US4688022A - Safety device for hang glider - Google Patents

http://www.google.de/patents?id=Z6k6AAAAEBAJ&pg=PA1&zoom=4&dq=hang+gliding+harness

A safety device to warn the pilot of a hang glider if take-off is attempted without the glider hook-up strap being connected to the pilot's harness includes two sensors arranged in series with an alarm. One of the sensors is arranged to close a…