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
Compounds, compositions and use
Business card assembly
Lubricant composition and antioxident composition
Administrable compositions
Emergency power-off button with proximity alarm
Avirulent oncolytic herpes simplex virus strains engineered to counter the innate host response
Method for encoding signal, and method for decoding signal
  Randomly Featured Patents
Mode changing means for accumulator conveyors
Heat engine and thermodynamic cycle
Planer and groover
Process for producing aromatic imide polymer hollow filaments
Integral resilient badge and sucker
Rotation control apparatus for constant linear velocity system information recording disc
Power steering apparatus
Coaxial cable
Power hydraulic gear
Tank for pressure feeding of paint or other liquids