Electric coffee maker with deposits indicator - has timer cutting off water heater with remaining water acting as signal of collection of deposits

摘要

The coffee maker is provided with a furring up indicator in the form of a timer which switches off the water heater (2) at the end of its run. With an average amount of chalk the separate end switch or regulator which responds when the heater is running dry switches off the heater but when there is too much chalk to impede the water flow the timer runs out before all the water has left the fresh water container (4) so that the remaining water provides a clear indication that the machine is chalking up. A simple form of timer is a bimetal strip (20) which has its own heating unit or is heated up by the water heater. The timer can be adjusted to correspond to the initial level of water in the fresh water container so that it is effective when preparing single or several cups of coffee.