Patent GB-976502-A (GB)
Title: Improvements in or relating to the production of embossing and/or printing rollers
IPC: B41C1/18
Filed: 1960-02-15
Abstract: 976,502. Printing and embossing surfaces; embossing. K. L. SMITH, and E. WATSON. May 9, 1961 [Feb. 15, 1960; April 5, 1960], Nos. 5247/60 and 11937/60. Headings B6C and B6J. A hard, metal pattern roller for use in impressing the design on to printing and/or embossing rollers is prepared by coating the blank roller with a resist, rolling the coated roller in contact with a pattern whereby parts of the roller surface are exposed and removing metal e.g. by etching, from the exposed parts of the roller. Apparatus for rolling the roller 55 over the pattern comprises a main frame 10 on which a horizontally slidable carriage 13 is mounted. A gearwheel 22 rotatably mounted on the carriage 13 engages a rack 33 on the frame 10 and is rotatable by means of a hand wheel 24 for effecting horizontal movement of the carriage. A support 31 is carried at the upper end of a vertical shaft 27 which is vertically adjustable in the carriage 13 by means of a hand wheel 35, a bevel gear 34 and a bevel gear nut 32 which engages a threaded portion of the shaft 27. A table 41 is mounted on the support 31 by means of a central, large ball 45 and three smaller balls 48, each of the latter being mounted on the head of an adjusting screw 49 in the support 31, whereby the table may be levelled. A short rail 51 is mounted at one end of the carriage 13 and is adjustable transversely of the carriage by means of a hand wheel 53. A toothed rack 54 extends the full length of the carriage 13 and is parallel to the rail 51. A pillar 58 is mounted on the frame 10 and is vertically adjustable by means of a hand wheel 65. At its upper end the pillar 58 carries a centring device 70, which is axially adjustable by means of a handwheel 71, and two parallel beams 66. At their ends opposite to the pillar 58 the beams 66 carry a centring device 68 which is axially adjustable and may be locked in adjusted position by a screw 69. Two wheels 72, 72a are secured to the ends of the roller 55, the wheel 72 being toothed. After being coated with an etching resist the roller 55 is placed on the apparatus in such a way that a marked tooth on the wheel 72 engages a marked V-cut in the rack 54 and the wheel 72a rests on the rail 51. The carriage 13 is then moved horizontally by means of the hand wheel 24 until the axis of the roller 55 lies between the centring devices 68, 70 which are then moved inwards so as to support the roller. The carriage 13 is then reciprocated a number of times so that a flat pattern block (not shown) mounted on the table 46 engages the roller 55, which is oscillated owing to the engagement of the wheel 72 with the rack 54, and removes part of the resist therefrom by friction or by chemical action. The roller is then removed from the apparatus and etched. Spark etching or electro-erosion may be used instead of acid etching. Thereafter the roller is recoated with resist, repositioned in the apparatus and subjected to the steps described above. The process is repeated until a sufficiently deep etch has been obtained on the roller. By varying the size of wheels 72, 72a and the height of the rails 51, 54, different sizes of roller 55 can be dealt with.