GB780773A - Improvements relating to electrically-operated pumps - Google Patents

Abstract

780,773. Diaphragm pumps. S.U. CARBURETTER CO., Ltd. April 18, 1956 [May 26, 1955], No. 15188/55. Class 102(1). [Also in Group XXXV] In a diaphragm pump the plunger 1, Fig. 1, is electrically operated to reciprocate and transmit motion, through a low-viscosity fluid in chamber 58, to the pumping diaphragm 42. The liquid is delivered to the pumping chamber 61 from an inlet 47, Fig. 2, through filter 51 and non-return valve 49 and discharged through non-return valve 50 and an outlet 48, Fig. 2. When the pump is not in use the plunger i assumes its lowest position and the working end 63 of the plunger 1, which is rounded, fits a depression 64 in the pumping chamber such that the diaphragm 42 is deformed to an extent that the volume of chamber 58 is increased by more than the volumetric displacement of the stroke. This prevents possible leakage of the fluid past the plunger 1. In operation the plunger 1 is urged downwards by the leaf springs 12 and upwards by a solenoid 3, stops 13 and 14 being provided. The make and brake of the electrical connection to the solenoid is controlled by the tongue 29, Fig. 2, of the blade-spring 26. When the plunger 1 is at the end of its downstroke the toggle device 33, 36 leans such that the top of the bow spring 36 leans towards the stem 32 so that the tip of the spring tongue 29 is deflected downwards and electrical connection is made between the contacts 25 and 22. This contact remains until the plunger 1 returning upwards causes an opposite action on the tongue 29 through the lower shoulder of the notched portion 31 of stem 32, when the contact is broken. The chamber 59 above the plunger is vented to atmosphere through a slot in stop 13 and an aperture 60 which also allows one end of the solenoid winding to be taken through the membrane 15. The membrane 15 prevents dust entering the chamber 2.