Patent GB-546649-A (GB)
Title: Sheet feeder
IPC: B65H3/08
Filed: 1941-01-22
Abstract: 546,649. Feeding sheets. BELLUCHE, F. R. Jan. 22, 1941, No. 867. [Class 100 (i)] A sheet-feeding apparatus of the continuous type is constructed so as to deal with banks of sheets of greater thickness than usual and the bank is advanced on an upper feed board C by bands 30 which are driven at a slower speed than the bands 33 on the lower feed board. The sheets are adapted to be fed in an overlapping stream and are separated and forwarded from the bank on the lower board by means of sheet combing devices 123 which buckle the rear edges of the top sheet into contact with suction separating devices 173, Fig. 13, adapted to raise the rear edge of the sheet to permit it to be engaged by reciprocating gripping devices 192, 193 which advance the separated top sheet into the bite of feed rollers serving to direct the sheets in overlapped form to a vertical conveyer E leading to a top horizontal conveyer F by which the sheets are conducted to a printing or like machine provided with a device for stopping the machine in the event of a double feed. The bank is acted upon by a pressing device 139 which also acts to supply an air blast, and the grippers 192, 193 are constructed to emit an air blast which assists in the forwarding of the sheet, and the grippers are slotted to permit of the actuation of sheet-registering devices of the pusher type which act on the rear edges of the sheet to square them as the grippers advance with the sheet. The whole machine is constructed so that the parts can be adjusted transversely of the supporting frames so as to deal with sheets of different widths and longitudinal adjustment is also provided for. The sheet-separating devices and associated mechanisms are mounted on a support 60 carried by an inclined slide 61 which is maintained at the correct level to enable the rear sheet to be operated upon by means of cam-and-link mechanism under the control of a feeler resting on the pile. This feeler operates in conjunction with an oscillating arm fitted with a pair of pivoted pawls one of which can engage a wheel on the cam shaft to operate the cam so as to raise the slide 61, and the other pawl causes a lowering movement of the slide. The feeler is adapted to act upon the bank at a point to the rear of the position at which the separators act. Normally this position is at the same level as the separators, but when the bank begins to run out the construction of the feeler shoe permits it to tilt and thus maintain its connecting point to the mechanism it operates at the same level as the rear edge of the top sheet. The separators 173 after gripping the sheets are given a diagonal movement inwards and outwards to tauten the sheets and facilitate the action of the grippers. The motions of the separating devices are controlled by cams which are splined to a shaft 110, Fig. 13. The advance of the bank is controlled by a pivoted trigger 230, Fig. 13, which is carried by the heel 194 of the lower gripper and can pass through a slot formed in the gripper to be engaged by the edge of the sheet held thereby. The sheet gives a clockwise motion to the trigger and the extent of this motion is determined by the position of the rear edge of this sheet. If this is such that the bank needs advancing the trigger 230 is raised far enough for a finger 236 thereon to operate a latch 237 which normally restrains cam-and-lever mechanism associated with a pawl 266, Fig. 2, which can operate a ratchet on a shaft geared to a sprocket which advances the bands which forward the band over the lower table, and also operates the drum 16 and the tapes which advance the upper bank. The throw of the lever 264 which operates the pawl 266 is adjustable by varying the point of connection between a lever 259 and a link 263 of the mechanism for oscillating the pawl 266. The drum 16 is associated with automatically adjustable rigid guides 46 at the throat of the feeder where the bank is reversed, and these guides are spring- pressed and carry a fence formed of curved bars 55, and the guides support arms carrying idle rollers 56 which guide the bank into the throat. The lower feed table is mounted on anti-friction devices to facilitate transverse adjustment, and the lower feed bands are geared to move at a greater speed than the upper ones so as to spread out the bank. The vertical conveyer E comprises feed rollers 270, 272 acting on opposite sides of the sheets which are advanced in overlapped condition, and the sheets pass to the top conveyer F comprising tapes 301 Fig. 31, which advance the sheets over boards 300 supported on side rails 288. The top conveyer can be moved bodily with relation to the vertical conveyer by means of pinions 305, Fig. 32, not shown, which engage racks on the rails 288 and permit the upper rail to be withdrawn to the position shown in dotted lines in Fig. 31. By this means the feed boards can be cleared without necessitating a great amount of head room, and in the withdrawn position the conveyer is supported on telescoping supports 307. The conveyers and a front trip device 291, which stops the machine in case of double feed, are driven from the printing-machine by an inclined shaft 283 and a clutch device which permits withdrawal of the top conveyer without affecting the trip device.