Rotary piston engine

An engine including a piston yoke assembly reciprocating within a rotor assembly disposed for rotation within a fixed casing. The rotor assembly is of elliptical configuration to form a pair of exhaust chambers located between the assembly and the casing interior. The rotor assembly defines closed end combustion chambers and fuel-air chamber within which the yoke portion of the piston yoke assembly reciprocates to pressurize fuel-air charges for transfer to the combustion chambers. The piston yoke assembly comprises a part of the rotor assembly but moves about a fixed component carried by the engine casing resulting in reciprocal movement of the piston yoke assembly within the rotor assembly. Power is delivered to the rotor assembly by ignition of a fuel-air charge acting on a piston and yoke assembly off center from the fixed casing component. Exhaust ports within the rotor assembly provide for the ejection of exhaust gases asymmetrical to the rotor axis to impart torque to the rotor. Engine cooling is accomplished by the admission of ambient air to the pair of exhaust chambers and by heat transfer from engine pistons to a fuel-air mixture. In a second described form of the engine the rotor assembly is provided with blades which move a cooling air flow axially through the fixed casing. The second engine form further includes ignition components located on the forward side of the rotor assembly. Combustion gases are exhausted from the casing interior by a barrier riding on the rotor periphery.

The present invention falls within that general class of engines having an 
internal rotor assembly with reciprocating piston means therein. 
The general concept of a cylindrical rotor assembly within an engine casing 
including a reciprocating piston or pistons is old in view of the 
following and perhaps other U.S. Patents: 
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890,532 3,279,445 
3,968,777 
4,030,458 3,289,655 
3,991,728 
French Patent 013,269 
German Patent 1,176,919 
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Common to known rotary engines of the type having reciprocating pistons 
within a rotor assembly is a sealing problem as the rotating combustion 
chamber in such engines is partially defined by an interior wall surface 
of a stationary engine casing. A precise fit between rotor and casing 
would obviate such seals but such an approach is unrealistic in view of 
the wear factor. Extreme temperatures and abrasive wiping contact with the 
casing or rotor surfaces resulting in a short seal life. Further, the 
rotary engines known are limited to low compression ratios because of such 
seals. Other drawbacks in some of the known engines include the use of 
connecting rods and reliance on powerless exhaust strokes for exhausting 
combustion gases. Such known engines, being limited to low compression 
ratios, cannot fully utilize energy available from the burning of 
hydrocarbon fuels at extreme temperatures and pressures. 
U.S. Pat. 890,532 is of interest for the reason that the engine disclosed 
includes an offset stationary crank pin about which pairs of pistons, rods 
and yokes rotate to impart reciprocating piston movement within a rotor 
assembly rotating about an axis offset from the crank pin. A crank chamber 
receives fuel via a crankshaft bore which is subsequently assertedly drawn 
into each cylinder behind the piston and thereafter urged by the piston 
inner end into an auxiliary fuel storage chamber from whence fuel 
subsequently moves into the cylinder ahead of the piston via a second 
intake port or passageway. The fuel chamber houses the pair of yokes 
moving at right angles to one another resulting in the chamber being 
incapable of pressurization. Further, routing of the fuel mixture includes 
first and second intake passages and an auxiliary chamber to severely 
hinder volumetric efficiency of the intake system. Still further, the 
ignition system includes slip rings each in wired circuit with a cylinder 
spark plug. No provision is made for a casing nor moving a cooling airflow 
past the rotating engine structure. 
French Pat. No. 013,269 discloses pistons each having a piston rod 
terminating in a yoke structure which structure additionally includes a 
piston facing surface which propels a fuel-air charge into an intake 
manifold ring. The fuel-air charge passes through flapper valves carried 
by said yoke member. Advancement of the yoke transfers the charge into 
said circular intake manifold for temporary storage prior to release into 
an engine cylinder. 
German Pat. No. 1,176,919 discloses a flat sided piston having a 
rectangular opening within which is a block with eccentric piston movement 
and rotary block movement compelled by a stationary crank pin offset from 
the axis of rotor assembly rotation. No provision is made for a yoke nor 
dissipation of heat. The engine does not lend itself to conventional low 
cost manufacturing operations. 
SUMMARY OF THE PRESENT INVENTION 
The present invention is embodied within an internal combustion engine 
having an internal rotor assembly including multiple pistons with closed 
end combustion chambers defined by rotor wall structure. 
The rotor assembly of the present engine is concentrically disposed within 
a stationary engine casing. Integral with the stationary engine casing but 
eccentric thereto is a stationary shaft about which a piston yoke assembly 
moves as it reciprocates within the rotor. The present piston yoke 
assembly includes a pair of pistons which reciprocate within rotor defined 
bores wholly defined by internal rotor wall surfaces to obviate a seal 
requirement. The yoke of the piston yoke assembly is disposed intermediate 
the pistons interconnecting same in a unitary manner. The yoke 
reciprocates within a rotor defined fuel-air chamber to pressurize a 
fuel-air mixture and form a charge momentarily stored with an intake port. 
Intake and exhaust flows from the cylinders are regulated by the cylinder 
piston thereby dispensing with valving. The yoke defines an elongate, 
shaft receiving opening whereby the said shaft, being static, will 
constrain the piston yoke assembly for reciprocal movement during rotor 
assembly rotation about the casing axis from which the shaft axis is 
offset. 
The rotor assembly has exhaust ports orientated so as to cause rotor 
exhaust to be discharged adjacent a rotor end and hence impart thrust to 
same. As earlier mentioned, the rotor assembly is elliptical and thereby 
defines, along with the engine casing interior, crescent shaped, moving 
exhaust chambers for the reception of exhaust gases. A barrier rides on 
the rotor periphery to compel scavenging of exhaust gases from the moving 
exhaust chambers. An air inlet permits entry of ambient air into a forming 
exhaust chamber coincident with rotation of the elliptical rotor assembly. 
Concentric with the rotor assembly is an output shaft and a lubricant 
reservoir provided with an oil pump disc for pressurizing engine lubricant 
lines. 
A second described form of the motor includes a rotor assembly with blade 
appendages which impel an ambient cooling airflow past the rotor and 
through ports in the end plates of the casing. Cam elements are mounted in 
an exposed manner exteriorly on the rotor assembly to trigger ignition 
impulses. 
Important objectives of the present invention include the provision of an 
engine of compact design having a rotor assembly including a unitary 
piston and yoke assembly with the yoke having fuel-air mixture compressing 
surfaces driving a fuel-air charge to an oppositely located remote 
combustion chamber; the provision of an engine wherein ignition components 
are within engine pistons; the provision of an engine design capable of 
extreme compression ratios to best utilize the fuel-air mixture from a 
power output standpoint; the provision of an engine having a piston yoke 
assembly wherein the yoke additionally serves to pressurize a fuel-air 
charge into an intake port for subsequent and direct release of the charge 
into the inner segment of an engine cylinder; the provision of an engine 
which has a power stroke every half-cycle; the provision of an engine 
partaking power from the exhaust of generated combustion gases into moving 
exhaust chambers within an engine casing; the provision of an engine 
having relatively few components for simplicity of construction and 
servicing; the provision of an engine utilizing a fuel-air mixture for 
cooling of reciprocating piston components; the provision of an engine 
having a rotor assembly with impellor blades thereon moving ambient air 
axially through the motor and past relatively large surface areas formed 
on the rotor to cool same; the provision of igniter elements carried by 
the rotor assembly in a highly accessible manner to simplify servicing and 
the remaining ignition system.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
With continuing attention of the accompanying drawings, reference numeral 1 
indicates an engine casing having an annular wall 1A and a back wall 2 and 
defining an interior cylindrical chamber 3 within which a later described 
rotor assembly is housed. The casing includes mounts at 5 for casing 
securement. Closing the casing is an end plate 6 having ears 7 thereon for 
the reception of casing engaging fasteners 8. 
A lubricant tank at 11 is affixed to back wall 2 of the casing with a pump 
disc at 12, carried by a motor output shaft 15 and pressurizing a 
lubricant flow through a line 13. A cover plate 14 closes the lubricant 
tank and includes a suitable shaft oil seal. 
Secured to end plate 6 of the engine casing is a fixed shaft 17 the axis X 
of which is offset from axis Y of the engine casing. A fastener 18 retains 
the shaft in fixed, offset relationship to the casing axis. For shaft 
support, end plate 6 is bored to receive an inset shaft end. Shaft 17 
serves to compel reciprocal movement of a piston yoke assembly within the 
later described elliptical rotor of the engine. 
An engine rotor assembly, hereinafter occasionally referred to as a rotor, 
as best viewed in FIGS. 3 and 4, comprises front and rear face plates 20 
and 21 between which a pair of opposed rotor heads 22 and 23 are secured 
by inset cap screws as at 19. The assembled rotor heads and face plates 
provide a rotor of elliptical configuration with rotor ends at E being 
formed on a radius complimentary to the radius of interior annular wall 1A 
of the casing. Rotor heads 22-23 each define a closed end combustion 
chamber 22A-23A. Rotor head 22 defines an exhaust port 24 while rotor head 
23 defines an exhaust port 25. Fuel-air intake ports at 26 and 27 in each 
rotor head as well as the exhaust ports 24-25 are laterally closed by the 
rotor face plates 20 and 21. The rotor heads include interior walls 28 and 
29 which, with said face plates and the later described piston yoke 
assembly, define communicating fuel-air chambers C in communication with 
said intake ports 26 and 27. The fuel-air chambers C receive a fuel-air 
flow via a port 30 in casing end plate 6 which port is served by a 
carburetor 31. Communicating fuel-air chambers C with port 30 is an 
intermediate open area 32 (FIGS. 4 and 5) jointly defined by an end plate 
bearing flange 33 plate 6 and the rotor assembly. Flange 33 exteriorly 
carries a bearing 34 the outer race of which seats within the inner 
periphery 20A of rotor face plate 20. 
A piston yoke assembly generally at 35 comprises first and second pistons 
36-37 both integral with a central yoke 38 having an elongate, 
transversely orientated opening 39 through which fixed shaft 17 extends. 
The front and rear sides or faces of the yoke adjacent front and rear 
rotor face plates 20 and 21 are each provided with seals as at 40 which 
ride on the inner surfaces of the rotor face plates during yoke 
reciprocation. As viewed in FIG. 3, the yoke during subsequent or downward 
movement in fuel-air chambers C draws a fuel-air flow through port 30 to 
charge that area forming above the yoke fuel compressing surface. It will 
be appreciated that the term "downward" is used simply for purposes of 
explanation as the piston yoke movement is of course rotational as well as 
reciprocal the latter relative to the rotor assembly. 
The pistons 36 and 37 have heat dissipating walls and include piston rings 
36A-37A (FIG. 5). The outer end of each piston is of concave, 
hemispherical shape at 41-42. An igniter element, which may be of the 
gapped type, is indicated at 43-44 suitably seated within each of the 
hemispherical piston walls. Ignition component leads 45 and 46 extend from 
a terminal on each of the igniters respectively to contacts 47-48 on the 
yoke front wall. Each of said contacts moves past the inner end of an 
ignition terminal 49 in casing end plate 6. 
With attention to FIGS. 1 and 2, an exhaust stack at 54 is in communication 
with casing interior via exhaust port 55 formed therein. To compel 
discharge of combustion gases from the moving, crescent-shaped exhaust 
chambers at 52-53, located intermediate the elliptical rotor assembly and 
the casing wall 1A, a barrier at 56 rides in lightly biased contact with 
the rotor which barrier is shown in combination with a flutter valve 57 
which opens and closes a casing port 58 in response to inward and outward 
barrier movement as biased by the elliptical rotor assembly wall. Cooling 
ambient air accordingly is admitted to the casing interior. For purposes 
of lubrication of casing and rotor surfaces, an oil atomizing device 61 is 
located within a flutter valve housing 60 for intake via port 58. 
In operation, initial cranking of the rotor assembly by a starter unit (not 
shown) rotates output shaft 15 with the rotor driven in a clockwise 
direction as viewed in FIG. 3. With attention now to FIG. 7, at 90 degrees 
of rotor movement, yoke 38 is medial of fuel-air chambers C and has drawn 
a fuel-air mixture into one of same via port 30 and space 32 while 
simultaneously pressurizing a fuel-air mixture in remaining chamber C in 
advance of the moving yoke to form a fuel-air charge in intake port 27. At 
180 degrees (FIG. 8), the piston 36 has moved outwardly past the discharge 
opening of port 27 for introduction of the pressurized fuel-air charge 
stored therein. Combustion chamber 22A is scavenged via port 24 by the 
charge. In FIG. 9 at 270 degrees of rotation, piston 36 has now advanced 
midway into rotor defined combustion chamber 22A to close both its intake 
and exhaust ports 27, 24 and to partially compress the fuel-air charge. At 
approximately 360 degrees or earlier in FIG. 6, ignition occurs. Rotor 
assembly inertia positions same clockwise past dead center whereat the 
major axis of piston 36 is now in a plane offset in the direction of rotor 
rotation from the axis of shaft 17. Further rotation of the rotor assembly 
increases the offset relationship of the above mentioned piston-shaft axes 
to provide an arm therebetween acting on the rotor and at its greatest 
magnitude at the 90 degree position of FIG. 7. Power is accordingly 
imparted to output shaft 15 by the rotor assembly. 
With continuing attention to FIG. 7, movement of the piston yoke assembly 
resulting from combustion will be in the arrow-indicated direction with 
yoke 38 both drawing in a fuel-air mixture into one rotor chamber C while 
advancing to pressurize the remaining chamber C and compress a fuel-air 
charge into intake port 27. 
With attention again to FIG. 8, with the rotor assembly at 180 degrees, 
piston 36 has moved outwardly of combustion chamber 22A and to open 
exhaust port 24 substantially contemporaneous with the opening of intake 
port 27 to permit the pressurized fuel-air charge entering the compression 
chamber to scavenge same. Importantly, opening of exhaust port 24 by 
cylinder extraction permits forceful expansion of combustion gases through 
port 24 into exhaust chamber 53 to impart asymmetrical thrust to the rotor 
end which thrust acts along an arm perpendicular to output shaft axis 15 
to contribute additional power to the rotor assembly. Combustion gases so 
ejected from the combustion chambers are received within the 
crescent-shaped exhaust chambers 52,53. Said chambers will be near ambient 
atmospheric pressure to permit admission of the exhaust flow from each 
compression chamber at each half-cycle of rotor rotation. Exhaust gases 
within the crescent-shaped exhaust chambers exhaust via port 55 in the 
engine casing as compelled by barrier 56. During formation of a new 
exhaust chamber upon passage of a rotor extremity past barrier 56, an air 
flow is drawn into the forming chamber to assist in engine cooling. 
Further cooling of the engine is realized from the reciprocation of 
pistons 36 and 37 into fuel-air chambers C for the transfer of heat to the 
fuel-air mixture. 
In the modified form of the engine as shown in FIG. 10 and subsequent 
Figures, reference numeral 60 indicates generally an engine casing having 
an annular wall 61 the interior surface 61A thereof defining a cylindrical 
chamber. Front and rear end plates 62 and 63 define openings 62A and 63A 
(FIG. 11) for the purpose of permitting axial passage of a cooling 
airflow. Bolts 64 tie the end plates to one another and to annular wall 
casing 61. Engine mounting brackets are at 65. An engine output shaft is 
at 75 suitably journalled within a bearing 76 in a bearing retainer 77 on 
plate 63. 
Secured to front end plate 62 is a fixed or static shaft means 66 which 
projects inwardly of the casing with a shaft axis at X' being parallel to 
and offset from a casing aixs Y'. Concentric with the casing axis Y' is a 
boss 67 formed integral with front end plate 62. Boss 67 additionally 
supports shaft 66 and defines a fuel-air intake means shown as a passage 
68 terminating forwardly in communication with a carburetor 70 carried by 
the front end plate 62. 
An internal rotor assembly generally at 71 includes front and rear plates 
80 and 81 with the former including a bearing retainer sleeve 82 within 
which is secured the race 83 of a roller bearing. Front rotor assembly 
plate 80 includes blade means 84 which are set at a pitch angle (not 
shown) to draw ambient air through casing front wall openings 62A and 
impart substantially axial movement to same for ultimate discharge through 
rear casing openings 63A. Such air movement is partially through rotor 
assembly open areas 85 in a rotor body 89. Blade securement to front face 
plate 80 may be by a pressed fit or other suitable securement. Rotor body 
89 includes rotor heads at 86 and 87 each of which defines a bore 88 and 
89 (also termed combustion chambers) closed by rotor body end walls 90 and 
91. Each rotor head 86 and 87 is provided with an igniter component block 
at 92 and 93 each internally threaded to receive an igniter or spark plug 
S having its electrodes disposed within block bores 92A-93A each in 
communication with the outer end of a rotor head bore. The terminal or 
innermost ends of the spark plug components terminate inwardly for contact 
with a stationary ignition lead as later described. Exhaust ports are at 
94 and 95 while intake ports at 96 and 97 serve the inner segments of 
combustion chamber bores 88-89 with each intake port in direct upstream 
communication with a fuel-air chamber C' defined by the rotor body 
interconnecting the rotor heads. Chamber C' is, during engine operation, 
in effect two chambers by reason of a piston yoke 100 reciprocating 
therein with first and second fuel compressing surfaces 100A-100B 
alternately pressurizing fuel-air charges for remote combustion chambers 
89 and 88. The intake and exhaust ports formed in each rotor head are 
disposed so as to be open concurrently for bore scavenging and admission 
of a fuel-air charge from chamber C' via an intake port. Fuel intake 
passage 68 terminates inwardly in open communication with chamber C' while 
front and rear face plates 80 and 81 axially define fuel-air chamber C'. 
A piston yoke assembly comprises, in addition to yoke 100, first and second 
aligned pistons 101-102 integral with an oppositely carried by central 
yoke 100. Said yoke defines an elongate, transversely extending opening 
104 therein which receives fixed shaft means 66 about which the piston 
yoke assembly eccentrically orbits during rotor assembly rotation. The 
pistons are suitably provided with piston rings. Seals at 105 are adjacent 
yoke fuel-air compressing surfaces and across the yoke ends. 
An exhaust port 106 in FIG. 11 vents a moving crescentshaped exhaust 
chamber as at 107 defined by casing wall surface 61A and the exterior 
surface of the rotor body. 
Carburetor 70 vaporizes a fuel-air mixture with the liquid fuel used having 
a lubricant premixed therewith in the ratio used for two-cycle engines. 
Engine intake passage 68 admits the fuel-air mixture to chamber C' in 
which the mixture is compressed by yoke surfaces 100A-100B for momentary 
confinement within a bore intake port 96 or 97 prior to direct discharge 
into the inner end segment of a combustion chamber. Beneficial heat 
transfer occurs from the piston yoke assembly to the compressed charge. 
Ignition of a fuel-air charge in a combustion chamber is triggered by rotor 
carried actuators 112-113 acting on a pair of aligned contacts as at 
110-111 the innermost contact 111 having its inner end disposed in the 
rotational path of the actuators shown as cams located on front rotor 
plate 80. A contact supporting ignition unit 114 additionally carries an 
ignition lead 115 located in the path of the ends or terminals of ignition 
component S. Lead 115 may be in circuit with the secondary coil with 
contacts 110-111 opening and closing a primary coil (not shown). The 
ignition system components of course may vary to include solid state 
components. Ignition support unit 114 is readily arcuately positionable by 
reason of a mounting arm 116 being swingably coupled to casing end plate 
62 enabling ignition advancement or retardation. Piston 101 is shown at 
top dead center in FIG. 13. Timing of ignition has been found suitable 
when occurring at twenty-five to thirty degrees before top dead center but 
may vary with the fuel utilized and other criteria. 
Rear face plate 81 of the rotor assembly receives, in a recessed manner, 
socket head cap screws at 117 having inset heads which serve to assemble 
the rotor assembly parts and to secure engine output shaft 76 to the rotor 
assembly. 
The operation of the second described preferred form of the engine is 
substantially as the earlier described operation of the first form of the 
engine. The second form may include a pressurized lubrication system as of 
the type earlier described. Importantly, both engine cooling and 
lubrication as wall as compact engine size is achieved by reciprocation of 
the pistons into the fuel-air chamber for a major portion of their length. 
In one embodiment of the engine the inside diameter of casing wall 61 is 
eight inches, piston yoke assembly is of a length of five and 
three-quarters inches with a yoke width of three inches; static shaft 66 
is of seven-eighths inch diameter with shaft axis X' offset from the 
casing axis Y' a distance of thirteen-sixteenths of an inch. 
Carburetion is suitably provided by a motorcycle engine carburetor of the 
type manufactured by the Honda Company. 
While I have shown but a few embodiments of the invention it will be 
apparent to those skilled in the art that the invention may be embodied 
still otherwise without departing from the spirit and scope of the 
invention. 
Having thus described the invention, what is desired to be secured under a 
Letters Patent is: