JPH0513346Y2 - - Google Patents

Description

[Detailed description of the invention] [Purpose of the invention] (Field of industrial application) This invention is a thread take-up threader that loosens or tensions the upper thread by manipulating the upper thread threaded through the sewing needle of the sewing machine. This invention relates to a guide mechanism that guides a hook for use. The present invention can be used in a take-up guide mechanism used in small household cycle sewing machines.

(Prior Art) A sewing machine is provided with a thread take-up for loosening or tensioning an upper thread threaded through a sewing needle. As a guide mechanism for the take-up thread, a guide part is disposed in the housing, and the hook of the take-up thread for operating the upper thread is guided along the guide part to reciprocate. In a sewing machine having a structure in which a guide part is arranged in this way, the guide part is arranged on one side of the hook of the thread take-up, as a representative row of the guide part is disclosed in Japanese Patent Application Laid-Open No. 44-30179. .

(Problem to be solved by the invention) By the way, in a sewing machine in which the guide section is disposed on one side of the hook as described above, when the upper thread is tensed due to thread tightening, etc. The hook is pushed and the hook tries to fall sideways. If the hook is guided along the guide portion while lying down, problems such as poor hook sliding and thread tightening may occur, and good sewing cannot be expected.

The present invention was devised in view of the above-mentioned circumstances, and its purpose is to provide a thread take-up guide mechanism for a sewing machine that improves the problems of hook sliding and thread tightening, and allows for good sewing performance.

[Structure of the invention] (Means for solving the problems) A sewing machine according to the invention includes a housing having a rotatable main shaft and a guide portion having a guide strip extending in one direction, and a main shaft held by the housing and having a main shaft at the tip. It consists of a take-up lever having a hook that reciprocates along a guide strip by the rotation of the guide section, and two guide strips of the guide part are arranged in parallel with a fixed interval apart, and the hook of the take-up bin is It is characterized in that it has two engaging portions provided on both sides thereof and engages with each guide strip, and is disposed between the two guide strips.

The housing has a main shaft rotatably held by the housing and a guide portion for guiding the hook of the take-up. The main shaft is the drive shaft,
Connected to the drive motor. In consideration of reducing the height of the housing, it is desirable that the main shaft be disposed horizontally within the housing.
The guide portion has a guide strip extending in one direction. Two guide strips are arranged in parallel at a constant interval. The guide strip can be formed by extending in a substantially horizontal direction. The guide portion may be formed by a wall of the housing having a slit extending in one direction through the wall of the housing. In this case, the guide strips are two longitudinal edges facing each other across the width of the slit hole.

The hook for threading the thread take-up has two engaging parts on both sides. The engaging portion engages with the guide strip.
The engaging portion can be formed by a groove or a protrusion. The tenbin is
A low-height rising arm that is connected to the main shaft and swings around the take-up shaft as the main shaft rotates;
It can be formed with a horizontally long arm that is pivoted to a rising arm and moves in a substantially horizontal direction. The take-up shaft can be arranged almost horizontally parallel to the main shaft. Usually, a hook for threading is provided at the end of the horizontally long arm. Note that the hook can be formed by bending a wire into an arc shape.

A needle bar arm having a needle at the tip can be provided adjacent to the take-up pin and can be swingably disposed in the housing. In order to swingably hold the needle bar arm, a swing shaft is disposed in the housing in a horizontal direction, and the needle bar arm is pivotally supported on the swing shaft. It is desirable that the axis of the swing shaft and the upper surface of the needle plate held in the housing and having the needle insertion hole are set at approximately the same height. If the heights are approximately the same in this way, when the needle held at the tip of the needle bar arm oscillates, the centripetal direction of the oscillating needle, the top surface of the needle plate, and the axis of the oscillating shaft are aligned. The direction of the line connecting the needles substantially coincides with the direction of the line connecting the needles, which is advantageous for vertically inserting the needle into the fabric held on the upper surface of the needle plate. Considering that the needle is inserted perpendicularly into the cloth, it is desirable that the swing axis, which is the center of swing of the needle bar arm, be located far from the needle at the tip of the needle bar arm. It is preferable that the needle bar arm is formed of a low rising portion pivotally supported on a swing shaft and a horizontally long arm portion pivotally supported on the rising portion. In this case, since the needle is attached to the tip of the horizontally long arm, the distance between the needle and the swing axis can be increased by the length of the horizontally long arm, which increases the radius of curvature when the needle swings. Furthermore, since the height of the rising portion is low, it is advantageous for reducing the height of the housing.

(Operation) When the main shaft rotates with the upper thread passed through the needle and the fabric set below the needle, the thread take-up operates, and the hook reciprocates along the guide strip of the guide section, and the upper Loosen or tension the thread.

When the upper thread is tense, the hook tends to fall, but since the hook is located between two guide strips, and the engaging portions on both sides of the hook engage with the guide strip, Even if the upper thread is tensed, the hook will not fall.

(Embodiment) Hereinafter, an embodiment of the sewing machine according to the present invention will be described with reference to the drawings.

The sewing machine according to this embodiment is applied to a small cycle sewing machine for home use that performs embroidery. Each component will be explained below with reference to the drawings. Figure 1 is a perspective view of the entire sewing machine, Figure 2 is an exploded perspective view of the main parts of the sewing machine, Figure 3 is a bottom view of the sewing machine with the bed cover removed, and Figure 4 is taken along the - line in Figure 3. A sectional view, FIG. 5 is a sectional view taken along line V-V in FIG. 3, FIG. 6 is a sectional view taken along line - in FIG. 3,
Figure 7 is a plan view with the top cover removed.
FIG. 8 is a cross section taken along the line -- in FIG. 3. Furthermore, the first
3 is a plan view of the sewing machine with the top cover removed, and FIG. 14 is a sectional view taken along the line X--X in FIG. 13.

(Structure) The housing 1 will be explained mainly with reference to FIG. As shown in FIG. 1, the housing 1 includes:
A bed housing 10 that forms a lower part and is thinner in the height direction, an arm housing 11 that rises upward from the end of the bed housing 10 and extends laterally, and is detachably attached to an opening on the upper surface of the arm housing 11. It consists of a top cover 12 and a top cover 12. The bed housing 10 has an embroidery frame 1
3 is installed. The embroidery frame portion 13 is an outer frame 13
0 and an inner frame 131. Operator 13
0a to sandwich the cloth to be embroidered between the outer frame 130 and the inner frame 131. This embroidery frame section 13 is the moving section 1
32 and the motor part 10 of the housing 1
It is moved in the X and Y directions by an X-direction motor and a Y-direction motor, which are built-in stepping motors. The X-direction motor and Y-direction motor are driven by the CPU built into housing 1.
The embroidery frame section 13 is controlled and driven by a control section whose main components are moved to move the embroidery frame section 13 to appropriate positions in the X direction and the Y direction. Note that an embroidery program is stored in the memory element of the control section, and the X-direction motor and the Y-direction motor are driven in accordance with this program.

A needle plate 14 having a needle insertion hole 140 is attached to the upper surface of the bed housing 10 of the housing 1 and is located below the tip of the arm housing 11. Note that the Y motor is Y in FIG.
Illustrated as motor 16.

The needle bar arm 2 will be explained with reference to FIGS. 2, 4, and 5. The needle bar arm 2 is formed of a laterally elongated arm portion 20 that extends obliquely laterally and becomes narrower toward the tip, and a wider rising portion 21 that is integral with the laterally elongated arm portion 20 and has a lower height. Needle bar arm 2
The needle bar 22 is attached to the hole 20b at the tip of the horizontally long arm portion 20 with a set screw 223.
A needle clamp 23 is attached to the needle clamp screw 2 at the lower end of the needle bar 22.
30, and the sewing needle 2 is attached to the needle clamp 23.
4 is installed. Rising part 2 of needle bar arm 2
The height of needle bar 22 and needle 24 is set so that needle 24, which swings about swing shaft 30, is perpendicular to throat plate 14 or nearly vertical.
It is set taking into consideration factors such as the height of the Needle bar arm 2
A presser bar 25 is slidably inserted into a hole 20a at the tip of the horizontally long arm portion 20. The upper end of the presser bar 25 is prevented from coming off by a retaining ring 250 and an O-ring 251. A metal presser body 26 having a cloth presser function is attached to the lower end of the presser bar 25.
An elastic body 32 made of ring-shaped rubber and enhancing the buffering function and the presser function is attached to the lower surface of the presser main body 26 so as to surround the needle hole 260. In the elastic body 32, the guide bar 27 attached to the presser main body 26 is inserted through the guide hole 28 of the needle bar arm 2, so that the presser bar 25 is prevented from rotating. A spring 29 is interposed between the presser foot body 26 and the needle bar arm 2.

Further, the explanation will be made mainly with reference to FIGS. 2, 4, and 5. A sliding shaft 30 is inserted into a hole 21a formed in the lower part of the rising portion 21 of the needle bar arm 2, with the sliding shaft 30 oriented in the horizontal direction. The swing shaft 30 includes a bearing 300, a spring 301, and a retaining ring 30 shown in FIG.
As shown in FIG. 4, the housing 1 is pivotally supported in the horizontal direction by a wall 10a near a recess 10b formed in the bed 101 of the bed housing 10 of the housing 1. In order to swing the needle bar arm 2, the fourth
A drive motor 40 is held on a motor mounting plate 400 which is fastened with a screw 400a to a strut 10h formed in the bed housing 10 of the housing 1 shown in the figure, an intermediate pulley 41 with a large diameter for deceleration, and an intermediate pulley 41. 41 and a pulley 40a press-fitted into the motor shaft of the drive motor 40.
8, a large gear 42 that meshes with the gear 41a of the intermediate pulley 41, a main shaft 43 that rotates together with the large gear 42 as shown in FIG. 2, and a top fixed to the end of the main shaft 43 with a pin 440. bin crank 44
and a needle bar crank rod 45 having a hole 45a that fits into a cam portion 44a of the take-up crank 44, as shown in FIG. As shown in FIG. 5, a spherical bearing 43a is inserted through the main shaft 43. As shown in FIG. 3, the spherical bearing 43a is held via a mounting portion 10e of the bed housing 10 and a holder 10h tightened by a screw 10q. As shown in FIG. 3, the intermediate pulley 41 is supported by a support shaft 49. The support shaft 49 is attached to the motor mounting plate 400 via a retaining ring 49a.

As shown in FIG. 2, a shaft 46 is inserted into the hole 45c of the connecting rod portion 45b of the needle bar crank rod 45 and the hole 21b of the rising portion 21 of the needle bar arm 2.
It is held through a. Here, as is clear from FIG. 5, the cam portion 44a of the crank 44 is eccentric with respect to the axis of the main shaft 43. Therefore, when the main shaft 43 rotates, the eccentric cam portion 44a rotates, so that the needle bar crank rod 45
The connecting rod portion 45b reciprocates in the vertical direction. As a result, the rising portion 21 of the needle bar arm 2 reciprocates in the vertical direction, so that the needle bar arm 2
0 as the center and in the direction of arrow A shown in FIG.
It swings back and forth in the A′ direction.

As shown in FIG. 2, a thread take-up 6 is provided beside the needle bar arm 2 to loosen or tension the needle thread. The take-up bin 6 is a rising arm 6 with a low height.
0 and a horizontally long arm 61 pivotally supported by a bottle 60a. The take-up bin 6 operates by a so-called slider link mechanism. That is, a slide shaft 62 is fixed to a hole 6a formed at the lower end of the rising arm 60 of the take-up 6. A powder alloy bushing 64 functioning as a slider is slidably inserted into the slide shaft 62, and the bushing 64 is held by bushing holders 65 on both sides of the slide shaft 62 in the axial direction.

As shown in FIG. 4, a take-up shaft 63 is inserted through a pivot hole 60a formed near the hole 6a of the rising arm 60 of the take-up 6 via a bearing 60b. The take-up shaft 63 is pivotally supported to swing around a take-up shaft 63. Here, as shown in FIG. 2, a crank bin 47 having a U-shaped portion 470 having a U-shaped tip is rotatably fitted into the hole 44b of the take-up bin crank 44. As shown in FIG. 4, the U-shaped portion 470 holds the bushing 64. Horizontal arm 6 of take-up bin 6
An upwardly directed hook 66 is provided at the tip of the hook 1, and two engaging grooves 67 as engaging portions are provided on both sides of the hook 66. Figure 4 and 1
As shown in FIG.
are arranged horizontally via a set screw 15a. A slit hole 150 extending in one direction is formed in the guide portion 15. Slit hole 150
extends between the take-up top dead center and the take-up bottom dead center of the hook 66. The slit hole 150 is formed by two guide strips 151, which are the peripheral edges in the longitudinal direction. Two guide strips 151 and hook 6
The engagement grooves 67 on both sides of 6 fit and engage with each other. Therefore, the guide strip 151 and the engagement groove 67 of the hook 66 remain engaged with each other, and the hook 66 is guided in a substantially horizontal direction along the guide strip 151. At this time, since the guide strips 151 are located on both sides of the hook 66, it is advantageous to prevent the hook 66 from falling. As shown in FIG. 14, a take-up cover 69 is disposed above the hook 66 and in close proximity to the hook 66. The ceiling bottle cover 69 is a ceiling wall 69 that covers the upper part of the hook 66.
0, a projecting wall 6 extending downward from the side wall 691 and the ceiling wall 690 and close to the hook 66 through a small gap;
92. As shown in FIG. 14, a thread take-up lever 17 and an upper thread sensor 18 are disposed in the arm housing 11 via a thread take-up spring 17a.

As shown in FIG. 4 and FIG.
It is located below. The hook 7 is fixed to the hook shaft 79 with a set screw 792, and the hook shaft 79 is attached to the spherical bearing 7.
Bed housing 1 of housing 1 via 90
0 in the horizontal direction and parallel to the main axis 43. As shown in FIG. 3, the spherical bearing 790 is held in a mounting portion 10i in the bed 10 via a holder 10L tightened with a screw 10k. In addition, in FIG. 4, 7a is a hook retainer fixed with a screw 7b.

As shown in FIG. 6, a small timing gear 78 is attached to the hook shaft 79 via a set screw 780. On the other hand, as shown in FIGS. 2 and 5,
A clutch operating ring 70, a one-way clutch 71 made of a leaf spring, a ring 72, and a large timing gear 73 are attached to the main shaft 43. The large timing gear 73 includes a shaft portion 731 and a set screw 7.
It is connected to the main shaft 43 via 3a and interlocks with the main shaft 43. Slit 70 in clutch actuation ring 70
0 is engaged with a protrusion 710 of a one-way clutch 71. Projection piece 711 of one-way clutch 71
is engaged with the slit 730 of the large timing gear 73.

As shown in FIGS. 2 and 8, a solenoid 74 is attached to the clutch operating ring 70, and a clutch operating pawl 7
5 are located next to each other. Hole 75 of clutch actuation pawl 75
A support shaft 49 is inserted through a, and the clutch actuating pawl 75
swings around the hole 75a. The pin 75b of the clutch actuating pawl 75 is connected to the rod 7 of the solenoid 74.
40 through a retaining ring 742. The clutch operating pawl 75 is a spring 76
The clutch actuating pawl 75 rotates around the hole 75a due to the biasing force, and the pawl 751
attempts to press the pawl 701 of the clutch actuating ring 70, but the solenoid 74 causes the rod 740 to
Since the clutch actuating ring 70 is being sucked through the pawl 701, the clutch actuating ring 70 is disengaged from the pawl 701. Therefore, the one-way clutch 71 operates in the direction of tightening, and the main shaft 43 and the large timing gear 73 are connected via the one-way clutch 71 that is tightened.
Therefore, when the large gear 42 rotates and the main shaft 43 rotates, the large timing gear 73 rotates in conjunction. Then, the toothed timing belt 77 rotates, the small timing gear 76 rotates, and the hook shaft 7
7, The pot 7 rotates. In this embodiment, the number of teeth of the large timing gear 73 is set to twice the number of teeth of the small timing gear 78. Therefore, when the large timing gear 73 rotates once, the small timing gear 7
8 rotates twice. That is, when the main shaft 43 rotates once and the needle bar arm 2 reciprocates once, the hook 7 rotates twice. Note that the end 76a of the spring 76 is locked in a locking hole 823 of a bracket 80, which will be described later.

When it is desired to stop the rotation of the hook 7 to finish sewing, etc., the above-mentioned control section operates the solenoid 74. Therefore, the rod 740 moves forward and the clutch operating pawl 75 rotates around the hole 75a, and the pawl 751
and the pawl 701 of the clutch actuation ring 70 are engaged. Therefore, the one-way clutch 71 operates in the opening direction, and even though the large gear 42 rotates, the main shaft 43 and the large timing gear 73 do not rotate. The timing gear 73 does not rotate. Large timing gear 7
3 is stopped and the timing belt 77 does not operate.
Rotation of the pot 7 is stopped. As shown in FIG. 8, the solenoid 74 is mounted inside the bed housing 10 via screws 743 to a motor mounting plate 400 held by a support 10h formed on the bed 10.

As shown in FIGS. 2 and 8, a bracket 80 is attached above the timing belt 77. As shown in FIGS. The bracket 80 is formed of a metal plate and includes a fixing part 81 having a fixing hole 810 and a holding part 82 that rotatably supports a tension pulley 820.
and a deformable portion 83 located between the holding portion 82 and the fixed portion 81. In the deformed part 83,
A slit 830 is formed to facilitate deformation;
The holding portion 82 is bent into a U-shaped cross section so as to have a reinforcing rib effect to ensure strength. A protruding piece 821 is formed on the holding part 82, and the protruding piece 821
A threaded hole 822 with a female thread is formed in the hole. As shown in FIG. 8, the bracket 80 is fixed to the lower surface of the head 101 of the bed housing 10 by inserting a set screw 810a into a fixing hole 810. Here, an adjustment screw 84 with a male thread is screwed into a screw hole 822 of the projection piece 821. The tip of the adjusting screw 84 is in contact with an abutting portion 10c provided on the lower surface of the head 101 of the bed housing 10. Therefore, when the adjustment screw 84 is operated and turned, the screw hole 822 screwed into the adjustment screw 84 is displaced in the vertical direction through the deformation of the deformation part 83, and the holding part 82 of the bracket 80 and the tension Pulley 8
20 is adjusted in the vertical direction, and the tension of the timing belt 77 is adjusted. Therefore, loosening of the timing belt 77 can be prevented, which is advantageous in ensuring the synchronization between the hook 7 and the needle bar arm 2, that is, the synchronization between the upper thread and the lower thread.

In addition, as shown in FIGS. 2 and 5, the main shaft 4
A detection plate 85 consisting of a large circle and a small circle is attached to 3, and a handwheel 86 manually operated by the user is also attached with a set screw 861. The rotation of the detection plate 85, that is, the rotation of the main shaft 43, is detected by a photo interrupter 850.
The photo interrupter 850 is attached to the bed housing 1
0 and functions as a visual sensor. Note that when the handwheel 86 interferes with the embroidery work, such as when the thread gets tangled, the operator manually turns the handwheel 86 with the drive motor 40 stopped to rotate the main shaft 43. This is for correcting the positions of the hook 7, needle bar arm 2, and take-up pin 6. Note that the spherical bearing 860 is
As shown in the figure, a holder 1 is fastened to a mounting portion 10d of a bed housing 10 with a screw 10f.
It is held through 0h.

(Function) Now, the function of the sewing machine according to the above embodiment will be explained. First, the user
At the same time, as shown in FIG. 13, the needle thread from the set thread cassette 19 is hung on the thread take-up lever 17, the hook 66, and the thread guide plate 17b, and the needle thread is also hung on the needle 24. With the upper thread threaded in this manner, the operating switch is operated to rotate the drive motor 40. Therefore, drive motor 4
0 rotation causes the belt 48, intermediate pulley 41, large gear 42, and main shaft 43 to rotate counterclockwise in FIG. Then, as described above, the cam portion 44a of the take-up crank 44, which is eccentric with respect to the main shaft 43, rotates, so that the connecting rod portion 45b of the needle bar crank rod 45, which is fitted into the cam portion 44a, swings in the vertical direction. do. Therefore, the needle bar arm 2 connected to the connecting rod portion 45b by the shaft 46
The rising portion 21 of moves vertically, and as a result,
Direction of arrow A and arrow shown in FIG. 4 on needle bar arm 2
It swings back and forth about the swing shaft 30 in the A' direction.
Therefore, the needle 24 passes through the needle hole 260 of the presser foot body 26 and is inserted into the needle insertion hole 140 of the needle plate 14.

The horizontally long arm portion 20 of the needle bar arm 2 is long in the horizontal direction and the swing shaft 30 is located far from the needle 24, so that the radius of curvature around which the needle 24 swings is large. Since the needles 24 are set at substantially the same height as the upper surface of the needle 24, the needle 24 that has swung in the direction of the arrow A is perpendicular or nearly perpendicular to the throat plate 14 in the vicinity of the throat plate 14. Therefore, the needle 24 is inserted into the cloth held in the embroidery frame 13 and into the needle insertion hole 140 in a vertical or nearly vertical state. FIG. 9 shows a state where the needle bar arm 2 is fully raised and the needle bar is at the top dead center.
FIG. 11 shows a state in which the needle bar arm 2 is at the bottom dead center of the needle bar. As the main shaft 43 rotates, the needle bar arm 2 swings in the order of FIGS. 9, 10, 11, and 12.

In this embodiment, when the main shaft 43 rotates, the large timing gear 73 is connected via the one-way clutch 71.
rotates, and the hook 7 rotates in synchronization with the swinging of the needle bar arm 2 via the timing belt 77, small timing gear 78, and hook shaft 79. In other words, when the needle bar arm 2 reciprocates once, the hook 7 rotates twice. However, when the needle 24 passes through the needle insertion hole 140 through the cloth held in the embroidery frame 13 above the needle plate 14, the needle thread 33 hooked on the needle 24 is exposed to water from the hook 7. The bobbin thread 35 gets caught,
A stitch is formed in the cloth of the embroidery frame 13 by the upper thread 33 and the lower thread 35.

Next, the operation of the take-up 6 will be explained. Main shaft 4
3 rotates counterclockwise, the take-up crank 4
The bushing 6 held in the U-shaped portion 470 of 4
4 rotates about the axis of the main shaft 43 counterclockwise, that is, in the direction of arrow C shown in FIG. At this time, the crank pin 47 rotates relative to the hole 44b of the take-up crank 44, so the U-shaped portion 470 and the bushing 64 change direction. When the bushing 64 rotates in the direction of arrow C as described above, the bushing 64 held by the U-shaped portion 470 slides on the slide shaft 62 and repeatedly slides back and forth along the length of the slide shaft 62. At this time, as shown in FIG. 4, the base end 62b of the slide shaft 62 is restricted by the hole 6a, so as the bushing 64 rotates in the direction of arrow C, as shown in FIGS. , the inclination angle of the slide shaft 62 changes. With such fluctuations in the tilt angle of the slide shaft 62, the take-up lever 6 to which the slide shaft 62 is fixed
The rising arm 60 of
It swings back and forth in the D′ direction.

On the other hand, as described above, the engagement groove 67 of the hook 66
is guided by the guide strip 151 of the guide portion 15, so the hook 6 at the tip of the horizontally long arm 61 of the take-up lever 6
6 is approximately horizontal, that is, in the direction of arrow E and arrow
It reciprocates in the E′ direction between the top dead center of the take-up and the bottom dead center of the take-up.

Furthermore, the operation of the take-up 6 will be explained. When the needle bar arm 2 is at the top dead center of the needle bar, as shown by the solid line in FIG.
When rotated in the direction of arrow C about , the slide shaft 62 whose inclination angle is regulated by the bushing 64 and the hole 6a rises slightly as shown by the two-dot chain line in FIG. Therefore, the rising arm 60 begins to swing in the direction of arrow D' in FIG. Therefore, the hook 66 of the take-up lever 6 moves in the direction of arrow E', that is, in the return direction, and approaches the top dead center. FIG. 10 shows a state in which the take-up thread 6 is at the top dead center position where the upper thread is taut.

By the way, when the needle thread is tense, the hook 66 tends to fall toward the guide strip 151 side by being pushed by the needle thread, but as mentioned above, the hook 66 is disposed between the two guide strips 151, Since the engagement grooves 67 on both sides of the hook 66 are engaged with the guide strips 151, the hook 66 is prevented from falling even if the upper thread is tensed. Furthermore, when the take-up crank 44 rotates from the top dead center position of the take-up 6 shown in FIG. 10 and the bushing 64 further rotates in the direction of arrow C shown in FIG. As shown, the slide shaft 62, whose inclination angle is regulated by the bushing 64 and the hole 6a, is tilted in a slightly more reclined direction than before. As a result, the rising arm 60 of the take-up bin 6
begins to swing in the direction of arrow D, and the hook 66
It begins to move in the direction of arrow E shown in the figure. As a result, the tension on the upper thread hanging on the hook 66 is relaxed. still,
Even if the upper thread becomes loose and comes off the hook 66, the upper thread will remain in the arm housing 1 because of the thread take-up cover 69.
The needle thread does not come off from the top plate 110 of the arm housing 11, and the needle thread is placed on the top plate 110 of the arm housing 11, and when the hook 66 moves again, the needle thread is automatically removed from the top plate 110 of the arm housing 11.
Can be hung on.

Here, FIG. 10 shows the state just before the needle 24 is inserted into the fabric. Immediately before the needle 24 is inserted into the fabric, the upper thread is cut in order to prevent the upper thread from being cut due to tension. We need to loosen the tension. Therefore, as described above, the hook 66 moves in the direction of the arrow E to loosen the upper thread hooked on the hook 66.

In FIG. 11, the state in which the bushing 64 is further rotated in the direction of arrow C is shown by a solid line. In Figure 11, the first
The hook 66 has moved further toward the needle 24 than in the case of Figure 0, loosening the upper thread. When the take-up crank 44 further rotates and the bushing 64 rotates in the direction of arrow C shown in FIG. 11 from the state shown by the solid line in FIG. Approach the direction of sleep in a nearly horizontal position. Therefore, the rising arm 60 of the take-up 6 further advances its swing in the direction of arrow D shown in FIG. Therefore, the hook 66 of the take-up lever 6 is connected to the needle 24.
Move further to the side and approach the bottom dead center of the balance. FIG. 12 shows a state where the take-up lever 6 has advanced to the bottom dead center of the take-up lever.

By the way, the above-mentioned take-up 6 has a quick return mechanism. That is, from the state of the take-up top dead center shown by the solid line in Fig. 10, through the state shown by the solid line and the two-dot chain line in Fig. 11, until the take-up bottom dead center state shown by the solid line in Fig. 12. between, that is, hook 66
When the needle 24 is directed toward the needle 24, the bushing 64 must rotate around the main shaft 43 by an angle equivalent to 1, as shown in FIG. On the other hand, during the period from the bottom dead center of the take-up shown by a solid line in FIG. 12 to the top dead center of the take-up shown by a solid line in FIG. When returning to the side, it is sufficient for the bushing 64 to rotate around the main shaft 43 by an amount equivalent to the angle θ2. Here, the relationship is θ1>θ2. Therefore, the hook 66 returns quickly and returns in a short time.

(Effects) In the present embodiment described above, the hook 66 tends to fall down when the upper thread is tensioned, but the hook 66 is disposed between the two guide strips 151, and the hook 66
Since the engagement grooves 67 on both sides of the hook 6 are engaged with the guide strips 151, the hook 66 can be prevented from falling even if the needle thread is tensed.

In this embodiment, the needle bar arm 2 is configured to swing relative to the housing 1 about the swing axis 30, so compared to a conventional sewing machine in which the vertical bar-shaped needle bar moves back and forth in the vertical direction. , the overall height of the sewing machine can be lowered. In particular, since the length of the horizontally long arm portion 20 of the needle bar arm 2 is long, the distance from the axis of the swing shaft 30, which is the center of swing, to the needle 24 can be increased.
Therefore, the radius of curvature when the needle 24 swings toward the needle insertion hole 140 can be increased, and the needle 2
4 is advantageously inserted perpendicularly to the needle insertion hole 140.

In addition, the swing shaft 30, main shaft 43, take-up shaft 63, and hook shaft 79 are arranged horizontally, and the needle bar crank rod 4
5. Since the take-up crank 44 and the like are arranged in the bed 10 which is thinner in the height direction, the housing 1
It is advantageous to reduce the overall height.

[Effect of the invention] As mentioned above, in the sewing machine according to the invention, the hook tends to fall when the upper thread is tensed, but the hook is arranged between two guide strips, and the hooks on both sides of the hook tend to fall down. Since the engaging portion and the guide strip are engaged, even if the upper thread is tensed, the hook is prevented from falling. Therefore, unlike conventional methods, it is possible to improve the problem of hook sliding and thread tightening when the hook moves back and forth.
You can expect good sewing results.

In the sewing machine according to the present invention, in particular, the needle bar arm is
When the sewing machine is formed with a horizontally long arm and a low rising part, the length of the horizontally long arm is long, so the distance from the center of rotation to the needle can be increased while lowering the height of the sewing machine. Therefore, the radius of curvature when the needle swings toward the fabric can be increased while the height of the housing is kept low, which is advantageous for inserting the needle perpendicularly into the fabric.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention; Fig. 1 is a perspective view of the entire sewing machine, Fig. 2 is an exploded perspective view of the main parts, Fig. 3 is a bottom view of the sewing machine with the bed cover removed, and Fig. 4 is a perspective view of the sewing machine. is a sectional view taken along the - line in Fig. 3,
Figure 5 is a sectional view taken along the line V-V in Figure 3, Figure 6 is a sectional view taken along the - line in Figure 3, Figure 7 is a plan view with the top cover and take-up cover removed, and Figure 8 is a sectional view taken along the line -V in Figure 3. The figure is a cross-sectional view taken along the line - in Fig. 3, Fig. 9 is a side view showing the top dead center of the needle bar arm, Fig. 10 is a side view showing the top dead center of the take-up lever, and Fig. 11 is a bottom dead center of the needle bar arm. FIG. 12 is a side view showing the bottom dead center of the take-up. FIG. 13 is a plan view with the top cover removed, and FIG. 14 is a sectional view taken along line X--X in FIG. 13. In the figure, 1 is a housing, 10 is a bed housing, 11 is an arm housing, 12 is a top cover, 15 is a guide part, 150 is a slit hole, 15
1 is a guide strip, 2 is a needle bar arm, 20 is an oblong arm portion, 21 is a rising portion, 22 is a needle bar, 24 is a needle, 3
0 is the swing axis, 43 is the main shaft, 44 is the take-up crank, 45 is the needle bar arm crank, 6 is the take-up, 63 is the take-up shaft, 64 is the bushing, 66 is the hook, 6
Reference numeral 7 indicates an engaging groove (engaging portion).

Claims (1)

[Claims for Utility Model Registration] (1) A housing having a rotatable main shaft and a guide section having a guide strip extending in one direction; It consists of a take-up bin with a reciprocating hook, two guide strips of the guide section are arranged parallel to each other at a constant interval, and the hooks of the take-up bin are provided on both sides of the guide strip. A thread take-up guide mechanism for a sewing machine, characterized in that it has two engaging portions that engage with each guide strip, and is disposed between the two guide strips. (2) The housing has a swing shaft parallel to the main shaft, and a needle bar arm that is swingably held relative to the housing via the swing shaft and has a needle at its tip. The thread take-up guide mechanism of the sewing machine described in Scope 1.