The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 02, 1994
Filed:
Aug. 03, 1992
Richard H Clewett, Los Angeles, CA (US);
Claude O Pering, Ranchos Palos Verdes, CA (US);
Daniel B Sharitz, Lawndale, CA (US);
Ace Medical Company, Los Angeles, CA (US);
Abstract
A fixation screw for attaching to a bone has at least one flute which traverses the proximal portion of the thread to form reverse cutting faces on the thread at the proximal portion. The cutting faces are arranged to cut the bone when the screw is rotated in a reverse rotational direction to ease in withdrawal of the screw. The flute forms a first plane containing the cutting faces on the thread and the axis of rotation of the screw. A base surface is formed by the flute forwardly of the cutting faces when the screw is rotated in a reverse direction. The base surface includes a rotational portion at the root diameter of the thread and a planar portion in a plane tangential to the rotational portion and arranged so that a substantial portion of the cutting face is axially offset from the leading thread to thereby engage the bone. Additionally or optionally, the thread is tapered at the proximal end to form a reverse self-tapping thread.