EP0694649A2

EP0694649A2 - A resilient connecting device

Info

Publication number: EP0694649A2
Application number: EP95111785A
Authority: EP
Inventors: Giovanni Cinel
Original assignee: NUOVE OFFICINE MECCANICHE CINEL SpA
Current assignee: NUOVE OFFICINE MECCANICHE CINEL SpA
Priority date: 1994-07-27
Filing date: 1995-07-26
Publication date: 1996-01-31
Also published as: ITVI940119A0; ITVI940119A1; EP0694649A3; IT1267841B1

Abstract

The invention provides a resilient connecting device for fixing a rail (7) to a support medium; the device comprising a curved resilient element (1), with two ends (2,2'), connected by one or more curved (6) or straight (5) connecting portions; characterised in that the portions (3,3') next to said ends (2,2') cooperate to define a seat in which a fixing means for fixing to an underlying support medium (9) may be accommodated, one of the connecting portions (5,6) being arranged in use to rest on the base (8) of the rail (7), and at least one of the connecting portions (5,6) being arranged in use to rest directly, or through an interposed medium, on the support medium.

Description

This invention concerns a resilient connecting device for fixing rails to support media, in accordance with the pre-characterising portion of claim 1.
Rails are typically fixed to underlying sleepers by means of the interposition of a suitable connecting device between the sleepers and the base of the rails. The connecting device must allow the rail a degree of elasticity in relation to the underlying sleeper while the train passes over the rail. Some existing connecting devices have variously curved shapes with one of the ends placed against the sleeper fixing piece and the other interacting directly with the base of the rail. The main aim of the present invention is to provide a connecting device which is free from the drawbacks found in existing connecting devices and which will improve certain aspects of same, in particular making it possible to achieve the desired pressure rating on the base of the rail, at the same time maintaining a high level of resistance to metal fatigue and yield, as well as a high degree of elasticity.
Another important aim of the invention is to produce a device which combines the preceding characteristics with the ability to regulate, within a broad range of values, the pressure exerted on the base of the rails, without thereby changing the slope of the stress strain curve characteristic of the connection, over a broad range of working loads or, in other words, without reducing the degree of elasticity of the connection.
Within the above requirements, another important aim is to produce a connecting device which can be used safely, reducing maintenance operations and which could, were such operations to be necessary, be quickly and easily disconnected without impairing its flexibility. A further important aim of the invention is to produce a device which combines with the preceding characteristics that of eliminating the possibility that it could accidentally be uncoupled from a means of anchoring to the sleeper.
Another important aim is to produce a device which combines with the aforementioned characteristics the ability to be interposed quickly and easily between the base of the rail and a means of anchoring to the sleeper, without the need to resort to complicated tooling or special equipment for assembly. Last but not least, it is aimed to produce a device which, along with the preceding characteristics, is structurally simple and is economical. These aims and further characteristics and advantages, which will be seen to a greater extent in the following description, are obtained in accordance with the invention, as defined in the characterising portion of claim 1. Thus, the aims of the invention are met by providing a resilient connecting device for fixing a rail (7) to a support medium; the device comprising a curved resilient element (1), with two ends (2,2'), connected by one or more curved (6) or straight (5) connecting portions; characterised in that the portions (3,3') next to said ends (2,2') cooperate to define a seat in which a fixing means for fixing to an underlying support medium (9) may be accommodated, one of the connecting portions (5,6) being arranged in use to rest on the base (8) of the rail (7), and at least one of the connecting portions (5,6) being arranged in use to rest directly, or through an interposed medium, on the support medium.
Particular and preferred embodiments of the invention are set forth in the dependent claims appended hereto.
The invention will now be illustrated in more detail, but not limited, by reference to the particular embodiments shown in the accompanying drawings in which:

Figures 1 to 3 represent three views of a connecting device according to one embodiment of the invention; and
Figures 4,5,6 and 7 each represent one way of using the connecting device of Figures 1 to 3.

Referring now to the drawings, it can be seen that in figures 1 to 3, the device comprises a resilient element (1) whose two ends (2,2') may or may not lie on the same plane. Starting from these two ends (2,2'), there are two portions (3,3') which each have a loop (19,19'), these loops being of reciprocal concavity. Portion (3,3') then extend into curved portions (4') with convexity in the opposite direction in relation to the ends (2,2'). These curved portions in turn extend into subsequent portions (5,5'), which are in their turn connected by a further curved section (6).
In Figure 4, it can be seen that resilient element (1) is used to fix a rail (7), and in particular its base (8) to an underlying support medium (9) which may be for example, a sleeper or a cement platform or a plate formed of metal or another material, held up by a supporting means, (not illustrated in the figure). In this case, the means of fixing is a screw and, in Figure 4, a dowel (10) onto whose shank a boss (11), preferably made of plastics material, is screwed, which is in its turn embedded in the body of the support medium or inside any piece which enables it to be anchored to the support medium. This dowel is of the right thickness to be housed exactly in the space between the loops (19, 19') present in sections 3 and 3' (figure 2) of piece 1.
As shown in Figure 4, portions (5') rest on the base (8), of the rail (7) and portions (5) rest on the plates (12), which in turn rest on support medium (9). Plates (12) will preferably be made of a plastics material with insulating properties in order to ensure proper insulation of the rail (7) in relation to the ground. Plates (12) have a bearing surface (12') into which portion (5) of the resilient element (1) is rabbeted. The height of the surface (12') of the plate (12), in relation to the height of the base (8) of the rail, determines the working preloading of the resilient element itself. The plate (12) also provides a rabbeted surface (12'') which, interacting with the base of the rail, allows the gauge of the track to be maintained.
The base (8) of the rail (7) rests on the support medium (9) by means of an interposed plate (13), also made of an insulating material which should preferably also have resilient and damping properties.
In Figure 5 it can be seen that, in this case, connecting device has housed within it, specifically between its loops (19,19') (Figure 2) a dowel concrete screw (14) for fixing the rail (7) to a supporting medium (9) which in this case comprises a wooden sleeper. A plate (15), made of metal, is interposed between the rail (7) and said supporting medium (9), this also being connected to the sleeper, (9) by means of the dowel-concrete screw (14). If necessary, it is possible subsequently to fix the plate (15), with two or four further dowels inserted in appropriate holes in the plate itself (not indicated in the figures).
It is also possible to use the same type of connection shown in Figure 6, replacing the dowel-concrete screw (14) with an ordinary dowel. In this case, the portions (5) of the resilient element (1) rest on raised portions (15') of piece (15), while the portion (5') of resilient element (1) rest directly on the base (8) of the rail (7). Even in this case, the height of the raised portion (15') in relation to the base (8) of the rail determines the working pre-loading of the resilient element (1).
Plate (15) has shoulders (15''), and the interaction of shoulders (15'') with the base (8) of the rail maintains the gauge of the track. Figure 6 shows a possible connection using the dowel-concrete screw in the case where the support (9) is made up of a cement sleeper. The remarks made in relation to the preceding embodiment are also applicable here, except that in this embodiment, the dowel-concrete screw (14) is screwed onto a boss (11'), preferably made of a plastics material, embedded in the body of the supporting medium. The plate (15) is flat and it is preferred to interpose a sub-plate (13') between the plate (15) itself and the sleeper (9), preferably made of resilient material, with insulating and damping properties. In this, as well as the previous embodiment the dowel-concrete screw (14) may be replaced with an ordinary dowel.
In this embodiment of the invention, as in the other embodiments illustrated in the figures, it is intended that a pair of resilient elements (1), should be used, corresponding to both sides of the base (8) of the rail, said resilient elements (1) being placed with the ends (2) turned in opposite directions.
Finally, in Figure 7, a dowel (16) is used as a fixing piece in order to enable the rail (7) to be fixed to a supporting medium comprising a sleeper made of wood or cement. In this embodiment also, there is a plate (15) on the supporting medium, with raised portions (15'), which, as in the preceding embodiments, determines the working pre-loading of the resilient element (1). Plate (15) also has shoulders (15'') which interact with the base of the rail to maintain the gauge of the track. In the event that the supporting element (9) is constituted by a cement sleeper, it is advantageous interpose, between the sleeper itself and the plate (15), a sub-plate, preferably made of a plastics material with insulating as well as resilient and damping properties.
Holes (18) are shown in the plate (15), into which dowels to fix the plate itself may be inserted if necessary. Of course, it is also possible to use other ways of fixing the resilient element to the supporting medium and the embodiments illustrated clearly demonstrate the great flexibility of the connecting device. Returning to Figures 1 to 3, it should be pointed out that the description given of the invention therein of the way the resilient element is made is simply one example amongst many, although of course its basic characteristics remain unchanged.
Referring again to Figures 1 to 3, it can be seen that portion 6 has a pair of curved portions (18, 18') which lie on inclined planes in relation to those of the ends (2,2'). Moreover, portions (4) and (4') also lie on inclined planes in relation to said ends (2,2'). The foregoing shows clearly how the connecting device of the invention makes it possible to achieve the aims previously set out.
The connecting devices of the invention do indeed have a high degree of elasticity, which is obtained mainly because the portion of the device on which the stress is distributed is of a greater length than that in existing devices.
Such distribution of stress on longer portions includes more uniform distribution of stress on the resistant section. The fact that the resilient element interacts with the means of anchoring to the support along two sections, instead of only one, means that the stress is distributed along the resilient element from both of them. This makes it possible to obtain, if required, greater fixing strength in the base of the rail, while subjecting the material to lower stress per unit of surface area. What we have just described also explains the high resistance to fatigue of the resilient element, thus giving a device which is longer lasting in terms of fixing and is safer to use, as well as requiring consequently less maintenance. As already shown, the presence of two portions interacting between the resilient element and the means of anchoring to the support also makes it possible to pre-load the resilient element itself, thus regulating the working pressure within a broad range, while maintaining a high degree of elasticity in the connection.
A further advantage provided by the connecting device of the invention lies in its ability to exert precise, constant pressure on the rail.
A further increase in the security of the connecting device derives from the fact that it is impossible for the resilient piece inadvertently to come undone or accidentally become detached from the means of anchorage.

Claims

A resilient connecting device for fixing a rail (7) to a support medium; the device comprising a curved resilient element (1), with two ends (2,2'), connected by one or more curved (6) or straight (5) connecting portions; characterised in that the portions, (3,3') next to said ends (2,2') cooperate to define a seat in which a fixing means for fixing to an underlying support medium (9) may be accommodated, one of the connecting portions (5,6) being arranged in use to rest on the base (8) of the rail (7), and at least one of the connecting portions (5,6) being arranged in use to rest directly, or through an interposed medium, on the support medium.
A connecting device according to claim 1, further characterised in that the two ends (2,2') have extending therefrom adjacent portions (3,3') each of which comprises a loop region (19,19'), the said loop regions (19,19) being of reciprocal concavity and together forming the said seat; the said adjacent portions (3,3') extending into curved portions (4,4') having convexity in the opposite direction in relation to the ends (2,2'); the said curved portions (4,4) extending into further portions (5,5'), which in turn are reciprocally connected by a further curved portion (6), the resilient element (1) being adapted to rest on the supporting medium (9) and on the base (8) of the rail at said further portions (5, 5'), the fixing means being of a suitable thickness to be housed in the seat defined by the loops (19,19').
A connecting device according to claim 2 further characterised in that between the two ends (2,2'), there is present a curved portion (6) which has a pair of curved regions (18,18') lying in a plane which is inclined relative to the planes in which the ends (2,2') lie.
A connecting device according to claim 2 further characterised in that the said curved portions (4,4') lie a plane which is inclined relative to the plane in which the ends (2,2') lie.
A connecting device according to claim 2, further comprising a plate (12), whereby in use a resilient element (1) is placed on each of the two opposite sides of the base (8) of a rail (7), each said resilient element (1) resting on a plate (12), each plate (12) in turn being placed on the support medium (9), a fixing means in the form of a screw (10) of the right thickness being inserted between the loops (19,19') and screwed directly or through an interposed anchoring piece to the supporting medium (9).
A connecting device according to claim 5 further characterised in that the screw is in the form of a dowel (10).
A connecting device according to claim 5 further characterised in that the screw is made up of a dowel-concrete screw.
A connecting device according to claim 5, further characterised in that the anchoring piece is in the form of a boss (11) embedded in the supporting medium (9).
A connecting device according to claim 2, further characterised in that a resilient element (1), is adapted to be placed on either side of the base (8) of the rail (7), the resilient element (1) resting on the base (8), as well as on a single plate (15), placed underneath the base itself, said plate (15) resting in its turn, directly or indirectly, on the supporting medium (9) to which it is held by at least two fixing elements, the resilient element (1) being adapted to be secured to the plate by means of a fixing element to be housed in the seat defined by the two loops (19,19').
A connecting device according to claim 9, further characterised by the fact that the fixing elements for securing the plate (15) to the support (9) are in the form of two or more screws.
A connecting device according to claim 10, further characterised by the fact that the screws are in the form of dowels.
A connecting device according to claim 9 further characterised by the fact that the fixing element for securing the resilient element (1) to the plate (15) is in the form of a screw.
A connecting device according to claim 12 further characterised by the fact that the screw is in the form of a dowel.
A connecting device according to claim 12, further characterised by the fact that the screw is in the form of a concrete screw.
A connecting device according to claim 12, further characterised by the fact that the screw is in the form of a dowel-concrete screw.
A connecting device according to claim 10 or 12, further characterised by the fact that the said screws are screwed directly to the supporting medium.
A connecting device according to claim 10 or 12, further characterised by the fact that the said screws are screwed to an anchoring piece providing anchorage to the supporting medium.
A connecting device according to claim 17, further characterised by the fact that the anchoring piece is made up of a boss, preferably made of a plastics material, embedded in the supporting piece.
A connecting device according to claim 9 further characterised by the fact that a sub-base (13) made of insulating material, preferably plastic, is interposed between the base (8) of the rail (7) and the underlying plate (15).
A connecting device according to claim 9, further characterised by the fact that a sub-plate (13'), preferably made of a plastics material is interposed between the plate (15) and the supporting medium (9).
A connecting device according to claim 9, further characterised by the fact that the fixing elements holding the resilient elements to the plate (15) are constituted by same elements which hold the plate itself to the underlying supporting medium (9).
A connecting device according to claim 9, further characterised by the fact that the fixing elements which hold the plate (15) to the supporting medium (9) are constituted by the same elements which hold the resilient elements to the underlying plate, or are constituted by other fixing elements.