US3038428A - Stitching machines - Google Patents

Description

June 12, 1962 H, JUDET 3,038,428

STITCHING MACHINES Filed Jan. 16, 1959 3 Sheets-Sheet 1 In veh Hen/'4 jun/er 7 WM 9- qf'forneysj June 12, 1962 H. JUDET 3,038,428

- STITCHING MACHINES Filed Jan. 16, 1959 3 Sheets-Sheet 2 Imus/1753K WM {My M fifforg ys H. J UDET STITCHING MACHINES June 12, 1962 Filed Jan. 16, 1959 3 Sheets-Sheet 3 J7 ve/ 7'bk Hen/'1 Lei 8T Jiy W.

United States Patent Ofitice 3,@38,4Z8 Patented June 12, 1962 3,038,428 STITCHING MACHINES Henri Judet, Paris, France, assignor to Soeiete d Applications Generales dElectricite et de Mecamque S.A.G.E.M., Paris, France, a corporation of France Filed Jan. 16, 1959, Ser. No. 787,146 Claims priority, application France Jan. 20, 1958 7 Claims. (Cl. 112-37) This invention relates to sewing and stitching machines and more especially though not exclusively to lookstitching machines as used in particular for the stitching of soles on footwear.

Broadly speaking a sewing or stitching machine of the general "class to which the invention relates comprises a needle having a thread-engaging hook portion at an active tip thereof, drive mechanism for reciprocating said needle in a sequence of stitching cycles to bring said active tip into and out of work material, means operative at each cycle to present a thread at a looping station on one side of the work for engagement by said hook so as to be carried therewith through said work, and means operative thereafter at each cycle to pick off said thread at a stitch-forming station on the opposite side of the work to form a stitch. Further, said drive mechanism includes means operable on termination of a stitching process to arrest the reciprocation of the needle.

In a first type of machine of this general class, the stitch forming station is positioned on the vertical plane of the needle which is arcuate in form, while in another type the stitch forming station is positioned to one side, specifically the left side, from said plane, at a distance corresponding to the length of a stitch. In this latter type of machine, when the arresting means are operated on completion of a stitching operation, so that the needle is brought to a stop in a position overlying and disengaged from the work, the thread retained in the needle hook interferes with a ready removal of the work, eg a shoe, from the machine. The work cannot be removed sideways as would be most convenient, owing to the presence of the thread, but must be swung in an upward direction to disengage the thread from the needle hook. In my copending application U.S. Ser. No. 557,209, now Patent No. 2,981,214, granted April 25, 1961, means have been disclosed whereby withdrawal of the work from a machine of this kind is facilitated. It is an object of this present invention to provide an alternative form of means, in some ways more practical than said earlier means, for achieving a similar result. Broader objects of the invention are to provide improvements in sewing and stitching machines whereby the operation of the machine and handling of the work will be made easier and more efiicient, especially as regards the termination of a stitching operation.

In one aspect of the invention there are provided, in a machine of the type specified in the second paragraph of this specification, means operative in response to operatio not said needle-arresting means, for so modifying the reciprocation of the needle during an ultimate cycle of the stitching process prior to the instant at which said needle is finally brought to a stop that the thread-engaging hook of the needle cannot engage the thread as presented thereto at said looping station. It will be understood that owing to this provision, in said ultimate machine cycle, the needle performs the end phase of the cycle in an idle, thread-less condition, no thread being carried thereby through the work and towards said stitching station and such thread therefore will not interfer with an easy sideways withdrawal of the work.

The modification of the needle reciprocation during said ultimate cycle may assume the form of a reduction in the total angular range of reciprocation of the needle so that the needle in said ultimate cycle does not attain said looping station but will stop somewhat short of it, or it may assume the form of an upward shift of said range of reciprocation Without reduction of the amount of reciprocation, in a direction away from the looping station, so that here again the needle in the ultimate cycle will stop somewhat short of the looping station; in either case the needle, in the ultimate stitching cycle, does not attain the looping station and hence its hooked tip will not engage the thread, so that when the threadless needle finally comes to a stop above the work there is no thread to impede an easy sideways removal of the work.

Ad-vantageously the means for thus modifying the reciprocation of the needle in the ultimate cycle of a stitching process are operated in response to the conventional clutch and brake means provided for the purpose of arresting the reciprocation of the needle. Usually such clutch and brake means are arranged for operation by a foot-lever or pedal. Depression of this pedal at the start of a stitching operation first releases a brake and then acts to engage a friction clutch whereby drive power, egg. from an electric motor, is transmitted to the needle operating mechanism of the machine. When desired to terminate a line of stitches, the operator releases said pedal, whereupon the clutch is first released and the brake is then applied so as to block the machine components in a condition where the needle is disengaged from the work, the conventional presser foot is open, and the awl, whereprovided, is also disengaged from the work. In accordance with a preferred embodiment of the invention, this clutch-releasing and brake-applying movement at the end of the stitching process is utilized to alter the position of a pivot on which a rocker lever serving to reciprocate the needle is journalled, thereby foreshortening or shifting the range of reciprocation of said rocker lever and of said needle in the ultimate cycle to accomplish the result described above. The displacement of said lever pivot is advantageously efiected by means of a toggle linkage.

An exemplary embodiment of the invention will now be described for purposes of illustration but not of limitation with reference to the accompanying drawings, wherein:

FIG. 1 illustrates an assembly comprising an arcuate needle supported in its angularly reciprocable needle carrier, shown in the position where the needle is at the stitch-forming station and carries a length of thread about to be picked off for the formation of a stitch, i.e. during a normal stitching cycle;

FIG. 2 is a similar view of the same assembly with the needle in a similar position but in the ultimate cycle of a stitching process according to the invention, the needle being free of thread;

FIG. 3 is a view taken at right angles to FIG. 1 showing the needle at the lowermost point of its reciprocation during a normal or conventional stitching cycle, with the needle hook having just engaged the thread presented to it at the looping station;

FIG. 4 is similar to FIG. 3 but illustrates the needle at the lowermost point of its reciprocation during an ultimate cycle according to the invention, with the needle so positioned that it cannot engage the thread presented to it at the looping station;

FIG. 5 is a side view, partly in section, of the needle operating mechanism in the condition occupied by said mechanism during a normal stitching cycle;

FIG. 6 is similar to FIG. 5 but illustrates the condition assumed by the needle drive mechanism in an ultimate cycle according to the invention;

FIG. 7 is a sectional side view of a further part of the needle operating mechanism according to the present invention; and

3 FIG. 8 is a plan view with parts in section and parts broken away, generally corresponding to FlG. 7 and illustrating the cam means used in the invention for acting on the needle during an ultimate stitching cycle. I The sewing machine here illustrated is of a conventional type wherein the stitch forms to one side, specifically to the left side, of the plane of the needle. The sewing machine includes an arcuate needle 1 having an end hook or latch, and operating in a needle guide 2, which needle coacts in generally conventional fashion with an arcuate awl 3, a looper member 4, a thread hook 5, a pressed-foot 6, and a thread divider hook 7, these being the principal operating components all illustrated in FIGS. 1 to 6 and of more or less conventional construction. Further, an automatic braking system is provided, as shown more particularly in FIG. 8, which is adapted, on the operator releasing foot pressure on a clutch pedal, to arrest the machine in that position in its sewing cycle were both the needle and awl are disengaged from the work, as shown in FIGS. 1 and 2.

The needle operating mechanism is illustrated in FIGS. 5 and 6 as comprising a crankshaft 9 rotated from any suitable source such 'as an electric motor not shown and a connecting rod .10 extending therefrom and connected to imp-art an oscillatory motion to a rocker lever 11 journalled in a relatively fixed bearing 12, presently described in further detail.

Peivoted to the free end of the rocker lever 11 is an arcuate link 13 the free end of which is pivoted to a sectorshaped needle carrier 14 journalled on a pivot 15-, so that oscillation of lever 11 imparts an angular reciprocation to the needle carrier 14 and to the needle 1 fixedly carried therein.

In accordance with the invention, the journal 12 for the rocker lever 11 is pivoted on an excentric pivot 16 as shown. During normal stitching operation, the pivot 16 is maintained fixed in an upper position as shown in FIG. 5, whereby the rocker 1 1 imparts through link 13 and needle carrier .14 a reciprocation of constant amplitude to the arcuate needle 1, such that said needle, during each sewing cycle, is driven to a lowermost position sufficiently below the work to cause the end hook of the needle to engage under the thread which is being presented to it by the lopper member 4; this condition of engagement between the needle hook and the thread is illustrated in FIG. 5 and also in FIG. 3 However, in the ultimate stitching cycle, the pivot 16 is turned to a lower position as shown in FIG. 6 by means that will shortly be described. As a result the rocker lever 11 now imparts to the needle carrier and needle 1 an angular reciprocation about the pivot 15 within a modified angnilar range, such that the needle only reaches a lowermost position such as shown in FIG. 6, where its end hook cannot engage the thread from looper 3. This condition is illustrated both in FIGS. 6 and 4. Automatic mechanism will now be described for thus shifting the position of the rocker lever pivot 16 in the ultimate cycle of a stitching process.

The bearing 12 at the pivot end of the rocker lever 11 is carried at one end of a yoke-like lever 17 pivoted at 18 in the stationary frame of the machine. The lever 17 has a pivotal connection 19 with. a link 44 which is further pivoted at 2% to a lever arm 2l1 keyed on a rotatable shaft 22. This shaft further has keyed at another point of it a lever arm 23 the free end of which is formed with an elongated slot 24 which receives a pin projecting from a swivel link 25 of adjustable length having its opposite end pivoted at 216 to one end of a forked lever 27 (see FIG. 7) pivoted at 28, so that adjustment of the length of swivel link 25 and hence of the position of the end pin thereof within slot 214, will adjust the amplitude of oscillation of the lever 23. The forked lever 27 has another branch 29 (see FIG. 7) formed with a slot engaged around a pin 3 pivoted in an intermediate point of a slideway 3 1 of the brake system mentioned before. The slideway 31 is normally held in position abutting a stationary stop member 32 by the biassing action of a spring 33. The various levers and links described are adjusted at such relative setting, that in this normal abutting position of the slideway 3 1 the pivot point 19, 2t) and 2 2. are in alignment, as shown in FIG. 5, with a projecting heel 45- of the link 44 abutting a cooperating surface of the lever arm 21. In this position therefore, the lever .17 is blocked in a position wherein the pivot 16 is at its upper position shown in FIG. 5. The machine therefore will operate normally, with the needle hook engaging the thread from the looper to form a loop therefrom at each successive stitching cycle, as already explained above.

Slidable in a transverse bore of the slideway 31 a plunger 34 (FIG. 7) which is connected by way of linkage only part of which is shown, with the clutch pedal of the machine, not shown. The arrangement is such that so long as a foot pressure is maintained by the operator on the clutch pedal during a sewing process, the plunger is retained in a lowermost position against the biasing action of a spring 43, while on'release of the pedal the spring urges the plunger to an upper position.

A bellcrank lever 35 (FIGS. 7 and 8) isjournalled at 36 in the machine frame andoarries at the end of one of its arms 37 a follower roller 33 engaging a camway 39 formed peripherally of a dmm-type cam 40, yieldably mounted on the general drive shaft of the machine through means to be later described in detail. The lever 35- has its other branch 41 formed with an end socket 42; which is adapted, during reciprocation of the bellcrank lever 3-5 due to the cam action on rotation of the machine drive shaft, to assume at one point in each cycle a position overlying the top end of plunger 134-.

Thus, with the arrangement described, as the operator releases the clutch pedal to terminate a sewing operation, the plunger 34 is urged upwardly by the spring 43. At a predetermined instant of the cycle the lever 35 is brought to a position where its socket 42 is presented in register with the upper projecting end of the plunger 34 and the plunger enters said socket, whereby thebellcrank lever 35 becomes rigidly connected with the slideway 31. The bellcrank lever 35 is now in effect blocked by the engagement of the plunger in the socket 42. As the cam 40 proceeds to rotate with the driveor camshaft due to the rotational inertia of the assembly, it exerts pressure against the follower roller 38 due to the blocked condition of the lever arm 37 carrying said roller, so that the cam is constrained to move axially against a compression spring 46 interposed between it and an axially stationary thrust bearing of the shaft. As the cam 40 is thus axially depressed, a frustoconical clutch annulus 49 secured to the cam enters into frictional engagement with a complementary frustoconical clutch surface 47 formed internally of a gear annulus 47 which, through means not shown, is continually driven at a slow rate of rotation from the general drive of. the machine. -Due to the frictional engagement between clutch parts 47 and 49, the cam 40 is now positively driven in rotation in an appropriate direction during a final stage of the last cycle of operation, and in so doing it actuates the lever 35 to cause angular displacement thereof about the pivot 36 to displace the slideway 31 and the pivot 30 secured therein. This compresses a spring 33 while at the same time displacing the lever 27 about its pivot 28 so'that the lever arm 27 acts by way of the swivel link 25 and lever 23 to impart an angular displacement to the shaft 22. This angular movement of the shaft switches the toggle linkage formed by the lever 21 and link 44 from the aligned condition of FIG. 5 to the broken condition of FIG. 6, whereupon the rocker bearing pivot 16 is moved to its lower position.

It will be understood from the above that this breaking of the toggle linkage out of its aligned condition occurs by the action of the cam 40 at an accurately determined point in the last operative cycle, and the needle tip then moves past the looper member 3 above the path of the latter, as shown in FIG. 4, so that the needle cannot now engage the thread.

Since the cam 40 (FIG. 8) is still being driven by the gear annulus, the follower roller 38 carried by the lever 35 eventually reaches a position where it registers with a socket or notch 48 formed in the slideway 39. The lever 35 is now allowed to respond to the urge from the spring 33 as transmitted through the sideway 31, and is thereby displaced to release the cam 40. The came in turn is then moved by the spring 46 back into its abutting position out of engagement with the gear annulus 47.

The sewing machine now comes to a final stop and at the same time the slideway 31 on returning to its idle position acts by way of lever 27 to restore the toggle-pivots 19-20-22 into alignment, so that lever 17 is again latched in the normal sewing position (FIG. 5). The machine is now in condition for commencing another sewing operation.

It will be understood that various modifications may be made in the forms of embodiment illustrated and described without departing from the scope of the invention. The invention is applicable to various types of sewing or stitching machine capable of performing lock stitches, chain stitches and equivalent stitches, regardless of whether or not automatic braking means are provided.

What I claim is:

1. In a sewing machine having a curved needle the combination comprising a control mechanism for said needle giving it an angular movement about the center of its arc in a succession of sewing cycles to lead the active point of said needle into a piece to be sewed and to withdraw it therefrom, said needle comprising a book at the level of its active point in which the thread engages, means for presenting a thread to said hook when the latter reaches a loop at one of the sides of the piece to be sewed, thus bringing about the introduction of said thread into the hook and its entrainment across the piece up to the opposite side thereof towards .the place of sewing, means for engaging cyclically said thread in its sewing place, in order to form a stitch, and means for stopping the movement of the needle at the end of its sewing process, said means comprising a ball and socket joint arrangement which comprises a lever and a link, an oscillating lever connecting said link to the needle, said last-named lever being connected to the braking arrangement of said machine through the intermediary of a connecting system, the articulation of the oscillating lever upon said link, the articulation of said link upon the lever of the ball and socket arrangement and the articulation of the lever of the ball and socket arrangement upon the connecting system with the braking arrangement being placed according to the same alignment, while the sewing cycle, the means for the entrainment of said braking arrangement bringing about the placing out of alignment of said above three articulations and consequently the clearance of the oscillating lever and the displacement of the needle across its sewing course.

2. In a sewing machine having a curved needle the combination comprising a control mechanism for said needle giving it an angular movement about the center of its arc in a succession of sewing cycles to lead the active point of said needle into a piece to be sewed and to withdraw it therefrom, said needle comprising a hook at the level of its active point in which the thread engages, means for presenting a thread to said hook when the latter reaches a loop at one of the sides of the piece to be sewed, thus bringing about the introduction of said thread into the hook and its entrainment across the piece up to the opposite side thereof towards the place of sewing, means for engaging cyclically said thread in its sewing place, in order to form a stitch, and means for stopping the movement of the needle at the end of its sewing process, said means comprising a ball and socket joint arrangement which comprises a lever and a link, an oscillating lever connecting said link to the needle, said last- 6 named lever being connected to the braking arrangement of said machine through the intermediary of a connecting system, comprising a lever keyed at one of its ends to said lever of the ball and socket arrangement, a forked lever connected to one of the ends of said first lever, one branch of said forked lever being engaged upon an axis which pivots in the slide of the brake stop, the articulation of the oscillating lever upon said link, the articulation of said link upon the lever of the ball and socket arrangement and the articulation of the lever of the ball and socket arrangement upon the connecting system with the braking system extending along the same alignment during the sewing cycle, the entrainment means of said braking arrangement bringing about the placing out of alignment of said above three articulations and consequently the clearance of the oscillating lever and the displacement of the needle during its sewing course.

3. In a sewing machine having a curved needle the combination comprising a control mechanism for said needle giving it an angular movement about the center of its arc in a succession of sewing cycles to lead the active point of said needle into a piece to be sewed and to withdraw it therefrom, said needle comprising a hook at the level of its active point in which the thread engages, means for presenting a thread to said hook when the latter reaches a loop at one of the sides of the piece to be sewed, thus bringing about the introduction of said thread into the hook and its entrainment across the piece up to the opposite side thereof towards the place of sewing, means for engaging cyclically said thread in its sewing place, in order to form a stitch, and means for stopping the movement of the needle at the end of its sewing process, said means comprising a ball and socket joint arrangement which comprises a lever and a link, an oscillating lever connecting said link to the needle, said lastnamed lever being connected to the slide of the stop brake of the machine which is operated by freeing a finger by disengaging the pedal of the connecting gear and operating the stop brake of the sewing machine which engages in a recess provided in one of the branches of a lever which carries at the end of its other branch a roller which engages in the track of an eccentric cam entrained in a positive direction by a tangent wheel, and Whose rotation which corresponds to the end of the last cycle of sewing brings about the pivoting of said lastmentioned lever, which drives the slide of the stop brake of the machine, which slide brings about the placing out of alignment of the articulation of the oscillating lever which carries the needle upon said link, of the articulation of said link upon the lever of the ball and socket arrangement and of the articulation of the lever of the ball and socket arrangement upon the connecting system with the braking arrangement.

4. In a sewing machine having a curved needle the combination comprising a control mechanism for said needle giving it an angular movement about the center of ts arc in a succession of sewing cycles to lead the active point of said needle into a piece to be sewed and to withdraw it therefrom, said needle comprising a hook at the level of its active point in which the thread engages, means for presenting a thread to said hook when the latter reaches a loop at one of the sides of the piece to be sewed, thus bringing about the introduction of said thread into the hook and its entrainment across the piece up to the opposite side thereof towards the place of sewing, means for engaging cyclically said thread in its sewing place, in order to form a stitch, and means for stopping the movement of the needle at the end of its sewing process, said means comprising a ball and socket joint arrangement which comprises a lever and a link, an oscillatmg lever connecting said link to the needle, said lastnamed lever being connected-to the slide of the stop brake of the machine which is operated by freeing a finger by disengaging the pedal of the connecting gear and operating the stop brake of the sewing machine which engages in a recess provided in one of the branches of a lever which carries at the end of its other branch a roller which engages in the track of an eccentric cam entrained in a positive direction by a tangent wheel, and whose rotation which corresponds to the end of the last cycle of sewing brings about the pivoting of said lastmentioned lever, which drives the slide of the stop brake of the machine, which slide brings about the placing out of alignment of thearticulation of the oscillating lever which carries the needle upon said link, of the articulation of said link upon the lever of the ball and socket arrangement and of the articulation of the lever of the ball and socket arrangement upon the connecting system with the braking arrangement, the liberation of said finger being realized by the thrust of a spring which thrust is determined by the operation of the stop brake of the sewing machine.

5. In a sewing machine having a curved needle the combination comprising a control mechanism for said needle giving it an angular movement about the center of its arc in a succession of sewing cycles to lead the active point of said needle into a piece to be sewed and to withdraw it therefrom, said needle comprising a hook at the level of its active point in which the thread engages, means for presenting a thread to said hook when the latter reaches a loop at one of the sides of the piece to be sewed, thus bringing about the introduction of said thread into the hook and its entrainment across the piece up to the opposite side thereof towards the place of sewing, means for engaging cyclically said thread in its sewing place, in order to form a stitch, and means for stopping the movement of the needle at the end of its sewing process, said means comprising a ball and socket joint arrangement which comprises a lever and a link, an oscillating lever connecting said link to the needle, said last-named lever being connected to the braking arrangement ofisaid machine through the intermediary of a connecting system, comprising a lever keyed at one of its ends to said lever of the ball and socket arrangement, a forked lever connected to one of the ends of said first lever, one branch of said forked lever being engaged upon an axis which pivots in the slide of the brake stop, which slide is maintained in position of thrust by the action of a spring, during the normal operation of the machine, the articulation of the oscillating lever upon said link, the articulation of said link upon the lever of the ball and socket arrangement and the articulation of the lever of the ball and socket arrangement upon the connecting system with the braking systern being placed in the same alignment during the sewing cycle, said driving means of said braking arrangement bringing about the placing out of alignment of said three articulations and consequently the clearance of the oscillating lever and the displacement of the needle during the sewing course.

6. In a sewing machine having a curved needle the combination comprising a control mechanism for said needle giving it an angular movement about the center of its arc in a succession of sewing cycles to lead the active point of said needle into a piece to be sewed and to withdraw it therefrom, said needle comprising a hook at the level of its active point in which the thread engages, means for presenting a thread to said hook when the latter reaches a loop at one of the sides of the piece to be sewed, thus bringing about the introduction of said thread into the hook and its entrainment across the piece up to the opposite side thereof towards the place of sewing, means for engaging cyclic-ally said thread in its sewing place, in order to form a stitch, and means for stopping the movement of the needle at the end of its sewing process, said means comprising a ball and socket joint arrangement which comprises a lever and a link, an oscillating lever connecting said link to the needle, said last-named lever being connected to the braking arrangement of said machine through the intermediary of a connecting system, comprising a lever keyed at one of its ends to said lever of the ball and socket arrangement and comprising at its other end a slit for the regulation of the amplitude of said first-mentioned lever, in combination with a swivel joint link of regulatable length, and consequently regulating the movement of the needle, a forked lever, connected at one of its ends to said first lever and one of whose branches is engaged upon, an axis which pivots in the slide of the brake stop, the articulation of the oscillating lever upon the link, the articulation of the link upon the lever of the ball and socket arrangement, and the articulation of the lever of the ball and socket arrangement upon the connecting system with the braking arrangement being located in the same alignment, during the sewing cycle, means for driving said braking arrangement to bring about the placing out of alignment of the three mentioned articulations and consequently the clearance of the oscillating lever and the displacement of the needle during its sewing course.

7. In a sewing machine having a curved needle the combination comprising a control mechanism for said needle giving it an angular movement about the center of its arc in a succession of sewing cycles to lead the active point of said needle into a piece to be sewed and to withdraw it therefrom, said needle comprising a hook at the level of its active point in which the thread engages, means for presenting a thread to said hookwhen the latter reaches a loop at one of the sides of the piece to be sewed, thus bringing about the introduction of said thread into the hook and its entrainment across the piece up to the opposite side thereof towards the place of sewing, means for engaging cyclically said thread in its sewing place, in order to form a stitch, and means for stopping the movement of the needle at the end of its sewing process, said means comprising a ball and socket joint arrangement which comprises a lever and a link, an oscillating lever connecting said link to the needle, said last-named lever being connected to the slide of the stop brake of the machine which is operated by freeing a finger by disengaging the pedal of the connecting gear and operating the stop brake of the sewing machine which engages in a recess provided in one of the branches of a lever which carries at the end of its other branch a roller which engages in the track of an eccentric cam entrained in a positive direction by a tangent wheel, and whose rotation which corresponds to the end of the last cycle of sewing brings about the pivoting of said lastmentioned lever, which drives the slide of the stop brake of the machine, which slide brings about the placing out of alignment of the articulation of the oscillating lever which carries the needle by the hook upon said link, of the articulation of said link upon the lever of the ball and socket arrangement and of the articulation of the lever of the ball and socket arrangement upon the connecting system with the braking arrangement, the rep-lacing into the normal work position of the needle being carried out by replacing in alignment said articulations, obtained by the return to the abutment position of the slide due to the fact of stopping the sewing machine and by the return of said cam into the abutment position under the action of said forked lever.

References Cited in the file of this patent UNITED STATES lATENTS 1,500,688 Topham July 8, 1924 1,552,961 Schoenky ept. 8, 1925 1,716,561 Oliver June 11, 1929

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