LINEAR FORCE LIMITER USED IN AIRCRAFT ASSEMBLY TOWER
SAFETY LIMITER PREVENTS OVERLOADS
A special linear force limiter developed by Italian specialist ComInTec is used in a tower for the assembly of aircraft wings. ComInTec, who design and manufacture both torque limiters and linear force limiters, developed the new 20000N force limiters as a mechanical device that detects overloads in both tension and compression. In this case the limiter is part of a locking mechanism for a rail-mounted tower used in Airbus production. It is mounted on the output of a screw jack that holds the tower in a fixed position. By preventing excessive forces, the limiter ensures stability and safety for the tower.
The DSA range of linear force limiters with ratings from 30 to 7000N is an established product used to prevent force overloads, for example in gearbox torque arms and reciprocating mechanisms. Inside a compact central module are spring loaded fingers that locate into a groove on the central shaft. An overload in either tension or compression causes the fingers to move out of the groove and the resulting axial movement is detected by a proximity switch to turn off the drive. For this tower a new size was designed with a rating of 20000N and a body diameter of 105 mm. A force overload results in axial movement of 2 mm.
The ComInTec DSA force limiters and ComInTec torque limiter products available in friction, ball and roller designs are sold in the UK by Techdrives, a division of Lenze Ltd.