US2704526A

US2704526A - Needle threading device

Info

Publication number: US2704526A
Authority: US
Priority date: 1951-08-24
Publication date: 1955-03-22
Anticipated expiration: 1972-03-22
Also published as: CH310790A; GB721329A; BE513705A; FR1065661A; NL91408C

Description

Mmh 22, 1955 C. J. M. BENINK ET AL v NEEDLE THREADING DEVICE Filed Aug. 2l, 1952 6 Sheets-She@I l nvemons @mh 22, i955 c. J. M. BENINK ET Al.

NEEDLE THREADING DEVICE Filed Aug. 21,` 1952 6 Sheets-Sheet 2 arch 22, 1955 c. J. M. BENINK ET Al- 2,704526 NEEDLE THREADING DEVICE Filed Aug. 21, 1952 6 Sheets-Sheet 3 Japan/ors March 22, 1955 c. J. M. BENINK ET AL NEEDLE THREADING DEVICE 6 Sheets-Sheet 4 Filed Aug, 21, 1952 March 22, 1955 Filed Aug. 2l, 1952 c. J. M. BENINK ET A1. 2,704,526

NEEDLE THREADING DEVICE 6 Sheets-Sheet 5 Jaffa/www, ,4a-,020 .fc/wsrf@ inve/Vian;

March 22, 1955 c. J. M. BENINK ET AL NEEDLE THREADING DEVICE 6 Sheets-Sheet 6 Filed Aug. 21, 1952 innen/ons @y www United States Patent Av() NEEDLE TrmEADlNG DEVICE Christian Josef Marines Benink, Heinrich Bungert, Emil Clauss, Ludwig Meissler, Herbert Schumann, and Alfred Schuster, Kaiserslautern, Germany, assignors to G. M. Pfaff A.G., Kaiserslautern, Germany Application August 21, 1952, Serial No. 305,674

7 Claims. (Cl. 112-225) The present invention relates to threading devices f or sewing machines, particularly to a threading device which can be conveniently and simply manipulated.

The threading devices for sewing machines known heretofore were not employed in actual practice because their form of construction was in most instances too involved. As a rule the operation vrequired several manual operating members.

Thus a threading device is known which is mounted on the head of the sewing machine and operatively connected with the gear, which is intended to make possible the threading of torn threads in any position of the needle bar. Furthermore, a threading device has been known where a guiding bar which is axially and rotatably movable is mounted in the bore for the needle bar. The bar is pulled down until the height of the ear of the needle is reached. Then the threader is swung manually into the ear of the needle and the threading is undertaken. A spring which snaps into a groove of the needle bar serves for the correct alignment of the threader relative to the ear. This operation requires the manipulating of two manual operating members.

It is the object of the invention to find a way to overcome the above ditiiculties and a new solution which meets all the requirements for the construction of a threader. The threading device in accordance with the invention not only avoids the disadvantages of the devices known heretofore but has many important advantages over them, particularly that of easy manipulation and great safety and reliability of operation.

The new device is provided at the head of the sewing machine and consists of an axially and rotatably movable bar with a threader provided at the lower endthereof in the form of a hook or a notched needle. This bar is so disposed and guided that upon being shifted downwardly by means of an; operating member it automatically eifects the swinging movement which brings the threader through the ear of the needle at a predetermined height. For this purpose the swinging movements of the bar are guided by suitable means, for example, by using a curved groove. One or several springs make possible the automatic return of the threader to its free position after each threading operation.

For the operation of the threader in any desired position, suitably within a limited range above the presserfoot bar the guiding bar is in operative relationship with the needle bar by means of a rod or the lke, which abuts the needle bar socket or the upper end of the needle bar.

The mechanical portion of the device is provided on the head of the sewing machine while in the position of rest only the threader is disposed closely adjacent the lower portion of the head and the operating member on the outside of the head. As compared with devices known heretofore the sewing operations are thus not disturbed because the sewing space is free of obstacles. The principal advantage of the invention resides in that in threading a single operative step is undertaken and the return of therthreader to the starting position takes place automatically under the effect of a spring.

The operation can be undertaken from any desired position. Thus the operating member, for example, a lever or a push button may be arranged within reach either above, below or laterally of the sewing machine.

Since it may happen that with the lever pressed down the hook is already'in the ear of the needle and the machine is put in operation by inadvertent touching of the starter in electrically operated machines or of the treadle in non-electric machines, the abutment member, for example the rod mentioned above, which is provided on the guiding bar for producing the coordination or the operative engagement with the needle bar can be guided still further in accordance with the invention during its swinging movement by a track provided along the abutment plane which may be constituted by a slot or a groove so that also in such cases the hook is moved out of the ear of the needle without damage as a result of the controlled guidanceof the rod or the like.

Also the automatic control of the threader obtained by such a controlled guidance is of particular advantage if the needle bar is outside of the limited range within which the threader is alone able to operate. Such a situation arises when the person operating the sewing machine is unable to accurately recognize the lower and upper limits of this range or when the lighting conditions are unfavorable. Thus the lever may be pressed down without paying attention to the position. It is merely necessary to slightly turn the machine onward. Only at the time when the exact adjustment of the threader with respect to the needle ear is attained the threader swings automatically into the ear and the threading can be effected. The operation of the threading device is thus substantially facilitated without particular requirements being necessary as to the dexterity of the person sewing.

As the controlled guiding track for the pin or the like a plate may be provided on the needle bar socket, for example of angular shape, in which manner a slot or the like is formed between the plate and the top side of the socket for guiding the pin, which upon operation of the operating lever for the guiding bar establishes operative connection with tlie needle bar. The pin or the like then no longer rests freely and openly upon the needle bar socket but is given guidance in the slot by means of the plate. It is thus achieved that with the up and downward movement of the threader the pivoting movement of the threader is always insured.

In accordance with another form of such a guiding track this arrangement may be mounted at a distance from the needle bar socket as an independently adjustable element for example, in the form of a ring, a disc or the like von the needle bar proper. Such an embodiment offers additional advantages with respect to the foregoing arrangement and permits in the simplest manner an adjustment of the differences in distance between the needle bar lug and the needle ear. This difference can be caused by increases in the length of the needle and in the position of the ear of the needle. On the other hand, however, the threader must be in exact alignment with the ear of the needle when in operative position. The adjustment by moving the hook carrier by means of set screws requires a certain skill not possessed by everyone. As compared to that, no particular adaptability is necessary to move the ring or the like along the needle bar until the alignment of the threader with the ear of the needle is reached. For such purposes the set screws need only be loosened on this ring and tightened again after the adjustment is made.

The invention is illustrated in the drawings in several embodiments where:

Figs. 1-3 show a threading device on a sewing machine having a needle bar guided in fixed bearings with the ear of the needle disposed transversely to the direction of sewing and where the threading device is provided laterally of theneedle bar, with Fig. l showing particularly a front view of the head, Fig. 2 the operative connection of the bar with the needle bar lug and Fig. 3 the end with the protective shield removed;

Figs. 4-6 illustrate the position of the hook in various steps of the threading operation; Figs. 7-.11 show the device partly in perspective view in connection with a sewing machine having an oscillating needle rod, the needle ear of which is disposed in the direction of sewing and where threading can be effected only with the bar in the highest position, and the operation of which is by pulleys;

Figs. 12 -14 show a perspective view of several steps of the threading operation;

Fig. 15 shows a sewing machine with oscillating needle bar of the same construction as above where the threading can be eiected in any desired position above the pressure foot;

Figs. 16-18 illustrate a front, side and top view of the controlled guiding of the abutment element (pin) upon a ring which is adjustable on the needle bar;

Figs. 19-21 show a modified form of the controlled guidance by means of an angular plate secured to the needle bar lug also in front, side and top view; n

Figs. 22-24 show the hook with protective shield strip on the bar in a front view, plan view and cross section.

The bar 2 is guided in upper and lower bores in the head 1 of the sewing machine at the lower end of which a clamp 3 is fastened by means of the screw 4 which simultaneously holds the hook 5 besides the reinforcement plate 6 on the clamp 3. The sliding member 7, of sheet metal, is bent at right angles inwardly at the top and at the bottom. The bar 2 is passed through the bores in the two

angle arms

8, 9. At the lower angular' member 9, the lug 10 is provided which is guided in the slot 11 provided in the plate 14 secured to the head-1 o f the machine by means of

screws

12, 13. A pin rigidly mounted in and extending through bar 2 is provided the front part of which is disposed and guided in a grooved track 16 of the sliding member 7 and the back portion of which provides the operative connection with the socket 17 of the needle bar. The pressure spring 18 which at its lower end rests against the head and at its upper end against the sliding member 7 provides for the returning of the bar 2 while the pressure spring 19, supported against the pin of the bar and resting at the top against the sliding member 7 tends to press the bar 2 downwardly. The operating lever 2t) on the sliding member 7 projects through the aperture 21 in the head 1 of the sewing machine.

The threading device operates as follows:

When pressing downwardly on the lever sliding member 7 and the bar 2 are moved downwardly against the force of pressure spring 18 until the pin 15 abuts the needle bar socket 17. In this position the hook 5 is aligned at the same level with the ear of the needle 23. Further pressing on the lever 20 causes bar 2 to be moved by the front part of the pin 15 which is disposed in the grooved track 16, thus causing the rotation with simultaneous swinging of the hook 5 into the ear of needle 23. The hook in this case is moved from the right to the left. The thread 24 is put on and the lever 20 is released somewhat. The bar 2 swings back under the effect of spring 18 thus pulling the thread 24 through the ear whereupon it is manually removed from the hook 5. Lever 20 is now completely released causing the bar 2 with hook 5 to be automatically returned by pressure spring 8 to the starting position.

In the sewing machine having an oscillating needle bar in accordance with Figs. 7-11 the threading arrangement is secured to the needle bar oscillator 25 by means of screws. The supporting member comprises an open shell 26 in which the sliding member 27 is disposed for axial movement. The shell 26 is provided with a lug 28 which is securely fastened to the needle bar oscillator 25 by means of screws 29. A further lug 30 is bent around the needle bar oscillator 25 in order to provide support for the upper portion of the supporting member. In the shell which is formed as a unitary structure with the sliding member 27 the bar 31 is rotatably guided (see Fig. l0). The little arm 32 formed as a clamping member and having a hook 33 is secured to its lower end. Arm and hook are manufactured by a precision casting method. The hook 33 may also be made of sheet metal bv stamping. In the shell 26 moves the sliding member 27 which is provided with the grooved track 34 for guiding the pin 35 of the bar 31. The pin 35 during the downward movement of the sliding member 27 and of the bar 31 results in engagement of pin 35 with lug 36. At this point the hook 33 and the ear of the needle 37 are at eoual height if the needle bar is in its uppermost position. Further pressure on member 27 results in pin 35 following the track 34, thereby rotating the bar 31. ln the upper portion of the sliding member 27 bolt 38 is arranged as a shoulder member for the spring 39 which at its lower end rests against the bar 31. Spring 39 is compressed when pin 35 engages lug 36 and member 27 continues to move downwardly. A pulling spring 40 is fastened by meaens of ring 41 to the Sliding member 27 while at its upper portion it is clamped to the shell 26 by means of ring 42. The end of a pulling cord 43 is secured to the sliding member 27, the cord being brought around the return roller 44 upwardly along the three rollers 45 over roller 46 and secured to the guiding member 26 at the top. A bolt 48 with a pressing button 49 is provided on the protective shield 47. The spring 50 presses the bolt and button outwardly. On the inside of the protective shield 47 a bifurcated pusher member 51 is provided, the two arms of which press on the cord 43 between rollers 45 upon pushisng on the button 49 thus causing downward movement on the sliding member 27 and the bar 31. The operation of the threading is shown in Figs. l214 and described in connection with the preceding embodiment.

The needle threading device in accordance with Fig. l5 is fundamentally similar in construction and operation to the previously described device according to Figure 1, but here the device is associated with an oscillating needle bar. It also provides for threading in any desired position of the needle bar. The device is fastened to the needle bar oscillator 52 in a manner that the two

bearings

53, 54 for the bar 55 are made in one piece with the needle bar oscillator 52. The lower pressure spring 56 is not arranged inside the head due to lack of space but is disposed upon the clamp member 57 and at the top it rests against the lower portion of the bearing.

The sliding member 58 is elongated towards the bottom and ends in the operating lever 59 with the bent end 60. Sliding member 58 and operating lever 59 thus form a unitary structure. The operating lever 59 differs from the first embodiment in that it is provided at the bottom. The lever 59 is moved manually downwardly and thus the sliding member 58 is pulled and not pressed. For the safe guiding the sliding member 58 is bent over at its left side and besides it is guided by the bar 55 which slides in the two bores of the sliding member 58 which is bent at the top and at the bottom.

A pin 15 extends through bar 55 resting with one end in guiding slot 16. When moved downwardly pin 15 strikes a at abutment on a member which is stationary relative to the bar 55, and continued downward pull on the bar 58 causes the pin to follow the slot 16, thereby rotating the bar 55. The arrangement may be as illustrated in Figs. 16 to 18.

In accordance with Figs. 16-18 a ring 64 or the like is secured to the portion of the needle bar 61 disposed above the needle bar socket 17 bv means of two set

screws

62, 63. The ring member 64 is provided with a slot 65 to present a guide track in which pin 15 of the guide bar 2 is guided when the pin 15 executes its rotary movement after the alignment of the threader 5 (Figs. 22-24) with the ear of the needle bv way of the aforementioned grooved track. The pin. 15 together with the bar 2 which carries the threader 5 can move vertically upwardly or downwardlv before or after the swinging movement when it has disengaged the guiding slot 65.

In the modified embodiment of a guide track illustrated in Figs. 19-21 a plate 66, for example of angular shape is provided upon the needle bar socket proper to constitute the guiding slot for the pin 15. At a distance corresponding to the thickness of the pin 15 an intermediate member 67 is provided for that purpose above the upper end of the needle bar socket 17. At the lower end of the bar 2 a clamp member 70 is provided as a carrier arm for the threader 5, which member is axially movable upon the bar. This clamp member 70 is secured to the bar 2 by means of screws 68, 69 (Figs. 2, 23). Two protective shield strips 72, 73 are fastened to this clamp with a screw 71 together with the hook 5 of the threader. These protective shield strips 72, 73 are somewhat split apart at the free front ends as clearly shown in Fig. 24.

In sewing machines having an oscillating or pendant needle bar the device is mounted on the needle bar oscillator or connected with it. This obtains that the distance of the threader remains always the same in any position which deviates from the vertical and the threading operation is not affected thereby. The device can also be installed in sewing machines which were not originally provided with it.

Having now described our invention, what we claim is:

l. A needle threading device for a sewing machine of the type having a reciprocating needle bar disposed in the machine head and supporting a needle having an eye,

said device comprising a guided bar disposed adjacent said needle bar and movable relatively thereto, a pm carried by said guided bar and projecting outwardly therefrom, an arcuated threading element carried by said guided bar proximate the needle supporting end of said needle bar, an actuating mmber mounted adjacent to and in operative engagement with said guided bar for sliding movement and presenting an operating arm for moving said actuating member and said guided bar relative to said needle bar, abutment means disposed in the path of travel of said pin for engagement by said pin and presenting a shoulder at a prdetermined distance from the eye of the needle to limit downward movment of said guided bar, a guiding track defined in said actuating member having engagement with one end of said pin and spring means supported at a fixed point relative to said guided bar and said actuating member for biasing said guided bar and said actuating member in inoperative position, whereby pressure on said arm first moves said actuating member and said guided bar axially to establish engagement between said pin and said shoulder and align said threading element with the eye of the needle, and continued pressure causes sliding movement of said pin on said track and on said shoulder, thereby rotating said guided bar and causing said threading element to engage the eye of said needle.

2. A needle threading device for a sewing machine of the type having a reciprocating needle bar disposed in the machine head and supporting a needle having an eye, said device comprising a guided bar disposed adjacent and parallel to said needle bar and movable relatively thereto, a pin carried by said guided bar and projecting outwardly therefrom, an arcuated threading element carried by said guided bar proximate the needle supporting end of said needle bar, an actuating member mounted around and in operative engagement with said guided bar for sliding movement and presenting an operating arm for manually moving said actuating member and said guided bar longitudinally relative to said needle bar, abutment means mounted on said needle bar in the path of travel of said pin and presenting a shoulder for engagement by said pin at a predetermined distance from the eye of the needle to limit axial downward movement of said guided bar, a guiding track defined in said actuating member having engagement with one end of said pin and spring means supported at a fixed point relative to said guided bar and said actuating member for biasing said guided bar and said actuating member in inoperative position, whereby pressure on said arm first moves said actuating member and said guided bar axially to establish engagement between said pin and said shoulder and align said threading element with the eye of the needle, and continued pressure causes sliding movement of said pin on said track and on said shoulder, thereby rotating said guided bar and causing said threading element to engage the eye of said needle.

3. A needle threading device for a sewing machine of the type having a reciprocating needle bar disposed in the machine head and supporting a needle having an eye, said device comprising a guided bar supported by the needle bar oscillator adjacent and parallel to said needle bar and movable longitudinally relatively to said needle bar, a pin carried by said guided bar and projecting outwardly therefrom, an arcuated threading element carried by said guided bar proximate the needle supporting end of said needle bar, an actuating member mounted around and in operative engagement with said guided bar for sliding movement and presenting an operating arm extending outside the machine head for manually moving said actuating member and said guided bar longitudinally relative to said needle bar, abutment means mounted on said needle bar in the path of travel of said pin having a set screw for adjustment on said needle bar and presenting a shoulder for engagement by said pin at a predetermined distance from the eye of the needle to limit axial downward movment of said guided bar, a guiding track defined in said actuating member having engagement with one end of said pin and helical spring means around said guided bar supported at a fixed point relative to said guided bar and said actuating member for biasing said guided bar and said actuating member against said needle bar oscillator in inoperative position, whereby pressure on said arm first moves said actuating member and said guided bar axially to establish engagement between said pin and said shoulder and align said threadingy element with the eye of the needle, and continued pressure causes sliding movement of said pin on said track and on said shoulder, thereby rotating said guided bar and causing said threading element to engage the eye of said needle.

4. A needle threading device for a sewing machine of the type having a reciprocating needle bar disposed in the machine head and supporting a needle having an eye, said device comprising a guided bar supported in the machine head adjacent said needle bar for sliding movement, a pin carried by said guided bar, and projecting outwardly therefrom, an arcuated threading element carried by said guided bar proximate the needle supporting end of said needle bar, an actuating member mounted around and in operative engagement with said guided bar for sliding movement and presenting an operating arm for moving said actuating member and said guided bar relative to said needle bar, abutment ments disposed in the path of travel of said pin and presenting a shoulder for engagement by said pin mounted on said needle bar at a predetermined distance from the eye of the needle to limit axial downward movement of said guided bar, a guiding track defined in said actuating member having engagement with one end of said pin and spring means supported at a fixed point relative to said guided bar and said actuating member for biasing said guided bar and said actuating member in inoperative position, whereby pressure on said arm first moves said actuating member and said guided bar axially to establish engagement between said pin and said shoulder and align said threading element with the eye of the needle, and continued pressure causes sliding movement of said pin on said track and on said shoulder, thereby rotating said guided bar and causing said threading element to engage the eye of said needle. i

5. A needle threading device for a sewing machine of the type having a reciprocating needle bar disposed in the machine head and supporting a needle having an eye, said device comprising a guided bar lsupported in the machine head adjacent said needle bar for sliding movement, a pin carried by said guided bar and projecting outwardly therefrom, an arcuated threading element carried by said guided bar proximate the needle supporting end of said needle bar, an actuating member mounted around and in operative engagement witljrsaid guided bar for sliding movement and presenting an operating arm for moving said actuating member andg'said guided bar relative to said needle bar, abutment means disposed in the path of travel of said pin presenting a shoulder for engagement by said pin mounted on said needle bar at a predetermined distance from the eye of the needle to limit axial downward movement of said guided bar, a guiding track defined by a slot extending obliquely of said actuating member and having engagement with one end of said pin, and spring means biased against the lower end of the machine head holdingvl said guided bar and said actuating member in inoperative position, whereby pressure on said arm first moves said actuating member and said guided bar axially to establish engagement between said pin and said shoulder and align said threading element with one eye of the needle, and continued pressure causes sliding movment of said pin in said slot and on said shoulder thereby rotating said guided bar and causing said threading element to engage the eye of said needle.

6. A needle threading device for a sewing machine of the type having a reciprocating needle bar disposed in the machine head and supporting a needle having an eye at its lower end said device comprising a guided bar disposed adjacent and parallel to said needle bar and movable relatively thereto, a pin extending transversely of said guided bar and projecting outwardly therefrom, an arcuated threading element carired by said guided bar proximate the needle supporting end of said needle bar and having a hook adapted to enter the eye of the needle, actuating means including a guiding member mounted around and in operative engagement with said guided bar provided with an obliquely extending slot to receive one end of said pin and with manual operating means presenting a member projecting from said machine head for moving said guided bar longitudinally of said needle bar and said pin in said slot, abutment means presenting a shoulder in the path of travel of said pin at a predetermined distance from the eye of the needle to limit downwardmovement of said guided bar and spring means extending between a fixed point in said machine head and said actuating means for biasing said actuating means and said guided bar in inoperative position.

7. A needle threading device for a sewing machine of the type having a reciprocating needle bar disposed in the machine head and supporting a needle having an eye at its lower end, said device comprising a guided bar disposed adjacent and parallel to said needle bar in a channel shaped member rigidly supported in said machine head and movable relatively to said needle bar, a pin extending transversely of said guided bar and projecting outwardly therefrom, an arcuated threading element carried endwise of said guided bar proximate the needle supporting end of said needle bar and having a hook adapted to enter the eye of the needle, actuating means including a guiding member mounted in said channel shaped member around and in operative engagement with said guided bar and provided with an obliquely extending slot to receive one end of said pin and with manual operating means presenting a member projecting from said machine head formoving said guided bar longitudinally of said needle bar and said pin in said slot, abutment means presenting a shoulder in the path of travel of said pin at a predetermined distance from the eye of the needle to limit downward movement of said guided bar and spring means extending between a xed point in said machine head and said actuating means for biasing said actuating means and said guided bar in inoperative position, and a exible cable or thc like extending around freely mounted rollers intermediate said guiding member and said manual operating means.

References Cited in the le of this patent UNITED STATES PATENTS 479,426 Jenkins July 26, 1892 640,919 Kobler Jan. 9, 1900 2,544,577 Weber Mar. 6, 1951