US3929054A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fastening element adapted for tightening to predetermined torque
Assignee: Elco Industries Inc
•
Filing: 1972-12-01
•
Granted: 1975-12-30
•
Expires: 1992-12-01
Abstract
Abstract A fastening element such as a screw adapted to be tightened in a workpiece by a tool to a predetermined torque includes a head comprising a base member integrally formed on the upper end of a threaded shank. A projection extending upwardly from the base telescopes through a central opening in a hexagonal plate shaped for engagement by the tool to tighten the screw in the workpiece and a boss on the upper end of the projection holds the plate on the base. In one embodiment, vertical splines on the projection mate with similar splines formed around the opening in the plate and the splines are of a predetermined strength correlated with the predetermined torque to keep the plate from turning relative to the base until the tightening torque applied by the tool exceeds the predetermined torque. This causes the splines to fracture so the plate slips around the projection to prevent the screw from being tightened excessively in the workpiece. In another embodiment, mating radial serrations formed in the lower surface of the plate and the upper surface of the base keep the plate from sliding loosely around the projection until the tightening torque exceeds the predetermined torque. Upon reaching the predetermined torque, the serrations slide over each other camming the plate upwardly and thereby bending the boss upwardly to free the plate to slip loosely around the projection and thereby prevent the screw from being tightened excessively in the workpiece.
Inventors
- 👤 Charles E Gutshall
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 15:51
CPC Classifications
F; F16; F16B; F16B31/00; F16B31/02; F16B31/021
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
296 words
A fastening element adapted to be threaded into a workpiece to a predetermined torque by a tool, said element including an elongated threaded shank, and a head on one end of the shank comprising a base member integrally formed with the upper end of said shank, a projecting member extending upwardly from said base member, a plate member with a central opening telescoped on said projecting member and being shaped for engagement by said tool to tighten the screw in the workpiece, and permanently yieldable means adapted to hold said plate against turning relative to said projecting member until the tightening torque applied to said plate exceeds said predetermined torque and said means thereafter being permanently deformed so said plate member may slip freely around said projecting member, said means including a boss formed on the upper end of said projecting member and being spaced from said base member a distance substantially equal to the thickness of said plate, said boss engaging said plate member and holding the latter on said projecting member and against said base member, said means further including a first series of parts integrally formed of the material of said plate member, a second series of parts integrally formed of the material of another of said members, said first and second series of parts being oriented on their respective members to allow said plate member to be telescoped onto said projecting member with said parts in said first and second series interfitting with each other to hold said plate against turning relative to said projecting member until the tightening torque applied to said plate by the tool exceeds said predetermined torque, at least one of said boss and said interfitting parts being permanently deformed when said tightening torque exceeds said predetermined torque.
Claim 2
Dependent Claim
296 words
A fastening element adapted to be threaded into a workpiece to a predetermined torque by a tool, said element including an elongated threaded shank, and a head on one end of the shank comprising a base member integrally formed with the upper end of said shank, a projecting member extending upwardly from said base member, a plate member with a central opening telescoped on said projecting member and being shaped for engagement by said tool to tighten the screw in the workpiece, and permanently yieldable means adapted to hold said plate against turning relative to said projecting member until the tightening torque applied to said plate exceeds said predetermined torque and said means thereafter being permanently deformed so said plate member may slip freely around said projecting member, said means including a boss formed on the upper end of said projecting member and being spaced from said base member a distance substantially equal to the thickness of said plate, said boss engaging said plate member and holding the latter on said projecting member and against said base member, said means further including a first series of parts integrally formed of the material of said plate member, a second series of parts integrally formed of the material of another of said members, said first and second series of parts being oriented on their respective members to allow said plate member to be telescoped onto said projecting member with said parts in said first and second series interfitting with each other to hold said plate against turning relative to said projecting member until the tightening torque applied to said plate by the tool exceeds said predetermined torque, at least one of said boss and said interfitting parts being permanently deformed when said tightening torque exceeds said predetermined torque.
Claim 3
Dependent Claim
66 words
A fastening element as defined by claim 1 wherein said plate member is generally polygonal in shape, said projecting member having a vertical side wall, said interfitting parts including interfitting splines formed in said side wall and in said plate member adjacent said opening, said splines being of a predetermined strength correlated with said predetermined torque to yield as the tightening torque exceeds said predetermined torque.
Claim 4
Dependent Claim
50 words
A fastening element as defined by claim 2 wherein said base member is of a predetermined shape similar to and smaller than the shape of said plate to enable a second tool to fit beneath said plate and around said base to loosen and retighten the screw in the workpiece.
Claim 5
Dependent Claim
39 words
A fastening element as defined by claim 3 wherein said projecting member is generally cylindrical in shape and said plate member is generally hexagonal in shape, said boss being formed by staking said plate member on said projecting member.
Claim 6
Dependent Claim
20 words
A fastening element as defined by claim 4 wherein the cross-sectional shape of each of said splines is generally rectangular.
Claim 7
Dependent Claim
124 words
A fastening element as defined in claim 1 wherein said plate member is generally polygonal in shape and includes a lower surface, said base member having an upper surface and being integrally formed with said shank, said interfitting parts including mating radial serrations formed in the lower surface of said plate member and in the upper surface of said base, said boss normally holding said plate member downwardly against said base member to hold said serrations to interfit with each other, said boss being of a predetermined strength correlated with said predetermined torque to be bent upwardly by said plate as the latter is cammed upwardly against said boss as the serrations slide across each other when the tightening torque exceeds said predetermined torque.
Claim 8
Dependent Claim
79 words
A fastening element as defined by claim 6 wherein said plate members includes aN upper surface and a downwardly and inwardly formed beveled surface on the upper surface of said plate around the edge of said opening, said boss having an under surface tapering downwardly toward said projection from the top of said boss, said beveled surface camming against said tapered under surface to move said boss upwardly on said projection as said tightening torque exceeds said predetermined torque.
Claim 9
Dependent Claim
98 words
A fastening element as defined by claim 7 wherein each of said serrations includes two generally radial sides of generally equal size and shape, each of said sides being slanted relative to vertical at the same angle to converge toward each other upon progressing vertically from the surface within which the serration is formed so that said plate member is cammed upwardly by the relative sliding between the sides of the serrations in said plate member and the sides of the serrations in the base member regardless of the direction which the screw is threaded into the workpiece.
Claim 10
Dependent Claim
28 words
A fastening element as defined by claim 8 wherein the two sides of each of said serrations converge upon each other at an included angle approximately ninety degrees.
Claim 11
Dependent Claim
50 words
A fastening element as defined by claim 9 wherein said base member is of a predetermined shape similar to and smaller than the shape of said plate to enable a second tool to fit beneath said plate and around said base to loosen and retighten the screw in the workpiece.
Claim 12
Dependent Claim
39 words
A fastening element as defined by claim 10 wherein said projecting member is generally cylindrical in shape and said plate member is generally hexagonal in shape, said boss being formed by staking said plate member on said projecting member.
Claim 13
Dependent Claim
141 words
A fastening element adapted to be threaded into a workpiece to a predetermined torque by a tool, said element including an elongated threaded shank, and a head on one end of said shank comprising a base integrally formed with the upper end of said shank, an integral projection with a side wall extending upwardly from said base, a polygonal plate with a central opening telescoped over said projection, a boss on the upper end of said projection holding said plate against said base, vertical splines formed in said side wall and in said plate adjacent said opening, said splines interfitting with each other and being of a predetermined strength correlated with said predetermined torque to fracture as the tightening torque applied to said plate by said tool exceeds said predetermined torque thereby causing said plate to slip loosely around said projection.
Claim 14
Dependent Claim
141 words
A fastening element adapted to be threaded into a workpiece to a predetermined torque by a tool, said element including an elongated threaded shank, and a head on one end of said shank comprising a base integrally formed with the upper end of said shank, an integral projection with a side wall extending upwardly from said base, a polygonal plate with a central opening telescoped over said projection, a boss on the upper end of said projection holding said plate against said base, vertical splines formed in said side wall and in said plate adjacent said opening, said splines interfitting with each other and being of a predetermined strength correlated with said predetermined torque to fracture as the tightening torque applied to said plate by said tool exceeds said predetermined torque thereby causing said plate to slip loosely around said projection.
Claim 15
Dependent Claim
176 words
A fastening element adapted to be threaded into a workpiece to a predetermined torque by a tool, said element including an elongated threaded shank, and a head on the end of said shank comprising a base having an upper surface and being integrally formed with the upper end of said shank, an integral projection extending upwardly from said base, a polygonal plate having a lower surface and a central opening telescoped over said projection, mating radial serrations formed in the lower surface of said plate and in the upper surface of said base, a boss formed on the upper end of said projection, engaging the plate and normally holding the latter downwardly against said base with said serrations interfitting with each other, said boss further being of a predetermined strength correlated with said predetermined torque and swaged upwardly by said plate and permanently deformed thereby as said plate is cammed upwardly against the boss as the serrations slide across each other when the tightening torque applied to said plate by said tool exceeds said predetermined torque.
Claim 16
Dependent Claim
176 words
A fastening element adapted to be threaded into a workpiece to a predetermined torque by a tool, said element including an elongated threaded shank, and a head on the end of said shank comprising a base having an upper surface and being integrally formed with the upper end of said shank, an integral projection extending upwardly from said base, a polygonal plate having a lower surface and a central opening telescoped over said projection, mating radial serrations formed in the lower surface of said plate and in the upper surface of said base, a boss formed on the upper end of said projection, engaging the plate and normally holding the latter downwardly against said base with said serrations interfitting with each other, said boss further being of a predetermined strength correlated with said predetermined torque and swaged upwardly by said plate and permanently deformed thereby as said plate is cammed upwardly against the boss as the serrations slide across each other when the tightening torque applied to said plate by said tool exceeds said predetermined torque.
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) | 1978-12-29 | 1979-06-30 | 1979-12-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-29 | 1983-06-30 | 1983-12-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-29 | 1987-06-30 | 1987-12-30 | $7700.00 | Window Closed / Lapsed |