US108982A - Improvement in valve-gear for steam-engines - Google Patents

Description

3 Sheets-Sheet 1. W. B. DODDRIDGE.- VALVE GEAR FOR STEAM ENGINE.

r Patented Nov. 8, 1870:

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3 SheetsSheet 2;

W. B. DOD'DRIDGE.

VALVE GEAR FOR STEAM ENGINE.

No. 108,982. v Patented Nov. 8, 1870.

"" gin THE Norms Pzrzns co, Pnmuuma. WASHINGTON. u. c.

3 Sheets-Sheet 3.

W. B. DODDRI-DGL. VALVE GEAR FOR STEAM ENGINE.

No. 108,982. Patented Nov. 8. 870

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WILLIAM B. DODDRIDGE, or enson, INDIANA.

The Schedule referred to in these Letters Patent and making part of the lame.

-I,.W1LI.IAM B. Donnnmes, of Hebron, in the county of Porter and State of Indiana, have invented 'ncw'and useful Improvements in the Valve-Gear for Steam-Engines, of which the following is a specification.

The first part of my invcntion'relatcs to the operation of the valves of a steam-engine, by means of hand-wheels pivoted upon a revolving shaft, so that they may be inclined, more or less, to its axis, combined with valve-rods, placed at rightangles to said revolving shaft, having terminal arms or forks, which embrace the band-wheels, andarc pivoted tothe bands .thereon at diametrically opposite points. Thus, these bands are held by the arms offthc valve-rods pivoted thereto, while thc'whecls are left free to revolve casil y within them; when t-hehand-whecls are turned upon their axes, so that they stand each at a right angle to the axis of the shaft, their revolution with the shaft will produce no movement-of the "a-lve'-rods,hnt if they betnm'ed, more or.lcss, upon their pivots, so as to be inclined to the axis of the shaft, their revolution will cause the pivot points of the valverods upon the hand-wheels to traverse back and forth in the line of said axis, and thus produce a rocking movement of the valve-rods, the extent whereof will be determined by the degree of the inclination of the hand-wheels. The rocking movement thus produced in the valverods, and readily controlled, is easily made available for operaiingthc valves of the engines, by means 'of connecting devices of any suitable character. By pivoiing thc baml-whcclsnpon the shaft, ,so that theiraxes shall be at right angles to each other, as well as to -thc shaft, an alternate movement of the valverods is produced, and a proper consecutive movement of the valves in opening and closing thereby obtained.

The second part of my invention relates to the form of valves which I regard to be best adapted-for use inconnectiou with the first part of my invention. These improved valves are attached directly to the ends of the rocking valve-rods, so as to rock therewith, and, by their movements, open and close the partscommw nicuting with the steam-chest and cylinders of the engine, and with their exhaust-pipe In the accompanying drawingl igure 1 is a plan view of a steam-engine operated byqlncans of my improved valve-gear and valves.

, l igurc 2,11. vertical section, taken centrally, through jthe Jinaii-i-sliaft and the driving-wheels, in the line ant,

Figure 3, an horizontal section, likewise ta'ken centrally, through the axis of the main-shaft, showin the hand-whecls inclined.

.higurc. 4, a second central vertical, section, taken longitudinally, through the axis of the main shaft,

showing the band-wheels thereon inclined in the same position as illustrated in fig. 3.

Figure 5, a detached view of a band-wheel, illustrating more fully the manner of combining the valverod therewith;

Figurefi, a detached view, in elevation, of the lever by which the band-whcelsare turned upon their pivots. Figure 7, a central vertical sect-ion of one of the vvalves in line y y of fig. 1.

Figures 8 and 9 vertical sections of the two valves operating the engine, taken, respectively, in the lines 1),the main driving-shaft, to which the driving" wheels B B are attached.

E E, two band-wheels, having each a rectangular openingat the center thereof,to receive a corresponding rectangular block, 0, firmly united or secured uponthe shaft 1).

llhesc band-wheels, being placed upon said blocks,-

are pivoted thereto at right angles to each other, by means of pins, t, inserted fromtheit peripheries, to pass cent-rally through the blocks'and shaft, and project beyond the same into the wheel on the outer side,

as illustrated in figs. 2. and .3. Y The band-wheels are thus left free to turn upon their pivots, so as to be inclined, more or less, to the axis of the shaft, see figs.

2 3, and 4, or to remain at right-angles thereto, sce

figs. 1 and 2. V

a a- (see' fig. 3) are the bands encircling the periphcries of the wheels E E loosely enough to move freely and easily thereon.

F is awide'flange, projecting from the inner end of a collar, sliding loosely upon the shaft D, but made torevolvctherewith by means of a feather or key, 3, (figs. 2 and 3,) projecting longitudinally from the shaft Dflin'to a counterpart notch in the inner perimeterof the collar.

A smaller flange, f, is formed upon the outer end of thecollar, and the two embrace a sliding bar or box, fitted between them, and extending out from the shaft far enough to rest and slide upon ways formed on the upper edge of blocks or supports H H, placed longitudinally upon each side of the shaft, and extending out to the pillar-block supporting its bearing.

I is a second sliding bar, placed upon the shaft, whiclipasses freely through the same, and which rests at either end, and slides, like the first, upon ways on the upper edge of the blocks H H.

The two sliding bars, and I, are coupled together by the" rods extending between them, so that the two Glide together, carrying with them the collar and flange F, embraced by the first, 4

K (figs. 1 and 3) is a link,'pivoted, at one end, to the flange F, and at the other to an ear or lug pro jecting from the side or face of the band-wheel E, atv apoint in a line at right angles to the pivotal axis of the wheel.

K (iigs. 2 and 4) is a second link, pivoted, in like manner, at one end to the flange F, at a point thereon removed one-fourth of a circle from the pivot-point of the first link K, and which, extending through an aperture cut for the purpose in the body of the bandwheel E, is pivoted, at its outer end, to an ear or lug projecting from the side or face of the second handwheel, at a point in a line at .right angles to its pivotal axis.

By means of these connecting links a sliding movement of the collar and flange F will cause the two band-wheels to turn upon their pivots in either direction, so as to incline to the axis of the shaft, the one at right angles to the other, as shown in iigs.3 and-4.

L is a plate or bar, sliding upon sui table ways transvcrsely tothe shaft D.-

In this plate L two or more diagonal slots, 1) b, are cut, at an angle of forty-five degrees to its length, and through these slots pins project from the ways beneath, upon which are placed nuts or plates 0 c, to prevent an upward movement of the plate from its seat By means of-these inclined slot-s,'aud the pinsthcrein, the forward mot-ion oi the plate. transversely to the shaft produces a simultaneous lateral movement thereof iiithe line of the shaft.

M is a link pivoted to said plate L and to the slid; ing bar I, coupled to the collar and flange F, by means whereof the movement of the plate L, in the direction of the shaft, is communicated to said collar, and thence to the band-wheels E E, for t-he purpose of turning them upon their pivots and inclining them 'to the shaft.

N is a connecting-rod, coupling the plate Lwith an ordinary upright lever 0, (see fig.6,) pivoted to swing in a vertical plane to and from theplate, so that=the' movement of this lever shall'move the plate L," and,

through it and the intermediate connections, the hand wheels E E, to turn them as described.

A bell-crank, or other form of bent lever, connected by a link to the sliding collar and'ilange F, may besubstituted for the sliding plate L,,operating as set forth, where the operating lever is so placed.- as to 'move at right angles to the shaft 1), as in the machine herein described; and I contemplate the use of any mechanical appliances for turning the band-wheel so as to incline them, more or less, to their axis of revolution.

1 I are valve-rods, connected to the loose hands a a of the band-wheels E E, by embracing arms Q Q, secured to said hands by means of pivot-pins (L (I, placed at diametrically opposite points in their circumference, as illustrated in fig. 1.

S is the steam-chest of the engine, into which the valve-rods P I extend with suitably packed joints.

T T', figs. 2, 7, S, and 9, are semicircular hollow valves, whose upper straigh edges or rims are secured at their central point to the ends of the valverods in the st-canhchest, so that the rocking movement of the rods will be imparted thereto.

Theopen face of e'aclrvalve is made to fit closely U, figs. 3,

against and slide freely upon a face-plate, 7, 8, and 9.- a In the lower portionof this face-plate an aperture, 4-, is pierced centrally below the axis of the valve, so as to be covered 'thereby throughout its entire movement, and.., hich ismade to communicate with an exhaust-pipe, V, as illustrateo in fig. 7

m m, are also piercedthroughthe Two steam-ports, horizontal line, just below the,

both of these" ports will be covered and closed by a plate, a, projecting downward from the inner upper edge of the valve, and made wide enough to barely cover them when in said position, (see fig. 8.)

Instead of extending this valve-plate it across the entire length of the valve, two' separate plates of equal width, one for each port, may be employed.

These two steam-ports m m in the face-plate 'of each valve communicate, by means of suitable pipes, with the either end respectively of one of the cylinders A or Af of the engine, (see diagrams figs; 2, 8, and 9.) Hence, so long as the upper straight-edge or rim of the valve is in a horizontal plane, so that its inner the connected cylinder is cut off from the steam chest.

The valves T T are so secured to the valve-rods P 1", as that when the two pivots, by which each rod is secured to the band upon its band-wheel on the shaft, are in a line with each other 'at right angles to the shaft, as shown in 2, (see also E, fig. '4,) the straightcdge or rim of the valve connected to the rod line, fig. 2,) covering andclosing the steam-ports to the cylinder, and thus shutting off all steam therefrom, as in fig. 8. i

The band-wheelsarc also pivoted right angles to each other, (see figs. 2, 3, and 4,) with driving-wheels of the engine as that when either crank and piston is at its dead-pointKsec diagram fig. 8) the pivots connecting to its band-wheel the valverod of the valve controlling the admission of steam to the cylinder on that side will he in a right line with the axis upon which said band wheel inclines, (see fig. 4,)

' closed, as shown and illustrated in fig. 8, while the other halal-wheel E, being inclined upon a pivotal axis at right' angles to the iiist, (see 'fig. 4,) will tum ,theJvalve-rod so as to -cause its valve to be thrown eopen as shown and illustrated in figJ).

Hence, to shut ofi' steam necessary to throw the band-wheels into a position at right angles to their shaft. When they are thus placed at right angles to their sham-as illustrated in position, as shown by positive lines, fig. (i.

' If, however, the lever be'thrown forward, as shown by dotted lines, fig. 6, the two baud-wheelswiil at once he turned and inclined tdthe axis'oi' their shaft by means of the rod N, plate I1, sliding collar F, and links K K, as hereinbefore described, the one, E, (operating the valve covering 'the steam-ports of 'that' piston which is at thedead-point,) upon a pivotal axis coincident pi -i a; line passing through the pivot points nor the valve '1. connected therewith, (see fig. 8,) the other,l l', (operating the valve of the piston, which is on its ccntcu) upon an axis at right angles to a line passing through the pivots'of'its'valve-rod P, so as to turn said rod and open the valve J, as shown in' fig. 9. The steam from the steam-chest will passthus at once to the proper cylinder A, and start the engine.

So soon, then, as the shaft 1) begins to revolve, the. valve T of the cylinder A whose piston wasat its deed-point will open, and in due time the other, T, will close, the valves being made to open and close alternately by the rotation of theshaft D operating upon the valve-rods? 1", by means of their inclined band-wheels E E, as described.

, It will be observed that the valves are thrown wide valve, so that when the up:

plateor plates acover. both ports m m, (see fig. 8,)'

will bell) a horizontal or right position, (see dotted upon the shaft at such reference to the position of the cranks of the "so that the steam-ports tothat cylinder will'he wholly from the engine, it is only figs. l and 2, the operating lever is in a pcrpcmlicular .of its valve-rod P, so that it will not move saidrod,

open, or are entirely closed, at a dead-point in the rocking movement of the valve-rods, so that while pasing this dead-point the valves are kept'momeub' It will be also observed that the exhausts are at once thrown open the moment the ports admitting steam to the' cylinder begin to open, (see dotted lines, fig. 8,) and that they remain open until the steam is entirely shut ofi' from the cylinder.

The valves may be made to open more or less by :a change in the inclination of the band-wheels, produced by means of a move'ment'of the lever o.

The engine may be reversed by reversing the inclination of said hand-wheels, and when the engine is stationary, the direction in which it will move in starting is determined simply by the direction in which the lever o is thrown.

As there can be no communication established between the cylinder ports and the exhaust until the valve is inclined to one side or the. other, the "valve may he made with two lobes, as illustrated in fig. 10, instead of in an entire semicircle; or it may be made of a form as illustrated in fig. 11, or'other'u'ise moditied, so as to adapt it to special positions.

The valve-rods P P may be made to work in any position, and the hand-wheels. E E may he placed upon a secondary shaft, instead of upon the main shaft.

I contemplate .operating any of the well-knowu forms of slide-valves by means of my band-wheels and rocking valve-rods by simply converting the rocking movement of the rods P 1 into a reciprocating movernent by any well-known meehanicaidevice for this purpose. Hence my invention is applicable to nearly all direct-acting engines, and I contemplate such adaptation and applications thereof.

I claim as my invention-- volving shaft at right angles to its axis as to admit of being inclined thereto at pleasure, in combination with a rod pivoted to the band of said wheel, for the purpose of producing, by the revolution of the shaft and wheel, a rocking movement of the rod to operate the valve of an engine, substantially in the manner and for the purpose herein set forth.

heing inclosed within a steam-chest, S, and made tooperate substantially as herein set forth.

The'iore oin" s eification of m im rovements in O O steam-engines signed by me this 14th day of March,

A. 1). 1870. WM; B. DODDRIDGE.

Vt'itnesscs DAVID A. Dunn, H. H. Yousa.

1. A band-wheel, E or E, so pivoted upon a re- 2. The two pivoted band-wheels E and 1', arranged iber and with a revolving shaft, D, valve-rods P P,

control an inclination of said wheelsupon the shaft,

4. The valve-plate n of a holiowvalve, '1, 'which.

bination with ports at m in a face-plate, U, the whole

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