US3763804A

US3763804A - Method and apparatus for threading yarn ends into the working needles of embroidery stitching and sewing machines

Info

Publication number: US3763804A
Application number: US00244206A
Authority: US
Inventors: R Reich
Original assignee: Individual
Current assignee: Individual
Priority date: 1971-04-29
Filing date: 1972-04-14
Publication date: 1973-10-09
Anticipated expiration: 1990-10-09
Also published as: DE2121223B2; CH547381A; JPS5529719B1; IT958760B; AT316970B; FR2136776A5; DE2121223A1; DD97240A5

Abstract

The invention concerns a method and an apparatus for threading of yarn ends into the working needles of embroidery, stitching and sewing machines. This is achieved by clamping the end of the yarn which is to be inserted, to the open end of a compressed air channel; the end of this channel is connected to a hollow needle bar, and, after its release, the yarn is guided by compressed air through the hollow needle bar to a threading loop which can move through the eye of the needle.

Description

United States Patent 1 Reich METHOD AND APPARATUS FOR THREADING YARN ENDS INTO THE WORKING NEEDLES OF EMBROIDERY STITCIIING AND SEWING MACHINES [76] Inventor: Rudolf Reich, 545 An der Ringstr.

6, Neuwied, Germany [22] Filed: Apr. 14, 1972 [21] Appl. No.: 244,206

[30] Foreign Application Priority Data Apr. 29, 1971 Germany P 21 21 223.7

[52] US. Cl. 112/225' [51] Int. Cl D05c 11/00, DOSb 87/02 [58] Field of Search 112/78, 80, 83,98,

[56] References Cited UNITED STATES PATENTS 2,413,014 12/1946 Wall ..112/225 .'1 I ii Oct. 9, 1973 2,767,671 10/1956 Shapiro 112/225 3,508,690 4/1970 Pozzolo.... 223/99 3,540,392 11/1970 Kaplan 112/225 Primary Examiner-'Werner Schroeder Att0rneyMichael P. Breston [57 ABSTRACT The invention concerns a method and an apparatus for threading of yarn ends into the working needles of embroidery, stitching and sewing machines. This is achieved by clamping the end of the yarn which is to be inserted, to the open end of a compressed air chan-.

nel; the end of this channel is connected to a hollow needle bar, and, after its release, the yarn is guided by compressed. air through the ho1low needle bar to a threading loop which can move through the eye of the needle. I

11 Claims, I8 Drawing Figures PATENTED UB1 9 5 SHEET 30F 7 F ig.13

PATENTEU BET 91973 SHEET 7 [IF 7 C") CD METHOD AND APPARATUS FOR THREADING YARN ENDS INTO THE WORKING NEEDLES OF EMBROIDERY STITCHING AND SEWING MACHINES BACKGROUND OF THE INVENTION In known machines of this kind the yarn ends are threaded through the eye of a working needle with great manual effort when the machine is at standstill. In some cases small accessories such as threaders are used for this purpose. Experienced operators can undertake this work in the case of large slow embroidery machines while the machine is running. This is no longer possible when the machines make more than l80 stiches per minute. In most cases the machines must be stopped. This, however, in addition to loss of production also leads in many cases to new faults on re-engagement of the machine when the machine becomes out of step.

While the loss of production and expenditure of labor due to pulling individual thread ends through the eye of the needle may still be within acceptable limits and no appreciable increase in cost of the embroidered fabric occurs, the situation changes considerably when the whole machine must be set up for a new yarn for reasons of color, gauge or kind of material. In machines which have up to 1,000 yarns this means a production loss of up to a whole working shift in which, in many cases, several persons must carry out the changeover work.

This changeover process occurs frequently in embroidering owing to the variety of fashions and always i at irregular time and event intervals.

It is an object of the invention to solve the problem of pulling individual yarns through the eye of the needle while the machine is running by means of a simple arrangement without using the assistance of specialists. In addition the loss of production, due to changeover of all the yarns of a machine from one color, yarn gauge and yarn quality to another, when the machine is at a standstill, is reduced to a minimum, in accordance with this invention, by the use of a pneumatic threading arrangement. At present this takes about 7 hours in the case of a machine with 1,000 yarns. In addition the pneumatic threading arrangement according to the invention will always remove yarn residues, lint and debris from the point of contact with the needle yarn, at the given embroidering position. Finally a straighter path of the yarn through the embroidering head markedly reduces the friction resistance, which is highly advantageous for the running behavior of the yarn.

SUMMARY OF THE INVENTION According to the method of the invention the object is achieved by clamping the end of the yarn which is to be inserted, to the open end of a compressed air channel; the end of this channel is connected to a hollow needle bar, and, after its release, the yarn is guided by compressed air through the hollow needle bar to a threading loop which can move through the eye of the needle. The threading loop is then retracted in the usual manner through the eye of the needle to complete the threading of the yarn.

The laborious and time-consuming manual threading is eliminated and the threading can be carried out very rapidly through the hollow needle bar by compressed air. Since the yarn passes through the hollow needle bar the yarns runs also through the embroidering head almost in a straight line without any appreciable deflections or changes of direction. This considerably reduces the frictional resistance; yarn breakage due to such bends is practically eliminated.

The apparatus for carrying out the method has a hollow needle bar which can slide in the embroidering head; this needle bar is held in the embroidering head by a release pawl. The needle end of the needle bar is provided with a tubular channel which is directed to a threading loop which can be inserted through the eye of the needle. The threading device which can be attached to each embroidering head has a coupling for the retracted needle bar in the form ofa needle bar nipper defining an air channel. The air channel is coupled to a compressed air line with adjustable compressed air supply.

Hence the invention consists of two parts: an embroidering head which has a hollow needle bar, and a threading device which can be attached to each embroidering head for supplying compressed air for feeding the yarn. The threading device is preferably pistol shaped.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a cross-sectional view of the front part of the embroidering head through the needle bar and the threading bar;

FIG. 2 shows a cross-sectional view of the rear part of the embroidering head through the needle bar and the threading bar;

FIG. 3 shows a cross-sectional view of the embroidering needle with the threading loop inserted;

FIG. 4 shows a cross-sectional view of the embroidering needle with the threaded loop retracted;

FIG. 5 shows the embroidering head viewed from the fabric side with the retracted threading loop;

FIG. 6 shows the embroidering head viewed from the fabric side with the inserted threading loop;

FIG. 7 shows the embroidering head viewed from the yarn guide side with the threading bar in the retracted position;

FIG. 8 shows the embroidering head viewed as in FIG. 7 with the threading bar in the inserted position;

FIG. 9 shows a side elevation view of the front part of the threading device in partial longitudinal section;

FIG. 10 shows the rear part of the threading device in side view, partly in section;

FIG. 11 shows the front part of the threading device in plan view and the adjoining part of the embroidering head in section;

FIG. I2 shows a transverse section of thecoupling I arrangement between the embroidering head and the threading device;

FIG. 13 is a transverse section through the frontal part of the threading device along line BB in FIG. 9; FIG. 14 is a transverse section along the line CC in FIG. 10;

FIG. 15 shows a side view of a modified model of the needle head with an embedded embroidering needle;

FIG. 16 is a view of the needle head viewed from the tip of the needle;

FIG. 17 is a section DD through FIG. 15; and

FIG. 18 is a longitudinal section through the needle head placed in the tube.

In order to facilitate rapid reyarning during the running of an embroidery machine, a threading device is provided which decouples the needle bar from its drive and pulls it into a threading dead center which is behind the rear working dead center; a threading loop is inserted and the yarn is blown by compressed air through the hollow needle bar into the threading loop so that when the threading loop is retracted the yarn is threaded. This arrangement can be used for recoupling the needle bar to its drive.

Each embroidering needle is provided with an embroidering head 1. The embroidering heads 1 are arranged on reciprocating T (F168. 5 and 6) between an upper and lower traverse. The beams can be adjusted laterally and the embroidering heads are vertically ad 'justable. The embroidery needles are driven by reciprocating driving shafts which are parallel to the embroidering head supports. Theneedle bar 2 with the needle 5 is reciprocated by a connecting rod P, a driving slider block 9, and a pawl 23. The driving slider block 9 is connected with the needle bar 2 by a pawl 23 and a collar 8 which is fixed on the needle bar 2 so that detachment is possible. The pawl 23 is held by a spring inengagement with the collar 8 and the lug of the pawl 23 engages behind collar 8. The collar rests in the forward position of the pawl 23. Hence when the pawl 23 is pushed against the spring force, the needle bar 2 is disengaged from the driving slider block 9, and, as a result, the driving slider block 9 will carry out a eciprocating movement without the needle bar 2.

The needle bar 2 which reciprocates in the embroidering head 1 is made hollow according to the invention and it has at the needle end a needle bar head 3 which is provided with a bore which runs almost parallel with the needle bars longitudinal axis. This bore is used as a yarn channel 4 through which a yarn 22 can reach the eye 7 of the needle. The embroidering needle Sis fastened to the center of the needle bar head 3. The embroidering head 1 is provided in addition with a threading bar 10 which is parallel to the needle bar; the threading bar 10 can rotate but not slide. At the needle end there is a threading head provided with a guide lever 11 which is attached to the threading bar 10. A guide 12 with an opening for directing the compressed air is fitted on the guide level 11. The opening is con nected to the yarn channel 4 and it is curved foward in such a manner that the air stream is deflected through this to the opening of the threading loop 13. The lengths of the guide lever 11 and the guide 12 are such that the threading loop 13 is guided, on rotating guide lever 11 counter-clockwise in FIG. 5, through the eye 7 of the needle as shown in FIGS. 3 and 6.

On the rear end of the embroidering head 1 is fitted a threading bar 10 which is connected to the lever 14 which is in turn connected by a pin joint at 15 to a connecting rod 16. The connecting rod 16 is connected at its lower end by another pin 15 to a two armed lever 17 which is mounted on the embroidering head 1 by a pivot pin 18. The free arm 17 of this lever acts together with a two armed lever 61 which is able to rotate on the threading device F.

A tension spring 19 holds lever 14 and with it the threading bar 10 in a neutral position, i.e., it is held in a position in which the threading loop 13 is retracted from the eye 7 of the needle, as shown in FIG. 5.

The threading device F, which can be mounted on every embroidering head 1, has a pistol grip G, a straight part L, and two lateral housing plates 24. Between these plates are arranged the actuating components. The frontal housing plate 24 is removed in FIGS. 9 and 10. The housing plate 24 has a takeup shoe 28 whose opening matches the mounting foot 20 on the embroidery head 1. The pushing distance of the takeup shoe 28 is limited by a stop, preferably in the takeup shoe 28. After the takeup shoe 28 is pushed on the mounting foot 20, the threading device F is aligned with the embroidering head 1.

A push rod actuator 29 which passes through the straight part L of the threading device is depressed until a pin 54 which is loaded by a compression spring 55 is latched behind a cone 56 which is fastened on the push rod actuator. A coupling slide 30, which slides in the rear housing plate 24, is fastened to the front end of the push rod actuator. The coupling slide 30 has a couplng finger 31 which projects forward over the front end of the threading device. The forward inclined surface of the coupling finger 31 slides on the inclined surface of the pawl 23 and pushes it out of engagement with the collar 8 on the needle bar 2. As long as the push rod actuator 29 is depressed and held in this position by the pin 54, the connection between the driving slide block 9 and the needle bar 2 is interrupted and the needle bar 2 can be pulled backwards out of the embroidery head 1. On the push rod actuator 29 is arranged in addition an adjusting collar 57 which moves together with the push rod actuator 29.

In addition, a compression spring is arranged on the frontal part of the push rod actuator 29; one end of the compression spring 70 rests against a stop 74 on the housing plate 24; the other end rests against a stop 73 which is fastened on the push rod actuator 29. The spring 70 is compressed when the push rod actuator 29 is depressed.

The threading device F has in addition an actuating lever 32 which is arranged to rotate between the housing plates 24. An actuating pawl 33 pivots about an actuating pawl pin 37 on the actuating lever 32. This actuating pawl 33 engages with a lug 34 against a projection on the nipper actuating lever 38 so that, when the actuating lever 32 rotates counter-clockwise, the nipper actuating lever 38 is also driven counter-clockwise. A nipper connecting rod 39 on whose front end is fastened a clamping piece 40 is pivoted on the free end of the nipper actuating lever 38. A nipper actuating bar 41 is fastened to the hollow clamping piece 40. To the front end of the nipper actuating bar 41 is attached a needle bar nipper 42 which will move together with the nipper actuating bar 41.

A crank lever, whose one arm 51 rests against the nipper actuating lever 38 and whose other arm 44 rests against the circular contact face of the actuating lever 32, is arranged on the housing plate 24 at the back face of the nipper actuating lever 38. This contact face has an actuating lever notch 46 into which an arm 44 is pressed by the spring 45 when the nipper actuating lever 38 is moved forward in the counter-clockwise direction. it releases the arm 51 and the crank lever is pressed by the spring 45 against the contact face and into the actuating lever notch 46.

The front part of the nipper actuating bar 41 carries a compression spring 43 which rests at its front end against a stop in the housing plate 24. Its other end rests against a stop on the nipper actuating bar 41. When the nipper connecting rod 39 moves forward, the nipper actuating bar 41 is moved forward by the clamping piece 40 and the spring 43 is loaded.

A push rod 49 is arranged into the hollow nipper actuating bar 41 so that the push rod 49 is able to slide relative to the hollow nipper actuating bar 41. To the rear end of push rod 49 is attached a release bar 47 which rests on the actuating pawl 33 which has at the contacting end an actuating pawl jaw 35. The toggle linkage 50 is connected with the clamping piece 40 by a tension spring 58. The push rod 49 carries on its front end a feeler lug 48 which projects through a slot in the needle bar nipper 42 into the takeup bore for the needle bar 2. To the front end of the nipper actuating bar 41 is fastened the needle bar nipper 42, which together with the nipper actuating bar 41 is arranged to slide between the housing plates 24. When the nipper connecting rod 39 moves, on actuation of lever 32, simultaneously also the nipper actuating bar 41 is moved through the clamping piece 40. Then the tension spring 58 pulls along the push rod 49 and also the release bar 47, and the end of the latter will drop into the pawl jaw 35.

The needle bar nipper 42 which is able to slide along between the two housing plates 24 is fastened at the front end of the nipper drive bar 41. The needle bar nipper 42 has a bore 42' for the needle bar 2. The bore 42 is open upwards and it forms an air channel 26. The two lateral jaws thus formed are flexible and they grip the needle bar 2 which is pushed into it for the threading process. The bore 42' has a slot for passage of the feeler lug 48 which is held on the push rod 49.

The actuating lever 32 carries a cam 52 which is in contact with the roller of the follower lever 53. The lever 53 has an arm 53' which extends to the other side of the pivot point. A connection bar 59 is pivoted on the arm 53'. The connection bar 59 is loaded by a tension spring 60. The front end of the connection bar 59 is pivoted on one arm of the crank lever 61 whose other arm 61' is in contact with the free arm of the crank lever 17.

The follower lever 53 has an actuating finger 62 which is in contact with a stop 54' on the pin 54.

On further movement of the actuating lever 32, its cam 64 contacts a compressed air valve 63 and opens it. The compressed air valve 63 is connected to a compressed air line 65 whose compressed air nozzle 27 projects into the bore 42 of the needle bar nipper 42.

The actuating lever 32 carries an additional pin 66 which, in the final phase of movement of the actuating lever 32 contacts an arm 67 of a crank lever which at 75 is pivoted on the housing plates 24. The other arm 67' of this crank lever is pivoted on a connecting bar 68 whose other end is pivoted on another lever'76 which in turn pivots on one housing plate 24. The other end of the lever 76 carries a yarn clamping lever 25. The connecting bar 68 is pulled into the clamping position of the clamping lever 25 by a tension spring 71. During the last stage of movement of the actuating lever 32, the stop pin 66 strikes'against the arm 67 of the yarn clamp actuating lever 67, and the actuating

lever

67, 67 is rotated clockwise. ln this case the connecting bar 68 in FIG. is moved to the right; it carries the lever 76 along and as a result the, yarn clamping lever 25 is raised.

In operation, on the embroidering head 1, in which a yarn breakage has occurred, the yarn 22 is in the first place pulled out manually so far from the brake and yarn guides that it reaches the embroidering level and, in addition, that it has such an excess length that after v 6 threading it cannot slip from the needles eye on starting. The yarn 22 is pushed about 8 cm behind the breakage point under the yarn clamping lever 25 of the threading device 24 and the starting length of the yarn 22 is inserted into the air channel 26. Then the threading device 24 together with its takeup shoe 28 is guided into the mounting foot 20 of the embroidering head 1 up to a stop in the takeup shoe 28.

The threading process is started by pushing the push rod 29 until the pin 54 is latched behind the cone 56. If this push rod is not actuated then the device is blocked for the threading process and it is only ready for the coupling process after the completed threading process. When the push rod 29 is depressed then the coupling slide 30 and the coupling finger 31 fastened to it move so far forward that the pawl 23, on return of the driving slide block 9, is lifted from the collar 8, so that the needle bar 2 can be pulled out backwards (FIG. 11). The pin 54 latches on actuation by spring 55 behind the cone 56 and hence holds the push rod actuator 29 together with the coupling slide 30 and the coupling finger 31 in the forward position. The adjusting collar 57 on the push rod actuator 29 in this case increases its distance relative to a stop 69 which is mounted on the toggle linkage 50. The spring 70 is compressed by this movement of the rod 29.

The threading process continues on retracting the actuating lever 32. On retraction ofthe actuating lever 32, the actuating pawl 33 which pivots on the actuating lever 32 pulls along by its pawl lug 34 the nipper actuating lever 38. By means of the clamping piece 40 and the hollow nipper actuating bar 41, the nipper connecting rod 39 pushes forward the needle bar nipper 42 until the pawl 44 latches into the notch 46 on the actuating lever 32. The needle bar nipper 42 is fastened on the nipper actuating bar 41, and the pawl 44 has been released by the movement of the nipper actuating lever 38 which actuates the actuating arm 51. During the last movement stage of this process the release bar 47 latches into the actuating pawl jaw 35 by its movement relative to the actuating pawl 33. The compression spring 43 which is situated on the nipper drive bar 41 is compressed at the same time. The needle bar nipple 42 is now in the position determined by the pawl 44 for taking up the needle bar 2. The subsequent backward stroke of the embroidering machine now pushes the needle bar 2 into the needle bar nipper 42. The accommodating bore 42 of the needle bar nipper has a slot in order to grip the needle bar 2 in a sprung close fitting arrangement and for allowing free passage of the yarn through it when thedevice is removed after completion of the threading.

On pushing the needle bar 2 into the needle bar nipper 42, the needle bar end comes into contact with the feeler lug 48 shortly before reaching the rear dead center of the needle bar actuator, and it pushes rod 49, which is accommodated within the hollow nipper actuating bar 41, backwards against the tension spring 58. Hence the actuating pawl 33 moves away from the release bar 47 which is connected to the toggle linkage 50 so that the actuating pawl lug 34 releases the nipper actuating lever38. The loaded compression spring 43 now pushes the nipper actuating bar 41 and hence also the needle bar 2 which is held in the needle bar nipper 42 in the. threading position, determined by the stop 73 which is attached to the housing plate 24. The nipper actuating lever 38 is brought simultaneously into its original position and it lifts the pawl 44 out of the actuating lever notch 46 by means of the actuating arm 51. The mechanism is now free to carry out further move ments.

On further pulling of the actuating lever 32, the attached cam 52 moves the roller follower lever 53 which rotates via the connecting bar 59 against the tension spring 60 of the crank lever 61. The crank lever 61 transmits its movement to the crank lever 17 which is pivoted on the embroidering head; the crank lever 17 in turn rotates the threading bar against the tension spring 19 through the connecting rod 16 and the lever 14. This action moves the threading head 11 which is connected to the front end of the threading bar 10. The threading loop 13 which is connected to the threading head 11 is now inserted into the eye 7 of the needle.

The push rod actuator 29 is released simultaneously by the pin 54 which is actuated by the actuating finger 62. The push rod actuator is restored to the original position by the compression spring 70.

During the last movement stage of the actuating lever 32 the actuating cam 64 contacts and opens the compressed air valve. Air flows into the compressed air line 65, the compressed air nozzle 27, the air channel 26, the hollow needle bar 2, the yarn channel 4, the air deflector 12 and the threading loop 13.

When the air flow has been built up, then the yarn 22 which is still held under the clamping 25 is released at the end of the actuation movement of the actuating lever 32. This is carried out by rotating the yarn clamp actuating lever 67 by the pin 66 which is connected with the actuating lever 32. The yarn clamp actuating lever 67 lifts the yarn clamp lever 25 through the connecting bar 68 against the force of the tension spring 71. The yarn 22 is entrained in the air stream and blown through the threading loop 13.

Subsequently the actuating lever 32 is released so that the tension spring 72 will restore it to its original position. The loaded tension spring 60 simultaneously moves the roller follower lever 53 so that it follows the returning cam 52 and in doing so it brings the crank lever 61 into its original position through the connecting bar 59. Further the loaded tension spring 19 simultaneously restores the threading bar 10 with its threading head 11 into its original position so that the threading loop 13 pulls the yarn 22 through the eye 7 of the needle. The end of the yarn is completely pulled through the eye only when the needle bar is re-engaged with the drive and when the needle moves towards the fabric. In the course of the embroidering process, the end of the yarn can release itself unimpeded from the threading loop 13.

After the actual threading process is concluded, the threading bar is once again coupled with the needle bar drive. This is carried out by retracting once again the actuating lever 32 which has returned to its original position. The needle bar nipper 42 is moved by the nipper actuating lever 38, the nipper connecting rod 39, the toggle linkage 40, and the nipper actuating bar 41 until the pawl 44 once again engages with the lever notch 46. This brings the needle bar 2 into the coupled position. During the subsequent return stroke of the needle bar drive, the pawl 23 ratchets into the collar 8 of the needle bar 2 and on forward movement of the needle bar drive it pulls the needle bar 2 out from the needle bar nipper 42. This is now possible because the push rod actuator 29, which is depressed at the start of the threading process, has moved during the threading by delatching into the original position and consequently the coupling slide 30 together with the coupling finger 31 are not in the active position.

When the needle bar 2 is pushed into the needle bar drive, the travel of the toggle linkage 50 is restricted by the adjusting collar 57 on the push rod actuator 29 which is in the original position. The adjusting collar 57 acts as a stop. This limitation of travel prevents repeated insertion movement of the threading bar 10 together with the threading head 11 and'the threading loop 13 towards the needle bar 2 which is once again operative. The release bar 47 is prevented from dropping into the actuating pawl jaw 35. This interrupts the release mechanism, and further working cycles of the threading device are blocked.

The threading device can now be detached from the embroidering head and prepared for another application.

In the needle heads shown in FIGS. 15 to 18, the shank of the embroidering needle is notched and/or upset so that the needle after the completion of embedment is attached firmly into the needle head 81 and it is fastened against rotation about the longitudinal axis. The needle head has a collar 82 which transmits the penetration force from the tube to the needle head and hence to the needle. The head beads 83 are pushed into corresponding grooves of the tube 84 and they lock the head on the longitudinal axis. A circular spring 85 rests in a circular groove in the head and in a matching groove in tube 84. The circular spring 85 ensures the movement of the head on the return of the needle. The head 81 is replaced by ejecting it from the rear side of the tube 84 with a plunger. The collar 8 which is coupled to the embroidering head drive is attached to the tube 84. The embroidering yarn is guided to the eye of the needle through the yarn channel 87.

According to this modification of the invention, a conventional commercial sliding tube with drive collar is used in place of the hollow needle bar described.

According to the invention this tube accommodates an insert with an embedded needle. The tube and the insert are firmly engaged in a conventional manner by a bayonet lock stop pin against a backward movement and against rotation.

In contrast to a hollow needle bar, the needle mounting, fastening and guideing are simpler.

Above all other aspects, the invention leads to an improved machine performance by reducing idle time. As is well known the fabric to be embroidered and the needle yarn gauge on an embroidering machine are often changed depending on the change of fashions. It is usual that on a changeover from a fine fabric to a thicker one, the needles of the whole machine must be changed over" to a different gauge and this requires many working hours. To this must be added the inspection for checking whether the needles are correctly inserted with eyes and whether a correct needle gauge has been selected.

This considerable labor and hence also the machine time consumption are eliminated when the needle is already embedded (e.g., into plastics). Changeover hazards can be virtually eliminated by using colored granules with different sizes.

The insert shape can be made aerodynamic by casting in order to guide the yarn which is to be blown through with specially favorable sliding properties. This is considered an additional advantage.

The small additional effort in making the casting with embedded needles (as in knitting machines) is balanced by the lower cost of the embroidering needles since the needle shanks do not have to be made with any special care (smooth shanks for fastening).

What is claimed is:

l. A method of inserting a thread or yarn into the eye of a working needle of a machine, such as embroidery, stitching and sewing machines, comprising the steps of:

maintaining the thread in a gas channel which communicates at one end with a threading loop adapted to be pushed through the eye of the needle,

supplying compressed gas into the channel to propel the thread into the threading loop, pushing the threading loop through the eye of the needle, and

retracting the threading loop from the eye of the needle to complete the threading operation.

2. An apparatus for inserting a thread or yarn into the eye of a working needle of a machine comprising:

a working head,

a hollow needle bar slidable within said head,

a needle support in one end of said needle bar for supporting a needle therein, said support defining a thread channel,

a threading loop in alignment with said thread channel, said loop being adapted to be pushed through the eye of the needle,

a threading device adapted to be coupled to said needle bar, said threading device defining a gas channel for receiving one end of the thread,

said gas channel being adapted to be coupled to a source of compressed gas for propelling the thread end into the thread channel and into the loop, and

means for controllably pushing the threading loop through the'eye of the needle for threading the needle.

3. The apparatus according to claim 2, and

a needle bar nipper defining said gas channel for coupling the needle bar to the threading device, and

a compressed gas line including a nozzle for controllably pressurizing said gas channel.

4. The apparatus according to claim 3 and,

an actuating pawl holding said needle bar, and

a sliding push rod actuator for releasably actuating said pawl.

5. The apparatus according to claim 4 wherein,

said push rod actuator comprises a cone, and

a spring loaded pin coacting with said cone.

6. The apparatus according to claim 5 and,

a housing for said threading device,

said needle bar nipper being slidably mounted within said housing,

an actuating bar attached to said needle bar nipper,

and

an actuating lever for actuating said actuating bar.

7. The apparatus of claim 6 wherein,

said actuating lever comprises an actuating trigger rotatably mounted on an actuating nipper, and

an actuating pawl connecting said nipper to said actuating lever.

8. The apparatus according to claim 7, and

a needle bar head which fills said hollow needle bar at its needle end and which carries the working needle, and

said needle bar head defining said thread channel which communicates with the hollow chamber of the needle bar.

9. The apparatus according to claim 8, and

a compressed air valve in the path of the actuating lever, said valve being actuated by said actuating lever for controlling the flow of gas in the gas line.

10. The apparatus according to claim 9, and

a takeup foot operatively associated with said working head, and

a takeup shoe for fitting the threading device onto said working head.

11. The apparatus according to claim 10, and

a needle head for holding said needle and defining said thread channel, and

said needle head being detachably secured to a needle shank.

Claims

1. A method of inserting a thread or yarn into the eye of a working needle of a machine, such as embroidery, stitching and sewing machines, comprising the steps of: maintaining the thread in a gas channel which communicates at one end with a threading loop adapted to be pushed through the eye of the needle, supplying compressed gas into the channel to propel the thread into the threading loop, pushing the threading loop through the eye of the needle, and retracting the threading loop from the eye of the needle to complete the threading operation.

2. An apparatus for inserting a thread or yarn into the eye of a working needle of a machine comprising: a working head, a hollow needle bar slidable within said head, a needle support in one end of said needle bar for supporting a needle therein, said support defining a thread channel, a threading loop in alignment with said thread channel, said loop being adapted to be pushed through the eye of the needle, a threading device adapted to be coupled to said needle bar, said threading device defining a gas channel for receiving one end of the thread, said gas channel being adapted to be coupled to a source of compressed gas for propelling the thread end into the thread channel and into the loop, and means for controllably pushing the threading loop through the eye of the needle for threading the needle.

3. The apparatus according to claim 2, and a needle bar nipper defining said gas channel for coupling the needle bar to the threading device, and a compressed gas line including a nozzle for controllably pressurizing said gas channel.

4. The apparatus according to claim 3 and, an actuating pawl holding said needle bar, and a sliding push rod actuator for releasably actuating said pawl.

5. The apparatus according to claim 4 wherein, said push rod actuator comprises a cone, and a spring loaded pin coacting with said cone.

6. The apparatus according to claim 5 and, a housing for said threading device, said needle bar nipper being slidably mounted within said housing, an actuating bar attached to said needle bar nipper, and an actuating lever for actuating said actuating bar.

7. The apparatus of claim 6 wherein, said actuating lever comprises an actuating trigger rotably mounted on an actuating nipper, and an actuating pawl connecting said nipper to said actuating lever.

8. The apparatus according to claim 7, and a needle bar head which fills said hollow needle bar at its needle end and which carries the working needle, and said needle bar head defining said thread channel which communicates with the hollow chamber of the needle bar.

9. The apparatus according to claim 8, and a compressed air valve in the path of the actuating lever, said valve being actuated by said actuating lever for controlling the flow of gas in the gas line.

10. The apparatus according to claim 9, and a takeup foot operatively associated with said working head, and a takeup shoe for fitting the threading device onto said working hEad.

11. The apparatus according to claim 10, and a needle head for holding said needle and defining said thread channel, and said needle head being detachably secured to a needle shank.