This invention relates to electric toasters, and particularly to toasters which can be electronically controlled and programmed to various tastes.

Automatic electric toasters have been used in the home for decades to toast slices of bread and other bakery items such as english muffins, crumpets, bagels and prepared pastries. Most toasters include simple adjustment mechanisms to regulate the degree of toasting by the setting of a mechanical timer to raise the toast at the appropriate time and simultaneously turn off the toaster at the desired degree of toasting from light to dark.

Alternatively, the degree of doneness can be determined by the use of temperature and/or humidity sensors such as thermistors. Unfortunately, automatic toasters must be reset to vary the degree of toasting according to individual tastes or variety of bakery goods toasted. This is usually accomplished by trial and error, resulting in unsatisfactory results and waste.

According to the invention, there is provided an automatic electric toaster including a housing; toasting means located within said housing for receiving and radiantly toasting food products; automatic elevator means associated with said toasting means; programmable control means for operatively controlling said toasting means and said elevator means; said programmable control means including means for recording and operatively running a plurality of predetermined and preselected toasting cycle programs.

The automatic toaster embodying the present invention provides a simple, efficient and attractive means of toasting a variety of bakery goods to different tastes and degrees of toasting, without the need to reset a timer or other such control each time such conditions change.

The toaster, in its preferred embodiment, includes a programmable automatic elevator system which can be set to a variety of tastes. The automatic elevator system is controlled by a microchip which includes a programmable timer function. A number of programs are available, e.g. three, corresponding to three different time settings, which in turn correspond to three different degrees of toasting. In use, after toast is inserted in the unit's slot, the toaster is programmed to a specified time, preferably by pressing a single button, and started. The toast is then automatically lowered and toasted. Near the end of the allotted time the toast is automatically elevated while an alarm tone is sounded.

It is a principal feature of the invention to provide a digitally programmable automatic toaster capable of toasting a variety of bakery goods to a variety of tastes.

It is another feature of the invention to provide such a toaster with an automatic toast elevator system.

It is a further feature of the invention to provide such a toaster with a digital clock display to count down the remaining time until the toast is ejected from the toaster.

It is a still further feature of the invention to provide a toaster which will include a compensation factor to adjust for various degrees of preheating of the unit.

An embodiment of the invention will now be described by way of example only and with reference to the accompanying drawings. Brief Description of the Drawings

Figure 1 is a general perspective view of a toaster embodying the present invention.

Figure 2 is a partially broken away front elevation of the toaster as shown in Figure 1.

Figure 3 is a top plan view of the toaster as shown in Figure 1.

Figure 4 is a left side elevation of the toaster as shown in Figure 1.

Figure 5 is a partially broken away right elevation of the toaster as shown in Figure 1.

Figure 6 is a view of an electronic controller • assembly of the toaster as shown in Figure 1.

Referring now to Figure 1 of the drawings, an automatic electric toaster embodying the present invention is generally indicated by reference character 10. Shown in this figure is the exterior housing 12 which includes forwardly extending control panel 14 and single, elongated toast slot 16.

The toaster shown is of a cool-wall design and construction with the outer housing 12 formed of any suitable material such as plastic. As shown in Figure 2, elevator structure 18 is located within housing 12 on and fixed to housing base 20. As shown in Figures 2 and 3, elevator structure 18 is aligned with housing slot 16 to provide for insertion of toast through slot 16. into structure 18.

Structure 18 includes elevator housing 22 which is formed of metal. Horizontal toast support 24 is located within elevator housing 22 and aligned with slot 16.

Also located within housing 22 are inwardly biased vertical toast support grids 26 and 28 which serve to centre the toast and maintain it in a vertical position as it is being toasted, as well as to automatically adjust to the width of the bread inserted. Support 24 includes horizontal tabs 30 bent from support arm 32. Appended to arm 32 at one end is link extension 34.

Upper and lower parallel links 36 and 38, respectively, substantially encircle elevator structure 18 and are pivotally mounted to link extension 34 and pivotally mounted in slots 40 and 42 respectively in structure 18 at the opposite end thereof.

Upper link 36 is provided with crank 44 adjacent to slot 40. Rotatably attached to crank 44 is lower end 46 of actuator band 48, which in turn is driven by elevator

motor 50. As actuator band 48 is raised by motor 50, crank 44 is raised. This movement, in turn, pivots upper link 36 downward to the position denoted as 36' shown in phantom on Figure 2. As this occurs, lower link 38, being attached to link extension 34, moves downward toward lower position 38' _r also shown in phantom. Support arm 32 is maintained in horizontal position by parallel linkages 36 and 38. In this manner, the toast is lowered into the toaster. The opposite action raises the toast.

The actions of motor 50 and the corresponding linkages are controlled by a microchip control device (Fig. 6) contained within lower housing 52 at the base of toaster 10. The control device is shielded from the heat of the toaster. The microchip control device includes a clock function to include the time of toasting. Operatively connected to the microchip control device is light emitting diode (LED) clock/timer display 54 which may ordinarily display the time of day. When the toaster is in use, however, the LED display 54 displays the time remaining in the toasting cycle.

Also included on control panel 14 are program select buttons 56, 58 and 60 and associated LED indicator lights 62, 64 and 66 respectively. Timer control, pressure sensitive switches 68 and 70 flank LED display 54. Also provided is start/stop button 72.

The electronic controller assembly 80 shown in Fig. 6 is mounted in the lower housing 52 with LED display 54 visible through a suitable window or aperture in the housing. Power is supplied to the assembly through connector 81 from a suitable transformer (not shown) within the toaster housing. The circuit uses conventional techniques and includes rectifiers 82, regulator 83 and capacitors 84 for providing a regulated d.c. supply, CPU chip 85 (e.g. NEC T15566) for executing a stored program of instructions, acoustic transducer 86, and the necessary interfacing components. Outputs from

the assembly are taken via connector 81 to motor 50 via a relay (not shown) .

In this embodiment, three program times may be stored in the memory of the microchip control device. This memory will be maintained as long as an AC current is provided to the unit. The microchip may be preprogrammed in manufacture to times corresponding to typical light, medium or dark toast settings.

To set a program, the timer display is adjusted by means of timer control switches 68 and 70 to decrease or increase the number shown on the display. When the appropriate time is displayed it may be entered into any of the three memories by pressing any one of the three program buttons 56, 58 or 60 and holding the button for a specified period of time.

In use, toast or other suitable bakery product is placed in slot 16 between inwardly biased grids 26 and 28, which automatically adjust to the width of the bread. A program is then recalled by momentarily pressing one of the program buttons 56, 58 or 60, which then illuminates corresponding LED indicator 62, 64 or 66 and displays the appropriate time on LED display 54. When the start/stop button is pressed, the toast is automatically lowered by the elevator mechanism into housing 22 which contains typical radiant heating elements (not shown) . As the bread is toasted the display 54 counts down the remaining time left in the program. With approximately five seconds remaining on the program, a regular tone, controlled by the microchip control device, is sounded as the toast is slowly raised by the automatic elevator.

When the toasting cycle is complete, the previously programmed time is then automatically reset and displayed on display 54. At any time prior to the completion of the cycle, the cycle may be aborted by pressing the start/stop button.

A compensation factor is mathematically built into the logic in the microchip to compensate for the preheating of the toaster and its gradual cooling. This

compensation factor subtracts time from the selected program in inverse relation to the amount of time since the last use of the toaster. In this manner a toaster which has been recently used will toast a second bath of bread in a correspondingly shorter period of time to the • same degree of toasting.

It is also contemplated, although not shown in this embodiment, that a defrost cycle may be provided to warm frozen bakery goods at a lower power setting. A fourth program button may be provided for this function and the reduced power may be provided by cycling the heater on and off with an appropriate duty ratio. If desired the defrost cycle may automatically be followed by a period at full power, for toasting the thawed product.

The foregoing specification describes only the embodiments of the invention shown and/or described. Other embodiments may be articulated as well. The terms and expressions used, therefore, serve only to describe the invention by example and not to limit the invention. It is expected that others will perceive differences, which, while different from the foregoing, do not depart from the scope of the invention herein described and claimed. In particular, any of the specific constructional elements described may be replaced by any other known element having equivalent function.