US2377300A

US2377300A - Stabilizer for regulators

Info

Publication number: US2377300A
Application number: US454856A
Authority: US
Inventors: Wilbur F Pray
Original assignee: Askania Regulator Co
Current assignee: Askania Regulator Co
Priority date: 1942-08-14
Filing date: 1942-08-14
Publication date: 1945-05-29
Anticipated expiration: 1962-05-29

Description

May 29, 1945. w E PRAY 2,377,300

STABILIZER FORY REGUIZIATORS Filed Aug. 14, 1942 mi, a

Patented May 29, 1945 UNITED STATES PATENT OFFICE STABILIZER FOR REGULATORS Wilbur F. Pray, Dobbs Ferry, N. Y., assignor to Askaiiia Regulator Company, Chicago, 111., a corporation of Illinois Application August 14, 1942, Serial No. 454,856

6 Claims. (Cl. 121-41) This invention relates to stabilizers for regulators of the hydraulic or fluid jet type and, among other objects, aims to provide important improvements in compensating mechanism for such jet pipe relays. The idea is to minimize objectionable hunting due to control impulses and to simplify the system by reducing friction and rendering it more stable. One of the principal aims is to provide in a regulator of the type employing a servo-motor and a stabilizer cylinder, a split fluid control circuit so that both the servomotor and stabilizer are actuated simultaneously by the operating fluid. Another aim is to provide in a regulator of this type, a double jet pipe, movable as a unit, in which the operating hydraulic fluid is divided into two streams to actuate the servo-motor and the stabilizer piston. Still another aim is to provide a regulator apparatus wherein the stabilizer cylinder is preferably larger than the control cylinder and the rates of flow of the operating fluid are so controlled as to obtain proportional movements of the stabilizer and the the servo-motor.

Other aims and advantages of the invention will appear in the specification, when considered in connection with the accompanying drawing,

wherein the figure is a, diagrammatic illustration of one form of apparatus embodying the invention.

The pipe or conduit 3, through which a fluid under pressure is flowing, is provided with a throttle valve 4 controlled by a piston 5 in a cylinder 6. The pressure of the fluid is transmitted to a diaphragm I in a casing 8 by means of a pipe 8, the diaphragm being connected to a jet pipe ID by means of a rod II. The branch pipes |2 of the well known jet pipe relay I0, l2 are connected to opposite ends of the cylinder 6 by means of pipes I3 and H, the latter pipe having a throttle valve I5 therein. This valve increases the overall stability of the control by increasing the time of travel of the control valve 4 between its fully open and fully closed positions.

The force exerted by diaphragm I through the rod II on the jet pipe I0 is counteracted by a compression spring l6 connected at one end to the opposite side of the jet pipe and at the other end to a micrometer adjusting device or screw Ill, the latter being mounted on one end of a lever I8 pivoted at a fixed and appropriate intermediate point; IS. The other end 2001! the lever is connected to a piston 2| mounted in a stabilizing cylinder 22. A pipe 23 with a throttle or bypass valve 24 intercommunicates the ends of the cylinder 22 and a pair of

pipes

25 and 28, the 66 .the piston 2|, after a certain length of time.

latter with a throttle valve 21, connect the ends of the cylinder 22 with the branch pipes 28 forming with jet pipe 29 another jet pipe relay. The valve 21 reduces the speed of the piston 2| to the right and exercises a stabilizing influence on the servo-motor of the second relay.

A compression spring in in a casing 3|, mounted on one end of the cylinder 22, acts in such a way that upon either right or left movement of the piston 2| the spring 30 is compressed to thereby urge the piston 2| to its central or normal position in the cylinder 22.

The pipes Ill and 29 form a double jet pipe 32 integral or suitably connected together and pivotally mounted at an intermediate point 33. A pipe 34 supplies oil under pressure to the jet pipes l0 and 28.

The pressure in the conduit 3 is controlled by means of the throttle valve 4 and the latter is controlled by the movement of the piston 5 in the cylinder 6. An increase in pressure in the conduit 3 transmitted through the pipe 9 and to the diaphragm 1, moves the jet pipe Ill to the left and thus throttles or closes the valve 4 as the hydraulic fluid from the jet pipe ||l enters the pipe |2, l3 and into cylinder 6, the valve 4 closing until balance is obtained. As the jet pipe ||l moves to the left, the opposite jet pipe 29 moves simultaneously to the right and thereby controls the operation of the piston 2| which, as the hydraulic fluid enters the

pipes

28, 26 and in the cylinder 22 on the right side of the piston 2|, compresses the spring 30, due to the movement of the piston 2|. Movement of the piston 2| operates the lever I8 and changes the compression of the spring IS. The spring pressure will be increased when the piston 2| moves to the left, so that it will quickly restore the jet pipe ID to its neutral position.

The adjustable by-pass valve 24, connecting both ends of the stabilizing cylinder 22, permits the spring 30, which has been placing the piston under tension, to return the latter to its middle or intermediate position in its cylinder and thereby compensate for the original displacement of In other words, the compensating cylinder constitutes a double-acting dash-pot.

The two Jet pipes l0 and 23 move together or simultaneously in opposite directions around a common pivot axis 33 through which the hydraulic fluid is supplied to both jet pipes from a common supply pipe 34. Also, the

cylinders

6 and 22 are not in series but they are operated from the same pilot 32 which latter is a double 2 2,s77,soo

t pipe or two oppositely directed jet pipes II or pipe 84, or which one operates the stabilizer pistonii andtheotherthecontrolpistonl. The control and stabilizer device has many advantages oi which a number are the following: 1. The reset time can be controlled by the throttle valve 24 without interfering with the throttling range or total controlled condition change.

2. The throttling range is controlled by the fulcrum II and the opening in the valve 21.

3. By using sumcient volume of hydraulic fluid through jet pipe it. any relation of throttling rangetoresettimecanbesecured.

4. The adjustment of the throttling range and the reset time are independent of the diameter and stroke of the control piston 5.

5. One standard stabilizer will take care of all requirements so that it should always be D 8 ble to obtain proper adjustments in the fleld.

The operation oi the stabilizer will be obvious upon reference to U. 8. Patents Nos. 1,959,889 and 2,227,170, over which the present invention is an improvement. The double Jet pipe is ad- Justed to its central or neutral position by means of the micrometer adjustment l1 and the needle or throttle valves ii, 24 and 21 are opened to provide for the desired rate of control and to proportion the flows to the respective cylinders. It the control impulses imparted through the diaphragm I to the jet pipe move it in either direction from the neutral position, it will be seen that the pistons I and II will be operated in opposite directions and the stabilizing piston 2i will exert opposing force through the compression spring II on the jet pipe to prevent over-shooting or by manipulation oi the throttle or needle valves or the size oi the Jet pipe nozzles and the receiving oriflces.

The particular form or the double iet pipe and the mode of dividing the control fluid into two streams may be varied without departing from the spirit of the invention. Any convenient arrangement of jet pipes operating together to divide the fluid stream into separate circuits will accomplish the results.

It will be understood by those skilled in the art that the term stabilizer" is used herein in the same sense as it is used in the aforesaid Patents Nos. 1,959,889 and 2,227,170. It is employed to minimise objectionable hunting of a regulator and tends to stabilize the movement or operation oi the control element or valve. It can properly bearestoringmeanaasappfledtoa tpipe. Itwillalsobeunderstoodthatthetermthrottling range," sometimes called "droop," represents theamountotchangeinthecontrolledpreasure between diflerent valve settings. It can be broadly stated that the greater the time lag, the greater must be the throttling range, or total pressure variation to avoid hunting.

Obviously, the present invention is not restricted to the particular embodiment thereof herein shown and described. Moreover, it is not indispensable that all the ieatures oi the invention be used conicintlv. since they may be employed advantageously in various combinations and subcombinations.

What is claimed is:

i. In combination with a hydraulic regulator having a servo-motor and a stabilizer, a movable jet Pi having two branches tor dividing the operating fluid into two streams. one for actuating the servo-motor and the other for simultaneously actuating the stabilizer, said stabilizer being connected to act on the jet pipe, and tending to restore it to its neutral position. 1

2. In combination with a regulator 01' the hydraulic type having a controlling servo-motor and a fluid operated; stabilizer, a plvotally mounted pipe having two nozzles supplied with operating fluid one nozzle connected to actuate the control motor and the other nozzle to actuate the stabilizer simultaneously, said stabilizer acting on the Jet pipe, and tending to restore it to its neutral position.

3. In combination with a regulator according to claim 2, in which the Jet pipe is in the form of two oppositely directed nozzles supplied from acommon fluid source.

4. In combination with a regulator according to claim 2, in which the servo-motor and the stabilizer are each provided with an operating piston of which the stabilizer piston is larger than the servo-motor piston.

5. In combination with a regulator according to claim 2, in which the servo-motor and the stabilizer are each provided with an operating piston of which the stabilizer piston is larger than the servo-motor piston, and in which control valves are provided to proportion the flow oi fluid to operate the pistons.

8. A regulator of the hydraulic type having two movable jet pipe nozzles supplied with fluid from a common source, said regulator including a servo-motor operated by fluid delivered from one of said iet pipe nozzles, and a stabilizer connected to be operated by fluid from the other or said jet pipe nozzles and acting on both 01' them to restore them toneutral position.

WILBUR F. PRAY.