US 3675630 A
An internal combustion engine in which a power generating cylinder has a piston drivingly coupled with a piston in a combustible fluid compressing cylinder by means of gears connected with a power delivery shaft and which are adjustable to vary the timed operating relationship at which the pistons reach their respective dead center positions, the compressing cylinder having a valve controlled inlet for a combustible fluid which is precompressed therein and delivered through an interconnecting valve controlled passage to the power generating cylinder into the space above the piston therein where it is confined under pressure and ignited after the piston in the power generating cylinder has passed and is moving away from its dead center position. Electrically energizable solenoids are provided for operating the respective valves in timed relationship as determined by timing switching means synchronized with the rotation of the power delivery shaft.
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Description (OCR text may contain errors)
United States Patent Stratton [451 July 11, 1972  ENGINE 1,679,158 7/1928 French............................123/90.1l X
 Inventor: Cleo C. Stratum, 2123 Kern St., San
Bemardino, Calif. 92405  Filed: July 2, 1970  Appl. No.1 51,820
 US. Cl. ..l23/70 R, 123/9011, 123/70 V [5|] Int. ..F02b 13/22  Field otSenrch123/7O R, 70 V, 68, 90111,
Primary Examinerwendell E. Burns Auorney-Whann & McManigal 5 7] ABSTRACT An internal combustion engine in which a power generating cylinder has a piston drivingly coupled with a piston in a combustible fluid compressing cylinder by means of gears connected with a power delivery shaft and which are adjustable to vary the timed operating relationship at which the pistons reach their respective dead center positions, the compressing cylinder having a valve controlled inlet for a combustible fluid which is precompressed therein and delivered through an interconnecting valve controlled passage to the power generating cylinder into the space above the piston therein where it is confined under pressure and ignited after the piston in the power generating cylinder has passed and is moving away from its dead center position. Electrically energizable solenoids are provided for operating the respective valves in timed relationship as determined by timing switching means synchronized with the rotation of the power delivery shaft.
4 Claims, 3 Drawing Figures ENGINE BACKGROUND OF THE INVENTION The present invention relates to power generating apparatus, namely, an internal combustion engine.
Basically, the inherent relatively low efficiency of internal combustion engines has long been realized, and efforts are continually being made to improve the efficiency of conversion of the available fuel energy into usable mechanical power at the output shaft of the engine. These improvements have been directed to diverse objectives, and as a result much progress has been made. For example, a great deal of work has been done with respect to the design of the head end of the cylinder, and top of the piston with a view to improving combustion and increasing the pressure of the fuel mixture at the time of ignition. These improvements were closely allied with the developments of better fuels which would permit the use of higher compressions.
Another approach began with the discovery that long stroke engines were inefficient due to the quick loss of pressure when the pressure of the gas was suddenly released by the downward movement of the piston. While a tremendous pressure was produced on the top of the piston at the time of ignition, which was at the time when the piston was close to its dead center position, this high pressure was not available during the portions of the crank movement in which the mechanical leverage would be the greatest. As a result of this discovery, the short stroke high speed internal combustion engine was developed and gained favor over the long stroke slower speed engines. in this new development, a greater amount of the potentially available power could be utilized by having a greater number of very short power pulses.
In considering the improvements which have been made, in eluding the improvements noted above, it becomes apparent that these improvements have not eliminated a major and important source of inefficiency which results from the utilization of a firing point substantially at the dead center position of the piston. While it has been found that some gain in power will be obtained by advancing the ignition point slightly ahead of the dead center position, this gain in efficiency is costly for the reason that the forces applied to the piston are at a point of zero or low crank leverage. These forces are accordingly applied directly against the crank shaft at a time when they are substantially ineffective to produce shaft rotation.
Another observed source of inefficiency results from the necessity of having to utilize two valves in four-cycle engines. The size of the valves is thus restricted, and to overcome this problem superchargers were used to force the mixture through the valve openings. Further, in conventional fourcycle and two-cycle engines, inefficiency results due to the use of the same chamber for combustion, intake and compression. For example, the intake of combustible mixture from the carburetor enters the heated combustion chamber, and as the mixture heats up it expands. The pressure within the chamber quickly equalizes the admission pressure so that a lesser quantity of the entering mixture will be received as a potential source of power. Accordingly, the hotter the engine runs the less will be its efficiency.
The engine of the present invention is so designed as to overcome and improve those areas of inefficiency in the conventionally known engines, and including those areas which have been specifically indicated above. Briefly, this is accomplished by providing a pair of cylinders having pistons coupled with a power delivery shaft, and arranged so that the combustible fluid will be compressed in one cylinder and delivered under pressure to the other cylinder after the piston therein has moved away from its dead center position, ignition of the fluid taking place at a time when the crank leverage is approaching maximum, rather than at a time when the leverage is zero or at a low value. Single valves are utilized in the cylinders, thus permitting the use of valves which are relatively unrestricted as to size and may approach the diameter of the cylinder, thus enabling rapid flow through the valved passages.
In my disclosed improvement, the combustible fuel mixture enters a relatively cool power cylinder, and even though operating temperatures may be above normal, the fuel will be forced into it under a pressure which will assure a full power charge. Transfer of the fuel from one cylinder to the other provides for increased and better vaporization. Moreover, since the pistons reach dead center position at different times, the angular relationship is such that the crank leverage on the power piston will be increasing at the same time that the leverage with respect to the compression piston is decreasing so that the power needed to compress the charge at the greatest point of pressure will be substantially cancelled. Since ignition takes place after the power piston passes dead center position, backfire or backward running is prevented. The engine operates with a minimum of vibration.
SUMMARY OF THE INVENTION The present invention relates generally to power generating apparatus, and is more particularly concerned with improvements in engines of the internal combustion type.
It is one object of the herein described invention to provide an internal combustion engine having improved operating efiiciency, high power delivery, which is substantially free of vibration, and which will not kick or tend to run in a reverse direction when starting.
A further object is to provide an improved internal combustion engine having reciprocable pistons, wherein a combustible fuel mixture will be ignited while confined under high pressure, and after the piston has moved away from its dead center position.
A further object is to provide in an internal combustion engine of the reciprocable piston type a power generating cylinder and a compressing cylinder, and wherein the piston of the power generating cylinder is coupled with the piston of the compressing cylinder through a power feedback connection.
Another object is to provide an internal combustion engine wherein a combustible fluid mixture is admitted to the space above the piston, and in which the ignition is timed to occur after the piston has passed its dead center position and during which the angle of the crank is such as to provide high leverage.
Still another object is to provide in such an engine two interconnected pistons coupled with a single power delivery shaft, one of the pistons being in a cylinder of relatively large diameter provided with a single intake valve and operating to compress a combustible fluid for delivery to the cylinder of the other piston which is of smaller diameter for power generation, this cylinder having a single exhaust valve; which operates at high efficiency and provides better vaporization of the combustible fluid than is possible with a single cylinder type engine.
It is also an object to provide an internal combustion engine which makes use of interconnected cylinders having cooperatively associated pistons connected with separate crank shafts, these crank shafts being interconnected by gearing which permits quick change of the timed relationship of piston movements and consequent change of compression ratios to suit operation with different types of fuels.
Yet another object resides in the provision of means for varying the amount of intake combustion fluid in accordance with changes in ambient atmospheric pressure, as a safeguard against excessive cylinder pressures which could cause damage.
Further objects of the invention will be brought out in the following part of the specification, wherein detailed description is for the purpose of fully disclosing the invention without placing limitations thereon.
BRIEF DESCRIPTION OF THE DRAWINGS Referring to the accompanying drawings, which are for illustrative purposes only:
FIG. I is an elevational view, partly in section, illustrating the operative relationship of the component parts of the engine embodying the present invention, and including schematic disclosure of timing means for the valves and ignition components;
FIG. 2 is a top view of a butterfly valve combustible mixture control as utilized with the engine, with variable atmospheric pressure adjusting means; and
FIG. 3 is a side view of the same.
DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now more specifically to the drawings, for illustrative purposes there is shown in FIG. I an internal combustion engine constructed with a suitable casing or housing, as generally indicated at 10, and which may vary depending upon different installations. For example, the casing may be arranged for water cooling or air cooling. Likewise, the disposition of the parts may vary as to configuration and dimensions, while basically conforming to the broad concepts of the present invention. As shown in FIG. I, the casing is constructed to provide a crank case portion ll having a cylinder block section I2 secured thereto as by bolts I3, this section having external fins 14 providing the necessary heat radiating surfaces to accommodate the engine for air cooling. Above the cylinder block, there is provided a head section I which is removably secured as by anchor bolts 16.
The engine of the present invention differs from conventional two-cycle and four-cycle engines in which each cylinder module is composed of a single cylinder and piston. In the present invention, instead of utilizing a single cylinder for combustion, intake and compression, the module utilizes two cylinders and associated pistons to perform the same functions as the one cylinder of conventional engines. Of course, a single engine may comprise several of the two-cylinder modules. More specifically, as shown in FIG. I, the cylinder block I2 is constructed to provide a first cylinder cavity 17 and adjacent second cylinder cavity I8 which are transversely aligned. Associated with the cylinder I7 is a reciprocably mounted piston 19 of conventional construction, this piston being pivotally connected with one end of a connecting rod 20 by means of the usual wrist pin 21. The other end of the connecting rod 20 is connected with a crank pin 22 carried by a disc-gear 23 removably retained by a securing nut 24 on a power delivery shaft 25 mounted in appropriate bearings (not shown) in the crank case section.
In a similar manner, the cylinder 18 has reciprocably mounted therein a piston 26 which is secured to one end of connecting rod 27 by means of wrist pin 28, the other end of the connecting rod being similarly connected with a crank pin 29 carried by a disc-gear 30 removably mounted on a shaft 31 by nut 32. This shaft is also supported on suitable bearings (not shown) in the crank case section. The gears 23 and 30 are shown as being of similar diameter and as having intermeshing teeth. As thus drivingly connected, the shafts 25 and 3! will at all times rotate in opposite directions, and by changing the engaged circumferential points of the respective gears, the timed relationship of the crank pins 22 and 29 may be varied so that the respective pistons will occupy different axial positions at any given time within their associated cylinders. As arranged in the illustration, the piston I9 will be moving away from its dead center position at the top of its cylinder, when the piston 26 is moving towards its dead center position. The relative angular relationship of the crank pins 22 and 29 may be varied, and for purposes of illustration the crank pin 22 is shown as having a leading angle of substantially 45 with respect to the crank pin 29. Thus, when the piston 26 is at its top dead center position, the piston I9 is moving away from its dead center position on its power stroke.
It is one of the features of the present invention that one of the pistons, in this case piston 19, is utilized as the power generating piston, while the other piston 26 is utilized as a compressor piston for the fluid mixture. For such operations it has been found desirable to construct the compressor piston 26 of greater diameter than the piston I9.
The power cylinder 17 is provided with a single exhaust valve 33 which is positioned in a recess 34 of the head block section so as to permit the use of small clearance between the cylinder end and the upper end of the piston, when the piston is in dead center position. The valve 33 has a conventional stem 35 which is reciprocably supported in the head section IS and at its outer end has a shoulder 36 forming an abutment for one end of a compression spring 37 having its other end engaged with the top of the head section. The spring 37 thus acts to normally move the valve 33 to a closed position For opening the valve, an electrically energizable solenoid 38 is operatively connected with the stem 35 in a well known conventional manner. In the open position of the valve 33, the upper end of cylinder I7 is connected with an exhaust port passage 39 leading to an exhaust connection 40. As an aid in exhausting waste gases from the cylinder 17, after ignition, there is also provided an exhaust port 4i which is controlled by the piston 19 in such a manner that when the piston reaches the lower limit of its travel in the cylinder I7, port 4I will be open.
In a similar manner, the upper end of cylinder 18 is provided with a single inlet valve 42 which is mounted within a recess 43, this valve having a stem 44, a shoulder 45, compression spring 46, and solenoid 47. In the open position of the valve 42, the upper end of the cylinder I8 is connected with an intake port passage 48 which leads to an inlet connection 49. This inlet connection is connected with a carburetor or other means for providing a source of combustible fluid (not shown). For controlling the flow of combustible fluid to the cylinder 18, suitable control means such as a butterfly valve 50 of conventional construction may be provided. Normally provided throttle controls for changing the position of the butterfly valve may be used. However, since it is possible in the engine of the present invention to obtain pressures at low altitudes which could damage the engine, means are provided for regulating the extent of opening of the butterfly valve in accordance with changes in the ambient atmospheric pressure. At low altitudes, the butterfly opening will be restricted, whereas at the higher altitudes the limit of opening will be greater. For such purpose, there is provided an aneroid as sembly which includes a bellows 52 which is anchored at one end to a bracket 53, and connected at its other end to an actuating rod 54, the outer end of this rod being provided with a hook 55 which extends over an arm 56. The arm 56 is con nected with the butterfly valve and assumes a position corresponding thereto. Depending upon the position of the hook 55, the opening limit of the valve will be established, while still permitting free closing movement of the valve from this limit position.
In order to conduct compressed combustible fluid from the compressing cylinder 18 to the power cylinder I7, the top ends of the cylinders are interconnected by a flow passage 57 which is controlled by a valve member 58 in the form of a solid rod, and which is supported for reciprocable movement within a cylindrical bore 59 provided in the cylinder block section body between the cylinders 17 and I8. The valve member is movable to a position closing the flow passage 57, and to a valve open position wherein a transverse passage 60 in the valve member will be aligned with the passage 57. The lowermost end of the bore 59 opens into the interior of the crank case so that the valve parts receive splash lubrication from the crank case. The valve member 58 is normally urged to a closed position by means of a compression spring below the valve member, this spring 61 having one end bearing against the valve member and its other end bearing against the screen filter 62 at the lower opening of the bore 59, this filter being retained against outward movement by means of a threaded bushing 63. At its upper end, the valve member is sealed by means of an O-ring 64 retained by the bushing 65.
The uppermost end of the valve member is operatively connected with a solenoid actuator 66 which, upon being energized, will motivate the valve 58 to a valve opened position against the action of spring 61.
Since in the engine of the present invention the ignition of combustible mixture in the power cylinder 17 takes place after the piston has passed through its upper dead center position, it is not necessary that the ignition means, such as a spark plug 67 shall be installed in the head of the cylinder. Accordingly, the spark plug can be mounted at the side of the cylinder and arranged to be energized through a timing distributor 68 of conventional construction driven by the power delivery shaft 25. This is an advantage over the usual location in the head of the cylinder, which tends to restrict the size of the valve or valves which are mounted therein according to conventional practice.
While the enclosed embodiment shows the use of solenoid actuators for the valves, it will be appreciated that in the broad concept of the invention it is also possible to utilize mechanical actuators operated from valve cam shafts according to conventional practice.
The utilization of solenoid actuators facilitates the timing of the valve operations, which in this case is accomplished by means of a valve timer switching means, as generally indicated at 69. This timer comprises three separate insulating discs 70, 71, and 72 which are fixedly secured to a common shafl, as indicated in phantom lines at 73, this shaft being synchronously driven from the power delivery shaft 25. In the position of these discs, as shown in FIG. 1, the disc 70 has a conducting strip 74 which extends from l80 in a clockwise direction to the 360 point. The disc 71 has a conducting strip 75 which ex tends from the point in a clockwise direction to a 45 point. The disc 72 has a conducting strip 76 which extends from the 45 point in a clockwise direction to a 225 point. Brushes 77, 78, and 79 are respectively shown for the discs, these brushes being at the 0 position of each disc. The conducting strips are connected to one side of an electric source 80a. The brush 77 connects with one terminal of solenoid actuator 47 through a conductor 80. Brush 78 connects with one terminal of solenoid actuator 66 through a conductor 81, and the brush 79 connects with one terminal of the solenoid actuator 38 through a conductor 82. The other terminals of the solenoid actuators are connected through a common conductor with the other side of the electrical source as indicated at 80b. At the relative positions of the discs 70, 71, and 72, as just described above, it will be observed that the piston 26 is at the upper limit of its travel and is in a dead center position, while the piston 19 at this point in timing is at a position going away from its dead center position, and wherein the crank pin 22 is at a 45 angle with respect to the dead center position. This is a point at which the combustible fluid above the piston 19 may be ignited, and at this position the crank arm will have an increased leverage as compared to substantially zero leverage in conventional engines where the firing is accomplished slightly before the piston reaches its dead center position. Because of this feature, greater power will be obtained from the power generating piston, than in the conventional type of engine.
With the clockwise rotation of the discs of the valve timer switching means, it will be seen that the conducting strip 75 will have opened the valve 58, when the piston 26 is moving towards its dead center position, and while the piston 19 is beginning to move away from its dead center position. Due to the different volume displacement of the piston 26 with respect to the piston 19, a large volume under pressure of compressed combustible fluid will be forced into the area above the piston 19 so that when ignition takes place, full ad vantage may be taken of the potential power developed by the combustion of the mixture. The timed relation for opening of the intake and exhaust valves 42 and 33, as well as the closing of these valves, will be accomplished by the conducting strips 74 and 76 as the timer is operated.
From the foregoing description and drawings, it will be clearly evident that the delineated objects and features of the invention will be accomplished.
Various modifications may suggest themselves to those skilled in the art without departing from the spirit of my invention, and, hence, I do not wish to be restricted to the specific forms shown or uses mentioned except to the extent indicated in the appended claims.
1. An engine comprising:
a. a crank case;
b. a first cylinder and a power delivery piston reciprocable therein;
0. means connecting said piston with a power delivery shaft, including a connecting rod having one end connected to a crank on the shaft operable between dead center positions corresponding with the inner and outer limits of travel of the piston in said cylinder;
d. a second cylinder and a piston operable from said power shaft reciprocable therein to provide a source of compressed combustible fluid;
e. means operable to admit compressed combustible fluid from said source into the first cylinder space above its piston to provide a sustained pressure of combustible fluid therein during movement of the piston away from its inner limit of travel to a predetermined ignition position and at which the crank will have substantially maximum turning leverage, comprising:
a valve controlled connection between said first and second cylinders for conducting compressed combustible fluid from said second cylinder to said first cylinder, including a valve chamber having an end opening into said crank case,
an elongated valve member slidably reciprocable in said valve chamber for movements to valve closed and valve opened positions,
spring means normally urging said valve member to said closed position, and
means for actuating said valve member to said opened position, said valve member and spring being positioned to receive splash lubrication from the crank case through said chamber and opening;
f. means operable in timed relation to the power delivery piston movement for igniting the admitted combustible fluid at said ignition position of the piston; and
g. other means operable in timed relation to the power delivery piston movement for connecting the cylinder space above the piston with an exhaust flow passage for the products of combustion.
2. An engine according to claim 1, including filter means in said valve chamber positioned between said spring and the chamber end opening.
3. An engine according to claim 1, wherein the actuating means comprises an electrically energizable solenoid.
4. An engine comprising:
a. a first cylinder and a power delivery piston reciprocable therein;
b. means connecting said piston with a power delivery shaft, including a connecting rod having one end connected to a crank on the shaft operable between dead center positions corresponding with the inner and outer limits of travel of the piston in said cylinder;
c. a second cylinder and a piston operable from said power shaft reciprocable therein to provide a source of compressed combustible fluid;
d. means operable in timed relation to the movement of the piston in said second cylinder for connecting the cylinder space thereabove with an intake flow passage for a combustible fluid;
e. an adjustable butterfly throttle valve for controlling said intake flow passage;
f. means for adjustably limiting the extent of opening of the throttle valve in accordance with changes in ambient atmospheric pressure;
g. means operable to admit compressed combustible fluid from said source into the first cylinder space above its 7 8 piston to provide a sustained pressure of combustible fluid at said ignition position of the piston; and fluid movemen P 'y i. other means operabie in timed relation to the power piston away from its inner limit of travel to a predetermined ignition position and at which the crank will have substantially maximum turning leverage;
h. means operable in timed relation to the power delivery piston movement for igniting the admitted combustible delivery piston movement for connecting the cylinder space above the piston with an exhaust flow passage for the products of combustion.