GB2518422A

GB2518422A - Electrically powered and hand-held kitchen appliance

Info

Publication number: GB2518422A
Application number: GB1316827.3A
Authority: GB
Inventors: David Harvey; Paul Palmer
Original assignee: Kenwood Ltd
Current assignee: Kenwood Ltd
Priority date: 2013-09-23
Filing date: 2013-09-23
Publication date: 2015-03-25
Anticipated expiration: 2033-09-23
Also published as: GB2518422B; GB201316827D0

Abstract

An electrically powered kitchen appliance 10 comprises an electric motor (14, Fig.1), a container 12 in which foodstuffs can be processed and a tool that can be housed in the container and rotated therein by means of the motor to effect the desired processing of the foodstuffs. The appliance is configured to be hand-held and the arrangement is such that an operating function of the motor is influenced by the attitude at which the appliance is held. The appliance may comprise an acceleration/motion sensor (26, Fig.1) and the operating function which is influenced may be the direction of rotation of the motor. Tilting of the appliance in one direction may cause clockwise rotation of the tool whereas tilting in the opposite direction may cause counter-clockwise rotation of the tool. The responsiveness to the attitude of the appliance can be selectively over-ridden by a switchgear allowing the appliance to be placed on a work surface and run as a free-standing processor.

Description

ELECTRIC ALLY POWERED AND HAND4IELD KITCHEN

APPLIANCE

This invention relates to electrically powered and handhe1d kitchen appliances for blending, mixing or otherwise processing foods tuffs.

It is currently typical with such appiances fbr a tool, usually a blade, to he rotated by means of an electric motor so as to process the foodstuffs, which are held in a container. This general arrangement works well in many circwnstanc.es, but known appliances tend to suffer from the difficulty that some types of Ibodstuffs being processed can adhere to the walls of the container and thus fail to reliably come into the necessary contact with the processing tool. This can leave foodstuffs unprocessed, or partially processed, unless the user repeatedly stops the appliance, scrapes the adherent foodstuffs from the container ails: and restarts the appliance, continuing this sequence of operations until, the required degree of processing has been uniformly achieved.

The invention aims to reduce or eliminate the difficulty referred to above by providing an electrically powered kitchen appliance comprising an electric motor, a container in which foodstuffs can be processed and a tool that can be housed in the container and rotated therein by means of the motor to effect the desired processing of the foodstuffs, wherein the appliance is configured to be hand-held and wherein the arrangement is such that an operating fruiction of the motor is influenced by the attitude at which the appliance is held.

in one preferred embodiment of the invention, the operating function of the motor which is influenced by the attitude of the appliance is its direction of operation.

In some such preferred embodiments of the invention, the arrangement is such that tilting the appliance in one direction causes clockwise rotation of the tool whereas tilting the appliance in the opposite direction causes counterciockwise rotation of the tool. By this means, the appliance may be tilted from one side to the other, such that the physical motion tends to dislodge adherent foodstuffs from the container walls whilst the accompanying reversals of the motor's operating direction assist iii rapidly processing the foodstuffs.

Delay components may be incorporated into the appliance so that the motor reversals only occur if the appliance is tilted and held for a predetermined time in a direction tending to trigger a motor reversal. By this means, the appliance as a whole may be gently shaken so as to dislodge adherent foodstuffs without necessarily triggering a motor reversal.

In some preferred embodiments of the invention, the responsiveness to the tilt direction of the appliance can be selectively overridden, by means of useractuated switchgear, allowing the appliance to be placed on a suitable work surface and run as a freestanding processor.

Preferably the motor speed is controllable by means of a pressure operated switch that can readily be operated by the user, with a thumb, for example, whilst holding the appliance in both hands. Such pressure switches may be configured to provide a change in an electrical characteristic, such as resistance, in response to applied pressure. By this means, progressive speed control is provided without compromising the integrity of the casing, thereby avoiding the risk of fiujd ingress.

in some prefeiTed embodiments of the invention, the said pressure-switch comprises material disposed behind a flexible membrane sealingly mounted to the appliance casing, and is either formed integrally with or bonded to or otherwise supported by the membrane. This configuration provides C-or direct application of user-applied pressure to the material of the pressure switch.

In other preferred embodiments of the invention, an actuating member for the pressure-sensitive material is disposed, within the appliance casing.

behind a flexible membrane sealingly mounted to the casing, and a user-actuatabie switch member is either formed inte'rally with or bonded In or otherwise supported by the membrane. This configuration provides for indirect application of user-applied pressure to the said pressure-sensitive material; an arrangement hi which the actuating member may conveniently comprise, or be associated with, a mechanical system configured to amplify or otherwise mnodit' the pressure applied by a user.

By this means, a pref erred pressure profile can be applied to the pressure-sensitive material.

in other preferred embodiments of the invention, there is no user-actuatahie switch as such, but the casing itself is formed, for example by localised thinning at a selected region thereof, to permit a user to apply pressure directly or indirectly to the pressuresensitive material by squeezing the casing at or near the selected region.

Preferred embodiments of the invention incorporate safely interlock means to ensure that the tool of the appliance cannot he driven by the motor mless the appliance is in a safe condition, with its container closed so as to prevent user access to the tool.

In some preferred emhodimenl:s, the casing further supports a display indicating instructions, warnings and/or the status of one or more operational parameters, such as the speed of the motor. The display may comprise an LCD or LEDs, for example.

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, iii cross-sectional view, a hand-held kitchen appliance in accordance with one embodiment of the invention; Figure 2 shows, in schematic and block diagrammatic form, circuit components used. in the embodiment of Figure 1; and Figure 3 shows how the appliance is intended to he held by a user.

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Referring now to the drawings, the appliance of the present invention is shaped and dimensioned to be picked up and held in both hands so that it can be shaken, its orientation changed and pressure applied to it, all whilst in operation.

The appliance 10 comprises a main casing 12 which is preferably shaped as shown, but which can take other forms if desired, bearing in mind that (as illustrated in Figure 3) it is intended to be held in both hands of a user whilst it is operating. The casing 12 houses an electric motor 14, a gear system 16 and a drive shaft 18, which is driven in rotation by the motor 14 via the gear system 16. It will be appreciated that the gear system can take any suitable form, such as a sequence of gear wheels. In this example, however, the gear system 16 takes the form of a belt and pulley system consisting of gear wheels 20 and 24 linked by a belt 22, with the gear wheel 24 being directly coupled to the drive shaft 18.

Also housed within the casing 12 are a motion sensor 26, in this example an acceleration sensor, a pressure sensor 28 associated with a switch area on the casing 12, an electronics assembly 32 including a microcontroller, and (optionally) a local energy source 34, such as a battery pack or a super-capacitor drive system. Alternatively, the appliance 10 can be mains powered, in which case there is the need to provide a cable for connection to a mains power outlet and for power rectification and voltage reduction circuitry to be incorporated within the casing 12. If mains power is utilised, the cable may be permanently connected to the casing 12, or the casing may be provided with a socket from which the cable can be disconnected. In some embodiments of the invention, the facility is provided for both mains and battery/super capacitor operation.

Associated with the casing i 2 and nestable into a circular recess 36 S formed therein, is a food processing bowl 38. The bowl is provided with a removable lid 40 and contains a food processing tool 42 which is designed to fit over and he driven by the drive shaft 18 and which, in this example, caries a pair of foodprocessing blades 44 and 46.

The bowl 38 is removable from the casing 12 for cleaning and is prevented from rotating when the tool 42 is driven, ftw example by means of a couple of splines, fonned at diametrically opposed locations on the exterior of the side wail 48 of the howl 38, which run in slots formed in the facing wail 50 of the casing 12. It will be appreciated that the locaiions of the splines and slots could be reversed and, indeed, that any suitable coupling technique may be used to allow ready insertion and removal of the bowl 38 into and from the recess 36 whilst preventing rotation of the bowl within the recess.

in alternative embodiments of the invention, the recess 36 and the. bowl 38 may be made slightly elliptical, thereby preventing rotation of the bowl within the recess simply by their elliptical shaping.

It will also he appreciated that the tool 42 may he captive within the bowl 38, or t may be releasably coupled to the reentra.nt huh 52 of the bowl to allow its removal from the bowl to facilitate cleaning. in any event, the tool 42 is mounted so that it can rotate within the bowl and is securely fitted to the bowl during such rotation. In some embodiments of the invention, the tool 42 is provided with a superstructure designed to extend up to the lid 40 of the bowl 38, and to run upon and bear against a suitable receptor region, such as a bearing surface, formed on the S underside of the lid.

In order to protect users against a risk of contacting the blades 44, 46 of the tool 42 whilst in motion, the appliance 1 0 preferably incorporates a safety interlock of any convenient kind to prevent operation of the motor 14 unless the lid 40 is securely in place on the bowl 38. Many suitable interlocking systems are known and used in kitchen appliances of various kinds and any convenient system can he used in this case, though a simple mechanical device on the lid 40 actuating a. micro-switch or similar component in the casing 12 is preferred, as such systems are proven to be reliable and rugged in operation. It is preferred that the lid can be securely latched in place for operation, particularly if the tool 42 is designed, as described above, to hear against the lid in operation.

in this embodiment of the invention, and as shown in block schematic form in Figure 2, the direction in which the motor 14 runs (i.e. clockwise or anticiockwise) is controlled by the electronic.s assembly 32, in response to control signals generated by the acceleration sensor 26 and initiated by movements of the appliance 10, specifically in this case tilting motions, made by the user. The sensor 26 measures static and dynamic acceleration and may comprise an accelerometer, a gyroscope or another inertial device, The control signals output from the sensor 26 may be either digital or analogue but, in any event, they are appIed to the

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microcontroller in the electronics assembly 32 which contains processing circuitry programmed to interpret the control signals, thereby to determine the orientation and motion of the appliance 10. This information generates.' signals applied to power eiectromc components 32a, associated with the electronics assembly 32, and organised to provide drive signals suitable for driving the motor 14 as required.

The speed of the motor is controlled by pressure applied by the user to the pressure sensor 28. Conveniently, the casing 12 is shaped so as to present the sensor 28 at a location 30 where the sensor 28 can be operated by a thumb or a finger of the user. The signal from the pressure sensor is sent to the electronics assembly 32 which interprets the data and determines the correct motor speed.

it will he appreciated that different sensors such as 28, and differing numbers of sensors, may be provided, depending upon factors such as aesthetic design considerations, the range of.functionalities offered by the appliance 10 and/or the price point at which the appliance 10 is aimed.

For example, separate on/off and speed control switches may be provided, in which case, the two switches may be located close together, perhaps in a single panel. or they may be separated.

Where a single switch/sensor device such as 28 is provided., it is preferred.

that ills so connected to the control circuitry 32 that initial pressing of the device 28 causes the motor 14 to start and run at a predetermined, relatively slow operating speed. When a user wishes to increase the motor speed, the device 28 is pressed progressively more firmly, with a squeezing action. This causes the motor speed to increase progressively until it reaches the speed required by the user for the task in hand, whereupon the motor continues to run at the chosen operational speed.

The motor can be further speeded up by applying further squeezing pressure to the device 28, or slowed down by reducing the pressure applied. The motor can be stopped by releasing all pressure from the devwe 28.

In any event, the region 30 of the casing 12 that is pressed by the user to control the motor speed is operatively coupled (either directly or 1 0 indirectly) to the pressure-sensitive material 28, which latter is elastically defoimable and undergoes a reliable and progressive change in its elecirical resistivity when subjected to a progressive squeezing action as described above. One such material is that known by the Registered Trade Mark QTC, supplied by Peratech Limited of Durham (GB), and described inter alia in Peratech's International Patent Applications Nos. WO 99/33193 and WO 99/38173. This material comprises a polymer composition in which an electrically conductive filler powder is dispersed within, and encapsulated by, a cured, nonconductive elastomer such as silicone rubber, and can he made into various geometric forms, such as (without limitation) strips, cubes, discs, spheres arid cylinders.

Alternative materials may be used, however, such as an elastically deformable resistor of the kind described in DE 19510100 Al Operation of the appliance lO involves holding it in both hands, as shown in Figure 3. Applying pressure to the casing 12 of the appliance in the switch area 30 controls the speed as described above. In this embodiment, the arrangement is such that the motor 14 will not operate unless a static or dynamic acceleration is also applied. Thus, tilting the appliance 10 to the left results in motor rotation one direction, whilst tilting the appliance in the opposite direction causes the motor to rotate in the opposite direction. Shaking the appliance alternately from left to right causes the motor to alternate between clockwise and counter clockwise rotation. In this embodiment, placing the appliance 10 at rest in a horizontal position stops all motion of the motor 14.

In some other embodiments of the invention, it is preferred to configure the motor 14 to operate primarily under pressure control via sensor 28, and to respond also to attitude changes, such as shaking movements as described above by way of slugging, or time-delay, components incoiporated into the electronics assembly 32, whereby motor reversals are implemented only in response to attitude changes held for at least a predetermined time. By this means, the appliance 10 can be shaken rapidly to dislodge adherent materials without repeatedly changing the direction of rotation of the motor 14.

Such embodiments, fbrthennore, allow the motor 14 to be run whilst the appliance 10 is placed, stationary, on a supporting surface such as a worktop. By this means, the appliance 10 can be additionally used in a more conventional maimer for added convenience to the user.

If preferred, the appliance 10 can be configured to be switchable between two operating modes in which it operates selectively in either of the ways described above; i.e. in a first mode in which attitude-changing movements sensed by the device 26 are required in order for the

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appliance to run, and rapid motor reversals occur in response to tilting or other characteristic movements; or in a second mode in which the primary motor control is via the pressure sensor 28 and motor reversals occur only if the appliance 10 is held in a characteristic movement (eg. a tilting movement) for more than a predetermined time.

It can he advantageous, in some for the casing 1 2 to support a display which advises the user of paramelers such as the current operating speed of the motor, since the user is effectively able to set the motor speed anywhere within its operational range, simply by squeezing the device 28 via the casing region 30, and there may be certain operations which are optimally carried out at particular speeds. Thus, in one example, the casing 12 supports a liquid crystal display (LCD) or a display using light-emitting diodes (LEDs) (neither shown) to indicate the actual operational speed of the motor, The display may comprise a numeric display or a variable-length strip, for example. 1 fl 14;

Claims

Claims: 1. An electrically powered kitchen appliance comprking an electric motor, a container in which foodstuffs can he processed and a too! that can be housed in the container and rotated therein by means of the motor to effect the desired processing of the foodstuffs, wherein the appliance is configured to be handheld and wherein the arrangement is such thai: an operating function of the motor is influenced by the attitude at which the appliance is held.
2. An appliance according to claim 1, wherein the operating thnction of the motor which is influenced by the attitude of the appliance is its direction of operation.
3. An appliance according to claim 2, wherein the arrangement is such that tilting the appliance in one direction causes clockwise rotation of the tool whereas tilting the appliance in the opposite direction causes counterclockwise rotation of the too].
4. An appflance according to claim 2 or claim 3, further comprising delay components configured such that motor reversals only occur if an attitude of the appliance tending to trigger a motor reversal is held for a predetermined time.
5. An appliance according to any preceding claim, wherein the responsiveness to the attitude of the appliance can be selectively ove ridden, by means of user-actuated switchgear, allowing the appliance to be p'aced on a suitable work surface and run as a free-standing processor.
6. An appliance according to any preceding claim, wherein the motor speed is controllable by means of a pressure-sensitive switch that can readily be operated by the user, with a thumb, for example, whilst holding the appliance in both hands.
7. An appliance according to claim 6, wherein said pressure-sensitive switch utilises material configured to provide a change in an electrical characteristic thereof in response to applied pressure.
8. An appliance according to claim 6 or claim 7, wherein said pressure-sensitive switch comprises material disposed behind a flexible membrane sealingly mounted to the appliance casing, and is either formed integrally with or bonded to or otherwise supported by Lhe membrane.
9. An appliance according to claim 6 or claim 7. wherein an actuating member for the pressure-sensitive switch is disposed, within the appliance casing, behind a flexible membrane sealingly mounted to the casing, and a user-actuatable switch member is either formed integraHy with or bonded to or otherwise supported by the membrane.
10. An appliance according to any preceding claim, further comprising safety interlock means to ensure that the tool caimot be driven by the motor imless the appliance is in a safe condition, with its container closed so as to prevent user access to the tool.
ii. An appliance according to any preceding claim, wherein the casing thither supports a display indicating instructions, warnings and/or the status of one or more operational parameters, such as the speed. of the motor.
12. An. electrically powered kitchen appliance substantially as herein described, with reference to and/or as shown in the accompanying drawings.