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. 28, 1989
Filed:
Sep. 17, 1987
Applicant:
Inventors:
Assignee:
Hilti Aktiengesellschaft, , US;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B28D / ; B23B / ;
U.S. Cl.
CPC ...
125-1 ; 408 / ; 408-7 ; 408 12 ; 408 15 ; 29407 ; 29593 ; 175 50 ;
Abstract
In a process using a hand-held drilling device for forming openings in a construction material containing steel reinforcing members, during the drilling step the electrical resistance between the drill bit and the reinforcing members is continuously measured. If the drill bit contacts the reinforcing member the measuring circuit is shorted out and the electrical resistance drops. The drop in resistance can be used as a signal for cutting power to the drilling device or for declutching or braking the device.