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
Liquid crystal display and method of driving the same
Compositions substantially free of sodium chloride and methods for the storage of red blood cells
Method of fabricating display device
Video-recording reservation management apparatus, method, program, and system
Architecture for accelerated computer processing
Internal wiring structure of semiconductor device
System of providing an internet web site that assists medical professionals draft a letter of medical necessity or other documentation for transmission to a third party payer on behalf of a pa
  Randomly Featured Patents
Pneumatic tool
Dual channel delay sensing circuit
Multiple use fabric conditioning composition with improved perfume
Process for manufacturing improved dispensing devices
Ferrite and inductor
Method and control device for triggering passenger protection means for a vehicle
Method to reduce mol damage on NiSi
Skate body
Brake pedal feel simulator
Optical cable based directional way finding apparatus and method