Motion and orientation responsive device for seismic, intrusion, and tilt alarms and the like
US4945347A · kind A · utility
Inventor
Key dates
| Filing date | Mar 17, 1988 |
| Grant date | Jul 31, 1990 |
| Priority date | — |
| Expiry date | Mar 17, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG08B13/1436
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A motion and orientation responsive device having a pendulum pivotally mounted between its ends, and means for detecting relative displacement of the upper pendulum end and a zero position reference on the pendulum support from certain normal relative positions thereof in response to either or both translational and rotational displacements of the device. Presently preferred embodiments of the invention are a seismic or earthquake alarm, an intrusion alarm, and a tilt alarm. In these preferred embodiments, the pendulum shaft is a slender resilient wire, and its pivot is situated close to its lower center of mass in order to amplify the lateral motion of the upper pendulum end for a given angle of pendulum rotation and thereby enhance the sensitivity of the device to low magnitude displacements. The pendulum and zero position reference in one preferred embodiment are uniquely constructed and arranged to automatically align themselves in a zero position when the device is stationary in its normal orientation without the necessity of precisely positioning or adjusting the alarm device to compensate for manufacturing tolerances or improper orientation of the object which supports the d…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.