Steel railroad sleepers
US6230981A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 11, 1999 |
| Grant date | May 15, 2001 |
| Priority date | — |
| Expiry date | Jun 11, 2019 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE01B3/16
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A steel railroad sleeper of inverted channel section whose open ends can selectively be closed by end plates detachably connected one to open end of the sleeper and whose sides incline downwardly and outwardly from the upper rail supporting surface of the sleeper, the sleeper being produced by cold forming strip steel. The sleeper may be produced by cold pressing or cold rolling and the end plates may also be produced by cold forming steel strip. In one embodiment the sleeper has a waisted section of reduced width. This waisted section may be positioned generally midway along the length of the sleeper. The central section of the sleeper interior may be filled with a material to prevent the ingress of ballast to this central region.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.