GB946265A - Improvements relating to conveyor systems - Google Patents

Abstract

946,265. Delivering sheets. S. D. WARREN CO. March 13, 1962 [March 13, 1961], No. 9612/62. Heading B6H. [Also in Division B8] A conveyer system for cut sheets of paper in which the sheets are carried by a high-speed conveyer to a low-speed conveyer so that they are overlapped on the low-speed conveyer, includes means for stopping the low-speed conveyer when sheets are not being fed thereto with the result that no spaces are left between the sheets on the low-speed conveyer. A web of paper is cut into sheets by knives 27, 28, the latter knife being carried by a drum 29. The leading edge of a cut sheet is stripped off the drum 29 by a Venturi head 31 and is directed into a high-speed tape transport system 33 which delivers the sheet either to a high-speed conveyer system 41, or, if the sheet is defective, to another conveyer system 42, depending upon the position of a reject gate 36 controlled by a faulty sheet detector. The conveyer system 41 comprises a set of upper tapes 47 and a set of lower tapes 53. Discs 52 adjacent to one end of the tapes 53 are driven from a roller 48, over which the tapes 47 pass, and co-operate with corrugating rollers 40. A sheet passes from the conveyer system 41 between the discs 52 and rollers 40 and is thereby stiffened by temporary corrugations. As it leaves the nip of the discs and rollers the leading end of a sheet is blown upwards by a blast of air from a nozzle 68 which holds it in contact with the tapes 47 until it has overlapped the trailing end of the preceding sheet. The sheet continues to move at the speed of the conveyer system 41 until the leading edge passes into the nip of discs 65 and rollers 66 which decelerate it to the speed of a further set of tapes 61 driven at a slower speed than those of the conveyer system 41. Simultaneously the trailing end of the sheet is urged downwards into contact with the tapes 61 and with a rotating, braking, suction roller 64 by a blast of air from the nozzle 68 directed at the underside of the succeeding sheet which is deflected downwards from the underside of that sheet. The overlapped sheets are finally deposited by the tapes 61 in a layboy 50. The discs 65 and rollers 66, together with a tensioning roller 67 for the tapes 61, are mounted on brackets 89 slidable on rails 90 and may be adjusted between the full- and dotted-line positions shown by a rack-and-pinion drive so as to accommodate different lengths of sheet. Two photo-electric detectors 75, 76 are positioned below the upper run of the tapes 53 spaced apart a distance slightly greater than the normal space between sheets in the conveyer system 41. When the detectors simultaneously register absence of a sheet above them on the tapes 53 a magnetically-controlled brake and clutch device in the drive to the tapes 61 is actuated so as to stop the low-speed conveyer. As soon as one of the detectors registers the presence of a sheet above it the drive to the tapes 61 is re-engaged. The rejected sheets are carried by the conveyer system 42 round a turn-around roller 43 from which the sheets run to a high-speed conveyer system 44 which is substantially identical with the conveyer system 41. A set of tapes 61<SP>1</SP> corresponds to the tapes 61 and cooperates with the system 41 to produce an overlapped stream of rejected sheets which is finally stacked in a layboy. Detectors 75<SP>1</SP>, 76<SP>1</SP> correspond to the detectors 75, 76. Specifications 932,003 and 932,004 are referred to.