A fastening device for rails

Abstract: A fastening device for rails comprising a rigid structure (2) having a first and a second end portion (6), (7) and an intermediate portion (8) connected between the end portions, and whereon are mounted a hinging element (3), a contact element (4), and adjustment means (5). A first direction of development of the structure (2) extends from the first end portion (6) to the second end portion (7). The hinging element (3) is mounted on said structure (2) in correspondence with the intermediate portion (8), develops substantially transversely to the first direction of development, and can be pivotally associated to a hitching element (15) in proximity to a rail (25). The contact element (4) is fastened to the structure (2) in correspondence with the first end portion (6), and has an operative face (23) able to be associated in abutting contact to the rail (25). The adjustment means (5) are mounted on the structure (2) in correspondence with the first end portion (6), to adjust the pressure of the contact element (4) against the rail (25).

Description: The present invention relates to a fastening device for rails of the type comprising the characteristics expressed in the preamble to Claim 1. The rails that compose tracks are supported by sleepers, made of wood or cement, whereto they are fastened by means of fastening devices. Currently, many types of fastening devices are known, such as those with track bolts or springs. One of the most common fastening devices is constituted by a steel bar folded in the form of an elastic clip. An example of this type of device, known as "Pandrol", is disclosed in US Patent 5,191,838 (in particular in Figures 25 and 26). The widespread use of the "Pandrol" device is due to its lesser cost relative to traditional devices, such as those with track bolts. The "Pandrol" device comprises a base element fastened in the sleeper supporting the rail, and having in correspondence with the surface of the sleeper itself a tubular seat in which a first end of the clip is inserted. The "Pandrol" device, however, give rise to problems when the adjustment of a long welded rails needs to be performed. To carry out its adjustment, the rail must be at least partially free to slide longitudinally, but at the same time it must be held laterally, since a certain number of trains must be made to travel over the track in order to perform a correct adjustment operation. Contrary to track bolt devices where this is easily achieved by slightly loosening their grip, the "Pandrol" device does not allow to adjust its gripping action on the rail. Fastening devices allowing for adjustment of the grip are further known from documents US-A-2 432 816 and DE-C-664 274. For this reason, when adjusting a long welded rail on rails fastened with the "Pandrol" device, all fastening devices must be removed to allow longitudinal expansion. Consequently, however, trains can no longer be allowed to travel over the track, and the adjustment needs to be performed without train passage. This represents a considerable drawback, as it makes it difficult to perform a sufficiently accurate adjustment of the rail. If the adjustment is not carried out precisely, the rail, once placed back in service, has in its interior a non uniform tension, with compressed areas alternating with areas under traction. In the long run this situation can lead to the warping or breakage of the rail, especially in correspondence with weld points. In this situation the technical task constituting the basis for the present invention is to obtain a fastening device for rails that overcomes the aforementioned drawbacks. In particular, a technical task of the present invention is to obtain a fastening device for rails that can allow the longitudinal sliding of the rail and, at the same time, guarantees lateral grip on the rail itself. A further technical task of the present invention is to obtain a fastening device for rails that allows the temporary substitution of the clip used in "Pandrol" devices. The specified technical task and the indicated aims are substantially achieved by a fastening device for rails, as described in the accompanying claims. Further features and the advantages of the present invention shall become more readily apparent from the detailed description of a preferred, but not exclusive, embodiment of a fastening device for rails, illustrated in the accompanying drawings, in which: Figure 1 shows a lateral view of a fastening device for rails according to the present invention applied to the flange of a rail; and Figure 2 shows a plan view of the fastening device of Figure 1. With reference to the aforementioned figures, the reference number 1 globally indicates a fastening device for rails according to the present invention. In the illustrated embodiment, the fastening device 1 comprises a structure 2 in which are mounted a hinging element 3, a contact element 4 and adjustment means 5. The structure 2 has a first and a second end portions 6, 7 and an intermediate portion 8 connected between the two end portions 6, 7. The direction that goes from the first to the second end portion 6, 7 can be defined as a first direction of development of the structure 2. In the illustrated embodiment, the structure 2 comprises a main plate 9 presenting an upper surface 10 and a lower surface 11 and two shoulders 12, substantially specular relative to each other and positioned facing each other and mutually distanced. Each shoulder 12 is laterally fastened to the plate 9 and develops mainly in a plane parallel to the first direction of development and perpendicular to the lower surface 11 of the plate 9. In correspondence with the intermediate portion 8, the structure 2 has at least two through holes 13, mutually coaxial according to a direction of development that is substantially perpendicular to the first direction of development of the structure 2. In the embodiment illustrated in the accompanying drawing, the through holes are obtained through the two shoulders 12 and develop according to a direction parallel to the lower face of the plate 9. In accordance with the illustrated embodiment, the structure 2 further presents, in correspondence with the second end portion 7, a threaded through hole 14 developing perpendicularly to the plate 9. The hinging element 3 can be pivotally engaged to an anchor member 15 mounted laterally of the rail in proximity thereof, and is mounted on the structure 2 in correspondence with the intermediate portion 8. The hinging element 3 develops substantially transversely to the direction of development of the structure 2 to allow, once associated to the anchor member 15, the oscillation of the structure 2 in a vertical plane passing through the first direction of development. In particular, the hinging element 3 is constituted by a first pivot pin 16 removably inserted in the two through holes 13 obtained in the shoulders 12. The first pivot pin 16 has, in correspondence with its own first end 17, an obstruction head 18 whose diameter is greater than that of the through holes 13. The second end 19 of the first pivot pin 16 is further provided with removable obstruction means 20 to prevent the passage of the second end 19 through the holes 13. Advantageously said removable obstruction means 20 are constituted by a removable pin 21, passing through the second end 19 of the first pivot pin 16. Further provided are both embodiments in which the first pivot pin 16, once it has been inserted through the holes 13, can rotate about its own axis relative to the structure 2, and other embodiments in which it is instead integral with the structure 2. As stated, said first pivot pin 16 can be pivotally inserted in a housing 22 which is obtained inside the anchor member 15 mounted in proximity to the rail, and which is constituted by a substantially rectilinear through hole. The contact element 4 is pivotally mounted on the structure 2 in correspondence with the first end portion 6 of the structure 2, and presents an operative face 23 able to be pressed against the surface of the flange 24 of the rail 25. In particular the operative face 23 can be associated in abutting contact against the upper surface 10 of the flange 24 of the rail 25, either directly or through a bearing element 26 which may or may not already be associated to the rail 25. The operative face 23 of the contact element 4 can further present a knurled surface, in order to exert a greater friction against the surface of the rail 5. Embodiments are provided in which the contact element 4 is rigidly fastened to the structure 2 (as in the accompanying figures), and other alternative embodiments in which the contact element 4 is instead pivotally fastened to the structure 2 itself. The adjustment means 5 are mounted on the structure 2 in correspondence with the first end portion 6 and serve to adjust the pressure of the contact element 4 against the rail 25. In the preferred embodiment (one of the simplest ones), the adjusting means 5 comprise a second threaded pivot pin 27 able to be screwed through the structure 2 according to a direction of development that is perpendicular both to the first direction of development, and to the main direction of development of the first pivot pin 16. In the illustrated embodiment said second pivot pin 27 is screwed in threaded through hole 14 obtained through the first end portion 6 of the structure 2. Depending on the use whereto the fastening device 1 is destined, it may or may not also comprise the anchor member 15 able to be fastened to the sleeper of a rail 25. If the fastening means 1 of the present invention is constructed to constitute a wholly autonomous fastening device 1, usable instead of traditional ones, it also comprises the anchor member 15, which has an arch seat portion or a tubular seat portion. Vice versa, if the fastening device 1 is constructed to be used to replace temporarily the elastic clips of "Pandrol" fastening devices, it lacks the hitching anchor member 15. From the functional point of view, the fastening device 1 is used in the following way. It the fastening device is to be used as an autonomous fastening device 1, the first step is to fasten the anchor member 15 to the sleeper of the rail 25. If, on the contrary, the clip of a "Pandrol" device is just to be replaced temporarily, the anchor member 15 of said device is used. To mount the fastening element 1, the first step is to extract the first pivot pin 16 from the through holes 13, after removing the removable obstruction means 20. The structure 2 is then positioned on the upper portion of the hitching anchor member 15 in such a way as to align the through holes 13 with the housing obtained on the anchor member itself, and in such a way that the contact element 4 is in correspondence with the flange 24 of the rail 25. The upper portion of the anchor member is provided with an arch seat portion or a tubular seat portion. The first pivot pin 16 is then inserted through the holes 13 and the housing, and the removable obstruction means 20 are positioned. At this point the structure 2 is in the condition to be able to rotate about the first pivot pin 16, relative to the anchor member 15 in a substantially vertical plane. Acting now on the second pivot pin 27, the pressure exerted by the contact element 4 on the flange 24 of the rail 25 can be adjusted. By screwing the second pivot pin 27 in the structure 2 in such a way as to increase its projection from the lower face of the plate 9, thereby increasing the distance between the first end portion 6 and the sleeper supporting the rail 25, a rotation is caused of the structure 2 about the first pivot pin 16 and hence a crushing of the contact element 4 against the flange 24 of the rail 25. The present invention achieves important advantages. In the first place, the fastening device for rails of the present invention allows, by adjusting the pressure of the contact element against the flange of the rail through the adjustment means, the longitudinal sliding of the rail, whilst guaranteeing the lateral immobility of the rail itself. The fastening device for rails of the present invention can therefore be used to replace temporarily the clips of "Pandrol" devices during the adjustment operations of long welded rails. After removing all operative clips on the rail segment of interest, one can position, instead of a part thereof, fastening devices according to the present invention, in order to conduct the adjustment operation letting trains travel over the rail. This allows to achieve a better adjustment of the long welded rails held by the "Pandrol" fastening devices, and hence assuring its longer working life. On the other hand, the fastening device of the present invention can be used in a wholly autonomous fashion instead of the fastening devices in use today, also because it is relatively easy to produce and its cost is not very high. The invention thus conceived can be subject to numerous modifications and variations within the scope of the appended claims. All components can be replaced by technically equivalent elements and in practice all materials employed, as well as the shapes and dimensions of the various components, may be any, as dictated by requirements.

Claims: A rail fastening device for substitution to a steel bar folded in the form of an elastic rail clip and cooperation with an anchor member mounted laterally of the rail in proximity thereof and having an arch seat portion or a tubular seat portion, the longitudinal axis of said seat portion extending parallel to the rail, comprising a rigid structure (2) having a first and a second end portion (6), (7) and an intermediate portion (8) connected between said end portions, a first direction of development of said structure (2) extending from said first end portion (6) to said second end portion (7); a hinging element (3) mounted on said structure (2) in correspondence with said intermediate portion (8), developing substantially transversely to said first direction of development and able to be pivotally associated to said anchor member (15) mounted in proximity to a rail (25); a contact element (4) fastened to said structure (2) in correspondence with said first end portion (6), and presenting an operative face (23) able to be associated in abutting contact to said rail (25) and adjustment means (5) mounted on said structure (2) in correspondence with said first end portion (6), to adjust the pressure of said contact element (4) against said rail (25). A device as claimed in claim 1 characterised in that , in correspondence with said intermediate portion (8), said structure (2) presents at least two through holes, said through holes (13) developing in mutually coaxial fashion and substantially perpendicularly to said first direction of development, and in that said hinging element (3) comprises a first pivot pin (16) removably inserted in said through holes (13) and having a first end (17) and a second end (19), at least one of said ends (17), (19) being provided with removable obstruction means (20) to prevent the passage of said end through said through holes (13). A device as claimed in claim 2 characterised in that said structure (2) further comprises two shoulders (12) mutually distanced and developing, at least in correspondence with said intermediate portion (8), substantially parallel to said first direction of development, said through holes (13) being obtained through said shoulders (12). A device as claimed in claims 1, 2, or 3 characterised in that said adjustment means (5) comprise at least a second, threaded, pivot pin (27) screwed in a threaded through hole (14) obtained in said first end portion (6) according to a direction that is substantially perpendicular to said first direction of development of the structure (2) and a said first pivot pin (16). A device as claimed in any of the previous claims from 1 to 4 characterised in that said operative face (23) of said contact element (4) has a knurled surface. A fastening device for rails comprising an anchor member (15) having an upper portion provided with an arch seat portion or a tubular seat portion, the longitudinal axis of said seat portion extending parallel to the rail, and able to be fastened to a sleeper supporting a rail (25) laterally of the rail and in proximity to the rail (25) itself, characterised in that it comprises: a rigid structure (2) having a first and a second end portion (6), (7) and an intermediate portion (8) connected between said end portions, a first direction of development of said structure (2) extending from said first end portion (6) to said second end portion (7); a hinging element (3) mounted on said structure (2) in correspondence with said intermediate portion (8), developing substantially transversely to said first direction of development and pivotally and removably associated to said seat portion of the anchor member (15); a contact element (4) fastened to said structure (2) in correspondence with said first end portion (6), and presenting an operative face (23) able to be associated in contact to said rail (25) and adjustment means (5) mounted on said structure (2) in correspondence with said first end portion (6), to adjust the pressure of said contact element (4) against said rail (25). A device as claimed in claim 6 characterised in that , in correspondence with said intermediate portion (8), said structure (2) presents at least two through holes (13), said through holes (13) developing in mutually coaxial fashion and substantially perpendicularly to said first direction of development, and in that said hinging element (3) comprises a first pivot pin (16) removably inserted in said through holes (13) and having a first end (17) and a second end (19), at least one of said ends (17), (19) being provided with removable obstruction means (20) to prevent the passage of said end through said through holes (13). A device as claimed in claim 7 characterised in that said structure (2) further comprises two shoulders (12) mutually distanced and developing, at least in correspondence with said intermediate portion (8), substantially parallel to said first direction of development, said through holes (13) being obtained through said shoulders (12). A device as claimed in claim 6, 7, or 8 characterised in that said adjustment means (5) comprise at least a second, threaded, pivot pin (27) screwed in a threaded through hole (14) obtained in said first end portion (6) according to a direction that is substantially perpendicular to said first direction of development of the structure (2) and to said first pivot pin (16). A device as claimed in any of the previous claims from 6 to 9 characterised in that said operative face (23) of said contact element (4) has a knurled surface.

Inventors: CASONI MARIO, CASONI, MARIO
Applicants: THERMIT ITALIANA S P A, THERMIT ITALIANA S.P.A.
Application year: 2001
Main classification: E01B9
IPC codes: E01B9