Honeycomb sandwich panel structure and method of making same

Claim 1

THE METHOD OF MAKING A HIGH-STRENGTH SANDWICH STRUCTURE WHICH COMPRISES ASSEMBLING A PAIR OF METAL SURFACE SHEETS AT EACH FACE OF A LOW-DENSITY CELLULAR HONEYCOMB CORE WITH THE EDGES OF THE CELLS AT THE OPEN ENDS THEREOF OPPOSIRE THE SURFACE SHEETS, INTERPOSING BETWEEN EACH FACE OF SAID CORE AND ITS ADJACENT SURFACE SHEET A BONDING SHEET OF OPEN-MESH, GLASS-FIBRE FABRIC EMBEDDED IN A LAYER OF ADHESIVE CONSISTING OF AN UNCURED, DRY, SUBSTANTIALLY SOLVENT-FREE, THERMOSETTING PHENOL FORMALDEHYDE-VINYL ACETAL RESIN, APPLYING PRESSURE TO THE ASSEMBLED STRUCTURE TO CAUSE THE SURFACE SHEETS AND THE EDGES OF THE CELLS OF THE CELLULAR CORE TO BE FORCED AGAINST THE ADHESIVE OF THE INTERPOSED BONDING SHEET, AND, WHILE MAINTAINING SAID PRESSURE, APPLYING HEAT TO THE ADHESIVE IN AN AMOUNT SUFFICIENT TO CURE AND IMPART A FINAL SET THERETO IN SITU AND TO BOND SAILD ADHESIVE LAYERS DIRECTLY TO SAID SURFACE SHEETS AND THE EDGES OF THE CELLS OF SAID CELLULAR CORE.