Lifting mechanism for an apparatus for lifting contruction boards, lifting apparatus comprising such a mechanism, lifting method using such an apparatus

Lifting mechanism (100) for a board lifter, comprising, by reference to the use position:

• a telescopic mast (10) comprising a fixed segment (12), a first telescopic movable segment referred to as “intermediate” segment (14) mounted slidingly inside the fixed segment (12), and a second telescopic movable segment referred to as “end” segment (16) mounted slidingly inside the intermediate segment (14);
• characterized in that the lifting mechanism (100) further comprises:
• a chain (20) arranged inside the fixed segment (12) and forming a loop engaged around a first pinion (121) arranged at an upper end of the fixed segment (12) and around a second pinion (122) arranged at a lower end of the fixed segment (12), one of the two pinions being engaged with a control shaft (31) of a means (30) for rotating the shaft, a lower end (16a) of the end movable segment (16) being fastened to a strand (21) of the chain (20);
• and in that:
• the fixed segment (12) comprises an upper internal guide stop (123) for guiding the intermediate movable segment (14) during sliding;
• the intermediate movable segment (14) comprises a lower external guide stop (141) for guiding against the fixed segment, and an upper internal drive stop (142);
• and
• the end movable segment (16) comprises a lower external guide stop (163) for parallel guiding of the intermediate movable segment (14), and an upper external lifting stop (164) for lifting the intermediate movable segment.