Patent GB-555033-A (GB)
Title: Improvements in or relating to printing machines
IPC: B41L47/46
Filed: 1941-11-25
Abstract: 555,033. Addressing &c. machines. ADDRESSOGRAPH-MULTIGRAPH CORPORATION. Nov. 25, 1941, No. 15197. Convention date, Oct. 17, 1940. [Class 100 (ii)] In a printing-machine, particularly an addressing or like series-printing machine, an impression or platen roller is mounted in a carriage reciprocated over the printing plate the roller being positively rotated through gearing by the reciprocation of the carriage and being movable out of the printing plane during the non-printing stroke of the carriage, means being provided whereby the printing pressure of the roller may be adjusted without disturbing the phase relationship between the oscillation of the roller and the reciprocation of the carriage The printing plates D, Fig. 26, e.g. embossed address plates, are fed in sequence on to an anvil A beneath an ink-ribbon R and the sheet is pressed thereon by an impression roller P bearing a segmental impression surface. This surface is formed and angularly disposed according to the number of lines of the printing plate it is desired to print from, e.g., for printing envelopes the salutation would be omitted, and the impression surface would therefore not press the sheet on to the initial or final line on the plate D bearing such salutation. The roller P and its supporting and actuating mechanism are mounted on a reciprocating carriage c having guide rollers 90 (only one of which is shown) engaging guide tracks 91. The carriage is reciprocated by a rocking frame 113 and a connecting rod 124 having a notch yieldingly held by a spring 128 in engagement with a driving pin 22 on the frame 113. This construction forms a safety connection which can yield if the carriage C meets with an obstruction. The roller P is carried by toggle mechanism actuated so that the roller is held raised as shown in Fig. 26 during the non-printing stroke of the carriage C and lowered so as to roll over the sheet during the printing stroke. To provide for adjustment of the impression pressure, the guide tracks 91 are secured on a frame 92 carried by a pair of studs 166 in the fixed platen arm 72, the studs carrying springs urging the frame 92 upwardly. Three adjusting screws 170 for levelling and adjusting the height of the frame 92 and thus the impression pressure are slidably mounted in bores 171 in the arm 72 and are provided with nuts 175 in the form of pinions engaging a common gear wheel 176. One of the pinion nuts is in gear with a hand operated adjusting worm by which the vertical adjustment of the frame 92 may be effected. For levelling the frame, the screws 170 may be individually rotated through their stationery nuts and then locked against rotation by a clamping device 214. The toggle mechanism comprises upper links 242 fixed to a shaft 240 mounted in the carriage C and lower links 243 connected to the links 242 by a shaft 244 and also connected by links 25 to a bracket on the carriage C. The shaft 280 of the impression roller is mounted in the links 243, 251 and is operatively connected by gearing to a rack 320 on the platen arm 72 so that as the carriage reciprocates the roller P is oscillated. To prevent adjustments of the frame 92 from disturbing the angular setting of the roller P, the rack 320 is pivoted at one end 322 so that it can rise and fall with the adjustments of the frame 92. The gear 265 on the axis of the roller P and the adjacent end of the roller are so constructed that the roller can be located only in a definite angular position. The toggles are urged to the folded position by an adjustable spring on the shaft 240 and are strengthened by means of a control link 360 which is connected to the central shaft 244 of the toggles and is provided with a slot 367 engaging a pin 366 on the frame 113. When the carriage C moves to the right, the link 360 is moved with it at the same speed, but the pin 366 being at a smaller radius than the pin 122 moves more slowly and thus engages the outer end of the slot 367 after which the link 360 pulls on the shaft 244, thus straightening the toggle. The final straightening movement is effected suddenly by means of a pivoted latch member 370 having a notch 375 and cam surface 3701 cooperating with a pin 376 on an arm fixed to the shaft 240. Towards the end of the straightening movement of the toggle the pin 376 first depresses the latch 370 against the motion of a spring 378 and is then engaged by the notch 375 under the return action of the spring to snap the toggle into the fully straightened condition. The roller P remains lowered during the printing stroke of the carriage C until an adjustable lug 380 on the link 360 strikes an abutment 386 on the frame 113 after which the movement of the link 360 is retarded to release the latch 370 and the toggle is then broken rapidly by the action of the spring 378 and the spring on the shaft 240. If the lug 380 should fail to act owing to its being insecurely fastened, breakage of the toggle is ensured by the engagement of a pin 390 on the link 360 with a spring abutment 394 carried by the frame 92. In a modification, the rack 320 for oscillating the impression roller is also adjustable in the direction of its length into either of two positions so that either of two arcuate impression surfaces on the roller may be used. One such surface may print the whole of the matter on the plate and the other a part only of the matter or the surfaces may be of different hardness to provide prints of different appearance. For this purpose, the rack is provided with teeth 400, Fig. 49 engaging a pinion 410 operable by a finger piece 405 and held in either of two positions by a pin 406 engaging one of a pair of holes 407 in the framework. The rack is connected with the pinion so that it can pivot about the axis of the pinion when the impression pressure is adjusted. In a further modification, the rack is adjustable longitudinally to bring either of two impression surfaces into operation but the adjustment is effected automatically so that the change is effected between each printing operation. For this purpose, the pinion 426, Fig. 59. engaging the rack teeth 400 is operated by an oscillatable segment 440 carrying a roller 445 engaging a cam 460 having alternate high and low portions. This cam is turned intermittently by a ratchet wheel connected by a pawl on the frame 113 so that during one printing stroke of the carriage C a low portion of the cam 460 is presented to the roller 445 and during the next printing stroke a high portion is operable.