Bone screw and method for manfacturing the same
AssigneeMedical Facets LLC
InventorsWayne A. Willert, Glenn A. Rupp, Kevin J. Lovell
Life of this patent
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Abstract
A faceted bone screw and a method for manufacturing the same includes a screw thread configuration having facets that are substantially transverse to the thread. The facets are generally made up of a plurality of transitioning peaks and valleys which vary the depth of the thread and are disposed in one or more locations throughout the threaded portion of the bone screw. The facets operate to reduce the torque required to drive the bone screw into bone, while at the same time operate to assist in anchoring the bone screw within the bone once inserted therein, and thereby reduce the possibility for the screw backing out after insertion.
Claims10
A method of manufacturing an orthopedic screw comprising:
- loading a bar stock of material into a screw cutting machine;
- cutting a thread into at least a portion of the bar stock with a cutting head;
- forming a plurality of facets in said thread during said cutting by imparting a controlled vibratory effect on the bar stock and a cutting head, said facets being formed by a plurality of peaks and valleys of varying a depth of the thread for at least a portion of the same.
A method of manufacturing an orthopedic screw comprising:
- loading a bar stock into a bar feeder;
- selecting a guide bushing having a desired clearance related harmonic level, said harmonic level configured to impart a controlled milling effect to the loaded bar stock;
- selecting and installing a circular threading tool previously configured to a desired thread configuration;
- and
- cutting the bar stock at the desired harmonic level using the circular threading tool to produce a faceted thread milled into at least a portion of said bar stock under the controlled milling effect of the guide bushing.
An orthopedic screw comprising:
- a shaft;
- a thread cut into at least a portion of said shaft, said threads having a depth;
- and
- a plurality of facets formed in at least a portion of said thread and extending transverse thereto, said facets having peaks and valleys creating a varying depth of said thread and configured to reduce friction between a bone and the threaded shaft thereby reducing the torque required to drive said screw into a bone while simultaneously acting to prevent undesirable backing out of the shaft after insertion into the bone.
The orthopedic screw of claim 10, further comprising surfaces between said peaks and valleys, said surfaces being flat.
The orthopedic screw of claim 10, further comprising surfaces between said peaks and valleys, said surfaces being concave.
Dependencies are inferred from the claim text.