linear output hall effect sensor that is disposed within the ring magnet to produce an output voltage proportional to displacement of the stitch forming instrumentality application_number US 94453978 A description referring to fig1 of the drawings phantom lines 10 designate the outline of a sewing machine embodying the invention as shown such sewing machine includes a bed 12 a standard 14 rising from the bed and a bracket arm 16 overhanging the bed the driving mechanism of the sewing machine includes an arm shaft 18 and a bed shaft 20 interconnected in timed relation by conventional drive mechanism not shown a needle 22 is carried for endwise reciprocation by a needle bar 24 mounted for lateral jogging movement in a gate 26 in the bracket arm 16 conventional connections not shown are to be understood as existing between the arm shaft 18 and the needle bar for imparting needle reciprocation a drive link 28 is pivoted as at 30 on the gate 26 and provides a mechanical connection to an electromechanical actuator 32 a feed dog 34 is carried by a feed bar 36 as shown and mechanism is provided for imparting work transporting movement to these parts such mechanism includes a feed drive shaft 38 driven by gears 40 and 41 from the bed shaft a cam 42 on the feed drive shaft and a pitman 44 embracing the cam 42 and connected to reciprocate a slide block 46 in a slotted feed regulating guideway 48 a link 50 pivotably connects the pitman 44 with the feed bar 36 and the inclination of the guideway 48 determines the magnitude and direction of the feed stroke of the.