Cutlery – Cutting tools – Saw
Reexamination Certificate
2001-04-06
2003-04-08
Payer, Hwei-Siu (Department: 3724)
Cutlery
Cutting tools
Saw
C030S390000, C083S478000
Reexamination Certificate
active
06543143
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a circular saw and more particularly to a metal cutting circular saw having a viewing window on the upper guard, which is specifically designed to protect the user from metal chips.
BACKGROUND AND SUMMARY OF THE INVENTION
One of the problems associated with the use of a handheld circular saw is properly aligning the saw so that the desired cut is achieved. Typically, a user will draw a line on the material to be cut. This line represents the location of the desired cut. The problem arises when the user of the handheld circular saw attempts to align the blade with the line on the material. The problem continues as the user attempts to keep the blade tracking on the desired cut 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 or shoe 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. Because the blade is covered by a saw guard, the user cannot see the blade as it exits the material and therefore cannot directly monitor the travel of the blade. Attempts have been made to allow the user of the saw to view the blade as it exits the material, thereby allowing the user to properly guide the blade along the desired cut line. Viewing windows have been provided to allow the user of the saw to properly align the saw to the work piece by allowing them to view the blade. While this viewing window solves the problems to some degree, its positioning remains a problem.
If the viewing window is not properly positioned, the user will be unable to see the blade exiting the material due to the reflection of light by the transparent section of the viewing window. To compensate, the user may attempt to reposition the light sources, such as a flashlight, or may reposition himself/herself relative to the saw. This repositioning can affect efficiency as well the quality of the work being performed. If the user repositions himself/herself relative to the saw, the resulting position may be an uncomfortable or unsafe one from which to operate the saw. Further, the trial and error necessary to find a proper position of saw, user and light source waste the user's time.
The position of the viewing window and the saw guard must also account for the chips that are generated as the saw cuts through the work piece. This problem is particularly relevant when the circular saw is used for cutting metal. Thus, there is also a need in the art for metal cutting circular saws to be equipped to protect the user from chips and debris while cutting metal materials. Accordingly, it is an object of the present invention to provide a window assembly in the upper guard of a circular saw in a position so as to minimize any light reflected into the eyes of the person using the saw.
It is another object of the present invention to provide a guard design which controls and minimizes the ejection of chips along with a saw shoe, and lower guard design which is optimized for the same purpose. It is a further object of the present invention to provide an upper guard that is made of strong material, yet provides plenty of light to be passed therethrough to illuminate the cutting line and blade interface area.
These and other objects of the present invention are obtained by providing a circular saw including a motor and blade drivingly attached to the motor. An upper blade guard is provided in partial covering relationship over the blade and includes a perimeter outer surface disposed between first and second side surfaces. The upper blade guard includes a first sight window disposed in the first side surface and disposed in a plane angularly offset from a plane of the blade. The upper blade guard also includes a second sight window disposed in the second side surface of the upper blade guard. A light window is disposed in the front portion of the perimeter outer surface of the upper blade guard. The upper blade guard is made from metal and the first and second sight windows and light window are integrally formed as a one-piece member. The upper blade guard includes a first portion attached to the motor housing and a second portion attached to the first portion. The sight window unit is disposed between the first and second portions of the upper blade guard and is secured therein by a fastener.
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Moore Keith
Sayles Joel D.
Van Wambeke Weston J.
Black & Decker Inc.
Harness & Dickey & Pierce P.L.C.
Payer Hwei-Siu
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