Patent GB-117798-A (GB)
IPC: B42B2/02
Abstract: 117,798. Forrester, H. J. C., (Reavis, W. E.). May 10, 1918. Book-stitching machines.-In bookstitching machines, the signatures x, Fig. 7, are clamped between an adjustable bar 32 and a reciprocating table 8 moving in guides 6 on an inclined plate 4, the supporting bar 9 of the table being clamped with adjustable pressure to a block 13 by which it is actuated through the link 22, bellcrank lever 20, link 26, lever 27, and cam 30 on the main-shaft 31, so that constant pressure is maintained on the signatures in the building up of a book regardless of variations in number. A table extension 38 supported by a rod 39 mounted in lugs 40 on the plate 4 is provided to support temporarily a series of sewed sections while the threads are uncut. The plate 4 is pivotally and slidably supported on a fixed bar 2 and is given lateral jogging movements from a four-stop peripheral cam, Fig. 4, driven by four-to-one gearing from the main-shaft so as to displace successive stitches laterally in the manner indicated in Fig. 14. The steps b, d of the cam are preferably one and a half times as deep as the steps a, c, so that the lateral spacing of the second and third and fourth and fifth stitches is one and a half times that between the first and second, and third and fourth. The edge of the plate 4 is formed with fingers 51 tc support the signatures as added and the table 8 is formed with inclined grooves 52 to afford clearance for the needles and punches in sewing the first signatures. A series of punches 56 and a stripper-bar 59 are carried by the upper cross-piece 53' of a cross-head which works in vertical guides in the frame, and the lower cross-piece 53" carries a series of correspondingly placed threaded needles 66. The crosshead is reciprocated by the extension 69, link 70, and a lever 71 having two arms 72, 73 actuated by complementary cams 75, 77 on the main shaft. The shuttle race comprises an angle-bar 82, Fig. 9, and a flat bar 83 spaced from the horizontal and vertical walls of the angle-bar. The race is supported by arms 84, 85 pivoted on a fixed bar 86 and acted on by springs to place the bar in operative position from which it is withdrawn during the downward punching movement of the cross-head by interengaging lugs 111, 112. The shuttle-driver 90 is provided under spring control on a slide 91 working on the bar 86 and actuated by a cam-actuated lever which is adjustable to vary the throw of the shuttle in accordance with the length of the signatures and the consequent variation of the number of needles used. The locking thread 79 is led from the spool through suitable tension and take-up devices to one of the eyes 110 in the race, and the shuttle 80 is formed with a forwardly curved nose 80<1>, a tapered rear end 80", and a hook 80<111>. The form of the shuttle is such that in its rearward movement to initial position after passing through the needlethread loops, the rear end engages the locking- thread and forces it between the outer edge of the shuttle and the vertical face of the race into the hook 80<111> preparatory to another forward movement. The take-up device for the threads consists of a cam-actuated bar co-operating with a fixed bar. The manner of building up a series of signatures is shown in Fig. 13.