US2269945A - Internal combustion engine - Google Patents

Description

Jan. 13, 1 942. R. L. LANDRY 2,269,945

' INTERNAL GOMVIBUSTIONENGINE .Fi led act. 5, 1940 s Sheets-Sheet 1 NVENTOR.

I BY 7 RossMuNu L. LHNJJRYV Patented Jan. 13, 1942 UNITED STATES PATENT OFFICE KNTERNAL COMBUSTION ENGINE Rosamond L. Landry, Woodside, Y.

Application October 5, 1940, Serial No. 359,829

' 6 Claims. (c1. 123-78) This invention relates to new and useful improvements in internal combustion engines and has for its object to provide an improved construction whereby more space is provided for expansion to obtain more power from the gasoline fuel than is possible in internal combustion engines now in use.

Another object of the invention is to provide a movable cylinder head which may be adjusted in the bore of the cylinder for varying the ratio of compression.

The invention consists in an engine of this type wherein each cylinder is bored to three different diameters, the lower bore being of larger diameter than the intermediate bore, and the diameter of the top bore being slightly greater than the intermediate bore, but less than the bottom bore, said bottom bore forming an .expansion chamber for increasing the power stroke of the engine. The invention also contemplates the use in the top bore of a movable head, said head floating during the compression cycle of the engine, but being fixed during the combustion cycle, the extent of movement of said head in the top bore being adjustable whereby the ratio of compression may be varied to suit different grades of gasoline fuel.

With the above and other objects in view, which will appear as the description proceeds, the invention resides in the novel features hereinafter set forth, illustratedin the accompanying drawings and mor particularly pointed out in the appended claims.

Referring to the drawings in which numerals of like character designate similar parts throughout several views:

Fig. 1 is a top plan view of a portion or an internal combustion engine constructed in accordance with my invention;

Fig. 2 is a sectional view taken on line 2--2 of Fig. 1;

Fig. 3 is a sectional view taken on line 3-3 of Fig. 1, showing the position of th movable parts at the end of the compression stroke of the power piston;

Fig. 4 is a similar view but showing the parts at the end of the intake stroke of the piston;

Fig. 5 is a similar view but showing the parts at the end of the exhaust stroke of the piston,

and

Fig. 6 is an enlarged sectional view similar to Fig. 4, but showing the parts during the intake bored vertically into the desired number of cylinders, each of which is bored to three different diameters to form a top bore 2 of a predetermined diameter, an intermediate bore 3 of slightly smaller diameter than the top bore 2, and a bottom bore 4 of considerably larger diameter, depending upon the expansion ratio desired. The top bore 2 is formed in an upwardly extending portion 5 of the cylinder block I and accommodates an adjustable, movable head 6 in the form of a floating piston normally urged downwardly in abutting engagement with an annular shoulder 1 formed by the reduced intermediate bore 3, by means or compression springs 8 whose compression pressure may be adjusted by threaded guide studs 9 which project inwardly from threaded openings in a cover plate I!) secured on the top of the cylinder block I and closing the top of bore 2.- The upward travel of the movable head-8 is regulated by means of a stop plug ll screw-threaded into a central opening in the cover plate It. The periphery of the movable head 6 is referably provided with a plurality of annular grooves to receive expansion rings 6a.

The intermediate bore 3 and the bottom bore 4 accommodate a reciprocatin power piston P In the drawings, i represents a cylinder block having an upper head l2 fitting in the intermediate bore 3 and a lower head l3 in the bottom bore 4, the piston being connected to the conventional crankshaft l4 by mean of the usual connecting rod i5. Each of the heads l2 and 13 has peripheral grooves to-receive expan chamber It opens in communication with a shal low passage 24 which extends longitudinally inwardly in the block I and terminates in communication with the upper end of intermediate bore 3, as clearly shown in Fig. 6. From the valve chamber i8, where the width of the passage 24 issubstantially that of, the valve chamber, the passage 24 narrows down to approxi-. mately the diameter-of one 01' the valves l9 and 20, and the height of the passage 24 is equal to the vertical lift of. said valves in the valve chamber, thereby aiiording the necessary clearance.

Fuel is admitted to the cylinder through the shallow passage 24 and the charge is compressed between the upper head l2 of the piston P and the under side of the cylinder head 6, the comprcssion stroke of the piston forcing the cylinder head 6 against its stop plug H to form a compression chamber 2' in the top bore as clearly shown in Fig. 3.

. Valve chamber It also opens in communication with a second passage 25 (Figs. 3, 4, 5 and 6) extending longitudinally inwardly below passage 24 andvertically downwardly into the upper portion of the bottom bore 4, thereby establishing communication between the bottom bore 4 and the upper bores 2 and 3.

The enlarged bottom bore 4 together with the bottom head i3 of piston P operate only to increase the expansion ratio in the cylinder, and in order to prevent the fuel charge from entering this enlarged bore through passage 25 during the intake stroke of the piston P, I provide a balanced valve 26 in the valve chambers i8 intermediate the intake and exhaust valves 19 and 20, respectively, said valve being interposed in the passage 25 and adapted to reciprocate in a bore provided in the valve chambers. Valve 26 is preferably in the form of a piston having a bevelled inner end adapted to close on acomplementary bevelled valve seat in the bottom of the bore in chamber l8 and is operable by a cam 21 on cam shaft 23. Pressure is equalized on both the upper and under sides of the piston valve 26 by means of a by-pass 28; As in the case of piston P, piston valve 26 is provided with peripheral grooves to receive expansion rings 26a.

The upper portion of each of the valve chambers I8 is provided with threaded openings registering with the tops of the intake, exhaust, and piston valves I9, 20 and 26, respectively, to facilitate the removal and insertion of the respective valves, said openings being closed by threaded removable plugs 29, 30 and 3!, respectively.

In the side wall opposite the valve chambers i8, the block I is provided with a series of threaded openings for the reception of spark plugs 32, the inner ends of which openings terminate in the lower portion of the top bore 2 in communication with the compression chamber 2 formed between the top of the upper piston head i2 and the bottom of floating head 6, as seen in Fig. 3.

The three bores 2: 3 and] of each cylinder are cooled by means of a water jacket 33 surrounding the walls of, the cylinders.

It will be seen from the foregoing that there is no joint or gasket in any of the cylinders, and that the parts subjected to pressure from compression and combustion are all surrounded by the main cylinder block I'. Consequently, there can be no leakage of pressure or gasket blowouts, which have been a source of trouble with internal combustion engines now in use.

Having described the construction of my improved engine, its operation is as follows:

Referring to Fig. 5 wherein the cam 21 has just moved away from the piston valve 2! and the cam 22, not shown in this figure, but located behind cam 21 on cam shaft 23, has also moved away from its exhaust valve 20, said valves 2 and 20 having returned to closed position by their springs, the cylinder shown in this figure has just exhausted the gases and the floating head t is in abutting engagement with the shoulder I formed by the top of the intermediate bore 3. The reciprocating piston P has reached its top dead center and is about to start its downward stroke.

It will be observed from this figure that since there is practically no clearance between the floating head 5 and the piston P, all gases have been exhausted from the cylinder bore 3. During the downward movement of the piston P, the intake valve l5 opens by its cam 2|, while the piston valve 26 remains closed, allowing a fresh charge of fuel to be drawn only through passage 24 and into the intermediate bore 3 of the cylinder.

When piston P reaches its bottom dead center position as shown in Fig. 4, the intake valve l9 closes and piston valve 26. remains in closed position. 0n the upward movement of the piston P the charge in the intermediate bore 3 of the cylinder is compressed and the pressure created thereby forces the floating head '6 upwardly against its stop plug ii, thereby exposing the spark plug 32 to the compression chamber 2' formed between the floating head 6 and the top of the piston head I2. The compressed charge is ignited a few degrees before the piston P reaches its top dead center position, and combustion is completed as the piston starts its downward stroke.

Referring to Fig. 3 combustion has just taken place and is confined in the chamber 2' and narrow passage 24, all three valves 19, 20 and 25 being closed. As the piston P starts to move downwardly by the high pressure of the ignited gases. cam 21 has reached a position to raise piston valve 28 from its seat, allowing a part of the gases to enter passage 25 and into the bottom bore 4, creating an increased ratio of expansion on the bottom head [3 of the piston P. By having a definite ratio in area between the bottom bore 4 and the intermediate bore 3, considerable power is obtained to drive the crank shaft I 4, since practically all of the expansion pressure can be utilized, partly in the intermediate bore 3 and partly in the bottom bore 4. As the piston continues to move downwardly, the expansion pressure drops and when this pressure reaches the point at which the compression springs 8 for the floating head 6 have been set, the head 6 descends to its normal position on the shoulder 7.

The piston valve 26 remains open during the .entire downward travel of the piston P and when the latter reaches its bottom dead center position when the expansion is comple ed, cam 22 lifts exhaust valve 20. On the upward movement of piston P the piston valve 26 remains open so that all the expanded gases of combustion are ex- 5 hausted from the intermediate bore 3 through passage 24 and past valve 26, and from the bottom bore I through passage 25, and out through exhaust valve 20 into the exhaust manifold H.

The compression springs 8 on the floating head 6 are so designed that when the floating head is in normal abutting engagement with shoulder I, the pressure exerted by said compression springs will be slightly greater than the exhausting pressure, so that substantially all of the gases of combustion will be driven out of the cylinder since there is very little or no clearance between the upper head l2 of the piston P and the bottom of the floating head 8 when the power piston reaches its top center posltion,.and only the gas in passage 25 remains after exhaust. Thus, on the following intake stroke of the piston, the charge introduced will be uncontaminated with non-combustible gases with the result that a richer mixture is drawn in the cylinder which will produce better combustion and higher pressure.

The operation of the upper head l2 'of piston P is a four-cycle operation, namely, intake stroke, compression stroke, power stroke, and exhausting stroke, while that of the bottom head I3 is in the nature of a modified two-cycle operation,

that is, power stroke, and exhausting stroke, the succeeding two strokes not accomplishing any work or developing any power inasmuch as the piston valve 26 is closed. Thus the lower head I3 and bottom of large bore 4 are used merely to increase the ratio of expansion to drive the crankshaft M as no charge enters the bore 4, and no compression or combustion take place therein.

It is obvious that the expansion ratio can be so increased by this arrangement that the exhaust pressure will be only a few pounds above atmospheric, thereby obtaining all power possible from the expansion of the gases to drive the crankshaft, and more than doubling the power obtained. from gasoline with engines now in use.

It will also be seen that by having the floating head 6 whose extent of upward travel can be regulated by the adjustable stop plug ii, the area of the compression chamber 2' can be adjusted to vary the ratio of compression in the cylinder., It is well, known that this ratio of compression is based-on the grade of gasoline fuel to be used in the engine, and is usually restricted to within certain limits which cannot be exceeded, as otherwise pre-ignition would occur. Moreover, this ratio is set to operate where the highest grade of gasoline is used, and when a lower grade of fuel is employed in the engine, much power is lost by virtue of the fact that the lower grade fuel, which can be compressed more than the high grade cannot be compressed to its optimum pressure with the engine already set with a fixed, definite clearance between piston head and cylinder head. With the use of the floating head 6, such as described above, by

simply adjusting the pressure of the compression springs E] by the guide studs 8, and regulating the extent of upward travel of floating head 6 by screwing or unscrewing the stop plug II, the

I compression chamber can be aifiusted to render the engine equally eilicient with different grades of fuel.

Furthermore, this floating head becomes a fixed head during the combustion cycle of the engine, for the reason that just prior to the ignition of the charge, the head 6 has been forced upwardly against its stop plug H during the .compression stroke of the piston. Consequently, there is no loss of compression during combustion.

While I have shown and described the water jacket 33 as extending downwardly to surround the'walls of the enlarged bottom cylinder bore 4, this portion of the water jacket may be eliminated to advantage as this cylinder bore is used only for expansion. Therefore, a high temperature will tend to maintain a higher temperature for expanding gases so that the pressure will not drop as rapidly in this cylinder bore, giving a higher mean efiective pressure with resultant higher efliciency to the engine.

From the foregoing, it is believed that the construction and advantages of my invention may be readily understood by those skilled in the art without further description, it being borne in mind that numerous changes may be made in the detailsglisclosed without departing from the spirit of my invention asset out in the following claims.

said bottom bore, and valve means in said by- I pass for controlling the communication between said compression chamber and said bottom bore, said valve means opening during the power stroke of the piston to increase the ratio of expansion in said cylinder.

2. An internal combustion engine, comprising in combination a cylinder block with a plurality of cylinders, each cylinder in said block being bored to diiierent diameters to'iorm a top bore portion and a bottom bore portion, the diameter of said bottom bore portion being greater than that of said top bore portion and being dependent upon the ratio of expansion, 9. power piston in said cylinder having upper and lower heads of different diameters to fit said top and bottom bore portions, a compression chamber formed by. said top bore portion and said upper head, fuel igniting means in said compression chamber, and means for establishing communication between said compression chamber and said bottom bore portion during the power stroke of said piston to increase the ratio of expansion in said cylinder. 4

3. An internal combustion engine comprising in combination a cylinder block with a plurality of cylinders, each cylinder in said block being bored to different diameters to form a top bore portion and a bottom bore portion, the diameter of said bottom bore portion being greater than that of said top bore portion and being dependent upon the ratio of expansion, at power piston in said cylinder having upper and lower heads of different diameters to fit said top and bottom bore portions, a compression chamber formed by said upper head and said top bore portion, fuel igniting means in said compression chamber, a bypass connecting said compression chamber with said bottom bore portion, and valve means in said by-pass for controlling the communication between said compression chamber and said bottom bore portion, said valve means opening during the expansion and exhaust cycles of said cylinder, and closing during the intake and compression cycles of said cylinder.

Y tablishing communication between said compression chamber and said bottom enlarged bore during the power stroke of said piston, whereby the ratio of expansion is greater than the ratio of compression.

5. In an internal combustion engine, a cylinder block having-a plurality of cylinders, eachcylinder in said blockbeing bored todiiferent diameters to form upper and lower bore portions, the diameter of said bottom bore portion-being greater than said upper bore portion-and being dependent upon the ratio of expansion. a power piston in each of said cylinders having upper and lower heads of diiIerent diameters to tit said top and bottom bore portions, an intake and exhaust manifold secured to one side of said block, a separate valve chamber in said block for each cylinder in communication with said maniiold, a separate passage in said block for each cylinder in communication at one end with said valve chamber and at its other end with the top of said upper bore portion, inlet and exhaust valves in said valve chamber for selectively controlling the admission of a fuel charge and the exhaust of gases through said passage, said upper head of the piston cooperating with said top bore portion to form a compression chamber in said cylinder,

fuel igniting means in said compression chambers, and means for establishing communication between said'compression chamber and said bottom bore portion during the power stroke oi said powerpistcn to increase the ratio of expansion in said cylinders, respectively.

6. In an internal combustion engine, a cylinder block having a plurality of cylinders, each cylinder in said block being bored to difierent diameters to form upper and lower bore portions, a power piston in each of said cylinders having an upper and a lower head of diflerent diameters to fit said top and bottom bore'portions, said upper head cooperating with said top bore portion to form a fuel compression chamber, an intake and exhaust manifold secured to said cylinder block, a shallow passage for each cylinder opening at one end into said manifold and at its opposite end into said compression chamber, inlet and exhaust valves for selectively controlling the admission of a fuel charge to said compression chamber and the exhaust of gases therefrom, means in said compression chamber for igniting the fuel charge compressed, and a valved bypass for establishing communication between said compression chamber and said bottom bore portion during the power stroke of said power piston, for increasing the ratio of expansion in said cylinder beyond the ratio of compression.

ROSEMOND L. LANDRY.

Images