Position insensitive shock sensor with closure delay
US4943690A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 6, 1989 |
| Grant date | Jul 24, 1990 |
| Priority date | — |
| Expiry date | Mar 6, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01H29/002
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A shock sensor has a mercury wetted insert for supporting a mercury mass normally spaced from a terminal or terminals. The mercury and the terminal or terminals are contained within a sealed housing. When the sensor is subjected to a shock, the mercury is redistributed and protrudes from the insert so as to make contact the terminal or terminals and complete a circuit. By providing a mercury-non-wettable surface ahead of the mercury wetted insert, a closure delay time or operation time is selectively set. Additionally, the porosity of various membranes within the housing can be pre-selected to vary the speed in which the mercury is redistributed and thus also adjust the closure delay time. Also, a constriction in the non-wettable surface ahead of the mercury wetted insert can be utilized to provide a time delay by introducing a dash-pot effect.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.