| 摘要 |
A laser light referencing tool comprises laser means (314) for emitting a visible laser beam, portable power means for powering the laser means, and gravity-responsive directional means for establishing a datum director for the laser means, the gravity-responsive directional means preferably being batteries (208) contained within a cylindrical housing (301) which is axially attached to another cylindrical housing (302) in such a manner that the relative rotational positions of the two cylindrical housings (301,302) are controlled by friction. <IMAGE> |
