Patent ID: 6279370
Filing Date: 2001-08-28
Classification: B21D,F15B,Y10T

Abstract:
Arrangement for performing a secondary operation in a pressing tool for sheet metal forming, comprising a primary cylinder/piston unit (1) including a piston rod (1b) and a piston (1a) arranged to pressurise an operating fluid upon closing of said pressing tool for performing a primary forming operation on a sheet metal work piece, characterised in that a secondary cylinder/piston unit (7) is mounted within said pressing tool, said secondary cylinder/piston unit (7) having a piston (7b) and a piston rod (7c), and tooling for conducting said secondary operation mounted on said piston rod (7c), the arrangement further comprising means (2, 20, 21) for storing said pressurised operating fluid and means for selectively allowing a first volume flow of operating fluid of a first pressure to the secondary cylinder/piston unit (7), for advancing the piston (7b) and piston rod (7c) thereof until the tooling encounters the sheet metal work piece upon which it is designed to act and means for allowing a second volume flow of operating fluid of a second, relatively higher, pressure to the secondary cylinder/piston unit (7), as the tooling encounters said sheet metal work piece, for performing the secondary forming operation upon said work piece.