HK1025893A - Device for preparing coffee powder - Google Patents

Description

Apparatus for preparing coffee powder

The invention relates to a device for preparing coffee powder, comprising a coffee bean container, a grinding mill with an electric motor and a device for metering and/or braking the ground coffee powder, wherein the grinding mill has a stationary and rotating grinding disk with grinding teeth located inside, the distance between the grinding disks can be adjusted relative to each other, and the metering and/or braking device is arranged outside the grinding disk in the tangential direction and in the radial direction.

Electric coffee mills with a device for metering coffee powder in portions are known, which are used primarily in coffee machines of the catering industry, but are also increasingly used in offices and homes.

These known devices for preparing coffee powder are bulky and/or cause annoying noises when the coffee beans and/or the coffee powder flow is diverted by means of control elements required for this purpose. The coffee beans are fed concentrically through a central funnel in the region of the rotational axis of the grinding disk, which arrangement may even lead to jamming of the grinder due to limited space conditions, which occurs in particular if the coffee quality is not high enough.

The object of the invention is therefore to create a device which is reliable in operation, which does not have the disadvantages of the prior art, has an optimum material flow and does not cause annoying noises when metering portions and/or discharging coffee powder.

It is also an object of the invention to keep the device low in construction height or to design the device such that it allows space-saving arrangement of an existing coffee brewing component in the coffee machine.

According to the invention, the grinding disks are arranged in the vertical line or at an acute angle to the vertical line, in which case the static feed of the coffee beans takes place via a filling funnel essentially halfway between the grinding disks.

The input of coffee beans according to the features of claim 1 reduces the risk of clogging of the grinding discs, whereas the coffee beans reach substantially in the lower region of the mill under the influence of gravity acting along the vertical line, thereby leaving sufficient space for displacing and distributing the coffee beans along the two grinding discs. Furthermore, the drive power of the motor can be reduced and the coffee grinder operates with a reduced required torque.

Another advantage is that by preselecting the milling time, the reproducibility of the amount of coffee powder is improved compared to feeding coffee beans coaxially.

Advantageous further developments of the object of the invention are specified in the subsequent dependent claims.

The necessary construction height is considerably reduced by the device according to claim 2, but it allows the use of the free zone between the stator and the mill. Another advantage is that thermal expansion generated during operation of the coffee mill is absorbed by the mill housing; the grinding gap between the grinding discs is unchanged.

The adjustment device according to claim 3 can be realized particularly advantageously and economically.

The design according to claim 4 allows a very simple adjustment by means of a simple adjustment tool, i.e. a cylindrical pin.

Compensating for axial bearing play by inserting a compression spring according to claim 5; the mill is allowed to maintain its once adjusted position and compensate for thermal expansion. In addition, the resulting locking of the adjustment disk ensures that its position is maintained even in the event of vibrations.

It has proven expedient to dispense the quantity of coffee powder by adjusting the grinding time according to claim 6.

Due to the centrifugal force caused on the rotating grinding disc, the function of the freshly ground coffee powder is great; the spring steel sheet of claim 7 absorbs a substantial portion of the energy and prevents fouling of a coffee machine connected downstream.

The coffee dispensing opening according to claim 8 is a preferred embodiment; it takes the full function of ground coffee powder and fills it with proper sizing without backflow to the grinder.

The use of two hollow cylinders inserted into one another according to claim 9 provides a slot-like cover which can be easily moved even in the case of fine coffee powder.

The emptying of the coffee powder outlet can be improved according to claim 10 by means of a vibrating element, for example a piezoelectric element, which is supplied by a small HF generator.

In particular in larger coffee machines, it is desirable to use two or more different coffee varieties, so that a subdivision of the container according to claim 11 is desirable.

The use of a controllable rotary funnel according to claim 12 allows to simplify the coffee brewing unit connected downstream, and is therefore particularly economical.

The following figures further illustrate embodiments of the subject invention. Wherein:

FIG. 1 shows a practical embodiment of a coffee grinder installed in a coffee maker;

fig. 2 details one of the two coffee mills of fig. 1.

FIG. 3 shows a further development of a controlled coffee powder outlet with a vibrating element; and

fig. 4 is a cross-sectional view perpendicular to the longitudinal axis of fig. 3 of the slot of the discharge opening in the closed state.

Like parts are given the same reference numerals in the drawings.

In fig. 1 a coffee grinder is indicated with 1. Which are arranged perpendicularly to each other at an angle alpha of 45 deg. to the vertical L and with their two filling funnels 2 are flanged to a coffee bean container 28 with two chambers 28', 28 "via a selection plate 27.

In addition, FIG. 1 also shows a mill 3 with two grinding discs 4 and 5, which is inside a mill housing 15. A part of a rotatable support flange 6 with holes 10 is visible in a groove in the housing 15 formed by the web 15'.

Both mills 3 have the same coffee powder discharge 21 and spring blades 22 and 22' shown in broken lines. The outlet opening 21 opens into a rotary funnel 29 with an adjusting mechanism 29' which supplies coffee powder to a brewing chamber (not shown) located therebelow.

Fig. 2 shows a partial section of the coffee grinder 1 arranged on the right. From the figure, the coffee powder discharge opening 21 on the left and its spring plate 22 can still be seen, which is also shown in its discharge position 22' after deflection along the arrow. The side edges show the webs 15' of the housing 15 opposite each other; an axial bore 10 is formed in the support flange 6, above which a detent groove 24 in the form of a groove is formed. The support flange 6 is provided with an external thread 7 and screwed into an internal thread 16 of the mill housing 15. A commercially available ball bearing 8 is mounted on the central motor shaft 9, which is mounted with its outer ring in the bearing flange 6. In the bore of a larger support flange 6 above the support flange is a mounting flange 11, on which the lower rotating grinding disk 5 of the mill 3 is fixed in a centered manner by three fastening screws 14. Above the rotating grinding disc 5, at a small distance, there is a stationary grinding disc 4 with its fixing screws 14', the grinding disc 4 being screwed centrally in the upper grinding mill flange 17. The grinding discs 4 and 5 are provided with grinding teeth 23 in a known manner.

The mounting flange 11 is itself fixed to the motor shaft 9 by means of its centering hole 12 and centering screw 13.

The loading hoppers 2 located above them are indicated by dot-dash lines; the input of the coffee bean KB is indicated with 18.

As can be seen from fig. 2 in combination with fig. 1, the coffee beans KB slide vertically, that is to say due to gravity, into the grinding disk 4; 5 and thus provides space for the coffee beans to be displaced to the upper part of the grinder 3, so that the grinding disc does not get stuck.

Furthermore, recesses are formed in the disc support flange 6, which recesses form detent grooves 24, into which three radially arranged, arcuate pins 20 are inserted, which pins 20 are acted upon by springs 19.

On the side of the electric motor of the coffee grinder 1, a terminal box with electrical connections 25 is provided, which electrical connections 25 lead to a time-controlled power supply T.

As can be seen from fig. 2, the support flange 6, with its ball bearings 8, the shaft 9 and the grinding disk 5, can be moved in the direction of the arrow with respect to the stator S or the motor housing 42 by rotating the support flange 6 by means of, for example, a cylindrical pin, and in the process the arched pin 20 is temporarily lifted from the detent groove 24.

This allows to adjust the degree of crushing accurately and, in addition, prevents undesired displacements during vibration.

The metering of the quantity of coffee powder is preferably effected by means of a suitable power supply T with a pulse counter, which is known per se, by time control of the milling duration. The connection to the power source T is made via a pluggable connector 25.

It can also be seen from fig. 2 that the spring plate 22 activates the dynamic brake for the freshly ground coffee powder centrifugally thrown from the grinder 3 and thus deflects the spring plate in the direction of the arrow to the position of the spring plate 22' indicated by the broken line.

The coffee powder outlet 21' according to fig. 3 is an improvement over the outlet 21, which allows it to be completely emptied.

The discharge opening 21 ' is mounted via a flange 30 ' on a grinding mill housing 15 ' which is slightly modified in comparison with FIG. 2 and has a discharge pipe 30 in which a discharge cylinder 31 is rotatably inserted. The outlet cylinder 31 is provided with a ring groove 41, into which a shaft securing device 40 (a spline ring) is inserted, while being secured axially on its opposite side by means of a swivel lever 32.

The discharge pipe 30 and the discharge cylinder 31 have discharge slots 33, 34 which are closed by pivoting in fig. 4 or are opened as shown in fig. 3. This is effected by a swivel arm 39 which is connected to the electromagnet in the direction of the arrow in fig. 4 and rotates the swivel lever 32 by approximately 90 °.

In order to improve the emptying of the coffee powder outlet 21', a vibration element 35 is provided according to fig. 3, on which vibration element 35 a piezoelectric element 37 is mounted, which is connected via a feed cable 38 to a known HF generator G, by means of which the piezoelectric element 37 and the vibration element 35 are brought into resonance.

In this embodiment, the dose is set by a predetermined or preselected milling time, so that the subject matter according to the invention can also be used in conjunction with a volume metering device.

The structure shown in figure 1 is preferably used in a very compact and favourite coffee machine for the catering industry according to the parallel patent application (our number 21273 PCT).

Legend 1 coffee mill 2 charging funnel 3 grinding mill 4 stationary grinding mill 5 rotating grinding disc (adjustable) 6 support flange 7 external screw thread 8 ball bearing 9 motor shaft 10 hole (adjustment means) 11 mounting flange 12 centering hole 13 centering screw 14, 14 'fixing screw 15 grinding mill housing 15' connecting plate 16 internal screw thread 17 grinding mill flange 18 input hole 19 pressure spring 20 pin (arc) 21 coffee powder outlet 21 'coffee powder outlet (with slotted cover) 22 spring leaf 22' hinged spring leaf 23 grinding teeth (4; 5 teeth) 24 braking groove (groove in 6) 25 electric joint 26 scraping cam (three) 27 selection disc 28 coffee bean container 28 'first cavity 28 "second cavity 29 rotary funnel 29' 29 adjustment means 30 discharge pipe (fixed) 31 discharge cylinder (rotatable) 32 rotary rod 3331 discharge slit 35 in discharge slit 3430 in discharge slit 37 vibration element 36 Clamp ring 37 piezoelectric element 38 feed cable 39 swivel arm 40 shaft safety (stopper ring) 41 Ring 42 Motor housing alpha Angle (angle between vertical and crusher axis) G HF Generator KB coffee Bean L vertical line S stator T Power supply (time control)

Claims (12)

1. Apparatus for preparing coffee powder, comprising a coffee bean container, a grinder with a motor and a metering and/or braking device for ground coffee powder, wherein the grinder has in each case one stationary and one rotating grinding disk with grinding teeth located inside, the spacing of the grinding disks being adjustable relative to one another, and the metering and/or braking device is arranged tangentially and radially outside the grinding disk, characterized in that: the grinding discs (4; 5) are arranged in the vertical line (L) or form an acute angle (alpha) with the vertical line (L), and the static feeding of the coffee beans is performed by the charging funnel (2) substantially at the half side between the grinding discs (4; 5).

2. The apparatus of claim 1, wherein: the adjusting device (6, 10) of one of the grinding disks (5) is arranged between the grinding disk and the motor stator (S).

3. The apparatus of claim 2, wherein: the adjusting device (6, 10) consists of a bearing flange (6) with an external thread (7) and a drive-side ball bearing (8), the bearing flange (6) being screwed into the mill housing (15) in an axially adjustable manner.

4. The apparatus of claim 3, wherein: the mill housing (15) is connected to the front motor housing (42) by means of a connecting plate (15'); and, in the edge region of the support flange (6), an axially directed bore (10) is formed for inserting an adjusting tool.

5. The apparatus of claim 4, wherein: at least one compression spring (19) is provided, which is loaded axially on the support flange (6).

6. The apparatus of claim 1, wherein: the metered quantity of coffee powder is metered in portions by repeatedly preselecting the grinding duration (T).

7. The apparatus of claim 6, wherein: a spring piece (22) is arranged in the coffee powder outlet (21) and is used as a dynamic brake of the coffee powder.

8. The apparatus of claim 6, wherein: the coffee powder outlet (21') has a cylindrical shape and is closed at one end face; and coffee outlets (33, 34) are formed in the cylinders (30, 31).

9. The apparatus of claim 8, wherein: the coffee powder outlet (21') has two hollow cylinders (30, 31) which are inserted into one another and have coffee powder outlets (33, 34), are displaced relative to one another during the grinding process and are aligned by rotation after the grinding process has ended.

10. The apparatus of claim 9, wherein: a vibrating element (35, 37) is connected to the hollow cylinder (31).

11. The apparatus of claim 1, wherein: at least two cavities (28' ) for different coffee varieties are present in the container (28).

12. The apparatus of claim 11, wherein: at least two mills (3) are associated with the container (28), downstream of which a controllable rotary hopper (29, 29') is connected.