Method of making a rolled metal piston ring
US4085490A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 1, 1976 |
| Grant date | Apr 25, 1978 |
| Priority date | — |
| Expiry date | Apr 1, 1996 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/49281
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A rolled steel oil control piston ring for internal combustion engines is of generally U-shaped cross section with a pair of opposed rigid sidewalls projecting inwardly of the ring from a central peripheral wall thereof. A pair of flat-faced solid scraper rims formed by closed pleats rolled from the peripheral wall extend outwardly of the ring. The ring is made by rolling flat strip steel stock through a series of profiled rollers by guiding the edges of the stock without deforming the same, while taking up dimensional variations of the stock by displacement of the central portion of the strip. Pleats are formed in the central portion by the profiled rollers and the pleats are closed on themselves to provide the solid scraper rims. An extrusion-like profile-reducing rolling step provides dimensional accuracy to the finished strip which is then punched to provide the vent openings in the peripheral wall, and coiled and cut to form individual piston rings.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.