| 摘要 |
<p>The invention relates to a dental instrument, comprising at least one pneumatically driven hand piece, whose speed can be influenced by a control element, configured as a foot switch and an additional hand piece which can be driven by an electric drive. The compressed air which is found in the pneumatic hand piece influences the control of the electric drive. The invention is characterised in that a graduated filter (16) is mounted onto a hollow body which is subjected to a pneumatic force. Areas (16.1, 16.2, 16.3) are configured on the graduated filter (16) which can be scanned by a photoelectric beam (5) that generates an electric signal (21), based on the characteristics of the filter areas (16.1, 16.2, 16.3).</p> |
