.

The present invention will now be described in a further detail by way of the following examples as illustrated in the accompanying drawings, in which:

BRIEF DESCRIPTION OF DRAWINGS

Figure IA shows a cut-away schematic view of a plate according to one embodiment of the present invention;

Figure IB illustrates in greater detail the wall structure of the plate shown in Figure IA, specifically in a cross-sectional view along direction A-A' as depicted;

Figure 2A shows a side view of a plate according to one embodiment of the present invention; and

Figure 2B illustrates a plan view of the plate shown in Figure 2 A.

BEST MODE FOR CARRYING OUT THE INVENTION

The plate shown in Figure IA has side- 2a and base- 2b walls for containing food that may be either solid or liquid (for example, soup), as well as a rim 3 that can be3 grasped. The walls 2 comprise an inner section 4 and outer section 5, which are shown in greater detail in Figure IB.

Section 4 contains a plurality of layers, for example, the four layers shown in Figure IB.

Typically, section 5 comprises solely one or more thermoinsulating material(s). Layers 6, 7, 8 and 9 of section 4, however, usually comprise a composite of a plurality of materials having differing thermal characteristics, for example having some material of a thermoconductive nature and some material of a thermoinsulating nature.

In this way a functionally gradient material is used to form at least part of the walls 2 with a gradient 10 of increasing relative thermoconductivity towards the interior (food/drink containing part) of the plate.

In a specific embodiment, the composition of the layers is as follows:

- layer 6: 95% metal/ceramic composite; 5% ceramic

- layer 7: 90% metal/ceramic composite; 10% ceramic - layer 8: 85% metal/ceramic composite; 15% ceramic

- layer 9: 80% metal/ceramic composite; 20% ceramic

Stainless steel may be used as the metal and such a plate is suited for oven cooking. Other suitable metals can be used.

The ceramic material may comprise alumina (aluminium oxide).

Instead of a metal, zirconia (zirconium oxide) may be used to form the composite providing the majority percentage of the layers. Such a plate is suited to microwave cooking since the zirconia helps the layers to heat in the presence of microwaves.

On the base layer of the plate an optional small area of piezo-electric ceramic material may be present. When present this can act as a thermal sensor alarm that, on reaching a certain temperature, creates an electric signal in the ceramic in the form of a loud noise.

On the ήm of the plate an optional area of a different sensor material, such as a thermo- chromic, piezo-chromic or chromo-electric sensor material may be included. When the rim reaches the desired alarm level temperature, this type of sensor changes colour to provide a warning to help people with, for example, good sight and particularly those with impaired hearing.

The sensor can therefore act as a precautionary device to help alleviate any potential accidents should the plate be left in the oven for too prolonged a period of time and thus become too hot to touch. The sensors are typically triggered when the base layer temperature reaches an alarm level of approximately between 40 to 45 ⁰ C.

The letter 'O' can optionally be embossed on the underside of the bottom of the plate, so making it easier for users to distinguish it from other plates and to illustrate that it can be used for the 'O'ven.

In a preferred embodiment, shape of the plate is adapted to provide a steep-sided food holding part and a wide rim. This allows the plate to be easier to hold and to eat from, especially for those with dexterity and visual impairments.

Preferably, high-contrast colours are utilised in the plate design to enable the visually impaired to see the plate on the table, the food on the plate, and the cold rim from the central hot part. '

A raised internal lip 14 of the rim is added to the design to provide a tactile boundary defining where the cold rim ends and the hot ceramic starts. This is especially useful for the visually impaired.

As well as an upstanding lip 14 to the rim, the latter may also be provided with raised ridges 11 as a further guide for visually impaired users to help them to locate the lip 14.

The utensil need not be a plate, but the principles of construction can be extended to most products of tableware, dinnerware and kitchenware, thus examples of the utensil could include cups, mugs, saucers, bowls, cooking pots, baking trays and so forth.

In this way, the present invention provides a temperature-friendly plate or other such container that can be used safely for holding hot contents and/or for oven/microwave cooking of such contents, especially by vulnerable users.