US666565A - Steam-engine. - Google Patents

Description

No. 666,565 Patented Ian. 22, I901. H. F. SHAW.

STEAM ENGINE.

\ (Application filed Feb. 10, 1900.)

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H. F. SHAW.

STEAM ENGINE.

(Application filed Feb. 10, 1900.)

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TATES NITED HENRY F. SHAW, OF ROXBURY, MASSACHUSETTS, ASSIGNOR TO THE SHAW MOTOR VEHICLE COMPANY, OF BOSTON, MASSACHUSETTS.

STEAM-ENGINE.

SPECIFICATION forming part of Letters Patent N 0. 666,565, dated January 22, 1901.

Application filed February 10, 1900. Serial No. 4,758. (No model.)

To all whom, it may concern: as the valve is beginning to admit live steam Be itknown that LI-IENRY F. SHAW,of Roxto the high-pressure cylinder. Fig. 2 reprebury, in the county of Suffolk and State of sents a similar View with the parts in the Massachusetts, have invented certain new position at the time when the cutting off of 55 5 and useful Improvements in Steam-Engines, the live steam is just about to occur. Fig. 3 of which the following is a specification. represents a similar view with the parts in This invention has relation to compound position to admit the steam from the highsteam-engines, and has for its object to propressure cylinder to the low-pressure cylvide certain improvements therein whereby inder. 60 the pistons will be oppositely acting to-lessen The engine comprises the cylinders ctand b, or prevent vibration, and thereby adapt the of which the former is for low-pressure steam same for use on motor-carriages and other and the latter is for high-pressure steam. analogous mechanisms. They are placed end to end, as shown, and

In motor-carriages in which steam or gas open from one end to the other, one end 65 engines are employed serious inconvenience of cylinder I) being closed by the cylinderhas been experienced from the constant vihead 0. The outer end of the cylinder 0, is brat-ion caused by the engines. Many comclosed by a perforated plate 01, which admits paratively delicate mechanisms are employed air into the outer end of said cylinder. on carriages of the character referred to, and In the cylinder 1) is the piston 6, there be- 70 they become broken and dislocated from the ing a piston f in the low-pressure cylinder, jarring and vibration, causing endless repairs through which a piston-rod g extends,through and great annoyance. To prevent the vibrathe cylinder 6 and the piston e, to the contion, I employ an engine which is mechanicmeeting-rod h, which is attached to the crank ally balanced with respect to the pistons and 'i of the crank-shaft j. The piston-rod for 7 their connected parts, two pistons being used the piston e is in the form of a sleeve is, which and being arranged to move oppositely. passes through a stuffing-box Z, attached to The invention consists of a steam-engine the cylinder-head c, said sleeve encircling the comprisingalow-pressure cylinderand a highrod 9 and being connected to a sliding crosspressure cylinder arranged in axial alinement head m, which slides in guides n, attached to 80 0 and having their interiors freely communithe cylinder-head o. Said cross-head is concating with each other. In each of the cylinnected to a crank n on the crank-shaft j by ders is placed a piston, the two pistons being a connecting-rod 0. The two cranks 't' and it connected to the same crank-shaft and being are arranged at an angle diametrically oppoarranged to move in opposite directions. site each other or at an angle of one hundred 85 3 5 Suitable valve mechanism is employed to adand eighty degrees, so that when said pistons mit steam into the high-pressure cylinder move they move in opposite directions, as and from thence into the low-pressure cylinwill be readily understood. The piston f der, whereby the pistons will operate alterand the rod g for the low-pressure cylinder nately upon the crank-shaft. By means of are substantially equal in weight to the pis- 90 40 this movement of the pistons in opposite ton e, the hollow rod k, and the cross-head directions they counterbalance each other m, as will be observed from the drawings, and prevent vibration of the engine, as will so that the engine is mechanically balanced. be readily understood. Consequently when the two pistons move in The details of construction of the engine opposite direcions the equilibrium is not 5 are fully set forthin the accompanying speciaffected.

fication, taken in connection with the draw- Attached to the side or top of piston e is a ings. valve-ch est p, in which is placed a slide-valve Referring to said drawings, Figure 1 repq. From the chest ports r and s extend to resents in longitudinal section an engine emthe high-pressure and low-pressure cylinders, I00 bodying my invention, the pistons and valves respectively, there being an exhaust-port i, being in the position assumed by them just as shown. The valveqis connectedbyavalvestem to and by a rod '0 with the eccentricstrap of the eccentric m, fast upon the shaft j. Boiler-steam is fed into the valve-chest by a suitable pipe or duct and is admitted by the duct r to the outer side of the piston c, this taking place when the valve-crank m is at the end of the outstroke of the piston 6. Steam is continuously admitted until the parts reach the position shown in Fig. 2,when it is cut off and acts expansively to force the piston to the inner end of the cylinder. During this movement of the piston e the rotation of the crank-shaft causes the piston fto approach the piston e, the exhaust from the cylinder a passing through the duct 3 into the outlet to the chamber a; in the valve q.

Then the valve is shifted into the position shown in Fig. 3 to permit the steam to escape from the cylinder 1) through the ducts 'r and s and the chamber a: in the valve to the lowpressure cylinder, the two pistons being now close to each other. The piston f is subjected to an unbalanced pressure equal to the amount by which the pressure of the steam exceeds that of the atmosphere and is forced outward in its turn, causing the partial rotation of the crank-shaft. As the pressure is equal on both sides of the piston e, the latter is moved outward, the expansion in the low-pressure cylinder continuing until the pressure therein is reduced to the back pressure, after which the energy due to the momentum of the moving parts completes a cycle of operations and brings the mechanism to the position where steam is admitted for the next stroke. Thus it-will be seen that the crank-shaft is rotated a half-revolution by the high-pressure steam and the completion of the revolution is effected by the low-pressure steam.

The construction which I have described is particularly applicable for motor-vehicles, since the two pistons may be connected directly to the driving-shaft, the vibration being ml or so little as not to injure or jar the delicate parts of the mechanism.

Having thus explained the nature of the invention and described a way of construct-. ing and using the same, although without having attempted to set forth all of the forms in which it may be made or all of the modes of its use, I declare that what I claim is- 1. A balanced engine comprising a lowpressure cylinder, a communicating highpressure *cylinder, the two cylinders being placed end to end, a piston in each of said cylinders, the rod for one piston passing through the other piston, and means for admitting steam first on one side of the piston of the high-pressure cylinder and then between the two pistons, the weight of oppositely-moving parts beingsubstantially equal.

2. A balanced engine comprising a lowpressure cylinder, a communicating high: pressure cylinder, the two cylinders being placed end to end; a piston in each of said cylinders, and a rod connected to each piston, in combination with a shaft having cranks at an angle of one hundred and eighty degrees to each other, the piston and rods be ing connected to said cranks, the weight of oppositely-moving parts beingsubstantially equal.

In testimony whereof I have affixed iny signature in presence of two witnesses.

HENRY F. SHAW.

Witnesses:

Masons B. MAY, P. W. PEZZETTI.

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