WO2003013329A1

WO2003013329A1 - Bread toasting appliance

Info

Publication number: WO2003013329A1
Application number: PCT/IL2002/000644
Authority: WO
Inventors: Shimon Dotan; Offer Alexander Parezky
Original assignee: HOMECARE TECH PRODUCTS Ltd
Current assignee: HOMECARE TECH PRODUCTS Ltd
Priority date: 2001-08-11
Filing date: 2002-08-06
Publication date: 2003-02-20
Anticipated expiration: 2004-02-11

Abstract

A bread toasting appliance, includes: a pop-up stand (10) initially in an upper position for loading a bread slice thereon, depressible to a lower position for toasting the bread slice, and returnable to the upper position for removing the bread slice after having been toasted; electrical heating devices (5) on opposite sides of the pop-up stand for toasting a bread slice thereon; a plurality of manual control devices (30) including a device for specifying the degree of toasting of the bread slice on the pop-up stand; and a control system controlled by the manual control devices and the pop-up stand, effective: (a) upon the first depression of the pop-up stand, to fully energize the electrical heating devices to a toasting temperature for a full toasting time period to toast the bread slice on the pop-up stand to the specified degree of toasting; and then to return the pop-up stand to its upper position, and to partially de-energize the electrical heating devices to a stand-by temperature lower than the toasting temperature; (b) upon each subsequent depression of the pop-up stand to fully energize the electrical heating devices to the toasting temperature for a reduced toasting time period to toast the bread slice on the pop-up stand to the specified degree of toasting; and then to return the pop-up stand to its upper position, and to partially de-energize the electrical heating devices to the stand-by temperature; (c) and upon the expiration of a predetermined idle time period during which the pop-up stand was not depressed to completely de-energize the electrical heating devices.

Description

BREAD TOASTING APPLIANCE

FIELD AND BACKGROUND OF THE INVENTION

The present invention relates to bread toasting appliances, and particularly to an appliance which enables a succession of bread slices to be toasted in a relatively short period of time.

In the conventional bread toasting appliances a batch of one or more bread slices is simultaneously toasted by electrical heating devices which are energized at the beginning of the toasting operation and de-energized at the completion of the toasting operation. This means that the electrical heating devices tend to cool between toasting operations and therefore must be re-heated to the toasting temperature at the begim ing of each subsequent toasting operation. The toasting time for toasting one or more bread slices in each batch must therefore include the time required to re-heat the electrical heating devices to the toasting temperature.

In addition, bread slices to be toasted are now frequently frozen to preserve their freshness. Many toasters include a color sensor which senses the color condition of the toasted bread to terminate the toasting operation; the operation of such toasters, therefore, is not affected when the bread slice is frozen. Other toasters, however, merely terminate the toasting operation after the elapse of a predetermined time period according to the desired degree of toasting. In the latter type of toasters, the time required for toasting of a frozen bread slice is not the same as that of an unfrozen bread slice, and therefore the desired degree of toasting will not be produced when toasting a frozen bread slice as compared to that when toasting an unfrozen bread slice.

OBJECTS AND BRIEF SUMMARY OF THE INVENTION

An object of the present invention is to provide a bread toasting appliance having improvements in one or more of the above respects. More particularly, one object of the invention is to provide a bread toasting appliance which reduces the toasting time required for toasting successive batches of bread slices. Another object of the invention is to provide a bread toasting appliance which may be controlled to produce the desired degree of toasting whether the bread slice to be toasted is frozen or unfrozen. According to one aspect of the present invention, there is provided a bread toasting appliance, comprising: a pop-up stand initially in an upper position for loading a bread slice thereon, depressible to a lower position for toasting the bread slice, and returnable to the upper position for removing the bread slice after having been toasted; electrical heating devices on opposite sides of the pop-up stand for toasting a bread slice thereon; a plurality of manual control devices including a device for specifying the degree of toasting of the bread slice on the pop-up stand; and a control system controlled by the manual control devices and the pop-up stand, effective: (a) upon the first depression of the pop-up stand, to fully energize the electrical heating devices to a toasting temperature for a full toasting time period to toast the bread slice on the pop-up stand to the specified degree of toasting; and then to return the pop-up stand to its upper position, and to partially de-energize the electrical heating devices to a stand-by temperature lower than the toasting temperature; (b) upon each subsequent depression of the pop-up stand to fully energize the electrical heating devices to the toasting temperature for a reduced toasting time period to toast the bread slice on the pop-up stand to the specified degree of toasting; and then to return the pop-up stand to its upper position, and to partially de-energize the electrical heating devices to the stand-by temperature; (c) and upon the expiration of a predetermined idle time period during which the pop-up stand was not depressed to completely de-energize the electrical heating devices. According to further features in the preferred embodiments of the invention described below, the manual control device for specifying the degree of toasting of the bread slice on the pop-up stand includes a darkness indicator for specifying the desired toast darkness to be produced in the respective bread slice as a result of the toasting thereof. In the described preferred embodiments, the control system fixes the full toasting time period and the reduced toasting time period according to the specified toast darkness for the respective bread slice.

According to a further feature in one described preferred embodiment, the manual control devices further include a Defrost Selector for selecting a defrost operation to be performed on the bread slice to be toasted; and the control system is effective, upon selecting a Defrost Operation, to add a predetermined additional time period to the respective toasting period. According to another aspect of the present invention, there is provided, a bread toasting appliance, comprising: a pop-up stand initially in an upper position for loading a bread slice thereon, depressible to a lower position for toasting the bread slice, and returnable to the upper position for removing the bread slice after having been toasted; electrical heating devices on opposite sides of the pop-up stand for toasting a bread slice thereon; a plurality of manual control devices including a device for specifying the degree of toasting of the bread slice on the pop-up stand, and a device for selecting a defrost operation to be performed on the bread slice to be toasted; and a control system controlled by the manual control devices and the pop-up stand for energizing the electrical heating devices for a predetermined toasting time period according to the specified degree of toasting for the respective bread slice; the control system also being effective, upon selecting a defrost operation, to add a predetermined additional time period to the predetermined toasting time period for the respective bread slice.

In the described preferred embodiments, the predetermined additional time period during a defrost operation may be within the range of 2 - 10 seconds, preferably 4 seconds; and the predetermined idle time period for completely de-energizing the electrical heating devices may be within the range of 5 - 15 minutes, preferably 10 minutes.

As will be described more particularly below, bread toasting appliances constructed in accordance with the foregoing features enable successive batches of bread slices to be more quickly toasted, and also enable the toasting of each batch to be more closely controlled to produce the desired degree of toasting with respect to both frozen bread slices as well as unfrozen bread slices. In addition, such toasting appliances do not require color detectors, and therefore may be constructed less expensively than the toasting appliances including such color sensors, although it will be appreciated that features of the invention, such as the partial de-energization of the electrical heating devices between batches of toast, could also be used with toasters having color sensors.

Further features and advantages of the invention will be apparent from the description below. BRIEF DESCRIPTION OF THE DRAWINGS

The invention is herein described, by way of example only, with reference to the accompanying drawings, wherein:

Fig. 1 schematically illustrates the main components of one form of bread toasting appliance constructed in accordance with the present invention;

Figs. 2 and 3 are side elevational views of the appliance of Fig. 1 in two different positions of the pop-up stand receiving the bread slice to be toasted;

Fig. 4 illustrates the control panel in the appliance of Fig. 1;

Fig. 5 is a view similar to that of Fig. 1 but illustrating another form of bread toasting appliance in accordance with the present invention;

Fig. 6 illustrates a modification in the control panel of Fig. 5;

Fig. 7 is a block diagram illustrating the overall electrical system in the appliance of Fig. 1 including the control panel of Fig. 6; and

Fig. 8 is a flow chart illustrating the operation of the appliance of Fig. 1 including the control panel of Fig. 6.

It is to be understood that the foregoing drawings, and the description below, are provided primarily for purposes of facilitating understanding the conceptual aspects of the invention and various possible embodiments thereof, including what is presently considered to be a preferred embodiment. In the interest of clarity and brevity, no attempt is made to provide more details than necessary to enable one skilled in the art, using routine skill and design, to understand and practice the described invention. It is to be further understood that the embodiments described are for purposes of example only, and that the invention is capable of being embodied in other forms and applications than described herein.

DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

For purposes of example, the invention is described below with respect to the pop-up type electrical toasting appliance described in International Application No. PCT/ILOO/00020, published 20 July 2000 as International Publication No. WO 00/41606, the contents of which are incorporated herein by reference. It will be appreciated, however, that the invention could be implemented in other types of bread toasting appliances.

The toasting appliance illustrated in Figs. 1 - 3 includes a housing, generally designated 2, defining a vertically-extending toasting compartment 3 for receiving a slice of bread 4 (Figs. 2, 3,) to be toasted. Toasting compartment 3 is straddled on its opposite sides by a pair of electrical heating devices 5. As shown particularly in Fig. 1, each of the electrical heating devices 5 includes a mounting plate 6 formed at its opposite ends with in-turned flanges 7 and mounting a heat-resistant plate 8 carrying an electrical heating element 9 on the inner face of the heat-resistant plate facing the toasting compartment 3. In the construction illustrated in Fig. 1, the electrical heating element 9 is in the form an elongated heater wire wound in serpentine fashion to cover substantially the complete inner face of the heat-resistant plate 8. Fig. 5 illustrates a variation wherein the electrical heating element, therein designated 9', is in the form of a plurality of heater lamps, such as halogen lamps, extending across the inner face of the heat-resistant plate 8. The illustrated appliance further includes a pop-up stand 10 located within the toasting compartment for receiving a slice of bread 4 (Figs. 2, 3) to be toasted on its opposite sides by the two electrical heating devices 5. Pop-up stand 10 is normally in an upper position (Fig. 3) for loading a bread slice thereon and is manually depressible to a lower position (Fig. 2) for toasting the bread slice. After the bread slice has been toasted, stand 10 is returnable to the upper position (Fig. 3) for removing the bread slice.

Pop-up stand 10 is coupled by a coupling mechanism to the electrical heating devices 5 to move the heating devices towards the bread slice on the pop-up stand when the stand is moved to its lower position and thereby to speed-up the toasting of the bread slice. When the stand is moved to its upper position, it is moved away from the bread slice to permit unloading the toasted bread slice and the loading of another bread slice to be toasted.

Thus, as shown particularly in Figs. 2 and 3, the pop-up stand 10 is mounted to the appliance by a mounting member 11 which is urged to its upper position by a spring 12. When the pop-up stand 10 has been manually depressed to its lower position (Fig. 2), it is retained by a latch element 13 received within a notch 14 in the mounting member 11. After the toasting of the respective bread slice has been completed as will be described more particularly below, an electromagnet 15 is energized to withdraw latch element 13 from notch 14, and thereby to permit spring 12 to return the pop-up stand 10 to its initial, upper position, as shown in Fig. 3.

The illustrated appliance further includes an electrical switch, schematically shown at 16, which is actuated when the pop-up stand 10 is in its lower position. The actuation of switch 16 by the depression of the pop-up stand 10 starts a toasting operation.

The toasting operation is terminated when electromagnet 15 is energized to release the pop-up stand 10 to its upper position.

Figs. 2 and 3 also illustrate the coupling mechanism coupling the pop-up stand 10 to the electrical heating devices 5 to move the latter devices towards a bread slice on the stand when the stand is moved to its lower position, and away from the bread slice when the stand is in its upper position. Such a coupling mechanism includes a bell crank lever 20 for each of the electrical heating devices 5. Each bell crank lever 20 includes a first arm 21 coupled by a pivotal coupling 22 to the respective electrical heating device 5, and a second arm 23 normally engageable with a platform 24 underlying the pop-up stand

10 receiving the bread slice 4. Each bell crank lever 20 is pivotally mounted to the juncture 25 of the two arms 21, 23, and is urged by a piano spring 26 in the direction to move its respective electrical heating device 5 towards the bread slice being toasted, but not into direct contact with the bread slice, when the pop-up stand 10 is in its lower position. For example, the appliance could include stops, schematically shown at 27, engageable with the heating devices 5, for defining a small space between the electrical heating devices 5 and the respective side of the bread slice 4, when the pop-up stand 10 is in its lower position.

Preferably, platform 24 underlying the pop-up stand 10 is mounted on springs 28 to absorb the shocks when the bell crank levers 20 are pivoted by the downward movement of the pop-up stand 10 to the position shown in Fig. 2.

Fig. 4 illustrates a control panel, generally designated 30, for the illustrated toasting appliance. Such a control panel is provided with a presettable timing device, generally designated 31, for presetting an operative period of operation of the appliance for purposes to be described more particularly below. Timing device 31 includes an Up-button 31a, a Down-button 31b, and a display 31c for displaying the presetted operative period.

Control panel 30 further includes presettable darkness buttons 32a, 32b, 32c for presetting the degree of toasting desired. The control panel further includes an On switch 33 and an Off-button 34 for turning-on and tuming-off the appliance, and thereby for also fixing the operative period of operation of the appliance. The control panel further includes a light indicator 35 which indicates the status of the appliance with respect to its operative period.

The illustrated appliance involves two types of operations: a Stand-By Operation, during which the electrical heating devices 5 are only partially energized; and a toasting operation, during which the electrical heating devices 5 are fully energized. As will be described more particularly below, the control system is controlled by the manual control devices on the control panel 30, and also by the pop-up stand 10, so as to be effective: (a) upon the first depression of the pop-up stand, to fully energize the electrical heating devices to a toasting temperature for a full toasting time period to toast the bread slice on the pop-up stand to the specified degree of toasting; and then to return the pop-up stand to its upper position, and to partially de-energize the electrical heating devices to a stand-by temperature lower than the toasting temperature; (b) upon each subsequent depression of the pop-up stand to fully energize the electrical heating devices to the toasting temperature for a reduced toasting time period to toast the bread slice on the pop-up stand to the specified degree of toasting; and then to return the pop-up stand to its upper position, and to partially de-energize the electrical heating devices to the stand-by temperature; (c) and upon the expiration of a predetermined idle time period during which the pop-up stand was not depressed to completely de-energize the electrical heating devices.

When the appliance includes the control panel illustrated in Fig. 4, the toasting period is determined by the darkness buttons 32a - 32c which had been depressed at the beginning of the toasting operation. The light indicator 35 is energized at the beginning of the operative period and remains energized until the end of the operative period, that is, until the end of the predetermined idle time period during which the pop-up stand was not depressed. As indicated earlier, the end of the opposite period results in the complete de-energization of the electrical heating devices.

The predetermined idle time period for completely de-energizing the electrical heating devices is preferably within the range of 5 - 15 minutes, preferably about 10 minutes.

It will also be appreciated that the operative period can be terminated whenever desired by depressing the Off-button 34.

Fig. 6 illustrates another control panel which may be used in the toasting appliance. The control panel illustrated in Fig. 6, therein generally designated 40, includes an On-switch 41 which is depressed to start the operative period, an Off-button 42 which may be used to terminate the operative period, and a light indicator 43 which is energized at the beginning of the operative period and remains energized until the end of the operative period. The operative period, as described above, includes two operations, namely: a Stand-By Operation, during which the electrical heating devices 5 are partially energized to a stand-by temperature; and a toasting operation, during which the electrical heating devices are fully energized to the toasting temperature.

In the control panel 40 illustrated in Fig. 6, the degree of toasting is specified by a rotary knob 44. This permits a wide variation of toasting conditions to be selected, from very light to very dark.

Control panel 40 illustrated in Fig. 6 further includes a Defrost button 45, and a light indicator 46 to indicate when the Defrost button is depressed. Defrost button 45 would be depressed when the bread slice to be toasted is frozen. The depression of the

Defrost button adds a predetermined period of time to the toasting operation to allow for defrosting of the bread slice.

Fig. 7 is a simplified block diagram illustrating the control system included in the appliance. The illustrated control system includes a microprocessor 50 having inputs from the On-switch 41, the Off-button 42, the toast darkness knob 43, and the Defrost button 44. In addition, it has an input from the pop-up stand switch 16, which is actuated when the stand is in its lower position as illustrated in Fig. 2. Microprocessor 50 includes an output to the electrical heating devices 5 to control their full or partial energization, as will be described more particularly below. It also includes an output to the electromagnet 13 which, as briefly described above, is energized to release the pop-up stand 10 to its upper position at the end of a toasting operation.

Microprocessor 50 may be of a standard construction and includes, among other components, a real time clock RTC 51, which is involved in the various operations as described more particularly below.

Fig. 8 is a flow chart illustrating a typical operation of the appliance including the control panel of Fig. 6.

Thus, as shown in Fig. 8, the operation of the appliance starts with the depression of the On-switch 41 (block 60). When the pop-up stand 10 is manually depressed for toasting the first batch (e.g., two) of bread slices (block 61), the timer is started (block 62). The system then checks to see whether the toast darkness has been inputted, e.g., by darkness knob 44 in Fig. 6 or darkness buttons 32a - 32c in Fig. 4 (block 63). If the toast darkness has been inputted, the system inputs the toasting time for the specified darkness (block 64); but if the toast darkness has not been inputted, the system inputs the toasting time for medium darkness (65).

The system then checks to determine whether the Defrost button 45 has been depressed (block 66); if so, it adds the additional defrost time to the toasting time (block 67).

The system then fully energizes the electrical heaters (block 68), and retains them energized until the specified toasting time has been reached (block 69). At that time, the system releases the pop-up stand 10, to permit the use to remove the toasted bread slices, and only partially de-energizes the electrical heaters (block 70). The system then stands idle, but with the electrical heaters partially energized, until one of three events occurs: (1) the predetermined idle time period runs out; (2) the Off-button 42 is depressed; or (3) the pop-up stand is again pressed down. If the predetermined idle time period runs out (block 71), or if the Off-button 42 is depressed (block 72), the electrical heaters are fully de-energized (block 73), and the operation of the system terminates. On the other hand, if neither of these occurs, the system waits until the stand is then pressed down (block 61), whereupon it begins a new cycle of toasting bread slices, which cycle repeats until either the predetermined idle time period runs out or the Off-button 42 is depressed. However, in each such subsequent cycle, the "toasting time" of block 69, will be a reduced time interval, as compared to the first cycle, since the electrical heaters remained partially-energized at the beginning of the respective cycle. It will thus be seen that the described system enables successive batches of toast to be produced much quicker than in a conventional toaster where the electrical heaters are completely de-energized after each batch is toasted. The predetermined idle time period for completely de-energizing the electrical heaters could be preset by the manufacture, e.g., witliin the range of 5 - 15 minutes, preferably about 10 minutes; alternatively, it could be presettable by the user.

It will also be seen that when a frozen slice of bread is to be toasted, the Defrost button 45 (Fig. 6) may be depressed to add the additional toasting time required for defrosting the bread slice, to thereby produce uniformly toasted slices whether or not the bread slice is frozen or unfrozen. The additional Defrost time may be 2 - 10 seconds preferably 4 seconds.

While the invention has been described with respect to a toaster that does not use a color sensor to terminate the operation of the electrical heaters, it will be appreciated that the invention, particularly the partial de-energization of the electrical heaters between batches of toast, could also be included in toasters having color sensors. In such cases the Defrost button operation would not be required since the toasting time would be determined by color, and not by time alone.

Many other variations, modifications and applications of the invention will be apparent to those skilled in the art.

Claims

WHAT IS CLAIMED IS:

1. A bread toasting appliance, comprising: a pop-up stand initially in an upper position for loading a bread slice thereon, depressible to a lower position for toasting the bread slice, and returnable to the upper position for removing the bread slice after having been toasted; electrical heating devices on opposite sides of the pop-up stand for toasting a bread slice thereon; a plurality of manual control devices including a device for specifying the degree of toasting of the bread slice on the pop-up stand; and a control system controlled by said manual control devices and said pop-up stand, effective:

(a) upon the first depression of the pop-up stand, to fully energize the electrical heating devices to a toasting temperature for a full toasting time period to toast the bread slice on the pop-up stand to the specified degree of toasting; and then to return the pop-up stand to its upper position, and to partially de-energize the electrical heating devices to a stand-by temperature lower than said toasting temperature;

(b) upon each subsequent depression of the pop-up stand to fully energize the electrical heating devices to said toasting temperature for a reduced toasting time period to toast the bread slice on the pop-up stand to the specified degree of toasting; and then to return the pop-up stand to its upper position, and to partially de-energize the electrical heating devices to said stand-by temperature;

(c) and upon the expiration of a predetermined idle time period during which the pop-up stand was not depressed to completely de-energize the electrical heating devices.

2. The appliance according to Claim 1, wherein said manual control device for specifying the degree of toasting of the bread slice on the pop-up stand includes a darkness indicator for specifying the desired toast darkness to be produced in the respective bread slice as a result of the toasting thereof.

3. The appliance according to Claim 2, wherein said control system fixes said full toasting time period and said reduced toasting time period according to the specified toast darkness for the respective bread slice.

4. The appliance according to Claim 1, wherein said manual control devices further include a Defrost Selector for selecting a defrost operation to be performed on the bread slice to be toasted; and wherein said control system is effective, upon selecting a Defrost Operation, to add a predetermined additional time period to the respective toasting period.

5. The appliance according to Claim 4, wherein said predetermined additional time period is 2 - 10 seconds.

6. The appliance according to Claim 1, wherein said predetermined idle time period is 5 - 15 minutes.

7. The appliance according to Claim 1, wherein said pop-up stand is coupled by a coupling mechanism to said electrical heating devices to move the electrical heating devices towards a bread slice on the pop-up stand when the pop-up stand is moved to its lower position, and away from the bread slice when the pop-up stand is moved to its upper position.

8. The appliance according to Claim 7, wherein said coupling mechanism includes a pivotal lever for each heating device, said pivotal lever having a first arm coupled to the respective heating device and a second arm coupled to the pop-up stand.

9. The appliance according to Claim 8, wherein said pop-up stand is spring-urged to its upper position; and wherein the pop-up stand includes a latch for latching it in its lower position, and a releasing mechanism for automatically releasing the latch upon the expiration of the respective toasting time period.

10. A bread toasting appliance, comprising: a pop-up stand initially in an upper position for loading a bread slice thereon, depressible to a lower position for toasting the bread slice, and returnable to the upper position for removing the bread slice after having been toasted; electrical heating devices on opposite sides of the pop-up stand for toasting a bread slice thereon; a plurality of manual control devices including a device for specifying the degree of toasting of the bread slice on the pop-up stand, and a device for selecting a defrost operation to be performed on the bread slice to be toasted; and a control system controlled by said manual control devices and said pop-up stand for energizing said electrical heating devices for a predetermined toasting time period according to the specified degree of toasting for the respective bread slice; said control system also being effective, upon selecting a defrost operation, to add a predetermined additional time period to the predetermined toasting time period for the respective bread slice.

11. The appliance according to Claim 10, wherein said predetermined additional time period is 2 - 10 seconds.

12. An appliance according to Claim 10, wherein said control system is also effective:

(a) upon the first depression of the pop-up stand, to fully energize the electrical heating devices to a toasting temperature for said predetermined toasting time period to toast the bread slice on the pop-up stand to the specified degree of toasting; and then to return the pop-up stand to its upper position, and to partially de-energize the electrical heating devices to a stand-by temperature lower than said toasting temperature;

(b) upon each subsequent depression of the pop-up stand, to fully energize the electrical heating devices to said toasting temperature for a reduced toasting time period to toast the bread slice on the pop-up stand to the specified degree of toasting; and then to return the pop-up stand to its upper position, and to partially de-energize the electrical heating devices to said stand-by temperature;

(c) and upon the expiration of a predetermined idle time period during which the pop-up stand was not depressed, to completely de-energize the electrical heating devices.

13. The appliance according to Claim 12, wherein said predetermined idle time period is 5 - 15 minutes.

14. The appliance according to Claim 12, wherein said pop-up stand is coupled by a coupling mechanism to said electrical heating devices to move the electrical heating devices towards a bread slice on the pop-up stand when the pop-up stand is moved to its lower position, and away from the bread slice when the pop-up stand is moved to its upper position.

15. The appliance according to Claim 14, wherein said coupling mechanism includes a pivotal lever for each heating device, said pivotal lever having a first arm coupled to the respective heating device and a second arm coupled to the pop-up stand.

16. The appliance according to Claim 15, wherein said pop-up stand is spring-urged to its upper position; and wherein the pop-up stand includes a latch for latching it in its lower position, and a releasing mechanism for automatically releasing the latch upon the expiration of the respective toasting time period.