WO2007128993A1

WO2007128993A1 - A toaster

Info

Publication number: WO2007128993A1
Application number: PCT/GB2007/001327
Authority: WO
Inventors: Peter Ingledew
Original assignee: Alternative Products Limited
Priority date: 2006-04-07
Filing date: 2007-04-10
Publication date: 2007-11-15
Also published as: AU2007246927A1; EP2007258A1; GB0607016D0

Abstract

A traditional toaster (1) incorporates slots (4) to accommodate objects (6) such as bread, teacakes and other foods for toasting. Each slot (4) has heating elements to heat the object (6). When all the slots (4) not filled or only partially filled it will be understood that all the heating elements in a traditional toaster are operative. By providing a sensor to identify if only one slot (4) or part of a slot is occupied only the particular heating elements for that slot (4) or part of the slot may be rendered operational making considerable energy savings.

Description

A Toaster

The present invention relates to toasters and more particularly, but not exclusively, to multi slotted electric toasters.

Toasting such food products as slices of bread, teacakes, muffins and crumpets is well known. Such toasting can be performed with multiple slot electric toasters which have slots within which electrical heating elements are presented to the loaded food product, that is to say a slice of bread in order to ensure that bread is appropriately toasted. Generally, these toasters have a number of slots to enable more than one item, that is to say a slice of bread to be toasted at one time. This is in view of the conventional necessity for creating toast in a family environment where a number of slices of toast will be required. In such circumstances, a cradle is provided with an external handle to the toaster such that the slices of bread can be loaded, the cradle depressed in order to activate the electrical heating elements and then after an appropriate period of time or when ready the cradle released to expose the toasted bread as required.

As will be understood electrical heating elements consume relatively high amounts of electrical power. In such circumstances in situations where only one slot is operative, that is to say only one slice of bread is required to be toasted, electrical power is consumed by the,.heating elements in the unloaded slots as well as the loaded slots. This wastes a considerable amount of electrical energy.

In accordance with the present invention there is provided a toaster comprising a plurality of slot segments, each slot segment associated with a sensor to determine object location within the slot segment and a distinct heater to toast the object, the toaster having a control associated with each sensor to selectively activate each distinct heater dependent upon determination of object location within the slot segment.

Normally, each slot segment comprises a continuous slot within a housing.

Generally, the sensor is arranged to determine objects such as food products such as a slice of bread, a teacake, a crumpet, piklet or muffin within the slot.

Generally, each slot has a specific sensor. Alternatively, the sensor comprises an array of sensor elements configured to enable specific determination of object location within an individual slot.

Possibly, the distinct heater comprises a specific element in a heater array for the toaster individually addressable by the control for selective activation.

Possibly, the sensor comprises a sensor arm extending within the slot towards a switch, the sensor arm displaced when an object is located in the slot to engage the switch to provide a signal to the control. Possibly, the sensor arm extends along the slot. Alternatively, the sensor arm extends across the slot. Generally, the sensor arm is biased away from the switch whereby in use object mass causes displacement against the bias to engage the switch. Possibly, the switch is a micro switch having a button or toggle depressed by the arm. Alternatively, the switch comprises electrical contacts bridged by a portion of the sensor arm.

Possibly, the sensor comprises a light beam interruptible by the sensor arm. Possibly, the sensor comprises a light beam interruptable by an object in use within a slot.

Possibly, at least a part of the sensor is carried upon a cradle for entry of an object in use into the slot. Typically, the cradle acts for all slots. Generally, the cradle has an external handle extending from the toaster.

Possibly, the sensor provides an operational quotient for an object in use when loaded in the slot. Possibly, the operational quotient relates to weight, thickness, unacceptable object type or a factor influencing a period of time necessary to toast an object in use.

Possibly, the sensor comprises a clamp grill arrangement having sensor portions displaceable towards each other and a switch associated with at least one sensor portion, the switch operable when the sensor portions are displaced towards each other to determine location of an object within the slot segment.

Typically, the sensor portions are end portions of the clamp grill arrangement.

Generally, the clamp grill arrangement is part of the slot segment.

Typically, the clamp grill arrangement comprises two grill elements arranged to pivot about a pivot coupling at opposed end edge positions displaced from the sensor portion.

Normally, the switch is a micro switch secured to a first sensor portion and the other sensor portion includes an actuator to engage the microswitch when displaced towards the first sensor portion. Typically, the switch has a plurality of indicator positions and is arranged to provide a respective indicator signal to a controller for each indicator position. Possibly one indicator position is for no object within the clamp grill arrangement. Additionally, respective indicator positions are provided for different object thicknesses within the clamp grill arrangement.

Embodiments of the present invention will now be described by way of example only and with reference to the accompanying drawings in which:-

Fig. 1 is a schematic cross section of a toaster in accordance with aspects of the present invention;

Fig. 2 is a schematic perspective view of a slot within a toaster in a non loaded condition;

Fig. 3 is a schematic perspective view consistent with Fig. 2 in which a sensor in accordance with aspects of the present invention is utilised to indicate an object is located within a slot;

Fig. 4 is a schematic perspective view consistent with Fig. 2 and Fig. 3 in a toasting configuration;

Fig. 5 is a schematic end view of a slot in accordance with aspects of the present invention utilising a broken beam sensor;

Fig. 6 is a schematic side view of a switch in accordance with aspects of the present invention utilising bridged contacts;

Fig. 7 is a schematic view of a heater array in accordance with aspects of the present invention; Fig. 8 is a schematic side illustration of a single slot toaster in accordance with aspects of the present invention;

Fig. 9 provides a schematic end view of a further alternative sensor arrangement in accordance with aspects of the present invention in an open configuration;

Fig. 10 illustrates the sensor arrangement depicted in Fig. 9 in a closed configuration without an object ; and,

Fig. 11 is a front upper perspective view of the sensor arrangement depicted in Fig. 10.

As indicated above, it is known to provide toasters which have a plurality or multiple slot format or a single slot toaster of extended slot length to accommodate a number of loaded food products such as slices of bread, muffins, teacakes or crumpets. These toasters incorporate heating elements to effectively toast the object to a user's desired requirements. A cradle is generally depressed in which the object is loaded in order to activate heating elements to provide the toasting action. Aspects of the present invention utilise this typical toasting mechanism but ajlow individual selectivity with regard to operation of a slot or segments of a single slot in order that only the heating elements necessary to toast the desired object are powered. Thus, less electrical energy is utilised rendering the toaster more efficient and economical.

Fig. 1 provides a schematic cross section of a toaster 1 in accordance with aspects of the present invention. The toaster 1 comprises a housing 2 within which a cradle 3 is presented. This cradle 3 defines a number of slots 4 such that side walls 5 incorporating electrical heating elements are presented on either side with respect to outside walls 5a, 5e or both sides with respect to internal walls 5b, 5c, 5d. The cradle 3 is generally displaceable in the direction of arrowheads A in order to present objects 6 in the slots 4. It will be understood that generally the heating elements will not be located in the cradle 5 but will normally be static and act through apertures in the cradle 3 in order to toast the object 6. The object 6 as indicated previously, will generally be a slice of bread, muffin, teacake or other object food product desired to be toasted. It will also be understood that if an appropriate mechanism can be provided then these slots 4 may comprise an object in the form of a sandwich in order to create a toasted sandwich. Normally, the object is gripped or clamped by pivoted griddles or grills as part of the cradle. The grills embrace the object to ensure good positioning relative to the heating elements for appropriate toasting of the object.

As illustrated in Fig. 1, it is possible that it is only necessary to toast one object 6 in a slot 4a whilst the other slots 4b, 4c, 4d are not loaded with an object and therefore are vacant. However, without sensing in accordance with aspects off the present invention the electrical elements associated with each of these slots 4b, 4c, 4d will still be rendered operative by the typical cradle 3 displacement action to switch electrical power into these elements. In such circumstances electrical power is utilised in order to heat the whole array of heating elements rather than just those heating elements necessary to toast the object 6. This is clearly inefficient.

In accordance with aspects of the present invention a sensor is provided typically at a lower end 7 of each of the slots in order to determine whether an object 6 is loaded into a slot 4 and then through an appropriate control or switch mechanism, only electrical heating elements necessary to toast an object 6 in a slot 4 are activated. Only the heating elements in slots 4 which have an object such a slice of bread in them will be activated.

It will be appreciated it may be inconvenient to provide individually and separately switched heating elements for each slot 4 but a heating element array could be provided as described below with respect to Fig. 7 in which the switches act to tap electrical current to a respective heating element from a common supply. It will be understood, as indicated above, each slot 4 will generally have a pair of heating elements to heat the object from both sides.

Figs. 2 to 4 illustrate a schematic perspective view of a slot 14 in accordance with aspects of the present invention utilised in a toaster. Thus, the slot 14 is defined between walls 15a, 15b as a cradle which can be displaced generally vertically in the direction of arrowheads AA. The slot 14 has a cradle within which an object in the form of a slice of bread 16 depicted in Figs. 3 and 4 can be presented. Either the walls 15a, 15b or the slot 14 in the form of a cradle will incorporate appropriate heating elements to enable the object or slice of bread 16 to be toasted.

In Fig. 2 a toasting slot in accordance with aspects of the present invention is depicted in an empty state. Thus, an object, as described later as a slice of bread 16, is not loaded into the slot and therefore the toaster is not operative. However, it will be noted that a sensor is provided in the form of a sensor arm 17 and a switch 18. The sensor arm 17 does not engage the switch 18 and therefore electrical power is not provided to electrical heating elements in order to toast an object.

In Fig. 3 an object in the form of a slice of bread 16 is located in the slot 14. The mass of this slice of bread 16 acts upon the sensor arm 17 in order to cause engagement of a portion of the arm 17 upon the switch 18. In such circumstances the sensor comprising the arm 17 and the switch 18 has determined location of the object (slice of bread 16) in the slot 14 in order to close an electrical power supply circuit. This closed circuit may act as a control to enable electrical current to pass through heating elements associated with the slot 14 in order to toast the object or may be utilised in order to present a control signal to a control device which in turn controls operation of the heating elements associated with the slot 14. Generally, as indicated above, the slot 14 acts as a carriage or carrier for the object slice of bread 16 such that further depression in the direction of arrowheads A will cause coupling of electrical power to the heating elements. Thus, in accordance with aspects of the present invention the micro switch 18 may also be associated with that carriage mechanism as a switch within the electrical supply circuitry for the heating elements. In such circumstances in order to provide electrical power to the heating elements a double switch arrangement is provided in which first of all the sensor comprising the sensor arm 17 and switch 18 must be closed and then a switch associated with the normal carrier pop up mechanism typical within a toaster will also need to be closed in order to provide electrical power. This mechanism is further explained with regard to Fig. 7 below. Furthermore, as can be seen in Fig. 4, the micro switch and slot 14 along with arm 17 are further depressed into the housing defined in the walls 15a, 15b. It will be understood in accordance with conventional toasting mechanisms, a timer or potentially a simple thermocouple device may be utilised in order to define a period of time before the pop up mechanism of the toaster activates to lift a cradle or carrier and so break the electrical circuit powering the heating elements.

In view of the above it will be appreciated that an arrangement will be provided in each slot of a multiple slot toaster or in slot segments along a length of a single slot toaster in accordance with aspects of the present invention. Each heating element or pair of heating elements will be controlled through a respective sensor in accordance with aspects of the present invention to ensure that only heating elements in slots which are loaded with an object will be activated. A normal conventional pop up mechanism of a toaster will still be utilised in order to provide power to the heating elements when the toasting cradle or carriage is lowered, but only if the sensor determines an object is in a particular slot will the associated heating elements be activated. It will be appreciated that a number of mechanisms may be utilised in order to provide a sensor to determine location of an object in a slot in accordance with aspects of the present invention. Thus, for example, rather than using a button or toggle activated micro switch 18b the sensor arm 17 may be associated with an electronic switching circuit activated by simple movement of the sensor arm. It will also be understood that generally the sensor arm 17 will be biased away from contact with a switch 18 such that the mass of the object 16 causes displacement into engagement with the switch and therefore activation in accordance with aspects of the present invention.

An alternative sensor in accordance with aspects of the present invention is to utilise a light beam or infra red beam. Thus, Fig. 5 provides a schematic cross section of a slot 24 in which apertures 18, 19 are provided so that a beam projected from a source 20 can be detected by a detector 21 in order to control the electrical elements in accordance with aspects of the present invention. If no object, shown as broken line 26, is located within the slot 24, then a beam 22 will not be broken and an indication will be provided that there is no object within the slot 24. However, when an object 26 is located within the slot 24, the beam 22 will be broken and similarly a control signal can be provided indicating that the slot 24 has an object 26 within it so electrical heating elements associated with the slot 24 can be activated to toast that object 26.

Fig. 6 schematically illustrates a further possibility with respect to a switch for a sensor incorporated into a toaster in accordance with aspects of the present invention. Thus, a sensor arm 37 is displaceable as indicated previously, typically against a bias towards a switch 38. The switch 38 incorporates contacts 39, 40 of an electrical circuit incorporating the heating elements. In such circumstances when the sensor arm 37 is depressed in the direction of arrowhead C a portion of the sensor arm 37 provides an electrical bridge across the contacts 39. This displacement in the direction of arrowheads C as indicated previously, is generally due to the mass of an object loaded within a slot and therefore the bridge created across the contacts 39 provides an indication that an object has been loaded into the slot.

As indicated above, typically each electrical heating element in accordance with aspects of the present invention will be individually controlled and isolated by a sensor to ensure that the heating element is only activated when necessary. However, such an arrangement may be inconvenient so that a heating array may be provided comprising a number of heating elements associated with a common supply circuit with the sensor in accordance with aspects of the present invention acting as a switch selectively tapping or isolating a heating element from that common supply circuit as required. It will also be understood that this common electrical supply circuit will generally incorporate a main pop up switch mechanism for the carriage cradle. Fig. 7 provides a schematic illustration of such an arrangement. Thus, heating elements 45 are each associated with a common electrical supply circuit 40 through switches 48. If the switch 48 is closed then the heating element 45 is coupled to the main power circuit 40 and so operative. In such circumstances it will be appreciated that the switch 48 is representative of a sensor in accordance with aspects of the present invention in order to determine location of an object in a slot to be toasted.

As schematically illustrated in Fig. 7 the main power circuit 40 has a switch formed by contacts 41 , 42 which are closed in the schematic depiction by depression of a carriage 43 in the direction of arrowhead B in order to close the circuit and therefore provide electrical power from the power source 44, that is to say mains electricity. In such circumstances for each individual electrical heating element 45 to be powered it will be understood that both the respective switch 48 and the mains switch assembly schematically illustrated by bridging contacts 41 , 42 must be closed. As indicated above aspects of the present invention have particular applicability with regard to toasters which have a multiplicity or plurality of slots generally in a side by side configuration. However, it is also known to provide a single slot toaster of elongate length, that is to say longer than typically the width of a slice of bread to enable objects to be loaded into the toaster in alignment for toasting. It will again be appreciated that there may be situations where a single object such as a slice of bread or muffin or crumpet is loaded into such an elongate single slot toaster so that heating elements which are not adjacent to the object to be toasted will be inefficiently activated as they will not be required to toast the object. In such circumstances as depicted as a schematic side view in Fig. 8 a toaster 51 may comprise a housing 52 having a single slot 45 in which a carriage cradle is provided. In accordance with aspects of the present invention the carriage cradle 53 is divided into a number of segments 53a, 53b, 53c, 53d each with their own electrical heating elements (not shown) and, in accordance with aspects of the present invention, a sensor 58. In such circumstances in accordance with aspects of the present invention each sensor 58 will determine whether an object is loaded into its segment 53 and then appropriately control the associated electrical heating elements to toast the object. It will be understood that an object may be solely located within one segment 53 or span across two or more segments 53 but in any event only heating elements associated with segments 53 activated by a sensor 58 will receive electrical power .

As indicated above aspects of the present invention are arranged to ensure that electrical power is not lost by operating heating elements which are not required at a particular slot as no object needs to be toasted etc. Existing toasters generally incorporate a clamp grill arrangement comprising a clamp grill plate pair pivotally secured relative to each other along one edge and arranged to clamp an object such as a slice of bread between them. In such circumstances end portions of that grill arrangement are brought into association with each other in order to clamp the object between them. Aspects of the present invention can utilise this displacement of end portions of the respective grill plates as sensor portions in order to determine object location between the grill plates and so within a slot segment.

Fig. 9 provides a schematic end illustration of a clamp grill arrangement

90 within a slot 91. The arrangement 90 comprises grill plates 92 arranged to pivot inwardly and towards each other in the direction of arrowheads Z. As can be seen the pivots 93 are at one end of the slot 91 whilst end portions 94 are at the other end of the clamp grill arrangement 90 near to the open end of the slot 91. In accordance with aspects of the present invention a switch 95 is provided to determine position of the ends 94. The switch 95 is generally of a microswitch type and as can be seen is secured to one end 94a whilst the other end 94b engages the switch 95 to determine position. An object such as a slice of bread can be located within and between the plates 92 such that if an object is in place, the switch 95 will either be operated to indicate location of an object or through remaining open indicates an object is in place. As can be seen typically displaceable toggles 96 may be depressed by relative movement of the plates 92 and in particular 94a to give a sensor operation indicative of object location between the plates 92.

Rg. 10 provides a schematic end illustration of the arrangement 90 depicted in Fig. 9 in a closed position without an object, such as a slice of bread between the grill plates 92. As can be seen the plates 92 in particular have come into close association towards the ends 94 such that the switch 95 is operative to indicate closure. The closed configuration depicted in Figure 10 is indicative of no object to be toasted between the plates 92 and therefore in accordance with aspects of the present invention it will be understood that the switch 95 provides either an electrical signal or breaks an electrical circuit to heater elements in the slot 91 to prevent operation of those heater elements and therefore avoid wasting electrical energy in a slot 91 which does not require any toasting function. As can be seen the switch 95 is secured to one end 94a through a spring 97 to ensure appropriate operation of the switch 95 in use.

Fig. 11 provides an upper front perspective view of the arrangement 90 depicted in Rg. 10. As can be seen the arrangement 90 again sits within the slot segment 91. The grill plates are arranged to pivot about pivot ends 93 opposite to sensor end portions 94 so that dependent upon the degree of displacement inward there is activation of the switch 95 to indicate whether any object, such as a slice of toast, is located within the arrangement 90. The grill plates 92 comprise an open matrix so that heater elements in the slot 91 can act upon an object within the arrangement 90 if required. However, as depicted in Fig. 11 , no object is in position therefore the ends 94 are brought into closer proximity in order that the switch is operative to provide an indication that no object is in position. This^' action by the switch 98 may be through an electronic signal but alternatively simply arranges for an open circuit with respect to the heating elements in the slot 91 such that electrical power is not wasted in heating the slot 91 when not required.

The switch may act to provide varying signals dependent upon how far it is depressed so that the thickness of an object between the grill plates can be determined and indicated to a controller. Thus, the operation of the heater elements may be adjusted.

Modifications and alterations to the embodiments of the present invention will be understood by those skilled in the art in particular it will be appreciated that the form of sensor will be chosen dependent upon operational requirements, cost and accuracy. Sophisticated sensor devices may be able to determine in addition to simple location of an object within a slot or slot segment, the weight of that object, its thickness, its material type or even whether the object is unsuitable for toast, that is to say a metal in the form of a knife inserted into the toaster or a child's hand. Generally, as indicated above a cradle or a carrier will be provided within which the object is taken into the slot in order to be toasted. Thus a carrier will be associated with an external handle extending beyond the housing of the toaster and may be designed in order to move individual slots or groups of slots or all slots in one movement.

Whilst endeavouring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance it should be understood that the Applicant claims protection in respect of any patentable feature or combination of features hereinbefore referred to and/or shown in the drawings whether or not particular emphasis has been placed thereon.

Claims

1. A toaster comprising a plurality of slot segments, each slot segment associated with a sensor to determine object location within the slot segment and a distinct heater to toast the object, the toaster having a control associated in each sensor to selectively activate each distinct heater dependent upon determination of object location within the slot segment.

2. A toaster as claimed in claim 1 , wherein each slot segment comprises a continuous slot within a housing.

3. A toaster as claimed in claim 1 or claim 2, wherein the sensor is arranged to determine objects such as food products such as a slice of bread, a teacake, a crumpet, piklet or muffin within the slot.

4. A toaster as claimed in any of claims 1 , 2 or 3, wherein each slot has a specific sensor.

5. A toaster as claimed in any of claims 1 , 2 or 3, wherein the sensor comprises an array of sensor elements configured to enable specific determination of object location within an individual slot.

6. A toaster as claimed in any preceding claim, wherein the distinct heater comprises a specific element in a heater array for the toaster individually addressable by the control for selective activation.

7. A toaster as claimed in any preceding claim, wherein the sensor comprises a sensor arm extending within the slot towards a switch, the sensor arm displaced when an object is located in the slot to engage the switch to provide a signal to the control.

8. A toaster as claimed in claim 7, wherein the sensor arm extends along the slot.

9. A toaster as claimed in claim 7, wherein the sensor arm extends across the slot.

10. A toaster as claimed in any of claims 7 to 9, wherein the sensor arm is biased away from the switch whereby in use object mass causes displacement against the bias to engage the switch.

11. A toaster as claimed in any of claims 7 to 10, wherein the switch is a micro switch having a button or toggle depressed by the arm.

12. A toaster as claimed in any of claims 7 to 10, wherein the switch comprises electrical contacts bridged by a portion of the sensor arm.

13. A toaster as claimed in any preceding claim, wherein the sensor comprises a light beam interruptible by the sensor arm.

14. A toaster as claimed in any preceding claim, wherein the sensor comprises a light beam interruptible by an object in use within a slot.

15. A toaster as claimed in any preceding claim, wherein at least a part of the sensor is carried upon a cradle for entry of an object in use into the slot.

16. A toaster as claimed in claim 15, wherein the cradle acts for all slots.

17. A toaster as claimed in claim 15 or in claim 16, wherein the cradle has an external handle extending from the toaster.

18. A toaster as claimed in any preceding claim, wherein the sensor provides an operational quotient for an object in use when loaded in the slot.

19. A toaster as claimed in claim 18, wherein the operational quotient relates to weight, thickness, unacceptable object type or a factor influencing a period of time necessary to toast an object in use.

20. A toaster as claimed in any preceding claim, wherein the sensor comprises a clamp grill arrangement having sensor portions displaceable towards each other and a switch associated with at least one sensor portion, the switch operable when the sensor portions are displaced towards each other to determine location of an object within the slot segment.

21. A toaster as claimed in claim 20, wherein the sensor portions are end portions of the clamp grill arrangement.

22. A toaster as claimed in claim 20 or claim 21 , wherein the clamp grill arrangement is part of the slot segment.

23. A toaster as claimed in any of claims 20 to 22, wherein the clamp grill arrangement comprises two grill elements arranged to pivot about a pivot coupling at opposed end edge positions displaced from the sensor portions.

24. A toaster as claimed in any preceding claim, wherein the switch is a micro switch secured to a first sensor portion and the other sensor portion includes an actuator to engage the micro switch when displaced towards the first sensor portion.

25. A toaster as claimed in any of claims 20 to 23, wherein the switch has a plurality of indicator positions and is arranged to provide a respective indicator signal to a controller for each indicator position.

26. A toaster as claimed in claim 25, wherein one indicator position is for no object within the clamp grill arrangement.

27. A toaster as claimed in claim 25 or claim 26, wherein respective indicator positions are provided for different object thicknesses within the clamp grill arrangement.

28. A toaster substantially as hereinbefore described with reference to the accompanying drawings.

29. Any novel subject matter or combination including novel subject matter disclosed herein, whether or not within the scope of or relating to the same invention as any of the preceding claims.