Brewing Device With Ground Coffee Quantity Control and Coffee Machine Comprising Such a Device

• US 20110297002A1
• Filed: 06/02/2011
• Published: 12/08/2011
• Est. Priority Date: 06/08/2010
• Status: Active Grant

• Current Assignee: SEB SA
• Original Assignee: SEB SA
• Inventors: LEBUFFE, Gilles, VITEL, Arnaud, GAILHARD, Thierry
• Granted Patent: US 9,986,868 B2
• Time in Patent Office: Days
• US Class Current: 99/287
• CPC Class Codes: A47J 31/3614 Means to perform transfer from a loading position to an infusing position

Abstract

A brewing device (2) for an espresso-type coffee machine including a brewing chamber (12) for receiving ground coffee, a movably mounted pressure piston (13) in translation with a stroke that extends from an upper retracted position in which the pressure piston (13) is located above the brewing chamber (12) to a lower tamping position in which the pressure piston (13) enters said brewing chamber (12) and a potentiometer controlled by driving means during the stroke of the pressure piston (13) to measure the tamping position of said pressure piston and to thereby calculate the height of the compressed cake of ground coffee. The driving means only act on the potentiometer for a portion of the stroke of the pressure piston (13).

Claims

1. A brewing device for an espresso-type coffee machine comprising a brewing chamber for receiving ground coffee, a movably mounted pressure piston in translation with a stroke that extends from an upper retracted position in which the pressure piston is located above the brewing chamber to a lower tamping position in which the pressure piston enters said brewing chamber and a potentiometer controlled by driving means during the stroke of the pressure piston to measure the tamping position of said pressure piston and to thereby calculate the height of the compressed cake of ground coffee, the driving means only acting on the potentiometer for a portion of the stroke of the pressure piston.

2. A brewing device according to claim 1, wherein the potentiometer is a rotary potentiometer having an axis of rotation.

3. A brewing device according to claim 2, wherein the driving means comprise a lever arranged along the axis of rotation of the potentiometer that engages with the contact surface arranged at the end of an arm fixed to the pressure piston.

4. A brewing device according to claim 3, wherein the arm fixed to the pressure piston is an upper arm that drives the lever throughout a lower portion of the stroke of the pressure piston up to the tamping position and in which the driving means comprise a second contact surface arranged at the end of a lower arm fixed to the pressure piston, driving the lever through an upper portion of the stroke of the pressure piston up to the retracted position.

5. A brewing device according to claim 1, wherein the driving means act on the potentiometer for less than half of the stroke of the pressure piston.

6. A brewing device according to claim 2, wherein the axis of rotation of the potentiometer comprises braking means.

7. A brewing device according to claim 6, wherein the braking means are formed by an elastomer O-ring arranged in a cover arranged around the potentiometer, said O-ring being fitted to the diameter of the axis of rotation to produce friction when the axis is rotating.

8. A brewing device according to claim 2, wherein the lever and the cover comprise, respectively, stops and protrusions limiting the rotation of the axis of the potentiometer.

9. A brewing device according to claim 1, wherein said brewing device further comprises a hydraulic cylinder to drive the pressure piston.

10. An espresso-type coffee machine comprising a brewing device as set forth in claim 1.

11. A brewing device according to claim 2, wherein the driving means act on the potentiometer for less than half of the stroke of the pressure piston.

12. A brewing device according to claim 3, wherein the driving means act on the potentiometer for less than half of the stroke of the pressure piston.

13. A brewing device according to claim 4, wherein the driving means act on the potentiometer for less than half of the stroke of the pressure piston.

14. An espresso-type coffee machine comprising a brewing device as set forth in claim 2.

15. An espresso-type coffee machine comprising a brewing device as set forth in claim 3.