US678709A - Semicompound telescopic engine. - Google Patents

Description

vNo. 678,709. Patented July l6, I90I.

M. L. WHITFIELD. SEMIDOMPOUND TELESCOPIC ENGINE (Application filed Dec. 9, 1899.) (No Model.) 6 Sheets-Sheet l.

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No. 678,709. Patented July l6, I90l.

' M. L. WHITFIELD;

SEMICOMPOUND TELESCOPIC ENGINE.

(Application filed Dec. 9. 1899.) (No Model.) 6 Sheets-Sheet 2.

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N0. 673,709. Patented July "5, IQUI.

V M. L. WHITFIELD. SEMIGUMPOUMD TELESCOPIC ENGINE.

(Application filed. Dec. 9, 1899A (No Model.) B Sheets-Sheet 3.

6 Sheets-Sheet 4.

Patented .luly l6, 190i.

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M L WHITFIELD SEMICOHPOUND TELESBOPIC ENGINE.

(No Model.)

No. 678,709. Patented lul'y |6, l90|.

M. L. WHITFIELD.

SEMICOMPUUND TELESCDPIC ENGINE.

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No. 678,709. Patented July 16, l90l. M. L. WHITFIELD.

SEMICOMPOUND TELESCOPIC ENGINE.

. (Application filed Dec. 9, 1899.) In Model.) 6 Sheets-Sheet B.

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MARCY L. WHITFIELD, OF MEMPHIS, TENNESSEE, ASSIGNOR TO THE WHITFIELD COMPANY, OF SAME PLACE.

SEMICOMPOUND TELESCOPIC ENGINE.

SPECIFICATION formingpart of Letters Patent No. 678,709, dated July 16, 1901.

Application filed December 9,1899. Serial No, 739,838. (No model.)

To (tZZ 1072 0112, it may concern.-

Be it known that I, MARcY L. WHITFIELD, a citizen of the United States of America, re-

siding at Memphis, in the county of Shelby,

will enable others skilled in the art to which it appertains to make and use the same, ref erence being had to the accompanying drawings, and to letters and figures of reference marked thereon, which form a part of this specification.

This invention has relation to steam or other motive fluid engines and more especially to high-pressure double-acting steam-engines; and it has for its object a construction of engine which can be operated more economically, is more compact, and can be built at a less cost than similar engines of like power as heretofore constructed. These objects I attain, first, by combining with the powercylinder a differential piston and means for automatically causing boilersteam to act alternately on opposite faces of said piston; second, by combining with the power-cy1inder a differential piston, means for automatically causing boiler-steam to act alternately on opposite faces of said piston, and means for automatically causing the steam acting on the smaller piston area to also act, together with boiler-steam, on the larger piston area, the engine working what I term semicompound, in that when the steam acting on the smaller piston area is caused to act, together with boiler-steam, on the larger piston area such steam acts more or less expansively, as will be readily understood, the engine working therefore as a semicompound high-pressure double-acting engine; thirdly, by combining a stationary cylinder, a cylinder working therein and hereinafter referred to as the piston-cylinder, the inner head of which constitutes the piston for said stationary cylinder, and thus providing differential piston areas, and a stationary abutment on which said piston-cylinder reciprocates, the head of said abutment constituting the outer head of said piston-cylinder, with means for admitting boiler-stealn to the piston-cylinder to ef feet the instroke, means for exhausting the steam from said piston-cylinder into the stationary cylinder at or about the completion of suchinstroke and for, simultaneously admitting boiler-steam to said stationary cylinder for effecting the outstroke; fourthly, by using a bifurcated abutment, serving not only as a steam-supply duct, but providing a way between its legs, in which the cross-head connected to the piston-cylinder and crankshaft can reciprocate, whereby the length of the engine is materially shortened; fifthly, by connecting the steam-duct in one of the legs of the abutment directly with the eduction-port in the valve-chest for the distributing or expansion valves and by admitting boiler-steam through said abutment to and through the piston-cylinder to the stationary cylinder, whereby a complex arrangement of steam ducts and pipes, which would be otherwise necessary, is avoided; sixthly, by providing in the head of the piston-cylinder a cylindrical valve, hereinafter referred to as the intermediate va1ve,timed to open when said piston-cylinder is about to complete or has completed its instroke, causing the steam therein to exhaust and expand into the stationary cylinder, together with the boilersteam admitted simultaneously through the bifurcated abutment and piston cylinder, and, lastly, by carrying the rod connected with the intermediate valve in the head of the piston-cylinder in the direction of the crank-shaft, instead of carrying said rod in an opposite direction through the head of the stationary cylinder, with a view to a further reduction in the length of the engine.

That my invention maybe fully understood, I will describe the same in detail, reference being had to the accompanying drawings, in which- Figures 1 and 2 are opposite side eleva tions,the fly-wheel being removed in Fig. 1 and partly broken away in Fig. 2, in which latter figure the distributing or expansion valves and steam-passage controlled thereby, as well as the steam-passage in one of the legs of the bifurcated abutment, are shown in dotted lines. Fig. 3 is a top plan view, and Figs. 4t

and 5 vertical and horizontal longitudinal sections, of an engine embodying my invention, the fly-wheels in both the latter figures being partly broken away and the distributing or expansion valves and the steampassages controlled thereby, as well as the steam-passage in one of the legs of the bifurcated abutment, being shown in dotted lines in said Fig. 4. Fig. 6 is a detail top view of the bifurcated abutment. Fig. 7 is a. vertical longitudinal section of the distributing valve-chest and valves, a portion of the leg of the stationary abutment broken away to show the steam-passages therein in their relative positions shown in Fig. 1. Fig. 8 is a section of Fig. 7, taken on line matlookingin the direction of arrow 7 and Fig. 9 is a horizontal section taken on line y y of Fig. 7, said Figs. 7 to 9 being drawn to an enlarged scale.

The engine is attached to a suitable framing (it, provided with bearings for the power or crank shaft Z), which carries, as usual, a fly-wheel w, and to said framing is secured the bifurcated abutment f, the head 2 of which is constructed piston-like and fits fluidtight into the piston-cylinderd. As clearly shown in Figs. 4, 5, and 6, the legs 3 40f said abutment extend directly from its pistonhead 2, so as to form a guideway for the reception of the cross-head connected with the piston-cylinder and hereinafter referred to, and in leg 3 of said abutment is formed a steam-passage 5, which is connected to the inlet-port 6, Figs. 6, 7, and 8, through the main or distributing valve-chest is, secured directly. to said leg or preferably cast therewith, said steam-passage leading into the piston-cylinder (I through a port 7 in'the head of the abutment, which latter is braced on one side of the engine-frame by means of a brace-rod 72, Figs. 2, 3, and 5.

To the engine-frame y is bolted the large cylinder 0, in which works the piston-head 8 of the piston-cylinder d, and in said head is formed a valve-chamber for the semirotary or oscillating cylindrical intermediate valve 9, which has suitable ports or passages 10, Fig. 4, adapted to register with ports or passages 11, leading from said valve-chamber into said piston-cylinder d. On the outer head 31 of the large cylinder 0 is bolted a valve-casing 32 for an oscillating or semirotary cylindrical exhaust-valve e, provided with suitable ports or passages, adapted to place the exhaust-pipe g and cylinder 0 in communication.

The intermediate valve 9 has secured to its stem a radial arm terminating in a toothed sector 12 in gear with a like sector 13 on the actuating-rod i, oscillating in suitable bearings and feathered to a toothed sector or cam l, gearing with a toothed portion of a rocker m, rocked by a rod 07. through the main valvelever 0 of a well-known valve-gear, said main lever 0 being operated by the rod 19 of an cecentric g on the crank-shaft b, while the exhaust-Valve e receives its movements through a radial arm 14, adjustablyconnected to an actuating-rod 15, operated by the aforesaid rocker m. (See Figs. 1, 3, and 5.)

In Fig. 1, s and t indicate the main valves, connected, as usual, with pistons of dashpots u 1), said valves 3 tbeing under the control of a governor 00 through well-known connections, said governor being belted in a wellknown manner to the crank-shaft b, Fig. 1. These valves are arranged in a valve-chest 70, to which the boiler-steam-supply pipe is bolted.

The piston-cylinder d has formed thereon guide-blocks 16, reciprocating on and being guided by guides 00, which, with the intermediate portions y, to which said guides are secured, constitute the intermediate portion of the engine-frame a, and to said guide-blocks 1b is connected the cross-head z, reciprocating, as hereinabove stated, between the legs .3 and 4 of the stationary abutment f, said cross-head 2 being connected by the drivingrod 1' with the crank 17 of the crank-shaft b.

In order to avoid the formation of a partial vacuum in the stationary cylinder 0, which may happen when the engine is working un der a very light load and the cut-off very early by the steam expanding below atmospheric pressure, involving, as is well known, a great loss, I provide an automatic relief-valve 18, Fig. 4, suitably held by a spring 19 and seat ing in a passage 20 in the cylinder-head 31, so as to open inwardly against the stress of said spring, as more clearly shown in Fig. 4.

By using a bifurcated stationary abutment f, the legs of which extend directly from its piston-head 2 to form a way for the crosshead a", I am enabled to reduce the length of the engine to a minimum, as it is obvious that the-cross-head can work closer to the stationary cylinder than is the case in ordinary engines in which the travel is limited by a stuffing-box.

The operation of the variousvalves is so timed that when one of the distributing or expansion valves .9 or tis open the other is closed, that when valve t is open the inter mediate valve 9 is closed and the exhaust-' valve e is open, and that when valve sis open the intermediate valve 9 is also open and the exhaust-valve e is closed. 1

I have'referred to the valves 3 and t as expansion-valves, because they operate to out off steam at different points of the stroke of the piston.

Supposing the engine to be started with the crank in the position shown in Fig. 2, when the crank is in this position, the exhaustvalve 6 is closed and the expansion-valve s and intermediate valve 9 are open. Boilersteam will then flow from passage 6 in valvechest 70 and port 6 to passage 5 in leg of stationary abutment f, as shown in dotted lines in Fig. 2, through the abutment-head into the piston-cylinder d and through the latter into cylinder 0. Owing to the greater cross-sectional area of the inner face of the pistonhead of cylinder 61 relatively to the like area of the outer face of said head the piston will make or complete its outstroke, the crank and fly-Wheel revolving in the direction of arrow, Fig. 2. As the piston-cylinder cl com pletes or is about to complete its outstroke, Fig. 5, the exhaust-valve e will open to exhaust the steam from the engine, the intermediate valve 9 and the expansion-valve s will close, While the expansion-valve t opens, Fig. 7, to admit steam through passage 6 in valve-chest 75, port 6, passage 5 in leg of stationary abutment f, through the head thereof to piston-cylinder d, causing the latter to make its instroke. As said piston-cylinder d completes or is about to complete its in stroke the expansion-valve t and exhaustvalve 6 close, While the intermediate valve 9 and expansion-valve 5 open, so that the steam in piston-cylinder d is exhausted into cylinder 0, instead of being exhausted into the at mosphere, as is now the case, While at the same time boilensteam is admitted through passage 6, port 6, passage 5 in leg of abutmentf, as shown in dotted lines in Fig. 4:, through head of said abutment into the piston-cylinder cl, and through the latter cylinder into cylinder 0, causing the exhaust-steam from cylinder d and the boiler-steam to act expansively in a measure to effect the outstroke, the engine working semicompound, the described operations being repeated.

Inasmuch as the steam required to effect the instroke of the pistou cylinder d instead of being Wasted is utilized in conjunction With boiler-steam on the outstroke the engine is operated more economically than would be the case otherwise.

It will be obvious to any engineer that the described engine will Work Without the expansion-valves s and t, but not as economically as with them, the valves c and g being the main valves that control the operation of the engine, the valves 8 and t controlling the steam distribution the same as in the WellknoWn Corliss engine, with the same economical advantages.

In practice the best results are obtained by providing a differential cut-off for the two cylinders -such, for instance, as that when the governor a: causes the valve t for the piston-cylinder to cut-off at or about half-stroke the valve 3 for the stationary cylinder will cut-off at or about quarter-stroke.

I am aware that compound engines comprising a stationary low-pressure cylinder, a stationary abutment, and a high-pressure cylinder reciprocating on said abutment and Within the low-pressure cylinder are Well known, and I do not therefore desire to lay claim, broadly, to such an arrangement.

Having thus described my invention, What I claim as new therein, and desire to secure by Letters Patent, is-

1. In a double-actinghigh-pressure steamengine, the combination With the power=cylinder and a differential piston; of means for automatically causing boiler-steam to act al ternately on opposite faces of said piston, and means for automatically causing the steam acting on the smaller piston area to effect the instroke to also act together with boiler-steam on the greater piston area to effect the outstroke, for the purposes set forth.

2. In a double-acting high-pressure steamengine, the combination with a stationary cylinder, a stationary abutment, and a piston-cylinder reciprocating in said stationary cylinder and on said abutment; of means operating automatically to admit boiler-steam to the piston-cylinder to effect the instroke and to the stationary cylinder to effect the outstroke, for the purposes set forth.

3. In a double acting high-pressure steamengine, the combination With a stationary cylinder, a stationary abutment, and a piston-cylinder reciprocating in said stationary cylinder and on said abutment; of means for automatically admitting boiler-steam to the piston-cylinder to effect the instroke and to the stationary cylinder through said pistoncylinder to effect the outstroke, for the purposes set forth.

t. In a double-acting high pressure steamengine, the combination with a stationary cylinder, a stationary abutment and a pistoncylinder reciprocating in said stationary cylinder and on said stationary abutment; of means operating automatically to admit boiler steam through said abutment to the piston-cylinder to effect the instroke and to the stationary cylinder to effect the outstroke, for the purposes set forth.

5. In a double-acting high-pressure steamengine, the combination with a stationary cylinder, a stationary abutment and a pistonoylinder reciprocating in said stationary cylinder and on said abutment; of means operating automatically to admit boiler-steam through said abutment to the piston-eylinder to effect the instroke, and through said piston-cylinder to the stationary cylinder to effect the outstroke, for the purposes setforth.

6. In a double-acting high-pressure steamengine, the combination with a stationary cylinder, a stationary abutment and a pistoncylinder reciprocating in said stationary cy1- inder and on said abutment; of means operating automatically to admit boiler-steam to the piston-cylinder to effect the instroke, to exhaust the steam in said piston-cylinderinto the stationary cylinder and simultaneously admit boiler-steam to the last-named cylinder to effect the outstroke, for the purpose set forth.

7. In a double-acting high-pressure stean1- engine, the combination with a stationary cylinder, a stationary abutment and a pistoncylinder reciprocating in said stationary cylinder and on said abutment; of means operating automatically to admit boiler-steam to the piston-cylinder to effect the instroke, to exhaust the steam in said pistonwcyliuder into the stationary cylinder and simultaneously admit boiler-steam to the last-named cylinder through the piston-cylinder to efiect the outstroke, for the purposes set forth.

8.. In a double-acting high-pressure steamengine, the combination With a stationary cylinder, a bifurcated stationary abutment having a steam-passage through one of its legs and its head, and a piston-cylinder reciprocating in said stationary cylinder and on said abutment; of a valve-chest in direct communication with the inlet of the steampassage in the abutment-leg, and two alternately-operatirig main valves in said chest, and means operating automatically to admit boiler-steam from the abutment to the piston and stationary cylinders alternately, for the purposes set forth.

9. A semicompound engine comprising a stationary cylinder, a stationary abutment, a piston-cylinder having motion on said abutment and in said stationary cylinder, an ex haust-valve,means for admitting boiler-steam to'both cylinders, valves controlling the admission of steam thereto, and means for operating said valves, for the purposes set forth.

10. A semicompound engine comprising a stationary cylinder, a stationary abutment, a piston cylinder having motion on said abutment and in said stationary cylinder, an. exhaust-valve,means for admitting boiler-steam to both cylinders, valves controlling the admission of steam thereto, and independently timed appliances for operating said valves, for the purposes set forth.

11. A semicompound engine comprising a stationary cylinder, a stationary abutment, a piston-cylinder having motion on said abutment and in said stationary cylinder, an intermediate valve controlling ports in the head of the piston-cylinder an exhaust-valve for the stationary cylinder, means for admitting boiler-steam to said piston-cylinder to eifect the instroke, and two valves controlling said admission, and independently-timed appliances for operating said admission-valves and the exhaust and intermediate valves to admit boiler-steam to the stationary cylinder to efiect the outstroke, for the purposes setforth.

12. The combination with a stationary cylinder, a stationary abutment, and a piston= cylinder Working on said abutment and in said stationary cylinder; of a valve controlling the flow of steam from-the piston-cylinder to the stationary cylinder, the stem of said valve extending through the piston-head of the piston-cylinder toward the crank-shaft, for the purposes set forth.

In testimony that I claim the foregoing as my invention I have signed my name in presence of two subscribing witnesses.

I MAROY L. WHITFIELD.

Witnesses:

J. J. NELLIGAN, HENRY ORTH, Jr.

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