GB2272362A

GB2272362A - Electric toasting machines

Info

Publication number: GB2272362A
Application number: GB9323243A
Authority: GB
Inventors: Julian Snell
Original assignee: GORT BARTEN LESLIE ALEXANDER; GORT BARTEN MAXIMILIAN; MILTON MARION ALEXANDRA
Current assignee: GORT BARTEN LESLIE ALEXANDER; GORT BARTEN MAXIMILIAN; MILTON MARION ALEXANDRA
Priority date: 1992-11-13
Filing date: 1993-11-11
Publication date: 1994-05-18
Also published as: GB9323243D0

Abstract

An electric toasting machine incorporates at least one heating element for toasting at least one side of a food product, the power supply for the at least one heating element being connected for control thereof to a timing circuit, wherein there is provided time booster means associated with the timing circuit actuable to increase the power energisation time of the at least one heating element in dependence at least in part and directly or indirectly on the temperature of the toasting machine. <IMAGE>

Description

ELECTRIC TOASTING MACHINES This invention relates to electric toasting machines of the kind designed and arranged for the toasting of bakery products such as slices of bread, sandwiches, bread buns, teacakes, crumpets and baps for example.

Toasting machines for this purpose commonly have radiant heating elements which are arranged to be set a short distance from one or both sides of the food product to be toasted, and commonly the degree of toasting is determined in dependence on the length of time the heating element or elements is or are energised.

A problem does result from such an arrangement in that the heating elements operate more efficiently and provide a satisfactory toasting operation quicker if the heating element has been recently used so that the toasting machine is still hot from previous usage, in comparison with the time taken for satisfactory toasting when the machine has not been used for some considerable period of time so that the machine has no or little retained heat from previous usage.

It is an object of the present invention to overcome or at least significantly reduce this problem in a simple and effective manner.

In accordance with the invention there is provided an electric toasting machine incorporating at least one heating element for toasting at least one side of a food product, the power supply for the at least one heating element being connected for control thereof to a timing circuit, wherein there is provided time booster means associated with the timing circuit actuable to increase the power energisation time of the at least one heating element in dependence at least in part and directly or indirectly on the temperature of the toasting machine.

In a preferred embodiment the time booster means is actuable in dependence on a predetermined time lapse from the immediately preceding operation of the toaster machine whilst continuously connected to a power source.

Additionally or in the alternative the time booster means may include means to monitor the toasting machine temperature and to increase the power energisation time directly in dependence thereon.

The toasting machine may be of the kind having a plurality of slots in its outer casing within which the food product to be toasted is placed, heating elements being disposed adjacent each side of the slots within the machine, and again may be of the kind where selectively some or all of the heating elements may be energised depending upon the toasting usage required at any given time. In such circumstances the time booster means for increasing the energising time for the heating elements to be used for a toasting operation may be in dependence on the lapsed time since the last usage of the particular element or elements concerned, or alternatively may be in dependence on the lapsed time subsequent to previous usage of the toasting machine as a whole.

The means for increasing toasting time may be actuated on initial connection to a power source, as well as being actuated, when connected to the power supply, upon lack of usage of heating elements for a given predetermined period of time.

The predetermined time period may be within the range of 15 seconds to 45 seconds.

The timing control may be by means of electronic circuitry, which may include a programmed microchip, in which case the time booster means may be a sub-circuit within the electronic circuitry.

With a toasting machine for toasting slices of bread, the means for increasing toasting time may be arranged to increase it for between 10 and 20 seconds within a timing cycle range of the order of a minimum of 30 seconds to a maximum of 300 seconds.

Directly increasing the power energisation time in dependence on the toasting machine temperature, using a thermistor, for example, may be such as to give up to a 30 second time increase with a toaster temperature between 30"C and 35"C.

In order that the invention may be more readily understood one embodiment thereof will now be described by way of example with reference to the accompanying drawings in which: Figure 1 is a schematic isometric view of a toaster incorporating the present invention; and Figure 2 is a functional diagram of the circuitry for the toaster of Figure 1.

Referring now to the drawings it will be seen that the toaster 1 is of a kind commonly used in domestic or commercial establishments and is provided with a main body casing 2, an end assembly 14 carrying within it a control circuit 3 for the power supply 5, 6 to sets of heating elements 7, 8 which are disposed within the main body of the toaster disposed (in known manner) adjacent each side of each of four vertical slots 9, 10, 11. 12 extending from four openings in the upper wall 13 of the main body of the toaster.

Before operation the toaster is connected to a power supply 15 and the toaster can then be operated.

The control is by means of a main control circuit 16 including a micro-controller chip. The arrangement is such that the banks of heating elements are divided into two 7, 8 for operation of, say, toast slots 9, 10 and 11, 12 respectively, and the timing cycle can be started by depressing one or other of two touch buttons 17, 18, interruption of the timing cycle being by means of further depression of any of the buttons. Button 17 corresponds to operation of just one bank of heating elements 7 for two slots 9, 10, and button 18 for operation of both banks of elements 7, 8 for all four slots 9, 10, 11, 12. A rotatable knob 19 is provided for varying the timing cycle in association with a potentiometer. The toasting timing can be from a minimum of 30 seconds to a maximum of 240 seconds.The arrangement again is such that if during a particular timing cycle, the set time is adjusted it takes effect immediately. On completion of the time of period, a sound signal may be given, followed by the deenergisation of the elements concerned, and an LED 20 which may be of green colour, is illuminated. Thereafter the toasted bread may be raised for removal by vertical movement of knob 25 in slot 26. It is to be noted that two LED indicators 21, 22, which may be of red colour, provide indication of whether one bank or both banks of the elements are energised.

The microchip arrangement may include a fault detection system and can be arranged to indicate by means of flashing LED 21, 22 should any particular heating element fail. Additionally the arrangement may enable the failure of a timing potentiometer to initiate flashing of a further LED 24, which again may be red. The arrangement may be such that the unit can operate during a fault condition, but in this case without using the time boost facility of the invention. The arrangement may be such that if the time cycle setting pot fails then operation of the unit will automatically operate on a 150 seconds set time.

Figure 2 illustrates schematically the operating circuit 3 of the toaster. The main control element comprises the microchip circuitry.16, which is subject to user controls and time adjustment, as well as controlling the numerous status indicators (all of which are designated by box 27) as described above. In addition the main control circuit (which operate at 5 volts) includes a time boosting sub-circuit 28 which allows for an extra 15 seconds to be added to the set time period in two circumstances. Firstly if the toasting machine has not been used since first being connected to a power source, and secondly if the machine has not been operated for 30 minutes.

The sub circuit 28 also allows an extra 20 second heating time if the temperature of the toaster drops below 32"C (as detected by a thermistor, not shown).

As previously explained this time boost facility automatically allows extra heat to be supplied to the elements carrying out the toasting operation to compensate for the low temperature of the machine when it has not been used for some time, or if it is cold for any other reason. The time boosting function will not come into operation if the unit has been used within the last 30 minutes. In addition the arrangement is such that even if power to the relevant banks of heating elements is cancelled when the time boost facility is functioning, this will not prevent the time boost functioning on the next operation of the toasting machine unless the heating elements have been operating for more than 15 seconds in the first instance.

The main control circuit, with its time boosting subcircuit, and subject to the user controls and time adjustment, activate a mains supply voltage eg 240, 220, 12 volt power control 29, which in turn supplies power to the banks of elements in accordance with the requirements of the main control.

By means of the invention we have provided a toasting machine where a low temperature of the machine is compensated by extra toasting time so as to provide, even during this toasting operation, satisfactory toasting function.

It is to be understood that the foregoing is merely exemplary of toasting machines in accordance with the invention and that modifications can readily be made thereto without departing from the true scope of the invention. Thus although the invention is particularly described in relation to one particular form of bread slice toaster, it can be readily adapted to time functional toasters for food stuffs of many different configurations and is equally applicable thereto.

Claims

1. An electric toasting machine incorporating at least one heating element for toasting at least one side of a food product, the power supply for the at least one heating element being connected for control thereof to a timing circuit, wherein there is provided time booster means associated with the timing circuit actuable to increase the power energisation time of the at least one heating element in dependence at least in part and directly or indirectly on the temperature of the toasting machine.

2. A toasting machine as claimed in claim 1 wherein the time booster means is actuable in dependence on the predetermined time lapse from the immediately preceding operation of the toaster machine whilst continuously connected to a power source.

3. A toasting machine as claimed in claim 1 or 2 wherein the time booster means includes means for monitoring the toaster machine temperature and for increasing the power energisation time directly in dependence thereon.

4. A toasting machine as claimed in any one of the preceding claims having a plurality of slots in its outer casing within which the food. product to be toasted is placed, heating elements disposed adjacent each side of the slots within the machine, and including means for selectively energising some or all of the heating elements in dependence of the toasting usage required, wherein the time booster means for increasing the energising time for the heating elements to be used for a toasting operation is arranged such as to be operable in dependence upon the lapsed time following the last usage of the particular element or elements concerned.

5. A toasting machine as claimed in any one of claims 1 to 3 having a plurality of slots in its outer casing within which the food product to be toasted is placed, heating elements disposed adjacent each side of the slots within the machine, and including means for selectively energising some or all of the heating elements in dependence of the toasting usage required, wherein the time booster means for increasing the energising time for the heating elements to be used for a toasting operation is arranged such as to be operable in dependence upon the lapsed time subsequent to a previous usage of the toasting machine as a whole.

6. A toasting machine as claimed in any one of the preceding claims wherein the means for increasing toasting time is arranged to be actuated on initial connection to a power source, in addition to being actuated, when connected to the power supply, upon lack of usage heating elements for a given predetermined period of time.

7. A toasting machine as claimed in any one of the preceding claims wherein the predetermined time period is within the range of 15 seconds to 45 seconds.

8. A toasting machine as claimed in any one of the preceding claims including electronic circuitry providing the timing control, which circuitry includes a programmed microchip, the time booster means being a sub-circuit within the electronic circuitry.

9. A toasting machine substantially as shown in and as hereinbefore described with reference to the accompanying drawings.