Method for preparing a composite high strength to weight structure with fray resistance

Claim 1

A method of producing a structural member of high strength to weight ratio comprising forming an elongated core strip comprising a foamable resin composition, forming a shell about said core strip by wrapping said core strip with a veiling strip and thereafter wrapping at least one elongated sheet of resin-coated unidirectionally oriented graphite fibers about said core with the side edges of said graphite fiber strip running along the length of said core and the trailing edge of said veiling strip covering the leading edge of said graphite fiber strip, placing said wrapped core within a mold cavity, sealing said mold cavity, activating said foamable resin composition to cause expansion thereof and generate pressure within said mold cavity pressing said core against said shell and thereby providing intimate bonding of said core to said shell, and thereafter removing said core and said shell from said mold cavity as an integral composite structure.

Claim 2

A method of producing a structural member of high strength to weight ratio comprising forming an elongated core strip comprising a foamable resin composition, forming a shell about said core strip by wrapping said core strip with a veiling strip and thereafter wrapping at least one elongated sheet of resin-coated unidirectionally oriented graphite fibers about said core with the side edges of said graphite fiber strip running along the length of said core and the trailing edge of said veiling strip covering the leading edge of said graphite fiber strip, placing said wrapped core within a mold cavity, sealing said mold cavity, activating said foamable resin composition to cause expansion thereof and generate pressure within said mold cavity pressing said core against said shell and thereby providing intimate bonding of said core to said shell, and thereafter removing said core and said shell from said mold cavity as an integral composite structure.

Claim 9

A method of producing a tennis racket frame of high strength to weight ratio comprising providing a mold cavity shaped in the form of a tennis racket frame having a handle with a grip at one end and a head of ellipsoid shape attached to the other end, the handle grip of said mold cavity having two substantially parallel cavity portions corresponding to two sides of said handle, forming an elongated core strip comprising a foamable resin composition, wrapping said core strip with an elongated veiling strip aligned along the length of said core strip, wrapping said core strip within said veiling strip with a plurality of layers of resin-coated unidirectionally oriented graphite fibers, at least one of said 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 and the innermost of said layers having its leading edge below the trailing edge of said veiling strip, wrapping a second veiling strip about the outermost of said graphite fiber layers with the leading edge of said second veiling strip covering the trailing edge of said outermost layer, arranging said wrapped core within said mold cavity with both ends of said wrapped core at the grip end of said mold, said wrapped core extending from one of its ends at the grip end of said mold cavity, up one of said substantially parallel cavity portions in the handle portion of said mold cavity, around a major portion of the head portion of said mold cavity and down the other substantially parallel cavity portion in the handle portion of said mold cavity to terminate at the grip end of said mold cavity, thereafter sealing said mold cavity, heating said foamable resin composition to cause expansion thereof and generate pressure within said mold cavity pressing said core against said layers of graphite fibers and thereby provide intimate bonding of said core to said layers, and thereafter removing said expanded wrapped core as an integral composite tennis racket frame.

Claim 10

A method of producing a tennis racket frame of high strength to weight ratio comprising providing a mold cavity shaped in the form of a tennis racket frame having a handle with a grip at one end and a head of ellipsoid shape attached to the other end, the handle grip of said mold cavity having two substantially parallel cavity portions corresponding to two sides of said handle, forming an elongated core strip comprising a foamable resin composition, wrapping said core strip with an elongated veiling strip aligned along the length of said core strip, wrapping said core strip within said veiling strip with a plurality of layers of resin-coated unidirectionally oriented graphite fibers, at least one of said 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 and the innermost of said layers having its leading edge below the trailing edge of said veiling strip, wrapping a second veiling strip about the outermost of said graphite fiber layers with the leading edge of said second veiling strip covering the trailing edge of said outermost layer, arranging said wrapped core within said mold cavity with both ends of said wrapped core at the grip end of said mold, said wrapped core extending from one of its ends at the grip end of said mold cavity, up one of said substantially parallel cavity portions in the handle portion of said mold cavity, around a major portion of the head portion of said mold cavity and down the other substantially parallel cavity portion in the handle portion of said mold cavity to terminate at the grip end of said mold cavity, thereafter sealing said mold cavity, heating said foamable resin composition to cause expansion thereof and generate pressure within said mold cavity pressing said core against said layers of graphite fibers and thereby provide intimate bonding of said core to said layers, and thereafter removing said expanded wrapped core as an integral composite tennis racket frame.

Claim 12

A method of producing a structural member of high strength to weight ratio comprising forming an elongated core strip comprising a foamable resin composition, forming a shell about said core strip by wrapping at least one elongated sheet of resin-coated unidirectionally oriented graphite fibers about said core strip with the side edges of said graphite fiber strip running along the length of said core, wrapping a veiling strip about the outermost of said graphite fiber sheets, placing said wrapped core within a mold cavity, sealing said mold cavity, activating said foamable resin composition to cause expansion thereof and generate pressure within said mold cavity pressing said core against said shell and thereby providing intimate bonding of said core to said shell, and thereafter removing said core and said shell from said mold cavity as an integral composite structure.

Claim 13

A method of producing a structural member of high strength to weight ratio comprising forming an elongated core strip comprising a foamable resin composition, forming a shell about said core strip by wrapping at least one elongated sheet of resin-coated unidirectionally oriented graphite fibers about said core strip with the side edges of said graphite fiber strip running along the length of said core, wrapping a veiling strip about the outermost of said graphite fiber sheets, placing said wrapped core within a mold cavity, sealing said mold cavity, activating said foamable resin composition to cause expansion thereof and generate pressure within said mold cavity pressing said core against said shell and thereby providing intimate bonding of said core to said shell, and thereafter removing said core and said shell from said mold cavity as an integral composite structure.

Claim 14

A method of producing a tennis racket frame of high strengh to weight ratio comprising providing a mold cavity shaped in the form of a tennis racket frame having a handle with a grip at one end and a head of ellipsoid shape attached to the other end, the handle grip of said mold cavity having two substantially parallel cavity portions corresponding to two sides of said handle, forming an elongated core strip comprising a foamable resin composition, wrapping said core strip with an elongated veiling strip aligned along the length of said core strip, wrapping said core strip within said veiling strip with a plurality of layers of resin-coated unidirectionally oriented graphite fibers, at least one of said 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 and the innermost of said layers having its leading edge below the trailing edge of said veiling strip, arranging said wrapped core within said mold cavity with both ends of said wrapped core at the grip end of said mold, said wrapped core extending from one of its ends at the grip end of said mold cavity, up one of said substantially parallel cavity portions in the handle portion of said mold cavity, around a major portion of the head portion of said mold cavity and down the other substantially parallel cavity portion in the handle portion of said mold cavity to terminate at the grip end of said mold cavity, thereafter sealing said mold cavity, heating said foamable resin composition to cause expansion thereof and generate pressure within said mold cavity pressing said core against said layers of graphite fibers and thereby provide intimate bonding of said core to said layers, and thereafter removing said expanded wrapped core as an integral composite tennis racket frame.

Claim 15

A method of producing a tennis racket frame of high strengh to weight ratio comprising providing a mold cavity shaped in the form of a tennis racket frame having a handle with a grip at one end and a head of ellipsoid shape attached to the other end, the handle grip of said mold cavity having two substantially parallel cavity portions corresponding to two sides of said handle, forming an elongated core strip comprising a foamable resin composition, wrapping said core strip with an elongated veiling strip aligned along the length of said core strip, wrapping said core strip within said veiling strip with a plurality of layers of resin-coated unidirectionally oriented graphite fibers, at least one of said 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 and the innermost of said layers having its leading edge below the trailing edge of said veiling strip, arranging said wrapped core within said mold cavity with both ends of said wrapped core at the grip end of said mold, said wrapped core extending from one of its ends at the grip end of said mold cavity, up one of said substantially parallel cavity portions in the handle portion of said mold cavity, around a major portion of the head portion of said mold cavity and down the other substantially parallel cavity portion in the handle portion of said mold cavity to terminate at the grip end of said mold cavity, thereafter sealing said mold cavity, heating said foamable resin composition to cause expansion thereof and generate pressure within said mold cavity pressing said core against said layers of graphite fibers and thereby provide intimate bonding of said core to said layers, and thereafter removing said expanded wrapped core as an integral composite tennis racket frame.

Claim 16

A method of producing a tennis racket frame of high strength to weight ratio comprising providing a mold cavity shaped in the form of a tennis racket frame having a handle with a grip at one end and a head of ellipsoid shape attached to the other end, the handle grip of said mold cavity having two substantially parallel cavity portions corresponding to two sides of said handle, forming an elongated core strip comprising a foamable resin composition, wrapping said core strip with a plurality of layers of resin-coated unidirectionally oriented graphite fibers, at least one of said 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, wrapping an elongated veiling strip aligned along the length of said core strip about the outermost of said graphite fiber layers with the leading edge of said veiling strip covering the trailing edge of said outermost layer, arranging said wrapped core within said mold cavity with both ends of said wrapped core at the grip end of said mold, said wrapped core extending from one of its ends at the grip end of said mold cavity, up one of said substantially parallel cavity portions in the handle portion of said mold cavity, around a major portion of the head portion of said mold cavity and down the other substantially parallel cavity portion in the handle portion of said mold cavity to terminate at the grip end of said mold cavity, thereafter sealing said mold cavity, heating said foamable resin composition to cause expansion thereof and generate pressure within said mold cavity pressing said core against said layers of graphite fibers and thereby provide intimate bonding of said core to said layers, and thereafter removing said expanded wrapped core as an integral composite tennis racket frame.

Claim 17

A method of producing a tennis racket frame of high strength to weight ratio comprising providing a mold cavity shaped in the form of a tennis racket frame having a handle with a grip at one end and a head of ellipsoid shape attached to the other end, the handle grip of said mold cavity having two substantially parallel cavity portions corresponding to two sides of said handle, forming an elongated core strip comprising a foamable resin composition, wrapping said core strip with a plurality of layers of resin-coated unidirectionally oriented graphite fibers, at least one of said 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, wrapping an elongated veiling strip aligned along the length of said core strip about the outermost of said graphite fiber layers with the leading edge of said veiling strip covering the trailing edge of said outermost layer, arranging said wrapped core within said mold cavity with both ends of said wrapped core at the grip end of said mold, said wrapped core extending from one of its ends at the grip end of said mold cavity, up one of said substantially parallel cavity portions in the handle portion of said mold cavity, around a major portion of the head portion of said mold cavity and down the other substantially parallel cavity portion in the handle portion of said mold cavity to terminate at the grip end of said mold cavity, thereafter sealing said mold cavity, heating said foamable resin composition to cause expansion thereof and generate pressure within said mold cavity pressing said core against said layers of graphite fibers and thereby provide intimate bonding of said core to said layers, and thereafter removing said expanded wrapped core as an integral composite tennis racket frame.