US1649091A

US1649091A - Rotary internal-combustion engine

Info

Publication number: US1649091A
Application number: US579246A
Authority: US
Inventors: Zimmer Meade Lafayette
Original assignee: Individual
Current assignee: Individual
Priority date: 1922-08-02
Filing date: 1922-08-02
Publication date: 1927-11-15
Anticipated expiration: 1944-11-15

Description

M. L. ZIMMER ROTARY INTERNAL COMBUSTION ENGINE Nov. 15, 192

Inventor' l 7 V. Z JW/11er."

Nov. l5, 1927.

M. L. ZIMMER ROTARY INTERNAL COMBUSTION ENGINE Filed Aug. 2, 1922 m4 Sheets-Sheet 2 |||l|||llrn....

Nov. l5, 1927.

M. L'. ZIMMER ROTARY INTERNAL COMBUSTION ENGINE llsss 4 Sheets-Sheet 3 Filed Aug. 2. 1922 4 Sheets-Sheet 4 M L ZIMMER ROTARY INTERNAL COMBUSTION ENGIE Nov. 15, 1927.

@maia Nov. 1s, 1927.

UNITED STATES 1,649,091 PATENT OFFICE.

MEADE LAEAYETTEZIMMEE, or coEnoBA, ARGENTINA.

ROTARY INTERNAL-COMBUSTION ENGINE.

Application vfiled August 2, 1922. Serial No. 579,246.

This invention relates to an internal combustion engine of the rotary type.

vThe/principal objects of the invention are to provide a construction of very simple character which will be very light per unit horse power and can be made at small cost by anynechanicwithout any especially designed machines or tools; to provide such' a machine of such simple construction, lightness, efficiency and cheapness as to render it especially valuable for manufacture and in small. quantities and yet of such a nature that when manufactured in 4large quantities it can be put out on a very small cost basis. More specifically, the invention involves a construction comprising a cylindrical casing serving as a fly wheel adapted to rotate about a stationary shaft which carries elements for cooperating with the features of the casing to provide a pair of explosion chambers adapted to receive a compressed charge, explode it, and exhaust vit; and also to provide within the casing a compression element and to rotate the latter at the same speed as the casing but in the opposite direction so that it can be made substantially like the explosion chambers but will operate twice as fast so as to provide for compressing the charges for them alternately and thus reduce the size ofthe engine relative to the horse power generated.

An important feature of the invention consists of an expansion ring adapted to be forced aroundv on the spiral which constitutes the internal element of the explosion and compression chambers. This takes up'the contraction between the casing and the eccentric and is adapted" to prevent the passage of gas so as to constitute a substitute for the ordinary piston rings. With this I provide a substantially perfectly gas tight cylinder and Ai-t permits of such a loose adjustment of the expansion ring that the motor will turn with ease.

Additional objects and advantages of the invention will appear hereinafter.

Reference is to be had to the accompanying drawings, in whichV Fig. 1 is a side view, partly 1n central section, of a preferred embodiment of this 1nvention.; Y

Fig. 2 is an end view; D

Fig. 3 is an end view with the end .piece removed showing the shaft in sectlon on the line 3--3 of Fig. 1;

. chamber.

Fig. 4 is a similar' viewon the line 4--4 of Fig. 1;

Fig. 5 is an enlarg d edge view of the expaison ring and t e parts for closing its en s;

6 is a side vi'ew of the same;

Fig. 7 is a sectional view on the line 7-7 of Flg. 1, showing the gearing for rotating the compression element;

Fig. 8 is a sectional view of the same on the line 8.-"8 of'Fig. 74'

Fig. 9 is a sectional view on the line 9-9 of Fig. 2, showing the construction for in-`.

troducing the fuel and air;

Fig. 10 is a sectional view on the line 10`1O of Fig. 9, showing the port through which the fuel and air pass into the cylinder; Fig. 11 is an edge View of the device through which the gas enters the end of the cylinder;

Fig.l 12 is an end view of the same;

Fig. 13 is a side view of a sliding valve i ted lines the positions of the piston of the other explosion chamber, and

Fig. 22 is a diagrammatic longitudinal central sectional view of thecasing and ends with the interior parts removed.

I have shown the invention in a form in which a base 10 is employed having end standards 11 for supporting the whole device. Through t'hese standards extend two non-circular passages in alignment in which is carried a shaft 12 which extends the whole length of the device and has its ends broached off to fit the passage and hold it firmly in stationary position. This shaft is provided with a ball bearing 13 at each end having the usual cones and adjusting devices. On these bearings are supported two end pieces '14 and 15. These end pieces are 'secured to two cylinders'l which are just alike in all respects and which provide the two explosion chambers. Between them is fixe-d a third cylinder 17 which contains the compression These three

cylinders

16, 16 and los . be transmitted from them in any of the ordinary ways.

It will be noted that the shaft 12 is shown at one end as provided with passages intended to be connected with oil reservoirs, and the end pieces 14 are provided `with chambers 2O communicating with them through their radial ends and with `a passa e 18 it is connected with i fuel provided take pa through which the oil is pum' d into t e oil chamber and ball bearing or lubricating pur oses.

T e end of the shaft in addition to the oil passage 18 is provided with an air passage 19 to admit air to the oil chamber and also with a tube 8 through which the oil is siphoned out of the oil chamber when the motor is at rest. The air is ventedfro'm the oil' chamber through the passage 19 to permit the oil to be pumped in. As soon as the' motor stops the chamber 20 is emptied by oil sinnonmg out promptly through the tube 8. fhis tube is not absolutely necessary for the functioning of the engine but is highly desirable for various reasons. If the oil were allowed to remain in the chamber ywith lrhe motor at rest there would be a tendency for the oil to leak into the combustion chamber and be forced out and wasted at the first turn of thek motor on starting. The starting of the motor would be made a good deal harder especially in cold weather. The circulation of the oil while the motor is runmng also serves to cool the interior of the motor on account of the cool oil being continually pumped into' the chamber and the heated oil wforced out through the tube 8. Moreover, as the oil is not allowed to stand in the chamber no oil sediment collects in it but it colletts in the oil reservoir outside from which it is easily removed.

One of the

erds

14, 15 also is provided with an annular groove 22 which is designed to' be connected with a source of explosive through a carburetor 29. This constitutes the intake for the explosive mixture. Air isadmitted with it around this groove 22. This intake is provided with a rmg 23 in the ve 22 carrying sucti n vanes and runmng Eastfthe nozzle of t e carburetor to spray e gasoline into the in- .24. Thislsapassageinthe castmg whlch constitutes the end piece and a passage 25 exten through the wall of the cylinder 16. In the wall of the central cylinder 17 is a fuel pas- 26 registering with the passa 25. p 26 has a port 27 for condibting 32 for' ends are dat and continuous. The cylinders l 16 are substantially like them and' the two pairs of registering recesses 31 are filled with lead to form a counterpoise. The inner edges of 'all these ends in both kinds of cylinders are circular and concentric with the shaft. Inside these edges fit the ends of expansion rings 33 in al1 these cylinders. The inner surface of each expansion ringris slit radially at short intervals to facilitate its flexing and the inner surface is curved in the form of a plane spiral while its outer surface is cylindrical.

, As stated above, the shaft 12 is stationary. Fixed on thisshaft in each of the two explosionI cylinders 16 is ahub. Each of these central hubs is keyed to the Ystationary shaft 12 and has integral arms projecting therefrom' and a rim 40 arond them forming a spider 40 having a spiral outer surface on which fits the expansion ring, 33 havin a 4similar shape inside. As the rim of t is spider is of special significance I refer to it sometimes as the rim 40. This central hub has two pairs of passages therethrough par- I alle] witheach other fortwo pairs of springs 41. These sprin are mounted on rods '42 and at the lend t ese rods pass into a yoke 43 which is guided by the side of the passages in the hub. 'The sp bear on the inner surface ofthe rim and t e yoke 43 and tend to force the yoke outwar in a radial direction at all times'. On t e yoke 43 is' mounted a blade or piston 44. I have shown it as having a recessed end at 45 but the edges of this end constitute bearing surfaces. These surfaces bear against the interior surface of the cylinder 16, which is of cam formationyand 1n the general shape of a heart cam' 46. The rotation of the c linder about the stationary shaft causes t is piston to move in and out radially on account-of the shape of the cam surface 46.

iwi

The springs 41 keep the end of the piston in contact with 'the cam surfaces at all times. The piston 44 is also provided with expansion plates 44: for maintaining a gastight joint between the sides of the piston and the walls of the cylinder.

Mounted on the spiral outer surface of this rim 40 is the xral expansion ring 33 above described. 'is is not a com lete ding vring but it is provided with a longitu inal projection 52 at each Iof its ends adapted to almost abut| together and having e, narrow longitudinal space for a series of cloaing plates 53, 54.and 55, there being two of Y located at each end ol the ,cylinder iittingl in openings 59, one in each of the plates 53 Yno lill

the latten-one at each end. These plates are arranged to ht each other so as to keep the spiral expansion ring tight around the radially reciprocating piston or blade at all times. The

lates

53 and 54 are provided with projections 56 at'their opposite ends sliding in notches in the projections 52 in the ends ot Vthe expansion ring and they are provided with overlapping ends 57 which move on each other. The plates 55-are tor the purpose or closing the joint between these plates 57. A7V-shaped spring 58 is and 5l to normally hold them vin proper position tight against the projections 52. 'llhese springsA project inwardl and are supported inside the hub and t ey are set so that the legs tend to draw the

plates

53 and 54 toward each other. 4

This expansion ring, as stated, is mount- .ejd on the rim which is located on the rim'.

d@ in the cylinder. lt is provided with a spring 60 tending to push the spiral expan-l sion ring around the spiral hub to keep it tight. lt accomplishes this by acting on a lever 61 pivoted at 62 on' the hub and entering through an opening 63 in a notch in` the expansion ring to operate it. The explosion and compressing cylinders are lormed substantially alike except that the rims d6 in the explosion cylinders are keyed to the tixed shalt 12 while the rim 40 in the central compression cylinder rotates thereon.

The compression cylinder is connected with the two explosion cylinders through" two ports'Bl opposite to each other as shown in Fig. 22. Each ot these ports is closed 'by a valve 35 located in the recess 32, pivoted on a stud at 36, and having a pin 37 which piyotally connects it with an operating slide 38. These operating slides are moved back and lor-th to open and close the ports 34' as shown in Fig. 13 by a pair of cams 39. 'These valves control thepassage of the compressed explosive mixture from the compression chamber into the explosion chambers alternately` and each one is opened once during each 'rotation of the cylinder. The two explosion cylinders are located with their cams 16 in opposite positions cir-l cumlerentially, the right hand `one in Fig. 1 registering with the cam in the compression cylinder. v

Un the inner circumference of one, f or prelierably both, of the explosion cylinders there is an internal gear 67 meshing with a smaller gear 68 inside Vrotatable on a sta--y tionary shaft 69. fixed on the end of the explosion cylinder and having on it a pinion' 76 meshing with ai gear 71v fixed to the end wall ot the compression cylinder. This is Vduplicated on the other end. The gear ra.- tios of the two pairs of gears are the same.

so that the internal gear wheel 67, rotating y ings.

Vconstantly in theforward direction, will ,turn the gear 68 with it and also the gear 70,

compression chamber as stated above.' The compression' chamber compresses a charge and gets it ready to deliver to an explosion and expansion chamber twice during each rotation so that each explosionl chamber providesanexplosion once during each rotation and these explosions occur 180"` apart. Thus, the eil'ect of the machine is a double explosion per revolution ot the casing.

The oper tion V1will be understood more :tully by reference to the last sheet of draw- Fig. 22 shows the course of the explosive mixture into the compression chamber. ln the position shown in Fig. 18 t-hel mixture has been drawn into the compression chamber by its rotation and it is lilled. Now, as the casing continues to rotatevl in one direction and the piston in the other, the parts come to the position shown in Fig. 19 in which the mixture previously drawn in is being compressed at the top of the ligure while a fresh mixture is being drawn in at the bottom. Now the valve 35 on one side opens and the compressed charge is let into one ofthev explosion chambers. shows the next position, 180 trom Fig. 18, in which' the first mixture has all been compressed and `force'dout into 'one of the explosion chambers as shown in Fig. 14 throu h the port 34 and a new charge has been gully introduced intol the compression chamber ready for compression. Fig. 21 shows the last position which, in etlect, is the same as in Figli) although the parts are in theh opposite position and the other valve 35 opens and lets the second compressed charge into the other explosion chamber through the port 34 onthat side. Figs. 18 and 2 0 have the same relation to eachother also. At this instant the other cxplosionchamber is in the position shown in Fig. 17 but the piston 44 thereof is inthe vopposite position 180 away where it is per-1 'explosion chambers, ol course, are not rotat-L ing, as stated, but the chambers themselves are'rotating with the casing of the compression chamber. Figs. 14 and 18 show one position of the parts, The mixture, as stated, has been drawn into the compression chamber but is not yet being discharged into the opposite explosion chamber. As the parts move from the position shown in Fig. 18 to that shown in Fig. 19, the explosion cylinder moves from-the position shown in Fig. 14 to that shown in Fig. 15 one quart-3 ter of a revolution and the compressed mixture shown in Fig. 19 is readyto be forcedV Fig. 20- '7 i v f i into the 'opposite cylinder through the port 34, the valve opening automatically as stated. The explosion of the compressed mixture shown in Fig. 14 takes place at the 'oove 73 rovided to ensure a little space or the-exp osive mixture where the spark is caused in the usual way. Fig. 15 lshows the expansion andthe fact that the'cylinder is forced around from the stationar iston by the expahs'ion. The 4-same 'cylm er ghen comes to the ition shown in Fig. 1 in which one hal a revolution has begli accomplished and the power of the explosion is about exhausted.- The compression chamber is now in the /position shown in Fig. 20, having fully chargedthe opposite cy inder which is then in thesame position relative to they piston as shown inA Fig. 14 and ready to be 'e loded. It will be noted that the piston o the opposite cylinder being .180l from that shown in Fig'. .14 points m the opposite direction from the shaft. In Fig. 1 the exhaust takes place `through ports 74 and the, parts are then ready to receivea neg;7 charge in the position shdwn in Fig. 14. It will be noted that the two pistons 44 in A the two explosion chambers are located always exactlyin thesame position because stationary. They are shown also as extending in the opposite direction from the shaft,

- being 180 a art. The two explosion chambers are fixe `together so as tobe in opposite positins relative to the pistons.

The ignition system can be the same as for other vm'otors and is not shown except for binding osts 72. No-timer has been shown in the rawings, but this also would be attached to the end piece opposite to that;

- whichcontains the intakeLand would of one of the ordinary kinds.

From this description, it will be seen that considerable space is saved byrotating the and expansion and lrevents escape of the fuel at all times. e force exerted by the expansion of the exploded charge against the stationary piston or bladelocated in a radial .position is applied at right angles to 'the radius nearly throughout the whole 3.60 degrees of the circumference. The motor 1s very sim le in construction and extremely light per orse power. Almost any mechanic can make it without specially desi ed machines or tools and at small cost. lgs carburetor in the ordinary sense has to be employed as the intake ring. takes up the fuel and s rays it into the intake.

Alt oughfI have illustrated and described only a single form of this invention, I am aware of the fact that modifications can be made therein by any person skilled in the art `without departing'fromA the scope of the invention as expressed in the claims. Therefore, I do not wish to be limited to all the details of constructionf'herein shown and described, but what I do claim is 1. In a rotary internal combustion engine, the combination of two explosion cylinders .and one compression cylinder rotatable in the same direction, and means for compressing the explosive mixture twice in the compression cylinder toevery ex losion in each of theexplosion`cylinders, w ereby, char es of the explosive mixture can be introduce from the compression cylinder'into the two explosion cyllnders, alternately, during a single revolution, and two explosions can be obtained. 2. In a rotary internal combustion engine, the combination of two explosion cylinders and one compression cylinder fixedly connected together and rotatable about an axis, a piston in each cylinder, and means for ,rotating the piston in the compression cylin- -der in the opposite direction to the rotation n compression chamber eiectivelyrat twice the J,of the cylinder itself.

speed of the explosion hambers sofas to use .one compressionham er to -supply two exlosion chambers. .Also an increase in power 1s secured by this means for two explosions are provided for at each revolution. ordinay inlet andl nozzle valves are entirely avolde the only valves being used Vare those All 3. In a rotaryinternal combustion engine, the combination of two explosion cylinders and one compression vchamber, iixedly connected together and rotatable about a comlmon central axis, a piston in each cylinder, means for rotating thel piston in the' compression cylinder in the opposite direction between the compression and the .explosion to the rotation of the cylinder itself and atchambers which work very simply and which the same speed, and means for holding the `at the points -where the side pieces revolve von the expansion ring but these surfaces are the combination of afshaft, one compression will4 not give" veryfnuch-trouble on account pistons in the explosion cylinders stationary' of wear. Most of the bearing surfacesare during1 'the entire rotation. y

4. In a rotary internal combustion engine,I

so narrow'that they do not create much fricahd two explosion cylinders fifed" together tion and they can be lubricated by means and rotatable together about said ,shaft,

' o an oil groove. f

' l meansfor conducting an explosive nixtu'r The cylinder canbe maintained gas tight/into the compression cylinder, a piston in with comparatively loose adjustment of the the compressioncylinder, means for rotating.

expnsllon ring-so that the imotor will run said 'piston 1n the opposite direction to' the .wit t e 0 i atest freedom. This' ,expansion rotation of the cylinder and at the K same p rmg ls'an important feature of the invention speed, a piston in each explosion cylinder, all

i as it'automatically provides forcontraction of saidl cylinders 'having an internal cam d means td the combination of a stationary shaft, one

it ton in the compression cylinder compression cylinder and two explosion cyl- 'inder and 180 apart, one

inders fixed together and rotatable'about said shaitt, means for conducting an explosion mixture into the compression cylinder a pislocated radially, means for rotating the piston in a direction opposite to thatin which the cylinderfrotates, and at the same speed, statione ary pistons in the explosion cylinders, all

do of said cylinders having an internal cam ttt titi

dil

i: lll

Il ing for compressing two charges during each formation about the shaft. the casingrbeing 13' iormationior cooperatingwith their respective pistons, and means for conducting the compressed charges alternately into the two explosionv cylinders. r

d. ln a rotary internal combustion engine, the combination of a stationary shaft, one compression cylinder and two explosion cylinders iixed together' and rotatable about said shaft, means tor conducting explosive mixtures into the compression cylinder, means in said compression cylinder .for compressing the mixture during one half of `a revolution, ports for conducting the explosive mixture irom the compression cyl- -nder into each of the explosion cylinders,

valves for closing said ports, means tenutomatically operate said valves, means' in each explosion cylinder for receivin the impact of; the explosion and transmitting it to the cylinders to rotate them, said means in' the two explosion cylinders being located oppositely with respect to each other, whereby each one will provide an explosion during one revolution of the cylinder, said explosions being 180 apart.

7. ln a rotary internal combustion engine, the combination oi rotary casing, two ex-f plosion cylinders and one compression cylinderl in said casing rotatable in the saine direction, means for introducing an explosive mixture into the compression cylinder, means in said cylinder for compressing two charges during each revolution of the casing, means tor introducing one of said `charges into one ot the explosion cylinders and the other into the other, and means in said lexplosion cylinders for igniting the two charges therein once during each revolution.

8. ln a rotary internal combustion engine,l the combinationi a rotary casing, two explosion cylindeitv and one compression cylinder in said casing rotatable together, means for introducing an explosive mixture into the compression cylinder, means in said casrevolution of the casing,'means for in troducmg one of said compressed charges 1nto one of the explosion cylinders', and other into A the other,.means in said explosive cylinders for igniting the charges alternately once during each revolution, two valves for controlling the conduction of the compressed charges from the compression cylinder into the explosion cylinders, and two cams, one mounted on each side of the compression cylfor operating each of said valves. f

` 9. ln a rotary internal combustion engine, the combination of a rotary casing, said cas'- ing being divided up into three compartments, the central one constituting a compression chamber and the two end ones explosion chambers, the interior'of said casing in each of the chambers being in the form of a heart-shaped cam, a piston in each of the three. chambers, the pistons being yieldingly mounted to. move radially against the surfaces of said cams, whereby the pistons will contact with said surfaces throu'hout each revolution', means for holding' the pistons in the explosion chambers against rotation, means for rotating the piston in the compression chamber in the opposite direction to that of the casing and at the same` speed, the inward extension in the cam surface of the compression cylinder being located substantially in the same position as that of one ofthe explosion chambers'and in the opposite position to that of the other.

10. As' an article of manufacture, an expansion ring for a rotary engine having an outer circular surface and an inner spiral surface extending from a thin end of the ring substantially throughout a circle to an yopposite thick end ot the ring and an inner cave surface ofthe ring having radial slots. Y

i 11. lin a krotary internal combustion engine, the combination of a stationary shaft, a rotary cylinder having a cam-shaped surface inside, a piston mounted radially within said cylinder, yielding means for forcing said piston outwardly in a radial direction against said cam surface to l,form a tight joint, and means for rotating said piston at the same speed as the cylinder but in the opposite direction and about the sameaxis.

' 12. lin a rotary internal combustion engine, the combination with, a stationary shaft, a rojarycasi'ng having a cam-shaped surface inside, and a piston mounted iradiallyv within said casing, 'of va pair of rods o'n which the pistonl isguided to reciprocate, a pair of springs on the rods for holding the end oi the piston at .the extreme radial po.-

sition, a spider on the shaft on which said rods are located, said spider having a spiral rovided with a of concentric circular form in which saiife sp sii expansion ring between the surfaces of the spider and casing for preventing the e f the explosive mixture between em. 13. In a rotary internal combustion engine, the combination with a shaft, a rotary casing having a cam-shaped surface inside and a piston mounted radially within said casing, of 'elding means for supporting said y piston wit its end` against said cam surface a spider on said shaft for supporting said piston, said spider having an outer surface of spiral formation and' the casing having an inner concentric circular surface within which the spider is located, and an expan-v sion ring having an outer concentric circular surface fitting on the inside of the-casing and an inner spiralsurface fitting on the outside of the spider, and capable of moving around the shaft to ensure a ti ht -joint. 14. In a rotary vinternal com vstion Ven- 'gine, the combination with a shaft and a cylinder having a cam-shaped surface inside, said parts being relatively rotatable, A of a iston mounted radiall within said eylin er, inea'ns for yieldingy supporting said piston in a radial position against said camsurface a spider on said shaft for supd for lthe explosive mixture, the exterior of porting sai piston, saidJ spider having an outer surface of spiral formation andV the cylinder having an inner concentric circular surface within which, the spider is located,

an expansion rin havin an outer concentric circular ace fitting on the inside of the piston, and an inner spiral surface Aiittin on the outside of the s ider, and capabe of being moved circ erentially, and means of a yielding nature or pressing the ring :aroundA the circumference when the space between the casing and spider coinmences to change. l

15. In a rotary internal combustion en- 5 e, the combination of a shaft and casing, /relativeiy rotatable separately a spider on said shaft, a piston mounted on said spider --and adapted to move radially, thercasing having a cam-shapedinterior against which 5 the end of said piston is adapted to Yengage to provide a chamber for the explosive mixture, the exterior of said spider and theinterior surface of said casing at its ends having a space -between them `gradually 55, widening around the circumference, ,a tapered expansion ring fitting in and filling said space foipreventing the passage of the explosive mixture `between said parts, 'a lever mounted on the spider and engaging the expansion rin and a sprin onl the ider for yieldipg y forcing said ever in a 'rection to move the expansion around Jinadirectiontensureitslllingt espace between the spider and casi 5h16. Inarotaryinternalco f 'onengine,

ider is located, and,

the combination of a relatively rotatable shaft and casing, a spider on said shaft, a piston mounted on said spider and adapted to move radially, the casing having a camshaped interior against which the end of said piston presses to provide a chamber for the explosive mixture, the exterior of said spider v4aiid the interior surface of said casing at its ends having 'a space between them, an expansion ring fitting in and filling said s ace for 'preventing the=passage of t e ex p osive mixture between said parts, a lever mounted on'the spider and engaging the expansion ring, a sprin on t e spider for yieldingly forcing sai lever in a direction to move the expansion rin around for fillin the space between the spi er and casing, sai expansion rin being circular and concentric with the shat on one side and of spiral formation on the other, the casin and spider being similarly shaped so that the expansion rin will fill the space in allI positions.'

1%. In a rotary internal combustion engine, the combination of a relatively rotatable shaft and casing, a s ider on said shaft, a piston mounted on sai spider and adapt ed to` move on said spider and adapted to inove. radially, the casing -having a camsha d interior against which the end of said)e piston presses to provide 'a chamber saidspider and the interior surface of said casing at its ends having a space between them gradually widening from one point to another, aii expansion ring fitting in and filling said space for preventing the assage of the ex losive mixture between sai parts, means or moving the expansion ring around in a direction to increase its capacity for filling the space between the spider and casing, said expansion ring bein thicker atpone end than at the other, andiaving a longitudinal space between its ends extending through its length, and means for closingsaid space.

18. Iii a rotaryinternal combustion engine, the combination of a relatively rotatable shaft and casing, a piston adapted to move radially, the casing having a camshaped interior against which the end of sai piston presses to provide a chamber for the e losive mixture, an y expansion ring fitting inside the casing for preventin the ypassage of the explosive mixture, sai expansion ring being thicker at one end than at thether, and having a longitudinal space between its endsiextending throughout its length, means for closing said space comprising a pair of plates located along the edges of the expansion ring and interlocking with each other, and-leaving a spacebetween them for the piston said plates being slidable circumferentially on each other, and two small end plates at the ends 0f the piston.

19.111 a rotary internal combustion engine, the combination of a relatively rotatable shaft and casing, a spider on said shaft, la piston'mounted on said spider and 'adapt- -ed to move on said spider and adapted `t0 the explosive mixture between said parts,y

means' for moving the expansionl ring around in a direction to increase its capaclty for filling the space between the splder and casing, said expansion ring bein .thicker aving a.;

at one end than at the other, and longitudinal space between its ends extending `through its length, means for closing said space, said means comprising a pair of plates located' along the edges of the expansion ring longitudinally ofi-the shaft, and.

springs at their ends for normally ,holding there apart. o

20. ln agrotary internal' combustion engine the combination of'A a ,stationary shaft, and one compression and two explosive cyl inders xed together and rotatable together aboutsaid shaft, of means for 'conducting an explosive mixture into the compression y cylinder, a piston in eacli of the cylinders,

all of said cylinders having an interior cam formation 'for cooperatin with the` respective pistons, ande means or conducting the compressed charges alternately into the two explosion chambers, said sha-ft having atv the end passages for oil and air." f 21Min a rotary internal. combustion engine, the combination of an exuansionfring and having .a longitudinal. space between for preventing` the passage of the explosive mixture, said expansion ring being thicker at one end vthan at the other, an having a longitudinal 'space between its ends extending throughout its length, a piston movable through said space, means for closing` said s ace around the pistoncomprisng'a pair o plates loatedalong the edges of the expansion ring and interlocking with each other, and leavinfr a space betweenv them for the piston, said pilates being slidable circumferentially ongeach other, and two small en plates at the endsof the piston.`

22. In, a rotary'internal combustion'engine, the combination .with a shaft and a relatively rotatable cylinder,v the shaft have ing a hub having a spiral surface', of an ex`f pansion ring extending part -way around thecylinder for preventing the passage of the explosive mixture, means for moving the expansion ring, around in-the cylinder, saidexpansion ring being thicker" at one extreme end than at -the other to fit on said surface,

its ends extending 4thi-ou' h its width, a. pain. of plates located alongt e edges of the expension ring longitudinally of the shaft,

and springs at their ends for normally clos ing the space betweenthe ends of the expansionfrlng.

23. As an article of manufacture, an expansion ring for a rotary en e having an outer concentric circular sur ace, and a sin-` gle internal spiral surfacez and ca able of being moved circumerentially, an means of a yielding nature-for pressing the rin irzumferentially around the inner snit o y. v l -1 In testimony whereof I have hereunto affixed my signature.

LAFAYETTE znnmn.