US1786423A - Internal-combustion engine - Google Patents

Description

Dec. 30, 1930. c. P. CADY INTERNAL COMBUSTION ENGINE Filed May 7, 1928 ATTDH EVS Patented Dec. 30, 1930 UNITED STATES CHARLES I. GADY, OF CANAS'I'OTA, NEW YORK INTERNAL-COMBUSTION ENGINE Application. filed May 7,

This invention relates to an internal combustion engine and while it is adapted to be used more particularly in connection with engines of the four-cycletype it may obviously be used in connection with any internal combustion engine having a reciprocatory piston and crank shaft and refers more particularly to the means for transmitting motion from the engine to the crank shaft and vice versa.

The main object is to provide simple and eflicient means for producing differential lengths of strokes of thepiston in such manner as to result in more power and greater economy in operation than has heretofore been practiced.

One of the specific objects is to cause a continuation of the exhaust stroke beyond the limit of the firing stroke so as to effect a more thorough cleansing of the cylinder from the products of combustion than has heretofore been practiced.

Another object is to cause the fuel intake or suction to begin beyond the end of the compression stroke so as to take in a larger volume of the explosive mixture into the combustion chamber of the cylinder than the maximum volume of the compressed gases expelled by the exhaust stroke.

A further object is to continue the compression stroke to within a relatively short distance from the end of the exhaust stroke so as to effect a corresponding relatively high compression of the increased volume of the mixture preparatory to ignition.

Another object is to terminate the firing stroke a relatively short distance from the beginning of the compression stroke or at about the time that the exhaust valve begins to open so as to further expedite the expulsion of thespent gases during the succeeding but somewhat longer exhaust stroke of the piston.

Another object is to cause the piston to 5 move through its compression and exhaust strokes with greater speed than the actuating crank ofthe crank shaft so as to produce a more rapid compression of the mixture and also a more rapid expulsion of the r spent gases.

1928. Serial No. 275,728.

Other objects and uses will be brought out in the following description.

In the drawings Figures 1, 2, 3' and 4" are diagrammatic views of a cylinder and piston movable there- 1n together with the crank shaft and mechanism for transmitting motion from the piston to the crank shaft and vice versa showing the movable parts in different positions, as, for example, the end of the exhaust stroke or beginning of the intake or suction stroke, the end of the intake stroke or beginning of the compression stroke, the end of the compression of or beginning of the firing stroke and the end of the firing stroke or beginning of the exhaust stroke respectively.

Figure 5 is a diagrammatic View of slightly modified means for effecting the angular adjustment of the eccentric bearing for the lever.

The cylinder or cylinders 1- may be of any well-known construction having the usual valved intake and exhaust ports and other adjuncts, not shown but required in internal combustion engines of this type,

The piston as -2 may also be of any well-known construction commonly used in internal combustion engines adapted to be connected in a manner hereinafter described to the crank shaft -3 of the engine for transmittingmotion thereto and for receiving motion therefrom, it being understood that the crank shaft will be provided with the usual balance wheel, not shown.

The mechanism for transmitting motion from the piston to the crank shaft and vice versa comprises, in this instance, a lever 4 having one end connected by a pitman link 5 to the piston 2- and its intermediate portion connected by a link -6- to the crank arm as -3' of the crank shaft -3-.

The other end of the lever -4 ispivotally journaled or fulcrumed upon a journal bearing -7 which is eccentrically mounted upon a shaft -8- to move about the axis thereof for the purpose of varying the lengths of different strokes of the piston as will be hereinafter more fully explained.

The shaft 8- may be supported in any suitable manner not necessary to herein illus- 10( trate or describe to rotate about an axis parallel with the crank shaft 3 and preferably in a horizontal plane between the crank shaft and cylinder and in a vertical plane some distance to one side of the axis of the cylinder corresponding as closely as practicable to the length of the lever 4 so as to cause the pitman -5 to travel rectilinearly as nearly as possible to the axis of the cylinder and thereby to reduce lateral thrust upon the piston incidental to the changing positions of the pivotal connection between the pitman and lever.

The pivotal connections of the link -6 with the crank shaft 3 and lever 4- are also arranged in such manner as to cause the link to travel endwise as nearly as possible in a plane arallel with the axis of the cylinder. As ilustrated, the pivotal connection of the link 6- with the lever 4.- is approximately midway between the axis of the eccentric bearing 7 and pivotal connection of said lever with the pitman 5 for the purpose of moving-the piston through its exhaust stroke and compression stroke with an accelerated motion in excess of the speed of movement of the crank arm 3' of the crank shaft and thereby causing a more rapid expulsion of the spent gases from the combustion chamber and also producing a more rapid compression of the explosive mixture in said chamber.

This rapid expulsion of the spent gases from the combustion chamber is highly important in engines of this type for the reason that it produces a more thorough scavenging or cleansing of the spent gases from the cylinder.

The acceleration of the compression stroke of the piston produces a more thorough agitation and homogenization of the explosive mixture and at the same time increases the temperature of the mixture by reason of the ra id compression, all of which is desirable in t at it increases the inflammability and expansive force of the united gases, resulting in greater economy in fuel and also in greater power of the engine.

The eccentric shaft -8+ may be the cam shaft of the engine having the usual cams, not shown, for operating the valves which control the fuel intake and exhaust of the spent gases and for this purpose, the eccentric shaft is shown as driven from the crank shaft through the medium of a pinion 9- and gear 10 mounted respectively upon the crank shaft 3- and eccentric shaft 8 and having a gear ratio of, in this instance, one to two for operating the cam shaft 8 at half the speed of the crank shaft in a manner somewhat similar to the usual means for transmitting motion from the crank shaft to the cam shaft of four-cycle internal combustion engines.

It is evident, however, that the shaft 8- may be entirely independent of the cam shaft of the engine and may or may not be driven directly from the crank shaft or other parts of the engine so-long as the position of the bearing 7 is changed at intervals to produce the desired variation in the lengths of the strokes of the piston and, as illustrated, the movement of the eccentric bearing 7- around the axis of the shaft 8 and linkto expel all of the spent gases from the combustion chamber while the compression stroke of the piston is caused to terminate slightly short of the limit of the exhaust stroke, the firing stroke terminating slightly short of the limit of the intake and compression strokes as indicated b the indicia at the right hand end of the gures showing the relative lengths and limits of the various strokes of the piston.

For example, assuming that the fuel intake valve and exhaust valve are functioning in the usual manner for four-cycle internal combustion engines and that the moving parts are in the position shownin Figure 1 with the piston at the limit of its exhaust stroke or at the beginning of its fuel intake stroke considerably closer to the upper end wall of the cylinder than when it is at the limit of its compression stroke in which case the eccentric bearin 7 will be at an angle of approximate y forty-five degrees at the left of a vertical line passing through the axis of the shaft 8 and below the horizontal plane of said axis, then as the crank shaft continues to rotate in the direction indicated by arrow :v through one-half revolution the eccentric .7 will be moved in the direction indicated by arrow y through a quarter revolution thereby causing the piston to move through its complete intake stroke or some distance beyond the end of the firing stroke as shown in Figure 2.

Durin the next or second half revolution of t e crank shaft and resultant movement of the eccentric bearing 7 through its next or second quarter turn from the pos tions shown in Figure 2 the piston 2- will be moved. through its complete compression stroke which, however, will terminate somewhat short of the end of the compression stroke or to the position shown in Figure 3.

As the crank shaft continues to rotate through the next or third half revolution and the eccentric 7- is moved through its next or third quarter revolution from the positions ton 2 will be moved through its complete exhaust stroke beyond the limit of the compression stroke or to the starting posi tion shown in Figures 1 thus completing the cycle of operation of the engine.

It is now evident that the differential strokes of the piston is effected and controlled in the manner described by the different angular positions of the eccentric bearing 7 in their particular relation to the angular positions of the crank arm of the crank shaft as produced to the medium of the lever -4- and links -5 and -6.

The mechanism for varying the lengths of the different strokes of the piston as thus far described is entirely automatic and timed with the rotation of the crank shaft but, if desired, the lever-sup iiorting eccentric 7- may be adjusted angularly about the axis of the shaft 8- by manually operated means such as shown in Figure 5 in which case the pinion '9 could be omitted and a toothed rack -12-, Figure 5, engaged with the teeth of the gear 10- for rotating the gear and its eccentric bearing -7- as may be desired to produce the desired variations in the different strokes of the piston, it being understobd that in that event the rack 2- could be operated by hand or by power-driven means, if required.

The movement of the piston through its exhaust stroke beyond the limit of the compression stroke or close to the end of the cylinder assures a thorough cleansing of the cylinder from the products of combustion while the increased movement of the piston from the limit of its exhaust stroke beyond the limit of the firing stroke draws into the combustion chamber of the cylinder an increased volume of the explosive mixture so that during the compression stroke this increased volume of the mixture is compressed into a relatively small space as shown in Figure 3 and when ignited and expanded by such ignition acts with a greatly increased power in driving the piston through its firing stroke which terminates short of the intake. stroke or at about the time the exhaust valve is opened.

It, therefore, follows that immediately upon the opening of the exhaust valve the expansive force of the spent heated gases will assist in expelling such gasesfrom the cylinder to be followed up immediately by the exhaust stroke of the piston for completing the cleaning of the cylinder from the spent gases.

It will also be noted that the connection of the line -6 with the intermediate portion of the lever '4.- substantially midway between the ends thereof causes an accelerated movement of the piston through its exhaust stroke and also through its compression stroke to expedite the expulsion of the spent gases from the cylinder and also to effect a more rapid compression of the charge of the explosive mixture, all of which contributes to increasing the power of the engine and incidentally reducing the cost of fuel in the operation thereof.

The construction and operation of the invention has now been fully shown and described and although this construction is particularly simple and efficient in carrying out the objects stated it is evident that various changes may be made without departing' from the spirit of this invention.

What I claim is:

1. In an internal combustion engine having a reciprocatory piston, a rotary crankshaft and a rotary cam-shaft actuated by the crank shaft, a lever having one end eccentrically pivoted to the cam shaft, and pitmen connected to the lever at different fixed distances from the pivotal connection of the lever with the cam shaft, said pitmen being pivotally connected to the piston and to the crank shaft respectively.

2. In a four-cycle internal combustion engine having a reciprocatory piston, a rotary crank-shaft, and a rotary cam-shaft actuated by and at one-half the speed of the crank-shaft, an eccentric bearing on the cam shaft, a lever pivotally fulcrumcd on said bearing, pitmen pivotally connected to the lever at different distances from said bearing and also pivotally connected to the piston and to the crank-shaft respectively.

3. An internal combustion engine as in claim 2 in which the pivotal connection of the crank-shaft-pitman is nearer to the eccentric bearing than the pivotal connection of the piston pitman with said lever relatively to said bearing.

4. An internal combustion engine "as in claim 2 in which the pivotal connections of the pitmen are at one and the same side of the fulcrum of the lever.

5. An internal combustion engine as in claim 2 in which the pivotal connections of the itmen are at one and the same side of the ulcrum of the lever and the pivotal conneotion of the piston-pitman is farther from said bearing than the pivotal connection of the other pitman with the lever.

6. The combination with the cylinder, the piston and the crank-shaft of an internal combustion engine, a cam-shaft actuated by the crank-shaft and provided with an eccentric bearing, a lever journaled on said bearing, a pitman having one end pivoted to the lever a fixed distance from said bearing and its other end connected to the piston, and a link having one end pivoted to the crankarm of the crank-shaft and its other end pivoted to the lever a fixed distance from said bearing and between the bearing and pitman.

7. The combination with the cylinder, the piston, and the crank-shaft of a four-cycle internal combustion engine of a rotary eccentric actuated by the crank-shaft, a lever journaled at one end upon said eccentric, a pitman pivot-ally connected to the other end of.said lever and to the piston, and a link pivotally connected to the shaft-crank and to the intermediate portions of the lever, the pivotal connections of said pitman and link with the lever being in fixed relation to each other in all positions of movement of said lever.

8. In an internal combustion engine, the combination of a four cycle cylinder, a first connecting rod extending from said piston, a main crank shaft turning at two revolutions per cycle, a secondary crank shaft turning at half the speed, both shafts geared together, a lever pivoted at one end to said first connecting rod, other end of said lever pivoted to crank pin on said secondary crank shaft, a second connecting rod pivoted at mid portion of said lever and other end of said second connecting rod pivoted to crank pin on said main crank shaft.

9. In an internal combustion engine, the combination of a four cycle cylinder, a piston in said cylinder, a first connecting rod extending from said piston, a crank shaft, a second connecting rod extending from said crank shaft, a lever pivoted at mid portion to said second connecting rod, one end of said lever pivoted to piston connecting rod, other end of said lever pivoted to a movable fulcrum which is actuated by a secondary crank shaft which is driven at half the speed of said first crank shaft, by timing said crank shafts any combination of stroke lengths can be obtained in the various cycles.

10. In an internal combustion engine, the combination of a four cycle cylinder, a piston in said cylinder a first connecting rod extending from said piston, a lever pivotally connected at one end with said connecting rod, a movable support for the other end of said lever, a crank shaft, a second connecting rod articulating at its ends with the mid ortion of said lever and with said crank s aft, a secondarycrank shaft, rotating at half the speedof said first crank shaft, connected to a movable support for outer end of said lever,

said secondary crank shaft driven by-gearing from said first crank shaft and timed so that a long power and exhaust strokes and a short suction and compression stroke is obtained.

11. In an internal combustion engine, the

combination of a crank shaft having a plurality of cranks, a power unit for each of said cranks comprising a four cycle cylinder, a piston in said cylinder, a first connecting rod extending from said piston, a main crank shaft turning at two revolutions per cycle. a secondary crank shaft turning at half the speed, both shafts geared together, a lever pivoted at one end to said first connecting rod, other end of said lever pivoted to crank pin on secondary crank shaft, a second connecting rod pivoted at mid portion of said lever and other end of said second connecting rod pivoted to crank pin on said main crank shaft.

In Witness whereof I have hereunto set my hand this 1st day of May, 1928.

CHARLES P. CADY.

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