Patent GB-238547-A (GB)
Title: Improvements in sheet feeding devices
IPC: B65H9/00
Filed: 1925-08-10
Abstract: 238,547. Dexter Folder Co., (Assignees of Christophel, C. E.). Aug. 14, 1924, [Convention date] Stopping - arrangements. - A sheet - feeding mechanism for feeding sheets to cylinder printing-machines, or to other machines, is provided with an improved sheet-calipering device for stopping the feed, and, if desired, the press, if a double feed occurs, and also comprises a feelerdevice near the front stops for stopping the press and the feed if a sheet is not received correctly at the front stops. Also a detector similarly stops the machine if the sheets are not delivered correctly. As soon as the sheets reach the tapes 259, Fig. 1, they pass between a sheetcalipering device in the form of a roller driven by one of the tapes, and a sector which is arranged so as to be unaffected if a single sheet passes between the roller and the sector. If, however, a double feed occurs the sector is rotated and releases a catch from a gravity pawl 246, Fig. 15, which is thus allowed to engage a ratchet 252 on the shaft 112 of the feed roller 113 for the tapes. The shaft of the pawl 246 is thus rotated and is connected to a spring-toggle device 250, 253, 255, Fig. 1, which is operated to rotate a shaft 251 fitted with a lever arm provided with a roller. This roller is moved to separate a clutch which normally connects a shaft 91 with the shaft for driving the sheet separators and forwarders, and the drive to the feed is thus disconnected. The drive to the press is tripped consequentially by the failure of the sheet to arrive at a feeler 417, Figs. 22 and 35 arranged near the front stops. The feeler is normally moved by the sheet out of the path of an oscillating arm 407 secured to the tubular shaft 339. If however the feeler fails to be moved by the sheet, the arm 407 engages under a shoulder on the feeler and raises it together with an adjustable arm 413 on a spring-controlled rod 412 freely mounted in the tubular shaft 339. The. rotarv movement of rod 412 acts an electrical switch to stop the press and trip the machine., or stops the press by actuating a belt-shifting device. The rod 412 acts by lever-and-link mechanism 420, 422, 423, 424, to release a roller 429 on a spring- controlled bell-crank 425 from a notch in a. disc 430 mounted on a casting secured to a cylinder 435 containing a spring-pressed piston 436 and plunger rod 434. The disc 430 is fitted with a substantially radial slot 432 in which is guided a roller 433 on the spring-pressed plunger rod 434. The slot 432 normally holds the roller 433 raised, the roller being slightly eccentric to the axis of the disc 430. When, however, the disc 430 is released by the feeler 417 and associated mechanism, the spring-plunger rotates the disc 430, and the plunger 436 is depressed by the spring 437 and operates a treadle mechanism 443 associated with a trip arm 451 for tripping the press. The treadle mechanism is automatically locked until released by foot-action. The plunger rod 434 also carries a cam rod 456 which operates switch contacts on a bell-crank 458 for controlling the curent to the driving mechanism of the press. The feeler 417 is adapted to trip the press if the sheets are not delivered correctly from the impression cylinder. An adjustably mounted pivoted deflector 468 is operated by crumpled paper to release a dependent lever 418 which prevents the feeler 417 from being moved aside by the fed sheet. The feeler then acts as described above to trip the press.