Device for raising and unfolding the mast and for raising the jib of a crane

#The present invention is concerned with lifting or handling appliances and more particularly with cranes. This invention relates more specifically to a motorized device for raising and unfolding the mast and for raising the jib of a crane and even more particularly of a crane with a jib having multiple functions, such as is described by the document FR 2792627 A in the Applicant's name.

#The subject of this document is a crane of modifiable configuration which comprises a mast, mounted on a chassis, and a distributing jib, composed of successive elements articulated on one another about horizontal axes, the first jib element, called a jib foot, itself being articulated about a horizontal axis at the top of the mast. This first jib element and, if appropriate, the following element can be brought into a substantially vertical position, in alignment with the raised mast, so as to increase the height of this mast. All the jib elements comprise a rolling track for the same carriage. Thus, the crane may be used as a crane with a long or shortened, horizontal or inclined distributing jib or else as a crane with a “swan neck” jib, depending on the configuration of the jib elements, the height of the crane also being adjustable according to the number of jib elements brought into the prolongation of the mast.

#In such a crane with a jib having multiple functions, the mast may itself be capable of being unfolded and being used in a plurality of positions, and the various configurations of the jib elements may thus be combined with the variable configurations of the mast. In particular, the foldable mast is composed of two mast elements, to be precise a lower mast element, articulated on the chassis of the crane, and an upper mast element, articulated on the top of the lower mast element. In particular, the lower mast element is articulated on a revolving chassis orientable about a vertical axis on a basic chassis mounted an wheels, the crane thus being capable of taking the form of an independent rolling appliance.

#The invention will be understood more clearly from the following description, with reference to the accompanying diagrammatic drawing illustrating, by way of example, one embodiment of this device for raising and unfolding the mast and for raising the jib of a crane:

#FIG. 1 is a side view of a crane equipped with the device according to the invention, in folded transport position;

#FIGS. 2, 3, 4, 5 and 6 are aide views, similar to FIG. 1, illustrating successive phases in the raising and unfolding the mast and in the raising of the jib of this crane;

#The crane illustrated in the drawing in various positions possesses a basic carrying chassis 1 mounted so as to roll on wheels 2 and provided with stabilizers 3. Mounted on the basic chassis 1 is a revolving chassis 4 orientable about a vertical axis 5 and provided with a driver's cab 6 on one of its sides.

#On the other side of the revolving chassis 4 is mounted a foldable mast 7 composed of a lower mast element a and of a upper mast element 9, each of polygonal cross section and of caisson-type structure The lower mast element 8 is articulated by means of its base, about a horizontal axis 10 on a lower part of the revolving chassis 4. The upper mast element 9 is articulated by means of its base, about a horizontal axis 12, on the top of the lower mast element 8, this intermediate joint of the mast 7 allowing a relative pivoting of the elements 8 and 9 through an angle of approximately 180°.

#The foldable mast 7 is held by means of a double guy 13 which connects the base of the upper mast element 9 to the upper part of the revolving chassis 4.