US136324A - Improvement in sewing-machines - Google Patents

Description

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l. T. JONES.

Sewing-Machines.

N0136,324. P-at`enfdfeb.25,1873.

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,4M PHoHmlomPH/c ca M Masson/vele musees) .UNITED STATES PATENT OEEIOE,

JOHN vT. JONES, OF ILION, NEW YORK.

IMPROVEMENT IN SEWING- MACHlNES.

Specification forming part of Letters Patent No. 136,324, dated February Q5, 1873.

To all whom it may concern:

Be it known that I, JOHN T. JONES, of Ilion, in the county of Herkimer and State of New York, have invented an Improvement in Sewing-Machines, of which the following is a specication:

My invention relates to a peculiarity in the construction of the mechanism employed for taking up the slack thread and tightening the stitch. I employ a lever upon the front plate of the stationary arm. This lever is operated by a cam on the main drivin g-shaft, and acts to take up the slack by drawing the thread off laterally between two studs or rollers of peculiar construction. The said frontplate also carries a tension mechanism, from which the thread passes to an eye or guide upon the upper end of the needle-bar. By this arrangement the thread is relieved from unnecessary .strain when the stitch is being tightened, and there is but little lateral motion required at the eye or hook of the take up lever. The tension mechanism is provided with a two-part nut and contractile band that prevents the nut turning by the rotation of the thread-detainer, and insures uniformity of friction and prevents unequal wear, as in the split springnuts heretoforeemployed. The needle-bar is made trough-shaped to obtain strength with lightness, and wear upon the same is compensated by adjustable bearing-blocks.

In the drawing, Figure l is an elevation of the front plate and parts attached. Fig. 2 1s a horizontal section of the parts at the line w Fig. 3 is a section of the needle -bar and bearing-block at the line y y, and Fig. 4 is a section of the tension mechanism and two-part friction-nut.

The bed a, pressurefoot b, front plate c, and needle d are of the usual character, and the mechanism that moves the needle bar is a crank-pin and roller, f, at the end of the shaft g, acting in a cam-slot across the needle-bar e. The thread passes from the spool through the open eye e that is made by a rounded groove, over which is a slight spring to keep the thread from escaping, but allow it to be easily entered or withdrawn by the operator. The threadtension lt is made of two interlocked plates, (see Figs. l and 5,) similar to that in my patent No. 117,640, and the thread passes around below this and up over a stud, i, projecting from the upper endof the needle-bar, and having a groove for the thread and a spring over the groove. The nut i of the tension h is made in two separate parts with a neck, around which the split steel ring 10 is forced, and this ring' is partially opened in screwing the nut upon its screw; thereby the friction and consequent force required for turning the nut will be uniform, and the nut will not wear loose or unequally. The thread passesdown around the rollers or eyes atln, and through the eye or hook at the end of the controlling-lever m that takes up the slack; thence the thread goes through a groove in the needle stock having a spring closing-finger, o,- thence to the needle-eye. There is an axis, i', for the lever m, and the same passes through the front plate c, and has a crank-arm, t, contiguous to the cam s upon the shaft g. A. spring, e, around the axis r serves to keep the arm ttoward the cam. The bearing for the axis r is shown as a sleeve or tube passing through the front plate and held by a screw.

The shape of the cam s is such that as the needle descends the thread controller draws back, taking up slack thread between the rollers l n. As the needle complet-es its down` ward movement the controller yields up the thread for the shuttle to pass through the loop, and then the thread is drawn up to tighten the stitch at or about the termination of the movement of the shuttle.

In order to reta-in the thread in position on the rollers l a I employ the spring-fingers u fr, extending off from the centers of the rollers or studs7 and resting upon each other. To insert the thread it is to be passed betweenu and t, beneath the roller l; thence through the spring-hook at the end of the thread-conA troller; thence again between u and c in an upward direction, and then down behind c and around the roller fn. This thread-controlling mechanism is simple, durable, easily employed, and not liable to injure or break the thread.

The needle-bar c is made trough-shaped, so as to be very light and strong. This will lessen the wear due to concussion in machines of this character 5 and in order to compensate for wear and increase the bearingsurface lthe blocks l5 are introduced inside the bar near top and bottom parts of the front plate c, and a set-screw, 16, inserted through the arm and stantiallyjas setfrth, for'controllng the tension and the slack thread, substantially as set forth.

3. The two-part I lut if, made with a. neck that receives the contractile band 10, as and Yfor the purposes set forth.

Signed by me this 6th day of December, A.

' J. T. JONES.

Witnesses:

GEO. T. PINGKNEY, CHAs. H. SMITH.

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