GB200603A - Improvements in devices for registering photographic negatives for use with machins for producing offset press plates - Google Patents

Abstract

200,603. Imrie, H., (Offset Directoplate Co.). April 20, 1922. Printing-surfaces. - An may be accurately device in which negatives may be accurately registered in a plate-holder, which is subsequently transferred to a machine for producing offset press plates of the same image, comprises a base 3 having two aligned openings 5 in which slide blocks 6 carving register marks 7 and adjustable in opposite directions by a shaft 8 bearing opposite screw-threads. Guide-rods 15 prevent lateral movement of the blocks, and springs 17 prevent backlash. On the base is placed a chase 1, accurately positioned by the engagement of holes 22 in the chase with pins 20 on the base. A negative 24, which may be one of three negatives for multi-colour work, carrying register marks 25 is placed in the chase, and the blocks 6 and negative are adjusted to bring the marks 25 into register with any part of the register marks 7. The adjustment of the blocks is then noted on a scale 14. The negative is then clamped in the chase by screw clamping-members 26, and the chase is removed to a machine of known kind for making offset press plates, in which the chase is mounted in a carriage which can be accurately displaced over a sensitive press-plate to reproduce the negative in multiple thereon. With the aid of the scale reading previously noted, the second and third negatives may be mounted in the chase, in the same position as the first negative, in the production of the remaining press-plates.