Patent GB-116193-A (GB)
Title: Improvements relating to Thread Cutting and Thread-end Holding Devices for Embroidery Sewing Machines.
Inventor: LINDSAY JOHN
IPC: D05B65/00
Filed: 1917-08-21
Abstract: 116,193. Lindsay, J., Brown, W. H. E., and Bell, J. Aug. 21, 1917. Sewing-machines; thread-cutters and thread-end holders.-Thread-severing devices for use in embroidery and like sewing-machines are actuated by the movement of the presser-bar lifting lever 1 at the completion of a sewing operation, and a stop 30<a> is provided on a lever which is oscillated by a cam on the main shaft and a spring to prevent actuation of the lever 1 except when the needle is in its raised position. The thread-severing devices for the upper thread, which are also adapted to hold the end of thread for a predetermined number of stitches in the subsequent sewing operation, are formed on two levers 15a, 15b, pivoted on a plate 14<c> which is pivoted on a lever 14b. This lever is pivoted on a bracket 15 supported by the presser-bar and is connected by a lever 13 to a lever 8 pivoted to the head of the machine at 8b. The upward movement of the forward end of the presser-lifting lever 1 moves the members 15a 15<b> parallel to their length into a position where they can seize the needle thread. They are then moved together about their pivots to cut and seize the thread end by pins 16<c>, 16<d> on oppositely extending arms of a rod 16 which passes through the presserbar and has at its upper-end a crank 16<e> connected by a link 17 to a lever 18 pivoted on the lever 1 under control of a spring 21. During a sewing operation, a pin 19<c> carried by a lever 19, which is pivoted to the machine frame and acted on by a spring 26, lies against the lever 18 in the position shown. When the rear end of the lever 1 is depressed at the end of a sewing operation, the notch 18<a> allows the spring 21 to act and operate the cutting-members. When a subsequent sewing operation is started, the pin 19<c> remains resting on the lower side of the notch until it is stripped therefrom by a spring-controlled sliding member 22 which is mounted on the bar 19 and is advanced step by step by a reciprocating pawl 23 driven by the stitch-forming mechanism and a retaining pawl 24. The lever 19 is thereupon pulled down by its spring 26, and the slide 22, being clear of the pawls, is returned by its spring 27. The device for cutting the under-thread is shown at 33, Fig. 2, and co-acts with a fixed blade 34<a> secured to the underside of the throat plate. An extension 33<a> pulls off the amount of thread required for the initial stitches in a new sewing operation. The member 33 is mounted on a slide 37 actuated by a crank on a rock-shaft 36 which is provided at its rear end with a crank connected to the treadle or like rod 4 by which the lever 1 i; actuated. A manually controlled locking lever 31 is provided to prevent operation of the cutting devices until freed by the operator. Needle-driving mechanism, disconnecting and controlling.-The needle-bar 11 passes through a sleeve 11<a> which is reciprocated in the usual way and is connected to the needle-bar by a spring latch 10<a>. When the lever 8 is tilted by the upward movement of the presser-bar-lifting lever, an extension 8<c> with a slot 8<d> comes into the path of the extension 10<b> of the latch. The needle-bar is thereby disconnected from the sleeve 11<a> and held in its raised position.