Coffee grinder and coffee grinding method

Patent metadata

Field	Value
Publication number	US-10517434-B2
Application number	US-201415035247-A
Country	US
Kind code	B2
Filing date	Nov 11, 2014
Priority date	Nov 12, 2013
Publication date	Dec 31, 2019
Grant date	Dec 31, 2019

Abstract

A coffee grinder having a grinding tool ( 20 ) for grinding coffee beans, a motor ( 30 ) for driving the grinding tool ( 20 ), a stall detector ( 41 ) for detecting a stall condition of the grinding tool ( 20 ) and/or of the motor ( 30 ), and a reversal unit ( 40 ) configured to temporarily reverse a direction of rotation ( 28,28′ ) of the grinding tool ( 20 ) and/or of the motor ( 30 ) if the stall detector ( 41 ) detects a stall condition. Further, a corresponding coffee grinding method and a coffee machine having a coffee grinder are presented.

First claim

The invention claimed is:

1. A coffee grinder comprising:
a grinding tool for grinding coffee beans,
a motor for driving the grinding tool,
a stall detector for detecting a stall condition of the grinding tool and/or of the motor, and
a reversal unit configured to:
pause a rotation of the grinding tool and/or of the motor for a first predetermined amount of time when the stall detector detects the stall condition,
after the first predetermined amount of time is over, reverse a direction of rotation of the grinding tool and/or of the motor for a second predetermined amount of time, and
resume a preferred direction of rotation of the grinding tool and/or of the motor after the reversal of the direction of rotation is complete.

2. The coffee grinder according to claim 1 , wherein the reversal unit comprises a controller for controlling a direction of rotation of the motor.

3. The coffee grinder according to claim 2 , wherein the controller of the reversal unit is configured to:
pause the reverse rotation of the grinding tool and/or of the motor.

4. The coffee grinder according to claim 2 , wherein the controller of the reversal unit is configured to control a rocking motion of the grinding tool and/or of the motor by repeatedly changing the direction of rotation of the grinding tool and/or of the motor.

5. The coffee grinder according to claim 4 , wherein the controller of the reversal unit is further configured to control the rocking motion in response to detecting another stall condition within a predetermined time interval.

6. The coffee grinder according to claim 1 , wherein the reversal unit comprises a spring-loaded clutch.

7. The coffee grinder according to claim 1 , wherein the stall detector is configured to evaluate an electrical current of the motor for detecting the stall condition.

8. The coffee grinder according to claim 7 , wherein the evaluation comprises comparing a detected value with a threshold value and/or comparing an integral of a detected value over time with a threshold value.

9. The coffee grinder according to claim 1 , wherein the stall detector is configured to evaluate a rotation rate of the grinding tool and/or of the motor for detecting the stall condition.

10. The coffee grinder according to claim 1 , wherein the grinding tool has an abrasive surface, the coffee grinder further comprising a housing for putting the coffee beans and the grinding tool in a position for contacting each other, the housing having a surface for retaining the coffee beans in such a position, and wherein the motor is configured for performing a relative movement of the coffee beans and the abrasive surface.

11. The coffee grinder according to claim 10 , wherein the grinding tool is rotatably arranged in the coffee grinder, and wherein the motor is adapted to rotate the grinding tool at a speed which is at least 500 revolutions per minute for performing the relative movement of the coffee beans and the abrasive surface.

12. The coffee grinder according to claim 1 , further comprising a clutch arranged between the motor and the grinding tool, the clutch comprising a first clutch element and a second clutch element, wherein the first clutch element is configured for a rotational movement with respect to the second clutch element upon a rotation by the motor for a limited angle of rotation until, upon reaching a stop, the first clutch element and the second clutch element rotate together.

13. The coffee grinder according to claim 12 , wherein the clutch further comprises a spring element for causing the rotational movement of the first clutch element with respect to the second clutch element.

14. A coffee machine comprising a coffee grinder according to claim 1 .

15. A coffee grinding method comprising the steps of:
detecting a stall condition of a grinding tool for grinding coffee beans and/or of a motor for driving the grinding tool,
in response to detecting the stall condition, pausing a rotation of the grinding tool and/or of the motor for a first predetermined amount of time,
after the first predetermined amount of time is over, reversing a direction of rotation of the grinding tool and/or of the motor for a second predetermined amount of time, and
resuming a preferred direction of rotation of the grinding tool and/or of the motor after the reversal of the direction of rotation is complete.

Assignees

• Koninklijke Philips Nv

Inventors

• Lammers Jeroen Herman
• Huang Zhuangxiong
• Kooijman Gerben
• Te Velde Mart Kornelis-Jan
• Lipsch Job
• Suijver Jan Frederik
• Van Den Aker Karel Johannes Adrianus

Classifications

• A47J31/42

  Beverage-making apparatus with incorporated grinding or roasting means for coffee {(coffee mills A47J42/00; coffee roasters in general A23N12/08)} · CPC title

• A47J42/38

  Parts or details · CPC title

• A23F5/08

  Methods of grinding coffee (coffee mills A47J42/00) · CPC title

• A47J42/46

  Driving mechanisms; Coupling to drives · CPC title

• A47J42/36

  mechanically driven · CPC title