US Patent 7430808 Laser alignment device for drilling machine

A laser alignment device includes a base adapted to be installed in a drilling machine above the worktable of the drilling machine. The base has two through holes, a first laser module mounted in one through hole and operable to emit a first laser beam, a second laser module, which has a laser emitter mounted in the other through hole and operable to emit a second laser beam from its bottom side. The second laser module has a protruding portion extending around the periphery of the laser emitter and engaging the inside wall of the associated through hole to maintain the laser emitter away from the inside wall of the associated through hole Setting devices are mounted in the base and are inserted into one through hole to engage the periphery of the laser emitter of the second laser module.