Adjustable and lockable joint for floor cleaning machines

A joint for floor cleaning machines, comprising:

• a first portion,
• a second portion which is articulated to said first portion,
• a third portion which is articulated to said second portion,
• said joint further comprising:
• first stable inclination means for a stable inclination of said second portion with respect to said first portion,
• second stable inclination means for a stable inclination of said third portion with respect to said second portion,
• wherein said first stable inclination means and said second stable inclination means being connected to a single lever and being operable by said single lever, and
• wherein said first portion comprises two mirror-symmetrical first half-shells, respectively a first mirror-symmetrical first half-shell and a second mirror-symmetrical first half-shell, each one of said first and second mirror-symmetrical first half-shells having
• a base, and
• a bay, which is monolithic with said base, having a substantially triangular contour and which forms a tray-like seat with an axis of extension that is parallel to a plane of arrangement of said base and is provided with a first through hole.