Filter type automatic coffee machine - has water dispenser with magnetic piston which acts on magnetically controlled switches to control amount of water dispensed (NL13.4.77)

摘要

The automatic coffee machine contains a pump (MP) which pumps water via multi-directional valves (DV1, DV2) in a ring circuit (1.2.3.4) containing a measuring cylinder(5) to a water heater (EH) which heats the water to be passed on into the coffee filter. The measuring cylinder has a number of magnetic switches (S1, S2, S3) connected to the multi-directional valves (DV1, DV2). These switches are operated by a permanent magnet (9) in the piston (6) of the measuring cylinder so that the measured quantity can be changed to suit the size of container to be filled. Water passes from the pump through the first valve (DV1) into the first part (1) of the ring circuit and into the measuring cylinder (5). This pressure pushes the piston (6) up the cylinder until half the required amount of water in the top part of the cylinder has been forced out via the outlet tube (3) and outlet valve (DV2) to the heater (EH). At this point a magnetic switch (S1, S2, or S3) alters the direction of the valves (DV1, DV2) so that water is passed through the second inlet tube (2) to the measuring cylinder to return the piston (6) to the cylinder base and force out the remaining water quantity to the heater (EH). At this point a further magnetic switch (S0) cuts out the pump.