US450374A - Compound engine - Google Patents

Description

(No Model.) 3 Sheets-Sheet 1.

A. J. PITKIN. COMPOUND ENGINE.

No. 450,374. Patented Apr. 14,1891.

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(No Model.)

A. J. PIT'KIN. COMPOUND ENGINE.

Patented Apr. 14,1891.

NITE TATES PATENT FFICE.

ALBERT J. PITKIN, OF SGHENECTADY, NEW YORK.

COMPOUND ENGINE.

SPECIFICATION forming part of Letters Patent No. 450,374, dated April 14, 1891. Application filed January '7, 1891- Serial No. 376,986. (No model.)

To all whom, it may concern.-

Be it known that I, ALBERT J. IITKIN, a citizen of the United States, residing in the city and county of Schenectady, and State of New York, have invented certain new and useful Improvements in Compound Engines,of which the following is a specification.

My invention relates to compound engines of that class in which live or high-pressure steam simultaneously may be admitted to both cylinders or passed successively through one cylinder to the other. This end heretofore has been attained by means of a branched live-steam pipe and an intercepting-valve interposed between the cylinders and automatically actuated in one direction by the live steam to close it and in the other by the pressure of the steam in the low-pressure cylinder to re-establish this connection. United States Letters Patent No. 417,083, granted to me Docember 10, 1880, illustrate such an organization.

The objects of my present invention are, among other things, automatically to open and close the intercepting-valve by the direct action of live steam; to admit live steam to the low-pressure cylinder through a valve actuated by the intercepting-valve instead of opening it by the direct-pressure of the steam, and, finally, to open the intercepting-valve by steam-pressure from the receiver when the engine is running without pressure on the cylinders. These ends I attain by certain novel combinations and organizations of instrumentalities hereinafter claimed.

My improvements are applicable to either stationary, portable, or locomotiveengines.

The accompanying drawings illustrate so much of an engine of the latter type as is necessary to illustratethe subject-matter claimed. Unless otherwise indicated, the parts are of usual well-known construction.

Figure 1 represents a front elevation, partly in vertical transverse section, showing the cylinders, their saddles, the smoke-box, the receiver, and intercepting-valve and steam-passages Fig. 2, a horizontal transverse section through the interceptingvalve and other valves relating thereto on the line 2 2 of Figs. 1 and 4, showing the relation of the parts when the intercepting-valve is open; Fig. 3, a

similar view of some of the same parts in the position they assume when the interceptingvalve 1s closed; Fig. 4, a vertical longitudinal section through the intercepting-valve on the line 4 4 of Fig. 2 with the valve open. This figure is also a section on the line 3 3 of Fig. 1. Fig. 5 is a vertical transverse section through the regulating and intercepting valve actuating devices on the line 5 5 of Figs. 2 and 4; Fig. 6, a similar section on the line 6 6 of the same figures; Fig. 7, a vertical longitudinal section through the regulating devices on the line 7 7 of Figs. 1, 5, and 6; and Fig. 8, a vertical transverse section through the intercepting-valve on the line 8 8 of Fig. 4.

The feathered arrows indicate the direction in which the steam passes through the apparatus, While the short unfeathered darts in Fig. 2 show the movements of the regulatingvalve and the actuating-piston of the intercepting-valve.

Fig. 1 shows a smoke-box A, mounted on saddles B C, respectively connected with a high-pressure cylinder D and low-pressure The intercepting-Valve and its appurtenant apparatus are shown as mounted on the saddle Q of the low-pressure cylinder, while the live-steam connections and high-pressure exhaust devices are mounted on the other saddle B. The low-pressure exhaust-pipe E lies centrally between them. The interceptingvalve G somewhat resembles that shown in my patent above mentioned, but differs therefrom in several details of construction, organization, and operation. It consists, essentially, of two pistons G G mounted at suitable distances apart and in fixed relation to each other on a stem 9 and provided with longitudinal perforations g for the passage of live steam through these valves or pistons.

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side of the intercepting-valve when closed,

Consequently the live steam, which exerts the greater pressure, compensates any looseness in the fitting of the valve by tending to press itupward against its seat when closed, thus preventing the live steam leaking into the receiver.

A piston-rod Il, connected with the intercepting-valve, passes through suitable stuffing-boxes h h in the heads of the valve-chest and of a separate cylinder I, provided with a piston H, which actuates the interceptingval've. This actuating-cylinder I is provided with inlet-portst' z" and an exhaust-port The entrance of steam to this cylinder-is controlled by a slide-valve 7v on a stem 70, carrying two pistons K K, sliding in a chamber K Steam is admitted to this chamber through ports 9', j, and jithe first two admitting steam between the pistons, while the other admits it to act upon the outer end of the larger piston K, this piston being made larger than the other in order to insure its movement in the proper direction at the proper time. Live steam from the boiler passes through a pipe L directly to the high pressure cylinder. A branch pipe L from this pipe connects with a port Z of an auxiliary regulating-chamber M, provided with a piston-valve m, which I call a regulating-valve, traversing across the inlets jj of the regulating-chamber K to open or close them 'at the proper time. A pipe M connects the receiver F and its induction-pipe E with this auxiliary valvechamber M and with the port 7' Fig. 7, of the chamber K which is provided at its opposite end with an outletj for the escape of steam or water which may leak into that end of the chamber. The outlet 1' of this chamber is contracted, as shown in Fig. 5, or provided with means for regulating the escape of the steam therefrom, so as to prevent the slamming of the piston H and of the intercept ing-valves actuated thereby.

A valve-chamber N contains a puppet-valve N, having two seats n n and a stem N ,projecting outside the valve-chamber. A port 41 admits steam to this valve-chamber from the live-steam branch pipe L, and a passage n permits its escape into the intercepting-valve cylinder 0, and thence through the porte to the low-pressure cylinder E below the intercepting-valve, as above mentioned.

An elbow-lever O, rocking on a fulcrum or pivot 0, has its longer arm forked, so as to embrace pins 0 on the piston-rod H of the intercepting-valve The other arm 0 of this lever constitutes atappet or wiper, which acts at the proper time on the stem of the puppetvalve N to open it. This valve is so constructed that its outer member is of greater area than its inner. The preponderancy of pressure on the outer end of the valve tends to keep it closed when released from the wiper 0 The relation of the wiper and valve-stem may be controlled either by adjusting the collar on its piston-rod or adjusting the wiper.

The operation of the apparatus is as follows: The normal relation of the parts when operating asacompound engine is that shown in Figs. 2 and 4, in which the interceptingvalve is opened and the admission of steam to the low-pressure cylinder, except through the high-pressure cylinder, receiver, and induction-port E, is cut off. The apparatus is provided with suitable cutoff or throttle valves. (Not shown in the drawings.) To work both cylinders with high-pressure steam, a throttle-valve is opened, which permits live or high-pressure steam to pass through the branch pipe L and port Z to the auxiliary or regulating valve chamber M, the valve m of which it forces to the right, (see Fig. 7,) so as to open the port j and permit steam to pass into the valve-chamber K between its pistons K K. The right-hand one K of these pistons being of greater area than the other, the steam-pressure forces them to the right from the position shown in Fig. '2 to that shown in Fig. 3. This movement causes the slide-valve 76 to uncover the ports i of the cylinder 1, which in turn "forces the piston H to the right, closing the ports 0 o of the intercepting-valve, as shown in Fig. 2. The relation of theparts is such that as the intercepting-valve closes the wiper 0 strikes the stem N of the puppet-valve Nand opens it, thus permitting high-pressure steam to pass from the pipe L, through the passages 72 of, into the intereept-ingvalve cylinder, and through the port ethe'rein to the low-pressure cylinder E below the intercepting-valve, thus operating it with the full pressure of the live steam. The intercepting-valve, as before remarked, is already closed, and the tendency of the live steam is to press it upward in its seat, so as to prevent any leakage into the receiver and consequent back-pressure upon the high-pressure cylinder. The perforations g in the intercepting-valve prevent the steam from exerting any 'endwise pressure upon it in either direction, and it is consequently entirely dependent upon the action of the live steam upon its piston 11 in the actuatingcylinder I. The intercepting-valve should have sufficient lap to move slightly beyond its closing-point, in orderthatthe opening of the supply-valve N may not take place until the intercepting-valve is fully closed, the tappet 0 being correspondingly adjusted. hen it is desired to change from direct to ICC compound action, the live steam is cut off from the low-pressure cylinder. The pressure in the receiver and the induction-pipe E then soon becomes sufficient to force steam through the return-pipe M into the auxiliary chamber M and force the regulating pistonvalve m into its sea thus closing the ports Z andj and simultaneously opening the portj'. The steam then passes through this lastnamed port and the port 9' to opposite sides of the larger piston K, the result of which is to force the slide-valve k to the left in the position shown in Fig. 2, which opens the exhaust i and the inlet 2" of the cylinder I and forces the piston H to the left, thereby opening the intercepting-valve. This movement of the piston H detaches the wiper'o from the puppet-valve N and allows it to close quickly before the intercepting-valve opens. The parts having thus resumed the position shown in Fig. 2, the engine resumes its compound working. It will also be perceived from theforegoingdescriptionthattheinterceptingvalve will automatically be opened whenever the pressure in the receiver is sufficient to overcome that of the live steam in the auxiliary regulating-valve, and consequently it is not necessary even to cut off the live steam, unless it is desired, in order to open the valve quickly at any particular moment. The intercepting-valve will also be opened even when the steam is cut ofi, as in the case of a locomotive on a downgrade, should there be sufficient exhaust from the high-pressure cylinder to cause the requisite pressure in the receiver.

The operation maybe concisely stated thus: The opening of the throttle admits live steam simultaneously to both the high and low pressure cylinders, and by means of this samelive steam acting through a mechanism separate and distinct from the intercepting-valve itself the latter is automatically closed and the en-. gine starts with its full power as a simple or non-compound engine. The steam-pressure thus caused in the receiver actsthrough the auxiliary regulating-valve m upon the slidevalve k and opens the intercepting-valve, mechanism connected with which releases the valve controlling the admission of live steam to the low-pressure cylinder, which valve automatically closes itself, thus causing the parts to resume their compound working. The exhaust-steam does not move the intercepting-valve in either direction or exert any action upon it whatever.

Havingthus fully described the construction, organization, and operation of my improved compound steam-engine, what I claim therein as new and as of my own invention 1. The combination, substantially ashereinbefore set forth, of a high-pressure cylinder, a low-pressure cylinder, their connecting pipe or receiver, an interceptingvalve, its chest, its piston-rod, a separate cylinder, and a piston therein on the intercepting-valve rod automatically actuated in both directions by the direct action of the steam in said cylinder to open and close the intercepting-valve.

2. The combination, substantially as hereinbefore set forth, of a high-pressure cylinder,a low-pressure cylinder, their connecting pipe or receiver, an intercepting slide-valve therein, its valve-chest, its piston-rod, a separate cylinder, a piston therein on the intercepting-valve rod, and a slide-valve regulating the admission of steam thereto and automatically driven in both directions by the direct action of the steam therein.

3. The combination, substantially as hereinbefore set forth, of a high-pressure cylinder,a low-pressure cylinder, their connecting pipe or receiver, an intercepting-valve therein, its chest, its piston-rod, a separate cylinder, a piston therein on the intercepting-valve rod, a slide-valve regulating the admission of steam thereto, and .a steam-pipe connecting the receiver and actuating-valve chest, so as automatically to actuate the valve in both directions to open or close the intercepting- Valve. I

4. The combination, substantially as hereinbefore set forth, of an intercepting-valve,a piston connected therewith, valve mechanism automatically controlling the movements of the piston, and regulating mechanism controlling the admission of live or high-pressure steam to the automatic valve mechanism and piston by the direct action of the steam upon the regulating mechanism.

5. The combination, substantially as here inbefore set forth, of an actuating-cylinder, its piston, its automatically-actuated valve mechanism, and mechanism automatically regulating the admission of steam to the valve mechanism and cylinder by the direct action of the steam upon the regulating mechanism.

6. The combination, substantially as hereinbefore set forth,of an actuating-cylinder, its piston, its steam-ports, a slide-valve trav ersing these ports, pistons actuating the slide valve, a regulating-chamber, a valve therein, and steam-ports on opposite sides thereof admitting steam simultaneously on opposite sides of one of the valve-pistons to control its movements.

7. The combination, substantially as hereinbefore set forth, of a steam-cylinder, an intercepting-valve, means for actuating it automatically in either direction by the direct action of live or high-pressure steam, a valve controlling the admission of steam to the cylinder, and automatic mechanism actuated from the same source as the interceptingvalve to actuate the steam-inlet valve.

8. The combination, substantially as hereinbefore set forth, of ahigh-pressure cylinder, a low-pressure cylinder, a receiver, an intercepting-valve, mechanism for actuating it automaticallyin both directions by'the direct action of live or high-pressure steam, a valve, regulating the admission of steam thereto,

and steam-inlets on opposite sides of said valve respectively connected with the livesteam pipe and With the receiver, whereby the mechanism may automatically be actuated either by the direct action of the live steam or by the pressure of that in the receiver.

9. The combination, substantially as hereinbefore set forth, of ahigh-pressure cylinder, a low-pressure cylinder, a receiver, an intercepting-valve, its actuating mechanism, its regulating mechanism, a live-steam pipe admitting steam to the regulator, a pipe connecting the receiver and regulator, a valve controlling the admission of live steam to the low-pressure cylinder, and automatic mechanism for positively opening said valve.

10. The combination, substantially as here inbefore set forth, of an intercepting-valve, mechanism automatically regulating its movements, a valve admitting live steam to theintercepting-Valve, and mechanism adapted to open it automatically, mechanically, and positively independently of the direct action of the steam thereon.

11. The combination, substantially as herei inbefore set forth, of an intercepting-valve, its piston, a valve admitting live steam to the intercepting-valve, and mechanism controlled by the movements of the intercepting-valve positively, automatically, and mechanically to open the steam-valve.

12. The combination, substantially as hereinbefore set forth, of a high-pressure cylinder, a low-pressure cylinder, a receiver connecting them, a valve-casin g therein, a longitudinallyperforated intercepting-valve traversing said casing, a piston-rod connecting the intercepting-valve with an actuating-piston in a separate cylinder, a valve admitting live steam to the intercepting-valve, mechanism connected with the piston for positively opening the valve, and a port in the intercepting-valve casing communicating With the low-pressure cylinder.

in testimony whereof I have hereunto subscribed my name.

ALBERT J. PITKIN.

Witnesses:

ARTHUR M. LANE, R. M. GIFFORD.

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