Auto-torque, tamper-proof screws
OwnerMair Avganiminventor
Life of this patent
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Abstract
A screw having a screw-threaded shank and a circular head, the head being provided with three radially extending screwdriver tip receiving portions defined between three first, off central integrally formed projections designed to become shaved-off the screw head by a pre-set force applied during tightening of the screw, and three second, integrally formed projections designed to withstand a shear force greater than the pre-set force applied during slackening of the screw.
Claims9
A screw having a screw-threaded shank and a circular head, the head being provided with at least one radially extending screwdriver tip receiving portion defined between a first integrally formed projection of a generally right-angled triangle cross-section seen in a plane parallel to the axis of the screw head wherein the hypotenuse of the right angled triangle slopes from the bottom of the first projection to the top thereof such that it is designed to become shaved-off the screw head by a pre-set shear force applied during tightening of the screw, and a second integrally formed projection designed to withstand a shear force greater than the said pre-set force applied during slackening of the screw.
Dependencies are inferred from the claim text.