Patent · US Active

Rotary-percussion drill with a four-start helical shaft

US7628232B2 · kind B2 · utility

7Cited by

6References

10Claims

0Family size

Assignee

Hilti Aktiengesellschaft · LI

Inventors

Olaf Koch · Kirchdorf an der Krems, AT
Josef Starkmann · Hurlach, DE
Guenther Domani · Frastanz, AT

Key dates

Filing date	Apr 27, 2007
Grant date	Dec 8, 2009
Priority date	—
Expiry date	Oct 28, 2027

Classification

Technology area (CPC Y)Emerging Cross-Sectional Technologies
CPC primaryY10T408/9097
WIPO fieldMachine tools
WIPO sectorMechanical engineering

Abstract

A rotary-percussion drill includes a four-start helical shaft (3) having a fourfold rotationally and mirror-symmetrical helix cross-section, with radially projecting convexly formed helical webs (4) extending from a concave groove bottom (5) up to the envelope circle (6) and having an undercut (7) with respect to a web width (S).

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