DEVICE AND METHOD TO CONTROL PULLING JACK FOR TENSIONING OF PRE-STRESSED REINFORCEMENT ELEMENT Russian patent published in 2013 - IPC E04G21/12 

FIELD: construction.

SUBSTANCE: device comprises a casing in the form of a hollow cylinder, where a piston is installed as capable of longitudinal movement along the axis, and the piston is connected with the reference tensioning element. The casing and the piston enclose the pressure space, where hydraulic medium is supplied via a feed so that the piston may axially move in a reciprocal manner against the tension force of the reference tensioning element, and via a drain the space is connected to a pulling jack. Besides, the device comprises a valve unit for control of hydraulic medium supply into the pulling jack, besides, the valve unit is directly controlled by the reciprocal motion of the piston. The method according to the invention provides for tension of the tensioning element depending on the tension force of the reference tensioning element with the help of a piston cylinder block, the piston of which retains the reference tensioning element in the specified tightened condition. When the single tensioned condition has been achieved in all tensioning elements in process of tensioning of the tensioning element with the help of the pulling jack, supply of the hydraulic medium into the pulling jack is stopped directly as a result of reciprocal movement of the piston.

EFFECT: increased operational reliability.

24 cl, 4 dwg