WO2024125879A1

WO2024125879A1 - A braking device, bowl assembly and feed tube for a food processor

Info

Publication number: WO2024125879A1
Application number: PCT/EP2023/080276
Authority: WO
Inventors: Daniel LEBSACK; Christoph Eissengarthen; Christof Kleemann
Original assignee: De'longhi Braun Household Gmbh
Priority date: 2022-12-12
Filing date: 2023-10-30
Publication date: 2024-06-20

Abstract

There is provided a braking device for a food processor (1), comprising a plurality of discrete, preferably different, braking devices, wherein the discrete braking devices are operatively connected.

Description

A BRAKING DEVICE, BOWL ASSEMBLY AND FEED TUBE FOR A FOOD PROCESSOR

Field of the Invention

The present invention relates to a braking device for a food processor, as well as to a feed tube for a food processor, a bowl assembly comprising the braking device or feed tube and a food processor comprising a combination of the braking device, feed tube and/or bowl assembly.

Background on the Invention

Braking systems for food processing devices are often sold with food processing accessories. Those accessories commonly comprise a container, a lid and a number of different food processing tools, , within the container, the food processing tool being fully enclosed during use. A handheld motor unit commonly attaches to the lid to drive the tool. Those food processing accessories contain dangerous tools (such as knives, cutting discs, etc) which are rotating at high speed and pose a risk to safety. For this reason, international safety standards (such as EN 60335) require a safety function for these devices. If a user opens the lid of the processing container while running, the processing tool is required to stop rotating within a certain time to minimize the risk of injury.

For a food processing device in which the motor is inserted from the top of the container such as hand blender attachments with food processing tools, the tool is disconnected from the drive system when the lid is opened as the drive is removed with the lid while the tool remains in the container. As such the stopping function can only be realized by interaction of tool and container.

One such example is US6641298B2, in which a chopping knife is located in the attachment by an upper and lower bearing point. The upper bearing point is removed when the lid is opened. The lower bearing point is formed by an axle in the container and a bushing in the lower end of the knife. With the upper bearing point removed the knife starts to tumble in the container, thus creating friction which slows down the knife. However, this method generates only small stopping forces and as such it is suited only for lightweight tools. In addition, it requires the tool to have an imbalance to start the tumbling motion. Heavy and well balanced food processing tools, such as cutting discs however have a strong gyroscopic effect, which keeps them in a stable rotation even with the upper bearing point removed. Therefore, the tumble brake system is not effective for such tools. Another example is EP0529287B1 which discloses a braking system using a spring to lift the chopper knife inside the bowl when the lid is removed. Such a system has a number of tabs on the container axle which pass through slots in the knife bearing. When the lid is closed, the knife is pressed downwards and can rotate freely over the tabs. When the lid is opened, the knife is lifted by the spring and two effects occur; initially the tabs contact the top surface of the bearing and generate friction, which slows down the knife. However, due to the nature of the system, the material combination of axle and bearing needs to possess a very low coefficient of friction, to avoid heat generation while running. As such the generated stopping torques are very small and also not suitable for heavy tools, such as metal cutting discs. When the speed drops below a threshold the tabs enter the slots in the bearing resulting in a sudden stop of the tool. This is also disadvantageous for heavy tools because the resulting forces can lead to damage of the device and increase the risk of failure.

The present invention aims to at least partially ameliorate the above-described problems of the prior art.

Summary of the Invention

Aspects and embodiments of the present invention are set out in the appended claims. These and other aspects and embodiments of the invention are also described herein.

According to a first aspect of the invention, there is provided a braking device for a food processor, comprising a plurality of discrete braking devices wherein the discrete braking devices are operatively connected.

By providing a plurality of discrete braking devices that are operatively connected safety can be enhanced by affording more rapid braking of a processing tool or similar in the food processor, thus preventing harm to a user. This is especially the case where one braking device is a clutch-type braking device that is capable of particularly rapid deceleration and the other is a friction braking device that is capable of smoothing the deceleration in order to ensure that excessive loads are avoided. Hence, in preferred embodiments, upon opening of the lid, the tool bearing is immediately stopped by the form fit between the bearing and axle. A tool stem with the tool attached to it continues to rotate and is slowed down by the friction generated between bearing and tool stem. The friction can be adjusted to a suitable value, which allows to achieve the required stopping times, but prevents damage to the device from hard stopping too quickly. As used herein the term “clutch-type braking device” preferably connotes a, preferably mechanical, device that engages and disengages power transmission, especially from a drive shaft to a driven shaft; the term preferably includes form fit braking and dog clutch devices.

As used herein, the term “friction braking device” preferably connotes a braking device that uses friction, preferably between two opposing members (including surfaces) to brake one component with respect to another.

Preferably, one such discrete braking device is engaged before another such discrete braking device is engaged, although there may be a relatively short time (typically less than a second or half a second) when both devices are engaged.

Preferably, one of the discrete braking devices is a friction braking device. Preferably, the friction type braking device is engaged after the clutch-type braking device is engaged.

Preferably, for simplicity the friction braking device comprises an annular friction ring bearing against a friction surface. Alternatively or additionally, the friction braking device may comprise a plurality of friction surfaces bearing against each other, typically just two such surfaces.

Preferably, the friction braking device comprises a first part and a second part that rotate relative to each other, wherein the first and second parts each have at least one protrusion, and wherein the respective protrusions snap over each other during rotation. Such a friction braking device may be used as the only friction braking device, or in conjunction with any other friction braking device, whether as described previously or otherwise.

This important feature is also provided independently. Accordingly In a related aspect of the invention there is provided a braking device for a food processor, comprising a first part and a second part that rotate relative to each other, wherein the first and second parts each have at least one protrusion, and wherein the respective protrusions snap over each other during rotation. By providing such a snap action a particularly effective friction braking device can be afforded.

Preferably, at least one protrusion is formed on a bearing member, and at least one protrusion is formed on a stem which preferably engages with the at least one protrusion from the bearing. Also preferably, the at least one protrusion of the bearing member and at least one protrusion of the stem protrude into a space formed between the bearing member and the stem. Preferably, one of the plurality of discrete braking devices is a clutch-type braking device. Preferably, the clutch-type braking device comprises means for permitting rotation, said means comprising a formation for engaging with a complementary formation. Preferably, the means for permitting rotation is fixed against rotation with respect to the body of the food processor or processor bowl, and preferably the complementary formation is on a shaft or member (later referred to as a “bearing member”) that is intermediate between the clutch-type braking device and the friction braking device. As used herein, the term “intermediate” preferably connotes that the relevant shaft is both part of the clutch-type and part of the friction braking device. Thus when the clutch-type braking device engages, operates or activates, the intermediate shaft may be stopped, typically instantaneously. Friction between that intermediate shaft and a further shaft or axle that drives or includes a processing tool or device then may slow down that processing tool or device.

Preferably, the means for permitting rotation comprises a first section and a second section, wherein the second section has a smaller diameter than the first section. The different diameters may be employed for the purposes of engaging and disengaging the clutch-type braking device.

The formation on the means for permitting rotation may be a section having at least one tab. Alternatively, and preferably, the formation is a section having at least one braking plane.

This important feature is also provided independently. Accordingly In a related aspect of the invention there is provided a braking device for a food processor, comprising means for permitting rotation, said means comprising a formation for engaging with a complementary formation, wherein the formation is a section having at least one braking plane (so preferably a surface that is planar or otherwise flat). The use of a braking plane that engages with a complementary formation can yield a particularly effective braking device.

Preferably, the formation and complementary formation engage with a form fit to achieve maximum stopping force from the beginning. This is effective to slow down heavy tools in the required time. To encourage this, the face(s) of either the formation or the complementary formation, or both, preferably have an inclination or ramp that guides said formation into the other formation during rotation, similar to a thread. Hence, preferably, the at least one braking plane comprises an inclined surface, preferably at an end. Preferably, the complementary formation is located on a bearing, such typically as the intermediate shaft or bearing member.

Preferably, the bearing member is moveable, preferably translatable, from a first position wherein the intermediate shaft or bearing member is able to move with respect to the second section of the means for permitting rotation to a second position in which the formation is engaged.

In a further aspect of the invention there is provided a feed tube for a food processing device which has a cross-sectional shape that is non-circular and preferably kidney shaped, and preferably not elliptical, and preferably elongate (preferably along the food processing or cutting direction). Preferably, a part of a wall defining the feed tube describes the arc of a circle.

In a further aspect, this feed tube may comprise a change of direction, when viewed along the direction in which food is moved through the feeding tube, which is generally the vertical direction.

Typically, conventional food processors and food processor attachments are equipped with different slicing, grating or shredding discs, to cut the food into even slices or small fragments. Those discs require that the food is permanently fed onto the disc through a feeding tube. The feeding tube is located in the lid of the device or attachment and allows the user to safely feed food to the discs, while the lid is closed, thus minimizing the risk for injury. Such food processors are equipped with feed tubes of an approximately round cross section, elliptical cross section, square cross section or rectangular cross section, because this allows to feed large food items such as cucumbers, without the need to precut them into smaller slices. However, it has now been appreciated pursuant to the present invention that this feed tube shape has the following disadvantage. The processing discs contain a multitude of single cutting elements, which move in a circular motion, when the disc is rotating. When those cutting elements pass through the area of the feed tube, they describe a circular path. The side walls of the feeding tube are however not concentric with this path, which means that the distance from the single cutting element to the side wall of the feed tube varies as it passes underneath the feed tube. This can lead to unwanted motion of the food in the feed tube, which then results in an uneven cutting result. The present invention then can afford the advantage that the path of any single cutting element is always concentric with the side walls, which means that the distance between cutting element and side walls does not change over the path of the cutting element. This can keep the food more stable In the feed tube, leading to a cleaner and more even processing result.

A second disadvantage of conventional feeding tubes Is that they are essentially straight, In the direction In which the food Is moved through them. The width of a feed tube In the radial direction of the cutting disc Is limited by two factors; towards the Inside, the lid typically contains a gear system for driving the tool. This prevents Increasing the size of the feeding tube by placing the Inner section of the wall towards the centre of the device. T owards the outer section of the wall, the feeding tube Is limited by the dimensions of the device on Its outer edge. The outer edge of the disc Is required to maintain a certain distance from the container walls and the outermost cutting element on the disc needs to maintain a certain distance from the edge of the disc due to manufacturing tolerances. This provides a given limit for the maximum width of the feeding tube In radial direction of the device.

In a further aspect there Is provided a non-straight feeding tube. Viewing this feeding tube In a cross section through the rotation axis of the disc and the central axis of the feeding tube, the feeding tube preferably has a first section, which Is predominantly or essentially vertical In orientation. It also preferably has a lower section, which Is oriented at an angle towards or against the upper section. The lower opening of the feed tube Is preferably shifted towards the centre of the device, compared to the upper opening of the feed tube.

As a result, the food may be forced to change direction while It passes through the feeding tube. This can allow better utilisation of the space towards the Inside of the device, and allows the use of a larger feed tube width when compared to a straight design.

In a further related aspect, there is provided a feed tube for a food processing device, optionally being as aforesaid, comprising a first section and a second section, wherein the second section is inclined relative to the first section, preferably wherein the second section abuts a lid of the food processing device, and/or preferably wherein the angle of inclination is between 2 and 15 degrees, and/or preferably wherein the first section is longer than the second section.

For any of the embodiments of the feed tube, preferably an inner and outer part of the wall defining the feed tube describe concentric arcs, which are also concentric with the container and disc of the device. The feed tube may include a front wall, which is located in the direction of rotation and a rear wall, located on the opposite end of the tube. The front and rear walls may close the side walls towards the front and rear side of the tube. Preferably, both the front and rear walls may be part-circular In shape, In other words may define the arc of a circle, with their centre points being located on a circular line, which Is preferably equidistant between the side walls. This may result In a tangential transition between the side walls and the front and real walls. Other shapes of the front and rear wall are also possible, for example a straight wall or a curved wall of smaller curvature or Irregular curvature.

In a related aspect of the present invention there is provided a bowl assembly for a food processor incorporating a braking device as aforesaid and/or a feed tube as aforesaid.

In a further related aspect there is provided a food processor incorporating any combination of a braking device as aforesaid, a feed tube as aforesaid and/or a bowl as aforesaid. Preferably, the food processor comprises a lid and a means for urging to which the lid is coupled, wherein the means for urging is released when the lid is removed from the food processor. Also, preferably the food processor comprises a drive mechanism.

In general, the invention may comprise one or more of the following features in isolation or in any combination; a container, a lid, a bearing member, wherein the bearing member preferably comprises at least one protrusion wherein the at least one protrusion preferably engages with a stem, a stem, a container for permitting rotation preferably comprising a first section and a second section wherein the second section has a smaller diameter than the first section, a means for urging preferably in the form of a spring, a sliding pusher, a feed tube, a bowl, and a food processor.

Any apparatus feature as described herein may also be provided as a method feature, and vice versa. As used herein, means plus function features may be expressed alternatively in terms of their corresponding structure, such as a suitably programmed processor and associated memory.

Any feature in one aspect of the invention may be applied to other aspects of the invention, in any appropriate combination. In particular, method aspects may be applied to apparatus aspects, and vice versa. Furthermore, any, some and/or all features in one aspect can be applied to any, some and/or all features in any other aspect, in any appropriate combination.

It should also be appreciated that particular combinations of the various features described and defined in any aspects of the invention can be implemented and/or supplied and/or used independently. The invention extends to methods, system and apparatus substantially as herein described and/or as illustrated with reference to the accompanying figures.

The invention extends to any novel aspects or features described and/or illustrated herein.

In this specification the word 'or' can be interpreted in the exclusive or inclusive sense unless stated otherwise.

Furthermore, features implemented in hardware may generally be implemented in software, and vice versa. Any reference to software and hardware features herein should be construed accordingly.

Whilst the invention has been described in the field of domestic food processing and preparation appliances, it can also be implemented in any field of use where efficient, effective and convenient preparation and/or processing of material is desired, either on an industrial scale and/or in small amounts. The field of use includes the preparation and/or processing of: chemicals; pharmaceuticals; paints; building materials; clothing materials; agricultural and/or veterinary feeds and/or treatments, including fertilisers, grain and other agricultural and/or veterinary products; oils; fuels; dyes; cosmetics; plastics; tars; finishes; waxes; varnishes; beverages; medical and/or biological research materials; solders; alloys; effluent; and/or other substances. Any reference to “food”, “beverage” (or similar language) herein may be replaced by such working mediums.

The invention described here may be used in any appliance, such as a kitchen appliance, and/or as a stand-alone device. This includes any domestic food-processing and/or preparation appliance, including both top-driven appliances (e.g., stand-mixers) and bottom-driven appliances (e.g., food processors). It may be implemented in heated and/or cooled appliances. The invention may also be implemented in both hand-held (e.g., hand blenders) and table-top (e.g., blenders) appliances. It may be used in an appliance that is built-in to a work-top or work surface, or in a stand-alone device. The invention can also be provided as a stand-alone device, whether motor-driven or manually powered.

“Food processing” as described herein should be taken to encompass chopping, whisking, stirring, kneading, mincing, grinding, shaping, shredding, grating, cooking, freezing, making ice-cream, juicing (centrifugally or with a scroll), or other food-processing activities involving the physical and/or chemical transformation of food and/or beverage material by mechanical, chemical, and/or thermal means. “Food processing attachment” encompasses any attachable component configured, for example on rotation and/or energising, to carry out any of the previously described food processing tasks. Brief Description of the Figures

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

Figures 1a shows a food processor;

Figure 1 b shows the motor unit and coupling mechanism;

Figure 2 shows a food processor incorporating a friction braking device with an annular friction ring bearing against a friction surface in a first position;

Figure 3 shows a food processor incorporating the friction braking device with the annular friction ring bearing member against a friction surface in a second position;

Figure 4 shows a food processor incorporating the friction braking device with a bearing member having two friction surfaces bearing against each other in a first position;

Figure 5 shows a food processor incorporating the friction braking device with the bearing member having two friction surfaces bearing against each other in a second position;

Figure 6 shows a means for permitting rotation of a clutch-type braking device with at least one braking plane;

Figure 7 shows a bearing member of a clutch-type braking device with at least one corresponding braking plane;

Figure 8 shows a means for permitting rotation of a clutch-type braking device with at least one braking plane in a first position;

Figure 9 shows a means for permitting rotation of a clutch-type braking device with at least one braking plane in a second position;

Figure 10 shows a means for permitting rotation of a clutch-type braking device with at least one slot;

Figure 11 shows a bearing member of a clutch-type braking device with at least one tab;

Figure 12 shows a friction braking device with a first part and a second part that rotate relative to each other where the first and second parts each have at least one protrusion;

Figure 13 shows an attachment for a food processor showing a feeding tube that is predominantly straight;

Figure 14 shows the feeding tube that is predominantly straight; Figure 15 shows an attachment for a food processor showing a feeding tube with a first section that is predominantly straight and a second section that is inclined towards an axis of rotation of the food processor; and

Figure 16 shows the feeding tube with the first section that is predominantly straight and the second section that is inclined towards the axis of rotation.

Specific Description

Figures 1 show an exemplary food processor 1 with Figure 1 a showing the food processor 1 comprising: a processing container 10, a lid 20 and a motor unit 30 of the type used for handheld blenders and Figure 1b showing a disassembled food processor 1.

In more detail, and with reference for example to Figure 2, the lid 20 is connected to an urging system 40 which urges the lid away from the food processor.

The motor unit 30, shown in Figures 1 a and 1 b, is like the motor unit of common handheld or ‘stick’ blenders. The motor unit includes an electrical cable 32 and a power button 34 and is complementary to a coupling mechanism 22 on the top of the lid 20 of the food processor. The top surface of lid 20 is the outer surface when the lid closes the processing container 10, as shown in Figures 1. Henceforth, this surface of the lid 20 may also be referred to as the outer surface of the lid.

Alternatively, the motor / motor unit 30 may also be integrally and non-removably provided within the lid 20.

With reference also to Figures 13 to 16, the coupling mechanism 22 engages the distal end of the motor unit 30. It includes a shaft 222, the top end of which is driven by the electric motor unit 30. The other end of the shaft 222 engages a gear assembly 24 (shown in Figure 15) that is integrated into the inside of the lid 20 underneath the base of the coupling mechanism 22, as shown in Figures 14 to 16. The gear assembly 24 drives a drive coupling 26 (shown in Figure 15) which in turn drives the drive axle 50 and any engaged processing components 60 via the drive coupling 26.

The lid 20 additionally includes a feed tube 100 through which food can be inserted for processing. When the lid is seen in a plan view the feed tube wall is kidney or bean shaped. The feed tube is located opposite the coupling mechanism 22 on the lid.

The drive coupling 26 is complementary to the top (proximal) end of the drive axle 50 and located on the lower surface of the lid 20, such that it is opposite a means for permitting rotation 200 which is located in the centre of the circular floor of the processing container 10 when the container is closed by the lid, as shown in Figures 2 and 4. Henceforth, this lower surface of the lid 20, which is contained when the lid closes the processing container, may also be referred to as the inner surface of the lid.

As shown for example in Figures 2 to 5, the food processor 1 comprises a plurality of discrete braking devices; as will be described later the discrete braking devices are operatively connected via a bearing member 300, with a first discrete braking device being engaged before at least one further discrete braking device is engaged. In the preferred embodiments, the first discrete braking device to be engaged is a clutch-type braking device while the second is a friction braking device.

The clutch-type braking device generally comprises a means for permitting rotation 200 around which the bearing member 300 will spin in a disengaged position, both the means for permitting rotation 200 and the bearing member 300 having corresponding braking formations which prevent further rotation when the clutch-type braking device is engaged.

The friction braking device generally comprises at least two friction producing surfaces and/or formations interfacing between the bearing member 300 and the stem 400, which surfaces will begin frictionally rotating with respect to each other when the bearing member 300 stops rotating due to engagement of the clutch-type braking device. Operation of the friction braking device then decelerates the rotation of the stem and thus stops it rotating. This in turn stops rotation of the food processing disc 60. The rotation of the disc stops within a predetermined time (for example, within 1 .5, 3 or 5 seconds), and can be adjusted to a suitable value to meet international safety standards such as EN 60335.

The operation of first the clutch-type and then the friction braking devices is thus an important safety feature as it can rapidly slow down the processing disc thereby preventing harm to the user.

In the various embodiments of the braking devices, the means for permitting rotation 300 is made from stainless steel or another suitable metal material. It may also be made from a plastics material, which allows it to be either integrally moulded with the container or assembled as a separate component. The bearing member 300 is made from a low friction material to allow rotation against the means for permitting rotation 200. The dynamic coefficient of friction of the material combination is less than 0.5 and preferably less than 0.35 to prevent excessive heat generation and wear. The bearing member 300 is made from a plastics material such as POM, PBT, PA, PEEK, PTFE or PPS. The bearing member 300 may alternatively be made from metallic material such as bronze, or oil- infused sinter metals are also suitable. The stem 400 is made from an injection molded thermoplastic such as POM, PP or ABS. The low friction material of the bearing member 300 also exhibits low friction against the stem 400, making a number of embodiments of the friction braking device possible.

The Clutch-Type and Friction Braking Devices

Figures 2 to 5 show the processing container 10, which generally comprises: the stem 400; an annular snap member receiving slot 410; the bearing member 300; an annular snap member 310 received by the annular snap member receiving slot to prevent axial movement of the stem 400 relative to the bearing member 300; the means for permitting rotation 200; a base 210 for the means for permitting rotation; the urging system 40 including a spring 42 and a sliding pusher 44 employed with the spring 42 and the bearing member 300 (which will be described later); the food processing disc 60 with a plurality of processing elements 62 on that disc; and a disc retention member 64 for retaining the disc on the stem 400.

The means for permitting rotation 200 is fixed with respect to the base 210 and hence fixed with respect to the processing container 10, while the bearing member 300, stem 400 and processing disc 60 are permitted to rotate, and be braked, with respect to it.

As referred to previously, the clutch-type braking device (which generally comprises the bearing member 300 and the means for permitting rotation 200) and the friction braking device (which generally comprises the bearing member 300 and the stem 400) work cooperatively to slow down the stem 400 and disc 60. The clutch-type braking device will be engaged when the bearing member 300 is moved from a first disengaged position (shown in Figures 2, 4 and 8) relative to the means for permitting rotation 200 (which is fixed relative to the base 210) in which disengaged position it will freely spin around the means for permitting rotation 200 to a second, engaged position (shown in Figures 3, 5 and 9) where the bearing member 300 is engaged with the means for permitting rotation 200.

As such, engagement of the clutch-type braking device prevents the bearing member 300 from further rotating, which then causes due to inertia the stem 400 to rotate relative to the bearing member 300. By virtue of the friction braking member friction is then caused between the stem 400 and the bearing member 300, which by dissipation of kinetic energy slows the rotation of the stem 400 and then prevents the stem 400 from further rotation, thus in turn preventing the disc 60 from further rotation. Movement of the clutch-type braking device from the first disengaged position to the second engaged position, thereby engaging the braking of that device, is caused when the lid 20 of the food processor 1 is removed. Under the bias of the spring 42 of the urging system 40 as the spring pushes against the means for permitting rotation 200 via the sliding pusher 44, the entire assembly of the processing disc 60, stem 400 and bearing member 300 is urged upwardly. Conversely, the clutch-type braking device is disengaged by pushing down on the lid, thereby enabling the stem and processing disc to be rotated freely.

It will be understood that the processing disc 60, stem 400 and bearing member 300 move axially simultaneously, as an entire assembly. Axial movement between the stem and the bearing member is prevented by the engagement of the annular snap member receiving slot 410 and the annular snap member 310.

Two specific embodiments of the clutch-type braking device will be described in the next section.

As mentioned above, when the clutch-type braking device engages thereby stopping the bearing member 300, the friction braking device then operates to decrease the rotational speed of the stem 400 and thus stop its rotation. This is achieved by various embodiments of friction surfaces and/or formations at the interface between the bearing member 300 and the stem 400 (as will be described later).

Specific Embodiments of the Clutch-Type Braking Device

The clutch-type braking device includes the means for permitting rotation 200; this has a first section 220 and a second section 230, where the first section has at least one braking formation 240 on its outer surface (as shown in Figures 6 and 8 to 10), with the transition between the first section 220 and the second section 230 via a ramped section 250.

The clutch-type braking device also includes the bearing member 300; this has at least one corresponding braking formation 320 extending somewhat inwardly from its inner surface 330 and located at a distal end 340 (opposite a proximal end 350) of the bearing member 300, extending part way through the inner section of the bearing member (as shown in Figures 7 to 9 and 11). The braking formation 320 has a ramp 322 in order to facilitate engagement of that formation with the braking formation 240.

The first section 220 of the means for permitting rotation 200 has a diameter corresponding to the inner surface 330 of the bearing member 300 and the second section 230 has a smaller diameter, which allows the bearing member 300 to spin freely around the second section 230 of the means for permitting rotation 200 in the first position shown in Figure 8, without engaging with the braking formation 320.

As described previously, the bearing member 300 is moveable from the first position to the second position shown in Figure 9 in which the bearing member 300 has moved relative to the proximal end of the means for permitting rotation 200 and the at least one braking formation 320 of the bearing member 300 engages with the at least one braking formation 240 of the means for permitting rotation 200. This second position prevents the further rotation of the bearing member 300 relative to the means for permitting rotation 200 so that the bearing member 300 will be stationary.

A first preferred embodiment of the clutch-type braking device is now described in more detail with reference to Figures 6 to 9. In this embodiment the braking formation 240 is planar, in the shape approximately of an oval including the ramped section 250. Two such formations are provided, located opposite each other on the means for permitting rotation 200. Equally, the corresponding braking formation 320 on the bearing member 300 is also planar, being in the shape of a trapezoid, with one of the edges forming the ramp 322; again, two such formations are provided, located opposite each other on the bearing member 300.

A second preferred embodiment of the clutch-type braking device is now described in more detail with reference to Figures 10 and 11. In this embodiment the braking formation 240 in the means for permitting rotation 200 is in the form of four slots spaced evenly around the first section 220 of the means for permitting rotation 200. The corresponding braking formation 320 on the bearing member 300 is in the form of four tabs, again evenly spaced around the bearing member.

Specific Embodiments of the Friction Braking Device

A first preferred embodiment of the friction braking device is shown in Figures 2 and 3. The friction interface between the stem 400 and bearing member 300 is formed by an annular friction ring 500 located in an annular friction ring receiving slot 360. As can be seen in Figures 7 to 9 and 11 , the friction ring receiving slot 360 comprises side walls 362, 364 and a base 366 and is located on the outer surface 370 of the bearing member 300. The annular friction ring 500 is in frictional contact with both the stem 400 and the bearing member 300. The friction ring 500 is chosen from a high-friction material, such as an elastomeric material such as NBR, EPDM, FKM, TPE or Silicone. The dynamic coefficient of friction between the friction element and the stem is preferably less than 0.5 and preferably greater than 0.1. The coefficient and the contact force between friction ring and stem/bearing is chosen sufficiently high that there is sufficient friction for the bearing member 300 to co-rotate with the stem 400, and hence the processing disc 60, at the same rotational speed during processing, but sufficiently low that it affords adequate braking during the braking procedure.

The friction can be adjusted to the desired value by the combination of materials, the hardness of the friction element, the contact area between the friction ring 500 and the stem 400 and the bearing member 300, and compression of the friction element.

The softness of the friction ring 500 allows compensation for production tolerances of all of the components without resulting in high variations of the stopping force of the friction braking device. For this reason, the hardness of the friction element is preferably less than 80 Shore A and more preferably less than 60 Shore A.

A second preferred embodiment of the friction braking device is shown in Figures 4 and 5. In this embodiment there is no annular friction ring 500, and instead the friction is due to the stem 400 being in direct contact with the bearing member 300. The relevant surfaces of the stem and bearing member are chosen in similar fashion to that described with reference to the first preferred embodiment of the friction braking device.

A third preferred embodiment of the friction braking device in shown in Figure 12. Friction is caused by four equally radially spaced protrusions 420 on the inner surface of the stem 400 bearing against four equally radially spaced protrusions 380 on the outer surface of the bearing member 300, with an annular gap 600 permitting free rotation of the stem with respect to the bearing member when none of the protrusions are bearing against each other.

In more detail, the protrusions 420 extend from the inner surface of the stem 400 into the annular gap 600 and the protrusions 380 extend from the outer surface of the bearing member 300 into the annular gap 600. The protrusions 420, 380 are sized and arranged so that they engage with each other preventing free rotation between the components. The value of the interfering overlap between the protrusions 420 and the protrusions 380 is less than 1 mm, ideally less than 0.5mm, more preferably less than 0.1 mm (with respect to the radius and not the diameter). The protrusions snapping over each other as the stem 400 rotates while the bearing member 300 is stationary causes friction which dissipates the kinetic energy and slows then prevents the rotation of the stem 400 when the bearing member 300 is stationary due to the clutch-type braking mechanism having been engaged.

Specific Embodiments of The Feed Tube

Figures 13 and 14 show the feed tube 100 on the lid, together with the drive coupling mechanism 22. The feed tube 100 is non-circular and kidney shaped in cross-section, with the wall defining the feed tube being continuous but divided notionally into four sections (inner side wall, outer side wall, front wall and rear wall) as now described. The feed tube has an inner side wall 120 and an outer side wall 130 opposite the inner side wall 120; both side walls 120, 130 are concentric with the axis of rotation 140 of the food processing disc 60. Hence the path of any single cutting or other processing element on the food processing disc 60 is always concentric with those side walls so that the distance between cutting element and side walls does not change over the path of the cutting element. This can keep the food more stable in the feeding tube, leading to a cleaner and more even processing result.

The centre line 110 between the side walls 120, 130 is also evidently concentric with the axis of rotation 140. The feed tube 100 comprises a front wall 150 which is located in the direction of rotation 160 of the food processing disc 60, and a rear wall 170 located on the opposite end of the feed tube 100. The front wall 150 and rear wall 170 close the side walls 120, 130 towards each end of the non-circular feed tube 100. The front and rear walls 150, 170 are circular in shape and have their centre points 112 at the appropriate points on the centre line 110, which is equidistant between the side walls 120 and 130. This results in a tangential transition between the side walls 120, 130 and the front and rear walls 150, 170, hence avoiding any sharp edges or corners, which might be difficult to clean.

A first preferred embodiment of the non-circular feed tube is shown in Figures 13 and 14. The feed tub 100 comprises side walls 180 which are vertical and (in the preferred embodiment) straight with regard to the axis of rotation 140 over the length of the feed tube. A second preferred embodiment of the non-circular feed tube is shown in Figures 15 and 16. The feed tube 100 comprises side walls 180 which comprise a first section 190 and a second section 192. The first section 190 is (in the preferred embodiment) straight with regard to the axis of rotation 140. The second section 192 is inclined towards the axis of rotation 140 at an angle. The first section 190 is longer than the second section 192; indeed it may be twice or three times the length of the second section. The second section is inclined at an angle of approximately 5 degrees with respect to the first section; indeed that angle may be between 2 and 15 degrees, preferably between 3 and 10 degrees. Both the first section and the second section have side walls 120, 130, a front wall 150 and a rear wall 170 that have the same cross-sectional shapes and characteristics as described previously.

The Bowl and Food Processor Assembly

The food processor may have a bowl assembly incorporating any embodiment or embodiments of the braking devices described above and/or a feed tube. The food processor may incorporate any embodiment or embodiments of the discrete braking device and/or a feed tub.

As used herein, the term "removable attachment" (and similar terms such as “removably attachable”, “reversibly attached/attachable”, and “reversible attachment”), as used in relation to an attachment between a first object and a second object, preferably connotes that the first object is attached to the second object and can be detached (and preferably re-attached, detached again, and so on, repetitively), and/or that the first object may be removed from the second object without damaging the first object or the second object; more preferably the term connotes that the first object may be re-attached to the second object without damaging the first object or the second object, and/or that the first object may be removed from (and optionally also re-attached to) the second object by hand and/or without the use of tools (e.g. screwdrivers, spanners, etc.). Mechanisms such as a snap-fit, a bayonet attachment, and a hand-rotatable locking nut may be used in this regard.

As used herein, the term “processing” preferably connotes any action relating to or contributing towards transforming products into foodstuff, or transforming foodstuff into a different form of foodstuff, including - as examples - applying mechanical work (e.g. for cutting, beating, blending, whisking, dicing, spiralising, grinding, extruding, shaping, kneading etc.) and applying heat or cold. “Food” and “foodstuff” as used herein can include beverages and frozen material and material used in creating them (e.g., coffee beans).

“Food safe” in this context means any substance that does not shed substances harmful to human health in clinically significant quantities if ingested. For example, it should be BPA-free. “Dishwasher safe” means that it should be physically and chemically stable during prolonged exposure to the conditions prevailing within a dishwasher machine. For example, it should be able to withstand exposure to a mixture of water and a typical dishwasher substance (e.g., washing with FairyTM or FinishTM dishwasher tablets and water, at temperatures of 82 degrees centigrade for as long as 8 hours without visibly degrading (e.g., cracking)).

It will be understood that the present invention has been described above purely by way of example, and modifications of detail can be made within the scope of the invention. Each feature disclosed in the description, and (where appropriate) the claims and drawings may be provided independently or in any appropriate combination. Reference numerals appearing in the claims are by way of illustration only and shall have no limiting effect on the scope of the claims.

Claims

1 . A braking device for a food processor, comprising a plurality of discrete, preferably different, braking devices, wherein the discrete braking devices are operatively connected.

2. A braking device according to Claim 1 , wherein one such discrete braking device is engaged before another such discrete braking device is engaged.

3. A braking device according to Claim 1 or 2, wherein one of the discrete braking devices is a friction braking device.

4. A braking device according to Claim 3, wherein the friction braking device comprises an annular friction ring bearing against a friction surface.

5. A braking device according to Claim 3 or 4, wherein the friction braking device comprises a plurality of friction surfaces bearing against each other.

6. A braking device according to Claim 3, 4 or 5, wherein the friction braking device comprises a first part and a second part that rotate relative to each other, wherein the first and second parts each have at least one protrusion, and wherein the respective protrusions snap over each other during rotation.

7. A braking device for a food processor, comprising a first part and a second part that rotate relative to each other, wherein the first and second parts each have at least one protrusion, and wherein the respective protrusions snap over each other during rotation.

8. A braking device according to Claim 6 or 7, wherein at least one protrusion is formed on a bearing member, and at least one protrusion is formed on a stem.

9. A braking device according to Claim 8, wherein the at least one protrusion of the bearing member and at least one protrusion of the stem protrude into a space formed between the bearing member and the stem.

10. A braking device according to any of the preceding claims, wherein one of the plurality of discrete braking devices is a clutch-type braking device.

11. A braking device according to Claim 10, wherein the clutch-type braking device comprises means for permitting rotation, said means comprising a formation for engaging with a complementary formation.

12. A braking device according to Claim 11 , wherein the means for permitting rotation comprises a first section and a second section, wherein the second section has a smaller diameter than the first section.

13. A braking device according to Claim 11 or 12, wherein the formation is a section having at least one slot and the corresponding formation is a tab. A braking device according to Claim 11 , 12 or 13, wherein the formation is a section having at least one braking plane. A braking device for a food processor, comprising means for permitting rotation, said means comprising a formation for engaging with a complementary formation, wherein the formation is a section having at least one braking plane. A braking device according to Claim 14 or 15, wherein the at least one braking plane comprises an inclined surface. A braking device according to any of Claims 11 to 16, wherein the complementary formation is located on a bearing. A braking device according to Claim 17, wherein the braking device is moveable from a first position wherein the bearing is able to move with respect to the second section of the means for permitting rotation to a second position in which the formation is engaged, preferably wherein the braking device enters the second position when the lid of the food processor is not in place and the first position when the lid is in place. A feed tube for a food processing device which has a cross-sectional shape that is non-circular and preferably kidney shaped. A feed tube according to Claim 19 wherein a part of a wall defining the feed tube describes the arc of a circle, preferably wherein an inner and outer part of the wall defining the feed tube describe concentric arcs, more preferably wherein the inner and outer parts of the wall are concentric with the centre of rotation of a processing tool. A feed tube for a food processing device, optionally according to Claim 19 or 20, comprising a first section and a second section, wherein the second section is inclined relative to the first section, preferably wherein the second section abuts a lid of the food processing device, and/or preferably wherein the angle of inclination is between 2 and 15 degrees, and/or preferably wherein the first section is longer than the second section. A bowl assembly for a food processor incorporating a braking device according to any of Claims 1 to 18 and/or a feed tube according to any of Claims 19 to 21 . A food processor incorporating any combination of: a braking device according to any of Claims 1 to 18; a feed tube according to any of Claims 19 to 21 ; a bowl assembly according to Claim 22. A food processor according to Claim 23, wherein the food processor comprises a lid and a means for urging to which the lid is coupled, wherein the means for urging is released when the lid is removed from the food processor. A food processor according to Claim 23 or 24, wherein the food processor comprises a drive mechanism.