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US 4,070,020 AGranted
Composite high strength to weight structure with fray resistance
AssigneeFansteel Inc.
InventorPol Dano
Life of this patent
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AssigneeFansteel Inc.
InventorPol Dano
Estimating the term…
A novel structural member, such as a tennis racket frame, having an unusually high strength to weight ratio is provided comprising an expanded foamed plastic core integrally bonded to a shell comprising at least one layer of resin-coated unidirectionally oriented graphite fibers, the shell completely encasing the core at any transverse cross section of the structural member with a veiling strip wrapped around said core beneath the innermost or beyond the outermost of the graphite fiber layers, or both. The structural member is prepared by wrapping a veiling strip around a core strip comprising a foamable resin composition at least once around, wrapping at least one layer of resin-coated unidirectionally oriented graphite fibers about said veiling wrapped core with a starting edge of said graphite fiber layer below the outermost edge of said veiling strip, wrapping a second veiling strip about the outermost of said graphite layers with a starting edge of said last-named strip below the outermost edge of said last-named graphite layer, placing said wrapped core strip within a mold cavity, sealing the mold cavity and activating the foamable resin composition to cause expansion and generate pressure within the mold cavity and thereby provide intimate bonding of the core to the shell.
An elongated structural member of high strength to weight ratio comprising an elongated core of an expanded porous resinous material integrally bonded to a shell comprising at least one elongated layer of resin-coated unidirectionally oriented graphite fibers, said shell completely encasing said core at any cross section transverse to the length of said member, each of said elongated layers having graphite fibers oriented at an angle to its length, and being wrapped around said core widthwise with its side edges running along the length of said core, and a veiling strip of lightweight, loose construction of a material other than graphite wrapped around said core beneath the innermost of said layers and covering the leading edge of said innermost layer.
In a tennis racket frame having a handle and an ellipsoid head attached to one end of said handle and a grip element at the opposite end of said handle, an improved construction wherein said frame comprises an elongated structural member of high strength to weight ratio comprising a core of an expanded porous resinous material integrally bonded to a shell comprising at least one layer of resin-coated unidirectionally oriented graphite fibers, said shell completely encasing said core at any cross section transverse to the length of said member with a veiling strip of lightweight, loose construction of a material other than graphite wrapped around said core beneath the innermost of said layers and covering the leading edge of said innermost layer.
In a tennis racket frame having a handle and an ellipsoid head attached to one end of said handle and a grip element at the opposite end of said handle, an improved construction wherein said frame comprises a structural member of high strength to weight ratio comprising a core of an expanded porous resinous material occupying from about 20 to about 60 pounds per cubic foot, said core being integrally bonded to a shell comprising a plurality of layers of resin-coated unidirectionally oriented graphite fibers wound around said core with a veiling strip of lightweight, loose construction of a material other than graphite wrapped around said core beneath the innermost of said layers and covering the leading edge of said innermost layer and a second veiling strip of lightweight, loose construction of a material other than graphite wrapped around the outermost of said layers, at least one of said graphite fiber layers having its fibers oriented in a direction different from the direction of orientation of the fibers in at least one other of said layers, each end of said members being at the grip end of said handle, said member extending from one of its ends at the grip end of said handle up one side of said handle, around a major portion of the head of said frame and down the other side of said handle to the opposite end of said member at the grip end of said handle.
An elongated structural member of high strength to weight ratio comprising an elongated core of an expanded porous resinous material integrally bonded to a shell comprising at least one elongated layer of resin-coated unidirectionally oriented graphite fibers, said shell completely encasing said core at any cross section transverse to the length of said member, each of said elongated layers having graphite fibers oriented at an angle to its length, and being wrapped around said core widthwise with its side edges running along the length of said core, and a veiling strip of lightweight, loose construction of a material other than graphite wrapped around the outermost of said layers with the leading edge of the veiling strip covering the trailing edge of the outermost layer.
Dependencies are inferred from the claim text.