| 摘要 |
<p>A tool for use in removing plastics material from a hole comprises a work surface adapted to contact the material. Piezo electric transducer means operatively connected through a work horn to the work surface cause it to vibrate ultrasonically and thereby to heat locally the plastics material. A cavity is adapted to receive beated plastics material. The cavity is connected to a working zone adjacent the work surface. The work surface comprises an elongate boring member and rearwardly thereof a substantially annular cutting edge, said working zone being connected to said cavity means by means of apertures disposed between said boring member and said annular cutting edge.</p> |
