Abstract:
A system for unwinding and laying wires including a device for carrying a wire reel from which the wire to be laid is dispensed an device for unwinding and laying the wire, the device for carrying wire structured and arranged to be held against motion during the unwinding and laying of the wire, a vehicle to which the for unwinding and laying the wire is mounted, the vehicle being movable along a laying path. The device for unwinding and laying including a wire pulling unit with first and second clamping devices for gripping the wire, the first and second clamping devices being selectively adjustable from a clamped state in which clamping device holds the wire and a declamped state wherein the clamping device releases the wire and the first and second clamping devices being positionable from an extended clamped position in which the clamping device extends transversely beyond an obstacle located along the laying path a retracted declamped position in which the clamping device retracts to a clearance position transversely spaced from the obstacle.

Description:
FIELD OF THE INVENTION 
     The invention relates to a system for unwinding and laying wires such in particular as catenary power cables or like overhead contact wires with catenary suspension supported by a stationary supporting structure during the building and the renewal of catenary installations, of the type comprising a device carrying wire reels or drums from which are paid out the wires to be laid and means for unwinding and laying wires onto the supporting structure, the latter being likely to comprise obstacles opposing the unwinding and the laying, such as rigid gantry beams, crossings of catenary planes, crossed and communication equipments or the like. 
     BACKGROUND OF THE INVENTION 
     The systems of this kind, which are known, comprise a system carrying wire or cable reels which moves from one cable anchoring point to the following anchoring point upstream of an obstacle and then from an anchoring point downstream of the latter to the then next anchoring point. 
     The major inconvenience of the known systems is that they do not permit a continuous unwinding and laying of the wires in case of an obstacle. 
     OBJECTS AND SUMMARY OF THE INVENTION 
     The object of the present invention is to provide a system which copes with the inconveniences which have just been stated. 
     For these purposes, the system according to the invention is characterized in that the device carrying the reels or drums is a unit capable of being held against motion during the unwinding and the laying, the unwinding and laying device is mounted onto a vehicle displaceable along the unwinding path of travel and comprising a wire-drawing or pulling unit with two devices with a clamp or gripper for gripping a wire, mounted onto a support at a predetermined distance from each other in the axial direction of the wire, so as to be selectively displaceable between a position of the wire clearing the obstacle with the wire being held gripped and a position of the device clearing the obstacle without any wire. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will be better understood and further objects, characterizing features, details and advantages thereof will appear more clearly as the following explanatory description proceeds with reference to the attached diagrammatic drawings given by way of non limiting examples only illustrating several presently preferred specific embodiments of the invention and in which: 
     FIG. 1 is a diagrammatic side view of a system according to the invention; 
     FIG. 2 is a diagrammatic elevational view of a vehicle carrying an arrangement for unwinding and laying catenary cables according to the present invention, the arrangement assuming its expanded or spread out working position; 
     FIG. 3 is a view similar to FIG. 2 but showing the unwinding and laying arrangement in a collapsed or folded back position; 
     FIG. 4 is a view in the direction of the arrow IV of FIG. 2 in the case of a railway track in a superelevation or cant area; 
     FIG. 5 is a diagrammatic view illustrating the process of clearing an obstacle; 
     FIGS. 6 to  8  are side, axial and top views, respectively, of a first embodiment of a cable gripping clamp device; and 
     FIGS. 9 and 10 are two diagrammatic side views of two other embodiments of a cable gripping clamp device according to the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1 shows by way of example a system according to the invention conceived and designed for the unwinding and the laying of the power wires and cables of a catenary installation of a railway track. This system essentially comprises a first vehicle  1  which carries a number of cable reels or drums  2  from which the cables shown at  3  may be paid out and a second vehicle  4  which comprises an arrangement  5  for unwinding and laying the wires  3 . Both vehicles  1  and  4  are movable upon the railroad track shown at  6 . During the process of winding and laying, the vehicle  1  is held against motion whereas the vehicle  4  is moving in the direction of the arrow F. The unwinding is carried out under mechanical stretching or tensioning in order to achieve the laying quality required for a good collection of the electric current by the electric machines of the trains which are to be running on the railway truck shown at  6 . The vehicles  1  and  4  further comprise other equipments but since the latter do not relate to the invention, they will not be described. 
     Referring to FIGS. 2 and 3, an advantageous embodiment of the unwinding and laying arrangement  5  according to the invention will be described hereinafter, the vehicle  4 , which carries this equipment, being, differently from FIG. 1, shown as a non powered vehicle only. 
     The arrangement  5  essentially comprises a post  8  which is rotatably mounted about a vertical axis on the vehicle by means of a slewing base  9  pivotable about a horizontal axis  11  and carries an intermediate turret  12  for supporting an assembly  13  consisting in the example shown of two pivotally interconnected arms  14  and  15  and provided with means for varying the angle formed by the arms and of which the end carries a wire drawing or pulling head  16  with two cable gripping and holding clamp devices, namely a forward one  17  and a rearward one  18  spaced by a predetermined distance from each other, in the direction of unwinding of the cable as more clearly seen on FIG.  5 . The devices  17  and  17 ′ are carried by a support rotatably mounted about a vertical axis and pivoting in a vertical plane on the end of the end arm  15 . 
     The post  8  in the case of a railway track in a superelevation or cant area would pivot as a hole unit about the pivot axis  11  located at the level of the base  9 , by means of two side jacks or power cylinders arranged on either side of the axis  11  and pivotally connected, in the example shown, with the jack body or cylinder at  23  to the rotatable base  9  and with the end of the piston rod  24  to side brackets  25  made fast to the post. The jacks or actuators  20 ,  21  are used as jacks for correcting the track superelevation or cant to always provide a vertical position of the post irrespective and independently of the transverse angle of slope α of the track (FIG.  4 ). 
     The post  8  itself is made as a deformable parallelogram of which the long sides consist of two pillars or standards  27  and  28 , each one in the shape of a gantry (FIG.  4 ). Both pillars or standards  27 ,  28  are pivotally connected at  29  and  20 , respectively, to the base or bottom  31  of the post at different heights and at the top to a bent element  33  which comprises a horizontal portion  34  carrying the swivelling turret  12  and a vertical portion  35 , so that it may be pivotally connected to the upright  27  and to the upright  38 , at  36  and  37 , respectively, at different heights corresponding to the vertical shift or level difference of the pivotal connections  29  and  20  at the base of the parallelogram. The latter is deformable by means of a jack  39  of which the ends are pivotally connected to the top end of the upright  27  and to the bottom end of the other upright  28 . 
     The post  8  has a size designed for supporting a perpendicular load equal to the total value of the tension or tightness applied to each cable at a height variable from 3 to 9 meters above the level of the floor of the vehicle  3 . 
     Both gripping devices  17 ,  18  of the cable drawing or pulling unit  16  comprise each one a clamp for gripping cables  41  which is amovable between an upper cable gripping position A and a lower retracting position B in which the gripper or clamp may pass below or ahead of an obstacle when the cable has to be brought above or from the back of the latter as described hereinafter with more details with reference to FIG.  5 . For that purpose in the embodiment of the gripping devices shown on FIGS. 2 to  5 , both clamps or grippers are mounted onto a common support  42 , each one through the medium of two parallel links  43  which are pivotable between a vertical cable gripping position and a horizontal retracting position. Thus is provided a parallelogram-shaped gripping clamp support. 
     FIG. 5 illustrates the process of clearing an obstacle shown at  45  such as a gantry extending at some height above the track in perpendicular relation thereto. Upon approaching the obstacle  45 , the front or forward gripping clamp  17  is in its retracting position B with both links  21  in their substantially horizontal positions. The cable  3  is gripped and pulled by the reel gripping clamp only of which the links extend vertically. It is seen that the cable drawing head is placed vertically at such a height that the obstacle  45  is vertically located between the front and rear gripping clamps. During the displacement of the unwinding vehicle in the direction of the arrow, the front gripping clamp may pass underneath the obstacle whereas the upper rear gripping clamp may pass the cable above the obstacle or obstruction as seen on FIG. 5 a . Then the front gripping clamp is caused to pivot into its elevated cable gripping position A as seen on FIG. 5 b  and it is the rear jaw which releases the cable and retracts according to FIG. 5 c . It is only after the gripping head has reached the position shown on FIG. 5 d  in which the obstruction or obstacle is located behind the retracted rear gripping clamp that the latter is caused to return to its elevated position A according to FIG. 5 e.  As the cable  3  is again pulled by the rear gripping clamp, the front gripping clamp retracts again when approaching the next obstacle as seen on FIG. 5 f.  The front and rear gripping clamps  17  and  18  are therefore mounted onto a support, so as to be selectively displaceable between a position A of the wire clearing an obstacle with the wire  3  being kept gripped and a position B of clearing the obstacle without any wire. 
     Referring now to FIGS. 6 to  10 , three embodiments of the cable gripping clamps will be described. 
     In the embodiment according to FIGS. 6 to  8 , the gripping clamp  41  comprises two jaws  47 ,  47 ′ of which each one comprises a double-armed lever  48  pivotally mounted onto a bracket  49  made fast to one side face of a support mounted for being vertically movable on the support of the wire pulling head. Both levers would pivot or swing in opposite pivoting directions as shown by arrows under the effect of a common jack or actuator  50  interposed between both lower ends of the levers and extending through the support. The opposite end of each lever is shaped as a support for a plurality of cable clamping chaps  52  with a fluted or chequered attack surface. As seen in particular on FIG. 8, the ends of the levers exhibit the shape of combs  53 ,  53 ′, each tooth or prong exhibiting a U-shaped profile opening towards the cable  3 , with a chap  52  supported between both legs of the U, displaceable towards the cable under the effect of a spring.  54 . It appears from FIG. 8 that the comb-shaped end  53  of the lever  48  comprises three teeth or prongs  55  and therefore three clamping chaps  52  and the comb-shaped end  53 ′ of the other lever comprises two teeth or prongs  55 . As to the cable  3 , it rests upon the top face  56  of the support or holder  57  which exhibits a suitable concave profile adapted to the profile of the cable. The levers  48  supporting the clamping chaps  52  are mounted onto the support or holder  57  to be pivotable between a spread opening position of the clamp permitting the passage of the cable between the ends supporting the chaps (FIG. 7) and a closed position in which the combs are mutually overlapping or interfitting into each other and the chaps  52  are caused to bear upon the cable under the effect of the springs  54  (FIG.  8 ). Thus the cable is clamped between the chaps  52  and the top concave surface  56  of the support. For improving the clamping effect, the chaps  52  are not directed in perpendicular relation to the peripheral face of the cable but inclined with respect to the latter as seen on FIG.  6 . 
     As to the operation of the cable drawing head fitted with gripping devices according to FIGS. 6 to  8 , in order to bring a device into its retracting position B (FIG.  5 ), the opening of the gripping clamp through spreading of the supporting levers  48  are operated by means of the control jacks  50  and the support of each front or rear gripping clamp is then selectively lowered for releasing the cable  3 . For gripping the cable again, it suffices to impose on the gripping clamp the reverse movement and then to operate the closing of the clamp. 
     The embodiment of the cable pulling head shown on FIG. 9 exhibits the peculiarity that each gripping clamp  41  is mounted for being horizontally movable in the direction of the arrow on a support  57  itself displaceable in translation by means of an arcuate segment member  58  projecting from its bottom face and which is shaped as a toothed rack  59  meshing with a pinion or gear  62  rotatably mounted onto a support  63  which is common to both gripping devices  17 ,  18 . On FIG. 9, the clamps are shown diagrammatically only. They may be provided in any suitable shapes, for example in accordance with FIGS. 6 to  9 . 
     In the embodiment according to FIG. 10, the support of the clamps of the devices  17 ,  18  exhibits each one the shape of an L the horizontal leg  65  of which carries the clamp at its end whereas the vertical leg  66  is supported for being vertically movable and rotatable about its axis on a support  67  common to both devices. The various possibilities of motion are shown again by arrows. The figure shows both devices in their cable gripping position and in their retracted position with a view to clear an obstruction. 
     It should be pointed out that the clamp actuating jacks  50  and the displacements of the clamp supports may be remote controlled or automatically controlled by a suitable obstacle detecting or sensing device mounted onto the wire drawing head. 
     This FIG. 10 also shows that the arm supporting the cable pulling head, instead of consisting, in accordance with FIGS. 2 to  4 , of a pivotally connected arm, may be provided in the shape of a deformable parallelogram of which both parallel longitudinal sides or links are denoted at  69  and  70 . 
     Owing to its structure which has just been described, the invention permits the unwinding and the laying of the cables while clearing horizontal obstructions located at some height as seen on FIG.  5 . The invention also permits the laying of cables even if obstacles are formed for example of vertical poles or masts, where it is necessary with respect to the track to pass behind these posts or masts. It then suffices to position the cable drawing head sidewise with respect to the track and to then place the support of the gripping devices vertically by means of the orientation mechanism pivotally connected to the end of the terminal arm by means of an orientation jack not shown. 
     By fitting the bottom of the parallelogram-shaped mast or pole with an orientation ring permitting an angle of rotation of twice 120°, it is possible to position the parallelogram on either side of the vehicle in perpendicular relation to the track for working not only on the masts of the track where the vehicle is running but also on those of the adjacent track. The taking up of the pulling force of 2000 daN under this equipment positioned at 90° involves a consequent reinforcement of the base parallelogram and of all the elements. The versatility of the cable unwinding and laying system according to the invention is obtained owing to some structural characterizing features which have been described hereinabove but which are briefly repeated. As to the post or mast, it is seen that its lower portion provided with a great rigidity is arranged upon a table fastened onto the floor of the vehicle. This table comprises two semi-circular sectors in which the base of the parallelogram may be caused to pivot. That contrivance allows to keep the upper portion perfectly centred with respect to a track in a cant or superelevation area. This also provides a positioning of the axis of drawing the cable. The pulling force always lies along the axis of the parallelogram. The forces due to the height-tension torque of the cable always remain centred. The turret located at the end of the base parallelogram constitutes a perfect seat for orienting the upper portion comprising itself too a parallelogram or a pivotally connected arm. The support of the gripping devices may be oriented owing to a jack, the cable drawing head may be positioned during the pulling so that the jack be always capable of taking up the pulling forces as a thrust. The head is mounted onto a perfectly vertically swivelling orientation ring. During the pulling of the cable, when the latter is gripped within the reel clamp, this orientation remains floating. During the restarts upon moving past obstacles, the orientation is on the contrary blocked. 
     To avoid a problem of overlength of the cable due to taking it over again at each obstacle, the clamp may during the clamping either be moved backwards or forwards by the value of the clamp grip in order that at each obstacle, the original position be recovered or reassumed. This compensation may be done during the advancement between two obstacles and under tension by carrying out a very slow movement. The clamp supports may be fitted with height sensing cells in order to pass closest to the obstacle in the vertical direction. An additional detection may be achieved in order to cause the passing over an obstacle through successive retraction and positioning of the clamp as complete cycles in order to not stop the unwinding or forward running of the unwinding vehicle. 
     In summary, the fact of having the clamping support always in the horizontal position in parallel relation to the railway track and of being able to restart on a stable structure the pulling force on the cable, the whole unit may indifferently work in one direction or in the other one. The mast-intermediate turret-upper arm configuration, provided with orientation means, permits to reach great heights to obtain a very stable unit and to have the clamps not subjected to torsion or twist. Since the support of the clamps always is perfectly horizontal, it is possible to pass closest to the obstacles. The load and the taking up again of the cable on the obstacle may be carried out in automatic cycles, thereby permitting that the progress of the cable laying work be not discontinued.