GB711471A - Improvements in or relating to embossing devices for foil or other material - Google Patents

Abstract

711,471. Embossing rollers ; printing surfaces &c. HALL, C. T., and MOLINS MACHINE CO., Ltd. Aug. 2, 1951 [Aug. 2, 1950], No. 19311/50. Class 100 (2) A method of forming an embossed surface on a thermoplastic surfaced mating roller comprises pressing the mating roller and a patterned roller against each other while rotating them together and at the same time applying heat to the surface of the mating roller only at the region of the surface which at that moment is in contact with the surface of the pattern roller. The heat is applied to the surface of the pattern roller at a position remote from the contact position where the heat is transferred. An embossing device, Fig. 1, for embossing foil strip or other material comprises a steel.roller 2 engraved with the desired pattern and a mating roller 1 comprising a steel mandrel 8 with a thermoplastic sleeve thereover, the two rollers being spring-urged apart by light springs and supported in bearings 3, 4 in a frame 5. The roller 2 makes two revolutions to one of roller 1, the rollers being connected for rotation by spur gears. The bearings 3 are slidable in the frame 5 and in operation the rollers 1, 2 are pressed together by springs 6 bearing on a sliding bridge 33 supporting a spindle 31 having cams pressing against the bearings 3, the cams being operated by a lever 7 on one end of spindle 31. The embossing device is supported on a bracket 13 and has a fixed cover 10 and movable cover 11 which may be secured in position by a screw 12. To prepare the roller 1 for embossing, the embossing device, which may form part of a packing machine, is removed and mounted in the machine shown in Fig. 3, with the roller 1 disposed above the roller 2. This machine comprises a stand 16 with top plate 17 to which the bracket 13 of the embossing device is bolted. A motor 19 on a platform 18 drives an air compressor 20 for supplying air to a gas torch 21 and drives the roller 2 through a belt 22, gear box 23 and sprocket wheel 24 connected by a chain 25 to a sprocket wheel 26 on the spindle 28 of the roller 2. A hand crank 27 may also be provided for manual operation of the roller 2. A guard plate 29 is secured to the bracket 13 so as to lie close to the position of contact of the two rollers and the flame from the gas torch 21 is moved to and fro by the operator just below the guard plate and the flame adjusted to keep the temperature shown on a pyrometer 34 between 115‹ and 120‹ C. the pyrometer being positioned just before the contact position. Initially, the rollers 1 and 2 are separated until the temperature reaches 120‹ C. when the lever 7 is operated to bring them into contact. Two revolutions of the plastic roller are then made before lever 7 is operated to separate the rollers, the plastic roller being allowed to rotate once on its own while the temperature drops, the device then being ready for use.