Automatic clamping device for slab material and clamping method associated therewith

Automatic clamping device for clamping a slab (90) of rigid material on the machining table (18) of an operating machine, said automatic clamping device comprising a central body (42) terminating at both ends in a bottom cavity (72) and a top cavity (77) each having a suction cup function and being intended to engage, respectively, with the table (18) and the slab (90),

• characterized in that the bottom cavity (72) is designed to engage with a through-hole (30) formed in the thickness of said table (18) and communicating with an air suction duct (26, 28) in turn connected to an air suction source, so as to form a single air suction circuit, said through-hole (30) being associated with shut off means (32, 36) for interrupting communication between said cavity (72) and said suction source and in that said central body (42) has, formed therein, an inner cylindrical chamber (56) housing a piston (58) associated with a stem (60) acting as a closing member movable, together with said piston (58), between a first position where it prevents fluid communication between said bottom cavity (72) and said top cavity (77) and a second position where it allows said communication with said sole air suction circuit, causing clamping, via the suction cup effect, of the slab (90) to the central body (42) of the automatic clamping device (40).