Patent GB-430751-A (GB)
Title: Improvements in doctor blade mechanism for intaglio printing machines
IPC: B41F9/10
Filed: 1933-12-20
Abstract: 430,751. Printing-machines. LOUGEE, F. G., 109, Borough Road, London. Dec. 20, 1933, No. 35881. [Class 100 (ii)] Inking-apparatus.-A rotary intaglio printing - cylinder is provided with two doctor blade carriers so supported that they may be moved relatively to one another to bring the blades into and out of operative position and may also be held simultaneously so that both blades are in contact with the cylinder and make equal angles with the tangents through their lines of contact. One blade can thus be moved into engagement with the cylinder at the most satisfactory angle before the other blade is moved out of contact therewith. In one form, Fig. 1, the carriers 4, 5 of the doctors 2, 3 are mounted in supports 6, 7 secured to shafts 8, 9 which are supported by arms 10, 11 carried respectively by arms 12 fixed to a shaft 14 and arms 13 fixed to sleeves 15 rotatably mounted on the shaft 14. Springs 16, 17 urge the arms 10, 11 radially outward from the arms 12, 13. Manually operable worm gearing is provided for independently turning the shaft 14 and the sleeves 15. Trollies 26, 27 carrying rollers 30, 31 are secured to blocks 26<1>, 27<1> rotatably mounted on the shafts 8, 9 and the rollers engage fixed cam tracks comprising the portions 32<1>, 32<2>, 32<3>, 32<4>, 32<5>. Tension springs 28, 29 extending between arms 28<1>, 29<1> on the blocks 26<1>, 27<1> and arms 28<2>, 29<2> fixed to the shafts 8, 9 hold the blades resiliently in contact with the plate cylinder 1. In the normal position the operative blade occupies the position shown by the blade 3 in full lines and the reserve blade and its carrying devices the position shown in broken lines. To change the blades, the arms, e.g. the arms 12, carrying the reserve blade are turned in an anti-clockwise direction. When the trollies 26 reach the end of the cam portion 32<1>, the outward pressure of the springs 16 causes the rollers 30 to engage the portions 32<2>, 32<3> of the cam, turning the blade 2 into contact with the cylinder 1 as shown. The arms 11 are then turned to bring the blade 3 into the reserve position and the arms 12 further turned to bring the blade 2 into the normal operative position. The trollies are adjustable on the blocks 26<1>, 27<1> by screws 52, 53 for adjustment of the blades relatively to the cylinder 1. In the form shown in Fig. 3, the blade supports 6 are adjustably mounted on the blocks 26<1>, 27<1> which are fixed to the shafts 8, 9 mounted in stationary positions. Weights 39, 40 connected by cables 35, 36 to arms 33, 34 on the blocks tend to turn the blades into contact with the cylinder 1. An operating lever 48 is freely mounted on the shaft 9 and carries a pin or roller 46 adapted to engage an arm 47 on the shaft 9, and a link 44 having a slot 43 engaging a pin 42 on an arm 41 fixed to the shaft 8. A locking device engaging an aperture 49 in the lever 48 holds the lever in either of its extreme positions. By lowering the lever 48 the blade 2 is turned by the weight 39 into contact with the cylinder 1. At or after the time at which it contacts with the cylinder, the pin 46 engages the arm 47 and moves the blade 3 into an inoperative position. In a modification of this form, the lever mechanism for operating the blade carriers is replaced by a suitably shaped rotary cam engaging followers on arms fixed to the shafts 8, 9. Downward extensions 54, 55 on the blade carriers 4, 5 screen the operating mechanism from the ink removed by the blades and also promote the flow of ink from the blades. Specification 8924/11, [Class 100 (ii)], is referred to.