Abstract: A surface-reinforced article includes a core assembly (12) comprising a foam core (20) with a surface region (22) that includes fine fibers, and an outer reinforcing covering (14) which includes thicker fibers in a resin (30). The fine fibers includes coupling fibers (100) with outer ends (106) embedded in the resin. After the core assembly is molded, the spacers are removed, the core assembly is wrapped in the outer fibrous material, and the wrapped core assembly (120) is placed in the second mold cavity that is formed by the original mold but without the spacers.

Abstract: An article (10) such as a grid fin that controls the direction of flight of a vehicle, has precisely formed passages (14) with porous locating walls (52A, 52B) and a layer of fibrous material (86) such as graphite cloth lying against one or both opposite sides of the locating wall, and with the locating wall and fibrous material impregnated with resin (84). Locating blocks (30) of foam are molded and the fibrous material (42) is wrapped around each block. The wrapped blocks (44) are each inserted into a passage (54) of a locating grid (50), so the fibrous material is compressed. The locating grid lies in a grid-holding mold (60). With the fiber-wrapped blocks inserted, the grid-holding mold is closed and resin is injected into the mold and allowed to harden. The foam blocks are removed by eroding them, as by sand blasting them, to leave a final article.

Abstract: A surface-reinforced article includes a core assembly (12) comprising a foam core (20) with a surface region (22) that includes fine inner fibrous material intimately surround by foam that is integral with foam of the core, and an outer reinforcing covering (14) which includes an outer layer (32) of fibrous material and a resin (30) surrounding the outer layer of fibrous material and covering the primarily foam core assembly. The fine inner fibrous material (91-94) includes coupling fibers (100) with inner ends (102) embedded in the foam and outer ends (106) embedded in the resin, to better hold the resin to the foam. The primarily foam core assembly is molded within a first mold cavity (64) formed between spacers (60, 62) that lie within a second mold cavity (50).

Abstract: An article (10) such as a grid fin that controls the direction of flight of a vehicle, has precisely formed passages (14) with porous locating walls (52A, 52B) and a layer of fibrous material (86) such as graphite cloth lying against one or both opposite sides of the locating wall, and with the locating wall and fibrous material impregnated with resin (84). Locating blocks (30) of foam are molded and the fibrous material (42) is wrapped around each block. The wrapped blocks (44) are each inserted into a passage (54) of a locating grid (50), so the fibrous material is compressed. The locating grid lies in a grid-holding mold (60). With the fiber-wrapped blocks inserted, the grid-holding mold is closed and resin is injected into the mold and allowed to harden. The foam blocks are removed by eroding them, as by sand blasting them, to leave a final article.

Abstract: A surface-reinforced article includes a core assembly (12) comprising a foam core (20) with a surface region (22) that includes fine inner fibrous material intimately surrounded by foam that is integral with foam of the core, and an outer reinforcing covering (14) which includes an outer layer (32) of fibrous material and a resin (30) surrounding the outer layer of fibrous material and covering the primarily foam core assembly. The fine inner fibrous material (91-94) includes coupling fibers (100) with inner ends (102) embedded in the foam and outer ends (106) embedded in the resin, to better hold the resin to the foam. The primarily foam core assembly is molded within a first mold cavity (64) formed between spacers (60, 62) that lie within a second mold cavity (50).

Abstract: A method is provided for molding an article (10) that includes a polymer (100) such as an epoxy resin, reinforced by fibrous material (102) such as fiberglass which is embedded in the polymer material, especially for a hollow article such as a shell. The method includes placing spacers (42, 44) in a mold cavity (30), where the spacers conform closely to the cavity surface and leave a free, or empty volume (64) within themselves. Foamable material (60A) is placed in the free volume and allowed to expand and push the spacers toward the cavity walls while forming a foam core (70) within the spacers. The mold is opened and the spacers and foam core are removed. Next, the foam core is covered with an impervious layer and the fibrous material (72) is wrapped around the foam core. The foam core is placed back in the mold, with the fibrous material spacing the foam core from the walls of the mold.

Abstract: A surface-reinforced article includes a core assembly (12) comprising a foam core (20) with a surface region (22) that includes fine inner fibrous material intimately surround by foam that is integral with foam of the core, and an outer reinforcing covering (14) which includes an outer layer (32) of fibrous material and a resin (30) surrounding the outer layer of fibrous material and covering the primarily foam core assembly. The fine inner fibrous material (91-94) includes coupling fibers (100) with inner ends (102) embedded in the foam and outer ends (106) embedded in the resin, to better hold the resin to the foam. The primarily foam core assembly is molded within a first mold cavity (64) formed between spacers (60, 62) that lie within a second mold cavity (50).

Abstract: A shell part formed of honeycomb (20) with fibrous reinforcing regions (21, 24) at inner and outer surfaces of the honeycomb and with foam material (26) penetrating the honeycomb cells and reinforcing regions, where the outer surface of the article is convexly curved and the inner surface of the article is concavely curved. This permits the construction of a hollow object (10) by connecting the ends of two shell parts together. Each shell part is formed by laying an outer region of fibrous material including cloth (30) sandwiched between tissue paper layers (32, 34, 35), against a mold wall 44. Next, a honeycomb sheet is laid over the outer region and an inner region (21, 60, 62) of fibrous material is laid over the honeycomb. Then, foamable material (26) is laid in the mold and the mold is closed to cause the expanded foam to penetrate the honeycomb and most of the fibrous layers.

Abstract: An article such as an airfoil that is of light weight and high bending strength, includes a primarily foam core part (20), fibrous strengthening layers (22, 24) at the top and bottom of the core part with the strengthening layers held by threads (64, 72) sewn through the combination, and with resin (32) forced into spaces between the fibers of the strengthening layers and forming smooth surfaces at the top and bottom of the article. The core part includes a thick body (40) of light weight foam (42) and top and bottom reinforcing layers (44, 46) lying against the top and bottom of the body, with the reinforcing layers each having spaces or pores that are filled with foam that is integral with the foam of the body. The moderate strength near the surfaces of the core part, enable the core part to resist crushing of the light weight foam during sewing of the threads and can resist pullout of fasteners that project only partially into the core part.

Abstract: A shell part formed of honeycomb (20) with fibrous reinforcing regions (21, 24) at inner and outer surfaces of the honeycomb and with foam material (26) penetrating the honeycomb cells and reinforcing regions, where the outer surface of the article is convexly curved and the inner surface of the article is concavely curved. This permits the construction of a hollow object (10) by connecting the ends of two shell parts together. Each shell part is formed by laying an outer region of fibrous material including cloth (30) sandwiched between tissue paper layers (32, 34, 35), against a mold wall 44. Next, a honeycomb sheet is laid over the outer region and an inner region (21, 60, 62) of fibrous material is laid over the honeycomb. Then, foamable material (26) is laid in the mold and the mold is closed to cause the expanded foam to penetrate the honeycomb and most of the fibrous layers.

Abstract: A window frame assembly is described which mounts a window pane (12, FIG. 2) in an opening (14) of a building wall, which minimizes the number of parts and their complexity. The assembly includes an outside frame (30) which surrounds an axis (34) of the wall opening, the outside frame having a radially outer part (40, FIG. 2) forming a flange that lies against the outside surface of the building wall, an inward arm (44) that extends inwardly against the edge (46) of the wall opening, and a radially inner part (42) that forms a window pane-supporting ledge (45). An inside frame (32) has a radially outer part (50) that lies against the inside surface of the building wall and an outward arm (52) that extends outwardly against a side of the inward arm, with the outer end (54) of the outward arm substantially abutting the window pane (12).

Abstract: A retainer is described for holding the fin box of a surfboard, windsurfer, or small sailboat very securely to the rest of the board to greatly resist breakout of the fin box from the board, which is of relatively low cost and of light weight. The retainer is formed primarily of foam of a density greater than the foam in the rest of the board, and is molded to the fin fox to bond thereto. The retainer extends up from the fin box so the assembly formed by the retainer and fin box has a height equal to the thickness of the unfinished board. A groove is cut in the unfinished board through the entire thickness of the board, and the retainer/fin box assembly is placed in the groove with the upper and lower surfaces of the assembly even with the upper and lower surfaces of the unfinished board.

Abstract: A surface-reinforced lightweight article is described, which includes a honeycomb structure whose sidewalls are reinforced by an expanded foam. The article can be manufactured by laying a fibrous third layer, such as several layers of dry tissue paper backed by a layer of dry fiberglass cloth, on the walls of a mold, laying a second layer of multi-cell honeycomb-like material against the third layer, and laying a finely porous first layer such as tissue paper over the second layer. Foamable plastic is poured in the mold over the three layers and the mold is closed. As the plastic foams and expands, it forces the three layers into a tight sandwich and permeates the layers to reinforce them. Specifically, expanded foam in the cells of multi-cell honeycomb-type material braces the honeycomb sidewalls against collapse, to greatly increase the strength and rigidness of the article.

Abstract: An improved method is described for molding an article having a core of foam and a surface reinforced by fiberglass cloth or the like, which enables more rapid setup for molding and which creates a stronger and more uniform article. The method includes laying several layers of dry tissue paper on the walls of the mold to form a first layer, laying dry fiberglass cloth over the first layer to create a second layer, and laying a sheet of dry tissue paper over the second layer to form a third layer. Foamable plastic is poured in the mold over the three layers and the mold is closed. As the plastic foams and expands, it first presses against the third layer to press it and the underlying first and second layers firmly against the mold walls to thereby position them evenly at the outer portion of the mold cavity. The foam material then penetrates the tissue paper of the third layer, the openings of the cloth of the second layer, and some of the layers of tissue paper of the first layer, before finally hardening.

Abstract: An improved method is described for molding an article having a core of foam and a surface reinforced by fiberglass cloth or the like, which enables more rapid setup for molding and which creates a stronger and more uniform article. The method includes laying several layers of dry tissure paper on the walls of the mold to form a first layer, laying dry fiberglass cloth over the first layer to create a second layer, and laying a sheet of dry tissue paper over the second layer to form a third layer. Foamable plastic is poured in the mold over the three layers and the mold is closed. As the plastic foams and expands, it first presses against the third layer to press it and the underlying first and second layers firmly against the mold walls to thereby position them evenly at the outer portion of the mold cavity. The foam material then penetrates the tissue paper of the third layer, the openings of the cloth of the second layer, and some of the layers of tissue paper of the first layer, before finally hardening.