US355035A - Talve gear for steam engines - Google Patents

Description

(No Model.) 6 8heets-Sheet 1.

G. s. STRONG. VALVE GEAR FOR STEAM ENGINES.

No. 355,035. Patented Dec. 28, 1886.

N. PETERS. Phom-Lilhcgraphm, wasmn mu, D. c

(No Model.) 7 6 Sheets-Sheet 2.

G. S. STRONG.

VALVE E AE FOR STEAM ENGINES.

No. 355,035. Patented Dec. 28, 1886.

N. PETERS. Piiclo-Lithalnplwr, Wialingion. D. C.

(No Model.) 6 Sheets-Sheet 3.

G. S. STRONG.

I VALVE GEAR FOR STEAM ENGINES. No. 355,035. Patented Dec. 28, 1886.

# m A H Z/ so 20 N. PETERS, Fholo'Lilhogrnpher. Wauhlngluu. D. C.

(No Model.) 6 Sheets-Sheet 4.

G. S. STRONG.

VALVE GEAR FOR STEAM ENGINES.

(No Model.) v 5 s Sheets-Sheet 5.

' G. S. STRONG.

VALAVE GEAR FOR STEAM ENGINES. No. 355,035. Patented Dec. 28, 1886.

N versus. vhmumn mbm Walhlnglon. 0' c BSheets-Sheet e,

( No Model.)

G. S. STRONG. VALVE GEAR FOR STEAM ENGINES.

Pabte nwdl Dec- N PETERS. Phmum m mr. Wllhington. m;

UNITED STATES GEOEGE s. STRONG,

PATENT @EEicE.

OF NEW Y RK, N. Y.

VALVE-GEAR FOR STEAM-ENGINES.

SPECIPICATICN forming part'of Letters Patent No. 355,035, dated December 28, 1886.

Application filed August 30, 1886. semi No. 212,154. x0 mo le.)

To all whom it may concern:

Be it known that I, GEORGE S. STRONG, a citizen of the United States, residing at New York, county of New York, and,State of New York, have invented certain new and useful Improvements in Valve-Gear for Steam-Engines, fully described and represented in the following specification and the accompanying drawings, forming a part of the same.

This invention relates to a valve-gear which is adapted to be used in connection with either locomotive, stationary, or marine steam-engines, it being the object of the invention to provide a reversible valve-gear which is operated from a single eccentric and is without sliding frictional surfaces, all the parts working from stationary centers.

It is also the object of the invention to provide a valvegear which is operated from a single eccentric and imparts an independent motion to the induction and exhaust valves, by which the point of cut-off can be changed without changing the exhaust, and by which the compression can be changed without chang ing the admission.

It is also the object of the invention to so organize and arrange the valvegear of a locomotive that the movement of the valve or valves will not be affected by the movement of the engine on its springs.

As a full understanding of the invention can be best imparted by an illustration and detailed descriptionof the organization and operation of the valve-gear embodying the invention, all preliminary explanation of the invention will be omitted and a detailed description given, reference being had to the accompanying drawings, in which a valve-gear constructed according to the present invention is shown as applied to a locomotiveengine, only such parts of the invention being shown, however, as are necessary to illustrate the manner in which the valvegear is applied.

In said drawings, Figure 1 is a side elevation of the valve-gear for one side of the engine, the engine being provided wit-h separate induction and exhaust valves. Fig. 2 is a plan view of the same. Fig. 3is a cross-section taken on the line was of Figs. 1 and 2, looking toward the-left. Fig. 4 is a similar view taken 011 the line y y of the same figures, looking toward the right.

Fig.,5 is a view similar to Fig. 2, illusit is to be understood that A represents the steam-cylinder, and a the connecting-rod, upon one side of an ordinary locomotive, B the forward driving-wheel, and Z) its crank-pin, upon the same side of the engine, and O the axle of the forward pair of driving-wheels.

D represents a portion of the framework,-

which rests upon the axles of the drivingwhecls and trucks and supports the boiler and other parts of the engine.

The val ve-gear for-only one side ofthe locomotive will be described, it being understood that the gear for the other side is the same.

The axle G is provided with the usual eccentric, 0, the strap 12 of which is connectedto two forwardly-extending levers, 2O 21, the former of which is rigidly connected to the strap 12, while thelatter is pivotally connected either to the strap, as shown at 11, or to the lever 20. The levers 20 21 are bifurcated at their forward ends, and are fuloru med by being pivotally connected to thelower ends of a pair of radius-rods, 18 19, which are pivotally connected at their upper ends to blocks 22 23, which are arranged to move freely on fixed segments 24: 25. The blocks 22 23 are pivotally connected to rods 16 17, which rods are pivotally connected at their opposite ends to arms 14 15, extending from a rock-shaft, 27. The arm 15 is rigidly connected to the shaft 27, and the shaft extends transversely across the engine and is rigidly connected to the arm corresponding to the arm 15 on the opposite side of the engine. The arm 14: is not connected to the shaft 27, but is rigidly connected to a hollow shaft or sleeve, 26, which surrounds the shaft 27, and turns freely thereon, and also extends transversely across the engine, and is rigidly connected to the arm corresponding to the arm let on the opposite side of the engine. The arms 14 15, or the corresponding arms upon the opposite side of the engine, are

connected to rods 28 29, which are connected to levers located in the cab of the engine, so as to be under the control of the engineer. By this means the blocks 22 23 and thecorresponding blocks upon the opposite side of the engine can be moved along the segments, so as to regulate the movement of the induction and exhaust valves to reverse the engine and vary the point of cut-off, as will be hereinafter fully explained.

The short armsc of the levers 20 21 are pivotally connected at their forward ends to rods 30 31, which are in turn pivotally connected to arms 32 33, extendingfrom a transverse rockshaft, 34. The arm 32 is rigidly connected to the shaft 34, while the arm 33 is rigidly connected to a hollow shaft or sleeve, 35, which surrounds the shaft34 and turns freely thereon. The shaft 34 is provided with a second rigid arm, 36, which is pivotally connected to the rod 38, which operates the induction-valves 40, v

the two valves being connected by a rod, 42, and the hollow shaft or sleeve 35 is also provided with a second rigid arm, 37, which is pivotally connected to the rod 39, which operates the exhaust-valves 41, these two valves being also connected by a rod, 43. The induction and exhaust valves 40 41 are of the gridiron-slide form shown and described in my prior Letters Patent Nos. 320,892 and 320,894, and consequently require no detailed description.

The several parts of the valvegear just de scribed are supported as follows: The shafts 34 35 are mounted in a long bearing, 49, which is supported on a light framework, (1, formed of a pair of plates, which are secured to and extend forward from the axle-box roof the axle C. The frame 12 is secured to the axle-box w by means of hooked portions 13, which hook over the rear side of the box, as shown in Fig.

1. The segment 24 is supported at its forward end on the inner end of the shaft 34 (seeFigs; 2 and 3) and at its rear end upon an upright rod, 48, rising from thehollow shaft 26. The segment 25 is supported at its forward end by being attached to the bearing 49 (see Fig. 2) and at its rear end by being attached to a bracket, 47, rising from the frame d. (See Figs. 2, 3, and 4.) The shaft 26 is supported at one end in a bearing, 46, secured to the inner one of the plates forming the frame d, (see Figs. 1, 3, and 4,) and at the other end in a similar bearing secured to the inner one of the plates of the corresponding frame on the other side of the engine. i,

From the foregoing it will be seen that the valve-gear is supported entirely upon the axlebox to, and is wholly independent ofthe main frame-work D. This is a feature of impor tance, as by this means all parts of the valvegear are always maintained in the same position with relation to the eccentric, so that the movements of the valves are regular and uniform, and are not affected by the movementof the engine upon its springs. This is not the case where the valve-gear is partly or wholly supported upon the main frame-work of the engine, because in such case the movement of the frame-work D with relation to theaxle O, and consequently-with relation to the eccentric, caused by the compression and expansion of the springs which are interposed between the axle and the frame work, causes changes in the position of the valve-gear with relation to the eccentric, which prevents the regular and uniform movement of the valves. In order to give lateral support to the light frame-work cl which supports the va1ve-gear, the main frame D is provided with a vertical guide, 45, which extends upward between the plates forming the frame d, and moves freely up and down between them as the position of the frame D varies. This guide, as will read il y be seen, affords a rigid lateral support to the frame d in whatever position it takes with relation to the frame D. It may also in some cases be desirable to provide a yielding support for the forward end of the frame carrying the valve-gear. This can readily be done by means of a spring, as 44, located between the plates forming the frame (I and interposed be tween the frame D and a cap, 9, secured to the frame d, as shown.

Referring now particularly to the diagrams, Figs. 7 and 8, the operation of the valve-gear will be explained. In these diagrams the curved line at represents the position of the segments 24 25,- the line Z represents the valverods 38 39; the circle b indicates the travel of the crank-pin b; the circle 0 indicates the throw of the eccentric c,- the line a indicates the position of the connecting-rod a when the crank-pin is at either its forward or rear dead center, which points are indicated on the circle I) by the numbers 48 24, and the lines a a indicate the positions of the connecting-rod when the crank-pin is at the limit of its downward and upward movement, respectively, which points are indicated upon the circle I) by the numbers 12 36. The numbers 0 to 48 at the right of Fig. 7 indicate the position of the cross-head pin when the crank-pin is at the various points in its travel indicated by the corresponding numbers on the circle I). The position of the piston will of course always correspond-to that of the cross-head, but for convenience only the crosshead will be referred to.

In describing the operation of the val vegear, it will first be assumed that the blocks 22 23 are adjusted to the same position on their respective segments, and that that position is at the middle of the segments, or what is termed midgear, as indicated atthe point z in Fig. 7. With the blocks 22 23 in this position the lines it indicate the positions of the eccentric levers 20 21, arms 32 33, and arms 36 37, when the crank-pin is at 48; the lines n indicate the positions of the same parts when the crankpin is'at 24; the lines a indicate the positions of the same parts when the crank-pin is at 12 and 36; the linesoindicate the positions of the rods 18 19 and 30 31 when the crank pin is at 48 and 24; the lines o the positions of the same parts when the crank-pin is at 12, and the lines 0 the positions of the same parts when the crank-pin is at 36.

Let it now be assumed that the cross-head pin is at 48 or 0-that is to say, at the limit of its-forward stroke-and the crank-pin at its forward dead-centerthat is to say, at the position indicated by 48 and 0 on the circle I). As the eross'head moves rearward from 0 to 24, thereby making its rearward stroke, the crank-pin will move from 0 to 24, thereby making one-half of a revolution. During this time the eccentric 0 will move the eccentric-1evers20 21 from the position indicated by'the linento the positionindicated by the line a, and then on to the position indicated by the line a. This will imparta compound movementto theeccentric levers. consist in part of the longitudinal reciprocating movement due to the throw of the eccentric,whieh movement will, since the eccentriclevers are pivoted to the radius-rods 181.9 and to the rods 30 31, cause said rods to move from the positions indicated by the lines 0 to the positions indicated by the lines 0, and then back to the positions indicated by the lines 0, thus causing the-ends of the eccentric-levers to move through arcs of circles the radii of which are the rods 18 19 This movement of the eccentric-levers will not, however, owing to the position of the blocks 22 23, impart any movement to the valves. In addition, however, to this longitudinal reciprocating movement the eccentric-levers will, owing to the change in their position from theline n to the linen, and then on to theline n he rocked upon their fulcra in the ends of the radius-rods 18 19,- so that their forward ends will be vibrated in the arcs of circles the radii of which are the arms '0 of thelevers. This compound movement of the levers will cause their ends, which are connected to the rods 30 31, instead of moving forward and back in the same path, to take the curved path of travel indicated by the outline of the figure g from 48 to 12 and then back to 24, and will, through the rods 30 31, rock the arms 32 33 and 36 37 from the positions indicated by the lines a to the positions indicated by the lines a, and then on to the positions indicated by the lines a and impart a corresponding movement to the valves.

From this it will be seen that the movement imparted to the valves during the stroke, as just described, is due entirelyto the rocking of the eccentric-levers upon their fulcra in the ends of the radius-rods 18 19, and not to the longitudinal reciprocation of the levers. The extent of this movement, which is represented by the distance between the numbers 48 and 24 on the figure g, is governed by the length of the arms 1; of the eccentrio-levers, and relates only to the lap and lead of the valves. When, therefore, the blocks 22 23 are in this position-t. 6., midgear-the induction-ports are opened only to the extent of the lead of the valves. As the cross-head makes its return'stroke from 24 to 48, and the crank- This compound movement will pin'moves from 24 to 48, thereby completing the other half of its revolution, the operation just described will be reversed, the eccentriclevers will move back from the line a to the line a, the radiusrods and the rods 30 31 will be vibrated from the lines 0 to the lines 0 andback, the ends of the eccentric-levers will the position assumed at the commencement of the operation.

Let it now be assumed that the blocks 22 23 are shifted from the point z to the point :0, the crank-pin still continuing to move in the direction indicated by the arrow. When this is done, the positions of the radius-rods 18 19 will be changed, as indicated by the light dotted lines; and although the endsof the eccentric-levers will continue to travel in a path of the same form, as indicated by the outline of the figure g, the position of' the path will be changed to that indicated by the outline of the figure h, and the result will be that the ends of the arms 12 of the eccentric-levers as they travel from the point 48 to the point 12 and back to the point 24, instead of vibrating the arms 32 33 and 36 37 from the lines 12 to the lines 1?, will vibrate these arms fromthe lines it to the lines a and back to the lines a and in traveling from the point 24 to the point 36 and back to the point 48 will vibrate the. arms 32 33 and 36 37 from the lines a to' the lines a and back to the lines a, and give a corresponding movement to the valves. The movement between thelines n and a" still represents the lap and lead of the valves, while the extended movement from n to 02* and from n to n -gives an additional movement to the valves, which opens them to a greater extent and keeps them open for a longer time. When the blocks 22 23 are adjusted to the position indicated at x, as just assumed, the valves will have their maximum throw, and this may be reduced to any desired extent by adjusting the blocks from the point :0 toward their original mid-gear position.

Toreverse the engine it is only necessary to adjust the blocks 22 23 in a contrary directionthat is to say, to the other side of their IIO mid-gear positionfor instance, to the point 3 \Vhen this is done, the radius rods 18 19 will take the positionsindieated by the heavy dotted lines, and although the path traversed by the ends of the arms a of the eccentric-levers will remain the same in form, its position will be again changed, so that it will now occupy the position indicated by the outline of the figure It, and as a consequence the engine will be reversed.

In the explanation of the operation of the valve-gear which has thus been given it has been assumed, as before stated, that the blocks 22 23 are adjusted to the same positions upon their segments. This will not, however, always be the ease, and, it! fact, it will usually happen that the blocks for the induction and exhaust valves will be adjusted to different positions, as it will frequently be desirable to change the throw of the induction-valves with out changing the throw of the exhaustvalves, and vice versa. This, of course, can be readily done by shifting either one or the other of the blocks by means of the rods 28 29. This eapability of adjusting the throw of the induetion and exhaust valves independently of each other constitutes one of the important features of the invention.

The organization shown in Fig. 5 is the same as that already described, except that the rods and arms for operating the induction and exhaust valves are located upon the inside instead of upon the outside of the steam chests. This permits the shafts 3i 35 to be dispensed with, the motion of the rods 30 31 being in this case transmitted to the valve-rods 38 39 by means of a pair of bell-crank levers,which are mounted to rock on a rod, 50, and the arms 32 33 and 36 37 of which correspond to the arms 32 33 and 36 37 of the rock-shafts. This brings the whole valveoperating mechanism inside the line of the drivingwheels, as shown. In this organization, also, the rock-shafts 26 27 and arms 14 15 are dispensed with, the blocks 2223 being connected directly to the operating-rods 28 29, and the rear end of the segment 24 supported upon an extension of the same rod-which supports the rear end of the segment 25. This organization will in many cases be found the most desirable. The operation is the same as already described.

It will also be readily understood that the valve-gear can be so modified, without radical change, as to be applied to those engines in which the induction and exhaust is controlled by the same valve.

A modified organization of the valve-gear for accomplishing this purposeis illustrated in Fig. 6. I11 this case the induction and exhaust valve is of the ordinary sliding form and is controlled by a rod, 38, connected to the arm 36, extending from the rock-shaft 34. The hollow shaft and arm 37 are of course omitted, as is'also the arm 33, rod 31, radiusrod 19, block and segment 23 25, rods 17 and 29, and the eccentric-lever 21, it being in such easenecessary to have but one segment and block and one operating-rod for shifting the block, and this being the case the rod 14 is connected rigidly to the shaft 27 and the hollow shaft 26 is omitted. In other respects the valve-gear is the same as already described and has the same mode of operation.

It will of course be seen that the apparatus may be modifiedin other respects without departing from the invention. This is especially the case in regard to the devices for adjusting the blocks 22 23 upon the segments. The shafts 26 27, when used, need not be supported upon the frame (I, and these shafts therefore may be located in any other convenient posi- I that by means of the valve-gear herein described the valve 01' valves is or are so moved as to secure a quick opening of the inductionport and a quick admission of the steam during the early part of the stroke ofthe-piston, which is a result which it is always desirable to attain. At the same time the exhaust is not closed until the piston has nearly completed its stroke and the crank-pin has nearly arrived at its dead-center. This long-continued. opening of the exhaust is another result which it is also desirable to attain.

From the foregoing it will be seen that the valve-gear containing the present invention is easily and readily reversible and that a single eccentric serves to operate it'in all positions, and, furthermore, that, when desired, the single eccentric can be made to operate independent induction and exhaust valves, and that themovement of eitherthc induction or exhaust "alves can be changed without changing the movement of the other.

Itwill also be seen that the whole valve gear is so supported that it is not disturbed by the movements of the engine upon its springs, and consequently all parts of the. apparatus always remain in their proper position with relation to the eccentric, thereby insuring a regular and uniform movement of the valve,

or valves.

\Vhat I claim is- 1. In a valve-gear for steam-engines, the combination, With a fixed segment and a block adjustable thereon, of a radius-rod pivoted-to said block, and the eccentric 0, having its eecentric-lever fulcrumed to said radius-rod and connected to the valve-rod, substantially as described.

2. in a valve-gear for steam-engines, the combination, with a fixed segment and a block adjustable thereon, of a radius-rod pivoted to said block, the eccentric 0, having its eccentric-lever fulcrumed to said radius-rod, and two rock-arms which are connected together and one of which is connected to the eccentriclever and the other of which is connected to the valve-rod, substantially as described.

3: In a valve-gear for steam-engines, the combination, with a single eccentric and its eccentricstrap, of the two levers 2021, one of which is rigidly secured to said eccentricstrap, and the other of which is pivoted to said strap or to the rigid lever, and both of which are fulcrumed so that each receives a compound motion, one part of said motion serving to cause the lap and lead of the valve, while ICS the other part effects the opening of the valve in addition to the lead, substantially as described.

4. In a valve-gear for steam-engines, the combination, with the two fixed segments having blocks'adjustable thereon, of the radiusrods 18 19, pivoted to said blocks, the eccentrio 0, having the rigid eccentric-lever 20, fulcrumed to one of said radius-rods, and the pivoted lever 21, fulcrumed to the other of said radius-rods, one of said levers being connected to the induction valve or valves and the other to the exhaust valve or valves, substantially as described.

5. Ina valve-gear for steam-engines, the combination, with the two fixed segments having blocks adjustable thereon, of the radiusrods 18 19, pivoted to said blocks, the eccentrio 0, having the rigid eccentric-lever 20, fulcrurned to one of said radius-rods, and the pivoted lever 21, fulcrumed to the other of said radius-rods, rock-arms 32 36, which are connected together and to one of said levers and the induction valve or valves, and rockarms 33 37 which are connected together and to the other of said levers and the exhaust axle-box of the engine, whereby the valvegear partakes of the motion of the axle-box and the relation of its parts is not disturbed by the'movements of the main parts of the engine, substantially as described.

7..In a valvegear for locomotive-engines, the combination, with the axle O, eccentric c, and axle-box w, of the frame d, mounted on the axle-box and supporting the various parts of the valve-gear, substantially as described. In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses.

GEO. S. STRONG.

Witnessesz' J. A. HovEY, Ms. J. KENNEDY.

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