GB2515737A - Bread-making kitchen appliance - Google Patents

Abstract

The present invention relates to a front-loading bread maker (1, Fig.1). The front-loading bread maker has a hinged front-opening door (3, Fig.1), and a removable container (7, Fig.3) in which bread-making ingredients are processed and baked. Presentation means urge the container out of the oven cavity through the door. A drive means for a motor comprises a coupling 24 between a first drive member 30 coupled to a bladed means and a second drive member 23 driven by said motor. The second member comprises second engagement means adapted to couple with a first engagement means of the first member when the container is in the cavity. The engagement means have co-operatively shaped engagement for disengagement irrespective of their orientation relative to the direction in which the container is urged by the presentation means. In another aspect, a sensor (36, Fig.4) senses the angle of rotation of rotating parts to interrupt drive to stop the rotation in an alignment that facilitates extraction of the container.

Description

I

BREAD-MAKING KITCHEN APPLIANCE

This invention relates to kitchen appliances for making bread, and it relates in particular to such appliances having front-loading capabilities, and to associated arrangements facilitating i:he insertion and ext raction of bread containers into and from such appliances.

Whilst domestic bread-making appliances are well known and generally efficient, especially bearing in mind the pt-ices at which they are made and sold, they can exhibit certain disadvantages. in particular, many such appliances are provided, on their top surfaces, with hinged or slidable lids through which bread containers are loaded, and this can result in difficulties, for example, where the appliance is to be used on a worktop and in the relatively restricted space beneath a kitchen cabinet.

It is therefore preferable from the above standpoint to provide bread-making appliances with a front-loading capability and indeed some appliances are currently configured in that way, having front-facing apertures closable with doors hinged either to one side or the other, or above or below the aperture. The bread containers can be inserted into and withdrawn substantially horizontally from such appliances, thus improving access. However, it will he appreciated that, during the bread-making process, the ingredients in the container are acted upon by one or more blades, driven from beneath the container and used to knead, stir or mix the ingredients. This creates particular difficulties for front-loading bread makers, since there is a tendency for the drive system to interfere with the clean insertion and withdrawal of the container into an.d from the appliance and this can be exacerbated where, as is convenient, the container is associated with a carriage means that is automatically guided out of; or withdrawn into, the bread-maker's oven cavity when the door is opened or closed, since a user may well open or close the door without considering the operational state of the bread-maker.

From. one aspect, therefore, the invention seeks to address these difficulties.

1.0 According to the invention from said one aspect, there is provided a front-loading bread maker having an oven cavity with heating means associated therewith; the cavity being closeable by means of a hinged door, a removable container, in which breadmaking ingredients are processed and baked in the oven cavity, and presentation means for urging the container out of th.e oven cavity through the door; the bread maker further including a bladed means for mixing, kneading and/or stifling ingredients in said container and drive means including a motor for moving said bladed means in rotation to effect said nnxing, kneading and/or stirring thnctions, wherein said drive means farther comprises a coupling between a first drive member associated with the container, said first drive member being coupled to the bladed means and having first engagement means disposed beneath the base of the container, and a second drive member, driven by said motor and comprising second engagement means adapted to couple with said first engagement means when said container is seated in said cavity, wherein said first and second engagement means are configured with co-operatively-shaped engagement surfaces whereby said first arid second engagement means can be readily disengaged irrespective of their orientation relative to the direction in which said container is urged by the presentation means, Preferably, said first and second engagement means comprise respective elongate rnerribers Lomied with respective end-pieces shaped to slide relative to one another during disengagement.

In some preferred embodiments, the end-pieces incorporate respectively chamfered extremity portions.

It is ftirther preferred that said end-pieces comprise, inboard of said extremities, respective concave and convex surface portions configured to inter-engage when the container is in its baking position in said cavity.

Another difficulty which arises with bread making appliances in general is that of minimising damage to the bread by the blade or paddle used to knead the mixture during the proving and/or baking process. The blade or paddle necessarily embeds itself into the bread mix, arid the removal of the bread from the container can significantly impair the appearance of the undersurface of the loaf According to the invention from another aspect, therefore, there is provided a front-loading bread maker having an oven cavity with heating means associated therewith; the cavity being closeabie by means of a hinged door, a removable container, in which bread-making ingredients are processed and baked in the oven cavity, and presentation means for urging the container out of the oven cavity through the door; the bread maker further including a biaded means for mixing, kneading and/or stirring ingredients in said container and drive means including a motor for moving said biaded means in rotation to effect said mixing, kneading and1or stirring functions wherein said drive means further comprises sensor means for sensing the angle of rotation of said bladed means arid control means for responding to a signal comprising an instruction to stop the rotation of said bladed means by interrupting the operation of said drive means when the bladed means is in substantial alignment with the direction in which said container is urged by the presentation means. 1.0

Preferably, said direction is substantially parallel to the direction in which bread baked in the container will] be sliced, thereby limiting to one, or at most a few slices, the visual effect of damage to the underside of the loaf by the bladed means.

In one preferred embodiment of the invention, the sensor means utilises Halheffect sensors and associated magnets to sense the angle of rotation of said hiaded means.

It is further preferred that the rotational drive imparted to said biaded means is permitted to overshoot somewhat the intended angular position at which said bladed means is to stop, and the drive is then reversed to ensure the preferred alignment.

In order that the invention may be clearly understood and readily carried into effect, one embodiment thereof will now be described, by way of example only, with reference to the accompanying drawings, of which: Figure 1 shows an external, perspective view of a front-loading bread maker in accordance with one embodiment of the invention; Figure 2 shows a view similar to that of Figure 1, hut with part of the casing removed to show components of an automatic system, used in one embodiment of the invention, to move a container into and out of the bread maker; Figure 3 shows the bread maker of Figures 1 and 2 with the door and roof removed to display the container in situ and certain associated components; Figure 4 shows a view of the brea.d maker from the underside and with the bottom casing removed, to illustrate the position of a large gear which carries sensor components; and Figure 5 shows a perspective view into the oven cavity of the bread maker, to illustrate the means of ready engagement and dis-engagement of couplings used to drive a kneading blade within the container in which loaves are baked.

Referring now to the drawings, wherein identical components carry the same reference numbers throughout, a bread maker I comprises an outer casing 2 which defines a heatabie oven cavity having a front-opening door 3 hinged at its lower edge 4 to the casing 2. The roof 5 of the casing 2 is formed with a window 6 through which the progress of the baking process can be observed; the bread-making ingredients being worked and baked in an open-topped container 7 (Figure 3) that slides into and out of the oven cavity and is presented for removal from the cavity by means of a suitable automatic ejection mechanism which urges the container 7 outwardly when the door 3 is opened and likewise draws the container 7 towards its correct position in the oven cavity when the door is closed.

The ejection mechanism can take any convenient form. In this example however, as shown in Figure 2, it comprises a system of levers, generally shown at 8, coupling the door 3 to a carriage (not shown) that comprises an aperture shaped to accommodate the container 7. The carriage, together with the container 7, is pulled outwards from the oven cavity by actuation of the lever system when the door is opened, and is moved back into the cavity by the reverse process when the door is closed. The container 7 is provided (Figure 3) with feet 9 containing angled portions configured to dovetail with correspondingly angled portions 11 of a track 12 (see Figures 3 and 5). fixed into the base of the oven cavity, which is intended to hold the container 7 securely in place whilst it is positioned for baking and engaged with a drive mechanism provided to turn a kneading blade or paddle within the container.

The lever system 8, as shown in outline in Figure 2, comprises an intermediate lever 13 pivotally mounted both to a bracket 14 attached to the door 3 and to a main lever IS whose upper end 16 is pivotally mounted to the frame of the oven cavity, permitting the lower end 1 7 to move to and fro adjacent the right-hand edge of the oven cavity base when the door 3 is opened or closed. The movement of the lower end 17 of the main lever 15 is, of course, arcuate so it is slotted at 18 in order that it can permanently engage with a pin 19 extending transversely from the aforementioned carriage, and thereby drive the carriage out of or into the oven cavity each time the door 3 is opened or closed.

In some embodiments of the invention, the lever system is provided at one side only of the oven cavity. In preferred embodiments, however, duplicate lever systems are provided, one to either side of the oven cavity, thereby providing a more reliable and more powerftil ejection and withdrawal system.

The aforementioned dovetailing surfaces 10 and 11 are quite critical to this particular system, in that they need to be sufficiently tight-fitting to i s ensure that the container 7 is held firmly in place during the proving and baking process whilst permitting ready withdrawal and insertion of the container 7 by relative sliding motion. If necessary, the fixed dovetail surfaces 11 and/or the facing surfaces 10 of the associated runners 9 carried on the underframe of the container 7 can be coated or otherwise provided with a layer of a slippery substance such as that known by the Registered Trade Mark Teflon, in order to promote ready release/engagement and sliding of the facing surfaces.

The oven cavity can heated in any convenient way but, in this example, a blown air heating system is used, and some outlet vents for hot air can be seen at 20 in Figures 3 and 5.

The bread maker includes, within the container 7, a blade or paddle for mixing, kneading and/or stirring ingredients and there is ffirther provided a motor for rotating the blade or paddle. The motor is mounted in a location where it is protected, at least to a degree, from the heat used for S baking, and it drives the blade or paddle indirectly, via a drive system including a large gear 21 (Figure 4). which is mounted beneath the floor 22 of the oven cavity.

The gear wheel. 21 is arranged to rotate a shaft which passes through the floor 22 of the oven cavity and drives a first elenient 23 of a coupling 24 located inside the oven cavity and close to the floor 22 thereof The element 23 comprises an elongate member 25 extending radially in both directions from the shaft, and formed at each end with an enlarged head portion 26, 27, each containing arcuate cut-outs such as 28 and being formed with chamfered ends such as 29, for reasons that will be made clear later.

A second element 30 of the coupling 24 is associated with and coupled to the aforementioned container 7 in which the bread is baked. The element 30 comprises an elongate member 31 of similar length and format to the elongate member 25 of element 23, and its ends are similarly shaped, except that the arcuate cut-outs such as 28 are replaced by rounded protrusions such as 32 which can engage into the cut-outs such as 28 when the coupling 24 is being driven. The ends of the elongate member 31 are chamfered, as shown at 33, similarly to the ends 29 of the elongate member 25.

The element 30 has a sha:ft 34 which passes through the base of the bread-making container 7 and terminates in a portion 35 which has a flattened side or some other convenient configuration allowing it to receive and drive a hollow shaft to which a stirring or kneading blade or paddle is mounted so as to be rotatably drivable through the ingredients in the container 7.

The co-operatively-shaped engagement surfaces such as 29 and 33 of the elongate members 25 and 3 1 are configured to ensure that the coupling 23 can readily engage or disengage, irrespective of the orientation of the elongate members 25 and 3 1 relative to the direction in which said container is loaded and unloaded from the oven cavity.

It is preferred however that, at least once the bread is baked or nearly baked, such that a loaf is substantially formed in the container 7, the rotational movement of the paddle is stopped with the members 25 and 3 1 in a preferential disengagement position with respect to the loading and unloading direction, for two main reasons. First, the base of the loaf will have formed around the blade, and it is undesirable to attempt to enforce further rotation of the blade since that would likely cause significant damage to the underside of the loaf and may also cause damage to the drive system. Secondly, it is desirable to confine the inevitable damage caused by the blad.e to the base of the loaf to as few slices of the bread as possible. By stopping the blade in a predetermined position, this can he made to lie across the narrower dimension of the bread, i.e. parallel to the natural direction of slicing. Accordingly, the damage caused by the blade can he confined to one, two or in any event just a few slices, depending how thickly the bread is cut.

This latter requirement implies that the long dimension of the bread should lie from side to side across the oven cavity and thus that the stirring/kneading blade should be stopped with its flat surface disposed in the plane of the withdrawal drec1:ion, At the same time, the elongate members of the coupling 23 should be disposed to ensure ready disengagement.

The stopping orientation of the blade and of the coupling 23 can be controlled by means including a sensor 36 (Figure 4) configured to detect part at least of the angular motion of the coupling 23 arid to respond to a "stop" instruction only when the orientation conforms to a desired range is of angular positions. It will be appreciated that the "stop" signal will usually be automatically generated by the hreathmaker when it is determined (either by a timing process or otherwise) that the proving process is complete, or at least that further stirring/kneading is no longer required, although the signal may alternatively be generated in response to manual. actuation of a control button by a user of the appliance.

in any event, the requirement is to note the stop signal, to stop the drive to the blade when the blade is in its preferred orientation arid to place the elements of the coupling 23 in condition for easy separation from one another.

In this embodiment, the sensor 36 comprises a Halheffect magnetic sensor (Figure 4) which responds to magnets (not shown) mounted over an arc of the gear wheel 21 and terminating at the desired orientation or thereabouts. In principle, the arrangement could be such that the motor is stopped under the control of a processor device when a stop signal has been received and the sensor has detected the passage of the arc of magnets. In practice, however, this is not the case, partly because the motor is necessarily quite powerful and is thus difficult to stop on the fly at a predetermined orientation, or socalled "homing" angle and partly 1.0 because of the need to ensure ready separation of the elements of the coupling.

Accordingly, ii is preferred, iii accordance with an aspect of this invention, to provide a homing protocol. that involves subjecting the motor to reduced speed operation and a reversal of the drive direction.

The techniques used to achieve speed reduction and drive direction reversal will depend to an extent upon the kind of motor employed, but such techniques are well known to those skilled in the art and are thus not thrther described herein.

A procedure that has been found satisfactory in practice involves the following steps: Full speed operation (forwards direction) fbr dough mixing/kneading; then, following receipt of a "stop" signal: Slow speed forwards until the magnets are sensed by the HaI1effect sensor 36; Quick stop (e.g. by dumping back-e.mf from the motor across a resistor); Slow speed backwards until the magnets are no longer sensed by the Hall-effect sensor; and Quick stop (as before).

The above procedure has been found to reliably stop the motor with the drive coupling 23 (and thus the stirring1cneading blade) in the chosen, homed orientation, whilst the reverse motion is effective to separate the elements of the drive coupling 23 and facilitate their disengagement from one another.

In the event that a user opens the door 3 whilst the bread-maker is in operation, it has been found thai: the shaping of the complementary elements of the drive coupling allows the automatic withdrawal system 8 to separate the elements 23 and 30 of the drive coupling 23 withoul placing undue pressure on the door opening mechanism and without requiring significant user effort. Similarly, if the door is closed whilst the drive system is in operation, the shaping of said complementary elements allows them to dock reliably and without offering significant resistance to the door-closing operation.

Claims (12)

1. CLAiMS 1. A front-loading bread maker having an oven cavity with heating means associated therewith; the cavity being closeable by means of a hinged door, a removable container, in which bread-making ingredients are processed and baked hi the oven cavity, and presentation means for urging the container out of the oven cavity through the door; the bread maker further including a biaded means br mixing, kneading and/or stining ingredients iii said container and drive means including a motor for moving said bladed means in rotation to effect said mixing, kneading and/or stirring thnctions, wherein said drive means frirther comprises a coupling between a first drive member associated with the container, said first drive member being coupled to the bladed means and having first engagement means disposed beneath the base o:f the container, and a second drive member, driven by said motor and comprising second engagement means adapted to couple with said first engagement means when said container is seated in said cavity, wherein said first and second engagement means are configured with co-operatively-shaped engagement surfaces whereby said first and second engagement means can be readily disengaged irrespective of their orientation relative to the direction in which said container is urged by the presentation means.
2. 2. A bread maker according to claim 1, wherein said first and second engagement means comprise respective elongate members formed with respective end-pieces shaped to slide relative to one another during disengagement.
3. 3. A bread maker according to claim 2, wherein the end-pieces incorporate respectively chamfered extremity portions.
4. 4. A bread maker according to claim 2 or claim 3, wherein said end-pieces comprise, inboard of said extremities, respective concave and convex surface portions configured to inter-engage when the container is in its baking position in said cavity.
5. 5. A front-loading bread maker having an oven cavity with h.eating means associated therewith; the cavity being closeable by means of a hinged door, a removable container, in which bread-making ingredients are processed and baked in the oven cavity, and presentation means urging the container out of the oven cavity though the door; the bread maker further including a bladed means for mixing, kneading andior stirring ingredients in said container and drive means including a motor for moving said bladed means in rotation to effect said mixing, kneading and/or stirring functions wherein said drive means further comprises sensor means for sensing the angle of rotation of said bladed means and control means for responding to a signal comprising an instruction to stop the rotation of said bladed means by interrupting the operation of said drive means when the bladed means is in substantial alignment with the direction in which said container is urged by the presentation means.
6. 6. A bread maker according to claim 5, wherein said direction is substantially parallel to the direction in which bread baked in the container will be sliced, thereby limiting to one, or at most a few slices, the visual effect of damage to the underside of the loaf by the bladed means.
7. 7. A bread maker according to claim 5 or claim 6, wherein the sensor means utihses Haiheffect sensors and associated magnets to sense the angle of rotation of said biaded means.
8. 8. A bread maker according to any preceding claim, wherein the rotational drive imparted to said bladed means is permitted to overshoot somewhat the intended angular position at which said bladed means is to stop, and the drive is then reversed.
9. 9. A bread maker according to any preceding claim, wherein said container is associated with a carriage automatically moveable into and out of the oven cavity by means linking it to the door.
10. 10. A bread maker according to claim 9, wherein said carriage is linked to said door by means of at least one ever system disposed adjacent a side wall of said oven cavity.
11. 11. A bread maker according to claim 9 or claim 10, wherein said container is provided with a base having angled protrusions intended to dovetail with complementary protrusions fixedly mounted to the base of the oven cavity to firmly hold the container in place during the baking operation.
12. 12. A front-loading bread maker substantially as herein described and/or as shown in the accompanying drawings.