US2085036A - Internal combustion engine - Google Patents

Description

June 29, 1937. G. w. MEREDITH INTERNAL COMBUSTION ENGINE Filed Oct. 22, 1954 3 Sheets-Sheet l fullllll "I'I'I'I'IJ June 29, 1937- e. w. MEREDITH INTERNAL COMBUSTION ENGINE 3 Sheets-Sheet 2 Filed Oct. 22, 1934 ik I I 6 f/7V5/7/0/ i MM Jun- 29, 1937.

G. W. MEREDITH v INTERNAL COMBUSTION ENGINE Fi led Oct. 22, 1934 s Sheets-Sheet3 Patented June 29, 1937 UNITED STATEEi FATE??? GFFECE INTERNAL COMBUSTION ENGINE George W. Meredith, Cincinnati, Ohio Application October 22, 1934, Serial No. 749,368

4 Claims.

The two-cycle type of gas engine (the term gas engine being hereinafter employed as synonymous with internal-combustion engine), while extremely simple in the matter of mecha- 5 nism, is ordinarily deficient in performance. Except for the small sizes, such as those used in out-board motor combinations, the two-cycle gas engine is deficient in power output at the high speeds at which automobile and airplane engines .10 are customarily operated. The chief reason for this lack of power at high speed is the impracticability of incorporating adequate intake and exhaust passages in two-cycle engines of the usual type. The chief purpose of the engine hereinafter described and illustrated in the accompanying drawings is to produce a type of engine design that will permit of adequate intake and exhaust passages in combination with certain features illustrated and described in certain other applications of mine. One such application is that filed August 31, 1934 and bearing Serial No. 742,277, series of 1925. A second application has been prepared and is being filed concurrently with this application. In the present engine, I

.35 have incorporated certain of the features of the engines which are the subjects of the applications referred to, and have added thereto certain additional features hereinafter illustrated and described.

In addition to the chief object of the present design, which is to secure adequate gas passages for high speed operation, my further objects are to secure an intimate mixture of fuel and air, a certain measure of stratification between the 85 entering fresh mixture and the out-going exhaust gases, avoidance of dilution of the mixture by l residual exhaust gases about the igniters, unidirectional flow of the exhaust and incoming gases, and turbulence of the fresh charge. 7

In processing'my invention, I retain the gencral plan of providing a conduit in the wall of the cylinder leading from the crankcase to the closed end of the cylinder as in my application bearing Serial No. 742,277, and provide a second and similar passage in that lateral wall of the cylinder diametrically opposite the first. Furthermore, in

the present design, I provide two exhaust ports through the wall of the cylinder and locate the exhaust; ports at a right angle to the conduits. As in the engine which is the subject of my prior application, the piston uncovers the exhaust ports as it nears the end of the power stroke, and shortly thereafter a pair of ports provided in the 55 wall of the piston register with the entrances to the conduits provided in the lateral walls of the cylinder.

The exit from the conduit into the closed end of the cylinder is, in each conduit exit, directed toward the wall of the cylinder in one type of exit and toward the wall of the cylindrical mouth of the second type of exit. Thus the columns of gas on their way into the cylinder are constrained to follow a path tangential to the cylindrical surface and thereby to go into a spiral swirling motion. The intimacy of the mixture promoted by the turbulence induced by the whirling of the gases, tends toward perfection of combustion; thereby securing high mean elfective pressures and the maximum economy of fuel.

It will be noted that the conduits referred to are open at all times to the cylinder, and comprise a portion of the combustion space into which the mixture is compressed at the end of the compression stroke. Because of the attenuated form of the combustion space, special igniter arrange- H As in the engine described in my prior applica- 0 tion, I so locate the igniters that one is located in proximity to the exit from the conduit into the cylinder and another at that end of the conduit near the entrance thereto from the crankcase. Since there are two conduits in the present design, an igniter is located in each in proximity to the entrances to the conduits from the crankcase. Therefore there are three igniters employed. Thus the distance through which flame is propagated through the mixture is only that from one igniter half way to the next, and therefore the period of inflammation is correspondingly shorter than if but one igniter were to be employed.

For the reason that the rush of the fresh charge entering the conduits from the crankcase will drive out of the conduit any residue of burned combustible which may remain from a prior explosion, fresh mixture, undiluted by exhaust gases, is certain to surround the igniters near the entrances to the conduits. The igniters near the conduit entrances are certain to be thus surrounded regardless of how low the engine may be throttled. Thus the missing of explosions, so

characteristic of both two-cycle and four-cycle engines at low throttle, is prevented.

In the accompanying drawings, I illustrate four types of exit from the conduits into the cylinder. In one, the flow is from the conduits along a plane at a right angle to the axis of the cylinder. In the second, the mouth common to both exits is along the axis of the cylinder extended. In the third, the first and the second types of exit are employed in combination. The fourth is a simplified modification of the second.

In the drawings:

Fig. l is an elevation in section of one form of my improved engine, the section being taken along line l-l of Fig. 3. The piston is shown at the end of the power stroke.

Fig. 2 is an elevation in section of the engine of Fig. l, the section being along a plane at a right angle to that of Fig. 1, and along line 2-2 of Fig. i.

Fig. 3 is a plan in section of the engine of Figs. 1 and 2, the section being taken along line 3-3 of Fig, 1, and through the combustion space.

Fig. 4 is a plan in section of the engine of the previous figures, the section being taken through the exhaust ports along line d@ of Fig. 2.

Fig. 5 is an elevation in section of a fragmentary portion of the cylinder of an alternate form of my invention, the section being taken along line 55 of Fig. 6.

Fig. 6 is a, plan view in section of the engine of Fig. 5, the section being taken along line 66 of Fi .5.

ig. '7 is an elevation in section of a fragmentary portion of the cylinder of a third form of my invention, the section being taken along line 'i-l of Fig. 8.

Fig. 8 is a plan view in section of the engine of Fig. '7, the section being taken along line 8-3 of Fig. 7.

Fig. 9 is an elevation in section of a fourth form of my invention, the section being taken along line 9 of Fig. 10.

Fig. 10 is a plan view of the engine of Fig. 9, the section being taken through the combustion space along line iii-4i of Fig. 9.

Fig. 11 is a fragmentary half-sectional elevation of the engine of Fig. 9, the section being taken along line l ll of Fig. 10.

In the figures, in which similar numerals refer to similar parts throughout the several drawings, the cylinder is designated by the numeral 42. The cylinder is attached to crankcase 53, provided with a valve housing i i in which is rotated the crankcase inlet valve 55. Within the cylinder is the piston it linked to crankshaft H by means of connecting-rod l8. Attached to the piston, and integral therewith, is the piston head it? (Figs. 1-4) of disk form and H5" (Figs. 9-11) of conical form. In the lateral walls of the oylinder are provided the conduits l9 leading from the ports 2t provided through the walls of the cylinder to the exists 2i and 2! provided in that end or" the cylinder opposite crankcase iii. In the walls of piston 55 are provided ports 22 adapted to register with ports 2d when the pistc'in is at the end of its power stroke. In Fig. 9, the position of the piston head i 5" at the end of the compression stroke is designated by broken line 56".

Exhaust ports 23 (Figs. 2 and 4) and 23' (Fig. 11) are provided through the walls of cylinder 5 2. Ignition is provided for by the spark plug 24 in the closed end of cylinder l2 and spark plugs 24 in the lateral walls of the cylinder and project- 25" provide a seal against the passage of gases 5 past the piston from conduits l9.

In describing the operation of my improved engine, it will be assumed that an explosion has taken place in the cylinder and that the piston l6 has started on its compression stroke toward 10 the crankcase l3. As it nears the end of the power stroke the piston uncovers exhaust ports 23 or 23' and the products of combustion escape to the atmosphere, being driven from the cylinder by the pressure therein. Shortly thereafter ports 15 22' are brought into registration with ports 20, and a charge of fresh mixture, previously compressed in crankcase 53, passes through ports 2!] and it into conduits l9 and thence through exits 21 or 2i into the interior of cylinder l2. the next or compression stroke of the piston, a

fresh charge of combustible and air is drawn into crankcase i 3 through ports 2% and 21 provided in the rotating inlet valve l5 and crankcase 53 respectively. being filled with a fresh charge, the previous charge is beingcompressed in the cylinder, and is ignited by sparks generated at spark plugs in the end of the cylinder and in the conduits re spectively. Thus the cycle is completed. It will be noted that the series of events in the cycle is precisely the same as in the average two-cycle engine of the base compression type. The direction of the flow of the gases into and from the cylinder is indicated by arrows with shafts having solid lines to designate fresh mixture and by arrows with shafts comprised of broken lines to represent products of combustion. Ignition may be timed to ensue at all spark plugs simultaneously or at different periodsin the cycle,

plugs 2 3' being timed to fire either before or after plug 28.

Provided that the electrical ignition equipment is functioning properly, there is little difficulty in igniting a mixture of correct proportions of fuel and air when the throttle is fully open and the cylinder receiving a full charge. Owing the factthata two-cycle working under reduced throttle and not receiving a full charge of new mixture from the crankcase will draw in more or less exhaust gas from the exhaust passages, the charge at reduced throttle will be mixed in the cylinder with a considerable proportion of products of combustion.

cult as the throttle is closed more and more, since the igniter is surrounded with a mixture that has a considerable proportion of burned gas.

In my improved engine, spark plugs 24 are certain to be surrounded by mixture undiluted ensure ignition at lower positions of the throttle when it is nearly closed. This causes. wastageof 70 fuel and poor economy at light loads. My invention avoids this.

For operation at high speeds, where the-ordinary engine provided with'but one exhaust port F.

and one inlet port will not be able to receive a 7 While the crankcase is Thus ignition in the cylinder of two-cycle gas engine becomes increasingly difii- Thus ignition is ensured at full charge nor discharge the exhaust gases effectually due to inadequate passages, the double porting herein illustrated and described as a feature of my invention, will provide sufficient areas to function efilciently. This feature, in combination with the arrangement of conduits l9, provides for efiicient performance over a wide range of engine speeds.

I claim:

1. In a two-cycle gas engine, the combination with a cylinder having a cylinder head provided with conduits leading from ports midway of the cylinder to ports immediately within the cylinder head, an igniter in the cylinder at the center of the cylinder head, an igniter in each conduit in proximity to the ports midway of the cylinder and a rotary valve controlling the admission of gas to the crankcase.

2. In a two-cycle gas engine, the combination with a cylinder having a cylinder head provided with conduits leading from ports midway of the length of the cylinder to a port in the cylinder head opening into the cylinder, of a piston in the cylinder provided with ports in the lateral wall of the piston, igniters in the cylinder head opposite the port therein and in the conduits in proximity to the ports midway of the cylinder and a rotary valve controlling admission of gas to the crankcase.

3. In a two-cycle gas engine, the combination with a cylinder having a cylinder head provided with conduits leading from ports located midway of the length of the cylinder to ports in the cylinder immediately within the cylinder head and to a port in the cylinder head, the conduits open continuously through said ports to the cylinder, of igniters located in the cylinder head at the port therein and in the conduits in proximity to the ports midway of the length of the cylinder.

4. In a two-cycle gas engine, the combination with a cylinder having a cylinder head provided with conduits leading from ports midway of the length of the cylinder to a port in the center of the cylinder head opening into the cylinder and further provided with a bore ending in a truncated hollow cone with the smaller end of the truncated cone at the port in the cylinder head, of a piston in the cylinder provided with ports in the lateral wall thereof, the piston ports adapted to register with the ports midway of the cylinder when the piston is at the end of its power stroke, and the piston having a piston head in the form of a truncated cone of a form conforming with the conical interior of the cylinder.

GEORGE W. MEREDITH.

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