Grinding spindle for screw grinder

A grinding spindle for use in a screw grinder, comprising:

• a quill to be mounted on a spindle housing;
• a whetstone provided on the leading end of the quill;
• and
• a flexible drive shaft provided within the quill for driving the whetstone, with the rotation axis of the whetstone being inclined relative to the axis of the quill according to the lead angle of a screw groove to be formed in the inner peripheral surface of a work to be mounted on a spindle disposed opposed to the spindle housing, wherein:
• the quill includes a fixing side quill to be fixed to the spindle housing and a leading end side quill having the whetstone mounted thereon and removably connectable to the fixing side quill;
• in the connecting portions between the fixing side quill and the leading end side quill, the end face of the fixing side quill perpendicular to the axis of the quill and the end face of the leading end side quill are combined with each other;
• the drive shaft includes a first drive shaft provided within the fixing side quill and a second drive shaft provided within the leading end side quill and rotatable integrally with the whetstone;
• and
• the first and second drive shafts are removably connected to each other.