US711952A - Rotary engine. - Google Patents

Description

1. mnew ea mix. 29, 190

4 Sheets-Sheet I.

(No Model.)

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Nu. 7|l,952.

Patented Oct 28, I902. H. T. DUNN.

ROTARY ENGINE.

(Ap led Jan. 18, 190 Renewed Mar. 29, 1902) animal.) 4 Sheets$heet 2.

.17 w 9 1 "H e o I l L 0 Q 6 8 I. I I O %"930: I l E {Z I] H In x I o P% 4i 9 0 HI No. 7||,9s2. Patented Oct. 28, 1902;

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ROTARY 'ENGINE.

(Application filed Jan. 18, 1901. Renewed Mar. 29, I902.)

(No Model.) 4 Sheets-Sheet 3.

2 n W 8 2 c o B t n e t a P E N N.- E N E .Y R A T HO R Z 5 N I (Application filed Jan. 18, 1901. Renewed Mar. 29, 1902.)

4 Sheets-Sheet 4.

(No Model.)

UNITED STATES PATENT Trice.

HUGH THOMAS DUNN, OF NEW YORK, N, Y., ASSIGNOR OF ONE-HALF TO BENJAMIN A. JACKSON, OF NEW YORKQ N. Y.

ROTARY ENGINE.

SPECIFICATION forming part of Letters Patent N 0. 711,952, dated October 28, 1902. Application filed January 18, 1901. Renewed March 29, 1902. Serial No. 100,590. (No model.)

To all whom it may concern: close the lubricating-groove. Fig. 2 is aver- Be it known that I, HUGH THOMAS DUNN, a tical longitudinal view with the cylindercitizen of the United'States of America, residhead, shaft, and flange removed. Fig. 3 is a ing in New York city, in the county and State vertical transverse section through the entire 55 of New York, have invented certain new and machine. Fig. 4 is a detail of one of the pisuseful Improvements in Rotary Engines, of ton and sliding cam-plates. Fig. 5 is a detail which the following is a specification. showing the manner of packing employed in My invention relates to improvements in the piston. Fig. 6 is a detail showing the rotary engines, and more particularly to that grit-traps and connected parts. Fig. 7 is a 60 class known as eccentric-piston rotary endetail of a section of the cylinder, showing gines, the object being to produce a machine the grit-traps and bridges. Figs. 8 and 9 are of this character which is capable of effecting views in plan and side elevation, respectively, better results, as well as one in which the luof the manner of compounding several enbricating system is superior to any heretogines of my improved construction. Fig. 10 '65 fore known. is a modification of my cam-plate. Fig. 11 is A further object is to provide a means a detail of the bearing-block or bridge-packwhereby to collect and accumulate refuse in ing, and Fig. 12 is a detail sectional view of the shape of dirt and other injurious matter a portion of the'lubricating system. which may gain entrance to the engine at A represents the cylinder-band of the en- 20 points where they may be easily and quickly gine. This is provided with the usual boltremoved. holes 1 to receive bolts 4; in the cylinder-heads Another object consists in the improved 3, suitable packing being placed between the manner and arrangement of packing emcylinder and heads. This band is of a peculployed whereby the escape of power is preiar construction, being approximately heart- 25 eluded, which packing when worn out may shaped or like a cylinder, the top portion of be replaced with lesstrouble and labor than which'is flattened. The usual pipes 5 and 6 hitherto, and it is so located as to secure the afford an extrance and exit, respectively, for vital places, where power would otherwiseesthe motive power employed to operate the encape. gine. This cylinder is supported by means 0 My improvement is more easily adapted to of a standard 7, cast integral therewith. Gritbe connected with similar devices in what is traps S 8 are formed transversely across the commonly known as compoundingthat cylinder-band from side to side at suitable is, to combine several machines-whereby intervals; These grit-traps consist of deep greater power is gained and more work acgrooves generally circular in cross-section 5 complished and yet at the same time the moand opening into the interior of the cylinder tive power employed to drive said engines through narrow passages. Situated at suitbeiug used in an economical manner, ashereable distances across these passages are inafter more fully described. bridges 9 9, countersunk in the cylinder- A further object is the provision of imband, so that their surfaces are in the samego 0 proved bridge-packing between the inlet and curved surface as the interior of said cylinexhaust pipes, whereby the escape of motive der and form continuations thereof across power around the cylinder is entirely obvisaid passages. The bridges are set at an anated, together with certain novel COHSlJIUC- gle to each other as a precaution against the tions of the sliding cam-plates and connected passage of dirt thereacross. The grit-traps 5 parts and other features and combinations of obviously are designed to catch and'retain parts, as will be more fully described hereinany dirt or other foreign matter which if not after and particularly set forth and pointed caught and removed would tend to scratch out in the claims. or otherwise injure the band or working parts In the accompanying drawings, Figure 1 is of the machine. The bridges across said. too 50 a perspective view of my engine when fully traps prevent the cam-plates from catching assembled, showing parts broken away to distherein. At each end of said bridges shallow grooves 10 10 are formed. These grooves meet at an angle the apex of which is at the ends or heads of the bridges 9 9 and lead therefrom to the grit-traps. These shallow grooves prevent dirt from crossing the bridges and conduct it instead to the grit-traps. The

lower grit-trap is provided with a drain-cock 15, whereby to drawoff fluid accumulating in the cylinder.

At the top and in the body of the band an offset 17, containing a transverse recess or chamber 11,is formed,which recess opens into the cylinder. This recess is of a general wedge shape, with its narrowest portion opening in the interior of the cylinder-bands. A block of frictionless metal is received and held tightly in the chamber 11, the block conforming in size and shape with the interior dimensions of the chamber, this frictionless bearing being suitably curved on its inner or lower faces to conform to the curve of the piston against which it bears, firmly providing an abutment which prevents the steam from passing from the inlet to the exhaust pipe directly without exercising its energy to propel the motor. The distance between this bridge and the exhaust-pipe 6 is the same as between said dividing-bridge and the inletpipe 5. This bridge-packing just described is constructed as shown in detail Fig. 11 in order that a tight frictionless packing may be had upon the revolving piston and one which will absolutely prevent the escape of motive power from the inlet to the exhaust pipe without first having carried the piston around by exerting its force against the camplates in the usual manner, which latter are thrust outward by the pressure of springs and against the tendency of which they are pushed in by the sidesof the cylinder-band. This friction-block is held firmly in the recess in the dividing-bridge and cannot in view of the shape of the recess become loose, but is held rigidly in place.

Eccentrically of the cylinder the cylinderpiston B is located. This piston is provided with a transverse slot 18, extending from the outer plane radially to a point beyond the center of said piston. On either side of this slot screw'holes 19 19 are formed for the reception of tap-bolts 2O 20, which secure the piston to the flange 21, the latter provided with bolt-holes therefor. This flange 21 is integral with and forms one end of the shaft 23. Thus it will be seen that the piston, flange, and shaft are made substantially integral with one another and revolve together.

Annular grooves 24 24 are formed oppositely to one another in the side edges of the cylindrical piston, said grooves being constructed in a general wedge shape, narrowing as they approach the longitudinal center of the piston and their widest parts opening outward on the sides of the piston. One side of these grooves is tapered to or nearly to the edge of the piston,while the other side of the grooves is straight. These grooves'are connected with each other through the web of the piston by means of apertures 25 25,formed through the thin dividing-wall, and these grooves give a general dovetail form to the piston when seen in cross-section, as in Figs. 3 and 5. In these grooves an gularly-cut wedgeshaped packing rings 26 26 of some fric-' tionless metal are placed and so shaped and constructed as to fit together and be pressed outward against the cylinder-heads, whereby to form an effectual packing and prevent the leakage of motive power. Blocks 27 27 are fitted in the bottoms of these grooves, and springs 28, extending through the apertures 25, operate to continually press the packingrings outward, forming a tight packing against the cylinder-heads at the outer rim of the piston. It will be seen that this arrangement of sectional-ring packing allows for wear of the parts,which can be taken up by the pressure of the springs 25 against the packing-rings 26 26. By means of these peculiarly-shaped rings a better and more secure packing is obtained than anyheretofore in use and one which will take up any wear of the parts and may be easily replaced. It fits the groove completely, owing to its annular wedge-shaped construction, and because of this same construction a large portion of the rings may be worn away, if not all, before the block 27 comes in contact with the cylinderhead, when it will become necesary to replace the packing. The angles at which the rings are cut or formed into sections are set away from each other, which admits of a very tight and secure packing. The novel construction of the groove adds to this and permits of the arrangement of the packing-rings as shown and described, which is applied directly to that part most necessary to be protected.

The slot 18 in the piston is formed for the reception of the sliding cam-plates 29 29 and 30. These cam-plates are constructed of angularly-cut wedge-shaped portions dovetailed together, forming the plates, as. shown in detail in the drawings. The plates are formed of bronze or some other suitable material and are provided at their outer ends with frictionless metal, which ends are rounded and bear against the cylinder-band A. These ends may be provided with antifriction-bearings 15, as shown in Fig. 10, if desired, and are wider than the passages leading to the grittraps in order that they may pass over more easily, as well as prevent the escape of motive power while the cam is passing over the grittrap. Oil-holes 31 31 are formed in the sides and ends of the said plates, whereby lubricant may have ready access to all parts thereof to avoid friction in any of the hearings or bearing-surfaces. Bow-springs 32 32, riveted at their ends, are placed in slot 18 and bear against plate 33, which is located against the rear ends of said cam-plates, which latter are thus evenly forced out automatically and continuously in contact with the cylinder-band. The sides of the cam-plates bear against rollerbearings 34 34, set in frictionless metal located in recesses 35 35 in the piston B, where? by the amount of friction between the sides of slot 18 and the plates 29 29 is greatly lessened. In order-to avoid any liability of these cam-plates wedgin g before they extend to their full length after passing the dividingbridge 12, the area of the cylinder from the dividing-bridge to each of the inlet and ex haust pipes is the same. These cam-plates allow a take up for any wear occurring in the parts, this wear being taken up by the springs 32 in slot 18. It will be noticed that cam-plate-3O is set oppositely to plate 29 29 and the whole plate connected bylap-joints tightly and compactly.

The cylinder-head 3 is provided witha central annular recess 36 for the reception of the flange 21 on shaft 23, which when in position lies flush with the inner surface of the head. A vertically-slotted aperture 37, formed eccentrically of the head, admits the shaft 23, a stuffing-box 38 and suitable packing being placed about the shaft at its juncture with the head to afford a bearing and prevent the escape of motive power. The stufi'ing-box is suitably secured to the cylinder-head and is provided with a verticallyslotted aperture 61 in exact alinement with the slotted aperture 37 in the cylinder-head. The general conformation of the stuffing-box is rectangular, and the shaft 23 of the engine is received in these vertically-slotted openings. On either side of that portion of the shaft which is contained within the stuffing-box bearing metal blocks 62' 63 are set. These blocks are cut angularly and fitted together, the adjoining edges provided with a kind of tongue-and-groove joint. The central blocks 63 are grooved on the faces which contact with the shaft 23 to conform therewith. Strong springs 64 64 are placed in each end of the stuffing-box and by their tension cause the blocks 62' to press tightly against blocks 63, which in turn hold the shaft'23 firmly against any vertical movement. A set-screw 65 enters this stufiing-box from beneath, and locknuts 66 are screwed on the threaded end of'the screwone on the inside and the other on the outside of the stuflingbox. The inner locking-nut is provided with a plate or broad bearing-surface 67 to support spring 64, and the tension of thesprings, together with the position of the piston 13, flange 21, and shaft, may be adjusted so that the piston will bear firmly against bearingblock 12 in the dividing-bridge 17 to prevent the escape of power. For this purpose the flange 21 of the piston is allowed some degree of movement in the recess 36, which is larger than the flange. The springs 32 in recess 18 of the piston press the cam-plates 29 30 outward to take up any space left by the adjustment of the piston. These bearing-blocks fit the stuffing-box so snugly as to prevent the escape of power through the stufiing-box and out ofthe slot 61. A soft packing 6 8,of asbestos or other suitable material,is placed between the blocks 63 and around the shaft 23, whereby to form a completely-tight joint between the two blocks 63 and aiding to prevent the escape of any substance. Oil-holes extend partly through blocks 63 from the inner edges, and leading from the main duct smaller ducts 7O conduct the lubricant to the shaftbearing. Grooves 71 on the face of flange 21 permit the lubricant to have access to the studing-box. of these cylinder-heads, which holes register with the grit-traps S 8, and secured therein are valves 39 39, which permit of the cleaning of said traps whenever desired. A lubricantgroove 40 is also formed in the cylinder-head and concentric with the shaft-opening 37, and an annular ring 41,T-shaped in cross-section, is bolted over said groove, the stem of the T extending a little distance thereinto, suitable packing being interposed between to form a tight joint. Ducts 42 42 43 43 lead radially to and from said groove and open on the interior face of the cylinder-head. Oil is supplied to the engine by means of suitable oilcups 45 45 on either side of dividing-bridge 17. From this point it finds it way to inletducts 42, the opening of which is located near the junction of the piston and dividingbridge. Check-valves 46 46, held in their seats in the lubricating-grooves 40 by means of springs 44, admit the entrance of lubricant to the groove through inlet-ducts 42, but prevent its return therethrough. From this groove 40 the lubricant is distributed to all parts of the engine by means of the ducts 43 43, the oil permeating to all bearings and tending to greatly lessen any friction. The stems 47 of these check-valves are held in holes made for their reception in annular castings 41, whereby to retain the valve in place. There are four inlet-ducts and four checkvalves-two in each cylinder-head and placed on either'side of the dividing-bridge 17, so that the system will operate when the engine is revolving in either direction. The construction of both cylinder-heads is similar. Consequently it is only necessary to describe one. The oil is used over and over again, having a regular circuit through the bearings, back into the cylinder through the inlet-ducts to the groove, and out again continuously, the movement of the sliding camplates operating to force the lubricant along at each stroke. A governor may be attached to regulate the speed of the engine, if desired.

In compounding devices of this character I have invented the following apparatus for connecting one engine to another, which apparatus is simple, cheap, and easily operated, besides facilitating the accomplishment of the results desired in a most effective and novel manner. In compounding enginessay in triplicate-4t has been found to be most advantageous to place the smallest first,

.the next larger next, and the largest of all at the end, whereby the steam or other mo- Holes are formed near the edges &

tive power after exerting its force in the first or smallest engine passes on to the next with a diminished power, but has therein a larger surface upon which to act, and so in the third or largest engine. Of course either more or less than three engines may be connected together in this manner, and I have shown threemerely as an example. It will be understood, of course, that the pistons must be set on the shafts so that the sliding cam-plate is at the beginning of its stroke in the first engine, in the second engine it will have partly completed its stroke, and in the third the cam-plate will be at the end of its stroke, and the constantly-increasing area in the size of the cam-plates allows the decreased power to exert the same amount of pressure against the last cam-plate as was received by the cam-plate in the first engine, thus equalizing the pressure received by the cam-plates in all the engines. In order to lessen the friction as much as possible, antifriction-bearin gs can be placed in the shaft-bearings.

In my arrangement I provide a main pipe 48, conveying the power to the engines from any suitable source. by a throttle-valve 19, and a governor-valve to regulate the speed may also be attached.

A system of piping connects the inlet and exhaust pipes of the first engine to the ex haust and inlet pipes, respectively, of the second machine, and so on with as many engines as are compounded, the pipes alternating and intersecting one another at points intermediate of the engine and enlarging in size from the smaller to the larger, as shown. At these points of intersection fourway valves 50 51 are located, said valves provided with arms 53 54, pivoted at their free ends to a reversing-lever 56, by means of which said valves are controlled. It will be seen that the pipe system conveying the steam or other motive power from engine to engine combines into one pipe 57, which conveys the exhaust away, a three-way valve 52 being placed at the meeting-point of the pipes, thus controlling the exhaust. This valve is connected to the reversing-lever by an arm 55. A similar valve 58, provided with an arm 59, connected to the reversing-lever, admits the power to the engines. By means of this construction the engines may be easily and quickly reversed by means of lever 56, which when moved to one extreme position will admit the motive power to the inlet-pipes of all the engines through valves 58, 50, and 51 and when moved to its opposite extreme position will admit the power to the engines through their exhaust-pipes, thus reversing the direction of their movement. Intermediate of throttle 49, by which the supply of power employed in running the compound engines is governed, and the valve 58 there is placed a steam-chest 60, containing a slide-valve 61, adapted when in a certain position to close pipe 48. This slidevalve is operated by means of a rod 62, connected at its free end to an eccentric 63, jour- This pipe is governed naled on shaft 23. As the shaft revolves it will cause the reciprocation of the slide-valve in the steam-chest through eccentric 63 and rod 62, thus alternately opening and closing pipe 48, and in this manner the motive power is out 01f momentarily from the engines at any portion of their stroke, thus effecting a great saving in energy, which is of first importance in engines of this type. In the event that the slide-valve 61 should cover the steam-port in the steam-chest I provide the auxiliary connection 72, which consists of a by-pass pipe, which connects with the main pipe 48 at a point between the throttle-valve 49 and the steamchest and leading around the steam-chest again makes connection with the main pipe at a point between the steam-chest and valve 58. This by-pass is controlled by a valve 73. By means of this construction I can start the engines when the slide-valve covers the stea mport, and then when the engines are in running order I shut off. the by-pass by the valve 73 and permit the engines to operate through the main pipe by the slide-valve. Thus I can apply full power to the engines either to start them or at other times when it may be deemed desirable. The steam or other motive power admitted to the engines before the interval during which the power is cut off by the slide-valve operates by its expansion to move the cams around until the supply of power is again unimpeded. Thus it is seen that the quality of expansion is utilized, as were the flow of power uninterrupted live steam orother motive power would issue from the exhaust, as the energy contained in its expansive qualities would not have time to be utilized. So it is to be noted that I make use of every ounce of pressure obtainable, and the use of my engine results in greater economy than that of any other heretofore employed. A condenser may be used to obtain the full benefit of the power, if desired.

It will be seen from the foregoing that the device operates in a most simple and practical manner with the greatest possible economy and with less friction than any ever before devised. It can be used as an explosive-engine, if desired, in which event it would be surrounded by waterjacket, and in com pounding two or more the slide-valve would be omitted.

It is evident that slight changes other than those heretofore noted might be made in the form and arrangement of the several parts described without departing from the spirit and scope of my invention, and hence I do not wish to restrict myself to the exact construction herein set forth; but,

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

1. The combination with a piston provided with annular wedge-shaped slots arranged oppositely to and connected with each other, of a plurality of rows of packing arranged in the slots, the packing so formed that each row will bear against the sides of the cylinder, and spring-pressed wedges located in the inner end of each slot for causing a direct outward pressure on the packing-rings.

2. The combination with a piston having annular, wedge-shaped slots arranged oppositely to each other, of packing in said slots,

wedges located in the inner ends of the slots, the piston having apertures at intervals of smaller size than the slots therethrough connecting said slots at theirinner ends, springs in said apertures, said springs adapted to press against the wedges whereby to force the packing outwardly against the cylinderheads.

3. The combination with a piston having a slot therein, of a plurality of sectional packing-rings being angularly cut and disposed with reference to each other to entirely fill theslot and arranged to be forced equally outward against the cylinder-head.

4:. The combination with a piston provided with a radial groove, of cam-plates located in said groove, said cam-plates provided with oil-holes therein, and springs seated in said groove for continuously projecting said camplates from said groove and against the tension of which, said cam-plates are adapted to bear.

5. The combination with a piston provided with a groove, of a set of cam-plates located therein, the plates composed of a plurality of an gularly-shaped sections, the adjacent edges of which are formed with lap-joints adapted to interlock with one another whereby the sections are mortised together, a flange to which the piston is removably secured and a shaft integral with the flange.

6. The combination with a piston having a groove therein, of cam-plates made in wedgeshaped sections and angularly mortised together, the cam-plates located in the groove and provided with frictionless metal at their outer ends.

7. The combination with a piston having a groove therein, and cam-plates reciprocating in the groove, of slots formed in the piston at an angle to the groove therein, frictionless metal set in the slots and roller-bearings j ournaled in the frictionless metal, against which bearings the cam-plates contact whereby they are enabled to slide freely in and out of the groove.

8. The combination with a piston having a groove therein, of a single set of plates located in the groove, the cam-plates composed of angularly-shaped sections lap-jointed on their adjacent edges, whereby the sections are mortised to each other, a spring seated in the groove beneath the cam-plates, a pressureplate situated between the cam-plates and the spring against the respective sides of which plate and spring the cam-plates bear, the opposite end of the spring bearing against the rear or inner wall of the groove in the piston, whereby the cam-plates are pressed upon evenly and forced outward by the tension of the spring.

9. The combination with a motor comprising a cylinder-band, a head, and a piston and cam-plates operating in the cylinder, of grittraps formed in the band, and means whereby access may be had to the traps to remove their contents without dissembling the parts.

10. The combination with a motor, comprisin gheads, band and piston and cam-plates operating therein, of a plurality of grit-traps sunk in the inner surface of the band, bridges crossing the grit-traps at an angle thereto and means whereby accessmay be obtained to the grit-traps without dissembling the parts.

11. In a motor provided with a cylinderband and piston and cam-plates operating therein, of grit-traps formed in the cylinderband, bridges extending across the grit-traps, the cylinder having grooves therein, leading from the bridges to the grit-traps and means for obtaining access to the traps for cleansing or other purposes.

12. In a motor, comprising heads, band and piston and cam-plates operating therein, of grit-traps formed in the band and means whereby access may be had to the grit-traps for cleansing or other purposes, the cylinderband also provided with a recess and a bearing-block of frictionless metal snugly received in the recess, the block adapted to be borne against by the piston whereby to form a tight joint.

13. The combination with a cylinder-head having a groove therein, of ducts leading to said groove from the interior face of the cylinder-head and valves controlling said ducts.

14. The combination with a cylinder-head having an annular groove therein, of a band closing said groove, ducts leading from the interior face of the cylinder-head to said groove, and a valve located in said groove and bearing against said band to control the lubricant-supply to and from the groove.

15. In a motor, the combination with heads, band and piston and cam-plates operating therein, of grit-traps formed in the band and valves in the cylinder-head, the valves communicating with the grit-traps whereby access may be had thereto for cleansing or other purposes. V

16. The combination with a cylinder-band having grit-traps therein, and a dividingbridge, of a piston provided with sliding cam-- operating therein, of grit-traps formed in the band, bridges across the grit-traps and means on the cylinder-head whereby access is had to the traps for cleansing or other purposes.

IIO

18. The combination, in a motor, with a shaft, of a stu thug-box surrounding the shaft, a plurality of bearing-blocks superposed upon each other in the stuffing-box, means for antomatically and yieldingly holding the blocks in contact with the shaft, the blocks being so arranged and shaped with relation to the shaft and to each other as to admit of their being packed closely together and yet allow a slight play with reference to each other. r

19. In a motor, the combination with a cylinder-band, a dividing-bridge located therein a piston, a shaft provided with an integral flange, the flange secured to the piston, a stuifing-box surrounding the shaft, angularlycut, wedge-shaped plates located in the stuffing-box on either side of the shaft, means for automatically and yieldingly holding the blocks in contact with the shaft, means for effecting an adjustment ofv the shaft and thereby adjusting the position of the piston in the engine and lubricating means for the shaft.

21. The combination with a plurality of rotary engines arranged in graduated sizes,

the smallest one first, the next largest next and so on, whereby the steam may act upon gradually-increasing pistons and cam-plates as its motive power diminishes, pipes alternately connecting the inlet and exhaust ports of each engine with those of the next and valves located at the intersection of the connecting-pipes, the valves connected with each other whereby the direction of motion of the engines may be simultaneously reversed, of means for controlling the original supply of motive power to the first of the engines, a steam-chest located between the governing means and the first of the valves, a reciproeating slide-valve in the chest, an eccentric on the engine-shaft and a rod connecting the slide-valve and eccentric whereby the supply of power to the engines is intermittently interrupted.

22. The combination with a plurality of engines, having exhaust and inlet ports, of a system of pipes connecting alternately these ports, valves at the intersections of said connecting-pipes,said valves provided with arms, a lever to which said arms are pivoted and by which the valves are controlled whereby to admit steam or other motive power to either the exhaust or inlet ports of the engines as desired, means for governing the original supply of power to said engines and means for intermittently interrupting said supply of power, the last-named means located be tween the governing means and the first reversing-valve. I

23. The combination with a plurality of rotary engines, pipes alternately connecting the inlet and exhaust ports of each engine with those of the next, the pipes connecting the second and third engines being larger than those connecting the first and second and so on, and valves located at the intersection of the connecting-pipes the valves connected with each other whereby the direction of motion of the engines may be simultaneously reversed, of means for controlling the original supply of motive power to the first of the engines and means for temporarily interrupting the fiow of this original supply of motive power before it enters the first engine.

24. The combination with a plurality of rotary engines, pipes alternately connecting the inlet and exhaust ports of each engine with those of the next, the pipes connecting the second and third engines being larger than those connecting the first and second and so on, and valves located at the intersection of the connecting-pipes, the valves connected with each other whereby the direction of motion ofthe engines may be simultaneously reversed, of means for controlling the original supply of motive power to the first-of the engines, means for temporarily interrupting the flow of this original supply of motive power before it enters the first engine, and a by-pass whereby full power may be conveyed to the engine around the last-named means when desired.

25. The combination with a plurality of engines, of a main pipe for conveying steam thereto, a steam-chest located in the pipeand independent of the engines, a slide-valve in the steam -chest whereby vto intermittently interrupt the supply of power to the engines, a by-pass valve consisting of a supplemental pipe connected with the main pipe on opposite sides of the steam-chest and a valve controlling the admission of steam to the bypass. a

26. In a motor, the combination with a piston and cylinder-heads, a cylinder-band having inlet and exhaust openings therein, adividing-bridge located equidistant between the openings, bearing metal in the dividingbridge, a shaft secured to the piston and projecting through the cylinder-heads, stuffingboxes surrounding the shaft, frictionless material in the stufiing-boxes in contact with the shaft, springs bearing against the frictionless material and devices for increasing or diminishing the tension of the springs whereby to force the shaft and consequently the piston against the bearing metal in the dividing-bridge to cause a tight joint between the inlet and exhaust openings.

27. The combination in a motor, provided with a cylinder, a piston operating therein, and a dividing-bridge formed in the cylinder, of a shaft upon which the piston is mounted and means on the shaft for effecting an adjustment of the piston with relation to the cylinder, said means consisting of bearingblocks held against the shaft by springs and adjustable means for increasing the tension exerted by the springs on the bearing blocks whereby to force the piston against the dividing-bridge and automatically and yieldingly retain it in such position to form a tight joint.

28. The combination with a motor,the cylinder-band of which is provided with a dividing bridge or abutment, of cylinder-heads formed with elongated bearings, a shaft received in the bearings, a piston carried by the shaft, and automatic means whereby to adjust the shaft with relation to the cylinder-heads in order that the piston may bear against the dividing-bridge to maintain a tight joint therebetween.

29. The combination in a motor, the cylinder-band of which has a dividing-bridge therein, of cylinder-heads provided with elongated bearings, a shaft received in the bearings, a piston carried by the shaft, and means in connection with a set-screw for causing the adjustment of the shaft in the bearings Wl]6l6- by the piston is automatically and yieldingly held against the dividing-bridge to maintain a tight joint.

30. The combination in a motor, the cylinder-band of which is provided with a dividing-bridge, of cylinder-heads having elongated bearings formed therein, a shaft received in the bearings, a piston carried by the shaft, a stuffing-box on the shaft surrounding the elongated bearings, a plurality of superposed bearing-blocks angnlarly cut and arranged to pack closely in the stuffingbox, means for automatically and yieldingly retaining the blocks in contact with the shaft and means for adjusting the pressure of the bearing-blocks against the shaft whereby to automatically hold the piston in contact with the dividing-bridge to maintain a steam-tight joint.

31. The combination with a piston having a groove therein, of a single set of cam-plates located in the groove, the cam-plates composed of angularly-shaped sectionslap-jointed on their adjacent edges, the sections mortised to each other by means of the lap-joints, a bow-spring seated in the groove beneath the cam-plates, a pressure-plate situated between the cam-plates and the spring against the respective sides of which plate the spring and cam-plates bear, the opposite end of the spring bearing against the inner wall of the groove in the piston, whereby the cam-plates are pressed upon evenly and forced outward by the tension of the spring.

The combination in a rotary engine, comprising a cylinder, heads therefor and a piston'and cam-plates operating therein, of grit-traps formed in the cylinder, the traps extending across the cylinder from side to side, and means whereby access may be had to the traps for cleansing or other purposes.

33. The combinationin a motor comprising a cylinder, heads therefor, and piston and cam-plates operating therein, of grit-traps formed in the cylinder, the grit-traps extending across the cylinder to one side thereof, and means whereby access may be had to the traps for cleansing or other purposes.

3t. The combination, in a motor, with cylinder-band, heads therefor, a piston operating therein and a shaft secured to the piston and projecting through'the heads, the shaft surrounded by stuffing-boxes, of alubricating means mounted on the cylinder-band, ducts connecting the lubricating means with the interior of the motor through the cylinder-' band whereby the lubricant is gravity-fed, ducts in the cylinder-head to receive and conduct the lubricant to various portions of the motor, and ducts in the stuffing-box whereby to conduct the lubricant to different points on the shaft from the motor.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

HUGH THOMAS DUNN.

Witnesses:

ALFRED F. HIRSCH, BENJAMIN COHEN.

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