US752398A

US752398A - kieffer

Info

Publication number: US752398A
Authority: US
Publication date: 1904-02-16
Anticipated expiration: 1921-02-16

Description

" PATENTED FEB. 16, 1904.

v J. L, KIBPFER. STITCH FORMING MECHANISM FOR SHOE SEWING monnms.

urmomron FILED JULY 14, 1902.-

4 EHEETS-SHEET 1 HO MGDEL.

CZVSQ/J/ Inventor,

V Attorneys i'HE cams PETERS co, Pnurau'mu. WASHINGION. 0. 12V

PATENTED FEB. 16, 1904.

J. LLKIEFFER. STITCH FORMING MECHANISM FOR SHOE SEWING MACHINES.

APPLICATION FILED JULY 14. 1902.

4 sums-sum 2; 7

Inventor,

(Jase 23 Kieffiaz:

mh n w NO MODEL.

Witn's'ses:

Attorneys No. 752,398. PATENTED FEB. 1-6, 1904. f

- J. L. KIEEPER.

STITCH FORMING MECHANISM FOR SHOE SEWING MACHINES.

APYLIOATIDH P ILED JULY 14 1902.

v 4 SHEETS-SHEET 3Q N0 MODEL.

F 05' ep/ /zffieff inventor,

By; t

Attorneys mus PETERS cu, vnoroumm. wAsnmdtQn n c PATENTEDIFEB. 1-6, 1904.

J. L. KIE ER; v i STITCH FORMING MECHANISM FOR SHOE SEWINGMAGHINBS KPPLIGATIDN FILED JULY 14. 1902.

4 SHEETS-BHBET 4.

hls.

Witnesses 0567M lalll sj yfr |nvent0fl Attorneys PETERS co PKDTULD'HOY. wnsumsrout n. c

Patented February 16, 19 04: I

I UN STATES PATENT OFFICE.

- ing in the city and district of Montreal, Prov- I shoe and leathermachinery, because of-the' formed in a given space-of time.

JOSEPH Louis KI-EFFER, or MONTREAL, CANADA.-

STITCH-FORMING MECHANISM FOR SHOE-:SEWING MACHINES.

SPECIFICATION formingrpart of Letters Patent No. 752,398, dated February 16, 1904;.

Application and July 14, 19 02. 1 stab No. 115,589. (No model.)

To all whom, it may concern." I

Be it known that I, Josnru Loms KIEFFER, a subject of the King of Great Britain, residince of Quebec, Canada, have invented certain new and useful Improvements in Stitch-Forming Mechanism for Shoe-Sewing Machines; l and I do hereby declare thatthe following is i a full, clear, and exact description of the inyehtion, such aswill enable others skilled in the art to which it appertains to make and use fibers of thread have to undergo a rubbing the same.

My invention relates to improved stitch-- forming mechanism adapted for shoe and leather. sewing machinery of that class known as the. outsole-stitcher, and especially that type forming the stitchknown. as ,a lock stitch,,wherein an upper or bobbin thread and a lower or machine thread are employed and interlocked one with the other. 7 The object of my present invention'is to produce an improved stitch-forming-mechanism of the revolving-hook class which shall em- .body all the advantages of the oscillating hook described inmy Patent No. 719., 980, dated Feb- 1 ruary 3, 1903, while at the same time embody- I ing the additional advantages which are inherent in the revolving-hook over. the oscillating-hook type of apparatus. The particular object had vention herein described. is to greatly increase the capacity of the machine by doubling or a tripling the number of stitches which may be A comparatively slow speed is necessarily inherent .in

Weight and momentum of the movingparts,

a much greater rate'of speed than an oscillating hook, because the motion is, comparatively speaking, continuous, whereas that of: the: os-

cillating hook requires to be reversed twice during the formation of each stitch. The inertia of the hook puts alimit,depending. on the strength and resistance of the materials, upon the rate of speed at which the hook travels, and hence the revolving hook can be run in View in the in- I at a much greater speed than the oscillating hook. V y

A further object of this invention is. to improve the motionof-the parts in carrying the thread over the bobbin, by. which friction between; the bobbin-case and the box in which it lies is, as far as possible, eliminated. That this is avery important feature ofshoe-sewing machines is a matter of experience with all those who have had occasion to test them,

because the number of times which the same action in being drawn over the bobbin is great in proportion to the amount of threadneces- I sary in order to form the drawn-out threadloop as compared with the finished stitch, and

this makes the question of friction byabrasion of the thread during the formation of the stitch an extremely important one. The difference is seen to a marked degree in comparing several of the differentmachines now on the market, because in some there is so great 'an abrasion of the thread (although thisis. not noticeable to the eye or to ordinary inspection) that the stitch cannot be drawn up tight without breaking the thread, and therefore a loose and inferior quality of work is the necessary result.

In my present invention I have so arranged the parts as to practically eliminate altogether the rubbing or bruising of thethreadbetween the bobbin-caseand the bracket which supports the same, except at a single pointduring the formation of-a stitch; l 7

my present inven It is a further ob'ect of tion to. eliminate altogether a veryimportant but hitherto. apparently unnoticed source of abrasion of the thread, which lies in the manner' in which the thread is removed from the barbed needle, which brings. up thethreadloop through the work. The inventions heretofore produced for delivering the thread from the needle and carrying it around the bobbin havenot had sufficient regard for the sharp edge of the barb of the needle whereby every:

time the thread was removed it was caused to rub or scrape over said barbed edge, and

thereby become abraded, and inasmuch as the same fibers were thus cut and abraded over nose, one limb of which is adapted to receive the thread, while the otherthat is to say, the outer limbis simply a guide to direct one lap of the thread-loop over the bobbin.v

These two limbs of the hook take the place,

respectively, of the recurved nose and of the body of the oscillating hook described in my former applications. The hook thus formed is attached to a rotating disk at the rear of the bobbin-case and in the center thereof, and on the edge of this disk, at a point just in advance of the nose of the hook, is formed a forwardly-projecting rim or flange which is adapted to serve partly as a shield to cover the point of the needle during the drawing up of the thread-loop by the take-up mechanism and partly to operate the bobbin-case to throw it from one side to the other in connection with the means for preventing the friction of the thread between the bobbin-case and bobbin-bracket, as will be presently referred to.

My invention also comprises a longitudinal or arcuate groove formed in the rear side of the hook, into which the needle is adapted to pass during the delivering of thethread-loop therefrom, combined with a certain cam movement whereby the hook is brought to a stop while the needle is passing into said groove and caused to start again only after the barb of the needle has completely entered the groove and the threadhas been completely delivered therefrom.

My invention further consists in the particular form of the inside surface of the bobbin-bracket, which is not, as heretofore was the case, a perfect surface of revolution fitting thebobbin-case all round, but is cut away all around except at three points equally or otherwise spaced around the inner periphery of the bracket, so as to support the bobbin-case from these three points only, but rather from two of these points only, the bobbin being arranged to rest on the bottom or lower of the three bosses or knobs thus formed and slightly also against one of the others, whereby the thread in passing over the bobbin cannot rub between the two surfaces at any more than two points from beginning to end. With this conformation, moreover, is conjoined a finger or trip extending inwardly from the threadhook or the disk by which it is carried, so as to strike against the bobbin and push it over from one side to the other in advance of the thread, and thereby just before the thread passes between the bobbin case and bracket at a point of contact of the two they are caused to be separated, so that the thread passes through without friction, and the same operation is performed at the other side of the center. This operation will be understood more clearly from the accompanying drawings and description.

My invention further consists in the peculiar construction and combination of parts, which will be hereinafter described, and more particularly pointed out in the claims.

As many of the features of my present invention can be equally well applied to the oscillating thread-hook formerly invented by me, I have illustrated the oscillating threadhook in conjunction with the rotating hook to show the application of these features.

The elements and construction of my invention in its most improved form and modifications are shown in the accompanying drawings, in which Figure 1 1s a side elevatlon of the new form of revolving thread-hook in the act of formthread-loop is being delivered from the needle.

Fig. 3 shows the third step in the formation of the stitch,in which the thread-loop is being car'- ried over the bobbin. Fig. 4 is a similar view to Figs. 1, 2, and 3, but showing the'fourth stepin' the formation of a stitch, in which the thread is being cast off and the stitch drawn up by the take' up mechanism. Fig. 5 is a similar view showing the last step in the formation of the stitch. Fig. 6 is a central vertical transverse section through the stitch-forming mechanism, the parts being in the position shown in Fig. 1. Fig. 7 is a similar view to Fig. 6, the parts being in the position shown in Fig. 2. Fig. 8 is a similar view showing the parts in the same position as in Fig. 4:. Fig. 9 is a perspective view of the thread-hook from the front side. Fig. 10 is a similar view of the hook from the rear side. Fig. 11 is a perspective View of an oscillating thread-hook having my invention applied thereto. Fig. 12 is a front elevation,.on an enlarged scale, of a modified form ofistitch mechanism, showing more distinctly the method of operating the bobbin-case. Fig. 18 is a similar view of the same device as in Fig. 11, illustrating a subsequent step in the formation of a stitch.

Fig. 14 is a perspective view of the bobbinbracket from the rear side. Fig. 15 is a side elevation of parts of a machine embodying my improvements in situ, the rotating hook being shown in central section to illustrate the timing of the relative movements of the thread-hook and needle; and Fig. 16 is a velocity-diagram of the movements of the hook. The same numerals of reference denote like parts in all the figures of the drawings.

In the drawings, designates a block, as of metal, which is herein called the threadhook block, because it serves to support the thread-hook and the other operative parts of the stitch-forming mechanism. This block is supposed to besecured on thework-head of the machine and is not fully shown herein, because its form is a matter of indifierence' to the present invention, although that shown in my previous application, Serial No. 105,493, filed May 1, 1902, is an appropriate form. This block 15 is formed with a shallow cylindrical recess 16 in its front face, in which operates the revolving hook 17, which is formed as an arcuate extension of the thread-hook disk 18, mounted to rotate upon a spindle 19, which passes through the "rear side of the block 15. The thread-hook disk 18 forms the secured by bolts 21 to the block 15, and having a depending annular portion 22, which serves to loosely confine the bobbin-case 23, this case being, as shown in Figs. 6, 7, and

and then against the other.

8, of a double-conical form having a surface of revolution with a sharp elbow 24, which is. adapted to divide the thread-loop. The

front face of the bobbin-case 23 is left open by means of the central aperture 25, formed in the bobbin-bracket. bobbin-bracket is of roughly-conical form, corresponding to the exterior surface of the bobbin-case; but it has not a surface of revolution, because, as shown, it has three irregu- 'larly-spaced bosses thereon, (designated, re-

spectively, '27, 28, and 29.) It is on these three 'bos'ses that the bobbin-case 23 rests; but it;

The inner side 26 of this does'notrest on all three at once, because it is loose within the box and has a considerable amount of play and is caused to be thrown from side to side by the motion of the threadhook in a manner which Will be described. 'The lowermost boss 27 forms a constant resting-point for the bobbin-case; but the other twobosses 28 and 29 are merely buffers which that the bobbin-case rests first-against one The

bosses

28 and 29 are not at equal distances from the bottom boss 27; but, as shown, the boss 28 on the right or rising side of the thread-hook is about ninety degrees from the boss 27, whereas the other boss, 29, on the left or descending side of the thread-hook is about one hundred and sixty degrees from the boss 27. i The ring 22 of the bobbin-bracket has also a notch 30 in the center of the boss 27, which coacts with a depending lip 31, formed on the bobbin-case, to prevent the same from rotating slipped easily thereover and to pass out from between the bobbin case and bracket.

Before describing further the mode of operation of the thread-hook in connection with the bosses 27, '28, and 29 and the bobbin-I case I will describe the general form and mode of operation of my improved revolving thread-hook, which is shown in Figs. 1 to 8, inclusive, and in enlarged perspective view in Figs. 9 and. 10. The disk 18 has at the center thereof a bored-hub 32, through which passes the shaft 19, which projects at the rear ofthe block 15, and has also mounted thereon back of the hub 32 a screw-gear pinion 33, having a long bearing-sleeve 34 projecting into the bearing-block 35, secured on the work-head of the machine, and the several parts are clamped up together on the shaft 19 by means of lock nuts 86 passing over the screw-threaded end 37 of the shaft. In order to tighten the lock-nuts 36 in place, I preferably recess the end of the shaft 19 and split thesame laterally, as by cuts 37, and insert in the recessed end a wedge-screw 37 The screw-gear and thread-hook disk are also prefably-keyedtogether in proper relative position by any suitable means, such as interlocking lugs 38. v

WVith the screw-gear pinion 33 coacts a similarly-formed pinion 39, whose shaft 10 is at right angles to the shaft 19, but does not intersect the same, and the shaft 41-0 is kept in continuous but irregular rotation by means of suitable 'cam mechanism, 'so as to give the proper motions, which will be hereinafter described, to the thread-hook 17 in its rotation.

The thread-hook 17 is formed, as shown, with a double forwardly-directed nose having two limbs, (designated, respectively, 11 and ea) the upper of which, 11, is the effective or operative limb, which serves to remove the thread-loop from. the needle and carry it around'the bobbin, while the lower limb, 12,

of the nose is somewhat shorter than the limb 11 and has its forward end directed somewhat backwardly, so that it is inserted behind the rear lap of the thread-loop and serves to push it out and cause it pass through the bight or slot -13 between the two limbs of the hook.

The book 17, behind the junction of the two

limbs

11 and 42, has a reduced neck 44:, which serves to permit the easy passage of the thread over the bobbin in a manner which will be which form a part of my invention.

of the cam motions given to the hook and needle, respectively, in such a manner as to leave the thread-loop clear of the barb of the needle without causing abrasion on the sharp edge of the barb, and the particular motions by izvhich this result is produced will be described ater.

The front side of the thread-hook disk 18 is dished out to form a shallow recess 47, having conical sides and corresponding to the shape of the bobbin-case, so'as to allow the same to sit loose therein; but it only touches the bobbin-case normally at one pointthat is to say, the point designated herein, 48-which is in the shape of a slightly eccentric heel formed just in advance of the point of the upper limb 41 of the hook. The object of this is to push the bobbin-case at all times into a position.

farthest from the point of the hook, and with it coact the three

bosses

27, 28, and 29, so as to push the bobbin-case over first to the left and then to the right as the hook revolves. In advance of the heel 48 is formed an outwardlyprojecting rim 49, which forms a shield or guard for the barb of the needle during the drawing up of the thread-loop after its passage around the bobbin and to prevent the loop from becoming entangled with the needle.

In Fig. 15 I have shown in side elevation and partly in section the hook and needle, together with their cams and cam-levers, in order to illustrate the interaction of theparts At 61 is shown the main shaft of a shoe-sewing machine of any suitable type, on which shaft is keyed a cam-block 62 by means of the keyv 63. This cam-block has a cam-groove on each side, (designated 64 65,) in which work the rollers 66 67 of a pair of interacting cam-levers 68 69, which are pivoted on pins 70 71, the former of these levers being arranged to occupy a generally vertical position and the latter a horizontal. On the end of the shaft 40 is formed a crank 72, having a pin 7 3, on which is pivoted the end of a link 74, which is joined by a pivot-pin at an intermediate point thereof to the end of the lever 69, while its upper end is connected by a link 76, pivoted at 77 to the upper end of the lever 68. The formation of the cam-grooves 64 65 is such as to cause the crank 72 to rotate continuously in one direction, being counter-- clockwise, as shown by the arrow in Fig. 15, the shaft 61 also rotating in a counter-clockwise direction, and not only this, but the formation of the cam-grooves 64 65 is such as to impart a variable rotative speed to the crank- 72, and hence to the thread-hook, the variaat the back of the machine (herein shown as coaxial with the pin 71) and is operated by a roller 83, mounted on it at an intermediate point and running in a cam-groove 84 in the side of another camblock behind the camblock 62, as is usual in such machines. At 85 is shown a needle-guide which embraces the stem of the needle and at 86 the table on which the work rests, these being customary parts of the mechanism and forming no part of the present invention.

The mode of operation of' my improved rotating hook may be described as follows: The bobbin-case, mounted in its box, rests loosely against the lower boss 27 of the bracket, in which position it is slightly below the axis of the revolving hook. Supposing now the thread-hook (which in the present drawings rotates in a counter-clockwise direction, as shown by the arrows) to be in the position shown in Fig. 1, in which the needle has reached the top of its stroke, carryinga threadloop 50 through the work 51. The point 41 of the hook is so positioned as to enter between the two laps of this loop in the manner shown in Fig. 1, and as the motion of the hook proceeds the lower limb 42 of the hook passes beneath and behind both laps and causes the rear lap to be inserted into the bight 43. When the hook has reached the position shown in Fig. 2, its motion ceases for an instant, and during this period of rest the needle moves forwardly and enters the groove 45, having previous to that time remained outside this groove. The advance of the needle is sufficient to entirely deliver the thread-loop therefrom, leaving it cast off the barb of the needle onto the limb 41 of the hook, (see Figs. 7 and 15,) and after this cast-ofl movement has been accomplished, which occupies but an instant, the hook moves forward again and carries the loop around the bobbin in the manner indicated in Fig. 3, the two laps of the loop passing, respectively, on opposite sides of the bobbin, which is enabled to take place by means of the reduced neck 44. It will be observed, further, that the ring 26 of the bobbin-bracket has on its inner right side adjacent to the boss 27 a slight nick or recess 51, which further enables one lap of the threadloop to pass around the bobbin without excessive friction. Further,.it will be noticed that when the thread-hook reaches the position shown in Fig. 2 and after that the heel 48 thereof will strike against the bobbin-case and throw it over, so as to cause it to rest against the boss 29, as indicated, and in this case the thread can pass between the boss 28 and the bobbin-case without touching the former. When, however, the hook reaches the position shown in Fig. 3, the heel 48 now strikes the bobbin-case from the other side and throws it back so as to rest against the boss 28, and the boss 28 having been now passed the thread can likewise pass the boss except at a single point-that is to say, at the 1 lower boss'27, on which the bobbin-case is supported. i

In Fig. 16 is given a velocity diagram to illustrate the velocity of the thread-hook at each point of its revolution. The thread-hook is shown, at the center of the diagram in its zero position, thezero-point being taken on a line 87, extending vertically downward from the central point 0. The velocity of the thread-hook at any point of its revolution is indicated by that portion of a radius-vector included between the circle 88 and the curve 89; The numerals, ranging from 1 to 20 on the outside of the circle 88, represent equal angles passed through by the thread-hook, the corresponding'abscissas representing velocity being drawn in each case. On the inside of the circle is a second series of numerals 1 to 20, which represent the positions of the hook at equal intervals of time. The positions of these angles are taken for a point on the hook lying in the line 87 in the zero position.

It will be seen from the diagram that the motion of the hook starting from the zero position increases uniformly up to the position 7 and from there decreasesagain to the position 14, this being during the operation of carrying the thread over the bobbin after the same has been released from the needle, and which, therefore occupies but about fourtwentieths of the time of a complete cycle. At theposition 14 the hook becomesnearly or quite stationary, giving time for the successive operationof the take-up, the feed mechism, the needle, and the looper, this occupying.

about twelve-twentieths of the timeof a complete cycle, and at the end of this time the thread-hook again advances as rapidly as possible to its zero position, where it comes to a stop long enough to allow the needle 59420 move forward into the groove 45, as already explained, and cast off the thread-loop drawn up by it during the time interval4to 16, whereupon another cycle is commenced. It will be seen that at the zero-point a small loop is 1 formed in the curve 89 within the circle 88,

indicating that a small backward motion may be given to the hook, if found desirable, during the period 18 to 20, which will absolutely secure that the thread-loop is pressed against the stem of the needle during the time that the latter is entering the groove 45, or to counteract the tendency of the thread-hook to a slight torsional bending due to the sudden checking of its forward momentum, By

following out thecam-

grooves

64, 65, and 84 it will be seen that they are so arranged as to give the thread-hook the motion illustrated in Fig. 16, and also during the interval 4' to 16 to advance the needle and again retract it to its highest position, and then to slightly again advance it in the interval 18 tofZO. The

thread-hook is shown as having a very slow advance movement during the period 14 to 17, it being limited in its advance to the position 17 up to the end of the time interval 16 order to give time for the needle to return to its original position, carryingthe thread-loop before the point of the thread-hook crosses the needle.

It will be understood that the motion of the thread-hook thus described is practically continuous and nearly uniform, except at two pointsthat is to say, in the position shown in Figs. 4 and 5 and in that shown in Fig. 2.. In the former of these it stops or is retarded during a short interval to give time for the thread to be taken up and also for the advance of the needlethrough the work to form an additional thread-loop. In the second position it stops to enable the loop carried by the needle to be cast off without any abrasion of the thread against the barb. The latter is.

an important featureof this invention inasmuch as all previous devices for delivering the thread-loop from the needle have entirely overlooked this point or have failed to solve it satisfactorily, so that the thread was carried off the barb of the needle so as to scrape or rub thereon, and thereby cause the fibers of the thread to become broken. The instantaneous stoppages of the thread-hook, however, are comparatively unimportant when considered in connection with the oscillating book, because the latter had not only to be stopped at a certain point in its motion, but it had additionally to have its motion reversed twice in a single cycle, and the reversal of so heavy a part necessarily requires time. In

consequence I find that I can operate my pres- 'ent revolving hook at a much greater speed than the oscillating book, so as to form from six to eight hundred stitches per minute. As,

as described in my former application, consists of a forwardly-directed point 53, a recurved nose 54 behind the point, and a grooved tail-shield 55. A groove 5'6 is also formed in the rear face of the hook, into which a needle passes in the operation of delivering the thread from the needle. In this case just behind the nose 54 is provided a triangular hump 57 cient distance below the axis of the threadhook to enable the hump 57 to pass over thetop thereof. The operation of this form of the device is precisely similar to that first described, because the hump 57 takes the place of the heel 48 and serves the same function of tipping over the bobbins lightly in advance of the hook.

While I have shown in the accompanying, drawings the preferred form of my invention, it will be understood that I do not limit myself to the precise form shown, for many of the details may be changed in form or position without affecting the operativeness or utility of my invention, and I therefore reserve the right to make all such modifications as are includedwithin the scope of the following claims or of mechanical equivalents to the structures set forth.

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

1. In a stitch-forming mechanism for shoesewing machines, a thread-hook comprising a forked nose, one limb of which is adapted to enter and deliver the thread-loop from the needle, and the other to guide the rear lap of theloop into the bight of the hook.

2. A stitch forming mechanism for shoesewing machines comprising a barbed needle adapted to enter the work and bring up a thread-loop therethrough, and a continuouslyrotating thread-hook having a forwardly-directed forked nose, the inner limb ,of which is longer than the outer and is adapted to enter the thread-loop and deliver it from the needle, andthe outer limb of which is adapted to push forward both laps of the thread-loop and cause the rear lap to fall into the bight of the hook.

3. A stitch forming mechanism for shoesewing machines comprising a barbed needle adapted to enter the work and bring up a thread-loop therethrough, and a continuouslyrotating thread-hook having a forwardly-directed forked nose, the inner limb of which is longer than the outer and is adapted to enter the thread-loop and deliver it from the needle, and the outer limb of which is adapted to push forward both laps of the thread-loop and cause the rear lap to fall into the bight of the hook, said upper limb of the hook having a groove in its inner face into which the needle is adapted to pass.

4. A stitch forming mechanism for shoein its rear face into which the needle is adapted to pass, means for rotating the hook and stopping the same at a point wherethegroove is opposite the needle, means for thereafter causing the needle to enter the groove while the hook is stationary and leave the thread on the hook, and means for thereafter continuing the rotation of the hook, substantially as described. v

5. A stitch-forming mechanism for shoesewing machines comprising a barbed needle adapted to enter the work and bring a threadloop therethrough, a rotating disk forming the rear of a bobbinbox, a bobbin-bracket closing the front of said box, a bobbin loosely mounted in said box, a thread-hook having a forwardly directed forked nose extending from the periphery of said disk, .the upper limb of said nose being adapted to enter the thread-loop and deliver it from the needle, and the lower limb being adapted to push back the rear lap of the loop, and a shield adapted to cover the point of the needle subsequent to the casting off of the thread-loop and during its drawing up by the take-up motion.

6. A stitch-forming mechanism for shoe-- sewing machines comprising a barbed needle adapted to enter the work and bring a threadloop therethrough, a rotating disk forming the rear of a bobbin-box, a bobbin-bracket closing the front of said box, a bobbin loosely mounted in said box, a thread-hook having a forwardly' directed forked nose extending from the periphery of said disk, the upper limb of said nose being adapted to enter the thread-loop and deliver it from the needle, and the lower limb beingadapted to push back the rear lap of the loop, and a shield adapted to cover the point of the needle subsequent to the casting off of the thread-loop and during its drawing u by the take-up motion, the upper limb of said thread-hook having a groove in its rear face into which the needle is adapted to enter and to leave the thread-loop on the hook.

7. A stitch-forming mechanism for shoesewing machines comprising a barbed needle adapted to enter the work and bring up a thread loop therethrough, a rotating disk forming the rear of a bobbin-box, a bobbinbracket closing the front of said box, a bobbin loosely mounted in said box, a threadhook having a forwardly-directed forked nose extending from the periphery of said disk,

the upper limb of said nose being adapted to enter the thread-loop and deliver it from the needle, and the lower limb being adapted to push back the rear lap of the loop, a shield adapted to cover the point of the needle subsequent to the casting oif ofthe thread-loop and during its drawing up by the take-up motion, the upper limb of said thread-hook having a groove in its rear face into which the needle'is adapted to enter and to leave the thread-loop on the hook, means for rotating 7 the hook continuously in one direction, means 8. Inastitch-formingmechanism, in combination, a bobbin -case, a circularly-moving member adapted to carry a thread thereover and a bobbin-bracket supporting the case, the adjacent surfaces of the bobbin case and bracket being so conformed to each other. as to touch in only three possible points, so situated with respect to each other that each point lies on the opposite side of a diameter from the other two. 7

9. In a stitch-forming mechanism for shoesewing machines, in combination with a bobbin-case, a bobbin-box, and the hook, of a bob bin-bracket having a ring forming the cover of the bobbin-box, said ring being cut away on its inner surface to form three bosses on the lower one of which the bobbin-case is adapted to rest, and against the upper two of which the bobbin-case is adapted to rest alternately. I

10. In a stitch-forming mechanism,the combination of a bobbinbox, a bobbin-case loosely mounted therein, the hook and a bobbinbracket forming the cover of said box and having three raised points around its periphery,

upon one of which the bobbin-case is adapted to be supported, and against one of the other two of which the bobbin-case is adapted to alternately rest.

l 1. In a stitch-forming mechanism,the combination of a bobbin box, a bobbin-case loosely mounted therein, a bobbin bracket forming. the cover of said box and having three raised points around its periphery, upon one of which the bobbin-case is adapted to be supported, and against one of the other two of which the bobbin-case is adapted to alternately rest, and means for throwing the bobbin-case first to one side and then to the other in advance of the passage of the thread between said raised points and the bobbin-case.

12. A stitch-forming mechanism for shoesewing machines comprising a barbed needle adapted to enter the work and bring a threadloop therethrough, a thread-hook block having a shallow cylindrical groove therein form ing the bobbin-box, a thread-hook adapted to move around the periphery ,of said box, a

bracket formingrthe coverof said box, a circular bobbin-case loosely mounted 111 said box, a

recess therein forming a bobbin-box, a spindle passing through the rear of said block in the center of said recess, meansfor unevenly r0 tating said sp1ndle,'a disk mounted on the foran arcuate thread-hook mounted on said disk and having aforWardly-directed forked nose, the inner limb of said nose being longer than the outer, a bobbin-bracket having a ring closing the front of said bobbin-box, a bobbincase loosely mounted in said box, means for preventing said bobbin-case'from rotation, and a shield adapted to cover the barbed needle during the drawing up of the thread-loop.

14. A stitch-forming mechanism for shoe and leather sewing machinery comprising a ward end of ,said spindle within said recess and forming the rearface of said bobbin-box,

an arcuate thread-hook mounted on said disk and having a forwardly-directed forked nose, the inner limb of said nose being longer than the outer, a bobbin-bracket having a ring closing the front of said bobbin-box, a bobbincase loosely mounted in said box, means for preventing said bobbin-case from rotation,

, ward end of said spindle within said recess and forming the rear face of said bobbin-box,

IIO

said bobbin-bracket having a series of three 15. A stitch-forming mechanism for shoe and leather sewing machinery comprising a thread-hook block having a shallow cylindrical recess therein forming a bobbin-box, a spindle passing through the rear of said block in the center of said recess, means for unevenly rotating said spindle, a disk mounted on the forward end of said spindle within said recess and forming the rear face of said bobbin-box, an arcuate thread-hook mounted on said disk and having a forwardly-directed forked nose, the inner limb of said nose being longer than the outer, a bobbin-bracket having a ring closing the front of said bobbin-box, a bobbincase loosely mounted in said box, means for preventing said bobbin-case from rotation, said bobbin-bracket having a series of three raised points or bosses on its inner periphery which serve as supports and stops for said bobbin-case, and an eccentric heel or hump carried by said thread-hook and adapted to strike against the side of the bobbin-case for throwing the bobbin-case over to the side farthest from the nose, whereby the thread is permitted to pass over the bobbin-case without friction between it and its supports, substantially as described.

16. A stitch-forming mechanism for shoesewing machines comprising a thread-hook block having a shallow cylindrical recess therein,-a shaft passing through the rear of the block in the center of the recess, means for unevenly rotating said shaft continuously in one direction, a thread-hook disk secured on the forward end of said shaft within said recess and having a dished front face adapted to conform with the shape of the bobbin-case and to form the back of the bobbin-box, a bracket coacting with said disk to form the cover of said bobbin-box and having a ring adapted to surround the bobbin-case, a bobbin-case loosely mounted between said disk and ring, a series of three raised points respectively at the bottom and on opposite sides of the inner periphery of said ring on the first of which the bobbin-case is supported and against one of the other two of which the bobbin-case rests alternately, a thread-hook having a forwardly-directed nose adapted to enter the thread-loop and deliver it from the needle, a barbed needle coacting with said thread-hook, and an eccentric heel or hump in advance of said thread-hook, whereby the bobbin-case is thrown over in advance of the passage of the thread thereover to cause it to" pass between it and its supports frictionlessly.

17. A'stitch-forming mechanism for shoesewing machines comprising a thread-hook block having a shallow cylindrical recess therein, a shaft passing through the rear of the block in the center of the recess, means for unevenly rotating said shaft continuously in one direction, a thread-hook disk secured on the forward end of said shaft within said recess and having a dished front face adapted to conform with the shape of the bobbin-case and to form the back of the bobbin-box, a bracket coacting with said disk to form the cover of said bobbin-box and having a ring adapted to surround the bobbin-case, a bobbin-case loosely mounted between said disk and ring, a series of three raised points respectively at the bottom and on opposite sides of the inner periphery of said ring on the first of which the bobbin case is supported and against one of the other two of which the bobbin-case rests alternately, a thread-hook having a forkedforwardly-directed nose, the inner limb of which is longer than the upper and provided with a groove in its rear face, a barbed needle adapted to enter the work and bring a thread-loop therethrough and to coact with said hook, means for advancing said hook to a point opposite said needle and then momentarily stopping said hook, means for subsequently advancing the needle into said groove a suflicient distance to clear the loop from the barb thereof and leave it on the hook, means for thereafter advancing the threadhook and carrying the loop over the bobbin, and an eccentric heel or hump adapted to strike againstsaid bobbin-case slightly in advance of the hook and throw it over so as to permit the thread-loop to pass between the bobbin-case and its supports frictionlessly.

In witness whereof I have hereunto set my hand in the presence of two witnesses.

JOSEPH LOUIS KIEFFER.

Witnesses:

J. A. MARION, T. MYNARD.