Patent US3789896A successfully refreshed from Google Patents.
US3789896A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Screwdrivers and like tools
Assignee: Individual
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Filing: 1972-06-14
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Granted: 1974-02-05
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Expires: 1992-06-14
Abstract
Abstract A screwdriver or like tool incorporating a rotatable shaft which is driven by axially movable members mounted therein, and having helical drive connection therewith, is provided with two helical grooves of different pitch associated with corresponding drive means, whereby the shaft is driven at comparatively high speed when encountering comparatively low resistance torque, and is thereafter driven at lower speed but with greater applied torque when the resistance increases. The shaft may be fitted with a hollow, axially movable handle, having pin and helical groove connection therewith, to form said higher-torque driving means. Spring means may be provided to prevent relative axial movement of handle and shaft until the resistance torque on the shaft exceeds a prearranged value.
Inventors
- 👤 Yarborough E Cooke
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 12:01
CPC Classifications
B; B25; B25B; B25B15/00; B25B15/06; Y; Y10; Y10T; Y10T74/00; Y10T74/15; Y10T74/1526; Y10T74/1527; Y10T74/18; Y10T74/18568; Y10T74/18576; Y10T74/18752; Y10T74/19; Y10T74/19642; Y10T74/19698; Y10T74/19702; Y10T74/19721
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
139 words
A handtool incorporating a shaft having externally a first helical groove, and a first drive means in the form of a nut on said shaft internally formed to engage said first helical groove and to rotate said shaft about its own axis when moved axially along said shaft, and wherein there are provided second drive means for rotating said shaft comprising a tubular member axially slidable in relation to said shaft and having driving engagement therewith in the form of a projection from one cooperating with a second helical groove on the other, said second helical groove being of substantially coarser pitch than the said first helical groove, and means for preventing relative sliding movement of said second drive means on said shaft until the torque resistance of said shaft to said first drive means exceeds a predetermined value.
Claim 2
Dependent Claim
139 words
A handtool incorporating a shaft having externally a first helical groove, and a first drive means in the form of a nut on said shaft internally formed to engage said first helical groove and to rotate said shaft about its own axis when moved axially along said shaft, and wherein there are provided second drive means for rotating said shaft comprising a tubular member axially slidable in relation to said shaft and having driving engagement therewith in the form of a projection from one cooperating with a second helical groove on the other, said second helical groove being of substantially coarser pitch than the said first helical groove, and means for preventing relative sliding movement of said second drive means on said shaft until the torque resistance of said shaft to said first drive means exceeds a predetermined value.
Claim 3
Dependent Claim
23 words
A handtool according to claim 1 wherein said second drive means comprise a hollow handle slidably mounted on the end of the shaft.
Claim 4
Dependent Claim
52 words
A handtool according to claim 1 wherein said second drive means comprise a hollow handle slidably mounted on the end of the shaft, and spring means for preventing relative sliding movement of said handle and said shaft until torque resistance of said shaft to said first drive means exceeds a prearranged value.
Claim 5
Dependent Claim
44 words
A handtool aCcording to claim 1 wherein said second helical groove is formed in said shaft, and said second drive means comprise a hollow handle slidably mounted on the end of said shaft, and having an inward projection engaged with said second helical groove.
Claim 6
Dependent Claim
35 words
A handtool according to claim 1 comprising a hollow handle slidably mounted on the end of said shaft, and wherein a projection from said shaft engages said helical groove formed internally of said hollow handle.
Claim 7
Dependent Claim
83 words
A handtool according to claim 1 wherein said second drive means comprise a hollow cylindrical member formed with said second helical slot in its surface, mounted coaxially on said shaft, a hollow handle slidable in relation to said shaft, and co-operating with said hollow cylindrical member to move the latter axially in relation to said shaft, a nut on said shaft having a pin-like extension engaging said second helical slot, whereby said shaft is rotated by axial movement of said hollow cylindrical member.
References Cited (Backward Citations)
US959157A
Cited
US1531086A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-02-04 | 1977-08-06 | 1978-02-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-04 | 1981-08-06 | 1982-02-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-04 | 1985-08-06 | 1986-02-05 | $7700.00 | Window Closed / Lapsed |