Resources Contact Us Home
Browse by: INVENTOR PATENT HOLDER PATENT NUMBER DATE
 
 
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
Transferring a document
System and transceiver clocking to minimize required number of reference sources in multi-function cellular applications including GPS
Efficient implementation of hash algorithm on a processor
Pointer display device, pointer display/detection method, pointer display/detection program and information apparatus
Adapter plate for use in mounting an audio/visual device or the like to a surface
Variants of a family 44 xyloglucanase
Inductive signal transfer system for computing devices
  Randomly Featured Patents
Radiography device
Apparatus for securing an IC-card issuing station
Compliant hydrodynamic fluid bearing with resilient support matrix
Excavating apparatus with adjustable breaker bar
Nitrogen treating method
Process for preparing printed-circuit board
Application compatibility in multi-core systems
Apparatus and a method for measuring radiation
Method of making a nonvolatile memory programmable by a heat induced chemical reaction
Specimen culturing assembly suitable for use in in-vitro fertilization and in other cell culturing procedures