US1475965A - Valve operating mechanism for internal combustion e - Google Patents

Description

Dec; 4 1923.

LI V. FENCE VALVE OPERATING MECHANISM FOR INTERNAL COMBUSTION ENGINES Filed March 12. 1920 2 Sheets-Sheet l awue mic z LAFE V FENCE flbto z nm a Dec. 4, 1923. 1,475Q365 L. v. FENCE VALVE OPERATING MECHANISM FOR INTERNAL COMBUSTION ENGINES Filed March 12, 1920 2 Sheets-Sheet z gvwewtoz @31 G'HZOZMGLAA LAFB FENCE Patented Dec. 4, i923.

UNITED STATES PATENT OFFICE.

LAFE V. FENCE, OF FLINT, MICHIGAN, ASSIGNOR TO GENERAL MOTORS CORPORATION,

OF DETROIT, MICHIGAN, A CORPORATION VALVE- OPERATING OF DELAWARE.

IeIECHANISIv'X FOB INTERNAL-COMBUSTION -ENGINES.

Application filed March 12, 1920. Serial No. 365,291.

To aZZ whom it may concern:

Be it known that I, LAFE V. France, a citizen of the United States, and a resident of Flint, county of Gcncsee, and State of lvlichigan, have invented certain new and useful 1mprovements in l alve-Operating Mechanism for Intcrnal-Combustion Engines, of which the following is a full, clear, concise, and exact description such as will enable others skilled in the art to which the invention relates to make and use the same, reference being made therein to the accompanying drawings, which form a part of this specification.

My invention relates to valve operating mechanism for internal combustion engines; and the principal object thereof is to provide valve operating mechanism the operation and adjustment of which will not be disadvantageously affected by the expansion of the cylinder and other parts which occurs when the engine becomes heated, and in which the contraction due to the cooling of the engine can in no event result in a condition of the valve operating mechanism such that the valves will be held off their seats when the engine is cool.

A further objectof my invention is to provide improved valve operating mechanism for internal combustion engines in which the parts thereof and the number of the joints or connections through which motion is communicated to the valves are reduced to a minimum, thereby providing valve oierating mechanism which will be simple in construction and little affected by wear; which will be quiet in operation, and which will not be likely to get out of adjustment when the engine is in use due to wear of the joints or connections between the elements thereof, or to other causes.

A further object of my invention is to provide improved valve operating mechanism for internal combustion engines in which the force necessary to accomplish the opening of the valves is materially reduced, because of the construction of the parts thereof and their arrangement relative to one another; thus on the one hand providing valveoperating mechanism in which the force communicated therethrough to operate the valves is materially reduced, and on the other hand providing valve mechanism in which stiffer springs are or may be used for accomplishing the closing of the valves than has heretofore commonly been the case.

With the above and other objects of invention in view my invention consists in the improved valve operating mechanism illustrated in the accompanying drawings and hereinafter described and claimed; and in such variations and modifications thereof, within the scope of the concluding claims, as will be obvious to those skilled in the art to which my invention relates.

Referring now to the drawings wherein the preferred embodiment of my invention is illustrated:

Figure l is a view for the most part in section showing my improved valve operating mechanism as appliedtoamultiple cylinder internal combustion engine ofthe V-type or class, wherein the cylinders are arranged at an angle to one another.

Figure 2- is a fragmentary view upon a larger scale illustrating mechanism whereby and through which a single valve of the engine is operated, the mechanism being associated with a cylinder upon the right hand side of the engine, referring to Figure 1.

Figure 3 is a fragmentaiyview upon .a still larger scale illustrating the mechanism associated with the lower end of one of the pull rods of the valve operating mechanism and the cam whereby the same is operated.

F igure l is a fragmentary view showing the upper ends of twopull rods, together with the cross heads and guide mechanism associated therewith, through which motion is communicated to two of the valves of the engine.

Figure is a fragn'ientary view illustrat ing the connection between the upper end of a pull rod and the stem of a valve which is operated thereby.

Figure 6 is a view showing a section taken upon a transverse plane indicated by the line 6(3, Figure 5.

Referring to the drawings, the reference numeral 6 designates the upper half and T the lower half of a two part crank case which is divided along a central horizontal plane passing through the crank shaft 8 of the engine; and 9' designates two cylinder blocks supported by the upper half of the crank case and upon seats or surfaces which are inclined relative to one another, so that the two cylinder blocks as well as the cylinders within the same are arranged at an angle to one another as in the ordinary form or type of multiple cylinder engine. Each of the cylinder blocks ordinarily has a plurality of cylinders formed integrally with one another and the axes of which when prolonged pass through the axis of the crank shaft 8 of the engine; altho it will be appreciated that my invention is applicable to en gines of any type or form and is not limited to engines of the V-type or form, nor to multiple cylinder engines.

The pistons ll, one only of which .is shown, are connected with the canl'; pins of the crank shaft 8, one of which is indicated by the reference numeral 12, through suitable connecting rods l3, 14: as is usual in multiple cylinder engines, and the upper portion of the crank case section 6 is provided with a recess or chamber 15 within which a valve operating cam shaft 16 is rotatably supported in suitable bearings not shown, and which valve operating shaft is driven at the usual two to one ratio from the crank shaft 8 by any suitable driving mechanism which, however, is not shown in the drawings, as the same forms no part of the invention to which this present application relates.

The open upper end of the chamber 15 is closed by means of a cover 18, and said chamber is intended to contain a considerable quantity of oil wherein the valve operating shaft as well also as the valve operating levers operated therefrom and hereinafter referred to are submerged to a greater or less degr e, in order to thereby provide adequate lubrication for the parts in ques tion of the valve operating mechanism, The lubricating system of the engine, however, is not involved in this present application, for which reason the same is not disclosed in detail.

The open upper ends of the cylinders 10 within the cylinder blocks are closed by means of cylinder heads 19 secured to said cylinders, and the stems 20 of the supply and exhaust valves of the engine are slidable in bearings 21 secured Within passages provided in said heads; one of said valves, its stem, and the sleeve whereby the said stem is guided being shown in Figure l and indicated therein by the reference numeral 22, and which valve controls the flow through a passage provided in the head. As a matter of course the valve illustrated in Figure 1 may be either the supply valve or the exhaust valve of the cylinder 10 with which it is associated, as both the supply and exhaust valves are alike so far as concerns the general type thereof and the operating, means through which they are opened. Each valve is acted upon by a spring, one of which is indicated by the reference numeral 23, which spring acts between a fixed abutment provided upon the head and a cup shaped stop or washer 24 secured to the upper end of the valve stem.

The reference numeral 25 designates a cross head through which motion conin'iunicated to the valve stem 20, one such cross head being associated with each of the valves to be operated and all being substantially alike, for which reason the following description will be in the singular; although it will be appreciated that the mechanism described will be duplicated for each valve to be operated by my improved valve operating mechanism. The cross head for one of the valves is shown enlarged and detail in Figures 5 and 6 of the draw': s from which it will. be seen that the same is provided with an opening 26 through which the upper end of the valve stem p: and with a threaded passage above and "a line with said valve stem through which an adjusting screw 27 extends and the position of which screw when properly adjusted may be fixed by a lock nut 28 which engages with the upper surface of the cross head; the purpose of the screw and lock nut being to adjust the effective length of the pull rod through which the valve is operated as it will be appreciated that movement is communicated to the valve stem through the screw 27, and that the cross-head as a whole is capable of adjustment upon and relative to the stem of the valve by the said screw.

The cross-head in question provided with a slot 29 for the reception o.-. the upper properly shaped end 30 of the pull rod 31 through which the cross head is operated, the said upper end being secured to the cross head by pins 32' extending through the same. The pull rods are of small diameter, and may in fact be referred to wires as the valves are operated by tension forces transmitted along and through the said pull rods or wires; from which it follows that inasmuch as said members do not have to withstand conngression forces no provision has to be made to prevent the buckling ot the said rods and rods or wires of small size, and having little inherent stifiiness, may be employed for communicating opening move ment to the several valves.

The lower ends of the pull rods 31 are secured to yoke members or links as by extending said lower ends into sockets provided at the upper ends of said yokes; and in this ronnection it will be observed that it e upper and lower ends of the pull rods are so formed as to facilitate their connection one with the said socket S3, and the other with the cross head 25 through the slot and pin connection provided at said upper end, as above pointed out. The yoke mav be properly referred to as a floating yolu: and the same partakes of both a downward and a sideways motion when an 5" .cnt il -t. upon its lower end is acted upon by the can:

upon the cam shaft 16 which operates any particular yoke and valve operated through the same; such movement being due to the fact that the lower end of the yoke is pivotally connected at 36 with the free end of a rocking arm 37, which arm partakes of an oscillatory movement about a shaft 38 as a center and which shaft in turn is supported in bearings 39. see Figure 1, within the lubricant containing chamber 15 above referred to.

It will be seen, referring to Figure 1, that when my invention is applied to a multiple cylinder engine of the V type or form the shat 38 which supports the oscillating arm 37 associated with a particular valve is upon the side 01" the alve operating shaft 16 opposite to that of the engine cylinder the valve of which is to be operated by a pull rod 31 the lower end of which is connected with the yoke 32 which is pivotally connected with the particular arm 37 herein contemplated; such a disposition of the parts being present in the operating mechanism for each separate valve. This arrangement, as will be understood from Figure 2 of the drawings. results in valve operating mechanism in which each pull rodv 31 moves both downward and toward the engine cylinder a valve of which is operated by the rod in question in each particular case; this statement being true as to the individual valve operating mechanisms associated with each 01 the various valves.

The pull wires extend through the interiors o'E housings 40 formed integrally with the cylinder blocks, and through passages ail formed in the heads 19 of the cylinders. The heads themselves are open at their upper ends so as to permit access to the adjusting screws 27 and to the guiding mecha nism tor the cross heads hereinafter described; and hoods 42 are secured in place over these openings when the engine is in use which hoods, in connection with the heads and the housings L0. and the lubricant containing chamber 15 and its cover 18, obviously provide a closed protecting casing within which the entire valve operating mechanism enclosed and protected from injury.

In order to prevent binding of the valve stems 20 as force is communicated to them through the pull rods or wires 31. which bracket in the embodiment of my invention illustrated serving to support a shaft upon which guide rollers for the cross heads which operate two valves are supported.

These brackets 48 are provided with internal annular channels 50 within which wicks 51 are located which wicks extend downward through a passage 52 provided in the bracket in each instance, and into a oil reservoir 53 formed in the upper surface of the head 19; which construction and arrangement provides for the lubrication of the bearings between the rollers 43 of the shaft 457, as well as for the wearing surfaces between the rollers and the cross head which latter surfaces, however. require little lubrication as the contact between them is a rolling contact in each case. In order to secure and maintain a proper relationship between the brackets 48 and the rollers which they carry and the cross heads 25 upon the upper ends of the valve stems one or more dowel pins 5st are provided, which pins extend through openings in the bases of the brackets and serve to definitely position the said brackets.

It will be appreciated that as the valve operating shaft 16 rotates the cam 35 thereupon, referring to Figure 2, will act upon the abutment or cam face of the yoke and move said yokedownward. said yoke also partaking of a movement to the right because of the pivotal connection at 36 between its lower end and the oscillating arm 37. This movement of the yoke 32 will move the pull rod or wire 31 downward and to the right; and the upper end of said pull rod will also partake of a movement downward and to the right because of the angular arrangement of the valve stem 20 relative to the said pull rod and which valve stem is obviously capable of movement in an inclined direction only, because of the inclined arrangement of the bearing 21 wherein it is supported. During this downward movement of the valve stem binding between the said stem and the sleeve 21 will be prevented by the rollers 43 which serve as guides for the cross head 25 the flat surface 46 of which moves in engagement with said rollers.

It will be appreciated that valve operating mechanism such as has been above described in detail will be provided for each of the valves of the engine which are to be positively operated; and it may be herestated that when my invention is applied to a multiple cylinder engine of the V-t vpe in the manner illustrated in Figure 1 the abutments 34: of the yokes 32 associated with like valves of oppositely disposed cylinders will be offset. as shown in Figure 41. so that for example one exhaust cam will engage the abntments ill of two yokes and communicate motion to both of them and to the exlit-3 haust valve of two oppositely located cylinders; while one inlet cam 55 will likewise, and through similarly arranged yokes, communicatc motion to the inlet valves of two cylinders also located one upon each side of the engine.

It will be seen that there are open passages leading downwardly from the interiors of the caps d2 through the passages 4:1, then through the interiors of the housings -10 and to the interior of the lubricant containing chamber 15; so that the lubricant V supplied to the chambers and to the guide rollers associated with the cross heads is tree to return to the lubricant containing chamber Suitable pumping mecluinism may be provided -for forcing lubricant from the chamber 15 to the interior of the chambers 53; from which it returns to the said chamber 15 in continuous cycle, thus maintiitin ing an adequate lubrication oil? the valve mechanism in its entirety; altho as hereinbeitore explained the lubricating System of the engine is not involved in this present application, and is consequently not illustratcd in detail.

The adjustment of the screws 2? will be such that when the engine is running and is in a heated condition the valve lash or lost motion between the cams upon the valve operating shaft and the abutments upon the yokes through which the pull rods are up erated will be at a minimum; which lost motion need be only so much as to insure that the valves will not be held of their seats slightly, because of insuliicient or no lost motion at all in the valve operating; mechanism, when the engine is in a heated condition. hen the engine is cold, however, the reduction in length of the cylinders and heads due to contraction of said members will increase the valve lash whicln however, will in no way interfere with the operation of the engine, as the reduced opening movement of the valves will in no way interfere with their closing tightly upon their seats and the proper operation of the Pug-inc at start ing,

Une oi the advantages oi" my invention over prior coi'istrluztions will be ap in'eciatml from the above explanation oi": operation tor, in valve operating mechanisms in wiIch the opening" movement Of the valves is commie nicated to them through push rods operating under compression stresses, the contraction of the engine cylinder upon cooling will (if the adjustment is such as to reduce the lost motion to a minimum when the englue is cold, as isnecessary to secure as great a valve opening possible when the engine is hot) take up the lost motion and often result in lifting the valves slightly oi their seats, thus making the starting of the en 'ine difiicult because of the failure of the valves to seat tigl'itly; while the expansion of the engine as it becomes heated will in mechanisms ot the old type here referred to reduce the opening movement communicated to the valves when as a matter of tact the valves should open to their maximum extent when the engine is heated and in operation. in my improved valve operating mechanism, on the contrary, no degree of contraction can result in the holding of the valves 05; their seats; while the elongation ot the cylinders as the engine becomes heated will take up such exeess'lost motion as may be present when the engine is cold and secure a degree of opening of the valves corresponding; with that required tor the most ellicicnt operation of the engine, and which lost motion is determincd by the adjustment ot the mechanism when the engine hot and under the precise temperature conditions under which maximum cliiciency should he provided for.

.t will be further appreciated that the -valve litters and rocker arms ordinarily present in prior valve operating mechanisms wherein the valves are operated through push rods are eliminated in my improved valve operating mechanism, thus greatly simplifying the said mechanism and reducing the number of parts thereof; with an ac companying elimination of wear at several joints or points of contact, and ot' the greater part of the noise heretofore often present in vabxe operating mechanisms and due to looseness of; joints, and in general to lost motion throughoutthe mechanism in question.

In fact, in my improved valve operating mechanism the yoke, the pull rods or wire, the cross head, and the valve in its entirety are in effect and as to each valve a single unitary device or structure; thus materially simplifying the valve operating mechanism, reducing its initial cost, and providing a mechanism which is less likely to get out of adjustment or to require attention when the engine is in. use than has heretofore commonly been the case ll inally, the angular arrangement of the valves to be rugeraled relative to the pull rods or wires through which motion communicated thereto provides valve operating mechanism in which the force i'ieeei-zsr 'y to open the valves is reduced, or. assuming a given opening force avz'iilaljile, then provides mechanism in which a stiller spring may beused to close the valve, both of which are features of advantage in valve operating mechanism; and provides also valve operat ing mechanism in which such wear as ,ccurs has less effect in producing lost motion in the mechanism that would be the case if he lines of opening movement of the valves were not inclined relative to the pull rod whereby the valves are opened.

Having thus described and explained my invention, I claim and desire to secure by Letters Patent:

loo

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1. In an internal combustion engine, a cylinder head having a passage; a reciprocating valve carried by said head and adapted to control the flow through said passage, and which valve is provided with a stem extending therefrom; a cross head carried by said stem and having a bearing surface; a bracket carried by said head; a shaft carried by said bracket and which shaft extends at right angles to said valve stem; a roller supported by said shaft and the periphery of which is in engagement with the bearing surface aforesaid of said cross head; a pull rod the upper end of which is connected with said cross head, and which pull rod acts at an angle to the path of movement of said valve stem in transmitting movement there to; a rotating valve operating shaft; a yoke with which the lower end of said pull rod is connected, and which yoke is provided with an abutment located beneath said valve operating shaft; an oscillating arm pivotally supported at a. point located to one side of said valve operating shaft and upon the side thereof opposite to that at which said pull rod and yoke are located, and the free end of which arm is pivotally connected with said yoke; and a cam carried by said valve operating shaft and adapted to engage said abutment.

2. In an internal combustion engine, a cylinder head having a passage; a reciprocating valve carried by said head and adapted to control the flow through said passage, and which valve is provided with a stem extending therefrom; a cross head carried by said stem and having a bearing surface; a bracket carried by said head; a shaft carried by said bracket and which shaft extends at right angles to said valve stem; a roller supported by said shaft and the periphery of which is in engagement with the bearing surface aforesaid of said cross head; a pull rod subjected to tension and the upper end of which is connected with said cross head, and which pull rod acts at an angle to the path of movement of said valve stem in transmitting movement thereto; a rotating valve operat ing shaft; a cam carried by said valve operating shaft; and means engaged by said cam and operatively connected with said pull rod for communicating motion thereto.

3. In an internal combustion engine, a cylinder head having a passage formed therein; a reciprocating valve carried by said head and adapted to control the flow through said passage, and which valve is which serves as a guide therefor; a pull rodthe upper end of which is connected with said cross head, and which pull rod acts at an angle to the path of movement of said valve by said valve operating shaft and adapted to engage said abutment to thereby move said yoke downward.

I. In an internal combustion engine, a cylinder head having a passage; a reciprocating valve carried by said head and adapted to control the flow through said passage, and which valve is provided with a stem extending therefrom; a cross head carried by said stem and having a bearing surface; a bracket carried by said head; a shaft car ried by said bracket and which shaft extends at right angles to said valve stem; a roller supported by said shaft and the periphery of which is in engagement with the bearing surface aforesaid of said cross head; a pull rod subjected to tension and the upper end of which is connected with said cross head, and which pull rod acts at an angle to the path of movement of said valve stem in transmitting movement thereto; a yoke with which the lower end of said pull rod is connected; an oscillating arm the free end of which is pivotally connected with said yoke; a rotating valve operating shaft; and a cam carried by said valve operating shaft and adapted to engage an abutment upon said yoke to thereby transmit motion thereto and to said pull rod.

5. In an internal combustion engine, a cylinder head having a passage provided therein; a reciprocating valve carried by said head and adapted to control the flow through said passage, and which valve is provided with a stem extending therefrom; a cross head carried by said stem and having a bearing surface; a roller against the periphery of which said cross head bears, and which serves as a guide therefor; a pull rod the upper end of which is connected with said cross head, and which pull rod acts at an angle to the path of movement of said valve stem in transmitting movement thereto; a reciprocating yoke with which the lower end of said pull rod is connected; an oscillating arm the free end of which is pivotally connected with said yoke; a rotat ing valve operating shaft; and a cam car ried by said valve operating shaft and adapted to engage an abutment upon said yoke to thereby transmit motion thereto and subject said pull rod to tension.

6. In an internal combustion engine, a cylinder head having a passage formed there" loo with an abutment located beneath said valve operating shaft; an oscillating arm the free end of which is pivotally connected with said yoke; and a cam carried by said valve operating shaft and adapted to engage said abutment to thereby depress said abutment and subject said pull rod to tension.

7. In an internal combustion engine a cylinder head havinga passage formed therein; a reciprocating valve carried by said head and :ulapted to control the flow through said passage and which valve is provided with a stem extending therefron'i; a pull rod subjected to tension and the upper end of which-is operatively connected with said valve stem and which rod acts at an angle to the path or movement of said stem in transmitting movement thereto; a rotating valve opera-ting shaft; a yoke with which the lower end of said pull rod is connected, and which yoke is provided with an abutment located beneath said valve operating shaft; an oscillating arm the free end of which is pivotally connected with said yoke; and a cam carried by said valve operating shaft and adapted to engage said abutment.

8. In an internal combustion engine, a cylinder having a passage adjacent its upper end; a reciprocating valve adapted to control the flow through said passage, and which vznve is provided with a stem extending therefrom; a pull rod operatively connected with said valve stem through which movement is communicated thereto by tension transn'iitted through said pull rod; a rotating 'valve operating shaft; a cam carried by said shaft; and means through which said cam acts to move said pull rod both longitudinally and in a direction transverse to its axis to thereby communicate motion to said valve through said pull rod by tensile force transn'iitted alonpsaid rod.

9. In a multiple cylinder internal combustion engine. two cylinders arranged in V relation to one another; a rotating Salve operating shaft located between said cylinders and adjacent their lower ends; an oscillating arm supported adjacent one of said cylinders and extending toward the other cyliner; a reciprocating yoke one end of which is pivotally connected with the free end of said oscillating arm and which yoke is provided with an abutment which lies beneath said valve operating shaft and the other end of which yoke is connected with tie lower end of a pull rod located adjacent and extending ujm'ardlv dongside the other of said cylinders; a valve located at the upper end of said last mentioned cylinder and adapted to control a passage leading thereinto; means whereby and through which the upper end of said pull rod is operatively connected with said valve to open the same by tensile force transmit ted through said pull rod; and a cam upon said valve operating shaft and adapted to engage the abutment aforesaid to thereby move said yoke downward.

10. In a multiple cylinder internal combustion engine two cylinders arranged in V relation to one another; a rotating valve operating shaft located between said cylinders and adjacent their lower ends; an oscillating arm supported adjacent one of said cylinders and extending toward the other cylinder; a pull rod located adjacent and extending upwardly and alongside the other of said cylinders and the lower end of which pull rod is connected with said oscillating arm; a cam carried by said'valve operating shaft; an abutment engaged by aid cam and operatively connected with said pull rod to thereby subject said pull rod to tension; a valve located at the upper end of said second mentioned cylinder and adapted to control a passage leading thereinto; and means whereby and through which the upper end of said pull rod is operatively connected with said valve.

ll. In a multiple cylinder internal combustion engine two cylinders arranged in V relation to one another; a rotating valve operating shaft located between said cylinders and adjacent their lower ends; two orcillating arms supported one adjacent each of said cylinders and. which arms extend each toward the other cylinder; two recipro eating yokes the lower ends of which are pivotally connected one with each of said oscillating arms and which yokes are provided each with an abutment which abutments lie beneath said valve operating shaft and the other ends of which yokes are connected with the lower ends of two pull rods located one adjacent and extending upward alongside each cylinder; valves located at the upper env s of said cylinders and adapted to control passages leading one into each of said cylinders; means whereby and through which the upper ends of said pull rods are operativoly connected one with each of said valves; and a cam upon said valve operating shaft so located and ar ranged to engage both the abutments aforesaid to thereby operate both said valves from a single cam.

In testimony whereof I atlix my signature.

LAFE V. PENCE.

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