Patent GB-190112179-A (GB)
Title: Improvements in Buttonhole Cutting and Stitching Machines.
Inventor: LUFKIN JOHN WILLIAM
Filed: 1901-06-14
Granted: 1901-10-12
Abstract: 12,179. Lake, H. H., [Lufkin, J. W.]. June 14. Buttonhole-sewing machines; buttonholes, cutting ; multipleneedle machines stopping, automatic; stopping-gear; governing needle thread and under thread; thread-cutters.-Relates to machines of the Reece and similar types, and its main features are as follows :-The work clamp lever has two movements By the first of these the work is clamped, and, when this is seen to be satisfactorily done, a further movement of the lever starts the machine, by clutching the shaft B<3> to a continuously-rotating worm-wheel. The shaft B<3> then makes a single revolution, during which, by means of special eccentrics, it operates the anvil and cutter to cut the slit. Towards the end of this single revolution, the shaft B<3> moves an arm f<31> to the right, thus moving the belt-shifter lever f<38> so as to shift a moving belt on to the fast pulley G<2> of the stitching and feedoperating shaft G'. The stitching is thus started before the slit-cutting levers have completely returned to their inoperative positions. The shaft B<3> stops in a position to retain the belt on the fast pulley G'. During the cutting operation the slitcutting lever B<4> is connected by means of a latch to the work clamp table, which is thus moved to cutting position, and then back to stitching position, when the latch is released in order to allow the work being fed during the stitching. Instead of being fed step by step, the work is fed continuously, but with a variable speed, the arrangement being such that the work is moving slowest when the needles are in it, while the needles are then moving at their quickest. For this purpose the worm G, from which the feed-wheel, and also the looper and spreader, are operated, is driven from the shaft G' through an improved variable gearing. The needles are driven by a variable gearing of ordinary construction. The speed at which the work is moved to and from cutting position is less than that at which it is moved during sewing. At the conclusion of the stitching, a lever connected with the feed-mechanism raises the arm f<31> by means of an improved trigger system, thus allowing the belt-shifting lever f<38> to return the belt on to the loose pulley G<2> ; and, just after this, the shaft G<1> is positively stopped by the engagement of a lug on the worm G with a member of the trigger system. Accidental starting on the shaft B<3>, and operation of the slit-cutters during the stitching, is prevented by the engagement of the starting-lever with the underside of the feed-wheel. The invention also comprises an under-thread cutter, operated by raising the clamp lever, an improved needle-thread take-up and pulloff device which pulls off less thread for the slit needle than for the other, a device for pulling off a loose end of under thread on the completion of a buttonhole, a device for relieving the tension of the needle thread to allow of the work being shifted, an improved feed-cam with pivoted followers and a guide-way for the pin which engages in the feed cam-groove, and, lastly, stitching-mechanism comprising two needles, an interlacer I having a lengthwise and oscillating movement, and a spreader and looper.