Removable gripping set screw
US6454768B1 · kind B1 · utility
Inventor
Key dates
| Filing date | Dec 5, 2000 |
| Grant date | Sep 24, 2002 |
| Priority date | — |
| Expiry date | Dec 5, 2020 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B2090/037
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A medical implant set screw having a base joined to a head by a breakaway region. The set screw has a longitudinally and axially extending bore that passes through the head and into the base. The bore has a stepdown within the base so as to produce a first circumferential edge. The base breaks away from the head at a predetermined torque during installation so as to expose an upper surface. The portion of the bore in the base intersecting with the upper surface forms a second edge that is spaced above the edge formed by the step and which has a somewhat greater diameter than the edge formed by the step. The two edges of the bore are sized, positioned and spaced so as to allow an easy-out to simultaneously engage both to improve gripping by the easy-out of the base during removal thereof. The set screw base also includes a threadform having a leading edge and a trailing edge that both intersect with a plane passing through an axis of rotation of the set screw so as to form intersections that both slope rearwardly from an inner edge to an outer edge thereof.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.