CHEMCO

INTERVAL TIMERS FOR USE IN PHOTOENGRAVING AND PHOTOMECHANICAL REPRODUCTION-NAMELY, TIMERS CONTROLLING THE OPERATION OF PLATE WHIRLERS, TIMERS CONTROLLING THE LENGTH OF EXPOSURE WITH CONTACT PRINTERS, LIGHT-CONTROLLED OR PHOTOELECTRIC TIMERS CONTROLLING THE DURATION OF OTHER EQUIPMENT SUCH AS A CAMERA SHUTTER, AND TIMERS FOR USE WITH PHOTOENGRAVING AND PHOTOMECHANICAL CAMERAS FOR CONTROLLING THE LENGTH OF EXPOSURE