Invalidity dossier
US 4740123
Re-usable expandable plastic nut for two-piece fastener
Current assignee: Illinois Tool Works Inc
Added 9/24/2026, 12:46:10 AM
Active provider: DeepSeek · deepseek-flash
Patent summary
Title, assignee, inventors, filing/issue dates, abstract, and a plain-language overview of the claims.
Patent Overview — US 4,740,123 A
Title: Re-usable expandable plastic nut for two-piece fastener
Source: https://patents.google.com/patent/US4740123/en
Bibliographic data (as supplied):
- Application number: US07/012,785
- Inventors: Burnell Wollar; Richard J. Schwind
- Original assignee: Phillips Plastics Corp
- Current assignee (listed, may be inaccurate): Illinois Tool Works Inc; Phillips Medisize LLC
- Priority/filing date: 1987-02-09
- Publication (grant) date: 1988-04-26
- Anticipated expiration: 2007-02-09; status: Expired – Lifetime
- Classification: F16B13/061 (expanding sleeve, buckling type)
Purpose: The invention relates to a re-usable expandable plastic (injection-molded) nut for a two-piece fastener used to releasably secure two components, such as panels. It addresses prior-art problems: difficult initial thread engagement, cross-threading (compounded when the nut rotates in its panel aperture), and flimsy nut threads easily damaged by over-torquing of a metal screw.
Plain-language scope: The fastener comprises a screw (metal or plastic) with a threaded shank and head, and a plastic nut with a head, a shank, and a bore. The nut shank has an expandable portion near the head end — thin, resiliently flexible, outwardly foldable walls with a non-circular external cross-section so the nut cannot rotate in a similarly shaped panel aperture — and an internally threaded portion near the insertion end, joined by a common wall. Each flexible wall has a parabolic cross-section depression inside defining a fold region of reduced thickness. Discrete screw-engaging thread sections are axially spaced on opposite side walls of the threaded portion, with the same size and pitch as the screw thread. A single screw-engaging thread in the common wall holds the screw in pre-assembled position and guides it into the thread sections. Rotating the screw expands the nut shank, entrapping one panel between nut head and expanded walls and the other between screw head and nut head.
What the excerpt does not establish: The full description and claims are abridged ("[Excerpt only]"); independent claim language, exact claim scope, figure details, and the complete list of stated advantages are therefore not verifiable from the supplied text. The excerpt supplies no information on prior-art references, validity, litigation, or ownership transfers beyond the assignment entries shown.
Generated 10/1/2026, 9:31:54 PM
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Litigation summary
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PTAB challenges
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Assignment history
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Prior art
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Obviousness
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Extensions
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Derivative works
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