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:
May. 23, 1995
Filed:
Dec. 15, 1993
Hilti Aktiengesellschaft, Furstentum, LI;
Abstract
A hollow crown drill has a set of cutting members (2, 3, 4) positioned on the leading or cutting end of an annular axially extending carrier member (1). The radial width of the cutting faces (2a, 3a, 4a) of the cutting members (2, 3, 4) increases opposite to the rotational direction (D) of the carrier member (1). In addition, the cutting members (3, 4) in the set disposed counter to the rotational direction (D) are offset in the direction parallel to the axis of the carrier member relative to the cutting member of the set leading in the rotational direction. This dimensional feature relates to the increase in the size of the cutting faces (2a, 3a, 4a). With the cutting faces (2a, 3a, 4a) dimensioned as above, each of the cutting members penetrates deep into the material being drilled, so that if the usual contact pressure forces are applied abrasive wear resulting in premature failure of the hollow crown drill does not occur.