Milk frother
Patent Information
- Authority / Receiving Office
- AU · AU
- Patent Type
- Applications
- Current Assignee / Owner
- DE LONGHI APPLIANCES SRL
- Filing Date
- 2025-01-29
- Publication Date
- 2026-08-06
AI Technical Summary
Existing milk frothers face challenges in producing high-quality frothed milk and are difficult to clean due to milk residue formation, particularly in the air and milk suction channels, which are hard to calibrate and result in milk waste.
A milk frother design featuring a removably supported tubular insert within the milk container, forming a milk riser cavity open at the bottom and sealed at the top, with precise channels and gaskets for easy cleaning and calibration, ensuring minimal milk waste and high-quality froth production.
The design allows for easy cleaning, minimizes milk waste, and ensures high-quality frothed milk production by optimizing the Venturi effect with precise flow control and easy access to internal parts.
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Abstract
Description
[0001] MILK FROTHER
[0002] DESCRIPTION
[0003] The present invention relates to a milk frother.
[0004] Techniques for preparing frothed milk for coffee machines or similar appliances have been known for some time. These primarily rely on Venturi-effect suction systems triggered by a flow of steam used to heat the milk. These steam-powered systems draw milk and air via the Venturi effect, incorporating them into the steam to create milk emulsions.
[0005] There are also systems on the market for preparing frothed milk that include mechanical whisk mixers, and in professional settings, systems with pumps and frothing mechanisms.
[0006] Traditional milk frothers have been implemented in various forms, ranging from external carafes connected to coffee machines, standalone devices, systems integrated into the coffee machine's spout or steam wand, to accessories connected to the coffee machine or integrated systems within the coffee machine itself.
[0007] For all technical solutions adopted, the two main challenges are the quality of the frothed milk produced and the cleaning of the milk frother.
[0008] In particular, the cleaning of milk frothers has been extensively studied and developed but remains an area of continuous improvement.
[0009] The primary issue to address is the difficulty of removing milk residues after preparation, as they can quickly form a film that obstructs the proper flow of milk during operation.
[0010] The cleaning of milk frothers has thus focused on technical solutions that allow for easy disassembly and access to all internal parts, the adoption of low-adhesion / low-porosity materials, the design of surfaces specifically crafted to reduce milk retention, and the execution of cleaning cycles with hot water or steam.
[0011] EP 3 731 705 Bl describes a milk frother based on the Venturi principle with the injection of a steam flow, whereby milk and air are drawn into a collector body. The milk carafe is divided into two parts to allow for extremely easy cleaning, and the channels and collector body are vertically developed, created between a rigid first part and a second part overmolded with silicone. Despite the ease of cleaning, the frother has difficulties with calibrating the air suction channel and milk suction channel, which depend on the compression of the parts. Additionally, during disassembly, milk trapped in the milk suction channel is lost.
[0012] The technical task of the present invention is therefore to create a milk frother that eliminates the technical disadvantages of known solutions.
[0013] In the context of this technical task, one objective of the invention is to create a milk frother that is easy to use, clean, and inspect.
[0014] Another objective of the invention is to create a milk frother that is easy to calibrate to optimize preparation.
[0015] A further objective of the invention is to create a milk frother that prevents milk waste.
[0016] The technical task, as well as these and other objectives, are achieved by the present invention, which provides a milk frother comprising a milk container, a collector body with an outlet for frothed milk, a steam inlet, an air inlet, and a milk inlet connected to a milk suction channel from the milk container via the Venturi effect triggered by the steam, characterized by the fact that said channel includes a tubular insert removably supported inside said milk container, which defines a milk riser cavity that is open at the bottom and sealed at the top, and a connecting passage from the cavity to said milk inlet.
[0017] Further characteristics of the present invention are also defined in the subsequent claims.
[0018] Additional features and advantages of the invention will become more apparent from the description of a preferred but non-exclusive embodiment of the milk frother according to the invention, provided as an example and not as a limitation, in the attached drawings, in which: Figure 1 shows the milk frother as a whole;
[0019] Figure 2 shows an exploded view of the main components of the milk frother; Figure 3 shows a bottom view of the lid assembled with the collector body and milk dispenser;
[0020] Figure 4 shows a vertical section of the lid assembled with the collector body and milk dispenser, with directional arrows indicating the flows of air, milk, and steam within it;
[0021] Figure 5 shows a perspective view from below of the tubular insert;
[0022] Figure 5a shows an enlarged detail of the shelf of the tubular insert where the suction well is positioned.
[0023] Figure 6 shows a perspective view of the milk container.
[0024] Figure 7 illustrates a diagram of the assembly of the lid, tubular insert, and milk container.
[0025] Figure 8 provides a vertical section of the milk frother, with an enlarged detail to illustrate the specifics of the area around the suction well.
[0026] Figure 9 depicts a schematic of the milk flow in the milk frother shown in a vertical section, in two successive moments: the moment when the Venturi effect is triggered, and the moment when the milk has already reached the collector body.
[0027] Referring to the cited figures, a milk frother is shown, identified overall with reference number 1. The milk frother 1 comprises a milk container 2 associated with a collector body 3.
[0028] During the normal operation of the milk frother 1, the milk container 2 holds the milk that will subsequently be frothed.
[0029] The collector body 3 features an outlet for frothed milk 4, a steam inlet 5, an air inlet 6, and a milk inlet 7.
[0030] Inside the collector body 3, there is a meeting zone 36 where the steam flow Fl entering from the steam inlet 5, the air flow F2 entering from the air inlet 6 and drawn in by the Venturi effect triggered by the steam flow Fl, and the milk flow F3 entering from the milk inlet 7 also drawn in by the Venturi effect triggered by the steam flow Fl converge. The air inlet 6 may have a valve for total or partial closure to produce frothed milk or not, by mixing milk, steam, and a limited or zero amount of air. The practical effect of varying the amount of air entering via the closure valve is milk with a different amount of foam.
[0031] The milk inlet 7 is connected to a milk suction channel from the milk container 2, via the Venturi effect triggered by the steam.
[0032] The milk suction channel includes a tubular insert 8, which is removably supported inside the milk container 2.
[0033] The tubular insert 8 and the milk container 2 are complementary in shape to ensure a proper formfitting assembly.
[0034] In particular, the tubular insert 8 and the milk container 2 are co-axially coupled.
[0035] In a preferred embodiment, the milk container has a parallelepipedal geometric shape with rounded comers.
[0036] The tubular insert 8 features external centering ribs 9 inside the milk container 2.
[0037] The centering ribs 9 serve three purposes: ensuring the correct insertion of the tubular insert 8 into the milk container, maintaining the correct relative position between the tubular insert and the milk container 2, and spacing the external surface of the tubular insert from the internal surface of the milk container 2, to allow the upward flow of milk, as will be better explained later.
[0038] The milk container 2 is also equipped with a lid 10.
[0039] The lid 10 is removable from the milk container 2.
[0040] In the illustrated solution, the lid 10 houses the collector body 3, which is itself a removable component of the lid 10.
[0041] The outlet for frothed milk 4 from the collector body 3 is connected to a milk dispenser 11, which dispenses the frothed milk into a container, typically a cup. The tubular insert 8 and the milk container 2 define a milk riser cavity 12, which is open at the bottom and sealed at the top, and a connecting passage between the riser cavity 12 and the milk inlet 7.
[0042] The riser cavity 12 has a thickness between 0.05 mm and 0.5 mm and is shaped to allow the upward flow of a thin layer of milk.
[0043] Since the centering ribs 9 are calibrated for alignment but do not provide a hydraulic seal between the tubular insert 8 and the milk container 2, the thin film of milk rising is distributed along the entire annular development of the riser cavity 12 around the axis of the tubular insert 8 and the milk container 2.
[0044] The milk riser cavity 12 and the connecting passage between the milk riser cavity 12 and the milk inlet 7 together form the milk suction channel.
[0045] The milk container 2 features an upper peripheral flange 13 for support.
[0046] This flange 13 is flat and positioned on a plane perpendicular to the axis of the milk container 2.
[0047] In particular, since the axis of the milk container 2 is oriented vertically when the frother device is placed on a horizontal surface, the flat flange 13 extends horizontally.
[0048] Furthermore, the flange 13 extends along the entire upper perimeter of the milk container 2 in a radially outward direction.
[0049] The tubular insert 8 includes an upper peripheral counter-flange 14 supported by the flange 13.
[0050] This counter-flange 14 is also flat and positioned on a plane perpendicular to the axis of the tubular insert 8.
[0051] Similarly, since the axis of the tubular insert 8 is oriented vertically when the frother device is placed on a horizontal surface, the flat counter-flange 14 extends horizontally.
[0052] The counter-flange 14, in combination with the flange 13, defines the upper boundary of the riser cavity 12. A first sealing gasket 15 is interposed between the flange 13 and the counter-flange 14 to seal the upper part of the riser cavity 12.
[0053] The first sealing gasket 15 is a flat ring positioned co-planar between the facing parallel surfaces of the flange 13 and the counter-flange 14.
[0054] More specifically, the first sealing gasket 15 is affixed to the flange 13 and matches its shape and size.
[0055] The connecting passage between the riser cavity 12 and the milk inlet 7 includes a suction well 16.
[0056] The suction well 16 is formed by a recess on the upper flat surface 32 of a shelf 17 projecting inwardly from the tubular insert 8.
[0057] In particular, the shelf 17 projects from the upper end of the tubular insert 8.
[0058] In a preferred embodiment, the upper flat surface 32 of the shelf 17 is on the same plane as the upper flat surface of the counter-flange 14.
[0059] The suction well 16 has a bottom with a through-opening 18 connecting the riser cavity 12 to the suction well 16.
[0060] A raised portion 19 at the bottom of the suction well defines a calibrated channel 20 connecting the milk inlet 7 in the collector body 3 to the suction well 16.
[0061] A second flat sealing gasket 21 is placed over the recess of the shelf 17 to seal it.
[0062] Specifically, the second gasket 21 seals the top of the suction well 16 and the calibrated channel 20.
[0063] The second gasket 21 is located between the upper flat surface 32 of the shelf 17 and the lower flat surface 33 of the lid 10.
[0064] More precisely, the second gasket 21 is affixed to the underside of the lid 10.
[0065] This second flat gasket 21 has a through-hole 22 providing access to a duct 23 in the lid 10, which connects the calibrated channel 20 to the milk inlet 7 in the collector body 3. The upper flat surface 32 of the shelf 17 features a first rib 24 along a perimeter edge of the shelf s recess.
[0066] The upper flat surface 32 of the shelf 17 also features a second rib 25 surrounding the first rib 24. The first rib 24 and the second rib 25 engage with the second flat gasket 21 and are designed to improve the sealing of the second flat gasket 21.
[0067] The upper end of the tubular insert 8 includes a milk filling opening 26 bordered by the shelf 17.
[0068] The milk filling opening 26 allows milk to be added without removing the tubular insert 8 from the milk container 2, thus enhancing the usability of the milk frother 1.
[0069] The lid 10 includes clamping mechanisms 27 for the first and second sealing gaskets 15, 21.
[0070] These clamping mechanisms 27 can be manually released by the user when it is necessary to add milk to the milk container 2, by pressing one or more buttons 28.
[0071] The clamping mechanisms 27 securely connect the lid 10 to the milk container 2, pressing the first gasket 15 against the flange 13 and the counter- flange 14, and the second gasket 21 against the lower flat surface 33 of the lid 10 and the upper flat surface 32 of the shelf 17.
[0072] The clamping mechanisms 27 include at least one locking lever 29 that fits into a corresponding snap-fit seat 30 on the milk container 2.
[0073] In a preferred embodiment, the clamping mechanisms 27 for the gaskets 15, 21 are comprehensive of designed snap-fit components.
[0074] Specifically, a locking lever 29 is provided on each of two opposite sides of the lid 10, with a rotation fulcrum supported by the lid 10 and a lever arm equipped with a locking tooth 34 that engages with a corresponding snap-fit seat 30 and is actuated by a corresponding button 28.
[0075] Each locking lever 29 is pivoted with a horizontal axis to the lid 10 and extends downward from the lid 10.
[0076] Each snap-fit seat 30 is located in a collar 31 that extends peripherally from the flange 13 and surrounds the counter-flange 14. The collar 31 extends orthogonally from the flange 13.
[0077] The operation of the milk frother 1 according to the invention, as described and illustrated, is essentially as follows.
[0078] The tubular insert 8 is placed inside the milk container 2, after which milk is added to the milk container 2 through the milk filling opening 26.
[0079] The lid 10, already assembled with the collector body 3 and milk dispenser 11, is then secured to the milk container 2 using the dedicated clamping mechanisms 27.
[0080] At this point, the steam and air inlets 5, 6 of the collector body 3 are connected to steam and air sources.
[0081] For example, the milk container 2 of the milk frother 1 may be placed on a cup holder platform of a coffee machine (not shown), and the steam and air inlets 5, 6 of the collector body 3 are connected to the steam and air sources within the coffee machine.
[0082] Activating the milk frother 1 by enabling the steam source, the steam flow Fl directed into the meeting zone 36 inside the collector body 3 through the steam inlet 5, by Venturi effect draws an air flow F2 from the air source and a milk flow F3 from the milk container 2 into the meeting zone 36.
[0083] Specifically, the milk drawn from the milk container 2 rises through the riser cavity 12, flows toward the through-opening 18, and sequentially passes through the suction well 16, the calibrated channel 20, the access hole 22 in the second gasket 21, the duct 23 in the lid 10, and the milk inlet 7.
[0084] After reaching the meeting zone 36 in the collector body 3 through the steam, air, and milk inlets 5, 6, 7, the resulting mixture flow F4 of steam, air, and milk enters a mixing zone 35, located between the meeting zone 36 and the frothed milk outlet 4.
[0085] Subsequently, the mixed milk flow F5 in the mixing zone 35 passes through the milk dispenser 11, which can be oriented for direct dispensing into a cup. It has been observed that the milk frother 1 according to the invention is particularly advantageous as it allows easy access to the main surfaces wetted by milk for thorough cleaning.
[0086] The tubular insert 8, in contact with milk on both its internal and external surfaces, is easily removable for washing and can be cleaned manually or in a dishwasher. The milk container 2 is similarly easy to clean, either by hand or in a dishwasher.
[0087] The connecting passage from the riser cavity 12 to the milk inlet 7 in the collector body 3 is easily accessible for cleaning once the lid 10 is removed from the milk container 2.
[0088] The reliability of the milk frother 1 is very high, as fluid seals are ensured by simple flat gaskets.
[0089] The quality of the frothed milk is very high, thanks to the fact that the shapes and dimensions of the meeting zone 36 and the calibrated inlets 5, 6, 7 can be designed and reproduced with extreme precision, allowing equally precise control of the flows triggered by the Venturi effect.
[0090] Finally, milk waste is minimized, as any unused milk at the end of preparation remains entirely in the milk container 2.
[0091] The milk frother 1 as conceived is subject to numerous modifications and variations, all falling within the scope of the inventive concept; additionally, all details can be replaced with technically equivalent elements.
[0092] In practice, the materials used, as well as the dimensions, can be chosen freely according to needs and the state of the art.
Claims
CLAIMS1. A milk frother (1) comprising a milk container (2), a collector body (3) with an outlet for frothed milk (4), a steam inlet (5), an air inlet (6), and a milk inlet (7) connected to a milk suction channel from the milk container (2) by means of the Venturi effect triggered by the steam, characterized in that said suction channel includes a tubular insert (8) removably supported inside said milk container (2), defining with it a milk riser cavity (12) that is open at the bottom and sealed at the top, and a connecting passage from the riser cavity (12) to said milk inlet (7), the external surface of the tubular insert (8) and the internal surface of the milk container (2) being spaced to allow the milk to rise.
2. A milk frother ( 1 ) according to claim 1 , characterized in that said milk container (2) includes an upper peripheral flange (13) for support, and said tubular insert (8) includes an upper peripheral counter-flange (14) supported by said flange (13), said counter-flange (14) in combination with said flange (13) forming the upper boundary of said riser cavity (12).
3. A milk frother (1) according to claim 2, characterized in that a first sealing gasket (15) is interposed between said flange (13) and said counter-flange (14) to seal the upper part of said riser cavity (12).
4. A milk frother (1) according to claim 3, characterized in that said flange (13) and said counter- flange (14) are flat, and said first gasket (15) is formed as a flat ring.
5. A milk frother (1) according to any of the preceding claims, characterized in that said milk container (2) is provided with a lid (10) housing said collector body (3).
6. A milk frother (1) according to any of the preceding claims, characterized in that said connecting passage includes a suction well (16) formed by a recess in an upper flat surface (32) of a shelf (17) projecting inwardly from said tubular insert (8), said suction well (16) having a bottom with a through-opening (18) connecting to said riser cavity (12) and a raisedportion (19) defining a calibrated channel (20) connecting to said milk inlet (7) in said collector body (3).
7. A milk frother (1) according to claim 6, characterized in that said shelf (17) projects from an upper end of said tubular insert (8).
8. A milk frother (1) according to any of claims 6 or 7, characterized in that a second flat sealing gasket (21) is positioned to seal the recess between said upper flat surface (32) of said shelf (17) and a lower flat surface (33) of said lid (10), said second flat gasket (21) having an access hole (22) to a duct (23) in the lid (10) connecting said calibrated channel (20) to said milk inlet (7) in the collector body (3).
9. A milk frother (1) according to any of claims 6 to 8, characterized in that said upper flat surface (32) of the shelf (17) features a first rib (24) along a perimeter edge of said shelf s recess.
10. A milk frother (1) according to claim 9, characterized in that said upper flat surface (32) of the shelf (17) features a second rib (25) surrounding said first rib (24) and engaging with said second gasket (21).
11. A milk frother ( 1 ) according to any of claims 6 to 10, characterized in that said upper end of said tubular insert (8) includes a milk filling opening (26) in the milk container (2) bordered by said shelf (17).
12. A milk frother (1) according to any of claims 8 to 11, characterized in that said lid (10) includes clamping mechanisms (27) for said first gasket (15) and second gasket (21).
13. A milk frother (1) according to claim 12, characterized in that said clamping mechanisms (27) include at least one locking lever (29) in a corresponding snap-fit seat (30) provided in said milk container (2).
14. A milk frother (1) according to claim 13, characterized in that said snap-fit seat (30) is located in a collar (31) extending peripherally from said flange (13) and surrounding said counter- flange (14).
15. A milk frother (1) according to any of the preceding claims, characterized in that said tubular insert (8) features external centering ribs (9) inside said milk container (2).