US2314789A - Internal combustion engine - Google Patents

Description

March 23, 1943; E, BSEN 2,314,789

INTERNAL COMBUSTION ENGINE Filed June l7,' 1958 2 Sheets-Sheet l March 23, 1943. E. JAcoBsEN 2,314,789

INTERNAL COMBUSTION ENGIiXE I I Filed June 17, 1938 2 Sheets-Sheet 2 INVEN TUE Patented Mar. 23, 1943 UNITED STATES PATENT OFFICE y INTERNAL COMBUSTION ENGINE Edwin Jacobsen, Glendale, Calif. Application June 17, 1938,-Scrial No. 214,229

7 Claims.

My invention relates to improvements in engines and the like in which the connecting rod is hinged intermediate of its ends and having a mechanism acting on the hinged connecting rod for varying the position of the piston relative to the position normally indicated by the position of the crank shaft.

The primary object of the invention is to provide an engine wherein the piston makes predetermined progress in its course of travel while the crank shaft travels at uniform angular velocity.

A further object of the invention is to provide an engine with greater thermo efliciency than heretofore attained.

A further object of the invention is to provide an internal combustion engine that will permit a higher compression ratio to be employed, than generally permissible, without detonation.

A further object of the invention is to provide an internal combustion engine wherein the maximum internal stresses are reduced.

A further object of theinvention is to provide an internal combustion engine that will produce a greater horse power per unit weight than heretofore attained.

With these and incidental objects in view, the invention consists in certain novel features of construction and combination of parts, the essential elements of'which are set forth in the appended claims, and a preferred form of embodiment of whichis hereinafter shown with reference to the drawings which accompany and form a part of this specification.

In the drawings: Fig. 1 is a side elevation of the engine. v Fig. 2 is an enlarged cross-sectional view taken on, line 2-2'Fig. 1.

Fig. 3 and Fig. 3A are diagrams of the positions I of the several parts of the engine, plotted-for every twenty-two and one-half degrees travel of the crank shaft.

Fig. 4 is a diagram of the piston positions of a conventional engine comparable'in size to the one shown in Fig. 2 and the diagram in Fig. 3.

.Fig. 5 is a fragmentary top view of the connecting rods showing the bifurcated ends.

The block and base casting l, its cylinder head 2. the valve cover 3, the gear case cover 4, and

the oil pan 5, constitute the main stationary part of the engine. The valve 8, the valve spring. I. the.vaive keeper 8, the valvelifter 9, and the cam shaft l are conventional in design and operation. The piston H and the crank shaft II are also conventional. The connection betil - secured to the piston by the piston pin l'l.

tween these two elements is accomplished with the connecting rods l3 and I4, and for this description are referred to as the main connecting rods. The auxiliary connecting rod I is freely hinged to the rods 13 and M by the common pin l6 and the upper end of the rod 13 is movably The lower end of the connectingrod I4 is journaled to the crank pin I 8 and the large end of the auxiliary connecting rod I5 is journaled to the crank pin l9, which is a part of the auxiliary crank shaft 20. Both of the crank shafts turn clockwise as indicated by the arrows and are geared together by the gears 2| to turn'in unison,

by which term is meant that 'the two shafts.

function in exactly the same manner, rotating at the same speed in the same direction. The

v cam shaft is also geared to the main crank shaft and the above mentioned gears are all enclosed by the gear case cover '4.

As force is applied to the piston it sets the crank shaft l2 in motion and it in turn imparts motion to the auxiliary crank shaft 20. The influence of the latter shaft on the connecting rods I3 and H is to either shorten or lengthen the distance between the piston pin l1 and the crank pin l8, and this action. gives the piston a mug-- ress in its travel not indicated by the position of the crank pin l8.- Hence by careful planning it is possible to give, the piston a predetermined motion desired to better conform to the burningand expansion characteristics of the fuels ticular application showing the relative posi-v tions, of the crank pins l8 and IS, the pin l6 and the piston. I use theletters in the diagrams to mark the position of these parts at twenty two andone half degree intervals of the crank shafts travel. The letter a designates the piston, crank pins, and the position of the pin l6, as-shown in Fig. 2. The piston positions ai'e indicated on thevertical line a to 1' on theright side of the line indicating the intervals "on the downward stroke. thence returning on he leftside k to 1 indicating the intervals on the upward stroke. For comparison and to better illustrate the in- Also to arrest undue conversion ofthe charts that in the first twenty-two and one:

. half degrees of crank shaft rotation that the piston travel a to b is much greater in Fig. 3 than in Fig. 4. This condition will permit the use of a higher compression ratio in the former and also reduce the maximum interval stresses which usually occur in this range. By further comparison of the charts it may be seen that not only are the torque characteristics of this engine different, but it also permits the utilization of a greater portion of the available heat. It is interesting to note that in the particular engine shown that the piston is not at bottom dead center until the crank pin 18 reaches the a position as noted in, the diagram, or twenty-two and onehalf degrees past bottom dead center. The character of the piston travelmay be varied by varying the timing between the crank shafts l2 and 20, or by changing the position of either of the crank shafts or by varying the link mechanism made up of the three connecting rods l3, H, and

I5. I prefer and show a harmonic link mechanism but good results and even greater latitude is offered by cam, intermitting or quick return motions so well known to the mechanical arts.

The action on the piston by any of the above mechanisms can be used to produce desirable results on the induction, compression, expansion and exhaust strokes of the four stroke cycle engine as shown in the drawings. It is obvious that it is just as applicable to the ported or two stroke cycle engines as well as other engines using pressure to move a piston. l

While the form of mechanism herein shown and described is admirably adapted to fulfill the objects primarily stated, it is tobe understood that it is not intended to confine the invention to the one form of embodiment herein shown and described as iti susceptible of embodiment in various forms all coming within the scope of the claims which follow.

I claim:

1. In an internal combustion engine, a piston, a crankshaft intersected by the piston axis, a connecting rod interconnecting the piston and crankshaft and made in two parts hinged together, an auxiliary crankshaft at one side of the piston axis, a pitman from said auxiliary crankshaft to the hinge of said rod, and means causing the two shafts to rotate at the same speed.

2. The combination with the piston and crankshaft of an internal combustion engine, of a connecting rod directly interconnecting said two parts, said rod having a hinge joint intermediate its ends, an auxiliary crankshaft at one side of said rod, a pitman from the crank of said auxiliary shaft to the hinge joint of the rod, and

means causing the two shafts to rotate at the same speed in the same direction.

3'. The combination with an engine piston and crankshaft, of a connecting rod therebetween,

and means operatively connected with said rod for imparting increased movement to the piston relative to the crankshaft movement at the beginning of the power stroke, deceased relative piston movementduring the center portion of the stroke and gradual increase of movement during the remainder of the power stroke.

4. In combination with the piston and crankshaft of an internal combustion engine, of a connecting rod directly interconnecting said two parts, said rod having a hinge intermediate its ends, an auxiliary crankshaft at one side of said rod, a pitman from the crank of said auxiliary shaft to the hinge joint of the rod, and means causing the two shafts to rotate at the same angular speed.

5. The combination with an engine piston and crankshaft, of a' connectin rod therebetween. and means operatively connected with said rod for imparting greatly increased movement to the piston relative to the crankshaft movement during the first twenty-two and one-half degrees of movement of the latter on the power stroke, sharply decreased relative piston movement during the center portion of the stroke and sufficient gradual increase. of movement of the piston during the remainder of the power stroke to equalize the power stroke with the intake stroke.

6. The combination with an engine piston and crankshaft substantially alined therewith, of a composite connecting rod directly interconnecting said parts, and means operatively connected with said rod gradually to modify the relative angular position of its component parts during the piston movement, thereby to cause greatlv accelerated speed of the piston during the initial power stroke, greatly decreased piston speed during the center portion of the stroke and graduall increased speed during the remainder of the stroke.

7. In an internal combustion engine having-its piston axis intersecting the crankshaft center, a two-part piston rod pivotally joined intermediate its ends, and means operatively connected to the joint of said rod'for controlling the angular in stroke, and sufllcient gradual increase of pistonmovement during the remainder of the power stroke to equalize it with theintake stroke.

EDWIN JACOBSEN.

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