Circular saw unit

A circular saw unit including a circular saw for cutting a work piece, comprising:

• a base member;
• a rotary table which is rotatably mounted on the base member and on which the work piece is placed;
• a hinge supported by the base member;
• and
• a bracket member pivotably connected to the hinge to support a circular saw;
• said hinge comprising a first hinge member having a first end pivotably supported by the base member so as to be swingable in lateral directions about a horizontal axis parallel to the rotary table and a second hinge member having a first end pivotably connected to a second end of the first hinge member so as to be swingable in front and rear directions of the rotary table, a second end of the second hinge member pivotably connected to the bracket member, and a hinge locking portion comprising said second end of said first hinge member, said first end of said second hinge member, and a hinge locking means for releasably and selectively locking said second hinge member to said first hinge member so as to maintain said second hinge member in one of a plurality of predetermined rotational positions with respect to said first hinge member when the hinge locking means is locked, and to permit said second hinge member to rotate freely with respect to said first hinge member when said hinge locking means is released.