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
Method and device for surface scanning of a patient
Light emitting device and light emitting device package
Canopy light fixture
Instance management of code in a database
Flame-proofed thermoplastic compositions
Integrated circuit with electromagnetic intrachip communication and methods for use therewith
Two dimensional magnetic sensor immune to skew angle misalignment
  Randomly Featured Patents
Automatic transmission system for vehicles
Immunoassay for N-desmethyldiazepam
Apparatus and method for protecting optical-fiber devices
Light emitting type push button switch
Optical waveguides and methods of making the same
Tool decontamination apparatus
Clear-coated body jewelry
Sun visor extension
Mechanism for preventing unintended rotation of reels of film storage cassette
Encoding device, encoding method, and program