US624700A - Steam-engine - Google Patents

Description

(No Model.)

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A. STEPHENS. STEAM ENGINE.

(Application led Sept. 13, 1898.)

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Y Patented May 9, |8991.

No. 624,700. Patented May 9, |899. A. STEPHENS STEAM ENGKNE.

(Application filed Sept. 13, 1898.)

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UNITED STATES PATENT OFFICE.

'ALEJANDRO STEPHENS, OF GUADALAJARA, MEXICO..

STEAMiENGINE.

SPECIFICATION forming part of Letters Patent No. 624,700, dated May' 9, 1899.

Application filed September 13, 1898. Serial No. 690,846. (No model.)

To all whom it may concern: y

Be it known that I, ALEJANDRO STEPHENS, of Guadalajara, Mexico, have invented new and useful Improvements in Steam-Engines, of which the followingis a full, clear, and exact description.

My invention has for its object to provide a steam-engine which will be simple in construction, reliable in operation, capable of great speed, and economic in the use of steam.

To this end I construct the steam-en gine as fully described hereinafter.

The novel features of my invention will be particularly pointed out in the claims.

Reference is to be had to the accompanying drawings, forming a part of this specification, in which similar characters of reference indicate corresponding parts in all the gures.

Figure l is a sectional elevation of my improved engine on line l l of Fig. 3 with the piston in its lowermost position. Fig. 2 is a similar view with the piston at the end of the upstroke, and Fig. 3 is a side elevation of the engine with part of the cylinder and its cap or shell in section.

A is the frame of the engine, in which is journaled the main shaft B and which carries the cylinder C. In the cylinder is arranged to move the piston D, connected by the piston-rod E and the connecting-rod F to a crank G on the shaft B.

The piston D comprises two parts of different diameters and practically forming two pistons. The inner section D is tted to slide upon the outer surface of a central body C', secured at the bottom of the cylinder C. At a point adjacentto the upper end of the section D' when the `piston is in its lowermost position the top plate C2 of the cylinder and the central body C are provided with packin g-rings H, adapted to engage the piston-section D upon its inner and its outer surfaces. During its upstroke the piston-section D moves into a chamber I, formed by an upward extension C8 of the cylinder C. This extension has an opening C4 connected to the steamsupply. The outer section D2 of the piston is annular and surrounds the cylindrical portion of the piston-section D at the bottom thereof.- This outer section D2 moves in the annular chamber I', contained` between the cylinder C and the central body or core C and must be provided with'a packing-ring, such as I-I. plate C2 is surrounded by a cap or shell J, forming a closed chamber I2, which by means of apertures G5 in the top plate C2 communicates with the chamber I. The central body or core C of the cylinder has a partition C(i dividing it into a central chamber I3 and an outer annular chamber I4 communicating by means of apertures C7 in the partition C6. yThe central chamber 1200mmunicates at the bottom with the exhaust-pipe K and is open atthe top (see Fig. 2) to the'chamber I5, inclosed by the piston-section D' during its-upstroke. Near its top the chamber I2 has an annular groove C8, into which projects an annular rib C9, having apertures C0, by means of which the said groove may communicate with the chamber I3 proper. At the bottom the chamber I2 has channels C10 leading outwardly into the chamber I'. At the top the chamber I2, or rather the groove C8, is in permanent communication by means of an opening C11 with the working chamber I5 of highpressure cylinder D.

Within the chamber I3 are located two cutoff valves, one of which, L, is double,having two pistons or heads L L2, of which the upper piston L controls the passage of steam through the ports CO-that is, from the working chamber I5 into the receiver formed by the chambers I3 I4. The lower' head L2 is adapted to connect the ports C10 (and thus the working chamber of the annular lowpressure cylinder) alternately with the eX- hau'st-pipe K and with the receiver I3 I4.` The Y other valve L3 is adapted to move in a guide or small cylinder D2, having apertures D4 leading into the space formed by the annular groove C8.

tion is established between the steam-chamber I and the interior of the cylinder D3. These apertures D5 are adapted to be throttled by a ring M, seated upon a concave surface at the top of the piston D and capable of turning on said surface with the pistonrod E as its axis. The ring M is pressed downward by a spring N' and has radial slots M', adapted to cover or uncover the apertures D5. trolled by a governor O, operated from the The extension@3 above the top The top of the piston D'4 hasapv ertures D5, by means of which a communica- IOO The position of the ring M is con- Y shaft B by bevel-wheels P P and connected with the ring M by means of a rod Q, a bellcrank lever R, fulcrumed at R', a connecting-rod S, a lever T, fulcrumed at T, and a connecting-rod U, whose ends are connected by ball-and-socket joints with one end of the lever T and with the free end of an arm M2, rigidly secured to the ring M.

The cut-off valve L3 for the high-pressure cylinder l5 is operated by means ot' a sleeve V, mounted to slide on the piston-rod E and pivotally connected with rods W, operated by a couple ,of eccentrics B on the shaft B.

y Similarly the valve LL2 for the low-pressure cylinder is operated by the sleeve X,mounted to slide on the'sleeve V and connected by rods .Y with the eecentrics Bzaon the shaft B.

It will be seen that the valve L2 is au admission and exhaust valve for the low-pressure cylinder, and the valve L is at the same time an exhaust-valve for the high-pressure cylinder and an admission-valve for the receiver, while the valve L3 is a cut-ott valve for the high-pressure cylinder and the ring M forms a variable cut-oii, depending upon the speed of the engine.

It will be understood 'that the relative location of the valves,eccentrics, Vand crank will be such as to secure the proper timing of the valves, as will be described presently.

1When the compound piston is at the end of the downstroke, Fig. 1, steam from the chamber l passes through the slots M and apertures D5 into the cylindrical chamber D3 and through the apertures D4 into the groove CB, the aperture C, and the working chamber I5 of the high-pressure piston D', thus equalizing the pressure on both faces of said piston. At the same time steam,which during the downward stroke has passed from the high-pressure working chamber liinto the receiver I3 I4, is allowed (by an appropriate movement of the valve L2) to pass through the channels G10 below the annular low-pressure piston D2, driving thev same upward. Thus during the Vupstroke only the low-pressure piston is active. The air above the lowpressure piston instead of being compressed within the chamber I (which would cause a considerable resistance as the proaches the top plate C2) is driven out through the apertures C5 into the chamber I2, and owing to the large area of the two chambers l I2 the degree of compression and the resistance due thereto are only slight. The advantage of having the apertures C5 lead into a closed chamber l2 instead of making them open into the surrounding air resides in the fact that the Vbod y of air passing alternately in and out through the apertures C5 remains the sam-e and can have no cooling action on the piston and steam.

As the compound piston finishes the upstroke, Fig. 2, the valve L2 is shifted to cut off the receiver I3 I4 from connection with the working chamber of the low-pressure cylinder and to connect said working chamber piston apwith the exhaust-pipe K. rThe pressure is A haust from the high-pressure cylinder passes into the receiver. Vmoving above the apertures D4 cuts the Finally the valve L3 by working chamber lr ott from connection with the steam-chamber l. There will therefore be a preponderance of pressure on the upper surface of the high pressure piston D', whether the valve-ring M be in the open position, Fig. 1,or the closed position,l*`ig. 2. Thus the piston D will be forced downward. During the downstroke only the high-pressure piston will be active. It will be seen that while each of the pistons is single-acting the engine is double-acting.

The cut-off ring or valve M will, it is understood, become operative only in case the engine exceeds a predetermined speed, when said valve Mwill cut off steam from the highpressure working chamber l5 during the upstroke before the piston-valve L3 closes the apertures D, and when the valve M closes the openings D5 during the upstroke the preponderance of steam-pressure on the upper surface of the high-pressure piston D will check the upward movement of the piston.

It will be understood thatmodilications, as long as they remain within the scope of the appended claims, will constitute no departure from the nature of my invention.

Having thus described my invention, l claim as new and desire to secure by Letters Patentf l. A high-pressure piston, an annular lowpressure piston surrounding the high-pressure piston and rigidly secured thereto, the high-pressure piston having a passage leading from one face thereof to the opposite face, a cut-oit valve controlling said passage, a cylinder having two chambers in which said pistons move, a receiver having a valve-controlled connection with the working chamber of the high-pressure cylinder, the low-pressure cylinder havingl av channel leading to the receiver and to the exhaust, and a valve for opening said channel to the receiver, when the high-pressure piston is vat the end of its working stroke, and for connecting said channel with the exhaust when the high-pressure piston is at the end of its inactive stroke, and means for actuating the valves, substantially as described'.

2, The combination of the annular low- IOO IIO

pressure cylinder, the receiver located cenl trally within the said cylinder, the high-pressure cylinder located substantially in axial alinement with the receiver, the low-pressure piston movable in the low-pressure cylinder, the high-pressure piston mounted to slide on the outside of the receiver, valves controlling 'the connections of the receiver with the high- 624,700 l g Y a pressure cylinder and the W-pressure cylinder, and the connection of the latter With the exhaust, substantially as described.

3. The combination of the single-acting cylinder, the piston therein, the cylinder having at one end a channel for the alternate admission and escape of the driving agent, a steamchamber adapted to communicate with said channel, a valve controlling said communication and a closed chamber in permanent communication with the other end of the cylinder and separated at all times from the steam-receiving end of the cylinder.

4. The combination of the high-pressure cylinder, the low-pressure cylinder, the 10W- pressure piston, the high-pressure piston having a passage leading from one face thereof to the opposite face, a valve controlled directly from the engine-shaft to close said passage at a predetermined period of the stroke, a variable-cut-off valve carried directly by one of the pistons and likewise arranged to close said passage, a speed-controlled governor operatively connected With said variable-cut -oft valve, and connections from the high-pressure cylinder to the low-pressure cylinder, substantially as described.

5. The combination of the high-pressure cylinder, the receiver, the low-'pressure cylinder, the pistons in said cylinders, the highpressure piston having a passage leadingzfrom one face thereof to the opposite face, and the receiver having passages by Which it may communicate with either of the cylinders, a piston-rod connected With one 'of the pistons, valves controlling said passages and provided With sleeves one of which slides on the pistonrod, While the second valve-sleeve slides on the one first mentioned, and means for actu- ALEJANDRO STEPHENS.

Witnesses:

LUIS lldormivinivl, V. HUBER.

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