» Dm 2À1,1946.» y 2,412,952 R. DAUB INTERNAL-COMBUSTION ENGINE Filed Nov. 20. 1944 i 10 N w \'\ 2.1, >52 » lll 9d à: 29 TÍ. Uf i à» _if i îër IN VEN TOR. -2,412,952 Patented Dec. 24,1946 UNirEo srA'ras PATENr orifice Y _ 2,412,952 _ mrERNAL-oormosrron monza Itudolph Danb, West Caldwell, N. J; Application November zo, 1944, serial No. 564,191 4 Claims. I Cl. 12S-51) i This invention relates to internal combustion engines of the two-cycle type, and particularly to such engines having opposed cylinders where two crank shafts are placed in opposite ends of the cylinder block and crank case. Ul In such engines one crank shaft operates a piston controlling the intake ports while the pis ton attached to the other shaft controls the ex haust ports of the same cilinder. The pistons are _ 2 v four cylinder units, such as shownl in the draw ing. The _combustion chamber 3| is formed in the main between the heads of pistons 23, 28, this being spaced to give a comparatively wide gap 35 at nearest approach while pistons I8, l1 and cylinder 22 at the same time form a very narrow gap 35 between their head faces at the time of injection of the fuel spray by the nozzle tip 30. This violently squeezes the air out from between phased in such a manner as to’eiîect an early the faces of pistons i8, 2l and projects it tur opening and closing of theexhaust ports in com~ bulently through the throat 36 into the gap 3G parison with the intake ports. between the pistons 23, 28, and in a direction op The object of the invention. is to provide in pOsite to the oncoming fuel spray. 'I'his causes creased power w. lin the overall dimensions oi an intimate and prompt mixing of fuel and air, the engine. good atomization and eñcient combustion since Further objects of the invention, particularly the velocity of the air. through the throat and in the employment of a minimum number of fuel the intensity of the turbulence reaches its maX injectors or nozzles and the attainment of better imum at about the time 0f the injection, i. e., cooling and scavenging will appear from the fol 20 the innermost positions of pistons I8, 27. The lowing speciilcation taken in connection with the result is a very thorough burning of the fuel. accompanying drawing showing a central sec 'I‘he shape of the throat and its location be tional view of a typical engine structure. tween the gap 35 and combustion chamber 3| may also be such as to cause a rotational whirl In the engine shown in the drawing a combined cylinder block and crank case housing l0 has the 25 of the air charge in combustion chamber 3| around the axis of the cylinder 25. The forma centers of the two crank shafts at || and i2 moving in opposite directions-with their positions with crank- pins i3, I 4. Operably 'connected to l tion of the piston heads lat both the narrow gap 35 and the wider gap 34 may be such as to give crank pin I3 is master rod l5. and articulated rod IB is hinged to master rod |5 by means of .30 any desired whirl, the throat outline and location being correspondingly arranged for cooperation if the fulcrum pin | l. desired. Similarly the number of injectors and Master rod |5 is attached to piston I8 by pis ton pin i9, the edge 20 of piston I8 controlling v their positioning may be varied to cooperate in creating the whirl. the opening and closing of the intake ports 2| of the cylinder 22. Attached to articulated rod 35 The intake 2| and exhaust 26 are formed as a belt of orifices surrounding the cylinders and I6 is the corresponding articulated piston 23 communicating with each other so as to provide having its edge 2t controlling the intake ports 2| for continuous distribution and passage of the of cylinder 25. gases into and out of the cylinders, suitable man The exhaust ports 26 of the cylinders 22, 25 are controlled by the other set of pistons 21, 28 con 40 ifolds being provided at the outside of the engine. Hitherto diiliculty has been experienced in op nected to crank pin It by master connecting rod posed cylinder engines in eiïectively cooling the -I 5a, articulated rod |6a and piston pins |9a. exhaust piston because the outer edge of the pis The geometry of piston motions, side pressures ton top is subjected to the scorching eiîect of the and the effect of the relative phasing of the pis tons are set forth in my copending application 45 exhaust flames passing at high velocity between said edges and the edges of the exhaust ports in Serial No. 510,717. _ the cylinders. While the latter can be cooled by Positioned in the cyllinder block |0 is the in water, heat dissipation from the piston edge and l jection nozzle 29, the inner tip 30 of which pro- ' piston top and piston rings must be provided by trudes into the combustion chamber 3|. Cam heavy sections of Äthe piston or by oil cooling, or shaft 32 by means of rocker 33 operates the noz both, if reasonably. high output is to be satisfac zle 29 to inject the fuel jet at proper time inter torily sustained. The larger the bore of the en vals. Cam shaft 32 is rotated at crank shaft gine the more this overheating is aggravated, and. speed by gears (not shown). Water jacketing y' in fact, this limits the size in.output per cylin is provided around al1 of the cylinders, the en der in present opposed two-cycle engines of this gine usually comprising a longitudinal series of 55 type. In the engine of this invention, the spe 2,412,952 ciiic power output per cylinder unit is increased by keeping the diameters of the pistons relatively small due to the division of the power between the two pistons for a given piston top area. This increases the combined piston circumference by 41% as compared to a single piston of similar area, thereby increasing the heat-dissipating area f circumference multiplied by piston skirt length) by the same amount. . - The use of two pistons instead of one, increas ing the circumference 41%, permits the equivalent enlargement in inlet and exhaust port areas re sulting in better scavenging and low pump losses, better fuel economy and attaining a more eili 4 two sets of oppositelymoving pistons in said cyl inders, one set being connected to one crank shaft and the other set to the other crank shaft. intake passages connecting said cylinders and controlled by one set of pistons and exhaust pas sages connecting said cylinders and controlled by' the other set of pistons. 2; In an internal combustion engine a pair of -parallel crank shafts having a series or crank pins, a pair of pistons connected to each crank pin, parallel cylinders containing said pistons be tween said crank shafts, a passage connecting each pair of cylinders midway between their ends and forming with the heads of the corresponding pistons a central combustion space, and intake cient and more economical power plant. and exhaust passages connecting said cylinders. In current engines of the opposed type, two, 3. In an internal combustion engine a pair of two, three or four injection nozzles are used per parallel crank shafts having a series of crank pins, cylinder unit because the combustion chamber is a pair of pistons connected to each crank pin, of the quiescent type with little turbulence and parallel cylinders containing said pistons between a rather flat shape, depending upon atomiza 20 said crank shafts, a passage connecting each pair tion to produce distribution of thefuel. In the of cylinders midway between their ends and form present engine, the distribution does not so de ing with the heads of the corresponding pistons pend upon atomization but is achieved rather a central combustion space, and intake and ex by the highly turbulent air projected towarda haust passages connecting said cylinders, said pas single nozzle to meet the merging fuel spray 25 sages and pistons on one side of the engine be head on. The _shape of the chamber is also ing further from the center than on the other very advantageous, being formed by the combined side of the engine. . strokes of two sets of pistons, four in all. 4. A two cycle internal combustion engine com ` In addition to these advantages the engine is prising parallel crank shafts-operating at the shorter and more compact, permitting a lighter 30 same speed, master and auxiliary connecting rods and safer structure with less tendency toward for said shafts, parallel cylinders between said torsional deflection of the shafting. The engine is thus improved in operation and at the same_` time reduced in cost and made more durable crank shafts, -'pairs of oppositely moving pistons in said cylinders journaled to said connecting rods, in service, and it is apparent that various changes 35 a combustion chamber for said pairs of pistons midway between the ends of said cylinders, in in the details of the construction may be made take passages connecting the cylinders for one of preserving these advantages and within the scope said crank shafts and controlled by _the corre of the invention. > sponding pistons of said cylinders, and exhaust 1. An internal combustion engine comprising 40 passages connecting the cylinders of the other crank shaft and controlled by the corresponding , parallel crank shafts operating at the same speed pistons thereof. and each having a crank pin, parallel cylinders RUDOLPH DAUB. between said crank shafts, a combustion chamber midway between the ends of said cylinders, and I claim: '