US2910029A - Needle threaders for sewing machines - Google Patents

Description

Oct. 27, 1959 E. J. HERBST 2,910,029

NEEDLE THREADERS FOR sEwiNc MACHINES Filed July 2:5. 1957 2 Sheets-Sheet 1 INVENTOR. Edward J. Herbs! TTORNEY Oct. 27, 1959 E. J. HERBST NEEDLE THREADERS FOR SEWING MACHINES 2 Sheets-Sheet 2 Filed July 23, 1957 INVENTOR. Edward J. Herbsf BY y ATTORNEY United States Fatet NEEDLE THREADERS FOR SEWING MACHINES Edward J. Herbst, South Plainfield, N .J., assignor to The Singer Manufacturing Company, Elizabeth, NJ a 'corporation of New Jersey Application July 23, 1957, Serial No. 673,676

12 Claims. (Cl. 112-225) The present invention relates to a needle threader for sewing machines and has for a primary object to provide a new and improved needle threader that is built into the sewing machine. More particularly it is an object of this invention to provide a sewing machine needle threader that is simple and easy to operate, dependable and durable.

It is a further object of this invention to provide a sewing machine needle threader that is economical in that it is composed of parts that are inexpensive to manufacture and that can be easily assembled in the machine.

It is also an object of this invention to provide a sewing machine needle threader that requires a minimum of preparation of the machine to receive the same so that the machine can be manufactured on a mass production basis and the needle threader thereafter added on an optional basis.

Having in mind the above and other objects that will be evident from an understanding of this disclosure, the invention comprises the devices, combinations and arrangements of parts as illustrated in the presently preferred embodiment of the invention which is hereinafter set forth in such detail as to enable those skilled in the art readily to understand the function, operation, construction and advantages of it when read in conjunction with the accompanying drawings in which:

Fig. 1 is an elevational view of the head of a sewing machine embodying the present invention.

Fig. 2 is a fragmentary vertical sectional view taken substantially on the line 2-2 of Fig. 1.

Fig. 3 is a fragmentary vertical sectional View similar to Fig. 2 but illustrating the needle threader bar partly in section to show more clearly the construction of the mechanism.

Fig. 4 is a fragmentary view similar to Fig. 2 but illustrating the parts in a position in which the threading device is inoperative.

Fig. 5 is a fragmentary view similar to Fig. 1 but illustrating the parts in threading position.

Fig. 6 is a fragmentary detail sectional View taken substantially on the line 6-6 of Fig. 5.

Fig. 7 is a detail sectional view taken substantially on the line 7-7 of Fig. 5.

With reference to the drawing, the present invention is illustrated as embodied in a sewing machine having a frame including a head 1 having a bottom wall 2. A needle bar 3 is mounted vertically in the bottom wall 2 of the head 1 for endwise reciprocation. At its lower end the needle bar 3 carries a needle 4 having a blade 5 provided with a thread eye 6 and a shank 7. To secure the needle 4 to the needle bar'3, the shank 7 is seated in a longitudinal slot 8 in the slabbed lower end of the needle bar 3 and is held therein by a needle clamp 9 in the form of a strap that surrounds the needle bar and the shank of the needle. A clamping screw 10 is threaded into the clamp 9 and bears against the needle bar 3 on the side opposite from the slot 8 so that as the screw 10 is turned, the shank 7 is drawn against the bottom of the slot 8 by the clamp 9 in the usual manner. The needle 4 is positioned vertically relative to the needle bar 3 by a pin 11 extending transversely of the needle bar 3 at the desired elevation and intersecting the slot 8 so that the upper end of the shank 7 will abut against the pin. The clamp 9 carries a thread guide 12 constructed in accordance with the invention disclosed and claimed in the copending application of Koenig, Serial No. 576,926, filed April 9, 1956.

In the disclosed embodiment of the invention, endwise reciprocation is imparted to the needle bar 3 by a counter-balanced crank 13 mounted upon the end of a rotary main shaft 14 journaled longitudinally of the bracket arm of the machine. The crank 13 has a crank pin 15 connected by a link 16 to a pin 17 extending laterally from a collar 18 secured on the needle bar 3 by a set screw 19 (Fig. 6).

The needle threader comprises a threader bar 20 mounted in the bottom wall 2 of the head 1 for axial sliding and for turning with the axis thereof arranged in spaced parallel relation with respect to the needle bar 3. At its lower end, the threader bar 20 carries an arcuate hook-ended threading finger 21 that is clamped between a pair of guide fingers 22 by a screw 23, Fig. 7. The guide fingers 22 are secured in a slot extending inwardly from the bottom of the threader bar 20 by a screw 24 which extends through an elongated slot in the guide fingers 22 to provide for adjustment of the guide fingers 22 radially of the threader bar 20 and relatively to the needle 4. The guide fingers 22 can also be pivoted about the screw 24 to provide for limited final adjustment of the threading finger axially of'the needle 4. The threading finger 21 is designed to be extended through the eye 6 of the needle 4, as illustrated in Fig. 7, upon turning of the threader bar 20 when the threading finger 21 and the eye 6 of the needle are aligned vertically. The thread, which is designated T in Fig. 7 is laid over the finger 21. Then, as the threading finger 21 is moved back through the eye of the needle, the hooked end engages the thread T and draws a loop thereof through the eye. In the illustrated machine, the needle 4 is threaded from left to right as seen in Fig. 2 so the threading finger is moved into and through the eye of the needle from right to left, or upon counterclockwise turning of the threader bar as seen in Fig. 7. With such an arrangementit is difficult for a right-handed person to place a limb of the thread T across the threading finger 21 as it extends through the eye of the needle because the threader bar 20 and the needle bar 3 are in the way. To facilitate this manipulation of the thread, the screw 24 is provided with a stud 25 on the end thereof, which stud extends from the periphery of the threader bar 20. The limb of thread T extending down from the thread guide 12 can then be passed under the stud 25 and across the end of the threading finger 21. a

To align the threading finger 21 vertically relative to the eye 6 of the needle 4, there is: provided a positioning element 26 including a sleeve 27 loosely mounted on the needle bar 3 below the bottom wall 2 of the head 1 and above the needle positioning pin 11. The element 26 also includes a plate 28 secured to and extending laterally from the top of the sleeve 27, a connecting portion 29 bent upwardly from the plate 23 and an ear 30 bent from the connecting portion 29 into a plane parallel to that of the plate 28. The plate 28 is disposed below the bottom wall 2, while the connecting portion 29 extends in front of the Wall 2 and the car 30 is disposed above the wall 2. The threader bar 20 extends loosely through aperturesin the ear 30 and plate 28. Downward movement of the positioning element 26 relative to the threader bar 20 is limited by a pin 31 arranged transversely of the threader bar 20.

The threader bar 20 is provided with an axial bore 32 extending downwardly from the top and with a diametrically arranged through slot 33 also extending downwardly from the top and thereby intersecting the bore 31 but being shorter than the bore '32. A stop collar 34 is secured on the threader 'bar 20 by a pin 35, a planar actuating element 36 is slidably mounted in the slot 33 and includes an intermediate portion 37 that is preferably as'wide as the diameter of the threader bar so that it will completely fill the slot 33 and thus form a smooth continuation of the periphery of the threader bar. The intermediate portion 37 of the actuating element 36 is, however, no wider than the diameter of the threader bar 20 so that it will slide relative to the stop collar 34 and will slide with the threader bar 20 into the bore in the bottom wall 2 in which the threader bar is slidably mounted. The actuating element 36 has a reduced lower portion 38 and an enlarged upper portion which extends laterally beyond the periphery of the threader bar and in effect provides a flange 39. The upper end of the actuating element 36 is bent at a right angle and extended to form a handle 40.

Disposed in the bore 32 is a compression spring 41, 'Fig. 3, into the upper end of which extends the reduced lower portion 38 of the actuating element 36, the spring 41 acting between the bottom of the bore 32 and the shoulder formed at the top of the reduced portion 38. The actuating element 36 has a longitudinal slot 42 extending from the upper end through the enlarged upper portion and, partially through the intermediate portion 37. A tension spring 43 arranged in the bore 32 and in the slot 42 has the lower end thereof connected to the actuating element and the upper end thereof connected to an arm 44 on a plate 45 secured to the open end of the head 1 by screws 46. A collar 47 is secured on the upper end of the threader bar 20 by a set screw 48 to limit the movement of the actuating element 36 under the action of the spring 41. The plate 45 has an L-shaped slot 49 through which the handle 40 extends, the slot 49 having a vertical leg 50 and ahorizontal leg 51.

Because of interference with the presser foot, the threader bar 20 cannot be turned to pass the threading finger 21 through the eye 6 of the needle 4 unless the needle is within a fixed distance of the top of its stroke, which in the illustrated machine is three-sixteenths of an inch. The needle threader is therefore designed to have an operating range of three-sixteenths of an inch.

The normal position of the parts of the needle threader is illustrated in Figs. 1, 2 and 3. The threader bar 20 is drawn upwardly by the tension spring 43 into the illustrated position with the pin 31 engaged against the bottom of the plate 28 of the positioning element 26 which is thus biased upwardly against the bottom of the bottom wall 2 of the head 1. The spring 43 holds the parts in this position during the normal operation of the sewing machine. The needle bar 3 is moved into a position in which the needle 4 is within three-sixteenths of an inch of the top of its stroke. This actuates the needle threader. The handle 40 of the actuating element 36 is then forced downwardly along the vertical leg 50 of the slot 49 against the action of the tension spring 43. Since the actuating element 36 is held captive relative to the threader bar 20 by the compression spring 41 which biases it upwardly against the collar 47, this actuation moves the threader bar 20 downwardly. As the threader bar 20 is moved downwardly the pin 31 thereon is also moved downwardly and the positioning element 26 is thus free to fall on the needle bar 3 until the bottom of the sleeve 27 contacts the needle locating pin '11, Fig. 5, with the amount that the positioning element 26 falls depending upon how close to the top of the stroke the needle bar 3 is at the time. Since the pin 11 is fixed relative to the eye of the needle 4, the positioning element '26 is thus located relative to the eye of the needle.

The threader bar 20 is moved downwardly by thehandle 40 until the stop collar 34 contacts the top of the ear 30 of the positioning element 26, as illustrated in Fig. 5 and is then held against any further downward movement. The threader bar 20 is now positioned vertically relative to the needle so that when the threader bar 20 is turned, the threading finger 21 will pass through the eye 6 of the needle 4 as illustrated in Fig. 7. If the handle 40 still is not at the end of the vertical leg 50 of the slot 49 opposite the horizontal leg 51, which again depends upon how far away from the top of the stroke the needle bar 3 is at the time, it cannot be turned. To get to the bottom of the vertical leg 50, the handle 40 is forced downwardly relative to the threader bar 20 against the action of the spring 41. The handle 40 can then be turned along the horizontal leg 51-of the slot 49 to rotate the threader bar 2% and thus pass the threading finger 21 through the eye 6 of the needle 4.

To insure that the threader bar cannot be turned unless the needle is within the required distance from the top of its stroke, there is provided an arm 52 on the needle bar driving collar 18, which arm extends into the path of travel of the flange 39 of the actuating element 36 when the needle bar 3 is not near the top of its stroke, as illustrated in Fig. 4. Thus the actuating element 36 cannot be turned. When the needle bar is within the required distance of the top of its stroke, the collar 18 and its arm 52 are disposed higher so that the flange 39 will pass beneath the arm 52 as it is turned, as illustrated in Fig. 5.

The arm '52 also constitutes a safety feature in that it will prevent accidental actuation of the machine when the threading finger 21 is in the eye of the needle since the the flange 39 is beneath the arm 52 and prevents its moving vertically downward beyond the range of action of the needle threader.

The illustrated machine is also provided with a hinged face plate 53, Fig. 2, which also has an L-shaped slot 54 corresponding to the slot 49 to .accommodate the handle 40.

Numerous alterations of the structure herein disclosed will suggest themselves to those skilled in the art. However, it is to be understood that the present disclosure relates to a preferred embodiment of my invention which is for purposes of illustration only and not to be construed as a limitation of the invention. All such modifications which do not depart from the spirit of the invention are intended to be included within the scope of the appended claims.

Having thus set forth the nature of the invention, what I claim herein is: i

1. In a sewing machine having a frame including a head, a needle bar mounted in said head for endwise reciprocation, a needle carried by said needle bar and having a thread eye, a threader bar mounted in said head for turning and for endwise sliding movement on an axis in spaced parallel relation to said needle bar, a. threading finger carried by said threader bar, means cooperating with said frame for positioning said threader bar endwise relatively to said needle bar with said threading finger in position to move through the eye of the needle upon turning of said threader bar, a flange extending laterally from said threader bar, an arm extending laterally from said needle bar into the path of movement of said flange upon ttuning of said threader bar, said flange being elongated in the direction axially of said threader bar and formed to pass under said arm upon turning of said threader bar when said threader bar is moved endwise to the position determined by said positioning means thereby permitting turning of said threader bar only when it is positioned endwise with said threading finger alined with the eye of the needle and preventing endwise movement of said needle bar when said threader bar is turned, and actuating means for effecting endwise movement and turning of said threader bar.

2. In a sewing machine having a frame including a hea a people bar mounted in said head for endwise reciprocation, a needle carried by said needle bar and having a thread eye, a threader bar mounted in said head for turning and for endwise sliding movement on an axis in spaced parallel relation to said needle bar, a threading finger carried by said threader bar, means cooperating with said frame for positioning said threader bar rel-atively to said needle bar with said threading finger in position to move through the eye of the needle upon tuming of said threader bar, a flange extending laterally from said threader bar, an arm extending laterally from said needle bar into the path of movement of said flange upon turning of said threader bar, said flange being elongated in the direction axially of said threader bar and formed to pass under said arm upon turning of said threader bar when said threader bar is moved endwise to the position determined by said positioning means thereby permitting turning of said threader bar only when it is positioned endwise with said threading finger alined with the eye of the needle and preventing endwise movement of said needle bar when said threader bar is turned, spring means for biasing said threader bar into a normally inoperative position endwise in a direction away from the needle, and actuating means for effecting endwise movement in the opposite direction and turning of said threader bar.

3. In a sewing machine having a frame including a head, a needle bar mounted in said head for endwise reciprocation, a'needle carried by said needle bar and having a thread eye, a threader bar mounted in said head for turning and for endwise sliding movement on an axis in spaced parallel relation to said needle bar, a threading finger carried by said threader bar, means for positioning said threader bar relatively to said needle bar with said threading finger in position to move through the eye of the needle upon turning of said threader bar, a flange extending laterally from said threader bar, an arm extending laterally from said needle bar into the path of movement of said flange upon turning of said threader bar, said flange being formed to pass under said arm upon turning of said threader bar when said threader bar is moved endwise to the position determined by said positioning means thereby permitting turning of said threader bar only when it is positioned endwise with said threading finger alined with the eye of the needle and preventing endwise movement of said needle bar when said threader bar is turned, actuating means for effecting endwise movement and turning of said threader bar comprising a handle extending laterally from said threader bar and a plate carried by said head and having a slot through which said handle extends, said slot having a first leg providing for movement of said handle in a direction to impart endwise movement to said threader bar while confining said handle against turning and a second leg providing for turning of said handle while confining said handle against movement in a direction endwise of .said threader bar.

4. In a sewing machine having a frame including a head, a needle bar mounted in said head for endwise ;reciprocation, a needle carried by said needle bar and j having a thread eye, a threader bar mounted in said head for turning and for endwise sliding movement on an axis in spaced parallel relation to said needle bar, a threading finger carried by said threader bar, means for positioning said threader bar relatively to said needle bar with said 7 threading finger in position to move through the eye of 1 the needle upon turning of said threader bar, a flange ex- 3 tending laterally from said threader bar, an arm extending laterally from said needle bar into the path of move- :ment of said flange upon turning of said threader bar, said flange being formed to pass under said arm upon turning of said threader bar when said threader bar is moved endwise'to the position determined by said positioning means thereby permitting turning of said threader 1 bar only when it is positioned endwise with said threading finger alined with the eye of the needle and preventing 6 endwise movement of said needle bar when said threader bar is turned, a handle connected to said threader bar for unitary turning and for relative movement endwise to said threader, resilient means connecting said handle to said threader bar for endwise movement in a direction toward said needle, and a plate carried by said head and having a slot through which said handle extends, said slot having a first leg providing for movement of said handle in a direction to impart endwise movement'to said threader bar while confining said handle against turning and a second leg providing for turning of said handle while confining said handle against movement in a direction endwise of said threader bar, the second leg of said'slot defining the maximum position of the range of operation of said threader bar and the resilient means connecting said handle to said threader bar accommodating movement of said handle relative to said threader bar to move said handle opposite said second leg after endwise movement of said threader bar has been stopped by said positioning means.

5. In a sewing machine having a frame including a head, a needle bar mounted in said head for endwise reciprocation, a needle carried at the lower end of said needle bar and having a thread eye, a threader bar mounted in said head for turning and for endwise sliding movement on an axis in spaced parallel relation to said needle bar, a threading finger carried at the lower end of said threader bar, abutment means on said needle bar at a predetermined distance from the eye of the needle, means including an element carried by said threader bar for engaging said abutment means to limit endwise movement of said threader bar downwardly to a position in which said threading finger will move through the eye of the needle upon turning of said threader bar, said threader bar having a bore and an intersecting transverse slot extending inwardly from the upper end thereof, a spring disposed in said bore, an actuating element mounted above said spring in said slot for unitary turning with said threader bar and for relative motion endwise of said threader bar and connected through said spring to said threader bar for moving said threader bar downwardly, a flange extending laterally from said threader bar, an arm extending laterally from said needle bar into the path of movement of said flange upon turning of said threader bar, said flange being formed to pass under said arm upon turning of said threader bar when said threader bar is moved endwise downwardly to the position determined by said abutment means thereby permitting turning of said threader bar only when it is positioned endwise with said threading finger alined with the eye of the needle and preventing endwise movement of said needle bar downwardly when said threader bar is turned, and a plate having a slot through which a handle portion of said actuating element extends, said slot including a first leg providing for endwise movement of said threader bar and a second leg providing for turning of said threader bar.

6. A needle threader for a sewing machine in accordance with claim 5 in which said flange is an integral part of said actuating element.

7. A needle threader for a sewing machine in accordance with claim 5 having means including an element secured to said needle bar for imparting endwise reciprocation to said needle bar and in which said arm extending laterally from said needle bar is an integral part of said element.

8. A needle threader for a sewing machine in accordance with claim 5 having a spring means for biasing said threader bar upwardly to an inoperative position.

9. A needle threader for a sewing machine in accordance with claim 8 in which said last mentioned spring means is connected to said actuating element and there is provided means on said threader bar for limiting movement of said actuating element upwardly relative to said threader bar.

10. A needlethreader for a sewing machine in accordance with claim 9 in which said last mentioned spring is 7 disposed in the bore in said threader bar and in which said actuating element has a longitudinal slot for accommodating the same.

11. In a sewing machine having a frame including a head, a needle bar mounted in said head for endwise-reciprocation, a needlecarn'ed at the lower end of said needle bar, and having a thread eye, a threader bar mounted in said head for turning and -for'endwise sliding movement-on an axis in spaced parallel relation -to said needle bar, a threading finger carried at the lower end of said threader bar, means for positioning said threader bar endwise relatively to said needle bar with said threading finger in position to move through the eye of the needle upon turning of said threader bar, said means comprising-a positioningelement mounted on-said needle bar for free sliding movement in a direction axially of said needle bar and including a laterally extending portion disposed adjacent to said threader bar, and an element carried by said threader bar to engage said laterally extending portion, spring means-forbiasing said threader bar and positioning element upwardly into an inoperative position, means for effecting downward endwise sliding movement and turning of said threader bar, and means for preventing-turning of said threader except when said threading finger is alined with the .eye of the needle and for preventing operation of the machine when said threader bar is turned.

12. In a sewing machine having a frame including a head, a needle bar mounted in said head for endwise reciprocation, a needle having a thread eye, a clamp for securing said needle to the lower end of said needle bar,

means for locating :said needle endwise of .said 'needle bar, a threader bar mounted in said head for turning and for endwise sliding movement, .on an axis in spaced parallelrelation to said needle bar, aLthreading finger carried at the lower end ofsaid-threader bar, means for positioning said threadenbar-endwise relatively to said needle bar with said threading finger in position to move through the eye of the needle upon turning of said threader bar, saidmeans-comprising a positioning element mounted on said needle bar immediately above said needle locating means {or free sliding movement in a direction axially of said needle bar and thereby adapted to fall into engagement with said needle locating means, said positioning element including a laterally extending portion disposed adjacent to-said threader bar, and an element carried by said threader bar to engage said laterally extending portion, spring means for biasing said threader bar and positioning element upwardly into an inoperative position, means for effecting downward endwise sliding movement and turning of said threader bar,.and means for preventing turning of said threader bar except when said threading finger is alined with the eye of the needle and for preventing operation of the machine when said threader bar is turned.

References Cited in the file of this patent UNITED STATES PATENTS 2,704,526 Benink et al. Mar. 22, 1955 2,707,448 Naas May 3, 1955 2,727,479 Meissler Dec. 20, 1955

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