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:
Sep. 23, 1980
Filed:
Feb. 14, 1979
Paul Deutschenbaur, Unterpfaffenhofen, DE;
Hilti Aktiengesellschaft, Schaan, LI;
Abstract
A self-drilling dowel assembly is made up of an expansion sleeve with an annular drill bit formed on one end and a spreader axially displaceable through the sleeve after it has formed a borehole for expanding and anchoring the sleeve in the borehole. The bore through the sleeve is divided by a transverse partition wall into two axially extending blind bores each extending inwardly from an opposite end of the sleeve. The blind bore extending from the drill bit end of the sleeve has a diameter which is 0.5 to 0.9 times the exterior diameter of the sleeve and the axial length of this blind bore is also about 0.5 to 0.9 times the exterior diameter of the sleeve. Axially extending grooves are formed in the exterior surface of the sleeve and recesses extend inwardly from the base of the grooves for facilitating the expansion of the sleeve.