Patent GB-720482-A (GB)
Title: Apparatus for registering printing plates
IPC: B41F27/00
Filed: 1952-01-17
Abstract: 720,482. Printing-surfaces. TIME, Inc. Jan. 17, 1952 [Jan. 17, 1951], No. 1432/52. Class 100 (2). Mechanism for registering and making printing plates comprises a base, plate-marking means on the base, registering means on the base, a turntable rotatable on the base, and means for mounting a printing-plate on the turntable. As shown, the machine comprises a frame 11 with a table top 12 provided with a central shaft 13 upon which is swingably mounted a turntable 14. The shaft has an arm 15 adapted to engage spaced stops 16 so as to limit the movement of the arm to an arc of 90 degrees. The turntable is provided with a handle 18 to facilitate manual swinging thereof and with a plurality of rotatable screws 19, 20, 21 and 22 having slides 24 threaded thereon. The slides are formed with clamp members 25 adapted to engage the side and ends of a chase 26 within which a plate 27 has been locked. Instead of chase 26, an electrotype plate or copper original may be placed on the turntable. The plate is positioned by adjustment of the screws 19, 20 ... 22. A stationary clamp bar 28 is received at one end of the turntable 14 by screws 28a. The bar 28 co-operates with plates 32, 32a between which is clamped a transparent sheet 33. Clamps 29 prevent the plates 32, 32a from tipping up. At the opposite end of the turntable 14 a movable clampbar 34 is provided with similar sheet-retaining plates 40, 40a. Eccentric cam levers 35 pivoted on extension 36 of the turntable 14 are adapted to engage adjustable pins 37 threaded in the clamp bar 34 in order that the bar may be moved against the action of springs 41 and the sheet 33 stretched as desired. A frame 44 is provided on hinged brackets at the back of the table 12 and carries a transparent glass plate 45 having ruled cross lines thereon. Lugs 46, 47 on the frame are adapted to engage recesses 48, 49 on the turntable 14 when the frame is lowered. In operation the frame 44 is swung down into position and properly locked with respect to the turntable 14, manipulation of the screws 19, 20 ... 22 permitting the plate 27 to be properly squared with respect to the screen 45. In order that the plate 27 may now be marked, spaced markers comprising standards 50, 51 slidable in guideways 52, 53 are provided on the table 12. Slots 54, 55 in the guideways receive downwardly extending pins 56, 57 the ends of which carry blocks 58, 59 which are received within bifurcated actuating levers 60, 61. The levers are pivoted at 62, 63 and are actuated by air cylinders 66, 67, pressure to which is regulated by a manual-control knob 76. The standards carry locating pins 77, 78 co-operating with apertures 79, 80 or apertures 81, 82 depending on the orientation of the turntable, the pins 77, 78 being carried on movable heads in the standards. A marking punch 83 is formed to make a cross-hair line and a marking punch 84 is formed to make a single line. Manual levers 87 are provided to actuate the punches. If electrotypes or stereotypes are being registered a round-hole punch is used instead of the punch 83 and an elongated-hole punch instead of the punch 84. Dies 83a and 84a set in turntable 14 co-operate with the punches. Thus after the plate has been registered with respect to the screen 45, the screen is removed, the standards moved in correct position as determined by the locating pins 77, 78 and the punches actuated to mark the plate. The standards are then retracted, the plate inked, the sheet 33 clamped on the chase and an impression of the plate taken on the sheet. By means of the key-sheet 33 various colour plates may be successively registered and marked.