US2729223A

US2729223A - Fluid pressure relays

Info

Publication number: US2729223A
Authority: US
Inventors: Albert J Rosenberger
Original assignee: Republic Flow Meters Co
Current assignee: Republic Flow Meters Co
Priority date: 1951-09-12
Filing date: 1951-09-12
Publication date: 1956-01-03
Anticipated expiration: 1973-01-03

Description

Jan. 3, 1956 A. J. ROSENBERGER FLUID PRESSURE RELAYS Filed Sept. 12, 1951 J? %%%Z4g ATTORNEY :phragm. mounted in resilient bushings which functions as -fluid *:seals and yield to permit the shaftto'turn.

Unitsrd States Patent O This invention relatesto fluid pressure relays. and. more particularly to a valve construction for controlling the relay output pressure.

Eluid'pressure relays as heretofore constructed comr'rn'ercially include a diaphragm-having'anopeningztlrerein -and=afixed valve-member cooperating With-the opening to, vary its effective size as'thediaphragm' moves. The 1 diaphragm is urged-in one direction-by anspring and in -the-other direction bypressure on the opposite 'side thereof and maintains the output pressure proportional to the-spring strength.

. In units'ofthis'type it is'necessary toprovidea-second diaphragm connected .to the first diaphragm if remote fluid pressure loadingris employedto change the output pressure. This complicates the unit and-increases its expense. 'It is furthermore desirable-to avoidopenings in -the diaphragm which complicate-the diaphragm construction and reduceits strength.

'ltis. accordingly one of the objectsof the present in- --vention to'provide ailuid pressurerel-ay in-which a solid flexible diaphragm is connected atone-sidetto a valveto operate it and mayhave fluid pressure applied to* its other -'side to change its loading.

:Anothenobject is to provide a-fluid pressure relay in which the output pressure is controlled by a; valve of .the supply and waste type having a single VaIVe memb'er Tto control both the supply and waste of fluid.

-According to one feature-of the invention the valve -is-formed by a hollow pivoted arm? havinga'vent nozzle thereon and a single valve-member which controlsthe vent nozzle and also controls asupply'nozzle.

Anotherobject is to provide a-relay inswhich-boththe supply and vent-nozzles are closedwhen the-pressureis at the desired value.

'In accordance with another feature the valve mechwanismsis contained in one chamber and". is connected through ashaft with an operating arm in anotherchamher which connects with one side of the operating dia- In the preferred construction=1the shaft is The above and other objects and features of the invention will be more readily apparent from the. following description'of'the embodiment shown in-the accompanying drawing in which 'Figure 1 is a bottom :view of a fluid pressure arelay embodying-the invention with the'bottom coiver removed;

I Figure 2 is a sectionon the line '2-2 of Figure 1;

Figure 3 is a section on the line 3.-3 -of- Figure l; and Figure 4 is a partial section similar to Figure 2 of an alternative construction.

Iljhe construction as shown in Eigures 1 3 com prises aumain. body formed by a central. ring '10 .and a coverplate 11 secured together by fastening bolts'12. The

. ring 1-0 and the coverplate are formed with. meeting cavi- I22 as indicated at 15 in communication with ithe -valve chamberelii preferably through a restricted neckrportion 16. .The'outlet connection 15 may be connected through :a. conduit to-any'desired type'of-device to be'operated 5 -in=response tothe fluid'pressure such. as a regulator or 1 positioner unit.

Fluid"under'pressure is suppliedto the chamberz13 "through: a fluidsupplynozzle 17"which extends'intosone endofthe 'chambersand'wwhich is connected through a 10-passage -18-to a fluid pump not shown. Fluid=is'-vented from the chamber through a .hollow arm xl9i=having a vent nozzle 21 in oneendx'thereof and secured. at its other 'endtoa shaft 22'which extendsinto both 'bfitthe chambers. The shaft 221as seenin Figure 1 has a'fb'ore 15.23 ttherein. communicating with 'the interior-of the *arrn 19 and openingat 1 its end to atmosphere outside i f the chamber. According to one of the features of the invention the'z-shaftt 22.:is -supp'orted in resilient bushings 24 formed of rubber or rubber-like material which :secur ely sealithe'ispa'ce aroundthe shaft and Whichwill yield to "permit a slight turningmovementof the s'h'aft.

The nozzles "17 and 21 are contr'olled by a-single flap- -per-25in the' form-of a resilient-=strip or metal orthe like whichis securely fastened atone end tothe ar-ni'19 25 and-whichextends beyond the arm -to over-lie the sup- -ply nozzle 17. "The" flapper is resiliently-biased towards the vent nozzle 21 and may, if desired, be pressed against the vent nozzle by a-leaf spring 26 mounted in the cover "When the arm 19 is-rocked'counter clockwise tornove theflappenaway from the supply nozzle"17,- fiuid will beadmitted to' the valve chamber 13 to build up 'the "pressure therein. When the arm is 'rockedclockwise, 'its end will' seat on 'the supply nozzleto cut ofI the-sup- -ply *of pressure'='and upon =further movement the "arm -vvill 'move away -'from 'the flapper to open the vent nozzle "21 andvent'pressurdfrom the chamber to atmosphere.

The arm is adapted to be 'm'oved-by 'an angularextensiori 27 on 1 thefsh'aft '22 which extends into' the chamber -14. As 'best'seen in Figure3the chamber 14isin open eonnec-tionwith the 'lowersu'rface of a flexible diaphragm "28 which is 'secured to "the ring 10. The diaphragm car- =ries a p'lunger 29'which' extendsinto the'char'nber' 14- to *e'ngagethe extension"27 and a spring-31"is=preferalb1y provided actingcn the end of the extension td-holdit againstthe plunger. ln' 'this way the shaft" 22' Will be turned as the: diaphragm moves tomove the arm 19-"and vary the pressure'in the v'alve ch'amber 1-3.

2 Theouter surfaceof'the diaphragm *isencloscdby a "housing 32 which has afluid supply connection 33 thereto for applying acon'trolling pressurefrom a'remote point td the upper sideof the -diaphragm. The'housing"also preferably carries a spring 34 adjustably anchored in-the 'Itop ofthe housing and conne'ctedtothe diaphragm to "exert a force thereon. .Whenit is desired to have-the io'utlet pressure greater 'thari the controlling pressure'supj plied at 33, a compression spring may" be employed in which case the outlet pressure will be equal tothe' Jsum of the control pressure and the spring 'force. "-Whenthe 6O outlet pressure is to be'less than thecontrolpressiire a tensionfspringmay"be. employed so that'its force will be subtracted'fro'mthe CO'HIIOlLPl'ESSHIG.

*Withthe unit as so far described; an on-offrelay operation isobta'ined. "For this purpose the spring-34" is a tension sprin'gwhich tends to pull the diaphragm outward so that the pin 29 will move away'from the. extension 27 and"'the"-fl, PPer 25 will .close'the supplynozzle 17 and will open. the vent nozz1e'21. When pressure is supplied throughthe connection 33 the diaphragm will move in- "Wardtortick thearm "19'counter cldckwise'thereby cldsing "'the"'vent' nozzle and opening the supply nozzle. At this tim full supply pressure vvill be buil't -up in"the ohanib'er directly above the nozzle 121.

13 and will be conducted through the outlet connection 15 the restriction 16 to the space below the diaphragm 28. .A small opening in this location is preferable since its small size will restrict flow therethrough so that it will act as a damper for the diaphragm. The location of the opening causes the pressure thereon to be affected by flow through the outlet connection so that the opening will sense a smaller pressure than actually exists and will in this way cause the valve to open further to compensate for the flow effect. Thus the pressure in the outlet connection will be maintained at the desired value regardless of variations in flow.

When this opening is provided the inner surface of the diaphragm is subjected to the outlet pressure and the force thereon will balance the control pressure and the spring force. In this way the arm 19 will be moved automatically to maintain the outlet pressure at the desired value at all times. It will be noted that when the pressure is at the desired value both nozzles are closed so that air will not be wasted.

In the construction of Figure 4 all of the parts except the valve member are identical with the parts in Figures 1 to 3 and are indicated by the same reference numerals plus 100. In this construction the air supply passage 118 opens into a chamber 136 which communicates past a valve seat with the valve chamber 113. The nozzle 121 on the hollow arm 119 directly underlies and faces the valve seat.

A valve member 137 which is dumbbell shaped has oneenlarged end lying in the chamber 136 to seat downward against the valve seat with its other enlarged end lying Preferably a light spring 138 is provided urging the valve member downward.

When the pressure is at the desired value the valve member will engage the seat and the nozzle 21 so that no air will be wasted. If the pressure drops the arm 119 will rise to raise the top end of the valve member from the seat while a rise in pressure will cause the arm to move down to open the vent nozzle 121.

To insure that the pressure will stay up to the full desired value at all times it may be desirable to provide a small leak past the supply valve. As shown, this is accomplished by forming a capillary passage 139 around the supply valve to supply a very small quantity of air to the valve chamber at all times. With this construction the vent nozzle 121 tends to remain very slightly open when the pressure is at the desired value to Waste a very small quantity of air. I have found, however, that this very small leak improves the sensitivity of the instrument and insures that the pressure is held at the full desired value under all conditions. Without this leak and in the event there is any leakage past the vent valve the pressure might tend to drop below the desired value at times.

With the construction of Figure 4 the pressure drop across the supply valve tends to close the valve and in this way compensates for variations in supply pressure. Even though the valve area is very small and the differential pressure across it produces a very small force this may be important in cases where the air supply is subject to substantial variations.

While two embodiments of the invention have been shown and described in detail, it will be understood that these are illustrative only and are not to be taken as a definition of the scope of the invention, reference being had for this purpose to the appended claims.

What is claimed is:

1. A fluid pressure relay comprising a body formed with a chamber having a fluid outlet connection, a fluid supply nozzle extending int -the chamber, a hollow arm pivoted in the chamber and having a nozzle near its free end communicating with its interior, means connecting the interior of the hollow arm to atmosphere, a flapper carried by the arm overlying the nozzle thereon and resiliently biased toward the nozzle thereon to close it and projecting beyond the arm into registry with the supply nozzle to move toward and away from the fluid supply nozzle as the arm pivots, and means to move the arm about its pivot.

2. A fluid pressure relay comprising a body formed with a chamber having a fluid outlet connection, a fluid supply nozzle extending into the chamber, a hollow arm pivoted in the chamber and having a nozzle near its free end communicating with its interior, means connecting the interior of the hollow arm to atmosphere, a flapper carried by the arm overlying the nozzle thereon and resiliently biased toward the nozzle thereon to close it and projecting beyond the arm into registry with the supply nozzle to move toward and away from the fluid supply nozzle as the arm pivots, a diaphragm communicating on one side with the chamber, means to exert a pressure on the other side of the diaphragm, and a connection from the diaphragm to the arm to move it as the diaphragm moves.

3. A fluid pressure relay comprising a body formed with a chamber having a fluid outlet connection, a fluid supply nozzle extending into the chamber, a hollow arm pivoted in the chamber and having a nozzle near its free end communicating with its interior, means connecting the interior of the hollow arm to atmosphere, a flapper carried by the arm overlying the nozzle thereon and resiliently biased toward the nozzle thereon to close it and projecting beyond the arm into registry with the supply nozzle to move toward and away from the fluid supply nozzle as the arm pivots, a diaphragm having restricted communication on one side with the fluid outlet connecvtion, means to exert a pressure on the other side of the diaphragm, and a connection from the diaphragm to the arm to move it as the diaphragm moves.

4. A fluid pressure relay comprising a body formed with a chamber having a fluid outlet connection, a fluid supply nozzle extending into the chamber, a hollow arm pivoted in the chamber and having a nozzle near its free end communicating with its interior, means connecting the interior of the hollow arm to atmosphere, a flapper carried by the arm overlying the nozzle thereon and resiliently biased toward the nozzle thereon to close it and projecting beyond the arm into registry with the supply nozzle to move toward and away from the fluid supply nozzle as the arm pivots, a diaphragm communicating on one side with the chamber, a connection from the diaphragm to the arm to move it as the diaphragm moves, a housing inclosing the other side of the diaphragm, and a fluid pressure connection to the housing.

5. A fluid pressure relay comprising a body formed with a first chamber and a second chamber, a fluid outlet connection from the first chamber, a fluid supply nozzle in the first chamber, a shaft extending between the first and second chambers, a hollow arm in the first chamber "carried by the shaft for swinging movement as the shaft turns, a nozzle on the arm communicating with its interior, means connecting the interior of the hollow arm to atmosphere, a flapper carried by the arm overlying the nozzle thereon and resiliently biased toward the nozzle thereon to close it and projecting beyond the arm into registry with the supply nozzle to move toward and away from the fluid supply nozzle as the arm swings, at second arm extending from the shaft into the second chamber, and an operating member extending into the second chamber and engaging the second arm.

6. A fluid pressure relay comprising a body formed with a first chamber and a second chamber, a fluid outlet connection from the first chamber, a fluid supply nozzle in the first chamber, a shaft extending between the first and second chambers, a hollow arm in the first chamber carried by the shaft for swinging movement as the shaft turns, a nozzle on the arm communicating with its interior, means connecting the interior of the hollow arm to 5. atmosphere, aflapper carried by the arm overlying the nozzle thereon-:andi resiliently biased'atoward the nozzle thereon to close it and projecting beyond the arm into registry .with the supply. nozzle totmove=towardxand=away from therfluid supply.nozzle.as..thei-.ar m swings a second arm. .extendingirom .the .shaft .into .the. second; chamber, a diaphragm having restricted communication on one side to the fluid outlet connection, an operating member connected to the diaphragm and extending into the second chamber and engaging the second arm, a housing inclosing the other side of the diaphragm, and a fluid pressure connection to the housing.

7. A fluid pressure relay comprising a body formed with a pair of spaced chambers, an outlet connection for one of the chambers, a fluid supply nozzle in said one of the chambers, a shaft extending into the chambers and exposed at one end to the exterior of the body, a hollow arm in one of the chambers secured to the shaft, the shaft having a bore therein open at said end thereof to the exterior of the body and communicating with the interior of the hollow arm, a nozzle on the free end of the hollow arm communicating with its interior, a flapper carried by the arm overlying the nozzle thereon and resiliently biased toward the nozzle thereon and projecting beyond the end of the arm into registry with the supply nozzle to move toward and away from the fluid supply nozzle as the arm swings, an angular extension on the shaft extending into the other chamber, and operating means connected to the angular extension to turn the shaft thereby to swing the arm.

8. The construction of claim 7 in which the shaft is supported in resilient bushings which seal the space around the shaft and yield to enable the shaft to turn.

9. A fluid pressure relay comprising a body formed with a chamber, an outlet connection from the chamber, a fluid supply connection to one end of the chamber, a shaft extending into the other end of the chamber having a bore therein open to atmosphere, a hollow arm on the shaft communicating with the bore therein and extending toward the supply connection to pivot about the 'shaft axis, a nozzle on the arm communicating with its interior, and a valve member cooperating with both the supply connection and the nozzle to control both the supply and exhaust of fluid from the chamber as the arm moves the nozzle moving away from the valve member to open the nozzle when the arm swings in one direction and the nozzle engaging the valve member to close the nozzle and to move the valve member to open the supply connection when the arm swings in the other direction.

10. A fluid pressure relay comprising a body formed with a chamber, an outlet connection from the chamber, a fluid supply connection to one end of the chamber, a shaft extending into the other end of the chamber having a bore therein open to atmosphere, a hollow arm on the shaft communicating with the bore therein and extending toward the supply connection to pivot about the shaft axis, a nozzle on the arm communicating with its interior, and a valve member cooperating with both the supply connection and the nozzle to control both the supply and exhaust of fluid from the chamber as the arm moves the nozzle moving away from the valve member to open the nozzle when the arms swings in one direction and the nozzle engaging the valve member to close the nozzle and to move the valve member to open the supply connection when the arm swings in the other direction there being a restricted passage from the supply connection to the chamber around the valve member.

11. A fluid pressure relay comprising a body formed with a chamber having a fluid outlet connection, a fluid passage communicating with the chamber, a hollow arm pivoted in the chamber on an axis transverse to its length and having a nozzle near its free end communicating with its interior, means connecting the interior of the arm to a point outside of the chamber, a unitary valve member movable relative to the fluid passage and the nozzle to er the 'valve' member.

12. -*A"-fluid*pressure-"relay comprising a body formed with a chamber having a fluid outlet connection, a fluid passage communicating with the chamber, a hollow arm pivoted in the chamber on an axis transverse to its length and having a nozzle near its free end communicating with its interior, means connecting the interior of the arm to a point outside of the chamber, a unitary valve member movable relative to the fluid passage and the nozzle to control both supply and exhaust of air for the chamber the nozzle moving away from the valve member to open the nozzle when the arm swings in one direction and the nozzle engaging the valve member to close the nozzle and to move the valve member to open the supply connection when the arm swings in the other direction, an imperforate flexible diaphragm communicating on one side with the chamber, means to exert a pressure on the other side of the diaphragm, and a connection from the dia- I phragm to the arm to move it.

13. A fluid pressure relay comprising a body formed with a chamber having a fluid outlet connection, a fluid passage communicating with the chamber past a valve seat, a hollow arm pivoted in the chamber and having a nozzle near its free end communicating with its interior and aligned with the valve seat, means connecting the interior of the arm to a point outside of the chamber, a unitary valve member having a reduced stem extending through the valve seat and terminating in an enlarged head to close on the seat, a part on the stem movable toward and away from the nozzle to close or open it, and means to move the arm the nozzle moving away from said part to open the nozzle when the arm swings in one direction and the nozzle engaging said part to close the nozzle and to move the valve member in a direction to move the head thereon away from the seat to open the fluid passage to the chamber when the arm swings in the other direction.

14. A fluid pressure relay comprising a body formed with a chamber having a fluid outlet connection, a fluid passage communicating with the chamber past a valve seat, a hollow arm pivoted in the chamber and having a nozzle near its free end communicating with its interior and aligned with the valve seat, means connecting the interior of the arm to a point outside of the chamber, a unitary valve member having a reduced stem extending through the valve seat and terminating in an enlarged head to close on the seat, a part on the stern movable toward and away from the nozzle to close or open it, a diaphragm communicating on one side with the chamber, means to exert a pressure on the other side of the diaphragm, and a connection from the diaphragm to the arm to move it the nozzle moving away from said part a to open the nozzle when the arm swings in one direction and the nozzle engaging said part to close the nozzle and to move the valve member in a direction to move the head thereon away from the seat to open the fluid passage to the chamber when the arm swings in the other direction.

15. A fluid pressure relay comprising a body formed with a chamber having a fluid outlet connection, a fluid passage communicating with the chamber past a valve seat, a hollow arm pivoted in the chamber and having a nozzle near its free end communicating with its interior and aligned with the valve seat, means connecting the interior of the arm to a point outside of the chamber, a unitary valve member having a reduced stem extending through the valve seat and terminating in an enlarged head to close on the seat, a part on the stem movable toward and away from the nozzle to close or open it, and means ama ,,to move the arm, the fluid passage being connected to a .lsource of fluid under pressure,,and means forming a re- .fstricted connection from the fluid passage to the chamber around the valve seat the nozzle moving away from said part to open the nozzle when the arm swings in one direction and the nozzle engaging said part to close the nozzle and to move the valve member in a direction to move the head thereon away from the seat to open the fluid passage to the chamber when the arm swings in the other direction.

References Cited in the file of this patent UNITED STATES PATENTS 2,327,898 Hubley Aug. 24, 1943 2,588,678 Wills Mar. 11, 1952 2,593,906 Markson Apr. 22, 1952