US1253528A - Internal-combustion engine. - Google Patents

Description

S. A'. REEVE,

INTERNAL COMBUSTION ENGINE r APPLICATION FILED APR. 15. I914. L w mfio Pateirtedi Jan.15,1918. I 2 SHEETS-SHEET 1- Fig.

S. A. REEVE.

INTERNAL COMBUSTION ENGINE. APPLICATION FILED APR. [5. I914. lfififigu Pmtentefi Jan.15,1918.

2 SHEETS-SHEET Z! SIDNEY A. REEVE, G1 'IOIVIPKINS'VILLE, NEW YORK.

INTERNAL-COMBUSTION ENGINE.

Specification of Letters Patent.

Patented Jan. f5, 11ers.

Application filed April 15, 1914. Serial No. 832,034.

To aZZ whom it may concern."

Be it known that I, SIDNEY A. Brave, a citizen of the United States, residing at Tompkinsville, in the county of Richmond and State of New York, have invented a new and useful Improvement in Internal- Combustion Engines, of which the following is a specification.

My invention relates to engines having two or more cylinders operating upon the Beau de Rochas or other so-called fourstroke cycles, in which theback-strokes of the piston are used alternately for exhausting the burnt charge and compressing the next charge. Its object is to improve the efiiciency and power by perfecting the scavenging of the burnt gases from the cylinder, increasing the expansion and freeing the exhaust. It also gives the designer of the engine a greater-latitude in choice of degree of compression to be employed.

Referring to the drawings, in which corresponding parts are designated by corre sponding marks of reference,-

Figure 1 is a partial section on the plane of the crank-shaft and cylinder-axes of two cylinders of such an engine in which the two cylinders illustrated are arranged side by side in that plane, their pistons working in substantial unison upon a single crank.

Fig. 2 is a partial section on a planenormal to the crank-shaft and containing the axis of the left-hand. cylinder of Fig. 1 viewed from the left.

Fig. 3 is a partial section through the plane of the axes of a similar pair of cylinders, but showing a modification of my in vention from the form shown in Figs. 1 and 2.

Fig. 4 is a diagram of shaft, crank-pin and eccentric centers of a ten-cylinder engine having its cylinders arranged radially about the shaft in five pairs, each pair similar to Figs. 1 and 2. I

Fig. 5 is a similar diagram of shaft crankpin and eccentric centers of nine-cylinder engine having its cylinders arranged each in a d fferent plane radiating from,and coinciding with the axisof, the crank-shaft.

Fig. 6 is a longitudinal vertical section of the eccentric-element (with crank-shaft in elevation) of the engine of Fig. 5.

Fig. 7 isa vertical section along the plane YY of Fig. 6, looking toward the left, the

cylinders in a periphery centering in thecrank-shaft axis, with the axis 55 55 of Fig.

Sparallel with and vertically above the shaft axis, as at I of Fig. 5.

In the drawings 1 is a cylinder-body comprising cylinders for thetwo pistons 2, 2; 3 is the crank-shaft; i is the crank and 5 the crank-pin driven in common by the pair of cylinders shown. The two sets of cylinders and pistons will be referred to in general as A and B respectively, as marked. In the drawings cylinder A is shown at the end of its exhauststroke and cylinder B at the end of its compresion-stroke. 7

Each piston 2 has a wrist-pin 7 and a coin necting-rod 6. Between the connecting-rods 6, 6 (Figs. 1 and 2) and the crank-pin 5 is a piece 10-11-1213-141516 (hereinafter referred to as the rock-sleeve)which, although it may be subdivided for purposes of construction, is virtually one solid piece. It comprises a concentric sleeve 13 on the crank-pin 5, eccentrics 11 and 12, arms and 16, and pin 14:. The two eccentrics are the equivalent of two short cranks having radii bearing a mutual angular relation, in Figs. 1 and 2, of preferably less than 180 and more than 90, but these limits may be disregarded without departing from the spirit of my invention. The two arms 15 16 have radii approximately bisecting the angle between the radii of the eccentrics. The two arms act as one, and are made duplicate only for convenience. To the extremities of the pin 1st in these arms are attached the tension- springs 17 and 18, the other ends of which are attached to the pins 19 and 19 fixed in the rods 6, 6. Except for the elastic action of the springs 17 and 18, which may not always be present, the rocksleeve rotates freely on the crank-pin. without constraint into any definite position.

In the modification shown in Fig. 8 the crank-shaft and crank are not shown, but are understood as driven by the connecting rods 26, 26 working upon a single crank. is a cross-head, suitably guided by slides not shown, driving the connecting-rods by the pin 27. The left-hand face of this crosslid of the two pistons. the back-stroke the pressures in the two head comprises a plane surface, and against this surface bears a rocker 21 in which are fixed pins 22, 22 and 29, supposedly protruding upon the far side also. The pins '22 are connected with the two'pistons respectively by the links 23, 23. The cross-head bears a pin 28 whichis connected by the tension-spring 36 with the pin 29. The rocker 21 is guided by the links 24:, 2 1, swinging onpins 25, 25 fixed in the crosshead (with the requisite lost motion or elasticity properly provided) so that each link 23 will coincide approximately with the axis of its cylinder when its end of the rocker cylinders are equal, the forces at work upon the two eccentrics 11 and12 are equal, and the tension of the two springsl'i, 18 will have drawn the arms 15, 16 into approximate coinc dence with the plane of Fig. 1. from which plane the two eccentrics will tend to bear equal departures. But as the back-stroke progresses the action of the valves imprisons the gases within cylinder B, while leaving open the exhaust for those of cylinder A; wherefore the-pressure rises rapidly in B. This unbalances the forces at work upon the rock-sleeve and tilts it gradually toward the position shown. This position will be assumed more or less accurately, according to the influence of the inertia of the various moving parts, before the compression-stroke is completed; but since the springs 17, 18 shown in Figs. 1 and 2 gain in mechanical advantage as the rock-sleeve assumes angularity, whereas the fluid forces uponv piston B lose it, the parts will never quite reach the position shown (-exceptas a possible result of inertia). It the springs 17, 18 vere absent from the structures of Figs. 1, 2 and 3, as in the structures ofFigs. at and 5 which ha veno springs, the positions shown in the drawings will still be assumed perfectly, as the from cylinder A.

A is driven'quite home (barring an in evltable nunln'uini of clearance), whereby the exhaust-gases are driven completely It is tobe understood that the springs of Figs. 1 and 2, when the eccentrics 11, 12

a beara relative angle appreciably. less than 180, are superfluous to the normal operation of'the engine, since the fluid forces at work upon the pistons suflice-to enforce all the requisite movements of the eccentrics; but when the engine has been at rest for a time eccentrics relatively "so: located-'rnight 'have become rota-ted by 'accident (-inthe absence of'the springs) intojthe position where eccentric'llwas vertically above the crank-pin, whereupon the starting of the engine would develop a destructive collision "before the usual fluid forces could assume control. If the relative angle of eccentrics in F :igs, 1 and 2 be substantially 180 the springs areplainly necessary for normal operation, tO throw the upper eccentric off center after the completion of the suctionstroke.

But where the eccentric angles and radii are such, in a two-cylinder engine like Fig. 1, or where the number or relative position there is no danger of the eccentric of the compressing piston being caught on upper center, or being improperly near the cylinder, so as to develop collision, springs are not necessary. Springs such as 17, 18 are therefore apart of my invention only as a well known'means for accomplishing what may-preferably be accomplished by the fluid forces acting upon the pistons, or by other means. Besides the fluid forces there are inertia-forces at work upon the pistons and eccentrics. In F igs. 1 and 2, as the pistons approach the upper endof their stroke, not only will the eccentric piston B be pressed downwardly by the -compression-pressure but that of piston A may be forced upwardly by inertia-forces. This would tend to rotate the sleeve beyond the dead-center position for piston B, were not the explosion-pressure thereon so heavy as to pre vent. In such case centrifugal force or inertia, acting upon eccentric A nay become the true motive force to be relied upon to actuatesaid eccentricyin domination over the fluid forces. Thus in high-speedengines the inertia-forces may become thecontrolling forces bothin design and operation, in my invention as in any otherfeature of-a high-speed engine.

As combustion and expansion ensue the heavy fluid forces-at work upon piston B can have no appreciable efiect-uponthe angularityof the rock-sleeve, because it already virtually upon dead-center; The

tive position shown until the opening of of cylinders is such, as inFigs. 4 aud o, that I two-pistons retain substantially"the reladeparture from my invention.

exhaust equalizes or reverses the pressures in the two cylinders. Owing to this fact the Working pistonwill travel farther down its cylinder than the idle one, thus uncovering the annular exhaust-port 30, which the idle piston fails to reach. This provides amore free exhaust and a greater degree of expansion than is ordinarily attainable in four-stroke cycle engines.

In the modification shown in .Fig. 3 the action is virtually the same, merely the struc ture being different in detail. The various angular positions of the rocker of Fig. 3 correspond with those of the rock-sleeve of Figs. 1 and 2. The spring 36 corresponds with the springs 17 18. If the face of the rocker be a circular cylinder the links cannot guide truly without lost motion or elasticity or slipping; but by making the rockerof a suitable ci'lrvature the links can be used Without lost motion, elasticity or slipping. Other forms of guides may be used for the rock-sleeve or rocker without The rock sleeve, for instance, may be located upon the wrist pin of a cross head, instead of a crank-pin as illustrated in, Figs. 4% and 5. The elastic control springs may likewise be replaced by pistons or diaphragms under fluid pressure including the main pistons themselves.

The invention thus appears as a device between the piston and the crank-pin which will let the former approach the latter, to Ward a dead-center condition, as the former becomes subject to major fluid forces, which will permit said piston to separate from its crank-pin in similar manner. as the former becomes subject to minor fluid forces or to dominating inertia-forces, and means for throwing the device off dead center at the proper time. This last mentioned means may be one of the pistons of the engine, as in Figs. 1, 2 and 3 (as drawn, but omitting the springs), or as in Figs. 4 or 5, or this means may be a metallic spring, as it must be in Figs. 1 and 2 if the eccentrics were at 180, or if Fig. 3 had ISO-degree eccentrics on its wrist-pin; or this means may take some other form. The only requisite is that it shall act without shock.

Figs. 1 and 2 are illustrative of what may be called an elementary pair of cylinders, of which pairs there may be any number grouped about the shaft, either on difierent radial planes, as in Fig. l, or in a single vertical plane, as in the ordinary marine engine. This elementary pair is not necessarily structurally segregated from the other cylinders, nor need it have its cvlinders oxactly in the same plane through the shaftaxis; for the operation of Fig. 5 shows such a pair formed by each two cylinders in turn, as theshaft rotates. \Vhen one such ele- .n entarypair appears alone, as in Figs. 1

and 2, metallic springs or some other dis placing device are obviously needed. for drifting purposes if the eccentric-angle be less than 180, or for normal operation if this angle be 180; but Where two or more such pairs are associated piston-action may be relied upon for displacing the eccentrics from dead center or for otherwise limiting properly itsmotion. The exact character of such means 1s not a feature of this invention,

so long as it operates without shock.

In engines having a sufficient number of cylinders located radially around the crankshaft the device of Figs. 1 and 2 is applicable by leaving the rock-sleeve free to rotate completely around the crank-pin under control by piston-forces only. The recurrent cycles in the successive cylinders will cause the sleeve to rotate, but irregularly. In such an engine the cylinders may be arranged in pairs like Fig. 1 or they may all be in the same plane, or they may combine these two plans. The only requisite is that combustion shall occur in adjacent cylinders at each alternate revolution, as is usual in four-stroke cycle engines. Fixing the crankshaft and making the cylinders the rotor has no bearing upon the applicability of my invention, although reversing some of the descriptive terms used.

Figs. l and 5 are diagrams of crank positions, and sleeve or eccentric positions, arranged to show how my invention may be. applied to engines of different arrangements of multiple cylinders.

Fig. 4 illustrates diagrammatically an en. gine of ten cylinders upon a single crank, arranged radially about the crank-shaft in five pairs, each pair parallel as in Fig. 1.

The five A cylinders of these five pairs drive upon a single eccentric common to the five, upon the crank-pin, while the five B cylinders drive upon another single eccentric common to the five, the two eccentrics being solidly connected upon common sleeve, as in Fig. 1.

Each of the five brokcn-anddotted lines radiating from the center of Fig. 4; represents the plane of a section similar to Fig. 1, the pitmen of the live A cylinders being journaled upon the eccentric 11 or upon the head of the left-hand piti'nan 6 in, any suitable manner, as is now commonly done, and the pitmen of the five B cylinders be ing similarly journaled upon the eccentric 1:2 or upon the corresponding pitman 6.

Fig. 5 illustrates diagrammatically an engine of nine cylinders upon a single crank, arranged radially about the crank-shaft at nine equal angles, all the cylinders being either substantially in the same plane trans verse to the shaft, or, if in three differentplanes, so distributed only for convenience of alinement with their respective eccen tries.

The sleeve on the cr'ank-pin in this case carries three eccentrics similar to 11, 12 of Figs. 1 and 2, the centers of which are marked a 7 and 2 respectively, bearing a mutual angular relationship of The nine cylinder-axes are in three different planes transverse to the crank-shaft, cylinders LIV and VII being in the plane of eccentrics, cylinders II, V andVIlI inthe plane of eccentric y, and cylinders III, VI and IX in the plane of eccentric 2. Each of these three sets of three cylinders drives the crank-pin through connecting-rods bearing upon the single eccentric respectively common to the three cylinders and lying in their plane.

In Figs. 6 and 7 the three eccentric- centers 50, 1 and 2 are those respectively of eccentrics 111, 211 and 311, the three eccentrics lying in the planes X, Y and Z respectively and being structurally solidified into a'unitrotating freely about the crankpin axis'50,which in turn rotates about the shaft-axis O.

In Fig. i the solid circle represents the path of the crank'pin and the two concentric dotted circles the extremes of piston-adjustment away from its mean position, in either direction, requisite for the functions of perfeet scavenging, extended expansion, over running of exhaust-port or clearance for suitable compression, as already described. The double small circles represent various posit-ions of the center of the crank-pin or sleeve, and the little adjacent single circles represent the centers of the two eccentrics, which are in this case separated by an angle oflSO and of a throw equal to the dis tance between solid and dotted large circles. The. two sets of five cylinders each, with the directions of their center-dines, are indicated by radii marked with the Roman numerals:

:1, 11, III, IV, v, vi, vii, viii, ix and X,

the capital letters referring to the cylinders in one plane attached to one eccentric and the lower-case letters referring to those in the'other plane attached to the other eccentric. The valve'gear is supposedly arranged to develop combustion in the ten cylinders in' their numerical order.-

"Starting first with cylinder I, the development of compression and explosion in this cylinder will force its eccentric and piston into'the'position B, Fig. 1, while the piston of cylinder VI is forced into the position A (exceptthat its eccentric is then directly above the crank-pin center, instead of obliquely as in Fig. 1). Throughout the arc of crank-motion III cylinder Iwill be chiefly in control of the angular position of the rock-sleeve, but as radius II is approached'the fluid force of cylinder I is dying out rapidly, while that of cylinder II is increasing rapidly, whereby as combusion occurs in cylinder II that piston supersedes masses cylinder. I in control, forcing the two'ecc'entrics approximately into alinement with radius II without shock. Continuing thus around the circle to" radius V,.eaclrcylinder of thisset assumes control of the rock-sleeve in turn, without shock, ther'ock-sleeve rotating with an average angular speed equal to that of the crank.

But when cylinder V has burnt and slightly expanded its charge a new state of equilibrium is reached, as indicated. When the crank is about midway between. radii V vi the rock-sleeve is rotated quickly and powerfully, but in stable equilibriumand without shock, in the opposite direction from that of the engine, bringing the eccentric of the second set of cylinders into the position of that occupied before by that of the first set. Thus during each revolution the eccentric of one working set of cylinders is held nearest to the crank-shaft,while that of the idle set of cylinders is farthest from it, thus accomplishing for allthe cylinders the operation described for Fig. 1.

InFig. 5, as in Fig.4, the axes of the nine cylinders are indicated by Roman numerals. But in this case the valve-gear is arranged to develop combustion in the several cylinders in the following order: :I', III, V, VII IX, II, IV, VI, VIII, I, etc. Starting with the crank-pin-in position I, the operation is a follows: The heavy working-pressure in cylinder I'forces eccentricw to itslower dead-center, as drawn. As the crank-pinpasses position II this cylinder (its piston attached to eccentric 3/) is idle at the end of its exhaust-stroke. The position of eccentric g at this time showshow the perfect exhaust desscriloed-in relat on to Fig. 1 is=performedin eylinder 'II of Fig. 5 As the crank-pin approachesposition III the angularity of connecting rod I brings the rock-sleeve into approximation to the position drawn at III; but'in'addition, the fluidforces of cylinder I are dying out rapidly, while the compressive resistance of cylinder III, acting upon eccentric .2, is rapidly increasing. Therefore near position III thecontrol of the rock-sleeve passes gradually and' without shock from cylinder I to cylinder-III.

The p'henornena just described-then repeat themselves in 1 the I are IIIV of i the crank circle, but with eccentric z playingthe part formerly performed by eccentric*w,' ete:, and

assesses in crank-arc VVII the performance is re- )eated with eccentric y in the leading role.

bus, as the engine rotates the roclesleeve also rotates virtually continuously, but in the opposite direction and at an average speed a little greater than that of the engine. In this case not only is the elastic control of the rock-sleeve no longer needed to overcome inertia, but the smoothness of operation may be enhanced by expanding the rock-sleeve into a little fly-wheel, the inertia of which will steady its otherwise somewhat irregular angular motion.

1th the particular number of cylinders illustrated in Fig. 5 the extra length of exhaust-stroke described in relation to Fig. 1 does not appear, the exhaust and suction strokes carrying the piston out to about the same extreme position; but with twelve cylinders, for instance, arranged as in Fig. 5, working upon a rock-sleeve of three eccentrics (eccentric m carrying cylinders I, IV, VII and X, eccentric y cylinders II, V. VIII and XI, and eccentric 2 cylinders III, VI, IX and XII) this feature of advantage reappears. This extension of the workingstroke beyond the end of the suction-stroke both permits a free-annular exhaust and also increases the degree of expansion.

Various other methods of adapting my invention to the many different arrangements of cylinders common in internal combustion engines will occur to the designer ofeach type, without the possibility of illustrating them all here. Thus a four-cylinder sin le crank \I-type engine, with the four eccentrics located relatively at 90, would operate as Fig. 1 does, except that the period during which re-adjustment of eccentrics was accomplished would occupy 180 of crank motion, instead of 72 as in Fig. 4, and so the engine would be smoother in operation. Such a single crank engine would be unbalanced; but an eight-cylinder two-crank V- type engine with cranks located at 180, would operate in the same way and in perfeet balance.

It will be noticed that in all of the structures described above, the opposing forces set up in the sleeve-and-eceentrics or rocker device by the pistons, together with any additional force introduced to throw an eccentric oft center, act always in stable equilibrium. That is to say, the resultant of all such forces in combination acts to rotate the rocker into a new position in such a way that the moment, or efl'eetiveness, of this resultant dies out gradually,- without shock, as motion progresses under its influence, until a final position is reached in which said moment has become zero. Also, for any given assortment of forces in the pistons there is always a single definite position of rocker corresponding thereto.

'Ihis is the essence of stability of can librium. It is also the essence of my ll'lVBIlt tion. I am aware that other suggestions have been made for devices displacing the pistons of internal-combustion engines relatively by the action of piston-forces; but they have been either such as to act always in unstable equilibriiunthe moment or of fectiveness ofthe forces increasing as motion progresses, until shock alone arrests said motion-01 they have been such as to act much of the time in neutral or indifferent equilibrium, there being no definite position of the rocker for any given assortment of forces on the pistons; or else, when stable equilibrium happens to be present momentarily, in the form of a dead center, no means is shown for throwing the rocker off center after its duty has been performed.

It is further to be understood that my invention consists in a merely relative arrangement of cylinde --axes and eccentric-radii such as will develop this stability of equilibrium. That is to say, whether the cylinder-axes be kept parallel, as in Figs. 1 and 2, while the eccentrics are set at odd angles, or Whether it be the cylindenaxes which are set at odd angles, as in Figs. at and 5, makes no difference. Nor again, whether, in Figs. 4t and 5, it be the mate of a parallel pair of cylinders which functions to throw the rocksleeve out of center with the working-cylinder, after its working-stroke is finished, or some cylinder oblique thereto, also makes no dilference. It is mere congregation of cylinders combined with obliquity between cylinder-axis and eccentric-radius, so as to produce stability of equilibrium in the rocksleeve, which constitutes the essence of my invention.

It is plain from the above that my invention may be embodied in many different relative arrangements of cylinder-axis and cocentric, and I therefore do not confine myself to those illustrated.

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

1. In an engine of the type described, the combination of a plurality of pistons and cylinders, a cranlcpin common to the pistons, and unconstrained means located between said pistons and crank-pin for displacing the pistons relatively to the crank pin in different directions, said means being actuated by the forces on the pistons and so formed that said forces always combine therein in stable equilibrium, substantially as described.

2. In an engine of the type described, the combination of a plurality of cylinders and pistons, a crank-pin common to the pistons, and unconstrained means actuated by the forces on the pistons located between said pistons and crank-pin for displacing the pistons relatively to the crank-pin in different directions and so formerlasqto assume radna-lly a dead-center position relative y to each, piston as said pistonin turn-becomes subject't-omajor'fluid force, substantially as described.

3. Inan engine of the type described, the combination of a pluralityot' cylinders and pistons, a crank-pin common to the pistons, -a pi'tman for each piston, an unconstrained sleeve rotating upon said crank-pin, a plu 'rality of eccentrics fixed on said sleeve, each eccentric forming a pitman journal for a piston, the eccentrics and piston-axes arranged in such angular relation that the sleeve-is rotated by the forces onthe pistons always in stable equilibrium, substantially as described.

4. In an engine of the type described, the combination of a plurality of cylinders, pistons and pitmen, a crank-pin common to all, a sleeve rotating unconstrainedly upon said crank-pin and eccentrics fixed upon said sleeve and forming journals for the pitmen, the angular relation between cylinder-axes and eccentric-radii being such that whenever major force upon one pitman has driven its rock-sleeve eccentric into a dead-center position relatively to that piston a piston engaged in compression is out of dead-center position relatively to its eccentric, substantially as described.

5; In an engine of the type described, two sets of parts, each set comprising a cylinder, piston and pitmanor a plurality of such, arranged for-alternate combustion between the two sets, a crank-pin common to the two sets, a sleeve rotating unconstrainedly on said pin, eccentrics forming pitman-journals fixed on said sleeve, the eccentrics bearingsuch angular relation to their respective cylinder-axes that the sleeve is rotated on the pin by the piston-forces always in stable equilibrium, substantially'as described.

6. In an engine of the type described, the combination of a plurality of cylinders-and pistons arranged for combustionin succession, a crank-pin common to said cylinders, and unconstrained means between said pistons andthe crank-pin actuated by the piston-forcesfor displacing-the pistons relati-vely to the crank-pin, said means being arangedto come gradually into dead-center position relatively to each piston which in turn undergoes compression and combustion, whilebeing at the same time off dead cens ter relatively-to the next piston to-undergo compression and combustion, substantially as described.

7 In anengme of the type described, two

sets of parts, each set comprising-1a cylinder and a; piston or a plurality 'ofisuch, arranged for alternate Combustion between the res sets, a crankepin common to theetwo sets, an annular exhaust-port in each cylinder at thexextreme point toward thecrank-pin'overrun by the piston, and unconstrained jmeans located between piston and cr-ank-pin and actuated by the piston-forces t'or displacing away from the crank-pin the pistoninomentarily subject to minor force by permitting the piston momentarily subject to major force to approach gradually the cranlopin, towarda deadenter position of said means, said means being always in stable equilibrium, substantially as described.

8. In a four-cycle engine having a plurality of cylinders burning their charges at diiferentxtimes, and llnflIlQjftCOll'lDlOll crank;- pin, an unconstrained: member transmitting forces from theseve al pistonsto the 001m moncranlopin sotorined as to assume sub stantially a dead-center position relative to the pistonri'orce momentarily superior'to the others, and means, for displacingsaid member from said dead-center position after said piston-force has. lost its superiority, sub, stantially as described. r I

9. In a. four-cycle engine having a plurality of cylinders burning their charges at diiierent times, and'having ,a common crankpin, an unconstrained member transmitting the forces from the several pistons tothe common crank-pin so termed as to assume gradually a stable posit=ionrelatively to each piston working in turmwith means for. displacingsaid member from said; position gradually and stably when said: piston has ceased working, substantially, as described;

10. Inan engin of the type described, the

combination. with a; plurality 0t cylinders and pistons, of a: crank pin common to the pistons, a pitman tor each piston, and an eccentric member rotating unconstrainedly on 'saidcrank pin and forming a journal for;

thesaid plurality of pitm'en, the piston axes being arranged in such angnlarrelation to the eccentric-radii that the eccentric member is rot-atetbby forces on the pistons always,

7 s mi ar A. Rnnvn \Vitnesses James T. LAW, SArrUEIr lV. BALCH.

C011! 50; this, patentmay bsobtained for five cents each. by,addressing thefifiommissioner of Patents,

WashingtonJJ. 10.? i

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