Automatic edge guide mechanism for sewing machines

Claim 1

A sewing machine having a frame provided with a head and a work surface for a work piece, a needle bar journaled in the head and carrying at its lower end an eye pointed needle, a presser bar journaled in the head and carrying at its lower end a presser foot, a feed mechanism alternately operative with the needle to raise into work engaging relation in opposition to the presser foot and feed the work piece held therebetween along a predetermined line, an automatic edge guide comprising: a. a sensing means mounted in front of the needle to sense the edge of the work piece approaching the needle, b. a guide support member affixed to the presser bar, c. a guide ring rotatively mounted and alternately operative with respect to the feeding mechanism in the guide support member substantially parallel to the work surface and surrounding the needle, and d. a guidance drive means operatively connected to the guide ring reversibly to rotate the same to shift the edge of the work piece toward or away from the line of feed responsive to the sensing means signal thereto, e. the guidance drive means including a servomotor, a drive shaft driven by the motor and a gear train driven by the shaft reversibly to rotate the guide ring, f. the drive shaft being disposed substantially parallel to the presser bar, g. the guidance drive means being mounted on the head, and h. said shaft including a universal coupling intermediate the ends thereof to permit the presser bar, guide support member and guide ring to be raised and lowered by the feed mechanism intermittently engaging the presser foot whereby said shaft is shiftable in the ''''X,Y and Z'''' plane of motion to eliminate binding or misalignment.