Hand-held power circular saws have been popular wood-working tools for many years. In a typical sawing operation, the user begins by marking or otherwise identifying a desired line along which to saw the material to be cut. The user then guides the saw during cutting, manually aligning the blade with the desired line of cut. Maintaining this alignment manually can be difficult because the typical circular saw has a blade guard that obscures the user's view of the blade at the point of cutting and thus impedes the user's ability to accurately align the blade with the desired cutting line.
To assist in the alignment, circular saws are typically provided with a guide slot. The guide slot is usually located on the planar cutting base of the saw, and is positioned in front of, and in line with, the circular saw blade. The user positions the saw so that the line on the material appears in the guide slot. While the provision of such a guide slot does aid the user in proper saw alignment, problems still exist. For example, because the blade is covered by a blade guard, the user cannot see the blade as it exits the material, and therefore cannot directly monitor the travel of the blade.
Circular saws generally include any number of a variety of features meant to address the issues with visibility and alignment to improve the user's efficiency, accuracy, and safety while performing a cutting operation. For example, some circular saws include a transparent portion in the blade guard to allow the user to view the blade as it exits the material, thereby allowing the user to properly guide the blade along the desired cut line. Such a transparent portion in the blade guard assists the user in manually aligning the circular saw blade with the cutting line by providing visibility of the saw blade adjacent to the cutting line. However, transparent portions in current circular saws become scratched by the debris around the saw blade, thereby reducing visibility. Additionally, transparent portions in current circular saws are prone to becoming foggy or dusty during use.
The position of a transparent portion on the blade guard also impacts the ability of the user to see the blade exiting the material. If the transparent portion is positioned too far from the blade, the view of the blade exiting the material will be obscured by debris and chips. However, if the transparent portion is positioned too close to the blade, there is a greater likelihood that flying debris and chips cut by the saw blade will break or damage the transparent portion. Additionally, if the transparent portion is positioned at an angle relative to a light source used to illuminate the workspace, the transparent portion may reflect the light from the light source, reducing the ability of the user to see the blade exiting the material.
Accordingly, there remains a need for transparent portions in the blade guards of circular saws that are scratch proof and maintain transparency while the user performs cutting operations. Additionally, it is desirable that the transparent portions in the blade guards be positioned to optimize the ability of the user to view the blade during cutting operations.