A device for producing milk foam uses Couette flow and a high shear stress that is accordingly applied to a milk-air mixture between two concentrically arranged cylinders. The cylinders are rotated relatively to another. The high shear stress leads to an emulsion of the milk and the air, which is the basis for a foaming effect, once the emulsion flows out of a gap between the two cylinders and expands. The parameters of the device that mainly influence the foaming effect are the width of the gap and the relative rotation speed of the cylinders.

A device for producing milk foam uses Couette flow and a high shear stress that is accordingly applied to a milk-air mixture between two concentrically arranged cylinders. The cylinders are rotated relatively to another. The high shear stress leads to an emulsion of the milk and the air, which is the basis for a foaming effect, once the emulsion flows out of a gap between the two cylinders and expands. The parameters of the device that mainly influence the foaming effect are the width of the gap and the relative rotation speed of the cylinders.

The present invention provides a device 1 for producing milk foam, which makes use of Couette flow and a high shear stress that is accordingly applied to a milk-air mixture between two concentrically arranged cylinders 2, 3. The cylinders are rotated relatively to another. The high shear stress leads to an emulsion of the milk and the air, which is the basis for a foaming effect, once the emulsion flows out of a gap 6 between the two cylinders 2, 3 and expands. The parameters of the device 1 that mainly influence the foaming effect are the width of the gap 6 and the relative rotation speed of the cylinders.

A drive assembly is disclosed, including a housing cylinder with a cap end, an attachment end with a first attachment surface, and gear teeth disposed around an inner circumference to form at least one ring gear. A planetary gear set may be surrounded by the housing cylinder and includes at least one sun gear and at least one set of planet gears. An output interface may include an interface body and an annular attachment lip with a second attachment surface. The housing cylinder may be attached to the attachment lip for operation of the drive assembly via the second attachment surface contacting the first attachment surface, with the cap end of the housing cylinder extending axially past an axial end of the attachment lip. Rotational power may be transmitted from the planetary gear set to the output interface via the gear teeth and the contact between the attachment surfaces.

A handheld, hand-operated blender may include a container, a lid threadably connected to an upper portion of the container, a bottom portion including a stationary bottom portion threadably connected to a lower portion of the container and a rotatable bottom portion rotatable with respect to the container. The blender may also include a blade assembly including a plurality of blades and a shaft rotatably connected to the rotatable bottom portion and a gear assembly mechanically connected to the blade assembly and the rotatable bottom portion such that rotation of the rotatable bottom portion rotates the blade assembly at a faster revolution per minute than the rotation of the rotatable bottom portion.

An automated coffee grounds homogenizer is disclosed. The homogenizing tool comprises a body having a central axis, a plurality of stirs extending away from the body, and a gear means for randomly rotating the plurality of stirs about the central axis of the body. The gear means has differently sized gears that may be interchangeable with one another whereby the path of rotation of the stirs about the central axis of the body may be changed by switching out one of the plurality of gears with another of the plurality of gears. In a similar vein, each stir is preferably magnetically detachable to the gear means wherein switching out the placement of each stir changes the path of random rotation of the stirs about the central axis.