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
ESD protection device and method for producing the same
Selection of a suitable node to host a virtual machine in an environment containing a large number of nodes
Data processing apparatus, activation control method, and computer-readable storage medium
Catalyst composition comprising shuttling agent for ethylene multi-block copolymer formation
Biodegradable aliphatic-aromatic copolyester for use in nonwoven webs
Method to prevent hyper frame number de-synchronization in a wireless communication system
  Randomly Featured Patents
Airbag with a double regulating venting device
Fast patch-based method calls
Electrophotographic light-sensitive material
Solar-powered charger with heat-dissipating surface
Inkjet printhead and method of manufacturing the same
Naphthyl acetaldehyde derivatives
Tamper-evident electric paper
Electromagnetic operating mechanism for gas exchange valves of internal combustion engines
Cathode-ray tube with multi-layer resin coating on faceplate providing implosion protection
Method and system for controlling an air-to-fuel ratio in a non-stoichiometric power governed gaseous-fueled stationary internal combustion engine