CS205814B1 - Method of dtretching the cables assembled e.g.by the prestressing cables - Google Patents

Description

BACKGROUND OF THE INVENTION The present invention relates to a method for providing a cable comprising, for example, pre-lanyard ropes, and to an apparatus for carrying out the method, in which the tension is solved. and anchoring the prestressing cable when prestressing, in particular, concrete structures.

Current methods of cable tensioning eg. The Stronghold, Stobet and Freyssinet d systems can be either external cable routing or internal cable routing in the tensioning press. Tensioning methods with external cable routing d have the disadvantage not only of variable loss of force depending on the stroke of the tensioning press, but also because of the difficulty of inserting the tensioning device into the fan of the projecting cable and the possibility of tensioning only one layer, for example. Tensioning methods with a cable guide through the center of the press are usually not provided with an anchor piston to ensure a reliable anchorage in the front anchor. In systems where such a device is absent, it is positioned around the cable so that cable observation during pre-tensioning and anchoring is limited, jaw observation and direct measurement of rope slippage is completely eliminated. Some systems have the rear anchor moved to the central part of the press, which deprives the operator of the possibility of affecting the correct anchoring of the cable at the rear anchor and eliminating any errors that may occur during prestressing.

Another disadvantage of some known systems is the need to fasten the rear anchor to the tensioning press.

Until now, all kinds of lubricants have been used as an anchoring layer except for widely used graphite.

205 814

The above drawbacks are eliminated by the cable tensioning method according to the invention, which is based on a method of prestressing by means of a central hole press in which the cable is moved through the press hole by means of a suitable rectifier and guide. , by sieving the press, the cable is tensioned and the pre-anchor cable is pushed into the jaws of the definitive anchor by means of an inserted cylinder with a retractable piston.

The new cable tensioning method according to the invention achieves a reduction in the time required to preload the cable, simplifies the handling of the device, the possibility of inspecting the cable and the definitive anchor during prestressing, thereby increasing the operator safety. In addition, there is no limitation in the direct measurement of the rope slips of individual ropes. The rear anchor structure is similar to the front anchor structure. The construction of the anchoring roller is compact, allowing it to be removed easily and quickly. it can be easily replaced if it changes the type of cable being tensioned. The same applies to the rear tensioning anchor and other components of the device according to the invention.

An example of an embodiment of the cable tensioning method according to the invention is shown in the attached drawing. In FIG. 1 shows the end of the cable protruding from the anchor of the tensioned structure; FIG. 2 is a ready-to-tension device shown in longitudinal section; FIG. 3, the device is slid onto a projecting cable; FIG. 4 is a cross-sectional view of the front of the apparatus; FIG. 5 shows the tensioned cable by extending the rear of the hydraulic press as well as its anchoring by the hydraulic cylinder in the front of the press, and FIG. 6 is a cross-sectional view of the inner bore of the press showing the deployment of the individual cable ropes.

On the cable 1, which here consists of 5 pairs of ropes and protrudes from the channel of the concrete prestressed structure 16, the front anchor 10 is pushed together with the deflector 17 if necessary and the conical jaws 11 are inserted into the respective cone holes. to the wall of the structure 16 such that the anchor 10 overlaps the modified channels of the channel.

Then, at the end of the protruding cable 11, the guide plate 2 is pushed to a depth such that the ends of the individual ropes still maintain the arrangement given by the holes in the plate 2 / FIG. 1 /.

The end of the cable 1 thus prepared is inserted into the base of the support stand 2 deep enough to reach the beginning of the baffle 6. Then the press 2 is sown on a protruding cable which gradually passes through the baffle 6, through the holes in the flange 4. 7. The press 5 is pushed all the way to the concrete structure 16 and in this state jednotlivéο the rear of the press 5 protrudes the individual ends of the cable ropes 2 so that after inserting the rear baffle 15 it can be anchored in the anchor 2 by conical jaws. 15 and the anchor 8 is secured by the anchor cover 14, which at the same time protects the operator from the consequences of an eventual tearing of the anchor 2 during tensioning / fig. 3 /.

Tensioning of the cable ^2, performs the rear of the sowing -list 2 · ^P of the tension of the cable ^{2, the} piston 12 actuated cylinder 13 pushes the guide plate 2 and the jaws 11 of the front plug 10, uM; the cable 2 is pre-anchored / FIG. 5 /. It is then possible to release the rear part of the press 2 ^{and the} cable 2 s ^is automatically engaged in the armature 10.

The example of using the cable tensioning method according to the invention described herein can be adapted to specific needs on a case-by-case basis. It is possible to tension cables consisting of individual ropes, double and triple cables. The anchoring roller may be at the center of the cable between the ropes or may be

20S 814 rollers more spaced symmetrically around the cable. The support base can also be in the form of an adit and can be exchangeable for different cable sizes varying in the number and placement of the individual ropes.

Claims (2)

Object of the invention A cable tensioning device comprising, for example, pre-tensioning ropes by means of a hydraulic press provided with a continuous circular hole and with a withdrawable part, characterized in that a guide plate (2) is slid onto the end of the protruding cable (1). and is inserted into the mouth of the support stand (3) mounted on the flange (4) at the front of the press (5) until the baffle (6) is in the shape of a longitudinally divided funnel, whereupon the press (5) moves together with the support stand (3) to the pretensioned structure along the protruding cable (1), which at the same time is moved through the continuous hole of the press (5) by means of a longitudinally oriented dividing guide (7) until the cable (1) projects beyond the press (5) of an anchor (8) in split jaws (9) of conical shape and by extending the rear part of the press (5) and tensioning, after which the tensioned cable (1) is anchored in the front anchor (10) by pushing the guide that (2) into the jaw (11) cone by ejecting the piston (12) from the cylinder (13) located in the space of the pedestal (3) and supported by the flange (4). 2. The method according to claim 1, characterized in that the jaws (9) are provided on the conical surfaces with a layer of a paste composed of a mixture of soap and graphite.