# US 4,391,301 A · Hole reinforcement

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- Number: US 4,391,301 A
- Document ID: US4391301A
- Status: Granted
- Kind: A
- Application number: 06/296,809
- Filed: 1981-08-27
- Granted: 1983-07-05
- Earliest claimed: 1981-08-27
- Assignees: A. O. Smith Corporation
- Inventors: Fred R. Pflederer
- Web page: https://patentgrep.com/patent/US4391301A

## CPC

- B29C 53/605: {by polar winding}
- B65D 90/029: {Wound structures}
- Y10S 138/02: Glass fiber
- B29C: SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING (making preforms B29B11/00; making laminated products by combining previously unconnected layers which become one product whose layers will remain together B32B37/00 - B32B41/00)
- B65D: CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
- Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS

## Abstract

A filament wound structural vessel includes a cylindrical wall formed of a cured thermosetting resin reinforced by fibrous material. An opening in the wall is reinforced by a series of reinforcement bands formed by filament windings that encircle the wall and run adjacent the opening.

## Claims

### Claim 1

A structural article comprising:
a cylindrical wall having a longitudinal axis and formed of a cured thermosetting resin reinforced by fibrous material, said wall having an opening therein; and
a plurality of pairs of opening reinforcement bands, said bands comprising a series of continuous filaments encircling said wall and bonded to the outer surface of said wall, with said bands in each of said pairs being disposed tangentially to the perimeter of said opening and on substantially opposite sides of said opening,
one of said pairs of bands disposed substantially normal to the longitudinal axis of said cylindrical wall and
at least one of said pairs of bands overlapping at least one other of said pairs of bands in the vicinity of said opening.

### Claim 2 (depends on 1)

The structural article defined in claim 1 wherein said cylindrical wall is formed by a plurality of fibrous strands disposed in a helical pattern and wherein some of said filaments of said reinforcement bands are wound around said wall at approximately the same angles as those used in said helical pattern.