MODULAR DEVICE FOR CLAMPING AND/OR SUPPORTING A PIECE TO BE WORKED

A modular device for clamping and/or supporting a workpiece (P) on a base plate (B) of a machine tool, which comprises a main body (2) with a central cavity (3), having a first longitudinal end portion (4) and a second longitudinal end portion, the latter having an external thread, first fixing means (11) comprising a pin (12) adapted to be introduced into the first end portion (4) of the body (2) and to be secured to the workpiece (P), second fixing means (13) adapted to be introduced into the second end portion and to be secured to the base plate (B), a ring nut (28) mounted outside the main body (2) and screwed onto the external thread of the second end portion, a plurality of locking members (19) adapted to be introduced into corresponding angularly offset seats (18) of the main body (2) and each having an outer end (21) adapted to cooperate with the inner surface of the ring nut (28) to exert a radial thrust thereupon. The pin (12) comprises an annular recess, proximate to a longitudinal end, with a substantially conical first contact surface. The locking members (19) have an inner end with a first portion whose concave shape is complementary to that of the conical first contact surface.