Abstract: A lockstitch sewing machine, particularly for use as an insole stitcher, having a stitching mechanism arranged for cyclically repeating operation and including a horizontally mounted rotary shuttle, has the shuttle arranged for rotation in a constant direction at a cyclically varying angular velocity such that a major part of each rotation, e.g., a complete rotation takes place in a minor part of each cycle, e.g., one quarter of the cycle. The rotation of the shuttle is provided, e.g., by a Geneva cam.

Abstract: A self-synchronizing optical radiation imaging device and optical delay circuit is provided with optics for receiving optical radiation and directing the radiation to an optical image delay system for delaying the optical radiation for a predetermined length of time. An optical radiation energy detector detects when optical radiation of a predetermined energy level has been received and actuates a gating circuit, which in turn, turns an image intensifier either on or off, depending upon the embodiment used, to coincide with the reception of the delayed signal by the image intensifier and to maintain the image intensifier on or off during the period that the receiving optics is receiving optical radiation of at least the predetermined level.