Brewing head for an espresso machine

• US 20060117960A1
• Filed: 12/02/2005
• Published: 06/08/2006
• Est. Priority Date: 12/04/2004
• Status: Abandoned Application

• Current Assignee: Eugster/Frismag AG
• Original Assignee: Eugster/Frismag AG
• Inventors: Fischer, Daniel
• Application Number:
  US11/292,486
• Publication Number:
  US 20060117960A1
• Time in Patent Office: Days
• US Class Current: 99/279
• CPC Class Codes: A47J 31/3614 Means to perform transfer from a loading position to an infusing position
• CPC Class Codes: A47J 31/3619 Means to remove coffee after brewing
• CPC Class Codes: A47J 31/4496 Means to produce beverage with a layer on top, e.g. of cream, foam or froth

Abstract

In a brewing head of an espresso machine including a pressure-tightly closable brewing compartment which comprises an inlet for hot water, a filling opening for fresh coffee powder and an outlet for freshly brewed espresso, a leached-out coffee powder cake (69) is lifted, after a brewing process, by means of a force-controlled lifting piston (4, 4a) disposed in the brewing compartment up to an upper edge of the peripheral wall. From that position, the coffee powder cake (69) is laterally removed by a scraper (36). The scraper (36) is associated with a carriage (19) which can be moved along a glide face (41) above an opening of the brewing chamber and which has a seal by which, in a work position of carriage (19), the opening of the brewing chamber can be sealed. In order to obtain a reliable and wear resistant seal of the brewing compartment with a flat brewing head, a brewing compartment sleeve (3) forming the peripheral wall of the brewing compartment and substantially movable perpendicularly to the plane of the glide face (41) is force-controlledly moved, in the working position of carriage (19), through the plane of glide face (41) into a sealing position at which the brewing compartment is sealed by means of the seal. After a brewing process, it is moved back from the plane of glide face (41) into a rest position so that carriage (19) can be moved into a start position next to the brewing compartment.

Claims

1. Brewing head of an espresso machine including a pressure-tightly closing brewing compartment, comprising an inlet for boiling water, a filling opening for fresh coffee powder, an outlet for freshly brewed espresso and a force-controlled lifting piston (4, 4a) disposed in said brewing compartment within the peripheral wall thereof, by means of which a leached-out coffee powder cake (69) is lifted, after the brewing process, up to an upper edge of said peripheral wall from which said coffee powder cake is laterally removed by a scraper, said scraper being associated with a carriage (19) which can be moved along a glide face (41) above an opening of said brewing compartment and which has a seal by which, in a working position of said carriage (19), said opening of said brewing compartment can be sealed,

characterized by

a brewing compartment sleeve (3) forming the peripheral wall of said brewing compartment substantially movable perpendicularly to the plane of said glide face (41) which can force-controlledly be moved, in the working position (FIGS. 2, 9) of said carriage (19), through the plane of said glide face (41) into a sealing position at which said brewing compartment is sealed by means of said seal and, after a brewing process, can be moved back from the plane of said glide face (41) into a rest position so that said carriage (19) can be moved into a start position (FIGS. 1, 3, 4, 7) next to said brewing compartment.

2. Brewing head according to claim 1

characterized in

that the seal is shaped as a ring seal (22) and is provided on an essentially piston shaped section (21) on the underside of said carriage (19).

3. Brewing head according to claim 2.

characterized in

that an upper section of said brewing compartment sleeve (3) can be moved above said ring seal (22) encompassing same in the sealing position.

4. Brewing head according to at claim 1,

characterized in

that said lifting piston (4, 4a) communicating with a lifting piston drive can be moved in said brewing compartment sleeve (3) and that said brewing compartment sleeve (3) is under a spring load which tries to move said brewing compartment sleeve (3) into said sealing position,

that said brewing compartment sleeve (3) includes a drag ring (11) which under spring load can get into touch with said lifting piston (4, 4a) in order to move said brewing compartment sleeve (3) together with said lifting piston (4, 4a) over a partial stroke, and

that said brewing compartment sleeve (3) can releasably be arrested by a locking nose (16) in the rest position thereof.

5. Brewing head according to claim 4

characterized in

that the spring load of said brewing compartment sleeve (3) is effected by at least one compression spring (12, 13) indirectly or directly engaging on said brewing compartment sleeve (3).

6. Brewing head according to claim 4,

characterized in

that a screw cylinder (5, 5a) is associated with said lifting piston (4, 4a) and that said screw cylinder (5, 5a) passes through said drag ring (11) and is in gear connection with an electromotoric lifting piston drive.

7. Brewing head according to claim 4,

characterized in

that said locking nose (16) by means of which said brewing compartment sleeve can releasably be arrested when in its rest position, is in operative connection with an electromotoric carriage drive.

8. Brewing head according to claim 7,

characterized in

that said electromotoric carriage drive comprises a drive motor (26) including gear (27) and that a termination (30) of said gear (27) communicates with a locking disc (17) into which a locking nose (16) engages along a portional rotation range of said locking disc (17).

9. Brewing head according to at least one of claims 1 through 7,

characterized in

said brewing compartment sleeve (3) can linearly be moved in a stationary guide sleeve (2).

10. Brewing head according to at least one of claims 1 through 8,

characterized in

that said plane of said glide face (41) of carriage (19) is essentially horizontal and that said brewing compartment sleeve (3) is substantially liftable and lowerable.

11. Brewing head according to at least one of claims 1 through 8,

characterized in

that said carriage (19) can only be moved between two end positions, i.e. the working position (FIGS. 2, 9) and a start position (FIGS. 1, 3, 4, 7).

12. Brewing head according to claim 1,

characterized in

that said scraper (36) comprises a forward scraper wall (37) and is supported on said carriage both in a cleaning position and in a return position in such a way that one underside (40) of said forward scraper wall when in the cleaning position of said scraper (36) is lowered down to said glide face (41) of said carriage (19) and when in the return position of said scraper (36) is lifted, in a spaced relationship, above said glide face (41).

13. Brewing head according to claim 12,

characterized in

that said carriage (19) can be moved within a sliding duct (20) between a front boundary (44, 45) at the working position of said carriage (19) and a rear boundary (47) at the start position thereof, and

that said scraper (36), by striking against the front boundary (44, 45), can be adjusted to its return position and by striking against the rear boundary (47) can be adjusted to its cleaning position.

14. Brewing head according to claim 13,

characterized in

that said scraper (36) is movably supported on said carriage in the movement direction thereof, that said scraper (36) comprises a cover bottom (39) with which it can be placed on said carriage (19),

that from the front-side ends of said cover bottom (39), said forward scraper wall (37) in front of said carriage (19) and a rear scraper wall (38) behind said carriage (19) are angularly bent downwardly,

that on said cover bottom (39) beveled drag noses (42, 42′

) are formed which, in the cleaning position of said scraper (36) rest in receiving grooves (43, 43′

) of the upper side of said carriage (19), when moving said scraper (36) relative to said carriage (19) by striking against said scraper (36) at the front of boundary (44, 45) glide out of said receiving grooves (43, 43′

) onto the upper side of said carriage (19) into the return position, and when moving said scraper (36) striking against the rear boundary (47) relative to said carriage (19) glide from the upper side of said carriage into the receiving grooves (43, 43′

) in cleaning position.

15. Brewing head according to claim 14,

characterized in

that at one of the end positions of the carriage, said forward scraper wall (37) and said rear scraper wall (38) each strike against the front boundary 44, 45) or the rear boundary (47), respectively.

16. Brewing head according to claim 15,

characterized in

that said scraper (36) is pressed by a scraper spring (48) onto said carriage (19).

17. Brewing head according to claim 8,

characterized in

that the electromotoric carriage drive comprises, in addition to said drive motor (26) with the gear, a swing lever (23) which is in operative connection with one termination (29) of gear (27) and is coupled to said carriage (19), and that said swing lever (23) is resiliently, elastically, flexibly formed near a carriage coupling location.

18. Brewing head according to claim 17,

characterized in

that said swing lever (23) comprises a driven swing lever arm (50) and, near said carriage coupling location, a coupling member (49) which communicates with said carriage (10), on one hand, and is swingably supported at said swing lever arm (50), on the other, and is biased by springs (51, 52) into a nominal position.

19. Brewing head according to claim 6,

characterized in

that said screw cylinder (5, 5a) is equipped with speed measuring means by which a drop in the speed can be recorded in order to stop the lifting cylinder drive.

20. Brewing head according to claim 6,

characterized in

that said piston shaped section (21, 21a) of said carriage (19, 19a) includes a crema valve (60).

21. Brewing head according to claim 6,

characterized in

that said lifting piston (4a) in said brewing compartment sleeve is biased by spring load to said piston shaped section (21a) of said carriage (19).

22. Brewing head according to claim 21,

characterized in

that the spring load of said lifting piston (4a) is effected by a compression spring (78) which is arranged in said hollow screw cylinder (5a) and presses against a lifting piston rod (4b) which is movable within said screw cylinder (5a).

23. Brewing head according to claim 13,

characterized in

that a coffee grinder (18) grinding directly into said brewing chamber is disposed above the opening of said brewing compartment, particularly above said sliding duct (20).