GB2578094A

GB2578094A - Manual Milk-Frother

Info

Publication number: GB2578094A
Application number: GB1816463.2A
Authority: GB
Inventors: Yazdani Gholamreza
Original assignee: Par2 Ltd
Current assignee: Par2 Ltd
Priority date: 2018-10-09
Filing date: 2018-10-09
Publication date: 2020-04-22
Also published as: GB201816463D0

Abstract

A manual milk frother 10 comprising an inner milk container 16 for holding milk at a first temperature, and an outer hot-liquid 5 container 12 for forming a heating jacket around the inner milk container 16. A manual agitator 18 is used within the inner milk container 16 to induce a foam in the milk. The manual milk frother 10 also has at least one openable closure element 42 for liquid-tightly closing the inner milk container 16 and the outer hot-liquid container 12. Milk at a first temperature within the inner milk container 16 becomes warmed when surrounded by an outer hot liquid in the outer container 12 and frothy when agitated by the manual agitator 18. The outer jacket container may also be used to cool the inner container. The manual agitator may comprise a stem 68a and a head 68b attached to the stem, the agitator head may further comprise a passage such as a hole, slit, or other means by which the inner fluid can pass to assist in froth generation.

Description

Manual Milk-Frother The present invention relates to a manual milk-frother for heating and frothing milk. The present invention also relates to a method of manually heating and frothing milk, using such a device.

The perfect mug of coffee should be steaming hot and have a frothy top. Cold milk is not conducive to achieving such a cup of coffee as cold milk immediately reduces the temperature of the beverage. Cold milk also alters the taste of coffee differently to hot milk and the resulting beverage may not be to the liking of a consumer. A solution is to heat the milk. However, heating the milk requires additional implements, such as a saucepan or microwave, and access to a source of heat and/or electricity. Frothing is usually achieved by using specialised frothing devices which may be expensive to purchase and impractical to transport. Heating milk and frothing devices usually require electricity to function, which is also impractical when on the go or camping.

Currently, users can use a travel mug or thermos to maintain their beverage to a hot temperature but in this case, the coffee is sub-optimal due to the lack of froth and being several hours old. Professionally-made take-away cups of frothy coffee are an expensive and environmentally-harmful alternative, due to the single-use cups provided, many of which are not recycled or compostable.

The present invention seeks to provide a solution to these problems.

According to a first aspect of the invention, there is provided a manual milk-frother comprising: an inner milk container for holding milk at a first temperature; an outer hot-liquid container positioned around the inner milk container for forming a heating jacket; a manual agitator received or receivable within the inner milk container; and at least one openable closure element for liquid-tightly closing the inner milk container and the outer hot-liquid container; wherein milk at a first temperature within the inner milk container becomes warmed when surrounded by a liquid which is within the outer hot-liquid container at a second temperature higher than the first temperature and aerated to induce froth when agitated by the manual agitator. The manual milk-frother allows a user on the go having access to hot water to prepare a cup of coffee using warmed, frothy milk without requiring any additional implements, such as to heat the milk or an electrically-powered frothing device, or access to a source of electricity or heat. As the milk is heated gradually, there is a reduced risk of the milk rapidly expanding in volume and spilling.

Preferably, the manual agitator is removable from the inner milk container for ease of 5 cleaning. This allows the components of the manual milk-frother to be disassembled and cleaned.

Furthermore, the manual milk-frother may further comprise a suspension element which is attached to the manual agitator to suspend the manual agitator within the inner milk container. Beneficially, the inner milk container may have a longitudinal direction and the manual agitator may be linearly movable along or substantially along said longitudinal direction. This increases the frothing efficiency of the manual agitator.

Alternatively, the manual agitator may be fixable relative to the inner milk container when the manual agitator is in an in-use condition. Additionally, the manual agitator may be fastenable to the openable closure element by at least one of interference fit and complementary screw-threaded engagement. Fcwcr moving parts means that the manual agitator is more robust to breaking during usage. Having a fixed manual agitator means that the inner milk agitator containing the milk must be shaken.

Beneficially, the manual agitator may have an agitator stem, and an agitator head connected or connectable to the agitator stem. The connectable nature of the head allows 20 for ease of cleaning and replacement or even customisability.

Preferably, the inner milk container has a first width, the agitator head has a second width, wherein the second width is smaller than the first width, such that an outer edge of the agitator head is partly or fully spaced-apart from the inner milk container, when inserted therein. This allows part of the milk and froth to move around the agitator head in the inner milk container without necessarily passing through the agitator head.

Advantageously, the agitator head may have at least one of a hole, a slot, a recess, a slit, and an aperture through which liquid can pass for generating froth. The advantage is that these features improve the frothing efficiency of the device.

Beneficially, the openable closure element may be sealingly engageable simultaneously 30 with both the outer hot-liquid container and the inner milk container. Furthermore, the openable closure element may be engageable with at least one of the outer hot-liquid container and the inner milk container by at least one of interference fit and complementary screw-threaded engagement. Advantageously, the manual milk-frother may further comprise a sealing element on at least one of the outer hot-liquid container, the inner milk container and the closure element for sealingly closing the closure element against the outer hot-liquid container and/or the inner milk container. Being able to seal the liquids within the containers means that there is no or limited spillage, whether during transport or use. This also reduces the heat loss as well as the health and safety hazard of burning one's fingers.

Preferably, the inner milk container is at least in part made of a heat-conducting material. The advantage of this feature is that the heat is more effectively transferred between liquids.

Advantageously, the manual milk-frother may further comprise an exterior container receivable around or within at least part of the said outer hot-liquid container.

Furthermore, at least one of the exterior container and the outer hot-liquid container at least in part comprises an insulating material. This reduces the heat loss from the liquid within the outer hot-liquid container and allows the user to handle the manual milk-frother with a reduced risk of injury.

Beneficially, the outer hot-liquid container may have a lip and the exterior container may be seatable on said lip. Additionally, the manual milk-frother may further comprise a fastening means via which the exterior container may be engageable with the outer hot-liquid container. Furthermore, the fastening means may be spaced-apart from the openable closure element along a longitudinal extent of the outer hot-liquid container. Beneficially, the fastening means may be at least one of interference fit and complementary screw-threaded engagement. All these features allow the outer hot-liquid container to take up very little additional space, to provide an extra insulating layer and an additional barrier to leakage.

Optionally, the outer hot-liquid container may have a level marker for indicating a maximum volume of liquid to insert into the outer hot-liquid container. This reduces the 30 chances of the hot liquid overflowing, such as when inserting the inner milk container. In turn, the risk of being burnt is reduced, as is resource wastage.

According to a second aspect of the invention, there is provided a manual beveragefrother comprising: an inner container for holding a liquid at a first temperature; an outer container positioned around the inner container for forming a heating or cooling jacket; and a manual agitator received or receivable within one of the inner container and the outer container; at least one openable closure element for liquid-tightly closing the inner container and the outer container; wherein the liquid at a first temperature within the inner container becomes warmed or cooled when surrounded by a further liquid which i s within the outer container at a second temperature different to the first temperature and aerated to induce froth when agitated by the manual agitator. In this aspect, as some users may prefer the use cold frothy milk over warm frothy milk, the liquid within the inner container may be cold or cooled, and froth generated without requiring electricity. Additionally, the liquid to be warmed or cooled is not limited to milk.

According to a third aspect of the invention, there is provided a method of manually warming and frothing milk using a manual milk-frother, the method comprising the steps of: a] surrounding milk at a first temperature with a liquid at a second temperature being higher than the first temperature; and b] with an agitator inserted, manually agitating the milk until the milk is warm and aerated to induce froth. This method allows a user to warm milk and generate froth when on the go or camping, without requiring access to a source of electricity.

According to a fourth aspect of the invention, there is provided a method of manually warming or cooling and frothing liquid using a manual beverage-frother, the method comprising the steps of: a] surrounding a liquid at a first temperature with a further liquid at a second temperature being different to the first temperature until the liquid is warmed or cooled; and b] with an agitator inserted, manually agitating the liquid until the liquid is aerated to induce froth. This allows a beverage, not limited to milk, to be warmed or cooled and have a frothy top.

The invention will now be more particularly described, with reference to the accompanying drawings, in which: Figure 1 shows a side view of a first embodiment of a manual milk-frother in 30 accordance with the first aspect of the invention, in an assembled condition; Figure 2 shows a longitudinal cross-sectional representation of the manual milkfrother of Figure 1; Figure 3 shows a side view of the manual milk-frother of Figure 1 with an exterior container disengaged from an outer hot-liquid container; Figure 4 shows an exploded side view of the manual milk-frother of Figure 1; Figure 5 shows a perspective view of a manual agitator of the manual milk-frother of Figure 1; Figure 6 shows a longitudinal cross-sectional representation of a second embodiment of a manual milk-frother in accordance with the first aspect of the invention, 10 in an assembled condition; Figure 7 shows a radial cross-section representation through line A-A of the manual milk-frother shown in Figure 6; Figure 8 shows a perspective view of a manual agitator of the manual milk-frother of Figure 6; Figure 9a shows a side view of the manual milk-frother of Figure 6, with an exterior container disengaged from an outer hot-liquid container and having the manual agitator in a low position; and Figure 9b shows a side view of the manual milk-frother of Figure 9a, with the exterior container removed for clarity and having the manual agitator in a high position.

Firstly referring to Figures 1 to 5, there is provided a manual milk-frother 10 or beverage-warming or cooling device or beverage-frother having an outer hot-liquid container 12, an exterior container 14, an inner milk container 16, and a manual agitator 18.

The outer hot-liquid container 12 is also referred to as a first container or an exterior or external chamber. The outer hot-liquid container 12 defines a first volume 20 in which a 25 first liquid or fluid is receivable. The outer hot-liquid container 12 is preferably an elongate member having a top outer end 22 and a bottom outer end 24, positioned at either end of an outer-wall 26, as shown in Figure 1 or 2. The outer-wall 26 has an outward face 28a and an inward face 28b. The outer-wall 26 meets the bottom outer end 24 at an edge 30 which may be right-angled, rounded or, as shown in Figure 2, truncated in longitudinal cross-section. The first liquid or fluid is receivable via the top outer end 22 or an opening in the top outer end 22. The outer hot-liquid container 12 is an integrally-formed cylinder open at the top outer end 22, although other shapes, such as a sphere, a cube, a cuboid or parallelepiped, regular or irregular shapes or alternative cross-sections may be envisioned. Such alternative cross-sections may include triangles, ovals, square, hexagons, octagons, regular or irregular polygons, or regular or irregular rounded shapes. The outer hot-liquid container 12 is made of metals, plastics, silicone or, in this case, a combination thereof The outer hot-liquid container 12 must be made of a material capable of withstanding high temperatures, of around 100°C. Preferably, the material may have insulating properties. The outer hot-liquid container 12 is at least partially transparent in this embodiment, so that the level of the liquid is visible, but this need not necessarily be the case. The outer hot-liquid container 12 also has at least one grippable portion 32, a lip 34 and may have a level marker (not shown).

The grippable portion 32 formed from an insulating material or materials. In this case, the grippable portion is an outer silicone layer overlaying at least a portion of the outer hot-liquid container 12. The grippable portion 32 is positioned at the bottom outer end 24, to allow the outer hot-liquid container 12, when containing boiling water, to be held and/or be placed on a surface without damaging said surface, although other positions of the grippable portion on the outer hot-liquid container could be envisioned.

Although the grippable portion 32 is a single layer of silicone in this embodiment, there may be more than one layer of silicone and/or one or more other insulating materials may he used in addition to or alternatively to silicone. There may also he more than one grippable portion or there may be no grippable portion. Furthermore, the grippable portion or portions may be positionable or detachably positionable on the outer hot-liquid container, such as by interference fit or by complementary screw-threaded engagement. The insulating material may alternatively cover the entirety of the outer hot-liquid container, to prevent heat loss or to prevent warming of a cold first liquid contained within the outer hot-liquid container.

The lip 34 is a protrusion, preferably positioned on the outward face 28a. Preferably, there is one continuous lip 34 but there may be any number of lips, including no lips, a plurality of lips spaced-apart along the longitudinal extent, and/or the circumference of the outer hot-liquid container and/or positioned at an end. The lip or lips may additionally or alternatively be on the inward face.

The level marker or indicator or notch, indicates the maximum level of the first liquid to pour into the outer hot-liquid container 12. The level marker may be positioned on the outward and/or the inward face 28a, 28b of the outer hot-liquid container 12. The lip 34 may be the level marker. Alternatively, there may be no level marker. There may additionally or alternatively be a level marker on or in the inner milk container 16, for example, so that there is a sufficient volume of milk for froth to form and/or sufficient space left to contain the froth.

The exterior container 14 is similar to the outer hot-liquid container 12, having a similar shape and being formed of similar materials. Detailed description of the common features is omittcd for brevity. The exterior container 14 is complementarily shaped to be engageable with the outer hot-liquid container 12, whether receivable within, or preferably around the outer hot-liquid container 12, as shown in Figures 1 and 2. The exterior container 14 has an open exterior end 36 and a closed exterior end 38, as shown in Figure 3. When the exterior container 14 and the outer hot-liquid container 12 are engaged, the open exterior end 36 seats flushly on the lip 34, although it could easily be envisioned that this is not necessarily the case. The exterior container 14 also has at least one grippable portion 40, similarly to the outer hot-liquid container 12. The exterior container 14 is also suitably shaped to fully enclose an openable closure element 42. The outer hot-liquid container 12 and the exterior container 14 are fastenable with each other by having complementary exterior screw-threads 44, although other fastening means, such as interference fit, or a groove and a protrusion or complementary protrusions could be envisioned. The fastening means is positioned towards the bottom outer end 24, spaced-apart from the openable closure element 42, but it may be anywhere along the longitudinal extent of the outer hot-liquid container. There may even be no fastening means or there may be a plurality of fastening means.

When in a disengaged condition from the outer hot-liquid container 12, the exterior container 14 is usable as a cup or drinking implement as shown in Figure 3.

When in an engaged condition with the outer hot-liquid container 12, the exterior container 14 functions as a lid. As shown in Figure 1, the exterior container 14 or lid extends along at least part of a longitudinal extent of the outer hot-liquid container 12. The exterior container 14 surrounds part of the outer-wall 26, however, it could easily be at least partly within the outer hot-liquid container. This latter case would enable the manual milk-frother to be more compact.

Alternatively, the exterior container may be receivable at the bottom outer end instead of 10 at the top outer end and/or may not extend along a longitudinal extent of the outer hot-liquid container. The exterior container may not necessarily be required.

In a further modification to the current embodiment, the outer hot-liquid container and/or the exterior container may comprise a further insulating material, or layer of insulating material and/or be surrounded by a vacuum, for further insulating the manual milk-frother 15 from the ambient environment.

The inner milk container 16 may also be known as a second container or internal or interior chamber. The inner milk container 16 is positionable within the outer hot-liquid container 12, whether permanently or, preferably, removably for ease of cleaning the various components of the manual milk-frother 10. In this arrangement, the outer hot-liquid container 12 forms a heating jacket around the inner milk container 16. The inner milk container 16 defines a second volume 46 in which a second liquid or fluid is receivable. Similarly to the outer hot-liquid container 12, the inner milk container 16 is a substantially cylindrical and elongate member, extending in a longitudinal direction. The cylindrical inner milk container 16 has a first width 48 or first characteristic length relative to the longitudinal direction of the inner milk container 16. In this case, the first width 48 is the diameter. The cylindrical container also has a continuous inner-wall 50, a bottom internal end 52 and a top internal end 54. The inner-wall 50 and the bottom internal end 52 meet at an internal edge 56 which may be right-angled, truncated or, as shown in Figure 2, rounded in longitudinal cross-section. The top internal end may also have a silicone seal or layer of any other material having liquid-tight properties, for providing a seal, although this feature is not necessarily a requirement.

The inner milk container 16 may be made of plastics and/or metal or metals and preferably, it is made of a heat-conducting material to allow heat exchange between the first liquid 5 and the second liquid. The inner milk container 16 may be of a similar or of a different shape or cross-section to the outer hot-liquid container 12. When the inner milk container 16 is received within the outer hot-liquid container 12, the inner milk container 16 and the outer hot-liquid container 12 are preferably orientated relative to each other such that the top internal end 54 and the top outer end 22 are adjacent to each other. The inner milk 10 container 16 and the outer hot-liquid container 12 are liquid-tightly closed or sealed by at least one openable closure element each or preferably, by the same openable closure element 42.

Optionally, the inner milk container may have at least one grippable portion such that the inner milk container may be held when hot, thereby reducing the risk of burning the user's 15 fingers.

The first liquid is preferably water, which is hot and/or has recently been boiled.

The second liquid is milk, which has preferably not been heated prior to being poured into the inner milk container 16. The second liquid has a first temperature, the first liquid has a second temperature, which is preferably different to the first temperature prior to using the manual milk-frother 10. In this case, the second temperature is higher than the first temperature.

Alternatively, the first liquid and/or the second liquid may be any other beverage or beverages such as water, coffee, tea, chocolate, soft drinks, wine, beer, mulled wine, mulled cider or spirits. Furthermore, it could easily be envisioned that the first liquid may 25 be icy water or a cold liquid, such that the second liquid is cooled rather than heated.

The openable closure element 42 is a lid-element which is engageable with the inner milk container 16 and/or with the outer hot-liquid container 12, but in this case, preferably both and preferably simultaneously. The openable closure element 42 also provides a support for the manual agitator 18. The openable closure element 42 is made of plastics, metals, silicone or a combination thereof for providing a tight-fit and therefore a liquid-tight seal with each of the inner milk container 16 and the outer hot-liquid container 12. The openable closure element 42 is fastenable to the inner milk container 16 by a fastening means. In this case, the inner milk container 16 and the openable closure element 42 have complementary inner screw-threads 58 or a ridge and a groove, but they could just as easily be fastenable by interference fit or any other fastening means. The openable closure element 42 is preferably also engageable with the outer hot-liquid container 12 by a further fastening means, in this case, complementary outer screw-threads 60 or ridges and grooves, similarly to the inner milk container 16. The openable closure element 42 forms a water-tight or liquid-tight seal, when engaged with the top internal end 54 and the top outer end 22, by having sealing elements 62a, 62b such as silicone seals positioned at or near the top outer end 22 and the top internal end 54 respectively. These liquid-tight sealing elements prevent or inhibit the first liquid and/or the second liquid from leaking. Alternatively, the sealing elements may comprise any other layer of material which has water-tight properties. In a further modification, the sealing elements may not necessarily be a requirement if the outer hot-liquid container and the openable closure element are sufficiently liquid-tight when engaged together. The openable closure element 42 has a first recess 64 or aperture.

The first recess 64 receives a portion of the manual agitator 18. Preferably the first recess 64 is complementarily-shaped with the manual agitator 18 so as to provide a tight fit. Thus, the in-use manual agitator 18 is fixed relative to the openable closure element 42 and thus the inner milk container 16. In this case, the first recess 64 and the manual agitator 18 are engageable with each other by having complementary agitator screw-threads 66 although interference fit or other fastening means could be envisioned.

The manual agitator 18 is a whisk which is partly receivable within and removable from the inner milk container 16 for ease of cleaning, as shown in Figures 4 or 5. In this case, the manual agitator 18 is suspended by the openable closure element 42 by a suspension element, which, in this case, is the openable closure element 42. The manual agitator 18 comprises an agitator stem 68a, and at least one agitator head 68b connected or connectable to the agitator stem 68a.

In an alternative embodiment, the manual agitator could be loose within or be integrally formed with or fixed directly to the inner milk container or the exterior container or the closure element.

The agitator stem 68a or stalk is an elongate element, the longitudinal extent of which extends sub stanti all y co-axial ly with the I ongi tudi nal di recti on of the inner mil k container 16. The agitator stem 68a has a first end 70a and a second end 70b, opposite the first end 70a. The agitator stem 68a is made of plastics, metal or a combination thereof A radial cross-sectional shape of the agitator stem 68a may be oval, square, triangular, any other regular or irregular polygon or shape or, preferably, circular, as shown in Figure 5.

Although in this embodiment, there is one elongate stalk element, there may be more than one stalk element, for increased robustness when frothing.

The agitator head 68b is required for manually aerating or frothing the milk. The agitator head 68b may also improve mixing if, for example, coffee granules, preferably dissolvable, have been inserted into the inner milk container 16. Each agitator head 68b is made of plastics, metal or metals, or a combination thereof. Preferably, the agitator head 68b is non-detachably bonded with and/or integrally formed with the agitator stem 68a, although it could be conceived that each agitator head is detachable, such as for ease of cleaning. The agitator head 68b has an outer edge 72 and a second width 74 or second characteristic length in a direction substantially perpendicular to the longitudinal direction of the inner milk container 16. The second width 74 is, in this case, a diameter of the agitator head 68b. The second width 74 is smaller than the first width 48 of the inner milk container 16. Thus, the outer edge 72 only partially contacts the inner-wall 50 of the inner milk container 16, if at all, when the manual agitator 18 is inserted within the inner milk container 16. This enables some flow of the second liquid around the agitator head 68b without necessarily traversing the agitator head 68b. In this arrangement, there are preferably three agitator heads 68b, preferably spaced-apart from each other along the agitator stem 68a as shown in Figure 4 or in Figure 5. Each agitator head 68b comprises at least one planar element 76.

Each planar element 76 is flat, substantially flat or substantially planar such as a disc or 30 cylinder, centered or substantially centered around the agitator stem 68a. Each planar element 76 is preferably a circle or oval in cross-section, although other cross-sections may be envisioned such as square, triangular, hexagonal, octagonal, any other regular or irregular polygon or irregular shape. The planar element 76 is perpendicular or substantially perpendicular to a longitudinal axis of the agitator stem 68a, although this need not necessarily be the case. Each planar element 76 has at least one hole 78, slot, recess, slit or aperture through which liquid can pass to generate froth.

In an alternative embodiment, it could be envisioned that the or each agitator head and/or planar element may be detachable for ease of cleaning, ease of replacement and/or customisability. There may be at least one agitator head and/or at least one planar element which may be offset from the centre of the agitator stem. There may be any number of agitator heads and/or more than one planar element per agitator head for more effective frothing. These planar elements may be co-planar, in parallel planes, in contact with each other or spaced-apart along the longitudinal extent of the agitator stem and/or angularly offset around the agitator stem. The agitator head may not even be planar. Instead, it could be spherical or substantially spherical, ovaloid, egg-shaped, cuboidal, tetrahedral or any other regular or irregular shape or polyhedron. The interior volume of such an agitator head may have at least one aperture or hole permitting the second liquid through. Additionally or alternatively, this alternative agitator head may have ridges, grooves and/or protrusions on the outer surface which also aid in aerating the second liquid. The alternative agitator head may alternatively be a coil, a ring of coiled wire or spring or a conventional whisk, which may even be rotatable about its axis.

In a further modification, the agitator head or heads and/or planar elements may be planar in an axis containing or substantially parallel to the longitudinal axis of the agitator stem. The agitator stem may be rotatable by rotating the graspable portion and thereby, the 25 agitator stem.

In use, whilst camping, a user wanting a frothy cup of coffee would retrieve the manual milk-frother 10 which is, at this point, in an assembled condition. The inner milk container 16 may contain cold milk at this point or be empty. The manual milk-frother 10 is positioned such that the grippable portion 32 is at the base, contacting the ground or surface. The user disengages the outer hot-liquid container 12 and the exterior container 14, in this case, by unscrewing one relative to the other. 1:3

The exterior container 14 is placed on the ground or on a surface such that the closed exterior end 38 contacts the ground. The exterior container 14 now functions as a cup and is ready to receive a hot beverage poured into it, as shown in Figure 3. Coffee granules and/or chocolate powder may be poured into the exterior container 14 at any time prior to adding the milk.

The openable closure element 42 is disengaged from at least the outer hot-liquid container 12. Hot water, which has preferably just been boiled, or any other hot first liquid, is then poured into the outer hot-liquid container 12. Care should be taken to not overfill the outer hot-liquid container 12 such that the hot water does not overflow and burn the user, particularly upon receiving the inner milk container 16.

If a maximal level marker or indicator is provided, the user should not fill the external hot-liquid container above the level marker.

If the inner milk container 16 is empty of milk, the openable closure element 42 is also disengaged from the inner milk container 16 by unscrewing and cold milk is poured into the inner milk container 16. If it is not already, the manual agitator 18 must be engaged with the suspension element, in this case the openable closure element 42, by screwing the manual agitator 18 into the first recess 64. The openable closure element 42 is re-engaged with the inner milk container 16 by screwing. The manual agitator 18 is now fixed relative to the inner milk container 16. The user should ensure that the openable closure element 42 is properly engaged with the inner milk container 16 such that the milk is tightly-sealed in and not at risk of leaking. The inner milk container 16 is then inserted into the outer hot-liquid container 12 containing a hot first liquid.

The heat of the first liquid which is, in this case, hot water, heats the inner milk container 16 and in turn, heats the second liquid without requiring electricity.

The user then creates the froth, if froth is desired. To do so, the user grasps the sealed manual milk-frother 10 or at least the inner milk container 16, which is sealed and contains milk. The user then vigorously shakes the manual milk-frother 10 and/or inner milk container 16. Froth is thereby generated manually, by the user, without requiring the use of electricity. Some of the second liquid, in this case milk, is able to flow around the or each agitator head 68b, in a space between the outer edge 72 of the agitator head 68b and the inner-wall 50 of the inner milk container 16. A portion of the second liquid also passes through the or each hole 78 of the or each agitator head 68b. Thus, the primary purpose of the agitator heads 68b is to create froth, rather than filtering the second liquid, although filtering may be a secondary function.

Once the second liquid is sufficiently warm, and if desired, frothy, the second liquid is ready to be received in a drinking vessel or the exterior container 14 which may, at this point, contain hot water or hot black coffee.

The openable closure element 42 is disengaged from the outer hot-liquid container 12 and is used to remove the inner milk container 16 from the outer hot-liquid container 12. The openable closure element 42 and the inner milk container 16 are disengaged by unscrewing, and the user can pour some or all the warm frothy milk from within the inner milk container 16 into the exterior container 14. The hot first liquid may also be used to make the hot beverage, once it has heated the second liquid, thereby providing a further use for the first liquid and reducing wastage. The user can thcn enjoy a frothy hot cup of milky coffee, made with hot milk.

Pouring the hot beverage into the exterior container 14, rather than preparing and drinking the beverage directly from the outer hot-liquid container 12, has the additional advantage of enabling the user to dip a sweet treat such as a custard cream or any other biscuit in the 20 frothy coffee or chocolate.

In a slight modification or as an additional step to the above, the manual agitator may also be used to mix a beverage. In this case, once the milk is warm and frothy, the user may add boiling water and coffee granules, preferably dissolvable, and/or chocolate, powdered or otherwise, into the inner milk container, provided there is sufficient unoccupied space within the inner milk container. The manual agitator may then be used to homogenise the beverage, and, if required, create more froth.

Milk powder, such as for babies, and water may be added instead of homogenous, cold milk and the manual agitator helps mix and homogenise the second liquid.

In the first embodiment, the inner milk container 16 is positioned within the outer hot-liquid container 12. However, it could be imagined that the outer hot-liquid container surrounds only a portion of the inner milk container and/or is receivable within the milk container. In the latter case, the heat would radiate outwards from the hot-liquid container to heat the liquid in the surrounding milk container. In an alternative arrangement, there may be more than two containers, and/or at least two containers may receive a beverage. There may be one or more manual agitation elements in the inner milk container or in the outer hot-liquid container or in each of the containers, and said manual agitation element or elements may be fixed or untethered within each container.

In this embodiment, the aim is to heat the second liquid by positioning it in proximity of the first liquid. However, heating could be achieved without the first liquid, but rather by a heating element, whether that be the outer hot-liquid container containing a powered heater element, an exothermic gel and/or the manual agitator being able to heat the second liquid as well as frothing it. The heater element may be powered by a battery or a solar cell, and if the battery is a rechargeable battery, it may be recharged by the solar panel or cell. Said solar panel or cell may be attached or attachable to the manual milk-frother.

Now referring to Figure 6, there is provided a manual milk-frother 110 or beveragefrother device having an outer hot-liquid container 112, an exterior container 114, an inner milk container 116, and a manual agitator 118.

Features of the second embodiment which are similar to the features of the first embodiment have similar reference numeral, with the prefix "1" added.

The outer hot-liquid container 112 of the second embodiment is similar to the outer hot-liquid container 12 of the first embodiment, having similar dimensions and shape, outer-wall 126, top outer end 122, bottom outer end 124, a lip 134, being formed of similar materials, having at least one grippable portion 132 and receiving a first liquid within a first volume 120. As such, detailed description of the common features is omitted for brevity. The outer hot-liquid container 112 does not have a level marker as in the first embodiment, but this feature could easily be envisioned.

The exterior container 114 of this embodiment is similar to the exterior container 14 of the first embodiment, having a similar shape, at least one grippable portion 140, and being formed of similar materials. Detailed description of the common features is omitted for brevity. Unlike the first embodiment, the exterior container 114 does not have a fastening means to engage with the outer hot-liquid container 112, but this feature could easily be envisioned.

The inner milk container 116 of the second embodiment is similar to the inner milk container 16 of the first embodiment, having similar geometry, top internal end 154, bottom internal end 152, a first width 148, a second volume 146, receiving a second liquid and the manual agitator 118. Detailed description of the common features is omitted for brevity. In the second embodiment, there are no first and/or second sealing elements or silicone seals although these could easily be envisioned.

The first liquid is preferably water, and the second liquid is milk, although the same caveats as in the first embodiment apply.

The openable closure element 142 of the second embodiment is similar to the openable closure element 42 of the first embodiment, being made of similar materials, being engageable with the outer hot-liquid container 112 and inner milk container 116, providing a support for the manual agitator 118, and having similar fastening means (not shown). Detailed description of the common features is omitted for brevity. In this case, the openable closure element 142 has a first aperture 180, instead of or in addition to a first recess.

The first aperture 180 surrounds a portion of the manual agitator 118. Preferably the first aperture 180 is complementarily-shaped with the manual agitator 118 so as to provide a liquid-tight fit and prevent or inhibit the second liquid from leaking via the first aperture 180. The first aperture 180 also permits the manual agitator 118 to be translatable along the longitudinal direction of the inner milk container 116. The first aperture 180 prevents or inhibits translation of the manual agitator 118 in a radial direction relative to the interior milk container 116, although in an alternative embodiment, this need not be the case. In this modified embodiment, the manual agitator or plunger may be translatable at least partially in a radial direction relative to the inner milk container. Furthermore, the frothy milk may be poured via the first aperture in this alternative embodiment.

The aperture 180 is elongate, extending into the milk container 116 along a depending passage forming a stop for the manual agitator 118. In this case, air apertures may be formed in the container 116 to enable or improve aeration of the liquid, and the stop inhibits or prevents the manual agitator from being extracted to far, thus causing discharge of liquid through the air apertures.

In a further modification to the present arrangement, the openable closure element may have a second aperture, distinct from the first aperture, such that the manual agitator traverses the first aperture and the aerated milk is pourable only through the second aperture or both apertures. Such a first and/or second aperture would permit hot frothy milk to be pourable without requiring the openable closure element to be disengaged from either the outer hot-liquid container or the inner milk container. This would be advantageous as the risk of accidental spillage is reduced, as is the risk of being burnt upon handling the inner milk containcr, particularly if there is no means to safely grasp the inner milk container when very hot. The first and/second aperture or apertures may be closed by a further closure element, stopper, bung or any other suitable means for selectably and liquid-tightly closing the aperture. The further closure element may have, on a top face, a graspable portion, a protrusion, a depression or preferably a pair of depressions, such that the further closure element may be removed by pulling or unscrewing the further closure element and vice-versa. Additionally or alternatively, the further closure element may have on a bottom face a depression for receiving part of the manual agitator.

The manual agitator 118 is also known as a whisk or plunger. The manual agitator 118 is partly receivable within and removable from the inner milk container 116 for ease of cleaning. The manual agitator 118 is linearly moveable within the inner milk container 116 along or substantially along the longitudinal direction. The manual agitator 118 comprises a graspable portion 182, an agitator stem 168a, and at least one agitator head 168b.

The agitator stem 168a or plunger stem or stalk is an elongate element which extends along at least part of a longitudinal extent of the inner milk container 116. The agitator stem 168a has a first end 170a and a second end 170b, opposite the first end 170a. The agitator stem 168a transmits motion of the graspable portion 182 to the agitator head 168b. 5 The agitator stem 168a is made of plastics, metal or a combination thereof The agitator stem 168a traverses the first aperture 180 when in use. Thus, whilst being moveable relative to the openable closure element 142, a portion of the agitator stem 168a is surrounded by the closure element 142 at all times when in use. The radial cross-sectional geometries of the first aperture 180 and the agitator stem 168a are complementary, such 10 that the they may both be oval, square, triangular, any other regular or irregular polygon or shape or, as shown in Figure 7, circular.

Although in this embodiment, there is one elongate agitator stem 168a or stalk element, there may be more than one stalk element, for increased robustness when frothing.

The graspable portion 182 is a handle or knob, positioned at the first end 170a of the agitator stem 168a, as shown in Figures 6 or 8. The graspable portion 182 is made of plastics, metals or a combination thereof The graspable portion may be removably engageable with the agitator stem although in this case, it is non-removably bonded and/or integrally formed with the agitator stem 168a.

The agitator head 168b or plunger head is required for manually aerating the milk. The agitator head 168b may also improve mixing if, for example, coffee granules, preferably dissolvable, have been inserted into the inner milk container 116. The agitator head 168b is positioned at or in direction of the second end 170b, spaced-apart from the graspable portion 182, such that the openable closure element 142 is positioned between the graspable portion 182 and the agitator head 168b. There is preferably one agitator head 168b which is non-detachably bonded with and/or integrally formed with the agitator stem 168a. The agitator head 168b is made of plastics, metal, or a combination thereof The agitator head 168b comprises at least one planar element 176. The planar element 176 is flat, substantially flat or substantially planar such as a disc or cylinder, centered or substantially centered around the agitator stem 168a, as shown in Figure 7 or Figure 8.

The disc is preferably a circle or oval in cross-section, although other cross-sections may be envisioned such as square, triangular, hexagonal, octagonal, any other regular or irregular polygon or irregular shape. Similarly to the first embodiment, the agitator head 168b of the second embodiment has an outer edge 172 and a second characteristic length or second width 174, which is smaller than the first characteristic length or first width 148 of the inner milk container 116. Thus, the outer edge 172 only partially contacts the inner-wall 150 of the interior milk container 116, if at all. This enables some flow of the second liquid around the agitator head 168b without necessarily traversing the agitator head 168b or plunger head. The planar element 176 is perpendicular or substantially perpendicular to a longitudinal axis of the agitator stem 168a, although this need not necessarily be the case.

The agitator head 168b of the second embodiment comprises a mesh or disc or discs, each having at least one hole 178, slot, slit or aperture. The mesh or disc or discs are held by a supporting structure 184, although it could just as easily be envisioned that the agitator head is a disc without necessarily requiring a supporting structure, similar to the first embodiment. The difference between the two embodiments is that that the manual agitator 118, and thus the agitator head 168b is moveable relative to the inner milk container 116 in the second embodiment, rather than immoveable relative to the inner milk container 116 as described in the first embodiment.

In an alternative embodiment, it could be envisioned that there may be more than one agitator head and/or more than one disc or planar element per agitator head for more effective frothing. The or each agitator head may be detachable head for ease of cleaning, ease of replacement and/or customisability. The agitator head or disc may be offset from the centre of the agitator stem and/or there may be multiple discs or alternative shapes attached to the agitator stem. These discs may be substantially co-planar, in parallel planes and in contact with each other or spaced-apart along the longitudinal extent of the agitator stem and/or angularly offset around the agitator stem. The agitator head may not even be planar. Instead, it could be spherical or substantially spherical, ovaloid, egg-shaped, cuboidal, tetrahedral or any other regular or irregular shape or polyhedron. The interior volume of such an agitator head may have at least one aperture or hole permitting the second liquid through. Additionally or alternatively, this alternative agitator head may have ridges, grooves and/or protrusions on the outer surface which also aid in aerating the second liquid. The alternative agitator head may alternative be a coil, a ring, a coiled ring or a conventional whisk, which may even be rotatable about its longitudinal axis.

In a further modification, the agitator head and/or disc or discs may be planar in an axis containing or parallel to the longitudinal axis of the agitator stem. The agitator head may 5 be moveable along the longitudinal direction of the inner milk container and/or may be rotatable by rotating the graspable portion and thereby, the agitator stem 168a.

The uses of the second embodiment are similar to the uses of the first embodiment, thus, detailed description of the common steps is omitted for brevity.

The differences in the uses of the second embodiment are as follow.

To aerate the milk, the user grasps the graspable portion 182 or handle. The graspable portion 182, and thus the agitator stem 168a and agitator head 168b, are raised and lowered a plurality of times between a lowered position, as shown in Figure 9a and a raised position, as in Figure 9b, with sufficient speed to aerate the warming or warmed second liquid. The raising and lowering of the graspable portion 182 is done manually, by the user, without requiring the use of electricity, although an electrical, mechanised, battery-powered alternative version could easily be envisioned. Some of the second liquid, in this case milk, is able to flow around the agitator head 168b or plunger head, in a space between the outer edge 172 of the agitator head 168b and the inner-wall 150 or wall. A portion of the second liquid also passes through the mesh and/or at least one hole 178 of the agitator head 168b. Thus, the primary purpose of the agitator head 168b is to create froth, rather than filter the second liquid.

Once the second liquid is sufficiently warm, and if desired, frothy, the second liquid is ready to be received in the exterior container 114 or another drinking implement which may or may not at this point contain hot water and/or hot coffee.

If the openable closure element has a first aperture and/or a second aperture through which frothy milk may be poured without the openable closure element being disengaged from the inner milk container, then the user would pour the frothy milk through the relevant aperture or apertures.

In the absence of such an aperture, the openable closure element 142 is disengaged from the outer hot-liquid container 112, similarly to the uses of the first embodiment, to pour the frothy milk.

Although in the current arrangement, the aim is to obtain hot frothy milk, some users may 5 prefer cold frothy milk. In this modified arrangement, the steps of heating the milk may be omitted.

In a further modified embodiment, the aim could be to cool the second liquid instead of heating it. This could be done for instance, by placing a cold liquid, coolant, wet or dry ice, liquid nitrogen, and/or a heat sink in a neighbouring container which surrounds or is receivable within the container containing the liquid to be cooled. The manual milkfrother could even be adapted to be used in cocktail making, with the frother being capable of crushing ice and/or mixing various liquids.

The first liquid may have multiple uses. The first use would be to warm or cool the second liquid. In a second use, the first liquid would be added to the beverage such that there is 15 no wastage of first liquid, particularly if the first liquid is scarce and/or additional weight that must be carried.

It is therefore possible to provide a re-usable manual milk-frother and a method of warming and frothing milk which are more affordable and practical whilst on the go or camping, without requiring additional implements or access to electricity to heat and/or 20 froth milk.

The words 'comprises/comprising' and the words 'having/including' when used herein with reference to the present invention are used to specify the presence of stated features, integers, steps or components, but do not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable sub -combi nation The embodiments described above are provided by way of examples only, and various other modifications will be apparent to persons skilled in the field without departing from the scope of the invention as defined herein.

Claims

Claims 1. 2. 4. 5. 6.A manual milk-frother comprising: an inner milk container for holding milk at a first temperature; an outer hot-liquid container positioned around the inner milk container for forming a heating jacket; a manual agitator received or receivable within the inner milk container; and at least one openable closure element for liquid-tightly closing the inner milk container and the outer hot-liquid container; wherein milk at a first temperature within the inner milk container becomes warmed when surrounded by a liquid which is within the outer hot-liquid container at a second temperature higher than the first temperature and aerated to induce froth when agitated by the manual agitator.
A manual milk-frother as claimed in claim 1, wherein the manual agitator is removable from the inner milk container for ease of cleaning.
A manual milk-frother as claimed in claim 1 or in claim 2, further comprising a suspension element which is attached to the manual agitator to suspend the manual agitator within the inner milk container.
A manual milk-frother as claimed in any of the preceding claims, wherein the inner milk container has a longitudinal direction and the manual agitator is linearly movable along or substantially along said longitudinal direction.
A manual milk-frother as claimed in any of claims 1 to 3, wherein the manual agitator is fixable relative to the inner milk container when the manual agitator is in an in-use condition.
A manual milk-frother as claimed in claim 5, wherein the manual agitator is fastenable to the openable closure element by at least one of interference fit and complementary screw-threaded engagement.
7. A manual milk-frother as claimed in any of the preceding claims, wherein the manual agitator has an agitator stem, and an agitator head connected or connectable to the agitator stem.
8 A manual milk-frother as claimed in claim 7, wherein the inner milk container has a first width, the agitator head has a second width, wherein the second width is smaller than the first width, such that an outer edge of the agitator head is partly or fully spaced-apart from the inner milk container, when inserted therein.
9. A manual milk-frother as claimed in claim 7 or claim 8, wherein the agitator head has at least one of a hole, a slot, a recess, a slit, and an aperture through which liquid can pass for generating froth.
10. A manual milk-frother as claimed in any of the preceding claims, wherein the openable closure element is sealingly engageable simultaneously with both the outer hot-liquid container and the inner milk container.
11. A manual milk-frother as claimed in any of the preceding claims, wherein the openable closure element is engageable with at least one of the outer hot-liquid container and the inner milk container by at least one of interference fit and complementary screw-threaded engagement.
12. A manual milk-frother as claimed in any of the preceding claims, further comprising a sealing element on at least one of the outer hot-liquid container, the inner milk container and the closure element for sealingly closing the closure element against the outer hot-liquid container and/or the inner milk container.
13. A manual milk-frother as claimed in any of the preceding claims, wherein the inner milk container is at least in part made of a heat-conducting material.
14. A manual milk-frother as claimed in any of the preceding claims, further comprising an exterior container receivable around or within at least part of the said outer hot-liquid container.
15. A manual milk-frother as claimed in claim 14, wherein at least one of the exterior container and the outer hot-liquid container at least in part comprises an insulating material.
16. A manual milk-frother as claimed in claim 14 or claim 15, wherein the outer hot-liquid container has a lip and the exterior container is seatable on said lip.
17. A manual milk-frother as claimed in any one of claims 14 to 16, further comprising a fastening means via which the exterior container is engageable with the outer hot-liquid container.
18. A manual milk-frother as claimed in claim, wherein the fastening means is spaced-apart from the openable closure element along a longitudinal extent of the outer hot-liquid container.
19. A manual m lk-frother as claimed in claim 17 or claim 18, wherein the fastening means is at least one of interference fit and complementary screw-threaded engagement.
20. A manual milk-frother as claimed in any of the preceding claims, wherein the outer hot-liquid container has a level marker for indicating a maximum volume of liquid to insert into the outer hot-liquid container.
21. A manual beverage-frother comprising: an inner container for holding a liquid at a first temperature; an outer container positioned around the inner container for forming a heating or cooling jacket; and a manual agitator received or receivable within one of the inner container and the outer container; at least one openable closure element for liquid-tightly closing the inner container and the outer container; wherein the liquid at a first temperature within the inner container becomes warmed or cooled when surrounded by a further liquid which is within the outer container at a second temperature different to the first temperature and aerated to induce froth when agitated by the manual agitator.
22 A method of manually warming and frothing milk using a manual milk-frother as claimed in any one of claims 1 to 20, the method comprising the steps of: a] surrounding milk at a first temperature with a liquid at a second temperature being higher than the first temperature; and b] with an agitator inserted, manually agitating the milk until the milk is warm and aerated to induce froth.
23. A method of manually warming or cooling and frothing liquid using a manual beverage-frother as claimed in claim 21, the method comprising the steps of: a] surrounding a liquid at a first temperature with a further liquid at a second temperature being different to the first temperature until the liquid is warmed or cooled; and b] with an agitator inserted, manually agitating the liquid until the liquid is aerated to induce froth.