Blind-side panel repair patch

A method for repairing the blind-side of a damaged section of a panel, comprising:

• cutting a circular opening in said panel to remove said damaged section;
• inserting a bolt through a central hole in a circular disc larger in diameter than said opening and smaller than twice the diameter of said opening;
• said circular disc having a slot from its outer peripheral edge to its central hole;
• flexing said disc to separate the edges of said slot;
• inserting one of said slot edges through said panel opening so that the radially outer portion of said disc is on said blind-side of said panel, and the radially outer portion of said disc on the other side of said slot is on said near-side of said panel;
• revolving said bolt around said panel opening to turn said disc entirely through said opening;
• pushing a plurality of fabric plies impregnated with a bonding agent through said opening;
• filling said opening with a plug of core material;
• laying a plurality of fabric plies impregnated with a bonding agent over the near-side of said panel on said plug and on the marginal regions of said panel around said opening;
• fitting a centrally bored support plate onto said bolt;
• and
• threading a nut onto said bolt and torquing said nut against said support plate to squeeze said blind-side and said near-side plies between said disc and said support plate to squeeze excess bonding agent into said opening and to express voids from said fabric plies.

A panel patch for repairing the blind-side of a damaged section of a panel from which the damaged portion has been cut out, leaving a smooth sided hole, comprising:

• a bolt, and a nut for threading on the distal end of said bolt, for exerting a squeezing force on said patch;
• a slit disc having a diameter larger than the diameter of said hole, and a central aperture for insertion onto said bolt, and a slit extending from the outer periphery of said disc to said central aperture, said disc being adapted to be secured and sealed to said panel blind-side on the marginal regions thereof around said hole;
• said slit disc being sufficiently flexible that one edge thereof adjacent said slit may be flexed out of the plane of said disc and inserted through said hole and over the blind-side of said panel on the marginal regions around said hole, and said disc may be turned through said hole from the near-side to the blind-side by revolving said bolt around the periphery of said hole;
• at least one ply of fabric adapted to be inserted on said bolt adjacent said disc, and larger in diameter than said panel hole so that it covers the marginal regions around said panel hole on said panel blind-side, and is urged thereagainst by said slit disc;
• a support plate having a central aperture for receiving the proximal end of said bolt and covering said panel hole and the marginal regions therearound, said nut adapted to bear against said support plate and apply pressure therewith against a plug of fill material filling said hole;
• at least one ply of fabric adapted to be impregnated with a bonding agent and inserted onto said bolt to lie between said panel, on the marginal regions thereof around said panel hole, and be compressed by said support plate against said panel and said fill material to express voids from said near-side ply while said bonding agent cures.

A blind-side repair patch kit for repairing a hole of a certain diameter in a composite material panel having a blind-side to which access is restricted, and a near side which is readily acessible, comprising:

• an elongated tension member having a distal end and a proximal end;
• an enlarged head means on said distal end for transferring tensional stress in said tension member to compressive stress in articles between said head means and the blind-side of said panel;
• means attachable to said proximal end of said tension member for creating and exerting tensile stress in said tension member;
• a circular disc having a central hole slightly larger in diameter than the diameter of said tension member for receiving said tension member, and having a slit extending from the outer periphery of said disc to the central hole thereof, said disc being sufficiently flexible that said disc may be twisted to open said slit so that one edge thereof my be slid through said panel hole and onto the blind disc thereof, and said disc may be rotated through said hole to lie completly on the blind-side of said panel overlying the marginal regions around said hole;
• at least one fabric ply about equal in diameter to said slit disc and adapted to be impregnated with an adhesive and impaled on said tension member between said slit disc and said panel, overlying the marginal regions around said panel hole and pressed thereagainst by said slit disc under pressure from said tension member head means, whereby voids and excess adhesive are squeezed out of said fabric ply and said ply is held firmly pressed against said panel blind-side while said adhesive cures.