Control system for longwall face support frames
AssigneeHermann Hemscheidt Maschinenfabrik GmbH & Co.
InventorsGuy Geuns, Werner Reinelt
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Abstract
A control system for longwall face support frames as used in mines, the system comprising pushing rams which are adapted to be actuated at two different pressures (for example, a low pressure of about 70 to 120 bar for non-defined cutting and a high pressure of 120 to 350 bar for defined cutting) with each pushing ram being individually actuatable by a respective non-return valve arrangement, the pushing rams being connected by a common pressure line to an hydraulic pressure unit.
Claims7
A control system for longwall face support frames as used in mines, the control system comprising pushing rams adapted to be actuated at two different pressures, namely, one pressure for non-defined cutting and the other pressure for defined cutting, a respective non-return valve arrangement for each pushing ram whereby each ram is individually actuable by its respective non-return valve arrangement, a common pressure line connecting the pushing rams to a hydraulic pressure unit, a further non-return valve arranged to be actuated in dependence on the pressure of the hydraulic pressure unit and disposed in the common pressure line between the hydraulic pressure unit and the pushing rams, and an electronic control unit arranged to actuate the further non-return valve via two-position valve actuated by an electromagnet so that the further non-return valve is closed when the electromagnet drops out.
Dependencies are inferred from the claim text.