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:
Feb. 14, 1989
Filed:
Mar. 26, 1987
John W Baker, Acton, MA (US);
Other;
Abstract
A new drill-type cranial perforator is disclosed of the type which comprises a front drill head assembly made up of a leading inner drill and a trailing outer drill, and a rear support and drive assembly adapted to enable both drills so long as the leading inner drill is encountering a resistive surface and to disable both drills when the leading inner drill stops encountering the resistive surface. The inner drill is coupled to the outer drill and to the rear support and drive assembly by a plurality of lugs, each of the lugs having a cam surface, and the outer drill includes a plurality of drive surfaces which coact with the cam surfaces. The new perforator is characterized by cam surfaces which are beveled outwardly toward an outer surface of the inner drill member in a helical twist, with the degree of bevel increasing progressively along the length of the cam surface.