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US3687587A Expired / Lapsed US ⏱️ 0.0 years remaining

Apparatus for forming fiber preforms

Assignee: Structural Fibers Inc
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Filing: 1970-05-14
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Granted: 1972-08-29
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Expires: 1990-05-14
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Abstract

Abstract A fiber preform for use in bag molding, fiber-reinforced molded resin articles is disclosed. The preform is a unitary, seamless, porous structure comprising short lengths of fibers which are bonded together by a resin binder. The preform has thickened areas which define zones of greater reinforcement for a finished structure. A machine for fabricating such a preform is also disclosed. The machine includes a screen form which is mounted within a surrounding vacuum chamber for rotation about its longitudinal axis. A fiber dispenser or cutter is mounted for movement in an axial direction with respect to the screen form but in a path corresponding to but spaced from the inner longitudinal profile of the screen form. The cutter is movable at a predetermined variable rate so that the wall thickness of the fibers may be varied to provide zones of greater fiber reinforcement. A resin binder spray gun follows the cutter along its path. The fibers are thrown against the screen by the cutter and are held in place by suction and by the binder. The binder is then cured by heat and the cured preform is removed from the screen by raising the screen from the vacuum chamber and then tilting the screen for easy access by an operator.

Inventors

  • 👤 Arthur J Wiltshire

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-27 23:27
CPC Classifications
B; B29; B29C; B29C41/00; B29C41/02; B29C41/08; B29C70/00; B29C70/04; B29C70/06; B29C70/10; B29C70/12; Y; Y10; Y10S; Y10S264/00; Y10S264/78

Claims Analysis

Total Claims: 7
Claim 1
Independent Claim 20 words
Apparatus according to claim 1, wherein said dispenser includes means to dispense a binder to inteRmix with said chopped fibers.
Claim 2
Dependent Claim 25 words
Apparatus according to claim 1, wherein said dispenser of chopped fibers includes a cutter operable to cut long strands of fiber into chopped fiber pieces.
Claim 3
Dependent Claim 16 words
Apparatus according to claim 1, wherein said cylindrical sidewall is closed by a hemispherical bottom portion.
Claim 4
Dependent Claim 66 words
Apparatus according to claim 1, including gripping means mounted above said form adapted to grip an upper portion of said form and to remove said form from said chamber, means pivotally connected to said gripping means to raise said form vertically out of said chamber, and means for tilting said removed form toward a horizontal position so that the preform may be removed from said form.
Claim 5
Dependent Claim 191 words
Apparatus for making fibrous preforms for use in molding fiber-reinforced plastic articles, comprising a perforated form which defines the shape of the preform to be formed, said form having an open mouth, a vertically extending cylindrical sidewall, and a closed bottom, and having its outside surface substantially enclosed by a chamber, vacuum means in said chamber for drawing air through said form, a fiber-dispensing assembly comprising a housing, said housing having a hemispherical, closed bottom end, a fiber dispenser pivoted for movement about said bottom end and along a path spaced a constant distance from said closed bottom, said bottom end having a slot therein coextensive with the pivotal movement of said fiber dispenser so that fibers may be dispensed through said slot and toward said form to cover a first portion of said form, push rod means for pivoting said fiber dispenser along said path, first cam means for driving said push rod, second cam means for lifting said assembly so that the fiber dispenser may throw fibers against remaining portions of said form, and means to rotate the form about an axis passing through the mouth of said form.
Claim 6
Dependent Claim 60 words
Apparatus according to claim 6, including gripping means mounted above said form adapted to grip an upper portion of said form and to remove said form from said chamber, means pivotally connected to said gripping means to raise said form out of said chamber, and means for tilting said removed form toward a horizontal position for removal of said preform.
Claim 7
Dependent Claim 16 words
Apparatus according to claim 6 wherein said first portion of said form comprises a hemispherical portion.

References Cited (Backward Citations)

US25587A Cited
US798642A Cited
US2870054A Cited
DE1187005B Cited
US3507011A Cited
US3410936A Cited
US3478387A Cited
US3555142A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1975-08-29 1976-02-28 1976-08-29 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1979-08-29 1980-02-28 1980-08-29 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1983-08-29 1984-02-28 1984-08-29 $7700.00 Window Closed / Lapsed

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