US1264714A

US1264714A - Sewing-machine.

Info

Publication number: US1264714A
Application number: US5538215A
Authority: US
Inventors: Vandiver J Van Horn
Original assignee: Individual
Current assignee: Individual
Priority date: 1915-10-12
Filing date: 1915-10-12
Publication date: 1918-04-30
Anticipated expiration: 1935-04-30

Description

V. J. VAN HORN.

Patented Aux-30, 1918.

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SEWING MACHINE.

APPLICATION FILED OCT. 12, 1915.,

Patented Apr. 30, 1918.

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SEWING MACHINE. APPLICATION man act. 12, 1915.

1 1% Patented Apr. 3O, 1918.

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VANDIVER J. VAN HORN, OF CHICAGO, ILLINOIS.

SEWING-MACHINE.

Application filed October 12, 1915.

To all whom it may concern:

Be it known that I, VANDIvnR J. VAN l-Ioan, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Sewing-Machines, of which the following is a specification.

My invention relates to improvements in stitch-forming mechanism for sewing machines. One of its objects is to provide a mechanism for making a plural-thread stitch wherein the thread-handling members that cooperate with the needle, for the formation of the desired threadconcatenation, are nonthread carrying, and are uni-directionally rotatable.

In my prior Patent No. 1,136,299 dated April 20th, 1915, some of the claimed fea tures whereof. are embodied in the present machine, I have shown and described mechanism for the formation of a single-thread chain stitch, such mechanism providing for cooperation with the usual needle, a loop handler that is formed as an arcuate band andthat is revoluble to pass endwise completely through the loopwhich it holds, in the exercise of its intended functions. Furthermore, in my prior Patent No. 1,143,? 95 dated June 22, 1915, 1 have shown and. described mechanism for the formation of a plural-thread chain stitch, some of the claimed features whereof are embodied in my present machine, such mechanism employing a single unidirectionally-rotatable, arcuate-band-form, loop handler but in cooperation with a second thread handler that carries the second thread and works transversely to the rotational plane of the first said member. 7 By each such construction 1 have provided for the attainment of objects valuable in sewing machinery, such as elimination of take up mechanism, minimization of the quantity of thread drawn off and handled in connection with the formation of each stitch, firm and advantageous set ting of each stitch, the simplification of, and condensation of size of, working parts; the provision of structure susceptible of very high speed operation, andthe like; and it will be understood that it is further inpur-v suance of, and for most satisfactory attainmentof, these and other objects that my present invention is designed.

Specifically an object of my present inyention is to provide a construction for the Specification of Letters Patent.

or threads will be interengaged.

Patented Apr. 30 191%.

Serial No. 55,382.

formation of a plural thread stitch, such as a double-thread chain stitch, doing away with non-rotating thread-handling parts, and providing for each thread employed in the stitch formation, a rotatable band-like thread retainer arranged to perform its functions during its endwise passage past the area of stitch-formation or, in other words, past the stitchmaking point.

A further specific object is to provide simple and adequate driving means whereby the desired rotation may be imparted to such members.

Another object is to construct the said mechanism in such compact and simple form that,"if desired, a plurality of said mechanisms for cooperation with a plurality of needles may readily be placed side by side to be mutually driven from a common shaft.

In the drawings 1 have shown my inven tion embodied only in a machine for making a double thread chain stitch, but it will be understood that features of my invention herein claimed are not restricted to such embodiment but are adaptable, within the generic idea of my invention, to specific embodiments for operation in forming other kinds of stitches in which loops of a thread For purposes of full disclosure, however, of one particular embodiment of my invention 1 will confine the specific description thereof to the single exemplification shown, but without intent thereby to limit my invention in this regard further than as set forth in the claims.

In the drawings Figure 1 is an end elevation, convention alized, of a sewing machine stitch forming mechanism embodying my invention;

Fig. 2 is a vertical section through a portion thereof on line 22 of Fig. 4;

Fig. 3 is a vertical section, looking in the opposite direction, on line 33 of Fig. i;

Fig. 4 is a transverse section on line 4-4 of Fig. 3;

Fig. 5 is a broken elevation showing the parts illustrated in Fig. 3 in a different relation.

F ig. 6 is a vertical section on line 6-6 of Fig. 5; and

Fig. 7 is an extended perspective showing the parts ready for assemblage and mount ing on the shaft.

Figs. 8, 9, 10 and 11 are diagrammatic views illustrating, in planar form, purely for explanatory purposes, the thread handling parts in several positions of progress past the stitch making point.

Fig. 12 illustrates the thread concatenat-ion, showing a few set stitches and others with the threads diagrammatically spread for clear display.

Referring to the drawings the sewing machine may comprise any suitable head A, presse'r foot B, slotted work-plate O, and suitable feed mechanism (not shown). With the nature of these (or equivalent) mechanisms for presenting and feeding work relative to the eye pointed needle n, my present invention has no direct concern, but itwill be understood that by the employment of features of my present invention the use of a take-up for the needle thread If (and also for the second thread 6 hereafter referred to) is made unnecessary, so that the needle thread may pass direct to the V needle from the tension device D and the second thread may be acted on by any suit able tension device diagrammatically shown at D. In the general arrangement of the parts so far referred to there is nothing peculiar or novel. The fabric or fabrics 7 (see Fig. 8) to be stitched are fed between the presser foot B and the work plate O, and

the needle in its descent may penetrate therethrough and, by partial retraction, throw out a loop 1, of needle thread 6, below the work as shown in Fig. 8, to be engaged with other thread-loops in the desired concatenation.

In the formation of the double thread chain stitch, for which the mechanism here- .in' specifically shown is particularly designed, a'seeond thread't is employed, and the general mode of operation, for proper interlooping of the threads, is as follows: Each time the needle effects a penetration and retracts sufficiently to throw out a loop 1 of the thread t, such loop 1 is held below the cloth while the needle fully retracts and a. work-feed takes place; the loop 2 of the second thread is passed through the loop 1 of needle thread, as illustrated in Fig. 10, just before the needle descends again, and on its said next descent the needle it passes through this second-thread loop 2, and throws out its next succeeding needle thread loop 1 whereupon the cycle is repeated, such repeated cycles resulting in a thread concatenation that is clearly illustrated in Fig. 12. Of course, the stitch per se is old and well known.

. Preliminarily, to an explanation of the detailed mechanical structure in which my invention finds its present embodiment, the principle of operation of my structure may readily be understoodwith reference to the diagrammatic vie s, Figs. 8 tofll he ein dam d-h ndl ng p s h e pe te with the needle are shown as straight, in-

stead of arcuate, and wherein only the parts acting on the thread are shown, without reference to any means of support or driving means, for diagrammatic simplicity.

' lVhen the needle n has descended through the fabric f, and has partly retracted to throw out its loop 1, a thread-handling band 20, having a point 21 at its forward end, passes alongside the needle through the needle thread loop 1, so that, as shown in Fig. 9, when the needle retracts the loop 1 is held in properly open condition by the band 20. The loop is not materially enlarged, but is merely retained in what we may term a static condition, so to speak, while the band 20 travels forward therethrough. Over this first said band 20 there is arranged a second thread-handling band 25 that travels in the same direction with, and at the same speed as, the band 20. This second band is proferably slightly narrower than the band 20 so as to pass easily through the loop 1, its point 26 is back of the point 21 in direction of travel; and the second band spaced apart from the band 20 sufficiently the second thread If to pass easily between the two bands. This second thread 6 may be presented at a proper elevation, just above the band 20 and below the band 25 by guidance through an eyelet 32 so that inevitably the point 26 of the second band 25 may pass over the affected portion of the thread 25. In consequence, during the major portion of the time that the two

bands

20 and 25 are passing endwise through the loop 1, the second thread t lies idly in the intcrspace between the two bands. And it is while the threads are thus in static condition, merely positioned for the action that is subsequently to interloop them, that the feed takes place moving the fabrics in a direction opposite to the direction of passage of the

bands

20, 25, and so shifting the needle thread loop, 1., a bit rearwardly along the bands, as suggested in Fig. 10.

On one of the bands-preferably the first mentioned band 20there is a projection 22 for coiiperation with the second thread If. It comes into action after the aforesaid feed has taken place. As herein shown this memi ber takes the form of a U-shaped rib open between the limbs of the U, and pro ecting upwardly from the rear end of band 20, in rear, (generally speaking) of the end of the upper band 25, the separation between projection 22 and band 25 being suliicient for thread-clearance. This U-shaped rib projecting upwardly from band 20 (across which lies thread t,) on its forward move ment forms and carries forward through loop 1 of thread t a secondary loop 2 formed in thread t. The timing of the parts is such that as the needle makes its second descent through the fabric (Fig. 10) it will pass down within the confines of the U- far to permit shaped. rib 22 aforesaid, of the band 20. The result of this coordination is graphically shown in Fig. 10: The feed of the goods in a direction opposed to the travel of the bands 20-25 has drawn the whole loop 1, that is being retained by the band 20, somewhat back of the vertical line of needle descent; the second thread t has been engaged by the U-shaped rib 22 of the member 20 and has been carried forward somewhat thereby in the form of a secondary loop 2 which is thereby passed through the primary loop 1; and next the needle, descending into the interior of the U-shaped rib 22, will pass its next primary loop 1 down through the secondary loop 2 of the second thread. Proper tension devices acting on the threads 25 and t resist their being drawn out into loop form and the resistance thus imposed on thread 25 will be sufficient to insure that said secondary loop 2 will slip ofl of the properly beveled and rounded surfaces of the rib 22- after the needle has passed down into the said secondary loop 2. Consequently the shedding of the loop 2 from the rib 22 leaves it lassoed around the needle n (as shown in Fig. 11) when, in the continuing progress of the machine cycle, the band 20 engages afresh with the needle thread, taking this newly formed loop 1, and starting a new cycle of operations under the same conditions that are shown in Fig. 8. Constant repetition of this cycle of operation obviously results in the enchaining of the two threads in the fashion shown in Fig. 12.

Aside from the structural details (hereafter to be explained) for one effective embodiment of my invention, it will be apparent to those skilled in the art that the structural principles exemplified in the diagrammatic views are highly advantageous. The inter-engagement of the thread loops on the under side, or wrong side, of the fabric is accomplished wholly by endwise moving bands, traveling always in the same direction; and these bands may be driven in constant time-relation to the main shaft. Such unidirectional, uniform-time movement is very advantageous in a high speed mechanism. The linear extent of such bands may be selected primarily .on the basis of mechanical. expediency in construction and in practice may be widely varied, for the reason that increase or decrease in length of the band 20, (with corresponding proportioning of the correlated ,band 25) will manifestly have no effect upon the amount of thread drawn off by such bands in their functional operations. This disassociation of the linear dimension of the thread-handling parts from any controlling relation to the amount of thread handled is mechanically of great importance and gives the mechanism susceptibility to many adap-'.

tive variations in design to meet particular machine requirements. Furthermore, as to each thread employed in producing the desired concatenation of threads, no more thread is drawn into looped form at any time than is necessary merely to secure the desired interloopage, and the loop forming elements themselves c. the needle which forms the needle thread-loop and the U- shaped rim operating with the second thread to make the loop-bend therein,) will act, in forming each respective thread loop, to set the thread of the preceding stitch, thereby obviating the necessity for any inde-.

pendent take-up devices, so doing away with a train of auxiliary mechanism. Also the relation of the bands enables the two threads to be positioned with respect thereto in such positive fashion that skipping of stitches is substantially impossible. And further, the only thread that need be passed through an eye in a moving part is the nee dle thread. Many other advantages due to the underlying principle of mechanical con struction will be apparent to those skilled in the art, but the foregoing brief suggestion of a few characteristics of the present invention will suffice to indicate its novelty and utility, and to indicate that the invention does not reside primarily in details of the single embodiment that specifically shown.

Referring now to the particular mechani cal embodiment of my invention shown in detail herein, I provide below the work plate 0 an annular race-way 15, flattened at its top and otherwise circular, said raceway having an opening 16 immediately through its flattened part below the work plate. The annulus has a recess 1'? and in its end wall has

concentric grooves

18 and 19 in which the

rotatable bands

20 and 25 respectively are mounted. The inner, loweig or primary band 20 has its point 21. adjacent its trans verse center so that its pointed end may travel very close to the needle for the purpose of taking the needle thread loop, and at its rear end it has the outwardly projecting U-shaped rib 22, having its external surfaces somewhat tapered toward the crest of the rib for proper thread-shedding purposes, and having between the limbs of the ribs the needle receiving opening 23. Dias metrically opposed slots or openings 24 are made in the band to cooperate with the driving shoes to be described.

The outer, upper, or secondary band 25, shorter than the band 20, has its point 26 preferably adjacent that side thereof which is guided in the circular guide way 19. Preferably the second hand 25 is somewhat narrower than the band 20 (see Fig. 1) so that it may easily travel through. the pri mary or needle-thread loop that is retained by the band 20. This secondary band 25- is provided with slots 2% radially registering,

with the slots 2a on the inner band 20, and at its rear end, (that, in a general way, terminates just in front of the rim 22,) it preferably has a finger 27 that extends along beside the loop-forming projection or rim 22 to afiord some slight retardation to complete thread-shedding from said rim, sufficiently retarding the loop-shedding to insure that the secondary loop will be caughtby the descending needle.

Since the inner or lower band 20 must always pass below the second thread, and the outer or upper band 25 above such thread, I preferably provide a guide for the secondthread so arranged as positively to lead the second thread into the interspace between thetwo said bands. To this end, I mount a thread guide 30 to span the opening 16 in the race-way ring 15 and on said thread guide I form a nose 31 that projects into the interspace between the two

grooves

18 and 19 in which the two bands are guided. The thread opening 32 in such guide may communicate, with angularly disposed slots 33 and 34: indirectly leading to the upper edge of the guide bridge so that the threading of the thread-guide may be very readily and positively accomplished by passing the second thread laterally into the slots.

The two

bands

20, 25 may be driven in rotation in constant time relation to the main shaft of the machine by any suitable mechanism that will exert its driving influence on the band always at such point or points as to leave the portion of the bands passing the stitch making point wholly free, thus, of course, to prevent the driving devices from interfering with the proper handling of thethreads which lie always at or adjacent to such stitch making point. In the particular construction shown, and constituting one effective and desirable driving means, I mount on the drive shaft a driving head 41 that fits neatly within the annular race-way 15, preferably securing such head to the shaft by a split clamp 12 fastened by a tension screw 13 to the shaft and by a connection screw 44 to the opening 15 in'the head. Across that face of the head 451 which I mayterm its inner face, (2'. e., the

face away from the observer in Fig. 1) I form a diametrical slot 47 in which are mounted sliding shoes 48, each having a point 49 that may pass through the registering

openings

24 and 24 in the two bands,

and each having an anti-friction roller 50 projecting beyond the head 41. The recessed raceway 15 is overlain on its'inner side by a cover plate 51 having therein a cam groove 52' suitable to receive the anti-friction rollers 50 of the driving shoes, and such cam groove being shaped so that as either shoe, during the rotation of the head 41, ap-

proaches the stitch making point, the portion 52 of the cam groove will retract said shoe out of driving engagement with both of the bands 20-25, so leaving them wholly free as they pass the stitch making point where they perform their thread handling functions. Thus in Fig. 4, one shoe is shown in full driving engagement with both of the bands, and the other shoe as passing out of engagement with both of the bands, having not yet completed its disengagei'nent from band 20.

Of course the driving head etl must not interfere with the proper penetration of the needle, and therefore, as best illustrated in Figs. 5 and 6, it is provided with a suitable recess in its periphery to receive the needle, one edge of the needle-receiving portion being left in full circular form as illustrated in Fig. 1 and the other being cut away, as at 62, thus to insure the needle thread loop being thrown out on the proper side of the needle, as will be well understood by those skilled in the art. Also, as a refinement, I preferably provide in the periphery of the driving head a diagonal slot 64 constituting in effect a thread guard, by which any loose thread, lint, or the like, that may accidentally get inside the inner band 20 and that would tend to clog the operation of the machine, may effectively be severed by the diagonal edge of the slot and gathered into the slot.

It will be apparent to those skilled in the art in the formation of a stitch involving secondary loops interengaged with primary loopsa condition present in a double thread chain stitch for specific example-J employ in the thread handling devices that cooperate with the needle, only unidirectionally rotatable parts, working in constant time with the driving shaft and so acting that no loop is formed of any substantially greater extent than is rcquisite to secure the intended interloopage of thread, and so that all stitches are set by the loop-forming n1echanisms themselves. As far as I am aware, I am the first to provide mechanism so characterized.

Further, it will be obvious to those skilled in the art that the entire structure below the race-way is very narrow, and may by more design be made even narrower than that herein shown, so that if it be desired to mount a plurality of these structures on a single shaft in association with a like plurality of needles, the structural principle of my invention lends itself adequately to such multiplication of parts.

It will be understood by those skilled in the art that many changes in specific construction and design, in carrying forth the application of my present invention, may be made without departure from the spirit and scope of the invention, and that in their broader aspects the claims appended are not loops. comprising, 1n combination with a tension device, a unidirectionally rotating member adapted to form a secondary loop, pass 1t through a pr mary loop, and, simultaneously with such secondary loop formation,

set the secondary stitch.

2. In a sewing machine, means for interengaging secondary loops with primary loops comprising, in combination with a tensioning device, a unidirectionally rotating loop of the preceding 'member adapted to form a secondary loop and pass it through a primary loop, and also, simultaneously with such secondary loop formation, set the secondary loop of the preceding stitch and draw through the tensioning device only such thread as is necessary to the formation of the new secondary loop.

3. In a sewing machine, means for interengaging secondary loops with primary loops comprising a unidirectionally rotatable member adapted to maintain a primary loop in distended position for a definite period and to form a secondary loop, pass the latter through the former, and simultaneously set a previously formed secondary loo t Means for forming a plural thread chain stitch comprising, in combination with a reciprocating needle for laying primary loops at a stitch-forming point, a plurality of unidirectionally rotatable members for respectively positioning the plural threads, said members providing means for interlooping said threads and shedding the same in the course of their endwise rotary movement past the stitch forming point.

5. In a sewing machine, means for interengaging secondary loops with primary loops comprising a plurality of unidirectionally rotating members arranged ]O1i1i1ly to pass endwise through a primary loop, positioning the primary loop in distended position and appropriatelyretainlng the thread to form a secondary loop, one of said memhers having means for engaging the last said thread to form it into a secondary loop and pass it through the primary loop.

6. In a sewing machine, means for interengaging secondary loops with primary loops comprising a unidirectionally rotating primary member adapted tomamtam a primary loop in distended position for-a definite period, a secondary member rotating in unison with said primary member for hold ing, in appropriate relationto said primary member, thread for forming a secondary loop, and means associated with said members for forming the secondary loop and passing it through the primary loop.

7. In a sewing machine, means for interengaging secondary loops with primary loops comprising a unidirectionally rotating primary member adapted to maintain a primary loop in distended position for a definite period, a secondary member rotating in unison with said primary member for holding, in appropriate relation to said primary member, thread for forming a secondary loop, and means carried by the primary member for forming the secondary loop and passing it through the primary loop.

8. In a sewing machine, means for interengaging secondary loops with primary loops comprising a unidirectionally rotating primary member adapted to pass endwise through a primary loop and retain it in substantially uniformly-distended position for a definite period, a secondary member rotating in unison with said primary member passing through said primary loop and holding, in appropriate relation to said primary member, thread for forming a secondary loop, and means on one of said members for forming, the secondary loop and passing it through the primary loop. o

9. .In a sewing machine, means for interengaging secondary loops with primary loops comprising a unidirectionally rotating primary member adapted to pass endwise through a primary loop and retain it in substantially uniformly distended position for a definite period, a secondary member rotating in unison with said primary member passing through said primary loop and holding, in appropriate relation to said primary member, thread for forming a secondary loop, and means on one of said members for forming the secondary loop and passing it through the primary loop, the last mentioned means drawing off only suchthread as is necessary to form the secondary loop.

10. In a sewin g machine, a driving shaft, a. reciprocating needle operable in predetermined time-relation to said shaft, means for interengaging primary and secondary loops, comprising a rotating member unidirectionally driven in constant time with the driving shaft and adapted to form a secondary loop and pass it through the primary loop for engagement by the next formed primary loop, saidmember arranged to tighten the previously formed secondary loop by its formation of the new secondary loop.

11. In a sewing machine, a shaft, a reciprocating needle operable in predetermined time-relation to said shaft, means for interengaging primary and secondary loops, comprising a rotating member unidirectionally driven inv constant time with the driving shaft, said member arranged for passage endwise through the primary loop and adapted to form a secondary loop and pass it through the primary loop for engagement by the next formed primary loop, sa1d member arranged to tighten the previously formed secondary loop by its formation of mined time-relation to said shaft, means for interengaging primary and secondary loops, comprlsmg a tensioning device, a rotating member unidirectionally driven in constant time with the driving shaft, said member ar ranged for passage endwise through the pnmary loop and adapted to form a secondary loop and pass it through the primary loop for engagement by the next formed primary "loop, said member arranged to tighten the previously formed secondary loop by its formation of the new secondary loop and drawmg through the tenslonmg device only such thread as 1s necessary to the formation of the new secondary loop.

13. In a sewing machine for forming a plural thread chain stitch, the combination with a drive shaft, of a reciprocating needle operable in predetermined time-relation to said shaft, a primary needle-carried thread, a tensioning device for said thread, a secondary thread, and means for interengaging primary and secondary loops formed in said threads respectively, comprising a rotating member unidirectionally driven in constant time with the driving shaft, said member arranged for passage endwise through the primary loop and adapted to form a secondary loop and pass it through the primary loop for engagement by the next formed primary loop, said member arranged to tighten the previously formed secondary loop by its formation of the new secondary loop.

14. In a sewin machine, means for interengaging seconc ary loops with primary loops, comprising a plurality of rotatable arcuate bands, means for rotating them in harmony to pass them endwise through a primary loop to maintain the primary loop in distended condition and maintain thread for the formation of a secondary loop in appropriate relation to the primary distended loop, one of said bands bearing means for forming the secondary loop, passing it through the primary loop and positioning it to receive the next-formed primary loop.

15. In'a'sewing machine, means for interengaging secondary loops with primary loops, comprising primary and secondary rotatable parti-ciroular bands, means for rotating them in harmony to pass them endwise through a primary loop to maintain V, the primaryloop' in distended condition and maintain thread for the formation of a secondaryloopin appropriate relation to, the primary distended loop, one of said bands bearing means for forming the secondary loop, passing it through the primary loop and positioning it to receive the next-formed primary loop and the other serving to position the thread for secondary loop formation.

16. In a sewing machine the combination with a reciprocating needle for forming a series of primary loops of thread in spaced relation, means for engaging secondary loops formed from a different thread with said primary loops comprising a plurality of unidirectionally rotatable bands arranged to pass endwise through each primary loop to maintain it distended during their passage, and also retaining in appropriate relation to the primary loop thread for the formation of a secondary loop, and means carried by one of said bands for forming the secondary loop and passing it through the primary loop into position to receive the next-formed primary loop.

17. In a sewing machine the combination with the reciprocating needle for forming a series of spaced primary loops, of a primary arcuate band, an overlying concentric secondary arcuate band, means for driving said bands in unidirectional rotation and passing them endwise through each primary loop, to hold the primary passage and to present thread for the formation of a secondary loop in appropriate relation to the primary loop, one of said bands having means for temporarily engaging the last said thread in passage, to form itinto a secondary loop and pass such secondary loop through the primary loop into position to receive the next formed primary loop.

18. In a sewing machine, the combination with a reciprocating needle for forming a series of spaced primary loops, and tension means to resist the loop-forming pull of the needle; of means for interengaging secondary loops with the primary loops comprising a plurality of unidirectionally rotatable members, means for rotating them to pass them through each primary loop, to maintain said primary loop distended during their passage and to position thread for the formation of a secondary loop in appropriate relation to the primary loop, one of said members carrying means for forming a secondary loop and passing it through the primary loop into position to receive the next formed primary loop; and tension means to resist the loop-forming pull of said means for forming the secondary loop.

19. In a sewing machine, means for forming a double thread chain stitch comprising, in combination with the feed and a reciprocating needle, concentric unidirectionally rotatable bands, means for driving them in unidirectional rotation endwise through each primary needle-thread loop,

loop distended during their whereby the lower band may hold the needle thread 100p in substantially-uniform distended condition during its passage, and the other band may hold a second thread transversely across the primary lOOp during a portion of its passage, one of said bands provided with a loop-forming projection for drawing said second thread in loop torm through the primary loop and presenting it in position to receive the next primary loop, before the first mentioned primary loop is shed.

20. In a stitch forming mechanism a circular aceway having an opening defining a stitch forming point, a plurality of arouate endwise traveling bands guidedly supported in said raceway in spaced relation, means for driving said bands unidirectionally in rotation, said means disengaging said band during passage of said means past said opening, one of said bands having on the rearward portion thereof a thread engaging projection.

21. In a sewing machine stitch forming mechanism, a rotatable arcuate band, means for driving the same in rotation comprising a rotatable head, a pair of independently radially movable band-engaging means car- *ried by said head, and cam means controlling the movements of each of said band engaging means.

22. In a sewing machine stitch forming mechanism, a plurality of radially spaced concentric hands, a thread carrying needle cooperating with one of said bands, a second-thread guide opening to the inter-space between said bands, and means associated with said bands for interlooping the second means associated with said bands for inter looping the second thread with the needlecarried thread.

24:. In a sewing machine stitch-forming mechanism, a raceway having concentric grooves and an opening transverse to said grooves, two arcuate bands of difierent angular extent rotatable in said grooves, a rotatable driver-head partially encompassed by said bands, and means carried by said driver head arranged to engage both said bands as points at all times remote from the raceway openin In testimony whereof I hereunto set my hand in the presence of two subscribing witnesses.

VANDIVER J. VANIIURN. In the presence of Fomin BAIN, MARY l3. ALLEN.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G.