GB387362A - Improvements relating to sheet delivery mechanism for printing presses - Google Patents

Abstract

387,362. Sheet-delivery apparatus. HEWITT, A., 25, Field Street, King's Cross Road, London. July 6, 1931, No. 19480. [Classes 100 (i) and 100 (ii).] A sheet-delivery mechanism for printing- machines, adapted to hold the sheets separate and out of contact with one another for a sufficient time to dry the impressions, comprises a series of platforms arranged in vertical sets which move alternately away from a position of vertical coincidence, the sheets being prevented from participating in the reciprocating movements so that they drop from platform to platform in a substantially vertical path to the delivery tray. As shown, two sets of platforms are employed comprising two series of horizontal rods b<1>, c<1> respectively. The rods b<1> are fixed to vertical bars b<3> mounted on a transverse member b<2> forming part of a carriage b reciprocated on rollers b<4> along rails a<2> on the supporting frame a. A similar carriage c running on rails a<3> carries vertical bars c<3> on which the rods c<1> are mounted. The carriages are reciprocated alternately from a shaft e by link mechanism j, k respectively, and as one carriage, e.g. b moves from the superposed position, Fig. 1, the sheets carried thereby are caused by the bars c<3> to drop on to the rods c<1>, and on the reciprocation of the carriage c, the sheets drop on to the rods b<1> and so on until the sheets reach the tray d. In a modified form, the bars b<3>, c<3> are replaced by short depending stops on the rods b<1>, c<1>, and the sets of rods are connected at each end by horizontal bars. The shaft e drives a shaft g carrying a semicircular gear g<1> and a disc g<2> which for the part g<3> of its circumference opposite to the teeth of the gear g<1> is of greater circumference than the gear g<1>. The gear g<1> imparts one revolution to shafts h<1>, il alternately, through gear wheels h, i on the shafts, which are half its size. Discs h<2>, i<2> on the shafts h, i have arc-shaped recesses h<3>, i<3> alternately engaged by the part g<3> of the disc g<2> so as to prevent movement of one disc while the shaft carrying the other is being rotated. A tooth g<4> on the gear g<1> engages a similar tooth h<4>, i4 on the shafts h<1>, i<1> alternately to start the rotation of the shafts. The link mechanisms j, k are pivoted to crank-discs h<5>, i<5> on the shafts h<1>, i<1>. The sheets delivered from the printing machine by tapes l are received by a platform b<5> on the carriage b as the latter moves to the right, Fig. 1, and a stop o limits the travel of the sheet. A stop m<1>, which held in a horizontal position during the reception of the sheet, drops to a vertical position to prevent backward movement of the sheet as the carriage b moves to the left. Stops n<1>, n<2> on the carriage b engage a projection m2 on the spindle m of the stop m<1> to operate the stop and springs m<3> hold the stop in either of its extreme positions.