UNA INSTALACION DE FRENO DE DOS CIRCUITOS POR AIRE COMPRIMI-DO.

摘要

The trailer brakes are fitted with a safety valve in the supply air line which operates when there is a lead in the trailer system, and which vents the brakes rapidly, while shutting off the line so that the hold-off brakes are applied with a minimum of delay. The valve is held in the closed position using a spring (27) loaded piston (28) which is also moved by the differential pressure in the towing unit and trailer brakes. In order to ensure that the valve element does not stick through corrosion, it floats when the brakes operate normally. The brake line pressure holds the piston away from its seating by having the minimum normal brake line pressure just greater than the spring pressure. The piston thus moves with changes in the line pressure to keep the piston seals freely moving.