Method of making a composite material orthotic insert for enhanced control and durability
AssigneeNorthwest Podiatric Laboratory, Inc.
InventorDennis N. Brown
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Abstract
A composite material blank for an orthotic insert. The device is formed of layers of fiberglass and graphite fiber material. A first graphite fiber layer provides the overall structure with increased strength, while secondary graphite fiber reinforcement strips are arranged below the first and fifth rays of the foot to provide additional rigidity and control in these areas. The edges of the graphite fiber layers are recessed inwardly from the edges of the fiberglass layers so as to provide a graphite-free border which prevents cracks from propagating into the graphite fiber layers. The layers are bonded together by heat curing over molds.
Claims7
A method for forming a blank for an orthotic insert, said method comprising the steps of:
- forming a fiberglass-resin base layer having a heel end, a forefoot end, and medial and lateral sides;
- forming at least one graphite fiber-resin reinforcement layer;
- positioning said graphite fiber-resin reinforcement layer on said fiberglass-resin base layer so that medial and lateral edges of said reinforcement layer will be spaced inwardly from finished medial and lateral edges of said blank so as to form clear borders of said fiberglass-resin base layer between said medial and lateral edges of said graphite fiber-resin reinforcement layer and said medial and lateral edges of said blank, said clear borders each having a width sufficient to prevent microcracks formed in trimming of said fiberglass-resin base layer from reaching and propagating into said graphite fiber-resin reinforcement layer;
- bonding said fiberglass-resin base layer and said graphite fiber-resin reinforcement layer so that resin matrixes thereof join together and said layers form a unitary structure for engaging a plantar surface of a person's foot;
- and
- trimming said fiberglass-resin base layer along said edges thereof so as to form said finished medial and lateral edges of said blank.
Dependencies are inferred from the claim text.