US2635847A

US2635847A - Turbine jet controller

Info

Publication number: US2635847A
Application number: US751549A
Authority: US
Inventors: Fred H Rued
Original assignee: PELTON WATER WHEEL CO
Current assignee: PELTON WATER WHEEL Co
Priority date: 1947-05-31
Filing date: 1947-05-31
Publication date: 1953-04-21
Anticipated expiration: 1970-04-21

Description

April 21, 1953 F. H. RUED TURBINE JET CONTROLLER Fil ed May 31, 1947 4 Sheets-Sheet l April 21, 1953 F. H. RUED .TURBINE JET CONTROLLER 4 Sheets-Sheet 2 Filed May 31, 1947 April ,1953 F. H. RUED 2,635,847

TURBINE JET CONTROLLER Filed May 31, 1947 4 Sheets-Sheet 5 FlE E FIELE1 Patented Apr. 21, 1953 TURBINE JET CONTROLLER Fred H. Rued, Lafayette, Califl, assignor to T he Pelton Water Wheel Company, San Francisco, Calif., a corporation of California Application May 31, 1947, Serial No. 751,549

My invention relates to means primarily useful in connection with the operation and control of hydraulic motors, more particularly water wheels of the Pelton type in which water under high pressure is discharged through a nozzle onto a rotary bucket wheel. a I V In some installations it is advisable to provide a water wheel fed by a plurality of jets or nozzles supplied with water through a penstock many hundreds or even thousands of feet in height so that the pressure is considerable. Most often the water wheel is directly connected to an electric generator in turn connected through switching mechanism to an electrical transmission line. Upon occasion the line load is suddenly removed from the generator and the tendency of the water wheel is then to drive itself and the loadless generator in excess of normal operating speeds and at speeds that are dangerous. A problem arises in that it is not possible satisfactorily to shut oif the how of water from the jet in a reasonably quick time, that is, a time short enough to prevent over speeding. A shutdown time of approximately a minute may be required in order to avoid disruptive strains or shocks in the penstock or allied water conduits. On the other hand, it is desirable to remove the effect of the water upon the wheel almost instantly, that is, within a matter of a very few seconds.

It is therefore an object of my invention to provide means for quickly depriving a water wheel of its motor power without producing any disruptive strains in the supplying penstock.

' Another object of the invention is to provide a means in multi-jet turbines for depriving the water wheel of motive power from all of the jets instantly or substantially so while slowing the flow in the penstock at a moderate rate.

An additional object of the invention is to provide a means for individually controlling the jets in a multi-jet installation, so far as certain operating characteristics are concerned.

, A further object of the invention is to provide in general an improved mechanism for controlling a jet, or the jets, in a turbine.

A further object of the invention is to provide a relatively simple control mechanism for exercising supervisory functions over a hydraulic turbine.

Other objects, together with the foregoing, are attained in the embodiment of the invention illustrated in the accompanying drawings and described in the following description.

- In the drawings: Figure 1 is a diagram showing largely in plan 4 Claims. (01'. 253-44) and partly in section a portion of a multi-jet turbine provided with the control instrumentalities of my invention.

Figure 2 is a side elevation of a control structure incorporated with the mechanism of Figure 1. Figure 3 is a plan of the control structure shown in Figure 2.

, Figure 4 is a cr-osssection the plane of which is indicated by the line-4 4 of Figure 3.

Figure 5 is a cross section the planes of which are indicated by the lines 5-5 of Figure 4.

Figure 6 is a cross section the planes of which are indicated by the lines 6-.6 of Figure 5.

Figure '7 is a cross section portions being broken away to reduce the size of the figure and the planes of the sectionbeing indicated by the lines 1-1 of Figure 5. j I

, Figure 8 is a cross, section of a modified form of centralizing plunger mechanism.

In its preferred form the turbine jet controller of my invention is for use with a turbine having a plurality of jets, and involves a number of defiectors, one for each jet, all actuated simultaneously in response to aspeed governor operated by the turbine. Also involved, and preferably installed one for each jet, are needle valves operated'by servo mechanisms in response to the position of the deflectors, but at a somewhat slower rate than that at which the deflectors respond to the speed governor. While the servo mechanisms are automatic in general operation they are provided with hand controls for manual operation, if desired.

The turbine jet controller of the invention can be embodied in numerous diiferent forms depending upon the particular performance desired, and depending also upon the particular environmentin which it is installed. It has successfully been embodied in the form shown in the accompanying drawings. In the illustrated installation there is provided a hydraulic casing 6, within which is disposed a turbine shaft 1, on which an impulse wheel 8 is mounted. A governor 9 is driven by and is responsive to the impulse wheel 8 and is effective to move a lever II in accordance with the speed of the turbine wheel. Ranged round the casing ii, at appropriate intervals,are nozzles 13 and M, for example, all of them being supplied with hydraulic fluid, usually water under pressure, from the end of a penstock I'B which curls around the casing 6. Each of the nozzles l3 and I4 is effective to release a water jet against the impulse wheel 8.

Associated with the nozzle I3 is a deflector I1 comprising primarily a curved plate formed at the extremity of a lever is mounted on and to pivot with a shaft I9. The deflector is movable to occupy one position as shown in Figure 1 entirely intercepting or deflecting the jet normally issuing from the nozzle I3 and to occupy another position at one side of the jet and completely clear of it so as not in any way to interfere with the issuance of a full jet. These motions of the deflector I1 and of the shaft I9 are eflectuated through a lever 2I connected by a rod 22 to a main connecting crank .23.

A similar arrangement is provided in connection with the nozzle I4 in that a deflector 24 is mounted on a lever 26 co'nnectedto a shaft "21 and also connected by a rod 28 to the rocker crank 23. Motions of the deflector I1 and of the deflector 24 are in unison and are in corresponding amounts. Similarly, there may be additional deflectors (not shown), rods such as 29 and 3! extending to them in order to provide appropriate action of all of the deflectors at once.

The motion of the various deflectors is made responsive to the governor -9. Any excessive speed over a set or predetermined value is immediately effective upon the governor. This is accompanied by corresponding motion of the lever II inorder to produce quickly, or at a desired rapid rate, a corresponding functioning of the deflectors.

Since the force available from the governor is not sufficient to actuate the deflectors directly, 7 an intermediate or servo mechanism is employed.

This is'of standard type and involves a main servo valve 33 having a plunger 34 connected through a rocker lever 36 by rods 31 and 38 to the governor lever II. The body of the valve 33 is supplied with pressure actuating fluid, usually oil, from a suitable source (not shown) through an intake conduit 39 leading back to the source of pressure 'fluid.

As the valve core 34 is actuated in response to the governor motion, pressure fluid is admitted to or released from the valve body 33 in a corresponding fashion. When the turbine speed is excessive, the valve core 34 is in a position to admit pressure fluid from the conduit 39 into a conduit 42 having branches '43 and 44 extending into hydraulically expansible chambers 46 and 41 sometimes called expans'ible chamber motors suitably mounted andcontaining pistons 48 and 49 reciprocable therein. The pressure fluid from the conduits 43 and 44 .drives the pistons in such a direction as to move the rods 22 and 28, through intermediate links and 52, in a direction .to impel the deflectors into the jets. When the valve core 34 is in an opposite position, pressure fluid is conducted through a pipe 53 having branches 54 and 56 into the opposite end of the hydraulically expansible chambers and then displaces the pistons and ultimately the rods 22 and 28 so as to move the deflectors out of the path of the several jets.

In this fashion, action of the governor lever I I is promptly followed by a corresponding movement of the deflectors I1 and 24. The position of the governor lever II is accurately reflected by a corresponding position of the deflectors within a very few seconds time, the delay of the hydraulic servo mechanism being very slight. Consequently, upon the beginning of over speeding by the turbine, the deflectors 11 and 24 move within a short time into the driving jets and deflect them thereby depriving the impulse wheel of its propulsive water and preventing excessive over-speeding and damage.

While it might sometimes be entirely satisfactory to control the jets solely by means of deflector plates IT and 24, such action is wasteful of water and does not provide-an eflicient intermediate range of operation. For those reasons, among others, I provide each of the nozzles I3 and I4 with suitable controlling instrumentalities eifective to vary the size or diameter of the respective jets from time to time so that 'the jets are operated at optimum characteristics for as long as possible, and so that by controlling the jets the deflector plates are called upon to operate only .in emergencies and during short periods of time.

Within the nozzle I3 there is provided a needle 6| movable axially in unison with a stem 62 in order to control the size of jet issuing from the nozzle. Since the movement of the needle requires considerable force it is done through the medium of a servo mechanism including an expansible chamber 63 sometimes called expansible chamber motor mounted on a connector 64 secured to the housing I6 and including a piston 66 translatable toward either end of the cylinder 63 to produce a corresponding motion of the needle.

and at times, and at rates so as to produce the desired motion of the needles SI and 67. Preferably each of the needles and its servo mechanism is arranged so that while it may be operated in unison with the others, it is also individually operable. The operating fluid ispreferably derived from the same source as that supplying the conduit 39. For that reason the conduit is provided with a branch I3 leading to a controller I4 for the needle BI and also with a branch 16 leading to a controller I! for the needle 61. ,Return lines 18 and I9 connect to the return conduit 4 I.

Since the controllers I4 and 11 are identical, a description of one of them applies equally to the other. The controller is responsive to an associated one of the deflectors, for example, the deflector 24. Projecting from and fastened to the shaft 21 is a lever SI joined by means of a compound rod 82 to an actuating lever 83. This is secured to a cross shaft 84 journaled in the casing 86 of the controller 11. Within the cas ing, :a cam 81 (Figure 4) is fastened on the shaft 84. Following the cam 91 is a roller 88 journaled on a compound lever 89, enlarged to provide an eccentric strap 9| encompassing an eccentric 92 fastened on a cross shaft 93 likewise journaled in the casing 86.

In order that the follower roller 88 will at all times abut the cam 81, a coil spring 94 is disposed within the casing and at its upper end is engaged with a pin 96 projecting from the compound lever 89 and at its lower end encircles a pin 91 fastened in the casing. The spring is effective to maintain the roller in contact with the cam even over a relatively abrupt portion "98 of'the cam face. The movement of the follower -88 over the cam face produces a corresponding motion of the com-.

pound lever 89 and is simultaneously effective to move a pivot pin 99 fast in the lever and engagingalink IOI.

Pivot pins I02 and I03 connect a cross lever I04 to the link IN and to a valve shuttle I05 respectively. Since the cross lever I04 serves primarily as a floating link, and is normally held in a neutral position, it is extended to a movable connection to a normally unstressed coil sprin I06. At its lower end the spring is threaded into a cap I01 mounted in the casing 86 and at its upper end is threaded onto a sleeve I08 secured firmly to a plunger I09 connected by a pivot pin I I I to the cross lever I04. With this mechanism, when the spring I06 is in its neutral position, motion of the link IOI is transmitted with substantially no change to the valve shuttle I05.

The valve shuttle is reciprocable within a port sleeve I I2 removably secured in a bore I I3 in the casing 86 by a fastening stud II4. Leading into the valve structure from the supply conduit 16 is an entrance passageway I I6 (Figure 6) formed in the casing 86 and opening into a peripheral groove II1 turned in the sleeve H2 and itself communicating through apertures II8 with a chamber H9 defined between two lands I2I and I22 on the valve shuttle I05. When the valve shuttle I05 is translated into an upper position, for example, it establishes communication then with a plurality of ports I23 leading into an annulus I24, in turn communicating with a conduit I26. This leads to one end of the ,expansible chamber II and consequently subjects the piston 69 therein to fluid under pressure from the supply line 16.

Since there must also be a corresponding connection at the other end of the expansible chamber to a drain line, a return conduit I21 simultaneously communicates through an annulus I28 and associated ports with :a chamber I20 defined between lands HI and I22 on the valve shuttle. Flow is therefore established in this position of the valve shuttle I05 through radial ports I32 and an annular groove I33 to a metering port I34. This port extends into a channel I36 formed in the casing 86 and opening at its top and bottom into the interior of the casing.

The rate of flow through the aperture I34 and consequently the rate at which the piston 69 can be displaced within the cylinder H is regulated by a variable screw I31 threadedly engaging the casing 86 and provided with a lock nut I38 and a cap nut I39 to secure it in any selected position. By appropriately setting the screw I31 the maximum rate of opening of the needle nozzle 61 is established at a value to preclude any deleterious pressures or shocks due to too rapid closure of the water outlet. Oil or hydraulic fluid from the cavity I36 finds ready access to the body or fluid within the casing 86 either by overflowing the top of the cavity or by flowing through a discharge passage I4I between the bottom of the casing 86 and a closure plate I42 forming the base thereof.

In an entirely comparable fashion, if the shuttle I05 is displaced downwardly rather than upwardly, pressure fluid is admitted to the conduit I21 rather than to the conduit I26 and return fluid then flows from the conduit I26 and through the apertures I23 into a chamber I43 defined by the land I2l and by the enlarged stem I44 of the valve shuttle I 05. From the chamber I43 flow is through apertures I46 and a peripheral groove I41 to a control orifice I48. This is regulated by a screw valve I49 threaded into the casing 86 and provided with a lock-nut I5I. and

a cap nut I52. The speed of operation of the hydraulic mechanism in the closing direction can be regulated to a rate preclusive of excessive forces. By appropriately regulating the screws I31 and I49 with respect to each other, and with respect to any absolute rates dictated by engineering requirements, it is possible to confine the needle nozzle 61 to motions that are satisfactory.

In the event that the supply of hydraulic fluid under pressure through the line 16 should. fail, or in the event during starting that there is no supply of hydraulic fluid under pressure, I provide an auxiliary means for furnishing pressure fluid. Built into the casing 86 is a pump barrel I53 in which a pump plunger I54 is reciprocable. ,The plunger is situated at the lower end of a stem I56 projecting out of. the casing 86 through a packing I51. The stem is joined to a hand lever.

I58 by a pivot I59. A mounting link I6I is connected by a pivot I62 to the lever I58 and by a pivot I63 to the cover I64 of the casing 86.

Hydraulic fluid. is supplied to the pump barrel I53 from the interior of the casing 86 through the passageway I4I. This afiords access to an inlet check valve I66 contained within a removable cage I61 having inlet apertures I68 therein and affording egress through a perforated spacer plate I69 and the lower end of an outlet check valve housing Hi to a passage I12 opening into the barrel I53. An outlet check valve I13 is disposed in the cage HI and is confined by an outlet plate I14 having perforations I16 opening into a chamber I11 which is in common with the passageway H6. The chamber is closed by a plug I19 threaded into it extendedto provide a positioning stem I82 for holding the check valves in assembled relationship.

With this structure when a supply of oil through the duct H6 is not available or is not under pressure, manipulation of the lever I 58 draws oil from the interior of the casing 86, passes it through the pump bore I53 and sends it into the same channel II6 that is normally utilized for supply so that the valve shuttle I05 functions in the previously described fashion. The conduit 16 is either closed or is provided with an appropriate check valve in order that the hand.

pumped fluid will flow only into the valve sleeve With the described structure, under pressure supplied either by hand or automatically, the position of the deflector 24 and of the shaft 84 is reflected by a corresponding position of the needle nozzle 61. This is accomplished through the servo mechanism comprised of the valve shuttle I05 and the expansible chamber 1I. When the deflector 24 moves into or toward the jet under the influence of the governor there is shortly thereafter a closing movement of the needle nozzle 61. The diameter of the jet is thus reduced away from the deflector so that water will no longer be diverted by the deflector. When conditions change, the deflector is then moved either farther into the jet or farther away from the jet. 'Shortly thereafter there is a motion of the needle nozzle either further to reduce the size oi the jet or in the opposite sense to increase the size of the jet in a corresponding amount. In this fashion the needle nozzle and the deflector are always operated in correct relationship with each other; the deflector quickly following the governor for accurate control, the needle nozzle slow- I 1y following the deflector to avoid damage.

Under normal operating conditions these motions' of'the. deflector and needle nozzle arerela-- tively'small and really-are minor corrections. In emergency there: is sudden removal of load from the? mechanism towhich the turbine wheel 9: is connected. ilt i'sessential thatthe'suppl'y of drivin'grfiuid to the turbine be quickly and completely interrupted. The governor 9 is-immediatelyaf'- fected and moves the various deflectors into thepaths of their respective streams despite needle position. This is provided for in the present structureby: arranging on the-cam 81 in addition tzr thecam=track 98 afurther cam track I83;

Under normal conditions; if the needle nozzle reduces the. size of the jet in close conformity with the movement. of the deflector into:t-he jet', the deflector needmove only'to the1axialcenter ofrthe jet: inorder to intercept/it completely as at thatlpointthe needlehas closed. If however, the deflector is calledupon suddenly: to intercept the entirejet' before movement'- of the needle occurs; it is'necessarythen for the deflector to traverse not only the radius of the jet'but rather its complete diameter. It-is-for that reason the cam 81 is providedwith-an overtravel face I83: not eifective to produce any particular-movementof. theneedle nozzle-but to permit overtravelof: the de-- flector: entirely'througli the unreduced jet.-

Under customar-y' operating conditions the servo m'echanism for moving the needle nozzle-tot follow: the deflector: thatin turn follows the governor: responsive to the turbine speed tends to makeinnumerable minor corrections in the: needle nozzle: position and also tends to hunt; thattis; to correct-excessively foreach variation and continually to oscillate on eitherside; of the desired mean i or intermediate-position:

In orderto preclude excessive hunting and in order to make the movable elementscorrespond quite closely to the demandsupon them, I provide means responsive to the actual movement of the" needle nozzle for assisting in: regulating it. The needle nozzle stem 68 is provided with aconnectcr I84 responsive to' its movement and; pivotallyconnected to alever I'35 f'ast on the'cross' shaft- 931 Eachmovement ofthe needle nozzle istherefore reflected by a motionof the cross shaft 93 and arotation of the eccentrie 92: to

produce a corresponding movement of 'the com:- pound lever 89& Since the" cam follower 88 is; held against the cam 81 by the spring 94 any mo"-- tion: of" the eccentric: 92' is immediately reflected in a corresponding-movement of theink llll an'd of the valve shuttle I 05.

In order to augment'this valve shuttle motion and the effects produced by it through-its'con'--- nect'edservo'mechanism I provid'e on theshaft- 93' in addition to the eccentric 92" a lever I86 having a plurality-of fastening holes I81 therein.

l'n' engagement withanyselected one of the-holes isa-pivot pin I88'-connectin'g the-lever I86-to a-- link= I89 depending within thecasing BBi- A pin I90 connects the link I89 to a plunger I92 re ciprocable within a bore I93 extending fromthe general interior'of the casing to a restricted-com-- partm'ent I94 defined between the lowerportion ofthe casing'andthe bottom plate I42 The: compartment I 94 is generally closed Without access: to the remainder oil the interiorof. the. casing except:through ani:aperture I 96. Flow through the: aperture is: regulated in. rate. or

amount by a needle: I91: extending. throughthe casing from ascrew. mounting; I98:threadedlyfene gagingthe. cover: I 64. The: adjustable needle I 9.7

is lockedirr any adjusted position by a,% 1001 nuti I99; and: cap" nuti 21H; 'Thesize of. the. aperture I 96 is regulated by theneedle so that the rate of flow out of thecompartment Hi l is less than that at which flow into the compartment'is' induced by the depression of theplunger I921 Consequently the pressure within the compartment instantaneously increases with motion of the plunger and is then effective to displace a follower' 202'. This is a piston-like body' movable within a. suitable bore within the casing andsubject on one side to pressure' within the compartment" I94 and on the other side topressure-with in the-interior of the-casing.

The plunger 2021s connected: by a pm 203 to the lower end of the member I09 so-that-moti'on of the plunger 202 is ultimately communicated through the:cross lever I04 to the valve shuttle I052 Themotion of the plunger 202' is limited after itsinitial stroke since a channel 204 out in the plunger admits of free communication betweenthecompartm'ent I94 and the: interior of the casing.

Com'parabl'y, the plunger 2B2 travels in areversedirection from central position in response to: alowered pressure within the compartment I94? due to lifting of the plunger I92 and them-- ability oi adequate liquid to now back quickly throughtheaperture I96. After the plunger has traveled more than afixed amount from central positionfur-ther movement is arrested as a groove 2062out: initheiplunger affords freeac'cess between the; casing interior. and the compartment 1 I 94.

With. this? mechanism: and thespring' N36 to urge the. plunger. 202': into an intermediate or neutraliposition; and" since over a period of time the pressure Within the compartment I94-andthe:

interior'of the casing can. readily equalize, the lever. I04 is.- normally held simply as anintermediary between the-link I0-I and the shuttle I05. The motionoffth'e shuttle I05thencorresponds almost exactly to the motion of thelink I01; Since: themotionof the needle nozzle producesnot: only a rotation. of the eccentric 92 to displacerthe valve shuttle I 05-butlikewise through displacement-of the plunger I92 produces acorresponding motionof the plunger 202 themember l09=andthespring I06 are'forced out of neu-- tral position so that the lever I04 augments theeffect of the link I 0|; The result is that: the

valve: shuttle: I 05' is; lifted; more than norma'llyit would-be. This produces a reduced or: slovvie'raction of: theservo mechanism and reduces thetendency of=the nozzle needle to overtravel. Correspondingly; when the: valve" shuttle I 05 is depressed. the: plunger I 92" is simultaneously lifted} arelated' depression of theplunger 202 results and a corresponding overtravel' in the reverse direction of the valve shuttle I05 isprcduced; Be'- cause of theaugmented movement of the valve shuttle, hunting: is minimized and the needle-6'! tends to-follow quite accurately the'movement'sof the deflector.

In.some instanceathe neutralizing or central,- iz ng plunger 202 operated" in conjunction with thespring I06 is not sufficiently sensitive or accurate inithat frictional restraintupon the piston 2021 causes-somedelayor lag in thecentrali zation of-the spring- I06; to havethe cross; lever I 04 always in a central' position. whenit is-not being; actuated. For that" reason thestructure-shownin Figure 8 is sometimes utilized in place'of that show-n'in' Figure 4a In-this instance a piston'29l is'secured by the pivot pin- 203 to. the lower'end of I 09 and. is; confined in neutral position between a pair: of apertured wasliers 2-3'2" and 233. Both It is believed important the member washers are normally urged by a pair of-coil one 234 not only abuts the washer232 but likewise is in contact with the cap I01. The other spring 236 abuts the bottom cover plate I42 of the housing. With this arrangement, thepiston 23! is always held in a central position despite minor variations in friction and inaccuracies in the

springs

234 and 236. Motion of the member I09 in either direction always produces a corresponding deflection of one of the two springs. Inthis fashion the floating lever I M is always retained in the same neutral position except when due to the operation of the plunger I92 it is displaced either upwardly or downwardly.

By an appropriate adjustment of the mechanism, whenever a movement of the deflector toward the jet is initiated, the needle nozzle then follows promptly thereafter insuch a carefully regulated amount that the size of the issuing jet is correspondingly reduced. As the deflector moves slowly toward the jet to intercept it, the jet itself is contractedor is reduced in size so that the deflector never actually enters the water stream.

For all normal regulation therefore, while the deflector is slightly spaced from the jet in an instantaneous position to move immediately into the jet under the influence of the governor in emergency, still the needle nozzle is effective to reduce the jet just in advance of leisurely entry thereinto by the deflector. No water whatsoever is ever, deflected or wasted except due to a sudden loss of turbine load or a failure of the mechanism otherwise. In that dangerous instance the deflector does actually intercept the hydraulic jet partially or entirely. This mechanism provides an entirely automatic and accurate non-hunting control for regulating an individual. nozzle needle in a multiple jet turbine even though the deflectors are operated simultaneously by the governor.

As an operating and testing convenience, as shown particularly in Figure 2, the shaft 93 is extended to the outside of the casing 86 andcarries an indicator wheel 2 located with respect to a pointer 2 I2 so that the instantaneous position of the respective nozzle needle can readily be observed.

In the event that the automatic mechanism is not to be utilized, or in the event a manually controlled position of a. nozzle needle is to be established a suitable mechanism is provided. The shaft 84 is extended from the casing 86 and on its projecting portion is provided with a hand lever 2 I3. An indicator needle 2I4 cooperating with a scale 2I6 on the casing 86 affords an indication of the position of the lever 2I3 and remotely of the needle 61. A pierced sector 2H extends from the lever and is clamped in position if desired, by a lever nut 2I8. After manipulation to set the shaft 84, the lever 2|3 can be locked in position by rotation of the nut 2I8. Normally, however, the nut 2; is entirely free so that the lever 2I3 and the indicator 2l4 move back and forth during automatic operation of the structure and afford an indication of the motion of the deflector mechanism.

The manual operation or locking of the lever 2 I 3 may involve a motion or position not participated in by the deflector 24 in that rotation of the shaft 84 not only revolves the cam 81 to secure a corresponding action of the nozzle needle through the servo mechanism but is also productive normally of a corresponding mechanical motion of the deflector. But the deflector servo structure may not be correspondingly energized by the governor. To permit motion of the lever 23 without corresponding motion of the deflector and vice versa, but in order that the deflector movement normally when the lever 2I3 is free is as previously described, the connecting rod 82 is not continuous. Rather it is provided with a pair of pro-compressed springs 22I and 222 respectively. These are situated within a housing 223 incorporated in one portion of the rod 82. Both of them abut a disk 224 integral with the other portion of the rod 82. In its intermediate position, the disk 224 is in approximate registry with an inturned flange 226 in the casing 223 and is also abutted by a pair of washers 221 and 228, respectively.

When the lever 2 I3 is free, motion of the lever BI produces a corresponding movement of the housing 223 and due to the rare-compressed springs 22I and 222 the washers are held against the piston 224 andthe rod 82 moves as a unit. But if the lever 8| is held stationary for example, as the lever M3 is rocked, then one or the other of the springs 22I and 222 is compressed while the other one is effective merely to hold its respective washer against the inturned flange 226 In this fashion, while the rod 82 normally acts as a solid connector, it is yieldable under the motion of the lever 2l3 when the deflector 24 is not correspondingly moved.

The foregoing structure provides in a multijet turbinemeans for simultaneously regulating deflectors in each of the jets in response to the governor not only to provide an intercepting control of the structure especially in emergencies when the impulse fluid must be immediately interrupted, but also to provide a supervisory structure capable of following accurately and without excessive hunting the requirements of the governor so that the size of the jets is economically controlled. Preferably the control is so precise that the deflectors never actually intercept the jets except in emergencies. Furthermore, by the provision of individual controls it is possible not only for the individualneedles to follow the particular requirements and idiosyn crasies of the particular nozzles with which they are associated but likewise for an individual needle to be manually closed and held. closed; For example, if conditions of operation make it advisable, two of the four jetsof the turbine illustrated can readily be cut out of operation completely. Indicators at each particular controlling mechanismshow the position of the nozzle needle and of the deflector associated therewith. The individual controllers are mounted quite close to the servo mechanisms they supervise in order that miscellaneous rods, links, and levers which otherwise would be necessary can be entirely dispensed with. Thus, a gen erally improved control mechanism for turbines has been provided.

I claim:

1. A jet controller for an impulse wheel having a nozzle and needle for establishing a jet for the wheel, an operating expansible chamber motor connected to said needle for moving the same to vary the jet diameter, a deflector, means for supporting the deflector adjacent to the jet for diverting the same when moved into the jet, a servo mechanism connected to said deflector to directly move the same, an operating fluid sup- My line .connected to the servo mechanism, a speedresponsive governor :driven ,by said-wheel, .a .valve in said line for controlling operating fluid .for said deflector servo mechanism, means con- .necting said valve to said governorso that the governor directly controls said servo mechanism to :move the deflector toward the jet \when the speedrof the impulse wheel exceedsa predetermined value, a second operatingfluid sup ly line connected to said needle operating motor, :a second valve in said Vlattersupply line for control- :ling operating fluid-for said needle operating mo- 1101331013085 lever connected to said second valve, a compound lever connected to said cross lever to move the cross lever-and valve attached thereto, means connected :to said deflector for moving said compound lever upon occurrence of movement :of the deflectortoward thegjet and thereby move the cross lever and second valve connected thereto for effecting movement of the needle valve toward its closing position, means operatively connected to the needle tor moving :said cross lever in'a direction'opposite to that which was effected by the deflector movement thereby to :produce a restoring action on the second valve through its connection to the cross lever, and means connected to the needle and to thecross lever for-additionally moving aid cross lever and the second valve connected thereto in said restoring direction in accordance with movement of the needle valve towards its closing position only when the rate of needle movement 'eEXCBBdS a predetermined value.

The combination set iorthin claim 1 gftu'ther characterizedin that the means forfrurther moving the cross lever for producing the additional restoring action on the second valve includes ,a hydraulic compartment, means for displacing fluid therefrom upon movement of the needle toward its :closing position, and meansres-ponsive to the displaced fluid in said compartment :ior moving said cross lever in its restoring direction.

3. The-combinationset forthinclaim -1-further characterized .in that the means for further moving the cross lever .in its opposite :direction for producing the additional restoring action includes ahydraulic compartment, means fordisplacing fluid therefrom upon movement of the needle toward its closing position, means responsive to the displaced fluid in said compartment for moving said cross lever in its restoring direction, and an escape port for said compartment whereby displaced fluid will flow through said escape port to the limit of :its capacity and any greater rate of displaced fluid will then effectaotuation :of said means which is responsive to displaced fluid inthe compartment.

supporting the deflector adjacent to the ,jetjor diverting the same when moved into the jet, a servo mechanism connected to said deflector to directly move the same, an operating nuidsup- ,ply line connected to said servo mechanism, a. speed responsive governor driven by said wheel,

.a valve in saidline for'controlling operating fluid for said deflector servo mechanism, means connecting said valve to .said governor so that the governor directly controls said servo mechanism to move the deflector toward the jet when the speed :of the impulse wheel exceeds .a ,predetermined value, a second operating fluidsupply line connected to said needle operating motor, ascoond valvein said latter supply :line for controllingoperating fluid for-said needle operatingmotor, means connected to said deflector and second valve for moving the second valve to operate said needle .expansible motor in a needle closing-direction upon occurrence of movement of the deflector toward the jet; means connected to the needle and to said second valve for moving the .second valve, upon occurrence of closing movement of the needle, .in :a direction opposite to that which was eflEected-by the deflector movement thereby producing a restoring actionon the second valve; means connected to said needle and to said second valve for additionally moving said second valve in a restoring direction .upon occurrence of closing movement of the needle, and means for rendering said additional restoring movement effective automatically in response to needle movementonly when the rateof movement of the needle exceeds a predetermined value.

FRED H. RUED.

References Cited in the file of this patent UNITED STATES PATENTS