JPH07236783A - Button hole sewing device for zigzag sewing machine - Google Patents

Abstract

PURPOSE:To provide a button hole sewing device able to form bar tacking on both ends and darns on both sides of a button hole continuously with least noise. CONSTITUTION:A first cam 16 for magnitude control, a second cam 17 for magnitude control and contact shoes 45, 46 and 47 for button hole sewing are usually detached and engaged only in button hole sewing work. A contact shoe corresponding to the cloth feed control cam is also engaged only in button hole sewing work.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The invention of this application relates to a buttonhole sewing device for a zigzag sewing machine, and in particular,
The present invention relates to a buttonhole sewing device capable of continuously forming both bartacking portions and both overlocking portions of a buttonhole.

[0002]

2. Description of the Related Art A buttonhole sewing device is known in which work can be easily performed by continuously forming bartacking portions on both ends and overlocking portions on both sides of a buttonhole (Japanese Utility Model Publication No. 1-24322, Japanese Patent Laid-Open No. 23432/1989). 57-64086).

[0003]

However, in any of the conventional buttonhole sewing devices, the contact operatively connected to the amplitude control mechanism is always engaged with the cam rotating in synchronization with the main shaft. Therefore, annoying noise is generated during sewing work other than buttonhole sewing, and the engaging parts of cams and contacts are easily worn. To obtain durability, expensive materials with excellent wear resistance are used. I had to do it.

According to the invention of this application, a zigzag sewing machine is provided, in which a cam and a contactor constituting a buttonhole sewing device engage with each other only during a buttonhole sewing operation, which is advantageous in terms of noise generation and wear of the cam and the like. An object is to provide a buttonhole sewing device.

[0005]

SUMMARY OF THE INVENTION In the present invention in accordance with the above-mentioned object, an uneven cam surface for controlling the swing of the needle bar at the time of forming both overedging portions of a buttonhole is formed on the outer periphery, Further, a first cam that rotates in association with the rotation of the sewing machine main shaft and an uneven cam surface for controlling the needle bar swing at the time of forming both end bartack portions of the buttonhole are formed on the outer periphery, Also, a second cam rotatable with respect to the first cam, and a concavo-convex cam for controlling the amount and direction of cloth feed at the time of forming each bar-tacking portion and each time of forming the overlocking portion. The surface is formed on the outer periphery,
Further, a third cam rotatable with respect to the first cam and the second cam and the third cam are interlocked with the rotation of the first cam when forming each bar-tacking portion. Then, the second portion is rotated at each formation of the overedging portion.
And a cam control mechanism for stopping the third cam and the second cam on the outer peripheral side of the first cam, and is engageable with the uneven cam surface of the first cam. And the first contactor which is normally urged by a spring so as to separate from the concave-convex cam surface of the first cam and the second cam on the outer peripheral side of the first cam. A second contactor that is supported, is engageable with the concave-convex cam surface of the first cam, and is normally biased by a spring so as to be disengaged from the concave-convex cam surface of the first cam. And a concave and convex cam surface of the second cam, and the first and second contact elements are pivotally supported in a disengageable manner, and the concave and convex cam surface of the second cam and the first contact element are always supported. Is urged by a spring so as to be separated from the second contactor and the second contactor, and A third contact operatively connected to the needle bar swinging mechanism and a third contact movably arranged from a position not engaged with the uneven cam surface of the third cam to a position engaged with the uneven cam surface. And a fourth contact operatively connected to the cloth feed mechanism and the third contact are forcibly rotated against the spring, and the third contact becomes the sewing machine main shaft. The concave and convex cam surfaces of the second cam and the first cam according to the rotation of the
Of the third contact and the second contact, and the fourth contact is connected to the third contact.
The buttonhole sewing device of the zigzag sewing machine provided with a contactor control mechanism that operates in conjunction with the operation of the pattern selection operation body in order to move from the position that does not engage the uneven cam surface of the is there.

In such a buttonhole sewing device for a zigzag sewing machine, in order to make the structure of the zigzag sewing machine simpler, the first cam, the second cam and the third cam are amplitude control cams. Is arranged coaxially with the cam group and the cloth feed control cam group, and the fourth contact is movable in the arrangement direction of the third cam and the cloth feed cam group. Of the desired cams in the amplitude control cam group, and is moved to a position in which the desired cams of these cams can be engaged. The fifth contact moved to the engageable position is further movable to a position not engaged with any cam of the amplitude control cam group, and the fifth contact is not engaged with the amplitude control cam. By being moved to It is preferred for the contacts in which the third contact is forcibly rotated against the spring.

[0007]

As apparent from the above construction, in the buttonhole sewing device for the zigzag sewing machine according to the present invention,
A third contact operatively connected to the needle bar rocking mechanism,
The fourth contact rocker operatively connected to the cloth feed mechanism always includes the second cam, the first contactor, the second contactor,
It is disengaged from the third cam, and is engaged with the second cam, the first contactor, the second contactor, and the third cam when the pattern selection operation body is operated to the buttonhole sewing position. . Therefore, noise is not generated by these engagements during sewing work other than buttonhole sewing, and there is no wear of the engaging portions, so the wear resistance of the cam or the like is not so high, but it is an inexpensive material ( For example, it can be formed of a resin material. If the cam or the like is made of a resin material, the impact sound generated by the resin material is small, so the noise during the buttonhole sewing operation is also reduced.

Further, the first cam, the second cam and the third cam are arranged coaxially with the amplitude control cam group and the cloth feed control cam group so as to be located between the amplitude control cam group and the cloth feed control cam group. The fourth contactor is arranged so as to be movable in the arrangement direction of the third cam and the cloth feed cam group, and is moved to a position where it can be engaged with a desired cam among these cams. The fifth contactor, which is arranged so as to be movable in the arrangement direction of the amplitude control cam group and is moved to a position where it can be engaged with a desired cam in the amplitude control cam group, is further connected to any cam of the amplitude control cam group. It is movable to a non-engaging position, and the fifth contact is moved to the position not engaging the amplitude control cam, whereby the fifth contact causes the third contact to resist the spring. Button hole sewing Since the amplitude control cam group or cloth feed control cam set while working does not engage the contacts, noise during buttonhole sewing work is small, becomes construction of Jiguzakumishin is inexpensive and easy. Since the cams of the amplitude control cam group and the cloth feed control cam group are also lightly worn, it is possible to form these cams with a resin material.

[0009]

Embodiments of the invention of this application will be described with reference to the drawings.

FIG. 1 is a schematic diagram mainly showing the relative positional relationship of the constituent members in the up-down direction and the left-right direction when viewed from the front of the zigzag sewing machine, and FIG. 2 is an amplitude control cam group, cloth feed control cam group, Figure 1 shows the main parts such as the cam for buttonhole sewing.
3 is a view as seen from the right side of FIG. 3, and FIG. 3 is a view as seen from the upper side of FIG. 2 (some components are omitted). 4 and 5
6 and 6 are cross-sectional views taken along lines AA, BB and CC in FIG. 2, respectively. FIG. 7 shows a state of the constituent members shown in FIG. 6 during buttonhole sewing.

1 to 3, a fixed cam shaft 12 is supported by a pair of front and rear mounting plates 11A and 11B fixed to the sewing machine arm 10. This cam shaft 12
Amplitude control cam group 13 located on the front side of the sewing machine, cloth feed control cam group 14 located on the rear side of the sewing machine, helical gear 15 located between these cam groups, and this helical gear 15 and the cloth. A first cam 16 and a second cam 16 for amplitude control for buttonhole sewing which are located between the feed control cam group 14 and
And a third cam 18 for cloth feed control are rotatably supported. The amplitude control cam group 13 and the cloth feed control cam group 14 are connected to the helical gear 15 so as to always rotate integrally, and the helical gear 15 is the sewing machine main shaft 1
It meshes with the multi-thread screw 20 fixed to 9, and therefore the amplitude control cam group 13 and the cloth feed control cam group 14 rotate in conjunction with the rotation of the sewing machine main shaft 19.

The mounting plates 11A and 11B support a fixed contact support shaft 21 parallel to the cam shaft 12. The contactor support shaft 21 has a contactor 22 (fifth contactor) to be engaged with an arbitrary cam in the amplitude control cam group 13 and a contact to be engaged with an arbitrary cam in the cloth feed control cam group 14. Each child 23 (fourth contactor) is rotatably and slidably supported. The contactor support shaft 21 is also rotatable about a suitable contactor support frame 24 that straddles the contactor 22 and a suitable contactor support frame 25 that straddles the contactor 23, but is not slidable. Support. A pin 26 that is parallel to the contactor support shaft 21 and slidably penetrates the contactor 22 is fixed to the contactor support frame 24. Therefore, the contactor 22 and the contactor support frame 24 are contactors. Although it always swings integrally with the support shaft 21, only the contact 22 is movable in the front-back direction of the sewing machine. Similarly, a pin 27, which is parallel to the contactor support shaft 21 and slidably penetrates through the contactor 23, is fixed to the contactor support frame 25. Therefore, the contactor 23 and the contactor support frame 25 are connected to each other. Always swings integrally on the contactor support shaft 21, but only the contactor 23 can move in the longitudinal direction of the sewing machine.

As shown in FIGS. 1 and 2, the contactor support frame 24 has an arm portion 24a, and the arm portion 24a is a link 28 which is a part of a known needle bar swinging mechanism.
Is pivotally attached. This link 28 is urged to the left in FIG. 1 by a spring 52, and therefore, in FIG.
At, the contact support frame 24 and the contact 22 are urged in the counterclockwise direction, the engagement between the contact 22 and any cam in the amplitude control cam group 13 is maintained, and the contact 22 and the contact 22 follow the rotation of this cam. The contactor support frame 24 swings to control the amplitude of the needle bar.

As shown in FIG. 5, the contactor support frame 25
Has an arm portion 25a, and this arm portion 25a is engaged with a link 29 which is a part of a known cloth feeding control mechanism. This link is biased downward in FIG. 5 by a spring (not shown). Therefore, in FIG. 5, the contact support frame 25 and the contact 23 are biased in the clockwise direction, and the contact 23 and the cloth feed control are controlled. Engagement with an arbitrary cam in the cam group 14 is maintained, and the contactor 23 is rotated as the cam rotates.
The contact support frame 25 swings to control the cloth feed.

As shown in FIGS. 1 and 2, the contactor support frame 24 also has an arm portion 24b. The arm portion 24b is engageable with a pin 31 fixed to the upper end of a lever 30 pivotally attached to the mounting plate 11A at an intermediate portion. The pin 32 fixed to the lower end of the lever 30 can be engaged with the concave-convex cam surface on the outer periphery of the cam 34 that rotates integrally with the pattern selection operation body 33. The lever 30 is urged clockwise by a spring (not shown) in FIG. 1, so that the engagement between the pin 32 and the cam 34 is maintained. The cam 34 swings the lever 30 in the counterclockwise direction in FIG. 1 during operation of the pattern selection operation body 33 to move the contactor support frame 24 and the contactor 22, and the contactor 22 to an arbitrary position in the amplitude control cam group 13. In order to allow the contactor 22 to move in the front-rear direction of the sewing machine by swinging from the a position where it engages with the cam clockwise to the a position where it does not engage with any cam in the amplitude control cam group 13. belongs to.

In FIG. 5, in order to move the contact 23 in the longitudinal direction of the sewing machine, the cloth is moved counterclockwise from the position where the contact 23 is engaged with any cam in the cloth feed control cam group 14. It is necessary to swing the cam to a position where it does not engage with any of the cams in the feed control cam group 14. Therefore, although not shown, the cam and the lever are used to operate the pattern selection operation body 33 during operation of FIG. In this case, the contact 23 is swung counterclockwise from a position where it engages with any cam in the cloth feed control cam group 14 to a position where it does not engage with any cam in the cloth feed control cam group 14. ing.

Another cam 35, which rotates integrally with the pattern selecting operation body 33, has concave and convex cam surfaces on the front and rear surfaces, and the cam surface on the front side is for moving the contact 22 in the longitudinal direction of the sewing machine. A pin 37 fixed to the lower end of the lever 36 can be engaged, and the contact 2 is provided on the cam surface on the rear surface side.
A pin 39 fixed to the lower end of a lever 38 for moving the sewing machine 3 in the longitudinal direction of the sewing machine can be engaged. Lever 3
Reference numerals 6 and 38 are pivotally attached to a support body 40 fixed to the mounting plates 11A and 11B between upper and lower ends thereof.
2 is urged in the counterclockwise direction in FIG. 2 by a spring (not shown), and the lever 38 is urged in the clockwise direction in FIG. 2 by a spring (not shown), whereby engagement between the pins 37, 39 and the cam 35 is achieved. Is maintained and the levers 36 and 38 occupy the swing position corresponding to the operation position of the pattern selection operation body 33.

A pin 41 fixed to the upper end of the lever 36 is engaged with a hole formed in the movement guide portion 22a of the contact 22, and the lever 36 is moved to the position shown in FIG. By swinging to a position corresponding to the position selected by the pattern selection operation body 33, the cam 34 is moved.
The contactor 22 separated from the amplitude control cam group 13 by the lever 30 is moved to a position on the contactor support shaft 21 corresponding to the position selected by the pattern selection operation body 33.
Similarly, the pin 42 fixed to the upper end of the lever 38 is engaged with the hole formed in the movement guide portion 23 a of the contact 23, and the lever 38 is operated in response to the operation of the pattern selection operation body 33.
2 swings to a position corresponding to the position selected by the pattern selecting operation body 33 in FIG. 2, so that the contact 23 separated from the cloth feed control cam group 14 by the cam and lever is placed on the contact support shaft 21. Is moved to a position corresponding to the position selected by the pattern selection operation body 33.

The first cam 16 for buttonhole sewing is connected to the helical gear 15 so as to rotate integrally therewith. The second cam 17 and the third cam 18 are connected so as to rotate integrally with each other, but the first cam 1
It is rotatable with respect to 6.

The third cam 18 is a ratchet type clutch 43.
By being connected to the first cam 16, the cams 17 and 18 rotate in conjunction with the rotation of the cam 16. As shown, the cam 16 has a substantially smaller diameter than the cams 17, 18.

As shown in FIGS. 9B and 11B, the ratchet clutch 43 is a ratchet wheel 43a connected to rotate integrally with the cam 16, and a ratchet wheel 43a is pivotally attached to the cam 18 on the outer peripheral side of the ratchet wheel 43a. And ratchet pawl 43 biased by a spring (not shown) so as to engage with the ratchet wheel 43a.
and the projection 43 of the ratchet claw 43b.
Engagement and disengagement is controlled by a switching lever 44 that is engageable with b ₁ . The switching lever 44 is rotatably supported around the cam shaft 20, and is operatively connected to a known position detection lever that cooperates with a presser foot.
Each time the buttonhole sewing reaches the end of the buttonhole, the camshaft 12 is moved by a predetermined amount in the radial direction. The ratchet type clutch 43 constitutes a cam control mechanism together with the switching lever 44 and the like.

An uneven cam surface is formed on the outer periphery of the cam 16 for controlling the swing of the needle bar when forming the overhanging portions on both sides of the buttonhole. On the outer periphery of the cam 17, a concave-convex cam surface for controlling the rocking of the needle bar at the time of forming both bartacking portions of the buttonhole is formed. Cam 18
A concave and convex cam surface for controlling the direction and the feed amount of the cloth feeding is formed on the outer periphery of the both sides when the bartacking portions are formed and when the overedging portion is formed.

A contactor 23 is engaged with the concave-convex cam surface of the cam 18, and a contactor 45 (third part) rotatably supported by the contactor support shaft 21 on the concave-convex cam surface of the cam 17. Contactor) is engaged. Also, the cam 16
A pair of contact elements 46, 47 (first contact element, second contact element) pivotally attached to the cam 17 on the outer peripheral side of the cam 16 can be engaged with the concave-convex cam surface. Child 4
The contactor 45 can be engaged with 6, 47. Contactor 45
Is a fixing member 48 fixed to this and the contactor support shaft 21.
By the spring 49 having both ends locked to and, clockwise in FIG.
That is, the cam 17 and the contacts 46, 47 are urged in the direction of being separated. When the contactor 45 swings clockwise in FIG. 6, the contactor 45 is pinned by the pin portion 48a of the fixing member 48.
It ends by abutting against. The contactor 46 is urged in a direction to be separated from the cam surface of the cam 16 by a spring 50 having both ends locked to the contactor 46. Contact 46
Is also biased in a direction to separate from the cam surface of the cam 16 by springs 51 having both ends locked to this and the cam 17. As shown in FIG. 6, in a normal state in which the contact element 45 is in contact with the pin portion 48 a of the fixing member 48 (normal state in which buttonhole sewing is not performed), the contact elements 46, 47 are located at predetermined positions separated from the cam surface of the cam 16. The contactor 45 is held and separated from the cam 17 and the contactors 46 and 47.

The contact element 45 is swung counterclockwise in FIG. 6 against the spring to push it against the contact element 22 to engage the cam 17 and the contact elements 46, 47 as shown in FIG. Part 2
2b is formed. When the pattern selecting operation body 33 is operated to the buttonhole sewing position, the contact 22 is swung from the position a to the position a in FIG. Face the back surface (right side surface in FIG. 6) of the contactor 45, and then contact the contactor 22.
By swinging from the position a to the position a, the contactor 45 is swung counterclockwise in FIG. 6 against the spring (the contactors 45, 46 and 47 are moved to the positions shown in FIG. 6). The urging springs 49, 50, 51 are not large enough to overcome the force of the spring 52 urging the contact 22 in the clockwise direction in FIG. 1).

Further, when the pattern selecting operation body 33 is operated to the buttonhole sewing position, the contact 23 is swung counterclockwise in FIG. 5 to be separated from the cam surface of the cloth feed control cam group 14, and in that state. The cam 18 moves most to the front of the sewing machine
The cam 18 is engaged with the cam 18 by facing the cam surface of the same and swinging clockwise in FIG.

The operation of the buttonhole sewing device constructed as described above will be described with reference to FIGS. 8A to 8C, 9A to 9C and 10A.
10C and 11A to 11C will be described next. 8A, B, 9A, B, 10A, B, and FIG.
The arrows in 1A and 1B indicate the direction of rotation.

When the pattern selecting operation body 33 is operated to the buttonhole sewing position, the contact 22 is moved to the rearmost side of the sewing machine to swing the contact 45 so as to engage with the cam 17, as described above. Further, the contact 23 moves most toward the front of the sewing machine and engages with the cam 18.

FIG. 8A shows the contactor 45 and the cam 1 at that time.
6 and 17 and the state of the contacts 46 and 47 are shown. Then, in that state, the switching lever 44 is moved to the buttonhole sewing start position,
In other words, when the button hole is operated to the formation position of the bartacking end, the switching lever 44 causes the projection 43 of the ratchet pawl 43b to move.
8B is positioned with respect to b ₁ .

After that, when the sewing machine is activated, the cams 17 and 18 are connected to the cam 16 by the engagement of the ratchet pawl 43b and the ratchet wheel 43a, so that the amplitude control cam group 1 is interlocked with the rotation of the sewing machine main shaft 19.
3, the cloth feed control cam group 14, the buttonhole sewing cams 16, 17 and 18 rotate integrally. As shown in FIG. 8B, the contact 23 engages the forward feed portion 18a of the cam 18 at the first stitch, but the feed amount zero portion 18 at the second stitch.
engage b. Further, as shown in FIG. 8A, when the buttonhole sewing is started, the contactor 45 is engaged with the concave portion of the cam surface of the cam 16, and the surface facing the contactor 45 is the cam 17.
Since it is positioned radially inward with respect to the cam surface, the contact element 45 engages with the cam surface of the cam 17 and swings according to the unevenness of the cam surface. The irregularities with which the contactor 45 engages from the first stitch to the fourth stitch are shallow, and the irregularities with which the fifth stitch to the ninth stitch engage are deep. The bartacking portion shown in FIG. 8C is formed by advancing the sewing from the first stitch to the ninth stitch (note that FIG. 8C is drawn so that the second and subsequent stitches also have feed, but there is actually no feed). .

At the 10th stitch of sewing, as shown in FIG. 9B, the contact 23 engages with the reverse feed portion 18c of the cam 18,
The ratchet pawl 43b is swung by the engagement of the projection 43b ₁ of the ratchet pawl 43b and the switching lever 44, and the meshing with the ratchet wheel 43a is released.
The rotation of the cams 17 and 18 is stopped. On the other hand, contact 4
As shown in FIG. 9A, 5 is engaged with the contact 47 which is engaged with the convex portion of the cam surface of the cam 16. By rotating the cam 16 with the contact element 45 engaged with the contact element 47 in this manner, the contact element 45 swings along the cam surface of the cam 16. By this operation and the reverse feed operation, the overhanging portion on one side of the buttonhole is formed as shown in FIG. 9C.

When the formation of the overlocked portion reaches the other end of the buttonhole, the switching lever 44 is moved by the action of the detection lever which cooperates with the presser foot, and the projection 43b ₁ of the ratchet pawl 43b is moved from the projection 43b ₁ as shown in FIG. 10B. I'm leaving,
The ratchet pawl 43b again meshes with the ratchet wheel 43a, so that the cams 17 and 18 start rotating again, and the contact 23 engages with the zero feed amount portion 18d of the cam 18. On the other hand, the contactor 45 engages with the cam surface of the cam 17 and swings along the cam surface. This results in FIG.
As shown in, the bar-tacking portion at the other end of the buttonhole is formed.

As the sewing progresses, the cams 15, 16 and 1
When 7 rotates to the position shown in FIGS. 11A and 11B, as shown in FIG. 11B, the protrusion 43b of the ratchet pawl 43b.
_{When 1} is engaged with the switching lever 44, the ratchet pawl 43b is disengaged from the ratchet wheel 43a, and the rotation of the cams 17 and 18 is stopped. On the other hand, the contactor 45
Is a contactor 46 engaged with a recess of the cam surface of the cam 16.
Engage with. By rotating the cam 16 with the contact element 45 engaged with the contact element 46 in this manner, the contact element 45
Oscillates according to the cam surface of the cam 16. By this operation and the reverse feed operation, the overhanging portion on the other side of the buttonhole is formed as shown in FIG. 11C.

As described above, the formation of both-end bar-tacking portions and the formation of both-side overlocking portions for one buttonhole are continuously performed.

[0034]

As described above, in the buttonhole sewing machine of the zigzag sewing machine according to the invention of the present application, the cam and the contactor constituting the buttonhole sewing machine are engaged only during the buttonhole sewing operation. Therefore, no noise is generated by these engagements during sewing work other than buttonhole sewing, and there is no wear on the engaging parts, so wear resistance of the cam etc. is not very high but it is cheap. It is possible to form it with a material (for example, a resin material). If the cam and the like are formed with a resin material, the impact sound generated by the resin material is small, so the noise during the buttonhole sewing operation is also reduced.

The first cam, the second cam and the third cam
Cams are arranged coaxially with the amplitude control cam group and the cloth feed control cam group, and the fourth contact is arranged with the third cam and the cloth feed cam group. Is arranged to be movable in the direction in which the desired cams can be engaged, and is arranged so as to be movable in the arrangement direction of the amplitude control cam group. The fifth contact, which is moved to a position where it can be engaged with the desired cam, can be further moved to a position that does not engage with any cam of the amplitude control cam group, and the fifth contact is associated with the amplitude control cam. When the third contactor is forcibly rotated against the spring by the fifth contactor by being moved to the unmatched position, the amplitude control cam during the buttonhole sewing operation. Group and cloth feed control cam group do not engage the contactor, so the button Less noise during Lumpur sewing work, one in which the configuration of the Jiguzakumishin becomes the thing is inexpensive and easy. Since the cams of the amplitude control cam group and the cloth feed control cam group are also lightly worn, it is possible to form these cams with a resin material.

[Brief description of drawings]

FIG. 1 is a diagram showing a schematic configuration of an embodiment of the invention of this application as seen from the front side of a sewing machine.

FIG. 2 is a diagram of a main part of the embodiment of FIG. 1 viewed from the right side of FIG.

FIG. 3 is a view seen from above in FIG.

4 is a cross-sectional view taken along the line AA in FIG.

5 is a cross-sectional view taken along the line BB in FIG.

6 is a cross-sectional view taken along the line CC in FIG.

FIG. 7 is a diagram showing a state of the constituent members shown in FIG. 6 during buttonhole sewing.

FIG. 8 is an explanatory view of the operation when forming one bartacking portion of the buttonhole, (A) shows the relationship between the amplitude control cam group and the corresponding contactors, and (B) shows the cam for cloth feed control. The relationship with the corresponding contactor is shown, and (C) shows how to proceed with the sewing of the bartacked end of the buttonhole.

9A and 9B are explanatory views of the operation when forming the overhanging portion on one side of the buttonhole. FIG. 9A shows the relationship between the amplitude control cam group and the corresponding contactors, and FIG. The relationship with the corresponding contactor is shown, and (C) shows how to proceed with the sewing of the bartacked end of the buttonhole.

FIG. 10 is an explanatory view of the operation when forming the other bartacking portion of the buttonhole, (A) shows the relationship between the amplitude control cam group and the corresponding contacts, and (B) shows a cam for cloth feed control. Shows the relationship between the contact and the corresponding contactor, and (C) shows how to proceed with the sewing of the bartacked end of the buttonhole.

11A and 11B are explanatory views of the operation when forming the overedging portion on the other side of the buttonhole. FIG. 11A shows the relationship between the amplitude control cam group and the corresponding contacts, and FIG. 11B shows the cam for cloth feed control. The relationship with the corresponding contactor is shown, and (C) shows how to proceed with the sewing of the bartacked end of the buttonhole.

[Explanation of symbols]

10 ... Sewing machine arm 11A, 11B ... Mounting plate 12 ... Cam shaft 13 ... Amplitude control cam group 14 ... Cloth feed control cam group 15 ... Helical gear 16 ... Button hole First cam for sewing 17 ... Second cam for buttonhole sewing 18 ... Third cam for buttonhole sewing 19 ... Sewing machine spindle 20 ... Multi-piece fixed to sewing machine spindle Threaded screw 21 ... Contact support shaft 22 ... Fifth contact 22b ... Pushing part 23 for rocking the third contact against a spring 23 ... Fourth contact 24, 25 ... Contact support frame 28 ... Link of needle bar swinging mechanism 29 ... Link of cloth feeding mechanism 33 ... Pattern selecting operation body 35 ... For moving contacts 22, 23 Cams 36, 38 ... Lever 43 for moving the contacts 22, 23 -Ratchet type clutch for connecting / disconnecting the cams 17 and 18 to / from the cam 16 ... Switch lever for controlling the ratchet type clutch 45 ... Third contactor 46 ... First contactor 47 ... Second contactor 49, 50, 51 ... Spring for urging contactor

Claims (2)

[Claims] 1. An uneven cam surface for controlling rocking of a needle bar at the time of forming both overedging portions of a buttonhole is formed on an outer periphery and rotates in association with rotation of a sewing machine main shaft. Of the cam and the barholes at both ends of the buttonhole are formed with an uneven cam surface for controlling the swing of the needle bar at the time of formation, and are rotatable with respect to the first cam. Second
And a concavo-convex cam surface for controlling the amount and direction of cloth feed at the time of forming each bar-tacking portion and each time of forming each overlocking portion, and the first cam. A third cam that is rotatable with respect to the first cam, and the second cam and the third cam that are interlocked with the rotation of the first cam at the time of forming each bar-tacking portion, A cam control mechanism that stops the second cam and the third cam when each part is formed, and an outer peripheral side of the first cam that is pivotally supported by the second cam. A first contactor engageable with the concave-convex cam surface of the cam and normally biased by a spring so as to be disengaged from the concave-convex cam surface of the first cam; and an outer periphery of the first cam. Is pivotally supported on the side by the second cam, A second contactor engageable with the concave-convex cam surface of the cam and normally biased by a spring so as to be disengaged from the concave-convex cam surface of the first cam; and the concave-convex shape of the second cam. The cam surface is rotatably and pivotally supported by the first contactor and the second contactor so as to be able to be engaged and disengaged, and the uneven cam surface of the second cam is always connected to the first contactor and the second contact. A third contactor that is biased by a spring so as to be separated from the child and that is operatively connected to the needle bar swing mechanism, and a position that does not engage with the concave-convex cam surface of the third cam. A fourth contactor that is movably arranged at a position where it engages with the concave-convex cam surface and that is operatively connected to the cloth feed mechanism; and a third contactor that resists the spring. And forcibly rotate the third contactor so that the third contactor has a concave and convex cam surface of the second cam according to the rotation of the sewing machine main shaft. So as to be driven by one of said first contact and said second contact, and,
A contactor control mechanism that operates in conjunction with the operation of the pattern selection operation body to move the fourth contactor from a position that does not engage with the concave-convex cam surface of the third cam to a position that engages with it. Zigzag sewing machine buttonhole sewing device equipped. 2. The buttonhole sewing device for a zigzag sewing machine according to claim 1, wherein the first cam, the second cam and the third cam are an amplitude control cam group and a cloth feed control cam group. It is arranged coaxially with these cam groups so as to be located between them, and the fourth contact is arranged so as to be movable in the arrangement direction of the third cam and the cloth feed cam group. Is moved to a position where it can be engaged with the desired cam, and is arranged so as to be movable in the arrangement direction of the amplitude control cam group, and moved to a position where it can be engaged with the desired cam in the amplitude control cam group. The fifth contact can be further moved to a position where it does not engage with any cam of the amplitude control cam group, and the fifth contact can be moved to the position where it does not engage with the amplitude control cam. The third by the contactor
The buttonhole sewing device for a zigzag sewing machine, wherein the contactor of the zigzag sewing machine is forcibly rotated against the spring.