GB1031027A - A process and apparatus for the manufacture of embossing rolls - Google Patents

Abstract

1,031,027. Embossing surfaces; etching. MODERN ENGRAVING & MACHINE CO. Sept. 10, 1964, No. 37154/64. Headings B6C and B6J. A process of making a rotating resist coated metallic cylinder into a female embossing roll 10, Fig. 1, by removing resist from the cylinder with the use of a mill 82 bearing the required design in relief, comprises maintaining consistent registration between the cylinder and mill during such resist removal by positively rotating said mill in synchronism with the rotating cylinder. The cylinder is treated by the mill in a series of successive circumferential strips of predetermined axial length and for this purpose the shaft and flexible coupling arrangement 76, 74, 72 carrying the mill and its rockably mounted head 152 is movable along the cylinder, the shaft 72 passing right through the bearing box 92 in which it is rotatably supported at the right-hand end of the cylinder embossing apparatus. After removing the resist in the desired design over the entire surface of the roll 10 an acid bath is placed beneath the latter and etching is effected. The mill 82 has projecting pins 208, 210 and 212 associated with its pattern and these bite into the material of the cylinder during the first full rotation of the cylinder in contact with the mill. The pressure of the mill on the cylinder is derived from a weight 200, Fig. 6, acting on a lever 198 which causes the pivoted bar 180 carrying the mill to arcuately move about its pivot 188. The holes made in the cylinder by the pin 212 during the treatment of the first strip of cylinder is used during the treatment of the second strip by the mill pins 208, 210 and thus positive registration is ensured between the mill and the cylinder throughout the whole resist removing operation. The drive to the apparatus is via gear-wheel 24 which rotates the roll 10 and simultaneously the mill 82 through gearing 64, 68, 70, shaft 72, coupling 74, shaft 76 and gearing 77, 79. The mill 82 is moved along the cylinder when required for treatment of the next circumferential strip thereon by mounting the mill 82, the mill head 152, the mill head adjusting devices 184, 186, 172, 174, 176 &c. and the mill &c. supporting structure 190, 180, 196 &c. along the bed 26 of the apparatus in a suitable guideway, through the interengagement of a nut 192 fixed to the structure 190 &c. with a rotatably mounted threaded shaft 194. The latter comprises an arresting device whereby " rough " registration of the mill and any particular part of the roll surface may be accomplished. The bearings at the right-hand end of the apparatus of Fig. 1 associated with both the roll and the mill are adjustable vertically to allow various diameter cylinders and mills to be used. By rockably mounting the mill head 152 the pressure of the mill on the cylinder may be evenly adjusted through activation of gearwheels 172, 174 and 176. By pivotally mounting the mill and the mill head &c. on the bar 180, adjustment may be effected through wheels 184 and 186 to ensure that the axes of the mill and cylinder are parallel. The process of cylinder resist coating, removal by the mill and etching may be effected over the entire roll several times in order to accomplish embossing of the required depth. A male embossing roll may be made from the female roll using the process and apparatus of U.S. Specification 2,662,002.