NL2015856B1 - Switching assembly for switching a point rail. - Google Patents

Abstract

A switching assembly for switching a point rail in and out of engagement with a stock rail comprising a frame and at least one organ that is at least partly rotatably attached to the frame, wherein the organ, when viewed from one side, is shaped as a segment of a circular body embodied with two linear edges meeting each other under a predefined angle in a corner- point, and an arcuate edge distant from the corner-point and connecting the linear edges, wherein said segment is attached to the frame at a position in the vicinity of said cor ner-point where both linear edges meet.

Description

Switching assembly for switching a point rail

The invention relates to a switching assembly for switching a point rail in and out of engagement with a stock rail comprising a frame and at least one organ that is at least partly rotatably attached to the frame.

Railroad switches are known from the rail transportation sector and are used to switch a pair of point rails in and out of engagement with a pair of stock rails. Switching assemblies are most often found in the vicinity of train stations where multiple railways have to cross each other. Depending on whether the point rails are in or out of engagement with the stock rails, a train passing such a switching assembly is forced to either stay on its current stock rails or switch to another stock rails, guided by the point rails. The sideways motion of a point rails in a direction perpendicular to the length of the stock rails, generates frictional forces. To more easily overcome these forces, rollers are often used that support a plate with the point rail resting thereon.

These rollers are equipped with bearings and their rolling motion during switching of a point rail reduces frictional forces .

Such a switching assembly is known from US 8,608,115 B2, that discloses a roller assembly comprising: a mounting plate securable to a rail base plate, a roller support pivotal about a support axis on the rail base plate, a roller carried on the roller support, and a spring biasing the roller upward with a predetermined spring force into a lifted position with the roller projecting upwards past the upper face for supporting the point rail on the roller.

Another switching assembly is known from WO 97/47811, that discloses a switching device for tongues (i.e. point rails) whose tips lie on the slide-chair roller plane. The switch tongues can be switched more easily if the front roller of the pair of rollers is positioned at a lower level than the rear roller.

Prior art switching assemblies rely on rollers to support the transition of the point rails and to reduce friction during switching. Such rollers are relatively small, due to the limited space available beneath the rails. The rollers therefore have to make a couple of revolutions during switching, causing that the bearings of the rollers are more prone to wear and tear. Moreover, the rollers are prone to obstruction by debris and are sensitive to weather conditions such as freezing.

It is an object of the invention to propose and alternative switching assembly which is less sensitive to wear and tear, and is more resistant to weather conditions and freezing conditions that result in blocking of the switching assembly preventing that the point rails are moved into or out of engagement with stock rails.

According to the invention an apparatus is proposed in accordance with one or more of the appended claims.

According to a first aspect of the invention the organ, when viewed from one side, is shaped as a segment of a circular body embodied with two linear edges meeting each other under a predefined angle in a corner-point. An arcuate edge distant from the corner-point connects the linear edges, wherein said segment is attached to the frame at a position in the vicinity of said corner-point where both linear edges meet. This organ has several advantages over conventional rollers. A relatively longer distance between the attachment point and the arcuate edge of the said segment as compared to a rotation axle and a circumferential surface of a conventional roller, ensures that a smaller (only partial) rotation is required to switch a point rail. Therefore relatively less force is required, as compared to a conventional roller, to overcome the frictional forces arising from the partial rotation of the organ around its attachment point. This decreases the switching assembly's vulnerability for malfunctioning due to debris, disadvantageous weather conditions, wear and tear and other factors that could increase friction between the organ and the frame at the attachment point. A preferred angle between both linear edges at the corner-point of the organ is 60° while the preferred length of the edges is 150 mm.

Preferably the height of the frame of the switching assembly is adjustable, relative to the point rail. This allows the organ to be adjusted to a desired height relative to the point rail at site, while the switching assembly is already installed between two sleepers. As the height of the rails may vary during use, the option to adjust the organ to a desired height relative to the point rail, ensures that the switching assembly can be adjusted to the correct height therewith ensuring its correct functioning. Suitably the switching assembly comprises therefore at least one adjustable screw.

The organ is preferably movable between two positions, a first position corresponding with the point rail being in engagement with the stock rail, and a second position wherein the point rail and the stock rail are out of engagement. These two positions allow a train passing the switching assembly to either continue on the current stock rails or switch to another stock rails via the point rails.

The shape of the organ is preferably arranged so as to ensure that partial rotation of the organ causes the point rail to lift and move while moving between the first and second position. Due to the arcuate edge of the organ, the point rail is forced slightly upwards, reducing frictional forces between the point rails and the switching assembly. The frictional forces are consequently reduced to virtually zero, reducing the required maintenance level to very low figures.

Preferably, the organ comprises a protrusion at the arcuate edge, extending one of the linear edges. This protrusion ensures that the point rail is carried along during moving of the organ between the first and the second position and prevents the point rail from slipping off the organ.

In a preferred embodiment, the organ is made from a plastic material, for example a combination of polyamide and fiberglass. An advantage thereof is that such a material does not conduct electricity, preventing short circuiting. Another advantage is that damage to the bottom of the point rail resting on the organ is prevented when the organ is in its disengaged position.

In another preferred embodiment, the organ comprises at least one recess and/or orifice. Manufacturing an organ comprising orifices saves material and makes the organ less susceptible to weather conditions.

The invention will hereinafter be further elucidated with reference to the drawing of an exemplary embodiment of an switching assembly according to the invention that is not limiting as to the appended claims.

In the drawing: - figure 1 shows a three dimensional view of the switching assembly according to the invention, - figure 2 shows in a front view the switching assembly according to the invention, - figure 3 shows in a side view the switching assembly according to the invention, - figure 4 shows in a top view the switching assembly according to the invention; and - figure 5 shows a front view of an organ, shaped as a segment of a circular body, when viewed from one side, according to the invention.

Whenever in the figures the same reference numerals are applied, these numerals refer to the same parts.

Figures 1-4 show a switching assembly 1 for switching a point rail 2 (only shown in figure 1 and figure 2) in and out of engagement with a stock rail 3 (likewise only shown in figure 1 and figure 2), which switching assembly 1 comprises a frame 4 and at least one organ 5 that is at least partly rotatably attached to the frame 4. The organ 5, when viewed from one side (as in figure 2 and 5), is shaped as a segment of a circular body embodied with two linear edges 6 meeting each other under a predefined angle in a corner-point 7, and an arcuate edge 8 distant from the corner-point 7 and connecting the linear edges 6. The organ 5 is attached to the frame 4 at a position in the vicinity of said corner-point 7 where both linear edges 6 meet. The shape of the organ 5 is such that only partial rotation of the organ 5 is required during switching of the point rail 2, resulting in less wear as compared to rollers as used in the prior art.

The height of the frame 4 is adjustable, relative to the point rail 2. The frame 4 comprises at least one adjustable screw 9 to adjust the height of the frame 4, relative to the point rail 2. A total of four screws 9 can be seen in figure 1 and figure 4 that allow fine-tuning of the height of the organ 5 relative to the point rail 2 to accommodate for slight deformations or changes in the rails 2,3 resulting from day to day use.

The organ 5 is movable between two positions, a first position corresponding with the point rail 2 being in engagement with the stock rail 3 and a second position wherein the point rail 2 and the stock rail 3 are out of engagement so that the point rail 2 moves to engagement with another stock rail to enable that a train passing the switching assembly 1 can change to the other stock rail via the point rails 2.

Partial rotation of the organ 5 causes the point rail 2 to lift and move while moving between the first and second position. Lifting of the point rail 2 reduces frictional forces between the point rail 2 and adjacent materials, thereby increasing the life time and reliability of both the point rail 2 and the switching assembly 1.

The organ 5 comprises a protrusion 10 at the arcuate edge 8, extending one of the linear edges 6. This protrusion 10 lies adjacent to the point rail 2 and prevents the point rail 2 from slipping off the organ 5 in the process of transferring it from one stock rails 3 to another.

Preferably, the organ 5 is made from a plastic material which does not conduct electricity, thus avoiding short-circuiting .

Figure 5 shows an alternative embodiment of the organ 5, comprising at least one orifice 11. These orifices 11 minimize material usage, reduce production costs and production time of the organ 5.

Although the invention has been discussed in the foregoing with reference to an exemplary embodiment of the switching assembly of the invention, the invention is not restricted to this particular embodiment which can be varied in many ways without departing from the gist of the invention.

The discussed exemplary embodiment shall therefore not be used to construe the appended claims strictly in accordance therewith. On the contrary the embodiment is merely intended to explain the wording of the appended claims without intent to limit the claims to this exemplary embodiment. The scope of protection of the invention shall therefore be construed in accordance with the appended claims only, wherein a possible ambiguity in the wording of the claims shall be resolved using this exemplary embodiment.

Nomenclature 1. Switching assembly 2. Point rail 3. Stock rail 4. Frame 5. Organ 6. Linear edge 7. Corner-point 8. Arcuate edge 9. Screw 10. Protrusion 11. Orifice

Claims (8)

1. A switching assembly (1) for switching a point rail {2) in and out of engagement with a stock rail (3) comprising a frame (4) and at least one organ (5) that is at least partly rotatably attached to the frame (4), characterized in that, the organ (5), when viewed from one side, is shaped as a segment of a circular body embodied with two linear edges (6) meeting each other under a predefined angle in a corner-point (7), and an arcuate edge ¢3) distant from the corner-point (7) and connecting the linear edges (6), wherein said segment is attached to the frame (4) at a position in the vicinity of said corner-point (7) where both linear edges (6) meet,.

2. A switching assembly (1) according to claim 1, characterized in that the height of the frame (4) is adjustable, relative to the point rail (2).

3. A switching assembly {1} according to claim 2, characterized in that it comprises at least one screw' (9) to adjust the height of the frame (4), relative to the point rail.

4. A switching assembly (1) according to any one of the previous claims 1-3, characterized in that the organ {5) is movable between two positions, a first position corresponding with the point rail ¢2) being in engagement with the stock rail (3) and. a second position wherein the point rail (2) and the stock rail (3) are out of engagement.

5. A switching assembly (1) according to claim 4, characterized in that partial rotation of the organ (5) causes the point rail (2) to lift and move while moving between the first and second position.

6. A switching assembly (1) according to any one of the previous claims 1-5, characterized in that the organ (5) comprises a protrusion (10) at the arcuate edge (8), extending one of the linear edges {6).

7. A switching assembly (1} according to any one of the previous claims 1-6, characterized in that the organ (5) is made from a plastic material.

8. A switching assembly (1) according to any one of the previous claims 1-7,. characterized in that the organ (5} comprises at least one recess and/or orifice (11).