in a stationary scale plate 39 and secured by a washer 40 and a nut 41 as well as a ball tie rod 44 connected to the free end of the extension 37 via a ball pin 43 and connected to an adjusting disc 46 via a ball pin 45 in order to transmit the requisite lifting motions to the support bar 5 and hence to the upper feed dog 2 a crank 47 is attached to the oscillating drive shaft 23 a pin 48 being firmly fixed in the free end of the crank 47 and reaching under the support bar 5 in order to dampen noise the bent free end of a leaf spring 49 screwed to the underside of the support bar lies against the pin 48 by means of these drive connections the upper feed dog performs elliptical operating motions the support bar 5 with the upper feed dog 2 is pressed downwardly with an adjustable pressure by a compression spring 50 the compression spring 50 is mounted on a presser bar 52 capable of shifting within a housing 51 and having on its lower end a press roller 53 that can turn around a peg 54 and rests on the support bar 5 the compressed length of the compression spring 50 can be changed by means of an adjusting screw 55 that screws into the housing 51 in order to change the.