US2719534A

US2719534A - Booster pilot valve relays of the pneumatic type

Info

Publication number: US2719534A
Application number: US446089A
Authority: US
Inventors: Ray S Williams
Original assignee: Hagan Corp
Current assignee: Hagan Corp
Priority date: 1954-07-27
Filing date: 1954-07-27
Publication date: 1955-10-04
Anticipated expiration: 1972-10-04

Description

Oct. 4, 1955 R. s. wlLLlAMS BOOSTER PILOT VALVE RELAYS OF' THE PNEUMATIC TYPE Filed July 27, 1954 A wm, A. M md 5%. m 5 Md .L QN hm Qvmwv m, QN WM A V l N L I. m N, @wf i vw 5. mcrw hm, N mm, DMW Nw mm w Q A h .,ll. m, mw@ H.u|d||f||| W a m n, www@ Patented Oct. 4, 1955 United States Patent Oce BOOSTER PILOT VALVE RELAYS OF THE PNEUMATIC TYPE Ray S. Williams, Orrville, Ohio, assignor to Hagan Corporation, Pittsburgh, Pa., a corporation of Pennsylvania Application July 27, 1954, Serial No. 446,089

4 Claims. (Cl. 137-84) This invention relates to pneumatic relays of the type which includes a signal-responsive pilot valve assembly and a booster pilot valve assembly that is actuated by the pressure output of the signal-responsive pilot valve relay of the type having a' diaphragm pilot valve assem' bly which receives a variable input pressure, and develops by its pilot valve a corresponding pneumatic pressure output, and which includes a booster pilot valve assembly that transmits quickly an output signal in responseto the pilot valve signal, and meansfor balancingv the :input signal with the booster valve output pressure.

A still further object of the invention is to .provide a relay which is compact and of relatively simple construction and which is an improvement upon the relay disclosed in my copending application Serial No. 371,275, tiled July 30, 1953.

Other objects of the invention will be apparent to those of ordinary skill in the art to which the invention pertains from the following description and drawings.

In the drawings:

Figure 1 is a view in longitudinal section of a. relay having an input signal pilot valve assembly and a booster pilot valve assembly, arranged and constructed in accordance with an embodiment of the invention; and

Fig. 2 is an enlarged view in section of a .portion of the signal input responsive pilot valve assembly.

In Fig. l of the drawings a relay 1, embodying4 what now appears to be a preferred form of the invention, is shown that comprises a housing composed of a` anged tubular member 2, a plurality of relatively thick disc-like members 3, 4, 5 and 6, a spacer 6' and an end cap member 7. 1

The relay includes a pilot valve 8 which is operatively connected to a pressure input signal responsive diaphragm .v

9 and a booster pilot valve 10 that is operatively connected to a pair of diaphragms 11 and 12.v As shown the marginal edge of diaphragm 9 is disposed between disc members 3 and 4 while the marginal edge of vdiaphragm 11 is disposed between member- 5 and the spacer disc 6', and diaphragm 12 is disposed between spacer 6 and disc member 6.

The abutting faces of members 4 and 5 and members 5 and 6 and 6 and 7 are sealed by

gasket members

14, 141, 15, and 15.

Member 4 is provided with an inlet port 17 that leads through a passage 18.into the space within member 4 and to the right of Vdiaphragm 9. Member 5 is provided with a port 19 to which a supply of air at constant pressure may be connected. Port 19 is provided with a passage 20 that leads to the inlet of valve 8. Members 5, 6, 6' and 7 are provided with connecting ports forming a passageway 21 leading to the inside of member 7 to K the right.

form a supply for valve 10. Members 6, 6 and 5 are also provided with connecting ports forming a passage 22 leading to an output port 23 in member 5. Members 3, 4 and 5 are also provided with communicating ports that form a passage 24 that connects the outlet port 23 with a chamber 25 on the left side of diaphragm 9.

Valve 8 controls the pressure supplied to the left side of diaphragm 11. That pressure operates valve 10 to lift it off its seat which is formed in a disc or plate 26. When lifted oit its seat, pressure is supplied from port 19 through passageway 21 through the Valve seat of valve 10 to the passageway 22 to the outlet port 23. The outlet pressure at port 23 is communicated through the passageway 24 to the space 25 so that that pressure acts on diaphragm 9 to oppose the pressure supplied through port 17 to the opposite side of diaphragm 9.

lf the signal pressure to port 17 decreases, valve 8 is moved in a direction to exhaust pressure from the diaphragm 11 through an exhaust passageway 28 formed in member 4. When pressure is relieved from diaphragm 11 diaphragms 11 and 12 move to the left whereby an `exhaust port member 30 is moved away from the inner end of valve 10 thereby allowing pressure in passage 22 to exhaust to atmosphere through an exhaust port 31. Pressure is also exhausted from the space 25 so that the pressure on diaphragm 9 is relieved to a value Where it balances the signal pressure acting on the opposite side of diaphragm 9.

The booster valve output pressure at port 23 is delivered to some suitable device to be actuated in accordance with the magnitude of the signal pressure delivered to port 17.

rThe 'pilot valve assembly that responds to the input signal at port 17 comprises the valve 8 and a valve body 33 that is seated in a bore 34 in member 5. The valve body 33 is provided adjacent its opposite ends with grooves for accommodating

sealing rings

35 and 36. Between the sealing rings 3S and 36 the valve body is ported as at 37 through which port the outlet pressure of valve 8 is transmitted through a passage 39 to the diaphragm 11. The valve body 33 has a bore extending through it in one end of which is a cup-shaped member 40 having in its closed end an inlet port 41 that is controlled by the tapered end 42 of valve 8. The opposite end of the Valve body is provided with a threaded cup-shaped member 43 that is screwed into the valve body as shown. The closed end of member 43 is provided with an exhaust valve port 44 that is controlled by the pointed end 45 of valve 8. Member 43 may be adjusted into or out of the valve body 33 to provide the proper spacing between the inlet port 41 and the exhaust port 44 with respect to the pointed or cone-shaped ends 42 and 45. The valve 8 is provided with a stem 46 that is connected to a link 47 that transmits motion from diaphragm 9 to the valve 8. Link 47 and member 43 are encased in a exible member such as a bellows 48. One end of bellows 48 is joined as by braz ing, welding or soldering, to a flanged apertured disc 49 that is clamped between the central portion of member 5 and a ange 50 of member 4, a gasket in the form of an O-ring 51 being provided to form a uid tight joint. The opposite end of bellows 47 is connected to a washer 53 as by soldering, brazing or welding. Diaphragm 9 is connected to a flanged sleeve 54 by means of a bolt 55 having a cupped head 56 which receives one end of member 47. Member 54 is internally threaded to accommodate a portion of member 55 that passes through the washer 53. By screwing member 55 into member 54 a pressure-tight joint is formed at the point where member 55 passes through the diaphragm 9.

A compression spring 56 disposed between a bonnet 57 and the flange of member 54, urges the diaphragm 9 to Member 57 as shown is threaded into the neck of member 2. A tension spring 58 is connected at one end by a threaded plug 59 to member 54 and by a threaded plug 60 to a ferrule 61 that is secured to a spindle 62. Thespindle 62 passes. through the headof member 57 and is threaded to accommodateanut 63 secured toa sleeve 64@ 5 providedwith a hand wheel'65;

As.shownfthecmemberx57 is-slotted as-at 66 to accommodatea screw 67 :by-which. the ferrule issecured to the spindle 62. Thus when-the hand :wheel 65.is turned the ferrule and spindle 62rrnove in. or out of the member 57 thereby increasingzordecreasingthetension in spring 58. By adjusting theltensionon spring 58 thenet force exerted; by spring 56'on the angedlmembertcan be adjusted. By adjusting :these ,spring/forces; theinitial loading on diaphragm 9-canzbe1preset.tofanyfdesiredvalue and thereby predeterminerthe fset pointof the relay.

A bellows ..70is.disposedabout'the shank of member 54. One end ofthe-.bellowsis -joinedtothe inner end of the shank 54, that is to the endadjacent. diaphragm 9, and the opposite rendfis-securerd as by brazing, welding or soldering, to an apertured. disc .71. The margin of thedisc 71 is clamped'between member.2.and a flange 72 of member 3, a-gasket intheifo'rm of :an 0.-ring.74 being provided toform apressureztight joint. The bellows 70 and diaphragm@ thus -formthe.pressure-.chamber 25 to which the. output pressuresfromvalve 10 is supplied. For the same reason the bellows 48 and .diaphragm 9 form the. pressure chamber forreceiving the input signalfrom port 17.

Valve 10 is urged towards its seat by means of a relatively lightcompression spring 74. Valvemember-30 is urged off its seat r out of engagement with the inner end of valve member by means of a compression spring 77.

As shown in the-drawing yvalve member 30 is provided with Ia a'ngedhead 78' that bears kon one side of diaphragm 12. The stem of valve 30 is threaded to accommodate aflanged member 79 which is screwed down tightly on the diaphragm 12 to sealthe opening through whichthe member 30 passes.

If it be assumed thatv the relative spring tensions of springs 56 and 58 'are such that both-ports of valve 8 are. closednwhen the vsignalepressure to port 17 -is Zero andif it befassumed-,thatunder these conditions of spring adjustment, thesignal pressure to port V17 is increasing from say zero: gauge, then. diaphragm 9 will be deilected to the left wherebyivalve.8is1movedtowards its exhaust por-tseat thereby opening: the:inlet port 41. Pressure will then lowtrorn` port: 182throughsthe cup member 40 intothe body 33.`fand thenceupWardly-- through port 37V andpassageway'39fto the :space to the `left of diaphragm 11. That pressure; .urges diaphragmv 11v to the right whereby valve 10 isopened andsupply pressure ows from port 19'into the;-bonnet'.of.xmember 7 thence through .valve 10- and passagei22`. to.theloutlet port 23. Pressure atthe *outlet port .is a'lsocommunicated `throughpassage M-to the left side'of diaphragm 9.` It will be observed fromthe drawing that..the;ar.eas-of :diaphragm 91exposed to pressure fromport 1-'7 and'from :theport v23` are equal. Therefore, as soon;rasstheapressureat the outlet port 23 is equal to the signal pressure, valve 8 will come to a position where the pressure: at thexoutletport 23 -balances the signal input pressure atport217l As'the signal input'pressure increases theoutput'pressure at port 23 will increase-but fory every value of .pressure establishedby the input signal pressure at port'-'17'there lwilllbe .aA-corresponding and equal pressureat the: outlet port 23.

Ifl the signal inputizpressure decreases'then the spring f tensionactinggon.diaphragm1-9-will move it towards -the right 'thereby-either throttling or closingthe inlet port 41v andopeningtheexhaust port 44.' The pressure acting on diaphragmzlls willmtherefore decrease, being exhausted'l through the exhaustport v44 vand .the exhaust passagewayj 28 to the atmosphere. As the pressure on diaphragmA 11 isdecreased,` the tensionA of `spring 77 will move valve member130itothe'left-andunseat it from the stern of valve"10"whereby the pressure at the outlet port 23 `willA Yexhaust through the member 30 to the atmosphere via the exhaust passage 31. When the pressure at port 23 has been decreased to a point Where the pressure acting on diaphragm 11 is balanced, the exhaust port member 30 is again closed.

Thus for every value:ofinput pressure through the signal input port 17 there will be a corresponding pressure delivered atthe -outlet'rport y23 `:and .that pressure will balance the input signal pressure;

As:-can.be seenfrom the-:drawingsthe pilot valve 8 is relatively small. and: handles. relatively l small .quantities of air. That pressure, however, is sufficient to actuate the larger boosterpilot valvewhich can handle larger quantities of v-air and thereby cause the apparatus responding to the pressureatthe-.outlet port 23 ,to respond quickly to any change in the signal input pressure at the port 17 By adjusting the relative tension of spring 58 with respect-to `the opposing-tension of .spring theset-point of Ithef-relayrcan bechanged. Iftheftension in.spring .53

isrincreased, to therebyfoffsetthe :compression of spring. 56,` .valve.8 will establish a pressure: at the outlet port 23,-.

that is a-function of .the-spring force acting` on thediaphragm. In .other words,.with. a zero .signal pressure at port 17 the spring-.tension SSmay-be so adjusted that the .pressure :atgthe-outletport 23 will besay ten vpounds gauge. If now the signal pressure is increased from zero gauge-toA some .higher Ivalue the Vpressure at the outlet port 23 willvbe :.tenl pounds plus. the I.pressure that is established bythe. signal input pressure.'-

If,thef-tension .inspring..58risrelieved.so as to cause spring-.56"` to` have greater force on'the diaphragm, then' the 4.valve-.8 :will not'be-actuateduntil v.the signal pressure atzport 17 issuiicientto overcomethe net spring force acting on the diaphragm.

Blymeans of .thehand wheel. 65.. the relative tensions ofxsprings'z andl58fmay also befadjusted manually to causefthexelayfto'.transmit.pressure through the outlet port 13.2 In'.such:a :casethez'value ofxtheoutput vpressure will be proportional to the spring.force acting on diaphragm z9xbecause. thepressure acting on :diaphragm 9 will come tto; equilibrium'at that value .which Will produceV a pressure force equaland oppositeto the spring force.

Having thus described the invention: `itfwill be apparentLto those skilled in vthisartthatvarious. modications and changes :may 1 be L madeA in. the. :illustrated embodiment without departingfrom either. the :spirit or the scope vof the invention:

Therefore what4 .is claimed as. new `and desired. to be secured by-Letters'Patent is:

l. A..pneumatic Abooster pilot relay comprising; a sectional housing,l one sectionoffsaidzhousing having therein aipilot valve.` body/provided with inlet and. exhaust portsand .anwoutlet port, and .alvalve memberffor controlling the exhaust and inletports, saidvalve member being movable from one port to the other to restrict the.

inlet port'whilefuncovering the-outlet port and viceversa, saidfone sectionk having a; port` for. thev supply-of iluid pressure1to-saidvalve, a secondsection of said housing being provided with a diaphragm-forming Within the same opposed chambers, linkv means connecting said diaphragm to saidpilot valve member for actuating the same to control said inlet and exhaust ports, spring means and a. coupling thereforconnected: to said link, ilexible seals in said chambers and disposed about said springmeans coupling and said linkto form with said diaphragm opposed pressure tight pressure-receiving chambers, one of said chambers being ported to receive a pressure input signalwhile -th'ef other chamber isported to receive a balancingboosteroutputpressure, a' third section of said relayA housingA comprising -a chambered member having within thechamber aboosterpilot valve comprising a movable valve member having-a stationary outlet seat, the interiortof the housing beingconnected-to the supply port-oftherst mentioned'section, at'diaphragmv assembly in said"A booster section which is'port' connected to the outlet port of said pilot valve, said diaphragm assembly having at its central portion an exhaust valve member disposed to engage and unseat the movable booster pilot valve member from its seat in response to pressure being supplied to said diaphragm assembly by said pilot valve, said booster pilot valve discharging pressure against the diaphragm assembly of said third section to cause said diaphragm to close the booster pilot valve when the forces of said booster and pilot valve outlet pressures on said diaphragm assembly are balanced, means connecting said booster outlet pressure to an outlet port and to the balancing chamber of the rst mentioned section, the exhaust valve member being actuated to exhaust position when the outlet pressure exceeds the pilot valve output pressure, whereby for every input signal pressure acting on the pilot valve actuating diaphragm the booster valve' transmits a pressure whose value is suiicient to balance the force exerted by the input signal on the pilot valve actuating diaphragm.

2. A relay as in claim 1 in which the booster pilot valve diaphragm assembly comprises spaced diaphragms the central portions of which are secured to the booster exhaust valve member, said exhaust valve member being hollow and open at its opposite ends, one end being connected to the space between said diaphragms and the other end being disposed to engage the movable booster pilot valve to open the same and when so engaged said exhaust valve is closed, the said third section having an exhaust port connected to the space between said diaphragms, and spring means urging the exhaust valve member away from the movable booster pilot valve member toward exhaust position.

6 3. A relay as in claim 1 in which the spring means connected to the diaphragm of the first section comprises a relatively strong compression spring adapted to exert if a force in the same direction as the balancing pressure acts on the pilot valve actuating diaphragm and a tension spring disposed to exert a force in opposition to said compression spring, and means connected to said tension spring for adjusting the force exerted by said tension spring relative to the force exerted by said compression spring whereby the set point of the relay may be adjusted and whereby the relay may be operated manually to eifect operation of the pilot and booster pilot valves.

4. A relay as in claim l in which the pilot valve of the first section comprises a cylindrical valve body having a cylindrical bore therethrough and inverted cup-shaped members in the ends of said bore, said cup-shaped members being provided with inlet and exhaust ports respectively, a movable valve member having conical surfaces at its opposite ends disposed to coact with said inlet and exhaust ports to control the relative restrictions thereof and thereby control the pressure transmitted through the outlet of said valve body, the cup-shaped member provided with the exhaust port being ported, said first section having an exhaust passage leading to the atmosphere and connected to said exhaust port.

Swenson Aug. 1, 1950 Caldwell et al May 19, 1953