US 319901 A
Description (OCR text may contain errors)
' (No Model.) 3 Sheets-Sheet 1.
J. A. GROSHON.
COMPOUND STEAM ENGINE.
N0. 319,901. Patented June 9, 1885.
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' J. A. GRO$HON.-
UOMPOUND STEAM ENGINE.
Patented June 9, 18 85.
llVVE/VTO/i By Affarney I W V W%@ 4 N. PETERS; P'wlmlilbogmuhnr; Washington, DC.
TATES JOHN A. GROSHON, OF NEWV YORK, N. Y.
SPECIFICATION forming part of Letters Patent No. 319,901, dated June 9,1885.
Application filed FebruarylG, 1885. (No model.)
To all whom it mag concern.-
Be it known that I, JOHN A. GROSHON, a citizen of the United States, and a resident of New York, in the county of New York and State of New York, have invented certain new and useful Improvementsin Compound Steam- Engines, of which thefollowing isthe specification.
My inventionrelates to an improvement in compoundsteam-engines,theobject ofthesame being to so construct and arrange the cylinders with their valves, &c., that after the piston in the high-pressure or initial cylinder has completed a predetermined portion of its stroke the live steam from the boileris cutofi'andthe steam in the said cylinder simultaneously admitted to the low-pressure or expansive cylinder, the latter having a piston of larger area than that of the initial cylinder, the result being that the steam will continue a pressure on the piston in the high-pressure cylinder and also ex ert a pressure on the piston in the low-pressure cylinder and complete the stroke, thus preserving a regularity of movement, the loss of pressure on the piston in the high-pressure cylinder being compensated by the increased area of the piston in the expansive cylinder. By thus constructing the engine so that the steam is cut off at a certain portion of the stroke and the steam already admitted made to perform the rest of the work, it will be readily seen that the amount of steam necessary to operate an engine as now commonly constructed will be greatly reduced, and as a consequence a great saving of fuel effected.
A further and more particular object of my present invention is the improvement of the engine shown and described in an application for patent filed by me November 10, 1884:,and numbered 147,518. In that application is shown and described an engine so constructed that the two pistons move simultaneously,and as they travel a certain distance before the steam is admitted from the high-pressure into the low-pressure cylinder a large space is left behind the piston in the latter cylinder. This I have found objectionable in that a portion of the pressure of the steam in the piston in the cylinder last aforesaid is wasted, due to the large space in which it is expanded. This feature I have avoided in my present application by so constructing and arranging the different parts of the engine that while the piston in the high-pressure cylinder makes a certain and combinations of parts, as will be hereinafter described, and pointed out in the claims.
In the accompanying drawings, Figure l'is a view in side elevation of an engine embodying my improvement, shown in connection with a direct-acting pump. Fig. 2 is a sectional view thereof. Fig. 3is a top plan view of a portion of the high-pressure cylinder and cross-head. Fig. 4 is a detached view of one of the valves leading from the high into the low pressure cylinders at a different portion of the stroke. Fig. 5 is a sectional View" of a modification of the engine shown in Figs. 1 and 2. Fig. 6 is a transverse section thereof, showing the pipe conveying the steam from the receiver into the low-pressure cylinder. Figs. 7 and 8 are detached views of valves in different positions.
A represents a high-pressure cylinder of any suitable dimensions, and A a low-pressure or expansive cylinder located in the rear of the former. In these cylinders are placed the pis tons B and B, the said latter piston within the low-pressure cylinder being of larger area than that in the initial cylinderA. O is the piston-rod connected to the highpressure piston B, and O O piston-rods connected'at one end with the piston B in the low-pressure cylinder, and at their opposite ends with the cross-head D, the rod 0 being continued through the cylinder A, and connected to a piston, D, within the cross-head.
On the opposite side of the piston D is se cured the water-rod G which is connected to the pump, and is in reality a continuation of rco ure cylinder A is formed the valve-chamber E, inclosing the valve F, said chamber being provided with a port, G, leading into the forward end of the cylinder A, and also with a port, H, leading into the passage I, which extends along the under side of the said cylinder A, and leading into the forward end ofthe cylinder A. When the valve F is in such position that the port G is open, the port H will also be open, as shown in Fig. 2 of the drawings, thereby allowing the steam to pass from the forward end of the high-pressure along through the passage I into the forward end of thelow-pressure cylinder A.
On the upper rear end of the cylinder A is formed the chamber E, inclosing a valve, F, similar to the valve F, said chamber being provided with a port, G, leading into the rear end of the cylinder A behind the piston B, and also with a port, H, leading into and con necting with one end of the passage 1, formed in the upper portion of the low-pressure cylinder A, and leading to the rear end thereof behind the piston B.
On the under side of the low-pressure cylinder, and at each end thereof, is formed the valvechambers E and E, inclosing the valves F and F, the former of said chambers being provided with a port, G, leading into the forward end of the low-pressure cylinder A, and the said latter chamber being provided with a port, G, leading into the rear of the low-pressure cylinder, and each of said chambers being connected with the passage G, leading into a condenser.
The valves F F F F are operated by the Corliss gear I I, well known in the construction of engines, and is not sought to be claimed in the present application. It is illustrated, however, in connection with my improved engine, for the purpose of conveying an accu-' rate idea of the invention as embodied in a compound directacting engine. This gear being well known, I have not deemed'it necessary to describe it, and only refer to it in the operation of the engine.
In the cross-head D is formed a port, J, communicating with each end of the cylinder and with valve-chambers a, the latter communicating with the cylinder by means of the ports b, and with the port J by means of the ports 0. To the ends of the cross-head D are secured the outwardly-extending lugs on bars d, to which are pivoted the levers e. To the upper ends of these levers are secured the valverods f, having on their inner ends the valves having their seats formed at the ends of the ports I). To the lower ends of the levers e are secured the springs 71, the tendency of which are to keep the lower ends of the leverse out and the valves g on their seats, closing the, ports-b, connecting the chambers a with the cylinder formed in the cross-head. The oppositeends of the springs are connected with the downwardly-projecting ends 1' of the crossnect the engine with the pump, are secured the cross-head is moved in close proximity thereto the lower end of one of the levers 0 will strike the said spring, causing theupper end of the lever to move outwardly and force the valve 9 from its seat.
Having described the construction of my improved engine, I will now set forth its mode of operation.
As shown in Fig. 2 of the drawings, steam is about to be admitted to the cylinder A,through the chamber E and port G, which will move the piston B from left to right. The valves at this period of the operation will be in the positions as shown in Fig. 2, the valve E being so turned that it will allow the exhaust or expanded steam inthe forward end of the highpressure cylinder to pass through the ports G, H, and I into the forward end of the low-press ure-cylinder. The valve F is so turned that it will allow the exhaust or expanded steam in the forward portion of the cylinder last aforesaid, with the exhaust from the highpressure cylinder, to pass out through the ports G and G"" into the condenser, thereby securing the benefit of the condenser on both pistons. The valves F and F will both be closed to prevent any steam from passing in behind the piston B..
As before stated, when live-steam is admitted through the chamber E the piston B will move from left to right, the low-pressure piston remaining at rest. This is accomplished by means of the cross head D in the following manner: The piston D within the cross-head being secured to the high-pressure piston-rod O and the water piston-rod G, and the lowpressure piston to the rods 0, secured to the outer portion of the cross-head, the said piston D is free to travel in the cylinder formed in the cross-head without moving the latter, which allows the piston B to remain at rest until said piston D has traveled the whole length of the cylinder. This cross-head is filled with oil or other suitable liquid, which is forced through the port J until the piston D covers or closes the end thereof. If the circulation of the liquid through the crosshcad were entirely checked at this point, it would move the cross-head with a sudden jerk; but this I have obviated by the use of the smaller ports b cand the valve After the piston D has closed the portJ, the liquid is forced through the port b through an opening formed in the valve 9, chamber a, and port 0 into the port J, and into the cylinder behind the piston D. The opening in the valve 9 allows only a small circulation of the liquid, the friction created by which, together with that created by the gradual closing of the port J by the piston D, causes the cross-head and the low-pressure piston secured thereto to move with the piston D when it has just reachedthe end of the cylinder within the cross-head and before striking the end thereof. After the pistons and cross head have traveled a certain distance, regulated by ICO means of the valve-gear, the valve F assumes the position of that shown in Fig. 4:, cutting off the live-steam from the boiler, and allowing the steam whiclris already admitted to the high-pressure cylinder to pass through the port I into the low-pressure cylinder and expand behind the piston B into the space formed by said latter piston moving the distance as above mentioned. The piston B being of larger area than the piston in the high-pressure cylinder, overcomes the loss of pressure of the steam by its expansion into the low-pressure cylinder, and prevents any irregularity in the motion of the engine, (which would be the case were the two pistons of equal area,) the pressure of the steam admitted being sufficient to complete the stroke. The pressure exerted in the piston B is transmitted through the rods 0 and cross-head D to the water-piston O. The tendency of the cross-head is to slide back on the rods 0 and C; but this is prevented by the piston D closing the port J and preventing any circulation of the liquid within the cylinder in that way, and the valve 9 having the pressure of the liquid on its outer sidethat is, on the side within the chamber a-is forced down tightly on its seat, thereby effectually preventing and stopping any and all return circulation of said liquid, and consequently preventing the cross-head from sliding. When the pistons have completed their stroke, the lever e is pressed against the spring 70, causing the valve 9 to open, making a free communication between each end of the cylinder, and allowing a free circulation of the liquid in order to make the return-stroke. Alter the pistons have completed their stroke the valve F is so turned that live steam is admitted through the pipe L connecting the chambers E E to the forward end of the highpressure cylinder and closes the port H. At the sametime the valve F closes. After the pistons have made a portion of their stroke the valve F assumes its original position and allows the steam already admitted to expand through the port I into the forward end of the cylinder A, and exerts its pressure on the piston B in order to finish the stroke.
In Fig. 5 I have shown a modification of my above-described engine, where instead of exhausting directly from the high into the low pressure-cylinder I exhaust into a receiver, lVI, formed around said high-pressure cylinder, as shown, and having a pipe, M", leading therefrom into the valve-chest M of the low-pressure cylinder. With this construction I use ordinary slide-valves, N and N, the valves N having ports m m adapted to register with the recess min the valve N, the Valve N having ports m m, and valve N the ports a n, and in connection with them the cut-off valves 0 O. The high and low pressure cylinders are each provided at their ends with steam-ports 0 0 and 0 0', respectively, which afford communication with the ports in the cut-off valves 0 and O. In the low-pressure cylinder is also formedthe exhaust-passage .P,.
which registers with the recess P, formed in the valve N. With this recess P is also adapted to register the ports 0 0, formed in the low-pressure .cylinder.
With this form of engine I am enabled to use a crr ss-head similar to that described above, or I may dispense with that and connect the two pistons to the same rod. For the sake of con;tr action I have shown this engine having its two pistons connected to the same stem.
It will be clearly seen from the above description that when the valve 0 is in the po-' sition shown in Fig. 8 the live steamv which is admitted to the chest M will pass down through the ports m 0, and moves the piston B to the point where it is desired to cut off the steam. This cut-off is effected by means of the valveo closingthe portm,which opei ation a1: 0 moves the valve 0, as both valves are connected to the same stem,0". When the valve 0 is at the point of opening the port 0", the valveo s at the point of closing the port m, and as the engine continues its stroke under the pressure of the steam the valves 0 and Of move so that the former keeps the port m closed and the latter keeps the port 0 open, admitting the steam from receiver, which is filled by exhaust-steam from the previous stroke, into the low-pressure cylinder against the piston B. The exhaust from the low-pressure cylinder passes through the port P to the condenser.
It will now be seen that by the above construction the space behind the piston in the low-pressure cylinder may be regulated, so that if the pressure on the high-pressure piston is small the space in behind the piston in the low-pressure cylinder may be made correspondingly small. By these means I obtain the full amount of pressure of the steam,
securing the same result from this engine with half the steam that I would with other engines is completed.
I would have it understood that I do not limit the application of my invention to a direct-acting engine, as it may be employed with engines of different construction as crank engines, simple, duplex, &c.nor where the valves of one engine are operated by the other engine; nor do I limit myself to the exactparts shown and described, as many slight changes might be made therein without departing from the spirit of my invention.
What I claim is 1. The combination, with a high and low pressure cylinder, of pistons working therein, valves for simultaneously cutting off the live steam after the pistons have made a portion of their stroke and admitting steam from the high into the low pressure cylinder, and
pressure cylinder and pistons working therein, the piston in the latter cylinder having a larger area than that in theformer, of valves for cutting off the steam after the pistons have made a portion of their stroke and allowa part of the steam then in the high-pressurecylinder to expand against the increased area of the piston in the expansive cylinder, and means, substantially as described, for regulating the relative distance traveled by the pistons before the cut-off, substantially as set forth.
3. The combination, with a high and low pressure cylinder and pistons working there in, of valves for simnltaneouslycutting off the live steam after the pistons have completed a portion of their stroke and admitting steam from the high into the expansive cylinders, and a compensating cross-head connected with said pistonsfor regulating the relative distance traveled by the pistons, substantially as set forth. f l
"4. The combination, with a high and low pressure cylinder and pistons working therein, the piston in the latter cylinder having a larger area than that in the form er,ofvalves for simultaneously cuttingofi' the live steam after the pistons have made a portion of their stroke and allowing the steam in the high-pressure cylinder to expandagainst the increased area 'of'the piston in thelow-pressure cylinder, and
a compensating'cross head connected with lowpressure piston-rods for regulating the relative distance traveled by the two pistons, substantially as set forth.
5. The combination, with a high and low pressure cylinder, the former-having ports JOHN A. GROSHON. Witnesses: GEORGE COOK,
FRED E. MURPHY.