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
Method and system for monitoring service quality in a mobile node
Extension of physical downlink control channel coverage
Vehicle display system or projection display for a motor vehicle, and calibration method
Undercabinet plug-in mount
Vehicle battery with cell balancing current paths and method of charging the same
Information processing device and display control method
  Randomly Featured Patents
Power steering hydraulic system with a low pressure expansible reservoir
Portion of a shoe upper
Combination retractable knife and saw utility tool
High power ultrasonic transducer
Semiconductor memory with improved auto precharge
Ferroelectric polymer memory with a thick interface layer
Emission driver and organic light emitting display using the same
Portion of a golf club head
Towel-mat with a frame member and removably attached membranes
Voice recording/reproducing device