Device for accessing an underground facility, comprising an adjustable assistance cylinder

A device for accessing an underground facility including a frame forming an opening for accessing the underground facility and a lid pivotally mounted relative to said frame between a closed position in which the lid closes off all or part of the opening of the frame and an open position in which the lid allows passage through the opening of the frame,

• the device further including a mechanical cylinder with a helical spring extending according to a so-called longitudinal direction, the cylinder including a body which can vary in length according to the longitudinal direction according to a longitudinal force which is applied to said cylinder, between a retracted configuration and a deployed configuration, the helical spring tending to bring the body of the cylinder into the deployed position,
• the device being configured so that the cylinder assists the passage of the lid from the closed position to the open position and exerts on the lid a force opposing closure thereof during passage thereof from the open position to the closed position,
• wherein the cylinder includes an adjustable head connected to one end of the body of the cylinder and a mechanism for adjusting the longitudinal position of the adjustable head with respect to the body of the cylinder.