Regulating device in which the pressure of a fluid is regulated

Claim 1

A regulating device for controlling the magnitude of a physical entity comprising: a sensor of magnitude variations of said physical entity, pressure sensitive means for controlling said magnitude, and a modulatable fluidic system under the modulating control of said sensor and delivering a modulated pressure signal to said pressure sensitive means, said fluidic system comprising: three sources of motive fluid at different pressures, namely a low-pressure source, a medium-pressure source, and a highpressure source, a power fluid discharge nozzle connected to said low-pressure source and producing a power stream, a movable modulator member cooperating with said nozzle and having a stream shearing rim of such progressively designed outline as to obstruct to a continuously varying extent the path of said stream when said rim progresses in stream shearing relationship crosswise of said path, whereby said stream is bodily deflected to a continuously varying degree as it issues from said nozzle, an adjustable mechanical transmission extending between said sensor and said modulator member for displacing said stream shearing rim across said path in response to said sensor, a power fluid collecting intake positioned opposite said nozzle, and a fluid amplifier with two stages in cascade, namely an upstream first stage and a downstream second stage, said upstream stage having a first power input connected to said medium-pressure source, a first control input connected to said intake and a first load output, and said downstream stage having a second power input connected to said high-pressure source, a second control input connected to said first load output and a second load output connected to said pressure sensitive means.