WO1994011578A1

WO1994011578A1 - Switch construction

Info

Publication number: WO1994011578A1
Application number: PCT/FI1993/000484
Authority: WO
Inventors: Jaakko Lappalainen
Original assignee: Railex Oy
Priority date: 1992-11-17
Filing date: 1993-11-17
Publication date: 1994-05-26
Also published as: FI94975C; FI94975B; FI925205A; FI925205A0; AU5467194A

Abstract

The invention relates to a switch construction where at least one rail portion is moved between two positions. A tie bar (3) has been attached to a rail or rails and it goes through a carriage (2) which has been installed so that it allows restricted movement. Power accumulators (4) secure that the positions of the rails are stable.

Description

Switch construction

The present invention relates to a switch construction and more closely to a construction in the railroad rail switches by which the movable tongue constructions of the switch can be set at a desired distance from the stock rail and the movable end part of a junction can be set into any of its end positions. The switch construction is applicable to any type of switches irrespective of their radius.

The known switch constructions have disadvantages which can, if not properly under control, cause serious problems, the worst case being the derailing of a train and with the consequent high damage. These problems are mainly due to the vibrations arising from the length and/or the movements of the tongues, causing movements of the tongues which are not completely under control. The problems are more difficult when the speed of the traffic rises.

No good solutions to restrict the vibrations caused by moving vehicles have been shown in the known constructions. Additional¬ ly the problems associated with the switches are increased by the impurities collected therein, due to which the tongues do not set so accurately in respect of the stock rails. As an attempt to control the problems the known solutions have used tie bar locking in the area of the moving part of the tongue. One or more lever devices and different lever mechanisms associated with the same have been in turn used to control the locking.

One solution according to the state of the art has been presented in the Finnish patent specification number 81646 concerning switch with at least one lever with several arms connected to the tongue rails and rotatable around a fixed swivel axle and loaded by a power device. The lever can be used with tongue rails which are operated by a lever device. In the device the distance of the tongue to the stock rail is determined by a fixed stopper which is separate from the stock rail and possibly adjustable and which functions together with the determining lever.

Generally speaking all the functions according to the afore men-

CO FIRMAΠON tioned patent go by lever mechanisms. The lever mechanisms are, however, in the rail traffic unsafe and problematic. For example supporting of the switches causes transitions in the constructions and the transitions should be avoided by all means.

Another disadvantage of the switch construction according to the above mentioned state of the art is the fact that the construction completely neglects the problems associated with the temperature extension of the long tongue constructions, as the extension naturally, achieves alterations in the angles of the lever mechanisms. On the other hand the vertical vibrations of the tongues considerably burden the lever mechanisms easily causing disturbances in the fuctioning of the mechanism.

Yet another disadvantage of the construction presented in the above publication is the fact that the switch remains in an inter¬ mediate position when being driven open whereby both of the tongues are open and it is completely impossible to use the switch. Control of the movable tip of a junction is according to the public- ation impossible or at least very awkward.

The object of this invention is to achieve a switch construction which solves the disadvantages of the state of the art given above and forms a mechanism which is simple in its construction and secure in use and in which the essential matters in respect of the reliability of the use and safety of the function have been taken into account.

The switch construction according to the invention is suitable to be used in any situation irrespective of the type or the radius of the switch. The construction takes into account, in a controlled manner, the changes in the length of the tongue and the changes of the angles during turning between the tongue constructions. Also the vertical movement of the tongues has been taken into account in the construction according to the invention by making the movement possible in a restricted manner. This fact inhibits the dangerous loading of the construction by the above-mentioned movements. The switch construction according to the invention is also suitable for use in switches which are driven open and also to control the movable tip part of a turnable junction. It is easy to encase the construction according to the invention completely, whereby the same is protected against impurities and is secure in its functions in that respect.

The before-mentioned and other good properties and advantages of the present invention have been achieved with a switch construc- tion the characterizing features of which have been given in the accompanying claims.

The invention is described in more detail by referring the accom¬ panying drawings in which:

Figure 1 shows the switch construction according to the invention seen straight from above:

Figure 2 shows another embodiment of the construction according to the invention;

Figure 3 shows the construction according to Figure 2, but now adapted into a switch of another type;

Figure 4a shows a carriage of the construction according to the invention as seen from above;

Figure 4b shows the carriage according to Figure 4a as a side view; and

Figure 5 shows the construction according to the invention adapted in a different way than before.

The constructions shown in the figures show principles of the invention and thus they are not meant to restrict the invention but to give the general outlines on how to implement the invention. Additionally, the construction according to the invention has been shown in the drawings without the lid portion of the case, which would normally be present in the construction. Thus figure 1 shows a general view of the embodiment of the construction according to the invention as seen from above and the lid open to show the parts. The switch includes stock rails 12 and 13 and tongue parts 6 and 7 of the switch in a normal way. It is thus possible to choose the desired one of the two driving direc¬ tions in the normal way by turning the tongue portions between the two positions so that the rail vehicle is directed to the other of these directions.

There is a tie bar 3 for guiding the tongues 6 and 7, the bar being of fixed length or adjustable in length if needed. The tie bar goes through the case 1 , which has been fastened to the railroad sleepers or is part of the sleepers, and at the same time the tie bar also goes through the carriage 2 and is supported by the support surfaces of the carriage. The tie bar 3 passes through the construc¬ tion of the carriage 2 so that it is free to move through the carriage 2 in its longitudinal direction but the fitting is more precise in other directions.

The locking of the tie bar into its extreme positions is made secure by power accumulators 4, especially spring means, which press the tie rod closely to its extreme position whether the position is, in the embodiment of figure 1 , the left or the right extreme position. Advantageously, there are two spring means 4 or an even number of the same, whereby the load they cause to the tie rod 3 is even and does not hinder the movement of the tie rod. The power accumulators 4 have been supported against the inner surface of the carriage 2.

The carriage 2 is located inside the case 1 and is supported in a restrictedly movable way on the bottom of the case. On the other hand the carriage per se can form the case construction whereby it is attached either directly to the railroad sleepers or alternatively to the carrier structure which can be especially a plate and is in turn fastened to the sleepers or is part of the sleepers. The fastening is described later more precisely. In figure 1 the fastening is designated generally by reference number 5.

s the switch according to figure 1 turns from the position shown in figure 1 to the other position directed to the right in the figure, the tongues 6 and 7 and the tie bar 3 connecting the same move to the right. The spring devices are compressed until they are perpendicular to the tie bar. When the motion goes on, the spring devices start to lengthen and they transmit their force to the tie bar and through the same to the tongues. In the final position the tongue 7 is against the stock rail 12 and the tongue 6 is in turn separate from the stock rail 13. The movement of the tongues from one position to the other can be achieved either by the wheels of a railroad vehicle or by using a separate lever mechanism which is not shown in the drawings.

Figure 2 shows another embodiment of the structure according to the invention where the structure described in connection with figure 1 is used so that it is connected only to one tongue 6 of the switch. In this situation the tie bar 3 is analogical to the one described above except for the fact that the portion of the bar extended to the other tongue has been removed. The locking of the structure according to the invention is very useful to control the curved tongue which generally encounters more problems. The tongues can be controlled in this embodiment by the aid of a separate lever mechanism from different transfer points.

Figure 3 shows an analogical structure with figure 2 now adapted to a junction with a turnable tip of the switch so that the tie bar 3 is attached to control the movable tip portion 14 of the junction.

The movement of the tip portion 14 between different positions is controlled by the aid of a separate lever mechanism (not shown).

Reference numbers 10 and 11 designate the stock rail against which the tip portion 14 is pushed in its different locations.

Figure 4a describes in more detail the carriage 2 of the switch structure according to the invention. It is essential to the invention that the carriage 2 is of such construction that it adapts to temperature-induced movements of the rails to which the tie bar 3 has been attached. On the other hand it is advantageous that the carriage 2 allows a restricted vertical movement and in this way prevents the vibrations of the rails from burdening the joints too much. One solution to allow the movement of the carriage 2, according to the invention, is thus shown in figure 4a as a side view and in figure 4b from above. In this special embodiment the carriage 2 is formed from a part which is for example in the form of an open box, through the side wall of which the tie bar 3 passes. Thus for example the movement caused by the extension of the rail, due to temperature rises, is transmitted from the tie bar 3 attached to the rails to the carriage, whereby the carriage is moved in respect of the fastening devices 5 in a corresponding manner.

This system 5, which has been shown as an example and which allows movement, is formed of at least one pin 52 fastened to the case 1 and passing through longish openings made in the bottom of the carriage 2, the width of which corresponds approximately to the thickness of the pin 52. The pin or pins 52 have been equipped at their upper ends with stopper plates 53 the purpose of which is to leave a small tolerance for the vertical movement of the car¬ riage, but nevertheless to restrict the movement so that it is very small. In other words the carriage can move in a restricted manner both in the longitudinal direction and in the vertical direction of the rails to which the tie bar 3 has been attached.

If desired, other restricting means can also be fitted to limit movement, such as spring like members which counteract the movement. For counteracting vertical movement in particular it is possible to use coil springs (not shown) which surround the pins 52. It is evident that also other types of restricting means than those described above can be used. Self-evident restricting means could be for example means that are bent from the side of the carriage above the bottom plate.

The solution according to the invention has been described above with reference to only one possible embodiment of the same. It is, however, evident that different alterations can be made in the invention without departing from the spirit and scope of the invention.

Claims

1. A switch construction with at least one rail which can be moved between two positions, with a tie bar (3) attached to the rail and power accumulators (4) associated in turn with the bar to keep the chosen position, characterized by a carriage (2) associated with the tie bar (3) and attached to its carrier movably at least in the longitudinal direction of the rails.

2. A switch construction according to claim 1, characterized in that the carriage (2) has been attached into its carrier movably both in the longitudinal and in the vertical direction of the rails.

3. A switch construction according to claim 1, characterized in that the fastening has been achieved by the aid of a longish opening or openings (51) and a pin (52) corresponding to the openings.

4. A switch construction according to claim 3, characterized in that the vertical movement of the carriage (2) has been restricted by the aid of stoppers (53) associated with the pin or pins (52).

5. A switch construction according to any of the preceding claims, characterized in that the structure of the carriage (2) is general- ly trough-like or box-like, whereby the tie bar (3) goes through the side walls of the carriage in a relatively tight manner.

6. A switch construction according to any of the preceding claims, characterized in that the carriage (2) has been located in a case structure (1).

7. A switch construction according to any of the preceding claims, characterized in that the case structure (1) forms part of the railroad sleeper structure.

8. Switch construction according to any of the preceding claims, characterized in that the carriage (2) per se forms an essentially closed case structure.

9. A switch construction according to claim 1 , characterized in that power accumulators (4) have been located in the carriage (2) so that they are supported by the side walls of the carriage (2) and direct an essentially symmetric force to the tie bar.

10. A switch construction according to claim 9, characterized in that power accumulators (4) are spring actioned.