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US4834602A
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US
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Tapping screw
Assignee: Yao Seibyo Co Ltd
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Filing: 1987-07-28
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Granted: 1989-05-30
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Expires: 2007-07-28
Abstract
Abstract A tapping screw having a tapered edge at a rear part of the tapered portion at its tip. The drill edge has the maximum diameter which is larger than the maximum thread diameter at the tapered portion and smaller than the maximum thread diameter at the shank. The drill edge allows the screw to be driven in more securely with a smaller driving force. The drill edge also has a greater lead angle than the lead angles of the threads on the tapered portion and on the shank rearwardly of the drill edge.
Inventors
- 👤 Seiichiro Takasaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 08:09
CPC Classifications
F; F16; F16B; F16B25/00; F16B25/0036; F16B25/0042; F16B25/0057; F16B25/001; F16B25/0015; F16B25/0073; F16B25/10
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
212 words
A tapping screw for tapping and screwing into a substrate comprising: a shank having a head end, a middle portion, and a tip end, and said tip end having a tapered portion; first threads on the outer periphery of said tapered portion of said tip end for tapping a first thread in a substrate; second threads on the outer periphery of said shank at said head end for tapping a second thread in a substrate, and separate from said first threads on said tapered portion; and at least one drill edge on the outer periphery of said middle portion of said shank for chipping off only a part of a first thread tapped in a substrate by said first threads and for sending the chipped off part of the first thread tapped in a substrate toward said head end of said tapping screw, said at least one drill edge being between said first and second threads, being separate from said first and second threads, said at least one drill edge extending helically around the longtiudinal axis of said shank, and having a lead angle larger than the lead angles of said first and second threads, and said at least one drill edge being an outwardly extending rib having an arcuate ridge line.
Claim 2
Dependent Claim
212 words
A tapping screw for tapping and screwing into a substrate comprising: a shank having a head end, a middle portion, and a tip end, and said tip end having a tapered portion; first threads on the outer periphery of said tapered portion of said tip end for tapping a first thread in a substrate; second threads on the outer periphery of said shank at said head end for tapping a second thread in a substrate, and separate from said first threads on said tapered portion; and at least one drill edge on the outer periphery of said middle portion of said shank for chipping off only a part of a first thread tapped in a substrate by said first threads and for sending the chipped off part of the first thread tapped in a substrate toward said head end of said tapping screw, said at least one drill edge being between said first and second threads, being separate from said first and second threads, said at least one drill edge extending helically around the longtiudinal axis of said shank, and having a lead angle larger than the lead angles of said first and second threads, and said at least one drill edge being an outwardly extending rib having an arcuate ridge line.
Claim 3
Dependent Claim
19 words
A tapping screw as in claim 1, wherein said at least one drill edge comprises two separate drill edges.
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) | 1992-05-29 | 1992-11-28 | 1993-05-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-05-29 | 1996-11-28 | 1997-05-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-05-29 | 2000-11-28 | 2001-05-30 | $7700.00 | Window Closed / Lapsed |