Abstract: A crane includes: a boom; a jib that is provided on a leading end side of the boom; and a strut that is provided at one or both of a leading end portion of the boom and a base end portion of the jib, and to which a jib support pendant is connected, the strut, to which the pendant is connected, being provided with strut rotationally moving means having: a first bar-like member rotationally connected, at a first end portion thereof on one side, to a leading end portion of the strut on an opposite side thereof to a side, on which the pendant is connected; and a direct acting apparatus that applies, to the first bar-like member, a force pulling the first bar-like member toward the other side along a longitudinal direction of the first bar-like member.

Abstract: A hoisting crane comprising a substantially hollow vertical column, a jib, a jib winch and a jib hoisting cable is provided. The crane further a hoisting winch and an associated hoisting cable, the hoisting winch being disposed in the column, so that the hoisting cable extends from the winch through the column. The jib winch and the hoisting winch are arranged on a rotatable winch support, such that the winch support is mounted movable with respect to the vertical column. The hoisting crane further comprises a deep water winch positioned below the rotatable winch support and an associated deep water cable for raising and lowering a load extending through the rotation axis of the rotatable winch support, so that the deep water cable extends from the deep water winch through the hollow vertical column. The present invention further relates to a vessel provided with such a crane.

Abstract: A jib crane which can prevent an unexpected movement of a burden and can sufficiently ensure the safety of a burden handling work is disclosed. The jib crane has hoisting wire ropes for lifting and landing a hook, derricking wire ropes for derricking operation of a jib, and a conversion device for fixing tips of the wire ropes to a revolving frame of a revolving table. The conversion device has a V-shaped link pivotally supported on a bearing bracket via a pivot pin. The tips of the wire ropes are connected to paired link arms of the V-shaped link.

Abstract: While a crawler body 110 is traveling, infrared sensors 144 and an elevational difference calculator 132 incorporated in a controller 130 detects the magnitude of a step present ahead of the crawler body 110. A safety speed calculator 134 calculates a safety speed based on the magnitude of the step detected and on the position of the platform 116 relative to the crawler body 110, which position is detected by various detectors 141˜143 and by a position calculator 133. A comparator 135 compares this safety speed with the traveling speed of the crawler body 110, and if the current speed of the crawler body 110 is greater than the safety speed, then the comparator 135 outputs a warning signal. Upon receiving this signal, a restrictor 136 controls a valve controller 131 to reduce the speed of the crawler body 110 such that the crawler body 110 can travel over the step safely.

Abstract: There is disclosed a mobile crane having at least one hollow load bearing support member which is rotatable about a base. The load bearing support member is pivotally connected to a hollow boom which telescopically receives a plurality of secondary hollow and interengageable booms. The load bearing support member and boom are pivotally connected by an inwardly collapsible support. The crane cable is connected to a drive source and extends within the hollow booms and load bearing support member and is releasably retained by at least one boom. The crane may be automatically unfolded from a storage position when the boom is substantially parallel to the mast, to an operational position when the boom is angularly inclined to the load bearing support member.