US1523583A - Valve mechanism - Google Patents

Description

Jan. 20. 1925. ,523,583

. R. CHILTON VALVE MECHAN I SM Filed Aug. 5, 1922 Patented Jan. 20, 1925.

UNITED STATES PATENT OFFICE.

ROLAND CHILTON, OF KEYPORT, NEW JERSEY, ASSIG-NOR T0 AEROMARINE FLAME da MOTOR COMPANY. A. CORPORATION Ol? Ifllllv YORK.

VALVE VIECHANISM.

Application filed August 3, 1922.

To cZZ fui/0m 'it may concern.'

Be it lrnown that I, ROLAND CHILTON, a subject ot' the King of England, and a resi dent ot` Keyport, in the county of Monmouth and State ot' New Jersey, have invented certain new and useful Improvew ments in Valve Mechanism, of which the following is a speciiication.

This invention relates to improvements in valve operating mechanisms in genera-l, and more specifically to that type ot mechanism which is frequently associated with aircraft and other high out-put internal combustion engines wherein over-head inlet and exhaust valves are operated from a common camshaft through the medium ot rocking levers.

Conventional practice in such mechanisms involves the use ot' a spiral spring around the valve stem for returning the valve to its seat and keeping 'the actuating parts in Contact with the cam profile. Springs oit' this type occupy a considerable length and involve proportionally long valve stems and rocking levers. It is one of the objects of this invention to reduce the weight of all moving parts, which is eli'ected in part by achieving extreme compactness in the whole design, by the use ot a flat valve-returning spring disposed above the valve levers, and attached to the valve stems by a new form ot unitary linlt. By this means the valve stems need only be made as long as is required to get adequate guiding surface instead ol: having to accommodate in addition considerable length ot spiral spring. At the same time owing to the angular disposi- Vtion ot the valves, which is necessary in a valve mechanism ot this type, relatively short rocking levers result from a shortening ot the valve stem.

Small mass in the moving parts is of paramount importance in valve mechanisms in general and this end is additionally achieved in this invention by an organization ot parts enabling the practical utilization ot rocking' levers fabricated from a relatively light material such as the modern aluminum alloys.

Vlonventional constructions in the rocker arms require these to be made from steel or similar high tensile material which can be hardened because such conventional practice involves a rounded tace at the end of the valve levers in contact with the end Serial No. 57/9A12.

of the valve stem, to allow of the oscillation ot the valve levers. Such a` round `contact iace has only point or line contact and even when made ot hardened material is apt to develop rapid wear. lt is accordingly one ot' the features of the present disclosure tiiat means are provided between the end ot the valve stem and its actuating lever, whereby adequate suriiace of contact is realized between these parte throughout their motion, thus permitting the use ot a relatively soit and accordingly light material Jfor the rocker arm.

lliccessibility and quickness of disassembly are further objects of this invention to which end this special :torni of valve linlr and spring arrangement described below contribute.

A further object ot this invention is to provide a valve mechanism wherein all the parts may be pressure lubricated. To admit oi this special precautions must be taken to prevent excess oil from the parts so lubricated from reaching the inlet valve guide in excessive Quantities. Trouble has been experienced iron'i this source in the past because such oil is drawn down the guide and into the combustion chamber. Accordingly the levers and associated parts are designed to minimize this oil splash.

ln the showing ot the drawings a detachable type ot cylinder' head is indicated and while this invention is applicable to nondetachable cylinder heads there are special advantages accruing from the specific construction oiE the showing7 in which the camshait is supported directly in bearings machined in the head casting.

in apparatus ot the class described an adjustment tor clearance between the operating parts when the valve is on its seat must be provided. rlhis is commonly achieved by a screw in the end ot the valve lever contacting with the end ot the valve stem and having locking means intended to prevent movement oi" the screw under vibration. rlhis screw and loch device constitute one of the sources otf weight ot the moving parts and aoco 'diugly this invention conten'iplates an adjusting means which does not move with the level'. Such means is constituted in the case ot' the showing by providing the tulcrum pin on which the lever actuates with eccentric end portions so disposed that by a rotation ot the tulcrum pin the rocker lli arni is displaced upwards or downwards in order to eliect the desired adjustment. Means are providedL for locking this fulcrum pin when the desired adjustment has been obtained and it is a feature of this invention that this fulcrum pin and its locking' means do not add to the Weight of the i'i'ioving parts.

'lo these and other ends, the invention consists in certain improvements andv the combinations and arrangement of parts, all as will be most fully hereinafter described, the t'eatures of my invention being pointed out particularly in the claims at the end of the specilication.

ln the drawings Figure 1 is a fragmentary transverse section olf a cylinder head taken on the line 1-1 of Fig. 2, showing the most approved lform of my invention.

Figure 2 isA a fragmentary side eleva'- tion ot vien7 in Fig. l.

Figure 3 is a fragmentary end view of the lever bracket in detail.

Figure l is a Jfra-gmentaiy longitudinal section o'l" the lever bracket taken on the line t ot Fig. 3 Al'ulcruin pin.

In the drawings 10 designates the cylinder head ot' an internal combustion engine, 11 the piston, 12 the camshaft, having' cams 18. 1st; the camshaft 12 is rotated in any suitable manner as by means otthe motor through intermediate gears v shown). rlhe levers 15 are. actuated by the camshaft 12, by means of the came 13,

1l acting on the rollers 16, p ivotedl in theV levers 15, said levers being mounted in. thebracket 18 upon the 'ulcrum pins'19, the rotary motion ot the shaft 12 being thus converted into a reciprocating motion which is transmitted in turn to the valve stemsy 20, which are slideable in the guides 21, thereby opening` and closingl the valves 22'. 2?), manner. rlhe bracket 18 has a housing 181l with openings 47 through which the levers 15 project7 the portion 48 of the housing 18d acting as a fulcrum for the springniembei' 29.

fis shown in Figures 1 and 2, inthe upper end olf the valve stems 20, l have Jformed elongated openings 2st; 25 designates the U shaped links having a lower portion 26 engaging in the opening 24 ol" the valve. stems 20, on the upper, end'ot thev links 25 there are formed projecting portions27 which engage the lip-turned ends 28 ofa laminated valve spring 29, composed oftiv-o substantially flat end portions with anintei-mediate arcuate portion. The links 25 nia'v he readily disengaged from said spring hv the application of pressure to the end ci' the spring mentioned, the links mayv then be disconnected Jfrom their associated showing the eccentricv (not in pre-determined sequence in the usual' val-ve. stems by vturning the links at rightangles thereto and passing the upper end of the stein out through the openings 30 of the links 25. ln the guides 21 there are formed on opposite sides thereof elongated,- openings 31 which give clearance tor the links 25 when in operation; in the event or fracture of the spring' 29, the links 25 will engage the guides 21 at the loiver portions ot the opening 81 and thereby prevent' the valves being projected into the cylinder where they would. cause serious damage.

ftsshown. in Figure 1 the ends oiC the levers 15 have recesses 83 Yformed i the underside to. receive a ball' 3st having a Hat side 35.01"' approximately the same area as the end of the valve stems 2O and having af, constant tace to tace contact therewith.; inthe previous art it has been customary to have spherical or cylindrical faces in Contactv with the flat valve stein ends toi'all'oiv ct oscillatingandv sliding mo tion relative tothe end ofk the valve stems, this gives only lineor point Contact and the resulting' high intensity oit pressure causes rapidi wear; it isone of the Yfeatures oftheY present, invention that a detinite and adequate area olfcontact secured between themoving par-ts.

In Figure 1l, I have shown the detail ot the-ulcrum pins 19fhaving two mutually concentric end portions 37, 38 and an intermediate relatively eccentric portion. 39. The end portion 37 is ol' greater diameter than, the end 38' to give it a greater bearingy surfacel and the pin has been stepped down t'opermit of the same being readily assembled intothe-levers, it also has a cutout' portion l0* anda slot 41'. Vlhe end portions-37', 38- have ay bearing in the bracket 18-y and the; center por-tion 39 acts as a tulcrunr for the levers 15, ther cut-out portion/t0' is a clearance` for the bracket retainingy studs 42, furthermore, said cut-ont portiontO prevents thev gin from being in correctly'assembled into the bracket 18; in

the'slot'll a'bar or suitable Wrench may be` inserted for-theV purpose ot` adjustment, upon the tightening of the` nuts LC-3 on the studs-l2 the pin 19 will be locked in positio'uby contraction of the-bosses 476 ot the bracket 18.1

Disposed intermediate the two ends ol the levers 15 and formed integral there with are` the upwardly and downwarly projecting portionslfl;y 4', the portions '-l-'lextending eXteriorly o'l" the bracket housing portion 18, the aforesaid projectingportions actingasbarriersto deflect any oil that may beprojccted inthe direction ot`v the valve stems tor the reason as hereintofore described; 49 is a cover Ytor thel above-described mechanism to prevent entrance ot dirt and leakage ot' oil.

lll() unitary links connectingl an end ol said spring' to each valve and embracing the valve end olf the rocking lever, and means between the end of the valve stem and the rocking' lever, said means shaped to lit contours on each, the one for sliding'` the other for oscillation.

2. In a valve actuating mechanism, the conibination of a lever, a valve having a stem, a spring, a one-piece open-ended dis engageable link connecting the valve stein and the spring, and a substantially semispherical contact member interposed between the end o't' the valve stem and the lever.

3. ln the art oit connecting a flat valve spring to a valve stem, a. slot through, the valve stein near the end thereof, a proximately U shaped link adapted to be assembled into said slot and having projections capable ot engaging' the end ot the spring'.

l. ln the art of connecting` a valve stern end to a spring, a slot in the valve stem end and a one piece link adapted to be threaded through such slot and "provided with abutments tor engagement ot said spring.

5. In mechanism of the class described, the combination ot a valve having' a stem, an actuating lever therefor, an oscillating` contact member disposed between the actuating lever and the valve, said Contact member having a flat tace bearing on the end of the valve stem, a spring, and an openended one-piece link forming a connection between the valve and the spring and adapted for disengagement trom both ot the members set forth.

6. ln the art of connecting a flat. valve spring` to a valve stem, a slot through the valve stem near the end thereof, a rectangular link having an opening in one side to admit ot assen'ibly into the stem with the side of the link opposite the opening engaging the slot, the internal width oit said link being greater than the width oli' said opening so as to provide an abutment tor the spring.

7. ln a valve mechanism, the combination of, a valve provided with a slotted stem, a valve lever, a spring, a connection between the valve stem and the spring); comilirisinpl a disengageable link disposed in the slotted portion ot the stem and engagiirg` the spring, and a connection betvveen the valve lever and the stem, comprising an anti-'triction ineniliier having two dissimilar contact itaces.

8. ln. apparatus of the class described, the combination of a pair of valves, valve actuating levers, semi-spherical contact members between the valves and the levers, a camshaft cooperating with one end ot the levers, 'tulcra for said levers, a bracket supporting said `tulcra constituting;- an oil guard over the camshaft end ot said levers, a llat valve spring', a one piece diseugageable link between said spring` and said levers, and means associated with the bracket tor supporting the spring.

9. A valve actuating mechanism tor valve in head motors, having,` in combination, a plurality ot' valves, said valves having' stems,

. a housing, levers 'liulcrumed in the housing' and adapted to actuate said valves, means for eccentrically adjusting the fulcra ol said levers, a resilient member supported on the housingl and adapted to maintain said valves, normally in their closed positions, one piece link members interposed between said resilient member and the valve stems, and means integral with said actuating levers adapted to interrupt and deflect oil projected in the direction ot said valve stems.

l0. In a valve actuating,` mechanism for valve in head motors, the combination ot a plurality oit valves having stems thereon, levers tulcrumed in a bracket and adapted to actuate said valves, means for eccentrically adjusting the tulcra ot said levers, rotatable members having a flat face associated with said valve stems and interposed between the end ot the levers and the end o't said valve stems so as to act as bearings thercbetween,y a resilient member, links havinn' an opening, said links connected to the valve stems and engaging the resilient inem ber, means associated with said actuating' levers and integral therewith and adapted to interrupt and detlect lubrication material projected in the direction ot' said valve stems.

ll. ln the art of operating a stein valve by means of a lever and a spring, an oscillatino,` Contact piece supported .in the lever and bearing on the valve stem said contact piece oscillating' relatively to said lever and not oscillating relatively to said stem, and an open ended link connecting' the stein to the spring.

l2, l'n apparatus ot the class described, the combination oit a housing, a cam shaft therein, levers adjustably tulcrumed in the housing and operated by the cam shalt, a tlat valve spring,Y supported on the housing, valves having); stems adjacent to said levers and operated thereby, a substantially semispherical member between the valve stems and the levers. an open one piece link connecting); the vali/'e stem to the spring and projecting portions on the levers acting as oil detlectors.

13. In un internal coniloustion engine, in combination, a housing, n calin shaft therein, levers mounted on adjustable eccentric ful# crunis and operated by the cam shaft, a tlat valve sprii'ig. supported' on the housing,- Varlves hzivii'rg stems AJdjuccnt to said levers und' operated thereby, slots in the vlve stems, u substantiullyY senti-spherical inemher between' the' vulve stems und the levers, un open one piece link in said slots connecting the valve stems to the' spring` und projecting portions on the levers zctingas oil detlectors.

14. In en internal combustion engine, the

conibin'a'tion of e housing, u c'znn shaft there'-v in, levers liming cupped: ends; saidv levers mounted on adjust-able eccentric ulfcruins :1nd operated by the camshaft', a Het vulve springsupported on the housing'` valves hiwiin'f` stems with flat ends adjacent to seid levers and operated therehyi slots vin ythe valve steine, oscillating Contact members having' a flatv face, said contact membersl disposed in the cuppe'dends of the levers in a inanner so as to afford oscillation therein, the flat faces of said contact members Abeering onthe flat' ends ofthe valvestenis so es tov afford sliding" Contact therewith, open ended links disengageably mounted in said slots, uhutnients on the links to engage the sprintf,- projecting portions on the levers' uct-ing as oil` detlectors, und f1 cover portion Jfor the Whole".v l Y Signed at Keyp'ort in' the co'unt37 of: Moin` mouth and State of New Jersey this 31st de v of July A, l). 1922;

RolANi') Cnn/rou'.

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