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(11) | EP 0 154 069 A3 |
(12) | EUROPEAN PATENT APPLICATION |
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(54) | A control system for an elevatable and extendible structure |
(57) A digital computer based control system for a turntable ladder mounted on a vehicle
is arranged to limit extension and minimum elevation angle of the ladder in accordance
with the intended loading of the ladder. The system performs initial checks on parts
of the system and will permit only manual control at low speed where the operational
state of a part involved is unsatisfactory or outside the limits. In addition to monitoring
the stabilising jacks on the vehicle and preventing movement of the ladder which would
tend to increase an excessive bending force on it, the system automatically plumbs
the ladder so that its rounds are horizontal. The system can also be applied to control
a cage or platform on a telescopic boom. |