US1502923A - Piston for internal-combustion engines - Google Patents

Description

1,502,923 R. L. SKINNER PISTON FOR INTERNAL COMBUSTION ENGINES Original F l d ay 26, 1921 2 Sheets-Sheet 1 iiiiii July 29, 1924. N

R. L. SKINNER PISTON FOR iNTERNAL COMBUSTION ENGINES Original F1106 y 26, 1921 2 Sheets-Shoo! 2 l I I 1 Patented July 29, 1924.

warren STATES PATENT oFFicE.

RALPH L. SKINNER, OF DETROIT, MICHIGAN, ASSIGNOR 'IO SKINNER, AUTOMOTIVE DEVICE CO., INC., OF SACRAMENTO, CALIFORNIA, A CORPORATION OF CALIFORNIA.

PISTON FOR INTERNAL-COMBUSTION ENGINES.

Original application filed May 26, 1921, Serial No. 472,746 Divided. and this application filed August 30, 1922. Serial No. 585,309.

To all whom it may concern:

Be it known that I, RALPH L. SKINNER, a citizen of the United States, residing at Detroit, in the county of \Vayne and State of Michigan, have invented certain new and useful Improvements in Pistons for Internal-Combustion Engines, of which the following is a specification.

The lubricating oil splashed or otherwise fed on to the inner walls of the engine cylinders of internal-combustion engines for friction reducing purposes by the moving crankshaft and connecting rods and possible accessories, in engines or motors of the present day, finds its way in substantial quantities past the reciprocating pistons into the fuel combustion chambers above them, due to several causes, including the excess of oil on the cylinder walls, the movements of the pistons, and the sub-atmospheric pressure in such chambers during the intake strokes of their pistons.

The oil thus present in the. chambers becomes converted into objectionable carbon on the piston heads, the walls of the chambers, and the spark-plugs'bringing about the well-known undesirable effects on the smooth and eflicient operation of the motor.

In addition, the direct contact of such lubricating oil with the spark-plugs, which is likely to occur if the pistons are somewhat loose fitting, brings about their short-circuiting hence rendering them useless until cleaned or replaced.

Such excess of oil as enters the firing chambers represents a substantial oil loss or needless consumption because it performs no useful function, its presence therein constituting a menace to the proper action of the motor. 1

Also, the more or less unconsumed gaseous or liquid fuel and products of combustion escape downwardly past the pistons into the crank-case where they seriously dilute and contaminate the supply of lubricating oil therein.

This is particularly true in winter when the fuel is not so readily vaporized and when it is more difficult to start the engine and is also-especially true if the pistons fit the cylinders somewhat loosel but such objectionable polluting of the Oll, thereby materially reducing its lubricating qualities, occurs to a serious extent. even in motors in the best runnlng order, due particularly to the low grade of liquid fuel now on the market and in common use.

0 The prime aim and salient purpose of this invention is the provision of an improved and novel style of piston adapted for association with simple, effective, economical and inexpensive means to prevent the upward passage of the excess oil by-the pistons into the explosion chambers and to preclude the downward flow of the fuel and combustion gases past the pistons into the crankcase.

In the use of an improved appliance of this kind including new pistons, there is a separate recovery of the excess oil and fuel, the former being returned to the engine crank-case .for further use and the latter introduced into the intake manifold of the engine for consumption in the combustion chambers thus effecting a radical saving in both elements.

Another goal of the invention is the production of an appliance of this kind, including the new styles of pistons, which will cf ficiently perform the functions specified and which may be installed in new motors at the time of manufacture or which may be readily incorporated in motors already in service.

The use of the improved pistons in cooperation with other parts of the. mechanism will permit the use of thinner or lighter grade of lubricating oil for the pistons of the motor than has heretofore been usual with its advantages of reduced friction losses but without incurring the usual disadvantages ordinarily incident to the employment of such kind or grade of oil.

To enable those skilled in this art to have a full and complete understanding of this invention both from structural and functional standpoints and to indicate how the above-stated and other objects of the invention are accomplished, I have illustrated in the accompanying drawings forming a part of this specification a desirable embodiment of the invention and like reference characters have been used to refer to the same parts throughout the several views.

' one of the engine cylinders and its In these drawings: Y I

Figure 1 is a side elevation of an internalcombustion engine equipped with the new style-and form of piston, although the latter are-not specifically illustrated in this view;

Figure 2 is a plan view of the same engine;

Figure 3 is a fragmentary section through improved form of piston; and

Figure 4 is a side elevation of the p ston.

By reference to these drawings, it will be seen that the multi-cylinder internal-combustion engine or motor of the usual form, and which may have any appropr ate or well-known splash or forced feed or other lubricating system for its cylinders and pistons, has been supplied as a whole w1th the reference numeral 21, each of its four cylinders, water-jacketed or air-cooled as the case may be, as shown in Figures 2 and 3, being designated 22.

Each hollow, open-ended, reciprocatory.

piston 23 at its upper portion, as is customary, has a plurality of piston-rings 24, 24, three being used in the present instance, and just below these the piston is provided with a shallow, annular groove or channel 25 extended entirely around the piston and adapted to be in substantial register, when the piston is atthe lowermost point in its stroke, with a port or aperture 26 through the cylinder wall and through which in a manner hereinafter explained suction or sub-atmospheric pressure is effected in the groove 'Diametrically opposite port 26, the piston has a small air-admisson relief or bleeder port or aperture 27 extended through His wall and therefore in communicatlon with the interior of the hollow piston and with the crank-case atmosphere.

-As is usual in this art, the external diameter of the lower portion of the depending skirt of the piston is slightly greater than that of the'upper part of the piston, the latter being subject to greater ranges of temperature and to greater degrees of expansion and contraction than the lower section of the skirt.

It is, therefore, somewhat more essential to effectively lubricate such skirt than the upper portion of the piston, and, heretofore, to prevent excess lubrication, its lower por tion has usually been 'itted with a pistonring to wipe off the s rplus oil from the cylinder wall.

In the present device, owing tothe removal of the excess oil in another way, such lower ring is omitted and hence there is decreased wear on the cylinder wall.

It is desirable to subject the oil or fluid collecting groove 25 to the suction or ex-.

hausting action through port 26 for an extended period of time for the effective and efficient removal of its contents, and this port 26, the piston is externally longitudinally grooved at 28, the upper end of such channel opening into the round or circumferential groove 25.

The piston on its longitudinally grooved side," although this is not necessary on some pistons, has an extension 29 having an external groove 30 in alignment with the companion groove 28, the former extending upwardly slightly on to the extreme lower portion or face of the piston skirt.

As is clearly shown in Figure 3, the middle section of the lower groove or channel 30 is connected through a passage 31 in an internal rib 32 on the piston skirt and its extension with the lower end of the upper groove 28 and groove 30 is fitted with a suitably-shaped leaf spring or flap valve 33 adapted to control-the opening and closin of the connection between such groove anil the passage 31. Such valve is held in place by a screw 34 through one end thereof which fastens it to-the base of the groove.

This piston skirt extension is required by reason of the fact that the piston in its lowermost position, as'is indicated in Fgure 3, projects below the bottom end of the cylinder wall. During the ascent of the piston, so long as any part of channel 28 is opposite port 26 suction will be exerted on the oil collecting groove 25, and because of such suction action valve 33 is maintained closed, although its spring force may be suflicient for the performance of this function.

When the part of the piston between the lower end of channel 28 and the top end of channel 30, during the rise of the piston, temporarily closes port 26, the suction or exhausting action on the groove encircling the piston is for the time being omitted.

During the registration of channel 30 with the suction-port 26, the exhausting action is restored, valve 33 opening outwardly under the suction influence so that the oil in groove 25 and any other fluids are drawn out through channel 28, passage 31, groove 30 and port 26.

Thus an effective oil removing suction action is exerted on the annular groove during the greater portion of the time, even though the piston is rapidly reciprocatin The air-admission port or its equiva eat is highly desirable, because if it or its equivalent is not employed, the suction will not remove the oil to a wholly effective and satisfactory degree.

Such air-inlet or bleeder port assures atmospheric pressure at that point and hence establishes a substantial difference in air pressure at the opposite points in the groove, this bringing about a rapid and energetic through a heater or heat exchanger or gasidischarge flow of the aerated oil and other fluids around both sides of the piston in grooves 25 and out through the cylinder port 26.

It is to be observed that by the means described a suction ring 'or zone around the rapidly traveling piston is established and maintained just below its piston-rings.

Any fuel, therefore, in liquid, vapor or. gaseous form. and any heated products of combustion escaping own past the piston rings come under the influence of this suction or exhausting action and they, with the oil, and the admitted air. are conveyed away through the port 26, all as will be readily understood.

By this comparatively simple means an excess of lubricating oil is prevented from entering the combustion chamber above the piston and dilution or contamination of the crank-case oil is eliminated at the same time by removing the elements which tend to pollute the oil before they reachthe crankcase.

The exhaust or suction ports 26 of the several motor cylinders are by suitable means connected to a pipe or manifold 35 common to all of them and the middle portion of this is connected to a pipe 36 communicating with an upright pipe 37 passing fier 38, the-upper end of pipe 37 being conneeted to the top of an oil trap or separator 39 by a pipe 40, the bottom of element 39 having a pipe connection 100 with the crankcase for the return thereto of the oil drawn from around the pistons.

The gases, freed from oil, leave the trap orseparator through a bent pipe connection 41 which at the rear end of the motor exhaust-manifold 42 communicates at 43 with a heater pipe 44 extending lengthwise through the interior of the manifold, whereby its gaseous contents are adequately heated by the hot exhaust gases of the motor flowing through the manifold around such interposed pipe.

The front end of heater-pipe 44 is connected by another pipe 45 to the heat-exchanger or gasifier 38, whereby such heated gases as flow through the pipe 45 may impart at least a portion of their heat to the mixture of air, gases and oil passing upwardly through pipe 37, thus assuring adequate, but not excessive, heating of the contents of suchpipe to insure proper volatilization of the gasifiable constituents preliminary to their passage into the oil-separator.

From the heater or gasifier 38 the' hot gases flow through a pipe connection 45* in to the intake manifold of the motor to be emplo ed as a part of and as a previously heate' ingredient of the explosive mixture in the running of the'motor.

This patent application constitutes a division of my eo-pending patent ap lication Serial Number 472,746, Internal combustion engine oil and fuel appliance, filed May 26th, 1921, and inasmuch as the details of construction of the separating tank 39 have been presented in such companion application and form no part of the present invention,

further description of thesame is apparently unnecessary.

By establishing and maintaining a belt -or band around each piston of a pneumatic case for further use, the gaseous mixtureheated by the exhaust of the engine, and such heated mixture used to heat the mixture containing the oil previous to the removal of the latter therefrom, and then passing into the engine intake-manifold as heated fuel to serve as part of the fuel used in running the engine.

plosion or firing chambers of the engine from the lubricating oil is prevented, and the dilution and pollution of the crank-case oil is avoided, a saving in oil and fuel bein effected at the same time.

n addition, the separated or collected oil, free from deleterious, volatile or diluent ingredients, is returned from the separator at intervals to the engine sump without destroying or modifying the fluid removing suction on the pistons.

By means of this structure, the skirt portion of the piston of larger diameter than the piston head and hence naturally requiring the greater lubrication, is treated to a liberal supply of oil for friction reducing purposes, and this is accomplished without danger of any substantial quantity of the oil reaching the firing chamber and forming carbon therein.

Thelubricating oil employed may also be lighter or thinner than is ordinarily used, because under present engine conditions without employing this invention the heavier oil is required to prevent too much from passing by the pistons.

Engineers are attempting to preclude or avoid the passage of the several fluids mentioned past the pistons by employing stifler and stronger piston-rings, but their use is objectionable because of the excessive wear which they necessarily produce on the cylinder walls.

Those acquainted with this art willreadily Thus the formation of carbon in the exparture from the substance andessence of.

the invention and without the sacrifice of any of its substantial benefits and advantages.

1 claim:

l. Aninternal-coinbustion engine piston having an external, transverse channel, an external longitudinal groove communicating with said channel and adapted when opposite a port in the engine cylinder wall to establish connection between such port and channel, and a lengthwise extension at one side of the piston-skirt in register with said longitudinal groove and adapted to co-' operate with said cylinder-port.

2. An internal-combustion engine piston having an external, transverse, fluid-collecting channel, an external, longitudinal groove comn'iunicating with said channel and adapted when opposite a port in the engine cylinder wall to establish connection hetweensuch port and channel, an airinlet port communicating with said channel.

at a point remote from its connection with said groove, and a lengthwise extension at one side of the piston-skirt in register with said longitudinal groove and adapted to cooperate with said cylinder-port.

3. A hollow, open-ended, internal-combustion engine-piston having an external, circumi'erential, fluid-collecting channel extended around it, an external, longitudinal groove communicating with said channel and adapted when opposite a port in the engine cylinder wall to establish connection between such port and channel, an airinlet port connected to said channel substantially diametrically opposite said longitudinal groove and extended inwardly through the piston wall to itshollow interior, and a lengthwise extension at one side of the piston-skirt in register with said longitudinal groove and adapted to cooperate with said cylinder-port.

4. An internal-combustion engine piston having an external, transverse channel, a. lengthwise extension at one side of its skirt, and an external longitudinal groove on said extension in communication with said channel.

5. An internal-combustion engine iston having an external, transverse channe and two external aligned spaced grooves in communication with said channel.

6. An internal-combustion engine piston having ail-external, transversechannel, two external aligned spaced grooves, one of which is connected to said channel, and a passage connecting said grooves.

7. An internal-combustion engine piston having an external, transverse channel, two external aligned spaced grooves one oi which'connects with said channel, a passage connecting said grooves, and a valve controlling said passage.

.8. An internal-combustion engine piston, the skirt of. which at one side has an extension, said piston having an external transverse channel and a pair of external aligned spaced grooves on said skirt and extension channel.

9. An internal-combustion engine piston having an external transverse channel, a lengthwise extension at one side of said skirt, an external longitudinal groove on said extension in communication with said channel, and a relief port communicating with said channel.

10. An internal-combustion engine piston having an external transversechannel provided with a relief-port and two external aligned spaced grooves in communication .with said channel.

11. An internal-combustion engine piston having anexternal transverse channel proin communication with said vided with a relief-port, two external aligned spaced grooves one of which connects with said channel, a passage connect-- ing said grooves, and a valve controlling said passage.

12. An internal-combustion en ine piston, the skirt of which at one side as an extension, said piston having an external transverse channel provided with a relief port, a pair of external aligned spaced grooves on saidskirt and extension, a passage connectin said grooves, and a valve controlling said passage.

13. An internal-combustion engine piston having one or more piston-ring grooves and piston rings at its upper end only, an external transverse channel below said piston ring or rings, an external longitudinal groove communicating with said channel, and a relief-port communicating with said channel remote from said longitudinal groove.

14. An internal-combustion engine piston having an external transverse channel, an external longitudinal groove communicating with said channel, and an air relief port communicating with said channel at a point remote from said longitudinal groove.

15. An internal-combustion en ine piston having an external transverse c annel, an external longitudinal groove communicating with said channel, and an air relief port communicating with said channel diametrically opposite said longitudinal groove.

16. A hollow internal-combustion engine piston having an external transverse channel, an external longitudinal groove'communicating-with said channel, and an air relief port communicating with said chanan external, circumferential, fluid-collect nel at a point remote from said longitudinal groove and extending inwardly through the piston wall to its hollow interior.

17. A hollow, open-ended, internal-combustion, engine-piston having one or more piston-ring grooves at its upper end only,

ing channel below the lowermost pistonring groove, an external, longitudinal groove communicating w1th said channel and adapted when opposite a port in the engine cylinder wall to establish connection between such port and channel, an air-inlet port communicating with said channel at a point remote from its connection with said groove, and a lengthwise extension at one side of the piston-skirt in register with said longitudinal groove and adapted to cooperate with said cylinder-port.

In witness whereof I have hereunto set 20 my hand and seal.

RALPH L. SKINNER. [L. 5.]

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