US3695321A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cavity head screw and driving tool therefor
Assignee: Individual
•
Filing: 1970-06-30
•
Granted: 1972-10-03
•
Expires: 1990-06-30
Abstract
Abstract The upper surface of the head of a screw has wedge-shaped cavities arranged on either side of, or around, a central hub or land. The cavities have undercut sidewalls, and the land has a central hole, preferably circular. A driving tool such as a screwdriver, or the like, is provided with multiple blades which are spaced apart on either side of or around a central aperture. A central pin depends from the shank of the screwdriver and is adapted to engage the hole in the central land of the screw. The bottoms of the screwdriver blades are of expanded thickness so that when these blades are inserted in and engage the screwhead cavities, the expanded bottom portions of the blades will lock under the undercut sidewalls of the cavities. Mating of the screwdriver blades and the screw head cavities is guided, aligned and axially stabilized by engagement of the screwdriver central pin in the hole in the central land of the screwhead surface. Expandable pin sections maintained under tension may be employed to temporarily lock a screw onto the screwdriver blades and held in positive axial alignment with said screwdriver for insertion and withdrawal.
Inventors
- 👤 Jacob W Garehime Jr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:58
CPC Classifications
B; B25; B25B; B25B15/00; B25B15/001; B25B15/004; B25B15/007; F; F16; F16B; F16B23/00; F16B23/0007; Y; Y10; Y10S; Y10S411/00; Y10S411/919
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
173 words
The combination of a driving tool and a screw to be driven thereby, said driving tool having a shank, a plurality of laterally spaced apart flat blades attached to said shank, the lower portions of said blades being of expanded thickness, and said screw having a plurality of radial cuneiform cavities in its head upper surface, said cavities having undercut sidewalls and a central land separating said cavities, said central land in said screwhead surface adapted to mate with the space between said screwdriver blades, and the expanded portions of said screwdriver blades engaging said undercut sidewalls of said cavities in the surface of said screw when said screwdriver and said screw are in working engagement, in which the improvements comprise: a said driving tool having a central pin depending from said shank between said laterally spaced apart blades; and, b said screw having a hole in the central land separating the cuneiform cavities in the head thereof adapted to mate with the said pin depending between the blades of said driving tool.
Claim 2
Dependent Claim
173 words
The combination of a driving tool and a screw to be driven thereby, said driving tool having a shank, a plurality of laterally spaced apart flat blades attached to said shank, the lower portions of said blades being of expanded thickness, and said screw having a plurality of radial cuneiform cavities in its head upper surface, said cavities having undercut sidewalls and a central land separating said cavities, said central land in said screwhead surface adapted to mate with the space between said screwdriver blades, and the expanded portions of said screwdriver blades engaging said undercut sidewalls of said cavities in the surface of said screw when said screwdriver and said screw are in working engagement, in which the improvements comprise: a said driving tool having a central pin depending from said shank between said laterally spaced apart blades; and, b said screw having a hole in the central land separating the cuneiform cavities in the head thereof adapted to mate with the said pin depending between the blades of said driving tool.
Claim 3
Dependent Claim
47 words
The combination of claim 1 in which the depending pin of said driving tool has resilient means to temporarily grip the walls of said hole in said central land of the head surface of said screw when said driving tool and said screw are in working engagement.
Claim 4
Dependent Claim
60 words
The combination of claim 1 in which the depending pin of said driving tool has an encircling groove around its outer surface and expandable spring means in said groove adapted to temporarily grip the walls of said hole in said central land of the head surface of said screw when said driving tool and said screw are in working engagement.
Claim 5
Dependent Claim
82 words
The combination of claim 1 in which the depending pin of said driving tool has an upper shoulder portion adapted to mate with said hole in the central land of the head surface of saiD screw, and a lower bulbous portion split vertically into a plurality of spaced apart sections and adapted to temporarily grip the walls of said hole in the central land of the head surface of said screw when said driving tool and said screw are in working engagement.
Claim 6
Dependent Claim
60 words
The combination of claim 1 in which the depending pin of said driving tool is of tubular form and split vertically into a plurality of spaced apart sections and adapted to temporarily grip the walls of said hole in the central land of the head surface of said screw when said driving tool and said screw are in working engagement.
Claim 7
Dependent Claim
38 words
The combination of claim 1 in which the cross section of the depending pin of said driving tool and the cross section of the hole of the central land of the head surface of said screw are circular.
References Cited (Backward Citations)
CA678265A
Cited
US1797390A
Cited
US2304704A
Cited
US2285956A
Cited
US2769471A
Cited
US3120251A
Cited
US3449988A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-10-03 | 1976-04-03 | 1976-10-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-03 | 1980-04-03 | 1980-10-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-03 | 1984-04-03 | 1984-10-03 | $7700.00 | Window Closed / Lapsed |