Patent ID: 6109090
Filing Date: 2000-08-29
Classification: B21D,Y10T

Abstract:
A machine for working sheet metal comprising:a work surface (3) for supporting sheet metal (2) to be punched;a fixed structure (4) which supports the said work surface (3);a work station (5) provided with a hammer (38) movable along a first vertical axis (P) along which punching of the said sheet metal (2) occurs;a plurality of punch units (7), each including a first holder (21) and a punch tool (22);a plurality of die units (11), each including a second holder (31) and a die tool (32);a first rotatable table (6) supporting said punch units (7) for transfer to the said work station (5), a second rotatable table (8) supporting said die units (11) for transfer to said work station (5), first means (42) at said work station for centering each said punch unit (7) at said work station with respect to the said first vertical axis (P) by securing the respective said first holder (21) to the said fixed structure (4), and second means (43, 81) at said work station for centering each said die unit (11) with respect to the said first vertical axis (P) by securing the respective said second holder (31) to the said fixed structure (4), and means for punching the sheet metal by applying force to the die and punch tools at said work station, the said tables (6 and 8) being excluded from the securing of the holders to the fixed structure and therefore not being affected by mechanical stresses generated by the punching of the sheet metal, said stresses being transmitted directly from the said first and second centering means (42 and 43) to the said fixed structure (4).