US1355158A - Internal-combustion motor - Google Patents

Description

G. A. METCALF. INTERNAL COMBUSTION MOTOR.

APPLICATION FILED SEPT. 23, 1918.

2 SHEETS-SHEET I- Patented Oct. 12, 1920.

G. A METCALF. INTERNAL comsusnou MOTOR.-

APPLICAII'ION HLED SEPT- 23, I918- Patented Oct. 12, 1920.

2 SHEETS-SHEET 2.

//\/ VEN TUE:

UNITED STATES PATENT OFFICE.

GEORGE A. METCALF, 0F MALDEN, MASSACHUSETTS.

INTERNAL-COMBUSTION MOTOR.

Application filed September 23, 1918.

T 0 all whom it may concern Be it known thatI, GEORGE A. METCALF, a citizen of the United States, residing at Malden, in the county of Middlesex and State of Massachusetts, have invented new and useful-Improvements in Internal-Combustion Motors, of which the following is a specification.

This invention has for its object to provide a compact internal combustion motor having a large. number of cylinders arranged in the smallest possible space, whereby to enable large powers to be developed in an eflicient manner without requiring a bulky power plant. On this account the invention is particularly adapted to furnish motive power for flying machines. A further object is to provide a motor having the characteristics above outlined and adapt.-

ed to be used with particular advantage with an upright main shaft. Other objects having to do with a novel compounded power transmission means, with controlling means for admission and exhaust. valves of the several cylinders of the motor; with cooling; with lubrication, and with features of construction and arran ement, appear from the following detailed escription of a particular embodiment of the invention which I have chosen to illustrate and describe herein for the purpose of illustrating the invention.

The invention consists in the means, instrumentalties and arrangements for accomplishing the above stated objects, and in the principles embodied in the same, as pointed out in the appended claim.

Referring to the drawings, Figure 1 is a vertical sectional view of a practical form or embodiment of the invention.- Fig. 2 is in part a plan and in. part a horizontal section of the motor thus shown. Fig. 3 is a horizontal section on line 3-3 of Fig. 1 showing in plan the parts below such line. Fig. 4 is a section on line 4.-4: of Fig. 1.

Figs. 5 and 6 are elevations of the external valve mechanism. Fig. 7 is a horizontal section through the tappets of said mechanism. Fig. 8 is a plan view of said mechanism.

Like reference characters designate the same parts in all the figures.

Referring to the drawings, 11 represents the main shaft of the motor on which is formed a crank consisting of the arms 12, 13 and pin 14, preferably made integral with the shaft, although they may be of separate Specification of Letters Patent.

Patented Oct. 12, 1920.

Serial No. 255,230.

parts assembled together if desired. The foot portion 11 is mounted in a step bearmg 15 in which there is a lining bushing 16, such step bearing being mounted upon or formed integral with a crank case 17, which is made in the form of a cup having rising sides 18 which surround the crank and the parts associated therewith presently to be described.

On the'case l7 thereis mounteda plate or frame 19 which forms a. cover for the space inclosed within the case, and also a support for the cylinders of the motor. Said plate or frame may be mounted in any desired way upon the'case, and is here shown as being .set within the rim of the side wall 8 resting upon a ledge 20 therein, to which it. is secured by bolts or in any other desired fashion.

Upon the plate 19 are mounted a number of cylinders 21, the latter being arranged with their axes parallel to the shaft 11 and in a series surrounding said shaft, all the cylinders being equally distant therefrom and preferably equally spaced apart from one another. Preferably the cylinders are placed as close together as they can be arranged and at the same time leave openings between them wide enough for flow therefrom of such volume of air as may be necessary to cool them. The bases or crank ends of these cylinders rest upon plate 19 and are provided with lugs or flanges 22 for connecting them with holding bolts. Preferably the lugs or flanges on each cylinder meet the adjacent lugs or flanges of the next cylinder, and each of these flanges isrecessed to register with recesses in the contiguous flanges, the registering recesses together forming openings throu h which holding bolts 23, 24 are passed. T he upper ends of said bolts are threaded and upon them are screwed holding nuts 25, 26 which bear upon the before mentioned flanges, each bearing on parts of the flanges of two adjacent cylinders. The lower ends of these bolts pass through the bottom of the crank case and carry nuts 27 28 which underlie the bearing shoulders formed on the under side of the crank case. Thereby the cylinders are firmly secured in the case and by the minimum number of holding means, since each of the holding bolts thus partly secures two cylinders.

I prefer to make the motor of such di mensions as to the individual cylinders and as to the radial distance thereof from the shaft, to accommodate an odd number of cylinders, preferably fifteen; although 1 do not limit the invention either to this specific number of cylinders or even to a motor having an odd number rather than an even number of cylinders.

In each cylinder is a reciprocating piston 29 having a wrist pin 30 by which is pivoted thereto a connecting rod 31. Said rod extends into the crank case and is connected by a knuckle pin 32 with a link 33 pivdtally mounted on an abutment pin- 34 which is supported by the crank case in a fixed location but in a manner permitting'it to turn about an axis parallel to the shaft and approximately in line with the axis of the cylinder. A convenient means for thus mounting said abutment pin comprises a cylindrical block 35 (Fig. 1) having a bearing for the pin 34 and mounted in a bushing. 36 placed in a socket 37 which is secured to the crankcase preferably by the bolts and nuts 27, 28, and opens into the interior of the latter. The block 35 is adapted to turn in the bearing thus formed in order that the linkage above described may oscillate conformably to the movements of the crank 14. Power is delivered from the knuckle 32 to said crank through a link or connecting rod 38 which is pivoted to the knuckle 32 and also to a second knuckle 39 which is carried by a pin 40 having its bearing in a crank disk 41. Said disk embraces the crank pin and provides a bearing for the latter, being lined with a bushing 42. Preferably this crank disk ismade in two parts which fit together about the crank pin and are secured together by bolts 43. All of the cylinders of the motor are thus connected to the same disk 41 by linkages and connecting rods iden ticalwith that just described. Thereby as each piston travels toward the crank case in its working stroke, it moves the knuckle 32 with which it is respectively connected toward the crank, and through the link 38and disk 41 applies force to the crank. The cylinders successively apply such pressure impulses in this manner to the one crank. It is to be understood, of course, that the cover or base plate 19 is provided with openings beneath the several cylinders of proper form and dimensions to permit unobstructed movement of the rod 31 both toward the shaft and also oscillatively about the axis of the crank pin. This means comprises one or more auxiliary cranks 44, there being preferably three such cranks inorder to distribute the guiding effect uniformly and prevent cramping of the disk. So far as the principle of the invention is concerned, there may be fewer or more of these guiding cranks; burt I prefer to use three of them rather than any other number in order both to secure equal distribution of the effect and also to avoid unnecessary weight which would be occasioned by providing more than three of them. Each of these cranks is mounted on a stud shaft 45 which turns in a bearing 46 fixedly mounted upon the bottom of the crank case; these crank arms are e ual in length to the arm of crank14, and t ey are connected to the disk 41 either by being engaged with one of the wrist pins 40 previously described, or with other 'pins similarly mounted in the disk 41. Of course the guiding cranks are spaced with approximate equality and uniformity around the axis of the main shaft. Obviously the effect of the auxiliary guiding cranks is to cause the disk to revolve about the axis of the shaft without turning about the crank in. p The points of connection of the several driving linkages with the crank disk thus mission o-f power from a cylinder to a shaftparallel to the cylinder I believe to be new and desire to protect broadly. Essentially it comprises acomposite connecting rod consisting of the links 31 and 38, a crank box, namely the disk 41, and an abutment, the link 33, which converts the axial thrust of the piston into a thrust at right angles thereto. By this means it'is made possible to arrange as many cylinders around the main shaft as it is physically possible to place in the space available, and to transmit force from each cylinder to the shaft with the maximum efiiciency.

I also claim broadly as my invention, and without limitation to its combination with cylinders parallel to the shaft, the idea of the disk 41, or any element substantially equivalent in function and result thereto, mounted on a crank and connected with the pistons or connecting rods of several cylinders in such manner as to transmit the force of pressure strokes therefrom to the crank;

that the points of connection thereof with the several connecting rods describe circular paths about different axes. This feature, in the scope in which I claim protection for it, is applicable in ways obvious to those skilled in the art to plural cylinder motors in which the cylinder axes are radial to the shaft, or are otherwise located in a plane or planes other than parallel to the shaft; and when so applied, causes the phases of all the cylinders tobe alike and the power impulses of i the several cylinders upon the shaft to be alike and equal. This result is due to the fact that the point of connection between each connecting rod and the disk is in effeet a crank which may be placed in relation to the cylinder such as to secure the desired effects, and that the line of thrust through the disk from each such point to the actual crank is equivalent to a transmission rod of which all the ositions are parallel to one another. In this description the term disk is intended to include all devices adapted to perform the functions and secure the results of the disk 41 as here described, and regardless of whether such devices are flat either within or outside of the circle of cylinders, and is connected at any suitable point with the air trunk; or I may provide a number of carbureters, if necessary, to supply a suflicient quantity of the mixture for running at maximum power. Any carbureter either those now used and well known, or others which may be devised may be provided in connection with this motor; wherefore, and because the present invention does not involve any new invention or design in a carbureter, I have simply indicated diagrammatically a carbureter at 48, without attempting to show the same in detail. This representation is intended to show that I contemplate as part of the operative motor combination, adequate means for furnishing combustible working fluid.

The distributing branches 49 lead from the trunk 47 to the head ends of the several cylinders, and each is under the control of an inlet valve 50. There is also arranged in each cylinder an exhaust valve 51 which controls the entrance to the exhaust passage 52 which discharges into the outer air, either directly or through any suitable muffler which it may be desired to use. These valves open inwardly, whereby the internal pressure developed in the cylinder tends to close them, and they are further constantly maintained against their seats by springs 53 and 54, such springs bearing against abutments on the stems of the valves and reacting against the housing 55 in which the inlet and exhaust passages are contained. For opening these valves at proper times to admit fresh charges and to exhaust the expanded charges, I provide valve mechanisms of which that for the inlet valve comprises an arm 56 mounted upon a stud 57 and having a tappet 58 which bears on the stem of valve 50. Arm 56 is connected to a rod 59 which carries a roll 60 bearing upon a cam 61 which is mounted on a tubular shaft 62 surroundin and rotatable upon the main shaft 11. exhaust valve is similar thereto and comprises an arm 63 pivoted upon the stud 57,

a tappet 64 connected to said arm and bearing against the stem of valve 51,- a link or connecting rod 65 connected to arm 63, and a cam 66 for actuating said rod. The cams 61 and 66 are rotated at one half the speed of the main shaft by gearing consisting of a spur gear 67 fixed to the main shaft 11, a compound gear 68, 69, ofwhich the part 68 meshes with the gear 67, and a driven gear in mesh with the gear element 69 and fixed by any suitable means, here shown as by set screws 71, upon the tubular shaft 62. The value of the gear train 67, 68, 69, 70 is such as to turn the shaft 62 at one half the speed of the main shaft since the operation of the motor is on the four stroke cycle. On account of the timing problem, I prefer to provide more than one cam of each sort; that is, instead of operating the inlet valves of all the cylinders by the same cam 61, and all the exhaust valves by the same cam 66, I provide one or more additional inlet cams 72 and one or more additional exhaust cams 73, each of these cams controlling the valves of only a part of the cylinders. The number of these cams may be indefinitely extended if desired, up to the limit where there is a separate cam foreach valve.

Cooling means-This motor is arranged to be air cooled, and for this purpose there is mounted on the main shaft 11 a fan 74 which drives air against the heads of the cylinders and into the space surrounded by the cylinders. In. escaping from this space the air flows through the openings between the adjacent cylinders and is thereby brought into intimate contact with the cylinder walls. There are also provided on the exterior of the cylinders conducting flanges or fins 75 to aid in the flow of heat from the cylinders to the outgoing air. By this means ample aeration and cooling of the motor is effected. In addition, when the motor is arranged in upright position and is carried by a rapidly moving flying machine or other vehicle. and is at the same time exposed to the outer air, external air currents have a powerful cooling effect upon the outer sides of the cylinders. Of course, if desired, "a watercooling system constructed and operated according to known principles may be pro vided in place of the air cooling system described or in combination with air cooling.

m'ti0n.-I have designed this motor with an ignition system operating on the jump-spark principle. In Fig. 1 I have illustrated the outer ends of spark plugs 76 in two of the cylinders, and have shown in a diagrammatic manner a source of current in the form of a battery 77, and also in a diagrammatic way, a transformer 78. It is to be understood, however, that a magnetic or other generator may be used instead of the battery as the source of current. one terminal as 79 of the transformer is shown as being grounded on the motor base while the other terminal 80 is joined by a conductor 81 with a distributer 82, the

' the latter and being latter'having a fixed member bearing separated contacts which are connected by wires 83 with the several spark plugs, and a movable member carried by the movable cam shaft 63 and having a single complemental contact with which the conductor 81 is in connection through any suitable sort of slip contact or brus Lubricatimz-.-The crankcase 17 is intended to be kept partly filled with oil. In the crank case and having its inlet dipping into the body of oil there contained is a pump 84 having admission and exhaust check valves and a plunger 85. One of the guiding crank shafts 45 is formed in part as a cam or eccentric 86, and the pump is so arranged that the plunger is actuated by said cam, being pushed inward with every rotation of alternately pushed outward by a spring 8 This pump discharges into a conduit 88 which carries oil to any desired point of discharge. It is here shown as )assin throiwh the up er end of the.

l n a P tubular cam shaft 62 and delivering oil so as to lubricate the latter. This conduit may have as many branches as desired leading to all points which require to be continuously lubricated; or there may be a number of mains leading to such points independently from the pump 84; or a number of such pumps may be provided, all according to the requirements of any specific motor built according to the invention described. Also oil is distributed by an arm 89 extending laterally from the main shaft and having a passage 90 which runs through the crank arm 12, crank pin 14, arm 13 and foot 11 of the shaft, through the end of which taining this oil pump in effective condition by preventing back flow of oil from the passage. It will be readily appreciated that the arm 89 is in essence a centrifugal. pump. The discharge orifice of this arm is near the line of cylinders and it ejects oil into them in turn as it revolves. Thereby the pistons are lubricated; and the oil which drips therefrom and is splashed by the movement of the reciprocating parts lubricates the other rubbing parts in the engine base.

Starting means.I have shown a starting 1 crank 93 mounted on a shaft 94, the bearings for which are provided by a bracket 95fixed to the crank case and by the post 96 which also supports the reducing gears 68, 69. On this shaft is fixed a beveled pinion 97 meshing with a beveled gear 98 fixed upon the main shaft. The pinion is mutilated in part so that it will not mesh throughout its entire circumference with the gear 98, in order that when the motor starts to run the shaft 94 will not be continuously rotated. Between the crank 93 and shaft 94 I may provide any relation of clutch such as are used in connection with automobile starting cranks. The foregoing describes the essentials of the motor and the principal structural details. Such other details as are common to all motors, or may be applied thereto by any competent machine designer without difficulty are not shown. Among the latter are such details as brackets or a bed for supporting the motor as a whole and mounting it upon the frame of the flying machine or other vehicle to which it is applied; the stiffening frame or other supports for holding the cylinders in their proper alinements; guides for the valve operating rods 59 and 65, etc. Any structural details suitable to serve the last named purposes may be added to the motor by the designer in adapting it to any special use.

To the extent that such details as may be necessary to make a structurally complete motor may be lacking from these drawings, the latter are to be considered as diagrammatic for the purpose of giving a full, clear and exact description of the principles of' the invention in such form as to enable those skilled in the art of constructing machines to apply such principles in a structurally perfect motor.

It will be apparent from what has gone 30 tions consistin to, and by enabling as many cylinders to be thus arranged as it is physically possible to vplace withln the line wherein they must be located. That is, nothing but the external diameter of the cylinders themselves limits the number which can be so placed.

Thus the desired object of high power with small bulk and relatively light weight is accomplished. This engine 1s adapted to be placed in an upright position, in which 16 the shaft is vertical, and thus to drive the horizontal fan propellers of a 'fiyin machine such as that shown in my prior atent No. 908794, dated January 5, 1909. Of course, power may be transmitted to a hori- 20.zont al or an inclined shaft by intermediate beveled gearing between the same and the main shaft for driving propellers or other instrumentalities which rotate on horizontal or inclined axes; or the entire motor may be mounted on its side for aeroplane, automob1le or motor boat use.

Advantages residing in the compound linkages or connecting rods between the cylinders and crank, that is, in the combinaof the rods or links 31, 33 and 38, to which I desire to call attention are the following: The links 31 and 38 form what is in effect a jointed connecting rod disposed to deliver force in a direction transverse (at right angles, or any other de-' sired angle) to the line in which the piston reciprocates; and the link 33 is an abutment and guide for the joint in such rod, enabling it to erform this -oflice. Thereby thrusts 40 are de 'vered laterally of the cylinder with better effect and greater efiiciency than is i found in other types of motor having cylinders parallel to the shaft. The same mechanism enables a large number of cylinders to be combined in one motor without requiring the disk 41 to be unduly lar e. Also such mechanism is exceedin 1y e cient in propelling the piston during its compression stroke, on account of the mechanical advantage resulting from the links 31 and 33 approaching a straight line at the same time that the I0 38 and the crank come into line. Thereby a higher degree of compression than can be secured in the ordinary type of reciprocating engine is attainable with less effort. This feature of the invention is not necessarily dependent on the disk 41, or equivalent, wherefore my broad claim thereto is not limited to a combination including the disk. And as the same feature is applicable to pumps or compressors in which one or more compressing pistons is, or .are, driven by a shaft, I desire to obtain protection for the same in such scope as will cover 66 the application thereof to pumps or compressors. Herein the swivel I or rotatable mounting of the links 31 and 33 is important, as it enables this linkage to swing in following the movements of the crank.

WhileI have described the cylinders as parallel to the shaft, I do not mean to exclude from the scope of my protection an' arrangement b which the cyilnders are more or less inc ined to the shaft without being perpendicular thereto. The particular connecting rod linkage herein described and claimed is operative when the cylinders are more or less steeply inclined to the shaft,

and is desirable in engines having that relation and therefore in the claim which is directed to this feature particularly, theterm parallel as defining the relation between the cylinders and the shaft is to be con--' strued as including all the combinations in which such or'an e uivalent linkage may be used, and in whic the cylinders are arran ed otherwise than perpendicular to the sha t. Also the crank may be inclined to a greater or less extent to the axisof the shaft and, the linkage usedas .before described, the cylinders being then either inclined or parallel to the shaft. In that case the disk used to transmit power to the crank will be complementall inclined to the shaft, and it may be withhe d from rotation about its own center by other means than the supplemental cranks; such, for example as ears of the sort' shown in Patent No. 790,3 4 of J. W. Maxwell, anted Ma 23, 1905.

Having now escribed t e principles of my invention, but without attempting to illustrate all the forms in which it may be embodied or all the ossible modes in which and pu oses for' w ich it ma be used, I declare t at what I claim and esire to protect by Letters Patent is A motor embod 'ng a crank shaft, and cylinders arran e crank shaft wit an axis parallel thereto, a disk rotatably carried by the crank of said in a series surrounding Y crank shaft, pins equal in number to the cylinders on same disk in a series surroundin the crank,a linka e associated with each cy inder consisting o a connecting rod attached to the piston of the cylinder, a second link joined to the connecting rod approximately at the plane of said disk, a link connecting the joint last identified with the disk-carried pin nearest thereto, a swiveled abutment substantially in the axis of the cylinder to which the first identified link is connected, and a guide crank in parallel with main crank engaged with said disk to prevent any effective rotation of the disk about the main crank under the impulse applied by said linkage.

In testimony whereof I have afiixed my signature.

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