US2782777A

US2782777A - Internal combustion engines

Info

Publication number: US2782777A
Authority: US
Inventors: Elmer P Jasper
Original assignee: Individual
Current assignee: Individual
Priority date: 1953-09-01
Filing date: 1953-09-01
Publication date: 1957-02-26
Anticipated expiration: 1974-02-26

Description

Feb. 26, 1957 E. P. JASPER INTERNAL COMBUSTION ENGINES Filed Sept. 1, 1953' 3 Sheets-Sheet l INVENTOR. Elmer- R Jasper BY Feb. 26, 1957 E. P. JASPER INTERNAL COMBUSTION ENGINES 5 Sheets-Sheet 2 Filed Sept. 1, 1953 INVENTOR. E/mer' P. Jasper Feb. 26, 1957 E. P, JASPER INTERNAL COMBUSTION ENGINES 3 Sheets-Sheet 3 Filed Sept. 1, 1953 ///llI//I///I//Il INVENTOR. E/mer R Jasper BY His flfforney United States Fatent Q INTERNAL COMBUSTION ENGINES Elmer P. Jasper, Algonac, Mich.

Application September 1, 1953, Serial No. 377,890

Claims. (Cl. 123-73) The invention relates to internal combustion engines and more particularly to internal combustion engines of the two-stroke cycle type utilizing crankcase compression for charging the combustion space.

It is an object of the invention to provide an improved internal combustion engine of the two-stroke cylce type utilizing crankcase compression for charging the combustion space, and which has better performance and smoother operation than has been previously available in such engines. I

It is also an object of my invention to provide such an engine having features which produce better turbulence and scavenging.

It is a further object of my invention to provide in such engines an arrangement which eliminates the diificulties caused by the accumulation of heavy fuel fractions and oil residues at the bottom of the crankcase, and which cause unsatisfactory performance.

Another object of the invention is to provide a combination intake manifold, valve and carburetor mounting bracket adapted for convenient mounting upon the crankcase of such an engine.

Further objects and advantages are within the scop of the invention, such as relate to the arrangement, operation and function of the related elements of the structure, to various details of construction and to combinations of parts, elements per se, and to economies of manufacture and numerous other features, as will be apparent from a consideration of the specification in conjunction with the drawings disclosing specific embodiments of the invention, wherein similar reference characters are applied to corresponding parts throughout, and in which: i 1

Fig. 1 is a sectional view taken axially through the cylinder of the engine, the connecting rod being shown in elevation, this view being partially diagrammatic with flow indicating arrows for explaining the operation of the engine;

Fig. 2 is an enlarged portion of Fig. 1 showing the combination crankcase intake manifold, valve and carburetor mounting bracket, portions of the crankcase and carburetor being shown dotted;

Fig. 3 is a plan view looking squarely at the valve plate;

Fig. 4 is an enlarged sectional view on line 4-4 in Fig. 3;

Fig. 5 is a sectional view on line 55 on Fig. 1; and

Fig. 6 is a sectional view on line 6-6 in Fig. 1.

Referring more specifically to Fig. 1 of the drawings, I have illustratively disclosed an air cooled internal combustion engine 11 comprising a closed crankcase 13 hav ing a crank shaft 15 rotatively supported in end wall bearings 17, shown clotted, in a usual manner. An air cooled cylinder 19 is provided having one end mounted and secured to the upper side of the crankcase structure from which it rises vertically enclosing a bore 21 wherein a piston 23 is disposed in a slidable power sealed relation, in a usual manner. If desired, the cylinder and Z ,78Z,7 77 Patented Feb. 26, 1957 crankcase may be integral. Power transmission connecting means, such as the connecting rod 24, connects operatively from a wrist pin 25 in the piston to the crank with its crank pin bearing 26 on the crank pin 27 of the crankshaft 15 so that the shaft is caused to rotate by the reciprocating movements of the piston in the cylinder. The shaft 15 may be extended to deliver power to be applied at a remote point in a usual manner, and a mounting flange 28, extending from the crankcase, may be suitably apertured for mounting the engine.

Also, as usual in engines of this type, the cylinder is formed to provide an intake port 29 and an exhaust port 31. These ports open through the sidewalls of the cylinder at suitable axial positions to be opened and closed at proper times by the reciprocating piston in accordance with the usual practice in two-cycle engines utilizing crankcase compression, and a transfer conduit 32 conmeets the intake port 29 to side port 34 in the crankcase.

In accordance with my invention the cylinder is provided with end closing wall means, which may be a detachable cylinder head 33, for closing the outer end of the cylinder and cooperating with the piston, to form a special dome shaped combustion chamber bulging outwardly. To provide this combustion chamber I form the inner surface 35 of the cylinder head 33 with a spherical shape which is substantially a sphere about the center, or point, designated X in Figs. 1 and 6.

As Shown, this spherical center point X is located.

approximately midway between the axis of the cylinder bore and the sidewall thereof. As shown, the axial position of this center point is at a point between the middle of the cylinder and the crankcase end of the who der, or it may be said to lie in a plane intersecting the cylinder axis at a position between the middle of this cylinder axis and the crankcase end thereof. The upper or closed end of the piston 23 is provided with a similar spherical surface 37 for defining the other side of the combustion chamber. As the piston arrives at the end of its upward or compression stroke, as shown in full lines in Fig. 1, the two spherical surfaces are substantially concentric, and the combustion chamber is the space S enclosed between these two surfaces. This arrangement of the cooperativesurfaces for thus enclosing the combustion chamber provides domed surfaces which are higher at one side of the piston than at the other side thereof. 'Into this high side of the bulged spherical domed piston, a charge receiving recess or cavity 39 is formed. This cavity 39 is at a position which comes into alignment with the intake port 29 when the piston is at the position, as shown, by the dotted lines, and it serves as a baffie to deflect the entering charge upwardly toward the combustion chamber and away from the exhaust port. When the piston moves up on its compression stroke, this charge receiving recess 39 is brought into the proximity of an ignition device 41, such as a spark plug, which is mounted in an aperture 43 in the cylinder head. This conditions the adjacent charge for effective ignition and firing of the remainder of the compressed charge, as well as also providing for improved turbulence and scavenging.

As may be seen in Fig. 1 and more clearly in Fig. 2, the bottom of the crankcase is provided with a large aperture 45, which is located slightly to one side of the center line C-C, and the crankcase is provided with an inclined drainage surface 46 sloping downwardly beyond the center of the bottom of the crankcase and into the side of the aperture which lies adjacent or toward the center line of the crank-case. As maybe seen in Figs. 1

and 2, this aperture in the bottom of the crankcase ex.

tends toward the left-hand side sloping upwardly and it is provided with square alignededges whereupon a valve plate or mounting base 47 may be snugly secured. Yieldable gasket means 51 may provide a snug seal. The valve plate 47 is provided with a valve port 53 and, as shown, there may be two such valve ports in a side-by-side relation, as seen in Figs. 2 and 3, or if desired more valve ports may be provided in cooperative relation in the valve plate.

To freely admit air into the crankcase while restricting the flow therefrom, this valve plate is provided with a pair of flap or reed valves 55, each being a thin sheet of resilient metal, or other material. These thin valve reeds 55 are disposed upon the upper inclined surface of the valve plate 47 in a snug seating relation over the respective valve ports 53. Theupper end of each valve reed 55 is secured upon the upper end of the inclined valve plate by a corresponding screw 57 passed th-erethrough into the base. These screws press the upper end of a guard plate 59 upon the upper ends of the valve reeds. The other or downward end of the guard plate 59 is curled up smoothly above the lower ends of the valve reeds 55 leaving these free to raise up a predetermined distance to open the valve ports 53- and admit air when there is a suitable pressure difference.

As may be seen in Figs. 2 and 3, the resilient valve reeds are made slightly larger than the valve ports 53 to seat thereon in a snug sealed relation. To hold the reeds 53 properly aligned upon the valve plate the upper portion of the latter is apertured to receive two pairs of reed positioning stop pins 60 spaced so that one pair of pins engages the upper edge of each valve reed. The upper end of each stop pin is cut away on opposite sides to provide fiat surfaces 61 for engaging the upper edge of each adjacent valve reed 55. As maybe seen more clearly in Fig. 4, these stop pins 60 are held down by the upper edge of a reinforcing strip cap 62 on top of the guard plate 59 and clamped thereon by the screw 57.

To serve also as a carburetor mounting bracket, the valve base 47 is also provided with a horizontally extended and vertically aligned base 63 having a flow passage 64 extended therethrough from the valve ports 53. The vertically disposed edges of this horizontally extended base 63 are provided in fiat alignment for snugly receiving a carburetor 65 by which the ingoing air stream is properly charged with fuel vapor as it fiows through the valve into the crankcase. The valve base 47 thus serves still further as a carburetor mounting bracket and also as an intake manifold for connecting from the carburetor to the engine. The charge is admitted substantially tangentially in the direction of rotation.

The heads of the bolts 57 are held in hexagonalapertures in a bolt head locking plate 67, to avoid loosening l locking plate 67 thereon and to thereby permanently hold the bolt in the snug clamping positions. In operation, the inward flow of fuel charged air picks up the heavier fractions of fuel and oil residuewhich settle to the bottomof the crankcase. This residue flows along the sloping incline 46 tothe low point at a position where the vibrating or fluttering movements of the free end of the valve reed provides agitation which causes it to be in a finely divided condition and aids in impregnating the air stream with it. And as these heavier products flow into. the charge receiving recess or cavity 39 in the top of the piston the vaporization. is further completed. The improved turbulence and scavenging provided by the especially. shaped combustion chamber cooperates in assuring good combustion of such'a charge and a smooth runningengine isthe result. v

The motions of. the crank pin bearing 26 are also utilized" to aid further in whipping up the heavy oil residues into the fuel charged air in the crank-case. This is accomplished by making the crankcase 13 of a. particular shape for this purpose, as, may be seen. in Fig s.1 and 5,

and also disclosed in my co-pending patent application Serial No. 377,893 executed and filed September 1, 1953, concurrently herewith. As shown in Fig. 1, the outer sidewall of the crankcase is shaped, at least on the inside, so that the inner adjacent surface 70 thereof closely follows the path of the outermost projecting corners, screw heads and outward projecting point of the crank pin bearing 26 as it is carried around by the crank pin 27. The adjacent crankcase surface follows the parallel lines generated by these outer points moving with this crank pin bearing as it rotates, which lines are not circles. This special outer sidewall shape is of course not present at the top of the crankcase where the cylinder is attached, nor at the bottom where the reed valve and intake manifold are attached, nor in the sloped surface 46 which leads down to this manifold from the bottom of the crankcase, and also opens into the side port 34 of the crankcase.

As a, resultrof the close fitting sidewall shape of most of the ,outer wall of the crankcase the high velocity rotation of the crank pin bearing 26 in the clockwise direction indicated by the arrow, pushes a cloud of gaseous mixture beforeit and throws it into the lower end of the intake conduit 32 to be carried up with the charge into the intake, port 29rof the cylinder. tively utilize the rapid motions of the' connecting rod bearing to whip up the gaseous mixture, the outer wall of the crankcase is made thick on both sides of the orbit of the connecting rod' hearing so that a narrow groove 71 is' defin'edfor closely confining it in cooperation with the outer wall or bottom surface 70, as may be seen in Fig. Send, as the crank pin bearing 26 of the connecting rod rotates withtlie. crank pin, being confined both at the front and rear. as well as on the outer side, its high velocity movements are effective to whip up the heavy fuel fractions and the oil residue which have been pickedup by the fuel charged air as it enters the crankcase, and keeps this oily mist in a stateof suspension. Also these movements of the crank pin bearing 26, so utilized, act to push this oily mist along in a clockwise direction, as seen in Fig. 1,. thereby lifting it to the side port 34 of the crankcase and throwing it into the side conduit 32 to be carried along up to the intake port 29 of the engine with the charge. Operation in this manner clears the crankcase'of the heavy oil residues and assures a smooth running engine at all times.

' The spark plug 41 is supplied with high tension electrical impulses in properly timed relation from a conventional magnetoor ignition system (not shown). Starting the engine is accomplished by giving it an initial rotation in a usual manner.

' The features of myimproved crankcase relating to the herein disclosed especially shaped groove 71 for closely confining the outer portions of the rotating crank pin bearingare also disclosed and claimed in a different crankcase structure and engine combination in my copending United States Patent Application for Versatile Internal Combustion Engine, Serial No. 377,893, filed September 1', 1953, concurrently herewith, as previously mentioned.

Itis apparent-that within the scope of the invention modifications and difierentarrangements may be made other than herein disclosed, and the present disclosure is illustrative merely, the invention comprehending variations thereof. w t w v What I claim as new and desire to secure by Letters Patent of the United States is:

' 1. Ina vertical cylinder two-cycle internal combustion engine utilizing crankcase compression for charging the combustion space, a crankcase having a bottom thereon, an intake 'manifoldmounted on the bottom of the crankcase. having an intake passage therein disposed tangentially thereto for admitting a charge of fuel. gas tangentially thereto at the low point in the bottom of the crankcase, and a reed type intake check valve mounted on To still more efiec-.

the crankcase attached end of the manifold with the vibrating end of the reed at a low point in the crankcase whereby to agitate the heavy fuel fractions and oil residues to commingle with the entering fuel charged air.

2. An internal combustion engine in accordance with claim 1 and further characterized by said reed being mounted in an inclined position with the secured end of the reed disposed at the high level of the inclined position and the vibrating end of the reed disposed at a lower level whereby to agitate and intimately commingle with the entering charge the heavy fuel fractions and the oil residues which tend to settle to the bottom of the crankcase.

3. An internal combustion engine in accordance with claim 1 further characterized by having a curved guard disposed snugly upon the upper end of said reed and curving above the reed at the lower end to limit its movement upwardly from said end of said manifold, and a screw extending through the upper end of said guard and the reed into said end of said manifold to clamp the guard and the reed snugly thereon.

4. An internal combustion engine in accordance with claim 3 further characterized by having reed positioning stop means abutting the upper edge of the reed to hold the reed properly aligned upon said end of said manifold.

5. An internal combustion engine in accordance with claim 4, and said reed securing stop means comprising a pair of stop pins disposed in spaced positions on said end of said manifold with the upper ends of said pins exposed, and the upper exposed ends of said stop pins having flattened surfaces for engaging the upper edge of the reed.

References Cited in the file of this patent UNITED STATES PATENTS 617,372 Truscott Jan. 10, 1899 1,214,396 Wainwright Jan. 30, 1917 1,404,551 Seymour Jan. 24, 1922 1,494,176 Little May 13, 1924 1,965,812 Shippee July 10, 1934 1,977,657 Watson Oct. 23, 1934 2,118,761 Johnson May 24, 1938 2,124,196 Kottsieper July 19, 1938 2,154,975 'Dufour Apr. 18, 1939 2,273,202 Jackson Feb. 17, 1942 2,289,201 Martin July 7, 1942 2,311,833 Holland-Letz Feb. 23, 1943 2,391,380 Barker Dec. 25, 1945 2,397,457 Krenzke Mar. 26, 1946 2,549,482 Kiekhaefer Apr. 17, 1951 2,607,329 Suhadolnik Aug. 19, 1952 2,639,699 Kiekhaefer May 26, 1953