JPH0740374Y2 - Hand stitch sewing machine thread tension adjusting device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a thread tightening adjustment for adjusting the thread tightening of each stitch in a sewing machine that forms a wavy stitch (hand stitch) on a cloth. Regarding the device.

[Prior Art] As a sewing machine that forms a wavy hand-sewn stitch using one thread instead of two threads as in a lockstitch sewing machine, for example, FIG. There is something like.

In the figure, 1 is a needle plate having a needle drop hole 1a, 2 is an upper needle bar provided above the needle plate 1, and 3 is a lower needle provided below the needle plate 1 so as to face the upper needle bar 2. It's a stick.

At the lower end of the upper needle bar 2 and the upper end of the lower needle bar 3,
A grip portion is provided for gripping and releasing the sewing needle N having both ends formed in a sharpened shape, and the sewing needle N is alternately held by this grip portion, and the sewing needle N is passed while passing the needle plate 1.
Is to be handed over. That is, the upper needle bar 2 and the lower needle bar 3 are the needle drop holes 1a formed in the needle plate 1.
When the upper needle bar 2 holding the sewing needle N reaches the bottom dead center and releases it as shown in FIG. 7 (b), the upper needle bar 2 holds the sewing needle N alternately. At the same time, the lower needle bar 3 located at the top dead center grips and lowers the lower end of the sewing needle N penetrating the needle drop hole 1a, and as shown in FIG. When the top dead center is reached again, the upper needle bar 2 located at the bottom dead center grips the upper end portion of the sewing needle N,
After that, as shown in FIG. 7A, the sewing needle N is moved up and down. Further, in synchronization with this sewing needle passing operation, a well-known cloth conveying mechanism (not shown) such as a feed dog intermittently conveys cloth, and a lower looper 4 provided below the needle plate 1 It is adapted to rotate together with the arm 6 which holds this. This lower looper 4 catches the loop yarn I1 formed when it is gripped by the lower needle bar 2 and slightly rises from the bottom dead center (see FIG. 8), and the free end of the yarn I
I1 is pulled out from the cloth W below the needle plate 1.

As described above, by the cooperation of the sewing needle N, the cloth conveying mechanism, and the lower looper 4, the hand stitch S as shown in FIGS. 9 (a) and 9 (b) is formed on the cloth W. .

[Problems to be Solved by the Invention] However, in the above conventional hand stitch sewing machine,
The tension generated in the thread when the lower looper 4 pulls out the free end I1 of the thread I from the cloth W causes excessive thread tightening of the formed seam S, which causes puckering and deteriorates the texture of the seam. There was a problem that In addition, this phenomenon becomes more prominent as the remaining amount of the yarn I becomes longer, so that the thread tightening changes depending on the amount of the remaining amount of the yarn.

The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to provide a thread tightening adjusting device for a hand stitch sewing machine that can always obtain an appropriate thread tightening regardless of the thread pulling operation by the lower looper. And

[Means for Solving the Problems] The present invention alternately raises and lowers an upper needle bar and a lower needle bar, which are provided above and below a needle plate so as to face each other, and transfers a sewing needle between both needle bars. The hand stitch is designed to catch the looper thread that is formed when the sewing needle goes up through the cloth by the lower looper that rotates in synchronization with the lifting operation of the sewing needle and pull the thread from the cloth to the lower side of the needle plate. In the sewing machine, a linear member held on the needle plate and a moving mechanism that moves the linear member along the upper surface of the needle plate in synchronization with the lifting operation of the upper needle bar are provided. A retracting mechanism for moving the linear member back and forth between a crossing position that is slightly rearward of the sewing needle dropping position and orthogonal to the stitch forming line to a retracted position that does not intersect the stitch forming line; Move the linear member at the position together with the cloth in the cloth conveyance direction. A horizontal movement mechanism for moving the linear member to the intersecting position immediately before the cloth conveying operation by the cloth conveying mechanism is started, and the linear member at the intersecting position is woven according to the cloth conveying operation. After the free end of the sewing thread is removed from the cloth by the thread catching mechanism, the linear member is moved to the retracted position.

[Operation] In the present invention, the sewing needle is pulled out upward from the cloth upper surface, and the linear member crosses the stitch forming line slightly behind the needle drop position in the cloth conveying direction immediately before the cloth conveying operation is started. When the needle drops onto the upper surface of the cloth, the linear member is inserted into the stitches and the stitches Is in contact with the outer periphery of the linear member and is curved. After this, the lower looper catches the loop thread formed on the lower surface of the cloth, and the linear member is positioned in the stitch until the free end of the thread is pulled out from the cloth. Evacuate from. As a result, a margin is formed in the seam by the amount of bending by the linear member, so that the seam is not overtightened, and good thread tightening can always be obtained.

[Embodiment of the Invention] An embodiment of the present invention will be described below with reference to FIGS. 1 to 6. The same or corresponding parts as those in the above-mentioned conventional example are designated by the same reference numerals, and detailed description thereof will be omitted.

1 and 2 are a plan view and a side view of this embodiment.

In the figure, 11 is a guide base fixed on the needle plate 1,
The guide shaft 16 is attached to the guide base 11 in the cloth conveying direction (direction A).
It is inserted so that it can move forward and backward in the direction orthogonal to (B1 and B2 directions), and at one end of the guide shaft 16, as shown in FIG. 12 is installed. A pin fixing block 13 is vertically movably fitted to the side surface of the pin mounting base 12, and a pin (linear member) 14 is fixed to the pin fixing block 13 with a screw 13a. The pin 13 projects along the direction of arrow B, and the pin mount 12
By moving in the B1 direction (projection direction), the tip end portion is positioned so as to be orthogonal to the stitch forming line L. The intersection of the pin 14 and the stitch forming line L is set slightly forward of the needle drop position P in the cloth conveying direction so as not to interfere with the sewing needle N. The pin mount 12
Of the locking screw provided on the stopper 15
It is regulated by contact with 15a, and the amount of movement thereof can be adjusted by adjusting the locking screw 15a. Also, the pin fixing block 13
It can be fixed integrally with the pin mount 12 by the screw 13a (see FIG. 3), and its fixing position can be adjusted in the vertical direction if necessary.

On the other hand, the other end of the operating shaft 16 is provided with a swing shaft through a square piece 17.
One end of 18 is rotatably connected. This swing shaft 18
Has an intermediate portion rotatably supported by a support shaft 20 of a holding member 19 provided on the sewing machine frame M, and a roller at the other end.
22 is pivoted. Further, the swing shaft 18 is urged in the counterclockwise direction in FIG. 2 by a spring 21, and the urging force causes the roller 22 to be constantly in pressure contact with the outer peripheral surface of the cam 23.

The cam 23 is attached to a shaft 25 pivotally supported by the machine frame M of the sewing machine, and a bevel gear 24 is integrally fixed to one side surface thereof. Further, 27 is a bevel gear provided on the drive shaft 26, and meshes with the bevel gear 24. The drive shaft 26 is interlocked with a drive source (not shown) that raises and lowers the needle bars 2 and 3, and rotates in synchronization with the raising and lowering operations of the needle bars 2 and 3.

It should be noted that the 16, 17, 18, 23 constitute a retracting mechanism, and a horizontal moving mechanism is constituted by 12, 15, 16, 16a, and further the moving mechanism X is constituted by the above 11 to 26 including both mechanisms. It is configured.

Further, 28 is a cloth pressing member for pressing the cloth W placed on the needle plate 1 in the vicinity of the needle drop position P, and is designed to be lifted and lowered in synchronization with the lifting operation of the sewing needle N.

Reference numeral 29 denotes a thread hooking finger provided between the needle plate 1 and the lower needle bar 3 (see FIG. 5 (e)), which is horizontally rocked at a predetermined timing based on the lifting operation of the needle bars 2 and 3. By the swinging motion, the thread I from the stitch S to the sewing needle N is pulled laterally.

Further, 30 and 31 are an upper feed tooth and a lower feed tooth (cloth feed mechanism) which are vertically arranged to face each other.
Numeral 1 is adapted to intermittently convey the cloth W in the direction of arrow A in synchronization with the raising and lowering operations of the needle bars 2 and 3.

The other configurations including the needle bars 2 and 3 are the same as those shown in the above-mentioned conventional example.

Next, the operation will be described based on the above configuration.

In the moving mechanism X, when the drive shaft 26 rotates, the rotation is transmitted to the cam 23 via the bevel gears 27 and 28, and the shaft 2
Rotate around 5. This allows this rotating cam 24
The roller 22 follows the outer peripheral surface of the, and while the cam 24 makes one rotation, the swinging member 18 makes one reciprocating motion in the arrow C and D directions about the support shaft 20.

When the swing member 18 moves in the arrow C direction,
The operating shaft 16 is pressed via the square piece 17 and moves in the direction of arrow B1. As a result, the pin mounting base 12 and the pin holding base 13a
At the same time, the pin 14 moves in the B1 direction, and as shown in FIG. 3 (b), the pin 14 is slightly behind the drop position P of the sewing needle N in the stitch forming direction and at a position orthogonal to the stitch forming line L ( Crossover position) Project to P1.

When the swinging member 14 moves in the arrow D direction from this state, the operating shaft 16 moves in the B2 direction via the square piece 17, and together with this, the pin mount 12, the pin fixing block 13, and the pin 14 are moved.
Both move in the B2 direction, and the tip of pin 14 has a stitch forming line L
Retreat to a position that does not intersect with.

In this way, the pin 14 reciprocates by the movement mechanism X, which is performed at the timing shown in FIG. 5 with respect to the stitch forming operation.

That is, immediately before the upper needle bar 2 holding the sewing needle N reaches the top dead center, that is, immediately before the cloth conveying operation is started,
The pin 14 projects to the intersecting position P1 (see FIG. 5 (a)). At this time, the cloth pressing member 28 is descending on the cloth W, and at the time of protrusion, the pin 14 is inserted into the pin insertion groove 28a formed in the cloth pressing member 28 as shown in FIG.

After that, the cloth pressing member 28 rises, and the pin 14 starts to rotate together with the cloth W in the C direction which is substantially the same as the cloth conveying direction A. Therefore, the sewing needle N is at the top dead center (see FIG. 5 (b)).
When the seam S3 is formed by penetrating the cloth W,
As shown in FIG. 5 (c), the pin 14 will be located in the seam S3. That is, the seam S3 is stretched over the pin 14 and is in a curved state.

After this, the sewing needle N is transferred to the lower needle bar 3 and the sewing needle N
When the cloth reaches the bottom dead center, the cloth conveying operation is started, and the pin 14 also starts moving again together with the conveying operation.
The relative position with respect to is held (Fig. 5 (d), (e)). At this time, the thread hooking finger 29 hooks the thread from the sewing needle N to the stitch S and pulls it sideways. As a result, an appropriate tension is applied to the thread on the stitch side, and a proper thread tightness is obtained in the stitch formed by the preceding stitch forming operation.

After that, when the sewing needle N slightly rises from the bottom dead center, the lower looper 4 captures the thread loop formed in the portion from the thread insertion hole of the sewing needle N to the free end of the thread, and the free end of the thread is The needle plate 1
(See Fig. 5 (f)). Then, when the free end of the thread is completely pulled out to the lower surface of the needle plate 1, the operating rod 16 moves in the b2 direction and returns to the initial position, so that the pin 14 is pulled out from the stitch S3. Therefore, at seam S3,
The pin 14 forms a margin for bending. That is, since the curved state of the seam S3 is held by the pin 14 during the thread drawing operation of the lower looper 4, even if some thread is drawn by the drawing operation, the margin is caused by the bending of the thread. This can be sufficiently offset by the minute, and the thread tightening becomes excessive, so that it can be prevented. Therefore, puckering does not occur in the sewn state.

By adjusting the fixing position (height) of the pin fixing base 13 with respect to the pin mounting base 12, a seam can be provided with a margin as necessary. Further, in the above-mentioned embodiment, the operating rod 16 is moved in the B1 direction, and the pin mount
Although the pin 14 is rotated in the cloth conveying direction by bringing the pin 12 into contact with the stopper 15, the movement of the pin 14 in the cloth conveying direction and the operation of projecting the pin 14 to the intersecting position are different. It is also possible to use the drive source of. For example, even if a cylinder or a solenoid for moving the pin mount 12 forward and backward in the cloth conveying direction and its reverse direction is provided and they are operated in synchronization with the raising and lowering of the needle, substantially the same effect as the above embodiment can be expected. . Therefore, the present invention is not particularly limited to the above embodiment.

[Effects of the Invention] As described above, in the thread tightening adjusting device for a hand stitch sewing machine according to the present invention, a linear member is inserted into a seam to be formed, and the thread catching mechanism determines the state of the insertion. Since it is held until it is pulled out below the needle plate, by removing the pin from the seam after that, it is possible to form a curved margin in the seam and always obtain a good thread tightness. be able to. Therefore, puckering does not occur after sewing, and excellent sewn product quality can be obtained.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of the present invention, FIG. 2 is a front view of what is shown in FIG. 1, and FIG. 3 (a) is an enlarged front view showing a mounting state of pins in the embodiment. FIG. 4B is a plan view of what is shown in FIG. 4A, and FIG. 4 is an enlarged perspective view showing a cloth pressing member and a pin in the embodiment.
FIG. 5 is an explanatory side view showing the operation in the embodiment, and FIG.
FIG. 7 is a perspective view showing a state in which a pin is inserted into a seam in the same embodiment, FIG. 7 (a) is a partially longitudinal side view showing a main part of a conventional hand stitch sewing machine, FIG. 7 (b), FIG. 8C is a side view showing the operating state of the one shown in FIG.
The figure is a side view showing the operating state of the lower looper in the one shown in FIG. 7, and FIGS. 9 (a) and 9 (b) are a vertical side view and a plan view showing a hand stitch. In the figure, 1 ... needle plate 2 ... upper needle bar 3 ... lower needle bar 4 ... lower looper (lower thread catching mechanism) 14 ... pin (linear member) 12 ... pin mounting first (horizontal moving mechanism) ) 15 …… Stopper (horizontal moving mechanism) 16 …… Operating axis (horizontal moving mechanism) 16a …… Joint part (horizontal moving mechanism) 16 …… Operating axis (withdrawal mechanism) 17 …… Square piece (withdrawal mechanism) 18… … Rotating shaft (withdrawal mechanism) 23 …… Cam (withdrawal mechanism) N …… Sewing needle W …… Cloth S …… Seam

Claims (1)

[Scope of utility model registration request] 1. A sewing needle having upper and lower ends formed in a sharpened shape and having a thread insertion hole through which a sewing thread is inserted, and a gripping mechanism for holding and releasing the upper portion of the sewing needle. Along with the needle plate, it has an upper needle bar that vertically moves up and down on a needle drop hole formed in the needle plate, and a gripping mechanism that holds and releases the lower end portion of the sewing needle, and below the needle plate, A lower needle bar that moves up and down alternately with the upper needle bar along a vertical line, and a cloth transport mechanism that intermittently transports the cloth placed on the needle plate in synchronization with the lifting operation of each needle bar. The sewing needle is passed between the upper needle bar and the lower needle bar, and the sewing needle is alternately penetrated from above and below the cloth placed on the needle plate. By supplementing the thread loop formed below the needle plate when it rises, the free end side of the sewing thread is In a hand stitch sewing machine provided with a thread catching mechanism for pulling out toward one side, the linear member held on the needle plate and the linear member on the upper surface of the needle plate in synchronization with the lifting operation of the upper needle bar. A moving mechanism for moving the linear member along the stitch forming line from a crossing position orthogonal to the stitch forming line at a position slightly rearward of the sewing needle drop position in the cloth conveying direction. A retracting mechanism for advancing and retracting between the retracted position and a horizontal moving mechanism for moving the linear member in the intersecting position in the cloth conveying direction together with the cloth are provided immediately before the cloth conveying operation by the cloth conveying mechanism is started. After moving the linear member to the intersecting position and moving the linear member in the intersecting position in the cloth conveying direction with the cloth conveying operation, the thread catching mechanism pulls the free end of the sewing thread from the cloth. , Move the linear member to the retracted position Thread tightening adjuster hand sewing machine, characterized in that to.