US3318294A - Two-cycle pressure charged engine - Google Patents

Description

5 Sheets-Sheet 1 Filed April 12, 1965 5 Sheets-Sheet 2 Filed April l2, 1965 NEU/d! BY J INVENTOI; Harris.

May 9, 1967 G, HARR|5 3,318,294

TWO-CYCLE PRESSURE CHARGED ENGINE Filed April l2, 1965 5 Sheets-Sheet 3 INVENTogL /7 Fuz/s'.

United States Patent Oflice 3,318,294 Patented May 9, 1967 3,318,294 TWO-CYCLE PRESSURE CHARGED ENGINE Gerald Harris, S015 Agnes, Detroit, Mich. 48214 Filed Apr. 12, 1965, Ser. No. 447,301 6 claims. (Cl. 12s- 61) This invention relates to auto cycle engines, rand particularly to an auto cycle engine of the two cycle type.

Heretofore it has been the practice in the art of two cycle engines to charge the cylinder at the bottom of the stroke and to compress and re the charge at the top thereof each reciprocation of the piston. To accomplish this, the charge was drawn into the crankcase and fed to the cylinder at the bott-om of the stroke at the time the burnt gases were being ejected from the cylinder on the opposite side from the charge intake. The gasoline employed for operating the engine was mixed with oil in a predetermined proportion to provide lubrication for the bearings, rings, piston, and the like.

In practicing the present invention, all of the beneficial features of the two cycle engines are maintained while the charge is -premixed and supplied under pressure to the cylinder near the bottom of the piston stroke. With this arrangement, an undiluted oil lubricating system is used for lubricating the bearings. In the example herein illustrated, a double-acting piston is employed each end of which compresses a charge each time it reaches the ends of the cylinder `and the compressed charge is immediately fired. The piston is moved in the opposite direction while operating a crankshaft and a charge is compressed at the opposite end of the cylinder and fired. The center of the piston is connected substantially to the center of a rocker arm, one end of which is pivoted to the engine frame, the opposite end of which is connected by a pin to one end of a connecting rod, the opposite end of which contains a bearing connected to the crank of the crankshaft. The rocker bar is extended and connected to a rod of a doubleacting piston in a cylinder which draws in charges from a carburetor in timed relation to the operation of the engine piston. The charges are delivered under pressure to opposite ends of the engine cylinder when the ends of the engine piston are retracted from the ends of the cylinder. In this manner, a -controlled mixture of :air and fuel, such as gasoline, is drawn from the carburetor into the secondary cylinder and alternately forced into passageways and delivered to opposite ends of the engine cylinder. This compressed fuel moves into a cylinder end when the intake apertures are uncovered as the ends of the engine piston approaches the end of its movement to the opposite end of the engine cylinder. The rocker bar operates the double-acting 4piston of the secondary cylinder to draw in charges from the carburetor and deliver them under pressure to opposite ends of the engine cylinders in timed relation to the movement of the engine piston therein.

The engine has the usual counterbalance crankshaft, a magneto and ywheel, a 4lubricating and electric system of conventional form which is not illustrated and described herein.

Accordingly, the main objects of the invention are: to provide a two cycle engine with a double-acting piston for compressing a charge of fuel from a carburetor which is delivered under pressure to the opposite ends of the engine cylinder; to employ a double-ended piston in a cyl inder connected to a rocker bar which is pivoted at one end rand joined by connecting rods to the crankshaft at the other end and to a double-acting piston which draws in charges of fuel and delivers them under pressure to opposite ends of the engine cylinder; to construct an engine with a cylinder having a double-acting piston and an oscillatable rocking bar which is pivoted at one end and joined to a connecting rod at the other end which end has an extension for operating a double-acting auxiliary piston for preparing and delivering charge-s of fuel under pressure to opposite ends of the engine cylinder, and in general, to employ a double-acting piston to deliver pressurized fuel charges from a carburetor to opposite ends of an engine cylinder Iwhich is simple in construction, positive in operation and economical of manufacture.

Other objects and features of novelty of the invention will be specically pointed out or wil-l become apparent when referring, for a better understanding of the invention, to the following description taken in conjunction with the accompanying drawings, wherein:

FIGURE 1 is a sectional View of a double-acting two cycle engine embodying features of the present invention;

FIG. 2 is a sectional view of the structure illustrated in FIG. 1, taken on the line 2 2 thereof;

FIG. 3 is `a broken sectional view of the structure illustrated in FIG. l, taken on the line 3 3 thereof;

FIG. 4 is a broken sectional view of the structure illustrated in FIG. 3, taken on the line 4 4 thereof;

FIG. 5 is a broken sectional view of the structure illustrated in FIG. 1, taken ion the line 5 5 thereof;

FIG. 6 is a broken sectional view of the structure illustrated in FIG. 5, taken on the line 6 6 thereof;

FIG. 7 is a plan View of the bushing illustrated in FIG. 6;

FIG. 8 is a perspective view of the wrist pin shown in section in FIG. S, and

FIG. 9 is a sectional view of an engine similar to that illustrated in FIG. 1, showing a yfurther form which the invention may assume.

Referring to FIGS. 1 to 8 of the drawings, a crankcase housing 10 has a portion 11 containing the lupper section 12 of an engine cylinder 13 with a cover portion 14 containing the upper section 15 of the engine cylinder. An arcuate end capl 16 encloses the bottom area traversed by a crank portion 17 of the crankshaft 18. The engine cylinder sections 12 and 15 are in aligne-d relation and enclose a double-acting piston 21 which reciprocates therewithin from one to the other end thereof. The opposite ends of the piston are of conventional form having sealing and wiping rings 22 thereon with a central baffle 23 on the heads ends.

The central portion of piston 21 has diametrically disposed longitudinally arranged slots 24 and diametrically aligned bosses 25 containing apertures 26 in which bushings 27 are press iitted, as illustrated in FIG. 5. The bushings contain a through slot 28 in which the flat end portions 29 and a wrist pin 31 extend for movement laterally within the slots. A central cylindrical portion 32 of the wrist pin 31 engages a bearing 33 of a rocker bar 34, the one extending end 35 having a sleeve bearing 36 which rocks upon -a fixed pivot 37. The opposite end 38 of the rocker bar 34 has a -blfurcated end 39 containing cylindrical bushings 41. A connecting rod 42 has a cylindrical end 40 disposed between the bifurcated ends 39 of the rocker bar 34 containing a bushing 41 and joined to the bifurcated end 39 by Va bearing pin 43. The opposite end of the connecting rod 42 has a bearing shell 44 upwardly and downwardly Iapplying a force to the connecting rod 42 `and the crankshaft 18 to thereby change the movement in reciprocation to one of rotation. With this arrangement, a force is applied by the piston 21 both downwardly and upwardly through the connecting lrod 42 to the throw 17 'of the crankshaft 18. Normally, the `connecting rod 42 appliesa force only in one direction when a single-acting piston of the conventional form is employed. y

The end 35 of 'the rocker bar 34 has an extending arm 51 containing a cylindrical end 52 located beyond the fixed pin 37.' The casting extension 53 at the lower end of the cylinder 12 has a cylinder 54 in threaded relation therewithY The casting 53 has .a portion 61 from which a tubular section 55 extends from the upper portion of the cylinder 54 to the upper portion 15 of the engine cylinder communicating therewith through apertures 56 in the cylinder wall as more clearly illustrated in FIG. 2.

The passageway 53 at the bottom of the cylinder 54 communicates kthrough apertures 56 to the bottom of the lower cylindrical section 12.' The apertures 56 are closed by the piston in its downward travel, as illustrated in the lower portion of the cylindrical section 12 of FIG. 1. At the same time, the apertures 56 at the top of the cylinder are open to permit a fuel charge to pass within the upper cylinder end. The reverse is true when the piston moves upwardly, the apertures 56 are closed and the apertures 56 are open to permit a pressurized fuel charge to move into the bottom end of the cylinder.

As illustrated in FIG. 3, the casting portion 61 between the casting sections 53 and 55 has a passageway 62 communicating through an opening 63 to the area below a piston 64 which'is reciprocated between the bottom and top of the cylinder 54. The passageway 61 is in communication withl the passageway 53 and the apertures 56 Lnear the bottomof the cylinder section 12. Reed valves 65 cover openings 66 in a carburetor` manifold 67 which is connected to an outlet 68 of a carburetor (not shown). Suction through the opening 63and passageway 62 produced by the upward movement of the piston 64, opens the reed valves 65 and draws in a charge of fuelffrom the manifold 67 and carburetor 68. Upon the downward movement of the piston 64 the fuel charge is delivered from passageways 62 and 63 through the passageway 53 to the apertures 56 near the bottom of the, cylindrical portion 24.

A passageway 69 is provided at the top of the casting 61 communicating through a passageway 71 to the upper n part of the cylinder 54 above the piston 64 and to the passageway 55 which communicates with the apertures 56 near the top of the cylinder section 15. A pair of reed valves 72 covers opening 73 between the passageway 69 and the manifold 67. The valves 72 are open on the downward movement of the piston 64 which sucks in a fuel charge from the carburetor 68 into the passageways 69, 71 from which it passes into the passageway 55 and through the apertures 56 into the end of the cylinder section 15.

The passageways 62 and 69 Vcommunicate with the passageways 53 and 55 and after a charge is sucked into the top or bottom of the cylinder 54 the reverse movement of the piston 64 will compress the charge, close the associated reed valves 65 or 72 land advance the charge under pressure to the passageways 53 and 55. These pressurized charges pass into the ends of the engine cylinder 13 when the openings 56 or 56 are uncovered. At the same time the burnt fuel is discharged from the same end of the cylinder 13 through the openings 70 which are diametrically disposed relative to the intake apertures 56 and 56'. The baffle 23 on the piston ends reduces the intermingling of the incoming charge with the outgoing burnt gases. The charge is initially under pressure and is compressed by the movement of the engine piston to the ends of the cylinder and is fired by the spark from the plugs 74 located thereat. The spark is controlled by a distributor on the magneto carried by the flywheel S2 attached to the crankshaft 18 in the conventional manner. It will be noted in FIG. l that the crankshaft throw 17 is counterbalanced by an oppositely extending weighted portions 75 which is conventionally provided.

The piston 64 has a piston rod 76 extending therefrom with bifurcated cylinder ends 75 `alined with the cylindrical end 52 of the arm 51 of the rocker bar 34. A cylindrical bushing is provided in the cylindrical end 52 of the arm 51 and bushings 78, similar to bushing 27, are press fitted within the bifurcated cylindrical ends 75 of the piston rod 76. A wrist pin 79, which is similar to the Wrist pin 31, is journaled Within the bushing in the arm 51 with the flat ends extending into the rectangular slots in the bushing 78.

Since the pins 31 and 79 operate in arcuate paths about the fixed pin 37, the change in radial position is permitted by the sliding of the at ends 29 in the slots 28 provided in the bushings-27 and 78.

As illustrated more specically in FIG. 4, the reed valve 72 is limited in its opening movement by the arcu= ate stop element 81. The flywheel 82, along with the magneto, distributor and breaker points are carried on the extension 83 of the crankshaft 18 enclosed by a cover plate 84. The piston 64 is placed within the cylinder 54 with the piston rod 76 extending through an aperture 80 in a plate 86 which contains a threaded shoulder 87 which is threaded onto the cylinder 54. The plate 86 is bolted to the casting 61 and to the top casting portion 14.

In operation, the compressed charge in the lower cylinder section 12 is red by the spark from the spark plug 74 controlled by the opening and closing of the breaker points within the cover plate 84. The piston is driven -upwardly and compresses the charge of gas delivered to the end of the cylinder section 15 through the apertures 56. Near the upper end of the piston stroke, the spark plug fires the compressed charge which drives the piston downwardly. Upon reaching the upper end of the stroke, the apertures 70 in the cylinder section 12 are uncovered to permit the burnt gas to escape and a charge of fresh gas under pressure lmoves in the cylinder section 12 through the `apertures 56'. This charge will be compressed by the downward movement of the piston 21 caused by the explosion of the gas in the end of the cylinder section 15. The movement of the engine piston 21 in reciprocation rocks the bar 34 on they pin 37 and reciprocates the connecting rod 42 to rotate the crank 17 and the crankshaft 18. The piston 21 produces a force in each direction of oscillation of the bar 34 and the reciprocation of the connecting rod 42. The piston 76 is reciprocated by each oscillation of the bar 34 by the extending arm 51 thereof to draw a charge of gas alternately into the passageways 62 and 69 from the carburetor manifold 67. The charges are pressurized and moved into one or the other passageways 53 and 55 in position to pass within one or the other ends of the cylinder 13 when the apertures 56 and 56 are uncovered. During the strokes of the piston 64, the reed valves 65 and 72 will be closed by the compressive force preventing the charge drawn into passageways 53 and 55 from being moved back into the carburetor manifold 67. In this manner, a precise charge of air and fuel mixture from the carburetor passageway 68 pressurized a predetermined amount and retained in one or the other passageways 53 or 55 until the apertures 56 and 56 to the cylinder 13 are uncovered by the piston 21permitting the pressurized fuel charge to move rapidly into the cylinder. This provides a predetermined charge of gas which Will be compressed by the piston 21 after closing the apertures 56 or 56 upon moving to the end of the cylinder. The firing of the compressed charges at opposite ends of the cylinder produces the reciprocation of the piston 21 with a force in both directions. It will be noted that a water jacket 88 is provided around the end sections of the cylinder 13 in the conventional manner for maintaining the cylinder and piston cool during the engine operation.

Referring to FIG. 9, a further form of engine is illustrated, that which is similar to the engine above described but which has a rocking bar 91 secured to a fixed pivot 92 between the ends thereof. The one end is secured by the pin 31 to the piston having the flattened ends 29 extending into the slots 28 in the bushing 27 while the opposite end has a connecting rod 93 secured thereto on a pin 94. The connecting rod has its opposite ends joined to a crank throw 95 of a connecting rod 96. The operation of the piston 21 in reciprocating in the manner pointed out hereinabove, produces the rocking of the arm 91 in a positive manner in both directions and reciprocates the connecting rod 93 thereby revolves the crank throw 95 and rotates the crankshaft 96. An arm 97 on the rocker bar 91 is connected by an oscillatable pin 98 which is similar to the pin 31 to an aperture in a cylindrical end 99 of a piston rod 101 which is connected to a piston 102. The flat ends 29 of the pin 98 oscillate within the slot in the spaced bushings similar to the bushings 27 of FIG. 7. The piston 102 reciprocates within a cylinder 103 drawing in a charge through reed valves (not shown) from a carburetor in one direction of movement while pressurizing the fuel charge drawn into the cylinder 103 on the opposite side of the piston. The reverse movement of the piston 102 pressurizes the drawn in charge and moves it into a passageway to be delivered into the opposite end of the cylinders. In the figure, a manifold 104 communicates with an opening 105 at one end of the cylinder 103 and with the apertures 56 at the top end of an engine cylinder 106. A manifold 107 connects the passageway 108 at the rod end of the cylinder 103 to the apertures 56 at the lower end of the cylinder 106. The piston 103 is guided in a sleeve 109 at the central part of an apertured plate 111, which is attached to the crankcase casting 112 by a plurality of screws 113. The cylinder 106 is provided with a plurality of fins 114 by which the cylinder and the piston are air cooled in the conventional manner.

The engine operates in the same manner as that described above in relation to the structure illustrated in FIGS. l to 8, the difference between the two structures resides in the rocking arms 34 and 91. In the former an arm 51 is employed in extension of one end thereof and the fixed pin 37 is remote from the pins 31 and 43. In the structure of FIG. 9, the fixed pin 91 is medially disposed between the pins 31 and 94, and the arm 97 for operating the piston 102 is located between the pins 92 and 94.

What is claimed is:

1. In a reciprocating engine a cylinder having inlet and outlet ports at each end and diametrically disposed slots through the cylinder wall between the ends thereof, a double-acting piston within said cylinder reciprocable between the ends thereof, a rocker bar pivoted to the piston near the central portion thereof and extending through the slots in the cylinder wall, means for xedly pivoting the rocker bar to the engine on one side of said cylinder, and an extension on said rocker bar on the other side of said cylinder pivoted to a connecting rod which operates the crank of a crankshaft.

2. In a reciprocating engine a cylinder having inlet and outlet ports at each end and diametrically disposed slots through the cylinder wall between the ends thereof, a double-acting piston within said cylinder reciprocable between the ends thereof, a rocker bar pivoted to the piston near the central portion thereof and extending through the slots in the cylinder wall, means for xedly pivoting the rocker bar to the engine on one side of said cylinder, and 4an extension on said rocker bar on the other side of said cylinder pivoted to a connecting rod which operates the crank of a crankshaft, the pivot connecting the rocker bar to the piston being rotatable on the rocker bar and slidable in the piston.

3. In a reciprocating engine a cylinder having inlet and outlet ports at each end and diarnetrically disposed slots through the cylinder wall between the ends thereof, a double-acting piston within said cylinder reciprocable between the ends thereof, a rocker'bar pivoted to the piston near the centr-al portion thereof and extending through the slots in the cylinder wall, means for xedly pivoting the rocker bar to the engine on one side of said cylinder, and an extension on said rocker bar on the other side of said cylinder pivoted to a connecting rod which operates the crank of a crankshaft, the pivot connecting the rocker bar to the piston being rotatable on the rocker bar l`and slidable in the piston, a second extension on thel rocking bar connected to a second piston within a second cylinder, and passagew-ays from the second cylinder on opposite sides of the second piston to the intake ports at opposite end of the engine cylinder.

4. In a reciprocating engine a cylinder having inlet and outlet ports at each end and diametrically disposed slots through the cylinder wall between the ends thereof, a double-acting piston within said cylinder reciprocable between the ends thereof, a rocker bar pivoted to the piston near the central portion thereof and extending through the slots in the cylinder wall, means for xedly pivoting the rocker bar to the engine on one side of said cylinder, and an extension on said rocker bar on the other side of said cylinder pivoted to a connecting rod which operates the crank of a crankshaft, the pivot connecting the rocker bar to the piston being rotatable on the rocker bar and slidable in the piston, a second extension on the rocking bar connected to a second piston within a second cylinder, and passageways from the second cylinder on opposite sides of the second piston to the intake ports at opposite end of the engine cylinder, a carburetor communicating with said second cylinder, and valve means between said carburetor and said passageways which are operated by the movement of the second piston in said second cylinder when drawing in a fuel charge from the carburetor and delivering it into the passageways.

5. -In an autocycle engine having a casting containing a double-ended cylinder, having inlet and outlet ports at opposite ends thereof, a double-acting piston within the cylinder reciprocable from one to the other end thereof, a rocker bar pivoted to the piston and extending through diametrical slots in the cylinder walls, means for pivoting the bar on a fixed pivot secured to the casting, means pivotally connecting the rocker bar to a connecting rod which is joined to -a throw of the crankshaft, -an auxiliary cylinder having a piston therein and a rod extending therefrom, an extension on said rocker bar connected to the rod of said auxiliary cylinder, said casting having passage- Ways from the auxiliary cylinder to said inlet ports, a manifold from a carburetor communicating with said auxiliary cylinder, and valve means between the manifold and passageways to the inlet ports which are opened and closed by the movement of the piston in the auxiliary cylinder.

6. In an autocycle engine having a casting containing a double-ended cylinder, having inlet and outlet ports at opposite ends thereof, a double-acting piston within the cylinder reciprocable from one to the other end thereof, a rocker bar pivoted to the piston and extending through diametrical slots in the cylinder walls, means for pivoting the bar on a xed pivot secured to the casting, means pivotally connecting the rocker bar to a connecting rod which is joined to a throw of the crankshaft, an auxiliary cylinder having a piston therein and a rod extending therefrom, an extension on said rocker bar connected to the rod of said auxiliary cylinder, said casting having passageways from the auxiliary cylinder to said inlet ports, a manifold from a carburetor communicating with said vauxiliary cylinder, valve means between the manifold and passageways to the inlet ports which are opened and closed by the movement of the piston in the auxiliary cylinder, and slidable ljoints provided in the pivoted connection with the rocker bar other than the xed pivot and that to the connecting rod.

References Cited by the Examiner UNITED STATES PATENTS Kulage 1213-61 Hornor 123-61 Dulche 12S-56 St-ickney 123-197 X Langrognet 123-197 MARK NEWMAN, Primary Examiner. 10 WENDELL E. BURNS, Examiner.

Claims (1)

1. 5. IN AN AUTOCYCLE ENGINE HAVING A CASTING CONTAINING A DOUBLE-ENDED CYLINDER, HAVING INLET AND OUTLET PORTS AT OPPOSITE ENDS THEREOF, A DOUBLE-ACTING PISTON WITHIN THE CYLINDER RECIPROCABLE FROM ONE TO THE OTHER END THEREOF, A ROCKER BAR PIVOTED TO THE PISTON AND EXTENDING THROUGH DIAMETRICAL SLOTS IN THE CYLINDER WALLS, MEANS FOR PIVOTING THE BAR ON A FIXED PIVOT SECURED TO THE CASTING, MEANS PIVOTALLY CONNECTING THE ROCKER BAR TO A CONNECTING ROD WHICH IS JOINED TO A THROW OF THE CRANKSHAFT, AN AUXILIARY CYLINDER HAVING A PISTON THEREIN AND A ROD EXTENDING THEREFROM, AN EXTENSION ON SAID ROCKER BAR CONNECTED TO THE ROD OF SAID AUXILIARY CYLINDER, SAID CASTING HAVING PASSAGEWAYS FROM THE AUXILIARY CYLINDER TO SAID INLET PORTS, A MANIFOLD FROM A CARBURETOR COMMUNICATING WITH SAID AUXILIARY CYLINDER, AND VALVE MEANS BETWEEN THE MANIFOLD AND PASSAGEWAYS TO THE INLET PORTS WHICH ARE OPENED AND CLOSED BY THE MOVEMENT OF THE PISTON IN THE AUXILIARY CYLINDER.

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