RIVING KNIFE DRIVE MECHANISM FOR A PORTABLE CIRCULAR SAW
 Inventors: William D. Sauerwein, Phoenix;
William R. Stumpf, Kingsville, both of Md.
 Assignee: Black ft Decker Inc., Newark, Del.
 Appl. No.: 995,499
 Filed: Dec. 23,1992
 Int. CI.* B23D 45/16
 VS. CI 30/377; 30/391
 Field of Search 30/375-377,
30/388, 390, 391; 125/13.01, 13.03
 References Cited
FOREIGN PATENT DOCUMENTS
1403722 1/1969 Fed. Rep. of Germany 30/377
2533296 2/1977 Fed. Rep. of Germany 30/377
Primary Examiner—Douglas D. Watts
Attorney, Agent, or Firm—Harness, Dickey & Pierce
A portable circular saw includes motor-and-gear case
[ii] Patent Number: 5,235,752  Date of Patent: Aug. 17,1993
pivotally supported on a guide shoe by a rear pivot mechanism for rotation about a transverse rear pivot axis, thus allowing for selective adjustment of the blade cutting depth on the opposite side of the shoe. In such an arrangement, the depth of cut setting is increased and decreased when the motor-and-gear case is rotated relative to the shoe in respective first and second directions, while an upper pivotal blade guard, which is mounted on the motor-and-gear case for rotation about the spindle, rotates in opposite rotational directions in response to respective increases and decreases in the depth of cut setting. Cam and cam follower mechanisms are provided for maintaining the riving knife and the blade and shoe in the same relative angular orientation in a fore-and-aft cutting plane regardless of the depth of cut setting. Such riving knife actuation is accomplished by such mechanisms in response to the rotation of the rear-pivoted motor-and-gear case and the corresponding opposite rotation of the front-pivoted upper gear case.
29 Claims, 5 Drawing Sheets