US3882756A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Self piercing structural fastener having a working transition section
Assignee: BTC ACQUISITION CORP A CORP OF
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Filing: 1973-05-03
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Granted: 1975-05-13
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Expires: 1993-05-03
Abstract
Abstract A fastener primarily intended for fastening a heavier gauge structural member to one or more members of lighter gauge. The fastener comprises a relatively small pilot point by virtue of which the fastener is self piercing with respect to the lighter gauge member or members to which the heavier gauge member will be fastened, an intermediate transition section immediately following the pilot point so as to stretch-extrude the initial hole to proper size, and a deep threaded body portion to anchor itself within the extruded hole. Preferably the working transition section is also threaded so as to lead the main body portion of the fastener into the pilot hole as enlarged by extrusion. The contour of the working transition section is such as to blend gradually into the larger main body portion of the fastener from the relatively small, self piercing pilot point.
Inventors
- 👤 Gilbert F Sauer
- 👤 Donald M Taylor
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 11:16
CPC Classifications
F; F16; F16B; F16B25/00; F16B25/0036; F16B25/0042; F16B25/0057; F16B25/001; F16B25/0031; F16B25/10
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
316 words
A self piercing structural fastener, for fastening relatively heavy gauge maTerial to relatively light gauge material, comprising a threaded main body having constant major and root diameters of the thread of said threaded main body, said root diameter being about two-thirds of said major diameter, a drill point for initially piercing the light gauge material and the diameter of which drill point does not exceed approximately onehalf the said major diameter of the said threaded main body, a tapered and threaded working transition section extending between said drill point and said main body, the length of said transition being at least the dimension of the said drill point diameter, the major and root diameters of the thread of said tapered and threaded transition section increasing gradually and uniformly from the said drill point diameter throughout the said transition section so as to blend respectively with the major and root diameters of said threaded main body, the said root diameter of said threaded main body being approximately one and one-third times the said diameter of said drill point, whereby said light gauge material is stretch-extruded as said transition section passes through the hole initially pierced by said drill point, and the pitch dimension of said threaded main body being sufficient to cooperatively receive the total thickness of said light gauge material as stretch-extruded by said transition section, whereby said stretch-extruded light gauge material will be in intimate contact with the said root diameter of said main body, and whereby said fastener may be passed through a preformed hole in said heavy gauge material of greater diameter than the major diameter of said main body and into the hole initially pierced in said light gauge material so that said main body may thread its way into said initially pierced hole as stretchextruded by said transition section speedily and with a minimum of pressure while achieving good holding power.
Claim 2
Dependent Claim
316 words
A self piercing structural fastener, for fastening relatively heavy gauge maTerial to relatively light gauge material, comprising a threaded main body having constant major and root diameters of the thread of said threaded main body, said root diameter being about two-thirds of said major diameter, a drill point for initially piercing the light gauge material and the diameter of which drill point does not exceed approximately onehalf the said major diameter of the said threaded main body, a tapered and threaded working transition section extending between said drill point and said main body, the length of said transition being at least the dimension of the said drill point diameter, the major and root diameters of the thread of said tapered and threaded transition section increasing gradually and uniformly from the said drill point diameter throughout the said transition section so as to blend respectively with the major and root diameters of said threaded main body, the said root diameter of said threaded main body being approximately one and one-third times the said diameter of said drill point, whereby said light gauge material is stretch-extruded as said transition section passes through the hole initially pierced by said drill point, and the pitch dimension of said threaded main body being sufficient to cooperatively receive the total thickness of said light gauge material as stretch-extruded by said transition section, whereby said stretch-extruded light gauge material will be in intimate contact with the said root diameter of said main body, and whereby said fastener may be passed through a preformed hole in said heavy gauge material of greater diameter than the major diameter of said main body and into the hole initially pierced in said light gauge material so that said main body may thread its way into said initially pierced hole as stretchextruded by said transition section speedily and with a minimum of pressure while achieving good holding power.
Claim 3
Dependent Claim
17 words
The fastener of claim 1 wherein said main body is surmounted by an integral one-piece washer head.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-05-12 | 1978-11-11 | 1979-05-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-12 | 1982-11-11 | 1983-05-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-12 | 1986-11-11 | 1987-05-13 | $7700.00 | Window Closed / Lapsed |