WO1989003654A1

WO1989003654A1 - Rotary toaster

Info

Publication number: WO1989003654A1
Application number: PCT/GB1988/000908
Authority: WO
Inventors: Michael Eugene Kavanagh
Original assignee: Michael Eugene Kavanagh
Priority date: 1987-10-26
Filing date: 1988-10-24
Publication date: 1989-05-05
Also published as: AU2618588A

Abstract

A rotary toaster has a casing (1) which is insulated from a housing (2). This housing is basically an oven which fits closely around a carrier (4). The carrier is disc-shaped and revolves about a central axis. The speed of rotation is controlled to produce the desired toast. Bread is delivered to the carrier via a chute (24) either manually or automatically from a magazine (16). Speed of delivery is controlled by the rotation of the carrier via a sprocket (19), a crank and lever arrangement (18) and a slice dispenser (17). The bread is located on the carrier by short spikes (25) and/or ribs. The degree of browning/colour of the toast is measured by a device which influences a speed control which in turn dictates the speed of the carrier. Toast is removed from the carrier by the action of a spring loaded lever (26).

Description

to this area). The bread is then carried by the carrier into the housing and initially into the part of the housing not directly heated by the elements 6A, 6B. As the bread follows its arcuate path through the housing it is dried. Having rotated through approximately half a revolution the bread is directly exposed to the heat from the elements 6A, 6B and is thereby browned. The bread then emerges from the housing 2 having travelled along an arcuate path of travel through the housing of the order of 3/4 of a revolution and is removed from the carrier by the operator. tfhile the operation of toaster has just been described in respect of a single slice of bread, it should be understood that in normal use an operator would load each of the regions between adjacent spokes 8 with a slice of bread so that 12 slices can be accomodated in the outer region of the carrier and 6 slices in the inner region.

If it is desired to toast only one side of the food item, which might apply particularly in the case of a bun, then the 1/2 sides switch 15 would be set to 1 side and only one of the heating elements 6A, 6B would be activated.

In a particular example of the invention with a toaster of the kind shown in the drawings, the casing 1 has a height h of 30 inches (76cm) a width w of 34 inches (66cm) and a depth d of 5 inches 12.7cm). The carrier 4

the housing, and one or more heating elements for heating the interior of the housing, wherein the heating elements are arranged such that in use the interior of the housing varies in temperature and bread on the carrier travelling through the housing along the arcuate path passes through a relatively cool first drying zone and then through a hotter second browning zone.

With the toaster of the present invention, bread travelling through the housing is first dried within a region of the housing which preferably is not directly heated by heating elements and then after drying passes through a hotter zone where the heating elements may be situated and is browned. The heat generated by the heating elements in the browning zone is used to heat the drying zone. Preferably the browning zone is situated at the end of the arcuate path through the housing so that the whole of the path through the housing can be fully utilised for toasting the bread.

The carrier is preferably mounted for rotation about a horizontal axis so that the bread lies in an approximately vertical plane and it is therefore relatively easy to apply equal heat to both sides of the bread. Preferably heating elements are provided on both sides of the arcuate path. In such a case the Dread can be toasted on both sides at once.

The housing is preferably closed apart from an opening at the bottom end. This ensures that the heat generated by the heating element is mainly kept within the housing rather than being disipated to the surroundings.

Although it is possible to turn the carrier by hand, it is prefered to provide motor drive means for rotating the carrier to carry slices of bread along the arcuate path. In a prefered form of the invention the motor means comprises an electric motor and drive sprocket drivingly engaging a periferal part of the toast carrier. Other drive arrangements may however be employed: for example, a chain drive may be used or a central axle of the carrier may be driven directly.

The carrier is preferably arranged to receive a single slice of bread only over any one region thereof. Such an arrangement enables a very small spacing only to be provided between opposite walls of the housing and thus the overall depth of the toaster can be kept relatively small. In an embodiment of the invention to be described the overall depth of the toaster is of the order of 12cm.

Preferably the bread is arranged to be loaded and unloaded at substantially the same location. It is also preferable to arrange for the bread to be heated within the housing over an arcuate path of travel of more than 180° and preferably more than 225º. In such an arrangement the bread is toasted over most of an entire revolution of the carrier and this again enables the toaster to be more compact than if, for example, the bread were toasted over less than 180 of the arcuate path of travel, being inserted at the top and removed from the bottom.

Preferably the housing has an arcuate top closely surrounding the carrier. In this case there is no region within the housing which is not in immediate proximity to the carrier and thus the whole of the hot region defined by the housing can be employed to toast the bread and thus the power required for the toaster reduced.

The present invention also provides a method of toasting bread in which the bread is toasted in a toaster as defined above, passing through the relatively cool first zone and being dried therein and then passing through the second hotter zone and being browned therein.

While in the description above reference is made to toasting bread, it should be understood that tne toaster may be used for toasting other food items such as buns.

By way of example an embodiment of the invention will now be described with reference to the accompanying diagrammatic drawings, of which:

Fig. 1 is a front view of a rotary toaster with most of the front wall of the toaster casing cut away and the whole of the front wall of a housing omitted; and

Fig. 2 is a sectional view along the lines II-II in Fig. 1.

Fig. 3 shows the automatic arrangement for positioning bread on the carrier.

Fig. 4 shows the method of removing toast from the carrier. The rotary toaster shown in the drawings has an external casing 1 in the top portion of which a housing 2 is situated. Sheets of thermal insulation 3 are provided between adjacent side walls of the casing 1 and the housing 2 (see Fig. 2 ) . The housing has an open bottom end but is otherwise closed. A disc-shaped toast carrier 4 in the form of a wheel is rotatably mounted in the housing 2 on a horizontal axle 5. Heating elements 6A and 6B are provided on one side of the housing 2 at the bottom on either side of the carrier 4.

A sprocket 7 driven by an electric motor (not shown) has teeth which engage a peripheral part of the carrier 4 and rotates in the direction indicated in Fig. 1 when the motor is actuated. The sprocket and motor assembly is resiliently biased into driving engagement with the carrier by a spring (not shown).

The carrier 4 is made up of an open framework generally comprising radial spokes 8, rim members 9 interconnecting adjacent spokes at their ends and connecting members 10 further interconnecting the spokes. The spokes 6 and interconnecting members 9, 10 are sized such that a slice of bread 11 (shown in dotted outline in Fig. 1) can be placed between adjacent spokes and between the members 9, 10 as shown in dotted outline in Fig. 1. Wire grids (not shown in the drawings; are also provided on the carrier and or on the walls of the housing 2 and over the heating elements 6A, 6B so that a slice of bread is retained in

position on the carrier when, in use, it is rotated. The region of the carrier inside the interconnecting members 10 may accomodate 6 slices of Dread or for example may accomodate buns. Forming the carrier from a simple framework assists in ensuring that the carrier does not deform when parts of it are heated. The details of construction of the carrier are not significant to the present invention. In the interest of clarity details of the carrier are not shown in Fig. 2.

The housing 2 has an arcuate top 12 which closely surrounds the periphery of the carrier 4.

Located on the exterior of the casing 1 are the toaster controls which in this example comprise an on/off switch 13, a thermostat 14 and a half sides switch 15. An additional control may be provided to vary the speed of rotation of the carrier.

In use, the on/off switch 13 is turned on with the result that the carrier begins to rotate in the direction shown by the arrow in Fig. 1 and the heating elements 6A, 6B are switch on (assuming that the 1/2 sides switch 15 is set to 2 sides). The heating elements cause the whole of the interior of the housing 2 to become hot and act as an oven and, in addition, create a zone which is particularly hot in their immediate vicinity.

Once the toaster has warmed up an operator places a piece of bread to be toasted in the position shown in Fig. 1 (the casing 1 having an opening to provide access ROTARY TOASTER

This invention relates to a rotary toaster of the kind in which bread or the like is carried by a rotating carrier through a heated zone and thereby toasted.

British patent specification No . 1 434 031 describes such a toaster. riotary toasters are commonly employed in the catering industry where a large volume of toast is to be produced in a relatively short time. Disadvantages of existing designs of rotary toaster are that they are relatively bulky, complicated, and expensive devices.

It is an object of the invention to provide a rotary toaster which is capable of being made cheaply in a relatively compact form, is of simple design and is able to toast at a relatively fast rate while consuming relatively little power.

According to the invention a rotary toaster includes a housing, a generally disc-shaped toast carrier mounted for rotation about a central axis, at least a part of the carrier being situated inside the housing with the side walls of the housing alongside the sides of the disc--shaped carrier, the toast carrier including means for carrying a plurality of slices of bread through the housing along an arcuate path when the carrier is rotated, the sides of the slices of bread extending generally parallel to the side walls of

rotates at a speed of 1 revolution per minute so that bread is dried for about half a minute and browned for about a quarter of a minute. Such a toaster can toast at a rate of 12 slices per minute if only the outer region of the carrier is used and requires a power input during normal use of the order of 2½ to 3 kw or less. Thus toast can be produced rapidly, by a compact machine consuming relatively little electrical energy.

If only the outer region of the carrier is to be used then the heating elements 6A, 6B may be confined to the outer region only.

Since the casing is so shallow the toaster can easily be accomodated on a worktop and occupies little space when not in use. The toaster may be used as a counter divider. It is also possible to mount the toaster on a wall. The simplicity of the dessgn keeps the cost of manufacture of the toaster low and also improves its reliability.

It may be desirable to provide an arrangement for automatically feeding slices of bread into the toaster and/or for automatically removing the slices of toast.

While the speed and degree of toasting bread depends on the water content of the slices of bread and can vary a great deal from batch to batch of bread, two day or one day old bread being recommended usually. A good degree of uniformity can be had by automating the machine. An automated machine would also free an operator for other work, it being only necessary to load the magazine and remove the accumulated toast. Fig. 3

The magazine 16 for the sliced bread may be located anywhere convenient but preferably above the toaster to utilise the heat rising from it to give the bread a period of pre- drying thereby saving energy.

Each slice is ejected from the magazine by the slice dispenser 17, which is operated by a rod and crank arrangement 18 which in turn is connected to a sprocket 19 engaging on the periphery of the carrier. The diameter of sprocket 19 regulates the number of slices of bread dispensed per revolution of the carrier.

Slices are positioned in the slice dispenser 17 by the action of the solenoid coil 20, the solenoid rod 21 and the slice rack 22.

The dropping of the slice dispenser 17 activates the micro-switch 23. This energises the solenoid coil 20 which pulls the solenoid rod 21 one notch (one notch being equal to one slice of Dread) which in turn moves the slice rack 22 the distance of one slice thereby filling the slice dispenser 17.

The ejected slice is deposited in a chute 24 shaped to direct and position the slice on the carrier where it is picked up and fed through the machine. The slices on this automated machine will be located on the carrier by short spikes rather than by ribs.

The colour of each slice of toast is measured by a device which acts upon a speed control which dictates the speed of the drive motor.

In short, toast which is to light will slow down the drive motor lengthening the time a slice is in the oven and slow the dispensing of slices to the carrier. Toast which is too dark will speed up the operation. Fig. 4

Unloading the carrier will be by the action of a springloaded lever 26 riding on and operating on the carrier removing each slice as it comes by.

The above operations and components are illustrated on attached sketches.

Claims

Claims :

1. A rotary toaster including a housing, a generally disc-shaped toast carrier mounted for rotation about a central axis, at least a part of the carrier being situated inside the housing with side walls of the housing alongside the sides of the disc-shaped carrier, the toast carrier including means for carrying a plurality of slices of bread through the housing along an arcuate path when the carrier is rotated, the sides of the slices of bread extending generally parallel to the side walls of the housing, and one or more heating elements for heating the interior of the housing, wherein the heating elements are arranged such that in use the interior of the housing varies in temperature and bread on the carrier travelling tnrough the housing along the arcuate path passes through a relatively cool first drying zone and then through a hotter second browning zone.

2. A toaster according to claim 1 in which the second zone is situated at the end of the arcuate path through the housing.

3. A toaster according to claim 1 or claim 2 in which heating elements are provided on both sides of the arcuate path.

4. A toaster according to any preceding claim in which the carrier is mounted for rotation about a horizontal axis.

5. A toaster according to claim 4 in which the housing is closed apart from an opening at its bottom end.

6. A toaster according to any preceding claim including motor drive means for rotating the carrier to carry slices of bread along the arcuate path.

7. A toaster according to any preceding claim in which the carrier is arranged to receive a single slice of bread over any one region thereof.

8. A toaster according to any preceding claim in which the bread is arranged to be loaded and unloaded at substantially the same location.

9. A toaster according to any preceding claim in which the bread is arranged to be neated witnin the housing over an arcuate path of travel of more than 180°.

10. A toaster as claimed in claim 9 in which the arcuate path of travel is more than 225°.

11. A toaster as claimed in any preceding claim in which the housing has an arcuate top closely surrounding the carrier.

12. A rotary toaster substantially as herein described with reference to and as illustrated by the Accompanying drawings.

13. A method of toasting bread in which the bread is toasted in a toaster as claimed in any preceding claim passing through the relatively cool first zone and being dried therein and then passing through the second hotter

zone and being Drowned therein.

14. A toaster as claimed in any preceding claim in which the bread is delivered to the carrier by a chute.

15. A toaster as claimed in any preceding claim in which the bread is delivered to the chute automatically from a magazine.

16. A toaster as claimed in any preceding claim in which the automatic operation of the magazine is controlled by the rotation of the carrier.

17. A toaster as claimed in any preceding claim where the bread is positioned in the magazine by the action of a solenoid coil.

16. A toaster as claimed in any preceding claim in which the bread is held in position on the carrier by spikes.

19. A method of toasting bread substantially as herein described with reference to and as illustrated by the accompanying drawings.