US703812A - Stitch-forming mechanism for sewing-machines. - Google Patents

Description

No. 703,812 Patented July I, I902.

L. onnznuoux.

STITCHFORMNG MECHANISM FOR SEWING MACHINES.

' (Applichtion filed Sept. 11, 1897. "lo M o d al 4 sheets-she th.

- N0. 703.8I2. I Patented m I902.

L. UNDEBDONK. STITCH FORMING MECHANISM FOR SEWING MACHINES.

(Application med'se e. 11, 1897. (No Moflel.) 4 Sheets-Sheet '3.-

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No. 703,312; Patented July |,.1902.

L. DNDERDUNK. I STITCH FUBMING MECHANISM FOR SEWING MACHINES. (Application filed Sept. u,'1s91.j (No Model.) 4 Sheets-8heet 4.-

- 3 'ewtoz lwfl-"mama I ablioz meq LANSING ONDERDONK, OF BOSTON, MASSACHUSETTS, ASSIGNOR TO THE UNION SPECIAL SEWING MACHINE COMPANY, A CORPORATION OF ILLIN OIS.

STITCH-FORMING MECHANISM FOR SEWING-MACHINES.

SPECIFICATION forming part of Letters Patent No. 703,812, dated July 1, 1902.

Application filed September 11, 1897. Serial No. 651,293. (No model.)

To all whom, it may concern:

Be it known that I, LANSING ONDERDONK, a citizen of the United States, residing at Boston, in the county of Suffolk, State of'Ma'ssachusetts, have invented certain new and useful Improvements in Sewing-lVIachines, of which the following is a description, reference being bad to the accompanying'drawings, and to the lettersof reference marked thereon.

My invention relates to an improvement in sewing-machines, andparticularly those of the chain-stitch variety, which employ a thread-carrying needle and an under threadcarrying looper and which make a double chain or look chain stitch. WVell-known machines of this class are of the Union Special type, and it is to this particular type of machine that my invention is especially applicable and in connection with which it is illustrated.

The invention relates particularly to the stitch-forming mechanism of such machines; and its object is to so arrange and time the three essential elements entering into the stitch-making organization that the looperthread is spread for the passage of the needle and its thread, the previously-formed nee-j dle-loop upon the shank of the looper will be forcibly and positively held away from the descending needle, the slack of the looperthread will be primarily temporarily disposed of or controlled by a device not forming a part of the usual take-up or thread controlling mechanism, and subsequently such slack will be controlled or taken up by the usual devices which, though they act later,. will quickly dispose of the last 'vestige ofslack of the looper-thread, thus forming a neat stitch.

As above indicated, there are three ele-' ments inthis organization which constitute the essentials for producing a stitch on my machine, and while these elements may be aided in perfecting the stitch by the usual thread-controlling devices, modified to meet the requirements of my arrangement of parts, it is in such elements, their disposition, and location, whereby the above results and objects are secured, that my invention primarily consists. Furthermore, the invention consists in so arranging the so called loopspreader that in its forward movement to spread the looper-loop, in order that the needle may properly engage it, it will pull off through the looper-from the spool more thread than will be taken up by the looper in its backward movement and more thread than will be drawn taut by the take-up, thus adding to the elasticity of the stitch, a very desirable thing in sewing certain classes of goods.

"My invention is illustrated in the accompanying drawings, in .which Figure 1 is a perspective View of a sewingmachine, partly broken away and illustrating my invention. Fig. 2 is a front side View of a portion of the bed-plate of a sewing-machine, illustrating myinvention. Fig. 3 is a top View showing the loop-spreader at its extreme forward point. Fig. 4 is a top plan 'view showing the loop-spreader at its extreme backward point.

Fig. 5 is a rear end cross-sectional View. Fig. 6 is a front side View, theloopers being shown in dotted lines,

this View being especially to illustrate how the bearing is formed for carrying the upright shaft upon which the loop-spreader is supported. Fig. 7isafront side view showing the loopers at their extreme forward points. Fig. 8 is an enlarged view showing the looper entering the needle-loop, the position of its thread, and the thread-groove on the back side of the looper; and Fig. 9 is an enlarged plan view'showing the formation of the stitches.

In the figures, A is the frame of the machine, of ordinary structure, the main shaft '13 being below the bed-plate and receiving its 1-I,'having conical recesses h at opposite sides thereof for the reception of conical screws h, affording a support and an adjustable bearing for said carrier. The screws are supported by lugs 72, forming parts of the main frame, and are held in adjustable position by any suitable device common for that purpose. The looper L is supported in the upper end of the carrier in any usual or approved manner and is arranged with its longitudinal axis extending lengthwise of the machine. The means for retaining the looper in its carrier will also afford a means for adjusting said looper vertically and laterally, so that it may be properly positioned relative to the needle and other parts of the machine. The carrier is provided with a lug or projection h preferably substantially spherical, to which is jointed the actuating connecting-rod G. It will be seen from this construction that the looper-carrier has but an oscillating movement in the direction of the length of the bed-plate and looper and about the conical bearings-that is to say, for reasons hereinafter stated the looper has no lateral vibration, as is usual in this class of machines, and consequently travels on but one side (the rear) of the needle during its operation. The looper is so arranged as to travel at the rear of the needle, considering the direction of feed, and in consequence the looper is grooved for the reception of the thread on its rear side, as shown at h in Fig. 8, this necessitating the threading of the looper from rear to front, being the reverse of the usual way.

The loop-spreader mechanism consists of the vertical shaft K, journaled in the inner of the two bearings 72/ and carrying at its upper end the spreader 70, which is held therein by any suitable means which will also permit of its being adjusted vertically and laterally for the purpose of properly positioning the same relative to the needle and looper. As will be seen on reference to Fig. i, the spreader is arranged in rear of the looper, and the shank of the spreader is supported by and is capable of being adjusted in the clamp-conneoting rod or device 70, a recess being made in the bearing 77, for the reception of the head of said rod or device. The outer end of said rod 7c is preferably spherical, affording a universal-joint connection with the eccentric-strap k embracing the ,-=dle and close to the bed or throat plate.

eccentric on the main shaft B. This mechanism upon revolving the main shaft causes an oscillating motion to be imparted to the spreader toward and from the plane of movement of the looper and needle and partially around the latter, the disposition of the spreader being above the looper in rear there of and of the needle, considering the direction of the feed, and to the left of the nee- The form of the spreader is best shown in Fig.

9, where it will be seen that the spreaderblade k is made, preferably, integral with its shank and is provided at its forward end with a notch 70 which catches, holds, and carries the looper-thread to the desired position; and in order to insure the positive and effective engagement'of the spreader with the looper-thread said spreader is provided with an elongated nose or-finger 7.5, Fig. 9, which in practice may be suificiently long to always extend into the path of movement of the looper-thread, so that as the looper moves forward its thread will contact with and lie against said nose or finger, thereby assuring the entrance of the thread into the notch of the spreader and the proper spreading of the loop of looper-thread for the entrance of the needle. Now while the elongation of this nose or finger is preferable, as above stated, it is not an essential to the proper working of the machine, and in some cases it may be desirable to dispense with said nose or finger.

As previously stated, the looper is confined to movements in the direction of its length, and which, as shown in this machine, is also lengthwise of the bed-plate. In the old fourmotion form of looper mechanism the lateral movements are depended upon for spreading or opening the looper-thread loop for the passage of the needle and for carrying the needlethread loop upon ,the looper-shank aside in order to avoid the needle, the same movement also making the looper a-voidcollision of the needle therewith in the operation of entering the looper-thread loop. The two lateral movements of the oldform are done away with in my organization, thus reducing the number of parts and simplifying the machine; but the important advantage is that the possibility of skipping stitch, ever present in the old form, is completely removed in my organization, the spreader always acting with certainty and precision and performing its functions in a manner to render the skipping of stitches a matter of impossibility.

The description so far, for the sake of simplicity, has been confined to a machine having but one looper and one spreader, as shown in Fig. 1; but in the other figures of the drawings a duplex arrangement is shownthat is to say, two needles, arranged diagonally relative to the direction of feed, two thread-carrying loopers, arranged one behind the other, the nose of one being slightly in advance of the nose of the other, and two spreaders, arranged side by side and at right angles to the loopers.

Manifestly the arrangements shown in the drawings are but examples of the cooperative relations of the three essential elements which enter into the stitch-forming operation, and it will be obvious to one skilled in the art that other arrangements of said essentials can be made without departing from my invention in spirit or principle. The needle-thread is indicated by the numoral l, and the looper-thread by the numeral 2, and Figs. 8 and 9 show the concatenation of threads in making the usual double or look chain stitch.

As a further and special improvement in devices of this character I have provided an arrangement whereby the loop-spreader acts to increase the elasticity of the stitch and with this end in view give to the same a suflicient oscillatory movement, as it engages the looper-thread and moves to its extreme position, that it will draw through the looper-eye from the spool a greater amount of thread than the looper in its backward movement will take up, therefore leaving a slackness to the stitch on the under side. Of course with this arrangement a special form of cam for the take-up must be used-this a cam which will not eat up all the slack taken ofi by the loop-spreader.

The operation of the parts thus described is as follows: Rotation of the main shaft imparts an oscillating movement to the looper through its connectionwith the needle-arm, and the latter imparts vertical reciprocation to the needle-bar, and the loop-spreader receives an oscillating movement from the main shaft through the described connections. The parts are timed and so arranged as to cooperate as follows: The needle having descended and risen slightly to throw out its loop, the looper advances and enters said loop at the rear of the needle, the latter continuing to rise, which needle-loop slips back upon the shank of the looper. The looper-thread extending from the work or throat-plate to the eye of the looper is by the continued advance of the looper brought into a position where the spreader will infallibly engage the same upon its forward movement, or if the nose of the spreader be elongated, as described, the forward movement of the looper will pass its thread into contact with said nose, thus effectually insuring the engagement of the spreaderwiththelooper-thread. Thespreader having become engaged with the looper-thread advances to substantially the position of Fig. 9, spreading and holding the looper-thread, as shown, so that the needle in making its next or second descent will enter the looperthread loop. Before the needle completes its second descent, however, the looper recedes, sliding out of the first needle-loop, but leaving its thread therein, which needle-loop is forcibly held back from the path of the descending needle by that portion of the looperthread loop extending from the point of the spreader to the throat-plate or work. Continued backward movement of the looper draws its thread oi the spreader, the latter in the meantime moving back to its original position. As the needle throws out its second loopand the looper moves forward the second time and enters the same the spreader again advances, as before described, to a second time carry the looper-thread forward of the path of the needle and hold it open for the entrance of the needle upon its third descent.

Obviously in order to obtain the best results and produce a perfect and neat stitch the looper-thread should be properly controlled in the formation of the stitches, and to that end a take-up mechanism should be employed, including nipper-springs for holding the thread at proper intervals. To obtain the best results in my organization, it becomes necessary to modify the shape of the take-up cam of the Union Special machine, if such be employed, so as to delay the takeup action.

The effect of the cooperation of the three essential elements of this] organization, together with a suitable take-up or thread-controlling mechanism ,is as follows: The spreader will positively place the looper-thread in position where the needle must pass into the loop thereof. This manipulation of the looperthread causes that strand of the loop which extends from the throat-plate or work to the end of the spreader (in its advanced position) to pass between the descending needle and the needle-loop previously entered by the looper, and still upon its shank, and positively and forcibly hold said needle-loop back and out of the way of the descending needle, (though the looperbe receding,) and thus prevents said needle entering said previouslyformed needle-loop or becoming entangled with it in any manner, and causes the needle to certainly pass on the proper side of said needle-loop and accurately enter the loop of looper-thread. The looper-thread will be kept taut, so as to properly control the needlethread loop which is around the looper and also to insure the spreader engaging the looper-thread. The spreader will take up or temporarily dispose of substantially all the slack looper-thread caused by the backward movement of the looper up to the time when the needle has reached substantially its lower limit. The continued backward movement of the looper (the spreader receding) will cause an additional amount of slack looper-thread, which will be properly taken care of by the take-up or thread-controller, the action of said take-up upon the thread when it acts being quicker than is now common in ma chines of this character, which, as before stated, necessitates a change or modification in the shape of the cam for the purpose of producing the best results.

It will be seen that in the operation of this machine all possibility of skipping stitches is practically avoided, and loop-retaining wires and devices may be dispensed with, the loop of needlethread being held forcibly and positively out of the way of the descending needle.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. A sewing-machine comprising a vibrating looper having a loop-taking and loopshedding movement in the direction of its length, a spreader having movement across the line traversed by said looper in the direction of the length of said looper and arranged to seize and convey the looper-thread, and means for imparting to said spreader an amount of movement to cause it to pull through the looper a greater quantity of thread than thelooper will take up in its backward movement; substantially as described.

2. A stitch-forming mechanism for sewingmachines, comprising a reciprocating threadcarrying needle, a cooperating thread-carrying looper, means for actuating the needle and looper, and a spreader with means for oscillating it to engage the looper-thread loop, and spread it for the passage of the needle, said looper and spreader being both adjustable whereby proper cooperation of the parts may be had; substantially as described.

3. A stitch-forming mechanism for sewing- LANSING ONDERDONK.

Witnesses:

A. H. HATCH, A. L. CooMBs.

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