Sonic drill head

Abstract

A sonic drill head comprising an outer housing, an isolation system, a sine generator and a spindle. The sine generator generates a linear sinusoidal vibration force through the rotation of a plurality of eccentric masses. The sine generator is configured to translate the linear sinusoidal force to the spindle in a direction corresponding to the spindle's axis of rotation. The sine generator supports the spindle within the housing such that the spindle is free to rotate about the spindle axis. The spindle is generally a hollow tube section thereby allowing the passage of drilling fluid, mud, cuttings, and/or tooling. The isolation system generally reduces the transfer of the vibration force generated by the sine generator to the outer housing, yet is able to transfer an applied thrust force from the outer housing to the sine generator.

What is claimed is: 
     
         1 . A vibratory drill head comprising:
 a housing;   a spindle mounted to said housing for axial rotation, said spindle presenting a passage therethrough extending between upper and lower ends of said spindle for introducing or removing materials through said upper end of said spindle during axial rotation of said spindle;   a sine generator in said housing coupled to said spindle between said upper end and said lower end of said spindle in a manner to apply a sinusoidal vibration to said spindle; and   an isolation mechanism in said housing acting between said sine generator and said housing to dampen the effect on said housing of the sinusoidal vibration applied to said spindle by said sine generator.   
     
     
         2 . A vibratory drill head according to  claim 1  wherein said sine generator comprises six eccentric rotors radially distributed about a center point, each said rotor having an eccentric weight, wherein all said eccentric weights reach top dead center and bottom dead center simultaneously. 
     
     
         3 . A vibratory drill head according to  claim 2  wherein each of said six eccentric rotors include an axis of rotation, wherein the six axes of rotation are spaced radially equidistant. 
     
     
         4 . A vibratory drill head according to  claim 3  wherein each of said axes of rotation are tilted from horizontal. 
     
     
         5 . A vibratory drill head according to  claim 2  wherein each of said eccentric rotors includes an inside face wherein said inside faces of said six eccentric rotors substantially define an aperture and said spindle passes through said aperture. 
     
     
         6 . A vibratory drill head according to  claim 1  wherein said spindle protrudes outside said housing. 
     
     
         7 . A vibratory drill head according to  claim 1  wherein said material is selected from the group consisting of cuttings, instrumentation, and drill tooling. 
     
     
         8 . A vibratory drill head according to  claim 1  wherein rotation of said spindle about a spindle axis is effected independently of the operation of said sine generator. 
     
     
         9 . (canceled) 
     
     
         10 . A vibratory drill head according to  claim 1  wherein said isolation mechanism is further configured to transfer a thrust force from said housing to said sine generator and wherein said sine generator is configured to transfer said thrust force to said spindle. 
     
     
         11 . (canceled) 
     
     
         12 . (canceled) 
     
     
         13 . (canceled) 
     
     
         14 . A vibratory drill head according to  claim 1  wherein said spindle being adapted for connection to a drill bit to effect a sonic drilling mode when said spindle is driven at a first speed and a rotary drilling mode when said spindle is driven at a second speed greater than said first speed. 
     
     
         15 . (canceled) 
     
     
         16 . (canceled) 
     
     
         17 . (canceled) 
     
     
         18 . (canceled) 
     
     
         19 . (canceled) 
     
     
         20 . (canceled) 
     
     
         21 . A vibratory drill head according to  claim 1  wherein said spindle has an axis of rotation and a rotational drive for said spindle is offset of said axis of rotation of the spindle. 
     
     
         22 . A vibratory drill head according to  claim 1  wherein said sine generator includes a plurality of eccentric rotors, all of said eccentric rotors being rotated by a single drive.