US1785523A - Valve-silencing mechanism - Google Patents

Description

Dc. 16, 1930. C` .,CLED 1,785,523

I VALVE sLENcING MEcHANIsM Filed Sept. 2e. 192e /f/ if if /Z /0 77' l Y Patented Dec. 176,A 1930 crirronnLivrcrinonoFk QUINCY, MASSACHUSETTS fvALvEp-sILE'NoInG:MECHANISMQy fi i 'Appneauq'n mea september 26, 19218.VV spriiv-nalsqsyiiks.

A 10 lhenlthe rocker arm or othervalve-openingmember moves tolperrnit, the, valve tol close under rthe action 'of its spring, the arm must Yordinarily be adjusted to move clear of the valve stem when the valve closes, in Vorder to valverin closingjhits its seatlwith the full pressure of the val-ve spring on i it..` This causesconsiderable noise and wear. When the rocker larm starts' itsValVe-Openinglmotion, it must first take 4up theclearan'ce space A between itf'and the'endofgthe gvalve stem before engaging` the stern'toy open the valve. This causes a click between the arm and stem which adds to the noiseand wear. Accord- 25 ing to the present invention I greatly reduce theenoise and wear on the valve and itsassof ciated parts by means oi. asimple and eiective device for resilientlyopposing the action Vof the valvefspring untiltl'ievalveis'seated, fand, for maintaining the? valve f stem and VroclnerK-armf inV mutual Contact i atfall times.V Various advantageouseatures of construe-i: tion will `be apparent to.V one skilled in theart from the description ofthe inventionwlrich follows, and i'`rom` the drawing; of which :`A

Figure lfisa perspectiveV view of an-element employed inthe mechanism. A l Figure-Zie a-side elevation ofthe same.4 :Figure 3 is a side elevation of a rocker bar formed for usewith the element shown'in Figure 1. *y p f v. r vFigure l is aside elevationipartly'broken away and'in section of a poppet valvewith valve opening mechanism and valve silencing mechanism. Y l, Figure 5 is a similar View showing therparts CTI in a different yposition of operation. f i Figure 6 isa perspective view of a modi- 50. fied form of elementtor valve silencing` mechanism. v

13. The. spring maybe; as usual Va helical s allow the valve to-'seat tightly.` Thus kthe `The .rockero bar v10' .ispro'videdwithfan `arm a small clearance between'thexend ofthe arm.

{tactf is established ,betweenftheend of -the Inworder to i -inotionl may :provide '1 an lintertting. tongue Figure 7 isa `flanged pintor usewith the elementvshown in 'F1'gure6. L

Figure 8 is a section of a rocker arm aclapt-z 4ed' to fcooperate fwitlr the elements shownQin .Figures and'l';V y, jReieIring toV the'` drawing in. detail, rl() represents ayroker barwhichfis vadapted to.

rock on a shaft 11, inn orderfto open a poppet i i valve' 12";which .is .constantly lpressed;to? i .ward its closed positionfby'avalve spring '6 coil underfcompression `between theinotor y casing `14C-and awasher l'whi'ch` secured adjacent to the end' of thel valve stem 16.

17, motion of which serves to` open thefvalve lehrte:permitira,.cioseimdepu1@ action of Y 'l "thespring The valve-opening motionof i the-.armml'may be producedas by ap'ush y In order to permit thevalve toseat tightly,

`and theend of thevalve stem must be allowed as otherwisegany wear on the valve seat or the vcontacting face of the valve would result infaffailure'of the yalve'ftojclose tightly.

According :to Y Vthis vinvention a resilient con- Varm-17y andthe endof the valve stem sothat the clickpusually incident-[to thei'meeting of i lfthe rockenarm-Land'thenvalvelstein is, thus avoided. To thisend airockable elementor shoe 19 maybe .p1'ovided,.` this shoe being carl yried byL the' rocker," arin y'17l and d held thereon againstglongitudinal or lateralsliding motionhtheshoe beingfreeyhowever, to rock on the arm. c: l' 7 90 prevent relativel longitudinal 20- and'r groove 21.r As shown on*k the drawing, the tongue is l:formed transversely on the rockerv arm 17', the groove `21*beingformed in the e5 shoe 19..n If desired, l1owever.,'the.tonguemayy be formed on the shoeyandthe-groove in the arm. The shoe may be providedwithacurved elongated portionQQ, this portion serving as a leverarniV which may bef engaged by a suit- 10u Y whichis opposed to the shoe may be'recessed able leaf spring 23 which is `mounted on the rocker bar. The elongated portion 22 may be provided with a pair of flanges or fins 24 which are arranged to engage thevsidefaces of the rocker arm 17 so asto prevent relative `lateral or transverse motion betweentheshoe 19 and the arm 17. The face of the arm as at 25 so that the shoe will normally pivot on a small portionl f the face of the arm VV17 Which is adjacent toanedge26. The :spring 231nay be secured to the rocker bar as by a suitable" screw 27 or by any other means `This spring, as shown inFigures 4 andr, is

preferably curved so as tocooperate with the curvature of theextension 22 of the shoe 19 in such fa Way as toengage thelface of the .shoe selectively at dierent pointsalong the length of the extension 22 according to the position Vofoperation of the valve opening and silencing mechanism. ,When the `valve is closed as shown in Figure 4, the end ofthespring 23 -which is remote from its pointof support engages the shoe 19 at apoint well spaced .from Iboth ends thereof. AllVhen the valve is openfthep'arts are as shown"in- Figure 5 wherein the spring 23 isrepresented as pengaging the .shoeV 19 at a'lpoint near the end ofthe shoe which is remote fromthe point of its Contact with the valvefsteni 16. "In this position the intermediate `portion of the springrather than vits free 'end engages' 'the shoe 19. `As this,` intermediate fportionl'is nearer to the pointof support' of the spring than is the free end,"the springfthusoiers a jstiffer'resis'tance, the eifect ofthis resistance on the shoe beingmagnified by the factthat the lever arm 22 which fulcrums on the surface adjacent to the edgej26V is effectively longer' when thevalve 12 is open, since the spring 23 in this case engages the extension 22'near lthe end remote from the `fulcrum rather than at a point nearer the fulcrum as inFigure 4. The resultof this construction is' to oppose an increasing "resistance to the rocking motion of the shoefas thei valve Y12 opens. Thus when the rocker bar 10 is rocked from its position, as .shown in Figure 4,`inv order to open thel valve 12, the ,'shoe19is pressed against the end of the valve vstemfl and, tends to rock onitsfulcrum in' opposition to the pres-sure of the spring 235011 its extension 22. Asv the rocker bar rocks further, an ,increasing pressure is thus'caused between the shoe 19 andthe stem 16V by the virtualincrease of the lever arm 22ffrom v,the

i f fulcrum to the pointof conta'ctof the arm 22"with thegspring`23, until the tendency of the springto roclrthe shoe in one direction .is balanced by the pressureagainst the valve stem 16-which tends to rock the shoe in the vopposite direction. Thereupon, further rocking motionof the rocker bar-1,0 serves to move the valve to its open position.A When l the valve returnslto its closed position, the' bal-V ,bpring 23.'

ance between the opposingirnoments on the shoe 19 lcaused by the pressure of the valve stem 16 at one end of thevshoe and the pressure ofthe spring23 'near the other end of ythe shoe is maintainedV until the valve reaches its seat, whereupon vthe shoe 19 rocks to reduce its pressure against the end of the valve stem when 'the arm is further withdrawn and thus increasingly lto permit the -valve spring 15 to press the valve'12 firmly against its seat. :In this Waytheblow of the valve 12 against its seat is minimized since at the in- Aorder to prevent side slipping ofthespring withlreference to the extension l22,'.I may mount in the latter a pin 28 which may eX-, tend Vto` a,y suitable ,perforation 29v inthe Figures 56 and i 8 .illustrate a 'modified einventing relative longitudinal and lateral mo-V tion between the slice and thefroclrer arm.

bodimentof they invention, different fmeansheilig employed in this embodimentjforpre- According to' this embodimentr the rocker arm f8() is 'providedwith a transverse recessl'near its end.' The shoe 32is likewise recessed as at 33, the recesses 1,- 'being opposite each other so as to form ane'arly cylindrical perforation in which ,inayfbe mounted arpin 34 having flanged ends '35'. :"Thebody ofthe pin 34, as shown, forms apivoton which the k'shoe may' roel; and 'prevents relative longitudinal movement` between vthe'shoe and the 'rockerarrm the' flanged' vends 35 serving to prevent lateral movement.A The'recesses 31, 331ma'y be shaped somewhat asshown in Fig ure 8 to allow thefbody of thefpin 34aslight. `rolling 'motion as the s'hoef 32.-' rocks on the. armBO; This redufces wear on the pin 34 and j thefcontacting faces; The'action of the shoe 32 is identical with the .action Aof the shoe 19. which has 'beenlhereinbefore`described in de- Having thus described 'an embodiment'of this invention, it should be evident to those skilled-ign the art thatvarious changes and ,modifications might,V "made therein without departing from itsfspirrt orscope'as delined bvV they appended claims. *Y I claim:

l OO

"1. The' combination `with a valve, `a stein thereon, and a valveiclosing spring, of. a inem- Y oer movable toopen the valveA against 'the pressure ofthe spring` a stem-contacting ele- Ament ,rockably'carried by said member and arranged to engage said stem adjacent to one "end of said element, and a spring secured to said member and engaging said element selectively at various points extending from the central portion of the element tothe end remote from said stem-engaging end, the point of contact between the element and tle element-eno'aeines rino' de endinf on the nosies c n n a i tion of operation of said member and stem.

2; Valve-silencing mechanism comprising a rocker bar having an arm, a valve stem moval'Jle by therocking motionof said arnnand yielding means carried bysaid arm and` en-V Y gaging said stem, said yielding means includ# yielding means carried bysaid. arm and engagin g said stem, said yielding means incl-uding a member having direct rocking contact with said arm, said stem being arrangedto bear en one end portion of said membergand a spring bearing on the opposite end portion 1 of said member at a point about half-way between the ends of the member when the valve is closed, and at a point near the end of the member when thevalve is open.`

4. The combination with a valve ll'iaving a stem anda valve-actuatingmember, of valve silencing mechanism comprising a .cooperating memberrroclrably carried by saidvalvey actuating member andengaging said'stem, said members having a transverse tongue and groove engagement whereby relative 'longitudinal motion between said members is prevented, one of said members having1 lateral lianges engamngtheother said inemberto prevent relative transverse motion between said members, and aspring carried by said valve-actuating member and engaging said cooperating member on its end portion remote fromv the 'point of engagement with said stem.

5. The combination with a valve` a stem thereon,cand al valve-closingspring, of a member movable to open the valve against the pressure of said'spring, a stem-contactfingelement rockably carried by said inember and arranged toengage said' stein adjazcent to one end of said element, and a spring secured to said member and engaging said Aelement selectively at various pointsextendsignature..l

-a member having direct rocking contact with said arm andn having an end portion bear` ing directly on said stem and a spring bearingon the opposite end portion'of `said member selectively at various points according im 4. tothe position'of operation ofsaid member,

Vsaid arm and member havingiopposed faces adjacent to the stem-engaging end .of said member and mutually engageable to preventlongitudinalgslip of said member on said arm.v

l -`TQValve-silencing mechanisml comprising a rocker bar havingan arm,` la Vvalve stem lmovable by rocking motion of said arm, a

member having direct rocking Contact with saidarm` and havingy anend portion bearing directly on said stem', and a spring bear- 1 ing on the opposite kend portionof said Inemy ber, said armandmember having opposed faces adjacent Vto the stem-engaging end of said member and mutually engageable to prevent longitudinal slip Vof saidmember on saidarm. '1f

l- 8. Valve silencing mechanism comprising a rocler'bar'having an arm,y a valve stem movable by rocking `motion of said arm, av

member having direct rocking contact with said arm and having an end portion bearing directly KVon said stem whereby pressure be-f tween said stem andV memberytends torock the member onthe arm, and lpaspring bearing on said member and tendingto rock said member in opposition to said stem, said arm and member having opposed faces thereon mutually engageableto prevent longitudinal slip of said membe'ronsaid arm. i I

In testimony whereof .Ifhave alfi'iedimy cerimonia,i MeLEoD;

ing from the central portion ofthe element Y to the end remote from said stem-engaging end, said member` and element havingr opposed faces thereon mutually engageable to ment and member.

prevent longitudinal slip between said ele? 6. Valve-silencing mechanism comprising a rocker-bar having an arm, a valve stem movable by the rocking motion of said arm',

fiio

Images