Patent GB-1277241-A (GB)
Title: Laundry folder
Inventor: GRANTHAM FREDERICK WILLIAM
IPC: D06F89/00
Filed: 1969-05-28
Abstract: 1277241 Folding sheets F W GRANTHAM 28 May 1969 26933/69 Heading D1S [Also in Division B8] A machine for folding laundered sheets comprises a conveyor belt 136 of substantial width for turning a sheet which has been oncefolded from a vertical disposition to a horizontal disposition, the belt 136 having an entry end passing around a vertical roller 138 and a delivery end passing around a horizontal roller 140, an auxiliary conveyor belt 150 positioned adjacent the upper edge of the belt 136 to hold the sheets in contact with the belt 136 while they are vertical.  The machine comprises a feed board 36, a cross-fold unit 38, a french-fold unit 40 situated above the unit 38, an extension conveyor 42, a pick-up conveyor 44, a delivery conveyor 46 and a stack table 34. A laundered sheet 47 is placed on the feed board 36 and passes through either the unit 38 or the unit 40. The feed board 36 comprises a plurality of narrow belts 56 arranged in two groups with a gap 58, Fig. 2, therebetween. The inclination of the feed board is adjustable, e.g. by means 60, about the axis of a roller 48 around which the belts 56 are entrained. The unit 40 comprises a conveyor 68 comprising either a single wide belt or a plurality of narrow belts and a slide 76, e.g. stainless steel plate, cooperating with the conveyor 68 and having an extension 78 which, in the operative position of the unit 40, extends into the gap 58 so that a sheet is fed from the feed board 36 into the bight 79 between the conveyor 68 and the extension 78. The sheet passes onto a curved extension 86 of the slide 76 and beneath a conveyor belt 69. Lateral spaced folding blades 88, Figs. 1 and 8, and forming blades 90 complete a french fold.. The blades 88 are adjustable towards and away from each other. The conveyor 68 and the slide 76 are swingable between the full-line operative position of Fig. 1 and an inoperative dot-dash-line position in which the sheet passes through the unit 38. A stop 80 limits the lower position of the conveyor 68. In the unit 38, when the conveyor 68 and the slide 76 are raised, the sheet passes onto a narrow conveyor belt 114 and its sides drop so as to be draped about a shield 126 comprising a pair of plates or an inverted U-shape plate. A connecting belt 122, Fig. 2, links the feedboard 36 and the belt 114. The shield is adjustable about a pivot 128 by a manuallyoperable cam 130. Means 134 may be provided for adjusting the shield horizontally so as to position it relative to the following conveyor 136. The shield 126 extends into a notch 156 between the belts 136, 150 and guides the sheet onto the belt 136 which turns it from a vertical to a horizontal disposition. In a modification, Figs. 5 and 6 (both not shown), the cross-fold unit is located above the french-fold unit. The conveyor 42 is located below the roller 140 of the belt 136 so that the leading edge of a sheet drops onto it and passes over a fluted roll 184 and over a curved apron 186 to engage a finger of a microswitch 188 which actuates a folding knife 192 to form a crossfold in the sheet. The fold is lifted by the knife 192 into the bight 210 between two belts 206, 208 forming the conveyor 44. If it is desired to selectively eliminate the crossfolder 192, a manual device 200 is actuated to raise a device 198 so that prongs thereof pass between spaced narrow belts constituting the conveyor 42 to deflect the sheet into the bight 210. The conveyor 46 comprises a belt 220 and a pair of blades 222, Fig. 10, pivotable between an operative position under the belt 220 and an inoperative position to release the sheet which drops onto the stack table 34. This action is controlled by a switch 224 actuated by the sheet.  The table 34, Figs. 10 and 11, has a vertically displaceable top 240 mounted on collapsible legs 244. A cross-piece 246 connects each pair of legs 244 and has a pull rod 248 connected thereto and to a disc 250 mounted on a shaft 252. A rod 256 of a piston in a cylinder 260 is connected to a radial arm connected to the shaft eccentrically to the axis of the disc. To raise the table top 240, a valve 266 is opened to allow compressed air to enter the cylinder 260 to retract the piston, rotate the disc 250, draw the rods 248 inwardly and extend the legs 244. A bleed valve 270 is provided in the cylinder 260 to permit the top 240 to lower, under gravity, so that the top of the stacked sheets is maintained at a constant level. Tension springs 272 are provided to bear a portion of the load of the top 240 and control its lowering. In a modification (not shown), the top 240 is movable normally between extreme upper and lower positions and over-centre means is provided to retain the top in either position. A stackdelivery conveyor 274 comprises a constantly running conveyor 278 and a normally stationary conveyor 280 which is operated automatically under the control of a counter for the sheets.  The table 34 may be provided with tamper means, Fig. 17, comprising two blades 285 pivoted at 286 and biassed downwardly by springs 288. The blades 285 are raised by an air cylinder 289 acting through a cross-bar 290 and cables 291 to permit a sheet to be dropped onto the stack and are released to tamp the sheets.  In Fig. 14, a conveyor 294 which may be either the french fold belt 69 or the belt 136 comprises a pair of spaced belts defining a gap therebetween in which a reflector 300 is located. A photoelectric cell 292 of retro-reflective type is mounted above the reflector 300. As the sheet passes along the conveyor it covers the reflector 300 and interrupts the light beam and, after a time delay, the blade 192 is actuated. The cell 292 and the reflector 300 are adjustable in position by racks-and-pinions 293, 378, respectively. A circuit for the operation is described, Fig. 12 (not shown). Means 450, Fig. 4, for ejecting unwanted or defective sheets comprises a pair of axially spaced wheels 454 rotatably mounted on a shaft 456 and driven at a peripheral speed proportional to the speed of the sheets through the folder. Each wheel has a circumferential groove 458 having side wall surfaces of resilient and high friction material 460. Upon depression of either of a pair of push buttons 478, 480, Fig. 1, a solenoid is energized to project the armature 466, Fig. 4, forward and force a ball 472 from a hopper 470 into the groove 458 of the corresponding wheel to actuate a switch 358 to disable the folding knife 192, Fig. 1. The sheet slides over the apron 186 and into a reject receptacle 482. After the ball passes the switch 358 it is returned to the hopper by a finger thereon.