# US 5,701,803 A · Light-metal piston for internal combustion engines

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 5,701,803 A
- Document ID: US5701803A
- Status: Granted
- Kind: A
- Application number: 08/737,252
- Filed: 1996-10-16
- Granted: 1997-12-30
- Earliest claimed: 1994-04-27
- Assignees: Mahle GmbH
- Inventors: Martin Lutz
- Web page: https://patentgrep.com/patent/US5701803A

## CPC

- F02F 3/022: {the pistons having an oval circumference or non-cylindrical shaped skirts, e.g. oval (F02F3/025, F02F3/027 take precedence)}
- F02F: CYLINDERS, PISTONS OR CASINGS, FOR COMBUSTION ENGINES; ARRANGEMENTS OF SEALINGS IN COMBUSTION ENGINES

## Abstract

In order to improve the guidance of a light-metal piston for an internal combustion engine of a motor vehicle by obtaining a uniform behavior under different stresses of the pressure and/or counter pressure side of the piston skirt, the wall thickness of the piston skirt is made different in the region of its pressure and/or counterpressure regions from that in its other regions. In the pressure and counterpressure regions, there is a thickening on the inner side of the piston skirt which is gradually reduced from the lower edge of the skirt in a central plane in the piston length and pressure/counterpressure direction back to the normal thickness.

## Claims

### Claim 1

A light metal piston for internal combustion engines, comprising:
a piston crown;
a piston bottom;
a piston ring groove part; and
a piston skirt, said piston bottom, said piston ring groove part and said piston skirt being integrally shaped in one piece, said piston skirt having a wall, a bottom edge, a height, an inside contour, a circumference, a pressure side and a counterpressure side,
wherein the wall forms a thickening only in the area around at least one of the pressure and counterpressure sides, and wherein the thickness of the wall substantially continually decreases, starting from the bottom edge of the skirt along the height of the skirt, such that the inside contour of the skirt extends substantially conically.

### Claim 2 (depends on 1)

A light metal piston according to claim 1, wherein the thickness of the thickening decreases in the circumferential direction along both sides of a center plane disposed in a longitudinal direction of the piston and extending through the pressure and counterpressure sides.

### Claim 3 (depends on 2)

A light metal piston according to claim 2, wherein the thickening has a length measured in the circumferential direction from the center plane, said length decreasing continuously from the bottom edge along the height of the skirt.

### Claim 4 (depends on 1)

A light metal piston according to claim 1, wherein the thickening continuously changes into the piston skirt on all sides.