GB494414A - Improvements in or relating to sheet folding machines - Google Patents

Abstract

494,414. Pleating. POLLAK, J. E. (Palmer, E. E.) March 22, 1937, Nos. 8403 and 22317. [Class 141] [Also in Group XVI] A folding machine for forming zigzag folds in sheets of paper or like material in the production, for example, of maps, time-tables or pamphlets, comprises platelike members adapted to fold the sheet by making similar movements in opposite directions, and having associated therewith mechanism whereby the depth of the folds produced may be varied. The sheets to be folded are arranged on an endless belt 6 in the form of a fanned-out pile with the front edges of the sheets folded back on themselves. They are fed forward at the required intervals into engagement with the lower fold plate 4 which is then in the raised position, by fingers 8 which engage the fold in each sheet and are carried by a frame reciprocated horizontally by a lever 9 oscillated by cams 30, 31 under the control of a spring 28 so as to have quick forward and return. movements followed by a period of rest. A ratchet mechanism 33, 34 operated by a link 32 from the lever 9 gives an intermittent movement to the belt 6. Additional fingers 10 are pivoted on the carriage, and extensions 11a thereon engage stops 13 so as to hold the folded front end of the sheet against the blade 4. The blade 3 is now moved downwardly to engage the sheet and the fingers 8, 10 are withdrawn. Subsequently the blade 4 is moved downwardly and then upwardly to fold the sheet over the blade 3. When this operation is completed, the blade 3 is moved in a similar manner to fold the sheet over the edge of the blade 4. Alternate movements of the blades 3, 4 continue in step with the feed mechanism to zigzag fold the sheets. The blade 3 is pivoted to a carriage 23 reciprocated vertically on guides 24 by a rotary cam 26 engaging a lever 25 resting on the pivot 22a of the blade 3. In addition to the reciprocating movement of its carriage, the blade 3 receives an oscillating movement from a rotary cam 27 acting against the pressure of a spring 22b. Similar mechanism is provided for operating the blade 4. The depth of the fold is varied by making the cam 26, Fig. 10, tapered or stepped in the axial direction and adjusting it axially according to the desired depth of fold. In order that zigzag folds of continuously-varying width may be imparted to a sheet, mechanism for effecting axial movement of the cam 26 is provided comprising a pivoted arm 54 actuated by a grooved cam 60, its free end engaging a grooved boss 56 on the cam 26. The folded sheets pass between guides 14, 15 and press against a slidable back-stop 18 having attached thereto a weighted' cord passing over a pulley. If unfolded sheets are fed to the machine, the initial fold may be imparted to the front edge thereof by a reciprocating member co-operating with the feedfingers for this purpose.