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
Flash drive
Deadline-driven parallel execution of queries
Method for production of a thermoelectric apparatus
Food-grade flour from dry fractionated corn germ and collet composition and method for producing same
Method, apparatus, computer program, and computer readable storage media for controlling the insertion of tab sheets into a print job
Methods and compositions to treat and detect misfolded-SOD1 mediated diseases
Aisle barrier
  Randomly Featured Patents
Reflective liquid crystal display device with removable auxiliary light source
Cell cycle nucleic acids, polypeptides and uses thereof
Electrically insulating cantilever magnetometer with mutually isolated and integrated thermometry, background elimination and null detection
HARP family growth factors
Phosphate catalyzed acylation of steroidal tertiary alcohols
Thin film high permeability magnetic core flux gate device for measuring a weak magnetic field
Chair seat
Multiple bit line memory architecture
Icon image for a portion of a display screen
Single panel color image projection system