Abstract: A tower pivotally connected to a base mounting on a platform is movable by raising and lowering means between a vertical operating position and a substantially horizontal stored position. A turntable has its non-rotatable part hingedly connected to the top of the tower and a jib support structure including a cab is connected to the rotatable part of the turntable and includes jib support brackets extending above the cab to which a jib is pivotally mounted for luffing movement by a power means connected between the jib and jib support structure. And second power means connected between the non-rotatable part of the turntable and the top of the tower are operative to fold the turntable, jib support structure and jib 180.degree. about the hinge connection to an inoperative position alongside the tower when the tower is moved to the stored position and unfold to an operative position on top of the tower when the tower is moved to the vertical operating position.

Abstract: A tower crane tower pivoted at its base to a mobile platform for movement from a horizontal travel position to a vertical operating position has a jib support structure mounted at the top of the tower which includes a part rotatable about the vertical axis of the tower, pivot structure connecting a jib to the tower including a jib pivot connecting the jib to the jib support structure, a hydraulic cylinder connected for luffing the jib, and jib alignment structure operatively connected between the jib support structure and the jib and being movable to alter the disposition of the jib pivot and an end of the jib luffing cylinder relative to the tower in such a way as to alter the angle between the jib and the tower axis without operation of the jib luffing cylinder, the jib alignment structure arranged to move between an operating position, in which the jib luffing cylinder can luff the jib between a raised position above the top of the tower and a lowered position in which the jib forms an angle of the order o

Abstract: A crane including a base, a tower pivoted thereto, a turntable mounted on top of the tower and a jib with a jib support platform hinged to the rotatable part of the turn table.

Abstract: A tower pivotally connected to a base mounting on a mobile platform is movable by raising means between a vertical operating position and a substantially horizontal travel position. A turntable at the top of the tower carries a tiltable unit which includes a jib support means and a jib pivotally connected to the jib support and adapted for luffing movement by a first hydraulic cylinder means connected between the jib and jib support means. The tiltable unit is pivotally connected to the tower and a second hydraulic cylinder means is connected to pivot the tiltable unit between an operating position and a folded position. After the jib is lowered by the first hydraulic cylinder means to an angle between about 60.degree. and 90.degree.