Patent GB-190412897-A (GB)
Title: New Process relating to Feeding Sheets of Paper to Machines and Means for Effecting its Operation.
Inventor: BLAISDELL FREDERICK ELIJAH
Filed: 1904-06-07
Granted: 1905-09-07
Abstract: 12,897. Blaisdell, F. E. June 7. Feeding sheets.-Relates to means (1) for separating the top sheet from the remaining sheets of a pile and (2) for detecting and rejecting sheets which are imperfect or fed awry. (1) The second sheet is prevented from adhering to the top sheet, when the latter is raised, by a needle which penetrates the top one and pushes back the next, a presserplate being introduced to hold down the pile. To separate effectively the top sheet throughout its whole area, blasts of air are directed from orifices in the edge of the presser-plate, which is made hollow to form a passage for the air. A suction apparatus which may be used to raise the top sheet consists of a row of suckers communicating with a cross-tube g, Fig. 4, carried by bars h sliding through the end parts of oscillating levers i, Fig. 1, which at the proper time feed forward the sheet to the feeding-tapes of the machine. The position of the bar h is determined by a cam-groove k<1> in an oscillating lever k. The separating-needle n<2>, Fig. 4, is carried by a piston n' pressed downwards by a lever m<6> against a spiral spring g<3>. Only the middle sucker is furnished with a separating-needle, the openings of this sucker being slits one on each side of the needle, these being sufficient to hold the sheet tightly to enable the top sheet to be properly perforated. The needle is hollow and has a side perforation at n<3>, through which a puff of air from a tube f is directed at the proper time to separate the sheets at the edge. To complete the separation, a presser-plate o is introduced as shown in Fig. 4, being ejected from its carrier o' by a lever o<2>, the carrier itself being draws down to press the plate on the sheet by a nose o<12>, on the arm o<3> of the lever o<2>, acting on the shoulder o<12>. Air is admitted to the presser-plate, when the latter is ejected, by a port o<15> opening to a chamber o<14>. The presser o is notched at o‹, Fig. 9, to escape the needle n<3>. The separation may otherwise be completed by thin metal blades of semicircular shape rotated between the top and the next sheets. (2) To detect an imperfect sheet, each sheet is drawn, in its passage to the feeding- tapes, between a metal roller p and feeler-discs p<4> in an electric circuit. When any one of the discs contacts with the roller p, a prop q<3>, Fig. 1, is withdrawn from the end of a hinged part r of the feedtable and the imperfect sheet is directed into a waste-box f<2> underneath the fixed part of the feedtable. The electric circuit is maintained closed at p<5> by adjustable sectors p<8> arranged fan-wise. These sectors may be adjusted to suit the different lengths of sheets which the machine is intended to feed. The table r is re-set by a rocking-arm r<2>. By means of a rod t<1> connected with the table r, the cylinder of the printing-machine may be tripped when a defective sheet is ejected. According to the Provisional Specification, the separation of the top sheet may be effected by grippers, clips, rollers, adhesion, or other means. The puff of air for the purpose of separating the edges of the sheets may be given after the needle has been withdrawn from the top sheet. Detaining-devices for the second sheet may consist of a second set of needles. Further means may consist of an arm or roller, or a strip carried by endless bands may be introduced between the sheets.