Abstract:
A device for securing railway rails ( 12 ) on a solid track includes a standard concrete sleeper ( 16 ) used for the ballast track. Each of the rails ( 12 ) is guided between two angle guide plates ( 30 ) and urged by a tensible clamp ( 34 ) against the concrete sleeper ( 16 ). A resilient intermediate plate ( 52 ) is disposed between the rail flange ( 14 ) and the standard concrete sleeper ( 16 ) and, at their ends remote from the rail ( 12 ), the angle guide plates ( 30 ) include a first ( 24 ) and a second surface ( 28 ), the first surface ( 24 ) being inclined obliquely to the vertical in the mounted position and abutting a correspondingly shaped sloping surface ( 44 ) of the standard concrete sleeper ( 16 ). The second surface ( 28 ) is aligned substantially vertically and rises over the top of the standard concrete sleeper ( 16 ).

Description:
BACKGROUND OF THE INVENTION 
     The invention relates to a device for securing railroad rails on a ballast track or a solid track in a highly resilient manner. 
     Two separate systems exist as devices for securing railroad rails. On the one hand, the attachments for sleepers or supports on a ballast foundation, and on the other hand the superstructure for a solid track, i.e. securing rails for a superstructure without ballast. The superstructure on a solid track is increasingly gaining in important as axle loads and journey speeds rise, whereby as regards the superstructure on a solid track it is essential to achieve a requisite track compression. 
     Yet ballast tracks which are fitted with the standard superstructure also frequently exhibit rail compression values that are too low for use in high-speed transport on new routes. The resilience of ballast permits track compression which results in a rail head depression of about 0.6 mm. This track compression is clearly below today&#39;s desired rail head depression of 1.5 mm. 
     The resilient intermediate layers used in the prior art, even the use of so-called “soft” intermediate layers with static spring rates of c=50-70 kN/mm, improve track compression only to a rail head depression of about 1.0 mm (in conjunction with the ballast track). 
     A device for securing railroad rails on a solid track is described in EP 0 295 685. To achieve good track compression, a resilient intermediate plate is disposed between the rail flange and the concrete railroad sleeper; this plate ensures sufficient compression. Above the resilient intermediate plate there is located a pressure distribution plate which is dimensioned such that it and the resilient intermediate plate laterally project above the flange of the rail. Angle guide plates which form a support for tension clamps to secure the rails and which press the same against the rail flange by means of a sleeper screw are arranged on both sides of the rail flange. The guide angle plates form a rail channel, absorb the horizontal forces and introduce them into the concrete sleeper via angled surfaces in contact with the sleeper. The angle guide plates have chamber-like recesses into which the pressure distribution plate (protruding on both sides across the width of the rail flange) and resilient intermediate plate can project. The concrete sleepers described in EP 0 295 685 are specifically adapted to use on a solid track, and in the securing region they have a very low recess that completely receives the angle guide plates. 
     SUMMARY OF THE INVENTION 
     The present invention is based on the object of using standard elements and standard concrete sleepers to design a rail attachment, by means of which high rail compression values can be achieved. 
     The device for securing railroad rails on a ballast track or a solid track includes a standard concrete sleeper used on the ballast track; two angle guide plates for a securing point of the railroad track on the standard concrete sleeper, the plates being arranged on both sides of the rail flange for lateral guidance thereof; one securing screw per angle guide plate, the screw passing though the plate and pressing a tensible clamp against the rail flange and pressing the rail flange and the angle guide plate against the standard concrete sleeper; at least one resilient intermediate plate arranged between the rail flange and the standard concrete sleeper; wherein the angle guide plates have a first and a second surface at their end facing away from the rail, the first surface being inclined at an angle to the perpendicular in the mounted position and abutting a correspondingly shaped angled surface of the standard concrete sleeper, and the second surface being essentially vertically aligned and rising over the upper side of the standard concrete sleeper. 
     By using angle guide plates which can be inserted almost completely into the concrete sleeper&#39;s depression, not only a resilient intermediate plate but also a pressure distribution plate and a plastic intermediate layer can be arranged between rail and concrete sleeper despite the use of standard concrete sleepers, with it being possible nevertheless to use a standard tension clamp. 
     By providing the angle guide plates with receiving spaces which are each open toward the rail flange in the mounted position, the resilient intermediate plate can protrude on both sides across the width of the rail flange and project into the receiving spaces of the angle guide plates arranged on both sides of the rail. 
     Both the resilient intermediate plate and the pressure distribution plate advantageously have a larger extension in the standard concrete sleeper&#39;s longitudinal direction than the rail flange and therefore protrude across the width of the rail flange on both sides thereof and project into the receiving spaces of the angle guide plates. As a result, the pressure distribution plate distributes over a large surface area the forces transferred by the rail flange to this plate and introduces them evenly into the standard concrete sleeper via the resilient intermediate plate. This embodiment also enjoys the advantage that when the pre-assembled securing devices are delivered on the sleeper, the resilient intermediate plate and the pressure distribution plate are undetachably arranged between the two angle guide plates which form a securing point. 
     The securing screws are preferably anchored in interchangeable plastic screw dowels located in the standard concrete sleepers. This makes it possible on the one hand to perform quickly any necessary maintenance work that requires the screw dowel to be exchanged, and on the other hand to allow the use of various standard tension clamps and to adapt quickly and reliably the concrete sleeper to the particular sleeper screws used for this purpose. 
     According to a preferred embodiment, the shape of the angle guide plates is adapted to the use of a standard tension clamp for securing the rail flange, as described e.g. in DE 39 18 091. It is therefore possible to fall back on a maximum number of standard elements and perhaps to perform conversion of existing track installations without changing the tension clamps. 
     Different angle guide plates which in their mounted position have a varying horizontal extension in the standard concrete sleeper&#39;s longitudinal direction can be preferably used. As a result, the position of the rail channel formed between two angle guide plates is variably designed and the gauge can be set or corrected within predetermined limits. 
     The rotational axes of the securing screws are preferably inclined at an angle to the perpendicular. This makes it much easier to place the rail into the rail channel formed between the angle guide plates. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     The FIGURE shows a cross-section through a symmetrical device for securing a rail according to the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The drawing shows a cross section through a symmetrical device  10  for securing a rail  12 . The rail  12  together with a second rail  12  forms a railroad track. The device  10  serves to tension the flange  14  of the rail against a support  16  which in its longitudinal extension runs transverse to the longitudinal direction of the rail  12 . 
     The support  16  preferably consists of concrete and represents for example a standard concrete sleeper, as used by the German railroad company Deutsche Bahn AG with the designation DB Standard Concrete Sleeper B70 W60. This standard concrete sleeper has so far been used in the ballast superstructure, but not on a solid track. 
     In the region in which one rail  12  of the rail pair is respectively received, the standard concrete sleeper  16 , henceforth abbreviated to concrete sleeper, has a depression  18  that runs perpendicular to the longitudinal sleeper axis and is composed of a planar support surface  20  and groove-like depressions  22 . The groove-like depressions pass in the longitudinal direction of the rail  12  and extend across the entire sleeper width or part thereof. The groove-like depression  22  has an angled surface  24  on the side that faces away from the rail  12 . 
     A plastic dowel ( 60 , see FIGURE), the longitudinal axis  26  of which is inclined with respect to the perpendicular in the mounted position, is also located in the concrete sleeper  16  for each securing device  10  in the region of the planar receiving surface  20 . The angle to the perpendicular is about 5° in the illustrated exemplary embodiment. 
     An angle guide plate  30 , which with the angle guide plate on the other side of the rail forms an exact rail channel, is respectively at the side of the rail flange  14  and is both supported on the planar receiving surface  20  and inserted into the groove-like depression  22 . The angle guide plates also serve to remove horizontal forces and to receive a rail attachment that can be pre-assembled. 
     The angle guide plate  30  has a guide surface  32  for the rail flange  14 ; in its mounting position, this guide surface is preferably spaced a minimal distance away from the facing side of the rail flange  14 . This makes it possible to obtain a rail head depression, as is required in the form of a predetermined rail compression value. The angle guide plate  30 &#39;s side that is at the to in the mounting position and which faces toward a tension clamp  34  is adapted to the shape and function of the particular tension clamp  34  used. In the present example, the angle guide plate has a guide channel  36  for receiving a rear support curve of the tension clamp  34 , a bore  38  for a sleeper screw  40  and a guide channel  42  for the inner shank of the tension clamp  34 . On the side facing the concrete sleeper  16  in the mounted position, the angle guide plate  30  is shaped to correspond to the concrete sleeper. The angled surface  44  of the angle guide plate  30  is shaped such that contact is made as completely as possible with the angled surface  24  of the concrete sleeper and hence any horizontal forces that arise can be removed as evenly as possible into the concrete sleeper. Support elements  46  are formed in the region of the concrete sleeper&#39;s planar receiving surface  20 ; the vertical forces which arise during tightening of the tension clamp  34  are transferred to the concrete sleeper  16  by these elements. 
     The angle guide plate  30  has, toward the rail  12 , a U-shaped profile parallel to the longitudinal rail axis when viewed in vertical section and whose shanks are formed by the support elements  46 . As a result, a chamber-like receiving space  48  is obtained between the planar receiving surface  20  of the concrete sleeper and the transverse element of the U-shaped profile on the one hand and between the two support elements  46  on the other. This receiving space serves to accommodate the following elements arranged between the underside  50  of the rail  12  and the planar receiving surface  20 . 
     An essentially vertical, outer terminating surface  28  that projects above the upper side  29  of the concrete sleeper  16  beyond the depression  18  adjoins the angled surface  44  at that end of the angle guide plate  30  which points away from the rail  12 . As shown in the drawing, surface  28  has a linear aspect forming an angle with a linear aspect of surface  44 . 
     To achieve a required rail head depression both in the case of a solid track and on a ballast track, the resilience of which permits a rail head depression of only about 0.6 mm, a resilient intermediate plate  52  is placed on the concrete sleeper&#39;s planar receiving surface  20  and hence is placed between the rail&#39;s underside  50  and the concrete sleeper. The resilient intermediate plate  52  is composed of an elastomer and has a static spring rate that is adjustable in accordance with requirements. 
     A pressure distribution plate  54  which is planar and can be easily produced in rolled steel is placed over the resilient intermediate plate  52 . The pressure distribution plate  54  and the resilient intermediate plate  52  have an extension in the concrete sleeper&#39;s longitudinal direction that is larger than the width of the rail  12  at the underside  50  thereof. As a result, the pressure distribution plate  54  and the resilient intermediate plate  52  each laterally project over the flange  14  of the rail. 
     The resilient intermediate plate  52  and pressure distribution plate  54  protrude into the chamber-like receiving spaces  48  of the angle guide plates  30  arranged on both sides of the rail and are each provided with a slot oriented in the longitudinal sleeper axis. The resilient intermediate plate  52  and pressure distribution plate  54  preferably make form-locked contact with the receiving space  48 &#39;s longitudinal walls that run in the longitudinal direction of the concrete sleeper. The clearance of the receiving space  48  is dimensioned to be larger than the total thickness of resilient intermediate plate  52  and pressure distribution plate  54 , thus essentially preventing the end sections of the plates  52  and  54  from pressing together when the angle guide plates  30  are pressed down onto the concrete sleeper  16 . The force applied by the tension clamp  34  is essentially transferred directly to the concrete sleeper  16  via the angle guide plate, which causes the rail&#39;s angle of inclination to keep to the required accuracy even if the two tension clamps of a securing point are perhaps unevenly pre-tensioned. 
     The highly resilient intermediate plate  52  allows the rail to exhibit the necessary vertical depression and can be selected such that the rail&#39;s desired compression is achieved. The steel pressure distribution plate  54  evenly distributes over a large surface area those vertical forces which act upon the rail. The pressure distribution plate  54  therefore acts as an artificial enlargement of the rail flange. 
     A plastic intermediate layer  56  is also disposed between pressure distribution plate  54  and the underside  50  of the rail  12 . 
     Various tension clamps  34  and sleeper screws  40  known in the prior art can be used in the device  10  for securing railroad rails on a ballast track or on a solid track. In the present example, the rail is tensioned with the resilient tension clamp SKL  14  common in the ballast superstructure. The two free spring arms  58  of the tension clamp  34  are supported on the rail flange. A center loop that prevents tilting also projects over the rail flange. The rail is vertically tensioned by tightening the sleeper screw  40  anchored in interchangeable plastic screw dowels. After tightening the tension screw  40 , the two free spring arms  58  of the tension clamp  34  exert a force of about 2×10 kN on the rail in the case of a resilient spring path of approx. 13 mm. 
     The rail attachment can be pre-mounted on the sleeper and then delivered. For this purpose, the tension clamps are in a pre-assembly position which is shown in the aforementioned DE 39 18 091 for the SKL  14  tension clamp depicted in the drawing. The sleeper screw  40  is screwed into the plastic dowels only by a few turns and enables the tension clamp  34  to be pre-mounted by being shifted to the left with respect to the mounting position shown in the drawing, i.e. it is moved away from the site where the rail is subsequently fitted only. To do so, the tension clamp  34  is no longer located in the guide channel  36  of the angle guide plate  30 . 
     The tension clamp  34  and the angle guide plate  30  on the one hand, as well as the resilient intermediate plate  52  and the pressure distribution plate  54  on the concrete sleeper  16  on the other are fixed into the mounting position via the sleeper screw  40 . When mounting the rails, only the plastic intermediate layer  56  has to be interposed between the underside  50  of the rail  12  and the pressure distribution plate  54 , the tension clamp  34  shifted in the rail flange&#39;s direction so that the free spring arms  58  are supported on the rail flange  14 , and the sleeper screw  40  finally tightened. 
     In the mounted state, the angle guide plates  30  arranged on both sides of the rail  12  form a rail channel, and remove the horizontal forces into the concrete sleeper  16  via the contact of the angled surfaces  44  and  24 . Part of the horizontal forces that arise are also introduced into the concrete sleeper by the axes  26 —inclined at an angle to the perpendicular—of the sleeper screws  40 . 
     The securing system  10  is designed to make height regulation possible up to 5 mm without tamping work. If desired, gauge regulation of up to ±10 mm can also be performed by using specially shaped angle guide plates  30  whose interaction on both sides of the rail  12  systematically shifts the rail channel in the longitudinal direction of the concrete sleeper  16 . 
     Since the resilient intermediate plate  52  permits the required high rail compression in the form of a predetermined rail head depression of about 1.5 mm, the described rail attachment is also suitable for the use of high-speed trains on new routes. It is therefore possible to convert an existing ballast track to the securing system according to the invention by continuing to use standard concrete sleepers, which also makes this system suitable for use in high speed transport. 
     It is also possible to fill up the cavities of the ballast track with concrete, asphalt of the like and therefore to continue using this securing system on a solid track without changing the system because the manner of securing rails according to the invention achieves the desired high compression values as regards overall resilience even without the ballast foundation&#39;s contribution.