Blind-side repair patch kit

A blind-side repair patch kit for repairing a first side of a damaged panel to which access is restricted and wherein the damaged portion of said panel is cut out with a hole saw leaving a circular hole in said panel, said repair being made from the other side of said panel, to which access is available, comprising:

• a tension member for transmitting a tensile force exerted from the other side of the panel to the first side;
• a tension maker attachable to said tension member for putting said tension member in tension;
• a substantially flat flexible disc having a diameter substantially larger than said hole and sufficiently flexible that it can be flexed and passed through the hole, and sufficiently stiff that it can exert sufficient pressure on the marginal regions around the hole on the first side of the panel to express air bubbles from an adhesive impregnated fabric patch and hold the patch in place under pressure against the first side of the panel on the marginal regions around the hole;
• a blind-side solid washer slightly smaller in diameter than the panel hole and adapted to be coupled to said tension member and passed through the hole for transmitting and distributing the tensile force exerted by said tension member through said flexible disc to the first side of the panel around the marginal regions of the hole;
• at least one fabric disc adapted to be impregnated with an adhesive and having a diameter about equal to the diameter of said flexible disc and adapted to be inserted coaxially onto said tension member and squeezed between said flexible disc and the first-side of said panel;
• a near side back-up plate adapted to be disposed on said tension member in force transmitting relationship with said tension maker for transmitting and distributing force from said tension maker to said panel near side over the marginal regions thereof around said hole.

A blind-side repair patch kit for applying, on one side of a panel, a load-bearing structural repair patch over a hole of a certain size through said panel, wherein the hole itself can serve as the sole avenue of access to said one side from the other side of the panel, comprising:

• at least one repair ply of sheet material adapted to be coated with a bonding agent for bonding said ply to said panel, said ply of sheet material having an area substantially greater than said hole area and a shape such as to substantially overlap said hole on all sides thereof, thereby overlying the marginal regions of said hole when placed thereover in alignment with the axis thereof;
• a tension transmission member having a distal end, with a head formed thereon for engagement with a solid washer, and a proximal end for protrusion through said panel hole to said other side of said panel;
• a tension source and locking means for engaging said proximal end and putting said tension transmission member in tension and maintaining said tension;
• a flexible washer having an outside dimension about equal to the outside dimension of said ply of sheet material, said flexible washer having a hole through the center thereof for receipt of said tension transmission member;
• said solid washer having a central hole larger in diameter than said tension transmission member for passage thereof through said central hole, and smaller than said head so that tension in said tension transmission member will cause said head to bear against said solid washer, said solid washer having an outside dimension slightly smaller than said panel hole for insertion through said panel hole before inserting said flexible washer therethrough, and thereafter lying on the side of said flexible washer remote from said panel and bearing thereagainst under the tensile force of said tension transmission member to apply pressure through said flexible washer to said ply of sheet material to ensure good adhesion to said panel.

A blind-side repair patch kit for securely adhering a load-bearing structural repair patch to one side of a panel over a hole in said panel, wherein access to said one side is by way of said hole from the other side of said panel, said kit comprising:

• at least one ply of a structural load-bearing filamentous sheet material having an area substantially greater than said hole and a shape such as to substantially overlap said hole on all sides thereof, said sheet material adapted to be adhered with a bonding agent to said one side of said panel over said hole and substantially overlapping all marginal regions therearound to provide a stress transfer structure across said hole to minimize stress concentration in said panel around the edges of said hole;
• a first flexible washer having an area substantially greater than the area of said hole, said flexible washer being sufficiently flexible to be flexed and inserted through said hole from said other side, and sufficiently resilient to exert a compressive force toward said sheet material over substantially the entire area of said flexible washer when pressed toward said panel by a rigid washer placed over said flexible washer and urged toward said panel by a tension member extending through said panel hole to said other side at said panel;
• said rigid washer having an outside dimension slightly smaller than said hole such that said rigid washer can pass straight through said hole;
• said tension member having a length sufficient to extend from said rigid washer, through said flexible washer, filamentous sheet material and said panel when assembled in that order and having a diameter smaller than said central hole;
• means for exerting tensile force on said tension member;
• means for engaging said tension member on said other side of said panel and preventing movement of said tension member toward said one side from said other side after said tension member is put in tension;
• means for coupling said tension member and said rigid washer, such that tension in said tension member is converted to pressure of said rigid washer against said flexible washer, whereby said filamentous sheet material is squeezed against said marginal regions around said panel hole on said one side of said panel to compress said sheet material and express air bubbles therefrom while said bonding agent cures.