Cable anchorage system

Abstract

A cable anchorage system for anchoring a cable to a support structure in a civil engineering construction comprises an anchorage socket attached to the cable, a support socket attached to the support structure and a longitudinal coupling rod, which couples the anchorage socket to the support socket. The coupling rod comprises a threaded end, which interacts with a counter thread on one of the two parts which are the anchorage socket and the support socket, and a mounting end with a radially extending rod shoulder. The other one of the two parts which are the anchorage socket and the support socket comprises a longitudinal opening for receiving the mounting end of the coupling rod, which opening comprises an inwardly extending abutment shoulder. The rod shoulder abuts on the abutment shoulder in a first longitudinal direction and is slideable within the opening in a second longitudinal direction opposite to the first direction, when the anchorage socket is moved towards the support socket for tuning the cable anchorage system.

Claims

1. Cable anchorage system for anchoring a cable to a support structure comprising an anchorage socket attached to the cable, a support socket attached to the support structure and a longitudinal coupling rod, which couples the anchorage socket to the support socket, wherein the coupling rod comprises a threaded end, which interacts with a counter thread on one of the anchorage socket and the support socket, and a mounting end with a radially extending rod shoulder, the other one of the anchorage socket and the support socket comprises a longitudinal opening for receiving the mounting end of the coupling rod, which opening comprises an inwardly extending abutment shoulder, wherein the rod shoulder abuts on the abutment shoulder in a first longitudinal direction and is slideable within the opening in a second longitudinal direction opposite to the first direction.

2. Cable anchorage system according to claim 1, wherein the coupling rod is supported within the opening in a rotatable fashion about a longitudinal axis of the opening.

3. Cable anchorage system according to claim 1, wherein the coupling rod is supported within the opening in a slewable fashion relative to a longitudinal axis of the opening.

4. Cable anchorage system according to claim 1, wherein the radially extending rod shoulder of the mounting end of the coupling rod runs circumferentially around an outer contour of the coupling rod and/or the inwardly extending abutment shoulder runs circumferentially around an inner contour of the opening.

5. Cable anchorage system according to claim 1, wherein the mounting end of the coupling rod comprises a circumferentially tapered section extending from the rod shoulder to the mounting end of the coupling rod and/or the abutment shoulder of the opening is of conical shape, which opens in direction of the mounting end.

6. Cable anchorage system according to claim 1, wherein an inner contour of the opening comprises a second section from the abutment shoulder towards the threaded end of the coupling rod, wherein the second section is of conical shape, which opens in direction of the threaded end.

7. Cable anchorage system according to claim 1, wherein a surface of the rod shoulder comprises a convex shape.

8. Cable anchorage system according to claim 1, wherein the support socket is connected to a clevis coupler, which is coupled to the support structure.

9. Cable anchorage system according to claim 5, wherein, when the coupling rod slides within the opening, an inner contour of the first section of the opening is a longitudinal guide of an outer edge of the rod shoulder and/or an outer contour of the coupling rod between rod shoulder and threaded end is a longitudinal guide of an inner edge of the abutment shoulder.

10. Cable anchorage system according to claim 1, wherein, the rod shoulder is on a separate rod shoulder element mounted on the coupling rod.

11. Cable anchorage system according to claim 1, wherein the system comprises a stressing unit for moving the anchorage socket towards the support socket, wherein the stressing unit comprises at least one stressing jack attachable to the anchorage socket and socket stressing brackets attachable to the support socket or a clevis pin.

12. Civil engineering construction comprising at least one cable, which is attached to a supporting structure of the construction at least on one end by the cable anchorage system according to claim 1.

13. Method for tuning the cable anchorage system according to claim 1 by a stressing unit, wherein the stressing unit comprises at least one stressing jack attached to the anchorage socket and socket stressing brackets attached to the support socket, wherein the stressing unit moves the anchorage socket towards the support socket, while the mounting end of the coupling rod slides longitudinally within the opening.

14. Method for tuning a cable anchorage system according to claim 13, wherein a force to stress the cable is transmitted from the support socket by the socket stressing brackets and the stressing jacks to the anchorage socket.

Description

(1) In the following, embodiments of the invention will be illustrated in the drawings, which merely serve for explanation and should not be construed as being restrictive. The features of the invention becoming obvious from the drawings should be considered to be part of the disclosure of the invention both on their own and in any combination. The drawings show:

(2) FIG. 1: a three-dimensional example of a cable stay using a cable anchorage system according to the present invention,

(3) FIG. 2: a longitudinal partial sectional view of a cable anchorage system according to the present invention in a first position,

(4) FIG. 3: a longitudinal partial sectional view of the cable anchorage system according FIG. 2 in a second position,

(5) FIG. 4: a longitudinal partial sectional view of the cable anchorage system according FIGS. 2 and 3 in a third position,

(6) FIG. 5: a partial sectional view of a further embodiment of a cable anchorage system according to the invention.

(7) FIG. 1 gives an overview of a stayed cable 3 in a civil engineering construction according to the invention. The cable 3 comprises a cable anchoring system according to the invention on both ends so that the cables is coupled to supporting structures 1 of the civil engineering construction. In the shown example the cable anchorage systems are covered by an anti vandalism pipe 15. The supporting structure 1 can be decks, pylons, arches, main cables in case of suspended bridges or suspended roofs, or any kind of civil engineering or building structure. A support socket 20 of the cable anchoring system is attached to a clevis coupler 6, which is fastened to a gusset flange 2 by a clevis pin 9. The gusset flange 2 is fixed to the support structure 1. The cable 3 can be constituted of one or many cable strands, wires 3a (see FIGS. 2-4). Also the cable 3 can be made of one or several rigid bar or a locked coil cable or an equivalent linear element. The anti vandalism pipe 15 provides mechanical protection to the entire cable anchoring system. Optionally the anti vandalism pipe can be mounted air or leak tight to provide high corrosion protection to the cable anchoring system.

(8) FIGS. 2 to 4 show a partially sectional view of the cable anchorage system according to one example in different positions. Generally the cable anchoring system comprises an anchorage socket 4 attached to the cable 3, the support socket 20 attached to the support structure 1 either directly or by connection to a clevis coupler 6 and a clevis pin 9 and a longitudinal coupling rod 10, which couples the anchorage socket 4 to the support socket 20. The cable 3 is anchored in the anchorage socket 4 in commonly known fashion. Opposite to the cable end the anchorage socket 4 comprises a receiving hole 16 with a female thread. The length of the anchorage socket 4 is determined according to the required strength and adjustability for the cable tuning. In one example the length of the receiving hole 16 is up to 500 mm and the female thread has a size as known from the state of the art.

(9) The coupling rod 10 transfers the cable load from the anchorage socket 4 to the support socket 20 and the clevis coupler 6 respectively. The coupling rod 10 has an elongated shape and in this embodiment is a single piece. It comprises a threaded end 10a with a male thread, a mounting end 10b supported in the support socket 20 and a rod shoulder 10d with a rod shoulder surface 10c. The female thread of the anchorage socket 4 serves as counter thread 4a for the male thread of the threaded end 10. The rod shoulder 10d can be monolithically included in the coupling rod 10, or can be made of an additional element, rigidly connected to the coupling rod 10 for example by a thread connection or other connection.

(10) The support socket 20 also has an elongated shape with an opening 5 extending along an axis (za) in the support socket 20. The opening comprises an abutment shoulder 20a with an abutment shoulder surface 20b, wherein the abutment shoulder 20a extends inwardly into the opening 5 from an inner contour of the opening. In this embodiment the abutment shoulder 20a can be realized as a circular step or protrusion on the inner contour of the opening 5. The abutment shoulder surface 20b faces towards the rod shoulder surface 10c. A first section 5c of the opening extends from the abutment shoulder 20a in direction away from the anchorage socket 4 towards the mounting end 10b of the coupling rod 10. A second section 5a of the opening 5 extends from the abutment shoulder 20a in direction of the anchorage socket 4 towards the threaded end 10a of the coupling rod 10. The threaded end 10a of the coupling rod 10 at least partially extends from the opening 5.

(11) The support socket 20 can be rigidly connected to the clevis coupler 6. Alternatively it can also be fixed to the clevis coupler by a thread connection for example. The clevis coupler 6 comprises two flanges 6a and 6b which enclose the gusset flange 2. The pair of flanges 6a and 6b and the gusset flange comprise through holes for the clevis pin as is commonly known. Furthermore the brackets of the clevis coupler 6 comprise protrusions 7 around or adjacent to the through holes, which define a flange 8 for attachment of a stressing unit for tuning the cable anchoring system.

(12) The coupling rod 10 comprises a circumferentially tapered section 10b extending from the rod shoulder 10d to the end of the coupling rod 10, which is located within the opening 5. The surface of the tapered section for example can be inclined about 5 to 15 relative to the axis of the coupling rod. An edge of the rod shoulder 20a terminates close to the inner contour of the opening in the first section 5c or may lay on the contour without pressure. The circumference around the end of the mounting end 10b is less than the circumference of around the rod shoulder. The section of the coupling rod extending from the rod shoulder 10d towards the threaded end 10a is basically cylindrically shaped with the same circumferential size.

(13) The second section 5a of the opening 5 is of conical shape, which opens towards the end, through which the coupling rod extends out of the opening 5, i. g. in direction of the threaded end 10a of the coupling rod 10. The abutment shoulder 20a reaches close to the coupling rod but does not pinch the coupling rod 10. Because of the conical shape, the circumference of the edge of the abutment shoulder is smaller than the circumference at the end of opening 5, where the coupling rod extends of the support socket 20. The first section 5c of the opening 5 is cylindrically shaped with the same circumference along its length in this example embodiment.

(14) The tapered section 10e of the mounting end 10b of the coupling rod 10 and the cylindrical first section 5c of the opening result in a first radial gap between the outer contour of the mounting end 10b and the inner contour of the first section 5c of the opening. The first gap decreases in size towards the rod shoulder 10d. Also the conically shaped second section 5a of the opening and the cylindrically shaped section of the coupling rod between the rod shoulder 10d and the threaded end 10a results in a second radial gap between the inner contour of the first section of the opening and the outer contour of the coupling rod. Again the second gap decreases from the end of the opening towards the abutment shoulder 20a. Generally there also can be a little radial play between edges of the rod shoulder and the abutment shoulder relative to the opposing contours.

(15) In FIG. 2 the cable anchorage system of this embodiment is shown in a first position, wherein the anchorage socket 4 is tilted relative to the longitudinal axis of the support socket 20. In this position the mounting end 10b of the coupling rod 10 moves within the first gap towards one side of the opening. The rod shoulder 10d rests within the circumferential boundaries of the first section 5c of the opening, whereby the coupling rod is centred within the opening. Also the section of the coupling rod between rod shoulder and threaded end is declined towards the inner contour of the conically shaped second section 5a of the opening. The coupling rod 10 can be tilted in any radial direction within the limits of free play between the inner contour of the opening and the outer contour of the coupling rod. As can be seen in FIG. 2 the axis (zb) of the anchorage socket 4 and the support socket 10 fixed in the anchorage socket 4 is inclined relative to the axis (za) of the support socket 20 and the opening 5. This can occur for example in the case of a misalignment between the cable axis (zb) and the axis of the gusset flange due to construction tolerances.

(16) The first position exists for example after the anchorage socket 4 with the cable 3 has been connected to the coupling rod 10. To do so the counter thread 4a is screwed onto the threaded end 10a of the coupling rod 10. The radial degree of freedom facilitates the screwing process and results in less stress on the single parts of the cable anchorage system. At the same time the mounting end 10b can rotate within the opening 5. The rotational degree of freedom also assists the mounting of the anchorage socket on the coupling rod and therefore the coupling of the cable 3 to the supporting structure 1. The anchorage socket then is fixed to the coupling rod and is hanging within the opening 5 of the support socket 20. In this position the rod shoulder 10d abuts against the abutment shoulder 20a of the opening. The rod shoulder surface 10c may slide on the abutment shoulder 20a in this position. The surfaces can be designed convex and concave respectively to enable easy centring and sliding between the coupling rod 10 and the support socket 20. Also the surfaces can be inclined relative to the radial direction as shown in the figure.

(17) In the second position shown in FIG. 3 the axis of the anchorage socket 4 and the coupling rod 10 fixed in the anchorage socket 4 is aligned with the axis of the support socket 20 and the opening 5. The second position exists for example when the cable is well aligned along the axis of the support socket 20 after it has been loaded. The inclined or convex/concave design of the rod shoulder surface 10c and the abutment shoulder surface 20b helps to align the two axes (za) and (zb).

(18) In the position of FIG. 4 a stressing unit of the cable anchorage system started to tune the cable length and the load on the cable, by pulling the anchorage socket 4 in direction of the support socket 20. The longitudinal cable force is transferred in this position by the stressing unit and not the coupling rod 10.

(19) The stressing unit comprises socket stressing brackets 11, which can be attached into the flanges 8 of the clevis coupler 6. Alternatively they might also be attached directly to the clevis pin 9 for example by providing the pin with an over length and matching reservations in the stressing bracket 11 or by providing the pin with reservations in its end faces into which protrusions of the stressing bracket 11 interlock. Furthermore the stressing unit comprises stressing jacks 14, which are attached to the anchorage socket 4 by stressing jack attachments 13. The stressing jacks 14 and the socket stressing brackets 11 are connected by stressing bars 12. Alternatively other stressing members such as ropes made of high tensile steel, carbon fibre or any other high tensile material may be used instead of the stressing bars 12. The socket stressing brackets make use of the attachment within the flanges 8 to transfer the cable load during operations of cable tension of length adjustment. The stressing bars 12 transfer the force of the cable during force or length adjustment operation between the socket stressing brackets 11 to the stressing jacks 14. The stressing jack attachment 13 transfers the load of the stressing jacks 14 to the cable, through the anchorage socket 4.

(20) The tuning process results in an axial movement of the mounting end 10b of the coupling rod 10 within the first section 5c of the opening 5. Thus the rod shoulder 10d removes from the abutment shoulder 20a so that a clearance e is formed between the shoulders 10d and 20a. The clearance e increases as long as the anchorage socket 4 moves towards the support socket 20. The clearance e can for example be up to 200 mm and preferably up to 50 mm. But the coupling rod 10 can be screwed further into the anchorage socket 4, so that the clearance decreases. Preferably the clearance e is adjusted to be less than 3 mm when the cable anchorage system is in a mounted position. This can be done easily because there is no load on the coupling rod anymore. When the coupling rod 10 moves within the opening 5, the edge of the abutment shoulder 20a is guided along the outer contour of the coupling rod 10 and also the edge of the rod shoulder 10d is guided along the inner contour of the opening. This helps to stabilize the cable anchorage system during tuning the system.

(21) When the tuning process is completed the force in the stressing system is released by retracting the stressing jacks 14 and the force is transferred to the coupling rod 10 when the rod shoulder 10d engages by contacting the abutment shoulder 20a. Once the force has been transferred in this manner the stressing unit consisting of stressing jacks 14 and stressing bears 12 and its stressing brackets 11 and stressing jack attachments 13 can be removed.

(22) In FIG. 5 a second embodiment of a cable anchorage system according to the present invention is shown. Parts with same function as in the first embodiment according to FIGS. 2-4 have the same reference numbers. In this embodiment the coupling rod 10 is designed as a longitudinal cylindrical bolt, which is threaded along its full length. The threaded end 10a thus extends far into the opening 5 of the support socket 20. The mounting end 10b comprises a rod shoulder element 19, which is a separate sleeve-like element. The rod shoulder element 19 comprises an interior thread that corresponds to the male thread of the coupling rod 10. Thus the rod shoulder element 19 can be screwed on the coupling rod 10. One end of the rod shoulder element 19 serves as the rod shoulder. The rod shoulder is designed as a conical surface. The outer contour of the rod shoulder element 19 is tapered relative to the axis of the coupling rod 10. Thus a gap is created between the tapered contour and the inner contour of the opening 5. The cable anchorage system is shown in an aligned position, wherein the rod shoulder 10d and the abutment shoulder 20a rest on each other. In this embodiment the abutment shoulder 20a is part of a further sleeve-like element 20c comprising an external thread that screws into an internal thread in the support socket 20.

(23) A cable anchoring system according to the present invention is described according to the embodiments shown in the FIGS. 2 to 4 and 5. But it is clear to a person skilled in the art, that specific features of the cable anchoring system can be realized by alternatives as mentioned in the general description above. First of all the opening can be realized in the anchorage socket instead of the support socket and the counter thread can be located on the support socket instead of the anchorage socket. Furthermore alternative variations for the design of the rod shoulder or the abutment shoulder are possible as long as the coupling rod abuts within the opening. Also instead of a clevis coupler other coupling elements are possible.

(24) TABLE-US-00001 Reference Numbers 1 supporting structure 2 gusset flange 3 cable 3a cable strands 4 anchorage socket 4a counter thread 5 opening 5a second section of opening 5c first section of opening 6 clevis coupler 7 protrusion 8 flange 9 clevis pin 10 coupling rod 10a threaded end 10b mounting end 10c rod shoulder surface 10d rod shoulder 10e tapered section 11 socket stressing brackets 12 stressing bars 13 stressing jack attachment 14 stressing jacks 15 anti vandalism pipe 16 receiving hole 19 rod shoulder element 20 support socket 20a abutment shoulder 20b abutment shoulder surface 20c sleeve-like element e clearance za opening axis zb coupling rod axis