US 4,046,059 A · Fluidic repeater

Abstract

Two fluid passages are connected through flow restrictors to a fluid supply. Downstream of the restrictors the fluid supply has a drooping pressure-load characteristic. Venting means for the fluid passages comprises vent openings therein downstream of the restrictors and variable position obstructor means cooperating with vent openings to vary venting and thereby vary fluid pressures in the fluid passages. This forms a mechanical to fluidic translator. Pressures at the translator's outputs are a function of the obstructor's position. This translator forms the transmitter of a servo or remote control or indicator system. Fluid conduits connect these pressure outputs to a fluid to mechanical translator comprising a double acting piston moving a cylinder whose opposite ends are connected to the fluid conduits. The piston and cylinder form the responder of the system, which may be adjacent the mechanical to fluidic translator and form part of the transmitter. A receiver is formed by a piston and cylinder or other fluidic motor remotely fluidically connected to the responder, the motor driving a load. Alternatively the remote motor may be omitted, the responder itself constituting a receiver and driving directly a load connected by a mechanical linkage to the responder. The responder may be remote from the translator and form part of the receiver. A feed back means controlled by the position of the responder piston and/or the load varies pressure in the fluid conduits by variably venting same. The degree of feed back venting is a function of piston position. The feedback means includes variable cross-section surface passages, e.g., sloping grooves, in the responder piston or fluidic load piston or both. Alternatively or additionally a separate feedback piston may be connected to the receiver or load piston. The venting means is preferably of the spool or other gate valve or needle valve type to provide a linear pressure change in response to position, however, a typically non-linear flapper and jet arrangement may also be used. A single line may then be used between transmitter and responder. Both rotary and linear types of transmitters and load feedback means and receivers may be used.

Claims13

Dependent claims

Fluidic repeater comprising

a cylinder
a piston axially movable in said cylinder, there being a space in said cylinder between one end of the cylinder and the adjacent end of the piston therein,
a source of pressure fluid connected through a flow restrictor to supply fluid to said space between one end of the cylinder and the adjacent end of the piston therein,
opposition means to supply an opposing force on the other end of the piston,
a fluid reservoir at lower pressure than said source connected through parallel variable flow restrictors to said space,
one of said variable flow restrictors constituting a transmitter for varying the pressure in said space and thereby cause a responsive change in the position of said piston relative to said cylinder, said force of the opposition means being independent of the position of said transmitter, and
feedback means including another of said variable restrictors actuated in response to change of position of said piston relative to said cylinder to restrict flow through said other variable restrictor a greater amount when said one restrictor is moved to a position restricting flow a lesser amount, and to restrict flow through said other variable restrictor a lesser amount when said one restrictor is moved to a position restricting flow a greater amount, said amounts being independent of the rate of movement of said piston relative to said cylinder and the duration of said change of position of said piston, thereby to cause an opposite change in the pressure in said space from that caused by the transmitter restrictor and bring the piston to rest relative to said cylinder.

4 more elements

Fluidic Repeater comprising:

a cylinder
a piston axially movable in said cylinder, there being a space in said cylinder between one end of the cylinder and the adjacent end of the piston therein,
a source of pressure fluid connected through a flow restrictor to supply fluid to said space between one end of the cylinder and the adjacent end of the piston therein,
opposition means to supply an opposing force on the other end of the piston,
a fluid reservoir at lower presure than said source connected through parallel variable flow restrictors to said space,
one of said variable flow restrictors constituting a transmitter for varying the pressure in said space and thereby cause a responsive change in the position of said piston relative to said cylinder, said force of the opposition means being independent of the position of said transmitter, and
feedback means including another of said variable restrictors actuated in response to change of position of said piston relative to said cylinder to restrict flow through said other variable restrictor a greater amount when said one restrictor is moved to a position restricting flow a lesser amount, and to restrict flow through said other variable restrictor a lesser amount when said one restrictor is moved to a position restricting flow a greater amount, said amounts being independent of the rate of movement of said piston relative to said cylinder and the duration of said change of said piston, thereby to cause an opposite change in the pressure in said space from that caused by the transmitter restrictor and bring the piston to rest relative to said cylinder, and
including a spool valve comprising said piston, said piston being provided with a plurality of lands in between the ends of the piston for controlling flow through a plurality of ports in the side of the cylinder, and
a second piston in a second cylinder, the second cylinder being selectively connected on opposite sides of said second piston through said spool valve to a source of pressure fluid and a reservoir thereby to be moved in response to movement of the first said piston,
said feedback means variable restrictor comprising a variable cross section groove formed between said second piston and second cylinder communicating at one end with said space in the first said cylinder at the other end with said reservoir.

7 more elements

Fluidic repeater comprising

a fluid supply passage having an inlet and an outlet with a fixed restriction therebetween whereby when said inlet is connected to a source of pressure fluid said outlet will provide a fluid supply having a drooping pressure versus rate of flow characteristic,
responder means including piston and cylinder means comprising a piston in a cylinder connected at one end of said piston to said fluid supply outlet for relative axial movement of the piston and cylinder in response to variation in the pressure at said fluid supply outlet,
said responder means further including opposition means to exert an opposing force on the other end of said piston independent of the position of the transmitter means referred to hereinafter,
transmitter means for venting said fluid supply outlet to a reservoir, other than said responder, of fluid at a lower pressure than said source, in accordance with the position of the transmitter means,
said transmitter means including a fluid path from said fluid supply outlet to the said reservoir and including a first opening forming part of said fluid path and first obstructor means which together with said first opening provides first opening and obstructor means for varying the fluid flow through said opening, and
feedback means actuated by displacement of said responder, without the necessity for the displacement to be changing with time, for venting the same fluid supply outlet to a reservoir of fluid at a lower pressure than said source,
said feedback means including a fluid path from said fluid supply outlet to the said reservoir associated therewith and including a second opening forming part of said fluid path and a second obstructor means which together with said second opening provides second opening and obstructor means for varying the fluid flow through said second opening,
said second opening and obstructor means being connected to the piston and cylinder means of said responder by connection means causing relative displacement of said second opening and second obstructor means and separating same, upon relative axial displacement of said piston and cylinder of said piston and cylinder means of said responder, in an amount dependent upon the amount of the last said displacement and independent of the length of time the last said displacement continues,
said fluid path of said feedback means and said fluid path of said transmitter means being separate paths at least to the extent that fluid flow through said first opening of the feedback means is in parallel with fluid flow through said second opening of the transmitter means with none of the fluid flowing through said first opening flowing through said second opening on its way to the associated said reservoir and none of the fluid flowing through said second opening flowing through said first opening on its way to said reservoir,
venting of said fluid supply outlet by said transmitter means being at a rate dependent upon the position of said first obstructor means without regard to the position of said second obstructor means and venting of said fluid supply outlet by said feedback means being at a rate dependent upon the position of said second obstructor means without regard to the position of said first obstructor means.

7 more elements

Fluidic repeater comprising:

a fluid supply passage having an inlet and an outlet with a fixed restriction therebetween whereby when said inlet is connected to a source of pressure fluid said outlet will provide a fluid supply having a drooping pressure versus rate of flow characteristic, responder means comprising a piston in a cylinder connected at one end of said piston to said fluid supply outlet for relative axial movement of the piston and cylinder in response to variation in the pressure at said fluid supply outlet,
said responder means further including opposition means to exert an opposing force on the other end of said piston independent of the position of the transmitter means referred to hereinafter,
transmitter means for venting said fluid supply outlet to a reservoir, other than said responder, of fluid at a lower pressure than said source, in accordance with the position of the transmitter means,
said transmitter means including a fluid path from said fluid supply outlet to the said reservoir and including a first opening forming part of said fluid path and first obstructor means for varying the fluid flow through said opening, and
feedback means actuated by displacement of said responder, without the necessity for the displacement to be changing with time, for venting the same said fluid supply outlet to a reservoir of fluid at a lower pressure than said source,
said feedback means including a fluid path from said fluid supply outlet to the said reservoir associated therewith and including a second opening forming part of said fluid path and a second obstructor means for varying the fluid flow through said opening,
said fluid path of said feedback means and said fluid path of said transmitter means being separate paths at least to the extent that fluid flow through said first opening of the feedback means is in parallel with fluid flow through said second opening of the transmitter means with none of the fluid flowing through said first opening flowing through said second opening on its way to the associated said reservoir and none of the fluid flowing through said second opening flowing through said first opening on its way to said reservoir,
venting of said fluid supply outlet by said transmitter means being at a rate dependent upon the position of said first obstructor means without regard to the position of said second obstructor means and venting of said fluid supply outlet by said feedback means being at a rate dependent upon the position of said second obstructor means without regard to the position of said first obstructor means,
said responder means further comprising:
a. a second piston in a second cylinder connected to pressure fluid supply passage means for relative axial motion of the piston and cylinder in response to pressure of the pressure fluid supply passage means, and
b. valve means controlled by the first mentioned piston and cylinder of the responder means for controlling the connection of said pressure fluid supply passage means to said second piston and cylinder,
said opening and obstructor means of said feedback means being provided by a variable cross section groove formed between a cylinder and the piston therein of said responder means, said feedback means fluid path including a portion extending from said associated reservoir through the side of the last said cylinder and thence through said groove and on to the end of the last said cylinder, the portion of said groove necessarily traversed by fluid in said feedback path varying according to the relative axial position of the last said piston and cylinder of said responder.

9 more elements

Dependencies are inferred from the claim text.

Fluidic repeater

Life of this patent

Fluidic repeater

Life of this patent

Abstract

Claims13