Resources Contact Us Home
Rotary earth boring tool

Image Number 4 for United States Patent #4406332.

The present invention provides a nonstalling system for advancing a boring tool in situations where the inclination of the bore hole with respect to the vertical is such that the force of gravity does not provide effective forward thrust. A hydraulically powered marine screw propeller adjacent the boring tool provides the necessary thrust for the drilling operation. Pressurized drilling fluid provides the required hydraulic energy. The characteristics of the marine screw propeller are such that it provides maximum thrust at maximum rotative speed but should the tool stall the forward thrust drops to zero preventing stalling.

  Recently Added Patents
Methods and apparatus for map detection with reduced complexity
Image heating device
Web-based system and method for video analysis
Glow in the dark swim goggle frame and band
Viruses lacking epithelial cell receptor entry
Direct file transfer between subscribers of a communications systems
Lighting device with device for regulating the illumination according to the luminance of the illumination field and corresponding use
  Randomly Featured Patents
Content validation for interactive dynamic documentation web site
Vehicle remote operation system and on-board device
Insulating cover for a terminal
Processes for preparing sulfonylureas
Bioreactors with substance injection capacity
Method to generate a formatted trace for an embedded device
Multiple routing options in a telecommunications service platform
Guide for mounting a brake lining onto a brake lining support of a disk brake for vehicles
Accelerator-pedal reaction force control apparatus
Load weighing system for a heavy machinery