US1990872A

US1990872A - Prime mover

Info

Publication number: US1990872A
Application number: US680317A
Authority: US
Inventors: Benjamin B Lacy
Original assignee: HENRY E ELROD
Current assignee: HENRY E ELROD
Priority date: 1933-07-13
Filing date: 1933-07-13
Publication date: 1935-02-12
Anticipated expiration: 1952-02-12

Description

4P91912, 1935. B, B, LACYv 1,990,872

PRIME MVER Filed July 15, 1933 3 Sheets-Sheet 1 l 31a/tunic@ @trouvez/2 Feb. 12, 1935. B. B. LACY 1,990,872

PRIME MOVER Filed July 15, 1933 5 Sheets-Sheet 2 Feb. 12, 1935. B, B, LACY 1,990,872

PRIME MOVER Filed July 13, 1933 3 Sheets-Sheet 3 gmnto Patented Feb. 12, V1935 i unir;151e.: .starr-:s

PRIME MOVER Benjamin-B. '.Lacy, -Houston,l Tex., assigner of one-halflto Henry E. Elrod, Houston, Tex.

Y ApplicationlJlily 13, 1933,.Seria1 No. 680,31-'2I l 21 Claims. (C1.253-52) i This invention relates toimprovements in turf bines and especially to a ytype .of vturbine which is frequently combined with a generator to .form a turbo-generator unit. Y

5 It isone object-of this invention .to desgn'the operative elements of afsteamfturbine so'thata most efficient operation mayrbeiobtained thereby.

It is a further object of Vthe invention to simplify the fmaintenance required by a. turbine unit. The adjustment as Well as the removabilityV of severakelementsin the turbine Vunit may be conveniently made,:according to ,the instant invention; .Without :dismantling fother `elements of the unit. Y

Itis a further object of th'e,inventionto so im.- prove the design of lthefngovernor element which is associated Withturbines of the l,type according to the instant invention .thatia 'sticking thereof is .ipreventezL anda frequent ,cleaningthereof, necessitated bympuritiesin the water forming the actuating. iiuid, is obViated.

Other objectsiand purposeswill'appear from a moreedetailed description ofthe invention .taken in conjunction with the accompanying drawings, wherein;

1 is va sectional View of s the.v turbine Vunit with certain .parts iny elevation,"

Fig. 2 is a rightend View. of Fig.- 1, and.

Fig. 3 is'aileft `end view thereof.

'In-Eig 1,.the turbine casing, generally designated as .lis;integral`witha `Wall2'onto which is .attached Vthe electric generator unit '70A (Fig. 3) .the 'outputof Whchis utilizedffor the energization of locomotive 'headlights or .other energy consuming elements. The 'shaft V3. `Which eX- tends along the .turbine unit 'rand vthe .electric generator ,is supportedin the 'bearingxl asv/ell asinA a bearing, not shown, at the remote end ofv thev electricgenerator-m, having Ventilating blades 5. The vturbine wheel, composed of a frame 8,:and. a series of'blades or buckets 9, is rigidly'nxed toshaftpandkis suitably designed for rotation ina bearing bush 7 Axedto theend Wall of the turbine :casing 1. The turbine :casing is completed. bya turbinehead: or cover `lflvvhich is detachablyziixed to'thegcasing .1 .bymeans of several bolts 60.V

The turbine wheel 8 is rotated by vmeans ofA a stream of an actuating lluid such as. stearn-issuing `'from the vnozzle v11` (Fig. 2) against the blades 9. To moreefficiently.utiliaeall theavailable energy, a guiding element `il-having channels` 42 therein is. fixed bylmeansvof'bolts 43 ;to the: casing ,1. These channels .redirect Qthe. steam ai exhausted '.f'rom. `.the wheel atrone pont t9 ith@ Wheel at Aanother point, before the final passage of the steamfromjthe ,exhaust chamber .through outlet 14. The nozzle 11 is removably xed in a valve unit 12; which is bodily detachable from the `turbine `casing by .the removal .ofV four bolts l5 (Fig.i3). A pipe 13 is connected ,toltheiinlet socketbfythe valve ,unit .for supplying rsteam to the steam chestfl'gand from there throughthe valveto .the nozzle. Thevalve unit-12 is formed With Ya chamber 16y in fthe. interior thereof in which is fitted aslidable shell 117. The latterhas a .shoulder 18 which is. maintained pressed against ka corresponding slopeonthe. inside of Valveunit'lZ by. means of a spring 31 in a recessed nut 30: operating. against ra seat v29A connectedwith the shell 17. .TheV spring may :be-removed independently of J the unit `by the withdrawaliof the recessednut' 30; The lcomplete 'valve assembly embodied in the. shell '-17 may then be .withdrawn from the jacket of the valve unit 12for cleaning or replacement Withoutremovingthe steamfpipe 13. An annular recess 19 on theinside of :the valve .unit 12 isin alignment with. apertures-21- in the hollow vportionof shell 17, which in turn are in communication Withrthe steam chamber 16 by means of apertures `22 in the shell. -Aplunger V20 at the end ofrstem 27 is operative in the bore of shell land hasenlarged portions 24, 24f cooperating with a constrictedportion-I 23in` the bore ofshell 1'7fto variably control the amount of steam passing from the chamber 16 to"A the ari-'- nularV recess 19 Which communicates With vrthe nozzle 111:. The steam'passage .in the interior` of shell 17 is normally maintainedopen to a predetermined amount by the 'tension of spring 27, iixedly seated atrone end to the shell 17, against the head 28, connected to the plunger stem`26'. Upon an increase in the speed-of rotationo'f the turbine wheel, the governor mechanism described hereinafter operates theplunger 20 through the control lever 36 with Aits adjusting screwV k33 against the tension ofv spring 277 to throttle the passage of steam to the nozzle 1:1. `Should 'this plunger `become inoperative for any reason, the lever 36acts upon the shell 1-7 through the intermediary of spring 27 to causefa shifting of the shellagainst the forcer eXertedl'by 'spring 31 to carry the apertures 21 in the shell out of alignment with the recess 19 in the valve unit to cause` a throttling of the steam tothe point where the' rotation of the` turbine wheelis Within the desired limit.

eArsiNr @FP1-ce A In order tto. vary the effect ofwthe governor mechanism upon the valve, the Yadjusting 'screw 33 mayfberotated bythe removal oicap' 35 from the turbine head 10 even while the machine is running. This is'possible because the end of the valve unit is disposed in an auxiliary casing which is separate from the exhaust steam chamber. The adjustment is set permanently in the split end of lever 36 by a tightening of screw 34.

vT'he improvementV in machines of this type is readily apparent by an examination of Figs. 1 and 3 wherein Vthe-simple detachability of the valve unit 12 together with the nozzle 11V is illustrated. Thereby defective parts may be easily replaced and nozzles may be interchanged without difficulty. Furthermore, because of the easy detachability of Vthe valve unit or of the valve-assembly only, Without requiring .the dismantling of any other part of the machine, the cleaning thereof is rendered very simple. 1

In order to exercise control upon the valve supplying steam to the nozzle, a governor mechanism is mounted upon shaft 3 and exercises theY desired control upon the valve in accordance with the speed of the shaft. In Fig-1 the governor' mechanism includes a plurality of angu- .larly shaped Weights 44, which are pivoted at 44h-in bearings 78 xed to the wheel, and which are Ycapable of assumingidifferent positions in accordance with the centrifugal force exerted thereby inthe course of rotation of the YWheel 8 and the shaft 3. ."I'he short arms 44ay of the Vweights 44.0perate against a sleeve 45 shiftable on shaft 3. The'force exerted by the centrifugal action of the 'weights 44 is imposed upon sleeve 45 against the tension of av spring 46 surrounding the, sleeve.- vThe effect of spring 46'may be adjusted by the shifting ofthe collar 62 against which one end-of the spring is seated. y'Ihis adjustment maybe made by rotating nut'68 into the end 50 of the housing described below. The end of sleeve 45 is tted as a thrustbearing 48 exerting a pressure against the extremity 49 of lever 38-Which is viixedly attached at its other end to a shaft 37 journalled` in the turbine head 10. An increase in speed of shaft 3 eifects an axial displacement of 'sleeve 45 by means .of the weights 44 acting thereon. Thethrust exercised by the'sleeve 45 is in turnrimparted to lever 38, shaft- 37, andlever 36 which, as explained above, causes a throttling of the steam by the valve unit, whichY in turn exercisesfits effect to decrease,r the speed of thewheel luntil a desired condition of equilibrium is're'ached. L A

Heretofore, the impurities in the water in some localities, and consequently in; the generated steam, caused sticking and` faulty operation of the governor elements.- To overcome these defects, a cleaning of the governor'wasfrequently necessary, representing a great Vexpense and loss in time.V According to the invention, an auxiliary protective housing 50 surrounds the operativey parts of the governor and protects them fromv the action of the steam-in the exhaust chamber 40.V This housing or casingis detachably connected to therwheel 8 Yby means of bolts 51 and is rotatable therewith. u The housing 50 may contain arlubricatingl oil which assures a smooth functioning of the operating parts of the governor mechanism. The extension 50' of the housing, having. bearing rings therein, isrrotatable ina bearing bush k53 fixed 'onto partition 58 in the turbine head l0, operating in the manner of a stuffing' box 'forthe steam in the exhausty steam chamber 40. Beyondthe partition" 58 is formed a chamber 64, maintained at atmospheric Vpressure by means of` a port 63 therein. A dusttight compartment is formedV at the end of-the the journal bearing 53 in partition 58, it would` exhaust to the atmosphere before itcould pass into the compartment 65 and from there to Vthe operating partsV of the governor mechanism.Y

The `interposition of chamber 64, although desirable, isnotessential for the obtaining ofV the many advantages resulting from the instant invention. In order to prevent any steam leakage around the valve from affecting the governor parts, the shaftr37 passes Vthrough ak close iitting portion 87 vof the housing between the auxiliary housing 65 and the auxiliary housing 89-formed in the lid 10. A relief port 90 adjacent the rock shaft 37 prevents any leakage steam from theV valve unit from passing on to the auxiliary housing 65 with likely admittance into the governorV mechanism casing 50. i

The turbine head 10 may be removed by. means of bolts 60 to gain access to the'turbine wheel 8 and the governor housing 50'when repairs upon those elements are necessary. The complete transmission mechanism between Vthe governor and the valve is removable with the head 10. On' the other hand, when the adjustment of the governor spring 46 isV desired, the cap 54 only need be removed to gain'access tothe corresponding adjusting mechanism; f f Iii-Figs. l and`2 are shown the supporting feet 61 for the turbine casing 1, which are 'in alignment with the feet 71v (Fig.,.3) supporting' the electrical Vgenerator unit. In-.view of the fact that the instant invention is not concerned with the electrical features,1the generator iszonlyrgenerally illustrated in Fig.V 3 atv 70, having.v the brushes 72 cooperating withthe'commutator 73 in the manner well known in that art...V f

Having describedmy'invention, f

ing,` a shaft rotatably mounted in said casing, 'an

impulse wheel'mountedon ysaid shaft, a valve unit in said casing, an inlet port in said 'unit for steam, an outletV in said casing for exhaust steam, f

a nozzle communicating Awith saidfvalve vunit directing steam upon said impulse wheel, said valve unit comprising throttling means for controlling the floW-ofsteam from said inlet port to said nozzle, a 'governor mechanism mounted for rotation within said casing atone side of said impulse wheel,v transmission means f for controlling said .throttling means` intermediate said valve unit and governor mechanism, and afhousing connected to said impulse Wheel and rotatableA therewith enclosing said governor mechanism within said casing to exclude: the exhaust steam from said mechanism, said housing adapted to contain a lubricating medium for said governor w mechanism. Y v 2. In a machine of they class described, va Vcasing, a shaft rotatably mountedV in"said casing,-v an impulse wheel `iixecl to said shaft, a-fvalvel unit 'in said casing, aninlet port in said unit-for .in ssaid valve `Vunit `for 'controlling the flow "of steamffromfsaid inletap'ort to saidf-nozz'la-vreadily detachable fmeans connecting. said V4valve unit, "With 'said f assembly andfvnozzle mounted therein,

5 ito zone fend of Asaid casing, imeans adjacent vsaid ureadily detachable Ymeans ipermitting the easy `yWithdrawal vof vsaid valve Aassembly only, vafgev- Aern'or mechanism mounted lv"Within sad Leasing, --and a` transmission "system for controlling Xsaid @valve fassembly adjacent the 'end cfrthe "casing opposite the ldetachable connecting lmeans, 'beftween said valve assembly and governor lmech- 'anism. f

.3. .In-amachine oftheclass'described, a casing, la shaftirotat'ably mounted in said casing, an impulse wheel ixed to -said 4vshaft, a nozzle "for directingfsteamonto said impulse Wheel, a valve forfcontrolling the supply of :steam to said 'nozn -zle,;an.outlet in said casing for'exhaust steam, a centrifugally operated governor mechanism mounted Within said casing upon one side of vsaid Wheelg comprising a tensioned sleeveslidable cn said Ashaft and a thrust bearing at 'the 'end 'of said sleeve, a removable head `for saidca'sing adn l-ja'cent `the end of said shaft, said vhead having a partition therein'for defining `the exhaust Vsteam chamber, a journal bearing in said pa 'it-ion, a --housing `iixed to said impulse Wheel separating said governor mechanism from said exhaust ysteam'chamber vand extending through said journal bearing, ra `dust-tight compartment formed on'thexopposite side of said partition, said thrust lbearing lextending therein, and transmission means in said dust-tight compartment for con'- vtrolling said Valve, one element of said'trans- Y"mission means abutting against said thrust vbearing.

4. In a machine of the class described, ya casa shaft rotatably .mounted in said casing, an .Y

yi'unpulse Wheel fixed to -said shaft, a nozzle for directing steam onto said impulse Wheel, a valve A-for controlling the supply 'of'st'eam to said nozzle, an outlet in said casingfor exhaust steam, a centrifugally yoperated adjustable governor mech- ;anism mounted Within said casing uponone side ofsaid Wheel, comprising a tensioned sleeveslid- 4able on said shaft and a lthrust bearing at 'the end of .said sleeve, a removable head :for said l,casing/adjacent the'end of said shaft, said head rhav-ing a partition therein for dening the .ex-

haust steam chamber, a `journal'bearing in said partition, a housing fixed rto said impulse Wheel .separating said governor mechanism from said exhaust steam'chamber and extending through vsaidjournal bearing, a dustetight compartment formed on the opposite side of said partition, said thrust bearing extending therein, transmission vrrn'eansin said dust-tight compartment for controlling said valve, one element of said transmis- Ysion means abutting against said'thrust bearing, and a detachable cover on'said head for gaining accessto said dust-tight compartment to effect the adjustmentof saidvgovernor mechanism.

5; In a'machine of the class described, a casing, a shaft rotatably mounted in said casing, an `impulse wheel fixed to said shaft, a nozzle for directing steam onto said impulse Wheel, a valve for controlling the supply of steam to said nozzle, an outlet in said casing for exhaust steam, a centrifugally operated governor mechanismmounted Within said casing upon one side of said Wheel, vcomprising a tensioned sleeveslidable on said shaft anda thrust bearing at the end oi said sleeve, a removable head for said casing adjacent theuen'd ofisaidfshaft, readily `detachable means :chamber against Asaid thrust bearing, anda v'housing containing a lubricating 'medium :nxed to Asaid irn- `pulse Wheel separating said :from said steam chamber :to-,exclude from said governor mechanism vmechanism thesteam therein.

"6. In 'a machine ofthe class described,ia'cas ing, a shaft rotatablymountedinsaid'casing,an impulse Wheel fixed to said shaft, a nczzlefor directing steamionto said impulse Wheel, a valve for controlling the supply ofsteam to'said nozzle, an outlet in said casing for exhaust steam,a cenrtrifugally operated governor mechanism'mounted Within said 'casing upon'one side of said wheel comprising a tensioned sleeve slidable on-said lshaft and a thrust bearing at the end of "said sleeve, :a removablev head` for .said casing adjacent the Vend oi the shaft, .readily detachable 1- means forxing said head to 'said-casing', said head lhaving partitions thereinior partially forming the exhaust steam ychamber oij'said casing, a chamber at atmosphericv vpressure i and a ldusteV tight compartment, a'lever in said dust-tight Acompartment for controlling' said. valve pivotally mounted on said head, onek end of fsaid lever abutting againstsaid thrust Vbearing, a 'readily detachablecover on said head for'gaining access to said dust-tight compartment and sai'dfcontrol- Va centrifugally operatedlg'overnor mechanism `mounted Within said casing upon one side of said Wheel comprising a tensioned sleeve 'slid'able on the free endoi said shaft and a thrustbearing 'at the end of `said sleevega removable head for f: `said casing adjacent the end of the shaft, readily detachable Vmeanslfor fixing said head to said casing, said head havingrpartitions therein for partially forming the exhaust steam chamberof said casing, achamber at atmospheric pressure and YVa dust-tight compartment, transmission *means in said dust-tight compartment forfcon- `tr-: llin`g'said valve, one element of said transmissi'onmeans abutting against said thrust bearing, and a housing xed to saidfimpulse Wheel separating said governor mechanism romsai'd steam extending through 'said exhaust steam chamber, said chamber at atmospheric pressure, and into said dust-tight compartment.

8. In a machine of the class described, a casing, a shaft rotatably mounted in said'casing, an impulse Wheel xed to said shaft,y a'nozzle `for directing steam onto said impulse Wheel, an outlet in said casing for exhaust'steam, a'. valve/for "controlling the supply oi steam to said-nozzle", a centrifugaliy operated governer -mechanism mounted on said shaft uponone'side of said Wheel comprising a plurality or angular Weighted levers pivoted adjacent said Wheel, a sleeve, slidable on theiree end'oi said shait,-spring-mans for press# v`ing said sleevetagainst said levers and a thrust bearing at the endrof said sleeve beyond said shaft, a removable head for said casing having a portion thereof extending beyond said shaft and `Qthrust bearing, readily detachable means for xing said Yhead to said casing, saidhead havingV partitions therein fork partially forming the exhaust steam chamber of said casing, a chamber `at atmospheric pressure and a dust-tight compartment, alever insaid dust-tight compartment .for controlling saidV valve pivotally mounted on lsaid-head, one end of said lever abuttingagainst said thrust bearing-a readily detachablecover on said head for gaining access to said dust-tight `compartment and said controlling lever therein, a

housing containing a lubricating medium detach- Vably fixed to said impulse wheelseparating said Y governor mechanism fromr said steam chamber and extending through said exhaust steam chamber, said'chamber at atmospheric pressure, and into said dust-tightcompartment, and adjusting means fitted in said housing :and accessible 'in Vsaid dust-tight compartmentV upon'the removal of said cover for adjusting `the tension of the spring means Aof said governor mechanism..

9. In a `device of the class described,1a rotary unit comprising an' impeller and shaft driven 'thereb'yi means including a valve for directinga controlled flow of steam tovsaid impeller; two casings, one within the other, the outer casingbeing stationary and housingV said impeller,V the inner rcasingbeing a rotary one mounted on said rotary unit; said outer casing having a bush providing; an opening therethrough andY said inner casingY having a hollow hub extending throughv said rotary groupl of Aelements'and said transmission mechanism. Y

10. Ina device ofthe class described, a-rotary unit comprising van impeller and shaft driven thereby; meansincluding a valve for directing a controlled now. of steam to said impeller; two casings, one within theother, the outer casing being stationary and housing said impeller, the

inner casing beinga rotaryl one'mountedV on said ing defining an exhaust steamv chamber, animrotary unit; said outer casing having a bush providingvan opening therethrough and said .inner casing having 4a hollow hub extending through said bush to the outside of said outer casing; a governor mechanism comprising a rotary group of elements mounted on said rotary unit including a shiftable sleeve mounted on said shaft, and a transmission mechanism interposed between said sleeve and said valve; said rotary group of elementsbeing housed in said inner casing,l said hollow hub providing an opening toiestablish operative engagement between said rotary group of elements and said transmission mechanism.

11. A device as described in claim 9,'in combination with a housing covering said transmission mechanism, in which housing terminate said bush and said hollow hub, and means within said `housing forming a partition between said transmission mechanism and the outer yterminus of said outer casing betweensaidcontact surfaces.

l2. A device as described in claim `9,' infcombination with a housing covering said transmission mechanism, in which housing terminate said bushand said hollow hub, and meanswithinrsaid f housing forming a partition between said transmission mechanism and the outer terminus Yof the contactfsurfaces between said bush and said hub, said housing'being provided with relief ports behind said partition means to permit escape to the atmosphere of steam leaking from said outer casing between said contact Lsurfaces, said housing extending over said transmission mechanism j to its point of engagement Vwith said valve, the latter part ofsaid housing including'a portionA closely tting said y'transmission mechanism, a relief port to the atmosphere being provided in'saidhousing between said close fitting portion and said valve ,to A

prevent leakage 'steam' from fsaid valve from Vpassing said close fitting portion. z..

13. In a machine of the class described, a casing dening an exhaust steam chamber, animpulse Wheel mounted in saidrchamben'a rotaryV l shaft driven thereby, ka nozzle for directing steam onto said impulse wheel, a valve for controlling the supply of steam to said nozzle, an outlet in said-chamber for exhaust steam, a governor mechanism mounted; within said chamber; transmis'- sion means for controlling said valve extending between said valve` and governor mechanism, a portion of said means traversing "a space under atmospheric pressure, and a. housing -Within said steam chamber enclosing said governor mechanism to exclude the exhaust steam therefrom;

r11i. In a machine of the class described, a casing defining an exhaust steam chamber, an :impulse wheel mounted in said chamber, a rotaryshaft driven thereby, a nozzle fordirecting steam V,onto

said impulse wheel, a'valve for controlling the supply of steam to saidY nozzle, an outlet-in said :chamber for exhaust steam, a governor mechanism within said chamber actuated by said im- :puls'e wheel comprising a' rotary memberand an' axially shiftable member,` transmissicn'means for controlling said'valve extending between said valve and said axially shiftable member, a housing within said steam chamber enclosing said 'governor mechanism and rotatable therewith, and means for maintaining the space at the juncture of said rotary housing and axially shiftable member at atmospheric pressure. v l f 15. In a machine of the class describedja caspulse wheel mounted in said chamber, aV rotary shaft driven thereby, a nozzle for directing steam onto said impulse wheel, a` valve for controlling the'supply of steam to said nozzle, an outlet in said chamber for exhaust steam,` a centrifugally operated governor mechanism within said chamber comprising a tensioned sleeve, a housing enclosing said governormechanism and rotatable therewith having an opening outside vof said steam chamber for the end of said tensioned sleeve, said opening Vbeing maintained Y'at atmospheric pressure, and transmission means for controlling said and governor comprising a tensioned sleeve, a housing enclosing said governor mechanism and rotatable therewith having an opening outside of said steam chamber for the end of said tensioned sleeve, said opening being maintained at atmospheric pressure, a removable head for said casing for bounding a portion ci said steam chamber, an actuating sha1" t mounted in said head, an auxiliary casing formed in said head adjacent each end of said actuating shaft, a lever in one of said auxiliary casings connected to said actuating shaft and abutting against said sleeve, a second lever in the other auxiliary casing connected to another part of said actuating shaft adapted to control said valve, and a port open to the atmosphere adjacent said actuating shait between said twoauxiliary casings.

17. In a machine of the class described-a casing dening an exhaust steam chamber, an impulse wheel mounted in said chamber, a rotary shaft driven thereby, a nozzle for directing steam onto said impulse wheel, a valve for controlling the supply of steam to said nozzle, an outlet in said chamber for exhaust steam, a centriiugally operated governor mechanism within said chamber comprising an adjustably tensicned sleeve, a housing enclosing said governor mechanism and rotatable therewith having an opening outside of said steam chamber for the end of said tensioned sleeve, said opening being maintained at atmospheric pressure, a removable head for said casing for bounding a portion of said steam chamber, a rock shaft pivotally mounted in said head, an auxiliary casing formed in said head adjacent each end of said rock shaft, a lever in one of said auxiliary casings connected to said rock shaft and abutting against said sleeve, a readily detachable cover for said one auxiliary casing for rendering said tensioned sleeve readily accessible for adjustment, a second lever in the other auxiliary casing connected to another part of said rock shaft adapted to control said valve, and a port open to the atmosphere adjacent said rock shaft between said two auxiliary casings.

18. In a machine of the class described, a casing defining an exhaust steam chamber, an impulse wheel mounted in said chamber, a rotary shaft driven thereby, a nozzle for directing steam onto said impulse wheel, a valve for controlling the supply of steam to said nozzle, an outlet in said chamber for exhaust steam, a governor mechanism mounted within said chamber; a housing within said steam chamber enclosing said governor mechanism to exclude the exhaust steam therefrom, a detachable cover for said casing for bounding a portion of said steam chamber with said housing therein, and a mechanical transmission system for controlling said valve extending between said valve and governor mechanism mounted on said cover, said transmission mechanism terminating in abutting relation only Without attachment to said valve and governor mechanism, whereby the removal of said cover permits immediate access to said housing and governor mechanism.

the flow of steam from said inlet to said nozzle,

readily detachable means connecting said valve unit consisting of said jacket with the Valve assembly therein to one end of said casing, a governor mechanism within said steam chamber operable with said impulse wheel, a mechanical transmission system ior controlling said valve assembly adjacent and outside the end of the casing opposite the detachable connecting means, and

an auxiliary casing for the portion of the transmission mechanism cooperating with the valve assembly in the jacket extending beyond the steam chamber casing, an auxiliary casing for the portion of the transmission mechanism cooperating with the governor mechanism, and a cover for said steam chamber casing having said two lastmentioned casings formed therein.

20. In a machine of the class described, a casing defining a steam chamber, an impulse wheel mounted in said chamber, a rotary shaft driven thereby, a valve unit comprising an external jacket extending beyond the ends of said casing, an inlet in said jacket, a nozzle mounted in said jacket adjacent said impulse wheel, a valve assembly mounted within said jacket for controlling the flow of steam from said inlet to said nozzle, readily detachable means connecting said valve unit consisting or" said jacket with the valve assembly therein to one end of said casing, a governor mechanism within said steam chamber operable with said impulse wheel, a mechanical transmission system for controlling said valve assemblyadjacent and outside the end of the casing opposite the detachable connecting means, and an auxiliary casing for the portion of the transmission mechanism cooperating with the valve assembly in the jacket extendingbeyond the steam chamber casing, and readily detachable closure means for said auxiliary casing for permitting an adjustment of said mechanical transmission system relative to said valve.

2l. In a machine of the class described, a casing defining an exhaust steam chamber, an impulse wheel mounted in said chamber, a rotary shaft driven thereby, a valve unit mounted in said casing comprising a jacket containing a steam chest, a valve assembly and a nozzle, said valve assembly controlling the flow of steam from said steam chest to said nozzle, readilydetachable means for mounting said complete valve unit in said casing, a governor mechanism controlled by said impulse wheel and, in turn, controlling said valve assembly, and readily detachable closure means in said valve unit for conveniently withdrawing said valve assembly only.

BENJAMIN B. LACY.