US1341961A - Locomotive - Google Patents

Description

W. E. WOODARD.

Locomonvs.

. 'APPUCATION FILED FEB, 27I 1918.

3 .3 1 9 9 1 o @atentedl June 1, 1920.

Z SHEETSSHEET l.

WITNESSES A TTORNEYS W. E. WOODARD;

LOCOMOTIVE.

APPLICATION FILED FEB. 27. 191B.

Patented June 1, 1920.

2 SHEET SSHEET 2.

A TTOR/VEYS WESSES v I a simple locomotive.

TES

UNITED sr WILLIAM E. WOODARD, or LIMA, oriro.

LOCOMOTIVE.

To all whom it may concern:

Be it known that I, WILLIAM Woon- ARD, a citizen of the United States, residing at Lima, in the county of Allen and State of Ohio, have invented certain new and useful Improvements in Locomotives, of which the following is a specification. I

This invention relates to improvements in locomotives, the purpose being the, 'ob taining of a locomotive engine which will be capable of exerting a relatively high tractive power at low speeds. The invention will be best understood by .a statement of the problem presented in' securing this result and the methods by which it has been heretofore attempted to accomplish the same. One of the operating conditions which confronts railway men is to secure suflicient power in locomotives, particularly in freight train movement, not only to move the train over the main line tracks at proper operating speeds, but also to promptly and quickly move heavy trains out of terminals, at sidings, and .over controlling grades. Attempts have been made to.'meet this condition in several different ways,'one of which is the use .of a Mallet type of locomotive as} The Mallet locomotive is a compound engine, but .it has the capacity of being operated as a simple locomotive, up to speeds of from 6 to 8 miles per hour. Such use of a Mallet locomotive, however,- is open to the objection that the operation of the low pressure cylinders as simple engines (by which means the Mallet engine accomplishes the desired result) severely racks the mechanism of such engine and-also quickly drains the-boiler out of steam'; that is to say, as thus operated, the-engine is over-cylindered, the capacity of the-cylin .der's being far 'in excess of *the boiler capacity, on which account, such operation of a Mallet locomotive is" limited to .speeds'of from 6 to Smiles 'per hour, after which the engine must be operated asa compound 10;

der dimensions to o crate both as a'c'ompound and as a simp e engine. D

Another means by whichthe desired-fife sult has been sought is in the use of auxiliary engines under the locomotive tender, such auxiliary engine being connected by fiexible It is further to Specification of Letters Patent. Patented June 1, 1920, Application filed February 27, 1918. a Serial No. 219,350.

steam-pipe connections to the locomotive.

When it is desired to utilize the extra power the\ tender. Moreover, such engines .are I 0 en to the same objection as operating allet locomotives as simple engines, in that the use of the auxiliary engine quickly drains the boiler out of steam. In addition, such engines when not in operation, impose an extra load upon the engine thereby reducingthe eifective'draw. bar pull back of the tender.

be noted that the solution of theZ-difliculty cannot be found in' sim ply extending and enlarging the conventional designs of locomotives into a larger and more powerful machine, as such a rocedure does not meet the requirements 0 the case which are .to produce a locomotive coming inside of normal wheel loads and in which the boiler size .shall be kept within practical limits andshall be capable of ordinary hand firing. Furthermore, the fact that the end cannot be obtained by merely increasing the size andpower of ordinary locomotiyes will be clear from the following: In a standard'locomotive design thereis a wellrecognized relation between the size of the cylinder, the boiler pressureand the horsepower output of whlch the engine cylindersarecapable. This relation is well defined in the locomotive art so that .itZmay be taken that the maximum cylinder horse-' 'powerioutpuefor a given gcylinder size is a well-established-figure The boiler of the locomotives is" proportioned so'that it will supply at its maximum output a quantity i of steam suflicient'to meet the demands of a the maximum cylin er horse-power require- 4 ments} However, the maximum cylinder "h-ors'epower output is notifreache'd until" a pistons'peed of; about" 1000' i200 feet er minuteis reached whichcorresponds witii .a

speed inmilesi perhour of about-35 to 45 for;

an ordinary freight locomotive. From .this, is evident-that, while the boilerihorse powerisfavaila'ble' for-steam capacity atany and all speeds, the full capacity of the boiler tive which will-utilize the full boiler ca-- pacity'at lower speeds, which means that there will be that much higher ,tractive power available at the corresponding lower speeds. This maybe illustrated by way of comparison with a simple two cylinder locomotive with four. pairs ofdriving wheels and having a maximumboiler capacity of about 2200 horse-power. Such an engine will develop at 35 miles per hour a cyllnder horse-power of about 2200, orattha't point,

the cylinder horse-power requirements will take the full boiler capacity.

hour will exert a maximum tractive power of only about 50,000 pounds and a cylinder horse-power of about 1300. By my improvement, at milesper hour, the cylinders will reach approximately the same cylinder horse-power as the two cylinder engine; namely, 2200, which will, of course, give the same tractive power;'but' atp 10.m1les per hour, the improved engine will develop a cylinder horsepower-of 1950 with a corresponding tractivepower of about 72,000.

Y Inbrief,-I accomplish the desired ends by providing a locomotive of any predeterminedboiler capacity with two or more grou s or sets of simplecylinders, the combme normal maximum horse-power output of which is greater than the capacity of the boiler. These groups of cylinders are coupled in any preferred manner to the driving wheels, and they are worked at respective full horse-power effort, up to speeds at which their combined horse-power efi'ort develops to a point approximately equal to the boiler capacity. hereafter, as the speed increases, I provide means for cutting down or reducin cylinders which otherwise would increase with the speed and thereby exceed the boiler capacity.) and maintain the horse-power effort within the capacity of the boiler, as will hereinafter be pointed out.

In the accompanying drawings, I have illustrated insomewhat diagrammatic form one embodiment or means for accomplishing the desired result.

Ofthe drawings,-Figure 1 is'a side elevation of a locomotive embodying my improve- ""ments; Fig. 2 is a diagrammaticplan view of a standard form of power means for op- '-erat'ing the valve motions adapted'to my improvements; Fig. 3 ,is afplan view of a detail of the power mechanism shown in Fig.- 2; Figs. 4 a'nd5 are respectively a side However, such a locomotive at speeds of 10 miles per' the horse-power effort of the and end elevation of a reverse lever having associated therewith a modification of my invention; Fig. 6 is a diagrammatic illus- I tration of a reverse lever mechanism embodying another modification of my'invention; Fig. 7 is. a diagram illustrating'stlll another form of modification of the application of my invention, Figs. 8 and 9 are diagrammatic views showing different positions of the power means for operating the valve motions to obtain a differential. cut-off relation; and Fig. 10 is a sectional view of a variable exhaust nozzle suitable for use in connection with my improvements.

Referring now to Fig. 1 it will be seen that I have-therein illustrated a locomotive,

the boiler A of which has any predetermined horse-power capacity. The locomotive is provided with a forward pair of simple cylinders B and a rear pair C, such cylinders being operatively coupled to any desired number of pairs of. driving wheels D, prefmay be coupled in any desired manner to the driving wheels, I prefer to couple three airs of drivers to each set of cylinders. team is suppliedto the forward group in the usual manner through the steam-pipes 7 from each of which a branch 8 leads to the respective cylinder of the rear set. The exhaust from the forward set of'cylinders is erably six in number. While the cylinders utilized to create a draft for the fire-box,

the exhaust pipe (not shown) bein preferably variable, while the rear set 0 cylin-- ders exhaust to the atmosphere.

The combined normal maximum horsepower output of the two groups of cylin- I ders, i. e. the horse-power developed at piston speeds at' which the cylinders are designed to produce maximum horse-power output, is reater than the horse-power capacity of t e boiler. I prefer,'although it is not necessary, that the two sets of cylinders be designed to have the same normal maximum horse-power output, and I furtherprefer that at least oneof the setsor groups of cylinders be designed to hav.e a normal maximum horse-power output corresponding to the horse-power capacity of,

the boiler.-- In this connection I prefer to so desi n the forward set, for the reason. that in the preferred embodiment of my inven t1on, I propose tobe using but one set of cylinders when theengine reaches a speed atwhich normal maximum cylinder horsepower output'ls. obtained, the horse-power ou't ht of the other group bein'g reduced to sue 'a point that such group is practically idling. Such being thecase, it is more suitable to use the exhaust from the forward group for producing draft in the fire boxbecause of the mechanical diflicultieswhich must be encountered in also using the exhaust from the rear group for this purpose.

i As heretofore pointed out,I,propose to 1.30 I

utilize the full horse-power output of both groups of cylinders while the engine is running below the speed at which the horsepower output developed by the cylinders is within the capacity of the boiler, and thereafter, I propose to cut down the combined horse-power output of the cylindersso as to keep it within the limits of the boiler capacity. This may be done in any number of ways, the preferred one being, as above indicated, the reduction of the horse-power output of the rear group and the gradual full utilization of the maximum horsepower output of the forward group.

As one means for cutting down the horsepower output of the cylinders, I may shift the valve motions so as to alter the relative cut-oifs of the two groups; of cylinders. In the drawings I have diagrammatically indicated a valve motion D for each group of cylinders. These valve motions are of the standard conventional type known as the lValschert gear, well-known in this art and requiring no statement as to construction or operation. The valve gears are also operated by a standard form of power reverse mechanism E, such, for example, as the wellknown Ragonnet power reverse. This power reverse is operatively associated with the reverse lever 9 in the cab in the usual manner. The reach rods 10 and 11, for respectively operating the forward and rear valve mo tions, are so connected with relation to the power reverse that a differential cut-ofi be tween the two valve motions is obtained. To accomplish this I mount on the cross head 12, of the power reverse piston 13, an L-shaped lever member 14, which has one leg pivoted to the cross head as indicated at 15. The other leg of said member extends at right angles and has .its end engaged in the groove 16 of a cam member 17, supported from the power reverse cylinder. The reach rod 10 is connected to one end of that leg of the member 14 pivoted to the cross head 12. and the reach rod. 11 is pivotedly connected to the other end of said leg in the manner indicated in Fig. 2. The groove 16 in the cam member 17 is given a reverse or ogee curve. The full forward, midgear' and full rear positions of the valve gears are indicated at a, Z and c in Fig. 2.

The operationisas follows. assuming that the valve gears are in the midgear position shown: lVh'en the reverse lever is moved to] full forward position, the member 14 will occupy the same relative position as in Fig. 2: that 1s to say, the'valve motions .controlhug the steam dlstrlbution of the two sets of cylinders will benperated in unison and will cut off at the same proportion of the engine stroke. The forward end of the groove 16, however. is so arranged that the valve motions will operate in unison in this manner until a speed of from 10 to 12 miles per'hour is attained. When, however, the speed is increased and the cut-off of the cylinders is shortened, as in the normal operation of a two cylinder locomotive, the cut-off in the rear group'of cylinders is shortenedat a greater rate than the cut-off in the forward group, for the reason that as the reverse lever is cut back, the cam member will rock the member 14 about the pivot point 15, thus shortening the cut-off of the rear cylinders much faster than the cut-off of the forward cylinders. This relation between the .per cent. of cut-off in the two sets of cylindersis. continued through the working range ofthe cut-offs of both cylinders. Stated'in other words, the front pair of cylinders is operated at about the normal cut-off point for an ordinary two cylinder simple operation, whereas, the back pair of cylinders is operated at a considerably shorter cut-01f for a speed above'lO'to 12 miles per hour. The relation of the cut-off between the two groups of cylinders is determined in the fol-' lowing manner. For-any given percentage of cut-off in a steam engine cylinder, there is a corresponding horse-power output, for a given boiler pressure. The cut-offs in the two sets of cylinders, therefore, are so arranged that at any given speed, say for example, 25 miles per hour, the horsepower I 'say for example, 30 to 35 miles perhour,

the front groupof cylinders is doing practically all the work and the rear group is operating at a cut-off such that it has developed a comparatively low horse-power, practically just enough to move itself. The foregoing will be clear on inspection of Figs. 2, 8 and 9 illustrating various positions of the Ragonnetfpower reverse and showing the differential effect of the lever member 14 on the valve motions.

This combination of groups of cylinders with variable or differential cut-offs prorides, the means for utilizing to the fullest possible extent the available horse-power at all speeds without overtaxing the boiler.

The same operation takes place when the engine is run in the reverse direction. It is to be understood that any suitable form of mechanism to secure the desired difi'erential rate of cut-off, between the two groups of cylinders, can be employed, the form in. Figs. 2 and 3 being outlined for purposes of illustration only.

I am well aware that it is not new to couple two groups of simple cylinders to sets of driving wheels in one locomotive structure, this being shown, for example, in the patent to Ball and Stafford, No. 1,208,078, the construction of which, however, is

subject to the samelimitations, which apply in the ordinary two cylinder-locomotive arrangementyin that it is necessary to design the boiler large enough to supply the maxihorse-power output of the two groups I of cylinders, in order to avoid overtaxing the boiler capacity. The general scheme illustrated in this-patent is but one of the ways in which it has been attempted to increase vthe tractive power. of locomotives by increasing the size with the resultant difliculty in wheel loads and size of boiler, etc.

By my improvements, I am enabled to supply, for example, a 0-12-0' type of 1000- motive having, amaximum tractive power of 77,000 pounds with a totalweight of only about 330,000'pounds and a wheel load of approximately 55,000 pounds per pair of,

driving wheels, which wouldbe entirely out of the question if the locomotive were designed with a boiler'of su'flicient capacity to supply the two groups of cylinders at their full cylinder horse-power, for the provision of such a boiler would involve greatly increased weights with no increase in tractive power at low speeds. As hereinbefore noted, the exhaust from the front group of cylinders is utilized for producing draft in the smoke box, this being preferable, not only for the reasons already considered, but because, in the preferred manner 'of cutting downthe horsepower effort of the cylinders, the front I eration of this exhaust will be readily understood by those familiar with the art, it being sufiicient to point -out that the movable head or nozzle 28 is o erated from the rod 29, lever 30 andsha t31 so as to increase or Q decrease the effective discharge area of the nozzle. that any preferred form of variable exhaust It will, of course, be understood may be employed, the details of the exhaust forming-no part of this invention.

In connection with the use of the exhaust ofthe forward group to roduce draft in in the smoke box, it, may' e observed that there is much to begained in cutting off in .the rear group of cylinders at a greater rate than infthe front 'grou ","instead of at 5 the same rate." If the cut-o s in thegroups' of cylinders be shortened ,at the same rate,

which, of course, may be done, the front group of cylinders would be discharging a comparatively small amount of steam through the blast pipe, which would be insuflicient to produce the necessary draft upon the fire.

If it is desired to reduce the horse-power output, or rather, maintain the horse-power output within predetermined limits, by shortening the cut-01f of both groups of cylinders in unison, the engineman would be required to ,cut back at a predetermined rate corresponding with the desired maximum horse-pow/er output of the cylinders. In order to determine this rate, a cut-off indicator could be placedin the cab of the 10-- comotive connected to a speed indicator. I have shown such an arrangement in Figs. 4 and 5, in which the reverse lever 9 is carried on a bushing 18 mountedin the quadrant 19. Through this bushing, a shaft 20,.of a speed record ng instrument 21, extends and is pro- -vided with a cut-off indicator arm 22. The speed indicator 21 ma be of any standard conventional type, of w 'ch there are a num her on the market, and it is operated in any of the well-known. methods by an operating shaft 23 driven, for example, by' a belt connection to an axle. Since the degree of cutoff is determined by the speed, it will be clear that this mechanism provldes a simple means for apprising the engineman of the proper notch to Wl'llCh he must cut back.

In Fig. 6 I have shown such a cut-off indicator as has justbeen described, but in this instance, the indicator arm or ointer' 22 is provided with means for releas ng the A latch 24 ofthe reverse lever, so that the pointer will shift the reverse lever to the desired notch, if the engineman should be neglectful.

For both the forward and back motion, the 1 pair of indicator arms 22 and 22' can be utilized, such arrangement being shown in diegrammatic form in Fig. 7. B connecting both pointers to a common 1010011 25, slidable in a groove 26-, by --links 27, the movement of. the pointer 22 would be imparted to the pointer 22', in like degree but in reverse direction. The sub'ect matter relating -to the com- :binationo the variable exhaust with a 1000- motive power unit equipped with more than two cylinders and the subject matter relating to the cut-ofi' indicator mechanism is not here specifically claimed but is claimed in copending applications Serial No. 355,392,

filed January 31, 1920', and Serial No. 355,393, also filed January .31, 1920, respectively.

'Iclaim:",

1. The combination with a locomotive and two.- groups of simple cylinders :operatively connected to driving wheels,-and 'a valve mo ,tion for each group,-of" mechani sm. for obtaining a differential cut-01f -i elation between the valve motions to maintain the cylinder horse-power within the capacity of the boiler at all operating speeds. I

2. The combination wlth a locomotive having a boiler of given capacity and. two groups of simple cylinders having a normal maximum horse-power output greater than 1 the capacity of the boiler, of a valve motion for each'group of cylinders, and a single.

means for obtaining a difierential cut-ofi between the valve motions tomaintain the cylinder horse-power within the capacity of the boiler at all operating speeds.

3. The combination with a locomotive having a boiler of given capacity, of two groups of simple cylinders, the normal maximum borse-power output of which is greater than that of the boiler, a single means for operating one of saidgr'oups of cylinders at substantially maximum horsepower output throughout the range of speed,

w andior operating the second group of cylare adapted to be relatively varied and a variable exhaust.

5. A locomotive power unit having more than two simple cylinders of a combined normal horse-power capacity greater than the boiler capacity,valv e mechanism for said cylinders, and means for unitarily operating said valve mechanism to limit the. horse-power output'in normal use within the boilercapa'city'while altering the cut-ofl'to suit varying speeds.

In testimony whereof I have hereunto signed my name. v

- WILLIAM E. WOODARD.

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