US755508A - Compound engine. - Google Patents

Description

No. 755,508. O PATENTED MAR. 22, 1904. P. LINCOLN, DEGD.

A. e. LINOOLN, ADMINISTRATRIX. COMPOUND ENGINE.

APPLICATION FILED FEB. 13I 1902.

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I. LINCOLN, DEGDQ A; G. LINCOLN, ADMINIBTRATEIX.

COMPOUND ENGINE.

APPLICATION FILED FEB. 13, 1902.

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UNITED STATES FREDERICK LINCOLN, OF WARREN, MASSACHUSETTS; ALICE G. LINCOLN Patented March 22, 1904.

PATENT OFFICE.

I COIVIPOUND ENGINE.

srncrrrcn'rroiv forming part of Letters Patent No. 755,508, dated March 22,1904.

Application filed February 13, 1902- Serial No. 93,951. (No model.)

To all whom it may concern:

Be it known that I, FREDERICK LINCOLN, a citizen of the United States, residing at Warren, in the county of Worcester and State of Massachusetts, have invented a new and useful Compound Engine, of which the following is a specification.

This invention relates generally to steam-engines, and particularly to compound engines, it being understood that the principle of the invention is applicable to triple-expansion engines and also to expansion-engines of higher multiples.

The object of the invention is to prevent back pressure, common in compound engines as now constructed; and incidental to the removal of the back pressure the invention also has for its object to increase the efficiency of the ordinary vacuum-pump now used in connection with compound expansive engines.

With these objects in view the invention consists in the novel features of construction and combination, all of which will be fully described hereinafter and pointed out in the claims.

In the drawings forming part of this specification, Figure 1 is a side elevation of an engine constructed in accordance with my inone set of cylinders and illustrating the relative position of the various ports and valves during the downstroke of the high-pressurecylinder piston A, intermediate-cylinder piston B, and upstrokeof the low-pressurecylinder piston C. 3 is a similar view 1 illustrating the relative position of the ports and valves during the upstroke of the said high-presSure-cylinder piston, piston B, and upstroke of piston C I In constructing an engine of the kind shown in the drawings I employ three cylinders A, B, and C. The cylinders A and B are integral and arranged tandem-like, the cylinder C being preferably arranged at one side of the cylinder B. The cylinder A is a high-pressure cylinder, and the cylinders B and C are respectively low-pressure, secondary, and tertiary cylinders; My invention relates especially to the manner of feeding the steam from,

one of these cylinders to the other. A piston A Works in the cylinder A, and a piston B in the cylinder B, both pistons being mounted on the piston-rod B In the cylinder C is a piston C, secured at the inner end of a pistonrod C The outer ends of both these pistonrods are secured to suitable crank-rods arranged at an angle of one hundred and eighty degrees to each other.

Before describing the construction of the valve passages and ports in detail it may be first stated that I employ the Corliss valve, though slide-valves could be used, and that any desired mechanism may be used for actuating these valves, and any suitable governor may,

be used with the engine, the valve-actuating mechanism not being a part of this invention.

Fresh live steam is admitted into the cylinder A only, and for this purpose the port A is provided on one side and midway the ends of the cylinder. This inlet A has direct communication only with the valve-casing A which in turn communicates with the valvecasing A* through a grated valve-seat A, and the casing A has communication with the cylinder A through an inletport A, communicating with the upper interior part of the cylinder. Adjacent the lower end of the cylinder A and on the same side as the former mentioned valve-casing is arranged a valve-casing A whichcommunicates with the interior of the cylinder through the inletport A, with the casing A through a passage A, with an exhaust-port A and with the cylinder B through means to be described hereinafter.

Valve-casing B is arranged adjacent the upper end of the cylinder B and a casing B adjacent the lower end of said cylinder. A passage B connects the valve-casings A and B and a passage B is a continuation of the passage B and leads to the valve-casing B. The casing B has communication with the interior of the cylinder B by means of an inletport B and with an exhaust-port, to which is attached a vacuum-pump, by the passage B The casing B communicates with the interior of the cylinder B through a passage B and also communicates with an exhaust-passage B, which is also connected to the. vacuumpump.

A passage B leads from the juncture of the passages B and B to the valve-casing C from which a port C leads into the cylinder C. Adjacent the opposite or lower end of the cylinder C is a valve-casing C", having communication with the interior of the cylinder through the passage C communication with the exhaust and vacuum pump through the passage C and with the valve-casing by means of the passage C Having now mentioned in detail all the valve-casings and their connecting passage-ways, I will state that a two-way valve D is arranged in the valvecasing A and a cut-off valve E in the casing A. Valves similar in construction to the valve E are arranged in the other casings: the valve F in the casing A, G in the casing B H in the casing B, I in the casing C and K in the casing G.

The operation of my engine is as follows: When the engine starts, the valves are assumed to be in the position shown in Fig. 2, and it will also be remembered that the exhaust-passages are connected to a vacuum-pump and that there is a vacuum below the pistons A and B and above the piston C. Live steam is admitted through the inlet-port A by way of the casing A A and port A", and the pistons on the rod B commence traveling in the direction of the arrows in Fig. 2. When about one-fourth of the stroke has been made, steam is cut off, and the steam works expansively during the remainder of the stroke. At the end of the stroke the valves are shifted to the position shown in Fig. 2. It will be borne in mind that up to this time there has been no steam in cylinders B and C. With the shifting of the valves steam passes from the cylinder A, from above the piston A, through passages A A B B, through the valve-casing B and port B to the under side of the piston B and also through the passage B to the valve-casing C and thence tothe upper part of the cylinder C through the port C. The pistons B and 0 therefore commence to move in opposite directions, and it will be remembered that on this movement the piston B has steam below it and a vacuum above and that the opposite is true of the piston C. The piston A, however, also originally had a vacuum below it, and in order to destroy this and to more easily enable the-pistons B and C to force the piston A back to its original position the passages and valves are so arranged that when the valves are shifted to the position shown in Fig. 3 there will be communication through the valve-casing A and port A between the passage A and the lower part of the cylinder A. The course of the steam has now been traced, and it has been noted that the steam expands first above the the cylinder A. The casing A is now in communication with the exhaust and the vacuumpump, and the same is true of the casing B, so that no steam will remain below the pistons A and B to cushion them on this second downward stroke. All of the steam which had been admitted to the cylinder A on the first downward stroke has not, however, been exhausted, for as the valves shift to their original position a passage-way is formed through the passages C, casing 0 passage B casing B and port B to the upper part of the cylinder B, which on the previous downward stroke had no steam in it, and also through the passage C casing C and port C establishing a balance on the two sides of the piston C, as had been previously formed in the cylinder A. It will be noted, therefore, that on the second stroke while live steam is working against the upper side of the piston A and a balance is being formed and maintained in the cylinder C what may be termed original steam is working in the upper portion of the cylinder B and is finally exhausted through the passage B at the end of the second downstroke of the pistons A and B.

The engine has now been fairly started, steam having been admitted on each side of each cylinder, and it is thought that the further operation of the engine will be clearly understood.

It will be further borne in mind that the aim and object of this construction is to relieve the' pistons of any back pressure, which is done in each case at the proper time by either balancing the pressure on each side of a piston or by connecting the exhaust end of the cylinder with a vacuum-pump. At no time during the operation above described is any piston moving against a back pressure.

Having thus fully described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. The combination with a high-pressure cylinder having inlet and exhaust ports, of a low-pressure cylinder arranged in tandem with the high-pressure cylinder, a valve-controlled passage being arranged between the two cylinders, the low-pressure cylinder having an exhaust-port adjacent the end opposite the high-pressure cylinder, a common piston-rod, pistons on said rod, one piston being arranged in each cylinder, a second low-pressure cylinder arranged adjacent the first low-pressure cylinder and having an exhaust-port adjacent one end and a valve-controlled inlet-port adjacent the opposite end in communication with the passage between the two first-mentioned cylinders, a piston-rod in the second low-pressure cylinder and a piston on said rod.

2. An engine of the kind described comprising three cylinders, two of said cylinders being arranged tandem, and having suitable pistons and piston-rods, a steam-pipe connected to one of said cylinders, a vacuum-pump having connection with each cylinder, valves adapted to admit steam successively through each of the three cylinders from the steampipe mentioned, and means for automatically actuating the said valves.

3. A compound engine comprising a highpressure cylinder and two low-pressure cylinders, a piston-rod common to the high-pressure cylinder and one of the low-pressure cylinders, a piston in each cylinder, a piston and piston-rod in the other low-pressure cylinder, means for creating a vacuum below the pistons on the common piston-rod and above the piston in the other low pressure cylinder, means for admitting live steam' to the highpressure cylinder only, means for cutting the supply of said steam ofi? when a quarter-stroke has been made, and means for passing a portion of said steam successively into and through the two low-pressure cylinders, substantially as and for the purpose described.

4. A compound engine, comprising a highpressure cylinder, having a steam-inlet, a twoway valve, inlet and exhaust ports and inlet and exhaust cut-off valves, a passage connecting the inlet and exhaust ports, an exhaustpassage leading from the exhaust-port, a secondary cylinder having inlet and exhaust ports, and inlet and cut-ofi valves adjacent thereto, a passage connecting the inlet and exhaust ports, an exhaust-port leading from the inlet-port and the exhaust-passage leading-

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