Resources Contact Us Home
Down-the-hole rock drill

Image Number 4 for United States Patent #5435401.

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.

  Recently Added Patents
Controlling transmission resources in mobile radio systems with dualtransfer mode
Display system with mounting assemblies and associated methods
Calendar integration methods and systems for presentation of events having combined activity and location information
Display sheet, display device, and electronic apparatus
Method of fabricating semiconductor light emitting device
Bezel-less electronic display
  Randomly Featured Patents
Modular computer support and display stand
Perforating gun with rotatable charge tube
Advertising device
Glycosides of 3'-deoxyaquayamycin antibiotics
(Meth) acrylate esters of dipentaerythritol caprolactone condensates
System and method of transmitting voice over digital subscriber line
Vented vacuum tube and stopper
Hollow piston for a piston engine and method for producing a hollow piston
Self-aligning integrated circuit assembly
Electric flash apparatus