GB1303984A - - Google Patents

Abstract

1303984 Feeding sheets J E THOMPSON 19 April 1971 [12 Nov 1969] 55437/69 Heading B8R [Also in Divisions B6 and F2] In a sheet-feeder apparatus for a printing- machine for printing sheets of paper or other material are separated from a pile 1, Fig. 1, and fed to registering apparatus 2 having a rising and falling front lay 12, beside which is a camoperated ram 6 which raises the leading edge of the sheets, after registration, into contact with suckers 17 or grippers (71) by which they are transported (Figs. 9 to 13, not shown) to a gripper roller 6 of the printing-machine, the suckers 17 or grippers (71) are carried by a tube or rod 16 fast with rotary arms 13, 14 connected by a rod 15 and freely mounted on a continuously rotating driving shaft 11 and cyclicly driven thereby via a rocker arm 31, connected at one end 31A to the arms 13, 14 by a link 30, and connected at the other end 31B to a cam follower roller 33 carried by an arm 32 which is fast with the driving shaft 11 and on which the rocker arm 31 is pivoted, the cam follower roller 33 being spring urged at 35 into contact with a stationary cam track 34 providing a dwell period whereby the suckers or grippers are arrested, i.e. stationed for a time (70 degrees of rotation) in the pick-up position, after which the suckers and grippers and the carrying arms 13, 14 may be accelerated to move faster than the driving shaft 11 to catch up with their initial position relative to the driving shaft 11 or alternatively at the end of the stationary period may initially again be moved at the same speed as the driving shaft 11 but in the position retarded (70 degrees) relatve to the original position, and then accelerated into their initial position relative to shaft 11. The suckers 17 are connected via ducts 18, 19, 20 to a source of suction or to atmosphere by a valve 22 controlled by a bell-crank 23 the outer end 27 of which is operated by an internal cam track formed on the driving gear 29 of the drive shaft 11 and is operative to connect the suckers to the source of suction at the appropriate dwell, i.e. pick-up position, the paper sheet being raised into contact with the suckers by a ram 5 operatively synchronized accordingly. Slightly modified arrangements of the rocker arms 31 and links 30 are illustrated in Figs. 4 and 6 (not shown) whilst in Fig. 5 (not shown) the connecting link 30 is replaced by a rack and pinion 51, 50, the rack being connected to the rocker arm end (431A). In the gripper embodiments of Figs. 9 to 13 (not shown) the grippers are arranged to be moved slightly past the pick-up position; opened via a cam control; moved slightly back into engagement with the sheet and then finally closed to then transport (as before) the sheet to the gripper roller.