US2611382A - Overspeed trip valve mechanism - Google Patents

Description

Sept..23, 1952 E. M. KUEMMERLEIN TAL 2,611,382

ovERsPEED TRIP VALVE MECHANISM Filed March 15, 1946 Il /////////////////////////////////////////////////z\Y ATTORNEY Patented Sept. 23, 1952 l UNITED STATES PATENT OFFICE OVEBSPEED TRIP VALVE MECHANISM Edward M. Kuemmerlein, Wauwatosa, and Goleman A. Newland, Waukesha, Wis., assignors to Allisfhalmers Manufacturing Company, Waulgee, Wis., a corporation of Delaware ApplcationMarch 15, 1946, Serial No. 654,758

- 9 Claims.

vThis invention relates generally to governing apparatus of the type including an overspeed responsive mechanism operatively associated with a driven part of a prime mover and with a valve or other means controllingv delivery of motive iluid to the prime mover in a manner effective to terminate the delivery of suchA fluid in response to the prime mover attaining or exceeding a predetermined speed.

Some types of prime movers, especially elastic fluid turbines, include a trip valve disposed in series with the usual governor actuated regulating valve. And this trip valve is' held in its fully open position by a part of the overspeed mechanism'until the speed of the prime mover becomes excessive whereupon such part is released and the trip valve is immediately closed through the action of a spring, counterweights and/or other suitable devices.

When in its fully closed position, an -opening movement of the trip valve is resisted by the pressure of the motive fluid on the upstream side of the valve (the pressure of any fluid remaining in the conduit on the downstream side of the trip valve is very low) and by the action of the above mentioned springs and counterweights. Consequently, it is difficult, if not impossible, for a person to reopen and reset the trip valve without' the aid of additional valve means effective to initially approximately balance the fluid pressures acting on opposite sides of the valve and without the aid of an opening force applying apparatusysuch as gearing and/or an electric motor, servomotor, or the-like, effective to overcome the .continuously acting' closing force of the .usual springs and/.or counterweights.

However, the provision of a manually operated gearing is objectionable in that considerable time is requiredV to fully reopen and reset the valve. And although a power actuated valve opening apparatus of the type above mentioned and -heretofore employed in general operates satisfactorily, such apparatus is relatively expensive to manufacture and install and i-n many cases requires a considerable amount of service in order toinsure satisfactory operation at all times.

The. present invention is directed toward and has as an object the provision of an improved trip valve mechanism-permitting the valve to be readily reopened and resetl with a minimum number of parts constructed and combined Vto afford-a -"si'i`npliiied,` durable and relatively inexpensive construction; y Y f p 1 Morev particularly, the present 'invention 11S di 2 rected toward and has as a further object the prof vision of an improved trip valve mechanism inf cluding a main valve and a pilot valve combined for limited. relativev movement and operatively connected with a releasably latched valve closing member in a manner eiective to immediately close the trip valve upon releasing such member and effective to vimmediately reopen the trip valve upon moving the member to its latched position.

The construction, application and operation of apparatus embodying the invention will become readily apparent as the disclosure progresses and particularly points out additional objects and advantages considered of special importance. And accordingly the present invention maybe considered 'as consisting of the various yelements and/or parts constructed and combined in lgen, eral as hereinafter more fully set forth in the detailed description and appended claims, refe erence being had to the accompanying drawing illustrating one embodiment of the invention and, in which:

The figure illustrates, in part schematically, a motive fluid controlling and regulating appara-y tus embodying parts constructed and combine in accordance with the invention.

In the illustrated embodimentofthe inven-v tion, I designates a valve casing internally par.;-

titioned to provide a chamber 2 having an inlet Y 3 connected with a suitable source of motive fluid (not shown), a chamberl 4 having a motive fluid outlet .6 through which motive fluid flows -to a prime mover of which only the rotating parts 5 and I0 are shown, and a passage 1 placing chamber 2 in communication with chamber 4. Passage -1 is formed in part `by an rupper valve seat 8 and in part by a pair of spaced coaxial valve seats '9. A balanced throttle or regulating valve Il, adapted to engage valve seatsi9, controls the flow of motive fluid from passage l into chamber 4. And a trip valve mechanism including a main valve I2 and pilot valve 2| operable to cause .the valve I2 to engagevalve seat 5' controls the ow of motive iluid from `chamber'2 into passage 1. y

Valve I2 `is constructed to include duct means comprising a central chamber I3, a pair of laterally extending ducts I4 placing chamber I3 in continuous communication with chamber 2 ,4 and a duct I5 extending coaxially from chamber `Ii and .through the downstream face of the'va'lve. A rod or actuator I'I is -reciprocably mounted in abushing I8 carried by a removableA cover portion I9 of casing I in coaxial relaticjrik with respect to passage I and valve seat 8 andthe inner end of rod I1 is enlarged to provide a pilot valve part 2I. Valve I2 is coaxially reciprocably mounted on rod I1 by means of a removable bushing 22 positioning and retaining pilot valve part 2I within chamber I3 in coaxial controlling relation with respect to duct I6. The part 2l is reciprocably movable within the chamber I3 independently of the movement of valve I2 to afford a lost motion connection means. And it should now be obvious that rod I1 can be moved coaxially longitudinally toward or away from annular valve seat 8 and that rod l1 may be moved coaxially relative to valve I2 or valve I2 may move coaxially longitudinally of rod I1, until the pilot valve part 2l thereof either engages the underside of bushing 22 or the seat therefor defining the chamber end of duct I6.

The outer end portion of rod I1 passes through or closely adjacent an intermediate portion of a lever 23 and is provided with a pair of longitudinally spaced stop parts 24 and 26 adapted to limit relative movement of the rod and lever. One end of lever v23 is pivotally supported on a fixed bracket 21 and its other end is operatively associated with a notched latch arm 28 of a pivotally mounted element having a trip arm 29 normally positioned, by means of a weak spring 3|, for actuation by a conventional overspeed responsive device 32 carried by rotating prime mover part 5. A strong spring 33 connects the latch arm end of lever 23 with a fixed bracket 34 and thus continuously acts to move lever 23 to its full line position shown in the drawing. When in this position, the free end of lever 23 abuts latch arm 28 and holds trip arm 29 out of the path of overspeed device 32. The foregoing structure, with the lost motion connection means including part 2l, provides an operating means for seating the valve I2 and releasing the valve for opening movement.

As illustrated, the position of throttle valve II is controlled by a centrifugal governor 36 driven by the rotating prime mover part I0. Valve II is provided with a stem 31 reciprocably mounted in a bushing 35 carried by casing I. And an operative connection between stem 31 and the yball actuated collar 38 of governor 36 may include a bell crank lever 39 having one arm engaged with collar 38, a lever 40 fulcrumed intermediate its ends on a bracket 4I and having one end operatively connected with valve stem 31, and a rod 42 reciprocably mounted in a guide bushing 43 and having one end engaged with the other arm of bell crank lever 39 and having its other end engaged with the other end of lever 40. A spring 44 surrounds stem 31 and contin- .uously acts through a collar carried by the stem to maintain same operatively engaged with lever 40 and the latter operatively engaged with rod 42. A similar function is also performed by the usual governor spring designated 46. And since valve II is of the balanced type, it should be obvious that a person can readily close same merely by pulling on the upper end of lever 40.

With the various parts positioned as shown, all that has to be done in order to open and reset trip valve I2 is to raise lever 23 until the free end thereof is disposed in the retaining notch shown in the opposed face of latch arm 28, thereby-resetting the latch for subsequent trip by overspeed device 32 and then pull on lever 40 so as to momentarily close throttle valve II. -InA this connection, lthe longitudinal spacing of stop parts 24 and 2B on rod I1 is such that just before lever 23 entersl the retaining notch in latch arm 28, the intermediate portion of the lever engages part 26 and moves rod I1 upward a slight distance relative to valve I2 thereby opening duct I6 and placing passage 1 in communication with chamber 2. And since valve II is then closed, the pressure immediately builds up in passage 1 to a value equal to thatin chamber 2 whereupon valve I2 is forced upward due to the fact that by upward movement of the valve body 2I against the outside of the bushing 22 the effective area of the downstream face of this valve is greater than the effective area of the upstream face thereof by an amount equal to the cross-sectional area of rod I1. Initial upward movement of valve body 2I takes place by reason of lifting of lever 23 and further upward movement so that the valve body 2| engages the under side of bushing 22 may be produced by any suitable means, in this instance the difference in effective areas of the valve body 2I and the rod I1, whereupon valve I2 and rod I1 then move upward as a unit until bushing 22 -en gages the adjacent end of casing mounted bushing I8. And in this connection it should be borne in mind that the longitudinal spacing of stop parts 24 and 26 must be such that when valve I2 is in its fully open vposition as determined by the above mentioned engagement of bushings I3 and 22, stop part 24 is in proximity to or just about to engage the underside of lever 23.

It should now be obvious that as long as lever 23 is retainably engaged by latch arm 28, valve I2 will be held in its fully open position by the pressure of the motive uid in chamber 2, and that if the supply of motive fluid to chamber 2 should for any reason fail, valve I2 will immediately gravitate downward and engage seat 8. However, it should also be obvious that in the event such a condition should occur, bypass duct I6 will remain open since a like downward movement of rod I1 will be arrested by engagement of itsl stop part 26 with the upper side of latched lever 23, and that as soon as the supply of motive fluid is reestablished, valve I2 and rod I1 will again move upward until bushing 22 engages bushing I8 as previously described.

Apparatus embodying the present invention may be of a form or construction considerably different from that herein shown and described for purposes of illustratori. And it should therefore be understood that it is not intended to linut the invention to details of the particular construction herein disclosed as various modifications within the scope of the appended claims may occur to persons skilled in the art.

It is claimed and desired to secure by Letters Patent:

1. A trip valve mechanism comprising a casing having a valve seat therein, a rod mounted in said casing for longitudinal movement toward or away from said seat and including an enlarged pilot valve portion adjacent the seat end thereof, said rod being disposed in upstream relation with respect to said seat and having a portion projecting externally of said casing and provided with a pair of longitudinally spaced stop parts, a main valve body adapted to engage said seat and having a fluid bypass duct extending therethrough and includingan enlarged intermediate `portion providing a valve chamber with a seat in a vwall portion thereof for controlling said bypass duct, said main valve bodybeing reciprocably mounted on the inner end of said rod with the pilot valve portion thereof'disposed within said-chamber forlimited movement tcwardiforaway from uthe valve I:seat1ttl:eroi-n. .said rod :and saidl lmain valvebody being freely fxnovf. ably i'mounted `to Amove as a unitinvresponse. to fluid' .pressure yon .the downstream side oftsaid unit; a 'member movable 'longitudinally of said rodand relative thereto for a distance .determined bythe llongitudinal spacingof said stop parts, means continuouslyy acting to :move said member -into engagement -with one of saidxstop partsxto thereby produce -a vmovement of said i.

:valve rod sufficient `to :firmly engage the. pilot valve end A,thereofl and said 'main valve body. with their respective valve seats, areleasableelement for latchingsaid member in ,a positionxsuoh Athat a Lmovement of .said member'into latching en- Vgagement with said element .causes saidl member torst engage the other one Aof :said stop parts and 'thereby produce a :movement of said rod and Ysaid :pilot Vvalve suiiicient 'to open said" bypass duct: and `further movement of said trod and opening movement `of said main lvalve body 'in response to uid `pressure on the downstream side 'of= said pilotvalveand main valve body, and means for termina-tingfthe-further lmovement oi ysaid rod' and the opening movement of saidmain valve body with lsaid one of said Istop parts dis-A posed in proximity -to said member when the latter ls'fin latched engagement with said element.

2; A tr-ip valve mechanism comprising a cas- 4ing having a valve seat therein, la rod mounted in saidfcasing for longitudinal movement toward or away from said sea-t and including an enlarged `pilot, yvalve portion adjacent the seat end thereof, said rod having a portionproject-ing externally off'saidycasing and Iprovided with Aa pair of longitudinally `spaced stop parts, `a -main valve body adapted to enga-ge saidk seat `and having a iluid bypass duct extending therethrough and inf cludingy an enlarged intermediateportion providing a rvalve chamber with aseat in a wall portionv thereof -forv ,controllingl saidbypass duct, said main valve body being `reciprooably mounted on the inner end `of said Vrod with the vpilot valve portion 'thereof disposed within said chan-doery for limited movement toward or, away irornjthe valve seat therein, saidvrod and said main valve'body being freely movably mounted toimove asa unit in response to iiuid pressure, on thev downstream vside of said-unit,l aV member movable 'longitudinally'of ysaid `rod and relative thereto .for a distance determined by the longitudinal spacing of `said stop -parts, means continuouslyecting to move said member4 into engagement with vone oi said Step partsto 'thereby produce a. movement of said valve rodA sufficient to firmlyl engage ,the pilot valve end thereof and said main valve 'body with` their vrespective valverlseats, and a releasable element for latching said. member in a position such that a movement of said member into latching engagement with said element causes said member lto rst engage the other one of said stop parts and thereby 'produce a `movement of said rod and said pilot valve suicient to open said bypass duct. Y f

3. A trip valve mechanism comprising a ycasing having 7a valve seat therein, -a rod .mounted in .said {ca-sing" for longitudinal movement toward r away 4.from said seat, said :rod havingafgportion projecting externally of said-casngandiprovided with a'pair of longitudinally spaced stop parts, .amain valve body and .a pilot valvebody carried by the casing enclosed end portion, of

.said rod for limited vlongitudii-ial movement irelative to each other, said main valve body being adapted to engage said seat and having a bypass ductsextending V.t171eretlnzongh i seat prtion. ,controlled by isald .pi1ot valve. body;

said; 'rod i yand said "valve body being :freely movably A:mounted .to moveas 1a unit in response. toil-uid pressure .on the downstream yside of v said unit, a rnem'ber movable vlongitudinally ofsaid `rod and relative thereto :for a distance- .deter-r mined bythe longitudinal spacing of saidl stop parts, vmeans continuously acting to move `said member 'into engagement lwith one ofv ysaid stop parts to thereby :produce a. moveinent of said rod sufficient to firmly engage said. :pilot andmain vvalve ybodies with their respective Yvalve seats, .a lreleasable .element `for latching said member-inrpositionsuch that a movement ofesaid l-znen'lber Ainto latching-engagement withsaidfelea ment causes said` member 4to ilrstengage the other -onenf said lstop 'parts and thereby 'produce' a movement of said 'rod' and of said pilot Avalve bodysuiiicient to open :said bypass duct and fur-l thermovement of said :rodand :opening-movement of said main valve body in response'to fluid pressure on the downstream sid-e ofsaid pilot valve and main valve body, and means cariried by said casingiorfterminatingthe further movement ofjsaid rod and the opening movement of- Asaid main valve body with said Aone of said stop 4parts disposed in proximityr to saidmember when 'the latter is 4in 'latched engage-l mentl withy said element.

4. A trip valve mechanism comprising -a casing having a valve seat therein, an actuator hav ing an end portion ydisposed Within said easing ,for 'movement generallyA `toward or away from said seat, said actuator having an externa-l pore tion provided with a pair of spaced stop parts, a main `valve body and a pilot vvalve bodycarried by the casing enclosed end portion of said act-uatorv for limited movement relative vto each other, said 'main valve body being ladapted to eng-age said seat and having a bypass vduet extending therethrough and including a seat port-ion'jfconfI trolled by said pilot valve body, said'actuator and 4said* main valve body l being freely movably mounted to lmove as a unit in response to iluidpressure on the downstream side ofl said a member movable in a path adjacent said act-u-` `ator and relative thereto for a distance deterf minedvrby the spacing of said, stop parts;l means continuously acti-ng to move said member into engagement with one vofgsaid stop parts-to tlfiere-A byproduce a movement of said actuator suillcient to lfirmly Vengage said pilot and main valve bodies' with-their respective seats, and a releasable element for latching said member in a Ipositionsuclfi that a i'novernent of'said mem-ber intolatching engagement with said element causes said` mem# ber :to first enga-ge the other one of saidstop parts and thereby produceA a movement of fsa'id actuator and-of saidr pilot valve body suino-lent to open said bypass duct. 4

5. A trip `valve for controlling u'ldpressure flow to a prime mover responsive tooverspe'ed thereofand comprisinga easing havinga passage therein for iluid pressure liiow and providing a valveseat, lamain valve cooperable wi-th'said seat for closing the passageinsaid casing, said main valve having a bypss lduct therethrough, a pot valve for.controlling ilow of iluid pressure through saidl bypass duct and into said casing-passage, a rodnconnected xwith said pilot valve 'for operating thev'sameand extending routside of `said casing, spaced/stops on the portion of said rod outside of said casing, va 'lever engageable with said stops for liftingsaid :pilot valve :from the seattherefor and for pressing said pilot valve on the seat therefor, means urging said lever toward one of said stops in the direction for pressing said pilot valve and said main valve on the seats therefor, movement of said lever into engagement with the other of said stops causing opening of said pilot valve and opening of said pilot valve causing fluid pressure produced further opening movement of said pilot valve and fluid pressure produced opening of said main valve, and a lever for releasably latching the ssaid rst lever lin the pilot valve opening position.

6. A trip valve for controlling fluid pressure flow to a prime mover, comprising: a casing having a passage therein for fluid pressure flow and providing a valve seat, a main valve cooperable with said-seatfor closing the passage, said main valve having a bypass duct therethrough, a pilot valve forcontrolling flow of fluid pressure through said bypass duct and into said casing passage to equalize fluid pressure on both sides of the main valve and cause opening of said main valve solely by fluid pressure, a rod connected with said pilot valve for operating the same and extending outside of said casing, a first lever having lost motion connection with said rod outside of said casing and engageable with said rod to move said rod in either valve closing or valve opening direction and having biasing means acting on said lever to move same in valve closing direction, and a lever for releasably latching said ilrst lever in pilot valve opening position.

7. Operating fluid control apparatus for a prime mover operable by fluid, comprising: conductor means for said fluid having `interposed therein regulating valve means and having biasing means operative to move said regulating valve means toward open position; speed responsive means; means for connecting said speed responsive means to said regulating valve means for causing opening or closing movement of said regulating valve means in response to decrease or increase respectively of the speed of said prime mover in a predetermined range of speeds, said connecting means comprising a portion movable at will for closing said regulating valve means separately from said speed responsive means; trip valve means interposed in said conductor means upstream of said regulating valve means, said trip valve means having a stem extending exteriorly of said conductor means; operating means having lost motion connection with said stern, said operating means engaging said stern in valve opening direction in a first position and in valve closing direction in a second position; means biasing said operating means in valve closing direction; latch means for releasably holding said operating means in said rst position; second speed responsive means separate from said first named speed responsive means and responsive to predetermined excess speed to release said operating means from saidfirst position to close said trip valve means; and means operativeV when said operating means is returned to said flrst position for causing opening of said trip valve means' upon closure of said regulating valve means by said portion.

8. A trip valve for controlling fluid pressure ow to` a prime mover responsive to overspeed thereof, and comprising a casing having a passage therein for fluid pressure flow and providing a valve seat, a valve cooperable with said seat for closing said passage, means for supporting said valve for guided 'movement toward and away from said seat, and operating means having an actuable portion extending exteriorly of said casing and having a lost motion connection means with said valve for positively moving said valve against said seat by movement of said operating means to arst position, movement of said operating means to an opposite second position leaving said valve free to be moved to open position, said valve including duct means extending therethrough for placing an upstream portion of said passage in communication with a downstream portion thereof when said valve is in its closed position, said lost motion connection means including a part operable to close said duct means when said operating means is in said rst position and operable to at least partially open said duct means when said operating means is in said second positionand said exterior actuable portion and the upstream side of said valve presenting an effective area somewhat less than that presented by the downstream side thereof whereby when the 'pressure in said passage is equalized on opposite sides of said valve, said valve will automatically move to a predetermined open position.

9. A ltrip valve for controlling fluid pressure flow to a prime mover responsive to overspeed thereof, and comprising a casing having apassage therein for fluid pressure ilow and providing a valve seat, a valve cooperable with said seat for closing said passage, means for supporting said valve for guided movement toward and away from said seat, operating means having an actuable portion extending exteriorly of said casing Vand having a lost motion connection means with said valve for positively moving said valve against said seat by-movement of said operating means to a first position, movement of said operating means to an opposite second position leaving said valve free to be moved to open position, and means for releasably latching said operating means in said second position, said valve including duct means extending therethrough for placing an upstream portion of said passage in communication with a downstream portion-thereof when said valve is in its closed position, said lost motion connection means including a part op- EDWARD M. KUEMMERLEIN. COLEMAN A. NEWLAND.

REFERENCES CITED The following references are of record in the le of thispatent: l

UNITED STATES PATENTS Number Name Date 98,688 Gould Jan. 11, 1870 378,140 Lozon Feb. 21, 188s 669,640 Hewlett Mar. 12, 1901 1,617,895 Butler Feb. 15, 1927 1,931,104 caughey oct. 17 1933 zsiggilig schienker oct. 21 1945 Hageman 2,410,105 oct. 2, 1945 Remus oct. 29, 1946

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