10. New Roller Point and Separable Electric Point Machine

(1) New roller point
      The roller point plays an important role in preventing switching failure of the electric point machine by reducing the point switching force, using a rolling switch movement by rollers when a point is switched. However, the conventional roller point has the drawback of requiring skill and time for roller height adjustment. The Railway Technical Research Institute (RTRI) has developed a new roller point system with automatic roller height adjustment for flexible switches (for 60-kg ballasted track) (Fig. 1). This roller point has a spring and a special mechanism enabling automatic height adjustment of rollers conforming to the tongue rail requirement, making conventional adjustments unnecessary. As a result, point switching force can be reduced reliably without skilled workers (Fig. 2). Several hundred sets of this new roller point have already been deployed by JR (Fig. 3).

(2) Separable electric point machine
The NS-type electric point machine most frequently used on conventional lines has been in practical use for 35 years. Recently, however, the nature of maintenance work has changed appreciably in factors such as the reduction in the number of skilled workers and decreased lead time allowance of work. This necessitates simpler maintenance work, size/weight reduction and performance improvement.
The Railway Technical Research Institute (RTRI) has developed a completely new system (Fig. 4) for electric point machines using a special crank mechanism to burden external forces (such as lateral train pressure), resulting in a simpler structure divided into switch device and locking parts. This enables weight reduction of the electric point machine from 345 kg to 250 kg (switch device 123 kg + locking 127 kg). An endurance test (Fig. 5) of the new system has already been carried out on the side track and its performance has been verified. By introducing a separable electric point switch with reduced size and weight, it is possible not only to replace the machine safely, swiftly and at low cost, but also to realize a maintenance-free switch device with the help of reduced mechanical wear. In addition, since the layout freedom of the switch, locking, and crank devices is increased, this machine can easily adapt to any type of switch. Plans are underway for endurance tests by mounting this machine on the high-speed turnout of the main track.

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