US1780829A - Piston for internal-combustion engines - Google Patents

Description

Nov. 4, 193 0.

A; LESAGE 1,780,829 PISTON FOR INTERNAL COMBUSTION ENGINES Filed July 24 1928 i 2 Sheets-Sheet 1 Nov. 4,. 1930.

A. LESAGE 1,780,829

.PISTON FOR INTERNAL COMBUSTION ENGINES 2 sheets-sfiaet 2 Filed' y 1928 J z w Patented Nov. 4,. 1930 UNITED STATES' PATENT OFFICE ALFRED LESAGE, on BRAND-ERIBISDORF, GERMANY, ASSIGNOR 'ro' ELITE-DIM!- wnaxn AKTIENGESELLSCHAFT, or BBAND-ERBISDORF, SAXONIA, GERMANY- PISTON FOR INTERNAL-COMBUSTION ENGINES Application filed July'24, 1928, Serial No. 294,968, and in Germany July 27, 1927. w

The invention relates toimprovements in pistons for internal-combustion engines.

, Pistons of that type are known, which consist of light-metal, for obtaining a better abstraction of heatfrom the highly heated piston head than at the known cast-iron pistons.

By this better abstraction of heat, a higher compression and a greater number of revolutions are made possible and the weight of the oscillating mass is greatly reduced.

. However such light-metal pistons offered the great drawback, that in reason of the great coefiicient of dilatation by heat of the light-metal, they must have a comparatively great clearance in their cylinders, so that it is necessary to let the motor run light for some time before loading it, until the pistons fit into their cylinderborings.

If, however, the engine was, loaded immediately after its starting, the pistons tended to stick in their cylinder-borings and thus very quickly became worn and accordingly had to be replaced by others.

It has been tried to remove these drawbacks by composing the pistons of two parts, namely the piston-head, consisting of lightmetal and a liner, consisting'of steel or castiron, screwedto the said piston head. Both parts however loosened after some time of running, so that the piston became waste.

In order to avoid this loosening the liner of steel has been refounded by the light-metal ofthe piston-head. As however the piston- 'pin bearings consisted of one piece with the liner, an immediate transmission of power from .the piston head to the piston-pins without any junctions cannot take place so thata beating of the junctions is the'result. Further, the abstraction of heat from the pistonhead to the cylinder walls is a very bad one, as the light-metal of thepiston-head does not get into contact with the said cylinder walls.

The mentioned disadvantages of the known devices are avoided according to the present invention by the fact, that in a piston with a light-metal head and with a liner of hard metal, such as steel or cast iron, refo'unded by the light-metal of the piston-head, that part of the liner, which is surrounded by the light-metal, forms an armature for the piston-head, which armature is provided with openings or perforations.

In this piston the piston-pin-bearings con sist of one piece with the light-metal-body and are arranged such in lateral openings of the liner, that they neither touch-the cylinder walls, nor the said liner.

It has been proposed, to provide in a piston for internal combustion engines a light metal piston-head, in which the light-metal of the liner, refoundetl by said piston-head,

has a greater strength than thatof the pistonhead and the same coeificient of dilatation.

With regard to these pistons there is obtainedthe advantage by the presentvinvention by the use of a liner with smaller coefficient of dilatation than that of the lightmetal of the pistoighead, that the different coefficients of dilatation of both parts comj pensate each other. In consequence the ad-- vantageous efi'ects of the use of light-metal are saved, although a great clearance of the avoided.

By the fact, that the piston-pin-bearings do not touch the cylinder walls, a grindin between these parts in reason of elastic d E ormations of the piston-pin-bearings cannot take place.

The abstraction of heat from the piston according to the present invention is as good as in pistons consisting entirely of lightmetal, and also the weight is not higher than that of the said known pistons, While the strength is equal to that of a steel-piston.

cold pistons in their cylinder-borings is '.founded in a chill by the piston-head e which consists of light-metal. For obtaining a better connection, that part of the "liner, which islsurrounded by the light-metal is provided with perforations 7.

In one piece with the light-metal body there are cast the pistonepin-bearin s g which are lying within openings h o the liner without being in contact with the same.

Hereby the force, exerted by the combustiongases to the piston-head is transmitted to the piston-pins Without any mechanical junctions, so that a loosening or wearing out of such junctions cannot take place. The liner, unmovably surrounded by the pistonhead, has not to vtransmit any considerable forces at its surface of contact with the light-metal, as said liner only has to effect a lateralguiding of the piston, by which only frictional forces at the circumference of the liner are caused.

fixed my signature.

I-claimzi A piston for'internal combustion engines comprising in combination a light-metal head and a hard metal liner in the head, the said liner having perforations in the head and lateral openings in the wall for the passage of the piston'pin bearings integral with the light-metal head while the said piston pin bearings do"not come in contact with the said lateral openings in the wall of the pistonand the cylinder wall.

In testimony whereof I ALFRED LESAGE.

have hereunto a f- Q

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