HK1119925B - Toaster - Google Patents

Description

Baking oven

Technical Field

The present invention relates to ovens and in particular, although not exclusively, to ovens for use in domestic kitchens.

Background

Electrically operated ovens are a stock item in most domestic kitchens and although relatively modest purchase prices are established for them, they tend to be rather durable and reliable in use. However, changes in traditional eating habits that have led to the development of a popular taste for more ovenable meals have recently led to the development of technologies that increase the complexity of ovens, increase their efficacy and provide greater flexibility of use.

One particular area of concern with ovens is their ability to process food items of considerably different sizes; in particular, the thickness dimension of the food that the user may wish to toast can vary widely. A number of so-called "variable slot" ovens have therefore been proposed that can accommodate food items ranging from relatively narrow, such as sliced bread, to relatively wide width sizes, such as bagels and similar products.

Not all of these proposals have been commercially successful, however, and it is believed that in this regard (among others) it is difficult to manufacture certain internal components whose dimensions need to be economically varied as a function of slot width, while maintaining strength and reliability in operation, noting that such internal components operate in extremely hostile and challenging environments.

This difficulty is particularly acute with respect to food support brackets that are movable within the oven slot; the rack is locked in a lower position to support food adjacent the heating element during toasting and then released to spring upwardly at the end of the toasting cycle to present the toasted food for easy removal from the toaster slot. It is known that the heating element is de-energised when the carriage is raised to its presentation position and the locking mechanism is deactivated unless the oven is energised.

It will be appreciated that regardless of the slot position set by the user, the rack needs to be able to reliably support a wide variety of foods, as otherwise potentially dangerous situations may result. For example, if food is pinched between the edge of the rack and the heating element or heater support, the oven may jam causing the rack to sag (and thus the heater to power up), which may lead to a potential fire hazard. Thus, it is noted that a user may inadvertently set (or hold) the slot in a wider position while attempting to toast a thinner food item.

Disclosure of Invention

It is an object of the present invention to provide a variable slot oven whose bracket can reliably accommodate slot width variations and which can be economically manufactured.

According to the present invention there is provided an oven comprising: the slot-shaped baking chamber can be used for placing food to be baked, and corresponding heating elements are arranged on two sides of the baking chamber; a rack having a food supporting surface; a support structure for the rack configured to allow the rack to be locked in a lower position in which food is exposed to the heating element for toasting, released upon completion of a toasting cycle, and raised to an upper presentation position in which toasted food can be removed from the toaster; and user operated means for varying the width dimension of the toasting chamber to accommodate different thicknesses of food; wherein, the support includes: first and second elongate members extending along the length dimension of the chamber and arranged on one and the other side of the chamber respectively; a plurality of connecting members connecting the elongated members and pivotally mounted to each elongated member, the connecting members collectively forming at least a majority of the food supporting surface of the rack; control means maintaining said elongate members in contact with opposite sides of the chamber such that said elongate members move relative to each other as the chamber width dimension changes; such movement of the elongate member is provided by pivotal movement of the connecting member whereby the carriage automatically accommodates said change in the width dimension of the toasting chamber.

In a preferred embodiment the control means comprises latching means for latching the elongate members to opposite sides of the chamber whereby movement of the width dimension of the chamber will urge the elongate members towards each other or away from each other depending on the user selected setting of said width dimension.

By this means, no special handling means are required to adapt the width of the carriage to changes in the width dimension of the firing chamber.

Conveniently in this arrangement the connecting means comprises a plurality of chevron-shaped links distributed along the length of the elongate member, said chevron-shaped links having a pivot axis at the apex of the chevron to allow the chevron angle to vary as the width dimension of the chamber varies.

The V-shaped links may be evenly distributed along the length of the elongate member and the elongate member may be formed with a notch for accommodating the V-shaped apex pivot axis when the chamber is adjusted to its narrowest width dimension.

In another preferred embodiment, the control means comprise elastic means acting on at least one of said connection members to drive said elongated members apart.

In one such preferred embodiment, the resilient means comprises a helical spring fixedly supported on one of said elongate members, said helical spring being configured to act in tension or compression and being connected to at least one of said connecting members. The required elastic drive is applied in a simple and cost-effective manner by means of the device.

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

In other preferred embodiments, a plurality of spring members carried by one of the elongate members provide the resilient drive; each of the spring members is connected between a respective fixed position of the elongate member and a respective one of the connecting members. More preferably, the spring members are evenly distributed in the connecting member. In this case, a coil spring or a torsion spring, or a combination thereof may be used.

More preferably, the pivotable mounting points for the connecting members are evenly distributed along the elongate member, thereby providing an evenly distributed resilient driving force.

In order that the invention may be clearly understood and readily put into practical effect, various embodiments are described below by way of examples with reference to the accompanying drawings.

Drawings

FIG. 1(a) shows in perspective a portion of a toaster according to a first embodiment of the present invention, wherein a toaster wall is removed to show a support frame with respect to other internal components of the toaster;

FIG. 1(b) shows a detailed top view of the oven slide element;

figure 2 shows in perspective the basic elements of a support for an oven according to said first embodiment of the invention;

figures 3, 4 and 5 show the basic elements of a support for an oven according to a second embodiment of the invention in a wide, medium and narrow setting, respectively, in partial top views from the top.

Detailed Description

Referring now to figures 1 and 2 of the drawings, an oven in accordance with one embodiment of the present invention comprises a main housing 1 in which is defined a slot-shaped oven chamber 2 flanked by either convenient heating element 3. The heating element is typically a generally rectangular planar element as shown, which is supported in a known manner so that it stands upright on either side of the chamber 2, effectively forming a side wall thereof. In this example, each heating element is protected from direct contact with food inserted into the toasting chamber 2 by a grid-like shield member 4.

In the chamber 2 there is provided a food supporting carriage 5, supported in a known manner by conventional supporting structures (not shown in the figures) configured to allow locking of the carriage in a lower position in which the food is exposed to the heating elements for toasting, releasing the carriage at the completion of a toasting cycle, and raising the carriage to an upper presentation position in which the toasted food can be removed from the toaster.

User operable means including a slide mechanism 6 are provided for varying the width dimension a of the chamber to accommodate food of different thicknesses. In this example, the sliding mechanism 6 is arranged inside a casing (not shown in the figures) of metal or plastic material and is operated by means of an operating lever arrangement (not shown in the figures) accessible by the user outside the casing. In this example, the internal sliding mechanism 6 comprises a slot structure 7 (best shown in fig. 1 (b)) comprising a plurality of constrictions of a respective discrete width arrangement defining the slot-like baking chamber 2. In an alternative embodiment, the width setting may be smoothly changed to any selected position between the two terminal ends.

As shown in more detail in fig. 2, the carriage 5 comprises a first elongate member 51 and a second elongate member 52 extending along the length dimension B of the chamber and arranged on one side and the other side of the chamber 2 respectively. Providing a plurality of link members 53a to 53n, each link member connecting the elongate members 51 and 52 and being pivotally mounted on each elongate member; and resilient means 54 are provided to urge the elongate members 51 and 52 apart whereby the carriage 5 automatically accommodates changes in the width dimension a of the chamber. Here, it should be understood that in the present embodiment the member 52 remains in contact with the heater guard member on one side of the slot 2, while the member 51 is movable laterally of the oven slot; toward or away from member 52 to properly maintain contact with the heater shield member on the other side of the slot. The part 51 is pushed towards the part 52 by contact with the heater guard 4 when the slot 2 is narrowed by the user, or the part 51 is pushed away from the part 52 by the resilient means 54 when the slot 2 is widened.

In this example of the invention, the resilient means 54 comprises a single helical spring fixedly supported on the elongate member 52 and configured to act in compression, although the helical spring could of course alternatively be mounted and configured to act in tension, depending on the detailed construction of the assembly. The spring is also connected to the connecting part 53a in this example, but it may alternatively or additionally be connected to one or more of the other connecting parts. By means of which the required elastic drive is applied in any case in a simple and cost-effective manner.

In a further alternative arrangement, the resilient drive may be provided by a torsion spring and/or a plurality of any convenient type of spring members carried by one, the other or both of the elongate members 51 and 52; each such spring member is connected between its respective fixing position of the elongate means and the respective one or more connecting members. If a plurality of spring members are provided, they are preferably evenly distributed in the connecting member.

It is particularly preferred (although not essential) that the pivotable mounting points of the connecting members 53a to 53n are evenly distributed along the elongate members 51 and 52, thereby providing an evenly distributed resilient driving force.

In some preferred embodiments of the invention, the movable member 5 (or at least a portion thereof) is effectively made of or coated with a durable and smooth material, such as ceramic or a non-stick material known under the registered trade mark "Teflon", that can withstand repeated frictional contact with the heater guard member 4.

Referring now to figures 3, 4 and 5, which illustrate different working thickness settings of a toaster according to a second embodiment of the present invention, a bracket 60 comprises first and second elongate members 61 and 62 extending along a length dimension B of the toaster chamber 70 and arranged on one and the other side of the toaster chamber 70, respectively, as previously described. Providing a plurality of pairs of V-shaped connector members, such as 63a and 63 b; each link member is pivotally connected to a respective elongate member 61 or 62, and each pair of link members, e.g. 63a and 63b, are pivotally connected to each other, as at 66. Each end of each elongate member 61, 62 is secured by an aperture such as 67 to an upstanding wire such as 68 forming part of the heater guard member on the associated side of the oven chamber 70 so that the carriage 60 can perform the required vertical movement only by each aperture such as 67 moving up and down on the respective wire such as 68. As the chamber is widened or narrowed, the elongate members undergo corresponding movement towards or away from each other due to the direct connection with the wires as at 68.

Thus, in this embodiment of the invention, there is no need for any resilient member to drive the elongate members apart as in the first embodiment, since by virtue of the direct mechanical connection of the elongate members 61 and 62 to the wires such as 68, the structure of the carriage 60 is such that it can accommodate variations in the width dimension a of the toasting chamber 70 simply by said elongate members 61 and 62 being pushed towards or pulled away from each other moderately.

It will also be appreciated that the overall longitudinal offset between the two elongate members 61 and 62 which needs to be accommodated in the second embodiment of the invention is only about half that required for the elongate members 51 and 52 in the first embodiment, due to the folding ability of the pair of link members such as 63a and 63b provided by the central pivot axis such as 66.

The inner surface of each elongate member 61 and 62 (i.e. the surface remote from the heater and into the toasting chamber 70) is formed with a plurality of notches such as 69 to accommodate the central pivot axes such as 66 of the respective pairs of link members such as 63a and 63b when the toasting chamber 70 is set to the narrow setting shown in figure 5.

In some preferred embodiments of the invention, the holes such as 67 are effectively made of or coated with a durable and smooth material, such as ceramic or a non-stick material known under the registered trademark "Teflon", which can withstand repeated frictional contact with the wire such as 68 during the up and down movement of the carriage 60 at different stages of the baking process. Alternatively or additionally, the filaments as 68 may be so made or coated. Alternatively, any convenient linear bearing operable in a bake chamber environment may be used to understand elongate members 61 and 62 to a wire such as 68.

Claims (15)

1. An oven, comprising: the slot-shaped baking chamber can be used for placing food to be baked, and corresponding heating elements are arranged on two sides of the baking chamber; a rack having a food supporting surface; a support structure of the rack configured to allow the rack to be locked in a lower position in which food is exposed to the heating element for toasting, released upon completion of a toasting cycle, and raised to an upper presentation position in which toasted food can be removed from the toaster; and user operated means for varying the width dimension of the toasting chamber to accommodate different thicknesses of food; wherein, the support includes: first and second elongate members extending along the length dimension of the chamber and arranged on one and the other side of the chamber respectively; a plurality of connecting members connecting the elongated members and pivotally mounted to each elongated member, the connecting members collectively forming at least a majority of the food supporting surface of the rack; control means maintaining said elongate members in contact with opposite sides of the chamber such that said elongate members move relative to each other as the chamber width dimension changes; such movement of the elongate member is provided by pivotal movement of the connecting member whereby the carriage automatically accommodates said change in the width dimension of the toasting chamber.

2. A toaster according to claim 1, wherein the control means comprises latching means for latching the elongate members to opposite sides of the chamber, whereby movement of the width dimension of the chamber pushes said elongate members towards each other or pulls them apart, depending on the setting of said width dimension selected by the user.

3. A toaster according to claim 1 or claim 2, wherein the connecting means comprises a plurality of chevron-shaped links distributed along the length of the elongate members, said chevron-shaped links having a pivot axis at the apex of the chevron so as to allow the chevron angle to vary as the width dimension of the chamber varies.

4. A toaster according to claim 3, wherein the V-shaped connectors are evenly distributed along the length of the elongate members.

5. A toaster according to claim 3, wherein the elongate members are formed with notches for accommodating the V-shaped apex pivot axes when the chamber is adjusted to its narrowest width dimension.

6. A toaster according to claim 1 or claim 2, further comprising a plurality of aperture members attached to each of said elongate members, and each aperture member is adapted to slide vertically relative to a corresponding fixed upright wire member to accommodate vertical movement of the support frame during the toasting process.

7. A toaster according to claim 6, wherein each of said aperture members and/or each wire member is made of or coated with a durable non-stick material which is capable of undergoing repeated frictional contact in connection with said vertical movement.

8. A toaster according to claim 1, wherein the control means comprises resilient means acting on at least one of said connecting members to urge said elongate members apart.

9. A toaster according to claim 8, wherein the resilient means comprises a coil spring fixedly supported on one of said elongate members, said coil spring being configured to act in tension or compression and being connected to at least one of said linking members.

10. A toaster according to claim 8, wherein the resilient means comprises a torsion spring fixedly supported on one of said elongate members and connected to at least one of said linking members.

11. A toaster according to claim 8, wherein the resilient means comprises a plurality of spring members carried by one of said elongate members; each of the spring members is connected between a respective fixed location on the elongate member and a respective one of the connecting members.

12. A toaster according to claim 11, wherein said spring members are evenly distributed about said connecting member.

13. A toaster according to any of claims 8 to 12, wherein the pivotable mounting points of the linking members are evenly distributed along the elongate members, thereby providing an evenly distributed resilient urging force.

14. A toaster according to any of claims 8 to 12, wherein at least a portion of one or both of said elongate members is made of or coated with a durable and/or non-stick material to facilitate sliding of the so-formed or coated elongate member relative to a guard juxtaposed with the heating element.

15. A toaster according to claim 4, wherein the elongate members are formed with notches for accommodating the V-shaped apex pivot axes when the chamber is adjusted to its narrowest width dimension.