Method and apparatus for cancelling the electrostatic potential of a helicopter relative to ground potential
US4736906A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 15, 1985 |
| Grant date | Apr 12, 1988 |
| Priority date | — |
| Expiry date | May 15, 2005 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB64D45/02
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
A rescuer (1) is lowered at the end of cable (2) from a helicopter having a winch (4) on which the cable is wound. The rescuer is provided with a electric field sensor (20) which is downwardly directed and which is connected to a radio transmitter (22). The helicopter (3) has a corresponding radio receiver (24) which serves to actuate an active static discharger which is servo-controlled to the electrical magnitude supplied by the sensor (20). The servo-control is such that the potential difference between the rescuer (11) and the person to be rescued (10) is progressively reduced as the rescuer approaches the person to be rescued. Practically all risks of an electric shock on making contact are thus avoided.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.