JPS6126392B2 - - Google Patents

Description

[Detailed Description of the Invention] This invention includes an overlocking mechanism, a lockstitch mechanism,
It has a switching mechanism and a cloth feeding mechanism, and by operating the switching mechanism, it is possible to select between safety stitching and the other two sewing types among the three sewing types: overlock stitch, lock stitch, and safety stitching with both stitches. Relating to a sewing machine selectively capable of at least one of:
In particular, one lower shaft drives the hook shaft and the looper shaft simultaneously, one upper shaft simultaneously drives the overlock needle and the lockstitch needle, and the throat plate is also used for overlocking and lockstitching. By using it in combination with sewing, it is possible to perform safety stitching by simultaneously performing overedge stitching and lock stitching, and also to simplify the structure.

Conventionally, a sewing machine that has an overlocking mechanism for overlocking an edge and a lockstitch mechanism for lockstitching in one sewing machine in appearance has been developed, for example, in Japanese Patent Application Laid-Open No. 53
-113649, 53-77747, etc. However, these can be evaluated as two machines that combine two machines into one sewing machine: a lockstitch-only sewing machine with only a lockstitch mechanism, and an edge-overlocking sewing machine with only an overlocking mechanism. The equipped sewing machine is simply a collection of both mechanisms and housed within a single sewing machine body. Therefore, it is only possible to selectively perform either the oversewing or lockstitching, and it is impossible to perform both of these sewing operations at the same time. Therefore, for sewing work that requires safety stitching such as side stitching, shoulder stitching, sleeve bottom stitching, and sleeve attaching stitching for shirt blouses, etc., according to the conventional sewing machine, there are two steps: an overedge stitching process and a lockstitching process. A two-step safety stitching process was forced.

Furthermore, although the conventional sewing machine has a single drive source such as a motor, a rotating shaft dedicated to overlock stitching, a rotating shaft dedicated to lockstitching, etc. are arranged in a complicated manner within the sewing machine body. The disadvantage is that the number of parts increases and the restrictions on the structure of each part increase accordingly, which causes failures, larger sizes, and increased costs.

Therefore, the present invention was completed in order to provide a sewing machine that eliminates all the drawbacks of the above-mentioned sewing machines.The purpose of this invention is to provide a sewing machine that can perform safety stitching using two sewing types, overlock stitching and lock stitching, in one machine. The object of the present invention is to provide a sewing machine in which at least one of the two sewing methods can be selected. The object of the present invention is to provide a sewing machine which can be shared as much as possible, has a simple structure, reduces malfunctions and costs, and is downsized.

That is, the present invention has a hem stitching mechanism, a lockstitch mechanism, an operation switching mechanism for these mechanisms, and a cloth feeding mechanism, and the hem stitching mechanism moves up and down to form a hem stitch. a darning needle; a looper that cooperates with the darning needle to form an darning stitch;
It consists of a cutting machine that cuts the edge of the fabric, and a throat plate that is provided with a thread guide piece that forms an overlock stitch at the edge of the fabric in cooperation with an overlock needle and a looper. a lockstitch needle that moves up and down at a position close to the cloth feeding direction in the width direction to form a lock stitch in line with the overlock stitch; and the overlock mechanism through which the lockstitch needle passes. It consists of a throat plate that is common to the throat plate to be formed, and a hook that moves circularly below the throat plate in synchronization with the lockstitch needle, and the switching mechanism is configured to switch between overlocking stitches by the overlocking mechanism and overlock stitching by the overlocking mechanism. The sewing machine has a structure that selects and switches between the safety stitch and at least one of the other two sewing formats from among the three sewing formats of lock stitching using the sewing mechanism and safety stitching using both mechanisms together, and The cloth feed mechanism includes a structure for advancing and retracting cloth feed teeth arranged facing the common throat plate, and a structure for raising and lowering the cloth feed teeth, and a looper shaft for swinging the looper of the hem stitching mechanism. , a hook shaft that moves the hook of the lockstitch mechanism in a circular motion, and a lower shaft that rotates horizontally at the bottom of the machine body, using communication means, respectively.
Communication means that connects the looper shaft and hook shaft so that they are interlocked, and allows the needle bars of the darning needle and lockstitch needle to be interlocked with an upper shaft that is horizontally suspended on the upper part of the machine body and rotates. furthermore, the cutting machine of the edge stitching mechanism is connected to the upper shaft or the lower shaft using a communication means, and one of the upper shaft and the lower shaft is a drive shaft, The present invention also relates to a sewing machine characterized in that the other shaft is an interlocking shaft of the drive shaft.

Next, the present invention will be explained with reference to illustrated embodiments. This embodiment is a sewing machine that can selectively select one of three sewing types: overedge stitching, lock stitching, and safety stitching.

An upper shaft 14 is horizontally suspended on a bracket arm 15 of a sewing machine body 11, and the right end of the upper shaft 14 protrudes outside the machine body 11, to which a pulley 17 is fixed. In this embodiment, the upper shaft 14 is the drive shaft, but
Of course, the lower shaft 12, which will be described later, may serve as a drive shaft.

A needle bar crank 18 is fixed to the left end of the upper shaft 14, and the other end of a needle bar link 19, which has one end pivoted to a needle bar holder fixed to the needle bar 13, is pivoted to the crank pin of the crank 18. Therefore, the upper axis 1
The needle bar 13 is configured to move up and down by rotation of the needle 4. Note that a balance arm 20 is attached to the crank pin.
One end of the auxiliary arm 22 is pivotally connected to the upper part of the auxiliary arm 22, one end of which is pivotally connected to a bearing 21 integral with the body 11, and the other end of the balance arm 20 is pivotally connected with a pin. Although not shown in the drawings, a lock stitch thread take-up for lock stitching is fixed to the thread take-up arm 20. Therefore, the balance is a so-called link balance. It should be noted that the needle bar 13 shown in FIG. 1 is attached with an overlock thread take-up for overlock stitching, as in another embodiment shown in FIGS. 16 and 17, which will be described later.

Reference numeral 23 designates a bearing for the upper shaft 14. The bearing 23 is placed in the middle of the needle bar crank 18, and an eccentric cam 24 is fixed to the upper shaft 14 as shown in FIG. A lifting rod 25 that extends downwardly is connected to the lifting rod 25, and a female rod 27 having an upper knife 26 attached to its lower end is connected to the lifting rod 25.

The female rod 27 is urged upward by a bullet 28, and communication between the female rod 27 and the elevating rod 25 is made through a locking/disengaging device 29. Unlatching device 2
9, a female rod 27 vertically passes through a frame 30 fixed to the lifting rod 25, and engages the tip of an engagement pin 32 within the frame 30 with an engagement hole 31 opened in the female rod 27; Moreover, the engaging pin 32 is elastically supported within the frame 30 by an elastic mechanism 33 in a direction in which it is always engaged. The rear end of the engagement pin 32 protrudes outside the frame 30 to form an operating portion 34. In particular, this situation is shown in FIG. If the operating portion 34 is pulled to the right in FIGS. 1 and 12, the engagement pin 32
The tip of the female rod 27 is disengaged from the engagement hole 31, and the female rod 27 is raised by the bullet 28. As a result, the upper knife 26
rises and moves to a position where it is not used. That is, the upper knife 26 is raised and is in the unused position, and the upper knife 26 does not operate even though the upper shaft 14 is rotating, so the safety of the sewing operation during lock stitching is improved. Further, when the upper knife 26 is pulled downward and the tip of the engagement pin 32 pressing the side surface of the female rod 7 by the elastic force 33 reaches the engagement hole 31 opened in the female rod 27, the elastic force is released. The female rod 27 and the lifting rod 25 are automatically fitted together by the urging force of the machine 33, and are in the use position. Thus, the locking and unlatching device 29 forms a part of the operation switching mechanism C of the present invention. It should be noted that, in place of the above-mentioned unlatching device 29, the operation switching mechanism C may be configured such that the female rod 27 or the like is detached from the lifting rod 25. 35
is the rising stop.

The upper knife 26 is attached to the knife rod 27 via a direction change mechanism 36. The direction change mechanism 36 is constructed so that the upper knife 26 can freely pivot between a downward use position and a rearward non-use position, and in both positions, the direction is stabilized as is known. It is composed of a combination of bullets and uneven surfaces. This direction changing mechanism 36 also forms a part of the operation switching mechanism C of the present invention. Another example of the switching mechanism C is a structure in which the upper knife 26 is removed by releasing a bolt or the like that fixes it. A series of configurations from the lifting rod 25 to the upper knife 26 as described above, and the lower knife (not shown)
The cutting machine 4 is configured by the above.

The lower shaft 12 is located at the bottom of the fuselage 11 and at the bed 3.
7 is horizontally suspended below and rotates in conjunction with the upper shaft 14. In this embodiment, the means for communicating with the upper shaft 14 is provided by a bevel gear 38 and a rotating vertical shaft 39, but it may also be provided by a timing gear and a timing belt, or other means may be adopted. You can also do that. In this embodiment, the lower shaft 1
2 and the upper shaft 14 is a 1:1 rotation ratio.

The left end of the lower shaft 12 is connected to a vertically extending hook shaft 10 with a horizontal full-rotation hook 7 attached to its upper end via a screw gear 40, so that the rotation ratio between the lower shaft 12 and the hook shaft 10 is 1:2. It is composed of A bevel gear can also be used instead of the screw gear 40. The relationship between the lower shaft 12 and the hook shaft 10 is particularly shown in FIGS. 2 and 7.
20 and 22.
A horizontal full-rotation hook 7 attached to the upper end of the hook shaft 10
The upper surface of the needle plate 6 is the same as that of the needle plate 6 on which a thread guide piece 6' (to be described later) is formed, and the upper surface of the needle plate 6 is covered with a sliding plate 16 configured to be able to slide on the bed 37. Can perform sewing work. Further, by sliding the sliding plate 16 to release the horizontal full-rotation hook 7, especially the upper part of the bobbin inserted therein, the bobbin can be easily replaced.

Loopers 2 and 2' are connected to the lower shaft 12. The loopers 2, 2' are shown in FIGS. 1 to 7. Here, upper looper 2 and lower looper 2'
Although a two-looper system is adopted, a one-looper system using only one looper may be adopted instead. Since the one-looper system is shown in FIGS. 20 to 26, the two-looper system will be explained here, and the one-looper system will be described later.

The lower shaft 12 and both loopers 2, 2' consist of spherical eccentric cams 42, 42' fixed to the lower shaft 12, and a reciprocating rod 4 that embraces the spherical eccentric cams 42, 42'.
3, 43', and are fixed to both the upper and lower looper shafts 9, 9' extending in the front-rear direction, and the reciprocating rod 4
3, 43' by ball arms 44, 44' which are each ball-coupled. This situation is especially visible in Figures 2 and 3.
As shown in FIG. The upper looper 2 has the lower end of a looper base rod 46, which constitutes the upper looper 2 together with the upper looper tip 3, pivoted to the tip of a swinging arm 45 connected to the upper looper shaft 9. 46
is supported by a rotary bearing 47 that allows the looper base rod 46 to swing and swing.

The looper shafts 9, 9' are inclined at an angle of about 18 degrees with the rear facing up, so the tip of the upper looper 2 is
Below the throat plate 6, it passes further behind the lower looper 3 that swings behind the darning needle 1, which moves up and down vertically, and above the throat plate 6, it passes through the front side of the darning needle 1 and lowers. It intersects with the looper 3 and the darning needle 1. By slanting the looper shafts 9 and 9', the darning needle 1 can be moved vertically up and down, and the lockstitch needle 5, which will be described later and which moves vertically at the same time, can also be attached to one needle bar 13. can.

Further, a clutch 48 is interposed at the communication portion between the upper looper shaft 9 and the swing arm 45, and the operation of the upper looper 2 is switched by connecting and disconnecting the clutch. The clutch 48 is shown in FIGS. 1 and 3. In particular, as shown in FIG. 3, the front end of the upper looper shaft 9 forms a plurality of parallel grooves like a spline shaft, and an engaging piece 49 that can freely swing in the axial direction is externally fitted into this. On the rear side of the engagement piece 49, the base end of the swinging arm 45 is externally fitted onto the upper looper shaft 9 so that it is not restricted by the rotation of the upper looper shaft 9 and cannot slide in the axial direction. An engagement groove 5 is formed on the front surface of the base end of the swing arm 45.
0 is formed, and a protrusion 5 that engages with this engagement groove 50
1 is formed on the rear surface of the engagement piece 49. As the engaging piece 49 slides, the protrusion 51 of the engaging piece 49 and the engaging groove 50 of the swinging arm 45 engage or separate, and the clutch 48 is disconnected. The driving of the upper looper 2 is intermittent.

Further, a circumferential groove 52 is formed on the outer periphery of the engaging piece 49, and the tip end point of the switching arm 53 engages with this groove. The switching arm 53 has its fulcrum 54 provided on the body 11, and is configured with a leaf spring so that the clutch 48 is normally engaged.
That is, by pushing the force point 53' of the switching arm 53 against the force of the leaf spring, the clutch 48 is disengaged. Thus, the clutch 48 is also an example of the switching mechanism C. Also, the upper looper tip 3
The structure in which the upper looper 2 is detachably attached to the looper base rod 46 by a screw 55 is also advantageous because when the upper looper 2 is not in use, the screw 55 can be loosened, the upper looper tip 3 can be removed, and the sewing can be switched to lock stitching. , which also constitutes an example of the switching mechanism C. Furthermore, upper looper tip 3
The same is true even if the structure is bent.

13 to 15 show the relationship between the darning needle 1, the lockstitch needle 5, and the needle bar 13. The darning needle 1 is attached to the darning needle holder 60, and the lockstitch needle 5 is attached to the lockstitch needle holder 61. Each is fixed and the lockstitch needle is held 6
1 is attached to the lower end of the needle bar 13. The darning needle holder 60 is rotatably attached to the lockstitch needle holder 61 by a bolt 62, and the darning needle 1 is configured to be rotatable. This pivoting is shown in FIG. 14 between a normal use position in which the darning needle 1 faces downward and a non-use position in which it faces backward. A protrusion 63 on the darning needle holder 60 that projects toward the lockstitch needle holder 61 is biased by a bullet 64 and engages with positioning holes 65 and 66 formed in the lockstitch needle holder 61. 65 is a positioning hole for the use position, and 66 is a positioning hole for the non-use position.

Although the darning needle 1 is configured to be freely pivotable, it is preferable that the lockstitch needle 5 is also configured to be freely pivotable in the same way. In this case, a needle holding base may be fixed to the lower end of the needle bar 13, and the darning needle 1 and the lockstitch needle 5 may be configured to be rotatable on the needle holding base as described above. In this embodiment, it is turned to the unused position by turning it backwards, but the turning direction may be forward or left/right, or it may be retracted upward to the unused position by sliding. Further, by arranging two needle bars 13 to which the darning needle 1 and the lockstitch needle 5 are individually fixed, it is possible to facilitate coordination with other operations.

Further, the means for fixing the darning needle 1 to the darning needle holder 60 is a removable fixing means using screws, and the fixing means for the lockstitch needle 5 is similarly fixed by screws.

The means for rotating the darning needle 1 and the lockstitch needle 5 to non-use positions is an example of the switching mechanism C, and the structure in which both the needles 1 and 5 are detachable using screws is also an example of the switching mechanism C. If this attachment/detachment is used for switching the sewing means, a switching mechanism C is formed.

The throat plate 6 is a common component that constitutes both the overlocking mechanism A and the lockstitch mechanism B, and is substantially one part.
Consists of two plates. Here, "substantially one plate" includes a structure in which a plurality of plate pieces are arranged adjacent to each other. As is clear from FIG. 19, the throat plate 6 is provided with a thread guide piece 6' oriented in the cloth feeding direction. The thread guide piece 6' forms the hem stitching mechanism A, and forms an overseam stitch on the edge of the cloth around the thread guide piece 6', and the thread guide piece 6' itself is publicly known. However, the needle plate 6 used for overlocking and lockstitching
This invention is unique in that the thread guide piece 6' is formed on the thread guide piece 6'.

A cloth feed shaft 70 is horizontally suspended below the bed 37, and the upper shaft 14 and the cloth feed shaft 70 are connected by a forked rod 71, as shown in FIGS. 1 and 3. That is, the feed cam 72 fixed to the upper shaft 14
A forked rod 71 is engaged with the forked rod 71, and the lower end of the forked rod 71 is pivotally connected to an arm 73 fixed to the cloth feed shaft 70. One end of a feed link 74 is pivotally connected to the middle of the forked rod 71, and the other end of the feed link 74 is pivotally connected to one end of a lever link 76 at a movable fulcrum 75. Further, the other end of the lever link 76 is a lever shaft 78 supported by a bearing 77.
Further, a heart-shaped cam 79 and a reverse feed lever are fixed to the lever shaft 78, and by pressing the heart-shaped cam 79 with a feed adjustment screw against the biased spring, the movable fulcrum 75 is fixed. By changing the position of the forked rod 71 and the feed link 74,
Select the swing locus of the pivot joint with the cloth feed shaft 70.
The cloth feed amount is determined by changing the amount of rotation of the cloth, and the reverse feed is performed by lowering the reverse feed lever further downward. It should be noted that there are various other adjusting mechanisms that allow reverse feeding, but since they are all known, detailed explanations will be omitted.

As shown in FIG. 6, the lower end of a swinging arm 80 is fixed to the cloth feeding shaft 70.
A cloth feed arm 81 is pivotally attached to the upper end of the cloth feeding arm 81. The cloth feeding arm 81 forms a fork in the middle, and an eccentric cam 8 fixed to the lower shaft 12 is installed in the fork 82.
3 and generates vertical movement. The cloth feed tooth 8 is attached to the tip of the cloth feed arm 81, and thus the cloth feed dog 8 performs a cloth feed movement that is a combination of forward and backward movement by the cloth feed shaft 70 and vertical movement by the lower shaft 12. .

Thus, cloth feeding mechanism D is constructed. The cloth feeding mechanism D can be used in common for overlock stitching, lock stitching, and safety stitching using both stitches.

Note that, in this embodiment, a cloth presser mechanism is not illustrated. This is because the structure is similar to that of a conventional presser mechanism. However, the presser mechanism also has a single mechanism and is commonly used for overedge stitching, lock stitching, and safety stitching using both of these stitches.

Other embodiments of the balance mechanism are shown in FIGS. 16 and 17.

That is, the needle bar 1 has an overlocking thread take-up 84 for overlocking and a lockstitch take-up 85 for lockstitching.
It is attached in connection with 3. The overlocking thread 84 has an overlocking thread 8 on its upper part at the final stage of descent.
A hook-shaped hook 87 is provided for pulling the thread 6, and a guide inclined side 88 is formed extending downward from the hook 87. Guide slope side 8
8 is the needle bar 13 sequentially from the hooking part 87 to the approximately middle part.
The needle bar 13 is inclined so as to be further away from the needle bar 13, and conversely, it is inclined downwardly from the intermediate portion so as to approach the needle bar 13, and the overall shape is formed as a large circular curve with a bulge at the intermediate portion.

The edge take-up lever 84 is attached to the needle bar 13 by a take-up lever 89 and is configured to move up and down in synchronization with the up and down movement of the needle bar 13.
The needle bar 13 may be attached to the needle bar 13 and moved up and down while swinging in synchronization with the up and down movement of the needle bar 13. In this case, the hem thread take-up 84 operates the oversewing thread 86 while performing a combination of lifting and lowering and rocking movements, so the hook portion 87 as in this embodiment may not be necessary, and the guide thread 86 may not be necessary. The shape of the inclined side 88 also changes.

The edge take-up lever 84 is exposed to the front through the elongated hole 91 of the jaw portion 90 of the bracket arm 15.
On both the left and right sides of the elongated hole 91, there are edge thread take-up levers 84.
Thread guides 92 and 93 are erected at the position of the hook part 87 at the bottom dead center of the thread guide so as to sandwich the hem thread take-up lever 84. Such a structure is already known as described in Japanese Patent Application Laid-Open No. 54-2847.

In this embodiment, the lock stitch thread take-up 85 is a so-called slide thread take-up. That is, the bending portion 95 of the lockstitch thread take-up lever 85 and the swinging rod 94 that extends vertically and integrally with the rear end thereof is pivotally attached to the sewing machine body 11, and the needle bar crank 18 of the upper shaft 14
A slide fitting 96 rotatably pivoted via a link is slidably fitted onto the swinging rod 94, and the slide fitting 96 slides on the swinging rod 94 as the needle bar crank 18 rotates. Then, the lock stitch thread take-up 85 is caused to swing. 97
is a lockstitch thread operated by the lockstitch thread take-up 85, and 98 and 99 are thread tension devices. The lower end of the needle bar 13 is provided with the above-mentioned darning needle holder 6.
0 and the lockstitch needle holder 61 are attached.

A front cover 100 is detachably attached to the front of the lower part of the sewing machine. A throat plate piece 101 is formed on the upper surface of the front cover 100 to be combined with the throat plate 6 to form a needle plate exclusively for lock stitching. The front cover 100 covers the front of the lower part of the sewing machine, both sides thereof, and the upper and lower surfaces thereof. Therefore, the area of the bed 37 is substantially increased, contributing to smooth lock stitching work. This front cover 10
FIG. 19 shows a plan view of the front part of the bed 37 with 0 attached. Figure 18 shows the front cover 100.
It is the same top view of the state where is not attached.

Therefore, mainly the darning needle 1, the needle bar 13,
Both upper and lower loopers 2, 2a, looper shafts 9, 9a,
The swiveling arm 45, the throat plate 6, and the cutting machine 4 constitute the overlocking mechanism A. Further, a lockstitch mechanism B is mainly constituted by the lockstitch needle 5, the needle bar 13, the hook 7, the hook shaft 10, and the throat plate 6. In addition, the main parts include a rotatable darning needle holder 60 and a cutting machine 4.
A switching mechanism C is constituted by the hooking/unhooking device 29, the direction changing mechanism 36 of the cutting machine 4, and the clutch 48 of the upper looper shaft 9.
is a mechanism that switches between overlocking and lockstitching, and therefore, during one sewing, the overlocking needle 1, lockstitch needle 5, upper knife 26, and upper looper 2 that get in the way of the other sewing. Even if it is a mechanism in which these are attached and detached using screws or the like that fasten them, the above-mentioned switching mechanism C is constituted. Also, mainly the cloth feed shaft 70, the arm 73, the forked rod 71, and the feed cam 7.
2. Swinging arm 80, cloth feeding arm 81, fork 8
2. A cloth feeding mechanism D is constituted by the eccentric cam 83, the cloth feeding dog 8, and a cloth pressing device (not shown).

The needle bar 13, throat plate 6, and cloth feed mechanism D have a common configuration for both overlock stitching and lock stitching, and are therefore also used for safety stitching using both stitches. One of the features of this invention is that many common configurations are used for overlocking and lockstitching.

In place of the two-looper system described above, FIGS. 20 to 26 show an embodiment in which a one-looper system is adopted. The looper 2 is connected to a looper shaft 9 that extends in the front-rear direction, which is a direction perpendicular to the lower shaft 12, and as the looper shaft 9 rotates in the circumferential direction, the looper 2 swings and the looper tip 3 is rotated. Do the so-called over-edge exercise.

The means of communication between the lower shaft 12 and the looper shaft 9 is the lower shaft 1.
an eccentric cam 56 fixed to
a reciprocating rod 58 which is held at one end and pivotally connected to one end of the swinging arm 57 at the other end.
One end is pivotally connected to the reciprocating rod 58, and the other end is fixed to an intermediate shaft 59 that is horizontally suspended parallel to the lower shaft 12, so that the rocker for reciprocating the intermediate shaft 59 is fixed. moving arm 57 and the intermediate shaft 59
and a pair of bevel gears 67 that are fixed to the intermediate shaft 59 and the looper shaft 9, respectively, and mesh with each other.
A screw gear can be used instead of the bevel gear 67, and a crank can also be used instead of the eccentric cam 56. Further, instead of the entire communication means, the communication means between the lower shaft 12 and the upper looper shaft 9 in the two-looper system may be used as is. In response to the rotation of the lower shaft 12, the advancing/retracting rod 58 moves forward and backward, and the intermediate shaft 59 rotates back and forth.
Similarly, the looper shaft 9 is rotated back and forth.

A swinging arm 45 is connected to the looper shaft 9 via a clutch 48, and the tip of the swinging arm 45 is connected to the looper 2.
The lower end of the looper base rod 46 forming the lower part of the looper base rod 46 is pivotally supported.
Also, the middle part of the looper base rod 46 is located at the sewing machine body 11.
A swinging link 68 which is pivotally connected at one end to the swingable link 68
is pivoted to the other end. The looper tip portion 3, which together with the looper base rod 46 constitutes the looper 2, is attached to the upper end of the looper base rod 46, and is detachably fixed with a screw 69.

As shown in FIGS. 21, 24, and 26, the clutch 48 includes a fixing piece 103 having an engagement recess 102 and fixed to the looper shaft 9;
pivotally attached to the end of the swing arm 45,
The fixed piece 103 includes an engaging piece 104 that engages with the engaging recess 102, and a leaf spring 105 that maintains the rotation angle of the engaging piece 104 constant. When the clutch 48 is released, the swing arm 45 has a structure in which only one end of the swing arm 45 is fitted onto the looper shaft 9 and does not interlock with the looper shaft 9. , the swinging arm 45 interlocks with the looper shaft 9. That is, when the engagement piece 104 engages with the engagement recess 102 of the fixed piece 103, the motion of the looper shaft 9 is transmitted to the swing arm 45, and conversely, when the engagement is released, the looper shaft 9 Although it rotates, the sliding arm 45 slides on the portion fitted onto the looper shaft 9 and does not swing. As will be described later, since the looper 2 is not used during lock stitching, the swinging arm 45 is switched so as not to swing. The clutch 48 is also an example of the switching mechanism C. Furthermore, the structure in which the looper tip 3 is detachably attached to the looper base rod 46 with a screw 69 is also such that when the looper 2 is not in use, the screw 69 is loosened and the looper tip 3 is removed, and the lockstitch can then be performed. Since it can be switched, this also constitutes an example of the switching mechanism C. Furthermore, the same holds true even if the looper tip portion 3 is bent.

Moreover, the looper shaft 9 is arranged so that the rear part is on top.
The looper 2 is tilted at an angle of about 18 degrees, so the looper 2 is tilted forward, and the looper tip 3 is connected to the darning needle 1, which moves vertically up and down above the throat plate 6.
It passes through the rear side and the front side of the darning needle 1 above the throat plate 6, respectively, and intersects with the darning needle 1.
For overlock stitching using the single looper method,
As mentioned above, since the darning needle 1 and the looper tip 3 must cross each other at the top and bottom of the throat plate 6, the vertical movement direction of the darning needle 1 and the vertical movement plane direction of the looper tip 3 are at a predetermined angle. must have.

Therefore, in this embodiment, the darning needle 1 is moved up and down in the vertical direction, and the looper shaft 9 is tilted by 18 degrees so that the rear part thereof rises. By configuring the darning needle 1 to move in the vertical direction, the lockstitch needle 5, which moves vertically up and down at the same time, can also be attached to one common needle bar 13.

Next, the operation of this sewing machine will be explained using a two-looper type embodiment.

The first is the effect when performing safety stitches by simultaneously sewing overedges and lockstitching. In the case of safety stitching, both the upper and lower loopers 2 and 2' are used, similar to the overlocking stitch described later, so the clutch 4
8 are connected so that the upper looper shaft 9 and the upper looper 2 are interlocked. and front cover 100
Also remove it. If this front cover 100 is formed with a pressing part for pressing the force point of the switching arm 53 that switches the clutch 48, the clutch 48 will be automatically engaged when the front cover 100 is attached or detached.
can also be switched. That is, when the front cover 100 is attached, the clutch 48 is released, and when the front cover 100 is removed, the clutch 48 is engaged.

Further, the darning needle 1 and the lockstitch needle 5 are both in the downward use position, and the cutting machine 4 is also in the use state as shown in FIGS. 1 and 8. And both needles 1,
5 and both loopers 2 and 2' are threaded with thread.

Power from a drive source such as a motor is transmitted from the pulley 17 to the upper shaft 14, causing the upper shaft 14 to rotate. The rotation of the upper shaft 14 operates all of the hem stitching mechanism A, lockstitch mechanism B, and cloth feeding mechanism D.

The rotation of the upper shaft 14 causes the needle bar crank 18 to rotate, swinging and raising and lowering the needle bar link 19, thereby raising and lowering the needle bar 13. When the needle bar 13 is raised and lowered, the darning needle 1 and the lockstitch needle 5 are raised and lowered at the same time. This is the operation of hands 1 and 5.

Further, the rotation of the upper shaft 14 operates the cutting machine 4 via the eccentric cam 24. That is, the elevator rod 25 is raised and lowered by the eccentric cam 24, and the unlatching device 29
The continuous female rod 27 and the upper knife 26 attached to its lower end also move up and down, and the upper knife 26 and
The ends of the cloth are trimmed by crossing over with a lower knife (not shown) fixed to the throat plate 6 or body 11.

Thus, the upper shaft 14 simultaneously operates the darning needle 1 and the lockstitch needle 5 and the cutting machine 4.

Further, the upper shaft 14 also operates the lower shaft 12 and the cloth feeding shaft 70 at the same time. The lower shaft 12 receives the rotation of the upper shaft 14 via the rotating vertical shaft 39, and rotates at the same speed as the upper shaft 14.

When the lower shaft 12 rotates, the hook shaft 10 rotates via the screw gear 40, and therefore the horizontal fully rotary hook 7 also rotates. The rotation of the hook 7 is such that the hook shaft 10 is rotated by the lower shaft 12.
Since the rotation ratio is twice that of the lower shaft 12,
Rotates in one direction by multiplying the ratio. Therefore, the pot 7
A lock stitch among the safety stitches is formed by the cooperation of the lock stitch needle 5 and the lock stitch needle 5.

Also, by rotating the lower shaft 12, both the upper and lower loopers 2,
2' is activated. That is, when the lower shaft 12 rotates, the spherical eccentric cams 42, 42' rotate, and the reciprocating rods 43, 43' move a distance twice the eccentricity of the spherical eccentric cams 42, 42'.
It advances and retreats while oscillating. And the advance/retreat rod 43,
As 43' moves back and forth, spherical arms 44 and 44', which are in a spherical pair relationship, swing, thereby rotating the upper looper shaft 9 and the lower looper shaft 9'. As the upper looper shaft 9 rotates, the swinging arm 45 swings, and the tip of the upper looper tip 3 draws a trajectory consisting of a constant curve between the lower and upper sides of the throat plate 6, resulting in a so-called overedge movement. do. The operations of the swing arm 45, the upper looper 2, the looper base rod 46, and the rotary bearing 47 at this time are similar to the upper looper mechanism in a known overlock sewing machine.

The lower looper 2' is swung by the rotation of the lower looper shaft 9', and below the throat plate 6 intersects the darning needle 1 when lowered, and on the right side the upper looper 2 when raised.
intersect with

By the cooperation of the darning needle 1, the upper looper 2, and the lower looper 2', the edges of the cloth whose edges have been trimmed by the cutting machine 4 are darned, and the darning stitches among the safety stitches are sewn. is formed.

It goes without saying that the locus of the upper looper tip 3 can be changed by appropriately changing the link ratio of the swing arm 45, the looper base rod 46, etc., the fulcrum of the rotary bearing 47, etc. Furthermore, an overlock stitch can be formed by using a hook looper instead of the upper looper 2.

Further, the rotation of the upper shaft 14 causes the cloth feeding shaft 70 to reciprocate through the forked rod 71. This is upper axis 1
The two-pronged rod 71 swings and moves up and down by the four feed cams 72, the movable fulcrum 75, and the feed link 74, causing the cloth feed shaft 70 to reciprocate and rotate via the arm 73. When the cloth feed shaft 70 reciprocates, the swing arm 80 swings to move the cloth feed arm 81 back and forth. Furthermore, as the lower shaft 12 rotates, the eccentric cam 83 that engages in the fork 82 of the cloth feed arm 81 rotates, giving vertical movement to the cloth feed arm 81. Thus, the cloth feed dog 8 performs a cloth feed operation by combining the back and forth movement and the vertical movement. It is well known that normal feed and reverse feed can be adjusted by moving the movable fulcrum 75 by switching the reverse feed lever. In this embodiment, a lower shaft 12 is provided between the cloth feed shaft 70 and the cloth feed tooth 8 to which an eccentric cam 83 is fixed for causing vertical movement. As a result, there is no longer a rotating shaft below the cloth feed dog 8 or in front of the horizontal fully rotary hook 7 for vertically moving the cloth feed arm 81. Therefore, the operation of both the upper and lower loopers 2, 2' is not adversely affected, and the horizontal full rotation hook 7 and both the upper and lower loopers 2, 2' are
We were able to bring them as close as possible. This cloth feeding mechanism D can be used for both overlock stitching and lock stitching, and is one of the features of this embodiment.

Next, the operation when performing overedge stitching using this sewing machine will be explained. In the case of this overlock stitch, since lock stitching is not performed, there is no need to pass the thread through the lock stitch needle 5. However, this is all you need to do an overedge stitch. In this case, the lockstitch needle 5 and the horizontal full-rotation hook 7 move in the same manner as in the case of safety stitching, but no lockstitch is formed because no thread is passed through the lockstitch needle 5. Therefore, an overedge stitch can be performed in the same way as an overedge stitch in the case of safety stitching. Therefore, in this case, the lockstitch needle 5 and the horizontal full-rotation hook 7 simply rotate idly.

At this time, if the lockstitch needle 5 is constructed so that it can be rotated to a non-use position like the darning needle 1, holes will not be formed in the fabric due to the lockstitch needle 5 idling, and the formation of holes can be prevented. There is no need to loosen the screw and remove the lockstitch needle 5 to avoid this.

Furthermore, the operation of lockstitching with this sewing machine will be explained. In this case, the above-mentioned configurations for oversewing are not necessary. Therefore, configurations used only for oversewing are allowed to idle, or configurations that are in the way for lockstitching are not only idle but also moved to a position of no use or are deactivated.

That is, the darning needle 1 is rotated to a position where it is not in use or removed, as shown by the chain line in FIG. 14, and the cutting machine 4 also raises the female rod 27 and below. The lifting of the female rod 27 is done by the unlatching device 2.
Pull the operation part 34 of 9 and insert the engagement pin 32 into the female rod 2.
When removed from the engagement hole 31 of No. 7, the female rod 27 rises due to the bias of the bullet 28, and therefore the upper female rod 27
6 also rises to a non-use position. In this case, the upper knife 26 is also rotated rearward by the direction changing mechanism 36, thereby ensuring the safety of the sewing operation.
Thus, in the cutting machine 4, only the lifting rod 25 and the frame 30 rotate idly.

The upper looper 2 cuts off the operation of the upper looper shaft 9 from being transmitted to the swinging arm 45 by the clutch 48,
It is also assumed to be in a stationary state. This presses the force point 53' of the switching arm 53 and releases the clutch 48. As a result, the swinging arm 45 is released from the operation of the upper looper shaft 9 and does not swing, so that the upper looper shaft 9 idles and the upper looper 2 does not operate. Since the upper looper 2 does not perform the above-described overedge movement, its tip 3 does not appear on the upper surface of the throat plate 6.

Therefore, the lockstitch needle 5, throat plate 6, and horizontal full-rotation hook 7 are
and cloth feed mechanism D to perform lock stitching. At this time,
As mentioned above, since the upper looper 2 is not exposed on the upper surface of the throat plate 6, the front cover 100 can be attached to the lower front surface of the sewing machine body 11. By attaching this front cover 100, the bed 37 is substantially enlarged, making it suitable for sewing work.

Further, the operation of the hem thread take-up lever 84 for oversewing shown in FIGS. 16 and 17 will be explained as follows. As the needle bar 13 moves up and down,
The darning thread take-up 84 also moves up and down, and to explain the relationship between the elevation of the darning thread take-up 84 and the darning thread 86, when the darning thread take-up 84 rises, the darning needle 1 and needle bar 13 also begin to rise. , the overlock thread 86 begins to loosen. The overhanging thread take-up 84 rises at a point where the slack should increase over time with these rises, and since the guide slope side 88 of the overhang thread take-up 84 is inclined as described above, the overhang thread take-up As the stitching thread 84 rises, the stitching thread 86 is pulled away from the thread guide holes of the thread guides 92 and 93 on both sides of the stitching thread take-up 84, thereby absorbing the slack and controlling it to have an appropriate tension. be done. Therefore, during this upward movement, the darning thread 86 does not become slack.

Next, when the needle bar 13 and the darning needle 1 start descending from the top dead center, the darning thread take-up 84 also descends, and at this time the darning thread 86 is pulled downward, which is the moving direction of the darning needle 1. At the same time, as the hem thread take-up 84 descends, the oversewing thread 86 absorbed during the ascent is loosened over time and supplied. Therefore, the darning thread 86 is supplied to the darning needle 1 without being strongly tensed or loosened, and a beautiful darning stitch with a nice texture can be obtained.

The guide inclined side 88 extending downward from the hooking part 87 of the overlocking thread take-up 84 and formed to be separated from the needle bar 13 is particularly important in the case where the overhanging thread take-up lever 84 is raised and lowered while swinging back and forth. This is effective in taking up the slack in the newly supplied darning needle thread 86. In the case of a sewing machine that moves up and down while swinging back and forth, the shape of the guide slope side 88 is different because the swinging takes up the slack in the overlock thread 86.

Further, the lockstitch thread take-up 84 for lockstitching is operated by the needle bar crank 18 which rotates together with the upper shaft 14.
The swinging rod 94 swings via the slide fitting 96,
The lockstitch thread 94 is smoothly supplied to the lockstitch needle 5 by swinging up and down around the bent portion 95.

Next, the operation of over-edge stitching in the case of the single looper method shown in FIGS. 20 to 26 will be explained.

As the lower shaft 12 rotates, the reciprocating rod 58 moves forward and backward, the swinging arm 57 swings, and the intermediate shaft 59 reciprocates. This reciprocating rotation similarly causes the looper shaft 9 to reciprocate by the bevel gear 67. Therefore, when the clutch 48 is engaged, the swinging arm 45 swings due to the rotation of the looper shaft 9, causing the looper 2 to move in an overedge motion, and working together with the darning needle 1 to form an overedge stitch. do. During lock stitching, the looper 2 constituting the overlocking mechanism A is not used. Clutch 48 is therefore released.
The clutch 48 can be released by rotating the engaging piece 104 and disengaging it from the engaging recess 102 of the fixed piece 103. As a result, the looper shaft 9 rotates idly, and the swing arm 45 and the looper 2 are not operated.

Therefore, according to these embodiments, it is possible to freely select and sew by appropriately switching overedge stitching, lock stitching, and safety stitching using a combination of these stitches. In particular, by using the throat plate 6 and the cloth feeding mechanism D in common for the various types of sewing mentioned above, it is now possible to perform safety stitching by combining lock stitching and overlock stitching at the same time. In addition, despite this remarkable effect, the horizontally mounted shaft has an upper shaft on the top.
4, one lower shaft 12 and one cloth feed shaft 70 at the bottom, there are only three shafts in total, and as mentioned above, there are only three shafts, including the throat plate 6, for stitch formation. The structure is simpler because many parts are shared. Using a single looper will greatly contribute to simplifying the structure. This results in the miniaturization of the fuselage 11 and a reduction in failures, which also contributes to cost reduction. In addition, by using the horizontal full-rotation hook 7 as the hook that forms the final stitch in cooperation with the lock stitch needle 5,
Since it does not interfere with the edge mechanism A located in front of it, it is not only easy to adjust each part, but also
The distance between the needle drop points of the lock stitch needle 5 and the darning needle 1 for safety sewing can be made as close as possible. Therefore, a proper safety seam can be obtained, and the workability for forming the seam has been improved. Furthermore, the bobbin for the bobbin thread of the horizontal full-rotation hook 7 can be easily attached and detached, which greatly contributes to improving work efficiency.

According to the present invention, by switching the sewing type, it is possible to perform at least one of overlock stitching and lock stitching, and safety stitching by using both of these stitches together, using one sewing machine. In particular, the fact that the safety stitching is now possible is an effect completely absent from the conventional example. The fact that the hook shaft and the looper shaft can be interlocked by the lower shaft and that the hook and looper can be driven by a single shaft is effective in simplifying the structure of the lower part of the sewing machine body.
Furthermore, the ability to interlock the darning needle with the upper shaft and drive both needles by one shaft has become effective in simplifying the structure of the upper part of the sewing machine. Furthermore, by making the throat plate and cloth feed mechanism common to all sewing types, the overall structure can be simplified, reducing malfunctions and costs, and at the same time making the sewing machine easier. There is also an effect that miniaturization can be achieved.

[Brief explanation of the drawing]

The drawings show an embodiment of the invention, and FIG. 1 is a partially cutaway front view of a two-looper system;
Figure 2 is a plan view of the lower structure, Figure 3 is a sectional view taken along the line 3-3 in Figure 1, Figure 4 is a vertical sectional view of the lower shaft, advancement/retraction rod, and ball arm, and Figure 5 is the same view as in Figure 3. Figure 6 is a view taken along the line 5-5 with the cover removed.
6 line sectional view, Figure 7 is a 7-7 line sectional view of Figure 2,
Figure 8 is a sectional view taken along line 8-8 in Figure 1, and Figure 9 is a cross-sectional view of Figure 8.
9-9 line sectional view in the figure, Figure 10 is the 10-9 line in Figure 8.
11 is a sectional view taken along the line 11-11 in Fig. 1, Fig. 12 is a sectional view taken along the line 12-12 in Fig. 8, and Fig. 13 is the left side of the darning needle holder and lockstitch needle holder. Fig. 14 is the right side view of the same, Fig. 15 is the 1st
4, FIG. 16 is a front view showing an embodiment of the balance, FIG. 17A is a vertical sectional view of FIG. 16, and FIG. 17B is a sectional view taken along BB-B of FIG. 17A. Fig. 18 is a plan view of the bed surface with the front cover removed, Fig. 19 is a plan view of the bed surface with the front cover attached, and Fig. 20 is a plan view of the lower structure in the single looper system. , Figure 21 is the 20th
22 is a sectional view taken along line 22-22 in FIG. 20, FIG. 23 is a sectional view taken along line 23-23 in FIG. 20, FIG. 24 is a sectional view taken along line 24-24 in FIG. 20,
Figure 25 is a view taken along the line 25-25 in Figure 24.
FIG. 6 is a sectional view taken along line 26-26 in FIG. 25. In the figure, A is the overlocking mechanism, B is the lockstitch mechanism,
C is an operation switching mechanism, D is a cloth feed mechanism, 1 is a hook needle, 2, 2' are a looper, 4 is a cutting machine, 5 is a lockstitch needle, 6 is a throat plate, 7 is a horizontal full rotation hook, 8 is a cloth Feed dog, 9, 9' are looper shafts, 10 is hook shaft, 11 is machine body, 12 is lower shaft, 13 is needle bar, 14 is upper shaft, 40
is a screw gear, 42, 42' is a spherical eccentric cam, 4
3, 43' are forward and backward rods, 44, 44' are ball arms, 5
7 is a swing arm, 59 is an intermediate shaft, and 67 is a bevel gear.

Claims (1)

[Claims] 1. It has an overlocking mechanism, a lockstitch mechanism, an operation switching mechanism for these mechanisms, and a cloth feeding mechanism, and the overlocking mechanism has a darning needle that moves up and down to form an overlock stitch, and A looper that cooperates with the darning needle to form an overcast seam, a cutting machine that cuts the edge of the fabric, and a thread guide piece that forms an overcast seam at the edge of the fabric in cooperation with the darning needle and the looper are provided. The lock stitch mechanism includes a needle plate that moves up and down at a position close to the width direction of the darning needle with respect to the cloth feeding direction to form a lock stitch in line with the overlock stitch. a sewing needle and a throat plate that is common to the needle plate forming the overlocking mechanism, through which the lockstitch needle passes;
It consists of a hook that moves in a circular motion below the throat plate in synchronization with the lockstitch needle, and the switching mechanism is configured to perform overlock stitching using the overlocking mechanism, lockstitching using the lockstitch mechanism, and a combination of both mechanisms. The cloth feeding mechanism has a structure that selects and switches between safety stitching and at least one of the other two sewing types among three sewing types of safety stitching, and furthermore, the cloth feeding mechanism is connected to the common throat plate. A looper shaft that swings the looper of the overlocking mechanism, and a hook that moves the hook of the lockstitch mechanism in a circular motion. The looper shaft and hook shaft are connected to the lower shaft, which is suspended horizontally at the bottom of the machine body and rotates, using communication means, respectively, so that the looper shaft and hook shaft are interlocked, and the needle bars of the darning needle and lockstitch needle are is connected to an upper shaft that is horizontally suspended on the upper part of the machine body and rotates, using a communication means that allows both needles to interlock, and further, the cutting machine of the edge stitching mechanism is connected to the upper shaft or the lower shaft. 1. A sewing machine characterized in that one of the upper shaft and the lower shaft is a drive shaft, and the other shaft is an interlocking shaft of the drive shaft.