JPH0592093A - Upper looper suspending device of sewing machine - Google Patents

Abstract

PURPOSE:To provide the upper looper suspending device which can easily hold the upper looper in a prescribed suspending position in the inside of a bed so that the upper looper does not protrude onto the bed at the time of forming only double ring sewing, in a sewing machine which can perform simultaneously overlock sewing and double ring sewing. CONSTITUTION:To a main shaft 1, a collar member 14 in which a recessed part 14a is formed is fixed, and a looper driving cam 6 is supported relatively rotatably adjacently to its collar member 14. On one side of the cam 6, a pair of arm parts 15, 16 are formed, and on the arm part 16, a clutch lug 22 having a lug part 22a is supported turnably, and between the arm part 15 and the clutch lug 22, a spring 24 is stretched. By fitting of the lug part 22a and the recessed part 14a, the cam 6 rotates integrally with the main shaft 1, and when they are detached, the upper looper 4 is suspended.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an upper looper pause device for a sewing machine.

[0002]

2. Description of the Related Art Recently, a lock sewing machine capable of overlock stitching and double chain stitching has been put into practical use. Usually, in the lock sewing machine, the upper looper is rotatably connected to a tip end portion of an upper looper swing arm provided on the upper looper drive shaft, and the upper looper drive shaft reciprocally rotates in synchronization with the rotation of the main shaft. When the double chain stitch is sewn in a portion other than the vicinity of the cloth edge, the upper looper projects to the upper surface of the needle plate and interferes with the sewing operation, as shown in Fig. 7. The upper looper swing arm 100 is rotatably provided on the upper looper drive shaft 101, and the connecting member 1 is fixed to the upper looper drive shaft 101 adjacent to the upper looper swing arm 100.
No. 02 is provided and when double chain stitching is performed at a portion other than the vicinity of the cloth end, the screw 103 is removed to make the upper looper drive shaft 101 and the upper looper swing arm 100 rotatable relative to each other, and the upper looper is attached to the upper surface of the needle plate. It is configured so that it can be held in a predetermined rest position where it does not protrude. On the other hand, Japanese Utility Model Laid-Open No. 61-25752 discloses a basting stitch in which a clutch mechanism is provided on an upper shaft which is driven to rotate by a sewing machine motor, and the power to a needle bar is intermittently stopped via this clutch mechanism. The device is described.

[0003]

In the lock sewing machine, the operation state in which the upper looper is swung and the rest state in which the upper looper is not swung are switched by attaching / removing the screw. Therefore, the lock sewing machine is switched to the rest state. Sometimes, after removing the screw, the upper looper is manually rotated to a predetermined rest position so as not to interfere with the lower looper, and when the operating state is switched, the screw hole formed in the connecting member and the upper looper swing arm are moved. It is necessary to manually rotate the connecting member to fasten the screw so that the screw holes formed in the two are exactly aligned.

An object of the present invention is to provide an upper looper pausing device for a sewing machine which can hold the upper looper in a predetermined rest position with a simple operation.

[0005]

SUMMARY OF THE INVENTION An upper looper pausing device for a sewing machine according to the present invention comprises a main shaft arranged in a bed and rotationally driven by a sewing machine motor, an upper looper drive shaft, and an upper looper fixed to the drive shaft. An upper looper mechanism including a looper swing arm and an upper looper rotatably connected to the tip end of the swing arm, an upper looper drive cam provided on the main shaft, and an upper looper drive shaft by the rotational force of the main shaft. In a sewing machine having an interlocking mechanism for interlockingly connecting an upper looper drive cam and an upper looper drive shaft so as to reciprocally rotate, the upper looper drive cam is provided relative to the main shaft so as to be rotatable relative to the main shaft. The force can be switched between a transmission position that transmits the force to the upper looper drive cam and a non-transmission position that does not transmit it, and the upper looper is held in a predetermined rest position that does not project from the upper surface of the needle plate and switched to the non-transmission position. A possible clutch mechanism is provided, it is provided with a manipulation means for switching operation over the clutch mechanism in both positions.

[0006]

In the upper looper pausing device of the sewing machine according to the present invention, the main shaft provided in the bed is rotationally driven by the sewing machine motor, and the upper looper drive cam provided on the main shaft is rotationally driven. The looper drive shaft connected to the upper looper drive cam via the connecting mechanism is reciprocally rotated, and the upper looper is swingably driven via the upper looper swing arm fixed to the upper looper drive shaft. A looper drive cam is relatively rotatably provided on the main shaft, and the upper looper drive cam and the main shaft are switchable between a transmission position that transmits the rotational force of the main shaft to the upper looper drive cam and a non-transmission position that does not transmit it. Since the upper looper is held at a predetermined rest position that does not protrude from the upper surface of the needle plate and is connected via a clutch mechanism that can be switched to the non-transmission position, the clutch mechanism is transmitted by the operating means. The upper looper is oscillated for sewing by a simple operation of selectively switching between the position and the non-transmission position, and the state where the upper looper is held at a predetermined rest position that does not project from the upper surface of the needle plate. It can be easily switched to the case of sewing with.

[0007]

According to the upper looper pausing device of the sewing machine of the present invention, as described in the above [Operation], the clutch mechanism and the operating means are provided in a simple structure so that the clutch mechanism can be transmitted to the transmission position. And the non-transmission position by a simple operation of the operating means to swing the upper looper for sewing and to hold the upper looper at a predetermined rest position that does not project from the upper surface of the needle plate. It is possible to easily switch between the case where sewing is performed in the closed state.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. This embodiment is applied to a lock sewing machine capable of overlock stitching and double chain stitching. As shown in FIGS. 1 and 2, the lock sewing machine includes a main shaft 1 which is arranged in the bed in a left-right direction and is rotationally driven by a sewing machine motor (not shown), an upper looper drive shaft 2 and the drive shaft 2. An upper looper mechanism 5 including a fixed upper looper swing arm 3 and an upper looper 4 rotatably connected to a tip end portion of the swing arm 3, and a relative rotation with respect to a main shaft 1 relative to the main shaft 1. Mounted on the upper looper drive cam 6, a clutch mechanism 7 that can switch between a transmission position that transmits the rotational force of the main shaft 1 to the upper looper drive cam 6 and a non-transmission position that does not transmit the rotation force, and the clutch mechanism 7 to the transmission position. The operating mechanism 8 for switching the position to the non-transmission position and the upper looper drive cam 6 and the upper looper drive shaft 2 are interlockingly connected so that the upper looper drive shaft 2 is reciprocally rotated by the rotational force of the main shaft 1. And an interlocking mechanism 9 for . The upper looper suspension device 10
Is composed of a clutch mechanism 7 and an operating mechanism 8.

The upper looper mechanism 5 will be described. As shown in FIGS. 1 and 2, an upper looper drive shaft 2 is provided below the main shaft 1 so as to be rotatable in the front-rear direction. An upper looper swing arm 3 extending leftward is provided in the vicinity of the front end, and an upper looper 4 extending upward is rotatably connected to a tip end portion of the upper looper swing arm 3 at a lower end thereof. The middle section of 4 is slidably mounted on a guide member 12 rotatably supported on the machine frame 11. The upper looper drive cam 6 is the main shaft 1
Is rotatably supported by the snap ring 13
And a ring-shaped collar member 1 fixed to the main shaft 1 in an externally fitted shape.
4, an eccentric shaft portion 6a is formed on the left part of the upper looper drive cam 6 so as to be eccentric to the shaft center of the main shaft 1 by a predetermined distance, and on the right part. A clutch support portion 6b having a pair of front and rear arm portions 15 and 16 extending outward is formed, and the rotation of the main shaft 1 is transmitted to the upper looper drive cam 6 via a clutch mechanism 7 described later.

The interlocking mechanism 9 will be described with reference to FIG.
As shown in FIG. 2, a balancer member 17 for balancing the upper looper 4 is fixed to a portion of the upper looper drive shaft 2 below the main shaft 1, and the balancer member 17 has the upper looper swing arm 3 attached thereto. Swing lever 1 extending in the same direction as
8 is fixed, a link member 19 is provided between the tip end of the swing lever 18 and the upper looper drive cam 6, and the upper end of the link member 19 is rotatably externally attached to the eccentric shaft portion 6a of the upper looper drive cam 6. The lower end portion of the link member 19 is swingably connected to the tip end portion of the swing lever 18 via the universal joint 18a, and the upper looper drive shaft 2 includes the link member 19, the swing lever 18, and the balancer member 17. Via the, the reciprocating rotary drive is performed in synchronization with the rotation of the upper looper drive cam 6. still,
The swing lever 18 may be directly fixed to the upper looper drive shaft 2 so as not to rotate relative to it. The upper looper 4 has an upper limit position shown in FIG. 1 in which an upper end portion of the upper looper 4 projects upward from the needle plate upper surface 20 when the upper looper drive shaft 2 is reciprocally rotated by the interlocking mechanism 9. Swinging is performed while drawing a predetermined locus over the lower limit position shown in FIG. 3 below the needle plate upper surface 20.

Next, the upper looper pausing device 10 including the clutch mechanism 7 and the operating mechanism 8 will be described. First, the clutch mechanism 7 for transmitting or not transmitting the rotation of the main shaft 1 to the upper looper drive cam 6 will be described. As shown in FIGS. 1 and 2, the clutch support portion 6b has a rear arm portion 16a. Is provided with a stepped pin 21 extending rightward, and a clutch claw 22 extending in a curved shape in a side view is rotatably supported in the stepped pin 21 in a direction substantially the same as the rotation direction of the main shaft 1, and the clutch claw 22 A claw portion 22a extending toward the main shaft 1 is formed in a projecting shape in the middle step portion, and a recessed portion 14 engageable with the claw portion 22a is formed in the collar member 14 fixed to the main shaft 1.
a is formed and the arm portion 1 on the front side of the clutch support portion 6b is formed.
5 is provided with a pin member 23 extending rightward, and a tension spring member 24 is stretched between the pin member 23 and the vicinity of the tip of the clutch pawl 22. The clutch pawl 22 is provided with a pawl portion 22a via the spring member 24. Is always biased in a direction in which the recess 14a and the recess 14a are engaged with each other. The clutch mechanism 7 includes a clutch pawl 2
By rotating around the stepped pin 21 of 2, the claw portion 22
2 is engaged with the concave portion 14a, and the claw portion 22a is separated from the concave portion 14a into the non-transmission position shown in FIG. 6, and the claw portion 22a and the concave portion are separated from each other in the transmission position. The rotation of the main shaft 1 is transmitted to the upper looper drive cam 6 through the engagement with 14a, and the rotation of the main shaft 1 is not transmitted to the upper looper drive cam 6 in the non-transmission position.

The operating mechanism 8 is for rotating the clutch pawl 22 to switch the clutch mechanism 7 between a transmission position and a non-transmission position. As shown in FIGS. An engaging portion 22b is formed at the tip end of the spindle 1
A support member 25 is provided on the rear of the machine frame 11, and an operation lever 27 is rotatably supported on the support member 25 via a pin member 26 oriented in the left-right direction at the middle portion thereof. An operating portion 27a protruding upward from the needle plate upper surface 20 is provided in the portion, a restriction hole 27b is formed in the lower step portion of the operating lever 27, and a supporting member 25 is provided for restricting the rotation of the operating lever 27. The regulation pin 28 has the regulation hole 2
7b is provided in a penetrating manner, and a locking pin 29 extending leftward is fixed to the lower end portion of the operating lever 27.
4 is located at the retracted position shown in FIG. 2 in which the locking pin 29 is located outside the movement locus of the engaging portion 22b, and in FIG.
Is supported rotatably over the locking position shown in the figure, and between the support member 25 and the upper step portion of the operating lever 27 extending substantially horizontally, the operating lever 27 is selectively moved between the locking position and the retracted position. The tension spring member 30 for holding is stretched, and the locking pin 29 and the engaging portion 22b are, as shown in FIGS. 3 and 4,
The upper looper 4 is arranged so as to abut when the upper looper 4 moves to the lower limit position. Reference numeral 31 is a needle bar, reference numeral 32 is a sewing needle for overlock sewing, and reference numeral 33 is a sewing needle for double chain stitching.

Next, the operation of the upper looper pause device 10 will be described. When the operation lever 27 is held in the retracted position, as shown in FIG. 2, the urging force of the spring member 24 holds the claw portion 22a and the recess 14a in the engaged state (transmission position), and the spindle 1 Is transmitted to the upper looper drive cam 6, the upper looper drive shaft 2 is reciprocally rotated via the interlocking mechanism 9, and the upper looper 4 is swingably driven. In this state, overlock stitching and double chain stitching can be performed at the same time, or only overlock stitching can be performed. That is, when sewing is performed with the sewing needles 32 and 33 set, an overlock seam is formed by the sewing needle 32 and the upper looper 34, and the sewing needle 33 and the double loop stitch looper (not shown) are formed. By this, a double chain stitch seam is formed, and when sewing is performed with the sewing needle 33 removed and only the sewing needle 32 is set, only the overlock seam is formed. When the operation lever 27 is operated to the locking position, as shown in FIG.
Moves on the movement locus of the engaging portion 22b of the clutch pawl 22 that rotates integrally with the upper looper drive cam 6, and the engaging portion 22b of the clutch pawl 22 contacts the locking pin 29. At this time, the upper looper 4 is moving to the substantially lower limit position, and when the upper looper drive cam 6 further rotates against the urging force of the spring member 24, as shown in FIGS. The clutch mechanism 7 is switched to the non-transmission position by being separated from the concave portion 14a, and the claw portion 22a is urged in the direction away from the concave portion 14a by the rotation of the upper looper drive cam 6 which tends to rotate together with the main shaft 1. The upper looper drive cam 6 is held at a position where this urging force and the urging force of the spring member 24 are in balance, and as shown in FIG. It is held in a raised rest position where it does not interfere with the lower looper 34. In this state, the sewing needle 32 for overlock sewing can be removed from the needle bar 33, and double chain stitching can be performed on a portion other than the vicinity of the cloth end.
The impact at the time of engaging the engaging portion 22b and the locking pin 29 is
The spring member 24 is absorbed by the energy absorbing action due to the expansion thereof, and a large impact does not act on both.
When the operating lever 27 is switched to the retracted position, the locking pin 2
9 is separated from the engaging portion 22b, and the claw portion 22a is attached to the collar member 1
4 and the main shaft 1 and the upper looper drive cam 6
While the claw 22a makes one relative rotation,
, The clutch mechanism 7 is switched to the transmission position,
The positional relationship between the main shaft 1 and the upper looper drive cam 6 is restored to the desired state.

As described above, by providing the upper looper suspension mechanism 10 including the clutch mechanism 7 and the operating mechanism 8 having a simple structure, the upper looper 4 is operated by operating the operating lever 27.
The sewing can be easily switched between the case of swinging the upper looper 4 and the case of swinging without swinging the upper looper 4, and the clutch mechanism 7 can be compactly mounted on the main shaft 1.
The spring member can absorb the impact when the engaging portion 22b and the locking pin 29 are engaged, and the operation lever 27 is selectively biased to the locking position side or the retracted position side via the spring member 26. Therefore, it is possible to prevent the operation lever 27 from being accidentally switched.

In this embodiment, the collar member 14 is provided with the concave portion 14a and the clutch pawl 22 is provided with the pawl portion 22a which engages with the concave portion 14a. However, the collar member 14 is provided with the pawl portion.
The clutch pawl 22 may be formed with a recess that engages with the pawl portion of the collar member 14. In this embodiment, the operation lever 27
Was manually operated, but it may be operated by an actuator such as an electromagnetic solenoid. In the present embodiment, the present invention is applied to a lock sewing machine capable of overlock sewing and double chain stitch, but the present invention can be similarly applied to various sewing machines having an upper looper pausing device. ..

[Brief description of drawings]

FIG. 1 is a front view of a main part of a mechanism for driving an upper looper.

2 is a sectional view taken along line 2-2 of FIG.

FIG. 3 is a view corresponding to FIG. 1 in a state in which an operation lever is operated to a locking position.

4 is a sectional view taken along line 4-4 of FIG.

FIG. 5 is a view corresponding to FIG. 1 in a state where the clutch mechanism is operated to the non-transmission position.

6 is a sectional view taken along line 6-6 of FIG.

FIG. 7 is a perspective view of a main part in the vicinity of an upper looper drive shaft according to a conventional technique.

[Explanation of symbols]

 1 main shaft 2 upper looper drive shaft 3 upper looper swing arm 4 upper looper 5 upper looper mechanism 6 upper looper drive cam 7 clutch mechanism 8 operating mechanism 9 interlocking mechanism

Claims (1)

[Claims] 1. A main shaft disposed in a bed and driven to rotate by a sewing machine motor, an upper looper drive shaft, an upper looper swing arm fixed to the drive shaft, and a tip end portion of the swing arm. An upper looper mechanism including an upper looper connected to the upper looper, an upper looper drive cam provided on the main shaft, and an upper looper drive cam and an upper looper so that the upper looper drive shaft is reciprocally rotated by the rotational force of the main shaft. A sewing machine having an interlocking mechanism for interlocking connection with a drive shaft, wherein the upper looper drive cam is rotatably provided on a main shaft, and a transmission position for transmitting the rotational force of the main shaft to the upper looper drive cam and a non-transmission A clutch mechanism that can be switched to a position and is capable of switching to a non-transmission position by holding the upper looper in a predetermined rest position that does not project from the upper surface of the needle plate is provided. Looper rest device on a sewing machine, characterized by comprising operating means for switching operation I.