GB1257604A - - Google Patents

Abstract

1,257,604. Coffee machine. G. ROSSI. March 18, 1970 [April 5, 1969], No. 12939/70. Heading A4D. A coffee machine comprises two equidiameter pistons 16 and 18, in fixed cylinders 11 and 19, connected by a shaft 17. The piston 16, which supports a coffee doseage discharged from funnel 34, is depressed against a spring 22 when water under pressure enters a port 55 of the cylinder 19. As the piston is forced past port 25 water is forced through the duct 59 into cylinder 47 whereby the piston 46, attached to vertical cylinder 36 is pushed in a horizontal direction on sliders 30, against a spring 32, until the cylinder 36 is in vertical alignment with cylinder 11. The port 50 having then been uncovered by piston 46 transmits the pressurized water into cylinder 36 via port 44 and depresses piston 39 and thus piston 37 against spring 40 so that piston 37 completes a working stroke in cylinder 11 and compresses the coffee doseage against piston 16 which is abutted against ledge 23. A charge of hot water is then passed via port 20 through channels 43 and filter 42 on piston 37, through the coffee, and the coffee brew is discharged from port 21 after passage through filter 27 and channels 28 on piston 16. When the brewing is complete magnetic valves 51 and 63 are operated to connect the cylinder 36 to discharge through a port 64 of the valve 63 to the discharge fitting 58, and so withdraw piston 37 under the action of spring 40 from the cylinder 11 until it shuts against flange 41. Cylinder 19 is simultaneously discharged by valve 51, which passes the water from port 55 through duct 56 to the discharge 58, and piston 18 returns to its position of abutment face 24 by the action of spring 22, whereby port 25 is once again uncovered causing water to discharge from port 48 of cylinder 47, and through duct 59 to cylinder 19 from which it discharges via duct 60. Meanwhile piston 46 returns under the action of spring 32 to its original position where the funnel 34 is vertically aligned with cylinder 11 which is maintained at a high temperature throughout by the passage of hot water in the annular space 13 via ports 14 and 15. A scraper 35 removes the spent coffee charge during this return stroke of piston 46, a chute 29 being provided for their final discharge. The degree of compression of the coffee may be adjusted by a nut and locking nut carried outside the top of cylinder 36 on the stem 38 of the piston 37.