Cartridge element control

Claim 1

A system for regulating the flow of a fluid in dependence of an input signal, comprising in combination: a valve housing including a fluid-pressure expansible chamber and having an inlet for receiving a fluid from a main conduit, and an outlet for discharging the fluid, main valve means adjustably positionable between said inlet and said outlet defining an adjustable passage upstream of said outlet to control the rate of flow of the fluid discharged from said outlet, said main valve means including a first passage for transferring the fluid from the main conduit into said expansible chamber for closing said main valve means a cylinder substantially closed off from said valve housing, a piston valve means in driving connection with said main valve means and being movable within said cylinder in opposite valve closing and valve opening directions, said cylinder having a first opening disposed on one side of said piston valve means, and a second opening disposed on the other side of said piston valve means for fluid to pass therethrough, the fluid on said one side of said piston valve means exerting a first pressure on said one side, the fluid on the other side of the piston valve means exerting a second pressure on said other side, resilient means urging said piston valve means to close said main valve means for throttling the flow of fluid through said adjustable passage, fluid control means in communication with said main conduit and with said first and second openings of the cylinder comprising: a fluid switch, having first and second active stations, and a neutral station, said fluid switch, when operative, occupying one of said active stations, and including a container, and a slider reciprocally slidable in said container along a predetermined direction, and along a direction opposite to said predetermined direction, said main conduit being connected to said first opening of said cylinder, said second opening of said cylinder being connected to a source of fluid, in said first active station, said main conduit being connected to said second opening of said cylinder, said first opening being connected to the source of fluid, in said second active station, fluid transmission to said first and second openings being blocked in said neutral station, magnetic means controlled by said input signal for exerting a force on said slider in dependence of said input signal, and means for transmitting any pressure differential between said first and second fluid pressures to said fluid switch so as to oppose the force of said magnetic means, whereby the fluid switch is changed from a corresponding one of said active stations to said neutral station upon said first pressure equalling said second pressure, so as to enable said piston valve means to expell the fluid from the expansible chamber through a second passage in said main valve means to control said main valve means to regulate the outflow of said fluid through said adjustable passage, the cross-section of of said passage being proportional to said input signal.

Claim 2

A system for regulating the flow of a fluid in dependence of an input signal, comprising in combination: a valve housing including a fluid-pressure expansible chamber and having an inlet for receiving a fluid from a main conduit, and an outlet for discharging the fluid, main valve means adjustably positionable between said inlet and said outlet defining an adjustable passage upstream of said outlet to control the rate of flow of the fluid discharged from said outlet, said main valve means including a first passage for transferring the fluid from the main conduit into said expansible chamber for closing said main valve means a cylinder substantially closed off from said valve housing, a piston valve means in driving connection with said main valve means and being movable within said cylinder in opposite valve closing and valve opening directions, said cylinder having a first opening disposed on one side of said piston valve means, and a second opening disposed on the other side of said piston valve means for fluid to pass therethrough, the fluid on said one side of said piston valve means exerting a first pressure on said one side, the fluid on the other side of the piston valve means exerting a second pressure on said other side, resilient means urging said piston valve means to close said main valve means for throttling the flow of fluid through said adjustable passage, fluid control means in communication with said main conduit and with said first and second openings of the cylinder comprising: a fluid switch, having first and second active stations, and a neutral station, said fluid switch, when operative, occupying one of said active stations, and including a container, and a slider reciprocally slidable in said container along a predetermined direction, and along a direction opposite to said predetermined direction, said main conduit being connected to said first opening of said cylinder, said second opening of said cylinder being connected to a source of fluid, in said first active station, said main conduit being connected to said second opening of said cylinder, said first opening being connected to the source of fluid, in said second active station, fluid transmission to said first and second openings being blocked in said neutral station, magnetic means controlled by said input signal for exerting a force on said slider in dependence of said input signal, and means for transmitting any pressure differential between said first and second fluid pressures to said fluid switch so as to oppose the force of said magnetic means, whereby the fluid switch is changed from a corresponding one of said active stations to said neutral station upon said first pressure equalling said second pressure, so as to enable said piston valve means to expell the fluid from the expansible chamber through a second passage in said main valve means to control said main valve means to regulate the outflow of said fluid through said adjustable passage, the cross-section of of said passage being proportional to said input signal.

Claim 4

A system as claimed in claims 1 or 2 wherein said resilient means is at least partially disposed in said cylinder.