US1226523A - Locomotive valve-gear. - Google Patents

Description

I. HWESJR.

LOCDMOHVE VALVE GEAR.

vvucmnu FILED math. 1917.

Patented May- 15, 1917.

2 SHEETS-SHEET I.

INVENTOR WITNESS ATTo R N EY T. JAMES, M, LUCOMOTIVE VALVE GEAR.

APPLICATION FILED FEB. 2!, 1917 1 ,226,523. Y Patented Ma 15,1917"..

2 SHEETS-SHEET 2.

A I VENT'Q W'TNESS 1720mm? Jar/may]? ATTORNEY rnoivias James, .73., or PHILADELPHIA, rnNnsYLjvAm'jm LocoMorxvn VALVE-GEAR).

Specification of Letterslatent.

Application filed February 21, 1917. Serial No. 150,101.

To all whom it may concern Be it known that i, TI-IO'M'AH JIABIES, Jr., a.

citizen of the lllnited States, i or. ng at 403 lielmont Apartnnn flhn v hearth and bprlng Garrilen SlI-I'QQlI-F-J, lhih lolphia, in the "county of Philadelphia and State of Penn 'sylvanla', have invented new and-useful Improvements in Locomotive Valve-Gears, of

' which the followin is a specification.

Thisinvention IBTEItGS to im1n'ovemen.ts in valve gears, and has particular reference to a. valve gear for use in connection with the usual reciprocatingpiston valves ofthe type now commonly em.1;nlo' \;'ed in locomotive en-- ginesg One of the main objects of the invention resides in a. valve gear of peculiar constructlon and operation for effecting the operatin'g movements of a steam distribution valve of a. locon'mtive engine, said gear being adapted to operate the valve to effect an acceleratd opening and closing of the steam ports governed thercby, and at the same time to permit of an extended open period of said ports, in order that a prolonged expansion ofstearn, admitted. by said ports into a cylinan, will'he obtained, together with greatly decreased exhaust compression.

helriniportant object of: the invention reside "providing a valve gear having adjumbl .catures of construction which will permit the lap and lead movements of the "steam distribution valve to be readily controlled, thus permitting the engine, with "which the valve gear is associated, to be readily and easily started in a gradual manner, and without unnatural jolting' or jarring. A'further object of the invention resides in a valve gear possessing the above character-ifstics, which will be positive and eflicient in: operation, not liable to become out of orderadjustment, and to permit the engine asso. ated therewith to be more economically operated;

Other objects will be in part obvious and in part pointedi'out hereinafter. i To this and other useful ends, the invention'consists of features hereinafter set forth and claimed.

In the accompanying drawings Figure 1 is a diagrammatic side elevatlon of the valve gear embracing the principles of the present invention, the same being 55 shown as applied to-a locomotlve steam engine, parts of the latter being broken away to disclose the underlying construction, the valve gear being shown in a. neutral or out of gear position. Fig. 2' is asimilar view showing the valve gear, disclosing the same in its extreme for ward position. 1 Fig. 3 is a transverse vertical along theline 3- 3 of Fig. 1. Fig. 4-is a horizontal sectional along the'linc 4-4ofFig. 1.

section taken view taken i Patented- May 15,1917.

Fig. 5 is a similar "view,- the plane of which being disclosed b y the line 5-45 of ig 6 is an enlarged horizontal sectional view taken through a portion of the mechanism. disclosed in Fig. 5.

Fig. 7 is a. detail vertical sectional view taken through a disclosed in Fig. 5.

Fig. 8 is a diagrammatic view illustrating the relative positions o'fESthe distribution valve, radius rod, combination lever, and the cooperating crosshead, when the latter is moving in the direction of the arrow, and

Fig. 9 is a similar view disclosing the positions of the parts enumerated in Fig. 8 when the crosshead is reciprocating in the opposite direction.

Similar characters of reference denote corresponding parts throughout the several figures of. the drawings.

.Referring to the drawings by numerals, the valve gear comprising the presentinvention, is shown asemployed in connection with a locomotive engine 1, consisting ofa cylinder 2, piston 3, steam distribut-ion valve 4, and steam ports 5. The valve 4 in this instanceiis of the usual piston valve type, and is constructed to permit of inside admission of steam into the cylinder 2.

The piston 3 is connected by means of a. piston rod 6 to a sliding crosshead 7, mounted in fixed guides 8, rod 9 is pivotally connected with the crosshead, and is swivelcd as at 10 to one of the driving wheels 11 of the-locomotive. A return crank .12 rotatable with the wheel 11, has pivotally connected to' of the valve e, whereby the forward, rear-- portion (of the mechanism and a pitmanhard or neutral (positions of the valve gear may be controlle To adjust the rod within the link, a bell crank 18 is provided, said crank having oneof the arms thereof movabl connected with one end of the radius rod? and the other end connected with a manually controlled rod 19, whereby the said end of the radius rod may be ad usted to different positions within said reverse link. The above parts are of the usual construction in operation, therefore, a more extended explanation relative thereto will b omitted.

Secured in any simple manner to the crosshead 7 is a plate 20, the latter being.

provided with an extended bifurcated extremity 21 in which is secured, by mechanism to be hereinafter fully described, the lower extremity of a combination lap and lead and cut elf lever 22. The latter e'xtends upwardly to a position substantially in axial alinement with the valve 4, and 15 connected with said valve through the provision of an elongated slot 23, formed in the lever 22. Mounted in the slot is a reciprocating block 24, through which a p 1n 25 passes, the latter having its extremities fixed 'in the bifurcated end 26 of a slldmg crosshead 27, which is mounted in fixed guide -protruding from the caslng of the engine .1. The crosshead 27 is suitably conthe directions indicated by the arrows.

nected with the outer end of a valve stem 28, extending from the distribution valve in order that the reciprocating movements of the crosshead 27 willbe synchronously imparted to said valve. It will be noted that the lower end of the lever 22, where'it is connected w th the plate 20, will move on a plane parallel to the direction of movement of the crosshead 7 and by the use of the slot and block connection 23 and 24, a peculiar movement will be imparted to the valve 4 so as .to effect the above stated objects- The outer end of the radius rod 17 is pivotally connected with the upper extremityofthe lever-22, at a oint above the block 24, said rod, in this instance, being employed to regulate the distance between the pin 25 and the point of pivotal connection between the rod 16 and the combination lever 22, whereby the out of gear or in ear positions of the valve gear will be obtainable. I

At this juncture attention is directed to the diagrammatic views illustrated in F 1gs. 8 and 9 of the drawings, which plainly 'disclosethe. movements of the distribution valve 4, when the crosshead 7 is moving 1in 11 these views the line A represents the direction. of travel of the valve, the line B the movement of the crosshead, .and the obliquely directed line C the various positions the lever 22 will assume when in o eration,

the upper ends of"the line C iridlcate the curve or path of travel of the forward extremlty of the radius rod 17 Thus in Fig.

8, where the line C intersects the line A,

the valve 4 will be in a line and line position closing the ports 5, but when the crosshead travels a relativel short distance. to the position indicated y the line G the valve 4 will be quickly reciprocated to effect a complete opening of the port, so that the cylinder 2 w ll receive an unobstructed flow of steam, and to simultaneouslypermit of a full and free exhaust of the spent steam reason of this substantially rapid, or in-' termitteut movements of the valve, together with the prolonged openmgof the ports 5,

ma) be briefly stated as follows: firstly, th

quick admission of steam into'thecylinder, effected from the rapid opening of the ports; secondly, the prolonged period of steam expansion; thirdly, the extended open position of the ports when steam is being exhausted therethrough, so as to eliminat -the back pressure upon the piston.

Cooperating with the valve reciprocating mechanism, above described, is a variable lead controlling device for regulating the admission of steam into'the cylinder 2. As is well known. in the ordinary VVals'chaert valve the lead remains constant. which is exceedingly objectionable when the engine;

is being initially started. this being due to thefact that steam is admitted into the cylinderan instant beforethe piston reaches the extremity of its stroke. thus causing a back pressure upon the slowly moving piston, which is a distinct detriment to the successful start of the engine. However,

the constant lead operates very eflicaciouslywhen the engine is running at full speed. For example, this action may be likened to the operation of an internal combustion mos tor.'when first started the spark for effecting. the explosions of the mixture within its cylinders is retarded, so that the explosion will not take place until the piston is on a down stroke. But after the engine gathers momentum the spark is advanced until the explosions created thereby occur just before the piston reaches the end of" its lip-strokes. Therefore. the variable lead device utilized by the present invention, presents means for regulating the movement of the valve 4 so that when the engine 1 is beinginitially started, steam will be admitted plate 20. A crank 33 issecured to one end cylinders will take placejust before said pis-- into the cylinder immediately subsequent to the period when the piston reaches the extremity of its movement. And further pro-- vides manually controlled means for shifting the valve, after the starting of the engine, so that the admission of steam into its ton arrives at its stroke extremities.

To effect this object the lower end o'fthe lever 22 is 'provided'with a circular opening in Which is positioned an eccentric 30,.the

latter being provided with a squared opening for the reception of, a s'imilarlyshaped portion 31 of a shaft 32, which is iournaled for rotation in the bifurcated end 21 of the of the shaft 32, and has its free extremity pivotally connected .with a link 34, the other end of said link being jointedas at'35 to a cocpe'rating link 36 pivotally-carried by the plate 20. Connected with the links -3 l and s 36 is a variable lead arm 37- the latter extending parallel with the lever 22, andhas its upper end swiveled to the radius rod 17, at a position contiguousto the joint existing between said rod and the lever 22'. It will be noted by reference to Figs. 1 and 2 that the combination lever and the arm 37 will extend in parallel relation; regardless of the-position of the crosshead, this being due to the block and slot connection utilized in associating said lever with the crosshead 27. I

In conclusion, it is-obvious that when the radius bar 17 is shifted to vary the cut-01f,

the link 27 pulls the eccentric 30 by means ofits connection therewith to cause the combination lever 22 to be'raised in order that the lead will'be progressively increased with the cut-off." It is due to the" adjustment of the rod 17 which causes the lead' to 'change,i

" the lead remaining constant after the adjustment is made. i

From the 'foregoing it will be the objects of the invention have. been achieved, and that all of the advantageous features above mentioned are, among others, present. The gear described may be readily attached, if desirable, upon any locomotive embracing the sliding piston valve construe tion, with but a minimum of cost and dlfii- Seen that there is provided mechanism through which culty. The construction of the gear. by reason of its'simplified nature, willfenable the same to be absolutely reliable'in o ration, and ,not likely to becomeout of or r, or to require constant attention and adjustment.

Moreover, theinvention does not employ any extra levers to enable the engineer of a locomotive to regulate its several positions, but is automatically operated by the usual reverse lever, common to all locomotives.-

Having described the invention what is claimed-as new and patentable is:

1. In valve gear of the class described, the combination with an engine including a reciprocating piston valve and crosshead, a

plate secured to the crosshead, articulated links pivotally connected with said plate, an eccentric carried by the latter and having the positions thereof regulated by said links,

of a lap and lead lever havjpg the substantia'lly lower extremities thereofrovided with an opening for the reception 0 said 'eccentric, wherebysaid lever will be capable of lllOVlIlgJH unlson with sald crosshead, a

radius rod connected with the upper extremity of said lever, a stem protruding from the valve and having a block and slot connection with said lever, and a variable lead controllingarm connected with said radius rod and with said links at a position contiguous to said'lever and adapted. to maintain substantially parallel relation with the latter, irrespective of the positions of said croshead..

2. In valve gear of the class described, the

,combination' with a'locomotive steam engine including a reciprocating crosshead. and a steam-distribution valve, a plate secured to said crosshead, an eccentric carried by said plate, a lap'and lead lever connected with said eccentric, a pin and slot connection providedcontiguous to the upper extremity of said lever, and having connections with said distribution' valve, a radius rod, pivo ted to said leverat a position above said pin and slot connection, and a variable lead arm connected with said radius rod and with said eccentric, and operable to regulate thev substantially vertical positions of said lever,

V In testimony whereof I afiix my signature.

] THOMAS JAMES, JR.

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