Patent ID: 6631658
Filing Date: 2003-10-14
Classification: B23D

Abstract:
In a saw sharpening machine of the type including a base adapted to support a saw blade for movement relative thereto and a grinding wheel mounted to the base, the grinding wheel driven for reciprocating movement relative to the saw blade, the saw blade including multiple teeth spaced apart along the saw blade, an improved indexing mechanism comprising:an indexing actuator; a feed finger driven to reciprocate by the indexing actuator for multiple indexing cycles, each indexing cycle comprising a feed stroke and a retraction stroke, the feed stroke including movement of the feed finger in a first direction for advancing the teeth of the saw blade and the retraction stroke including movement of the feed finger in a second direction opposite the first direction for resetting the index mechanism, the feed finger contacting a first tooth of a the saw blade during movement in the first direction and retracting past a second tooth of the saw blade adjacent the first tooth during movement in the second direction; a caliper finger mechanically linked to the feed finger for reciprocating movement therewith; a drag mechanism mechanically linked to the caliper finger, the drag mechanism urging the caliper finger closer to the feed finger during movement of the feed finger in the first direction so that the caliper finger presses against the second tooth during advancement of the saw blade; a sensor coupled to the caliper finger and the feed finger for measuring a pitch distance between the first and second teeth during movement in the first direction; and a control unit coupled to the sensor and the indexing actuator, the control unit including a feedback loop for controlling the feed stroke based on the pitch distance measured during a previous feed stroke, and to thereby accurately position the teeth of the saw blade for sharpening by the grinding wheel.