Patent GB-583323-A (GB)
Title: Improvements in or relating to printing machines
IPC: B41L45/00
Filed: 1944-10-17
Abstract: 583,323. Printing-machines. JENNINGS, H. W. K. (Addressograph-Multigraph Corporation). Oct. 17, 1944, No. 20088. [Class 100 (ii)] Addressing and like machines; stopping- arrangements.-In a printing-machine in which address &c. plates are fed in succession into printing position to print on a list-sheet carried by a sheet-holder moved step-by-step from an initial position into each of a series of positions, a device operated in timed relation with the impression mechanism is provided for initiating the operation of power-operated mechanism for returning the sheet-holder to its initial position after a printing operation while the sheet-holder is in one of the series of positions. As shown, a spring is wound up as the list advances, and a clutch preventing return movement is released by an abutment on a flexible rack. which pulls the list-holder through the machine. Printing-mechanism. A ddress plates or stencils may be employed, as shown, addressplates D, Fig: 3, are fed from a magazine M to printing position under a fixed head 130, and an impression roller PR mounted in a carriage C reciprocating on guides 130<1> is lowered into operative position towards the end of the stroke to the right and prints on the return stroke. Repeat-printing and skipping-mechanism may be provided, printing may be effected from selected parts of the plates D, and the machine may be stopped under certain conditions, e.g., when the magazine is empty. Specifications 372,337, 489,390, 555,033, 555,821, 558,793 and 560,570 are referred to. List-holder. The leading edge of a list 66, Fig. 2, is gripped by clamps 212 adjustable for width on a holder 211 fixed to an arm 210 slidable in a channelled guide 202 on a machine table T. Each clamp has a movable spring- pressed jaw opened to release the list by turning a lever 221<1> fixed to a cam-shaft and closed by turning a lever 222<1>. A guide 223 for the side edge of the list facilitates entering the list in the clamps. The cam-shaft may be operated automatically to release the list on return of the holder 211 to its initial position by the engagement of a pin 482 on an arm 481 on the cam-shaft with a stop device 483. The pin 482 is released from the stop when the clamp is closed to grip a new list-sheet and depresses and rides over the stop on the next advance of the holder. List-feed mechanism. The guide 202 is fixed by screws 265, Figs. 2 and 5, between ribs 263 on the top plate of a housing 200 containing the feed mechanism. The housing has feet 248<1> resting on a ledge 250 extending across the rear wall of the machine frame, and the head of a stud 251, Fig. 3, screwed to the housing engages a keyhole slot in the wall. The stud 251 is adjusted to level the guide 202 on the machine table. A flexible rack 203, Fig. 22, provided with spaced perforations 273 is attached to the list-holder 211, travels in the guide 202 across the table T and passes over a sprocket fixed to a shaft 271. Two guide discs 275 rigid with the sprocket, and stationary crescent shaped plates 276 having inturned flanges co-operate to engage the edges of the rack and form a continuation of the guide 202. The rack 203 is advanced step-by-step by pawls 305 engaging holes 290 in the rack, the pitch 291 determining the feed. The pawls are carried by an arm 300 rocked about the shaft 271 by levers 310, 311, the lever 310 being rocked about a pivot 232 by a rod 205 actuated through a pin and slot connection 208 from an oscillating arm 135 of the mechanism reciprocating the impression-roller carriage, the slot allows one space advance of the list by hand. The throw of the pawl-arm 300 may be varied by adjusting a pivot pin 320 along a slot 321, and a shield may be turned about the shaft 271 to disengage the pawls. To adjust the pin 320 to the correct positions, the rod 205 being disconnected, the shield is moved counterclockwise until its left hand edge is close to a perforation 290, the pawl carrier being carried along with the shield, then moving the arm 205 to the left as far as it will go, and adjusting the pin 320 along the slot 321 until it engages a slot in the end of the arm 205. Return of list to initial position. A spiral spring is wound up as the shaft 271 rotates on advance of the list and serves to return the list to its initial positions. A gear segment 370 is rocked from the position shown in Fig. 5 where it engages a stop 376, by a pinion on the shaft 271. The stop 376 may be rotated into a position where additional movement of the segment is allowed so as to release the rack 203 from the sprocket for substituting another rack. The rear end of the rack has shoulders 2731 spaced one pitch length from the nearest perforation 273, to facilitate engagement with the sprocket teeth. Return movement of the rack under the influence of the spring is prevented by a clutch 360 of the kind having caged spring-pressed rollers riding on inclined surfaces (Fig. 18 not shown). Return is allowed by means of a lever 410 fixed to a sleeve carrying pins adapted to release the rollers. The lever 410 is connected by a link 416 to an arm 415 adapted to rock about the shaft 271 and normally restrained by a latch 421. An auxiliary lever 430 also holds the arm 415. An abutment 435 on the rack 203 engages a slide 437 to release the latch 421 when the list arrives in position for the final impression, but the arm 415 is not actuated until the printing cycle is completed when an abutment 450 on the arm 205 rocks the lever 430. The slide 437 carries a finger 456 whereby a normally open switch 460 is closed to stop the machine when the list is fully printed. The list may be returned to its initial position at the end of any printing cycle by simultaneous operation of the lever 430 and a lever 421<1> on the latch 421, or by operating a lever adapted to operate a bar 475 slidably mounted in the arm 205 so as to engage the latch.