US1689752A - Lubricating system for internal-combustion engines - Google Patents

Description

Oct. 30, 1928. v 1,689,752

S. W. RUSHMORE LUBRICATING SYSTEM FOR INTERNAL COMBUSTION ENGINES Filed Oct. 9, 1924 ATTORNEY Patented Got. 30, 1928. v

UNITED, STATES SAMUEL wynnsnnonn, or rLAI vrInLi), NEW Jnnsny.

LUBRICATING sYsTEMro'R mrnnniin ooivrnusr on ENGINES.

Application fil ed October 9, 1924. Serial No. 742,637.

The object of the present invention is to provide improved means i'orinsuring correct lubrication for cylinders and pistons of internal COlllbllSblOl'l engines, particularly at the time that the engine is started. It is customary in starting the engine to make use'oi' a hand operated, carburetor choke valve, or a iloouer, or a supplemental gasoline duct, or similar deviceto supply the cylinders with an excess of gasoline, a largepart of which is uncvaporated. V

This liquid gasoline serves toquickly wash the lubricating oil from the cylinder walls thereby preventing proper lubrication of the pistons. Ii. contributing :tactor tothe harm- :tul eli'cci or operating the choke valve is the l fact that when the engine is cold it takes several minutes for a pressure feed lubricating system to get thecold sluggish oil intocirculation and for it to become fluid enough to be splashed on the cylinder walls. Inother words, the oil must be first warmed up suthciently to flow freely through the crank and connecting rod bearings.

Under ordinary conditions, the pressure feed system builds up averyabnormal pressure for the first few minutes after starting gasoline to prevent proper lubrication.

the engine, such pressure obtaining until the oil begins to flow freely. It will thus be evidcnt that the action of the excessive supply of liquid gasoline in washing the oil from the cylinder walls, occurs at the very time, when the piston lubrication depends mainly on the oil which is left on the cylinderwalls from a previous operation of the engine.

In accordance with the present invention, I obviate the danger of scuiiing or scoring the pistons during the first few minutes of a run by arranging an auxiliary oil line between the main reservoir pipe of the feed system and the interior ofthe cylinders. The valve which controls this oil is connected directly or indirectly to the operating means "for the carbureter choliefvalve or other richenfer or flooder so that whenever the latter is operated to floodgasoline into the cylinders such flooding is also accompanied by an e21 cessive flow of lubricatingoil which will in large n'ieasure counteract the tendencyoi the The invention maybebetter understood from following detailed description in connection with the accompanying drawings in which I i Figure 1 is a view in side elevation of an engine embodying the invention, parts being broken away and in section for clearness.

Figure :2 18 an enlarged detail view showing the choke and auxiliary oil valves and their common operating means.

cylinders receive a fuel mixture from the carburetc l7, Forpurposes of starting the en gine the usual chokc'valve 18 is provided in the air passage to the carburetor, said valve being adapted to throttle the air supply and to cause a very hoavymixture, largely of un cvag'iorated gasoline, to be drawn into the combustion ch ambers.

Th e pressure feed include a c1rculat1ng pump 20 drawing oil from a sump21 in the bottom of the crank case and delivering oil to a reservoir pipe 22 from which leads 23 are taken tolthe crank and connecting rod bearings. A pressure re-' lief valve 25 in the end of the reservoir pipe is operable to bypass lubricating oil dircctly back to the sump through a return pipe 26.

henthe cold engine 'is started, a very high pressure is built up inthe reservoir pipe due to the sluggishness of the cold'oil and such high-pressure tal is effect in the relatively small bypass pipe 26, and is greatest in the upper part thereof where backpressureot flow resistance is greatest;

In accordance with my invention I connect the interior of all of the cylinders with the bypass return pipe 26 preferably just beyondthe' bypass valve, by means of pipe 27 of relatively small diameter controlled by a valve 28 which is, preferably in the nature of a rotary plug valve equippcd'with an operating a nea The arm 29 is directly coupled lubricating system may witlrthe operating arm 30 of the choke valve or otlierflooder, link 31 so that closing the choke valve through lever against the action of spring 33opens thelubricant supply valve to thecylinders and vice versa.

As above noted the sluggisl'i flow of cold 7 oil often results in the engine running for sev 'n'al' minutes before any splash from the, crank connecting rod bearings reaches the cylinder walls and consequently the cylinders must relyfor lubrication merely on the oil which is caked therein during a previous run of the engine. Said caked oil is very readily washed away by the liquid gasoline which is flooded into the cylinders when the choke valve is operated. I By the construction above described however, said inrush of liquid gasoline is accompanied by a corresponding emergency supply of lubricating oil through the pipe 27 and proper lubricationo't thepistons during ,the time that the choke is closed is assured. Tlhesmall cross sectionof the return pipe QG andthe cylinder supply pipe 27 insures adequate pressure tor toreing o l into the cylinders. I

In accordance with a preferred embodimentof the invention each cylinder. is pro videdwith an annular oil distributing groove 35 just below the lowest portion of the cylinder swept by the uppermost of the piston rings and it is into these grooves that the supply line delivers. Annular grooves 35 rovide oil collectin chambers which areot material assistancein efl'ecting proper lubri cation of the pistons in case the engine started without usingthe choke.

Under normal conditions, a considerable quantity of oil will be flooded intothecyl'inder through the distributing groove 35 and in order to relieve this excess preferably provide other. annular grooves 36 just below the grooves 35, the former communicating directly with a series of spiraldrainage grooves 37 which extend to the bottom of? the cylinder.

The spiral grooves have a shearingefl'ecton the oil film with which the pistonis coated,

scraping excess oil from; the pistons and carrying it .ofito the crank case. The en'- cating therewith for supplying oil tothe cylinder-walls, a pi'essurecontrolled valve in sa d cyhnder wallsupply pipe, and flow con, trpl means in said cylinder wall supply pipe operatively connectcdto said flooding means, \x hcre'hy lubricating o l is supphed to the cylinder walls under abnormal pressure conditions, during the operationot said flooding means. V r I 2, In an internal combustion engine, a carburetor, a choke valve, and a pressure teed lubricating system comprising an oil supply conduit, pipes, communicating therewith. for

supplying oil to the bearings, a pipe also com-' municating therewith .for' supplying oil to the cylinder walls, a pressure controlled valve in said cylinder wall supply plpe, and aflow controlvalve in said cy' linderwall 'supplyv pipe op'eratively connected to said choke valve, whereby lubricating oil is supplied,

to the cylinder walls under abnormalpres sure conditlons, during the operation of said "choke valve.

Signed atPlainfield, in the county of Union andState of New Jersey, this 6th day of October, A. D. 1924. u f

' SAMUEL lV. RUSHMQRE.

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