US1517070A - Piston ring - Google Patents

Description

JELBERT J. JENKINS, OF IMIIDLANDy MICHIGAN, ,ASSIGNOR T0 THE DOW CHEMICAL4 COMJPY, OIF MIDLAND, MICHIGAN, A CCRIORATION D'F MICHIGAN.

ris'ron nine.

Applicaton fleol September To all whom t may concern.'

Be it known that I, ELBERT J. JENKINS, a citizen of the United States, and a resident of Midland, county of Midland, and State of Michigan, have invented a new and' useful Improvement in Piston Rings, of which the following is a specification, the principle of the invention being herein explained and the best mode in which I have contemplated applying that principle, so `as to distinguish it from other inventions. v i

liV am aware that so-called light metal alloys have been heretofore Iutilized with more or less success for the construction of pistons in internal combustion engines.

Thus notably an alloy composed of aliiminum as a predominant ingredient has been thus employed. I am notv aware, however, that such alloy, still less an-"alloy of the particular composition hereinafter set forth, has ever been utilized to form the rings which are a-n essential feature in the contruction of internal combustion engines; in

fact such an alloy composed principally of aluminum would not be entirely satisfactory for this purpose as it is not a good bearing metal in contact with the cast iron of the cylinder wall, and pistons composed of such an alloy require to be given more than the usual clearance for this reason and because of other features ,such as a tendency -to grow which such alloys show.

The objectv of the present invention accordingly is to provide a piston ring of light metal which will satisfactorily serve in the connection stated, by reason fof its composition and construction. To the accomplishment of this and related ends such piston ring then is composed of the ingredients and includes the structural features hereinafter 'fully described and particularly set forth in theJ claims, the annexed drawing and the following description settin forth but one of the various ways in which the principle of the invention .may be used.

In said annexed drawing f ig.v lis a central sectional view more or less ydiagrammatic in character illustrating a typical internal combustion engine e uipped with `my improved piston rings; ig. 2 is a similaki` section on a lar er scale showing one such ring together with the adjacent walls of a cylinder and piston, and Fig. '3 is a transverse section, i. e., in

2a, i920. serial No. 412,302.

the plane of such ring showing a portion of the ring with the vadjacent walls of the cylinder and piston.

In its general features of construction, the internal combustion engine shown in the drawing is of familiar design, comprising a cast iron cylinder 1, the upper portion of which is provided with a suitable water jacket 2 preferably integral therewith. Below the cylinder and enclosed in a suitable case 3 is a crank 4, which is connected by means of a connecting rod 5 with a transverse pin 6 secured in the piston 7. The specific design of the latter forms no'part of the present invention except that as previously indicated, such piston is formed of a light metal alloy. Preferablyv the prinl/cipal constituents of the alloy used in such piston, just as in the case of the piston rings 8 presently to be described, are inagnesium and aluminum, magnesium being the' rpredominating constituent. As most satisfactory for a piston thus designed for use in an internal combustion engine I find an alloy composed of from 8 to 15 parts aluminum and the balance magnesium gives the most satisfactory results, such alloy having a specific gravity yless than 2. The term light metal,l however, will .be understood to comprehend any alloy in which the predominant constituent is aluminum (sp. gr. 2.7) or magnesium `(sp. gr. 1.72) or the two metals taken together.

As just indicated, the composition of my improved piston rings 8 is the same asthat given as constituting the preferred com osition of the piston itself. It will be un erstood, however, that my improved piston rings may be employed with other light metal pistons and for that matter with the familiar cast iron piston that -is ordinarily j, used in internal combustion engines, superior results being obtained in all cases.

Such rings are formed ,by casting a cylinder of the light metal alloy, such cylinder having proper internal and external diameters, cutting off a section of such cylinder to form a ring of the desired yheight and then severing such ring at one point in its circumference.` The severed ring may then be rolled, peened, or other-v wise manipulated to bring the ends thereof into proper relation yand to give the ring the necessary degree of resiliency to insure close fitting contact between the same and iio' ' the cylinder wall when the ring is seated vrings ordinarily used, so that the heat froml the piston, forming as the latter does the go-between between the piston and the cylinder wall is quickly carried to the latter. Atthe same time the alloy rhaving the composition stated is not abrasive to cast iron and so insures that the cylinder wall will notbe scored from the action of such rings on any type'of piston. The weight being small in comparison even with light metal pistons in which aluminum instead of magnesium is the predominating ingredient, helps correspondingly to decrease the weight of the reciprocating parts, while the natural tension or resiliency of this special alloy is suflicient at all times to keep the rings in close fitting contact with the cylinder wall and so insuresl good compression in the engine.

Other forms may be employed embodyl ing the features of my invention instead of the one here explained, change bein made in the form of construction, provi ed the elements stated by any of the following claims or the equivalent of such stated elements be employed. c

I therefore particularly point out and distinctly claim as my invention 1. As a new article of manufacture, a piston Aring for an internal combustion engine composed of a light metal alloy, in

which the predominant constituent is magnesium.`

2. As a new article of manufacture, a piston ring for an internal combustion engine composed of a light metal alloy, in which the predominant constituent is magnesium and the principal remaining constituent is aluminum.

3. In an internal combustion engine, the combination witha cast iron cylinder, of a pistontherefor composed of a light metal alloy, and piston rings carried by said piston and likewise composed -of a light metal alloy, the predominant constituent of which is magnesium.

4. In an internal combustion en ine, the combination with a cast iron cylinder, of a piston therefor composed of a light metal alloy, and piston lrings carried by said piston and likewise composed of av light metal alloy, the predominant constituent of which is magnesium, and the principal remaining constituent is aluminum. A

Signed by me this 20th day of September, 1920.

' ELBERT J. JENKINS.

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