Patent GB-190900175-A (GB)
Title: Improvements in Thread Stitching Machine for Pamphlets and similar Articles.
Inventor: ROBERTS HORACE LUDINGTON
IPC: B42B2/02
Filed: 1909-01-04
Granted: 1909-03-18
Abstract: 175. Roberts, H. L. Jan. 4. Boot stitching machines; thread - cutters.- A pamphlet-sewing machine utilizing three straight needles is so constructed that the central needle first rises to penetrate the work which is placed, back downwards, on a V-shaped support, and grasps a thread stretched in the fold. The needle then withdraws and forms a loop, and the side needles ascend and withdraw with loops, the thread is then cut, after which a pair of horizontally reciprocating loopers draw the thread of the side needles through the central loop and draw the same tight, to form a knot when the loopers retire. The various movements for stitching a pamphlet take place during one rotation of the shaft, and automatic stopping-mechanism may be employed to arrest the machine after each rotation. After a book or pamphlet has been stitched, the presser-foot 50 is raised to permit of its removal and of the insertion of an unstitched pamphlet. The end of the thread is held by the carrier 87 and stretches therefrom along the groove of the work-support 34, to the holder 67, the tension-device 86, and the spool 85. The machine is then started to cause first the descent of the foot 50 by means of connexions to the cam 53, so that the pamphlet is forced into the furrow of the worksupport 34. The needle 25, whichhas its hook turned towards the front of the machine, then rises, its plunger 28 being driven by connexions 41,43 from a cam 38. After the needle has reached its highest position the shaft 65 is slightly rocked backwards by connexions 68, 71, 74, Fig. 3, from a cam 75 on the main shaft 37. The carrier 87, which is slidingly mounted on the shaft 65, and the holder 67, which is bolted thereto, thereby place the thread in the hook of the needle, which then descends and draws a loop through the work, the thread-end being at the time held by the clamp 98, 99, Fig. 12, so that the necessary thread is drawn from the spool 85. Meanwhile, the needles 26, 27 are raised by their respective cams 38, and, when they have reached their highest positions, the shaft 65 is rocked forwards so that the carrier 87 and the holder 67 place the thread in the backwardly-facing hooks of the needles 26, 27. All three needles then descend, the needles 26, 27 drawing their threads through the work after the needle 25 has made a large loop, and temporarily stopping slightly beneath the reciprocating loopers 105, 106. During the descent of the needle 26, the free end of the thread is drawn from the clamp 98, 99. While, during the last part of the descent of the needle 25, this is turned through 90 degrees by the engagement of a pin 49 with the inclined part of a groove 48 formed in the plunger 28; simultaneously the end of the plunger arrives opposite a recess 143, Fig 8, formed in shanks 137, which are mounted on the flange 31 and pressed forwards by the spring 140. The shanks 137, which tend to spring outwards, are held, when the needle 25 is in the upper part of its path, in the narrow part of a widening groove formed in the plate 141; but when the plunger 28 descends, the shanks are allowed to move to the right, and, entering the loop at the same time, spread this loop while it is still engaged by the needle 25. The loopers 105, 106, Figs. 4 and 7, which are provided with adjustable spring-pressed plungers 123 and are driven by connexion with racks 118, 120 mounted on slides 107, 108 and driven by a cam 117 on the main shaft, have meanwhile started their inward movement, and in the latter part of their movement have their plungers 123 retarded by the studs 127, Fig. 7, encountering fixed abutments 129, thus opening the throat 122 of each looper. Two bars 130, 131, which are oppositely reciprocated by connexion to a lever 132, are then moved by the engagement of this lever with an abutment 135, the bar 130 being advanced to force the thread from the needle 27 into the looper 106, while the bar 131 is drawn back to place the thread of the needle 26 into the looper 105. Meanwhile the carrier 87 has been moved along the shaft 65 by connexions from a cam 97, and during the last part of the movement the beak 78, Figs. 1 and 12, of the finger 77 enters between jaws 98, 99 and thereby opens the pivoted jaw 99, simultaneously placing the thread depending from the beak 78 between the jaws and between the cutters 104, that are fixed on the underside of the jaws. Finally, the beak 78 enters the recessed top of the jaws to permit the spring 101 to throw the jaws together, whereby the upper section of the thread is firmly grasped by the jaws and the lower section is severed by the cutters. The carrier 87 then returns to its original position, drawing a corresponding length of thread from the spool 85. After the loops of the needles 26, 27 have been introduced into the open throats 122 of the loopers, the needles descend further, and the loopers return. During the first part of this receding movement, the plungers 123 remain stationary, but when the beaks abut against the plungers the latter are carried along and the threads are held by the clamping-power of the springs 124. The movement of the needles and loopers is so timed that the loopers are not closed until the free end of each loop has cleared the looper. During this retracting movement, the needle 25 is slightly raised to liberate its loop, so that the loopers, in pulling their threads, close the central loop upon the free ends of the stitch thus formed, whereby these ends gradually slip out of the loopers. Since the needles pierce the pamphlet from the outside, the burrs formed project from the inner fold of the paper and are thus concealed. The number of needles may be multiplied if desired. The machine may be used for uniting different numbers of leaves without adjustment, for which purpose a spring is interpolated between the presser-foot and its actuating-cam, so that the greater the pamphlet thickness, the greater will be the pressure exerted by the presser-foot.