US1274980A - Internal-combustion engine. - Google Patents

Description

,P. BREVARD.

INIEjRNAL comsusnow ENGINE. APPLICATION FILED OCT; 29. I911.

1,274,980. Patented Aug. 6, 1918.

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INTERNAL COMBUSTION ENGINE.

APPLICATION nuzu 01:1,;9. I911 1;274,980.- Patented Aug. 6, 1918.

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PBOC'IEB BREVARD, 0F WEATHERFORD, TEXAS.

INTERNAL-COMBUSTION ENGINE.

bpectflcatlon of Letters Patent.

Patented Aug. 6, 1918.

Application filed October 29, 1917. Serial No. 198,953.

To all whom, it may concern.

Be it known that 1. Pmio'rnn Bnnvnnn. a citizen of the United States, residing at 'eatherl'ord, county. of Parker, State of Texas. have invented a certain new and use fnl lmln'oven'icnt in Internal-Combustion Engines. and declare the following to he a full, clear, and exact description of the same, such as will enable others skilled in the artto which it. pertains to make and use, the same. reference being had to the aoconr panying drawings, which form a part; of this specification.

This invention relates to gas engines, and has for its object an improved construction and arrangement of parts of a two cycle mo tor especiall as contrasted with the two and three port type. whereby at each complete cycle of movement an auxiliary or additional charge of explosive mixture is compressed and fed into the explosion chamher. My construction not only makes possible more efficient scavenging of the burned gases from the cylinder, but also results in the development of greater power per stroke. the avoidance of having an entering fresh charge of explosive mixture more or less mingled with burned gas. and a shortening of the piston skirt which aids in the cooling of the cylinder walls. because of the resultant uncovering of just that much more of their surface, for the entering cool chargeof gas to strike against. I also avoid the wearing of piston rings due to their constant passing of ports in the. cylinder. and compression in the crank case and leakage therefrom due to worn hearings.

While I consider my improvements especially applicable to vertical motors. and have illustrated the same accordingly, I

I l u desireall the explanations and descriptions herein made to be understood as easily ca- 'pahle of modification. in order to he used with horizontal and other types of motor.

I employ the usual type of crank case now familiar in four cycle motors. which may be open to the atmosphere; The total length of the two cylinders employed is slightly greater than an ordinary single cylinder, and they are arranged coaxially of one another.

In the drawings: Figure 1 is a sectional elevation of the cylinder and crank case and their contained parts.

Fig. 2 is a similar sectional elevation along the line. (I-(l of Fig.1,

Fig. 3 is a detail view of the rotary valve and its cage.

ligs. 4 to 9 inclusive are diagrannnatie views showing the relative position of the parts in six difl'crent phases of a single cycle of operation.

A represents a cylinder. whose upper portion constitutes a combustion chamber. Adjacent this portioirot the cylinder head is located an exhaust valve li ot any suitable type. controlling the exhaust passage. and a spark plug t. The cylinder A is somewhat shorter than usual and has arranged coaxially with it a second cylinder D bcing separated therefrom by the horizontal wall or partition (it. through whoseapcrtnred center portion. sealed by the slotting box l. reciprocates the piston rod F on whose upper end islocated the upper piston H. in thebody of thi upper piston ll is located the automatic valve J. which in the form shown nnseats in the opposite direction from the ex hanst valve B. and through which each fresh charge of explosive mixture passes from beneath the piston ll to the combustion chamber thcreahovc. The lower end of the piston rod llhas rigidly attached to it. a second piston li. which works in the. lower cylinder l below the wall (It. acting both as a piston and as a cross-head. Being fitted with a piston pin. it is connected to the uppercnd of theconnecting rod M. which is connected in the usual wav with the crank shaft S. within the crank casing N. p t

On one side of the cylinders A and adjacent the horizontal partition wall G. is located the rotary valve cage 0. connected with the upper cylinder above the horizontal wall G. by the passage X. and with the lower cylinder D by the passage Y. lVithin'this cage is the rotary valve member 1. whose periphery is provided with oppositely disposed l1v-passcs Z. and with the inlet port '1. through which the explosive mixture may flow from the carhureter connection Q. The shaft or stem of the, rotarv valve member 1 extends outside the cage and has keyed to its outer end the sprocket,

wheel V, over which passes the endless chain R, which similarly passes over the sprocket wheel \V, which is keyed on the crank shaft S. The two sprocket wheels V and W being properly proportional, the rotative movement of the crank shaft S is imparted at the desired rate to the rotative valve member P.

The lower cylinder D, which may or may not be of the same size as the upper cylinder A, is not intended to serve as a tiring cylinder, but rather as a means for compressing a supplemental charge of explosive mixture and supplying it in a partly compressed form to the upper cylinder A at a selected point in cycle of operation, and under the regulative control of the rotary valve P. To this end, the carburetor connection Qwith the valve cage 0 makes possible the flow of the explosive mixture through the inlet port T of the rotary valve 1 and throughthe passages Y and X in turn, into the cylinders A and D. The initial rotative movement of .the valve P is brought about by the manual or mechanical cranking of the crank shaft S, which results in the actuation of the valve member P through the chain R and sprocket wheels V and W, as already described.

The relative position of the parts at six different points in a single cycle of operation is shown successively in diagrammatic Figs. 4 to 9 inclusive. In Fig. 4 the upper piston H is shown at the upper limit of its travel, or rather started a trifle on its downward travel. A charge above the piston H has just been fired. The by pass Z of the rotary valve member P has just closed, the charge in the lower cylinder D having been forced by the upw'ard travel of the piston K through the passage Y, through the bypass Z, and thence through the upper passage X into the upper cylinder A below the plston H'. The force of the explosion above the piston H carries it (and consequently the piston rod E and lower piston K) downward. Fig.

5 shows the rotary valve P justbeginning,

to register its inlet port T with the passagr): Y, thereby connecting the lower cylinder with the carburetor pipe, so that during the downward travel of the piston K, now in progress, a charge of fresh gas is drawn thereinto. The charge already by-pa'ssed into the upper cylinder A below the piston H is of course being compressed by the downward travel of the piston H, the passage X being blanked during this period by the position of the valve In Fig. 6 the parts have reached such a position that the pistons H and K are nearly at their lower limit of their travel, and the exhaust valve B has justo ened to permit the release of the now expl oded gas above the piston H.

above the piston H sufll ciently for the in- This relieves the pressure creasing compression below the iston H tov unseat the automatic valve J t erein, thus permitting the relatively cool compressed charge to flow therethrough into the space above the piston H and driving the hotter burned gas out through the now opened exhaust valve B.

F ig. 7 shows the pistons and their related parts slightly past the lower limit of their stroke. The uppercylinder is now being cleared of its burned gas, and the fresh charge is passing from below the iston H to above it. The exhaust valve 13 is still at least partly open, as is also the valve J, through which the fresh charge has passed.

The passage Y has beenblanked by the rotation of the valve P, and the inlet port T is about to register with the passage X, to directly furnish its regular charge to the u per cylinder A below the piston H. T e crank shaft being carried around by the flywheel effect of moving parts the rotation of the valve P continues, and as shown in Fi 8 the upward travel of the lower piston begins to effect the compression of the charge above it. The upper piston H travels upward correspondingly, and as the valves B and J quickly close against the pressure generated, it is at thesame time compressing the fresh charge already described as having moved through the valve J and now above it, and is also drawing in a charge below it,

until about half of the upward travel of the piston H, when the further upward travel of the pistons again brings the parts to the positions shown in Fig. 4, and already described, except for the fact, now made evident, that the contents of the cylinder A below the piston H at the point of initial downward movement shown in Fig. 4 is an augmented charge, as is also the previously accumulated augmented charge which was transferred through the valve J and now ready for firing being the total of what both cylinders have drawn in. and partly compressed, although but one firing takes place and that in the upper part of theeylinder A. above the piston H.

While I have shown a well known form of rotary valve P for effecting the various functions desired, I desire it to be clearly understood that Ido not limit myselfto thisprecise form, since with little change of structure and no departure from operative principle, other forms of valves could be easily substituted therefor.

What I claim is:

1. In combination with a air of axially alined cylinder members, a piston rod common to both cylinders, pistons carried on the ends of the piston rod within their respec tive cylinders, a crank shaft, a connection between one end of the piston rod and the crank shaft, a valve cage located adjacent the meeting ends of the two cylinders and having a bypass connection with each and a carburcter connection, and a rotary valve member within said cage adapted to intermittently close and open said by-pass portions, thereby permitting a charge of explosive mixture which has been partly compressed within the lower chamber by the reciprocation of the piston therein to flow into the upper chamber as an additional charge to that primarily received therein.

2. The combination of a pair of axially alined cylinder members, a piston rod'adapt' ed to reciprocate through the common and wall of said cylinders, a piston member for each cylinder carried on the ends of said piston rod, a valve member in, the upper one of said piston members, a crank shaft, an operative connection between the lower end of the piston rod and the crank shaft, a valve cage connected with each of said cylinders, and. therebly afiording at certain times a direct connection between the cylinders, a carbureter connection for said valve shell, a valve member within the shell adapted to regulate the communication between the carbureter connection and the cylinders and to intermittently open and close the cylinder connections from, the valve shell, and means for operatively connecting the valve member and the crank shaft whereby the desired degree of actuation may be imparted to said valve member when the crank shaft is rotated.

8. In a two cycle motor, the combination point in each cycle of operation. to'p'ermit.

the flow of explosive mixture compressed in one of said cylinders into the other of said cylinders, a relief valve in one of said piston members adapted to open during its downward stroke an'dto close during the upward compression stroke, an exhaust valve adapted to open and close with said relief valve'to effect the release of the burned gases as the new compression charges enter the combustionchamber through said relief valve, and a spark plug located in the wall of the combustion chamber.

.4. In a gas engine, in combination with a pair of axially alined cylinders, a piston rod adapted to reciprocate through their adjacent ends, a piston member for each of said cylinders, carried on the ends of said piston rod, a relief valve in one of said piston members, an escape valve for burned gases in the end'of the cylinder adjacent to the piston having the relief valve, a crank shaft with which the piston rod is opcratively connected, a carburetor connection to each of the cylinders, and valve means controlling such connection, whereby the charge initially delivered to the cylinder containing the crank shaft connection is con ducted into the other cylinder after being partially compressed.

5. In a gas engine, the combination oi a pair of axially alined cylinders, a valve cage having a communication to each of said cylinders and a carbureter connection, a valve member. within said cage adapted to control the flow from the carburcter and to control the communication between the cage and the cylinders, a crank shaft, means operatively connecting said valve with the crank shaft whereby the valve may be ac tuatcd in timed relation to the rotation thereof, a piston member in each of said cylinders, a relief valve in one of said piston members, a piston rod common to both cylinders and on whose ends said piston members are mounted, said piston rod being operatively connected with said crank shaft.

6. A gas engine, havin in combination with a pair of 'coaxially disposed cylinders, a valve cage having a. carbureter connection and acommunication with each of said cylinders, a positively actuated valve member in said cage whereby the flow from the carbureter to said cylinders and the flow from one cylinder to the other is regulated in timed relation to the cycle of the engine, a piston rodeommon to both cylinders, 'a piston member on each end of said rod, an escape valve in one of said cylinders and a relief valve in the, piston of the cylinder wherein the escapevalve is located.

In testimony -whereof,I sign this specification in the dilesence of two witnesses.

PROCTER BREVARD.

Witnesses WILLIAM M. SWAN, HARRY F. MoMAs'rnR.

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