Title:
【発明の名称】穴降下式ロックドリル、ドリルビット及びガイド具
Document Type and Number:
Japanese Patent JP3378246
Kind Code:
B2
Abstract:
PCT No. PCT/SE93/00019 Sec. 371 Date Aug. 19, 1994 Sec. 102(e) Date Aug. 19, 1994 PCT Filed Jan. 18, 1993 PCT Pub. No. WO93/15299 PCT Pub. Date Aug. 5, 1993.A down-the-hole rock drill includes a top sub, a driver sub having a bore therein, and a piston case extending between and detachably connected to the top sub and the driver sub. A piston is located within the piston case, and a drill device is detachably connected to the driver sub. The drill device includes a shank and a head. The drill device also has a central passageway for a flushing medium. A tube is secured in the central passageway at a free end of the shank. The tube extends beyond the free end of the shank, and the piston has a central piston passageway that receives the tube. The piston is slidably movable relative to the tube. A first portion of the shank located closest to the head has a cross section, normal to a longitudinal center axis of the shank, in the shape of a multi-lobed figure that is continuously non-concave, and the bore of the driver sub is of a matching cross-sectional shape. In addition, the drill device is secured axially by a bit retainer that symmetrically cooperates with a circumferentially extending shoulder on a second portion of the shank. The second portion being located closest to the free end of the shank.
Inventors:
Hedrunto, Jean-Gunnar
Hedström, Leif
Hedström, Leif
Application Number:
JP51313093A
Publication Date:
February 17, 2003
Filing Date:
January 18, 1993
Export Citation:
Assignee:
Sandvik actie borrag
International Classes:
E21B17/046; E21B4/06; E21B4/12; E21B10/38; E21B17/07; (IPC1-7): E21B17/046; E21B4/12
Other References:
【文献】米国特許4706764(US,A)
【文献】西独国特許出願公開2401891(DE,A1)
【文献】西独国特許出願公告1221170(DE,B1)
【文献】英国特許出願公開1242052(GB,A)
【文献】仏国特許出願公開2192480(FR,A1)
【文献】西独国特許出願公開2401891(DE,A1)
【文献】西独国特許出願公告1221170(DE,B1)
【文献】英国特許出願公開1242052(GB,A)
【文献】仏国特許出願公開2192480(FR,A1)
Attorney, Agent or Firm:
Takashi Ishida (1 person outside)