Patent GB-385072-A (GB)
Title: A method of and mechanism for folding over the projecting edges of connecting strips applied to book covers and the like
IPC: B42C7/00
Filed: 1931-11-10
Abstract: 385,072. Bookbinding. POLLAK, J. E., 20, Holborn, London.-(Brehmer, Geb. ; Plagwitz, Leipsic, Germany.) Nov. 10, 1931, No. 31183. [Class 16.] In a method of folding over the projecting end of a connecting strip applied to a book cover, sheets, or the like, a strip-folding member is actuated to engage the projecting strip end in moving through the plane containing the book cover &c., and then to cross the edge of the cover &c. and press the strip end on to the cover &c. The machine for this purpose includes a tape conveyer system which may form part of a sheet-connecting or strip-pasting machine or, as shown in Fig. 1, incorporated in a separate unit with the end A positioned adjacent the delivery end of a sheet-connecting machine. Four conveyer tapes 11, which pass around pulleys 12, 13, are positioned to receive sheets or covers C, joined as shown in Fig. 7, and are driven by means such as spur-gears from the sheet-connecting machine. A sheetsupporting frame is positioned between the two inner tapes 11 and comprises longitudinal members 11a preferably slotted to receive two transverse right and left-hand members 11b, the right-hand member being fixed and the lefthand member slidably mounted. A pair of vertically movable stops 17, adapted to project into the path of the joined covers carried by the conveyer tapes 11, are secured to or formed integral with a bracket which is rigidly secured to the free end of one arm of a bell-crank lever 19 pivoted to the machine frame 10. A second arm of the bell-crank lever is provided with a cam follower which rests on a cam 20 mounted on an intermittently-driven shaft 21. Rotation of the shaft 21 moves the stops 17 at timed intervals into and out of the path of the conveyed covers. The strip-end folding-means comprises freely rotatable rollers 35, Figs. 1 and 6, which are carried by double-arm levers 31, 31a and 32, 32a located adjacent the outer edges of the transverse members 11b. A transverse bar 27 extending between the side frames 10 carries a slide post 28 on which slides a bracket 29 supporting a horizontal carrierbar 30. The levers 31, 31a and 32, 32a are pivotally mounted on the carrier-bar 30, the former being adjustably mounted in a slot and the latter fixedly mounted. On each of the free ends of the arms 31, 32 is pivotally mounted a pair of arms 33 carrying therebetween a roller 35. The arms 33 are pulled down by springs 33a into a horizontal position against stop lugs on the arms 31, 32. The arms 31a, 32a carry rollers 36 engaging the inclined edges of cam plates 37, 37a mounted upon a second carrier-bar 38, the plate 37 being adjustably mounted. The bar 38 is carried by a bracket 39 adapted to slide vertically on the post 28 through the medium of a pivoted bell-crank lever 43 and cam 42 mounted on the cam shaft 21. On the upward movement of the bar 38 the plates 37, 37a engage the rollers 36 in the arms 31a, 32a to lift the carrier-bar 30 and the strip-folding members upwardly. During the upward movement the rollers 35 contact deflecting plates 40 which project downwardly from the upper edges of the transverse members 11b. Immediately the horizontal axes of the rollers 35 are raised above the upper edges of the plates 40 the upward movement of the bracket 29 is arrested by a stop plate 28a on the post 28 and the upwardly rising plates 37, 37a force the double-arm levers to swing about their pivots 22 and the rollers 35 to perform a horizontal movement across the members 11b. The upward movement of the rollers 35 lifts the strip ends on which the previously applied adhesive is still wet, and the horizontal movement folds them over the ends of the cover C, the rollers being resiliently pressed into contact with the strip during the horizontal movement by the tension springs 33a. During the continued rotation of the cam 42 the carrier-bar 38 and cam plates descend under their own weight, and the double-arm levers 31, 31a and 32, 32a are allowed to be restored to their original position, preferably under the action of tension springs 30b. To prevent the rollers 35 from buckling or bending the edges of the covers &c. C, retaining-fingers, comprising curved blade springs 45 secured in holders 46 and mounted on rotatable stub shafts 47 secured to the deflecting plates 40, are positioned on each side of each roller. Each stub shaft 47 is provided with a bracket 48 connected to a rod 49 which passes through a bracket plate 50 on the carrier-bar 38. The rod 49 has springs 52 on each side of the plate 50. On the upward movement of the carrierbar 38 each blade spring 45 is resiliently moved about its pivot to engage and hold the cover or sheet edges during the operative movement of the rollers 35. The actuation of the foldrollers 35 and sheet-holding fingers 45 is automatically controlled by the advancing covers C. This control includes a finger 53, adapted to project into the path of the covers, forming part of a bell-crank lever 54 and carrying an electrical contact 55 on the second arm adapted to engage a similar contact 56 when an advancing cover depresses the finger 53. The electrical circuit includes an electromagnet 58 supported on the machine frame beneath a clutch-tripping finger 25. The cam shaft 21 is driven through a clutch device 23, 24 of known type adapted to be operated by the finger 25, so that on the closing of the electrical circuit by the depression of the finger 53 the electromagnet 58 attracts the finger 25 to permit the cam shaft 21 to be driven. In the operation of the machine the advancing book cover C encounters the finger 53 to actuate the cam shaft 21 and upward movement is imparted to the rolls 35 and the sheetretaining fingers 45. Continued rotation of the cam shaft 21 retracts the rollers 35, the fingers 45, and then the stops 17 ; on the withdrawal of the stops the constantly moving conveyer tapes carry away the completed cover C. Immediately the rear edge of the cover passes the deflected finger 53 the latter is raised and the cam shaft declutched after the stops 17 are restored to cover-engaging position. The adjustability of the left-hand member 11b, the double-arm lever 31, 31a and the cam plate 37 enables different sized book covers or sheets to be dealt with.