The invention relates to a rail mounting device for fixing railway rails to reinforced concrete sleepers, especially for fixing without a baseplate, which device has a non-fixing first state and a rail fixing second state, and which device contains an anchoring element fixed to the reinforced concrete sleeper provided with an open or closed bracket piece, and a rail-clamping plate partially or entirely encompassed by the bracket piece of the anchoring element.
The invention also relates to a method for fixing rails laid on reinforced concrete sleepers.
The task of the rail mounting device is to provide a firm yet flexible connection between the railway rail and the sleeper supporting it. Numerous rail mounting devices have been used in the course of the history of the railways, which may be classed into three big groups according to the method of clamping.
The first group includes the earliest solutions using direct rail spikes or rail bolts, which fixed the rail directly to the sleeper. Even today this solution is occasionally used due to its simplicity and cost-effectiveness, however, its significant disadvantage is that it is not suitable for fixing rails subjected to greater loads and the fixing of the rails soon becomes loose.
The second group includes the baseplate rail fixing solutions, in the case of which the baseplate is fixed directly to the sleeper, and the rail is fixed to the baseplate using fixing devices, such as rail bolts. The advantage of the solution is that a clamping force of the appropriate magnitude may be established with the rail bolts, therefore this technology may be used on railway lines subject to greater loads. However, the great disadvantage of baseplate fixing is that it provides a connection that is overly rigid, which may lead to increase fatigue of the connections and their breakage. A further disadvantage is that the regular inspection of the fixtures and the tightening of the rail bolts are time-consuming and costly.
The flexible connections belonging to the third group successfully overcome the disadvantages of the solutions presented above, with which it is possible to fix rails without the fixtures becoming loose. Rail fastening realizing flexible fixing is disclosed, for example, by patent application number WO0202873, which is used in the case of a well known type of railway baseplate, the K-plate type. The patent specification discloses a railway rail clip that does not have to be compressed when fitted. The task is solved by that the rail clip has an elongated member that is bent so that the member's lower part forms a lower limb portion and the member's upper part forms an upper limb portion. The lower limb portion forms the base portion of the rail clip, which engages the slot in the baseplate, the upper limb portion extends further than the lower limb portion, and its free end forms a toe portion of the rail clip, which rests on the rail foot. Similar rail clip structures are disclosed by patent documents U.S. Pat. Nos. 3,067,947 and 4,313,563. The main disadvantage of these solutions is that as a result of their special shape the manufacture of the rail clip is expensive, and they require a baseplate, which increases costs even further.
A mounting device for a rail having a rail base includes an anchoring element which defines an inclined plane and is adapted for attachment to a reinforced concrete sleeper, a bracket attached to the anchoring element, and a rail clamping plate slidably positioned on the inclined plane and at least partially encompassed by the bracket. The inclined plane defines an acute angle with the reinforced concrete sleeper of at least 5 degrees, preferably 5 to 20 degrees, and more preferably 10 to 15 degrees.
In use, the mounting device is positioned next to the rail so that the relatively lower end of the inclined plane is situated adjacent to the rail base and the rail clamping plate contacts a top portion of the rail base.
It was recognised that the flexible fixing of rails to sleepers can be provided in a simpler way and at a lower cost than the solutions according to the state of the art using a rail mounting device containing a rail-clamping plate established as an unbent flat plate, and an anchoring element encompassing it positioned at an angle to the upper plane of the sleeper, where the angle between the rail-clamping plate and the upper plane of the sleeper is at least 5 degrees, preferably 5 to 20 degrees, even more preferably 10 to 15 degrees.
It was also recognised that establishing the rail-clamping plate at the above angle to the upper plane of the sleeper makes it possible to create sufficient rail-clamping force using less material than in the rail fixing solutions according to the state of the art.
It was also recognised that if the angle between the rail-clamping plate and the upper plane of the sleeper is at least 5 degrees, then it is sufficient to use a rail-clamping plate which has a maximum thickness of 6 mm. The recognition also includes that the rail-clamping plate not exceeding 6 mm in thickness may be produced from sheet steel using a sheet cutting process. Sheet steel is significantly cheaper than cast steel, and sheet cutting losses and costs are lower than those of casting and other commonly used processes, due to this the production of the rail-clamping plate according to the invention is faster and simpler compared to the solutions according to the state of the art, and its production costs are significantly lower.
The objective of the invention is to provide a rail mounting device and method that is free of the disadvantages of the solutions according to the state of the art.
Further advantageous embodiments of the invention are defined in the attached dependent claims.
Further details of the invention will be apparent from the accompanying figures and exemplary embodiments.
The rail mounting device 10 serves for directly or indirectly fixing railway rails 12 to reinforced concrete sleepers. In the present specification indirect fixing is understood to mean that a spacer, such as an electrically insulating plate, is positioned between the rail 12 and the reinforced concrete sleeper 14, in this way the rail 12 and the reinforced concrete sleeper 14 do not come into direct contact with each other. Direct fixing is understood to mean the case when there is direct contact between the rail 12 and the reinforced concrete sleeper 14. The device 10 has a first state when it is not fixing the rail 12 and a second state when it is fixing the rail 12, which first and second state are presented in
In the context of the present invention reinforced concrete sleeper 14 is understood to mean the sleepers commonly used for railway tracks, such as pre-stressed reinforced concrete sleepers, as is known by a person skilled in the art.
The device 10 contains an anchoring element 18 fixed to the reinforced concrete sleeper 14 provided with an open or closed bracket piece 16, and a rail-clamping plate 20 partially or entirely encompassed by the bracket piece 16 of the anchoring element. The anchoring element 18 has the configuration of an inclined plane and has an upper surface which is formed substantially flat and which is at an angle to an upper plane 22 of the reinforced concrete sleeper 14 such that the distance between the first edge of the upper surface of the anchoring element 18 closer to the rail 12 and the upper plane 22 of the reinforced concrete sleeper 14 is smaller than the distance between the second edge of the upper surface of the anchoring element 18 more distant from the rail 12 and the upper plane 22 of the reinforced concrete sleeper 14.
The anchoring element 18 is fixed to the reinforced concrete sleeper 14 in a releasable or non-releasable manner. A releasable connection may be provided, for example, using the bolt 15 shown in
The bracket piece 16 of the anchoring element 18 partially or completely encompasses the rail-clamping plate 20, as can be seen in
The shape of the rail-clamping plate 20 may be rectangular, as can be seen in
In the context of the present invention the distance between the first end of the rail-clamping plate 20 and the upper plane 22 is understood to mean the length of the section from the first end to the upper plane 22 that is perpendicular to the upper plane 22. Similarly, the distance between the second end of the rail-clamping plate 20 and the upper plane 22 is understood to mean the length of the section from the second end to the upper plane 22 that is perpendicular to the upper plane 22. In the present specification the upper plane 22 of the reinforced concrete sleeper 14 is viewed as being the plane of the surface of the reinforced concrete sleeper 14 under the rail 12 directly supporting the rail 12. For the sake of clarity, the upper plane 22 has been marked by a dotted line in
The rail-clamping plate 20 of the rail mounting device 10 according to the invention is established as an unbent flexible flat plate, in other words as a planar leaf-spring. In the case of a particularly preferred embodiment the angle between the rail-clamping plate 20 and the upper plane 22 of the reinforced concrete sleeper is at least 5 degrees, preferably 5 to 20 degrees, even more preferably 10 to 15 degrees. In this case it is sufficient to select the thickness of the rail-clamping plate 20 to be 6 mm. The advantage of this is that the rail-clamping plate 20 not exceeding 6 mm in thickness may be produced from sheet steel using a sheet cutting process, in other words the rail-clamping plate 20 may be produced from cut sheet steel no thicker than 6 mm. Sheet steel is significantly cheaper than cast steel, and sheet cutting losses and costs are lower than those of casting and other commonly used forming processes. As a consequence of the above, the production costs of the rail-clamping plate 20 are significantly lower than those of the solutions according to the state of the art, which, taking into consideration the large number of rail-clamping plates 20 required for railway construction, represents a significant economic advantage.
With the rail mounting device 10 in its second state, in other words when fixing the rail 12 to the reinforced concrete sleeper 14, the rail-clamping plate 20 is fixed to the anchoring element 18, preferably in a releasable way, so that its first end is laid onto the base 12a, or rail foot of the rail 12, and the shape of the rail-clamping plate 20 is a convex curve viewed from the direction of the upper plane 22 of the reinforced concrete sleeper 14, as can be seen in
In the case of the embodiment shown in
The rail mounting device 10 according to the invention also preferably contains an electrically insulating spacer element 28 arranged on the rail 12 side of the anchoring element 18 fixed to the reinforced concrete sleeper 14, the purpose of which is to prevent electrical conductance between the rail 12 and the rail mounting device 10. The spacer element 28 is preferably made from plastic, but, optionally the use of other non-electrically conducting materials is conceivable, such as composites, as is known by a person skilled in the art. An electrically insulating sheet 26 is preferably arranged between the rail 12 and the reinforced concrete sleeper 14.
With the rail mounting device 10 in its second state the rail-clamping plate 20 is fixed to the anchoring element 18. The fixing may take place in a way that provides a releasable or non-releasable connection. In the case of the embodiment shown in
In the case of the exemplary embodiment shown in
The object of the invention also relates to a method for fixing rails 12 to reinforced concrete sleepers 14, during which the rail mounting device 10 in its first state presented above in the vicinity of the railway rail 12 is provided in such a way that the first end of the rail-clamping plate 20 encompassed by the bracket piece 16 faces the railway rail 12. In the case of a preferred embodiment, in practice this takes place so that at the site of the construction of a railway line a reinforced concrete sleeper 14 provided with the rail mounting device 10 according to the invention is laid on the track bed of the railway line, then the railway rail 12 is laid next to the rail mounting device 10 in the position shown in
In the case of a particularly preferred embodiment a rail mounting device 10 is provided on each of the two sides of the railway rail 12, essentially opposite one another, with which the rail 12 is fixed to the reinforced concrete sleeper 14 from two sides. With this solution movement of the rail 12 in directions perpendicular to the railway line can be prevented.
In the second step of the method according to the invention the rail-clamping plate 20 is pushed towards the rail 12, in other words the rail mounting device 10 is taken from the first state shown in
The rail-clamping plate 20 is at an angle to the upper plane 22 according to that described above. By pushing the rail-clamping plate 20 towards the rail 12, the first end is forced up against the base 12a of the rail 12, and the first end rises vertically, while the bracket piece 16 does not permit the rail-clamping plate 20 to move upwards. As a result, the rail-clamping plate 20 bends in such a way that it takes on a convex curved shape viewed from the upper plane 22 of the reinforced concrete sleeper 14. As a result of the bending spring force is created in the rail-clamping plate 20, which forces the rail 12 onto the reinforced concrete sleeper 14. As the rail-clamping plate 20 is established at an angle to the upper plane 22 of the reinforced concrete sleeper 14 as described above, by pushing the rail-clamping plate 20 towards the rail 12 the vertical increase in height of the first end is greater than if the rail-clamping plate 20 were parallel or at an inverted angle to the upper plane 22. As a result of this as with the same amount of displacement the first end of the rail-camping plate rises more than the ends of parallel clamping plates or clamping plates at an inverted angle, the use of a shorter and thinner rail-clamping plate 20 is sufficient to create the same magnitude of clamping force. This results in a saving of material and, ultimately in a reduction of production costs. According to this recognition, the aforementioned advantages come into effect if the angle between the rail-clamping plate 20 and the upper plane 22 of the reinforced concrete sleeper 14 is at least 5 degrees, preferably 5 to 20 degrees, even more preferably 10 to 15 degrees. According to experience, in the case of angles in excess of 20 degrees it is difficult or impossible to get the rail mounting device 10 from first state to second state.
The rail-clamping plate 20 is fixed to the anchoring element 18, as a result the rail mounting device 10 is taken from the first state to the second state. In the case of a preferred embodiment the rail-clamping plate 20 is fixed to the anchoring element 18 with the flange 29 presented previously in such a way that the rail-clamping plate 20 is pushed towards the rail 12 up until the second end of the rail-clamping plate 20 gets behind the flange 29 (see
In order to release the fixing of the rail 12 the device 10 is taken from second state to first state by using the tool 40 in the way shown in
The advantage of the rail mounting device 10 according to the invention is that there is no need for a base plate nor for a specially shaped rail-clamping plate, which significantly reduce the production costs. A further advantage is that by appropriately selecting the angle between the rail-clamping plate 20 and the upper plane 22 of the reinforced concrete sleeper 14, it is sufficient to use a rail-clamping plate 20 of maximum 6 mm thickness, which may be produced from sheet steel using a sheet cutting process quickly and cost-effectively as compared to the existing solutions.
As the rail-clamping plate 20 does not rest directly upon the reinforced concrete sleeper 14 anywhere, the pitting effect that significantly reduces the fixing effect can be avoided, due to which the lifetime can be significantly extended.
In terms of implementation, the amount of material used, the price of production of the materials used, the speed and simplicity of installation and construction, the rail mounting device 10 according to the invention represents a significant advance as compared to the solutions according to the state of the art.
Other alternative solutions as compared to the embodiments presented here will be apparent to a person skilled in the art without departing from the scope of protection determined by the attached claims.
Number | Date | Country | Kind |
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P1600654 | Dec 2016 | HU | national |
This application is a continuation-in-part of PCT/HU2017/050053, filed on Dec. 6, 2017, which claims priority of Hungarian Patent Application No. P1600654, filed on Dec. 7, 2016, each of which is incorporated herein by reference.
Number | Date | Country | |
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Parent | PCT/HU2017/050053 | Dec 2017 | US |
Child | 16434370 | US |