GB394794A - Improvements in and relating to gas meters - Google Patents

Abstract

394,794. Gas meters. DEUTRICH, J., 102A, Westendallee, Westend, Berlin. May 4, 1932, No. 12870. Convention date, May 4, 1931. [Class 54.] In order that a gas meter shall register correctly when overloaded the valves are operated to shut off the inflow of gas to the measuring chambers before the diaphragms reach the ends of their strokes. In the construction shown in Fig. 1 the plate 13 of the diaphragm 12 has still to travel a distance a to the end of its stroke when the inflow to the measuring chamber 11 is shut off bv the slide valve 5 which is operated by the plate 13 through a crank shaft 1 and connecting-rods 6, 16. Slots 17 may be provided in the parts b of the valve that overlap the inlet ports 7, 8 when the diaphragm is in its end positions. With increasing speed of the meter the gas inflow is increasingly throttled by the premature closing of the valve and the overlap may be so chosen as to correct or render constant the metering error. The amount of throttling and the period at which it occurs may be adjustable. Excessive stresses in the meter walls and diaphragm when the gas is throttled may be prevented by providing an auxiliary membrane 18 between the two measuring chambers. Fig. 3 shows a valveoperating mechanism in which a crank 2 operated by the diaphragm modifies the speed of a valve 5 having no overlap between its end positions I, III so that when the diaphragm is in its end position the valve has passed its mid-position at which the inlet port closes and has reached position 11 or IV. The valve is operated from a crank 2<1> on the shaft 1 of the crank 2 through links 19, 20, 21, the pivot pin between the links 19, 20 sliding in a guide 23 and the pivot pin between the links 20, 21 being carried by a link 25 connected to a crank arm 26 driven through gear wheels 28, 29, 30 by the crank shaft 1. In other constructions the premature closing of the valve 5 is attained by enlarging the angle between the two arms 2, 2<1> or by broadening the cross members of the valve box. When the measuring chambers consist of rigid bells a flexible membrane such as 18 may be provided or the measuring chambers may be connected to opposite sides of a floating bell. If lift valves are used instead of slide valves the valves are arranged to close initially only on one side and then to yield resiliently until complete closure is effected. Reference has been directed by the Comptroller to Specification 6463/12, [Class 54, Gas distribution].