GB823546A - Hydraulic coffee machine - Google Patents

Abstract

823,546. Beverage-making machines. WURTTEMBERGISCHE METALLWARENFABRIK. March 16, 1956 [March 17, 1955], No. 8384/56. Class 129. [Also in Group XXIX] Coffee and the like is prepared in a machine having convected working and restoring pistons 2, 4 displaceable respectively in cylinders 1 and 3, the cylinder spaces 8 and 21 of cylinders 1 and 3 being separately connected in the initial position of the pistons 2, 4 to a pipe 38 supplying a medium, e.g. water, under pressure. Cylinder 4 is also connected by at least one port in its wall to the impulse chamber of an adjustable control member by which the working chamber 8 of cylinder 1 can be separated from the pipe 38 so that the pistons 2, 4 rise until piston 4 passes the port leading to the control member, when the pressure medium acting on the control member restores the connection between cylinder 1 and pipe 38, piston 2 being restored to its original position, meanwhile forcing the hot water, drawn into the scalding chamber 9 as it rose, out through the coffee grounds or the like. Chamber 9 is separated by a sieve 10 from a detachable holder (not shown) held in a bayonet joint by claws 11. The chamber 9 is connected to the water boiler through a bore 17 and a valve 14, 15 which opens when piston 2 is raised. As shown, the wall of cylinder 3 has three ports 22, 23, 24 connected by pipes 25, 26, 27 to the three-way cock 5 whose plug 30 can be set by a hand wheel so that one of the ports is connected by pipe 31 to an impulse chamber 32 formed adjacent control cylinder 6. Between impulse chamber 32 and the space 39 of cylinder 6, an auxiliary piston 34 is displaceable in a small cylinder space 33. The cylinder space 21 of cylinder 3 is connected at the top and bottom respectively to a pipe 36 leading to the water boiler and by a pipe 37 to a pipe 38 conveying water under pressure. The control piston 7 in cylinder 6 has a rod 44 extending upwardly through the end of cylinder 6 and engaged by a spring-biased hand-operated lever 43 by which the operation is initiated. The space 39 is connected by port 47 and pipe 48 to chamber 8 and by port 45 to pipe 38. At its ends space 39 has valve seatings 46, 50. Fig. 3 shows a practical arrangement of the machine shown diagrammatically in Fig. 2.