Patent ID: 9732782
Date: 2017-08-15
CPC Classifications: F16B

Claim:
1. An attachment assembly comprising a screw having a non-sharp transition from a head of the screw to a shank of the screw, and a locking washer assembly comprising a first locking washer and a second locking washer, wherein the first and second locking washer comprise mechanism for engaging an element to be attached at a screw joint and further comprise mechanism for engaging each other, wherein the first and second locking washer are arranged parallel to a flat surface of the underside of the head of the screw and the first locking washer is positioned adjacent to the head of the screw wherein the first locking washer comprises a central through hole that is larger than a central through hole of the second locking washer, and wherein the diameter of the central through hole of the second locking washer is sized such that the second locking washer is prevented from engaging the head of the screw.