US678808A - Combined compound and semicompound engine. - Google Patents

Description

No. 678,808. Patented luly l6, IQOI. W. L. WHITFIELD.

COMBINED COMPOUND AND SEMICOMPOUND ENGINE.

(Application filed Dec. 11, 1899,)

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No. 678,808. Patented July l6, I901.

M. L. WHITFIELD. v COMBINED COMPOUND AND SEMICOMPUUND ENGINE;

(Application filed Dec. 11, 1899.) (No M 4 Shanty-Sheet z.

No. 678,808. Patented July "5, IQUI. M. L. WHITFIELD. COMBINED COMPOUND AND SEMIGOMPOUND ENGINE.

(Application filed Dec. 11 1899.) (No Model.) 4 Sheets-8heat 3.

,wlfllltvlillftaiill No. 678,808. Patented luly I6, H M.

, WI. LWHBTIFIELD.

COMBINED COMPOUND AND SEMIGOMPDUND ENGINE.

(Application filed. Dec. 11. 1899 (No Model.) 4 Sheeis-Sheet 4.

llnirnn Stains ATENT Prion.

MARGY L. \VIIITFIELD, OF MEMPHIS, TENNESSEE, ASSIGNOR TO THE WHITFIELD COMPANY, OF SAME PLACE.

COMBINED COMPQUND AND SEMICOMPOUND ENGINE.

SPECIFIQAZIFION forming part of Letters Eatent No. 678,808, dated July 16, 1901.

Application filed December 11, 1899. Serial No. 740,001- (No model.)

To all whom it may concern:

Be it known that I, IWIAROY L. WHITFIELD, a citizen of the United States of America, residing at Memphis, in the county of Shelby and State of Tennessee, have invented certain new and useful Improvements in a Combined Compound and Semicompound Engine; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference 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 a type of steam or other motive-fluid engine which I style a telescopic engine, and comprises a stationary cylinder, a stationary piston-abutment, and a cylinder having reciprocating motion on said piston-abutment and in said stationary cylinder, the piston-abutment constituting one of the heads of the reciprocating cylinder, whose other head constitutes the piston for the stationary cylinder, and said reciprocating cylinder constitutes the driving or power element of the engine. The only existing engines of this type are, so far as I am aware, compound engines, the instroke being effected by live steam and the outstroke by expansion of such steam, and they present the disadvantage of not being available for use in such' cases where a reversal of the direction of motion of the crank is desirable or in such cases where great variations in the load imposed on the engine may take place, as in marine and locomotive engines.

The generic object of my invention lies in the construction of an engine of the type referred to, whether stationary or locomotive, which shall afford a great reserve power which may be made use of for general work or upon emergencies only, the aim being also to simplify the construction of the operative elements, reduce their number to a minimum, and provide means whereby ready access may be had at all. times to said operative parts.

More specifically speaking, my invention has for its objects, first, the provisionof means for converting an engine of the type referred to from a semicompound double-acting to a compound engine and vice versa at the will of the operator, such an engine being in every sense of the term a combined semicompound and compound engine; secondly, the provision of means for reversing the direction of motion of the crank at any point of its revolution, whether the engine is working as a semicompound double-acting or as a compound engine; thirdly, the provision of means whereby the main or distributing valve, the exhaust valve, and what is hereinafter termed the intermediate valvename1y, that valve which controls the admission of steam to the stationary cylinder-are all controlled by a single element through an eccentric on the power or crank shaft; fourthly, the provision of means whereby the space (longitudinally or vertically) occupied by the engine is reduced to a minimum, so that an engine of the type referred to will not occupy much more space than any single-cylinder engine of usual construction, and, lastly, the invention has for its object structural features whereby the steam-distribution is greatly simplified.

I attain these objects in the manner and by the means now to be described, reference being had to the accompanying drawings, in which- Figure l is an elevation of a vertical ormarine engine embodying my invention. Figs. 2 and 3 are vertical axial sectional views thereof, taken at right angles to each other. Fig. 4. is a vertical sectional view of the main or distributing valve and its casing, drawn to an enlarged scale to more clearly show its construction. Fig. 5 is a sectional view illustrating my invention in its application to a locomotive-engine, and Fig.6 is a sectional detail view. 4, showing the valve in a different position.

In the drawings, aindicates the main frame, provided with bearings forthe power or crank 9 shaft b, and to said frame is bolted the cylinder c, hereinafter referred to as the stationary cylinder, in which works the reciprocating cylinder 61, hereinafter referred to as the piston-cylinder, and whose head 6 Fig. 7 is a view similar to Fig.

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constitutes the piston for said stationary cylinder, said piston-cylinder being of less in ternal cross-sectional area than said station ary cylinder.

The piston-cylinder d is fitted to reciprocate on a stationary abutment f, whose head g constitutes the outer cylinder-head for said piston-cylinder.

The abutmentfis bifurcated, its legs 2 2 extending directly from its piston-head g, Fig. 2, and in said legs 2 are formed steampassages 3, leading, on the one hand, to a central passage 4 in said head and to the casing for the main or distributing valve, as shown in dotted lines in Figs. 1 and 3 and herein- .after to be referred to, said legs having at their outer ends suitable bolt-flanges 5, bolted to the main frame a, Figs. 1 and 2.

To the piston-cylinder d or to extensions thereof is secured a cross-head 6, to which one end of the driving-rod 7 is connected, the otherend thereof being connected with the crank-pin 8 on crank-shaft b, said cross-head working in the space or way between the legs 2 of the stationary abutment f, whereby I am I the stationary abutment f-in fact, much closer than is the case in the ordinary construction of engines provided with a stuffingbox for thepiston-rodso that the total length l of the engine is'not much, if any, greater than that of an ordinary single-cylinder engine. I Of course but one steam-supply passage 3 may be provided, in which case, however, the leg of the abutment containing such passage would have to be of increased cross-sectional area, while the expansion of the legs and the weight of the abutment on the frame Would be unequally distributed, all of which is avoided by the described construction of the I valve 11 being closed and the exhaust-valve 7t abutment.

On the head 31 of the stationary cylinder 0- is mounted the valve -casing 32 for thee):- haust-valve It, said casing being provided with a suitable steam-passage 9, leading-from the valve-chamber to acondenser or to the atmosphere through the exhaust branch 10,

and said valve h is provided with suitable ports or passages 11, adapted to be brought:

. steam-chamber16,aud from thelatterthrough into register with the aforesaid passage 9.

In the head a of the piston-cylinder d is bore being closed by a screw-plug 40.

The casing for the main or distributing valve Zrhas two annular steam-chambers 15 and 16, communicating with the interior of valve 1 throughports 18, 19, and 20 and ports; 21, 24c, and 25, the chamber 15 being con-' nected through abranch 42with the source of live-steam supply and chamber 16 being in direct communication with passages 3 3 of the stationary piston-abutment.

The cylindrical main or distributing valve Z has an axial chamber and long ports 21 leading thereto between its upper head and the valve-face 22, and between the latter face and the valve-face 23 and said face 23 and the lower head the valve has short ports 24 and 25, respectively. The valve has two stems 26 and 27 extending from its lower and upper heads, respectively, through the heads of the valve-casing 7c. The lower stem 26 is linked to one end of a rock-lever m, fulcrumed on the engine-frame a, the other end of said lever being provided with a pin 28, fitting ahole in a block 29, seated in a segmental slot in a controlling-link 01, connected near its opposite ends to rods 0 p of two eccentrics q and r, secured to crank-shaft b, said link a being shifted to one or the other side of its vertical axial plane by means of a shifting-lever s on the quadrant or sector 15 on the main frame a and connecting-rod u.

The valve-stem 27 is connected to one arm 30 of a bell-crank lever 41, fulcrumed in a bearing won head 31 of the low-pressure cylinder c, the arm 33 of said lever i; being connected by a rod 34, secured to the attenuated portion or stem 35 of the exhaust-valve h, which stem projects out of the casing 32 for said valve.

The stationary cylinder 0 is or may be provided with the usual non-conductive jacket 39, as shown.

The operation of the engine when working asadouble-actiug semicom pound engine is as follows: The link it being shifted from its normal neutral position, Fig. 1, to move the main valve Z, so aslto bring its ports 21,24, and 25, re-

' spectively, into register with the ports 18, 19,

and 20, leading from the annular steam-chambers 15 and 16, respectively, the intermediate steam-passages 3 in the legs of the stationary abutmentf, thence through the centralipas sage 4=into the piston-cylinder, causing the latter to make its up or in stroke. As said cylinder reaches the limit of its said stroke the exhaust-valve h closes and the intermediatevalve t' opens, while the main valve, under the influence ofthe link n and one of 'the eccentrics q-or-r, moves down sufficiently to cause the valve-faces 22 and 23 to uncover ports 19 and 20, so that live steam will flow directly from annular chamber 15 to said ports 19 and 20 into annularchamber 16, Fig. 7, and thence, as aforesaid, through the staerases tionary abutment and piston-cylinder directly into the stationary cylinder, and, owing to the greater cross-sectional area of the piston of the latter relatively to the head of the stationary abutment, the piston-cylinder will under the increased steam-pressure make its down or out stroke. As the piston-cylinder reaches the limit of its outstroke the main valve Z is moved up again, thereby opening the exhaust-valve hand closing the intermediate valve 1' and simultaneously therewith, or substantially so, bringing the ports 21, 24, and 25 of said main valve, respectively, into register with the ports 18, 19, and 20, as in starting, and so on. It is obvious that if the controlling-link n were shifted toward the opposite side of its vertical axial plane on the block 29 the running of the engine would be reversed, since in the one case the eccentric q influences the operation of the main valve and in the other case the eccentric r, as will be readily understood. It will also be remarked that but one of the valves is directly controlled by said eccentricsnamely, the main valve Z-while the exhaust-valve h is controlled from said main valve and the intermediate valve 1' from the exhaust-valve, thereby simplifying the valve mechanism very materially. In this described operation of the engine the steam-power is made use of in a most economical manner, since the steam used to effect the instroke is caused to expand into thelow-pressure cylinder and is thus also used to assist in effecting the outstroke.

The operation of the engine when working compound is as follows, the stationary cylinder 0 acting as the low-pressure cylinder and the piston-cylinder das the high-pressure cylinder: The link a being properly positioned so as to setthe main valve Z to cause live steam to flow from annular chamber 15, main- valve ports 21, 2 1, and 25, and ports 19 and 20 to annular chamberlG, and thence, as aforesaid, through stationary abutment f to high-pressure piston-cylinder d, theintermediate valve 2' being closed and the exhaust-valve it open, said high-pressure piston-cylinder will make its up or in stroke. As the said high-pressure piston-cylinder reaches the limit of its said in or up stroke the main valve Z will be moved down to cut off the supply of steam, the exhaust-valve h will close, and the intermediate valve t' will open, thus allowing the live steam in the high-pressure piston-cylinder to expand into the low-pressure cylinder, and owing to the greater cross-sectional area of the piston-head for said low-press ure cylinder relatively to the like area of the pistonhead of the stationary abutment said highpressure cylinder will make its down or out stroke under expansion. As the high-pressure cylinder reaches the limit of its down or out stroke the exhaust-valve h will open, the intermediate valvet' will close,while the main valve will be positioned to again admit live steam to the high-pressure pistoncylinder (Z,

as above described. It is here also obvious that by reversing the link a the direction of motion of the engine will also be reversed. The operation of the engine as a semicompound double-acting or as a compound-engine depends, therefore, solely on the extent of travel of the main or distributing valve Z, since when it travels a comparatively short distance the ports 19 and 20 can only register with the ports 24, and 25, and this is possible only on or during the upstroke. hen, on the contrary, the said valve Z travels a comparatively long distance or makes its full stroke, the valve-faces 22 and 28 will uncover ports 19 and 20, and this cannot take place except on the down or out stroke of the high-pressure piston-cylinder cl.

The extent of travel of the main valve at any time is determined by the position of the lever s on the quadrant or sector t, since said lever controls the position of the link as. This link a, as will readily be observed, performs four distinct functions, to wit: First, it determines the direction of rotation of the crank-shaft, which is effected by shifting its radial center relatively to the axis of the pin 28 on rock-lever m, so as to cause one or the other eccentric q or r to influence the link and therethrough the main valve Z; secondly, the link determines the point of high-pressure cut-off when the engine is working compound, and this is effected by shifting said link just sufficiently to cause either one of the eccentrics to more or less influence said link, and therethrough the main valve, to regulate its travel, so as to result in a comparatively quick cut-off until this reaches, say, one-half on the high-pressure stroke; thirdly, the conversion of the engine from compound to semiccmpound by shifting the link a farther in the direction of later cut-0E when it begins to admit live steam to the lowpressure cylinder, and, fourthly, the link controls the admission and cut-off of steam to both low and high pressure cylinders.

I am not aware that attempts have ever been made to provide means for converting a reversible compound engine to a semicompound engine, and this could not possibly be done with a single set of valve-operating devices, because compound engines as generally constructed embody practically two separate engines coupled to one and the same shaft. Hence they could not be properly called combined compound and semicompound engines.

I have hereinbefore stated that my invention is applicable to both stationary and locomotive engines, and in Fig. 5 I have shown my said invention applied to the latter type of engine. In this application the stationary abutment fand the low-pressu re cylinder 0 are carried by the locomotive-truck, and, if desired, said low-pressure cylinder may be cast integral with the boiler-saddle, the abutment-head g constituting the outer head for the high-pressure cylinder d, which reciprocates on said head, the inner head a of said high-pressure cylinder constituting the piston for said low-pressure cylinder 0. On opposite sides of the abutment f are provided guides to w for the high-pressure cylinder d, which latter has a cross-head 6 secured to arms was, extending therefrom, and said crosshead is connected by rod 4 with the wristpin 2 of the forward drive-wheel in the usual manner. In the head 6 of the high-pressure piston-cylinder is formed a valve-chamber for an oscillating or semirotary discoidal intermediate valve 46, Fig. 5, the stem 13 of which reciprocates in the axial bore in the exhaust-valve,to which said stem is feathered, so that said intermediate valve is oscillated by said exhaust-valve. On the abutmentf is formed or mounted a valve-casing 48, in which works the main or distributing valve 49, having two ports and 51, adapted to be brought into register witha steam port or passage from the boiler and with steam-passages 3 in the stationary abutment f, leading into the high-pressure cylinder through a port 4 in the head of said abutment. The stem of the distributing-valve is directly connected with the usual link-motion and controllingbars, while the stem of the exhaust-valve is connected with said motion through the bellcrank lever 53 and rod 54. The steam is exhausted through the exhaust-valve box, through a passage 55 in the boiler-saddle, and thence into the stack 56.

The action of the locomotive-engine is substantially as hereinbefore described and within the control of the engineer, the relative arrangement of the intermediate and exhaust valves being also such that when one opens the other closes. The stationary abutment fis likewise slotted longitudinally and centrally quite close up to its head to form a way for the cross-head to which the high-pressure piston-cylinder is secured for purposes hereinbefore described.

The advantages of an engine such as above described will be readily understood by all engineers. Its convertibility from semicompound double-acting to compound, in conjunction with the reversibility of motion, is of the utmost importance in all cases where a reversible engine with a great reserve power is desirable, this being of specialimportance when such an engine is used for marine or locomotive purposes or in a stationary engine the load on which varies. Furthermore, the construction of the engine is of the simplest. Hence the operative elements are not liable to readily get out of repair, while access is readily had to all such elements. Finally, by constructing the stationary abutment f as described the steam distribution is also very materially simplified and, as hereinbefore stated, the longitudinal or vertical dimensions of the engine reduced to a minimum.

In Figs. 5 and 6 I have clearly shown my invention as a horizontal engine with such modifications as are required by the conditions of use. It is, however, obvious that by suitably modifying the main framing of the engine shown in Figs. 1 to 3 said engine can be used as a horizontal stationary engine.

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

1. A steam-engine comprising a stationary cylinder, a stationary abutment, a piston-cylinder having motion in said stationary cylinder and on said abutment, a valve mechanism operating to admit live steam alternately to said piston and stationary cylinders and the crank-shaft connected with the pistoncylinder; in combination with means connected with the valve mechanism for changing the direction of rotation of the crank, for the purpose set forth.

2. A steam-engine comprising a stationary cylinder, a stationary abutment, a piston-cylinder having motion in said stationary cylinder and on said abutment, a valve mechanism operating to admit live steam to the piston-cylinder, and live steam together with steam from said piston-cylinder to the stationary cylinder, alternately, and the crankshaft connected with the piston-cylinder; in combination with means connected with the valve mechanism for changing the direction of rotation of the crank, for the purposes set forth.

3. A steam-engine comprising a stationary cylinder, a stationary abutment, a piston-cylinder having motion in said stationary cylinder and on said abutment, a valve mechanism and steam-distributing ports and passages controlled thereby, and operating to admit live steam to the piston-cylinder and through said piston-cylinder to the stationary cylinder alternately, and the crank-shaft connected with said piston-cylinder; in combination with a reversing mechanism connected with the valve mechanism for reversing the rotation of the crank, for the purposes set forth.

4. A combined compound and semicompound engine, comprising a stationary cylinder, a stationary bifurcated abutment having a steam-supply passage in each of its legs and an outlet-port in its head, a piston-cylinder working on said abutment and in the stationary cylinder, a cross-head connected with said piston-cylinder and working between the legs of the abutment, a crank-shaft, and a connection between the cross-head and shaft, for

the purpose set forth.

5. A combined compound and semicompound engine, comprising a stationary cylinder, a stationary abutment, a piston-cylinder having motion on said abutment, means for causing the engine to work semicompound or compound and means for changing the direction of motion of the crank whether the engine works semicompound or compound, for the purposes set forth;

6. A combined compound and semicompound engine, comprising a stationary cylinder open at its outer end, a stationary bifurcated abutment arranged in the axial plane of said cylinder, a piston-cylinder open at its outer end and having extensions therefrom, said piston-cylinder working on the abutment and in the stationary cylinder, a cross-head connected with the piston-cylinder extensions and having motion between the legs of the abutment, a crank-shaft and a connectingrod connected with the crank on said shaft and with the aforesaid cross-head, for the purpose set forth.

7. A combined compound and semicompound engine, comprising a stationary cylinder, a stationary abutment, a piston-cylinder having motion on said abutment and in said cylinder, a crank-shaft, a connection between the crank of said shaft and the piston-cylinder, a main or distributing valve controlled by the movements of the crank-shaft, an exhaust-valve for the stationary cylinder, and an intermediate valve in the piston-head of the piston-cylinder, both said valves controlled by the movements of the distributingvalve, for the purposes set forth.

8. A combined compound and semicompound engine, comprisinga stationary cylinder, a stationary abutment, a piston-cylinder having motion on said abutment and in said cylinder, a crank-shaft, a connection between the crank of said shaft and the piston-cylinder, a main or distributing valve controlled by the movements of the crank-shaft, an exhaust-valve for the stationary cylinder, an intermediate valve in piston-head of the piston-cylinder, both said valves controlled by the movements of the distributing-valve, and means for adjusting the last-named valve to cause the engine to work semicompound or compound, substantially as set forth.

9. A combined compound and seinicompound engine, comprising a stationary cylinder, a stationary abutment, a piston-cylinder having motion on said abutment and in said cylinder, a crank-shaft, a connection between the crank of said shaft and the piston-cylinder, a main or distributing valve controlled by the movements of the crank-shaft, an exhaust-valve for the stationary cylinder, an intermediate valve in piston-head of the piston-cylinder, both said valves controlled by the movements of the distributing-valve, and means for adjusting the last-named valve to change the direction of motion of the crank, for the purpose set forth.

10. A combined compound and semicompound engine, comprisinga stationary cylinder, a stationary abutment, a piston-cylinder having motion on said abutment and in said stationary cylinder, a crank-shaft, a connection between the crank of said shaft and the piston-cylinder, a main or distributing valve controlled by the movements of the crankshaft, an exhaust-valve for the stationary cylinder, an intermediate valve in piston-head of the piston-cylinder, both said valves controlled by the movements of the distributingvalve, means for adjusting the last-named valve to cause the engine to work semicompound or compound, and means for adjusting said valve to change the direction of motion of the crank whether the engine works semicompound or compound, substantially as set forth.

11. A steam-engine comprising a stationary cylinder, a stationary abutment, a pistoncylinder working in said stationary cylinder and on said abutment, a main automaticallyoperated distributing-valve located outside said cylinders, intermediate and exhaust valves located within the steam area of the cylinders, and connections between the distributing-valve and said exhaust and intermediate valves for controlling the movements of the last-named valves by the movements of the distributing-valve, for the purposes set forth.

12. In a telescopic engine, the combination with the low and high pressure cylinders, of a stationary piston-abutment 011 which said high-pressure cylinder is mounted to reciprocate, said abutment bifurcated to form a Way in which the cross-head can reciprocate and serving also to admit live steam to said highpressure cylinder, for the purposes set forth.

13. In a compound engine comprising a lowpressure cylinder, a stationary piston-abutment and a high pressure piston cylinder working on said abutment and in said lowpressure cylinder respectively; avalve mechanism controlled by a moving element of the engine, said mechanism organized to establish direct com munication between the source of live-steam supply and the low-pressure cylinder through the high-pressure cylinder on the low-pressure stroke to change the operation of the engine from compound to semieompound, for the purpose set forth.

14. In a compound engine, the combination with the high and low pressure cylinders, of means for establishing at will direct communication between the source of live-steam supply and the low-pressure cylinder through the high-pressure cylinder on the low-pressure stroke to change the operation of the engine from compound to seinicompound, for the purpose set forth.

15. In a compound engine comprising a lowpressure cylinder, a stationary piston-abutment and a high-pressure pistoncylinder working on said abutment and in said lowpressure cylinder respectively; a valve mechanism controlled by a moving element of the engine, said mechanism organized to establish direct communication between the source of live steam supply and the low-pressure cylinder through the high-pressure cylinder on the low-pressure stroke to change the operation of the engine from compound to semi- IO gine from compound to semicompound and vice Versa, and means for reversing the rotation of the crank in either operation, for the purposes set forth.

In testimony that I claim the foregoing as my invention I have signed my name in pres I5 ence of two subscribing Witnesses.

MARGY L. WHITFIELD. Witnesses:

J. J. NELLIGAN, HENRY ORTH, Jr.

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