WO1997021376A1

WO1997021376A1 - An electric toaster

Info

Publication number: WO1997021376A1
Application number: PCT/GB1996/002943
Authority: WO
Inventors: Paul Southcote
Original assignee: C-Tan Limited
Priority date: 1995-12-11
Filing date: 1996-11-28
Publication date: 1997-06-19
Also published as: GB9525259D0; GB2308291A; AU7702596A

Abstract

An electric toaster for continuous operation comprises at least one radiant heat source (26) for toasting an article to be toasted, a rotatable carousel (2) for storing a plurality of articles to be toasted having an interchangeable support insert (4) and conveyor means (12) arranged to convey articles to be toasted from the carousel (2) past the or each heat source (12) to an outlet port (28).

Description

AN ELECTRIC TOASTER

The present invention relates to an electric toaster and in particular to such a toaster for continuous operation.

In the catering industry, there is a need for a large quantity of toasted articles to be available at peak times of the day e.g. at breakfast time, lunchti e and teatime. Given that the toasted articles must be laid out on a plate or the like and served to a customer, it is inconvenient if the toasted articles are all ready for consumption at the same time.

One approach to this need is to provide a plurality of conventional electric toasters comprising slots for receiving articles to be toasted, housing radiant heaters for toasting and having an automatic ejection mechanism operable after a predetermined time of toasting and/or temperature of toasting has been reached, to eject the toasted articles through the slot. The production of toasted articles in this manner in a catering context, is extremely labour intensive and requires the full-time attention of a member of staff who must be spared from other duties at the busiest times of the day. It is known to provide a toaster of the above described type with slots for six slices of bread. Even with the provision of a plurality of these toasters, the production of toasted articles is still labour intensive. It will be appreciated that it is not acceptable to pre-toast articles and to reheat these toasted articles since this greatly affects the texture and moisture content and therefore the quality of the toasted product.

An alternative approach uses a conveyor fed oven which is typically used in the manufacture of pizzas. This equipment is large and expensive since it is really designed for baking and not merely for toasting. Furthermore the job of providing toasted articles is still highly labour intensive since articles to be toasted must be fed manually onto a conveyer which moves the articles through the oven.

According to the present invention there is provided an electric toaster for continuous operation comprising at least one radiant heat source for toasting an article to be toasted, a rotatable carousel for storing a plurality of articles to be toasted having an interchangeable support insert and conveyer means arranged to convey articles to be toasted from the carousel past the or each heat source to an outlet port.

Preferably, the or each heat source is an electrical resistive heating element.

The provision of a carousel for storing articles to be toasted permits loading of the toaster to be limited to sporadic periods of increased activity. The carousel is preferably sufficiently large to hold more than the six articles to be toasted of the prior art toaster (preferably more than 20) and in operation, articles are fed automatically onto the conveyor means and ultimately to the output port where the articles are ready for consumption. Since the toaster is operated on a continuous basis, it does not produce a large batch of toasted articles which can become cold whilst the first articles of the batch are being served but instead, a steady stream of freshly toasted articles.

The provision of an interchangeable support insert in the carousel permits different articles to be stored in the carousel for toasting. It will be appreciated that in the context of this invention, toasting is not limited to the radiant heating of bread but to the radiant heating of any article e.g. sausages for human consumption.

Typically the interchangeable insert includes fins which radiate from a central hub about which the carousel rotates and define sectors for storing a single respective article to be toasted. As the carousel rotates, the insert moves in relation to the conveyer means and the carousel is arranged to allow the articles to pass through a floor of the carousel onto a conveyer belt forming the conveyer means. The carousel and conveyer belt are arranged relative to each other such that the article to be toasted lies flat on the conveyer as it passes the or each heating element. Preferably the or each heat source is arranged generally parallel to the surface of the conveyer upon which the articles lie.

Preferably the toaster includes speed control means for adjusting the speed with which the articles to be toasted are conveyed past the or each heat source. This has the effect of varying the duration for which the article to be toasted is proximal the or each heat source and thereby defines the extent to which the articles are toasted.

To further increase its storage capacity, the toaster may include a plurality of carousels stacked in vertical alignment and arranged such that when a storage position in a first carousel becomes empty it is automatically filled with an article to be toasted from the corresponding storage position in a second carousel located immediately above the first carousel. Thus as the lowest carousel becomes emptied articles to be toasted gradually cascade down the stack of carousels to maintain a constant supply of articles to the conveyer means.

The toaster may permit a plurality of parallel streams of articles to pass the or each heating element in a side-by-side arrangement. This allows the output rate of the toaster to be increased. In a preferred embodiment two streams of articles to be toasted are conveyed past the or each heat source and the articles are removed from the carousel at two respective positions. To improve the transfer of articles to be toasted from the carousel to the conveyer means, the rotation of the carousel is preferably arranged to occur in a stepped fashion i.e. the carousel is caused to accelerate and decelerate so that an article to be toasted falls through a slot in the base of the carousel at a controlled and predetermined time. This ensures that the articles to be toasted are spaced as required on the conveyer means which may allow for more efficient packing of the articles onto the conveyer means. This stepped rotation may for example may be achieved using an eccentric drive mechanism.

Preferably the toaster has two heat sources arranged respectively above and below a conveyer belt. Preferably the upper heating element is fixed to an upper cover of the toaster which is openable to permit cleaning and the removal of any jammed articles.

The upper cover may be interchangeable so that the toaster may for example be used as a griddle. The cover may automatically cause switching off of the lower heat source so that the upper heat source alone is used to heat the upper cover. Alternative upper covers may include a "toast" rack for keeping articles warm, a partially insulated cover arranged for defrosting of frozen articles, a cover arranged for use as a chopping board, or a cover arranged as a microwave oven.

The toaster preferably includes safety mechanisms for detecting a jam and stopping the movement of the carousel and/or conveyer when a jam is detected. This may be achieved by monitoring the current flowing into a motor driving these articles and switching the current off if it exceeds a predetermined level. A jam may also be detected using optical means to determine if articles to be toasted are curling and coming into contact with an upper heat source or if a heat source has become detached and is dragging on articles to be toasted. The optical means may comprise an LED and a optoelectric sensor, the light from the LED being obscured by such a fault.

Preferably the toaster incorporates a removable tray positioned beneath the conveyer means and heat source, for the collection and removal of debris produced during toasting.

The invention will now be described by way of example with reference to the drawings in which:

Figure 1 is a perspective view of a toaster in accordance with the invention;

Figure 2 is a sectional view through the toaster of Figure 1;

Figure 3 is a sectional view through the carousel of Figure 1;

Figure 4A is a plan view of conveyer means in accordance with the invention;

Figure 4B is a side elevation of Figure 4A; and

Figure 4C is a section on line A-A of Figure 4B;

Figure 5 is a plan view of Figure 1; and

Figure 6 is an end view from the right scale of Figure 2; and

Figure 7 is a plan view of an alternative embodiment in accordance with the invention.

With reference to Figure 1, a toaster has a carousel 2 with a removable support insert 4 which is mounted at one end of a housing 6. The housing has a removable upper cover 8 which may be opened using handle 10.

With reference also to Figures 2, 5 and 6, the housing 6 houses a conveyer belt 12 driven by a cog 14. The pulley is driven by a motor 15 whose speed is controlled by speed control 16 via an electronic speed control circuit. Drive is taken to the cog 14 via shaft 18. Another shaft 20 extending vertically upward through a central hub of the carousel 2 is driven from shaft 18 by a wormdrive mechanism. Thus the speed control 16 also controls the speed of rotation of the carousel 2. A transformer 22 reduces the voltage of mains electricity fed to the toaster, the reduced voltage supply then being used where applicable in the electronic control circuitry.

The upper cover 8 incorporates slots 24 which are available for the storage of toasted bread and which also provide airflow for cooling the interior of the housing 6.

The housing 6 also houses heating elements 26 for heating articles to be toasted as they pass along the conveyer 12 towards the outlet port 28.

The support insert 4 comprises a plurality of fins 30 which radiate from the central hub of the carousel to define sectors which form storage spaces for a respective article to be toasted. As the insert 4 rotates within the carousel 2, articles are moved around the carousel with a circular motion.

With reference to Figure 3, the floor of the carousel incorporates a plurality of concentrically arranged raised ridges 32 which serve to reduce friction between the articles and the floor of the carousel.

With particular reference to Figure 5, and Figure 2, a slot of similar size to one of the storage spaces is formed in the base of the carousel at the right side of the conveyer 12. As the articles are brought round to this position they fall through the slot (as shown in Figure 2 by an exemplary article 36) onto the conveyer where they are moved between the heating elements 26 ultimately to exit via the output port 28.

Figure 7 shows an alternative embodiment which provides greater throughput of toasted articles . In this embodiment two conveyers 12 or a wide conveyer 12 are arranged to receive articles from two slots 34 arranged either side of the carousel hub in a diametrically opposite fashion.

Figures 4A, B and C show the conveyer belt 12 in greater detail. The "belt" is constructed from two chains 38 with feeder struts 40 extending between respective pairs of links in each chain. The chains are driven as described above by shaft 18 via cog 14 (it will be appreciated that for clarity, Figure 4A does not show complete lengths of chain 38) . At the opposite end of its run, the chain passes around an idler cog 42.

The feeder struts 40 bear on inclined support bars 44 which are generally parallel to the heating elements and extend generally in the direction of travel of articles through the toaster. The purpose of the support bars 44 is to prevent articles from dropping straight through the conveyer belt 12 when they are loaded onto it from carousel 2 and also to support the feeder struts 40. The cogs 14 and 42 are mounted to a base of housing 6 by mounting members 46. The support bars 44 are inclined to avoid making consistent shadow marks on the article to be toasted. By inclining the support bars, the position of the bars in relation to the article to be toasted move as the article moves through the toaster.

Claims

£LAU1£

1. An electric toaster for continuous operation comprising at least one radiant heat source for toasting an article to be toasted, a rotatable carousel for storing a plurality of articles to be toasted having an interchangeable support insert and conveyor means arranged to convey articles to be toasted from the carousel past the or each heat source to an outlet port.

2. A toaster according to claim 1 wherein the carousel is arranged to hold more than six articles to be toasted.

3. A toaster according to claim 1 or claim 2, wherein the interchangeable insert includes fins which radiate from a central hub about which the carousel is rotatable and which defines sectors for storing a single respective article to be toasted.

4. A toaster according to any preceding claim wherein the carousel is arranged to allow the articles to pass through a floor of the carousel onto a conveyor belt forming the conveyor means.

5. A toaster according to claim 4, wherein the or each heat source is arranged generally parallel to the surface of the conveyor upon which the articles lie.

6. A toaster according to any preceding claim including speed control means for adjusting the speed with which the articles to be toasted are conveyed past the or each heat source.

7. A toaster according to any preceding claim including a plurality of carousels stacked in vertical alignment and arranged such that when a storage position in a first carousel becomes empty it is automatically filled with an article to be toasted from the corresponding storage position in a second carousel located immediately about the first carousel.

8. A toaster according to any preceding claim arranged to permit a plurality of parallel streams of articles to pass the or each heating element in a side-by-side arrangement.

9. A toaster according to claim 8 wherein two streams of articles to be toasted are conveyed past the or each heat source and the articles are removed from the carousel at two respective positions .

10. A toaster according to any preceding claim wherein the carousel is arranged to rotate in a stepped fashion whereby an article to be toasted is caused to drop through a slot in the base of the carousel at a controlled and predetermined time.

11. A toaster according to any preceding claim including an upper cover which is openable and interchangeable.

12. A toaster according to any preceding claim including means for detecting a jam.

13. A toaster constructed and arranged as described herein with reference to the drawings.