Patent GB-189722955-A (GB)
Title: Improvements in Book-sewing Machines.
Inventor: GERLACH ALFRED
Filed: 1897-10-06
Granted: 1897-12-11
Abstract: 22,955. Gerlach, A., [Rehwoldt, F.]. Oct. 6. Bookbinding.- The invention relates to a bookstitching machine. The open signatures are placed astride of a support C which is mounted on arms c<3> and moved forward to receive them one by one. The support then moves back and places the signature u n d e r needles f, f<2>, of which one or more pairs are carried in holders F attached to a laterally-movable bar E, the motion of which can be varied at will. The bar E is mounted in a vertically - moving frame D, which also carries hooks g<2>, and its movements drives both needles and hooks through the signatures. Two kinds of stitches are shown in Figs. 41 and 42. The former is employed when tapes O are to be stitched to the signatures, and the latter when they are dispensed with. They differ only in the fact that the bar E is moved laterally in the former case, but not in the latter. The mode of forming the stitching is shown in Fig. 26. The needles f, f and hook g<2> having penetrated the signature, the thread of, say, the needle f is engaged by a looper l<3> mounted on a reciprocating rod L<3> and shown in its initial position by dotted lines in Fig. 26. The looper carries a loop of thread up to the hook g<2>, and causes it to engage therewith by a slight tilting movement which is imparted to the rod L<3>. The needles and hook now ascend, and the latter draws up the loop, which is then released by the looper, through the loop pteviousiy formed. In order to clear the latter, the hook is made to rotate through 180‹ by a pinion g<3>, to which it is attached, engaged by a sliding rack g<4>. The other needle f has meanwhile merely pierced the signature without making a stitch. This needle, however, in conjunction with the hook and a similarlyactuated looper l<2> carried on a rod L<2>, makes the next stitch, of which the loop is drawn through the loop just made by the needle f', and so on alternately. The needles are guided and supported just before reaching the signatures by a fixed bar provided with holes through which they pass. By mounting the needles of each pair on separate frames, the necessity for one of them making an idle stitch each time can be avoided. The thread passes from spools at the back of the machine through slots in pins H<2> on the fixed bar H. The pins carry weights h<3> and pass through a vertically-reciprocating bar H<3>, between which and the weights the thread passes, and is locked and drawn upwards when the bar rises, but is released when it falls. The bar moves with the frame D. Thence the thread passes through a hole in a vertically-reciprocating bar k<7>, Fig. 8, and so through one of a number of holes f<5> in a lever f<4>, through an eye in an adjustable spring take-up f<9>, and through a fixed rod k<8> to the needle. The lever f<4> works on a fixed rod a<3>, and is pivoted to the top of the needle holder. A modified form of take-up for drawing the stitches tight is also described. The needle-supporting bar is perforated to receive plungers m<3> operated by arms m<5> on the rocking shaft M<2>. These plungers push back the signatures on to a support as they are sewn. An alternative form of this device is also shown. In order to prevent unevenness, consequent on the thread loops of the signatures being drawn alternately in opposite directions, there is provided a gauge or stop which is not shown, but which is actuated by a bell-crank lever N<2>. When the pull on the thread loop is towards the left, the gauge is moved to the right, and thus keeps the signature in its proper place. Tapes 0, when used, are carried on rollers O<2>, and passed in and out between rods o to give them a suitable tension.