Abstract: The specification relates to accessory device to be used in conjunction with a sewing machine having an automatic thread cutter. The accessory device is provided for enlarging the passageway between the sewing foot and the stitch plate, to enable bulky articles to be moved within said passageway at the time the thread is cut. The device includes a push-back mechanism comprising brake jaws as engaging elements acting upon the drive and mounted on an entrainer operationally connected with an activating device for the purpose of engaging the drive by means of said engaging elements, to push it back and bring the needle bar into its upper position, while the thread feeder remains in its lower position. The obtainable increase in the height of the passageway may be as high as 30%.