US3908488A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Minimum stressed wrench
Assignee: Individual
•
Filing: 1973-10-01
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Granted: 1975-09-30
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Expires: 1993-10-01
Abstract
Abstract A wrench for use on polygonal nuts wherein the distance between any two opposing nut engaging wrench surfaces is greater than the distance between the two opposing surfaces of the corresponding nut engaged by the wrench, such a wrench operates so as to set up minimum reactive stress in the wrench when conditions of maximum torque prevail, and to set up minimum stress in and deformation of the nut only when conditions of minimum torque generally prevail.
Inventors
- 👤 Alfred Frederick Andersen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 11:15
CPC Classifications
B; B25; B25B; B25B13/00; B25B13/02; B25B13/06; B25B13/065
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
361 words
A wrench for turning a nut or bolt of regular polygonal shape, said wrench having a cavity of subsurfaces for engaging and turning said nut in either a clockwise or counterclockwise direction of rotation about the central axis of said regular polygonal shape, which subsurfaces are symmetrical with respect to said axis when engaging said nut in either direction of rotation, and at which times the engaging subsurfaces of said cavity are all essentially parallel to said axis, and where during turning there are one or more sets of such subsurfaces employed exclusively in turning said nut in the clockwise direction and one or more sets employed exclusively in turning said nut in the counterclockwise direction of rotation, each such set having at least one pair of opposing subsurfaces, and where the magnitude of the acute dihedral angle formed by the intersection of the plane of any subsurface for turning in clockwise rotation and the plane of that adjacent subsurface for turning said nut in counterclockwise rotation which engages the nut in the vicinity of the same vertex of the nut as said ''''any subsurface'''' is substantially greater than 360*/n, where n is the number of sides in said polygonal shape, and where the perpendicular distance between any two opposing said subsurfaces of said wrench in any such set falls within the range from 0.01 of nominal below (that is, less than) nominal to 0.01 of nominal above (that is, greater than) nominal, thus making the range from 0.990 of nominal to 1.010 of nominal, when the nut to be turned is made of heated-treated and hardened steel; and falls within the range from 0.01 of nominal below 0.991 of nominal to 0.01 of nominal above 0.991 of nominal, thus making the range from 0.981 of nominal to 1.001 of nominal, when the nut to be turned is made of mild steel; and falls within the range from 0.01 of nominal below 0.982 of nominal to 0.01 of nominal above 0.982 of nominal, thus making the range from 0.972 of nominal to 0.992 of nominal, when the nut to be turned is made of soft metal, such as brass or aluminum.
Claim 2
Dependent Claim
361 words
A wrench for turning a nut or bolt of regular polygonal shape, said wrench having a cavity of subsurfaces for engaging and turning said nut in either a clockwise or counterclockwise direction of rotation about the central axis of said regular polygonal shape, which subsurfaces are symmetrical with respect to said axis when engaging said nut in either direction of rotation, and at which times the engaging subsurfaces of said cavity are all essentially parallel to said axis, and where during turning there are one or more sets of such subsurfaces employed exclusively in turning said nut in the clockwise direction and one or more sets employed exclusively in turning said nut in the counterclockwise direction of rotation, each such set having at least one pair of opposing subsurfaces, and where the magnitude of the acute dihedral angle formed by the intersection of the plane of any subsurface for turning in clockwise rotation and the plane of that adjacent subsurface for turning said nut in counterclockwise rotation which engages the nut in the vicinity of the same vertex of the nut as said ''''any subsurface'''' is substantially greater than 360*/n, where n is the number of sides in said polygonal shape, and where the perpendicular distance between any two opposing said subsurfaces of said wrench in any such set falls within the range from 0.01 of nominal below (that is, less than) nominal to 0.01 of nominal above (that is, greater than) nominal, thus making the range from 0.990 of nominal to 1.010 of nominal, when the nut to be turned is made of heated-treated and hardened steel; and falls within the range from 0.01 of nominal below 0.991 of nominal to 0.01 of nominal above 0.991 of nominal, thus making the range from 0.981 of nominal to 1.001 of nominal, when the nut to be turned is made of mild steel; and falls within the range from 0.01 of nominal below 0.982 of nominal to 0.01 of nominal above 0.982 of nominal, thus making the range from 0.972 of nominal to 0.992 of nominal, when the nut to be turned is made of soft metal, such as brass or aluminum.
Claim 3
Dependent Claim
246 words
A wrench for turning a nut of regular polygonal shape, said wrench having a cavity of subsurfaces for engaging and turning said nut in either a clockwise or counterclockwise direction of rotation about the central axis of said regular polygonal shape, which subsurfaces are symmetrical with respect to said axis when engaging said nut in either direction of rotation, and at which times the engaging subsurfaces of said cavity are all essentially parallel too said axis, and where during turning there are one or more sets of such subsurfaces employed exclusively in turning said nut in the clockwise direction of rotation and one or more sets of such subsurfaces employed exclusively in turning said nut in the counterclockwise direction of rotation, each such set having at least one pair of opposing subsurfaces, and where the magnitude of the acute dihedral angle formed by the intersection of the plane of any subsurface for turning in clockwise rotation and the plane of that adjacent subsurface for turning said nut in counterclockwise rotation which engages the nut in the vicinity of the same vertex of the nut as said ''''any subsurface'''' is substantially greater than 360*/n, where n is the number of sides in said polygon and where the perpendicular distance between any two opposing subsurfaces of any set of subsurfaces employed in turning the nut clockwise is less than the perpendicular distance between any two opposing subsurfaces of any set of subsurfaces employed in turning the nut counterclockwise.
Claim 4
Dependent Claim
246 words
A wrench for turning a nut of regular polygonal shape, said wrench having a cavity of subsurfaces for engaging and turning said nut in either a clockwise or counterclockwise direction of rotation about the central axis of said regular polygonal shape, which subsurfaces are symmetrical with respect to said axis when engaging said nut in either direction of rotation, and at which times the engaging subsurfaces of said cavity are all essentially parallel too said axis, and where during turning there are one or more sets of such subsurfaces employed exclusively in turning said nut in the clockwise direction of rotation and one or more sets of such subsurfaces employed exclusively in turning said nut in the counterclockwise direction of rotation, each such set having at least one pair of opposing subsurfaces, and where the magnitude of the acute dihedral angle formed by the intersection of the plane of any subsurface for turning in clockwise rotation and the plane of that adjacent subsurface for turning said nut in counterclockwise rotation which engages the nut in the vicinity of the same vertex of the nut as said ''''any subsurface'''' is substantially greater than 360*/n, where n is the number of sides in said polygon and where the perpendicular distance between any two opposing subsurfaces of any set of subsurfaces employed in turning the nut clockwise is less than the perpendicular distance between any two opposing subsurfaces of any set of subsurfaces employed in turning the nut counterclockwise.
Claim 5
Dependent Claim
140 words
A wrench for turning polygonal nuts of nominal size where said wrench has a gripping cavity with a central axis parallel to and equidistant from each of every set of opposing gripping surfaces in said cavity, and where, when said axis of said wrench coincides with the central axis of said polygonal nut and said wrench is turned about said axiss in a counterclockwise direction with respect to said nut until contact is made between said gripping surfaces and the corresponding nut faces the dihedral angle formed by any of said wrench gripping surfaces and the corresponding nut faces, herein called ''''the approach angle,'''' is such that at the time when maximum torque is applied to the nut by the wrench the magnitude of this dihedral angle, because of strain in the nut and the wrench, is zero or greater.
Claim 6
Dependent Claim
140 words
A wrench for turning polygonal nuts of nominal size where said wrench has a gripping cavity with a central axis parallel to and equidistant from each of every set of opposing gripping surfaces in said cavity, and where, when said axis of said wrench coincides with the central axis of said polygonal nut and said wrench is turned about said axiss in a counterclockwise direction with respect to said nut until contact is made between said gripping surfaces and the corresponding nut faces the dihedral angle formed by any of said wrench gripping surfaces and the corresponding nut faces, herein called ''''the approach angle,'''' is such that at the time when maximum torque is applied to the nut by the wrench the magnitude of this dihedral angle, because of strain in the nut and the wrench, is zero or greater.
Claim 7
Dependent Claim
38 words
A wrench of claim 3 where when said wrench is turned clockwise rather than counterclockwise the magnitude of said dihedral angle formed is substantially different from that formed when said wrench is used to turn said nut counterclockwise.
References Cited (Backward Citations)
US3079819A
Cited
US3242775A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-09-29 | 1979-03-31 | 1979-09-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-29 | 1983-03-31 | 1983-09-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-29 | 1987-03-31 | 1987-09-30 | $7700.00 | Window Closed / Lapsed |