JPH0810476A - Cloth presser of sewing machine - Google Patents

Abstract

PURPOSE:To obtain a perfect stitch good as a top stitch, in the cloth presser of a sewing machine using a DPS hook, by avoiding the generation of a hitch stitch without paying fine attention to various stitching directions such as square stitching or reciprocal stitching using a circular arc. CONSTITUTION:A cloth pressing frame 124 movable in straight line directions of X-Y crossing each other almost at a right angle on the basis of a needle falling position O and the synthetic direction of them is constituted so as to be inclined at a predetermined angle theta with respect to the X-Y directions. Concretely, in a sewing machine equipped with a DPS hook and the needle 113 inclined by about 15 deg. with respect to the rotary plane of the hook, the cloth pressing frame 124 is inclined by about 30 deg. in the counterclockwise direction centering around the needle falling position O.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cloth pressing device for a sewing machine, and more particularly to a cloth pressing device for a sewing machine using a so-called DP type half-rotary hook as an inner hook.

[0002]

2. Description of the Related Art There are a full rotary hook and a half rotary hook as a center hook of a sewing machine. Among them, a half rotary hook has a needle between a needle thread loop and a bobbin, that is, a bobbin lower thread lead-out. A half-turn hook with a needle drop position between the point and the tip of the inner hook (hereinafter called DBS hook), and a half-turn hook with an upper thread loop between the needle and the bobbin, that is, the needle drop position and the bobbin. Half-turn hook (hereinafter referred to as DPS) with a hook point inside the hook
There is a kettle).

First, in a sewing machine having a DBS shuttle, a perfect stitch is formed when it is forwardly fed (sending from right to left as seen from an operator), and a hitch stitch is formed when it is backwardly feeding (sending from left to right). Therefore, it is widely used for general lock stitches. That is, in the general lock stitch, the normal straight stitch needs to be a perfect stitch due to its stitching quality, and it is not necessary for the thread to be frayed at the beginning and the end of the sewing. Therefore,
DBS hook is used. The sewing machine having the DBS shuttle is not suitable for octagonal stitching.

A sewing machine having a DPS shuttle is also known (see, for example, Japanese Patent No. 99353), and since perfect stitches are formed by both forward and reverse feeds, it is suitable for eight-sided sewing, but is currently not available. It has not become popular. This DPS hook has good adaptability to changes in cloth thickness and is suitable for use with thick and thick yarns.

FIG. 12 shows the structure of a general sewing machine balance and a needle bar driving device, where 1 is a main shaft (upper shaft), and 2 is a main shaft.
Is a crank portion, 21 is a counterbalance, 22 is a balance, 23 is a needle bar crank, 24 is a needle bar crank rod, 25 is a needle bar,
113 is a needle. Further, FIG. 13 shows the structure of the shuttle drive device following FIG. 12, 3 is a crank rod, 4 is a large pendulum, 4a is a large pendulum shaft, 5, 6 are gears, 7 is a lower shaft, 8 is a large hook, 109 is a driver, 111 is a middle kettle (DBS
(Hook), 11 is a presser foot for the inner hook, 100 is a bobbin case, 103
Is a bobbin.

FIG. 14 shows a conventional bobbin case 100 used in a general half-turn hook. As shown in the figure, the bobbin case 100 is provided with rotation preventing corners 101. A threading hole 102 is formed in the corner 101. A bobbin thread 104 fed from a bobbin 103 housed in the bobbin case 100 is drawn out through the thread passing hole 102 of the corner 101.

Here, the bobbin case is installed in the sewing machine in a frontward direction for convenience of insertion and removal by an operator. Regarding the rotating direction of the inner hook, since the sewing thread of the sewing machine is basically Z twist, it is necessary to determine the rotating direction of the inner hook in the direction in which the needle side needle thread is twisted. In the case of the hook, the rotation direction is determined in the clockwise direction as seen from the operator side, and in the case of the DPS hook, the rotation direction is determined in the counterclockwise direction.

By the way, in a general sewing machine using the DBS shuttle 111, a stitch area diagram as shown in FIG. 15 is obtained. This stitch region diagram shows perfect stitches (P / S) and hitch stitches (H / S) when sewn radially from the center of the circle toward the outer periphery. That is, as shown in FIG.
Of 0 °, the left 120 ° range is the H / S area where the hitch stitch (H / S) occurs, and the 15 ° range on each side is the danger of hitch stitch (H / S). Area. Therefore, in the feed direction of 360 °, the range from 120 ° to 150 ° on the left side on the left side is the hitch stitch (H
/ S) has a possibility of occurring.

Therefore, for example, in the case of square stitching such as sewing a label with a perfect stitch (P / S), there is a possibility that a hitch stitch (H / S) may occur on the left side and the inner side area ( It is necessary to avoid the range from 120 ° to 150 °), but it is often used in the case of square stitching. When feeding to the front side when sewing to the back side and when feeding to the right side when sewing to the left side, hitch A stitch (H / S) is generated, and the appearance as a top stitch is deteriorated. Further, in a general sewing machine using a DBS shuttle, there is no effective means for avoiding the feeding directions to the front side and the right side.

[0010]

Next, the case of using the DBS shuttle and the case of using the DPS shuttle will be compared and examined. FIG. 16 compares the case of using the DBS shuttle and the case of using the DPS shuttle. In FIG. 16 (a), 111 is the DBS shuttle, 11
2 is the center hook point, 113 is the needle, 114 is the upper thread, R is the upper thread loop, and in FIG. 16 (b), 115 is DP
The S hook and 116 are the tips of the middle hook.

As for the distance between the needle drop point and the bobbin thread leading point on both sides, as shown in FIG. 16 (a), the DBS hook 1
As for the distance between the needle drop point and the bobbin thread deriving point when 11 is used, as shown in FIG. 16B, the needle drop point and the bobbin thread deriving point when DPS hook 115 is used. There is a problem that the distance between and becomes long. That is,
From the basic configuration, in the DPS hook 115, the distance between the lower thread leading point and the needle drop point is compared with the distance between the needle drop point and the lower thread leading point when the DBS hook 111 is used.
There is no choice but to shift (offset) laterally by the width of the race of the inner hook + α (plus alpha).

As a sewing machine using the DPS shuttle, it is possible to construct a shuttle driving device as shown in FIG. 1, for example. In FIG. 1, 1 is the upper axis and 2 is the upper axis.
Is a crank portion, 3 is a crank rod, 4 is a large pendulum, and 5,
6 is a gear, 7 is a lower shaft, 8 is a cauldron, 9 is a driver, 10
Is a DPS shuttle, 11 is an inner hook holder, 12 is a bobbin, and 13 is a bobbin case. Further, 21 is a counterbalance, 31 is a needle plate, and 32 is a thread cutting device.

In a sewing machine using such a DPS shuttle 10, a stitch area diagram as shown in FIG. 10 can be obtained. That is, as shown in FIG.
In the middle and right side, the hitch stitch (H
/ S) is generated in the H / S area and 1 on each side
The range of 5 ° is a dangerous area where hitch stitch (H / S) occurs. Therefore, in the feed direction of 360 °, the range of 20 ° to 50 ° on the right side and the front side is the hitch stitch (H / S).
It was an area that could occur.

For this reason, for example, in the case of square stitching such as stitching a label with a perfect stitch (P / S), the right side and front side area (where the hitch stitch (H / S) may occur ( 20 ° to 50 °) must be avoided, and hitch stitch (H) is used when feeding to the back side, which is often used for square stitching.
/ S) occurs, and the appearance as a top stitch deteriorates, so that a laborious work of avoiding the feeding direction to the back side is involved.

FIG. 11 shows a normal presser frame, which is X
On the upper surface of the XY table 121 that is controlled and moved in the direction (left-right direction) and the Y direction (front-back direction).
22 can be stacked. This cloth holding frame 12
2 is supported by a support arm 123, and the XY table 121 and the cloth pressing frame 122 move together in the X and Y directions. Such an XY table 121
When the cloth is sandwiched between the cloth holding frame 122 and the sewing machine, the cloth moves from the X direction to the Y direction and from the Y direction to the X direction with respect to the position of the needle 113 in the case of square sewing. As is apparent from the stitch area diagram shown in FIG. 10, a hitch stitch (H / S) is obtained by feeding to the back side while sewing to the front side.
Will occur.

However, when a hitch stitch (H / S) occurs, the appearance becomes poor as a top stitch, so that a laborious work to avoid such a feeding direction to the back side is forced. Further, not only in the case of the square stitching, but also in various hand-moving directions such as reciprocal stitching using an arc, it is necessary to pay close attention to avoid the occurrence of the hitch stitch (H / S). There is a problem of doing.

Therefore, an object of the present invention is to eliminate the occurrence of hitch stitches as a sewing machine using a DPS hook, while eliminating the need for detailed consideration in various needle movement directions such as square stitching and reciprocating stitching using arcs. SUMMARY OF THE INVENTION It is an object of the present invention to provide a sewing machine presser device capable of obtaining a good perfect stitch as a top stitch.

[0018]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides an XY which is substantially orthogonal to the needle drop position.
A cloth pressing device of a sewing machine having a cloth pressing frame movable in the linear direction and the combined direction thereof, wherein the cloth pressing frame is tilted around the needle drop position by a predetermined angle with respect to the XY direction. It is characterized by being configured as.

The cloth pressing device for a sewing machine according to a first aspect of the present invention is characterized in that, for example, the cloth pressing frame is tilted counterclockwise by about 30 ° about the needle drop position.

Further, in the cloth pressing device for a sewing machine according to claim 1 or 2, the sewing machine is provided with, for example, a DPS shuttle and a needle tilted by about 15 ° with respect to a rotation plane of the shuttle. It has a feature.

[0021]

According to the present invention, by tilting the cloth pressing frame around the needle drop position by a predetermined angle with respect to the XY directions, for example, D
In the case of a sewing machine using a PS hook, by sewing a pattern along the presser foot frame, it becomes possible to avoid the occurrence of hitch stitches. Therefore, particularly in reciprocal sewing using a perfect stitch arc, it is possible to sew an arc up to a larger angle and obtain a good top stitch.

By tilting the cloth pressing frame counterclockwise by about 30 ° about the needle drop position, for example, in the case of a sewing machine using a DPS hook, a pattern is sewn along the cloth pressing frame. As a result, the occurrence of hitch stitches can be most effectively avoided. As a result, when performing reciprocal sewing using a perfect stitch circular arc, the circular arc can be sewn to an angle as large as possible, and a good top stitch can be obtained.

In the case of a sewing machine equipped with a DPS shuttle,
By tilting the needle about 15 ° to the rotary plane of the hook,
In the stitch area diagram using the DPS hook, the stitching direction can be shifted by a predetermined angle to avoid the occurrence of hitch stitches. This makes it possible to obtain a good perfect stitch as a top stitch, especially when performing square stitching such as sewing a label with a perfect stitch, and fine care is unnecessary. Therefore,
As a sewing machine using a DPS hook, it is possible to widely support various hand movement directions such as square sewing and reciprocating sewing using an arc.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of a cloth pressing device for a sewing machine according to the present invention will be described below with reference to FIGS. First, Fig. 1
FIG. 1 is an exploded perspective view showing a configuration of a hook drive device of a sewing machine as an example to which the present invention is applied, and 1 is a spindle (upper shaft), 2
Is a crank portion, 3 is a crank rod, 4 is a large pendulum, and 5,
6 is a gear, 7 is an output shaft (lower shaft), 8 is a large hook, 9 is a driver, 10 is an inner hook (DPS hook), 11 is an inner hook presser, 12
Is a bobbin, 13 is a bobbin case, 14 is a corner, 21 is a counterbalance, 31 is a needle plate, and 32 is a thread cutting device.

Although not shown, a crank portion 2 is provided on an upper shaft 1 which is a main shaft of a sewing machine having a pulley to which a driving force from a motor is inputted via a belt on the right end side in the figure. The upper end of the crank rod 3 is connected to the lower end of the crank rod 3 is connected to the eccentric position of the pendulum 4. A gear 6 meshing with a gear 5 provided on the large pendulum 4 is provided on a lower shaft 7 which is an output shaft, and a fixed large hook 8 is arranged on the sewing machine main body side on the left end side in the figure of the lower shaft 7. . In this way, the conversion mechanism is constituted by the crank mechanism (the crank portion 2, the crank rod 3, the large pendulum 4) that converts the entire rotational movement of the upper shaft 1 into the swinging movement of the lower shaft 7.

A driver 9 integrally connected to the left end of the lower shaft 7 in the figure is rotatably accommodated in the large cauldron 8, and a DPS shuttle 10 which is an inner cauldron driven by the driver 9 is rotatably mounted. It is housed in. This DP
The S hook 10 is slidably incorporated into the race 8a on the inner circumference of the large hook 8 at the surface of the race 10a on the outer circumference thereof, and a sword tip 10b is provided on the extension of the race 10a. This D
The rotation direction of the PS shuttle 10 by the driver 9 is a counterclockwise direction.

At the opening of the cauldron 8, the inner hook presser 1
1 is attached and fixed, and the bobbin case 13 accommodating the bobbin 12 is inserted from the opening portion of the inner hook holder 11 into the large hook 8.
Is loaded. The bobbin case 13 is provided with a corner 14 for preventing rotation that protrudes to the outer peripheral side, and the inner hook presser 11 is formed with an engagement groove 11a with which the corner 14 can be engaged.

As shown in FIG. 2, the bobbin case 13 is
The corner 14 has a shorter amount of protrusion toward the outer peripheral side than the conventional one, and the corner 14 does not have a threading hole as in the conventional case. Therefore, the bobbin thread 15 wound around the bobbin 12 does not pass through the corner 14 and
3 is still derived from the outer circumference. Specifically, the specific length of the corner 14 is set based on the positional relationship of the driver 9. That is, the upper end of the corner 14 of the bobbin case 13 is lower than the upper surface of the driver 9 in the range of 5 ° to 35 ° in the rotation angle of the upper shaft 1 with the needle bar top dead center as a reference (0 °). It is assumed that it is formed so that

A counterbalanced cone 21 is integrally connected to the left end of the upper shaft 1 in the figure, and a balance 22 and a needle are provided from the counterbalanced cone 21 onward, as shown in FIG. Bar crank 23, needle bar crank rod 24, needle bar 25, needle 1
13 are connected. Further, above the cauldron 8,
A needle plate 31 is arranged, and a thread cutting device 32 and the like are arranged between them.

According to the above sewing machine, first, the driving force of the motor is input to the pulley via the belt to rotate the upper shaft 1 all the way, and the counterbalance 21, the balance 22, the needle bar crank 23, the needle bar crank. The needle 113 is driven via the rod 24 and the needle bar 25, and at the same time, the entire rotational movement of the upper shaft 1 is converted from the crank portion 2 to the swinging movement of the pendulum 4 via the crank rod 3. Furthermore, the swinging motion of this large pendulum 4 is
The lower shaft 7 is transmitted from the gear 5 to the gear 6 to be a half-rotation motion. Therefore, the DPS shuttle 10 driven by the driver 9 integrated with the lower shaft 7 makes a half-rotation movement in the counterclockwise direction.

Next, FIG. 3 shows an incliningly set cloth holding frame according to the present invention, in which 113 is a needle and 121 is an XY.
A table, 123 is a support arm, and 124 is a cloth pressing frame. First, the needle 113, which originally has a needle hole oriented at a right angle to the plane of rotation of the shuttle, is attached to the needle bar 25 at an angle of 15 ° in the counterclockwise direction.

Further, the cloth pressing frame 124 supported by the supporting arm 123 is controlled by a driving device (not shown) to move in a controlled X-direction (left-right direction) and a Y-direction (front-back direction). Is stacked on the upper surface with a cloth (not shown) interposed therebetween, and as is known, moves vertically and horizontally in synchronization with the XY table 121. As shown in the figure, the cloth pressing frame 124 has a substantially rectangular shape elongated diagonally in the lateral direction, that is, in the counterclockwise direction about the needle drop point O of the needle 113 with respect to the XY table 121. It is tilted by a predetermined angle θ.

As described above, in the sewing machine using the DPS shuttle 10, the needle 113, which originally has a needle hole oriented at a right angle to the plane of rotation of the shuttle, is attached to the needle bar 25 by inclining it counterclockwise by 15 °. A stitch area diagram in the attached state is shown in FIG. That is, as shown in FIG. 4, the feed direction is 360 °.
In the middle and right side, the hitch stitch (H
/ S) occurs in the H / S area, and the left 10 ° range and the right 20 ° range are the hitch stitches (H
/ S) is a dangerous area in which it occurs. Then, in comparison with the stitch area of FIG. 10, a hitch stitch (H /
The dangerous area where S) occurs is shifted to the right by 5 °.

Therefore, the feeding direction 3 is almost the same as in FIG.
In 60 °, the range of 20 ° to 50 ° on the right side on the right side is a region where hitch stitches (H / S) may occur, but 5 ° to the right side on the front side (counterclockwise direction). The area is excluded from the dangerous area. In this way, since the range of 5 ° to the right side on the front side (counterclockwise direction) is excluded from the area where the hitch stitch (H / S) may occur, for example, the perfect stitch (P / S) ), Square sewing such as sewing labels can be performed well. In this way, as shown in FIG. 4, the H / S region and its dangerous region can be canceled from the direction of the rectangular stitch (vertical and horizontal directions). Moreover, the H / S area and its dangerous area can be reduced to approximately 1/3 or less of the conventional one using the DBS shuttle shown in FIG.

By the way, in the sewing machine using the DPS hook 10, in addition to the fact that the needle 113 can be tilted by 15 ° with respect to the rotary plane of the hook, square sewing can be performed, and in addition, for example, reciprocation using an arc is performed. It is necessary to avoid the occurrence of hitch stitches (H / S) in various hand movement directions such as sewing as much as possible. Fig. 5 shows a hitch stitch area check sheet. This check sheet is made up of radial arrows in 5 ° increments and a circle surrounding it, and is divided into 90 ° in the XY directions. 0 ° to 90 ° → D region, 90 ° to 180 ° → A region, 180 ° to 270 ° → B region, 270 ° to 0 ° → C, respectively.
As an area.

The hitch stitch area check sheet shown in FIG. 5 shows a case where all directions of 360 ° are radially sewn from the center at intervals of 5 °. Hitch stitch (H / S)
As is clear from the stitch area diagram of FIG.
~ D11 may occur in the range of about 50 °, and other A area, B area, C area, D0 and D12 ~
The D17 direction is a perfect stitch (P / S).
And, in particular, the circular arc portions (the range of about 50 ° of A1 to A11 and the range of about 50 ° of C1 to C11) indicated by thick lines on the outer peripheral portion are respectively in the CW direction (clockwise direction) and the CCW direction (counterclockwise direction). It shows a portion where a hitch stitch (H / S) appears when sewing in a clockwise direction. Therefore, other A12-A17, B area, C12-C17,
The D area has a perfect stitch (P / P) in either the CW direction (clockwise direction) or CCW direction (counterclockwise direction).
You can sew with S).

From the above, the following can be understood. When a pattern is set in parallel with the XY table 121, A12 to A17 to
Up to about 60 ° of B1 to B6 and C12 to C17 to D1 to D
6 is up to about 60 °, which is the range where perfect stitch (P / S) is possible. If the pattern can be tilted, A12 to A1
In order to use the range of 7-B area and the range of C12-C17-D area sufficiently, by tilting upward by 30 °, in reciprocating arc sewing, up to about 120 ° of A12-A17-B area. About 120 of C12-C17-D region
Up to ° is the range where perfect stitch (P / S) is possible. In unidirectional circular stitching, perfect stitches (P / P) can be made up to a maximum of about 300 °, excluding thick line parts (range of about 50 ° of A1 to A11 and range of about 50 ° of C1 to C11).
S) is a possible range.

From the above consideration, as shown in FIG.
Pattern is counterclockwise with respect to Y direction (upward to the right)
It can be seen that tilting by 30 ° makes it possible to perform reciprocal arc sewing sufficiently using the range of the A12 to A17 to B regions and the range of the C12 to C17 to D regions. Therefore, as described above, the predetermined angle θ (see FIG. 3) for inclining the cloth pressing frame 124 counterclockwise with respect to the needle drop point O with respect to the XY table 121 is 30 °.

Next, a specific sewing example will be described. FIG. 7 shows a reciprocating sewing pattern using arcs, for example, FIG.
FIG. 9 shows Example 1 of sewing when the normal presser frame 122 shown in FIG. 2 is set in parallel with the XY table 121. In this way, the reciprocating stitching pattern using arcs is
-When set parallel to the Y table,
The range that can be sewn with perfect stitch (P / S) is
A maximum of 60 ° arc is possible. FIG. 8 shows a sewing example 2 in which the reciprocating sewing pattern using the same circular arc is set in parallel with the XY table 121 by using the ordinary presser frame 122 shown in FIG. Similar to the sewing example 1 in FIG. 7, the range in which all stitches can be performed by perfect stitch (P / S) can be up to an arc of 60 °.

FIG. 9 shows a cloth holding frame 124 in which the reciprocating sewing pattern using the same arc is tilted in the counterclockwise direction by a predetermined angle θ (= 30 °) around the needle drop point O shown in FIG. 13 shows a sewing example 3 in which the XY table 121 is used while being tilted by 30 ° and set. In this way, the entire reciprocating sewing pattern using the circular arc is used as the work clamp frame 1
By inclining 30 ° to the right using 24, the range that can be sewn by perfect stitch (P / S) is possible up to an arc of 120 ° at the maximum.

In the above embodiments, the cloth holding frame having a rectangular shape elongated in the lateral direction is used. However, the present invention is not limited to this, and the shape of the cloth holding frame can be freely selected. is there. In addition, it goes without saying that specific detailed structures and the like can be appropriately changed.

[0042]

As described above, according to the cloth pressing device of the sewing machine of the present invention, the cloth pressing frame is moved around the needle drop position in the XY direction.
Depending on the configuration tilted by a predetermined angle with respect to the direction,
In the case of a sewing machine using a PS hook, by sewing a pattern along the presser foot frame, it is possible to avoid the occurrence of hitch stitches. Therefore, especially in the case of reciprocal stitching using a perfect stitch circular arc, It is possible to sew an arc up to a large angle and obtain a good top stitch.

As described in claim 2, if the cloth pressing frame is tilted about 30 ° counterclockwise around the needle drop position, for example, in the case of a sewing machine using a DPS hook, By sewing the pattern along the presser frame, the occurrence of hitch stitches can be most effectively avoided.Therefore, it is possible to sew an arc up to the largest angle possible when performing reciprocal sewing using an arc with a perfect stitch. You can get a nice top stitch.

Further, in the case of the sewing machine equipped with the DPS shuttle as described in claim 3, the needle is approximately 1 with respect to the rotating plane of the shuttle.
If it is tilted about 5 °, in the stitch area diagram using the DPS hook, the stitching direction can be shifted by a predetermined angle to avoid hitch stitches. Therefore, square stitching, such as stitching a label with a perfect stitch, is possible. In this case, it becomes possible to obtain a perfect perfect stitch as the top stitch while eliminating the need for detailed consideration. Therefore, as a sewing machine that uses a DPS shuttle,
It becomes possible to widely support various hand movement directions such as square sewing and reciprocating sewing using an arc.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing a configuration of a hook drive device of a sewing machine as an example to which the present invention is applied.

FIG. 2 is a perspective view showing a bobbin case.

FIG. 3 is a perspective view of a main part showing a tilted and set cloth holding frame according to the present invention.

FIG. 4 is a stitch area diagram in a sewing machine in which a needle is attached at an angle of 15 ° using a DPS shuttle.

FIG. 5 is a plan view showing a hitch stitch area check sheet.

FIG. 6 is a plan view showing a pattern check example.

FIG. 7 is a plan view showing a sewing example 1 when a reciprocal sewing pattern using arcs is set parallel to an XY table.

[FIG. 8] Similarly, a reciprocating sewing pattern using an arc is used for XY.
It is a top view showing example 2 of sewing when it sets up parallel to a table.

[FIG. 9] Similarly, a reciprocating sewing pattern using an arc is used for XY.
It is a top view which shows the example 3 of sewing when it inclines 30 degrees with respect to a table, and sets it.

FIG. 10 is a stitch area diagram in a sewing machine using a DPS shuttle.

FIG. 11 is a perspective view of a main part showing a normal presser frame.

FIG. 12 is an exploded perspective view showing configurations of a general sewing machine balance and a needle bar driving device.

FIG. 13 is an exploded perspective view showing the configuration of the shuttle drive device, following FIG. 12;

FIG. 14 is a perspective view showing a conventional bobbin case used for a general half-turn hook.

FIG. 15 is a stitch area diagram in a general sewing machine using a DBS shuttle.

16 (a) is a partially cutaway side view showing the distance between the needle drop point and the bobbin thread deriving point when the DBS hook is used, and FIG. 16 (b) is D.
It is a partially broken side view showing the distance between the needle drop point and the bobbin thread deriving point when the PS hook is used.

[Explanation of symbols]

 1 main shaft (upper shaft) 2 crank part 3 crank rod 4 large pendulum 5,6 gear 7 output shaft (lower shaft) 8 large hook 9 driver 10 inner hook (DPS hook) 11 inner hook holder 12 bobbin 13 bobbin case 14 angle 15 bottom Thread 21 Balance screen 22 Balance 23 Needle bar crank 24 Needle bar crank rod 25 Needle bar 31 Needle plate 32 Thread cutting device 113 Needle 121 XY table 123 Support arm 124 Cloth holding frame

Claims (3)

[Claims] 1. An X which is substantially orthogonal to the needle drop position as a reference.
A cloth pressing device for a sewing machine, comprising a cloth pressing frame movable in a linear direction of -Y and a combined direction thereof, wherein the cloth pressing frame is provided around the needle drop position in a predetermined direction in the XY direction. A cloth presser for a sewing machine, which is configured to be tilted at an angle. 2. The cloth pressing device for a sewing machine according to claim 1, wherein the cloth pressing frame is tilted counterclockwise by about 30 ° about the needle drop position. 3. The sewing machine comprises an inner hook having a sword tip between the needle drop position and a bobbin thread leading point, and a needle tilted by about 15 ° with respect to the plane of rotation of the hook. The cloth pressing device for a sewing machine according to claim 1 or 2, characterized in that: