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
Chip on chip semiconductor device including an underfill layer having a resin containing an amine-based curing agent
Wireless refrigerant scale platform
Cable preparation tool
Pill identification and counterfeit detection method
Adaptive control for uncertain nonlinear multi-input multi-output systems
Display screen or portion thereof with animated graphical user interface
Power surface mount light emitting die package
  Randomly Featured Patents
Sanitary napkin
Apparatus and system for storing and collecting separated solid waste
Power supply apparatus, liquid crystal driving apparatus and display apparatus
Threaded fastener assembly
Process for preparing aminoacetaldehyde dialkyl acetals
In-solenoid chip for undertaking plural functions
Seal for shaft bearings
Method and system for multiple column/row data sorting in a display table
Information distribution and processing system