Marine knuckle boom crane
AssigneeItrec B.V.
InventorDiederick Bernardus Wijning
Life of this patent
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Abstract
A marine knuckle boom crane includes a pedestal and a crane housing rotational relative to the pedestal. A knuckle boom assembly is attached to the crane housing and includes a main boom and a spreader type jib. A hoisting system includes a first departure sheave and a second departure sheave on the jib, and a third departure sheave mounted to the main boom or to the crane housing. One or more winches drive a first, second, and third cable which are each connected to an object suspension device and each pass via the first, second, and third departure sheave, respectively, to the respective winch. The first, the second, and the third cable together define an inverted pyramid which diverges upwards from the object suspension device when handling the object.
Claims22
A marine knuckle boom crane comprising:
- a pedestal;
- a crane housing which is rotational relative to the pedestal about a vertical rotation axis;
- a knuckle boom assembly attached to the crane housing, the knuckle boom assembly comprising:
- a main boom having an inner end connected pivotally about a first horizontal pivot axis to the crane housing, an outer end, a topside, a bottom side, and opposed lateral sides;
- and
- a jib connected via a pivot structure pivotally to the main boom, the jib having a central longitudinal axis;
- a main boom luffing mechanism configured to pivot the main boom up and down relative to the crane housing;
- a jib pivoting mechanism configured to pivot the jib relative to the main boom, between a folded position of the knuckle boom assembly, in which the jib is folded back relative to the main boom, and extended positions of the knuckle boom assembly;
- and
- a hoisting system, comprising at least one departure sheave mounted on the jib,
- wherein the jib is a spreader structure jib having a load bearing spreader structure of which a base end connects to the pivot structure, which spreader structure supports remote from said base end a first departure sheave and a second departure sheave of the hoisting system, said first and second departure sheave being laterally spaced from one another at opposed lateral sides of the central longitudinal axis,
- wherein the hoisting system further comprises:
- a third departure sheave mounted to the main boom and/or to the crane housing;
- one or more winches;
- a first cable driven by one of said one or more winches;
- a second cable driven by one of said one or more winches;
- a third cable driven by one of said one or more winches;
- and
- an object suspension device configured to be connected to an object to be handled by the crane,
- wherein the first, the second, and the third cable are each connected to the object suspension device and respectively pass via the first, second, and third departure sheave, to the respective winch of said one or more winches, wherein the first, the second, and the third cable together define an inverted pyramid which diverges upwards from the object suspension device when handling the object.
Dependencies are inferred from the claim text.