GB384064A - Process and apparatus for the manufacture of printing blocks - Google Patents

Abstract

384,064. Copying -telegraphy. HASSING, O. S., 51, Hellerupvej, Hellerup, Denmark. Nov. 19, 1931, No. 32099. Convention date, Jan. 16. [Class 40 (iii).] In a process for the manufacture of printing- blocks by purely mechanical working of a plane or cylindrical blank by means of a cutting- tool, in which the block is made from an original which is covered point after point by a spot of light whereby a light-sensitive cell is actuated to regulate, in accordance with the current impulses suitably amplified, the depth and hence width of cutting for a tool working the blank, point by point, such point on the blank being displaced in accordance with the spot of light on the original, the cutting-tool cuts the block intermittently at one point after another, the depth of each cut varying with the variations in the energy liberated by the cell and the shape of the tool is such that the depth of each cut determines the width thereof. The original 9 is mounted on a support 10 which is displaceable in two directions in its own plane so that the spot of light 8 from the source 6 can cover successively all points on the original, or, when the latter is flexible, it may be mounted on a cylindrical support which is rotatable and axially movable. The beam of light passes through holes 4 arranged on a rotatable plate 3 and is reflected to the light-sensitive cell 11. The current impulses generated are amplified and pass to an inductor such as the electromagnet 15, between the poles of which spring held armature 16 is disposed. A cutting tool 26 having a triangular end is mounted over the blank 27 which is supported by a member 28, moved correspondingly to the support 10, and the tool 26 is operated by an eccentric cam 20 mounted on the shaft 21 which is rotated once for every hole 4 on the plate 3 which comes between the light source 6 and the original 9. The depth of the cut is regulated by a wedge 19 carried by the armature 16, which is attracted to a varying degree by the electromagnet 15 thereby inserting the wedge to a greater or less extent between the eccentric 20 and the head of the cutting tool to regulate the depth and consequently the width of the cut. The cutting tool used may be a graver, drill, grinding stone, &c., and the wedge 19 may be replaced by a stepped wedge or helical or stepped surface acting by displacement or rotation. The original may be opaque or transparent, and reproductions may be made to scale. Alternatively, a block may be prepared directly from an object in space, or the cutting mechanism and amplifier may be combined with a wireless receiving device while the lightsensitive cell pick-up is combined with a transmitter for wireless transfer of pictures. By using monochromatic light or colour filters, blocks for colour printing may be prepared.