Tongue rolling device
A tongue rolling device enables, instead of lubricated sliding plates and sliding chairs, a lubrication-free and low-friction adjustment of the switch blades of a railway switch .
Advantages of tongue rolling devices
- They are low-maintenance and reliable, and there is no need for labor-intensive and costly lubrication.
- Environmentally friendly as no further lubrication of the slide plates or chairs is necessary
- They improve the positional stability of the superstructure, as no lubricants are introduced into the bedding
- The change-over force to be applied by the drive is reduced by up to 50%, which is particularly important for mechanical actuation
- The changeover resistance is independent of the lubrication status and the weather conditions
- Increased safety for the staff, as it is no longer necessary to step onto the switch for lubrication. The lubricant-free underground is also safer to walk on.
Existing turnouts can be retrofitted, but only with types that are arranged in the sleeper compartment because of the effort involved. These may interfere with superstructure work such as the tamping and must then be removed. To retrofit tongue rolling devices integrated in the sliding plates would require these plates to be changed. This is hardly ever done because of the effort involved and because of the remaining idle time required for the switches concerned.
Components of a tongue rolling device
The basic idea was to move from sliding friction to rolling friction. The heart of the tongue rolling device is the storage of the parts.
Basically, a tongue rolling device consists of the following assemblies: roller block, roller unit and a mounting unit. The tongue rollers are adjusted so that the respective tongue rests on the sliding plates in order to keep the traffic loads away from the rollers. As soon as the tongue is moved when changing over, it runs onto the rolling devices and is lifted off the sliding plates. Exceptions in this regard are elastic tongue rollers, where the last roll is under the tongue and is pressed down by the traffic load (or with the help of the HRS locks used on high-speed routes).
There are different variants: Bearings which are completely encapsulated and therefore insensitive to the effects of the weather and therefore require little maintenance. Other systems are equipped with open slide bearings.
In the Netherlands it is customary to attach the rollers to the tongues, which then run over a ramp-shaped guide.
Installation of tongue rolling devices
Normally, the rolling devices are pre-assembled in the factory and the rollers are covered to protect against penetrating material (especially gravel and abrasion from it). In the case of types that are arranged in the sleeper compartment, the roles are only prepared in the switch factory and given loose. The rolling devices are adjusted when the switch has reached its final position (after tamping, in the case of a solid track after the concrete has hardened). After setting, only a function check is necessary as part of the normal turnout inspection .
literature
- Heinz Mooss: Eco-intelligent: brilliant ideas and products from Austria . Ueberreuter, Vienna ISBN 3-8000-7128-2
- DB reference book: Working procedures for the maintenance of the superstructure , (page 250). 6th edition. Eisenbahn-Fachverlag Heidelberg - Mainz, ISBN 3-9808002-1-0
Web links
- Roller device ( Memento from 1 April 2011 at the Internet Archive amstetten) of non-ferrous metals
- Tongue rolling device from Schwihag