There is described a mechanism for a hydraulic loading bridge for trucks and similar, with a load platform (26) which is moved up and down by hydraulic lifting arms (18, 20), which is provided with means (30) which after adjusting the platform to a determined angle, make it possible to move said platform up and down under said angle, and insure the tipping "to the front" of said platform (26) on the ground or work floor without any sliding of the platform thereon.