HYDRAULISCHE SICHERHEITS-STEUEREINRICHTUNG AN HYDRAULISCH ANGETRIEBENEN GERAETEN, INSBESONDERE SCHNEERAEUMMASCHINEN OD. DGL.

摘要

1. A hydraulic control device for the zero-pressure setting of a hydraulic drive line (3) between the pump and engine parts of the hydraulic drive unit of snow-clearing machinery in dependence on the attainment of a settable maximum pressure in the drive line, characterised in that the drive line (3) is connected via a pilot-operated two-way seating valve (4) to a hydraulic-liquid tank (6), and in that the control line (9) of the two-way seating valve (4) is connected to the drive line (3) by means of an electrically triggerable multi-way pilot valve (8) before the maximum pressure is reached, and in that, when the maximum pressure in the drive line (3) is exceeded, a plunger-type pressure switch (15) switches the pilot valve (8), and consequently the control line (9) to the two-way seating valve (4) and consequently the drive line (3), to through-passage to the tank (6) (interruption of the drive connection), and in that a pulse switch, which is provided within the reach of an operator, when operated switches the pilot valve (8) back to the operating position (maintenance of the drive connection).