GB268405A - Improvements relating to sheet feeding apparatus for printing machines - Google Patents

Abstract

268,405. Crabtree & Sons, Ltd., R. W., and Hawkins, G. Nov. 25, 1925. Tripping-arrangements. - A rotary printing- machine which is provided with means such as are described in Specification 179,637 for tripping the cylinders of the printing-couple and simultaneously moving the front stops o and sheettaking grippers to inoperative positions, so that when the printing-couple is tripped the sheet is not fed past the front stops o, is provided with an automatic or semi-automatic sheet-feed consisting of rising and falling runners l coacting with a driven bottom roller m, and the tripping- mechanism for the printing-couple causes the runners l to be held in their raised position shown, so that the sheet held by the stops o is not over-run by a second sheet when the printing- mechanism is checked. The runners l cooperate with sheet-stops b which are normally raised as the runners fall. The runners l may be held in their raised position by a catch d' associated with a rod z which controls the tripping motion of the press. The rod z and catch d<1> are connected by a bell-crank y and spring c<1>. The rod z may be hand-operated, but as shown is controlled by a feeler p near the front stops o and is arranged to trip the press if the sheet is not fed correctly. If the sheet is fed correctly it releases the feeler n from a bar u and permits motion of a lever-arm r on a shaft v connected by a lever w, rod x, bell-crank y to the rod z which can follow a cam b<1> and thus falls when the cam permits. As it falls it releases the catch d<1> and also moves a shoe z<3> on an oscillating lever z<4> out of the path of a rod z<6> connected to the tripping-mechanism of the press. If a sheet fails to act on the feeler p, the rod z is maintained in the position shown, and the rod z<6> is operated to trip the printing- mechanism. The catch d<1> also maintains the runners l in the raised position.