US568559A - Sewing-machine take-up - Google Patents

Description

(No Model.) 2 Sheets-Sheet 1.

J. BOLTON. SEWING MACHINE TAKE-UP.

m N NW Patented Sept. 29, 1896.-

' Waves;

' 2 Sheets-Sheet 2.

(No Model.)

.J. BOLTON. SEWING MACHINE TAKE-UP.

N5. 568,559. Patented Sept. '29, 1896.

Y s UNITED STATES JAMES BOLTON, OF CHICAGO, ILLINOIS.

SEWING-MACHINE TAKE-UP.

SPECIFICATION forming part of Letters Patent No. 568,559, dated'september 29, 1896. Applicatioh filed July 22, 1895. $erial No. 556,750. (No model.)

To all whom it may concern.-

Be it known that I, JAMES BOLTON, of Chicago, Illinois, have invented certain new and useful Improvements in Sewing Machine Take-Ups, of which the following isa specification.

This invention relates to take-up mechanisms for sewing-machines, and is particularly designed for use in connection with a sewingmachine having a rotary shuttle.

The object of the invention is to produce an efficient take-up device which can be operated without the employment of cams and which is so organized that theslack is drawn through the eye of the needle while below the throatplate of the machine.

In the modern sewingmachine the demand is for the most efficient form of stitch and the capacity for high speed. When cams are employed in a high-speed machine the wear is so great as to shorten the life of the parts. I have devised a construction wherein cams are dispensed with and a simple link-movement substituted therefor. I have also so arranged the parts that the drawing of the thread through the eye of the needle while in the cloth above the throat-plate is avoided and break-in g and tan gling thereby prevented.

This invention relates to the driving mechanism of a sewing-machine, which is so constructed and arranged as to draw the thread through the eye of the needle while below the throat-plate, as hereinafter described,and pointed out in the claim.

In the accompanying drawings, Figure 1 is a sectional elevation of a sewing-machine head. Fig. 2 is a side elevation of the driving-pitman and its cranks. Figs. 3, 4, 5, and 6 are detail views in elevation, partly broken away and parts omitted, showing various positions of mechanism. Fig. 6 is a sectional detail of the tension and slack-gatherer spring.

In the drawings, 7 represents the drivingshaft, 8 the cranked rock-shaft, and 9 the pitman, all of which are arranged and driven in the ordinary manner. The needle-bar 10 is given a reciprocating movement through the pitman 11 and crank 12 of the crankshaft 8. These devices constitute no part of my invention, but I have combined with the crank. 12 a crank for driving the take-up mechanism, which will now be particularly Y explained.

various parts are so proportioned that a rockin g movement of the shaft 8 through less than one-third of a circle will impart a rocking movement of about one hundred and eighty degrees to the take-up arm 14. This arrangement is highly important because it is desirable to restrict the rocking movement of the shaft 8 to the shortest possible are, in order to obtain great power and speed, While it is equally important to use as short a take-up arm as possible and to give it the greatest attainable range of motion. By employing a take-up arm which rocks through an arc of one hundred and eighty degrees the same effeet is secured as though it completed the circle, while with such range of movement a short arm may be employed, and therefore less strain is imposed on the parts in properly tightening the stitch.

The slack-gatherer spring 19 is shown in detail in Fig. 6*, as associated with a tension-sprin g 20. The hooked end of the spring 19 projects downwardly and engages the needle-strand of the thread, drawing it through the loop 21. The slack is therefore gathered at a point between the loop and the eye of the take-up lever, and therefore is kept free from the point of the needle and the needlebar.

The shuttle-race 22 contains the shuttle 23 and the shuttle-driver 24. A rotary motion is imparted to the latter by means of the crank 25 on the shuttle-driving shaft 26, which has the usual eccentric connections, as illustrated in Fig. 1. The movements of the parts are so timed that the thread is drawn through the point of the needle while the latter is below the throat-plate, while the pitnian and the crank are so connected as to raise the needle to provide the necessary slack for the formation of the loop.

Assuming the parts to be in the position shown in Fig. 5, in which the needle and the take-up arm are at the limit of their upward movements, it will be seen by the dotted lines that the crank 12 stands obliquely with reference to the pitman 11, and that their pivotal connection is in front of the needle-bars. As the crank and pitman come into line the needle reaches the lowest point in its movement and the parts are in position to form the loop. In order to give slack for the loop, the rocking of the crank-shaft continues and the upper end of the pitman 11 is carried back of the needle-bar, thus raising the latter, as shown in Fig. 6, and permitting the thread to slacken sufficiently to form the loop, which is then engaged by the hook 29 of the shuttle 23 and carried around therewith until it attains the position shown in Fig. 3, when the thread slips over the end of the shuttle-driver 24, as seen in Fig. 4. During this movement the take-up arm is rocked down to yield slack through the eye of the needle, which is then below the throat-plate. After the hook 29 of the shuttle passes the lowermost point of its revolution the take-up arm is raised and the needle lifts until the parts are again returned to the position shown in Fig. 5. As the thread is yielded to form the loop the slack is gathered by the hook of the slack-gathering wire, as shown in Fig. 3, and is prevented from falling so as to become entangled with or touch the needle-bar or needle.

It will be observed by a comparison of Figs. 3 and 5, which show the extreme positions of the take-up arm, that the latter rocks through a semicircle, while by comparing the positions assumed by the crank 18 it will be seen that the crank-shaft rocks through less than a third of a circle. By this mechanism, therefore, I am enabled to secure great speed and power in the drivin -shaft, and to employ a short take-up arm having a long range of movement, so as to take care of the slackthread necessary with the employment of a rotary shuttle, an object which has not before been successfully accomplished.

\Vhile I prefer to combine the several novel features of construction above pointed out in the same machine, obviously they are capable of separate use and of association respectively with other forms of cooperating mechanism.

I claim In a sewing-machine, the combination with the driving-shaft thereof, of a rock-shaft drix en therefrom, said rock-shaft having a double crank, one of the crank members being connected with and driving the needle bar, a rocking take-up arm and a link connecting the other member of said double crank and the take-up arm, the several parts being so proportioned that the rocking movement of the take-up arm exceeds that of the rockshaft, substantially as described.

JAMES BOLTON.

Witnesses:

C. O. LINTHICUM, FREDERICK O. Goonwm.

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