RAIL FIXING ELEMENT, IN PARTICULAR FOR TRAMWAY, SUBWAY AND RAILWAY TACKS

Abstract: An element for fixing rails (14) into box-like seats (12) having a compartment (32) located below said seat, said rails comprising holes (20) for the passage of bolts (24) which engage in said fixing element, the bearing surface (16) of said seat comprising a plurality of longitudinally slotted holes (18), characterised in that said fixing element consists of an elongate plate (2) of dimensions such as to enable it to be inserted through said slotted holes (18) in order to be positioned within said compartment (32), and of length greater than the width of said slotted holes, said plate (2) comprising a hole (4) for the removable engagement, by rotation, of one end of a bush (6) internally threaded for engagement by said bolts, said threaded bush being provided at its other end with an endpiece (8) for retaining an elastic means (10) coaxial with the bush, means (28) being provided to prevent the plate rotating once it is contained within said compartment (32) and lies in a position not aligned with said slotted hole, so that on screwing down the bolt (24) said bearing surface (16) becomes gripped by the rail and plate.

Description: RAIL FIXING ELEMENT, IN PARTICULAR FOR TRAMWAY, SUBWAY AND RAILWAY TACKS This invention relates to a rail fixing element, in particular for tramway, subway and railway tacks. Rails for tramway, subway and railway tacks are known to be housed in corresponding seats of substantially trapezoidal cross-section provided in the road surface or in concrete slabs, in such a manner as to bring the rolling track substantially parallel with the roadway. Said rails are currently fixed in said seat by cylindrical rubber bushes fitted between the rail flange and the oblique surfaces of the seat. This fixing system presents however the problem that with the passage of time the rubber tends to polymerize, so hardening and hence becoming difficult to extract when the rail requires maintenance. In addition, this hardening results in a loss of the damping effect for which the rubber was designed. An object of the invention is to eliminate these drawbacks by providing a fixing element which enables the rails to be fixed in their seat in a simple and comfortable manner. This and further objects are attained according to the invention by a rail fixing element, in particular for tramway, subway and railway tacks as claimed in claim 1. The invention is described in detail hereinafter with reference to the accompanying drawings, on which: Figure 1 is an exploded front view of the fixing member of the invention, Figure 2 is a longitudinal section therethrough during the initial stage of its assembly, Figure 3 shows it in the same view as Figure 2 during an intermediate stage of its assembly, Figure 4 shows in the final stage of its assembly. As can be seen from the figures the fixing element of the invention comprises substantially a rectangular plate 2 containing a hole 4 of square section. The hole 4 is engaged by the end of an internally threaded bush 6, the other end of which is welded to a circular disc 8 for retaining a coil spring 10. The use of the fixing element will now be described with reference to a support structure in the form of an H-shaped monolithic box structure 12 on which special rail pieces 14 without a shank and support leg are secured. The box structure and the rail pieces are described in Utility Model Application VE95U000004 filed on 26.01.1995, to which reference can be made. This box structure is embedded in the road surface such that the horizontal upper surfaces of the vertical portions of the H structure are substantially at the same level as the road surface. This fixing element can also be used to fix rails of traditional type to sleepers. In the horizontal portion 16 of the H structure 12 there are provided a plurality 18 of holes having the same shape as the plate 2 but with slightly greater dimensions. Said holes 18 are spaced apart by a distance corresponding to that of corresponding holes 20 provided in the groove 22 of the rail pieces 14. The fixing elements are applied to the rail piece by means of threaded bolts 24 which pass through the holes 20 and partially engage in the threaded bolts 24 which pass through the holes 20 and partially engage in the threaded bushes 6, the plates 2 being arranged substantially aligned with the longitudinal axis of the holes 18 in the horizontal portion 16 (see Figure 2). The rail pieces are then rested on the horizontal portion 16, on which a pad of damping material 25 has previously been placed, such that each fixing element becomes inserted through the hole 18 and the bush 6 lies within the compartment 32 below said horizontal portion 16. When the rail piece 14 rests on the box structure a pin 28 is inserted from above through a hole 26 provided in the groove 22 of the rail piece, to rest with its lower end 30 on the plate 2 (see Figure 3). The bolt 24 is then rotated in its unscrewing direction, this rotation initially causing the plate 2 to descend as it is housed in the rectangular hole 18. When the plate 2 is no longer housed within the hole 18, the friction between the internal thread of the bush 6 and the thread of the bolt 24 means that the subsequent rotation of the bolt 24 causes the plate 2 to rotate, thus no longer supporting the pin and hence enabling it to fall, until its head 34 rests on the rail piece to hence interfere with the sides of the plate. The effect of this interference it to prevent rotation of the plate, consequently further screwing of the bolt causes the bush 6 and plate 2 to rise until the plate 2 rests against the lower edge of the horizontal portion 16, to clamp the rail to it. During this stage it is also possibly to adjust the degree of preloading of the springs 10 for all the bolts, as the end-of-travel position is given by the resting of the upper end of the threaded bush against the lower surface of the portion 16. When a rail requires replacement, the bolts 24 are slackened so that the threaded bushes 6 disengage from them to rest on the base of the compartment 32, from which they are recovered after lifting the rail piece. From the aforegoing it is apparent that the fixing element of the invention enables the rails to be fixed in a simple and comfortable manner, as it can be secured to the rail before this is inserted into the seat. In a different embodiment, not shown on the drawings, instead of using the pin 28 a rib is provided on the lower surface in correspondence with at least one longitudinal edge of the rectangular hole 18, to interfere with the plate and prevent its rotation.

Claims: C L A I M S 1. An element for fixing rails (14) into box-like seats (12) having a compartment (32) located below said seat, said rails comprising holes (20) for the passage of bolts (24) which engage in said fixing element, the bearing surface (16) of said seat comprising a plurality of longitudinally slotted holes (18), characterised in that said fixing element consists of an elongate plate (2) of dimensions such as to enable it to be inserted through said slotted holes (18) in order to be positioned within said compartment 32, and of length greater than the width of said slotted holes, said plate (2) comprising a hole (4) for the removable engagement, by rotation, of one end of a bush (6) internally threaded for engagement by said bolts, said threaded bush being provided at its other end with an endpiece (8) for retaining an elastic means (10) coaxial with the bush, means (28) being provided to prevent the plate rotating once it is contained within said compartment (32) and lies in a position not aligned with said slotted hole, so that on screwing down the bolt (24) said bearing surface (16) becomes gripped by the rail and plate. 2. A fixing element as claimed in claim 1 , characterised in that said plate comprises a hole (4) of square section. 3. A fixing element as claimed in claim 2, characterised in that the elastic means consists of a spring of coil type (10). 4. A fixing element as claimed in claim 1 , characterised in that said means (28) consist of a rib provided on the lower surface of the horizontal portion (16) in correspondence with one of the longitudinal edges of the slotted hole (18). 5. A fixing element as claimed in claim 1 , characterised in that said rotation-preventing means consist of a pin (28) insertable through a hole (26) provided in the groove (22), to be supported by the plate when this lies longitudinally aligned with the slotted holes (18), but to interfere with the sides of the plate following plate rotation.

Inventors: FAVARON CLAUDIO, FAVARON, CLAUDIO
Applicants: FAVARON CLAUDIO, MECNO RAIL S R L, FAVARON, CLAUDIO, MECNO-RAIL S.R.L.
Application year: 1999
Main classification: E01B21
IPC codes: E01B5, E01B21