GB674139A - Improvements in or relating to devices for delivering measured quantities of liquid - Google Patents

Abstract

674,139. Delivering measured quantities of liquid. BULL & CO., Ltd., R. H. Nov. 10, 1950 [Oct. 3, 1949], No. 25334/49. Class 106(v) A device for delivering measured quantities of liquid comprises a measuring chamber 1 with an inlet port 5 at the top and an outlet port 2 at the bottom, a valve member 8 adapted to move between two extreme positions to open and close the ports, a snap-acting mechanism 17 for operating the valve and an unobstructed air vent 11 which allows air to enter the measuring chamber when the valve closes the inlet port and is sealed from the measuring chamber when the valve closes the outlet port. The stem of the hollow valve member 8 passes upwards through a neck 12 on the cover of the measuring chamber and projects a short distance through a resilient waterproof membrane 16. A supply pipe 13 leads from an inverted bottle or other supply container to the neck 12 and carries a bracket 18 for the spring-loaded toggle mechanism 17. The toggle is operated by a cranked lever 25, of which one end 27 is moved by hand, or by the agency of the receptacle held under the outlet port, and the other end 26 engages the toggle lever 19 with a small amount of lost motion in a channel-section 30; stops 28, 29 limit the movement of the lever. The other toggle lever 20 is forked to engage slots on each side of a ferrule 24 on the valve stem and its length is such that the valve, in both its raised and lowered positions, is slightly inclined to the vertical axis, to assist in overcoming surface tension and to improve the liquid flow. A cam or suitable linkage (not shown) operated by the lever 25 may be provided to hold the toggle lever 20 against movement until the other toggle lever 19 is well past dead centre, in order to make the snap action more rapid and to prevent attempts to jam the valve in mid position, particularly in coin-freed apparatus. A spring-loaded plug on a spindle passing through the hollow valve, or a hinged flap, may be operated by the lever 25 to close the outlet port and prevent drips when the outlet port is sealed. In a modification, Fig. 4, the measuring chamber 31 has a limited sliding movement in a cover 33, a resilient membrane 43 forming a liquid-tight seal between the two parts, and, when the chamber is moved up by a receptacle pressed upwards against arms 57 and the valve 46 has straightened a spring-steel strip 52, the strip snaps rapidly upwards and opens the outlet port and closes the inlet port. To prevent turbulent flow, an air pipe 55 extends into a recess 56 in the valve, in both its raised and lowered positions. In either version, the measuring chamber may be of glass.