Light beam alignment system

Abstract

A saw such as a chop saw, a circular saw, a compound miter saw or a sliding compound miter saw having a rotatable saw blade is provided with a laser arbor alignment system. The laser arbor may include a power generator that generates power as the saw blade and the laser arbor are rotated by a spindle. The generator may include a stator comprising an electrical magnet or a permanent magnet mounted on a fixed portion of the saw. The other portion of the generator is a rotor comprising a coil that is rotated with the laser arbor to generate power for the laser. Power may also be provided to the laser by slip ring contacts from a stationary source to the laser arbor.

1 . A laser arbor for a saw having a spindle that rotates a saw blade relative to a non-rotating portion of the saw, the laser arbor comprising: 
 a housing;    a laser light disposed at least in part within the housing; a circuit electrically connected to the laser for providing power to the laser, the circuit providing power for a voltage source that includes a portion secured to the non-rotating portion of the saw.    
   
   
       2 . (canceled)  
   
   
       3 . (canceled)  
   
   
       4 . The laser arbor for a saw having a spindle of  claim 1  wherein the circuit further comprises an inductively coupled power source comprising a first induction coil that is rotated by the spindle and a second induction coil that is on the non-rotating portion of the saw, and wherein power for the laser is provided by the inductively coupled power source.  
   
   
       5 . The laser arbor for a saw having a spindle of  claim 1  wherein the circuit further comprises a power source electrically connected by slip ring contacts that establish electrical contact between the power source and the circuit, wherein the slip ring contacts comprise a first set of contacts that rotate with the saw blade and a second set of contacts that are stationary which contact the first set of contacts.  
   
   
       6 - 13 . (canceled)  
   
   
       14 . A saw comprising: 
 a motor having a spindle;    a blade secured to the spindle and rotated by the motor to cut a workpiece;    a laser arbor having a housing secured to the spindle for rotation with the blade;    a light source disposed in the housing, the light source emitting a narrow beam of light adjacent the blade for providing a visual indication of the alignment of the blade with the workpiece; and    an inductively coupled power source electrically connected to the light source, wherein the power source includes a first induction coil associated with and rotated with the housing and a second induction coil secured adjacent to the housing, the second induction coil inducing voltage in the first induction coil to provide power to the light source.    
   
   
       15 . The saw of  claim 14  wherein the rotor is electrically connected to a power conditioning circuit that provides power directly to the light source.  
   
   
       16 . The saw of  claim 14  wherein the light source is a LED.  
   
   
       17 . (canceled)  
   
   
       18 . A saw comprising: 
 a motor having a spindle;    a blade secured to the spindle and rotated by the motor to cut a workpiece;    a laser arbor having a housing secured to the spindle for rotation with the blade;    a light source disposed in the housing, the light source emitting a narrow beam of light adjacent the blade for providing a visual indication of the alignment of the blade with the workpiece; and    a power source electrically connected by a plurality of slip ring contacts that establish electrical contact with the light source, wherein the slip ring contacts comprise a set of rotating contacts that rotate with the blade and a set of fixed contacts that are stationary and are mounted on the saw to contact the first set of contacts.    
   
   
       19 . A laser arbor for a saw having a spindle that rotates a saw blade relative to a non-rotating portion of the saw comprising: 
 a housing secured to the spindle;    a laser disposed at least in part within the housing; and    an electric circuit for providing an electrical connection between the laser and the voltage source, wherein electric current to power the laser is generated solely by rotation of the spindle with no electrical connection with the non-rotating portion of the saw.