US1784125A - Poppet-valve-actuation means - Google Patents

Description

Dec. 9, 1930. R. E. WILSON ET AL 1,784,125

POPPET VALVE ACTUATION MEANS Filed May 29, 1929 Z6 IIIVVENTORS- iolertllifilsamkioleziz'lfilsmg Patented Dec; 9, 1930 UNITED STATES PATENT OFFICE ROBERT EZEKIEL WILSON 3031mm EUGENE OI BELLEVILLE, NEW JERSEY POPPET-VALVE-ACTUATIOI MEAN I Application filed Kay 28, 1929. till I0. 368)".

This invention relates to an improved poppet valve actuation means for internal combustion engines.

This invention has for its principal object to provide an improved construction and arrangement of means for actuating spring closed intake and exhaust valves of internal combustion engines, to the end that valve operation is free from noise; that all working parts are maintained in continuous bearing contact; that actuating parts are self-compensating with respect to expansion and contraction under temperature changes; that heavy duty valve springs may be employed for high speed operation while nevertheless being counter-balanced for light pressure at valve seating osition.

This invention has for a further object the provision of a novel construction of counter-balancing spring structure for association with the valve actuating means, comprising novel forms of laminated spring elements having a two-point support in connection with one thrust member and a sin 1e intermediate contact in connection with t e cooperating thrust member of the valve actuating means.

This invention has for a further object to provide a means for regulating the normal initial pressure of the counter-balancing spring structure relative to the seating spring of the valve.

Other objects of this invention, not at this time more particularly enumerated, will be clearly understood from the following detailed description of the same.

An illustrative embodiment of the invention is shown in the accompanying drawings, in which Fig. 1 is a diagrammatic vertical section of part of an internal combustion engine showing the novel counterbalancing spring in operative relation to the valveactuating means;

Fig. 2 is a sectional view on an enlar ed scale of one form of the counter-balancing spring structure; Fig. 3 is a horizontal section of the same, on line 33 in Fig. 2; and Fig. 4 is a side elevation of another form of the novel counter-balancing spring structure.

Modern internal combustion engines, particularly of the type used in automotive work, are designed for high s eed operation, and are usually equipped witgspring closed poppet valves. Owing to the high speedof Operation desired, it is essential that the valve closing springs be of the heavy compression type in order to quickly overcome inertia of the valve when the same moves from open to closed or seated osition. Such heavy compression springs 0 er considerable resistance to the valve actuating devices, causing wear which in time produces loose contacts between the working parts of said actuating means, so that slapping or pounding noises occur both between the valve and its seat as well as between contacting parts of the actuating mechanism per se. In such cases frequent attention is required for the adjustment of actuating parts, and consequently entails a source 0 constant annoyance. Attempts have been heretofore made to obviate these difliculties by providing a cushioning spring between contacting parts of the valve actuating mechanism, but these springs have not heretofore been of a ty which fully overcome the difficulties soug t to be eliminated, being usually of the helical type or C-type, which are both difiicult to adjust and maintain at desiredinitial valve spring counter-balancin pressure, and which not only fail to build up over-balancing tension fast enough but require an excessive amplitude of movement before the desired over-balancing tension is attained, and consequently have been but partially successful for high speed valve operation.

The present invention provides a form of counter-balancing spring which comprises arectangular laminated spring structure supported at its ends for thrust and engaged intermediate its ends for transmission of thrust. This arrangement has all the advantages of initial sensitiveness whereby compensation for expansion and contraction of the parts associated therewith is attained without undue disturbance of the initial counter-balancing pressure desired to be effected there by, but also has the advantage of quickly building up an over-balancing tension within the range of a very small amplitude of movement, all of which is of distinct advantage. Furthermore, the laminated spring structure as herein disclosed is more durable, less likely to lose its resiliency under continued operation, and is more easily and sensitively adjusted to attain and maintain the desired initial valve spring counter-balancin pressure. I

Be erring now to the drawings, the reference character ,1 indicates a cylinder of an internal combustion engine. Associated with the cylinder 1 is a-valve port 2 having a valve seat 3 to receive the valve 4. i The stem 5 of the Valve extends exteriorly of the cylinder through a suitable guide 6. Mounted on the free end portion of the valve stem 5 is a seating washer 7 retained in place by a cross pin 8. Arranged between the seating washer and the top of the guide 6 is a valve closing spring 9, which is of the helical compression .type. Pivotally connected with a fulcrum 10 is a rocker arm 11, one end 12 of which contacts with the free end of said valve stem 5.

The reference character 13 indicates a rotary cam shaft which is suitably journaled in connection with the engine cylinder block, and mounted on this cam shaft is an actuating cam 14. Connected with the cylinder block, above the cam shaft 13, is a guide way 15 in which is mounted a slide-piece 16, for vertical reciprocating movement under the actuation of the cam 14. Preferably this slide-piece 16 is provided atits lower end with an anti-friction roller 17 to bear against the surface of the actuating cam 14. The exterior projecting upper end of said slidepiece 16 is provided with a thrust rod section 18 which is vertically aligned with another thrust rod section 19 extending upwardly therefrom. Connected with the upper end of the upper thrust rod section 19 is a socket piece 20, and threaded through the tail 11 of the rocker arm 11 is an adjusting screw 21 which has at its lower end a ball element 22 for engagement with the seat 23 of the socket piece 20, thus providinga ball and socket connection between the upper thrust rod section 19 and the tail 11 o the rocker arm 11. Threaded on the upper end of the adjusting screw 21 is a lock nut 24, to retain the same in desired adjusted position.

The novel counter-balancing spring structure which embodies the principles of the present invention is adapted to be engaged between the opposed ends of the lower thrust rod section 18 and the upper thrust rod section 19.- This counter-balancing spring structure comprises a bottom plate 25 having a receiving socket 26 integrally formed on its under side to receive the end of said lower thrust/rod section 18. Formed at the extremities of the upper surface of said bottom plate 25, so as to extend transversely across the said surface are supporting abutments 27 The reference character 28 indicates a top plate provided at itsouter or upper side with a central boss 29. Extending through said boss 29 and said top plate 28 is a slideway 30, through which the lower end of said upper thrust rod section 19 is movably engaged. The bottom plate 25 and the top 'plate 28 are secured in connected assembled provide a laminated spring body. The ends of the spring plates 34 are provided with indented notches 35 whereby the same may straddle the spacing posts 31. The laminated spring section A thus provided is supported at its ends on the abutments 27, thus holding the same against the thrust exerted by the lower thrust rod section 18 when actuated by the cam 14 and slide-piece 16, the intermediate body of the spring section being thus spaced from the bottom plate and being free for flexing movement toward the same. Overlying the ends of the laminated spring body thus provided are secondary abutment blocks 35 which are preferably perforated so that the same engage over the spacing arms 31. The reference character 36 indicates a second series of spring plates of the same kind as plates 34. The group of spring plates 36 form a laminated spring section B which is supported by the abutment blocks 35, so as to bridge across from one to the other thereof, and so that the intermediate portion of spring section B is spaced from the lower laminated spring section A and is capable of independent initial flexing toward the latter. The intermediate portion of the upper spring section B bears against the end of the upper thrust rod section 19 which extends through the top plate 28 and its boss 29.

From the above description it will be apparent that the spring structure is of the laminated type and that each section thereof is so mounted as to have a two-point bearing support against the thrust of the lower thrust rod section 18 while exerting a tensional or yieldable thrusting action through the flexible intermediate portions thereof'upon the upper thrust rod section 19.

It is highly desirable that the counter-balancing spring structure should-be adjusted to an initial tension adapted to more or less in spring '9' when the latter. is expanded to va ve seating position. For example, assuming that the valve closin spring 9 exerts a pressure of pounds on t e valve 4 when the latter is engaged on the seat 3; by turnin down the adjusting. screw- 21 at the tail 0 the rocker-arm 11, t-he up er thrust rod section ma be moved towar the upper spring section and itioned to place the same under an initia tension of about 40 pounds. It will thus be obvious that the pressure of the valve closin spring 9 is counter-balanced to the extent 0 the initial pressure to which the upper section of'the counter-balancing spring structure is set, and that consequently the valve closing spring 9 under valve seating conditions will exert a pressure of about 40 pounds. In the operation of the valve actuating mechanism, as the cam 14 rotates to move upwardly the 'slideiece 16 and lower thrust rod section'18, t e first efiect will be to increase the tensional pressure of the counter-balancing spring structure until the same is suflicient to overcome the tension of the valve-closingspring 9, whereupon the rocker arm will be actuated and-the valve stem 5 depressed to thereupon o n the valve 4. As the tension of the valve-c osing spring 9 increases under opening movement of the valve, the tension of the counter-balancing spring structure will correspondingly increase. It will thus be apparent that all contacting parts in the trainof actuating devices will be constantly maintained in contactand free from vibrations, slaps or pounds. As i the cam 14 moves away from the slide-piece 16, the tension of the counter-balancing sprin structure immediately tends to relax, and t e full tensional pressure of the valveclosing spring 9 is effective for rapidly overcoming the inertia of the valve so as to move the same toward closed position; when, however, the slide-piece 16 and lower thrust rod section 18 reaches the bottom of its stroke under the operation of the cam 14 the tension of the counter-balancing spring structure no longer relaxes and consequently it exerts its counter-balancing tension in opposition to the tension of the valve closing spring 9, so that as the valve reaches closed position the pressure of the valve-closing sprlng is materially reduced and consequently the valve is caused to seat quietly without sla or pound.

other advantage of the specific form of laminated spring structure above described, and as made in the two sections A and B, is that the upper section B may be made more sensitive and more easily flexed. This is an advantage in that it renders the structure more easily self-compensating under expansion and contraction of the thrust rods and other parts due to variations of temperature occurring during engine operations; furthermore, the upper section B- of the laminated sprin structure may. be utilized to provid'ethe esired initial counter-balancing tensional eflect on the valve closin spring 9 when in valve closing position, whi e under operation the upper section B quickly flexes under the opposing force of the compression of the valve-closing spring 9, so as to there-- upon engage the intermediate'portion of the lower laminated spring section A, which 1mmediately sets up a strong overbalancing pressure counter to. the valve-closing spring so that the actuating mechanismmay quickly transmitthe necessary power to compress the latter whereby the valve 4 is 'moved to open position. The laminated" spring sectionsA and B may comprise the same or difierent" numbers of laminations; for example, if it is desired that the u per section B be of v lesser tension than section A, then it may consist of fewer laminations, or vice versa.

While we have described our novel laminated spring structure as comprised of two sections A and B,-we do not desire to be limited to this particular form and arrangement thereof, since but a single section of laminations may be employed. This latter arrange;

ment we have .shown in Figure 4 of the drawings, wherein the ring structure comprises a single group of aminations C, which are mounted in connection with the bottom plate 25 and top plate 28 on abutments 27 in'a manner similar tothat described as to section A of the first described construction.

It will also be understood that the specific I ing transverse abutments, a thrust rod guide plate, means for connecting said guide plate in spaced relation to said thrust plate, a rectangular laminated spring means su ported at its ends on said abutments of sai thrust plate and intermediate the latter and said guide plate, a thrust rod slidable through said guide plate to bear on an intermediate joint of said spring means whereby under thrust the latter may flex toward said thrust plate.

2. A counter-balancing spring structure for the valve mechanism of internal combustion engines, said spring structure comprising a bottom plate carried on a thrust exerting member, abutments on said bottom plate adjacent its ends, a laminated spring section consisting in a plurality of superimposed spring plates, said spring section being supporte at its ends by and abutments, abutment blocks superimposed on the end porbebrought into tensional bearing upon said respective thrust exerting members, a guide tions of said spring section, a second spring section also consisting in a plurality of superimposed spring plates, said second spring section being supported at its ends by said abutment blocks, and a second thrust exerting member, all whereby the intermediate portions of said respective spring sections may means for said second thrust exerting memher, and means for retaining said ide means in fixed assembled relation to sai bottom plate.

In testimony that we claim the invention set forth above we have hereunto set our hands this 27th day of May, 1929.

ROBERT EZEKIEL WILSON. ROBERT EUGENE WILSON.

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