US4656674A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Composite helmet
Assignee: National Plastics Ltd
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Filing: 1985-10-24
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Granted: 1987-04-14
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Expires: 2005-10-24
Abstract
Abstract This invention relates to the production of composite helmets. Such helmets are sometimes used by soldiers to provide "ballistic protection" and are then sometimes referred to as "ballistic helmets". A method is disclosed that includes cutting a length of reinforced fabric along a zig-zag line to form two distinct parts, winding a number of layers of each part on formers, the layers having teeth formations in staggered relationship, bending the teeth, and introducing synthetic resin during a molding step.
Inventors
- 👤 Roger T. A. Medwell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 01:13
CPC Classifications
A; A42; A42C; A42C1/00; A42B; A42B3/00; A42B3/04; A42B3/06; A42B3/062; A42B3/063; A42C2/00; F; F41; F41H; F41H1/00; F41H1/04; F41H1/08
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
181 words
A method of making a composite protective helmet reinforced with fabric, said method including the steps of: cutting a length of reinforced fabric along a zig-zag line so that the length of the fabric is dividable along the cutting line into two parts, each part comprising an uncut longitudinally extending base portion and a series of teeth projecting from said uncut base portion along one edge thereof; winding a number of layers of one of said cut parts of the reinforcing fabric on a former having a diameter approximately the same size as the opening in a helmet to be manufactured, the pitch of the teeth in said fabric part being such that teeth of successive layers in the winding are in staggered relationship so that the teeth of one layer overlap gaps between teeth of the next lower layer; bending the teeth inwardly and securing them to form a dome shape constituting a helmet pre-form; molding said pre-form with synthetic resin to produce a helmet; and similarly using said other cut fabric part thereby reducing the amount of wasted fabric.
Claim 2
Independent Claim
181 words
A method of making a composite protective helmet reinforced with fabric, said method including the steps of: cutting a length of reinforced fabric along a zig-zag line so that the length of the fabric is dividable along the cutting line into two parts, each part comprising an uncut longitudinally extending base portion and a series of teeth projecting from said uncut base portion along one edge thereof; winding a number of layers of one of said cut parts of the reinforcing fabric on a former having a diameter approximately the same size as the opening in a helmet to be manufactured, the pitch of the teeth in said fabric part being such that teeth of successive layers in the winding are in staggered relationship so that the teeth of one layer overlap gaps between teeth of the next lower layer; bending the teeth inwardly and securing them to form a dome shape constituting a helmet pre-form; molding said pre-form with synthetic resin to produce a helmet; and similarly using said other cut fabric part thereby reducing the amount of wasted fabric.
Claim 3
Dependent Claim
25 words
A method according to claim 1, wherein the number of layers of said cut part wound on a former is from twelve to twenty four.
Claim 4
Dependent Claim
30 words
A method according to claim 1, wherein the teeth are bent inwardly so that teeth of the same layer meet and the inwardly bent teeth are secured to one another.
Claim 5
Dependent Claim
30 words
A method according to claim 1, wherein the dome shape is further reinforced by introduction of at least one further piece of reinforcing fabric in the region of the crown.
References Cited (Backward Citations)
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Cited
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Cited
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Cited
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Cited
FR2501851A1
Cited
GB2135173A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-04-13 | 1990-10-13 | 1991-04-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-04-13 | 1994-10-13 | 1995-04-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-04-13 | 1998-10-13 | 1999-04-14 | $7700.00 | Window Closed / Lapsed |