Twisted angle tie-bar for railway tie
FIELD OF THE INVENTION 
     The present invention relates to twisted angle tie-bars for the ties of railways of the mixed concrete-steel type. 
     PRIOR ART 
     The use of angles as tie-bars for mixed concrete-steel ties is known. French Pat. No. 1 429 382 proposes a tie equipped with a twisted angle tie-bar which is perforated at each of its ends embedded in the blocks to allow the passage and anchoring of bolts or screws for fixing the rails. Such a tie-bar, whose manufacture involves the use of powerful means for cutting out the perforations, also presents the drawbacks of affecting the mechanical strength of the angle, of necessitating high precision of positioning during manufacture of the ties and of requiring a very careful electrical insulation of the rails laid down on these ties since the bolts for fixing the rails are in direct contact with the tie-bar. 
     French patent application No. 82 07807 also discloses an angle tie-bar having wings extended locally at each of its ends in order to reduce the dimensions of the latter and to allow them to be embedded, between the rail screws, in the longitudinal central zone of the blocks. However, this solution, which provides electrical insulation, involves disposing the rail screws on either side of the longitudinal median axis of the blocks, this presenting the drawback of not allowing the use of the existing mechanized automatic track-laying machines which require an alignment of the rail screws. 
     SUMMARY OF THE INVENTION 
     To overcome the drawbacks of the solutions set forth above, it is an object of the invention to provide a non-perforated angle tie-bar allowing the alignment of the rail screws along the longitudinal median axis of the tie, which is economical to manufacture and adapted to be mounted easily in the blocks without risk of direct electrical contact with the rail fastening means. 
     To attain the object set forth hereinabove, the invention provides an angle tie-bar presenting a non-deformed central part separating the two blocks, comprising at each of its ends: 
     an end part which has undergone a transverse movement of rotation such that, in position of assembly, one wing of the end part may pass at a distance beneath the vertical orifices for passage of the rail screws and its other wing passes at a distance along said orifices. The end part is preferably not deformed with respect to its initial profile and its section occupies a position offset by about 45° with respect to that of the central part; 
     a shaped intermediate part which joins the end part to the central part of the angle. The intermediate part which is advantageously twisted is positioned on the angle to come into position in each block, between the inner orifice for passage of the rail screws and the inner lateral face of the block. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will be more readily understood on reading the following description with reference to the accompanying drawings, in which: 
     FIG. 1 shows a mixed tie equipped with the tie-bar of the invention, in front view for its left half and in plan view for its right half. 
     FIG. 2 is an enlarged sectional view taken on line II--II in FIG. 1. 
     FIG. 3 is an enlarged sectional view of the tie-bar alone taken on line III--III in FIG. 1. 
    
    
     DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT 
     Referring now to the drawings, the tie-bar of the invention is constituted by a metal angle (FIG. 1) shaped near each of its ends, on an intermediate part l2, so that its end parts l3 undergo a transverse movement of rotation about an axis lying in the vicinity of the outer edge of one leg or wing 5 (FIG. 3) of the angle 1, so that the sections S&#39; of the end parts l3 occupy, with respect to section S of the central part l1, a position offset towards the outer central edge of the angle part l1, by an angle α of about 45°. That portion of the axis about which transverse rotation of the end parts l3 is effected and which determines the position of these parts with respect to orifices 3 for passage of rail screws, may move away as much as is necessary from the outer edge of the wing 5, this axis being able to lie for example in the median zone of the wing 5. 
     The end parts l3 are preferably not deformed with respect to their initial profile. 
     The intermediate parts l2 for connection of the end parts l3 with the central part l1, may be made by twisting, bending or the like. Such forming may be effected by an appropriate means enabling a regular and progressive deformation of the metal to be obtained. 
     In order to facilitate understanding, a more detailed description of the preferred embodiment of the tie-bar of the invention is given hereinafter, situating said tie-bar with respect to the relative position that it occupies as mounted in the blocks of a mixed tie normally laid on the ground. 
     FIGS. 1 and 2 show a mixed tie equipped with the twisted angle tie-bar 1 of the invention. The concrete blocks 2 used are of the type each comprising two vertical orifices 3, provided with threaded linings (not shown) making it possible to fix the rail by rail screws. The vertical orifices 3 are aligned along the longitudinal median axis YY of the blocks. 
     The angle tie-bar 1 of the invention presents: 
     a central part l1, of section S, not deformed with respect to its initial profile, of a length at least equal to the space defined by the inner lateral faces 4 of the blocks 2. The central part l1 which is centered in the longitudinal axial zone of the blocks 2 is oriented so that the bisector plane XX of its lower and upper wings 5 and 6, respectively, is horizontal, i.e. parallel to the base surface 7 of the blocks 2; 
     at each of its ends embedded longitudinally in the blocks 2, a part l3, of section S&#39;, not deformed with respect to its initial profile and a shaped intermediate part l2 joining the end part l3 and the central part l1. 
     The end parts l3 which are oriented so that the bisector planes X&#39;X&#39; of their wings 5&#39;, 6&#39; form an angle β of 45° with respect to axis XX of the central part l1, occupy in the blocks 2 a position in which their wings 5&#39; extend horizontally at a distance beneath the vertical orifices 3, the other wings 6&#39; extending vertically at a distance from said orifices. This arrangement ensures free passage of the rail screws and provides a good electrical insulation between the latter and the tie-bar. 
     The shaped intermediate parts l2, which are embedded in each block 2 between the inner lateral face 4 of the block and its inner orifice 3 for fixation of the rail, are twisted over their entire length. They gradually connect the corresponding respective wings (5&#39; and 5, 6&#39; and 6) of the end parts l3 and the central part l1. 
     The tie-bar of the invention, which therefore makes possible manufacture of a mixed tie in which the orifices for fixation of the rail are aligned along the longitudinal median axis of the tie, makes it possible to use existing mechanized automatic track-laying machines. Furthermore, manufacture does not require equipment of unusual design and is effected in accordance with a rational modus operandi. 
     Furthermore, the manufacture of mixed ties using the tie-bar of the invention is easy, therefore inexpensive, as said tie-bar does not have to be positioned in the blocks with precision.