Dec. 31, 1946. R. L. SNYDER 2,413,590 ARGUATE PISTON Original Filed Aug. 5, 1943 2 Sheets—Sheet 1 GHQ-neg v13%.31, 1946. RLSNYDER ARCUATE >' PISTON ' 2,413,590 v Original Filed Aug. 5, 1945 ' 2 Sheets-Sheet 2 BLGWE/E - Inventor ?'zi‘ilanil.5rgder 8“ . Z. W‘ ' Gltorneg 2,413,590 Patented Dec. 31, 1946 UNITED STATES PATENT OFFICE 2,413,590 ARCUATE PISTON Richard L. Snyder, Glassboro, N. J., assignor of one-fourth to Henrietta B. Snyder, Glassboro, one-fourth to Richard L. Snyder, Jr., Prince ton, and one-fourth to Christopher L. Snyder, Metuchen, N. J. Original application August 5, 1943, Serial No. 497,420. Divided and this application March 27, 1945, Serial No. 585,139 2 Claims. (Cl. 121—49) 1 This application is a division of my copending U. S. application, Serial No. 497,420, ?led August 5, 1943, entitled “Internal combustion engines.” This invention relates generally to internal combustion engines and more particularly to valveless internal combustion engines having at least one continuous toroidal cylinder cavity in cluding therein at least one pair of double ended 2 ?tted thereto, and arranged to rotate within a continuous toroidal cylinder cavity. The invention will be described in further de tail by reference to the accompanying draw ings of which Figure 1 is a cross-sectional elevational view of one embodiment thereof taken along the section lines I, I, of Figure 2 which is a cross-sectional view of. the same embodiment taken along the arcuate pistons disposed in mutually cooperative rotary reciprocative relation. 10 section line 11, II of Figure 1; The preferred embodiment of the invention to be described in detail hereinafter utilizes rela tive reciprocative motion of double ended pistons Figure 3 is an enlarged fragmentary cross-sec tional view of a portion of the cylinder cavity showing the ring bearing-gas seal. . Similar reference characters are applied to combined with absolute rotary motion of said pistons for transmitting rotary motion to a drive 15 similar elements throughout the drawings in shaft. Power is transmitted through a trans lating system, comprising connecting rods jour order to illustrate better and simplify the accom panying description thereof. Referring to Figures 1 and 2, the preferred naled to said pistons and to a conventional crank embodiment of the invention is shown as a com shaft, and crank means secured to the drive shaft and journaled tovsaid ‘crank shaft. In 20 ponent of a four-stroke-cycle engine having means de?ning a single toroidal cylinder cavity operation, each “cylinder” comprises the space having four pistons disposed therein. The means intermediate adjacent ends of any two of the de?ning the toroidal cylinder cavity comprise a double-ended pistons within the continuous ?rst split casting portion I having a keyed por toroidal cylinder cavity. An explosive mixture is introduced into the space intermediate the 25 tion which engages a complementary keyway in a second split casting portion 2. The two casting ends of each of the two pistons progressing past portions l, 2 are clamped together by means of one or more ?xed valveless intake ports, the mix bolts which pass through coincidental apertures ture is then subjected to compression, and the 3 equispaced around the peripheral edges of the compressed mixture is next subjected to an ig nition device which explodes the compressed gas. 30 circular complementary casting faces adjacent the keyed portions thereof. The castings I, 2 in The exploded mixture delivers power which clude cut-out portions for providing a water drives the particular pair of pistons in relative opposite directions, thereby providing recipro jacket for cooling the cylinder cavity walls. The castings also include intake and exhaust aper cative piston motion with resultant rotary mo tion of the drive shaft. 'As the rotary recipro 35 tures 4, 5, respectively, which are connected to cative motion of the pistons again moves the ad suitable intake and exhaust manifolds 6, ‘I, re spectively. ’ jacent faces thereof toward each other, the rotary motion of the pistons brings the space interme The opposite ends of the castings l, 2 each are diate said pistons adjacent one or more ?xed‘ journaled to a main drive shaft 8. Fixed gears valveless exhaust ports which exhaust the ex 40 9, H! are adj'ustably secured to opposite end por tions of the castings l, 2, respectively. Adjust ploded gases due to the compression thereof by the pistons. Further rotary reciprocative'motion ment of the angular position of the gears 9, H1 is provided by a radially extending arm H, secured of this pair of pistons again brings the space in to both of the gears. The gears may be clamped termediate said pistons opposite the ?xed valve less intake ports described heretofore. It will 45 in any predetermined angular position by means of clamping bolts l 2 having external wing nuts l3. be'seen that the operation described provides a The bolts extend through the gears 9, l0 and conventional four-cyclesystem in which the same through slots in the adjacent end portions of the cycles are repeated by each adjacent “cylinder” castings l, 2. intermediate successive adjacent ends of each 50 A spark plug, or glow plug, l4 extends into a pair of double-ended arcuate pistons. spark plug port, proportioned therefor, which An object of the invention is to provide a novel opens into the cylinder cavity. Connections for counterbalanced double-ended arcuate piston for the spark plug M are made to a high tension a toroidal engine. Another object of the inven ignition coil I5. A battery. or other source of tion is to provide a counterbalanced double-ended arcuate piston having a plurality of vpiston rings 55 ignition potential I6, is connected to the primary 2,413,590 3 circuit of the ignition coil l5 through a conven tio‘ ignition contactor ll which is operated by a earn it. The cam i8 may be mounted on one end of the drive shaft 8, or may be actuated in any other known manner. If a glow plug is used, it may be energized continuously from the battery it, and ignition timing provided by piston posi tion. The drive shaft 8 extends centrally through the castings I, 2 normal to the plane of the cylinder cavity. An external ?ywheel l9 may, if desired, be secured to the opposite end of the drive shaft from the ignition cam H3. The ?ywheel i9 may 4 journaled on the main drive shaft 8. Similarly, the second and fourth connecting rods 21, 29 may comprise a second unitary or rigid structure also journaled on the main drive shaft 3 adjacent the ?rst and third connecting rods. A pair of co centric crank shafts 34, 35 are interposed be tween the inner peripheral limits of the cylinder cavity and the main drive shaft 8. The axial portions of the ?rst and second crank shafts 34, 35, respectively terminate at their ends in pinion gears 35, 3? which engage respectively the ?xed gears Hi, 9, respectively. The eccentric portions of the crank shafts 34, 35, respectively,'are each journaled to receive two auxiliary connecting include gear teeth 20 for drivinga load, and for cooperation with a starter motor of conventional 15 rods which, in turn,‘-are journaled to adjacent main connecting rods. type. For example, the ?rst eccentric crank shaft 34 Four pistons 2|, 22, 23, 24 are disposed within is journaled to a ?rst auxiliary connecting rod 38 the cylinder cavity. These pistons are arcuate which, in turn, is journaled to the ?rst main con in shape and double~ended to provide four cyl inders intermediate each two adjacent piston 20 necting rod 26. Likewise, a second eccentric por tion of the ?rst eccentric crank shaft 34% is jour faces. The pistons include conventional .piston naled to a second auxiliary connecting rod39 rings 25 and-a novel counterbalance arrange which is journaled to the fourth main connecting ment for minimizing radial thrust between the peripheral faces of the pistons and the interior rod 29, The wrist pin for the ?rst main connect of the cylinder cavity. The pistons 2|, 22, 23, 24 25 ing rod 23, as shown in Figure 1, is held in a rods 26, H, 28, 29, respectively, which as illus bracket 48 secured by bolts 4| to the side of the main connecting rod. The bracket to terminates trated comprise a pair of double-ended rods each ?oated upon the main drive shaft 8. auxiliary connecting rod 38 and which is pivoted are pivoted on corresponding main connecting in a forked portion 42 which receives the ?rst Considering the piston 2 l, for example, the pis 30 thereto by means of a wrist pin 43. The second, third and fourth main connecting rods are simi ton casting includes rotatable bearings 3|), 3| in larly journaled to corresponding auxiliary con which a piston pin 32 is journaled eccentrically. necting rods which, in turn, are journaled to A. counterweight 33, is secured to the rotatable either the ?rst or second eccentric crank shafts bearings 39, 3|. One end of the corresponding main connecting rod 26 is journaled to the cen ter portion of the piston pin 32 intermediate the 34, 35 as explained heretofore. As a matter of con venience, both the main and auxiliary connect ing rod. bearings may be of the conventional split internal ends of the piston bearings 30, 3|. It bearing type to facilitate assembly and replace will be seen that normal radial thrust of the pis ment thereof. Similarly, other bearings de ton due to rotation thereof within the cylinder cavity will be compensated for by means of the 40 scribed herein may be-of the split type for the same reason. resultant radial thrust of the counterbalance 33. The axial portions of the ?rst and second crank Radial thrust of the counterbalance 33 will ro shafts 34, 35 are also journaled in cylindrical tate the piston bearings 38, 3| counterclockwise, cranks 44, 45 which are disposed intermediate thereby increasing the radial thrust of the pis ton pin 32 in its bearing in the end of the con- = the main connecting rod bearings and the ?xed gears 9, i ii. The two cylindrical cranks 413, 45 are necting rod 25. ‘The connecting rod 26 may be both keyed by means of keys 4B, 47, respectively, ?oated on the main drive shaft 8, thereby pre to the main drive shaft 8. venting radial movement thereof. Since the con It will be seen that relative reciprooative mo necting rod 2t and piston pin 32 cannot move ra dially, the resultant compensation provides an 50 tion of the four pistons 2 I, 22, 23, 24 will provide‘ similar reciprocative motion of the correspond inward thrust on the piston 2| which tends to ing main connecting rods 26, 28 with respect to make it travel centrally of the toroidal cylinder cavity. . the remaining pair of connecting rods 21’, 29. > Considering only the main connecting rods 26, 29; The inner peripheral side of the cylinder cav ity includes a continuous slot adapted to receive 55 relative reciprocative motion thereof will pro vide rotary motion of the ?rst crank shaft 34 due the four connecting rods 26, 21, 28, 29 to permit to the coupling provided between the main con the journaling thereof to the main drive shaft 8. necting rod and the eccentric‘ crank shaft by A gas seal for the inner peripheral slot comprises‘ means of the auxiliary connecting rods 38, 39, a split-ring hearing which extends into the slot and includes apertures having ?exible faces 10 for receiving the corresponding connecting rods. The split ring bearings include two separate sets of ball'bearings ‘H, ‘l2 which contact raceways on the sides of a cylinder slot. The two portions '13, ‘M of the cylinder bearing are adapted to re ciprocate with respect to each other while at the same time providing an effective gas seal be tween the reciprocating portions and around the sides having the ball bearings in contact with the cylinder’ cavity bearing raceways. - respectively. Since the rotary motion delivered to the eccentric crank shaft 34 will be transmit ted-to the corresponding pinion gears secured to the axial ends thereof, the pinion gear will rotate ‘ about the ?xed gears 9, Hi. The rotation of the pinion gears about the ?xed gears will thereby provide rotary motion of the cylindrical cranks 44, 45 keyed to the main drive shaft 8, and of the corresponding eccentric crank shaft ‘about the; _main drive shaft 8, with resultant rotary motion~ 70 of the mainconnecting rods 25, 29 coupled there As explained. heretofore, thefour pistons 2 I, 22,. to.- Since the ?rst and fourth main. connecting 25, respectively, are pivoted on corresponding rods 26., '29, and the thirdand second connecting. rods 28;, 27 rigidly coupled respectively thereto, main connecting rods.v 26, 21., 2d, 29, respectively.’ are caused to rotate about the axis of the main The ?rst andth-ird connecting rods 26, 28 may comprise a unitary or rigid structure which is 75 drive shaft 8, the corresponding pistons 2|, 22, 2,413,590. 5 6 23, 24 will also rotate about the axis of the cen ter shaft 8. It therefore will be seen that the pis tons have relative reciprocative motion with re spect to each other-and, in addition, have rotary motion along the toroidal cylinder cavity due to gears 36, 3'! and the ?xed‘ gears l9, 9 respectively, drive shaft will be turned by the cylindrical cranks 44, 45, through one complete revolution the travel of the pinion gears around the comple plete revolution, thereby providing four explo mentary ?xed gears secured to the cavity struc sions of the gaseous mixture for each complete revolution of the main drive shaft. The external ?ywheel l9 may, if desired, be ture. are selected to be of one to two ratio, the main as each of the pistons turn through one com Similarly, the ring bearings providing the gas seal within the slotted inner periphery of the cyl 10 omitted, since considerable inertia is provided by the relatively heavy cylindrical cranks 44, 45 ?nder cavity will rotate as the corresponding con which are keyed to the main drive shaft 8. necting rods passing therethrough rotate about Oiling of the various bearings and moving sur the. main drive shaft 8. Also, the two portions of the split bearing-gas seal will reciprocate with faces described heretofore is provided by a cen tral oil pump 54 of conventional design. The respect to each other in the same manner and at oil under pressure from the pump 54 is intro the same time as the adjacent connecting rods and pistons reciprocate with respect to each duced, for example, into the end of the main casting i and passes therethrough through an other. oil duct 55, The bearing 55 in the end of the The locations of the intake and exhaust ports main casting l includes a slotted portion 51 4, 5, respectively, with respect to the location of which coincides with a hole 58 extending into the ignition plug Hi, are clearly illustrated in Fig the main drive shaft 8. The hole 58 terminates ure 2. If we consider a typical four-stroke cycle insofar as the “cylinder” intermediate the in a longitudinal hole 59 which extends substan third and fourth pistons 23, 24 is concerned, clockwise rotation of the pistons, as indicated by the arrow, will provide gas intake to the cylinder from the intake manifold ii through the intake ports fl, since in this position the third and fourth pistons 23, 26, respectively, are moving tially the full length of the main drive shaft 8. Radial holes, connecting the interior hole 59 of the main drive shaft to the periphery thereof, are provided at each of the bearings 56, 6| of the main connecting rods. The main connecting rod bearings Gil, 6! each include slotted portions 62, away from each other. As the clockwise rotation 30 63, respectively, which connect to radial oil ducts of the pistons progresses, the pistons commence to move toward each other, due to the reciproca tive motion thereof, and at ‘a point substantially coincidental with the ignition plug E4 the com- 55, within the corresponding main connecting rods. The radial oil duct 64 in the main con necting rod 26 extends the full length thereof to supply oil to the piston pin 32 of the piston 2|. pression of the explosive mixture between the The wrist pins 43, between the auxiliary con necting rods and the forked bracket bearings 42, pistons reaches a maximum value, The ignition provided by the ignition device 84 explodes the are lubricated through the duct 65 in the cylin compressed gases, delivering power to the pis drical crank 44 and the longitudinal duct 66 in the crank shaft 35, and thence through longitu tons tends to drive them farther apart, thereby delivering energy to the corresponding main con 4.0 dinal ducts in the auxiliary rods. Similarly, a portion of the oil circulating through the radial necting rods 28, 29. When the pistons 23, 211, reach a position approximately coincidental with duct Ell is diverted within the piston 2| to lubri cate the surface faces thereof adjacent the pis the illustrated position of the piston 22, as shown ton rings 25. Lubrication for the eccentric crank in Figure 2, they commence to move toward each other again, thereby providing pressure for ex- - " shaft bearings is provided by a radial duct 65 extending through the cylindrical crank 44 to the haustion of the exploded gases through the ex haust ports 5 and the exhaust manifold 7. After axial portion of the eccentric crank shaft 35 the “cylinder” has passed, the exhaust ports 5, journaled thereto, as explained heretofore with the pistons 23, 2:! again begin to move apartand respect to the wrist pins. Lubrication for the bearing in the end of the auxiliary connecting pass the intake ports 4 for a repetition of the four-stroke-cycle thus described. rods journaled on the eccentric portion of the crank shaft is provided by a longitudinal oil duct If desired, a scavenging blower 50 may be con nected to one or more of the exhaust ports to 86 through the center of the eccentric crank facilitate scavenging of the “cylinder” during the shaft. exhaust stroke. Any conventional type of car 55 Figure 3 shows, in cross-section, the double sealing rings 13, ‘M, which provide a gas seal buretor 5l' and intake manifold connection 52 for the slot on theinner peripheral surface of the may be provided which will furnish a suitable ex toroidal cylinder cavity. Each of the rings are plosive mixture to the intake ports 5. Similarly, apertured to receive di?erent ones of the several forced intake of the explosive gaseous mixture main connecting rods, as shown in Fig. 1. The may be provided by applying pressure to force sealing rings include polished complementary the mixture from the carburetor through the in surfaces ‘i5, 'e’i‘, which provide a satisfactory gas take ports 4 when they are uncovered by the seal for the cylinder cavity while permitting rela several pistons. tive reciprocative motion of the two rings. The It will be seen that the “cylinder” intermediate sealing rings are arranged to revolve with respect each pair of double-ended pistons will follow the to the cylinder cavity as the main connecting same four-stroke-cycle as that described hereto rods which pass therethrough revolve about the fore, and that a single set of intake ports, ex main drive shaft 8. The sealing rings are ac haust ports and a single ignition plug will pro curately centered adjacent the cylinder cavity vide similar operation for each of the successive “cylinders” passing these points. Therefore, it 70 slot by means of the ball or roller bearings ‘ll, 12 disposed in bearing guide channels TI, 18. One will be seen that each complete revolution of a sealing ring ‘M is split and is provided with an particular piston about the main drive shaft 8 expanding spring member 19 disposed inter will occur during four complete four-stroke-cycles mediate the sealing ring and the split ring por of the “cylinders” intermediate the various pis tons. Since the gear ratio between the pinion 75 tion 80. The expanding spring member is mor 2,413,590 7 8 tised'to~the main portion of. the sealing ring ‘HIV Thus the invention disclosed herein comprises a toroidal type internal combustion engine includ~ in any convenient manner to prevent substantial gas leakage. The continuous pressure provided , by the spring member 79 provides uniform con tact between the complementary surfaces of the reciprocating sealing rings, and also constitutes a simple and effective means for compensating for incidental wear of either of the reciprocating rings, or the cylinder cavity guides therefor. ing one or more toroidal cylinder cavities each having a plurality of arcuate double-ended pis tons disposed therein in mutual rotary recipro cative relation. A novel piston counterbalancing arrangement reduces cylinder and piston wear. I claim as my invention: 1. A counterbalanced piston for a rotary engine Additional springs 8|, 82 are interposed in slots 10 comprising a double-ended arcuate piston shell portion, a pair of eccentrically apertured bear in the cavity wall to exert pressure on the bearing ings having their outer surfaces journalled in portions ‘it, till, respectively. The split sealing said shell portion, at least one counterweight ring is preferably constructed so that internal pivoted on said outer surfaces of said bearings pressure aids the spring member ‘H to improve the gas seal. 15 and disposed to rotate with said bearings within said shell portion, a piston pin journalled in said It should be understood that these reciprocat eccentric bearing apertures, and journal means ing sealing rings may be employed to provide the for connecting said piston pin to an external actual power transmission means between the utilization device. rotary reciprocating pistons and the eccentric 2. A counterbalanced piston for a rotary engine crank shafts. It will be seen that the ball bear 20 comprising a double-ended arcuate piston shell ing arrangement for ?oating the sealing rings portion, piston rings on the periphery of said shell upon the inner peripheral wall of the cylinder portion, a pair of eccentrically apertured bear cavity provides a bearing surface which effectively ings having their outer surfaces journalled in prevents radial thrust of short connecting rod members which may be provided to connect the 25 diametrically opposite sides of said shell portion, at least one counterweight disposed within said individual pistons to corresponding ones of the shell portion and pivoted to rotate with said dia sealing rings. This arrangement saves the space metrically disposed bearings, a piston pin jour ordinarily required for the main connecting rods nalled in said eccentric bearing apertures, and which, as shown in Figs. land 2, are journaled to the main drive shaft, and thereby permits rela 30 means for connecting said piston pin to an external utilization device. tively heavier main drive shafts and eccentric crank shafts to be employed in engines of prede termined cross-sectional dimensions. RICHARD L. SNYDER.