Apparatus and method for detecting swimmers
US4932009A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 10, 1989 |
| Grant date | Jun 5, 1990 |
| Priority date | — |
| Expiry date | Mar 10, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG08B21/082
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
An apparatus and allied method for detecting the presence of submerged, possibly distressed swimmers in a body of water employs a plurality of pairs of transducers arranged on opposite sides of the body of water. Pulsed sequential excitation of the transducers is employed to monitor the body of water. A person disposed between a pair of transducers interrupts the transmission of ultrasonic waves. An alarm is triggered upon the interruption of the ultrasonic waves or after a delay to avoid false alarms, warning of the presence and location of a submerged, lingering swimmer even in the presence of other active swimmers in the body of water. The same apparatus can be employed as an intrusion detector to detect unauthorized entry of a person into an unguarded body of water.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.