US1829780A - Internal combustion engine - Google Patents

Description

Nov. 3, 1931. H. BEYTES ET AL INTERNAL COMBUSTION ENGINE Filed April 21, 1928.

172062220519 Leora HBeysJ B11571 Bevin,

Patented Nov. 3, 1931 UNITED STATES PATENT OFFICE "LEON IE. BEYTES, OF NORTH PLYMOUTH, AND HUGH BAIN, OF HINGHAM,

MASSACHUSETTS INTERNAL COMBUSTION ENGINE I Application filed A ril 21,

Our invention relates to internal combustion engines and aims to provide an improved, simplified and more efliclent mechanism of the class described.

'5 In the drawin s, illustrating by way of example one emb iment of our invent on Fig. 1 is a vertical section, partly diagrammatic, through an eng1ne;

Fig. 2 is a similar vertical sectional view of a single. cylinder and associated mechanism, being taken in a plane at right angles to that of Fig. 1; and

Fig. 3 is a partly diagrammatic view of means illustrating one feature forming a part of our invention.

Referring more particularly to the drawings, the shaft to be driven, hereinafter termed the power-shaft or cam-shaft, and which takes the place of the usual crank-shaft 2 of that type of engine, is indicated atl, it being supported in suitable bearings in a housing or case 2. Fast upon sald shaft is a cam 3. of which there may be one or more depending on the particular number, grouping and .25 positioning of cylinders. Said cam as shown 1s a radial cam, wherein the efiective variations in the cam path formation or formations are in directions radial of, toward and away from, the cam axis, the latter being also the an axis of the shaft 1.

Any number of substantiallyradially disposed cylinders, having reference to the cam axis, may be employed, one or more, and with a. plurality of cylinders their distribution circumferentially of the cam axis may be widely varied. Merely for the purpose of illustrating the principles of our invention we have indicated in Fig. 1 ei ht cylinders 4,, 4,

etc. equidistantly spaced't rough the entire 360 about the cam axis, and wherein the power stroke of each piston 5, 5, etc. is made to act through one quarter (two-eighths) of one cam revolution, that is, 90 of cam, thus giving a continuous torque on the cam shaft. A continuous torque may similarly be obtained with a greater or less number of cylinders, whether their. number is even or odd, the angular extent of cam through which the power stroke is efiective bein corre- 5Q spondingly varied; for example, w th nine 1928. Serial No. 271,794.

cylinders, the power stroke of each would preferably be made to act through two-ninths of a cam revolution, or 80 of cam arc.

As stated, the number, construction, and arrangement of cylinders illustrated is by way of example only. Should it be desired to confine any or all cylinders to the region either above or below the level of the cam axis that may readily be effected and a continuous torque obtained by arranging the cylinders in two or more groups or sets, each radially disposed with respect to the cam axis but each set in a different plane transverse of the latter. For example, with nine cylinders each acting through 80 of cam are three sets of three cylinders each may be employed, in each set there being one vertical cylinder and one cylinder at each side thereof, spaced 40, with a cam'for each set, each cam set 120 later than the one preceding it in operation. With eight cylinders, the piston of each having a power stroke acting through 90 of cam arc, a desired positioning of all cylinders either above or below the cam axis level and with the retention of a continuous torque on the cam may be provided with two groups or sets of three cylinders each and one of two, in any desired order, employing three cams, or with four sets of two cylinders each (V-tylpe motor) the latter using one more cam. umerous other combinations and distributions of cylinders may be employed as may best meet the particular requirements for a given use.

. Referring again to the drawings, the pi's ton 5 of each cylinder 4 is constructed and as at 7 and receives ast-ud 8 parallel with the.

cam axis and carrying three rolls, a roll 9 intermediate the forked portions and rolls I0, 10, one at each side thereof. Said roll 9 cooperates with the inner and central cam surface 11, and said rolls 10, 1O engage in. the respective oppositely facing cam paths 12, 12. The particular formation of a cam path 12 may vary widely under different circumstances. In the present illustrative embodiment of our invention it may be preferably such as is best seen in Fig. 1, wherein the engine is of the so-called 4-cycle type, each piston passing successively through the cycles of firing and power stroke of exhaust and herein scavenging, .of intake, and of com pression. As viewed in said Fig. 1 the cam.

the piston is effective to apply torque upon the cam driving itin a clockwise direction as indicated by the arrow.

There follows, for any given piston, the

exhaust and herein a scavenging stroke, effected, in the form illustrated, by that quarter-portion of the cam path between the points occupied by the piston at the left center of the figure and that at the bottom center. At the latter point the pistpn is shown at the outer end of its exhaust and scavenging stroke. It will be particularly noted that the piston has been caused to travel fully to the outer end or head of the cylinder, substantially into contact with the cylinder head, whereby a practically complete scavenging of waste gases is effected. This result isobtained through the particular formation of the cam path, substantially as illustrated,

,wherein the path recedes from the cam axis at the end of the scavenging stroke to a distance' greater by the length of the compression and firing chamber than at the beginning of the power stroke.

Following the scavenging stroke whereby substantiall all burned gases are forced out of the cylin er, the respective iston descends through its intake stroke, e ected by-that quadrant of the cam lying between the point occupied by the piston at the bottom center of the fi re and that at the right center. In accor ance with the volume of charge de-.

sired and the corresponding formationof the cam path, theintake' stroke of the piston may be varied in extent as desired. A's illustrated, each piston is withdrawn or descends during theintake stroke a distance less by the extent of the compression and firing chamber thanthat to which it travels at the end of a power stroke. This is evident from an inspection of the radial d stance of the cam path 12 from the cami axis at the right and left hand center portions of the Fig. 1, re-

ect-ively. The actual travel of a piston uring the intake stroke, as illustrated, is the same as during the power stroke, but since a piston starts its intake stroke from the -extreme end of the cylinder it terminates its inefi'ectcd through that portion of the cam path 12 lying between the point occupied by the piston of the cylinder at the right center of Fig. 1 and that at the top center, or through the first part of said portion. As illustrated, the compression stroke for each piston is shorter than the power stroke by a distance equal to the depth of the compression or firing chamber. It'will thus be seen that the total plstontravel during one complete four-cycle operatlon may be the same as in a crank-shaft type of engine of similar bore in spite of the fact that complete scavenging is herein effected by bringing each piston substantially into contact with the cylinder head during its exhaust stroke.

In accordance with our invention it is also possible to bring each piston to the top of its compression stroke well ahead of the point corresponding to the usual dead center occurring-in a crank-shaft engine. The cam path 12 as illustrated in Fig. 1 is shaped to effect such action. The piston at the upper right portlonof Fig. 1 is at a point where it has not completed its compression stroke; 'such stroke is completed at a location in the cam path distinctly before the point occupied-by the piston at the to center of the figure and approximately mi -way between said two points. From said intermediate point at which the piston reaches the top of its compression stroke, the cam pathis given a shght drop, continuing up to the point correspondm to the usual dead center of a crank-sha the point occupied by the pis-.

ton at the top center of Fig. 1. By reason of this construction and arrangement the charge may be fired well ahead of theactu al working point of the cam, that is, the point at which torqueactually is begun to be a plied upon the cam. Thus a set s ark may be employed as there can be no kick-back and an early spark on a throttled down engine would have no harmful result, the same being true under the circumstances of a hea' load and l R. P. M. vy Ow Ignition means for 'each' cylinder is indicated at 13, 13, etc., said means desirably being so positioned and constructedas not to interfere with the a proach of a piston into close proximity wit the cylinder head dur= ing the scav engi ng stroke and also desirably to provide no ob ectionable pocket formation from which gases would not be scavenged. While any desired intake and exhaust valve mechanism may be employed we deem it prefstable, largely fcr reasons similar to those stated in connection with the reference to iginstance we have indicatedv for this purpose a cam valve-actuating means including, for each of the two sleeves 14, 15, a valve cam 16 with which cooperates a roll 17 at the end of a lifter-rod 18, each of which latter is connected at its upper end to its respective valve sleeve 14 or 15. Said cams are formed and timed to effect opening and closing ofthe intake and exhaust valve ports at the proper times. In said Fig. 2 the exact timing for the valve sleeves and earns is not indicated. From the foregoing description taken in connection with the drawings it will be observed that a substantially complete scavenging of the burned gases is effected. Because of this scavenging action it will be further understood that a fresh charge will be taken into the cylinders regardless of the presence of a back pressure, if any, against the exhaust gases; so long as the cam-shaft s made to turn the engine cylinders will take 1n fresh fuel charges, differing in this respect. from the usual type of internal combustion englne, wherein if a substantial pressure is built-up on the exhaust, the burned gases merely follow down with the piston during the succeeding intake stroke and out through the intake manifold, resulting in no new charge being taken in. But with a scavenging action such as herein described each piston will develop below-atmospheric pressure in its cylinder regardless of the pressure upon the exhaust. Thus it is clear that the engine of our invention will run with the exhaust under pressure, if that pressure is kept somewhat below the mean effective pressure of a given power stroke, sufliciently below to take care of losses from friction, radiation, etc.

Such being the case, it is further apparent that if some exterior force be applied upon the cam shaft to keep it turning, the engine will continue to take in fresh fuel charges in each cylinder and to fire them even should a pressure he applied on the exhaust exceeding the mean efi'ective pressure of a given power stroke. An example of such external application of force arises where the engine of our invention is employed in an automobile and is used to partially brake the latter while descending a grade; so long as the driving wheels of the automobile turn and the engine and driving wheels are operatively connected through transmission and clutch, the engine parts must continue to function, that is the cam continues to rotate and the pistons and valves to move. Since it has been shown that a fresh fuel charge must enter the cylinders on the intake stroke regardless of the pressure upon the exhaust it will be understood that if, through suitable means, a pressure' against the exhaust is created, such pressure may be built up to apoint higher than the mean effective pressure of a given power stroke, especially under the condition of a closed throttle. In this manner an extremely eflicient braking action may be applied to the engine, of a strictly non-fric tional type.

Accordingly our invention contemplates the provision of means for creating a pressure upon the exhaust preferably controllable at will of one or more of the engine cylinders. A

Any suitable means may be employed for this purpose, for example such as illustrated in Fig. 3 and which, as shown, is particularly applicable to the engine as employed in an automobile. Where a pressure is to be applied against the exhaust of all cylinders, the control mechanism may conveniently be associated with the exhaust manifold of the engine, or it may be otherwise located, or separately controllable means may be provided for each or any number of cylinders. In said Fig. 3, we have shown a valve 19 in the path 20 of the exhaust, said valve having a seat 21 onto which it may be moved to re: tard or temporarily block the exhaust and cause a back-pressure to be built up against it. Any suitable means may be provided for operating this exhaust-pressure controlling device, automatic or otherwise, and herein we have illustrated means for operating the same under control of the operator. The slidably-supported valve stem 22 is pivotally attached at its outer end, as at 23,130 a lever 24 hung upon a stationary part, as at 25. The free end of said lever 25 is in turn pivotally connected, as at 26, to one end of a footoperable push-rod 27, the other end of which is swingably supported by an arm 28 pivotally hung upon a fixed support, as at 29. The valve is normally retained in open position, allowing a free exhaust, by means of a suitable spring 30. It will be noted that the mechanical efliciency of the mechanism illustrated by way of example is high, approximately one to four, due to the location of the point of connection 23 of the valve-stem near the fulcrum point 25 of the lever 24; thus a pressure of 25 pounds, for example applied to the push-rodv 27 will effect substantially 100 pounds pressure on the valve, to create a like pressure against the exhaust.

With such exhaust-pressure-controlling means applied to an automobile engine, it is true that if said means is employed to bring the car to a full stop the engine would stall.

But since the engine clutch must be left engaged to render said means effective, said pressure controlling means may conveniently be located for operation by the operators clutch foot, and just before the car is brought to a complete stop by the exhaust-pressure brake means the latter may be released and the clutch disengaged with the same foot which was previously used to operate the exhaust pressure means, permitting the engine to continue in operation as prior to the application of the pressure against its exhaust. Obviously there is substantially no wear with a brake applied in the manner described, the action being non-frictional in nature, as contrasted, for example, with the action of rubbing surfaces as in a usual mechanical brake. While we have illustrated and described one means of applying the non-frictional brake action it may be applied in various other ways, including for example the provision of apositive cam on the valve illustrated together with a safety-valve set for a given pressure, or by the provision of a cam constructed and arranged to operate with as many cylinders as desired under any particular circumstances, these likewise exhausting against .a set safety-valve mechanism.

We have previously stated that the engine will operate with its exhaust under pressure, if that pressure is maintained somewhat below the mean effective pressure of a given power stroke. However, if a much higher pressure of hot inert gas is desired it can be I obtained. For example, in an eight cylinder engine less than all of the cylinders, say seven cylinders, may be allowed to exhaust ordinaril under atmospheric pressure and the remaining cylinder or cylinders, in such case the eighth cylinder, may be exhausted against a pressure. Under such circumstances the power stroke of all eight cylinders would be working against the exhaust of one, the resulting pressure obtainable being substantially eight times the mean efl'ective pressure of the power stroke; for instance, if the engine is such that it will operate with all eight cylinders exhausting against 100 pounds pressure, then a pressure of approximately 800 pounds may be developed if seven of the cylinders are allowed to exhaust merely under atmospheric pressure. Intermediate pressures may be obtained by the cutting in or out of one or more additional cylinders to or from an exhaust against pressure.

Having thus described certain illustrative embodiments of our invention it will be understood that the principles thereof may be variously embodied, the invention being in nowise limited to the particular means shown and described its scope being set forth in the following claims. We claim: In an internal combustion engine, one

ormore cylinders each having a p)1ston, and means, including-provision for su stantially complete scaven ing of burned gases, whereby a piston may made to work against a pressure which may be greater than the mean effective pressure of any given power stroke.

2. In an internal combustion engine, a main element arranged to be rotated, one or more cylinders, each having a piston operatively connected with said element and in such manner that the exhaust gases are substantially completely scavenged from the cylinder or cylinders, and means whereby the piston or pistons of less than all cylinders may be worked against a pressure higher than the mean effective pressure of any given power stroke or strokes.

3. In an internal combustion engine, a plurality of cylinders and pistons therefor constructed and arranged to effect substantially complete scavenging of the spent gases, in combination with means for causing one or moreof the pistons to work againsta pressure which may be greater than the mean efi'ective pressure of any given power stroke.

In testimony whereof, we have signed our names to this specification.

' LEON H. BEYTES.

HUGH BAIN.

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