Patent ID: 7798290

Claim:
Arrangement in an elevator without counterweight, which elevator comprises at least a control unit, a hoisting machine and a traction sheave connected to it, as well as an elevator car suspended on hoisting ropes that are fixed to an essentially immovable place at their first end and adjustably at their second end, which elevator car is fitted to travel backwards and forwards in an essentially vertical direction, and which elevator also comprises a tightening element acting on the second end of the hoisting ropes, wherein an actively operating actuator is in connection with the tightening element, which actuator is fitted by means of information detected in the elevator or by means of the control data of the elevator to change at least one rope tension (T 1 , T 2 ) and/or to keep the ratio of the rope tensions (T 1 /T 2 ) above the elevator car and below the elevator car essentially at a predetermined level either by lightening or tightening the rope tension according to changes in the loading.