Lifting apparatus

In a lifting apparatus comprising:

• a movable chassis;
• a platform disposed over said chassis;
• an elongated telescopic boom body extending between said chassis and said platform, said boom body comprising a plurality of boom sections which are telescopable into and out of said telescopic boom body in the longitudinal direction thereof;
• inclining means interposed between said chassis and said telescopic boom body for raising said telescopic boom body so that it is inclined with respect to said chassis;
• extension means housed within said boom body for telescoping said boom body to elongate and contract same;
• wherein said platform, said telescopic boom body and said chassis are arranged to form a Z-shape when viewed from the side thereof and said telescopic boom body is telescopically moved and inclined relative to said chassis so as to move said platform vertically, the improvement which comprises an angle detecting means for issuing a signal corresponding to the angle of inclination of said telescopic boom body relative to said chassis when said telescopic boom body is inclined relative to said chassis, means responsive to a signal from said angle detecting means for operating said extension means for causing the elongation speed of the telescopic boom body to follow the variation of the angle of inclination of the telescopic boom body relative to said chassis so that the tip end of said telescopic boom body moves vertically relative to said chassis.