GB647087A - Electrically heated coffee maker - Google Patents

Abstract

647,087. Snap-action switches. DEHN, S. G. (Sunbeam Corporation). March 12, 1948, No. 7604. [Class 38(v)] [Also in Groups VI and XI] A switch for a coffee maker (see Group XI), comprises a contact 39 carried by a fixed conductor 41 and cooperating with a contact 38 carried by a flexible conducting member 37. A diaphragm 47, e.g. of a syphon bellows, is exposed on its lower face to the pressure in the lower vessel of the coffee maker, its upper face engaging a latch 45 pivoted at 55 between the arms of a bell-crank 51 pivoted at 52. A spring maintains a projection 54 on the crank 51 in contact with the diaphragm 47. Upon a pressure increase in the vessel, latch 45 is carried up, the crank 51 being rotated anticlockwise, and the contacts 38, 39 remaining closed. Upon a subsequent fall in pressure in the vessel, the member 37 is engaged in a notch 62 in the latch 45 which eventually depresses the member 37 to open the contacts 38, 39. To re-set the switch manually the crank 51 is moved clockwise, which, since the latch 45 engages a fixed stop 57, moves the pivot point 55 to swing the latch 45 anti-clockwise and release the member 37. A bimetallically-operated switch 64, 65 shunts the switch 38, 39. In a modification, Fig. 11 (not shown) the upper contact arm of the switch is retained in its uppermost position after a rise in pressure in the vessel, by friction washers. The lower contact arm follows the diaphragm down in its subsequent fall, to open the switch. Both contact arms can be independently pivoted manually by pressing external buttons to open or close the switch. Specification 625,797 is referred to.