Stress steel wire insertion rollers - have hydraulic stressing cylinder varying pressure dependent on motor torque

摘要

One or more pairs of motor-driven friction rollers are moved in relation to each other by a stressing element, to generate pressure between them and the length of prestressing steel wire running between them. The motor tongue is transmitted to the steel wire during inserting. The stressing unit, i.e. the upper part of a housing (2), is provided with an activating hydraulic cylinder (24) actuated by energy which varies according to motor tongue. The cylinder can have fluid connection to a motor connection (26) for hydraulic fluid. Thus a change in fluid pressure through the hydraulic motor (11) causes automatic adaptation of pressure generated by the cylinder. The roller slippage is reduced, without increasing the appliance size and weight.