Patent GB-190321914-A (GB)
Title: Improvements in Stitch Forming Mechanism for Book Sewing Machines.
Inventor: BREWER GRIFFITH
Filed: 1903-10-12
Granted: 1904-03-24
Abstract: 21,914. Brewer, G., [Smyth Machine Co.]. Oct. 12. Book-stitching machines ; double-loop stitching - machines ; multiple - needle machines. - Relates to double-loop stitching-machines for sewing together the signatures in forming a book. Fig. 2 is an elevation of the righthand half of the machine. The stitches are formed by threads carried by the loopers g, and separate threads which are interlooped with the looper threads by the action of the perforating hooks or needles n, working in conjunction with the loopers. The loopers are pivoted on the bar d, which is connected at its left-hand end to a swinging-arm, so that, by the movement of the operating-bar 15 acting through the lever 12, the bar d has longitudinal, swinging, and vertical movements imparted to it. The upper ends of the loopers are pivoted to the bar c, which is connected to the bell-crank lever 11 pivoted on the bar d, so that the bars c, d move together under the action of the bar 15. The lever c has also an independent motion, transmitted through the lever 11 and beam f, from the bar 14. A third bar e, provided with notched fingers e', is connected at one end through the lever 16 to the operating-rod 18, and at the opposite end to a swinging arm, the bar thus having a longitudinal swinging movement. The signatures are placed in succession on the signature-holding arm b, which is operated in known manner and fulfils the usual functions. In operation, the perforating hooks or needles n pass upwards through the signature placed on the arm b, into the position shown in Figs. 2 and 10, where they receive their threads. The needles then desend, and carry their threads to the right up to the loopers g, where they again ascend through the signature, and in rising pass through the previous needle-thread loops carried by the loopers. The loopers are then rocked into the position shown in Fig. 12, to shed their loops around the needles, and are again moved forwards above these loops to take up the new loops of the needle thread, after which they rise to slip the loops from the needles, the needles then returning without thread to their original positions. Needles, hook, threading devices for ; governing needle thread ; governing under thread.-The needle threads are placed in the hooks of the needles, and the slack of the needle threads is taken up, by the arms e<1>, which, in their lower position, also hold back the signatures previously sewed from the signature on the arm b. The looper threads are tightened by the upward movement of the loopers. Thread-guiding eyes.-The threads are guided by notches in the fixed arms 5. Each looper thread also passes through the eye 20 in the heel of its looper, along a recess in the underside of the curved arm of the looper, and through a second eye in the point of the looper. Needle-holders; needles, setting; needle-driving; needle-bars, vibrating laterally ; work-supports.- The needles n are fixed by screws 24 in the needlebar m, which is mounted between the side-plates h, h<1>, Figs. 2 and 8, on the signature-holding arm b. The screws 24 engage in recesses in the sides of the needles, and are flattened on one side, as shown in Fig. 9, the flattened parts permitting the removal of the needles when the screws are turned into suitable position. The bar m is operated from the swinging-bar k through the rack-bar i and wheels l. Each wheel consists of twin-toothed discs mounted on a single hub, the rack i being of corresponding form. The bar m is connected by pivots 23 to the wheel l, between the two discs of each wheel, and is suitably shaped to permit it to pass round the axes 22 of the wheels during the vertical and lateral movements of the bar. The stripping-plate o, Figs. 10 and 12, is slotted to permit the movements of the needles and the arms e', and is fixed under the head of the machine, preferably through a block o<1>, Fig. 8, which determines its distance below the head.