JPH0810480A - Hook device of sewing machine - Google Patents

Abstract

PURPOSE:To obtain a perfect stitch good as a top stitch, in the hook device of a sewing machine using a DPS hook or a full-rotating DP hook, by avoiding the generation of a hitch stitch while dispensing with fine attention especially at the time of square stitching. CONSTITUTION:The output shaft 17 cooperated in synchronous relation to the rotation of a main shaft 1 to drive a DPS hook or full-rotating DP hook having a point 10b catching the needle thread loop formed between a needle cast-off position and the bobbin thread lead-out point of a bobbin 12 is constituted so that the axial line thereof is inclined at a predetermined angle around the needle cast-off position. Concretely, the axial line of the output shaft 17 is inclined by about 20 deg. in a counterclockwise direction centering around the needle cast-off position. An intermediate shaft 7 to which shaking motion is transmitted by a conversion means converting the rotary motion from the main shaft l is formed and, further, a bevel gear 16 and a gear 18 connecting the intermediate shaft 7 to the output shaft 17 at a predetermined angle in a cooperative manner are arranged.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hook device for a sewing machine, and more particularly to a hook device for a sewing machine which uses 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). Similar to the DPS hook, a hook (hereinafter referred to as a DP hook) in which a sword tip is arranged between the needle drop position and a bobbin thread leading point and rotates fully (hereinafter, referred to as a DP hook) is also known (for example, Japanese Patent Publication No. 39-). 7695 gazette).

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. 9 shows the structure of a general sewing machine balance and needle bar driving device. 1 is a main shaft (upper shaft), 2 is a crank portion, 21 is a counterbalance, 22 is a balance, and 23 is a balance. Needle bar crank, 24 needle bar crank rod, 25 needle bar, 1
13 is a needle. Further, FIG. 10 shows the structure of the shuttle drive device following FIG. 9, 3 is a crank rod, 4 is a large pendulum, 4a is a large pendulum shaft, 5 and 6 are gears, 7 is a lower shaft, 8 is a large hook, 109 is a driver, 111 is a middle hook (DBS hook),
Reference numeral 11 is a presser foot for the inner hook, 100 is a bobbin case, and 103 is a bobbin.

FIG. 11 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. 12 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 it in the range of 120 ° to 150 °), and it is often used in the case of square stitching. Hitch stitch is used for feeding to the front side when sewing to the back side and for feeding to the right side when sewing to the left side. Since (H / S) is generated and the appearance as a top stitch is deteriorated, it has been a troublesome work to avoid the feeding direction 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. 13 compares the case of using the DBS shuttle and the case of using the DPS shuttle. In FIG. 13 (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. 13B, 115 is DP
The S hook and 116 are the tips of the middle hook.

Regarding the distance between the needle drop point and the lower thread leading point of both, as shown in FIG. 13 (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. 13B, 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 shuttle 115, the distance between the bobbin thread derivation point and the needle drop point is compared with the distance between the needle drop point and the bobbin thread derivation point when the DBS shuttle 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 a DPS shuttle, it is possible to construct a shuttle drive device as shown in FIG. 5, for example. In FIG. 5, 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. 6 can be obtained. That is, as shown in FIG. 6, in the feed direction of 360 °, the range of 20 ° on the right side and the front side is a hitch stitch (H / S).
In the H / S area in which the hitch stitches (H / S) occur, the areas of 15 ° on both sides are areas where the hitch stitch (H / S) occurs. Therefore, in the feed direction of 360 °, the right side is 2
The range of 0 ° to 50 ° is a region where hitch stitch (H / S) may 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) is generated, and the appearance as a top stitch is deteriorated, so that a laborious work for avoiding the feeding direction to the back side is involved. In order to perform the square sewing that does not require the troublesome work of avoiding such a specific feeding direction, it is necessary to take measures such as tilting the needle or setting the pattern by tilting.

FIG. 7 is a stitch area diagram showing a sewing machine using the DPS shuttle 10 with the needle attached at an angle of 15 °. That is, as shown in FIG. 7, in the feed direction of 360 °, the range of 20 ° on the right side is the H / S region where the hitch stitch (H / S) occurs, and the range of 10 ° on the left side and the right side. The range of 20 ° is the dangerous area where the hitch stitch (H / S) occurs. Then, in comparison with the stitch area in FIG. 6, the dangerous area where the hitch stitch (H / S) occurs is shifted to the right by 5 °.

Therefore, the feed direction 36 is almost the same as in FIG.
The range of 20 ° to 50 ° on the right side of 0 ° is a region where hitch stitch (H / S) may occur, but the range of 5 ° to the right side of the front side is excluded from the dangerous region. It had been burned. However, since such a range of 5 ° to the right of the front side is a slight angle range, for example, the front side often used in the case of square sewing such as sewing a label with a perfect stitch (P / S). It is also conceivable that a hitch stitch (H / S) may be erroneously entered in the dangerous area during the feeding to the inner side where the sewing is performed.
Therefore, for example, as shown in FIG. 8, the pattern is applied to a position to be sewn in the XY direction of the area sheet so that the sewing direction does not enter the H / S area and the dangerous area in FIG. , It becomes something that has to be checked.

As described above, in a sewing machine using a DPS hook, in the case of square stitching, the hitch of the square stitch may be adjusted by tilting the needle by 15 ° or by setting the pattern by tilting. There is a concern that stitches (H / S) may occur, and there is a problem that it is necessary to pay close attention to pattern creation that requires setting changes.

Therefore, an object of the present invention is to provide a sewing machine using a DPS shuttle or a fully rotating DP shuttle, particularly when square sewing is not required,
An object of the present invention is to provide a hook device for a sewing machine that avoids the occurrence of hitch stitches and obtains a perfect perfect stitch as a top stitch.

[0019]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides a needle thread formed between a needle drop position and a bobbin thread leading point by an output shaft which is synchronized with rotation of a main shaft. A hook device of a sewing machine having a sword tip for catching a loop, characterized in that the output shaft is tilted at a predetermined angle about the needle drop position.

The sewing machine hook device according to a first aspect of the present invention is characterized in that, for example, the output shaft is tilted about 20 ° in the counterclockwise direction about the needle drop position.

Further, in the hook device of the sewing machine according to the first or second aspect, for example, a swing motion is transmitted by the converting means, and an intermediate shaft for interlockingly connecting to the output shaft at a predetermined angle is provided. I am trying.

[0022]

According to the present invention, for example, in the case of a sewing machine using a DPS hook, the output shaft for driving the DPS hook is tilted by a predetermined angle around the needle drop position, so that in the stitch area diagram using the DPS hook, By shifting the sewing direction by a predetermined angle, it becomes possible to avoid the occurrence of hitch stitches. Therefore, particularly in the case of square stitching such as sewing a label with a perfect stitch, a good perfect stitch can be obtained as a top stitch, and fine care is unnecessary.

In the case of a sewing machine using a DPS hook, for example, hitch stitching is most effectively generated by inclining the output shaft about 20 ° counterclockwise around the needle drop position. It can be avoided. Therefore, at the time of square stitching, a perfect stitch that is good as a top stitch can be obtained.

Further, for example, in the case of a sewing machine using a DPS shuttle, an intermediate shaft to which the swinging motion is transmitted by a converting means for converting the rotary motion from the main shaft is provided, and the intermediate shaft is used as an output shaft at a predetermined angle. By interlocking with each other, the inclination of the axis of the output shaft at a predetermined angle around the needle drop position as described in claim 1 can be obtained, and specifically, the needle drop position as described in claim 2 is centered. About 20 in a counterclockwise direction
The inclination of the axis of the output shaft of about ° can be obtained.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of a hook device for a sewing machine according to the present invention will be described below with reference to FIGS. First, FIG. 1 is an exploded perspective view showing a structure of a hook drive device of a sewing machine as an example to which the present invention is applied, in which 1 is a main shaft (upper shaft), 2 is a crank portion, 3 is a crank rod, and 4 is a large size. Pendulum, 5, 6 are gears, 7 is an intermediate shaft (lower shaft), 8 is a large hook, 9 is a driver, 10 is an inner hook (DPS hook), 11 is an inner hook holder, 12 is a bobbin, 13 is a bobbin case, 14 Is a bevel gear, 16 is a bevel gear, 17 is an output shaft (hook drive shaft), 18 is a gear, 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 input 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 that meshes with a gear 5 provided on the large pendulum 4 is provided on a lower shaft 7 serving as an intermediate shaft, and a fixed large hook 8 is arranged on the sewing machine body side on the left end side of the lower shaft 7 in the figure. .

That is, as shown in FIG. 2, a bevel gear 16 is integrally provided on the tip end of the lower shaft 7, and a shuttle drive shaft forming an output shaft having a gear 18 meshing with the bevel gear 16. 17 are provided. The shuttle drive shaft 17 has axes intersecting the lower shaft 7 at an angle of 20 °, and is integrally provided with a driver 9 at its tip. More specifically, the axis of the shuttle drive shaft 17 is inclined 20 ° in the counterclockwise direction about the needle drop point O with respect to the axis of the lower shaft 7.
Thus, the crank mechanism (crank portion 2, crank rod 3, large pendulum 4) for converting the entire rotational movement of the upper shaft 1 into the swinging movement of the lower shaft 7 is constituted, and
A shuttle drive shaft 17 that has a gear 18 that meshes with a bevel gear 16 of the lower shaft 7 and that includes a driver 9 and that serves as an output shaft is provided.

As shown in FIG. 1, a driver 9 integrally connected to the left end portion of the shuttle driving shaft 17 in the drawing is rotatably accommodated in the large hook 8 and an inner hook driven by the driver 9 is provided. A DPS shuttle 10 is rotatably housed. This DPS shuttle 10 has a race 1 on its outer circumference.
It is slidably incorporated into the race 8a on the inner periphery of the cauldron 8 on the surface 0a, and a sword tip 10b is provided on the extension of the race 10a. The rotation direction of the DPS shuttle 10 by the driver 9 is a counterclockwise direction.

At the opening of the large hook 8, the inner hook holder 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. 3, 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 balancing cone 21 is integrally connected to the left end of the upper shaft 1 in the figure, and a balance 22 and a needle 22 are provided in front of the balancing cone 21 as shown in FIG. Bar crank 23, needle bar crank rod 24, needle bar 25, needle 11
3 are connected. Here, with respect to the needle 113, the hook drive shaft 17 is moved around the needle drop point O in the counterclockwise direction by 2
The needle 113 is attached to the needle bar 25 such that the needle hole (thread passing hole) is orthogonal to the plane of rotation of the shuttle due to the inclination of 0 °. Above the cauldron 8, the needle plate 31
Are arranged, and the thread cutting device 32 and the like are arranged between them.

According to the above-described sewing machine, first, the driving force of the motor is input to the pulley via the belt so that the upper shaft 1 makes a full rotation, 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.

The half-rotational movement of the lower shaft 7 is transmitted from the bevel gear 16 to the gear 18 and becomes the half-rotational movement of the shuttle drive shaft 17. The half-rotation motion of the shuttle drive shaft 17 is caused by the lower shaft 7
The phase is exactly opposite to the half-rotation motion of. Therefore, the DP driven by the driver 9 integrated with the shuttle drive shaft 17
The S shuttle 10 makes a half-rotation motion in the counterclockwise direction. In the embodiment, the bevel gear 16 is provided at the tip of the lower shaft 7 in order to make the axis of the hook driving shaft 17 intersect the lower shaft 7 at an angle of 20 °. The bevel gear 16 may be provided in the.

In the sewing machine using the DPS shuttle 10 as described above, as is clear from the comparison between FIG. 1 and FIG. 10, the case where the sewing machine uses the DBS shuttle 111 and the lower shaft 7 are used.
The structure of the DBS shuttle 11 is the same as that of the DBS shuttle 11 except that the shuttle drive shaft 17 is newly provided and the gear 18 provided on the shuttle drive shaft 17 is meshed with the bevel gear 16 provided on the lower shaft 7.
As the thread take-up curve of the DPS shuttle 10 having a rotation direction opposite to that of 1, a characteristic curve can be obtained which is approximately similar to an ideal characteristic that the thread take-up curve obtained by the DBS shuttle 111 is ideal.

Therefore, also in the sewing machine using the DPS shuttle 10, the same rotation transmitting members as those used in the sewing machine using the DBS shuttle 111, namely, the main shaft 1, the crank portion 2,
Since the gears 5, 6 and the lower shaft 7, the balance 22, the needle bar crank 23, the needle bar crank rod 24, as well as the crank rod 3 and the large pendulum 4, and the balance pan 21 can all be used as they are, The cost can be reduced. Moreover, as with the sewing machine using the DBS shuttle 111, noise and
It is excellent in terms of vibration and enables good sewing without threading defects.

In particular, since the hook drive shaft 17 has an axis inclined by 20 ° in the counterclockwise direction about the needle drop point O with respect to the axis of the lower shaft 7, it is suitable for a presser foot not shown. The axis of the DPS shuttle 10 is tilted counterclockwise about the needle drop point O by 20 ° with respect to the XY table, and is obtained by the drive device of the DPS shuttle 10 shown in FIG. The H / S area and the dangerous areas on both sides in the stitch area diagram shown in FIG. 2 are 2 from the front side to the right side (counterclockwise direction) as shown in the stitch area diagram shown in FIG.
It will be offset by 0 °. Therefore, as shown in FIG.
The H / S area and its dangerous area can be completely canceled from the direction (vertical and horizontal directions) of the square sewing. 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.

As described above, for example, in the case of a rectangular stitch such as a label stitch with a perfect stitch (P / S), it is not necessary to worry about the occurrence of a hitch stitch (H / S) which is not preferable as a top stitch. Will be things. Further, it is only necessary to newly add a shuttle drive shaft 17 and a pair of gears (bevel gear 16 and gear 18).
The construction of the lower shaft 7 may be the same as in the case of a sewing machine using an S hook, and conventional parts can be used as they are, which can contribute to cost reduction. Moreover, there is no need to worry about the details of pattern creation.

In the above embodiments, the sewing machine uses the DPS shuttle, but the same effect can be obtained even if the technique of the present invention is applied to the fully rotating DP shuttle. further,
In the embodiment, the crank mechanism is provided as the converting means for converting the rotational movement of the main shaft into the swinging movement. However, the present invention is not limited to this, and a transmitting means such as a timing belt mechanism or a shaft drive mechanism is used. The conversion means may be a combination of crank mechanisms. Further, it is needless to say that other power transmission mechanism may be used, and in addition, specific detailed structures and the like can be appropriately changed.

[0039]

As described above, according to the hook device of the sewing machine according to the present invention, the DPS hook and the output shaft for driving the DP hook are inclined by a predetermined angle about the needle drop position.
In stitch area diagrams using PS hooks and DP hooks, it is possible to avoid hitch stitches by shifting the sewing direction by a predetermined angle. Therefore, square stitching, for example, square stitching, such as stitching a label with perfect stitches, 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.

When a DPS shuttle or a DP shuttle is used, if the output shaft is tilted about 20 ° in the counterclockwise direction about the needle drop position, the hitch can be used. Since the occurrence of stitches can be most effectively avoided, it is possible to obtain a perfect perfect stitch as a top stitch during square stitching.

When a DPS shuttle or a DP shuttle is used, an intermediate shaft to which the swinging motion is transmitted by the converting means for converting the rotary motion from the main shaft is provided, and the intermediate shaft is provided. If the shaft is interlocked with the output shaft at a predetermined angle, the inclination of the axis of the output shaft at the predetermined angle around the needle drop position as described in claim 1 can be obtained. It is possible to obtain an inclination of the axis line of the output shaft of about 20 ° in the counterclockwise direction about the needle drop position as described in 2.

[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 plan view of essential parts showing a lower shaft and a shuttle drive shaft portion of FIG.

FIG. 3 is a perspective view showing a bobbin case.

FIG. 4 is a stitch area diagram in a sewing machine that uses a DPS shuttle when the sewing direction is tilted according to the present invention.

FIG. 5 is an exploded perspective view showing a configuration example of a hook driving device of a sewing machine using a DPS hook for comparison with the present invention.

FIG. 6 is a stitch area diagram in a sewing machine using a DPS shuttle.

FIG. 7 is a stitch area diagram of a sewing machine in which a needle is attached at an angle of 15 ° using a DPS shuttle.

FIG. 8 is a plan view showing a pattern check example.

FIG. 9 is an exploded perspective view showing configurations of a general sewing machine balance and a needle bar driving device.

FIG. 10 is an exploded perspective view showing the configuration of the shuttle drive device, following FIG. 9;

FIG. 11 is a perspective view showing a conventional bobbin case used for a general half-turn hook.

FIG. 12 is a stitch area diagram in a general sewing machine using a DBS shuttle.

13A is a partially cutaway side view showing a distance between a needle drop point and a bobbin thread deriving point when a DBS hook is used, and FIG.
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 intermediate 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 16 Bevel Gear 17 Output Shaft (Hook Drive Shaft) 18 Gear 21 Balancer 22 Balance 23 Needle Crank 24 Needle Crank Rod 25 Needle Bar 31 Needle Plate 32 Thread Cutter 113 Needle

Claims (3)

[Claims] 1. A sewing machine hook device in which a sword tip is arranged to catch a needle thread loop formed between a needle drop position and a bobbin thread leading point by an output shaft which is synchronized with rotation of a main shaft. A shuttle device for a sewing machine, wherein the output shaft is configured by inclining a predetermined angle axis around the needle drop position. 2. The shuttle device for a sewing machine according to claim 1, wherein the output shaft is tilted about 20 ° in a counterclockwise direction about the needle drop position. 3. The shuttle device for a sewing machine according to claim 1, wherein the converting means transmits a swinging motion, and an intermediate shaft which is interlockingly connected to the output shaft at a predetermined angle is provided.