US30634A - Improvement in sewing-machines - Google Patents

Description

2 Sheets-Sheet 1. R. LEAVITT. SEWING MACHINE.

No. 30,634. Patented Nov. 13, 1860.

- 2 Sheets-Sheet 2.

R. LEAVITT. SEWING MACHINE.

No 30,634. Patented; Nov. 13, 1860.

UNITED STATES PATENT OFFICE.

*RUFUS LEAVITT, OF MELROSE, MASSACHUSETTS.

IMPROVEMENT IN SEWING-MACHINES.

specification forming part of Letters Patent No'. 30,634, dated November 13, 1860.

To aZZ whom it may concern.-

Be it known that I, RUFUS LEAXITT, of Melrose, in the county of Middlesex and State of Massachusetts, have invented certain new and useful Improvements in Sewing-Machines; and I do hereby declare that the following, taken in connection with the drawings which accompany and form a part of this specification, is a description thereof so full and exact as to enable those skilled in the art to practice my invention.

The variety of sewingqnachines to which my invention particularly applies is well known as the shuttle-machine.

My invention relates to an arrangement and combination of parts by which I am enabled, at orabout the last part of the upward throw of the needle, to take off from the spool holding the needle-thread a suificient amount for the formation of each stitch, thereby dispensing with a length of reciprocation of the needle, which, but for these parts, would be necessary for this purpose and for no other, leaving the thread slack between the eye of the needle and the spool at the time when the shuttle passes between the needle and its thread, drawing down the latter and causing it to render through the eye of the former and the different parts back as far as the spool also, to a new combination of parts operating to take up the slack of the needlethread during the descentof the needle to the goods, to prevent kinking around and under the needle, or other entanglementof the thread, which it leaves free from its influence throughout the other portions of the stroke of the needle.

Similar letters refer to similar parts in the diii'erent figures of the drawings, in which- Figure 1 is a side elevation, Fig. 2 a plan, and Fig. 3 an end elevation, of a sewing-machine embodying my invention. Fig. 4 is the same with Fig. 3, with exception that part of the bed is shown as removed to exhibit the construction and manner of attachment of the part on which the feed-ring rot-ates, which is further illustrated in the detail drawings, Figs. 5 and 6.

The machine illustrated in the drawings and embodying my invention does not differ material] y in its feed, its shuttle and needle, presser-foot, and general relation of the bed and armor goo-seneck from others now public. These parts therefore, and their operation are sufficiently well known to those skilled in the art not to need description in this specification, which will be confined nearly as possible to the parts eii'ected, or modified by or embraced in the combinations of my invention.

The shaft f, to which motion is communicated to operate the sewing mechanism, passes through the upper and rear part of the arm A, as shown in the drawings.

At the end opposite to that on which the handwheel B is located, a disk, E, is fixed, whose periphery is cam shaped for the purpose of operating, in connection with the other means sh own in the drawings and hereinafter described, the takeup I). In the disk e a crank-pin, a, is fixed, which, in its rotation, operates upon the cams x and 3 formed, as illustrated, at the ends of the needle and shuttle levers C and D, thus giving to the needle and shuttle, through the connect-ions plainly shown in the drawings, the amount and times of linear movement and rest therefrom requisite (proper and common) for such instruments in their action in a sewing mechanism. As the form of these cam-shaped slots requires to be varied in machines of different sizes and for various kinds of work, and as I make no claim to the shape of the cam-slots, I do not herein give any rule for their sh ape, which can only be got at by actual reduction to practice. of theory by those skilled in mechanism.

Upon the shaft f and within A is fixed the belt-pulley, by which the machine can be operated. In one side of this pulley a cam is cut, which, through 5 and other illustrated parts, operates the feed. The pulley and cam not appearing in the drawings are here men: tioned solely for that reason. The spool h for the needle-thread is pivoted upon a stud fixed in arm i, which is pivoted upon the stud j, on which the needle-lever G vibrates. A projection from C is arranged so as to strike i during that part of the vibration of Cwhich raises the needle, moving the spool back from the needle-bar, and taking off from it a length of thread proportionate to the amount of the throw given to the spool. This saves an amount of vibration of the needle-bar which would otherwise have to be given it to take oii' thread enough from the spool. to form each stitch, which amount is saved by increment oi my take-oft, which iseasily adjustable in the amount of its throw to the requirements of the scam: but to change the throw of the needle, to take off from the spool different lengths of thread, would seriously interfere with the movements of other parts. The spool is drawn toward the needle-bar during the other part of the vibration of O by contraction of the spiral spring 12, and theextent of the movement of the spool is regulated by the position of the set-screw k, which can be adjusted so as to give any desired amount of throw to the spool called for by the i-equirementsof the seam; or

'it can prevent any throw of the spool, in which case its take-oiffunction is rendered inoperative. Tension upon the thread is obtained and varied by increasing or diminishing the friction between the spool and the washersl by adjusting the nut m. v

The device which is termed a take-up operates to take up the slack thread leftduring the descent of the needle to the fabric, which, if not taken up, would be liable to interfere by entanglement with the operations of the sewing mechanism. I

My take-up consists of the piece I), piy'oted at 0, and so formed that the thread passes through an eye or hook formed in its free end. .A lever, 12, is pivoted at q, carrying a-roll, 17, which is made to bear against the cam-shaped periphery of the disk e. The tendency of the spiral spring 8 to contract when extended, it

, being fixed by its ends to the-goose-neck and to the take-up b, acts to keep the latter drawn back toward the disk or cam e, and through the rod tkeeps the roll 1' on lever 19 constantly pressed against the cam e, which, by means of the same rod, t, communicates its throw to the take-up b, at the same time extending the spiral spring 8. The eye of the take-up b re-' mains in the line of the thread drawn from the eye of the needle to-the guide-hole .in

the top of the needle-bar during. the whole of the upward stroke of the needle; but as the downward stroke thereof commences it moves off toward spool h, taking up the slack formed in the thread by the descent of the needle-bana'nd by the forward throw of the spool, thus keeping the, slack from kinking orgetting entangled around the needle. Vhen the needle-point is fairly entered into thegoods, then the take-up moves forward to assume its place in the .line before mentioned, where it remains till the commencement of the next downstroke of the needle. The movements of .my take-up are regulated in extent and time by the cam e, the spring .9 keeping the roll 1' constantly pressed against the cam but it will be obvious that when any unusual occurrence takes place by'which the strain on the 1 thread is increased, the yielding of the spring will in many cases prevent the breakage of thethread, which would occur if the take-up was obliged to follow with a positive motion themovement of the cam. I am aware that there have been, previous to my invention, takeups which had the function of mine-viz. to keep the slack of the thread formed by the descent of the needle fromentanglement; but

instrument has a spring movementin one direction, uncontrolled except by the tautness of the thread to take it up till the needle enters the work, and then the take-up has a positive retrograde movement imparted to it equal to or in excess of the further movement of the needle, so that there may be sufficient slack in the needle-thread to permit the passage of the shuttlebetween the needle and its thread but during the upstroke of the needle, after the take-up is released from the mechanism which moved it positively, as before referred to, the spring acts again with its full force directly upon the thread, which is obj eetionable, as causing want of uniformity in the stitches and unnecessary wear upon and rendering of the thread. In this kind of take-up the instrument has no positive movement imparted to it during the upstroke of the needle, as do the take-ups of the second kind, for'the purpose of tightening the stitches, the operation of the second kind of take-ups being otherwise substantially the same with that of the first kind. A peculiar instrument for controlling the needle-thread may be found in the English Patent No. 2,649 for the year 1855. This-does not, like my take-up, operate to keep the threadtaut between then'eedle-eye and thefabric during the descent-of-the former to the latter, but works in'the reverse manner and continues operating after the needle has entered the goods to form slack in the thread to facilitate the passage of the-shuttle,.and

afterward to tighten the stitch by pulling on the needle-thread, which -is wound around the instrument to obtain the -'rcquisite degree of tension on the thread. .My take-up operates only to keep the thread from kinking and entangling from the .first part of the downstroke of the needle till this enters the work. It does not pull from the spool any thread to give a large loop for the passage of the shuttle, but simply leaves thethread loose and free between the needle and the tension, so that the shuttle (entering between the needle and its thread) draws upon the latter sufficiently topass through. Neither does my take-up operate or aid in any way to draw in or tighten the stitches. The function of my take-up is precisely that of an instrument in common use in shuttle-machines, which will be recognized,

when its action is described, to be that of the finger and thumb seizing the thread between the point ofthe needle on its downstroke and the goods, and drawing it away from the needle in the direction of the feed till "the needlepoint enters the goods, when the-thread becomes disengaged from such nippers by being pulled out of their grasp by movement of the sewing mechanism. But my take-up-h'as these advantages over that last described: It is less in the way of the operative, and not liable to the ring cast upon it.

30,634 V v e be caught in the work, is not sosubject to derangement, and is more easily and cheaply combined with the sewing mechanism.

' the thread.

In sewing-machines it is a desideratum to make all the rapidly-reciprocating parts light as possible. Any device, therefore, which ena- .bles me t use a light needle-bar is of importance.

The bar it has a collar, (1, around it, which may be adjusted anywhere on the length of the bar by a setscrew, c. To this collar and to thevibrating lever Othe link 1; is connected. It will be observedthat by slackening the setscrew in d the needlebar may be adjusted with reference to the distance of its end from the table, and by removing the needle-clamp w the bar may be entirely withdrawn from the machine without disturbing other parts thereof.

In other shuttlemachines in which the feeding instrument is a serrated ring, through which the shuttle-race passes, the carrier of the ring has formed part of the bed of the machine or of some portion thereof, or has had projections not concentric with the center of In all of these the turning of the ring-seat has been made inconvenient by reason of the parts attached to the the machine, I leave oft from the carrier at all such projections as are not concentric with it, such as cars and straight flanges. Upon the center I have a hub cast of suiiicient size to hold the carrier firmly on thearbor while it is turned, which hub may afterward be cut off. In the plane side of as a groove, 1/, is burrcd out, and the right-angled knee 2 is formed with a projection on one of its faces, fitting the groove. The screw which holds the carriei" to 2 plays in a slotted hole in the carrier, by which the feed-ring is set to any desired height. above the table, the knee being firmly screwed to the bed.

I claim in a sewing mechanisml. The arrangement and combination of the spool h with the lever G, or other moving part i to yield to avoid breakage of the thread, which yielding the spring as applied permits.

RUFUS LEAVI'ET.

Witnesses:

T. B. CROSBY, W. H. CADES.

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