1. Field of the Invention
The present invention relates to a circular saw unit such as a miter saw and a slide miter saw having a base, a turntable and a cutting mechanism.
2. Description of the Prior Art
A conventional circular saw unit having a turntable is disclosed in Japanese Laid-Open Utility Model Publications Nos. 3-79901, 4-130804 and 2-80401. The circular saw units disclosed in these publications have a common basic construction. The construction of the circular saw unit of Publication No. 4-130804 will now be explained with reference to FIG. 8.
FIG. 8 shows a turntable 82 and a base 84 of the circular saw unit in plan view. The turntable 82 has an extension 82a protruding radially from a part of the periphery of the turntable 82. The base 84 has a pair of work placing portions 84a and 84b which are formed on both sides of the base 84 for placing a work thereon. A turntable receiving recess 84c is formed in the central portion of the base 84. A cut-out portion 84d is formed on the front side of the base 84 so as to permit swinging movement of the extension 82a as indicated by an arrow 86 when the turntable 82 is rotated.
A slit 82b is formed in the extension 82a for receiving a part of a circular saw blade (not shown) which is moved vertically within a plane including the slit 82b or which is moved horizontally along the slit 82b. The extension 82a serves to support the work and to permit movement of the saw blade relative thereto. The extension 82a also serves as an operation member operable by an operator for rotating the turntable 82.
In case of the circular saw unit of Publication No. 3-79901, an extension of a turntable does not serve to permit horizontal movement of a cutting blade but serves as an operation member for rotating the turntable. The extension of this publication has a handle for fixing the position of the turntable.
In any of the circular saw units of the above publications, an oblique cutting operation of the work can be performed by varying the rotational position of the turntable.
Although the circular saw unit of this type is excellent in operation, it involves a problem that an effective width W for supporting the work cannot be broaden without causing interference between the extension 82 and the work placing portion 84a or 84b when the extension 82 is swung. Thus, when the effective width W is broadened, the range of swinging movement of the extension 82a becomes shallower. On the other hand, when the range of swinging movement of the extension 82a is broadened, the effective width W becomes narrower.
Of course, a broader effective width W can be obtained if the size of the circular saw unit is greater. However, in this case, the circular saw unit is difficult to be conveyed, and a larger space is required for storing the circular saw unit. Therefore, this measure does not provide an essential solution to the above problem.
USPTO Backgrounds
USPTO Backgrounds