Railing
US4922228A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 11, 1988 |
| Grant date | May 1, 1990 |
| Priority date | — |
| Expiry date | Aug 11, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG08B13/126
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
The present invention relates to a railing selected among hollow railings, grilles, tubes or the like in which a continuous sensor made of an optical fiber extends, which railing is filled with a suitable filling material, the sensor fiber being connected to outside control and/or alarm units to form a complete circuit. The optical fiber has advantageously a numerical aperture (NA) of 0.08.ltoreq.NA.ltoreq.0.5 preferably the following parameters: PA1 Bending loss .alpha.exp(-.beta.r), r-Bending radius .beta..alpha.N.A. (b/a) .gamma. b-cladding radius, a-core radius of the fiber, 0.1.ltoreq..gamma..ltoreq.3.0. The filling material has preferably the form of pellets and is suitably selected among glass, steel, ceramics or sand. The railing preferably comprises a binder selected among soft rubber and plastics, e.g. a polyester. The binder may comprise also a material selected among an irritating material and a dye. The railing may also be a system of railing wherein the sensor extends through all the railings.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.