초록 ▼

A novel, low-friction, low-inertia flexible diaphragm containing a magnet formed as an integral part of the diaphragm is mounted in a chamber (preferably cylindrical). The chamber comprises part of the flow meter in a flow control system. One or more sensing devices are mounted on the walls of the c

A novel, low-friction, low-inertia flexible diaphragm containing a magnet formed as an integral part of the diaphragm is mounted in a chamber (preferably cylindrical). The chamber comprises part of the flow meter in a flow control system. One or more sensing devices are mounted on the walls of the chamber to sense the instantaneous position of the diaphragm. A novel electronic control circuit processes the data from the one or more sensing devices to provide measures of the flow rate during the displacement of the diaphragm along the cylinder. Signals are generated by the electronic control circuitry for switching a pair of three-way valves (one valve comprising the input valve and the other valve comprising the output valve) such that during one-half of a cycle the intput valve transfers fluid into the cylinder on one side of the diaphragm and, during the other half of the cycle, transfers fluid into the cylinder on the other side of the diaphragm. The output valve is switched synchronously with the input valve to transmit fluid from the other side or one side of the diaphragm to the output valve. The electronic control system includes means for amplifying the output signals from the one or more sensing devices (“sensors”) to provide one or more signals representing the position of the diaphragm as a function of time, means for converting the output signals from these amplifiers to digital form, and computation means for operating on the digitized output signals from the sensing devices to provide control signals for controlling a second input valve thereby to control the flow rate of the fluid being metered to within a desired range.

대표청구항 ▼

Structure comprising: a chamber containing a first and a second opening through which fluid can pass; a flexible diaphragm located in said chamber so as to divide said chamber into two portions, a first chamber accessed through said first opening and a second portion being accessed through said seco

Structure comprising: a chamber containing a first and a second opening through which fluid can pass; a flexible diaphragm located in said chamber so as to divide said chamber into two portions, a first chamber accessed through said first opening and a second portion being accessed through said second opening; a magnet attached to said flexible diaphragm; means for directing fluid whose flow is being measured through said first opening into said first chamber while withdrawing the fluid whose flow is being measured through said second opening from said second chamber and, into response to a control signal, reversing the chambers in which the fluid is inserted and from which the fluid is withdrawn, the movement of fluid into one chamber and out of the other chamber causing said flexible diaphragm to move into the chamber from which the fluid is being withdrawn; means for continuously producing an output signal representative of the position of said magnet; means for converting said output signal to a sequence of digital signals; means for processing said sequence of digital signals to produce a second signal representative of the flow rate of said fluid into and out of said chamber; means for comparing said flow rate to a reference flow rate to produce a control signal representative of the difference between said measured flow rate and said reference flow rate; and means, responsive to said control signal, for changing the flow rate of said fluid.