JP2002095883A - Thread-detecting device of sewing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thread eyelet bushing device of a sewing machine for easily winding needle thread to a thread-detecting device and dispensing with rewinding the needle thread so that the needle thread cannot be removed from the thread-detecting device. SOLUTION: In the thread-detecting device 7 of a sewing machine where a wheel for winding thread T at one end of a shaft 11 that is rotatably supported by a mounting stand 4 is provided, and a rotary encoder 12 for detecting the rotation of a wheel 10 and the shaft 11 is provided at the other end of the shaft 1, a string-guiding member 14 for blocking thread T at the outer periphery of a gap so that the thread T is not wound around the shaft 11 from the gap between the wheel 10 and the mounting stand 4, and a thread removal-preventing member 15 for inhibiting the expansion of diameter at the immediate outer periphery of the wheel 10 so that the wheel 10 is not removed since the diameter of the loop of the loop-like thread wound around the wheel 10 is expanded are provided at the mounting stand 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thread detector for a sewing machine for detecting the occurrence of a thread break or controlling the tension of a thread based on the amount of thread progress of the sewing machine.

[0002]

2. Description of the Related Art Generally, in a thread detector of a sewing machine,
As shown in FIG. 8, the sewing head 39 of the multi-needle embroidery sewing machine is used.
A thread guide device 31 and a thread tensioner 34 are provided on the front of a mount 32 of the thread guide device 31 in a number corresponding to the number of needles of the sewing machine head 39. , A yarn guide hole 35 and a yarn detection device 36 are arranged in a state of being close to each other. A thread guide 33, a thread detection device 36, a thread tension 34, and a thread guide hole 35 are attached in order from the top. Then, the upper thread T is manually sandwiched between the thread guides 33, then wound around the thread detector 36, subsequently wound around the thread tensioner 34, and finally inserted into the thread guide hole 35 from above. Passed through.

The yarn detecting device 36 includes a shaft 41 (not shown) rotatably supported by the mounting table 32, a disc-shaped wheel 40 mounted on one end of the shaft 41, and a shaft 41 on the other end of the shaft 41. The attached rotary encoder 42 for yarn detection
(Not shown). The sewing machine is operated by winding the upper thread T around the wheel 40, the wheel 40 rotates, and the rotary encoder 42 is rotated via the shaft 41 to detect the upper thread T. At this time, the upper thread T is manually wound around the wheel 40.

[0004]

However, in the yarn detecting device 36, as shown in FIG. 9A, a gap is formed between the mounting table 32 and the wheel 40 via a shaft 41, and the wheel 40 Is provided deep in a narrow space between the yarn guide 33 and the yarn tensioner 34. Therefore, it is necessary to wind the upper thread T directly into the groove 43 of the wheel 40, and it is difficult to insert the upper thread T into the groove 43. As shown in FIG. It was taking time.

Further, during the operation of the sewing machine, if the tension of the upper thread T wound around the thread detector 36 fluctuates due to the action of the thread guide 33 and the thread tensioner 34, as shown in FIG. The loop-shaped upper thread T may increase the diameter of the loop. Particularly, when a strong thread such as a gold thread is wound, the tendency is strong. In some cases, the wheel 40 came off the wheel. When the upper thread T comes off and the wheel 40 does not rotate normally, the thread breakage is erroneously detected.
Each time it came off, it had to be re-wound each time, which required extra time.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, to easily wind the upper thread around the yarn detecting device, and to reduce the trouble of re-winding the upper thread without coming off from the yarn detecting device even if the diameter of the upper thread is increased. An object of the present invention is to provide a sewing machine thread detection device that can be omitted.

[0007]

In order to achieve the above object, a thread detecting device for a sewing machine according to the present invention is provided with a wheel for winding a thread around one end of a shaft rotatably supported on a mounting base. In a thread detecting device of a sewing machine provided with a detector for detecting rotation of a wheel and a shaft at the other end of the shaft, the gap between the wheel and the mounting base is adjusted so that the thread is not wound around the shaft. A yarn guide member for blocking the yarn on the outer periphery is provided on the mounting base.

In the above-described thread detecting device for a sewing machine, a loop-shaped thread wound around the wheel expands the loop to prevent the loop from expanding off the wheel so as to prevent the thread from coming off the wheel. It is characterized in that a yarn detachment prevention member is provided.

The distance between the wheel and the yarn detaching member is preferably 0.5 to 3 mm.

Further, in the same thread detecting device for a sewing machine as described above, the thread guiding member and the thread detachment preventing member are provided.

The yarn guide member may be provided on the entire outer periphery of the gap or partially provided on at least the side of the entire outer periphery on which the yarn starts to be wound.

Further, the thread guide member is a projection projecting from the mounting stand at the same height as the inner end surface of the wheel or at a height slightly exceeding the inner end surface, and the projection is continuous with the outer periphery of the gap. Examples include protrusions and a plurality of protrusions arranged on the outer periphery of the gap.

It is preferable that the outer peripheral surface of the thread guide member forms an inclined surface which approaches the outer peripheral edge of the wheel from the outside as it goes from the mounting base to the wheel.

The yarn detachment preventing member is provided on the entire outer periphery of the wheel.
Alternatively, it is preferable that the protrusion is provided at least partially at a position apart from each other in the entire outer circumference, and is provided on the mounting stand at the same height as the outer end surface of the wheel or at a height exceeding the outer end surface.

It is preferable that the inner peripheral surface of the yarn detachment preventing member is a concave arc surface following the outer periphery of the wheel.

In addition to the single-needle sewing machine, a mode in which the thread detecting device is attached to a multi-needle sewing machine having a plurality of needles can be exemplified. It is preferable to provide according to the number of needles.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a thread detecting device for a sewing machine according to the present invention will be described below with reference to FIGS. FIGS. 1 and 2 show a yarn path device 1 of a multi-needle sewing machine provided with a yarn detection device 7.
Is provided above the sewing head 3 of the multi-needle sewing machine 2 and applies tension to the upper thread T. The yarn path device 1 includes a thread insertion plate 5, nine sets of thread guides 6 with small knobs as tension applying members corresponding to the nine needles of the sewing machine head 3,
The thread detecting device 7 includes a thread tensioner 8 with a knob as a tension applying member, and a thread guide hole member 9 provided with a large number of thread guide holes 9a.

First, the respective members other than the yarn detecting device 7 will be briefly described. The yarn inserting plate 5 is provided on the upper part of the mounting base 4 of the yarn path device 1 so as to extend left and right, and an appropriate gap is provided. Nine upper threads T are collectively passed between the two plates 5a and 5b so that they can be smoothly guided. Thread guide 6
Is a member that holds the upper thread T from above and below to apply tension, and is disposed below the thread insertion plate 5 on the mounting base 4 in a line on the left and right at a constant interval. The thread tension 8 is the upper thread T
A member for applying tension to the bottom of the thread detector 7 of the mounting table 4 and arranged vertically in two rows (five rows in the upper row and four rows in the lower row). Immediately below each thread tension 8, a thread guide hole member 9 is appropriately disposed.
The upper thread T heading toward is guided so as not to be entangled with another thread tension 8, another upper thread T, or the like.

The yarn detecting device 7 is arranged between the yarn guide 6 and the yarn tensioner 8 in a line on the left and right at a constant interval. And, a shaft 11 rotatably supported by the mounting base 4.
And a disk-shaped resin wheel 10 attached to one end of the shaft 11 and a yarn detecting rotary encoder 12 attached to the other end of the shaft 11. In order to be able to wind the upper thread T around the wheel 10, the thread catching groove 13
Is cut, and the upper thread T is wound around the thread catching groove 13 once in a loop. The nine wheels 10 are rotatably supported on the mounting table 4 in a line in the left and right rows at fixed intervals, and the wheels 10 are disposed between the upper thread guides 6. The yarn detecting device 7 detects the occurrence of a yarn break or controls the tension of the yarn based on the amount of yarn progression detected from the amount of rotation of the rotary encoder 12.

As shown in FIGS. 3 and 4, a yarn guide member for blocking the upper thread T at the outer periphery of the gap so that the thread is not wound around the shaft 11 from the gap between the wheel 10 and the mounting base 4. 14 is provided on the mount 4. Yarn guide member 1
Numeral 4 is a projection projecting vertically from the mounting base 4 at a height slightly exceeding the inner end surface of the wheel 10, and more specifically, is a front arc-shaped projection continuous along the outer periphery of the gap. Further, in the present embodiment, even if the lower portion of the thread guide member 14 is interrupted by the step portion of the mounting table, the thread guide member 14 is provided at least on the side of the outer periphery of the gap where the thread is started to be wound. There is no problem. The inner diameter of the yarn guide member 14 is 1 mm larger than the outer diameter of the wheel 10 so as not to hinder the rotation of the wheel 10. The outer peripheral surface of the yarn guide member 14 is an inclined surface 19 approaching the outer peripheral edge of the wheel 10 from the outside toward the wheel 10 from the mounting base 4, and the inclined surface 19 serves as a thread guide when the upper thread T is attached. Plays a role.

Next, as shown in FIGS. 3 and 5, the loop-shaped upper thread T wound around the wheel 10 expands its loop so that it does not come off from the wheel 10, so that the upper thread T A thread detachment prevention member 15 that suppresses the diameter expansion of the thread T is provided on the mount 4. Thread detachment prevention member 1
The reference numeral 5 extends perpendicularly to the mount 4 and is provided at a height exceeding the outer end surface of the wheel 10 so as to be located between the wheels 10. And the yarn detachment prevention member 1
The left and right symmetric concave arcuate surfaces 16 are formed on the inner peripheral surface of the wheel 5 and extend right and left along the outer periphery of each wheel 10 upward from a central portion where the adjacent wheels 10 are closest to each other.
In the above “immediate outer periphery of the wheel 10”, the wheel 1
0, and at least the upper thread T
Is assumed to be secured, and in the present embodiment, the spacing is 2.5 m
m.

According to the yarn path device of the sewing machine configured as described above, the following effects can be obtained. When the upper thread T is wound around the yarn detecting device 7, as shown in FIG. When set between the surface 16 and the yarn guide member 14, FIG.
As shown in FIG. 6B, when the upper thread T is pulled downward while the upper thread T is wound in a loop toward the thread catching groove 13, the loop of the upper thread T is formed as shown in FIG. Is the slope 1
9 and is naturally wound around the threading groove 13 of the wheel 10. For this reason, there is no danger of being detached from the wheel 10 or being accidentally wound around the shaft 11, so that anyone can easily perform the winding operation. As shown in FIG. 7B, even if the loop of the upper thread T wound in a loop around the wheel 10 is enlarged due to a change in the tension of the upper thread T as shown in FIG. In addition, the upper thread having a larger diameter hits the concave arc surface 16 of the thread detachment prevention member 15, and as a result, the diameter can be suppressed from both the right and left sides. Further, since the height of the yarn detachment preventing member 15 exceeds the outer end surface of the wheel 10, for example, the upper thread T
Even if the diameter is increased by an extreme outside the, it can be suppressed. By suppressing the diameter expansion of the upper thread T as described above, the upper thread T does not come off from the wheel 10, so that an erroneous thread breakage detection is not performed and extra labor such as rewinding is eliminated. .

Note that the present invention is not limited to the configuration of the above-described embodiment, and can be embodied by appropriately changing, for example, as follows, without departing from the spirit of the invention. (1) The thread guide member 14 is formed as a continuous projection along the entire outer periphery of the gap.

[0024]

As described in detail above, claims 1 or 4 to
According to the thread detector of the sewing machine according to any one of the aspects of the eighth aspect, the work of winding the upper thread on the thread detector can be easily performed.

As described in detail above, claims 2, 9, 10
Alternatively, according to the sewing machine thread detecting device of the eleventh invention, since the upper thread does not come off the wheel, extra labor such as rewinding can be omitted.

According to the third aspect of the present invention, the above effects can be simultaneously obtained.

[Brief description of the drawings]

FIG. 1 is a front view of a thread detector of a sewing machine according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a perspective view of a main part of a thread detecting device of the sewing machine.

FIG. 4 is a sectional view taken along line IV-IV of FIG. 1;

FIG. 5 is a sectional view taken along line VV of FIG. 1;

FIG. 6 is a perspective view of an essential part showing a procedure for winding the upper thread around the thread detecting device.

FIG. 7 is a front view showing a state in which detachment of an upper thread is suppressed by a thread detachment prevention member.

FIG. 8 is a front view of a thread detection device of a conventional sewing machine.

FIG. 9 is a cross-sectional view showing a problem in a conventional thread detection device of a sewing machine.

[Explanation of symbols]

 Reference Signs List 4 Mounting stand 7 Thread detector 10 Wheel 11 Axis 12 Rotary encoder 14 Thread guide member 15 Thread detach prevention member 16 Concave arc surface 16 T Upper thread

Claims (11)

[Claims] 1. A thread for a sewing machine, wherein a wheel for winding a thread is provided at one end of a shaft rotatably supported on a mounting table, and a detector for detecting rotation of the wheel and the shaft is provided at the other end of the shaft. In the detection device, a thread guide member that blocks a thread on an outer periphery of the gap so as to prevent the thread from winding around the shaft from a gap between the wheel and the mounting base is provided on the mounting base. Thread detector. 2. A thread for a sewing machine, wherein a wheel for winding a thread is provided at one end of a shaft rotatably supported on a mounting base, and a detector for detecting rotation of the wheel and the shaft is provided at the other end of the shaft. The detection device is characterized in that a thread detachment preventing member is provided on the outer periphery of the wheel so as to prevent the loop-shaped yarn wound around the wheel from expanding from the loop and coming off the wheel, thereby preventing the diameter from expanding. Sewing machine thread detector. 3. A thread of a sewing machine, wherein a wheel for winding a thread is provided at one end of a shaft rotatably supported on a mounting base, and a detector for detecting rotation of the wheel and the shaft is provided at the other end of the shaft. In the detection device, a thread guide member that blocks a thread on the outer periphery of the gap so that the thread is not wound around the shaft from the gap between the wheel and the mount is provided on the mount, and the loop is wound around the wheel. A thread detecting device for a sewing machine, further comprising a thread detachment preventing member provided on the outer periphery of the wheel so as to prevent the thread from becoming larger from the wheel by expanding its loop. 4. The thread detecting device for a sewing machine according to claim 1, wherein the thread guide member is provided on the entire outer periphery of the gap or at least partially on the side of the entire outer periphery on which the yarn starts to be wound. 5. The sewing machine according to claim 1, wherein the thread guide member is a projection projecting from the mounting stand at the same height as the inner end surface of the wheel or at a height slightly exceeding the inner end surface. Yarn detection device. 6. The thread detecting device for a sewing machine according to claim 5, wherein the projection is a projection continuous with the outer periphery of the gap. 7. The thread detecting device for a sewing machine according to claim 5, wherein the projections are a plurality of projections arranged on the outer periphery of the gap. 8. The thread of the sewing machine according to claim 1, wherein the outer peripheral surface of the yarn guide member is a slope that approaches the outer peripheral edge of the wheel from the outside as it goes from the mounting base to the wheel. Detection device. 9. The sewing machine according to claim 2, wherein the thread detachment prevention member is provided on the entire outer periphery of the wheel or at least two parts of the entire outer periphery that are separated from each other. Thread detector. 10. The thread detachment preventing member according to claim 2, which is a projection protruding from the mounting base at the same height as the outer end surface of the wheel or at a height exceeding the outer end surface. The thread detecting device of the sewing machine according to the above. 11. The thread detecting device for a sewing machine according to claim 2, wherein the inner peripheral surface of the thread detachment preventing member is a concave arc surface following the outer periphery of the wheel.