JPS6125396B2 - - 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, there are three sewing types: overedge stitching, lock stitching, and safety stitching using both stitches.
It relates to a sewing machine that can selectively perform safety stitching and at least one of two other sewing types, and in particular, a sewing machine that simultaneously drives a hook shaft and a looper shaft with one lower shaft, and also has a needle plate. By using both hem stitching and lock stitching, it is possible to perform safety stitching by simultaneously performing hem oversewing and lock stitching at the same time, and the structure is simplified.

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 stitches by combining two sewing methods, overedge stitching and lockstitching, with one machine. The object of the present invention is to provide a sewing machine which allows the user to select at least one of the two sewing formats, and the purpose of the sewing machine is to provide a sewing machine that allows the user to select at least one of the two sewing formats. To provide a sewing machine which can be shared as much as possible for safety sewing, has a simple structure, reduces troubles and costs, and is miniaturized.

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.
The looper shaft and hook shaft are connected so as to be interlocked with each other, and the cutting machine with the edging mechanism is connected to the upper shaft which is suspended horizontally on the upper part of the machine body and rotates, or to the lower shaft using a connecting means, The shaft and the lower shaft relate to a sewing machine in which either one of the shafts is a drive shaft and 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, lockstitching, 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 as the needle bar 4 rotates. Note that the crank pin has a balance arm 2.
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.
Incidentally, the needle bar 13 shown in FIG. 1 is provided with an overlock thread take-up for overlock stitching, as in another embodiment shown in FIGS. 19 and 20, which will be described later.

Reference numeral 23 designates a bearing for the upper shaft 14. An eccentric cam 24 is fixed to the upper shaft 14 between the bearing 23 and the needle bar crank 18, 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 the female rod 27 and the elevating rod 25 are connected via 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. Then, when the operating portion 34 is pulled to the right in FIGS. 1 and 11, 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 27 by the elastic mechanism 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 hooking/unhooking device 29, the operation switching mechanism C may be configured to detach the female rod 27 or the like 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 constructed by combining a bullet with convex and concave 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 hook shaft 10 that extends in the front-rear direction and has a vertical front full-rotation hook 7 attached to its front end via a bevel gear 40, so that the rotation ratio of the lower shaft 12 and the hook shaft 10 is set to 1:1. It is composed of 2. A screw gear can also be used instead of the bevel gear 40. The relationship between the lower shaft 12 and the hook shaft 10 is particularly shown in FIGS. 2 and 18. Reference numeral 41 in FIG. 18 is a bearing, and its appearance is especially illustrated in FIG. 12.

A looper 2 is connected to the lower shaft 12. In this embodiment, a single looper system is adopted for the looper constituting the overlocking mechanism A. The looper 2 is connected to a looper shaft 9 extending 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 moves so-called. Do over-edge exercise.

The means of communication between the lower shaft 12 and the looper shaft 9 is the lower shaft 1.
an intermediate shaft 43 extending in the front-rear direction, which is a direction perpendicular to the lower shaft 12, and communicating with the lower shaft 12 via a screw gear 42; and an eccentric cam 44 fixed to the intermediate shaft 43.
a swinging arm whose one end is fixed to the looper shaft 9 and whose free end is connected to the other end of the moving rod 45 by a shaft 46. It consists of 47. A bevel gear may be used in place of the screw gear 42, and a crank may be used in place of the eccentric cam 44. The intermediate shaft 43, which rotates in response to the rotation of the lower shaft 12, causes the forward and backward movement rod 45 to move back and forth to the left and right to swing the swinging arm 47, thereby causing the looper shaft 9 to swing back and forth.

A swing arm 48 is attached to the looper shaft 9 and a clutch mechanism 49 is connected to the looper shaft 9.
The tip of the swinging arm 48 pivotally supports the lower end of a looper base rod 50 forming the lower part of the looper 2. Further, the intermediate portion of the looper base rod 50 has one end pivotally attached to the sewing machine body 11 and the other end of the swinging link 51 which is swingable. A looper tip portion 52, which together with the looper base rod 50 constitutes the looper 2, is attached to the upper end of the looper base rod 50, and is removably fixed with a screw 53.

As shown in FIGS. 1, 4, and 5, the clutch mechanism 49 includes a fixed piece 55 having an engaging recess 54 and fixed to the looper shaft 9, and an end of the swing arm 48. an engaging piece 56 that is pivotally connected to the portion and engages with the engaging recess 54 of the fixed piece 55;
and a leaf spring 57 that maintains the rotation angle of the engagement piece 56 constant. When the clutch mechanism 49 is released, the swing arm 48 has a structure in which only one end thereof is fitted onto the looper shaft 9 and does not interlock with the looper shaft 9.
The swinging arm 48 interlocks with the looper shaft 9 by the coupling operation. That is, when the engagement piece 56 engages with the engagement recess 54 of the fixed piece 55, the motion of the looper shaft 9 is transmitted to the swing arm 48, and conversely, when the engagement is released, the movement of the looper shaft 9 is transmitted to the swing arm 48. Although it rotates, the swinging arm 4
8 is a portion fitted onto the looper shaft 9 and does not slide and swing. As will be described later, since the looper 2 is not used during lock stitching, the swinging arm 48 is switched so as not to swing. The clutch mechanism 49 is also an example of the switching mechanism C. Furthermore, the structure in which the looper tip 52 is removably fixed to the looper base rod 50 with a screw 53 is also such that when the looper 2 is not in use, the screw 53 is loosened, the looper tip 52 is removed, and the stitching is switched to lock stitching. Because I can do it,
This also constitutes an example of the switching mechanism C. Furthermore, the looper tip portion 52 is configured to be bent and the same is true.

In this embodiment, the swinging arm 48 and the looper 2 are arranged on the right side of the looper shaft 9 by disposing the looper shaft 9 below the vertical front full-rotation hook 7, and the swinging link 51 and the pivot The landing point was configured so as not to interfere with pot 7.

The looper shaft 9 and the intermediate shaft 43 are inclined at an angle of about 18 degrees so that the rear side is upward, so that the looper 2 is inclined so as to fall forward, and the tip 3 of the looper 2 is Below the plate 6, it passes 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 intersects with the darning needle 1. In order to overlock using the single looper method, the overlock needle 1 and the tip 3 of the looper 2 must intersect at the top and bottom of the throat plate 6 as described above, so the vertical movement direction of the overlock needle 1 and the looper must be 2 must form a predetermined angle with the vertical motion plane direction of the tip 3.

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 a common needle bar 13, as will be described later. .

13 to 17 show the relationship among the darning needle 1, lockstitch needle 5, throat plate 6, and hook 7.
The darning needle 1 is fixed to a darning needle holder 60, the lockstitch needle 5 is fixed to a lockstitch needle holder 61, and the lockstitch needle holder 61 is attached to the lower end of the needle bar 13. Then, the darning needle holder 60 is attached to the lockstitch needle holder 61, and the bolt 62
The darning needle 1 is rotatably attached to the needle 1, and the darning needle 1 is configured to be rotatable. This rotation is the darning needle 1
The pivoting between a normal use position with the handle facing downward and a non-use position facing rearward is shown in FIG.
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.

In FIG. 14, 67 is the needle drop position of the darning needle 1, and 68 is the needle drop position of the lockstitch needle 5.
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. In addition, by arranging two needle bars 13 in parallel, to which the darning needle 1 and the lockstitch needle 5 are individually fixed, linkage with other operations can be facilitated. Reference numeral 69 in FIG. 13 is an inner hook stopper, which is also shown in FIG. 69' is a needle holder for the darning needle 1.

Further, the means for fixing the darning needle 1 to the darning needle holder 60 is a removable fixing means using a screw 58, and the means for fixing the lockstitch needle 5 is also a fixing means using a screw 59.
It is fixed in the same way.

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 needles 1 and 5 are configured to be detachable using screws 58 and 59. Moreover, 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. 14, 21, and 22.
As is clear from the figure, the thread guide piece 6' is formed to be oriented in the cloth feeding direction. Thread guide piece 6'
1 forms a hem stitching mechanism A, which forms a hem seam on the edge of the cloth around the thread guide piece 6', and the thread guide piece 6' itself is known. However, this invention is unique in that a thread guide piece 6' is formed on the throat plate 6, which is used for both oversewing and lockstitching.

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 to a bifurcated rod 71.
will be contacted by. That is, the forked rod 71 engages with a feed cam 72 fixed to the upper shaft 14, 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 part of the forked rod 71, the other end of the feed link 74 is pivotally connected to one end of a lever link 76 at a movable fulcrum 75, and the other end of the lever link 76 is fixed to a lever shaft 78 supported by a bearing 77, and furthermore, the lever shaft 7
A heart-shaped cam 79 and a reverse feed lever are fixed to 8, and the position of the movable fulcrum 75 is changed by pressing the heart-shaped cam 79 with a feed adjustment screw against the biased spring. Select the swing locus of the pivot joint between the forked rod 71 and the feed link 74, change the amount of rotation of the cloth feed shaft 70 to determine the amount of cloth feed, and lower the reverse feed lever further downward. This results in reverse feed. Note that there are various other feed adjustment mechanisms capable of reversing feed, but all of them are well known, so detailed explanations will be omitted.

The lower end of a swing arm 80 is fixed to the cloth feed shaft 70, and the cloth feed arm 81 is pivotally attached to the upper end of the swing arm 80. The cloth feed arm 81 forms a fork in the middle, and the lower shaft 12 is inserted into this fork 82.
The structure is such that the eccentric cam 83 fixed to the cam 83 is held in place to generate 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.

Another embodiment of the balance mechanism is shown in FIGS. 19 and 20.

That is, a thread take-up 84 for overlocking and a thread take-up 85 for lock-stitching are attached to the needle bar 13. The overlock thread take-up 84 is provided with a hook-shaped hook portion 87 on its upper portion for pulling the overseam thread 86 at the final stage of descent, and a guiding inclined side extending downward from the hook portion 87. 8
8 is formed. The guide inclined side 88 is the hook part 87
From the middle part to approximately the middle part, the needle bar 13 is gradually inclined so as to be away from the needle bar 13, and from the middle part downward, the needle bar 13 is gradually inclined to be closer to the needle bar 13. It is formed as a circular curve.

The take-up lever 84 is attached to the needle bar 13 with 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. However, it is attached to the needle bar link 19 and is configured to move up and down in synchronization with the up and down movement of the needle bar 13. It may be in a form that moves up and down while rocking in synchronization. In this case, since the thread take-up 84 operates the overlock sewing thread 86 while performing a combination of lifting/lowering and rocking movements, the hooking portion 87 as in this embodiment may not be necessary, and the guide slope The shape of 88 also changes.

The thread take-up 84 for overlocking appears on the front through a long hole 91 in the jaw portion 90 of the bracket arm 15, and the thread take-up 84 is provided on both left and right sides of the long hole 91.
The lever 84 is placed at the position of the hook 87 at the bottom dead center of the
Thread guides 92 and 93 are erected to sandwich the threads. Such a structure is already known as described in Japanese Patent Application Laid-Open No. 54-2847.

In this embodiment, a so-called slide take-up is used as the lock-stitch take-up 85. That is, the balance 8
5 and a swinging rod 94 extending vertically continuously and integrally at the rear end thereof, the bending portion 95 is pivotally connected to the sewing machine body 11, and is rotatably connected to the needle bar crank 18 of the upper shaft 14 via a link. A pivotally mounted slide fitting 96 is slidably fitted onto the swinging rod 94, and the slide fitting 96 is caused to swing while sliding on the swinging rod 94 as the needle bar crank 18 rotates.
The balance 85 is then oscillated. 97 is the balance 8
It is a lockstitch thread operated by 5, and 98,
99 is a thread tension device. The lower end of the needle bar 13 is provided with the above-mentioned darning needle holder 60 and lockstitch needle holder 6.
1 is 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 in order to combine 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
A plan view of the front part of the head 37 with the head 0 attached is shown in FIG. Figure 21 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,
The looper 2, the looper shaft 9, the swinging arm 48, the throat plate 6, and the cutting machine 4 constitute an edge overlocking mechanism A. Also, mainly the lockstitch needle 5 and the needle bar 13
A lockstitch mechanism B is constituted by the hook 7, the hook shaft 10, and the throat plate 6. Further, the switching mechanism C is mainly composed of the rotatable darning needle holder 60, the hooking/unhooking device 29 of the cutting machine 4, the direction change mechanism 36 of the cutting machine 4, and the clutch mechanism 49 of the looper shaft 9. , this switching mechanism C is a mechanism that switches when selecting overlock stitching and lockstitching, and therefore, the overlocking needle 1, lockstitch needle 5, and upper knife 26 that get in the way of sewing the other during one sewing. ,
Even a mechanism for attaching and detaching the looper 2 using screws or the like that fixes the looper 2 constitutes the switching mechanism C. In addition, mainly the cloth feed shaft 70, the arm 73,
Forked rod 71, feed cam 72, swing arm 8
0, cloth feed arm 81, fork 82, eccentric cam 8
3. A cloth feeding mechanism D is constituted by the cloth feeding teeth 8 and a cloth presser 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 the invention is that many common configurations are used for overlocking and lockstitching.

Next, the function of this sewing machine will be explained. At first,
The operation when performing safety stitching by simultaneously performing overedge stitching and lock stitching will be explained.

In the case of safety stitching, since the looper 2 is used in the same manner as the overlock stitching described later, the clutch mechanism 49 between the looper shaft 9 and the swinging arm 48 is connected to enable the looper 2 to operate. state. Also, at this time, the front cover 100 is removed in advance.

Further, both the darning needle 1 and the lockstitch needle 5 are in the downward use position, and the cutting machine 4 is also in the use state as shown in FIGS. 1 and 7. And both needles 1,
Needless to say, the thread should be passed through the looper 5 and the looper 2, and the thread should be wound around the bobbin.

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.

In this embodiment, the cutting machine 4 is driven by the rotation of the upper shaft 14;
4, a type in which the drive is driven by the rotation of the lower shaft 12 may also be adopted.

Thus, the upper shaft 14 in this embodiment operates the darning needle 1 and the lockstitch needle 5 and the cutting machine 4 at the same time.

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 bevel gear 40, and therefore the hook 7 also rotates. Since the hook shaft 10 has a rotation ratio twice that of the lower shaft 12, the hook 7 similarly rotates in one direction at twice the rotation ratio of the lower shaft 12. Thus, the hook 7 and the lock stitch needle 5 cooperate to form a lock stitch among the safety stitches.

Further, the rotation of the lower shaft 12 causes the looper 2 to operate. That is, when the lower shaft 12 rotates, the screw gear 4
2, the intermediate shaft 43 rotates, and thus the intermediate shaft 4
An eccentric cam 44 fixed to the rod 3 moves the forward and backward movement rod 45 forward and backward. As a result, the swinging arm 47, which is pivotally connected to the advance/retreat rod 45, swings, causing the looper shaft 9 to reciprocate in the circumferential direction thereof.

This rotation of the looper shaft 9 causes the swinging arm 48 extending to the right of the looper shaft 9 to swing up and down, thereby raising and lowering the looper 2. When the looper 2 is raised and lowered, since the looper 2 is supported by the swing link 51, the looper tip 3 moves up and down while passing between the lower and upper sides of the throat plate 6 and the right side of the throat plate 6. Do the so-called over-edge exercise. By the cooperation of the darning needle 1 and the looper 2, a darning stitch among the safety stitches is formed.

Therefore, a safety stitch is simultaneously formed by the lock stitch by the hook and the lock stitch needle and the overedge stitch.

It goes without saying that the locus of the looper tip 3 can be changed by appropriately changing the link ratios, fulcrums, etc. of the swing arm 48, swing link 51, looper base rod 50, etc.

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, the lower part of the cloth feed dog 8 and the hook 7
There is no longer a rotating shaft in front of the cloth feed arm 81 for vertically moving it. Therefore, the operation of the hook 7 and the looper 2 etc. is not adversely affected.
We were able to bring them as close as possible. One of the features of this embodiment is that the cloth feeding mechanism D can be used for both overlocking and lockstitching.

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 hook 7 move in the same way as in the case of safety stitching, but since no thread is passed through the lockstitch needle 5, no lockstitch is formed. 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 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. Screw 59 to avoid
There is no need to loosen the lock stitch needle 5 and remove the lockstitch needle 5.

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, as shown by the chain line in FIG. . The female rod 27 can be raised by pulling the operation part 34 of the hooking/unhooking device 29 and removing the engaging pin 32 from the engaging hole 31 of the female rod 27. Accordingly, the upper knife 26 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 looper 2 prevents the operation of the looper shaft 9 from being transmitted to the swinging arm 48 by the clutch mechanism 49,
It is also in a stationary state. The engagement piece 56 of the clutch mechanism 49 is rotated to engage the engagement recess 54 of the fixed piece 55.
When disengaged from the clutch mechanism 49 , the clutch mechanism 49 cuts off the operation of the looper shaft 9 from being transmitted to the swing arm 48 . Therefore, the looper shaft 9 rotates idly. Since the looper 2 does not perform the above-mentioned overedge movement, its tip 3 does not appear on the upper surface of the throat plate 6.

Therefore, lockstitching is performed using the lockstitch needle 5, throat plate 6, hook 7, and cloth feed mechanism D. At this time, since the looper 2 does not appear on the upper surface of the throat plate 6 as described above, the front cover 1 is placed on the front of the lower part of the sewing machine body 11.
00 can be installed. By attaching this front cover 100, the belt 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. 19 and 20 will be explained as follows. As the needle bar 13 moves up and down,
The balance 84 also moves up and down, but this overhanging balance 8
4 and the darning thread 86 will be explained. When the thread take-up 84 rises, the darning needle 1 and needle bar 13 also begin to rise, and the darning thread 86 begins to loosen. As the overhanging take-up lever 84 rises, and the guide slope side 88 of the overtaking take-up lever 84 is inclined as described above, the slack of the overtaking take-up lever 84 should increase over time due to these rises. As the stitching thread 86 rises, it is pulled away from the thread guide holes of the thread guides 92 and 93 on both sides of the stitching thread take-up lever 84, absorbing the slack and controlling it to have an appropriate tension. Ru. 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 guiding inclined side 88 extending downward from the hooking part 87 of the overlocking thread take-up lever 84 and formed so as to separate the needle bar 13 is particularly difficult to use, except in the case where the overhanging thread take-up lever 84 moves up and down while swinging back and forth. This is effective in taking up the slack in the newly supplied darning thread 86. In the case of the type that moves up and down while swinging back and forth, the shape of the guide inclined 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 97 is smoothly supplied to the lockstitch needle 5 by swinging up and down around the bent portion 95.

Therefore, according to the embodiment described above, 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 having such a remarkable effect, the horizontally mounted shaft has only one upper shaft 14 at the top.
There is one lower shaft 12 and one cloth feeding shaft 70 at the bottom of the book,
There are only three shafts in total, and as mentioned above, many parts, including the throat plate 6, are shared for seam formation, making the structure simple. 1 roopa
The use of this format also greatly contributes to the simplification of the structure. Therefore, the size of the fuselage 11 is reduced and failures are reduced, which also contributes to cost reduction.

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 hook shaft and the looper shaft can be interlocked by the lower shaft, and the hook and looper can be driven by a single shaft, which is effective in simplifying the structure of the lower part of the sewing machine body. In addition, by making the throat plate and cloth feeding 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 to use. There is an effect that miniaturization can be achieved.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a partially cutaway front view, FIG. 2 is a plan view of the lower structure, FIG. 3 is a sectional view taken along line 3-3 in FIG. 1, and FIG. The figure is a 4-4 line arrow view in Figure 3, and Figure 5 is a view 5-4 in Figure 4.
5 line sectional view, Figure 6 is a 6-6 line sectional view of Figure 4,
Figure 7 is a sectional view taken along line 7-7 in Figure 1, and Figure 8 is a cross-sectional view of Figure 7.
9 is a sectional view taken along the line 9-9 in FIG. 7, FIG. 12 is a sectional view taken along line 12-12 in FIG. 2, FIG. 13 is a front view of the needle and hook, and FIG. 14 is a plan view of the hook.
Figure 5 is a partial left side view of Figure 13, Figure 16 is a partial left side view of Figure 1.
Partial right side view of Figure 3, Figure 17 is 17 of Figure 16.
-17 line sectional view, Figure 18 is a plan view of the hook and hook shaft,
Figure 19 is a front view showing one embodiment of the balance;
The drawings are a longitudinal sectional view of FIG. 19, FIG. 21 is a plan view of the bed surface with the front cover removed, and FIG. 22 is a plan view of the bed surface with the front cover attached. In the figure, A is the overlocking mechanism, B is the lockstitch mechanism, C is the switching mechanism, D is the cloth feeding mechanism, 1 is the darning needle, 2 is the upper looper, 3 is the tip of the looper, 4 is the cutting machine, and 5 is the main stitching mechanism. Sewing needle, 6 is a throat plate, 7 is a vertical front full rotation hook, 8 is a cloth feed dog, 9 is a looper shaft, 10 is a hook shaft, 11 is a machine body, 12 is a lower shaft, 13 is a needle bar, 14
42 is an upper shaft, 42 is a screw gear, 43 is an intermediate shaft, 44 is an eccentric cam, 45 is a reciprocating rod, 46 is a shaft, and 47 is a swing arm.

Claims (1)

[Scope of 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 is configured to move up and down in order to form overseam stitches. A darning needle, 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 darning needle and the looper work together to form an overcast seam on the edge of the fabric. and a needle plate provided with a thread guide piece to guide the overlock stitch, and the lock stitch mechanism moves up and down at a position close to the darning needle in the width direction with respect to the cloth feeding direction to sew the lock stitch in line with the overlock stitch. A lockstitch needle that forms a stitch, and a throat plate that is common to the throat plate that forms 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 and rotates, using communication means, respectively, so that the looper shaft and hook shaft are interlocked. The upper shaft is suspended horizontally on the upper part and rotates, or is connected to the lower shaft using a communication means, and one of the upper shaft and the lower shaft is a drive shaft, and the other shaft is the drive shaft. A sewing machine characterized by an interlocking shaft. 2. The sewing machine according to claim 1, wherein the switching mechanism selectively switches between overlocking by the overlocking mechanism, lockstitch by the lockstitch mechanism, and safety stitching by using both mechanisms together. 3. The cutting machine includes an eccentric cam fixed to an upper shaft, a lifting rod connected to the eccentric cam, a female rod connected to the lifting rod, and an upper knife attached to the female rod.
The sewing machine according to claim 1, comprising a lower knife attached to the throat plate or the machine body. 4. The sewing machine according to claim 1, wherein both a hook needle and a lockstitch needle are attached to the lower end of one needle bar. 5. The sewing machine according to claim 1, wherein the needle bar to which the darning needle is attached and the needle bar to which the lockstitch needle is attached are separate needle bars.