The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 26, 2002
Filed:
May. 12, 1995
Ho Chong Lee, Endicott, NY (US);
Ganesh Subbarayan, Vestal, NY (US);
Paul Gerard Wilkin, Endicott, NY (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A method of punching a via or through hole in a polymer-metal laminate workpiece in a punch press. The punch press has a punch tool, a driver coil for driving the punch tool through the polymer-metal laminate workpiece, and a stopper for stopping the punch travel of the punch tool and mechanically returning the punch tool to its starting position. The method includes the steps of applying an electrical current pulse through the driver coil to electromagnetically drive the punch downward to and through the workpiece, and then elastically colliding the punch tool with the stopper to stop and return the punch tool on an upward return stroke. Subsequently a second, braking pulse is applied through the driver coil to electromagnetically brake the punch. The second electrical current is applied after the start of the punching pulse, for a time and magnitude sufficient to brake the punch press.