Patent GB-773086-A (GB)
Title: Improvements in or relating to apparatus for folding bed sheets and other sheets of supple material
IPC: D06F89/00
Filed: 1953-06-26
Abstract: 773,086. Folding sheets. JESUS, H. L. L. June 26, 1953 [June 27, 1952], No. 17736/53. Class 42 (2). Apparatus for folding sheets of flexible material, of the type comprising a feeding conveyer, feeding each sheet to be folded, holding means arranged to act on the front part of the sheet and to pick up and temporarily hold this part in a fixed position, control means for rendering the holding-means operative, these control means being responsive to the passage of the front end of the sheet, further includes a delivery means, separate from the feeding conveyer and with which the sheet enters into contact whilst its front end is held in the fixed position, the sheet being adapted to contact the delivery means in such manner that the latter does not exert any substantial force on the part of the sheet disposed between the contact point and the fixed end of the sheet which is thus free to lengthen under the effect of the delivery means and the fold thus formed in the sheet being accordingly adapted to change its position therein. Figs. 6 and 7 show apparatus in one of its simplest forms for folding a sheet into two and comprises a feeding conveyer 50, a delivery conveyer 51 on which the fold is made (Fig. 7) and pick-up and holding means comprising a bar 52 and a shutter 53 which is actuated by suitable detector means (not shown) responsive to the passage of the sheet on the conveyer 50. Fig. 1 shows apparatus for folding a sheet into four, comprising a feeding conveyer assembly 3 which is pivotable around the axis of roller 5; a pick-up member consisting of a cross-bar 10 co-operating with a stop-bar 10a which can be heated; a transfer member consisting of a deflector shutter 12 carried by arms 11 from the same spindle 8 as the cross-bar 10; means for controlling the spindle 8 consisting of a pinion 13, chain 14 and electromagnets 15 and 16 which are operated by contacts 17 and 18, these being actuated by means detecting the passage of the sheet over the feeding con veyer; two levers 23 pivoted at 24, the upper arms 23a of which carry a cross-bar 25 which forms a clamping means adapted to work in conjunction with the pick-up bar 10 for clamping the two ends of the sheet and the lower arms 23b of which carry a pressing cylinder 26, the levers 23 being operated by an electromagnet 28 controlled through a relay 29 by a photo-electric cell 30; and a delivery conveyer assembly 32. In operation a sheet is fed over the delivery conveyer 3, and by means of the detector disc 19, contactors 17, 18, electromagnet 15, chain 14 and spindle 8 causes the front edge of the sheet to be gripped by the cross-bar 10 against the stop-bar 10a. The sheet then forms a loop which becomes progressively longer until it intercepts the light rays directed on to the photo-electric cell 30. This causes excitation of the electromagnet 28 which lifts the levers 23 such that the rear end of the sheet is gripped between the cross-bar 25 and the cross-bar 10. At the same time due to the rear end of the sheet having passed beyond the detector disc 19 the latter returns to its off position and through contactors 17, 18, electromagnet 16, chain 16 and spindle 8, the shutter 12 is moved so as to bring the folded sheet to the conveyer 32 where the second fold takes place. When the bottom of the loop uncovers the source of light 31 excitation of the electromagnet 28 ceases, the roller 26 falls back on to the conveyer 32 and the ends of the sheet are released so that the sheet is fed over the conveyer 32 folded into four. It is stated that several of apparatuses may be arranged cascadewise so as to make multiple folds in a sheet.