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:
Oct. 18, 1983
Filed:
Mar. 12, 1981
Jurgen Kessler, Stuttgart, DE;
Hilti Aktiengesellschaft, Schaan, LI;
Abstract
A drilling tool for drilling a cylindrical borehole of relatively great depth in a soft material and then forming a conical enlargement adjacent the bottom of the borehole includes an axially elongated tool shank with a first drill at one end for cutting the cylindrical borehole and a second drill adjacent the first drill for cutting the conical enlargement. The second drill is formed of bit holders pivotally connected to a flattened part of the tool shank. An adjustable stop is provided on the tool shank for determining the depth of the borehole. A connecting link guide located within the tool shank interengages the bit holders and the tool shank. When the desired depth is reached, due to relative axial displacement between the tool shank and the connecting link guide, the bit holders are pivoted outwardly so that the second drill can cut the conical enlargement.