PARALLEL CYLINDER INTERNAL COMBUSΗON ENGINE

Technical Field

This invention relates to a new type of piston rotary engine.' More specifically it relates to a circular arrange¬ ment of pistons and cylinders around a mainshaft, which pistons act in concert to effect rotation of the mainshaft by virtue of pressure exerted on sinusoidal surfaces of a cam lobe encircling the mainshaft. Background Art

Various types of engines for developing mechanical power, such as for propelling vehicles, have been proposed and are in use. The most commonly used is the internal combustion engine. However, in spite of their widespread use, there are a number of disadvantages in the types of engines used, namely vibration, low efficiency, pollution, etc.

Vibration is generally due to the type of arrangement of the pistons with relation to the drive shaft, which in combination with poor timing, unequal power distribution, etc. , is very inefficient in eliminating vibration although much has been done in absorbing vibration or otherwise eliminating its transmission to the passenger-riding portion of an automobile. Since rotary engines may have pistons equally spaced around the mainshaft through Which power is transmitted, it is conceivable that such engines might have less problems with vibration. Various types of rotary engines have been proposed. U. _S . Patent 3,396,709 shows an engine design in which doubly opposed pistons transmit power to a geared cam wheel which power is in turn transmitted to a geared wheel around

the mainshaft. This indirect system of power transmission appears to be rather complicated.

U. S. Patent No. 3,456,630 discloses a rotary valve ca engine in which power is transmitted from pistons aligned around a shaft to two cams encircling the shaft and impart¬ ing rotary motion to the shaft. However, opposed pistons apparently operate simultaneously but not in unison and therefore poor timing and other factors may result in vibra¬ tion. U. S. Patent 4,090,478 describes a multiple cylinder sinusoidal engine comprising a plurality of piston arrange¬ ments parallel to and around a shaft cylinder. Power is. transmitted to the shaft by means of blocks at the sides of the cylinders which have ball bearings fitting into sinu- soidal grooves in the periphery of the shaft. As the piston moves along its linear axis, these bearings transmit force along the sinusoidal, path so as to rotate the shaft. However, since the force is transmitted to a point less than or no greater than the radius of the shaft, there is very little leverage obtained thereby. Disclosure of the Invention

In accordance with the present invention, a piston rotary engine has been designed which operates with excel¬ lent fuel efficiency, little or no vibration and a minimum of exhaust pollution. This engine has multiple pistons and cylinders arranged parallel to and in a circle around a mainshaft. The pistons and cylinders are arranged in pairs, each pair having a common axis with a connecting rod connec¬ ting the two pistons. One of the pistons in the pair goes through a firing cycle while its partner goes through a compression cycle and the two operate sequentially to drive the connecting rod back and forth along the common axis of the two cylinders.

In a preferred modification each connecting rod has attached to it a pair of roller bearings, each of which

alternately presses and rides against a cam lobe encircling the mainshaft.

In this preferred modification, this cam lobe has two sinusoidal surfaces, each having two symmetrically disposed high points and 90° from these high points there are corres¬ ponding low points or reverse rises with curved portions connecting these respective points. In other words, this cam lobe has two rises or high points 180° from each other and 90° from each high point there is a corresponding low point or a high point in the opposite direction (reverse rise) with curved sections connecting adjacent high and low points. While the two surfaces of the cam lobe are sinu¬ soidal, they are not parallel to each other since the thickness of the cam lobe varies between the rises as explained in greater detail hereinafter.

When a connecting rod moves in one direction in the path of its linear axis, one of the bearings carried by this connecting rod presses on the curved surface between a high and low point on the cam lobe, and by vector force causes rotation of the mainshaft. With an engine having eight . pairs of cylinders and pistons or 16 individual cylinders and pistons, there are 16 firings per revolution of the shaft which translates to 4 cycles per piston in one revo¬ lution of the mainshaft, and which results in a very smooth power transmission to the shaft with little or no vibration and with high efficiency.

With the engine of this invention there are a number of important advantages. First, as stated above, there are 16 firings per revolution of the mainshaft with four full piston cycles whereas with the present 8 cylinder engines, there are only two cycles per revolution of the cranksahft.

Second the distance of the contact point of the connec¬ ting rod bearing with the cam lobe to the axis of the mainshaft exceeds the stroke of the piston thereby giving improved leverage and requiring less power to turn the main-

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shaft as compared to present engines.

Third, because of the higher number of cylinder firing permitted per revolution, this new engine design can use a lower compression ratio, for example less than 8/1. There- fore a higher air ratio or leaner mixture can be used thereby resulting in more efficient use of fuel. Conse¬ quently low octane fuel may be used efficiently.

Fourth, since the engine is more compact in design, the size and weight of the engine may be very much smaller as compared to the present engines. For example, for comparabl power production, this engine will weigh one-fourth the weight of standard present engines.

Fifth, the engine design lends itself to the use of various fuels such as gasoline, diesel fuel and is even adaptable to the. use of steam.

Sixth, the engine can be air-cooled, in which case blades may be attached to the mainshaft to propel air through cooling fins.

Seventh, the cam plate design of this new engine permits increased travel for the lifter cam and thereby decreases the amount of spring pressure needed for valve closing and gives infinite variations in valve operation, including duration of lifts, etc.

Moreover, other advantages will become obvious upon detailed description of the invention. Brief Description of the Drawings

The description of the engine of this invention is -facilitated by reference to the drawings in which:

Fig. 1 is a side elevational cross-sectional view of a preferred modification of this engine taken at line 1-1 of Fig. 2;

Fig. 2 is a front elevational view, with several broken-away sections of the engine shown in Fig. 1;

Fig. 3 is a front elevational view of the cam lobe and cam drum as attached to the mainshaft;

Fig. 4 is a side elevational view of the cam lobe, cam drum and a portion of the mainshaft which are shown in Fig. ^• 3;

Fig. 5 is a schematic view in which the peripheral view of the cylinders, pistons, connecting rod, bearing and cam lobe has been flattened into a single plane;

Fig. 6 shows valve lifter wheels rolling on circular ridges on the cam plate;

Figs. 7a, 7b, 7c, 7d, 7e and 7f show side elevational views of the cam lobe and the positioning of the same pair of connecting rod bearings as they travel from a position adjacent to one high rise of the cam lobe in Fig. 7a to a low position in Fig. 7c and then adjacent to the opposite high rise as shown in Fig. 7f, during the course of half of a revolution of the mainshaft;

Fig. 8 is a schematic view showing a flattened peri¬ pheral two quadrent view of the cam lobe similar to Fig. 5 but having lines and dimensions illustrating a method of calculating or determining the shape of the sinusoidal curves;

Fig. 9 is another schematic view similar to that of Fig. 8 with dimensions different from those of Fig. 8;

-Fig. 10 is a side elevational cross-sectional view of a modification adapted for use as a compressor in which modification the sinusoidal surfaces are outer surfaces of the cam lobe;

Fig. 11 is a side elevational cross-sectional view of a modification adapted for use as a compressor in which modification the sinusoidal surfaces are the sides of a sinusoidal groove cut in the annular surface of the cam lobe; and

Fig. 12 is a side elevational view of a cam lobe showing a sinusoidal groove in its annular surface.

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Best Mode for Carrying Out The Invention

In Fig. 1, mainshaft 1 has attached to it cam drum 2 and to this cam drum 2 there is attached the cam lobe 3 wit the cam lobe having a high rise shown as 3' and a low section or opposite high rise shown as 3" . Pistons PA and PA' in cylinders A and A ¹ respectively are connected by connecting rod 4 and 5 which has attached bearing 6 which rotates on axle 7 and is made freely rotatable by ball bearings 8. Cam drum 2 has tapered circular ridges 9 and 9' on both of its plates 10 and 10' with periodic rises in these ridges. Grooved wheels 11 and 11' are part of the valve lifter and these ride on the ridges and are connected to push rods 12 and 12'. Push rods 12 and 12' press against and actuate rocker arms 13 and 13' . The rocker arms are supported by rods 14 and 14" which are screwed into the cylinder head 15. When a rise in ridge 9 (or 9') hits and pushes wheel 11 (or 11' ) outward, this movement also moves push rod 12 (or 12') outward against rocker arm 13 (or 13"). Outward movement of rocker arm 13 (or 13') pushes its opposite arm 16 (or 16') inward thereby opening valve 17 ^* (or 17') to allow passage through the intake valve opening.

Ridges 9 have the rises therein located in a position so that the opening movement of valve 17 is activated at the appropriate time for feeding fuel from opening 18 through the valve opening when intake valve 17 is in the opened position. The rise 9 is of sufficient length to hold the valve 17 in open position for the appropriate length of time in accordance with the operating cycle of the corresponding piston and cylinder. When the rise is terminated the valve is returned to its closed position by spring 19.

Ridges 9' have the rise therein positioned so that the opening movement of valve 17' is actuated at the appropriate time for exhausting gases from the cylinder through exhaust opening 18'. Again the length of the rise in ridge 9' is sufficient to keep the exhaust valve open for the appro¬ priate time. When the rise is terminated the valve is returned to its closed position by spring 19-' .

The engine block is preferably assembled from three separate castings 15, 15' and 15" and is extended into and supported by mounts 20. Cylinder blocks 31 and heads 15 may be individually fastened or bolted onto the engine block. Fig. 2 shows rocker cover 21 broken away and sections below shown for various inner level operations involving cylinders D, E, F and G. Cylinders A, B _: C and H are hidden by the rocker cover but their relative positions are shown by dotted circles. Mainshaft 1 is shown in cross-section. The broken section of the rocker cover above cylinder D shows cam lobe 3, cylinder head 15, cam drum 2, ridges 9 and 9' , intake lifter wheel 11, exhaust lifter wheel 11' , connecting rod 5 and roller bearing 6. Piston PE is shown in cylinder E and the exhaust push rod 12' and intake push rod 12 operating therewith.

The section showing the positioning of cylinder F has the rocker arms removed and shows sparkplug 22, intake valve 17, exhaust valve 17' , intake port 18, and exhaust oort 18'. With cylinder G tnere ar ^~ shown rocker arm shafts 14 and 14' and the forward portions of rocker arms 16 and 16'.

Figs. 3 and 4 show top and side elevational views respectively of cam drum 2 and cam lobe 3 with ridges 9 in the top and bottom surfaces of the cam plate and the high rise 3' and reverse rise 3" of cam lobe 3. In the cross-sectional view shown of a portion of cam drum 2, a rise in ridge 9 is shown to push lifter wheel 11 and push rod 12 upward thereby effecting opening of the intake valve (not shown) . At this position ridge 9 is at its normal level so that lifter wheel 11' and push rod 12' have not activated the corresponding valve so that the exhaust valve is in a closed position.

The schematic layout of Fig. 5 shows the relative positions of the various pistons at a particular instant. In this arrangement pistons A and E are at the top or crest of cam lobe rise 3' and pistons C and G ^! are at the top or

crest of reverse cam lobe rise 3". Each of these pistons is in a position for firing and as movement carries the bear¬ ings 6 off dead center of the cam lobe rises, the movement of the pistons, the connecting rods and the attached bear- ings will exert vector forces against the cam lobe and thereby cause rotation of the mainshaft.

It will be noted that two cylinders are firing simul¬ taneously, namely A and G' . At the same instant, cylinders B and H' are halfway through the firing cycle. Cylinders C and A' have completed their firing cycles and are ready to start their exhaust cycle, and cylinders E and C have finished their exhaust cycle and are ready to start the intake cycle, cylinders G and E' have finished their intake cycle and are ready to start the compression cycle. Cyl- inders H and B' are halfway through their compression cycles.

Fig. 7a shows the bearing 6 for piston PA positioned at the top of cam lobe rise 3" just off dead center and ready to start downward thereby exterting vector forces on the cam lobe which will cause mainshaft 1 to rotate. Bearing 6' ^" is under the cam lobe and has just completed its firing cycle travel for piston PA' and is starting its exhaust cycle. Fig. 7b shows bearing 6 and bearing 6' halfway down their paths with the cam lobe and mainshaft rotated part way. Fig. 7c shows the cam lobe and mainshaft rotated still farther and bearing 6 in its position at the end of the firing cycle for piston PA and bearing 6' is in its final -position for exhaust of cylinder A'. Fig. 7d shows bearing 6 starting its exhaust movement upward on the cam lobe and bearing 6' is also starting upward in its intake movement for cylinder A'. Fig. 7e shows bearing 6 and bearing 6' halfway in their upward movement for exhausting cylinder A and intake for cylinder A' respectively. Fig. 7f shows bearing 6 at the top of the opposite rise 3" for completing the exhaust movement of cylinder A and bearing 6' at the top of its intake cycle for completing the intake movement of

cylinder A' . Figs. 7a through Fig. 7f show the movement of bearings 6 and 6' for one-half revolution of the mainshaft. In subsequent movements (not shown) , bearing 6 goes through ■ positions for intake and compression of cylinder A taking bearing 6 back to the position of 7a for completion of the cycle and one complete revolution of the mainshaft. In subsequent movements (not shown) of bearing 6' , it goes through the compression and firing cycles of cylinder A' taking it also back to the position shown in Fig. 7a. While the drawings described above are directed to 8 pairs or 16 individual pistons and cylinders, the engine of this invention may also be operated with lower or higher numbers of pistons and cylinders. For example, four or six pairs may be used as well as ten or twelve pairs or even higher with appropriate arrangement and timing to effect smooth and efficient operation.

Fig. 8 illustrates a method of determining the sinu¬ soidal configuration of the cam lobe. In the top view of the cam lobe, cam drum and mainshaft shown in Fig. 3, the periphery of the cam lobe is shown to be circular. This- outer surface may be visualized as derived from a cylin¬ drical surface. For example, the outer peripheral surface of the lobe may be visualized as being part of a cylinder of sheet metal. If this sheet metal is flattened out into a planar surface, the configuration of the outer or peripheral surface of the lobe may be drawn on this flat piece of sheet metal or cut out from the sheet metal. Fig. 8 represents a manner of determining the dimensions and curvatures of the lobe peripheral surface on this flat piece of sheet metal. In order to design an appropriate cam lobe it is necessary to have certain information or dimensions pre¬ determined, such as the diameter of the bearings to be used on the cam lobe, the stroke of the piston (or the distance through which the bearings will be pushed by the piston) and possibly the thickness of the cam lobe at the rise or reverse rise of the lobe. The thickness of the cam lobe at this

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point may be limited substantially to the distance between the closest points of the two bearings that are in contact with the cam lobe and at opposite sides of the cam lobe, with a minimum amount allowed for clearance. In Fig. 8 bearing 6 is shown at various positions as it travels along the sinusoidal surface 24. On the opposite side of the cam lobe, bearing 6' is shown at various posi¬ tions as it travels along the sinusoidal surface 24'. In this drawing, the dimensions of the bearings, etc. are of actual size with the bearing diameters being 1.500 inches, the thickness of the lobe at its thickest point, or the distance between the closest points, bearings 6 and 6' being 1.000 inch and the stroke being 1.500 inches.

Where the bearings 6 and 6' are in contact with the rises and reverse rises of the sinusoidal surfaces 24 and 24' , center lines are drawn through the centers of the bearings 6 and 6' and extended above and below the bearings. The "roll separation" is the distance from the center of bearing 6 to the center of bearing 6' , which is equivalent to the bearing diameter plus the web (W) which is the thickness of the lobe at its thickest part. This roll separation distance (R) is measured on the center line running through bearing 6 from point 25 downward to point 26. The roll separation distance is also measured on the respective center lines running upward from the two 4' bear¬ ings, in each case from point 25' to point 26'. "Inner -face" radial lines 27 are drawn from point 26 to each of the points 25', which inner face radial lines form an angle of 45° with the respective vertical center lines. Likewise, inner radial lines 27' are also drawn from point 25 to point 26' respectively.

Using point 26 as the center and using the distance R ^• _- S as the radius, an arc is drawn from one line 27 to the other line 27. This gives the inner face line 29 of the cam lobe. Also using each point 26' as the center and the

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radius R + S, other arcs are drawn from one line 27' to the adjacent line 27' (only partly shown). This gives the inner face lines 29' .

Using point 25 as the center and a radius equal to the sum of the- stroke and the web (S+W) , an arc is drawn from one inner face radial line 27 to the other line 27. This arc gives the outer face line 30. Likewise, using each point 25' as a center and a radius equal to S + W, other arcs are drawn from one line 27 to the adjacent line 27 (only partly shown). These arcs give outer face lines 30'.

Fig. 8 illustrates a design in which the stroke (S) is 1.500 inches, the web (W) is 1.000 inches, bearing diameter is 1.500 inches and the roll separation (R) is 2.500 inches.

Fig. 9 represents a design in which the stroke is 1.500 inches, the web is 0.500, the bearing diameter is 0.750 inches and the roll separation is 1.250 inches. The method described for Fig. 8 is used for determining the sinusoidal curves for the cam lobe.

When the flattened surface is wrapped around the main- shaft and cam drum to form the cylindrical peripheral surface of the cam lobe, each point on the sinusoidal curves determined above as described may have a line drawn to and perpendicular to the center linear axis of the mainshaft and cam drum. This series of lines will determine the curved sinusoidal surface of the cam lobe.

While the above methods for designing the sinusoidal surfaces of the cam lobe are preferred to give the ideal dimensions for purposes of this invention, it is possible to vary somewhat from the exact dimensions determined by these methods. These variations may have some small effect on the smoothness and efficiency of operation but will still give effective operation according to the principles of the •invention. The primary requirement is that there is always one bearing of a pair in contact with one of the cam lobe surfaces. The other bearing of the pair may be in contact with the opposite cam lobe surface but preferably may have a

clearance of about 0.002 inch or more. When there is ^' a variation from the ideal design described above, there may be considerably less thickness in the cam lobe between rise and reverse rise, in which case there will be more clearanc of the second bearing during its non-contacting movement. When the two opposing bearings reach a rise or a reverse rise, there will be a changeover in the contact of the bearings. For example, the bearing in contact with the lobe surface as it moves down from the top of the rise to the dip or reverse rise after passing the thickest part of the lobe, becomes the bearing out of contact with the lobe surface, depending on the clearance, and the other bearing becomes the one in contact with the lobe surface until the next rise is reached. While it is preferred that there is at least about 0.002 inch clearance for the non-contacting bearing, it is possible with an ideally designed lobe that both bearings are in contact with the adjacent lobe surface

In both Figs. 8 and 9 the center line passing through points ^" 25 and 26 is identified as 0°. The center line at the bottom of the drawings passing through points 25' and 26' is identified as 90° and represents the first quadrant on the circumference of the lobe, and the center line at th top of the drawings passing through points 25' and 26' is identified as 270° and represents the third quadrant in the circumference.

Another method for determining a preferred design of the cam lobe is developed as follows. Figs. 8 and 9 show a center line running horizontally through the centers of the two bearings 6 and 6' which are positioned left and right o the lobe at the rise shown in the center of those figures. Point 32 is the contact point of this bearing 6' with the lobe at the right of the rise. W is the thickness of the web measured at this rise. S is the distance or length of the piston stroke and when measured to the left from the point of contact of bearing 6 with the inside of the lobe.

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it reaches to point 25 on the horizontal center line. R is the roll separation distance and is the distance between the centers of bearings 6 and 6' . R is equivalent to the sum of the web thickness W plus the bearing diameter. This roll separation distance R is measured on the horizontal center line left from point 25 to point 26.

A vertical line is drawn through point 32, which line makes a 90° angle with the horizontal center line passing through points 25 and 26. The distance between points 32 and 26 is the sum of W + S + R. Line 27 is the hypotenuse of the triangle formed between points 25', 26 and 32. Line 27 equals R + 2S + W. The cosine of the angle at point 26 is equal to the length of the line from 32 to 26 divided by the length of the line from point 26 to point 25'. There- fore the cosine of this angle is (R+S+W)/(R+2S+W) . By substituting values for R, S and W in this formula, the value of the cosine can be calculated and from a table of cosine values the angle at 26 can be determined. The corresponding angle can be used to draw line 27 and where line 27 intersects the vertical line passing through point 32, this will establish the exact location of point 25'.

Alternatively, once the value of the angle at point 25 is determined, the value of the sine of this angle may be obtained from a table for sine values and the distance from point 32 to 25' may be calculated from the equation: sine equals (distance of 32 to 25' )/(R+2S+W) . Then the calcu¬ lated distance can be measured off from point 32 to deter¬ mine the exact location of point 25' . The horizontal center line through point 25' is drawn at a 90° angle to the vertical line through 32 and 25' .

The sinusoidal curve line passing through the centers of the various positions shown for bearing 6 is identical to and parallel to the sinusoidal curve passing through the centers of the various positions shown for bearing 6'. Both of these sinusoidal curves are identical to and parallel to

the sinusoidal center line 33 of the cam lobe.

In Figs. 8 and 9, a line from the center of the bearin 6 which is on the center line passing through points 25' and 26' to the center of bearing 6' positioned to the right of the reverse rise (that is the bearing 6' on the center line passing through points 25 and 26) , should pass through the center line of the lobe at the lobe's smallest thickness and should make an angle of 45° or less with the center line passing through 25 and 26 and with the center line passing through 25' and 26'*.

In Figs. 8 and 9, using the center line passing through points 25' and 26' at both the top and bottom of the draw¬ ings, the left curve of the web is determined by using points 25' as the. center and S + W as the radius to draw the center arc of the rise. Then point 26' is used as the center and R + S as the radius to draw the arc which is the inside curve of the rise. Likewise, using ^" the center line passing through points 25 and 26, point 25 is used as the center and S + W as the radius to draw the outer (right) arc of the reverse rise, and point 26 is used as the center and R + S as the radius to draw the inner (left) arc of the reverse rise.

The distance from the center of the mainshaft to the contact points of the bearings on the lobe is calculated as four times the distance between points 32 and 25', which gives the circumference of the circle of contact points on the lobe. The circumference is equal to 2πR and from the value determined above for the circumference, R equals the value of the circumference divided by 2ττ. As a practical matter the circumference may be calculated by multiplying the number of cylinders by the bore of the cylinder plus the space between two cylinders to accommodate cooling. From this circumference, the radius may be calculated as des¬ cribed above.

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Obviously the farther the contact points are from the axis of the mainshaft, the greater will be the leverage for ^' turning the mainshaft. Since the cam lobe needs to be only wide enough to permit contact of the bearings with it, the cam drum may be big enough to occupy most of the space between the mainshaft and the bearing contact area on the cam lobe.

While the above methods for designing the sinusoidal surface of the cam lobe are preferred to give the ideal dimensions for purposes of this invention, it- is possible to vary somewhat from the exact dimensions determined by these methods. These variations may have some small effect on the smoothness and efficiency of operation, but will still give effective operation according to the principles of this invention. The primary requirement is that there is always one bearing of a pair in contact with one of the cam lobe surfaces. The other bearing of the pair may be in contact with the opposite ^" cam lobe surface but preferably may have a clearance of about 0.002 inch or more. When there is a variation from the ideal design described above there may be consideraly less thickness in the cam lobe between rise and reverse rise, in which case there will be more clearance of the second bearing during its non-contacting movement. When the two opposing bearings reach a rise or a reverse rise, there will be a changeover in the contact of the bearings. For example, the bearing in contact with the lobe surface as it moves down from the top of the rise to the dip or reverse rise after passing the thickest part of the lobe becomes the bearing out of contact with the lobe surface, depending on the clearance, and the other bearing becomes the one in contact with the lobe surface until the next rise is reached. While it is preferred that there is at least about 0.002 inch clearance for the non-contacting bearing, it is possible with an ideally designed lobe that both bearings are in contact with the adjacent lobe surfaces. As indicated above the engine of this invention may be

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designed for 4-cycle operation with 6, 8, 10, 12, 16 or mor cylinders to give smoother and more efficient operation and ^' more power than with conventional engines. In 4-cycle operation the firing exhaust, intake and compression are performed on separate strokes. In 2-cycle operation, the firing and exhaust are performed on one stroke, and the intake and compression are performed with a second stroke. With 2-cycle operation, the engine of this invention may be designed with 4 cylinders, that is with two pairs of oppo- sing cylinders and pistons. Such small engines may be used on motorcycles, bikes, etc.

It is also possible to adapt the engine of this inven¬ tion with certain modifications for use as a compressor. Thus if an external power source is used to drive the mainshaft, air or other gas may be taken into the cylinders compressed and exhausted under pressure. If desired, two engines of this type may be joined on the same mainshaft, with one engine providing the power to drive the mainshaft and the other to perform as a compressor. Moreover, an ^* engine of this invention may be used to drive the shaft of generator to provide electrical current.

In using one engine of this type as a compressor and another of these engines to deliver power to the compressor, the two mainshafts of these engines would be coupled with a clutch or another type of power source may be used to drive the mainshaft of the compressor engine. Poppet valves, spring operated or otherwise, may be used to deliver com¬ pressed air to the receiving line or reservoir.

Fig. 10 shows a modification in which the engine of this invention has been adapted to serve as a compressor. The various elements are as described above except that cylinder head 15 and various fittings and attachments are replaced by cylinder head 38 which has threaded openings into which intake valve 36 and outlet valve 37 are fitted s as to connect with the interior of cylinder A or A' . Mains 1 is driven as described below, while rotatably supported o

bearings 41, whereupon cam lobe 2 is rotated and thereby the sinusoidal surfaces press against the bearings 6. This produces a forward and backward motion of connecting rods 4 and 5 and therewith movement of pistons PA and PA' . Such movement of the pistons draws air or other gas into inlet valves 36 and then upon reversal of direction of the piston intake valve 36 closes and air under compression is forced out of outlet valve 37. Springs 39 serve to keep valves 36 and 37 closed until sufficient differential pressure is applied to open the respective valves.

In operating this engine as a compressor, either some or all of the cylinders may be equipped or designed as shown in Fig. 10. If all of the cylinders are so operated, then an external or separate driving force may be used to rotate the mainshaft 1. In such case another engine such as shown in the earlier figures may be used to drive the mainshaft or another type of internal combustion engine, electric motor, etc. may be used for this purpose.

Another alternative is to have some of the cylinders equipped to operate as a power engine as described above and the remaining cylinders equipped and operated to serve as a compressor. In such case, the two pistons attached to a particular piston rod can both serve the same function, namely either to supply driving force to the mainshaft or to serve as a compressor, or one can serve to deliver driving force while the other functions as a compressor. In either case, the pistons serving one function are staggered with those serving the other function so as to supply an even, uniform compressive force. Fig. 11 shows a design in which the sinusoidal surfaces are the side surfaces of a groove 40 cut into the annular -surface of the cam lobe as shown in Fig. 12. In Fig. 11 there is only one bearing 6 attached to each piston rod in contrast to the two shown in Figs. 1 and 10. Moreover the

width of the groove is substantially equal to the diameter of this bearing with a-small tolerance to allow rotation of the bearing while in contact with only one of the sinusoida surfaces during a particular period. Furthermore the groov may be completely surrounded by cam lobe portion throughout or may be open at the rises and reverse-rises as shown in Figs. 11 and 12.

The -operation of the engine with the groove shown in Figs. 11 and 12, either to deliver power or to produce gas compression is substantially the same as described above with respect to the design in which the sinusoidal surfaces are outer surfaces of the cam lobe. In both cases, however, the cam lobe surfaces with which the bearing or bearings are in contact are at a substantial distance from the linear axis of the mainshaft as compared with the distance from this linear axis to the annular surface of the mainshaft. The ratio of these distances is at least 2:1, and preferably at least 3:1.

A particular advantage of the engine of this invention is the simplicity of engine manufacture and assembly. F.or example, the engine block may be assembled from three separate castings 15' , 15' and 15" bolted together and the individual cylinder heads 15 may be bolted onto the engine •block. This bolting arrangement of the engine block and cylinder heads facilitates and makes less expensive the manufacture, assembly and repair of the engine or any part of it.

Moreover, cast aluminum may be used for the engine block, cylinder heads and pistons, thereby contributing to a considerable decrease in wieght. These factors, together with the smaller size, give a tremendous advantage in weight compared to conventional engines. For example, an 8-cyl- inder engine of this new design will weigh about 90 lbs. compared to a weight of about 325 lbs. for a standard conventional engine of equivalent power output.

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With an engine of this new design having 16-cylinders, the displacement will be doubled, giving only a 20% increase in size and weight with about a 100% increase in power output compared with a corresponding 8-cylinder engine. In a 402 cubic inch V-8 conventional engine the bore is 4.00" and the stroke is 4.00" which equals 2.00" of leverage from the. center line of the crankshaft to the center line of the connecting rod. This gives 6.283" travel at 180° revolution of the crankshaft. The V-8 engine has a 2/1 ratio crankshaft to cam shaft. One revolution of the crankshaft completes two cycles which means four cylinders fire per revolution. Thus the crankshaft uses 180° of rotation with 4.00" of stroke each cycle and 2.00" of leverage. In contrast, a rotary piston engine of this new design having a 4.00" bore .and 4.00" stroke has 5.55" of leverage or 5.55/2 or 2.775 times that of the V-8 engine. With the V-8 engine 180° travel gives a distance of 6.283" whereas the rotary piston engine with 180° travel gives a distance of 17.436 or 2.755 times that of the V-8 engine. By com¬ bining the leverage and distance factors, the rotary engine has 2.775 x 2.755 or 7.645/1 advantage over the V-8 engine.

It is estimated that a 400 cubic inch displacement engine of this new design will give at least 50 miles per gallon of gasoline in comparison to approximately 14 miles per gallon presently obtained by conventional 400 cubic inch displacement engines. Therefore, this new engine has an almost 4/1 advantage in economy and power for similar displacement in conventional automobile engines. While the arrangement of the cam drum with respect to the cam lobe and the mainshaft as shown in the drawings and as described above is preferred and is considered more practical and efficient, it is also contemplated that the cam drum may be omitted from its intermediate position between the mainshaft and the cam lobe. If desired, one or

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more cam drums may be attached to the mainshaft in a differe location to provide harmonic balance and to provide support for the cam plates to be attached to the ends thereof, on which cam plates the ridge risers may be located for actua- ting the valve lifters for the intake and exhaust operations Moreover, it is contemplated that the cam plates on which the said valve lifter actuating ridge risers are located may be plates or discs separated from the cam drum but still concentric with and attached to the mainshaft. Furthermore, the cam plates may actually be discs bolted, welded or otherwise fastened to the ends of the cam drum thereby facilitating flexibility in the design, replacement and location of the valve lifter ridge risers.

Nevertheless the design shown in the drawings whereby the cam drum is intermediate between the cam lobe and the mainshaft is preferred since this location requires less space on the mainshaft and provides flywheel action and harmonic balance. Mόreoever, the cam drum may be solid or partially hollow in accordance with its size and its desired effect.

In some cases where reference is made herein to sinu¬ soidal surfaces, they may only be substantially sinusoidal and not true sinusoidal. For example in Figs. 7a-7b, the centerline of the cam lobe is a true sinusoid but since the thickness of the cam lobe varies, the surfaces will vary from a true sinusoid.

Also, in the modification shown in Fig. 11, the shaft supporting bearing 6' may be extended to support a counter¬ rotation bearing (not shown) to prevent twisting. This counterrotation bearing will fit in a groove running paralle to the axis of piston rod 4,5.

While certain features of this invention have been described in detail with respect to various embodiments thereof, it will of course be apparent that other modificati can be made within the spirit and scope of this invention, and it is not intended to limit the invention to the exact details shown above except insofar as they are defined in the following claims.

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