EP2995719A1

EP2995719A1 - Turnout slide support with improved thermal contact

Info

Publication number: EP2995719A1
Application number: EP15183069.2A
Authority: EP
Inventors: Rob Rutjes
Original assignee: VolkerRail Nederland BV
Current assignee: Volkerwessels Intellectuele Eigendom BV
Priority date: 2014-08-28
Filing date: 2015-08-28
Publication date: 2016-03-16
Also published as: NL2015359A; NL2015359B1

Abstract

Method wherein a the heat conducting material (10) is applied against and/or between two turnout components of a railway turnout, wherein the heat conducting material can fill an empty space (11, 12, 13) between two turnout components. The heat conducting material can be lead, tin, zinc, aluminium, copper, heat conducting paste, gel or adhesive.

Description

The invention is aimed at preventing that the good operation of a railway turnout (also called switch), provided with a turnout heating (also called switch heating), is blocked by snow and ice.
The prior art shows many examples of protecting a turnout against snow and ice by heating, viz. e.g. EP1262597 , US-A-5004190 , WO2010142720 , EP2677079 , DE4325002 and DE19502125 .
The invention is directed to the improvement of the performance of a switch heating, without additional power consumption, which is applicable to new construction of turnouts (new) and above all is suitable for the improvement of existing, already in the railway installed systems (retrofit) and is easily applicable to existing, already installed systems in the track without the need to replace components, and without the need for long-term decommissioning of the track.
For this purpose, according to the invention a good heat conductive material, preferably initially in form free or pasty or gel-like state, is applied against and / or between two switch components, preferably to fill an empty space between the one switch component and a to it connected other switch component, preferably substantially completely, in order to get a good heat conducting intimate contact between these two components. Preferably, the one component, for example, stock rail (also called stop rail) or closure rail (also called rail tongue) is directly heated by the switch heating, for example, the switch heating is attached thereto and / or the other component, for example, slide chair plate (in other words slide support or slide base plate, providing sliding support to the moving closure rail that is resting onto this chair plate), is devoid of direct heating by the switch heating. By applying the thermally good conductive material a good indirect heating of the other component through the direct heated component is ensured. The material which is applied acts as a kind of interface.
The invention is on the one hand directed to avoid or remove an air gap by filling it with the heat-conductive material, on the other hand directed to enlarge the contact surface, for as good as possible contact heating. The invention is based on the recognition that, by ensuring a good heat conduction, or large contact area, a switch component can indirectly sufficient be heated by the switch heating by allowing the heat of the one switch component to flow via the good thermal conductive material to the other component.
Examples of the to be applied heat-conducting material are metal, preferably at low temperature melting such as lead, tin, zinc, aluminum, copper (or alloys of these metals), heat-conductive paste or adhesive, which preferably are applied in form the free state such as molten and then solidify or cure. By using form free material elimination of any air gap is safeguarded as good as possible.
Preferably, the lead, etc., is applied after the relevant two switch components are mounted permanently and without complete or partly disassembly of these two switch components. With an existing switch in the track the lead, etc., is applied without prior dismantling. Optionally, use is made of a formwork to keep the dispensed, form free, e.g. liquid, material in place, for example, until sufficiently solidified or cured. For new constructions, the material, for example, when it does not flow away automatically, e.g. in case of a gel or paste, can be applied at the desired location before or during the assembly of the two switch components.
The application of a the two switch components intimately contacting bead or dot of the good heat-conducting material, or the partly covering or embedding of one or both of the switch components with this material, is also part of the invention.
The state of the art (see above), mentions the use of lead, aluminum, copper, heat-conductive paste or adhesive in order to improve the transfer of heat from the heating element to the directly by the heating element to be heated switch component. The prior art is silent however, about the indirect heating of the one switch component by the other switch component in case of a with switch heating provided switch. Also, the state of the art is silent about a solution that is applicable to already in the track installed switches equipped with heating. The lead, etc., is according to the prior art applied before or during the mounting of the parts to each other. Applying tin or zinc as the heat conductive material is not cited by the state of the art.
Preferably, one or more of the following applies in the present invention: the stop rail or tongue rail is below the rail head provided with an along its length extending heating element, for example, electric or fire tube, and is heated directly by this heating element; the heating element at the stop rail is located at the to the rail tongue facing side or at the other side; the switch component of which the slide chair plate is an integral part engages over the rail foot of the stop rail to keep the latter in place; the switch component of which the slide chair plate is an integral part, is devoid of a heating element, in other words it lacks direct switch heating; the heat-conducting material is applied in the or an air gap between the rail foot and the part of the switch component to be heated indirectly, which overlaps with the rail foot, for example, an air gap under the rail foot, the rail foot at the side of or above the rail foot.
It is important that the good heat-conducting material is applied in such a way that it has intimate contact with at least two individual components of a railway switch so that the contact surface for heat transfer between these two components is increased substantially such that a maximum heat flow from the one to the other component is created. Preferably, both these components are made of metal, such as steel and / or are able to melt snow and ice.
Instead of casting, one could apply the material by injecting or spraying or pressing or pouring, etc. For example, one could inject or spray or spatula a paste or gel, into a narrow air gap.
The accompanying drawing shows three examples of the many embodiment variants that belong to the invention.

Fig. 1 shows a first system;
Fig. 2 shows a second system;
Fig. 3 and 4 show each an alternative to Fig. 2 resp. fig. 1.

Fig. 1-4 all show a schematic end view with the components shown at a distance from each other while they bear against each other in practice. The slide chair plate of Fig. 1 is also called German system (rail type UIC60), that of Fig. 2 is also called Dutch system (rail type UIC54). The invention is applicable to all types of slide chair and rail.
To the web of the stock rail at the to the switch tongue facing side or at the other side an elongated heating element is mounted. The slide chair extends below the rail foot and across its sliding surface the tongue rail slides (see the in the head of the rail tongue shown arrow).
In Fig. 1, engaging over the rail foot of the stop rail is the nose of the slide chair and, by defects in shape, surface roughness, etc. this nose has no perfect connection with the rail foot, so that the heat-conducting contact surface between the nose and the rail foot is small. In other words under this nose are air gaps with the rail foot. Lead 10 is molded against the nose of the slide chair and thereby penetrated into these air gaps. Heat flows from the heating element through the stop rail to the lead 10 and further on to the slide chair so that the switch tongue does not with his foot freezes to the slide chair, and on the sliding surface lying snow and ice are melted. Also in the air gap 11 to the side of the rail foot and in the air gap 12 under the rail foot, one can pour lead to improve the heat transfer of the stop rail to the slide chair.
In fig. 2 the lead 10 is molded against the to the rail tongue facing nose of the foot of the stop rail, and thereby flowed slightly below the rail foot into the air gap between the rail foot and the slide chair. The lead bead (thus the lead which aside against the rail foot and on top of the sliding support has solidified), and also the lead in the air gap contribute to the transfer of contact heat from the stop rail to the slide face of the sliding support. For maximum contact surface and therefore the best heat transfer in an alternative (illustrated by broken lines in Fig. 2) one ensured that the lead has flown everywhere under the rail foot, for example, by also pouring from the other side of the rail foot such that also there a lead bead 14 is created which also contributes to a better heat transfer.
In fig. 3 no lead 10 is penetrated below the rail foot. The molded lead bead provides additional heat transfer.
In fig. 4 a lot of lead 10 is poured on top of the rail foot and against the nose of the slide chair. The air gaps 11, 12 and 13 could also be filled with lead.

Claims

Method wherein a the heat good conducting material is applied against and/or between two turnout components of a railway turnout.
Method according to claim 1, with the material an empty space between the one turnout component and the to it connecting other turnout component is filled.
Method according to claim 1 or 2, the material is applied in initially form free or paste or gel like state.
Method according to any of claims 1-3, lead, tin, zinck, aluminium, copper (or alloys of these materials), heat conducting paste of adhesive, is in form free state, such as molten, applied and solidifies or cures.
Method according to any of claims 1-4, a stop rail is directly heated by the switch heating, the associated turnout slide support is devoid of direct heating by the switch heating, the good heat conducting material provides a good indirect heating of the turnout slide support through the stop rail.
Method according to any of claims 1-5, applied to an existing turnout in the track, and lead is, without prior disassembly, dispensed, wherein possibly use is made of a formwork to hold the dispensed lead in place.
Method according to any of claims 1-6, comprising the application of a with the both turnout components intimate contact making bead or dot of the good heat conducting material.
Method according to any of claims 1-7, comprising the partly covering or embedding of one or both turnout components with the good heat conducting material.
Method according to any of claims 1-8, the heat conducting material is applied in an air gap between the rail foot and the part of the indirectly to be heated turnout component which overlaps with the rail foot, e.g. an air gap below the rail foot, aside the rail foot or on top of the rail foot.
Turnout wherein a the heat good conducting material, preferably in initially form free or paste or gel like state, is applied against and/or between two turnout components, preferebly to fill an empty space between the one turnout component and a to it connecting other turnout component.