US2376968A - Two-cycle gas engine - Google Patents

Description

May 29, 1945. F. M. JONES TWO-CYCLE GAS ENGINE Filed Dec. 26, 1942 2 Sheets-Sheet 1 FIG.

May 29, 1945. F. M. JONES 2,376,963

I TWO-CYCLE GAS ENGINE Filed Dec. 26, 1942 2 Shets-Sheet' 2 FIG. 2.

13 /Vl// V/ 4a- 45 63 Ill" Ii. 4 54 FIG. 3. 2| 33 4r 43 'E 4s a 42 r s3 48w 55 I'll I J I I v q@ I j 25 2'! 23 225 I gwum vkvb FREDERICH M. JONES Patented May 29, 1945 UNITED TWO-CYCLE GAS ENGINE Frederick M. Jones, Minneapolis, Minn assignor to U. 8. Theme Control Company, a partner-. ship composed of Joseph A. Nnmero and M.

Green Application December 26, 1942, Serial No. 470,307

2 Claims.

My invention relates to two-cycle gas engines and has for its object to provide a gas engine of this type wherein two or more cylinders have their piston rods and the crank shaft extending into a common crank shaft chamber and provide double pistons and double cylinders, one part of each said piston and cylinder operating as a charging chamber.

Heretofore in two-cycle engine construction, each piston and the piston rod and crank shaft associated with it has operated in a separate closed cylinder, and the charge of fresh gas is drawn in to the lower part of the cylinder as the piston moves upwardly, at the same time compressing the charge of gas above the piston, and as the piston moves downwardly the gas drawn into the lower part of the cylinder is compressed and pushes into the upper part of the cylinder aiding exhaust, and the operation is repeated from firing point to firing point. It has been found desirable and eilicient to mount in a two-cycle engine two pistons, cylinders, and gas feeding appliances, so that as one piston goes up the other goes down. But each piston operates in its own cylinder throughout and both draws rods of the two cylinders operating in said single chamber.

in gas from the carburetor below the piston and 1 charges the cylinder above the piston so that each of the units thus operates independently of one another.

I have discovered that greatly improved operation is possible where the fuel gas is introduced into an enlarged cylinder about the piston proper as the piston moves outwardly under the force of explosion to be followed by compression of that gas so drawn in as the piston moves inwardly, the compressed gas being' forced into the other of two cylinders. In this manner, each of the cylinders receives its fuel charge from the piston of the other cylinder, the piston rods of each piston operating in a common crank chamber on a common crank and perfectly balanced opera- 1 tion and increased efficiency result.

It is a principal object of my invention, therefore, to provide a two-cylinder two-cycle gas engine with a piston having two diiferent sizes operating in two different cylinders, the smaller piston in the smaller cylinder being the power means and the larger portion of the piston and larger cylinder providing intake means for delivering a charge of explosive mixture to the other power cylinder.

It is a further object of my invention to provide a two-cycle two-cylinder gas engine having a single crank casing with crank shaft bearings at It is a further object of my invention to provide pairs-of superposed cylinders for each of the two cylinder units of the two-cycle gas engine, the upper of said cylinders being of smaller diameter than the lower cylinder, with a power piston of considerable length operative in the smaller cylinder and a piston of greater diameter attached to the bottom of the lower cylinder and operatlng in the larger cylinder so as to provide an annular space for inlet gas about said smaller cylinder at its outward stroke, where gas will be compressed in said annular chamber upon reverse movement of the piston.

It is a further object of my invention to provide a passageway connecting the annular chamber about the smaller piston part with the other smaller power cylinder.

It is a further object of my invention to form the opening from the passageway leading from the annular chamber of one cylinder to the power chamber'of the other cylinder so that it will be completely closed by'the piston during its outer stroke until substantially the end of said outer stroke, at which time the gas charge in the annular chamber of the second unit will have been very greatly compressed and will in expansion blow into the lower part of the other power cylinder against the customary baflie therein, thus acting to provide a succeeding fuel chargeand at the same time scavenging the powercylinder of the remnants of combustion gas mixture.

It is a further object of my invention to provide an exhaust passage running from the lower part of the chamber in each smaller or power cylinder, and to provide an inlet passage running to the upper part of each annular chamber with suitable check valve means therein to hold the gas within the inlet passageway and the annular chambers during the up or compression stroke of the larger piston part.

The full objects and advantages of my invention will appear in connection with the detailed description thereof given in the appended specification, and the novel features by which the above-noted advantages and valuable results are secured will be particularly pointed out in the claims.

In the drawings illustrating an application 0 my invention in one form:

Fig. 1 is a sectional elevation view of a gas engine embodying my improvements, taken along the line of the crank shaft.

each side, all of the crank shaft and the piston Fig. 2 is a transverse sectional view taken on line 2--2 of Fig. 1, and viewed in the direction of the arrows.

Fig. 3 is a transverse sectional view taken on line 3-3 of Fig. 1, and viewed in the direction of the arrows.

As illustrated the motor comprises a cylinder head casting I which provides cylinder wall II and I2 having integral therewith cylinder heads I3 and I4 through which extend open seats I5 and is for spark plugs I1. and I8.

The cylinder walls I I' and I: enclose explosion chambers I9 and 20 in which operate pistons 2| and 22, these pistons being of substantial length so as at all times to have the walls thereof substantially in contact with cylinder walls I I and.

I2 of explosion chambers I9 and 20.

As best shown in Fig. 3, a second cylinder block 23 is secured below the cylinder block I0 and has therein a pair of cylinder walls 25 and 26 enclosing cylinder chambers 21 and 28 as clearly shown in Fig.1. The cylinder chambers 21 and 28 are vertically concentric with cylinder chambers I9 and 20, respectively, and are of substantially larg= er diameter. Integrally connected to the lower ends of piston; 2| and 22 are short piston sec- . tions 29 and 3|! which are substantially of a diameter substantially that of chambers 21 and 28, and these pistons operate in said chambers, which, as clearly indicated at 3| of which, open at their bottoms into a common crank case chamber 32. It follows that the cylinder 29 and 30 at all times seal the chambers 21 and 28 from the crank case chamber 32. Further, that at the limit of the outward stroke of the-c0mbined pistons, as for example, pistons 2| and 29, Fig. 1, there is formed in the cylinder chamber 21 (or 28) an annular chamber 33 extending about the power piston 2| (or 22) and inside cylinder walls 25 (M26). j

The pistons 2| and 22 are provided with piston heads 34 and baiiles 35, see Figs. 1 and 2. Opposite the position of said baflles when the piston is in its outward position, as is piston 2| in Fig, 1, are peni gs 31 and 38 into cylinder chambers I9 and 20, respectively, which openings lead through a manifold passageway 39 in the cylinder block II) to an exhaust pipe 40 of common construcq tion.

As shown in Figs. 1 and 3, a manifold passageway 4| extends through the cylinder block 23 and opens at and 43 into the cylinder chambers 2! and 28, respectively. The passageway 4| leads is at the end of power expansion from explosion when-the explosion gases have reached one or the other or the openings 21 or a and the pressure within the explosion cylinder has therefore dropped, so the inrush of ga from the compression chamber against the baflle 25 will cause the explosion chamber I! or to be filled with inlet gas mixture and at the same time scavenge out" the remainder of the explosion gas going to the exhaust.

In a customary manner the pistons 2| and 22 are made hollow and are provided with wrist pins 54 which are connected by piston rods II with crank bearings 56 on a single crank shaft which has its ends 51 and is mounted in frame pieces 59 and '80 on ball bearings 6| and 62. Starter mechanism indicated generally at 63 is connected with the crank end 58 in a known manner. A pan 84 closes the crank case chamber 22 at its bottom in a customary manner.

From the above it will be seen that the piston rods and crank shaft for both cylinders of the two-cylinder engine operate in a single crank case chamber, which greatly facilitates lubrication, simplifies construction, and produces the balance of operation' which is requisite .for a multiple cylinder engine. It will be clear that while only two cylinders are shown and described herein, cylinders in any multiple of two, as tour, six, eight or twelve may be employed. A customary breather, not shown, going to the crank case chamber 32 may be applied in any desired manner.

to a valve chamber 44 in an extension casting 45 which carries a check valve 46. The valve seat passageway 41 leads into an inlet passageway 48 running to a carburetor of known construction, not shown.

In the cylinder block III are formed passages 49 and 50 extending respectively from compression chamber 28 to explosion chamber I9, and from compression chamber 21 to explosion chamber 20, all as clearly shown in Figs. 1 and 2. The openings 5| and 52 from passages 49, 50 into explosion chambers I9 and 20, respectively, are

positioned in the respective cylinder walls II and I2 at a point just above the point reached by the piston head 34 when the pistons 2| and 22 have reached the limit of their outward stroke, as indicated in dotted lines at 53 on Fig. 1. This.

brings the respective openings 5! and 52 opposite the bailles 35 on piston heads 34. Since the pas-3 sageways 49 and 50 extend respectively from upposite compression chambers to opposite explo-- sion chambers, it will be apparent that the charge 1 of fresh gas will be fully compressed in the an- The advantages of my invention have appeared quite mlly from the foregoing specification. A primary advantage is a perfectly balanced operation 01' a two-cylinder two cycle gas engine. This balance is produced by reason of the fact that as one piston operating in its double cylinder responds to the power explosion and simultaneously draws in a fresh charge of gas mixture, the other piston in the second cylinder is compressing the charge in the explosion cylinder and also the charge drawn in by it at the time oi the preceding explosion. The power stress of explosion in one cylinder is therefore to some degree compensated by the elastic compression stresses of the other cylinder. This balance in operation gives a remarkably smooth flow of power with a high degree of economy for the gas'burned.

A further very great advantage which flows from that above-noted, is that my invention admirably adapts a two-cycle principle of operation of a gas engine to use in a multiple cylinderexplosive engine.

I claim: I

1. A two-cycle gas engine, comprising a block having formed therein a pair of power cylinders, each of said cylinders being continued into an enlarged cylinder portion, said enlarged cylinder portions opening directly into a common crankcase chamber, an enlarged piston part in said enlarged cylinder, a source of explosive asvaaes the enlarged piston. and charging passageways in the block connecting the tops of each enlarged cylinder with the bottoms oi. opposite power cylinders, whereby explosive mixture will be drawn into an enlarged cylinder from said firstnamed passageway upon outward movement oi. its enlarged piston, and return movement of the enlarged piston will cause compression of the gas mixture about the explosion piston and the compressed gas mixture will ilow through the charging passageway to the opposite power cylinder at termination 01 the down movement of one and the up movement of the other piston.

2. A two-cycle gas engine, comprising a block having formed therein a pair of power cylinders, each of said cylinders being continued into an enlarged cylinder portion, said enlarged cylinder severally thereinto along a common plane at substantially the upper limit oi. the stroke oi the enlarged piston, and charging passageways in the block connecting the tops of each enlarged cylinder with the bottoms of opposite power cylinders, an exhaust passageway having enlarged openings into the bottoms of the power cylinders, said openings being directly opposite the openings from the said charging passageways, whereby explos'ive mixture will be drawn into an enlarged cylinder from said first-named passageway upon outward movement of its enlarged piston, and return movement of the enlarged piston will cause compression of the gas mixture about the explosion piston and the compressed gas mixture will flow through the char ing passageway to the opposite power cylinder at termination of the down movement or one and the up movement of the other piston, and exhaust will take place through said exhaust passageway at the same time that the gas is entering the power cylinder from the charging passageway and will act to scavenge the exhaust gases from said power cylinder.

FREDERICK M. JONES.

Images