US1539227A - Internal-combustion engine - Google Patents

Description

May 26, 1925. 1,539,227

M. L. WOOD INTERNAL COMBUSTION ENGINE Filed June 30, 1921 2 Sheets-Sheet l A? J hwwfiwvz/ $513 Z4, elf tom A afltwwt/ May 26, 1925. 1,539,227

M. L. WOOD INTERNAL COMBUSTION ENGINE Filed June 30, 1921 2 Sheets-Sheet 2 C 22 22 FI "1 K 1 1 I l 0 J3 f 3 9/ 8 a2 /0 W 1 I h- J; J L 1 Patented May 26, 1925.

UNITED STATES MARSHALL I. WOOD, .OF MONTPELIER, VERMONT.

INTERNAL-COMBUSTION ENGINE.

Application filed June 30, 1921.

To all whom it may concern..-

Be it known that I, MARSHALL L. W001), a citizen of the United States, and resident of Montpelier, in the county of Washington and State of Vermont, have invented certain new and useful Improvements in Internal- Combustion Engines, of which the follow ing is a specification, reference being had therein to the accompanying drawing.

The invention relates to internal-combustion engines, or motors, and more particularly to the subdivision of the general class known as the two-cycle or impulse-everyrevolution type; but while this special kind is primarily suggested, the invention is not confined to such, since many of its features and devices, which I shall hereinafter describe, are applicable to internal-combustion engines, or.motors, of the four-cycle type, as also to Steam and other engines and uses.

Among many objects or purposes of the invention, some which I will mention are:

First, to greatly increase the efficiency of motors of the two-cycle type; to overcome the difficulties of the control of such motors when running under partial load, and to secure silent operation.

Second, to obtain higher rotative speed, and to secure at like speeds at least the uniformity and continuity of torque or turning effort, of four-cycle motors having twice the number of cylinders, valves, and other parts.

Third, to produce at least double the efficiency-or power output of four-cycle motors having cylinders of like dimensions, or to produce equal power with a smaller and lighter motor.

With these and numerous other objects in view the invention may be said to consist essentially in the construction, arrangement and combination of parts, substantially as will be hereinafter described and claimed.

In the accompanying drawing, illustrating my invention:

Figure 1 is a transverse Vertical section of my improved internal-combustion engine.

Figure 2 is a detail plan View of one form of admission and control valve.

Figure 3 is a detail plan view of the valveactuating mechanism.

Figure 4 is an outline side elevation of a four-cylinder engine of my present improved type, and indicates particularly the means for controlling the quantity admitted of the gaseous fuel, and also shows the rela- Serial No. 481,516.

tive arrangement of one form of centrifugal compressor, or pump, for charging and exhausting the cylinders.

Similar characters of reference denote like parts throughout the different figures of the drawing.

Obviously the engine may be composed of as many cylinder units as desired; as for example, four, as shown in Figure 4; but an explanation of the details of a single unit, as indicated in section in Figure 1, will supply a full understanding of the operation, for a single unit will provide a complete and efiicient motor for many purposes.

Proceeding to describe the construction and arrangement of the various parts, 1 denotes an open-ended vertical cylinder, having a customary water-jacket 2, which may be omitted and radial fins or flanges or other air-cooling means substituted in lieu thereof if preferred. lVithin the cylinder 1 is a trunk piston 3 to which is pivotally connected the rod 4, that connects with the crank 5 of the main crank-shaft 6, around which is a crank casing 7, some of these parts being of the customary automobile or air-craft type, but the cylinder is provided with improved means for admitting, controlling and exhausting the gases.

The cylinder 1 is provided near one end, preferably the upper end, with an inletport or ports, and at the opposite end, preferably the lower end, with an exhaust port or ports. The fuel inlet or admission ports are-preferably dual at 8, 8, and admit into the combustion space A of the cylinder from opposite sides of the cylinder, the fuel supply being delivered to these ports 8 of a single cylinder, or of several cylinders, as the case may be, through the horizontal lateral supply pipes 9, 9. The exhaust ports are also preferably dual in arrangement, as at 10, 10, and they are opened and closed at the proper time by the action of the main piston 3 in covering anduncovering them, without the need of any valves. or other mechanism for the purpose. The exhaust is carried away by the horizontal lateral out.- let pipes 11, 11, that connect with the ports 10. These ports are all of large area so asto have a copious admission and outlet effect. 1

The inlet valve for the fuel is shown in Figure l. and in greater detail in Figure '2. In consists of a single circular ring 13. of sufiicient width to cover the inlet ports: a",

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' a spider 14 having curved sectors 14 concentric to parts of the circle of the ring 13, which sectors 14 extend part way around opposite sides of the cylinder between the ports 8. The spider 14 is attached to a vertical stem 15, like that of a poppet valve, which stem 15, at its juncture with the spider 14, has a small head 16, that seats against the cylinder head 1 or bushing 17 like a poppet valve, so as to prevent leakage around said stem where it passes upwardly and centrally through the cylinder head. A screw-threaded bushing 17 is screwed into head 1, to carry the stem 15 and give it a bearing above the cylinder and also afford a tubular guide in which the stem can reciprocate in performing its functions, and the stem is splined or feathered within the gland 17 so that the valve ring 13 and spider 14 may be prevented from turning in the cylinder. Valve 13 moves towards the piston 3 in opening ports 8, and away from piston 3 in closing them.

An important characteristic of the valve 13 is its action under pressure from within, it being exposed to pressure on three sides, but that on the inside is the only effective ressure, as that on the top and bottom edges Ealance each other. It also has the advantage of minimum travel to open and close the ports, as it is not encased or shrouded opposite the ports. When the'engine is run ning under full load, the admission valve 13 closes as soon as the charge is admitted, but when under partial load, the valve re- .mains open long enough to allow such portion of the charge as is not required to return to the admission system and thence into the cylinder that is ready to receive its charge. The charge, full or partial, is then compressed and ignited and expands in the usual way. The exhaust ports open near the end of the expansion stroke, but the admission ports do not open until the exhaust has reached approximatelyatmospheric pressure. It is apparent that a cycle is completed in each cylinder in one revolution of the crank-shaft.

This new type of admission and control valve is not only highly efiicient but noiseless in operation. It is a flexible split-ring valve that is self-cleaning and leak-proof, even if worn, being pressed tight against and sealing the ports by the pressure within .the cylinder during compression and expansion, but which is balanced as to pressure and frictionless whenever in motlon, and therefore the work of valve operationis muchless than in the case of a valve opening against considerable pressure. The ring slides down into the cylinder to open the ports, andreceives lubricant which is carried up by the piston. Poppet, piston or sleeve valves may be used instead, as the valve is cooled with every incoming charge, and with the same valve actuating mecha- IllSIIl.

With admission andexhaust of gases at opposite ends of the cylinder, as above described, the entering charge follows the .exhaust gases and does not rub against and mingle with, or become polluted by, the burnt gas, as in the conventional type of two-cycle motor, where the admission and discharge is through ports at opposite sides of the cylinder and the gases travel up one side and down the other. The dual admission and dual exhaust ports, of large area, and direct movement of the gases, make possible much higher speed of rotation, and with lower fan pressures and power demands. The invention entirely eliminates the use of exhaust valves and the various troubles incident thereto, since the exhaust is through the dual ports near the outer end of the cylinder. The dual ports being diametrically. opposite each other overcome the trouble due to unequal expansion.

The motor has a very novel and effective valve actuating mechanism by which a full charge is admitted into each and every cylinder, when there are several cylinders, and such portion is left therein as will generate the power required. The amount of charge -is easily and certainly regulated, none is lost, and the motor is as flexible in control as the best of the four-cycle type.

I will now explain a preferred specimen form of this valve actuating mechanism. It comprises two main parallel shafts 18 and 19 supported horizontally above the cylinders 1, see Figure 4, in suitable bearings or brackets 20 and 21. Each shaft carries a series of cams, one for each cylinder unit; thus shaft 18 has thereon cams 23, and shaft 19 has thereon cams 22, 22, 22 and 22. These cams operate in contact with anti-friction rolls 36 and 38 carried in levers 35 and 37, whose outer ends are pivoted in brackets 40 on top of the cylinder 1, and whose inner free ends bear upon and act against collars 39 on the valve stems.15 of the inlet valves 13. The stems 15 are provided with springs 41 which act against the collars 39.to return the valves 13 to their seat, and the levers 35 and 37 have springs 42 attached thereto and to the adjacent cylinder head to maintain contact of the levers 35 and 37 with the valve collars 39. The shafts 18 and 19 are driven by helical or'spiral gears 24 and 25 thereon respectively and which mesh with a central spiral gear 26 at right angles thereto on a vertical shaft 27 the lower end of which carries a bevel pinion 28, driven by a bevel gear wheel 29 on the main shaft, see Figure 4. The spiral gears 24-and 25 have teeth of such length as will permit of movement lengthwise of the shafts, either with said shafts or sliding thereon by a spline con nection, as at 10. Means are provided for movingone or the other or both of gear wheels 24 and 25, as shown in Figures 3 and 4, and consist of a fork 31 and a bell-crank lever 33, said fork loosely engaging the discs 30 on gear 25, and the position of bell-crank 33 being controlled by a leverage system 32 running to any point, as the steering wheel of a car. In this way the relation of the cams to each other can be subject to constant change and variation to control the admission of fuel.

As used on the two-cycle motor above de scribed, both cam shafts are set to open the admission valve when the exhaust has reached approximately atmospheric pressure, and are run at the same angle, for full power, but one of the shafts, with its cams, can be retarded by the means described and thus delay the point of closing the valve, for partial loads. The cams are formed to give a certain period of dwell at full opening and the period is lengthened by retarding one of the cam-shafts, in which case the valve is opened by the cam on one shaft and closed by the cam on the other. For longer periods than is possible with cams with the minimum dwell, cams having longer dwell are formed with or attached to the cams on the variable shaft, or both, as may be necessary, and act when the cams with shorter dwell have reached their limit of action. Thus, complete regulation of the amount of the charge, from full to idle loads, is accomplished. The inclines of the multiple dwell cams are at different angles, the dwell of top part covering arcs of different length, but the declines are coincident. Assuming the incline to cover 40 degrees of cam travel, the minimum dwell 40 degrees and the decline 40 degrees, the dwell of the next adjoining cam or step might be 80 degrees and the next say 120 degrees.

When using multiple dwell cams, the gear is fast to the shaft and both are moved lengthwise to change the position of the cams.

On four-cycle motors the valve actuator works in the same manner on the admission valve or valves, the throttle valve is discarded, the negative work due to throttling is eliminated, and the motor efficiency at partial loads is considerably increased. On steam engines, sliding one spiral will give constant lead or compression and variable cut-off, and sliding both spirals will give variable lead or compression and variable cut-off.

The motor embodies a simple and effective device for charging the cylinders with fuel and air, or air only, and which thoroughly scavenges them of the products of combustion, without pollution of .the incoming charge. As shown in the drawings, this con sists of a multi-stage fan or blower 34, which may be used either as a compressor or as a pump. If the former, it delivers into the admission system, through ports 8 by means of pipes 9; if the latter, it draws from the exhaust system through ports 10 which enter pipes 11 that will in this case be connected to the vblower instead of having the pipes 9 so connected. This'is clearly seen in Figure 4. It can of course be driven by gearing or otherwise, instead of being direct connected to the crank-shaft, if so desired, and other types of compressors or pumps can be employed, if preferred. The fan 34; when acting between a carburetter and the cylinders, thoroughly agitates the mixture of fuel and air and thus produces complete vaporization of the fuel, without addition of heat, and consequently a more efficient charge. The fan also increases the density of the charge and therefore the power of a given volume. The usual method of drawing the charge into the cylinder, andheating same to cause vaporization, obviously lessens the density and the power. A carburetter of customary design is ordinarily employed, but the throttle-valve is used only to adjust the rate of flow through the fan. A throttle for this purpose may be placed elsewhere in the system.

With the fan discharging into the admission system, and a carburetter connected to its inlet, a combustible mixture is delivered at a pressure suflicient to cleanse the cylinder of the roducts of combustion and leave therein a ull charge of clean gas. With the fan connected to the exhaust system, the burnt gases are drawn from the cylinder and the fresh charge follows into same. If the carburetter is omitted, air only will displace the burnt gases, and the fuel is introduced in some other manner, as in'heavy fuel or oil engines.

Itis commonly known that in two-cycle motors of the usual designs, especially when throttled down, more or less of the rod nets of combustion remain in the cylinder and pollute the charge, causing misfiring and other troubles; also that in four-cycle motors, there is always present a volume of burnt gas equal at least to the compression space, and generally more, due to the back pressure of the exhaust; and the charge drawn in, even in dual valve motors, at high speed, is considerably below atmospheric pressure when the intake valve closes. The

polluted charge and the lower density. ob-

livers two impulses per cylinder to one in the four-cycle type.

Any kind of ignition means may be utilized, as for example the ordinary spark plugs, and I can also add all the common accessories for starting, reversing, timing, carburetting, priming, lubricating, and other regulating means of various kinds, but I have not thought it necessary to show the details here.

The complete operation will be fully understood from the foregoing description of the construction and arrangement of parts without the need of much additional detail. When the engine is in operation the central worm or spiral gear wheel 26 will be constantly actuated by the connections described or in some othersuitable manner with the result that the parallel cam mecha nisms will be also actuated and the lever devices interposed between the cams and the valve stem will cause a regular opening and closing of the admission valve. When the engine is running under a uniform load, without any change in its requirements of any kind, both cam mechanisms will similarly act on the lever devices without producing different effects, but when it is desired to vary the speed, or when the load changes, or other conditions arise which involve the need of varyingquantities of fuel, one of the said spiral gear wheels 24 or 25 will be shifted on its shaft. so that although such shaft will continue to be revolved in the same way as before, I mean by the gear wheel 26. the cams belonging to one series will take a different relationship to those belonging to the other series, and the effect will be that the admission valve will be held open longer or will be closedmore quickly than before, and a correspondingly lesser or greater amount of fuel will be consumed at each explosion in the explosion chamber; that is to say, in a word, the essence of the operation consists in changing the relationship of the cams belonging to one set to the cams of the other set and thus varying the action of the fuel inlet valve so as'to effectually control the latter.

In carrying the invention into effect it will be quite evident that there may be a wide variation in the practical details and great changes may be made in all respects without exceeding the scope of the invention. As already stated, there may be any number of cylinder units; consequently a corresponding number of cams of the two sets. These cams may be arranged on two separate parallel shafts as separate cam members having their sliding parts similarly constructed, or each aggroupment of cams may have distinct characteristics so that they will be quite different from each other although having the same objective, as I have pointed out for the cams shown and described. In other words, the cam devices are susceptible of a very wide variation in construction and organization. Also in place of the sliding spiral gear wheel of the elongated type shown I may substitute other kinds of gears or worm devices for attaining the same object.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. In an internal combustion engine, the combination with an open-ended cylinder and a reciprocating piston therein, said cylinder having dual admission ports located opposite each other near one end of the cylinder, of an admission valve arranged in connection with said ports and reciprocating within the cylinder, and valve operating mechanism for imparting a variable actuation to the valve, the same consisting essentially of cams, valve-operating levers on which the cams act, rotary shafts carrying the cams, and means for retarding or accelerating the rotation of one of the shafts relatively to the other.

2. In an internal combustion engine, the combination with a cylinder having inlet and exhaust ports, a piston within said cylinder, and a' valve functioning in connection with the inlet ports, of mechanism for operaing said valve consisting essentially of gear actuated cams arranged to open the valve, and means for changing the relationship of said cams to each other so that the period the ports remain open may be variably timed, said means includin shafts carrying the cams, and means for riving said cam shafts simultaneously and also for retarding or accelerating the rotation of one of them relatively to the other.

3. In an internal combustion engine, the combination of-a cylinder having inlet and exhaust ports,' a piston in the cylinder, and a valve operated in connection with the inlet ports, of means for opening said valve, consisting essentially of cams and levers interposed between the cams and the valve so that the action of the cams may impart motion to the levers and open the valve, together with means including adjustable spiral gears and an intermediate gear between them for changing the relationship of the salient parts of said cams to their levers so that the resulting effect of one cam may be variable with respect to that of another.

4. In a device of the class described, the combination with an inlet valve, piston, and cylinder having inlet ports, of means for actuating the inlet valve, consisting essentially of parallel shafts, a cam device on each shaft, means for rotating the shafts, pivoted levers arranged beneath the cams to be acted upon and having freely movable ends, and interposed members between said free ends and the inlet valve, said member having resilient means for moving the valve in one direction, and means for driving the cam shafts simultaneously and also for retarding or accelerating the rotation of one of them relatively to the other.

5. In an internal combustion engine, the combination with the cylinders, pistons, and inlet valves thereof, the latter having collarprovided stems and a spring device for moving the valve in one direction, parallel shafts, cam devices on said shafts, spiral wheels also on the shafts, a spiral gear intermediate of and operating the spiral wheels, and means for moving one of the spiral wheels on or with its shaft so as to vary the position of the cams, together with lever devices acted on by the cams and having free ends engaging the stems of the valves, all arranged so that the cam shafts are driven simultaneously whileone of them may be retarded or aecelerated relatively to the other.

, 6. In an internal combustion engine, a valve-actuating mechanism consisting essentially of a valve having its stem provided with a collar, parallel shafts, cams on said shafts, spiral gear Wheels likewise on the shafts, one of them being adjustable, and

intermediate gear for driving these spiral wheels, lever devices arranged to act upon the valve stem with similar or different conditions accordingly as the cams have a similar or different action on said levers.

- In testimony whereof I hereunto afiix my signature.

MARSHALL L. WOOD.

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