US106899A - George westinghouse - Google Patents

Description

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team Patent No.106,s99, aan' August 3o, 1870.

IMPROVEMENT IN STEAMfENGINE AND PUMP.

The Schedule referred to in these Letters Patenta'nd making part of the name.

To all whom it may concern:

Be it known that I, GEoRGnWnsTINGHoUsE, J r., of the city of Pittsburg, in the county of Allegheny and State of Pennsylvania,have invented a new and useful Improvement in Steam-Engine and Pump; and I do hereby declare the following to be a full, clear, and exact description thereof', reference being had to the accompanying drawing, in two sheets, making a part of this speclcat-ion, in which- Figure 1 is a front elevation of my improved engine aud air-pump; y

Figure 2 is asectional elevation, as formed hy a vertical plane passing through the main steam and airpassages, a little back ot' the piston-stem;

Figure 3 is an enlarged (inverted) view of the main steam-valve, stem, and valves;

Figure 4 is a cross-section in the line x x, fig. 1;

Figure 5, sheet 2, shows a vertical section of the auxiliary cylinder, an outside view of which is contained in gs. 1 and 6, said section being taken in the line :c x, fig. 6.

Figure 6, sheet 2, is an enlarged view in perspective of the main and auxiliary cylinders and their conue'ctions;

Figure 7, sheet 1, is an end view of the main cylinder-head A, just under the auxiliary engine, and

showing the arrangement of ports for admitting/'stema To4 and from the auxiliary engine, by means of a valve and stem, of which latter- Figure 8 is a side elevation,.and Figure 9 is a View of the lower face. Figure 10, sheet 2, is an end view of the 'steam-piston-head, showingthe slot through which the pistoustem of iig. S operates and Figure 11 is au elevation of the mainsteam and air-- pistons, and of the stem which connects them.

Like letters of reference indicate like parts in each.

My present improvement relates Y more particularly to steam-engines and air-pumps for operating atmospheric power car-brakes, such as are described in Letters Patent granted to nie April 13, 1869 ;l but the devices presently to be described are, many or all of them, applicable to other uses, as will be obvious to those skilled in the art.

The nature of my invention consists in the construction of improved devices for operating steam-engines and air-pumps.

To enable others skilled in the art to make and use my improvement, I will proceed to describe its construction and mode of operation, with more particular reference to its use in connection with atmospheric steam-power car-brakes.

The main steam-cylinder A and air-pump barrel B are bored out each with the usual cylindrical cavity.

In the former I arrange a steam piston-head, A,

g, 11, and in the latterapumping-piston or plunger, B, both suitably packed.

The head A1 and plunger Bl are connected by a stem, A2, in such a way that at any part of the stroke they shall occupy corresponding positions in their respective cylinders.

The stem Az is square in cross-section, or of other than circular shape, so that, by passing through `a stuting-nut of like shape, it, as well as the head `Al and plunger B1, with which it is rigidly connected, will be prevented from turning around.

Between the cylinders AB is a stuing-box, O,figs. 1 and 4, through which plays the stem A. This box is mortised through ltransversely at or near its middle part, and a pair ot" stnfling-nuts, c c, with suitable packing, inclose the stem A2, the packing faces of the nuts being shaped to fit the stem. The nuts c c fit neatly into the nlortise of the box O.

The outer cnds'of thenuts areT-shaped, so that the projecting ends c of the T-heads shall project up and down beyond or outside of the mortise.

A pair of screw-bolts, c2 c2, are then passed through Y the ends c1 of the T-heads, so asto give the nuts c a `suiiciently secure hold on the stem A. At the same time I so proportion the several parts that the nuts c, when screwed up, shall have a little lateral play, that is, the distance between the opposite ends cl shall be a little in excess of the thickness of the box G, as shown. I thus prevent any excess of pressure and loss by friction thereby on either side ofthe stem A. The stuffing-nut c c adapts itself to the pressure, and constitutes a seliladjusting packing.

' The steau1-chest D has a port, d, for the admission of steam from the boiler. This chest has acavity, d, which connects the valve-seats and ports at its oppositeends. These valve-seats a, at the ends, are bored out with a slight taper, as shown.

Around each valve-seat is bored out an annular cavity, cl2. Through the opposite sides of each valveseats a are two steam-ports, al al, which lead from the cavity of the steam-chest d into the annular cavity d2, and thence steam passes into the cylinder through ports a?. The valves e are of conical form, and. operate by a rotary motion closely in their valve-seats a. They are rotated by a stem, es, which, at one end, projects through a stuing-nut, e", and packing, and onitsend is a crank, e, through which the rotary motion is 'imparted,.as presently to be explained.

In the faces of each of these valves c is a series of recesses, el, which alternate with another series, e, one series, el, opening at one end of the valve, and the other series, e, at the other. One of these series, e,

is for the supply of steam from the chest d1, throughV the ports al a2 to the cylinder A, and the other,e, for

the exhausting steam from the cylinderA through the same ports into steam-passages d3, which lead through the cylinder-heads A'1 A* to the exhaust D on the opposite side of the cylinder A, whence the steam passes oti' through an-eXhaust-port, d4.

The valves e are carefully and accurately adjusted n their seats a by `means `pt` set-screws ll l, the one, ll, passing directly through the cylinder-head A4, figs. l and 2, and the other, l, being supported by an arm, l, and post l, figs. 1 and 6. The inner ends of the set-screws l l bearagainst the ends of the valve-stem c", so that by loosening one and tightening the other, the valves e can he adjusted in their seats readily and with accuracy.

In order to impart thc desired rotary motion tothe val es e, I use an auxiliary steam-cylinder, E, which is 'tted with a piston,`E1, and stem E2. To furnish this cylinder E with steam, I run a. steam-port, c, g. 7, from the steam-chest D, through the bodyv of the cylinder A, through its outer head A3, and terminate it in the port c, on the outer faceot' the head A.

On the opposite side ofthe ports care two ports cl, each of which communicates by a steam-passage, c?, lending through the head A3, thence upward through the cylinder base E, tig. 5, into the cylinder E, one at or near each end, so as to admit steam on opposite sides of the piston E. l

To open and close the ports c c, I use a rotating disk-valve. g, figs. 8 and 9,` which has a stem, g, Hat, or of other than circular shape in cross-section, and twisted, as in iig. 8. This valve g operatesin achamber, h,g. 5, in the lower face of the cylinder base E3.-

The stem g extends through an opening, g, in the cylinder-head A, fig. 7, which openingis merely large enough to permit ot' its rotating, and thence through a slit, g2, in the end of the piston A1, fig. 10, in which slitit operates closely, so that as the piston moves up and down, the twists of the stem g1 following the slit shall give a slight rotary motion tothe valve g. These twists should be at only two points, and at such points as will beucted'on at or near the end ot' each stroke of the piston A. 'Below the slit qz the piston-head AI and stem A2 should be hollow or chambered outto a depth at least equal tothe length of the stem.

In the edge of the llower face of the.valve g, right over the ports c c is a notch, t, of suilcient extent to uncover two of the ports c cl at once, that is, the middle port c, and alternately one of the side ports' c1. Then, as the pistou A1 moves up and down, it rotates the valve g, uncovers the ports cl alternately, so that steam passes from'the steam-chest D, through the ports c2 c c alternately into the cylinder' E, on `opposides of the piston El.

' The stem E2 of this piston is attached by aneye, e, to the crank e5 on the end ofthe valve-stem e, sothat as the former moves back and forth, the latter will receive a short rotary motion, to open and close alternately the ports a, which lead by recesses ,el c2, in the valves e e from'the steam-chest D to the cylinder A, as already explained.

The eye eismade oblong, as shown in fig. 6, Vsothat "it mayshift the crank e5, when the latter passes outside the line of mot-ion of the stem E2. To exhaust the steam from the cylinder E, I use theports cl cl alternately as exhaust-ports. When either is cut olf byv the valve g from communication with the supplyport c, it opens into a groove, il, in the lower face of the disk g, which groove is always infcommunication with a port, c, fig. 7, which leads through the head A to the main exhaust d3. This exhaust c" is' made comparatively small, so that the steam shall escape slowly, and thereby/.cushion the piston El.

It will be observed that the stroke required in the piston-head' El is exceedingly short, in fact, barely low enough to turn the stein c3 and valves e sufficiently t0 cover and uncover the ports al. I makethe head lll light, so that it may have but small momentum, and I also secure for it a short stroke, by running an adas soon as the piston-head El has passed such port either way, the steam behind it is exhausted sofreely that the head E has nothing to carry it further, except its momentum, and even this', little as it is, is taken up by the cushioning steam in front.

the steam-chest D, along the recesses eL of one of the valves through the ports al, along the annular passage d2, to the front ofthe main piston A1, giving a'throw or starting it on a stroke. lAtrthe same time the exhaust-recesses e2 of the other valve coincide with the ports al of that yalve-seat, sol that the steam in front of the piston passes out into the exhaust.

The stroke of the pist-on .Al gives a. throw to the valve g, opens the ports for the passage of steam to the cylinder E, and it, by its piston El and stem E, rotates the main valve-stem e, so as to shift the recesses e* e2 of the main valve e, whereby steam is admitted 'onto thefother side of thel main piston A1, and exhausted where before it was supplied and so on alternately and continuously.

In this-way I communicate motion to the plunger Bl of the pump-barrel B. This pump I use as an air,- pnmp to compress the air, so as to make it operative by its elasticity in the application of car-brakes, or for other uses. The pump is designed for use in an upright position, as shown in tig. 1.

Along one side ot' it is an air-chamber, B, into which air is supplied through any suitable port b.

through which, and out at a port, b, .the air is forced seat, onto which it falls by its own weight.

Directly above this, in the chamber u, orin a valvebox, 1d, adjusted in such chamber, is a like valve, c* with stein s* operating in a similar manner.

The port m comes between these two valves.

In the lower end of the chamber B, or rather in s, falling by its own gravity onto a seat, and directly labove it, resting on a seat iu the lower eiid of the chamber B, is a'likevalve, v3 and stein s3.

A little above this valve c is a stop, w, to keep the valve frombeing driven too far from its seat.l The port ml comes between these two valves.

It will be. observed that all the valves described are seated by their ownvweight, and' remain seated, except when raised. bythe incoming or outiiowing air.

The operation is, then, as follows:

,With the downwardl stroke of the plunger B1 .the air is forced out at the port ml. Its pressure, in esbaiting, raises the' valve c, through which it passes, and thence alongthe chamber B, and out at the port b. At 'the same time, to supply what would otherwise be a vacuum above the plunger, the air enters at the supply-port J1, rises and passes through the valve c, and into the cylinder through the port m. With .theupward strokc'of the cylinder, the air above the pist-n Bl passes out at the port m, lifts and passes through the valve cl, follows the chambers'ab2 u B3 to the port b1, whence a pipe conducts it to the reservoir.

To furnish a new supply of air beneath the pistou,

ditional exhaust port, o, iigs. 5 and 7,l rom near the middle of thecylinder E to the main exhaust d. Then It will now be observed that the steam passes from I .On the opposite side is a like .'1irchamber,l3,`

through pipes to the reservoir, or direct to the brakesuch valve being such as to guide the valve to its the chamber yu,i,s a similar poppet-valve, v2, W'ith stem the air rushes in at the supply-port b, follows the chambers B2 ul. b3 u, lifts the valve c2, and enters at the port ml, and so the operation goes on continuously.

In many of the features described I do not desire to limit myself to the exact construction set forth.` The valves e may be made cylindrical, instead of conical, and the seats shaped accordingly.' Also, 'the same result may be accomplished, though less advantageously, with a single pair of recesses, cl e", on each valve, and a single port, al, as with two or more pairs oi'such recesses and a corresponding number of ports; but by the use of a double set of recesses, el e2, the two ports al in each valve e, and the annular chamber d2, surrounding each valve-seat, I provide for a more perfect balancing of the valves; also, in the construction of a valve ,for opening and closing the ports c c of the engine E, and in operating the same by means of a hollow piston-head and stem, I do not limit myself to the disk-valve g and twisted stern g, described. A slid-y ing valve ot' short throw might be made to do the same work by means of the valve-stem entering the hollow of the piston-head and stem, the two being so constructed that at any desired part of the stroke of the piston-head A, it shall engage some fixed pointA in or part of the valve-stein; hence, in this connection, I claim, broadly, a piston-head and stem, made hollow, for the insertion of a valve-stem, which latter is to be actuated thereby. y

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

1.v A pair of rocking-valves, e e, on a common stem, each valve having two or more recesses, el e2, such recesses alternating with each other, and opening on oppositeV directions'on the same valve, substantially as and for the purposes described.

2. A valve-seat, a, having ports al, which open into an annular steam-passage, de, in combination -with the valve c of the previous claim. 5

3. A piston-head and stem, made hollow for the insertiontherein of a valve-stem, which latter is to be actuated thereinand thereby, substantially as described.

4. A steam-valve, g, having a stem, g1, twisted at such points, head and stem, it shall, by the motion of such head and stem, be rotated orirocked, substantially as described.

5. A groove, t", in the lower face of the disk-valve y; in combination with the ports c, c1, and c, arranged substantially as described. j;y 6. A central auxiliary exhaust, arranged at or yneary the middle of that part of a steam cylinder through which the piston-head operates, for the purpose of arresting the stroke of the piston-head, substantially as set forth.

7 A studing-nnt, o c, formed in two or more parts, so constructed together and arranged with reference te the stnfng-box as automatically to bear with equal pressure'on the opposite sides of the stem, substantially as described. n

8. rllhe subject-matter of the last claim in combination with a piston-stem, A, of other than cylindrical form. l

9. The-air-inlet fines B2 b3 and air-outlet ues WB, in connection with the air-ports m m and valves o c* v2 c3, arranged substantially as described.

l0. In combination with the valve-stem e3 and valves e, the adjusting set-screws Z P, arranged substantially as described.

11. The arrangement of the auxiliary steam-cylinder E, with its axial line at right angles to the axial line ofthe-main cylinder, substantially as set forth.

In testimony whereof, 1', the said GEORGE Wns'r- INGHoUsE, Jr., have hereunto set my hand.

GEORGE WES'IINGHOUSE, Jn.

Witnesses: A. S. NICHOLSON,

THos. B. KERR.

that entering a slit in a hollow piston-

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