US93383A - Improvement in steam-engines - Google Patents

Description

ltati? taies stent (twine.

Letters Patent No. 93,383, Ia-ted Aut/ust 3, 1869.

IMPROVEMENT IN STEAM-ENGINES.

The Schedule referredtoin these Letters Patent and making' part of the same.

To all whom it may concern.-

Y,Be it known that I, JAMES D. WILLoUGnnY, of Shippeusburg, iu the county of Cumberland, and State of Pennsylvania, have invented a new and useful Improvement in Steam-Engines; and I do hereby declare that the following is a full, clear, and' exact description thereof', reference being had to the annexed drawings, and to the Vletters ot' reference marked thereon.

This invention relates to steam-engines; and

It consists in the construction, combina-tion, and arrangement of its parts, as will be more fully described hereinafter.

Figure l is a side elevation;

Figure 2 is a transverse vertical section on line x a of tig. 5;

Fig-ure 3 is a longitudinal vertical section on line W W, iig. 5;

Figure 4 is a vertical longitudinal section on line z e, iig. 5;

Figure Figure of tig. 5;

Figure 7 is a transverse vertical section W ot' iig. 5;

Figure S shows the position the crank and shattare in, when the eccentrics are in the position shown in iig. 6; and

Figure 9 shows the position the cr'ank and shaft are in, when the eccentrics are in the position shown in iig. 7. Y

A is the steam-cylinder; B, the piston-rod; c, the crank; and D, the shat't, all made as such parts are usually made.

E E are bearings, that hold the shaft in its proper position.

F Fl F? F3 are the eccentrics, that are on the shaft D. Their position is shown in figs. (i and 'L Fig. 6 shows the position oi'thc cccentrics when the 5 is a plan view; 6 is a transverse vertical section on line y y on liuc W engine is on its dead-centre, as shown by the positiony of the crank in fig. S.

Fig. 7 is the position the ecrentrics are in when the engine is at halt' stroke, as is shown bythe position of the crank in tigri). i

The eccentric Fi is shown, in dotted lines, behind F1, in figs. 6 and i, It is placed olrthe shaft D, at a right angleto'thc crankc.

The eccentric F is placed on the same shaft, onefourth of a revolution behind F2.

G and 'Gr1 are rods, extending tioin the eccentn'cs F and F to the link L, and are pivoted to each end lof the link, inl the usual manner.

This link has aV slot in it, longitudinally. Into this siot, one end of the rod H is entered, thc other end beingattached to the valve H2.

G: and G are rods, of equal length,l that extend from the eccentrics FZ and F3 to the link L1.

One rod is pivoted to the upper end of the link, and the other to the middle of the link, as seen iu iig. 3.

The link has a longitudinal slot in it, into which one end of the rod H1 is put. The other end of the rod is attached to the valve H3.

T 'J1 are levers, or devices to raise and hold the links in any desired position, to operate on the valves.

H'Z is an induction and eduction steam-valve.`

Over the back of, this valve is placedI a partitionplate, P P, which divides the steam-chamber into two parts.

The valve Hl is like other valves on its face or under side, but has packing around it, so as to fit upward against the plate P P, and on each side against the steam-chamber, so as to prevent the steam from" passing from one end of it to the other. This packing may be secured either to the valve or to the steamchamber, and, if desired to relieve the valve from pressure, may be put on at two points, as seen in the drawings at S.

The plate P P has two ports in it, Ii i, for the admission of steam to the chambers o and c', or to each end of the valve H2, the packing on that valve having made two chambers below the plate P P.

H" is a valve, that lies on plate P P, and is of sut'- ticient length to extend from the middle ot' one part to the middle ofthe other.

By this arrangement, when the valve closes one port halfway it will have halt` opened the other, and when thc valve has completed its stroke in either direction, it will have to travel just as far hack to'close the port last opened as it did travel forward since it opened that port, thus occupying 'a halt' stroke, or `the time of a halt stroke of the engine, and insuring therelby uniformity in time in cutting off steam, either on the -forward or backward strokel ofthe engine.

K K are elevations around the ports fi t', and other points, for the valve to rest steam-tight upon, and allow steam elsewhere to get underthe valve, to avoid downward pressure.

R is a pipe, for the admission .of steam Ainto the chamber M, where the cut-oit' valve H-operates.

The mode of connecting the piston-rod v with the piston-head, or oscillating the rod in the cylinder-head, as well as the device for holding the links in any desired position, and the mode of connecting the valves wit-l1 the links, may all he varied to suit circumstances, and thc most approved known forms can besubstitutcd. Cams or cranks, under certain circumstances, may lbe used instead o f ecceutrics to operate the valves, andthe valve' H2 may be made in whatever forni is most convenient for receiving the packing.

The Operation.

Steam is admitted, through the'v pipe R, to the steam-chamber M, around the valve H. As 'thev valves now stand in gs. 1 and 4, the steam would pass down, through the port i', into the steam-chamber o', and, through the port u', into the cylinder A. As the cut-oil` link L1 is now held, the cut-olf valve H3 wouldnot close the port i much before the end ofthe stroke of the engine, for the reason that the eccentrics F2 and F3, which move the link, are so placed on the shaft I) that they cause the lower end of the link, which is now controlling the valve, to be so late in reaching the cutting-olf point that the stroke ofthe engine is nearly completed before that point is reached.

If the link had been so held as to cause the middle of it to control the valve, then the steam would have been cut ol at half stroke; or, if held so as to cause the upper end torcontrol the valve, then the steam would have been cut o' at the commencement ofthe stroke of the engine.'

Any variation in the point of contact between the link and valve, will produce a corresponding difference in the time ol'cuttiug off.

The eccentiics are so arranged on the shaft that the return motion cuts off as did the forward motion.

The lower end of the link Ll might be dispensed with in engines which did not require a greater range of cut-ting off than is found between the two pivoted points of the link; and if that limited range were required nearer the middle or last part of the stroke of the engine, the eccentrics might both be placed further back on the shaft, to accomplish the object desired.

It is obvious that the eccentrics may be made larger or smaller, and maybe varied in size relatively to veach other; they may be put a little closer together, or further apart; the pivoted points may be varied; the projecting end of the link may be put upward; and various other modifications might be made, which are regarded as the same thing to accomplish the same purpose, which is to cut ofi' steam with as wide a range as may be desired, and 'to close and open the ports when the valve is making its most rapid motion, and, if possible, at the same point of stroke in the forward and backward mot-ion ofthe engine.

By this arran gemen t, there will, alternately, be more' pressure of steam on one end of thevalve than ou the other, which pressure will urge the valve in the direction it should travel during the last half of each stroke of the engine. This device becomes an auxiliary engine, to move the valve without the loss of steam.

It' two valves, with no comm unication between zwere used, one for each part, instead of the one valve H2, and if the cut-oli` valve H3, either as one valve, or in two parts, were made to open and close the ports, as desired, the same results would be reached as'by packing the valve H2, except the aid rendered bythe steam in the chamber to'move the valve.

lhe link L is the same as that now in general use for moving valves, and will answer well in this case, as by it the steam can be reversed.

In locomotives, and some other engines, the linkmotion is used as a means of cutting otf steam, which can only be done by shorteningthe stroke of the valve and, when the stroke is much shortened, the ports are never fully opened, and any shortening of the stroke causes the ports to b'e opened and closed more slowly, and is followed by a corresponding throttling of 4the induction and eduction-steam.

By using the cut-ofi` valve H3, the valve H.z can be made with reference onlyto receiving and discharging steam, and be free from vthe defects incident to cutting olf steam by'that valve.

It will be seen, that whenever the cut-ott valve H closes one port it opens the other. This arrangement is necessary, for the reason that this mode of cutting off steam-requires the valve to travel the same distance each way over the ports, no matter at what point of the stroke of the engine the cutting oi' may take place. the port is always-done when'the valve is moving most` rapidly, and not, as in many other cases, when the valve is at or near its slowest motion.

rlhe fact that the valve H, or cut-ofi` valve, always opens a port into the lower `steam-chamber, at the same time that it closes one, would be a defect, if there had not been devised some mode of preventing the in-` flowing steam from reaching the cylinder-port, which the valve H2 or cylinder-valve has not yet closed, and from which it is desired to eut oii the steam. p

This end has been accomplished, by making the valve H2 steam-tight in the chamber, as` has been specified, so that the steam, which is admitted b'y the cut-off valve into the chamber o, cannot get to o',`

neither can the steam get from the chamber o' to the chamber o. n

The port leading directly from chamber o or o' to the cylinder, is always closed by the cylinder-valve H, at the time the steam commences to enter the cham ber, and remains closed until the proper time arrives to admit steam to the cylinder, which admission is caused by the cylinder-valve moving from over the port.

What I claim as my invention, and desire to secure by Letters Patent, is-

1. The construction of the induction and eductionvalve H, with packing upon its surfaces, which serves to prevent the passage of steam from one of its ends to the other, substantially asshown and described.

2. The construction of the cutoff valve H, substantially as and for the purpose. described.

3. 'lhe combination and arrangement of the valves' H2 H3, and induction-ports i i', substantially as shown and described.

4. The construction of the link L', substantially as shown and described.

5. The combination of the link L1, eccentric rods Gr2 and G, and eccentrics F2 and F3, substantially as shown and described.

(S. The combination of the link L1,'valve-rod H1, valve H3, which it moves, substantially as shown and described.

In testimony whereof, I have signed my name to this specification, in the presence of two subscribing witnesses.

J. D. WILLOUGHBY.

Witnesses A. RUPPERT, C. F. OLAUSEN.

By so doing, the opening and closing oli'`

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