FISHING TRAWL Russian patent published in 1998 - IPC

FIELD: commercial fishery. SUBSTANCE: trawl has mouth, enclosure and acoustic emitting system for generating acoustically sonicated space within trawl working zone. Acoustic emitting system has converter, exciter and remote-control switch for changing over angle of deviation of converter axis from trawl axis. Remote-control switch has unit for generating and transmitting deviation angle signals, control signal receiving unit, unit for separating control signals and unit for controlling rotation of converter in plane perpendicular to trawl movement axis. Angle of deviation of converter axis from trawl axis is selected on the basis of geometrical sizes and position of fish shoal so that concentrated fish shoal is within the zone of action of acoustic emitting system. EFFECT: increased efficiency in fish catching and enhanced reliability in operation. 2 dwg