Patent GB-674675-A (GB)
Title: Improvements in automatic folding machines for flexible sheet material
IPC: D06F89/00
Filed: 1950-04-04
Abstract: 674,675. Folding fabrics. ABELL, H. DE F., and ABELL, H. E. April 4, 1950 [April 27, 1949], No. 8415/50. Class 42 (ii). The invention relates to machines for folding flexible sheets such as laundered articles, of the type comprising folder blades to tuck the material between two adjacent conveyer belts and control mechanism to actuate the folder blades to fold the sheet at the desired fraction of its length. According to the invention such a machine comprises infeed, central, first delivery, second delivery, and intermediate sets of endless parallel tapes, the latter set being so arranged as to contact successively and in one to one relation the tapes of the infeed, central and second delivery sets, a first set of folding blades which operate to tuck the material between the control and intermediate tapes at their initial point of contact, and a second set of folding blades which operate to tuck the material between the intermediate and second delivery tapes at their initial points of contact. As shown, articles placed on infeed tapes 20, Fig. 1, are carried past feelers 150 between tapes 20 and intermediate tapes 22 to be tucked by a first folder 169 between rolls 13, 14 whence they are carried between central tapes 21 and tapes 22 to be deposited on to first delivery tapes 23 leading to a table 192 ; when a second fold is required the once folded sheet is tucked by a second folder 169 between rolls 8, 10 supporting tapes 22 and second delivery tapes 24 respectively, whence it is delivered by tapes 24 and a deflector 191 to table 192. Tapes 20, 21 22, 23, 24 are respectively driven by rolls 16, 7, 9, 18 and 10 and tensioned by rolls 19, 12, 4, 17 and 11; the latter are each carried by arms 29, Fig. 9, fixed to a tubular pivot 31 to the centre of which is secured a torsion rod 32, the ends of which are provided with heads 40 each adjustably secured to a frame bracket 43 by engagement of a pin 45 with notches in the head 40 and bracket 43, a vernier adjustment being given by providing one more notch in one set than the other. Each folder 169 comprises fingers, adapted to enter spaces between the tapes, projecting from a frame 170 carried by rocking arms 173 coupled to a bell-crank lever 167 actuated by a fold timer 50 or 52 controlled by feelers 150. Each timer, Figs. 14, 24, consists of a box 57 housing a five-toothed disc 90 fast on a shaft 85, driven, through gearing 59, 60, 87, from a constantly rotating shaft 56 at a speed proportional to the speed of feed of articles through the machine, and a friction disc 93 also driven from shaft 56 via gearing 79, 81 or 80, 82 at a speed either <SP>1</SP>/ 2  or <SP>2</SP>/ 3  that of disc 90; the drive to disc 93 is selected by rocking a lever 69 to cam outwardly or inwardly a shaft 62 so as to clutch gear 60 to gear 79 or gear 80 through a pin 75 and clutch teeth 77 or 78. The speed of disc 90 is selected according to whether it is desired to fold a sheet at half or one-third of its length. A number of arms 99 are rotatably mounted so that they can be carried around shaft 85 individually by disc 93 or disc 90. Depression of feelers 150 by an article to be folded acts through a lever 147, link 144 and arm 140, Fig. 1, pivoted to the timer to (a) operate an escapement 138, Fig. 24, and release an arm 99 and (b) move a cup plate 119 to the dotted-line position, Fig. 14, so as to depress the tail of a pawl 104 on the arm 99; the arm is carried around by frictional contact with the reduced-speed disc 93. When the trailing edge of the article leaves feelers 150, plate 118 retracts and pawl 104 is released to engage the teeth on disc 90; from this point the arm is carried around by the full speed disc 90 until it engages a folder-actuating pawl 156 and pushes it into engagement with teeth 157 of a ratchet 158 keyed to constantlyrotating shaft 56. Pawl 156 is carried on discs 163 fixed to bell-crank 167 which is thus rocked to actuate the folder; pawl 156 is subsequently disengaged by a stop 161. After arm 99 has passed pawl 156, pawl 104 is released from disc 90 by engagement of the pawl tail with a stationary track 113; the arm is then carried around by friction disc 93 until it is arrested by the other arms piled up against escapement 138. The line of pressure between the arms and the escapement passes through the axis of oscillation of the escapement. Any of the folders can be put out of action by depressing the corresponding feelers below the path of the work by rotating an eccentric 152 bearing on an arm 151 of lever 147 carrying feelers 150. Deflectors 197 at the delivery end of the machine can be raised or lowered according to whether the work is to be delivered by tapes 24 or 23. Each set of tapes is arranged in two side-byside groups, providing two independent lanes through the machine, each with its own folders and timers. Deflectors 197, folder throw-out eccentrics 152, and clutch-operating levers 69 for determining the fold position are con-, trolled from the side of the machine separately for the two lanes, and the timing controls and folder mechanisms for each set of tapes are mounted on a common channel 53 extending across the machine and resting on angles 54, 55 so that the channel 53 and both sets of control and folder mechanisms mounted thereon can be withdrawn simultaneously from the machine.