| Patent Number |
Title Of Patent |
Date Issued |
| 5179770 |
Machine and method for fabricating a sheet metal structure having a corrugated core |
January 19, 1993 |
| Three metal foils are simultaneously fed in opposing relationship through a machine which automatically fabricates a sheet metal sandwich structure therefrom. The foils are first tensioned in aligned opposing relationship. The center sheet is then fed through a pair of free floating gear |
| 4311419 |
Method for drilling circuit boards |
January 19, 1982 |
| An entry material for use in drilling circuit boards to avoid marring of such boards comprises a wood pulp-glass composite substrate having aluminum foil bonded to the opposite surfaces thereof. This entry material is relatively economical and has a stiffness sufficient to avoid upward |
| 4269549 |
Method for drilling circuit boards |
May 26, 1981 |
| Backup material is formed from a pair of oppositely positioned metallic foil sheets between which an open metallic core having oppositely running node portions is sandwiched. The core may be sinusoidal with each node extending from one of the edges of the sheets to the opposite edges. Th |
| 4019826 |
Method for drilling circuit boards |
April 26, 1977 |
| A metal foil, of a metal such as aluminum, is held in place over the drilling entry surface of a circuit board to be drilled. The drill thus first enters the foil which acts as a shield which takes burrs, pressure foot marks and particle marks which would otherwise be imparted to the |
