US1137296A - Internal-combustion engine. - Google Patents

Description

R. D. STEVENS.

:NTERNAL coMusTloN ENGINE.

APPLICA-HON HLED OCT. 28| 1912- -1 ,137,296. Patented Apr. 27, 1915.

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INTERNAL COMBUSTION ENGINE.

APPLICATION FILED 00128. I9I2.

i foreign matter U] TES PATENT OFFICE,

" nay D. STEVENS, or sAN BEnNARDINo, CALIFORNIA.

, INrnnNAL-coMBUs'rIoN ENGINE.

To allee/omit may concern:

Beit known that -I, RAI citizen of the United States, .residing at San Bernardino, in the county of San Ber- 5 nardno and.' State of California,vhave in vented V.new and useful Improvements in ,Interni-'Qnbilstion Engines,"'of which the followin' 'g2 alspecication. v "ventionv latesto internal comengiiesfof .the four-cycle type in whichffaeombustible mixture ,formed outside the engine' is introduced into thercylin- Vder' durin he suction stroke of the piston and inf w return of the pistons:

My invention relates particularly to the devices that control the admission of the fresh gases and the escape of burned gases.

` In engines of this type, as heretofore con.

structed, lift' or puppet valves operated either by the pressure of the gases or of the atmosphere, -or by suitable cam mechanism have generally been employed and experi! ence shows that the use of such valves is' open to many objections.

, The' general object of m 1'invention is to provide for admission an exhaust vof the gases by means which shall obviate the obso )actions above 'referred to, and this result is attainedby using reciprocating piston valves 'having'j'in 4911 their ends. 'These rings preventjl ge of gases, assist in the lubrication, "and wip: out Vcai-ben and other oxmthe valveseat and so prevent it fromffnseatingjthe valve. The rings alsopause tire-valve chamber to wear even,'. and expand as the chamber becomes worn," jtl iusfpreventing leakage. 40.

One 'specific object of my invention is to secure*- self-lubrication of. the valves,l the same being surrounded with. a water-jacketed'yalvechamber in which said valves operate easily andl coolly.

is -to securev the automatic removal of. dirt, cai-bon and grease from the valve seat and to convey the same to some exterior point where the same may'be conveniently disv5t.) charged.

Another specific object of ray-invention is to securea considerable reduction in.' the gasfrictionfas the mixture passes'through the valve ports, the same permitting a freer Specicati'on of Letters Patent.

D. STEVENS, aV

ch the burnt gases are driven l5 from the cylinders after.v combustion by the vshows the square bushin Another, specific object of my invention rush of said mixture into' and exhaust strokes.- This feature operates to increase the useful power of my engine by reducing lost work of admission and exhaust, and obviously secures the admin-- ytage. of an increased over all engine ei- V ciency.

' Another specific object of' my'inventionfis to secure va. positive return ofthe valves,v

' is that I secure rapid valve motion during.

the haflf cyclein which the valves are active and secure a valve dwell or rest during the hal-f cyclein which the valves are inactive. This feature permits the-use of a comparatively short valve and valve seat and reduces wear on the same.v

lhe accompanying drawings illustrate the invention.

Figures 1, 2" and 3 are diagrammatic views in axial section through anl engine embodying my invention,and showing the position of the valve operating gear at critical points of the cycle. 'Fig 4 isl an enlarged plan section'of .the engine taken on line ic,

Fig. 5, the dust guards surrounding the valve casings being omitted 'in the interest of clearness. 'Fig. 5 is a vertical'axial secand out of the combustion chamber during the admission Patented Apr, 27,1915.

application ined octqber ae, 1912. sei-iai No. 728,273.

tion through the engine showing the details i and relative position ofthe valve operating gear, piston and the c linder. Section is taken on line w, and 6. Fig. G is a sectional'elevation along line ai of Figs. 4 and 5, showing myv improved valves.v Fig. 7 is a plan section on line :v-?, Fig. 5, and and square rod for carrying the roller fo lower..

1 is an ordinary four cycle gas engine cylinder provided with 3, and spark plug 4.

piston 2, Vwater jacket At diagonally opposite points',and built i integral with the cylinder,l are the valve chambers 5 and 6, having the transverse inlet port 7 and exhaust port 8 respectively. Through' these valve chambers pass the cylindrical apertures 9 and 10- serving as seats 'for valves as later described, the said apertures or seats being closed at their upper ends by; walls 11 and 12. Through'tliese walls pass oil ports 13 and 14, connected with a suitable oilvsupply not shown and.v

also breathingapei'tures 15 and 1("perinit ting the admission and discharge of air from the upper portion ofthe chambers during normal operation of the valves 17 and 18.

Each 'of the valve chambers is provided with a novel cylindrical piston v a'lve as shown at 17 and 18, similarly constructed,"

and having the packing rings 19 and 20. to form a gastight joint between the valve and its seat. These ringsare resilient and will automatically adjust themselves to take up lany wear of the cylindrical seats J and 1Q.

- Valves 17 and 18 are each provided with a funnel shaped inwardlyl expanding' port 21 bounded above by the upwardly and inwai'dly extending wall :22, on'tlie side by the inwardly diverging walls 23,' and on the bottomby the horizontal wall 24. As the lcontrollingedge 25 of port 21 is raised, un-

covering the lower outer edge 26 of port '7,

an expanded passagel through tlie'valve is pnovided, permitting gas to rush freely into the cylinder. Due to the expanded shape of said valve port the gas will be subject to 'l minimumiriction or resistance during its sion stroke thisreduct-ion of gas friction re` passage through the saine. On the adinisduces the back pressure on the piston face and thereby the lost or pumping work-of ad' mission. Durin the l`exhaust stroke the similar easier exit lol" burntgases through The lubricating oil, entering vthe valve' chambers by'p'orts 13 and 14, fills the reservoirs 27, and as the valve oscillates during operation, theoil is thrown out covering the upperx'portion of the valve seat. The oil will flow down along the seat to the rings 19 and 20 making a more perfect seal between the ringsand seat, and also reducing Vthe sliding friction between the saine. Un-

-. dervlthe influence A,of theexploded or comy Through this notch an additional aniountol lubricant over and above the normal qua-npressed gases the valves are pressed most forcibly against the outer portion of the va'lve seatl tending to cause the'greatest friction and wear there, and in order to supply a proportionately Vgreater amount'of lubricant .to this side, notch 28is cut vinto the upper edge of reservoir 27 at its outer point.

5 ti'ty-provided by the splash system will feed to the outer surface of the valve and coun.-

teract the increased wearing tendency. The

"valve chainbersgare also built tion in Fig. 5.

"3l and 232 oll the ports with. a 'Water jacket :29 surrounding both the vertical valve seat and the horizontal ports 7 and 8. Bv

this provision the valve is kept cool and its lubrication more readily effected. and at the saine time the gases passing through the ports are kept cool and therefore condensed.,

.securing the. passage ofniaxinium weight of gas with ininnniini expenditure ot power.

A downwardly and outwardly inclined -dirt groove 3U is cut into valves 17 and 18,

the former being shown in its-lowest posil-`roni this figure it is seen that the inner extremity of the dirt groove is never uncovered to the c vlinder side ot' ports 7 or S, but that the lower outer ex treniity of the groove is vopened to the outer side of ports 7 oi' b' when the valve has reached thc-lowest point in its travel. .The

edges of this groove will scrape the dirt, cai-bon and other foreign matter oiithe valve seat into the groove, such dirt passing down the inclined groove falling onto the ledges 7 and S respectively. If permitted to remain on ledge 31 of the inlet po1t,the inrusliiiig gases would draw the 'grit into the engine cylinder where damage might be done by cutting the cylinder i-ore. The ledge 31 is therefore inclined and the grit will run down and olf the saine into tlieadjaccnt receptacle 33 provided in the inlet pipe 3-1. The receptacle 33 is provided with a detachable portion 35 from which the grit may be discharged at suitable intervals. No such provision need-be iii-ade at the exhaust ledge 32 the grit being carried away from the engine by the exhaust gases issuing through the valve port.

Each of the valves are connected through pins 36 to the rods37 carrying at their lower; ends'the cain follower 3S operating iii con-v j iinction with positive return cains described below, to move the valves in 'correct time relation. with respect to the position of the powerpiston 2. ,f v

, The piston :2 carries the connecting rod 39, coperating with-crank l0 and power shaft 41 in the usual manner. The gear lil on the' power shaft, meshes witlipinions 43, carried by the lay shafts 44. Thepinions 43 are of the same diameter, and double that of gear 12, this'ratio causing cach pinion to'` make one revolution during four strokes or one cycle of the engine, the gear having inade two revolutions'in the same time. Mounted on the lay shafts 44 and revolving withv the pinions are the rapidly acting positive return cams 45 seen best in Fig. 6,- tliese rains being formed withfthe grooves 46 in which run the followers 38 imparting thev cani motion to valves 17 and 18.

In Fig. 5,v the piston is shown at its mid poii 1 t during the exhaust stroke, and it is s efen that the-follower 38 of the admission valve is at the end of a dwell or rest period determined by the dwell lobe extending from point 4i' to point 4S on the semi-circular portion l5) ot' the cam groovev and lasting from` the iiiiilcoiiipression to theinidexhaust points of the cycle. During this dwell there has been no function for the admission valve to perform and it has been allowed to rest motionless,causing no un-- necessaiv wear either upon the valve -or its the follower lies under line ac, shown best in Fig. 5. proximately 45 to the major cam diameter (al. T he exhaust fcam and valve operate in a manner identical with that of the inlet mechanism. except in po'int of time, the eX- l'iaust cam leading the inlet cam by 90 on the lay shafts. By use .of my valve operating. gear thc life of the valves is prolonged,

all unnecessary wear being avoided, and during the operating portion of its stroke thc inotiiin ot; -the valve is accomplished with despatch. securing an 'effective opening of both .ports for the admission and exhaust "of the gases. From the foregoing it is seen that the cylindrical valve chambers 9, 10 eut through the'ports 7, 8 so as to divide said ports into axially al'ined inner and4 outer bores that are rectangular in cross section and that vthe cylindrical valves 17, 18 reciprocating in said valve chambers are provided with transverse ports .therethrough and that each of said valve ports has an oblique upper wall designed to extend downward and outward between said bores from the upper side of the inner bore to the lower side of the outer bore when lthe valve is closed. .This construction .is of advantage to secure maximum thrust of the compressed gases in the cylinder against the valve so as to produce maximum tightness of the valve against leakage and, furthermore, is very important for reducing impediment of the fiow of gases to and from the cylinder since the valve ports 21, 22 are always fully openedl to the inner bores of the ports 7, 8 even when the. valves are closed,'so that in reality the onlyr obstruction to the flow of gases is the outer walls 'of .the valves. v

In Figs. 5 and 6 are sliown dust guards. or protecting hoods 50, suitably attached to the cylinder by means of studs 51 and wing nuts 52, the guards surrounding the valves and operating rods to prevent dust from ac-` cumulating and interfering with -the op'erathe lower valve portions for repair or adtion of the same. To expose the rods 37 and The lines ab and ac are located ap.

justment, the guards 50 may be-rapidlyre- Q moved byv merely unscrewing .the wing nuts 52. l

The engine -works according'to the wellknown four cycle principle, and from the foregoing itisA thought the operation of the elements embodying my invention. will be readily understood.

1. The combination with an engine cylinder having a, port, .of a cylindrical valve chamber cutting through the port and dividing saidA port into inner and puter bores,

and a cylindrical valve reciprocating in said valve chamber and provided with a transverse port therethrough, said valve port having an oblique upper wall designed to extendl downward and outward between said A bores 'from the upper side of the inner bore to'the lower side ofthe outer bore when the valve isclo'sed. l

2. Inlet valve mechanism for gas engines, said mechanism comprising a cylindrical valve chamber, a cylindrical piston valve adapted to operate in said chamber, said valv chamber having one port communicating ith the engine and another port leading into saidvalve chamber, the lower portion of the last said port being inclined downwardly, outwardl and away from said valve chamber, the cy indrical face of said piston valve having a downwardly and outwardly extending dirt groove cut therein, said dirt groove .-being adapted to open into the last said port and to deliverdirt thereto` and a removable receptacle mounted adjacent the lower portion of the last said port, said receptacle being adapted to collect the dirt deposited by vsaid dirt oove.

33. A valve mechanism Aor gas engines comprising a cylindrical member to form a valveV chamber, a cylindrical piston valve adapted to operate in said cylindrical member, a. port communicating with the engine being 'formed in one side of said cylindrical member; and a second port being'formed in the other side of the cylindricalxmeinber, there being a transverse port in said piston valve adapted to register with the ports through the cylindrical member, and a groove cut lin the cylindrical face of said piston; said groove extending downwardly and outwardly.and being adapted to-open into said second port and to deliver c abon' ber, an inlet pipe secured to said cover and affording communication into said valve chamber, a cylindrical'piston valve adapted to 'operate'in said chamber, said piston valve ino -valve chamber, a cover for said valve cham i being formed with an` upwardly open` g i cup-shaped portion adapted to form a Vredgvoir for lubricating oil which may be supplied thereto through said inlet pipe,'ss 1d,

YVthrough that partl Aof its side. which vis re nfl'oved from. the piston cylinder, said aper`l Vinle'fbeirlg adapted to feed lubricating 'ol l5 :.frbmsalid up-shaped reservoir n the valve to the walls of thegva1 vechamber which are removed from the enginel cylinder.

In testl-of"Whereof I have hereunto st` 11.1l piesenvce o-f-,g

OLGAv S. CASEY, WM. MANsoN.

RAY D. STEVENS.

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