The invention relates to a device for moving a tongue rail of a switch, having a retaining element attached to a stock rail and at least one roller attached thereto, the axis of rotation of which is substantially parallel to the rail course, and which is arranged in such a way that the tongue rail can roll up onto the roller from a lower resting position on the stock rail, and having a spring element.
Devices for moving tongue rails in switch systems are regularly exposed to high forces when trains pass over the switch. At the same time, the movement of the tongue rail must be made as smooth as possible when the switches are changed in order to prevent unnecessary wear and to minimize the consumption of lubricants. For this reason, systems are already known which provide for the rolling of a tongue rail onto a roller system. Such devices are typically designed in such a way that the tongue rail adjacent to the stock rail rests on a slide chair, which also absorbs the weight forces of a train running over it. A roller of the roller system rests against the side of the rail foot of the tongue rail opposite the stock rail, the upper vertex of which is slightly above the plane of the slide chair. This ensures that the stock rail lifts off from the slide chair at the start of any movement and rolls smoothly with low friction on the roller. Such a device is described in EP 0 654 561 B of the applicant. It can also be seen that the roller is typically spring-loaded to allow easier gliding and to compensate for tolerances. In the known solution, the spring is designed as a leaf spring extending between two supports attached to adjacent sleepers. Roller arrangements of this type are robust and functionally more than satisfactory. The production and the installation, however, are relatively complex.
Such arrangements, in which a retaining element is fastened directly to the stock rail, allow simplified installation. The roller is then typically mounted on a spring-loaded suspension, which achieves a similar behavior to the devices of the type described above. However, the spring-loaded suspension also causes a far from inconsiderable manufacturing and maintenance effort in this case.
From the US 2002/0079634 A1 an alternative device is known, which has tiltable rollers, and which also allows a rolling up of the tongue rail. After rolling up, the tongue rail is guided on further rollers. However, systems of this type also have the problem of high maintenance costs, as they are quite complicated in structure. In addition, they are very susceptible to errors due to the weather, as dirt and icing can occur despite tight maintenance and monitoring.
DE 44 05 115 A1 describes devices which have rollers on a support. A spring element arranged under the rollers tilts a part of the roller suspension in the adjacent position of the tongue rail so that it rests on a slide chair with reduced contact pressure. Some of the rollers have an elastic shell to reduce friction when the tongue rail slides along the slide chair. This construction is very complex and error-prone. As the spring element ages, the spring constant may change, resulting in increased friction and malfunctions. In addition, due to its complex design, the well-known device is very susceptible to malfunctions caused by impurities.
KR 20120076926 A describes a further embodiment that has several rollers mounted on an intermediate bearing, with the intermediate bearing being arranged on the retaining element so that it can be moved. Here, too, rolling off is not provided, which leads to a load on the fragile components. In addition, due to the arrangement at the intermediate bearing, only all rollers can be moved at the same time, which makes optimal positioning more difficult.
It is the object of the present invention to avoid these disadvantages and to provide a solution which, in its function, is as similar as possible to the devices described above, but which has a simplified design, can be manufactured inexpensively and requires little maintenance.
According to the invention, these objects are solved in that the spring element is arranged in the interior of the roller and that the roller is fastened by at least one screw connection and is adjustably fixed in a slide rail on the retaining element. In this way it is possible to support the roller itself essentially without springs and thus achieve a considerable simplification of the structure.
Spring-loaded rollers, i.e. rollers which have a spring element between a hub and the outer circumference, are known per se, but are not known to use a roller which is inherently spring-loaded but mounted in a non-spring-loaded manner instead of a spring-loaded suspension of a roller which is intended for the sliding on of a tongue rail.
An important aspect of this invention is the simple attachment of the device to the stock rail so that it can be mounted independently of the configuration of adjacent sleepers, provided that only the space required to accommodate the device is available.
Preferably it is provided that the outermost shell of the roller is made of metal. In this way it is possible to absorb the relatively high mechanical load at the beginning of the sliding on without damage and without impairing the spring effect.
It is particularly advantageous if the roller is designed as an elastomer-sprung roller. The choice of suitable materials makes it possible to achieve a very long service life.
A particularly simple assembly and adjustment of the device can be achieved in such a way that the roller is fastened by at least one screw connection and the slide rail is fixed to the retaining element. By moving the roller along the slide rail, the correct position of the roller can be easily adjusted crosswise to the longitudinal direction of the stock rail. It is particularly advantageous in this context if the roller is attached to the retaining element by at least one eccentric fastening. In this way, the height of the roller can also be optimized in the same adjustment procedure.
The above embodiment variant can be further improved in particular in such a way that the eccentric fastening has at least one polygonal plate fixed in a slide rail on the retaining element and at least one screw, wherein the screw runs through an acentric hole through the plate. The many-sided plate, for example, is designed as an octagon so that eight different setting positions are available.
In certain installation situations it is possible that the required range of displacement of the tongue rail is larger than the width of the foot of the tongue rail. In order to ensure low-friction displacement over the entire adjustment range, it is preferably provided that at least one second roller is attached to the retaining element, wherein the axes of rotation of the rollers are arranged substantially parallel to each other.
A preferred embodiment variant of the invention provides that the bearing of the roller on the retaining element is formed rigidly. The suspension of the roller is achieved exclusively via the spring element built into the roller, which ensures a particularly simple construction.
It is particularly advantageous if the spring element is designed as a hollow cylinder whose inner diameter is in a range between 30% and 60%, preferably between 45% and 55% of the outer diameter. In this way, the required mechanical stability can be guaranteed and at the same time sufficient suspension can be achieved.
In the following, the present invention will be explained in more detail by reference to embodiment variants depicted in the figures, wherein:
Number | Date | Country | Kind |
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A 51193/2016 | Dec 2016 | AT | national |
Filing Document | Filing Date | Country | Kind |
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PCT/AT2017/060342 | 12/21/2017 | WO | 00 |