HK1113296B - Egg cooking apparatus - Google Patents

Description

Egg cooking device

The present invention relates to an egg cooking apparatus and the like.

Boiling eggs is the traditional choice for breakfast. While egg boiling is relatively simple, it can also be a somewhat awkward and somewhat difficult task, requiring a pan, water, and cooking on a cooker with careful attention to the correct time. Therefore, various proposals have been made for automatically cooking eggs to a certain degree. The object of the present invention is to provide an improved apparatus for cooking eggs.

According to the present invention there is provided a cooking apparatus for a food product such as an egg, comprising a cradle for the food product containing electrical resistance means, and a control circuit for heating the resistance means.

Preferably the cradle comprises a flexible sheet means wrappable around the food item, preferably comprising a pair of half shell units mounted for opening and closing around the food item. Preferably, the half-shell units are of silicone elastomer with crimped resistance wire contained therein, and each half-shell unit is supported by a set of resilient fingers. Preferably, the control circuit comprises temperature sensing means adjacent the resistance means and means for setting the desired temperature and cooking time.

An egg cooking apparatus embodying the present invention will now be described, by way of example, with reference to the accompanying drawings, in which:

FIG. 1 is a perspective view of an apparatus;

figure 2 shows two half-shell heating units and a set of resilient fingers; and

fig. 3 shows a control circuit.

Referring to figure 1, the apparatus comprises a base 10 and a lid 11 hinged together at 12. The base 10 comprises a half-shell 13; the cover 11 comprises mating half-shells 14. The base also includes control circuitry (described with reference to fig. 3) and has various control knobs, switches and indicators 15 thereon.

Fig. 2 shows the half shells 13 and 14 in more detail. Each half shell is a piece of silicone elastomer (silicone elastomer) formed as a flat plate 20 having a half egg depression 21 therein (the depression in half shell 14 is inverted). Each recess has a nickel-chromium resistance wire 22 embedded in the elastomer; such resistance wires are generally in the form of a large spiral (which may conveniently be double-spiral, so that both ends can lie on the outer edges of the recesses), and are in the form of corrugations or serrations so that the half shells can be deformed when an egg is placed therein. The ends of the resistance wire terminate at contacts 23.

In use, an egg is placed in the recess of half shell 13 and half shell 14 is placed over the egg. In relaxation, the depressions 21 are slightly undersized relative to the size of the small eggs so that closing them onto the eggs causes them to expand to accommodate the eggs. Thus, the dimples can conform themselves to the shape of the egg, ensuring good thermal contact.

To assist in such shape conforming, the recess 21 may be supported by a gripping element 24 comprising a set of fingers 25. The element 24 is a flexible and resilient material. A spring (not shown) may be provided behind the center of the element 24 to urge the element 24 adjacent the egg. Preferably, the half-shell 14 is also equipped with a similar gripping element (not shown).

Fig. 3 shows the circuitry of the device in block form. The power supply unit 30 supplies power supply power to the circuit, and the power supply unit 30 converts the power supply voltage into a safe and appropriate value or values. The PSU 30 supplies power to a controller unit 31 that drives the resistance wire (heater element) 22. One or both of the recesses 21 also have a thermistor or other temperature sensor 35 embedded therein, which feeds signals to the controller unit 31.

The controller unit is fed with suitable control signals from the control elements 32-34. In a simple form there may be a single control 33 (in addition to the double control switch) which sets the cooking time, however, preferably element 32 is used to set the desired cooking time and element 34 is used to set the size of the egg. The signal from the egg size controller is used to adjust the actual cooking time according to the nominal value set by the controller 32 so that large or small eggs can be cooked for a slightly longer or shorter time than the time used for a standard egg. If desired, additional controls may be provided to set the desired cooking temperature. The controller may be a potentiometer, a multi-position switch, or a digital form each of which may be selected in turn by a suitable menu system.

The controller unit controls the current fed to the heater elements so that the egg is cooked in the desired manner. The time of cooking is set by the controller 33; typical times for boiling eggs are 3, 4 or 5 minutes. The bigger the egg, the longer the cooking time; the controller 32 allows the cooking time to be adjusted to automatically compensate for the size of the egg.

Alternatively, the rate of temperature rise at the start of cooking may be measured. The rate of heat generation is fixed, although the larger the egg, the greater the surface area of the egg will apply. Thus, large eggs heat more slowly than small eggs. Thus, the size of the egg can be estimated from the speed of temperature rise as measured by the sensor 35, and thus the cooking time can be automatically adjusted.

The sensor 35 also makes it possible to control the temperature of cooking to a desired level. In a simple system this level will be set to the temperature of boiling water, about 100 ℃, to match the effect of boiling eggs. However, if the temperature controller 34 is provided, the cooking temperature can be controlled; this enables the hardness of the yolk to be controlled relative to the hardness of the albumen. The controller unit either adjusts the level of the heater current or provides a pulsed current with a variable duty cycle.

When cooking is complete, the controller unit shuts off the heater current and sends a signal, here shown as being fed back to the alarm unit 36, which alarm unit 36 may conveniently generate an audible signal and/or may turn the indicator light on or off. The apparatus may also be arranged to open automatically or be arranged so that the cooked egg pops up or pops up, as in a pop-up toaster (pop-up toaster). For this purpose, a wire rack holder is preferably provided to hold the egg and to enable the egg to be lowered into and raised from the trough.

Means for weighing the eggs, connected to the controller unit, may also be provided, so that the cooking time can be automatically adjusted according to the weight of the eggs. If a wire rack fixture as described above is provided with strain gauges or other weight sensing units attached to the wire rack, it may be relatively easy to implement such an arrangement. Alternatively, the size of the egg may be measured.

Means may also be provided for sensing changes in the properties of the egg as it cooks, for example by sensing its light or ultrasonic propagation properties, and controlling the cooking time accordingly.

If desired, the apparatus may be provided with multiple cradles so that multiple eggs may be cooked at once. Preferably, each cradle has an independent control circuit so that different eggs can be cooked separately. A micro switch may be provided so that only the trough being used is powered.

Preferably, the controller unit activates the heater only when the cover is closed on the base. Alternatively, the on-off switch may be omitted by automatically initiating cooking with the lid closed. Preferably, means may be provided for detecting the presence of an egg in a cradle, so that only the cradle being used is powered (this function may be achieved by the weighing means, if provided).

Obviously, the present apparatus can be used to cook eggs in a manner entirely equivalent to cooking, without the need for a steamer and water, and without the need to pay attention to the time of the cooking operation. No lime scale is left after use and no cleaning is required. The apparatus is also faster because the time delay required to heat and boil the water is eliminated and for these reasons it uses less energy than traditional cooking. Furthermore, because the temperature can be set to various values, different cooking methods are provided, for example, by using a lower temperature, the egg can be efficiently poached (poach).

Claims (12)

1. Cooking apparatus for a food product, the apparatus comprising a cradle for the food product containing electrical resistance means (22), and a control circuit (31) for heating the resistance means, characterised in that the cooking apparatus comprises a recess arranged to close on the food product causing the recess to expand to accommodate the food product so as to conform to the shape of the food product, thereby ensuring good thermal contact.

2. Cooking apparatus according to claim 1, wherein the depression comprises flexible sheet means wrappable around the food product.

3. The cooking apparatus according to claim 2, wherein the cooking apparatus comprises a pair of half-shell units mounted for opening and closing around the food product.

4. Cooking apparatus according to claim 3, characterised in that the half-shell units are of silicone elastomer with crimped resistance wires contained therein, and each half-shell unit is supported by a set of resilient fingers (25).

5. Cooking apparatus according to any one of the preceding claims, wherein the depression is arranged to conform itself to the shape of an egg.

6. Cooking apparatus according to claim 4, wherein a gripping element (24) is provided comprising said set of resilient fingers (25) for supporting a recess, each gripping element (24) being made of a flexible and resilient material, said recess being arranged to conform itself to the shape of an egg.

7. Cooking apparatus according to any of claims 1-4 and 6, characterized in that the control circuit comprises temperature sensing means (34) adjacent to the resistance means, and means (15, 33) for setting a desired temperature and cooking time.

8. Cooking apparatus according to claim 5, comprising a controller (33) for setting the nominal cooking time.

9. Cooking apparatus according to claim 8, wherein the control circuit comprises a sensor for measuring a temperature rise rate in order to estimate the size of an egg and for automatically adjusting the nominal cooking time in dependence of the estimated egg size.

10. Cooking apparatus according to claim 5, wherein the control circuit comprises a sensor for measuring the temperature rise rate in order to estimate the size of the egg and for automatically adjusting the nominal cooking time depending on the estimated egg size.

11. Cooking apparatus according to claim 5, comprising several of said cradles, so as to be used for cooking several eggs at a time.

12. Cooking apparatus according to claim 1, 2 or 3, wherein a gripping element (24) comprising a set of resilient fingers (25) is provided for supporting the recess, each gripping element (24) being made of a flexible and resilient material.