US279484A - Peters - Google Patents

Description

\No Model.)

- F. POSDIGK. STEAM ENGINE VALVE.

Patented June 1-2 Willi E55 E5.

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FREDERICK FOSDICK, FITCHBURG, MASSACHUSETTS, ASSIGNOR TC; THE FITGHBURG STEAM ENGINE COMPANY.

STEAM-ENGINE VALVE.

SPECIFICATION forming part of Letters-Patent No. 279,484, dated June 12, 1883.

Application filed January 2, 1883.

To all whom it may concern.-

Be it knownthat I, FREDERICK FosDIoK of Fitchburg, countyof WVorcester, State of assachusetts, have invented an Improvement in Steam-Engine Valvesfof which the following description, in connection with the accompanying drawings, is a specification, like letters on the drawings representing like parts.

My invention relating to a steam-engine is IO embodied in an engine of that class in which independent live-steam and exhaust valves control the flow of steam through the ports lead ing to each end of the cylinder.

The invention has for its object to enable I 5 what is known as the wrist-plate valve-gear to be employed in connection with pistonvalves controlling the admission of steam to the cylinder. With awrist-plate valve-gear, or valve-gear in which the movement of the 2o eccentric is transmitted to one pin of a disk or crank-arm of a rock-shaft having two other pins or crank-arms connected with the valves at either end of the cylinder, the movements of the said valves are different, and they have to be made independent of one another, so that when piston-valves are employed the steam in the steam-chest, with the usual arrange ment, would press upon one side only of each independent piston-valve, which would thu, be unbalanced. The present invention consists, partly, in provi ding a passage from the interior of the steamchest at one end of each of the said pistonvalves to the other end of the said valves, adding, if necessary, a bonnet or auxiliary cham her to receive the steam from the said passage, and also to receive the said valves in their travel outward from the steam-chest. The steam thus acts upon both ends of each of the said piston-valves with equal pressure, thus balancing each valve independently. The eX- haust-valves may be connected together and operated directly from an eccentric on the engine-shaft in the usual manner, thus both hav- 4 5 ing the same movement, and bonnets are preferably provided to receive them in their outward travel. The live steam, acting as above described, upon both ends of the piston-valves, equalizes the temperature of the said valves and the metal surrounding the valves through- (No model.)

out their length, thus causingtheir expansion to be more uniform, and their operation consequently improved.

The invention also consists in details of construction of some portions of the engine, as hereinafter specified.

Figure 1 is a plan view of a portion of an engine embodying this invention. Fig. 2 is a side elevation thereof; Fig. 3, a horizontal longitudinal section thereof on line 00 m, Fig. 2, the valve-actuating mechanism being shown in plan; and Fig. 4, a detail to be referred to.

The engine-cylinder a and its framework or bed-plate b may be of any usual construc tion, the latter containing the main shaft 0, upon which are mounted the eccentrics d e, for actuating the valves. The eccentric d, for actuating the live-steam or inlet valves, is preferably made movable 011 the shaft, its position being controlled by a governor such as described in Letters Patent N 0. 221,296, November 4, 187 9, granted to me, to which reference may be had. The eccentric-rod f of the said eccentric (l is connected with a crank-pin, g, mounted on acrank fixed upon a rock-shaft, h, 7 5 provided with two other cranl -arms, i k, the crank-pins. of which are connected by links 112 n with the val ve-rods p 0, mounted in a guide, '1', upon the bed-plate I) of the engine. The valve-rod o is made tubular, and is connected with a pistoirvalve, o, controlling the flow of steam from the live-steam chest 8 into the port 1, leading to one end of the cylinder (I, while the other valve-rod, 2, passes through. the tubular valve-rod o and the live-steam chest 8, and is 8 5 connected with the piston-valve-p, controlling the flow of steam from the said chest to the port t, leading to the other end of the enginecylin'der. The valves 0 thus connected with the cranksi 7c, have an independent movement, and are each acted upon at one side by the steam in the chest .9. In order to equalize the steam-pressure upon each of the said valves 0 p independently, passages 11. are provided leading from the interior of the steam-chests to the other side of the cylindrical portionin which the valves 0'1) travel, bonnets o being in this instance provided ateithcr end of the steam-chest to receive the steam from the passages n, which thus acts equally upon both ends of each valve p, perfectly balancing the said valves and maintaining the temperature sub stantially uniform throughout their entire length. The valve-rod p is extended beyond the piston-valve p, as shown at p", passing out through the bonnet v at that end of the chest The bonnets o are each provided with a tubular projection, 12, containing a hard bushing, oflwhich serves as a guide and support for the valvestems 0 p, the said tubular projection t being also provided with a gland or stuffingbox, 10, containing an annular chamber, which is intended to be kept filled with oil for the purpose of lubricating the rods where they travel through the packing in the stuffingboX w and through the bushings o. A small St1llfil1g-bOX,l0 ,lS provided at the end of the stuflingbox w, so as to prevent the escape of oil from the chamber 10 along the rod 0. A similar oil-receptacle, w, and packing-box 10", are provided at the end of the tubular rod 0, inclosing and lubricating the rod 1), which passes therethrough, as shown in Fig. 4.

The valves controlling the flow of the exhaust-steam from the ends of the cylinders through the ports t 1 into the cxhaustchcst R are connected together upon a single rod, and are actuated by a single eccentric-rod, c, and eccentric c. Bonnets v are preferably provided for the said exhaust-Valve, having similar bushings and stuffing-boxes for guiding, supporting, packing, and lubricating their valvestems.

It is obvious that the chambered bonnets v might be omitted, the piston-valves then traveling wholly in the chest, the ends of which might be closed by ordinary heads; but by the employment of the said chambered bonnets it is possible for the ports 1 leading to the ends I of the cylinder, to be made straight, as shown, without making the steam-chest portion of the castin longer than the cylinder, and the short est and most direct passage possible for the steanr'isthus afforded and the clearance reduced to a minimun.

I claim- 1. The combination, substantially as shown and described, of the cylinder a, steam-chest s, steanrports t 75, leading from the steam-chest to the cylinder, the piston-valves 0 p, operating independently upon the ports t i, re speetively, and the passages u a, connecting the steam-spaces on opposite faces of the pistonvalves to balance said valves, as and for the purpose specified.

2. The combination, substantially as shown and described, of the valve-actuating eccentric and oscillating wrist-pins operated thereby, with the balanced piston-valves connected with and independently actuated by different ones of said wrist-pins, as and for the purpose set forth.

8. The combination, substantially as shown and described, of the piston-valves with a steam-chest, the external bonnets, o, communicating with said chest, and into which the valves move, and passages u, communicating between the steam-chest and said bonnets, and thereby admitting steam to both ends of and thereby balancing the valves, as and for the purpose specified.

4. The engine cylinder, steam chest, and independent piston-valves, one having a tu bular rod through which the rod of the other valve operates, combined with valve-actuating mechanism connected with the said rods, sub stantially as described.

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

FREDERICK FOSDIGK.

\Vitnesses: v 'Jos. P. LivnRMoRn, \V. H. SIGSTON.

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