Cable tension regulator for trawl net - uses compressed gas to apply pressure via oil to pistons in cylinder and supporting cable pulleys

摘要

The traction cables for a trawling net pass round pulleys (14) on a tensioner (9) which is mounted across the deck of a trawler. The tensioner comprises a cylindrical chamber (10) filled with oil and communicating with a spherical enclosure (12) containing oil over which there is a compressed gas. The pulleys are mounted on the ends of pistons (11) in each end of the cylindrical chamber. The chamber is supplied with oil from a reservoir (18) by a pump (19) and via a pressure reducer (20). A manometer (21) monitors the pressure. The feedback pressure from the spherical enclosure to balance the forces on the cables is adjusted by alteration of the gas pressure. As the trawler rolls the force on one piston due to the cable is therefore balanced by movement of the other piston.