Modular unit for converting punching machines from single-punch to multiple-punch

A punching machine comprising:

• a turret at an upper portion of said machine;
• a worktable below said turret;
• an upper main cylindrical magazine rotatably supported by said turret and provided with a plurality of angularly spaced radial seats, a respective upper secondary cylindrical magazine accommodated in each of said radial seats, a plurality of punches in each of said secondary magazines, and a corresponding number of hammer elements above the punches in each of the secondary magazines, each of the secondary magazines being rotatable in the upper main cylindrical magazine;
• a corresponding lower main cylindrical die-holder magazine received in said worktable, rotatable synchronously with said upper cylindrical magazine and vertically aligned coaxially therewith, said lower main cylindrical die-holder magazine having angularly spaced further radial seats adapted to register with the radial seats of said upper main cylindrical magazine;
• lower secondary die-holders accommodated in said further radial seats and supported so as to be vertically aligned with said upper secondary magazines, each die-holder being provided with a plurality of dies in a number equal to a number of said punches in a corresponding upper secondary magazine;
• a first motor for producing a controlled rotation of said upper main cylindrical magazine with respect to said turret;
• a second motor with alternating operation for actuating, in controlled rotation, said hammer elements with respect to the corresponding secondary cylindrical magazines, said second motor having a vertically protruding transmission shaft, and a sprocket keyed onto said transmission shaft for engagement with corresponding sets of teeth formed perimetrically on each of said hammer elements;
• a third motor for actuating in a controlled rotation said lower main cylindrical magazine synchronously with said upper main magazine;
• a feeler element and a track formed perimetrically said upper main cylindrical magazine and being provided along its circumference with a plurality of recesses located substantially radially at each one of said radial seats for said upper secondary cylindrical magazines;
• and
• a supporting means for supporting said second motor, said supporting means floating on a horizontal plane and being actuated between two positions, a proximal position and a distal position, with respect to each of said hammer elements, by way of said feeler element which is elastically biased into constant contact with said track.