| 摘要 |
<p>The hand held power drill has a spirit level to check that the drill is held in the horizontal position. The spirit level consists of a cylindrical chamber (1) attached to a clip (14) which is clamped to the drill housing by a bolt (17) which passes through holes in the lugs (15, 16). The cylindrical chamber is divided into two equal parts by a vertical central wall with small holes (11) around its periphery. The volume of liquid inside the chamber is such that the surface of the liquid coincides with the chamber diameter when the drill is horizontal.</p> |
