US1538744A - Sewing machine - Google Patents

Description

May 19, 1925.

1,538,744 E. J. RAY I SEWING MACHINE inal Filed Auz. 20. 1 17 w? %/M WSZLJVMX Patented May 19, 1925'.

UNITED STATES EUGENE J. RAY, O-F'BEVERLY, MASSACHUSETTS, ASSIGNOR TO UNITED SHOE MA- CHINERY CORPORATION, OF PATERSON, NEW JERSEY, CORPORATION OF NEW JERSEY.

snwrne MACHINE Continuation of application Serial No. 187,194, filed August 20, 1917. Patent No; 1,492,084, dated April 29, 1924. This application filed November 11, 1919. Serial No. 337,147.

To all wlaom z't' 'nm concern Be it knownthat I, EUGENE J. RAY, a citizen of the United States, residing at Beverly, in the county of Essex and State of l\lassachusetts, have invented certain new and useful Improvements in Sewing Ma- 'hincs; and I do hereby declare the follow mg to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

The invention relates to mechanism for actuating stitch-forming devices of sewing machines.

The object of the invention is to provide a simple and etficient mechanism which may be operated at high speed without strain or material Wear on the parts and which is well adapted for securing a comparatively wide variation in the rates of move' ment of a needle during successive half revolutions of the driving shaft for the stitch-forming mechanism.

To this end a variable or differential movement is transmitted from a uniformly rotating crank to a needle carrier of a stitch-forming mechanism through a lever having a shiftable fulcrum and connected at one end to the needle carrier and at the other end to the crank so that during its rotationthe crank will shift the lever endwise while rocking it about its fulcrum. These parts may be readily so proportioned and arranged that comparatively little movement will be transmitted to the needle during a half revolution of the crank and a comparatively rapid movement during the succeeding half revolution.

While the invention is of general application it may be utilized with particular advantage in buttonhole sewing machines in which the stitch-forming mechanism comprises an upper needle, a looper which takes a. loop of upper needle thread below the work and an under needle which carries a loop of its thread up through the loop held by the looper and into posit-ion above the work for the passage down therethrough of the upper needle. The mechanism outlined above may be utilized to reciprocate either needle and to properly time it with the other needle and in the accompanying drawings a construction is shown in which this mechanism is utilized to reciprocate-the upper needle.

The drawing shows a vertical, sectional elevation of so much of a buttonhole sewing machine as is necessary to illustrate the application of the present invention thereto.

This application is a continuationof ap plication No. 187,194, filed August 20, 1917,

Patent No. 1,492,084, dated April 29, 1924, which shows and describes a machine to which the invention has been applied.

The machine indicated in the drawings comprises, in general, a cutter for cutting the buttonhole slit, a travelling work clamp, indicated at 2, which is movable lengthwise and laterally of the buttonhole, and a stitch-forming mechanism which is rotated during the sewing about the eye and about the'bar end of thebuttonhole. The stitchforming mechanism comprises a straight eye-pointed upper needle 4, which is arranged to penetrate the work a short distance from the. edge of the buttonhole slit, a curved eye-pointed under needle 6, which is arranged to pass up through the buttonhole slit and which, at the upper end of its stroke, is dipped to throw out a loop down through which the upper needle passes and a looper 8 arranged below the work and operating to take a loop of upper needle thread and carry it into such position that the under needle will pass up through it during its up stroke.

The upper needle is secured in the lower end of a hollow needle bar 10, which is mounted to reciprocate through a stationary upper bearing 12 and through a rotary head 14, with which the bar is so connected that it will rotate with the head while being free to reciprocate therethrough. Thencedle bar is reciprocated by a crank 16 formed on the uniformly rotating driving shaft 18 and engaging the rear end of a lever 20, the forward end of which is connected by link 22 with a-sleeve 24 on the needle bar. The sleeve is confined between collars 26, which may be adjusted to determine the path of reciprocation of the needle. The lever 20 is fulcrumed at 28 on a link 30, which is free to swing about a shaft 32 as the lever is oscillated by the crank 16. The under needle is reciprocated by a second crank 84, which engages the upper end of a link 36,

dips the under needle and is also connected to operate the looper, as fully shown and describedin Patent No. 1,134,046, to G. S.

Hill, dated March 30, 1915. r

The crank 34 is so arranged that during the first half revolution of the shaft 18the under needle will be advanced and dipped to throw out its loop of under-thread, while the crank 16 and links 22 and are so arran ed and proportioned that during this hal revolution of the shaft the fulcrum 28 will swing downward and then upward with the downward and upward movements of the crank as it rocks the lever and moves it lengthwise, thus giving the forward end of the lever a path of movement which is approximately in an are described about the lower end of the link 22 as'a center. Only a slight vertical movement is, therefore, transmitted to the upper; needle during the first half revolution of the crankshaft, which completes the upward stroke and dipping of the under needle. During the second half revolution of the shaft the upper needle is rapidly moved down through the loop presented by the under needle andthrough the work and is returned to its initial upper position while theunder needle is returned to its retracted initial position and the looper is operated to take a loop of upper needle thread from the upper needle and carry it into position above the under needle. The needles are thus operated from the uniformly rotating cranks through simple and easily moving connections, which properly and accurately time their relative movements and consequently the stitch-forming mechanism may be operated at a high rate of speed and may be brought to rest at the completion of the sewing operation without strain or undue wear upon the parts.

lVhile it is preferred to employ the specific construction and arrangement of parts shown and described in embodying the invention in a stitch-forming mechanism of the character shown it will be understood that this construction and arrangement is not essential and may be varied or modified as found desirable or best suited to the type of stitch-forming mechanism in which the invention is to be embodied.

What is claimed is:

1. A stitch forming mechanism having, in combination, a needle carrier, a lever, a link having one end pivoted to one end of the lever and the other end pivoted to the carrier for: oscillating the carrier in unison with the end of the lever, a crank engaging the other end of the lever, and a shlftable fulcrum for the lever.

2. A sewing machine having in combina tion, astitch-forming mechanism comprismg a vertically reciprocating upper needle carrier, an under needle and looper, a substantially horizontal needle carrier actuatinglever, a swinging link on which the lever is fulcrumed, a crank acting on the rear end of the lever, and a link connecting the forward end of the lever with the carrier.

3. A .stitch forming mechanism having,

in combination, a reciprocating needle carrier, a lever arranged substantially at right angles to the needle carrier, a shiftable fulcrum for the lever, a crank engaging one end of the lever, and a eonneetion'between the other end of the lever and the needle carrier for transmitting to the carrier endwise movements corresponding to the sidewise movements of this end ofthe lever.

4. A stitch forming mechanism having, in combination, a vertically. reciprocating needle bar, a substantially horizontal lever,

a crank engaging one end of the lever, a linkconnecting the other end of the lever to the needle bar to transmit to the needle bar vertical movements corresponding to the vertical movements of this end of the lever, and a pivoted link on which the {lever is iulcrumed.

5. A stitch forming mechanism having, in combination, a lever, aneedle carrier, a

connection between one end "of the lever and carrier through which sidewise movement of the end of the lever in one directlon ad vances the carrier and sldewlse movement of the lever in the other direction retracts the carrier, a crank engaging the other end of the lover, a fulcrum for the lever mounted to move with the lever in a direction to reduce the movement transmitted from the crank to the needle carrier during one half revolution of the crank and to increase such movement during the succeeding half' EUGENE J RAY.

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