GB2504493A

GB2504493A - Milk frother with magnetic drive

Info

Publication number: GB2504493A
Application number: GB1213540.6A
Authority: GB
Inventors: Alex Gort-Barten
Original assignee: Alex Gort-Barten
Priority date: 2012-07-30
Filing date: 2012-07-30
Publication date: 2014-02-05
Anticipated expiration: 2032-07-30
Also published as: GB201213540D0; GB2504493B

Abstract

A frother for heating and frothing milk for use in hot beverages such as coffee and hot chocolate. The frother comprises a flat-bottomed tank 5 for receiving the milk or other liquids to be frothed and heated. A whisk means 3 is positioned within the tank and comprises a whisk 10 connected to a central spindle 9. The whisk 10 is rotatably mounted on a support which holds the whisk off the bottom of the tank 5. The whisk 10 is driven by a magnetic drive means contained within the main body 2, which also contains a heater for heating the liquid as it is frothed or stirred. The whisk means 3 may have an arm to interrupt the vortex formed within the liquid during operation. The frother may also have a controller for the magnetic drive means, such that it can control the speed of rotation of the drive means. The magnetic drive means can be actuated by the switch 6 located on the exterior wall of the main body 2 at two different speeds.

Description

Milk Frother The invention relates to a milk frother and a drive mechanism for a milk frother.

Espresso based coffee drinks such as caffe latte and cappuccino have become increasingly popular and consumers want to be able to easily and reliably produce these drinks. Traditionally, baristas have been trained to use the steam generated by an espresso machine to heat and froth milk in a jug to produce the hot milk and froth required for these drinks. Producing the appropriate amount of hot milk and froth without burning the milk or damaging the jug requires some training or experience.

Smaller espresso machines are also much harder to use to treat the milk.

A number of separate milk frothers have been produced which are suitable for home or small scale commercial use. EP1 656866 discloses a frother with a tank to receive a milk-based liquid food with a magnetic beater. A magnetic beater driving system produces a magnetic field which drives the beater in rotation in the tank. The system, beater and a beater positioning unit break or prevent symmetrical circulation of the liquid around a median of vertical axis of the tank. Heating units are disposed in association with the tank for heating the liquid. This is used for preparing foam from a milk-based liquid food product.

GB2454421 discloses a device for frothing milk that is provided with a rotating heating element to be inserted in the milk. The device is provided with a whisk attachment for producing froth and a paddle attachment for producing a more creamy finish.

EP1827188 discloses a cordless milk frother having a stirrer mounted on a spindle, wherein the stirrer is held and driven magnetically in the tank by the stirrer drive system.

These devices share a number of problems. For example, the frothers (with internal elements and mains power) operate on fast speed so when using the whisk you get too much froth to milk, meaning you waste milk and energy but the paddle doesn't produce enough. Milk froth is moreover generally fairly tasteless.

Another problem with the known frothers having a whisk shaft powered from the lid of the frother is that when the milk is ready, the whisk is removed from the frother and is generally placed on a countertop, which results in some mess that needs to be cleaned up. The use of an internal spindle such as in EP1827188 also makes cleaning the tank harder.

A further problem with the known frothers is that the milk tends to burn on the element as when the frother has frothed the milk, the user immediately pours the milk out and a small residue remains behind, which burns on the element. If this is not cleaned quickly, the burnt on residue becomes difficult to remove and also affects future performance. The standard approach to this has been to reduce the temperature to which the milk is heated to around 60 C but at this temperature, the frothed milk is not suitable for use in other beverages such as hot chocolate, which would require a higher temperature to be palatable.

The present invention therefore seeks to provide a milk frother that is easier to use but more closely replicates the performance of an espresso machine.

According to the invention, a milk frother comprising a tank for receiving milk or a milk based liquid, which tank has walls and a bottom, magnetic drive means adapted to drive whisk means, which whisk means is adapted to rotate in the milk or milk based liquid to mix the heating milk or milk based liquid and to produce foam, the frother further comprising heating means adapted to heat the milk or milk based liquid, the magnetic drive means being located outside of the tank, wherein the whisk means comprise a support, on which support a whisk is rotatably mounted, which rotatably mounted whisk is rotatable by the magnetic drive means, wherein the support holds the whisk off the bottom of the tank.

Preferably, the whisk means comprises an arm, which arm is adapted to interrupt, in use, a vortex formed in the milk or milk based liquid.

Preferably, the support comprises an annular wall. Preferably, the annular wall is connected via a radial arm to a spindle on which spindle the whisk is rotatably mounted.

Preferably, the frother comprises a lid, which lid is provided with at least one hole to permit air in the tank which has been heated to escape from the tank.

Preferably the tank has a flat bottom. Preferably, the whisk means, in use, sits on the bottom of the tank.

An exemplary embodiment ot the invention will now be described in greater detail with refeience to the drawings in which: Fig. 1 shows an exploded view of the milk frother Figure 1 shows an exploded view of the frother comprising a base 1, a main body 2, whisk means 3 and a lid 4. The frother is cordless and the base is provided with an upstanding boss to provide the electrical connection from mains electricity to the frother body 2 such that the frother body can rotate through 3600 on the base and be lifted cleai when the milk or liquid is frothed without a cable be attached to the body 2.

The main body 2 comprises at its upper end a tank 5 which leceives the milk or liquid to be frothed and heated. The tank has a flat bottom 14. Magnetic drive means and heating means are located in the main body beneath the flat bottom of the tank 5.

The magnetic drive means is provided with a controller, which controller is adapted to control the speed of rotation of the drive means such that it can operate at at least two speeds. The magnetic drive means can be actuated by the switch 6 located on the exterior wall of the main body 2. It is possible to provide for more than one programme with the single switch. By way of example, pressing the switch once could provide for hot froth, pressing twice could provide by hot milk and press and hold could piovide for cold froth. The hot milk would be provided by slowing the motor speed and the cold froth by not actuating the heating element located beneath the flat bottom. This enables the same whisk to be used for froth and stirred/heated milk. Thus the whisk or stirrer is held in position by the whisk means rather than the magnetic drive means.

The whisk means 3 comprises an annular upstanding wall 7, which wall is joined by two radial arms 8 to an axial spindle 9. The spindle 9 extends above and below the radial arms 8. A whisk 10 is rotatably mounted on a rotatable drive shaft at the lower end of the spindle 9, which drive shaft is housed within the spindle 9. The upper poition of the spindle is provided with first and second annular protruding walls 11, 12. The first, lower wall 11 indicates the maximum advised level foi fiothed milk.

The second, upper wall 12 indicates the maximum advised level for heated milk. The height of the iadial aims indicates the minimum advised milk level.

The lid is provided with a seal around its edge to seal the tank in use and has two holes 13, which allow heated air to escape hereby increasing the working volume of the tank to be larger than it otherwise would be.

In use, the whisk means holds the whisk 10 substantially concentrically with the magnetic drive means located in the main body. The whisk 10 is held above the surface of the flat bottom, typically by about 3mm, thereby avoiding that the surface of the flat bottom might be scratched by the whisk action. This permits the interior of the tank 5 to be provided with either a polished stainless steel surface or alternatively a non stick coating. This also facilitates the magnetic drive means to run on for 20-seconds after the heating element is switched off. This enables the milk to be heated to a higher temperature suitable for hot chocolate dnnks. The heat is dissipated throughout the milk and does not burn on the bottom surface of the container.

The radial arms 8 will also interrupt the vortex that would develop due to the rotation of the whisk, which advantageously results in a better froth as well as increasing the working volume of the tank. The whisk means are also easily removable and are hence easy to clean. It would also be possible to ensure that the whisk means is dishwasher safe.

Claims

Claims 1. A milk frother comprising a tank for receiving milk or a milk based liquid, which tank has walls and a bottom, magnetic drive means adapted to drive whisk means, which whisk means is adapted to rotate in the milk or milk based liquid to mix the heating milk or milk based liquid and to produce foam, the frother further comprising heating means adapted to heat the milk or milk based liquid, the magnetic drive means being located outside of the tank, wherein the whisk means comprise a support, on which support a whisk is rotatably mounted, which rotatably mounted whisk is rotatable by the magnetic drive means, wherein the support holds the whisk off the bottom of the tank.
2. A milk frother according to Claim 1, wherein the whisk means comprises an arm, which arm is adapted to interrupt, in use, a vortex formed in the milk or milk based liquid.
3. A milk frother according to Claim 1 or Claim 2, wherein the support comprises an annular wall.
4. A milk frother according to Claim 3, wherein the annular wall is connected via a radial arm to a spindle on which spindle the whisk is rotatably mounted.
5. A milk frother according to any one of claims 1 to 4, wherein the frother comprises a lid, which lid is provided with at least one hole to permit air in the tank which has been heated to escape from the tank.
6. A milk frother according to any one of Claims ito 5, wherein the tank has a flat bottom.
7. A milk frother according to any one of Claims 1 to 6, wherein the whisk means, in use, sits on the bottom of the tank.
8. A milk frother according to any one of Claims 1 to 7, wherein the magnetic drive means is provided with a controller, which controller is adapted to control the speed of rotation of the drive means such that it can operate at at least two speeds.
9. A milk frother according to Claim 8, wherein the whisk is operable at a first speed to produce foam and a second speed to produce warm milk.
10. A milk frother according to any one of Claims ito 9, wherein the heating element is turned off a predetermined time prior to the magnetic drive means.
ii. A milk frother according to Claim 10, wherein the predetermined time is in the range of 20 to 30 seconds
12. A milk frother substantially as described herein with reference to and as illustrated in the accompanying drawing.