Patent · US Expired

Drilling tool

US4406334A · kind A · utility

24Cited by

7References

14Claims

0Family size

Assignee

Robert Bosch GmbH · DE

Inventors

Otto Baumann · Echterdingen, DE
Hans-Peter Dohse · Waiblingen, DE
Wilbert Reibetanz · Leinfelden, DE
Karl Wanner · Echterdingen, DE

Key dates

Filing date	Sep 4, 1981
Grant date	Sep 27, 1983
Priority date	—
Expiry date	Sep 4, 2001

Classification

Technology area (CPC Y)Emerging Cross-Sectional Technologies
CPC primaryY10T408/895
WIPO fieldCivil engineering
WIPO sectorOther fields

Abstract

A drilling tool has a drilling shaft member, a crown drilling member with an annular wall provided with a plurality of cutting edges and detachably mounted on the shaft member, a center drilling member detachably mounted on the shaft member inside the crown drilling member and having a further cutting edge, and elements for limiting a drilling depth of the tool when the center drilling member is mounted on the shaft member. Thereby, the operator of the drilling tool, after drilling a guiding groove in a rock, is forced to remove the center drilling member from the drilling tool and drill further without the center drilling member, which increases the drilling efficiency.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.