US2552731A - Sewing machine needle threading device - Google Patents

Description

y 1951 c.. A, PINKHAM ETAL v 2,552,731

sswmc ucnms NEEDLE 'msnpmc navxcz: Filed July 26, 1949 INVENTORJ CLARENCE A. P/NKHAM B y AAPTHOLOMEW yam/104M ATTORNE Patented May 15, 1951 i UNITED STATES PATENT OFFICE SEWING MACHINE NEEDLE THREADING DEVICE Application July26, 1949, Serial No. 1065906 6 Claims. 1

This invention relates to threading appliances and, more particularly, to a needle threader particularly adapted for use with sewing machine needles although usable with any commercial needles.

Needle threaders known to the art have generaly involved a manually guided hook or the like which is inserted through the eye of a needle, engaged with a thread, and withdrawn to pull a loop of thread through the needle eye. Such manually operable threaders are diflicult to operate and inefiicient insofar as time saving is concerned. While various automatic needle threaders have been proposed, they have either been complicated and expensive in construction, or unadapted for use with all types and sizes of needles. In particular, there is a demand for an efficient automatic threader for sewing machine needles whereby production sewing operations may be more efficiently performed.

With the foregoing in'mind, the present invention is directed to a compact, simple and efficient needle threader which is particularly designed for use in threading sewing machine needles. The invention threader includes a housing or casing in which is reciprocably mounted a spring biased needle guide. A threading hook is pivotally mounted in the casing and spring biased to project across the guide passage of the needle guide.

In its inoperative position, the needle guide restrains swinging of the hook across the passage. When the eye end of a needle is engaged in the guide to depress the same. the hook swings across the passage through the eye of the needle. A thread slot intersects the guide passage so that, when the hook extends through the needle eye, a thread laid in the slot will overlie the hook. As the needle is released, the spring biased guide cams the hook backwardly to draw a thread loop through the needle eye.

In sewing machineneedles, the eyes are at different distances from the end of the needle. Consequently, the needle guide will be depressed correspondingly different distances before the hook end will be aligned with the needle eye. To accommodate these factors, the pivot arrangement for the hook includes a pin in the casing and a slot in the hook. Consequently, when the threader is used with a needle having an eye adjacent its lower end, the hook enters such eye and, as the needle guide is moved downwardly, the hook moves down through the last motion arrangement provided by the pin and slot. The threader is "thus usable with needles having eyes at varying distances from the needle end.

It is, accordingly, among the objects of this invention to provide a simple, compact and inexpensive automatic needle threader particularly adapted for use withsewing machine needles.

Another object is to provide such a threader usable with needles having eyes located a varying distance from the endof the needle.

These, and other objects, advantages and novel features of the inventionwill be apparent from the following description and the accompanying drawing. Inthe drawing:

Fig. 1 is a-sideelevation view of the invention threader as arranged to thread a sewing machine needle;

Fig. 2 is an inside elevation view of one-half of the casing of the'threader having the operating elements mounted thereon;

Fig. 3 is an inside'elevationview ofthe-mating half ofthe casing;

Fig. 4 is a horizontal sectional'view on the line 44"of Fig. 2,

Fig. 5 is a plan view' ofthe'threader Fig. 6 is atransverse'sectional view on the line 6 6 of'Fig. 5; and i Fig. 7' is a view similar to Fig. 1 showing the hook engagedthrough a needle eye.

Referring to Fig. 1,-theneedle threader includes a casing or housing] Dsufficiently small in size to fit readily beneath the point of a sewing machine needle 20, mounted in a reciprocable head 2|, whenneedleZB is in the upper or retracted position. Casing H] has a recess H in itsunder surface'for clearance with the bifurcated inwardly extendingelements 22a and 22b of the pressure foot 22, disposed above the work surface 23 of the-sewing machine. The threader is properly alignedwith'needle 20 by virtue of a needle guide 30 projecting somewhat beyond the lower surface or'base 12 of the threaderand engaging ina needle receiving aperture 24 in work surface 23.

The internal construction and the arrangement of the several coacting' elements of the threader will be best understood by reference to Figs. 2 through 7. As best seen in Figs. 2 and 3, casing orhousing [0 includes a pair of mating half sections i3; 53' which may be formed of any suitable material such as wood, metal, or a synthetic resin composition. Section l3 has the left half of its inner surface formed with a shallow recess l4 bounded by a marginalwall 16. Re-

cess 14 opens into a'pai-rpof coaxial, semi-cylindrical recesses l1, l8 which formone wall of therein. Pin 21 acts as a mounting support for a,

coil spring 28 having a short arm. engaged in a depression 29 and a long arm extending into passage I and engaged beneath a head 3| on guide 30. Spring 28 acts to bias guide 36 upwardly, and upward movement of the guide is limited by a button 32 which partially overlies passage l5. Button 32 has a frusto-conical stem 33 lying in a correspondingly shaped recess in wall- 6.

On the other side of passage |5,'s'ection l3 has a second shallow recess 4| in which is a projecting pin 42 acting as a pivotal mounting for the threading hook 4|]. The latter is a Z-shaped flat, thin member having a hook 43 arranged to project through the needle eye, a, mid-section 44 and a rear arm 46. Section 44 has a slot 41 receiving pin 42 and cooperating'therewith to form a lost motion pivotal mount for hook 4|]. Arm 46 has secured thereto one end of a coil spring 45 lying in a relatively deep recess 48- and having its other end secured to a pin 5| projecting into recess 48. Beyond recess 48, section l3 has an externally countersunk aperture 52 for receiving a fastening element. Section l3 has a thread receiving slot 53, intersecting passage l5.

Needle guide 36 includes the head 3| which rides in the large diameter section of passage l5 and a stem 34 riding in the small diameter sec- 7 tion of the passage. Head 3| has a tapered axial recess 35 arranged to have the end of a needle engaged therein.

Mating section I3 is formed with shallow recesses l4 and 4| matching recesses l4 and 4|, and with semi-cylindrical recesses I1 and I8 cooperating with recesses ll, l8 to form passage l5. Recess I4 has a depression 54' arranged to receive pin 21 and a tapped hole 56 alignable with hole 26. Similarly, recess 4| has a depression 51 arranged to receive pin 42. Section l3 has a recess 48 matching recess 48 and a tapped hole 58 alignable with aperture 52. Wall l6 has a frusto-conical recess 59 arranged to engage stem 33 of button 32. A thread slot 53' intersects passage l5.

In assembling'the threader, springs 28 and 45, button 32, guide (ill and hook 40 are all placed in position on section l3 and properly interrelated. Section I3 is then juxtaposed on section l3 and screws or bolts 6| (Fig. 4) are set into countersunkapertures 26 and 52 and threaded into tapped holes 56 and 58 to secure the casing sections together. It will be noted from Figs. 4 and 6 that the external surfaces of the casing sections are concaved, as at 62, 62 to form a grip whereby the threader may be readily and conveniently gripped.

In the inoperative position of the threader, spring 28 biases guide 30 upwardly, and the guide engages end 43 of hook 40 to bias the hook clockwise, as seen inFig. 2. For this purpose, spring 28 is made stronger than spring 45. The action of the two springs also biases hook 46 upwardly so thatthe lower end of slot 41 engages pin 42. To thread a sewing machine needle 2|],

the threader is placed in the position shown in Fig. 1 and needle 20 moved down to engage in tapered recess 35.. As the needle moves guide 30 downwardly, spring 45 biases hook 40 counterclockwise so that end 43 projects through the eye 25 of the needle. Downward movement of needle 26 and guide 30 is limited by guide 3| abutting the shoulder formed by the juncture of the small and large diameter sections of passage l5.

When hook end 43 projects beyond needle 20, thread 50 is laid in slots 53, 53 so that it overlies the hook. When needle 20 is retracted upwardly, spring 28 biases guide 30 upwardly which cams hook 46 clockwise. Hook end 43 thus draws a loop of thread 50 through needle eye 25, threading the needle. The threading operation is speedy, efiicient, and completely automatic.

A feature of the invention is the lost motion pivotal mounting for hook 40 allowing the hook to function automatically irrespective of Whether the needle eye 25 is right at the lower end of the needle 20or a substantial distance thereabove. During downward movement of needle 20 and guide 30, spring 45 continually biases hook 40 to engage end 43 with the needle. Should eye 25 be right at the lower end of the needle, end 43 pierces the eye after only a slight downward movement of the needle. Upon further downward movement of guide 30 and needle 2|], hook 40 while rocking about pin 42 moves downwardly by virtue of the lost motion connection of pin 42 and slot 41. This condition, in the lowermost position of needle 20 is shown in full lines in Fig. 7.

Should the needle eye 25 be a substantial distance from the lower end of the needle 20, (see dotted line showing in Fig. 7) the hook end 43 biased as aforesaid by spring 45 will not enter the needle eye 25 until after a substantial downward movement of the needle. Further downward needle movement, once end 43 has pierced needle eye 25 causes, in addition to the rocking movement of hook 40, a downward movement thereof, by virtue of the lost motion connection of pin 42 and slot 41 (see dotted lines in Fig. 7) but the latter movement to a lesser degree.

In the event the needle eye is a considerable distance from the needle end, hook end 43 will not enter the eye until a .very substantial downward movement of the needle, in which event further downward needle movement will merely rock hook 40 about pin 42 with a minimum of downward displacement of hook 4|].

Thus, by virtue of the aforesaid lost motion arrangement our device is adapted for use with needles having eyes located over a substantial range of needle length.

While a specific embodimentof the invention has been shown and described in detail to illustrate the application of the principles thereto, it should be understood that the invention may be otherwise embodied without departing from such engage the eye end of aneedle, first spring means biasing said guide toward the needle receiving end of the passage, a hook pivotally mounted in said casing for movement in a plane including the axis of such passage, said hook having a thread engaging end normally adjacent the pass sage and engaging said guide in the retracted position of the latter, second spring means biasing said hook to swingin a direction to project said thread engaging end to project across the passage through the eye of a needle engaged.

said, guide, a thread receiving slot said :casing intersecting th passage whereby, whensaid hook end has passed through a needle eye, a thread may be placed in such slot to engage said hook end, said first spring being stronger than said second spring to bias said guide to a retracted position to cam said hook toa retracted position to draw a loop of thread through the needle eye, and the pivotal mounting of saidhook-comprising a pin and. slot connectionproviding.for bodily movement of said hook parallel to the passage whereby the thread engaging hook end is cooperable with needle eyesarranged at varying distance from the needle end engaged in said guide.

2. A threading appliance comprising, in combination, a, casing having an elongated passage; a needle guide reciprocably mounted in such passage, said guide having a seat formed therein to engage the eye end of a needle, first spring means biasing said guide toward the needle receiving end of the passage, a hook pivotally mounted in said casing for movement in a plane including the axis of such passage, said hook having a thread engaging end normally adjacent the passage and engaging said guide in the retracted position of the latter, second spring means biasing said hook to swing in a direction to project said thread engaging end to project across the passage through the eye of a needle engaged in said guide, a thread receiving slot in said casing intersecting the passage whereby, when said hook end has passed through a needle eye, a thread may be placed in such slot to engage said hook end, said first spring being stronger than said second spring to bias said guide to a retracted position to cam said hook to a retracted position to draw a loop of thread through the needle eye, and the pivotal mounting of said hook comprising a slot in said hook engaging a pin in said casing providing for bodily movement of said hook parallel to the passage whereby the thread engaging hook end is cooperable with needle eyes arranged at varying distance from the needle end engaged in said guide.

3. A threading appliance comprising, in combination, a casing having an elongated passage, a needle guide reciprocably mounted in such passage, said guide having a seat formed therein to engage the eye end of a needle, first spring means biasing said guide toward the needle receiving end of the passage, a hook pivotally mounted in said casing for movement in a plane including the axis of the passage and having a thread engaging hooked arm projecting from the pivot point toward the passage and second arm projecting from the pivot point in the opposite direction, second spring means connected to said second hook arm and biasing said hook to swing in a direction to project said thread engaging end to project across the passage through the eye of a needle engaged in said guide, a thread receiving slot in said casing intersecting the passage whereby, when said hook end has passed through a needle eye, a thread may be placed in such slot to engage said hook end, said first spring being stronger than said second spring to bias said guide to a retracted position to draw a loop of thread through the needle eye, and means providing for bodily movement of said hook parallel to the passage whereby the thread engaging hook end is cooperable with needle eyes arranged at varying distance from the needle end engaged in said guide.

4. A threading appliance comprising, in com- III bination, a casing having an elongated passage; a ,needle guide-reciprocably mounted in such passage, said guide having a seat formed therein to engage the eye end of a needle, first spring means biasingsaid guide toward the needle receiving end of the passage, a hook pivotally mounted-sin said casing for movement in a plane including the axis of the passage and having a thread engaging hooked arm projecting from the pivot. point toward the passage and a second arm projecting from the pivot point in the oppositedirection;.secondspring means connected to said secondhookarm and biasing said hook to swing in a direction toproject said thread engaging end to project across the passage through the eye of a needle engaged in said guide, a thread receiving slot in said casing intersecting the pas-- sage whereby, when said hook end has passed through a needle eye, a thread may be placed in such slot to engagesaid hook end, said first spring being stronger than said second spring to bias said guide to a retracted position to cam said hook to a retracted position to draw a loop of thread through the needle eye, and the pivotal mounting of said hook comprising a pin and slot connection providing for bodily movement of said hook parallel to the passage whereby the thread engaging hook end is cooperable with needle eyes arranged at varying distance from the needle end engaged in said guide.

5. A threading appliance comprising, in combination, a casing having an elongated passage, a needle guide reciprocably mounted in such passage, said guide having a seat formed therein to engage the eye end of a needle, first spring means biasing said guide toward the needle receiving end of the passage, a hook pivotally mounted in said casing for movement in a plane including the axis of the passage and having a thread engaging hooked arm projecting from the pivot point toward the passage and a second arm projecting from the pivot point in the opposite direction, second spring means connected to said second hook arm and biasing said hook to swing in a direction to project said thread engaging end to project across the passage through the eye of a needle engaged in said guide, a thread receiving slot in said casing intersecting the passage whereby, when said hook end has passed through a needle eye, a thread may be placed in such slot to engage said hook end, said first spring being stronger than said second spring to bias said guide to a retracted position to cam said hook to a retracted position to draw a loop of thread through the needle eye, and the pivotal mounting of said hook comprising slot in said hook engaging a pin in said casing providing for bodily movement of said hook parallel to the passage whereby the thread engaging hook end is cooperable with needle eyes arranged at varying distance from the needle end engaged in said guide.

6. A threading appliance comprising, in combination, a casing having a base arranged to rest upon the work surface of a sewing machine and having an elongated passage perpendicular to said base, a needle guide reciprocably mounted in such passage and having an extension projecting beyond said base to engage in the needle aperture in such work surface to align the passage with the needle of the machine, said guide having a needle receiving seat in its upper surface, first spring means biasing said guide toward the needle receiving end of the passage, a hook pivotally mounted in said casing for movement i in a plane including the axis 'of such passage, said hook having a thread engaging end normally adjacent the passage and engaging said guide in the retracted position of the latter, second spring means biasing said hook to swing in a direction to project said thread engaging end to project across the passage through the eye of a needle engaged in said guide, and a thread receiving slot in said casing intersecting the passage whereby, when said hook end has passed through a needle eye, a thread may be placed in such slot to engage said hook end, said first spring being stronger'than said second spring to bias saidguideto' a retracted position to 6am said hook to a retracted position to draw a loop of thread through the needle eye. n

1 v CLARENCE A. PINKHAM.

BARTHOLOMEW HOLOI-IAN. J

REFERENCES CITED UNITED STATES PATENTS Name Date Pinkham et a1. Dec. 13, 1949 Number

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