Patent ID: 8814153

Claim:
Automatic clamping device for clamping a slab of rigid material on a machining table of an operating machine, said automatic clamping device comprising: a central body terminating at respective ends thereof in a bottom cavity and a top cavity, the bottom and top cavities having a suction cup function and being intended to engage, respectively, with the table and a slab; wherein the bottom cavity is designed to engage with a through-hole formed in the thickness of said table and communicating with an air suction duct connected to an air suction source, so as to form a single air suction circuit, said through-hole being associated with shut-off means for interrupting communication between said bottom cavity and said air suction source; and wherein said central body has, formed therein, an inner cylindrical chamber housing a piston associated with a stem acting as a closing member, said stem being movable, together with said piston, between a first position where the stem prevents fluid communication between said bottom cavity and said top cavity and a second position where the stem allows said communication with said single air suction circuit, causing clamping, via suction cup effect, of the slab to the central body of the automatic clamping device; and wherein the central body has a first internal duct connecting the bottom cavity and the inner cylindrical chamber, and a second internal duct connecting the top cavity and the bottom cavity, and wherein the stem in the second position allows fluid communication between the top cavity and the bottom cavity via the second internal duct and apart from the inner cylindrical chamber being used as an intermediary for said communication.