Jan. 23, 1945. H. R. RICARDo 2,367,963 TWO - CYCLE SLEEWE WALWE ENGINE Filed June 1, 1943 3. Sheets-Sheet i

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Patented Jan. 23, 1945 2,367,963

UNITED STATES PATENT OFFICE 2,367,963 TWO-CYCLE SEEVE-WALWE ENGINE Harry Ralph Ricardo, London, England Application June 11, 1943, Serial No. 490,494 In Great Britain July 22, 1942 3 Claims. (C. 123-56) This invention relates to an internal combus driving eccentrics. If the engine has two or tion engine operating on the two-stroke cycle more main crank-throws it is unnecessary to pro and of the type provided with a single OScillating vide any driving or phase retiming gearing be sleeve valve in each cylinder which is Operated tween the main and secondary crankshafts. at the same speed as the engine crankshaft. The The accompanying drawings illustrate by Way object of the invention is to improve the means of example a construction in which the invention by which the valve of Such an engine' is driven. is embodied. In these drawingS According to this invention cranks on the en Figure 1 is a diagrammatic view showing the gine crankshaft actuate one or more sleeve valves invention as applied to an internal combustion through at least one pair of members which im 0. engine of the type having horizontally opposed part uniform angular velocity to each sleeve cylinders, the view being taken from the end of operating member in two planes normal to the the main crankshaft and showing the engine crankshaft axis. Each valve-actuating member cylinders and the sleeve valves therein as in lon which is driven directly by a crank on the engine gitudinal section. crankshaft drives also a secondary crankshaft 5 Figure 2 is a sectional elevation of a construc which in turn may operate one or more auxiliary tion looking in the direction of the crankshaft mechanisms. These valve-actuating members axis and showing the opposed cylinders in lon constitute in effect coupling rods between cranks gitudinal Section. on the engine crankshaft and cranks on the sec Figure 3 is a sectional plan in which are seen ondary Crankshaft and since the angular velocity 20 two pairs of opposed cylinders and a pair of coll of the whole of each member is uniform they im pling rods actuating the sleeve valves in these part a drive at constant angular velocity to the cylinders. Operating member of each Sleeve valve. This Referring to Figure 1, this shows one of the mechanism for operating the sleeve valves is par driving plates which functions as a coupling rod ticularly applicable to an engine operating on 25 between the main crankshaft A, the Secondary the two-stroke cycle having two single acting crankshaft B, and the driving pins C and D of cylinders the pistons in which are coupled to One the sleeve valves in the two opposed cylinders. crank pin, the cylinders being disposed for exam The crank pin Ai is connected by the rods E and ple horizontally, with their axes at 180° about F to the pistons E! and Fi in the opposed cylin the crankshaft axis. It is also more especially 30 ders E2 and Fa. On the shaft A is an eccentric Suitable for use with sleeve valves of the open G which imparts oscillation to the driving plate ended type in which the exhaust takes place over or coupling rod member H. As will be seen this the end of the sleeve instead of through ports is shaped somewhat as an inverted T with one in its wall. arm H directed upwardly and the shorter arms In practice it is convenient to employ eccen- : H? and H3 extending laterally and oppositely. trics as the driving cranks on the engine crank The arm H engages the pin B On the Secondary shaft, with each eccentric strap formed as a driv crankshaft B which is thus driven at uniform ing plate or coupling rod with an arm extending velocity from the main crankshaft A. The sleeve into a Suitable position where it engages a crank valves J and K respectively in the cylinders E on the secondary shaft which has a throw equal 40 and F2 are driven through the coupling rod mem to the eccentricity of the driving eccentric. By ber H whose arm H engages the operating pin this means the secondary shaft is driven in phase C of the sleeve E while the arm H engages the with the engine crankshaft and the driving plate operating pin D of the sleeve valve F. constitutes a coupling rod not only between the The arrangement as thus shown diagrammati two crankshafts but also between these shafts 45 cally in Figure 1 is carried into effect in the and the operating pins or other members of the construction shown in Figures 2 and 3. In prac sleeve valves so that the whole rotates with uni tice it is essential that there be at least one pair form angular velocity. of eccentrics and a corresponding pair of driv The connection with each sleeve valve may be ing plates through which the drive is transmitted by means of suitably formed arms or lugs project 50 from the main crankshaft. A to the Secondary ing from the main part of the driving plate, these crankshaft B and to the sleeve valves. The One projections being arranged as may be convenient driving plate His seen in Figure 2 and the second in accordance with the respective positions of the one H is there indicated in dotted lines. The sleeve Operating pins, since it is immaterial where arms H., H and H3 of the driving plate H are these pins may be disposed in relation to the main 55 seen as engaging respectively the crank pin B 2 2,367,963 of the secondary crankshaft B, and the operat the sleeve operating mechanism is subjected no ing pins C and D of the sleeve valves J and K in only to inertia forces, the weight of these valves the cylinders E2 and F2. It will be seen in Figure being considerable, but also to the effect of great 2 that the driving plate or coupling rod H is gas pressure. When, however, two cylinders are formed from the two halves of the strap of the 5 opposed and the sleeve valves of both cylinders eccentric G which are bolted together around are connected to one and the same driving plate that eccentric and also around the pin B1 of the or coupling member which is operated by a single secondary crankshaft B. The arms H2 and H3 eccentric, it follows that the gas pressure when are Constituted by lugs projecting from the two exerted on the one sleeve is partially balanced halves of the eccentric strap. The manner of 10 by the inertia of the sleeve of the opposite cyl engagement between these arms and the operat inder and the bearings of the eccentric are sub ing pins of the valves is in some known way which ject only to the difference between these two op permits of the combined reciprocating and oscil posing forces. lating movements imparted to the sleeve valves. The detail construction of the driving plate In Figure 3 there can be seen the disposition of 15 member may vary in accordance with the desired the pair of eccentrics G and G1 which are neces relative disposition of the Secondary crankshaft Sary to transmit the drive through the two cou and the sleeve valve operating pins and of all pling rods to the secondary crankshaft. The lat these in relation to the main crankshaft. eral arms H and H of the second coupling rod What I claim as my invention and desire to se member H are shown as engaging the operating 20 cure by Letters Patent is: pins C and D of the sleeve valves J1 and K1 in 1. An internal combustion engine Operating on a Second pair of Oppositely disposed cylinders E3 the two-stroke cycle comprising in combination a and F the pistons in which act on the crank pin main crankshaft, at least one pair of cylinders A. If the engine has not a second pair of cyl oppositely disposed with respect to the said inders then the second driving plate need not be 25 crankshaft, a single sleeve valve in each of such formed with lateral arms or lugs since it merely cylinders, a secondary crankshaft parallel to the Serves as a Second coupling rod between the main main crankshaft, at least one pair of coupling Crankshaft A and crank pins B and B2 on the rods extending between cranks on the main shaft Secondary shaft B. It may be noted that in any and cranks on the secondary shaft through which case the crank pins of the secondary shaft which 30 rotation is imparted to the secondary crankshaft are coupled to a pair of eccentrics on the main from the main crankshaft, and an operative Con shaft are set at 90° to each other or at some nection between at least one of the said coupling other suitable angle, the eccentrics being simi rods and the Sleeve valve in each of the said larly arranged on the main shaft. Provided cylinders. there is at least one pair of coupling rod mem- 35 2. An internal combustion engine operating on bers, then for every additional pair of oppositely the two-stroke cycle comprising in combination a arranged cylinders only one further coupling rod main crankshaft, at least one pair of cylinders op need be used. As shown in Figure 3 the one positely disposed with respect to the said crank pair of coupling rods serves for transmitting the shaft, a single sleeve in each of such cylinders drive to two pairs of cylinders, but a similar 40 adapted to receive both oscillating and recipro pair of coupling rods would be necessary if the cating movement in the cylinder through an op engine had only one pair of cylinders whether erating pin, a secondary crankshaft parallel to these be disposed oppositely or otherwise as for the main crankshaft, at least one pair of cou instance in V-form. Even if the engine has only pling rods extending between cranks on the main one cylinder, the sleeve valve may be operated 45 shaft and cranks on the secondary shaft through by such a coupling rod with arms connecting the which rotation is imparted to the secondary main Crankshaft to the secondary crankshaft and crankshaft from the main crankshaft, and an to the valve operating pin, but a second coupling Operative connection between at least one of the rod would be necessary between a second eccen said coupling rods and the operating pin of each tric on the main shaft and a second crank pin on 50 sleeve valve. the Secondary shaft, this crank pin being set at 3. An internal combustion engine operating on approximately 90° to the crank pin of the first the two-stroke cycle comprising in combination a coupling rod member. main crankshaft, at least one pair of cylinders The power transmitted by these plates to the oppositely disposed with respect to the said crank Secondary crankshaft can be utilised for the driv is 5 shaft, a single sleeve valve in each of such cyl ing of such auxiliary mechanisms as a scavenge inders, a secondary crankshaft parallel to the pump or blower which can be driven direct and main crankshaft, at least one pair of coupling without the interposition of gearing. rods of which at least one has a T-form with a Where the sleeve valves driven by the improved central main part and lateral arms, these rods means are of the type mentioned in which the 60 extending between cranks on the main and sec exhaust gas passes over the end of the sleeve and ondary crankshafts, and an operative connec not through ports in its wall, each sleeve is ex tion between each lateral arm of at least one of posed to the full gas pressure in the cylinder and the said coupling rods and the sleeve valve in forms in effect an annular piston of substantial One of the cylinders in the said pair. total area around the main piston. Consequently 65 HARRY RALPHRICAROO.