Patent US5001948A successfully refreshed from Google Patents.
US5001948A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Screwdriver blade with curved tip
Assignee: SK Hand Tool Corp
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Filing: 1989-11-02
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Granted: 1991-03-26
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Expires: 2009-11-02
Abstract
Abstract A stronger screwdriver blade is disclosed which is particularly effective for driving round-headed screws. The screwdriver blade has an elongate shank with a tapered end extending from the shank and terminating in a tip. The tip has a straight edge perpendicular to the shank and has a predetermined length and thickness, with side edges extending back toward the shank from ends of the end edge. The tip has substantially parallel, planar sides extending back toward the shank from the end edge to inner edges which, at the side edges, are spaced a distance from the end edge which is approximately equal to the thickness of the end edge. The inner edges are curved with the planar sides being from one and one-half to three and one-half times as wide at central portions as at end portions. From the inner edges, opposite side surfaces of the tapered end extend abruptly outwardly in a direction toward the shank so that the blade tip is thicker at high stress areas thereof.
Inventors
- 👤 Warren W. Weible
- 👤 Steven C. Simpson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 14:27
CPC Classifications
B; B25; B25B; B25B15/00; B25B15/001; B25B15/004; B25B15/007
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
135 words
A screwdriver blade comprising an elongate shank, a tapered end extending from said shank and terminating in a tip, said tip having a straight end edge perpendicular to said shank and having a predetermined length and thickness, said tip having side edges extending back toward said shank from ends of said end edge, said tip having substantially parallel, planar sides extending back toward said shank from said end edge to inner edges a minimum distance along said side edges which is approximately equal to the thickness of said end edge, said inner edges being curved with a center of curvature being beyond said end edge of said tip, opposite side surfaces of said tapered end extending abruptly outwardly from one another in a direction toward said shank from said inner edges of said planar sides.
Claim 2
Dependent Claim
135 words
A screwdriver blade comprising an elongate shank, a tapered end extending from said shank and terminating in a tip, said tip having a straight end edge perpendicular to said shank and having a predetermined length and thickness, said tip having side edges extending back toward said shank from ends of said end edge, said tip having substantially parallel, planar sides extending back toward said shank from said end edge to inner edges a minimum distance along said side edges which is approximately equal to the thickness of said end edge, said inner edges being curved with a center of curvature being beyond said end edge of said tip, opposite side surfaces of said tapered end extending abruptly outwardly from one another in a direction toward said shank from said inner edges of said planar sides.
Claim 3
Dependent Claim
30 words
A screwdriver blade according to claim 1 wherein said opposite side surfaces form angles of ten degrees to twenty degrees with respect to a longitudinal axis of said screwdriver blade.
Claim 4
Dependent Claim
28 words
A screwdriver blade according to claim 1 wherein said opposite side surfaces form angles of approximately fifteen degrees with respect to a longitudinal axis of said screwdriver blade.
Claim 5
Dependent Claim
46 words
A screwdriver blade according to claim 1 wherein said side edges of said tip extend outwardly from one another in a direction toward said shank from said straight end edge at angles of approximately four degrees with respect to the longitudinal axis of said screwdriver blade.
Claim 6
Dependent Claim
31 words
A screwdriver blade according to claim 1 wherein said opposite side surfaces extend abruptly outwardly from said inner edges for a minimum distance of 0.2 inch from said straight end edge.
Claim 7
Dependent Claim
27 words
A screwdriver blade according to claim 1 wherein said opposite side surfaces extend abruptly outwardly from said inner edges beyond maximum stress areas of the tapered end.
Claim 8
Dependent Claim
122 words
A screwdriver blade comprising an elongate shank, a tapered end extending from said shank and terminating in a tip, said tip having a straight end edge perpendicular to said shank and having a predetermined length and thickness, said tip having side edges extending back toward said shank from ends of said straight end edge, said tip having substantially parallel, planar sides extending back toward said shank from said end edge to curved inner edges, opposite side surfaces of said tapered end then extending abruptly outwardly from one another in a direction toward said shank from said curved inner edges with said opposite side surfaces along said side edges extending beyond maximum stress areas of said tapered end located along said side edges.
Claim 9
Dependent Claim
122 words
A screwdriver blade comprising an elongate shank, a tapered end extending from said shank and terminating in a tip, said tip having a straight end edge perpendicular to said shank and having a predetermined length and thickness, said tip having side edges extending back toward said shank from ends of said straight end edge, said tip having substantially parallel, planar sides extending back toward said shank from said end edge to curved inner edges, opposite side surfaces of said tapered end then extending abruptly outwardly from one another in a direction toward said shank from said curved inner edges with said opposite side surfaces along said side edges extending beyond maximum stress areas of said tapered end located along said side edges.
Claim 10
Dependent Claim
25 words
A screwdriver blade according to claim 7 wherein said inner edges at said side edges are less than 0.2 inch from said straight end edge.
Claim 11
Dependent Claim
32 words
A screwdriver blade according to claim 7 wherein said side surfaces extend abruptly outwardly at angles of ten degrees to twenty degrees with respect to a longitudinal axis of said screwdriver blade.
Claim 12
Dependent Claim
28 words
A screwdriver blade according to claim 7 wherein said opposite side surfaces form angles of approximately fifteen degrees with respect to a longitudinal axis of said screwdriver blade.
Claim 13
Dependent Claim
112 words
A screwdriver blade comprising an elongate shank, a tapered end extending from said shank and terminating in a tip, said tip having a straight end edge perpendicular to said shank and having a predetermined length and thickness, said tip having substantially parallel, planar sides extending back toward said shank from said end edge to curved inner edges, with the width of central portions of said planar sides being from one and one-half to three and one-half times the width at end portions thereof, opposite side surfaces of said tapered end then extending abruptly outwardly from one another in a direction toward said shank from said curved inner edges of said planar sides.
Claim 14
Dependent Claim
112 words
A screwdriver blade comprising an elongate shank, a tapered end extending from said shank and terminating in a tip, said tip having a straight end edge perpendicular to said shank and having a predetermined length and thickness, said tip having substantially parallel, planar sides extending back toward said shank from said end edge to curved inner edges, with the width of central portions of said planar sides being from one and one-half to three and one-half times the width at end portions thereof, opposite side surfaces of said tapered end then extending abruptly outwardly from one another in a direction toward said shank from said curved inner edges of said planar sides.
Claim 15
Dependent Claim
30 words
A screwdriver blade according to claim 11 wherein said opposite side surfaces form angles of ten degrees to twenty degrees with respect to a longitudinal axis of said screwdriver blade.
Claim 16
Dependent Claim
28 words
A screwdriver blade according to claim 11 wherein said opposite side surfaces form angles of approximately fifteen degrees with respect to a longitudinal axis of said screwdriver blade.
Claim 17
Dependent Claim
53 words
A screwdriver blade according to claim 11 wherein said tip has side edges extending back toward said shank from ends of said end edge, ends of said curved inner edges at said side edges being at a distance from said straight end edge approximately equal to the thickness of said straight end edge.
Claim 18
Dependent Claim
26 words
A screwdriver blade according to claim 11 wherein said opposite side surfaces extend abruptly outwardly for a minimum distance of 0.2 inch from said straight edge.
Claim 19
Dependent Claim
27 words
A screwdriver blade according to claim 11 wherein said opposite side surfaces extend abruptly outwardly from said inner edges beyond maximum stress areas of the tapered end.
Claim 20
Dependent Claim
23 words
A screwdriver blade according to claim 11 wherein central portions of said planar sides are approximately twice as wide as end portions thereof.
Claim 21
Dependent Claim
24 words
A screwdriver blade according to claim 11 wherein centers of curvature of said curved inner edges are beyond said end edge of said tip.
References Cited (Backward Citations)
GB395165A
Cited
US4878406A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-03-25 | 1994-09-24 | 1995-03-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-03-25 | 1998-09-24 | 1999-03-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-03-25 | 2002-09-24 | 2003-03-26 | $7700.00 | Window Closed / Lapsed |