Apparatus for determining the position of a moveable structure along a track
US5090304A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 28, 1990 |
| Grant date | Feb 25, 1992 |
| Priority date | — |
| Expiry date | Sep 28, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05D3/1472
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A sensing means for determining the absolute position of one or more structures such as doors, windows or the like that are moveable in sets of tracks. Apparatus comprises an electrical switching means having an elongated electrical resistance means with a predetermined resistance value per unit length located adjacent to one of the sash doors, actuator means associated with the sash doors for operating said switching means, circuit means adapted to provide a substantially constant electrical current through a portion of said resistance means between an end portion of said resistance means and the nearest switch location, said circuit means thereby providing a voltage signal having a magnitude that is proportional to the distance between said end portion of said resistance means and the switch location.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.