| 摘要 |
<p>A device for exposing worn button pegs in drill bits comprising a milling head with an axial recess accommodating a centering pin displaceable in the axial direction of the milling head. Said pin has an inner end acted on by a compression spring means, and an outer end projecting from the milling head. The outer end of the centering pin has a bowlshaped recess with a shape which is preferably hemispherical and corresponds to the shape of the button end of the carbide peg extending out of the drill bit. The button end of said peg is enclosed by the bowl-shaped recess when exposing the body portion of the peg.</p> |
