GB2466954A

GB2466954A - Variable width toaster

Info

Publication number: GB2466954A
Application number: GB0900576A
Authority: GB
Inventors: David Downie; Nigel Wilkinson
Original assignee: Kenwood Ltd
Current assignee: Kenwood Ltd
Priority date: 2009-01-15
Filing date: 2009-01-15
Publication date: 2010-07-21
Also published as: GB0900576D0

Abstract

The invention relates to toasters intended for use especially, but not exclusively, in the domestic kitchen, and it relates in particular to such toasters having first and second toasting chambers (12, 18) of user-variable width to cope with foodstuffs of quite widely differing thickness, such as bread slices and bagels. The chambers have respective, individually energisable heaters, though they share a common partition wall that supports respective parts of the heaters for both. Operation of the heater for the second chamber is automatically inhibited when the first chamber is user-set, via use of lever 20which runs in slot 22, at or close to its maximum width. The lever 20 carries a mechanical actuator 26 which engages and depresses plunger 28a of a microswitch 28associated with the heating elements of second toasting chamber 18. This arrangement allows the second chamber to be used for toasting relatively thin items whilst the first chamber accommodates relatively thick items.

Description

TOASTER

This invention relates to toasters, and it relates especially, though not exclusively, to toasters intended for use in the domestic kitchen.

Our co-pending UK patent application No. GBO8 14473.5, which is incorporated herein by reference, describes a toaster having first and second toasting chambers arranged side by side and separated by a common, mobile partition. Each chamber is provided with its own heating means, and the relative width of the chambers can be adjusted by moving the aforesaid partition. This permits the first chamber to be set to a maximum width to accommodate relatively thick foodstuffs, such as bagels, by moving the partition so that the second chamber is of zero, or minimal, width.

When the partition is moved, so as to reduce the width of the first chamber, there comes a point at which the two chambers are each of substantially the same thickness. At this point, where both chambers can accommodate foodstuffs of similar dimensions, it will be appreciated that the width of the first slot is at or near its minimum dimension whilst that of the second slot is at or near its maximum dimension. The aforementioned patent application provides that operation of the heating means for the second chamber is inhibited unless the said first chamber is set at or near its minimum width dimension.

It is an object of this invention to increase further the practical utility of such toasters and accordingly the present invention provides that operation of the heating means for the second chamber is only inhibited for partition settings at which the second slot is too narrow to usefully receive any foodstuff for toasting; thereby allowing the second chamber to be additionally used for toasting thin items.

In preferred embodiments, the means for setting the width of said first toasting chamber comprises a lever member, manually movable along a slot between first and second extreme positions, associated respectively with said maximum and minimum width dimensions of the first chamber.

In such embodiments, it is further preferred that an operating member formed as part of, or otherwise associated with, said lever member is provided with means configured and dimensioned to actuate a switch member when said lever member is sufficiently far from its first extreme position to ensure that the second chamber is wide enough to accept a thin item for toasting.

Preferably, said switch member comprises part of an energisation circuit for the heating means for said second chamber.

In one preferred embodiment, the switch member comprises a mechanically actuated switch having normally closed contacts; said switch further having a casing, and a plunger normally urged outwardly of said casing by resilient means; said contacts being opened when said actuator means contacts said plunger with sufficient force to move said plunger against the urge provided by said resilient means.

In another preferred embodiment, said switch member comprises a magnetically operated reed switch and said actuator member comprises a magnetic member.

In some preferred embodiments the common mobile partition, shared by the first and second toasting chambers, is configured to support components of the heating means for both chambers.

In such embodiments, the said common mobile partition may comprise an electrically insulating support member supporting respective heating elements for the first and second toasting chambers.

Further preferably, the elements may be supported on a substantially planar and rectangular support member, for example of mica; one element being wound between connection points spaced apart along the upper and lower edges of the support member and the other being wound between connection, points spaced apart along the upright edges of the support member.

Conveniently, in any of the foregoing embodiments, at least said first toasting chamber includes a food-supporting carriage comprising respective elongate members mounted to either side of the toasting chamber and linked together by linking members which form part of the food-supporting surface and are pivotally attached to the elongate members to accommodate lateral relative movement between the elongate members as the width of the said toasting chamber is varied; as described in WO 2007/007038 and GB 2427998 A. In some such embodiments, it is preferred that unitary linking members link the two elongate members and the elongate members are urged apart by a spring. In other such embodiments, the linking members comprise a plurality of chevron-like links distributed along the length of the elongate members and having pivots at the chevron points permitting the chevron angle to vary with variations in the width-dimension of the chamber.

The chevron-like links may be regularly distributed along the length of the elongate members, and the elongate members may be notched to receive the chevron point pivots when the chamber is adjusted to its narrowest width dimension.

In another preferred embodiment, the control means includes resilient means acting upon at least one of said linking members for urging said elongate members apart.

In one such preferred embodiment, the resilient means comprises a coil spring, configured to operate in either compression or tension, fixedly supported upon one of said elongate members and connected to at least one of said linking members. By this means, the necessary resilient urge is applied in a simple and cost-effective manner.

In another preferred embodiment, the resilient means comprises a torsion spring; the shape and dimensions of which may, in some configurations, prove more convenient or more compact in use than a coil spring.

In other preferred embodiments, the resilient urge is provided by plural spring members carried by one of said elongate members; each of said spring members being coupled between a respective fixed location on said elongate means and a respective one of said linking members. It is further preferred that said spring members are evenly distributed among said linking members. In such circumstances, coil springs or torsion springs, or a combination of both, may be used.

It is further preferred that pivotal mounting points for the linking members are regularly distributed along the elongate members, thereby providing an even distribution of the resilient urging force.

In order that the invention may be clearly understood and readily carried into effect, embodiments thereof will now be described, by way of example only, with reference to the accompanying drawings, of which: Figure 1 shows a toaster having first and second slots divided by a common, mobile partition, in which the partition is set so that the first and second slots are substantially equal in width; Figure 2 shows the toaster of Figure 1, in which the partition is set so that the first slot is at its maximum width and the second slot is substantially closed; Figure 3 shows schematically a circuit arrangement for controlling the enrgisation of the heaters in the second slot; and Figure 4 shows schematically a possible arrangement of heating elements on the aforesaid partition.

Referring now to the drawings, a toaster 10 is provided with a first toasting chamber 12, accessible by way of a slot 14 in the upper surface 16 of the toaster 10. Figure 1 shows the toaster 10 configured with its first toasting chamber 12 (and associated slot opening 14) set at its minimum width, whereas Figure 2 shows the toaster configured with its toasting chamber 12 (and associated slot opening 14) set at its maximum width. Conversely, a second toasting chamber 18, disposed beside the first chamber 12, is shown as having a minimal width in Figure 2 whereas, in the setting shown in Figure 1, the chamber 18 is of substantially the same width as the first chamber 12.

The width of the chamber 12 is manually adjustable by means of a lever which runs in its own slot 22, running fore-and-aft of the toaster, and which is coupled to a mobile wall 24 defining one side of each of the chambers 12 and 18.

Use of the lever 20 permits a user to manually adjust the width of the toasting chambers 12 and 18. The lever 20 may be freely movable, to provide so-called infinite adjustment, or it may be settable at a number of discrete positions along the slot. In any event, in this embodiment, the lever 20 carries a mechanical actuator member 26 (see Figure 3), which preferably comprises a pad of firm, but resilient material capable of absorbing mechanical shock, at least to a degree. The actuator member 26 is sited so as to physically engage and depress the plunger 28a of a microswitch 28, firmly mounted by any convenient means to the chassis of the toaster 10 until the lever 20 has been moved sufficiently far along its slot 22 to ensure that the width of the second slot is sufficient to usefully accommodate at least thin items of foodstuff for toasting. The microswitch 28 is configured to be open whilst its plunger 28a is depressed; the plunger 28a being resiliently urged to a closed position for the switch, in which the plunger protrudes from the body of the microswitch, and is only urged into its open position for so long as the actuator 26 engages the plunger sufficiently firmly to overcome the resilient urge applied to the plunger. The resilience of the pad comprising actuator member 26 is preferably designed to protect the microswitch in the event that the lever 20 is moved towards the minimum-width setting position with undue force.

The actuation of switch 28 into its closed position (i.e. with its plunger 28a urged outwards) applies a low voltage signal to a controller 30 which is configured to enable a router 32 which controls the supply of electrical power to heating elements 34 associated with the second toasting chamber. Thus the operation of switch 28 is such as to disable the supply of power to the heating elements 34 associated with the second chamber 18 until the lever 20 is set to the position associated with a minimum useful operating width of the second toasting chamber 18.

It will be appreciated that the point of energisation of elements 34can be changed, in set-up during manufacture, merely by changing the thickness of the pad comprising actuator 26.

It will further be appreciated that the microswitch and pad actuator could, if desired, be replaced by a non-contact proximity switch, such as a reed switch, and a magnetic actuator.

Naturally, the elements 34 will not need to be energised each time the lever 20 is moved to or past the minimum useful width setting for the second toasting chamber 18, and thus an individual set of the standard toaster controls, or at least an on-off selector switch, may be provided for the second toasting chamber; this switch being settable by a user of the toaster so as to enable power to be supplied to the elements 34 only if the user wants to utilise the second chamber 18 for toasting.

In one such embodiment, a convenient on-off selector switch is provided by using a non-contact, proximity reed switch and an electro-magnetic actuator, the power to which can be switched on or off by the user, depending upon whether or not the second chamber is to be used.

In circumstances where power is enabled (by the combination of the setting position of the lever 20 and user-actuation of the selector switch) to flow to the elements 34 of the second toasting chamber 18, the toasting operation within that chamber may be controlled either in common with settings chosen for the first chamber 12 by user-actuation of standard controls such as those shown at 36 and 38 in Figures 1 and 2, or individually by way of a second set of such controls (not shown).

The position of the mobile common wall 24 between the two toasting chambers 12 and 18 is adjustable by means of the lever 20, as has been described, and it is desirable that this common wall is configured to support a respective electrical heating element for each of the toasting chambers.

Conveniently, the common wall 24 consists of or includes a rectangular, plate-like supporting member of electrically and thermally insulating material, such as mica, supporting respective heating elements for the first and second toasting chambers. It is then preferred that one element is wound between connection points spaced apart along the upper and lower edges of the support member and the other element is wound between connection points spaced apart along the upright edges of the support member, as schematically shown in Figure 4, wherein the supporting member is shown at 40 and the respective heating elements at 42 and 44. The heating elements are tape-like resistance elements of well-known kind; those of element 42 being wound between upper and lower arrays 46 and 48 of connection points distributed regularly along the upper and lower edges of the member 40 and those of element 44 being wound between arrays 50 and 52 of connection points distributed regularly along the vertically disposed edges of the member 40.

The arrays 46, 48, 50 and 52 of connection points are not necessarily distributed regularly along the edges of the support member 40, as described above. Indeed, in some circumstances, it may be preferred to use non-regular spacings in some or all of the arrays to achieve a desired heating pattern for the elements as a whole. It will be understood by those skilled in the art that the number of connection points shown in the arrays 46 to 52 is not representative of the number that would be used in practice, where a significantly greater number of connection points would be used. Figure 4 is intended merely to conceptually illustrate how tape-wound heating elements could be arranged on a common wall or support member.

If desired, thermal insulation between the two toasting chambers can be improved by incorporating a thermally reflective interlayer into the support member 40.

It will be appreciated that the heating means provided for the two chambers 12 and 18 need not have the same performance, or even be of the same kind. Thus it is feasible, for example, to provide wound tape resistance elements for one chamber and quartz halogen or other heating lamps in the other. In such circumstances, the differing heater types in the two chambers may respectively be chosen for optimal performance with differing kinds of foodstuffs and if desired the toaster may bear icons or other markings to indicate which foodstuffs are preferentially toastable in the two slots.

Claims

CLAIMS: 1. A toaster having first and second toasting chambers arranged side by side, each chamber being provided with its own heating means; wherein the first toasting chamber is variable in width and manually settable to a plurality of settings between a minimum width dimension and a maximum width dimension; operation of the heating means for the second chamber being inhibited for settings at which the second chamber is too narrow to usefully receive any foodstuff for toasting.
2. A toaster according to claim 1, wherein the means for manually setting the width of said first toasting chamber comprises a lever member movable along a slot between first and second extreme positions, associated respectively with said maximum and minimum width dimensions.
3. A toaster according to claim 2, wherein an operating member formed as part of, or otherwise associated with, said lever member is provided with actuator means configured and dimensioned to actuate a switch member.
4. A toaster according to claim 3, wherein said switch member comprises part of an energisation circuit for the heating means for said second chamber.
5. A toaster according to claim 3 or claim 4, wherein said switch member comprises a mechanically actuated switch having normally closed contacts; said switch further having a casing, and a plunger normally urged outwardly of said casing by resilient means; said contacts being opened when said actuator means contacts said plunger with sufficient force to move said plunger against the urge provided by said resilient means.
6. A toaster according to claim 3 or claim 4, wh'erein said switch member comprises a magnetically operated reed switch and said actuator member comprises a magnetic member.
7. A toaster according to any preceding claim, wherein the first and second toasting chambers share a common, mobile wall configured to support components of the heating means for both chambers.
8. A toaster according to claim 7, wherein the said common wall comprises an electrically insulating support member supporting respective heating elements for the first and second toasting chambers.
9. A toaster according to claim 8, wherein the elements are supported on a substantially planar and rectangular support member, for example of mica.
10. A toaster according to claim 8 or claim 9, wherein one element is wound between connection points spaced apart along the upper and lower edges of the support member and the other is wound between connection points spaced apart along the upright edges of the support member.
11. A toaster according to any preceding claim, wherein at least said first toasting chamber includes a food-supporting carriage comprising respective elongate members mounted to either side of the toasting chamber and linked together by linking members which form part of the food-supporting surface and are pivotally attached to the elongate members to accommodate lateral relative movement between the elongate members as the width of the said toasting chamber is varied.
12. A toaster according to claim 11, wherein unitary linking members link the two elongate members and the elongate members are urged apart by a spring.
13. A toaster according to claim 11, wherein the linking members comprise a plurality of chevron-like links distributed along the length of the elongate members and having pivots at the chevron points permitting the chevron angle to vary with variations in the width-dimension of the chamber.
14. A toaster according to claim 13, wherein the chevron-like links are regularly distributed along the length of the elongate members, and the elongate members are notched to receive the chevron point pivots when the chamber is adjusted to its narrowest width dimension.
15. A toaster according to any of claims 11 to 14, wherein the control means includes resilient means acting upon at least one of said linking members for urging said elongate members apart.
16. A toaster according to claim 15, wherein the resilient means comprises a coil spring, configured to operate in either compression or tension, fixedly supported upon one of said elongate members and connected to at least one of said linking members.
17. A toaster according to claim 15, wherein the resilient means comprises a torsion spring.
18. A toaster according to any of claims 15 to 17, wherein the resilient means comprises plural spring members carried by one of said elongate members; each of said spring members being coupled between a respective fixed location on said elongate means and a respective one of said linking members.
19. A toaster according to claim 18, wherein said spring members are evenly distributed among said linking members.
20. A toaster according to claim 19, wherein pivotal mounting points for the linking members are regularly distributed along the elongate members, thereby providing an even distribution of the resilient urging force.
21. A toaster according to any preceding claim, wherein the heating means associated with the first and second chambers are of differing kinds.
22. A toaster according to claim 21, wherein one of said heating means comprises a resistive tape wound on an insulative support member and the other heating means comprises a quartz halogen or other heating lamp device.
23. A toaster substantially as herein described.