Manhole comprising a device for safety closing and locking the manhole

A manhole (50) comprising a device for safety closing and locking the manhole (50), the device comprising:

• a cylinder (7), attached to a slab (8) which comprises centering pins (17, 17′), the cylinder (7) being rotatable around an axis a-a′ by action of an operating key (29) acting on the centering pins (17, 17′);
• and
• at least one anti-burglary block (1), which in locked position is positioned inside the cylinder (7) with one of the centering pins (17, 17′), said block (1) having a thickness equal to a height of the cylinder (7) and a curved surface matching an inner wall of the cylinder (7),
• wherein said block hides and protects an anti-theft bolt (2) inside a hole (2a), which crosses the entire anti-burglary block (1), said hole (2a) having a diameter, in a front portion, larger than a diameter of the anti-theft bolt (2) and said hole further having a diameter, in a back portion, equal to the diameter of the anti-theft bolt (2), an inner wall of the cylinder (7) having a threaded spot (16) configured to receive the anti-theft bolt (2), the anti-theft bolt (2) engaging within a body of the anti-burglary block (1) when tightened into the threaded spot (16), and
• wherein an end of the anti-theft bolt (2), in a closed position of the manhole, is housed in a locking hole (15) on a circular support (13) of a cover (4) of the manhole.