Optical alignment system for circular power saws

A power saw with an optical system for projecting an optical alignment marker onto a workpiece, comprising:

• a power saw housing;
• cutting means generally contained within the housing including a circular blade for cutting the workpiece, the blade having a radius, two sides, and a width determined by teeth projecting from the blade, and motor means for rotating the blade, the maximum projection of the teeth along each side of the blade defining a corresponding blade side plane;
• and
• light projection means located proximate to the cutting means for projecting a coherent planar beam of visible light past one of the sides of the blade and onto the workpiece in order to form a linear optical alignment marker on the workpiece along the one side of the blade, the linear optical alignment marker having a thickness and two sides, the light projection means further comprising adjustment means for selectably adjusting the position of the alignment marker so that the side of the alignment marker facing the one side of the blade is coincident with the corresponding blade side plane, the adjustment means comprising:
• lateral adjustment means for moving the position of the optical alignment marker laterally with respect to one of the sides of the blade;
• and
• means for rotating the position of the optical alignment marker on the workpiece in order to adjust the parallelism of the optical alignment marker with respect to one of the sides of the blade,
• whereby the side of the linear optical alignment marker that is coincident with the blade side plane designates the location at which the maximum projection of the teeth along the one side of the blade will enter the workpiece.

A power saw with an optical system for projecting an optical alignment marker onto a workpiece, comprising:

• a power saw housing;
• cutting means generally contained within the housing including a circular blade for cutting the workpiece, the blade having a radius, two sides, and a width determined by teeth projecting from the blade, and motor means for rotating the blade, the maximum projection of the teeth along each side of the blade defining a corresponding blade side plane;
• and
• light projection means located proximate to the cutting means for projecting a coherent beam of light past one of the sides of the blade and onto the workpiece in order to form an optical alignment marker on the workpiece, the light projection means further comprising adjustment means for adjusting the position of the beam of light so that a selected portion of the alignment marker is coincident with the blade side plane defined by the adjacent side of the blade, wherein the alignment marker portion that is coincident with the adjacent blade side plane designates the location at which the adjacent side of the blade will enter the workpiece, the adjustment means comprising:
• lateral adjustment means for moving the position of the optical alignment marker laterally with respect to one of the sides of the blade;
• and
• means for rotating the position of the optical alignment marker on the workpiece in order to adjust the parallelism of the optical alignment marker with respect to one of the sides of the blade.