Abstract: A plurality of key switches are provided, each of which is connected, at one end, to the ground, and at the other end, to a power supply, by means of a resistor. The key switches are coupled, at the connection point with the resistor, to input buffers. Each input buffer outputs an electrical signal when the corresponding key switch is turned on. A counter circuit is provided for counting clock signals supplied from a CPU at predetermined intervals. The output data of this counter circuit is supplied to selectors, which select one of the input buffers, in accordance with the output data of the counter circuit, and supply the output signal of the selected input buffer to the CPU.

Abstract: A device for increasing the factor of adhesion between the wheel of a railway vehicle and a rail, in which adhesion increasing grains are ejected together with air to a point between the wheel and the rail. The vertical aim of the ejection nozzle is automatically controlled depending on the deflection of an elastic member between the undercarriage and the wheel.

Abstract: A sanding apparatus improves adhesion between a railcar wheel and a rail by supplying adhesion intensifying particles to the contact faces. Sand and/or quartz particles, having diameters such that at least 50% of the particles are 100 to 300 micrometers, are mixed with compressed air and jetted at high velocity through a U-shaped storage chamber, out a nozzle, to the wheel-rail contact area. In the nozzle, a compressed air supply pipe surrounds and projects beyond the end of the particle supply pipe to create an air curtain surrounding the jetted particles. A heater, a heat insulation member, or constantly leaking air may be used to prevent freezing in the pipes.