| 摘要 |
<p>A handheld medical instrument (10) for rotating a tool (25) including a housing (12) having a portion that may be gripped by a user, and an electric motor (14) having an output (16) rotatable at a first speed. A tool rotating shaft (23) extends from the housing (12) and is adapted to be coupled to a tool (25) to rotate the tool (25) at a second speed. A variable speed transmission in the form of a gear system (20) is operatively coupled between the output (16) of the electric motor (14) and the tool rotating shaft (23) to transfer rotation therebetween and is selectively adjustable between at least two different ratios of the first speed relative to the second speed.</p> |
