JPH119868A - Movable blade drive device of sewing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify and miniaturize a movable blade drive device by a method wherein a movable blade which vertically moves to cut a cloth in conjunction with a stationary blade is vertically moved by a rocking link member and the rocking link member is secured to a pivot which swingably supports the lower end of a cloth feed blade. SOLUTION: A rock sewing machine M includes a lengthwise drive mechanism 5 which transmits a lengthwise drive power to a main feed tooth member 2 and a differential feed tooth member 4, a differential feed device 6 which can switch a cloth feed rate of the member 4 with respect to the member 2 in two steps, and a vertical drive mechanism 7 which transmits a vertical drive power to a movable tooth 55, the member 2, and the member 4. The mechanism 7 has a vertical drive power transmitting member 51 in engagement with a vertical drive cam 50 and secures the lower end of the member 51 to a pivot 13, which also supports the mechanism 5. And the tooth 55 is connected to a rocking link member 52 fixed to an end of a pivot 13 through a pin 54 so that a cloth is cut by the vertical motion of the tooth 55 operating in conjunction with a stationary blade.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a movable blade driving device for a sewing machine, and more particularly, to a swing link member that transmits vertical driving force to a movable blade, and a main feed arm that transmits longitudinal driving force to a feed dog. The present invention relates to one fixed to a supporting pivot shaft.

[0002]

2. Description of the Related Art As shown in FIG. 24, a conventional lock sewing machine includes a feed dog 200 for feeding a cloth to be sewn on a needle plate,
A feed arm 201 for transmitting a front-rear feed driving force to the feed dog 200,
A left and right pivot shaft 202 that pivotally supports the lower end of the feed arm 201, a movable blade 206 that cuts the cloth in cooperation with the fixed blade 205, and a feed tooth 200 and a movable blade 206 that move up and down. A vertical drive mechanism 210 for transmitting the driving force is provided, and by driving the feed arm 201 to swing back and forth about the pivot shaft 202, the front-rear drive force is transmitted to the feed dog 200 and the feed dog 200 is moved forward and backward. I do.

[0003] The vertical drive mechanism 210 is provided with a swing link member 211 pivotally supported by a pivot shaft 212.
The movable blade 206 is connected to the tip of the
A transmission part 213 is formed in the middle of 211, and a feed dog 2
A base end of an upper and lower drive arm 215 connected to the transmission arm 001 is supported by a transmission portion 213. By driving the swing link member 211 to swing about the pivot shaft 212, the feed dog 200 and the movable blade
The vertical drive force is transmitted to the motor 206. As described above, the conventional lock sewing machine requires the pivot shaft 202 for the front-rear drive mechanism and the pivot shaft 212 for the vertical drive. (Japanese Patent Publication No. Hei 2-13599, JP-A-60-2277)
No. 95).

[0004]

In a conventional lock sewing machine, since two pivot shafts are provided for a front-rear drive mechanism and an up-down drive mechanism, the entirety including parts for supporting these pivot shafts is included. There is a problem that the number of parts becomes very large, the structure becomes large, and the manufacturing cost becomes high. In addition, since these pivot shafts take up a considerable amount of space, it is very disadvantageous when one end of the bed portion incorporating the pair of pivot shafts is formed as a cantilevered free bed portion.

SUMMARY OF THE INVENTION An object of the present invention is to fix a swinging link member for transmitting a vertical driving force to a movable blade to a pivot shaft for pivotally supporting a main feed arm for transmitting a front-rear driving force to a feed dog. It is an object of the present invention to provide a movable blade driving device for a sewing machine which can be configured as follows.

[0006]

According to a first aspect of the present invention, there is provided a movable blade driving device for a sewing machine, comprising: a feed dog for feeding a cloth to be sewn on a needle plate; a feed arm for transmitting a front-rear feed driving force to the feed dog;
A left and right pivot shaft that pivotally supports the lower end of the feed arm, and a movable blade that moves up and down in conjunction with the vertical movement of the feed dog and cuts the cloth in cooperation with the fixed blade. And a swing link member for transmitting a vertical drive force to the movable blade, wherein the swing link member is fixed to the pivot shaft at a rear end portion.

When the feed arm swings about the pivot axis,
The forward and backward feed driving force is transmitted to the feed dog, and when the pivot shaft is rotationally driven, the swing link member swings, and the vertical driving force is transmitted to the movable blade. Since the rear end of the swinging link member that transmits the vertical driving force to the movable blade is fixed to the pivot shaft that pivotally supports the feed arm, the movable blade driving device can be configured with a simple structure with a small number of parts. .

According to a second aspect of the present invention, a movable blade driving device for a sewing machine according to the first aspect of the present invention includes a cam body provided on a drive shaft of the sewing machine, and a forked cam driven portion that engages with the cam body. A vertical drive force transmitting member fixed to the pivot shaft. Therefore, the bifurcated cam follower is pushed by the cam body that rotates together with the drive shaft, the vertical drive force transmitting member swings, and the pivot shaft rotates. When the pivot shaft rotates, the swing link member swings, and the vertical driving force is transmitted to the movable blade. Other operations are the same as those of the first aspect.

According to a third aspect of the present invention, in the second aspect of the present invention, the bifurcated cam follower includes a first cam follower integrated with the vertical drive force transmitting member, and a vertical drive force transmitting member. A second cam follower which is pin-connected and faces the first cam follower with the cam body interposed therebetween; and a spring member for urging the first and second cam followers toward each other. It is. Therefore, the cam body is engaged with the bifurcated cam follower so as to be always in contact with the cam body, so that the rattling due to a manufacturing error or the like is absorbed, and the vertical drive transmission member can be swung. Other effects are the same as those of the second aspect.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. This embodiment is an example in which the present invention is applied to a lock sewing machine for sewing mainly the edge of a cloth. However, the description will be made with the front side being the front side and the left-right direction being the left-right direction based on the operator who operates the lock sewing machine.

As shown in FIGS. 1 to 5, a lock sewing machine M
Has a bed part 80, a pillar part 81 erected on the right part of the bed part 80, and an arm part 82 extending leftward from the upper part of the pillar part 81, and the left end part of the bed part 80 is cantilevered. It is configured in a free bed portion 83 having the shape of a circle. Free bed section 8
A needle plate 84 is provided on the upper surface of the differential feed dog 3 and the main feed dog 3 which are operated so as to be able to protrude from an elongated hole (not shown) formed in the needle plate 84 in the cloth feeding direction. 1 are arranged before and after. A presser foot 85 for holding the cloth to be sewn between the main feed dog 1 and the differential feed dog 3 is provided on the arm portion 82.
And a switching lever 86 for switching the presser foot 85 between the lowered position and the raised position is mounted, and in cooperation with the presser foot 85 switched to the lowered position, the main feed dog 1 and the differential feed dog 3 cause the needle plate to move. The cloth to be sewn on the cloth 84 is fed in the cloth feeding direction (front-back direction).

The arm 82 has a pair of sewing needles 88 at its lower end.
And a needle bar 87 that is vertically moved by a needle bar vertical drive mechanism (not shown) is supported. At the rear end of the pillar portion 80, a plurality of (for example, four) thread stands 92 and a thread guide member 89 are provided.
A thread tension adjusting knob 90 is provided on the front surface of the pillar 81, and a feed amount adjusting knob 107 for adjusting the feed amount of the main feed dog 1 is provided on the right side of the pillar 81. A rotary operation member 91 connected to the drive shaft 10 is provided, and a front end portion of the knob member 40 of the differential feed device 6 protrudes from the front side of the free bed portion 83.

As shown in FIGS. 4 to 10, a main feed dog member 2 having a main feed dog 1 is provided inside a lock sewing machine M.
A differential feed dog member 4 having a differential feed dog 3; a front / rear drive mechanism 5 for transmitting a front / rear drive force to the main feed dog member 2 and the differential feed dog member 4; Tooth member 4
A differential feeder 6 capable of switching the cloth feed amount in two stages;
A vertical drive mechanism 7 for transmitting a vertical drive force to the movable blade 55, the main feed dog member 2, and the differential feed dog member 4, and a height capable of finely adjusting the height positions of the differential feed dog 3 and the main feed dog 1, respectively. A position adjusting device (a first adjusting mechanism 8 and a second adjusting mechanism 9) and the like are provided.

The main feed dog member 2 is connected via a second adjusting mechanism 9 to a mounting member 17 pivotally attached to an upper end portion of a main feed arm 14 to a pin member 16 oriented in the left-right direction, so that the height position can be adjusted. The differential feed dog member 4 is moved at its rear end via the slide mechanism 20 of the differential feed device 6 to the main feed dog member 2.
And at its front end, a tension coil spring 1
8, the transmission portion 62 of the swing transmission member 60 is urged downward.
Slidably supported by

The front-rear drive mechanism 5 will be described. The front-rear drive mechanism 5 is a sewing machine motor (not shown) in the bed 80.
, A front-rear drive cam 11 fixed to the drive shaft 10, and a front-rear drive force transmitting member 12 slidably contacting the front-rear drive cam 11 at a substantially middle portion in the vertical direction.
And a main feed arm 1 pivotally supported by a horizontal pivot shaft 13 which is rotatably supported by a frame at a lower end portion and is oriented in a horizontal direction.
4, and the lower end portion of the front-rear driving force transmission member 12 is swingably pin-connected to the lever portion 14 b of the main feed arm 14.

The front-rear drive force transmitting member 12 is disposed on the rear side of the drive shaft 10 and is biased obliquely upward and forward by a tension coil spring 15 having one end connected to the frame. The sliding surface 12a is slidably in contact with the front and rear driving cam 11. The main feed arm 14 has a pair of bent portions 14a at both left and right end portions, and the lower ends of these bent portions 14a are pivotally supported by the pivot shaft 13, and the lever portion 14b extends forward from the lower end of the right bent portion 14a. Extending to A pin member 16 pivotally supporting the mounting member 17 is non-slidably and swingably mounted on upper end portions of a pair of left and right bent portions 14a.

A square piece 101 of a feed amount adjusting mechanism 100 is rotatably connected to the upper end of the front-rear driving force transmitting member 12.
This square piece 101 is slidably engaged with an engagement groove 102a of an engagement member 102 supported on a frame around a horizontal axis. When the front / rear driving force transmitting member 12 is driven back and forth by the front / rear driving cam 11, the square piece 101 is engaged with the engaging groove 102a.
The swing angle of the main feed arm 14 is determined according to the moving direction of the square piece 101, and the mounting member 17
And the feed amount of the main feed dog member 2 is determined.

In the state shown in FIGS. 6 and 7, when the drive shaft 10 is rotated in the direction of the arrow, and the longitudinal drive cam 11 pushes the longitudinal drive force transmitting member 12 against the urging force of the coil spring 15. The square piece 101 is provided with an engaging groove 102a of an engaging member 102.
And the main feed arm 14 swings rearward. Here, the cloth feed amount adjusting mechanism 100 capable of adjusting the feed amount of the main feed dog member 2 will be briefly described with reference to FIGS. The cloth feed amount adjusting mechanism 100 includes an engaging member 102 having a square piece 101 and an engaging groove 102a,
A disk 104 fixed to the left end of a shaft member 105 rotatably supported by a frame, the disk 104 having a groove cam 104a with which a pin 103 at the tip of an engagement member 102 engages; It comprises a feed amount adjustment knob 107 fixed to the right end of the shaft member 105 and the like.

By rotating the feed amount adjusting knob 107 to rotate the disk 104 via the shaft member 105, the square piece 101 is rotated.
Is moved in the direction of the arrow β, the front and rear drive force transmitting member 12 does not swing back and forth with the main feed arm 14 even when driven by the front and rear drive cam 11, and the mounting member 17 and the main feed dog The member 2 stops feeding and the square piece 10
When the angle in the direction of the arrow β with the movement direction of 1 increases, the feed amount of the main feed dog member 2 also increases. As shown in FIG.
For example, the feed amount adjustment knob 107 can be rotated in four stages, including a swing amount of 0, by rotating the knob. still,
A leaf spring 106 is in sliding contact with the shaft member 105.

The differential feed device 6 will be described. FIG.
As shown in FIG. 13, the differential feed device 6 moves the differential feed dog member 4 up and down integrally with the main feed dog member 2 and is relatively movable in the front-rear direction with respect to the main feed dog member 2 by a predetermined stroke. , A compression coil spring 21 (spring member: omitted in FIG. 8) that elastically biases the differential feed dog member 4 forward with respect to the main feed dog member 2, and a differential feed dog member 4. In the first state in which the feed operation is performed integrally with the main feed dog member 2 (see FIGS. 10 and 11), the differential feed dog member 4 is about twice the feed amount a (for example, 8 mm) of the main feed dog member 2. A differential feed connecting mechanism 22 for operatively connecting the differential feed dog member 4 and the main feed dog member 2 is switchable to a second state (see FIGS. 12 and 13) in which the feed operation is performed at the feed amount 2a. Have.

The slide mechanism 20 has an inverted U-shaped (see FIG. 8) connecting metal fitting 26 fixed to the differential feed dog member 4.
And a pair of support portions 26a of the connection fitting are slidably attached to a shaft member 25 that penetrates through the main feed dog member 2 and protrudes forward and backward and is fixed to the main feed dog member 2 with a set screw 25a. And fitted into the elongated hole 26b formed in the connection fitting.
By engaging a pin 2a protruding leftward from the main feed dog member 2, the differential feed dog member 4 moves up and down integrally with the main feed dog member 2, and moves relative to the main feed dog member 2. It is supported so as to be relatively movable in the front and rear direction by a predetermined stroke without rotating. The compression coil spring 21 is provided on the front shaft member 25 between the main feed dog member 2 and the front support portion 26a of the connection fitting.

The differential feed connection mechanism 22 has a middle part in the height direction pivotally connected to the main feed arm 14 and an upper end part having a connection fitting 26.
(That is, the link member 30 operatively connected to the differential feed dog member 4) and the engagement portion 30 at the lower end of the link member 30.
and a switching operation for switching the differential feed connection mechanism 22 between the first state and the second state by engaging and disengaging the pin member 42 with the engaging portion 30a. It has a mechanism 31. A shaft member 35 protrudes leftward from the bent portion 14a on the left side of the main feed arm 14, and a halfway portion of the link member 30 in the height direction is swingably connected to the shaft member 35. A pin 36 projects leftward from the left end of the connection fitting to which the differential feed dog member 4 is fixed.
And a U-shaped engaging portion 30b at the upper end of the link member 30 is rotatably engaged and connected.

The switching operation mechanism 31 includes a knob member 40 that is operatively connected to a pin member 42 via a rocking body 43 and engages and disengages the pin member 42 with the engaging portion 30a. And a torsion spring 44 for urging the pin member 42 via the rocking body 43 so as to hold the engaged position when the pin member 42 is engaged and to hold the detached position when detached from the engaging portion 30b. . The pin 42 is fixed to the rear end of the rocking body 43. The rocking body 43 is pivotally attached to the frame by a pin 43b oriented in the left-right direction. A long hole 43a is formed at the front end of the rocking body 43. Hole 43
A pin 40a at the rear end of the knob member 40 is inserted into and connected to a. The front end portion of the knob member 40 is guided by the guide member 41 and protrudes forward of the free bed 83, and a grip portion 40b is formed at the front end of the knob member 40.

FIGS. 10 and 11 show a first state of the differential feed connection mechanism 22 in which the pin member 42 is not engaged with the engagement portion 30a of the link member 30. From this first state,
When the grip portion 40b of the knob member 40 is operated downward, the rocking body 43 swings, and the pin member 42 is guided by the guide portion 30c at the lower end of the link member 30 to engage with the engaging portion 30a, and the differential The feed coupling mechanism 22 enters the second state (FIG. 1).
2, see FIG. 13).

The torsion spring 44 is provided with one end thereof connected to the rear portion of the rocking body 43 and the other end thereof connected to the frame. When the differential feed connection mechanism 22 is in the first state, FIG.
As indicated by a chain line at 0, the rocking body 4 by the torsion spring 44
3 is directed downward from the support shaft 43b of the oscillating body 43, the oscillating body 43 is rotationally urged in a counterclockwise direction in FIG. Is held in the disengaged position. Differential feed connection mechanism 22
Is in the second state, the biasing direction of the rocking body 43 by the torsion spring 44 is changed to the rocking body 43 as shown by a chain line in FIG.
12, the rocking body 42 is rotationally urged clockwise in FIG. 12 (in the direction of the dashed line arrow in FIG. 12), and the pin member 42 is held at the coupling position.

Here, the differential feed dog 3 with respect to the main feed dog 1
Will be described. Pin member 42
In the first state in which the link member 30 is not engaged with the engagement portion 30a, the rotation of the link member 30 is not restricted, so that the main feed dog 1 and the differential feed dog 3 are caused by the urging force of the compression coil spring 21 of the slide mechanism 20. The cloth is fed at the same feed rate. On the other hand, in the second state in which the pin member 42 is engaged with the engaging portion 30a, the feed amount of the differential feed dog 3 becomes about 2a when the feed amount a of the main feed dog 1 is obtained.

That is, as shown in FIG. 10, the distance b2 from the pivot shaft 13 to the shaft member 35 is about 0.65 times the distance b1 from the pivot shaft 13 to the pin member 16, and is shown in FIG. Thus, the distance c from the pin member 42 to the pin member 36
2 is approximately 3.0 times the distance c1 from the pin member 42 to the shaft member 35, so that the feed a of the main feed dog 1 (the pivot shaft 16)
Of the main feed dog 1 (the amount of movement of the pivot 16) is about 0.65 ×
The feed amount of about 2a amplified by 3.0 is the feed amount of the differential feed dog 3. That is, as shown in FIG. 14, in the first state, the main feed dog member 2 and the differential feed dog member 4 perform the feed operation integrally with the feed amount a, and in the second state, the differential feed tooth member 4 The feed operation is performed at a feed amount 2a which is about twice the feed amount a of the main feed dog member 2. Of the two feed dogs, the front-rear movement range of the main feed dog 1 located on the rear side mainly affects the stitch pitch desired by the user near the needle drop point, and the differential position located on the front side. The forward and backward movement range of the feed dog 3 is mainly on the labor side of the forward and backward movement range of the main feed dog 1. Therefore, the fabric being sewn is
5, the movement of the cloth is restricted to some extent. When the cloth with great elasticity is moved backward by the main feed dog 1 in a state of being pressed, the cloth expands as in the second state. When the feed amount of the differential feed dog 3 is larger than the feed amount of the feed dog 1, since the differential feed dog 3 simultaneously feeds more than the main feed dog 1, pulling by the main feed dog 1 is eliminated. Shrinkage after sewing is absorbed and cloth shrinkage after sewing can be prevented. In particular, such a differential feed stitch is effective for a knitted fabric or a jersey fabric having a large elasticity. The main feed dog 1 and the differential feed dog 3 are connected to the drive shaft 1
At 0, the cloth feeding operation is performed at a predetermined timing when the sewing needle comes off the cloth.

The vertical drive mechanism 7 will be described. FIG.
As shown in FIG. 9, the vertical drive mechanism 7 includes a drive shaft 10,
An up-down drive cam 50 fixed to the drive shaft 10, an up-down drive force transmission member 51 engaged with the up-down drive cam 50, and a pivot shaft 13 common to the front-rear drive mechanism 5; A pivot shaft 13 to which the lower end of the pivot shaft 51 is fixed, a swing link member 52 to the left end of the pivot shaft 13, and a vertically movable member connected to the swing link member 52 by a pin 54. 53.

To the right end of the drive shaft 10 is connected a turning operation member 91 which projects to the right of the pillar portion 81 and can turn the drive shaft 10 manually. The vertical driving force transmitting member 51 has a bifurcated cam driven portion 54 that engages with the vertical driving cam 50, and is disposed between the pair of bent portions 14 a of the main feed arm 14. The pin member 16 of the main feed arm 14 is inserted through an arc-shaped long hole 51a formed in the middle portion in the vertical direction of the main feed arm 14.

As shown in FIGS. 6 and 7, the bifurcated cam follower 54 comprises a first follower 54a and a second follower 54 which face each other.
b, the first driven portion 5
When the vertical drive force transmitting member 51 swings rearward, the swinging link member 52 swings upward about the pivot shaft 13, and the movable blade 55 and the differential feed dog member 4 rise. The second driven part 54b is pushed and driven. When the vertical driving force transmission member 51 swings forward, the movable blade 55 and the differential feed dog member 4 are driven to descend.

The movable member 53 is a plate-like frame 9 in a vertical posture.
5 (refer to FIG. 8), a shaft portion 57 (pin member) oriented in the left-right direction is integrally formed at the upper end of the movable member 53. The shaft portion 57 and the pin 54 are connected to the movable member 5.
3, and is guided in the vertical direction by passing through vertically long holes 58, 59 formed in the plate-like frame 95. The front and rear end faces of the shaft portion 57 are chamfered and slidably contact the vertical surfaces of the long holes 58, respectively.

As shown in FIG. 8, the shaft 57 is
3 extends to the left, a shaft member 57a is slidably inserted into the shaft portion 57, and the plate member 9 is inserted into the shaft member 57a.
The movable blade 55 is fixed on the right side of the fifth blade 5. on the other hand,
The fixed blade 56 is attached to the upper end of the plate-shaped frame 95 so as to slightly protrude above the needle plate 84. Shaft member 57
a retaining ring 57b is attached to the left end of the retaining ring 57a.
A compression coil spring 57c is externally mounted on the shaft member 57b between the b and the left end of the shaft portion 57. The movable blade 55 is kept in sliding contact with the fixed blade 56 by the urging force of the coil spring 57c, and is fixed to the movable blade 55 that moves up and down. In cooperation with the blade 56, the cloth edge just before sewing, which is sent rearward, is cut.

The plate-like frame 95 has a swing transmission member 60
Of the differential feed dog member 4 is slidably supported in the vicinity of the upper end in the middle of the swing transmission member 60 so as to be slidable. A shaft-shaped transmitting portion 62 for transmitting the vertical driving force to the member 4 is formed in a left-projecting shape. At the other end of the swing transmission member 60, a long hole 63 whose long axis faces the pivot pin 61 is formed.
3 is engaged with the shaft portion 57 of the movable member 53 (FIGS. 16 to 16).
See FIG. 19).

An eccentric pin 66 is formed integrally with the pivot pin 61, and the front end of the swing transmission member 60 is pivotally supported by the eccentric pin 66. FIG. 16 shows a state where the movable blade 55 and the differential feed dog member 4 are located at the ascending limit position.
7 shows a state in which the movable blade 55 and the differential feed dog member 4 are located at the lower limit position, and the transmission portion 62 and the differential feed dog member 4
Moves up and down by about の of the vertical stroke h of the movable blade 55.

The height position adjusting device will be described.
The height position adjusting device includes a first adjusting mechanism 8 included in the vertical drive mechanism 7 for finely adjusting the height position of the differential feed dog 3.
And a second adjustment mechanism 9 included in the front-rear drive mechanism 5 for finely adjusting the height position of the main feed dog 1.

As shown in FIGS. 15 to 19, the first adjustment mechanism 8 includes an eccentric pin portion 66 integrally formed with a pivot pin 61 for pivotally supporting the swing transmission member 60 to the plate-like frame 95. An eccentric mechanism 65 capable of finely adjusting the height position of the transmission portion 62 of the swing transmission member 60 is provided. Shaft center 61 of pivot pin 61
The axis 66a of the eccentric pin portion 66 with respect to a
(E.g., 1.5 mm), the eccentric pin 66 is rotated by a screwdriver to eccentric in all directions with an eccentricity e, and the height of the transmitting unit 62 is finely adjusted to provide a differential. The height position of the feed dog member 4 can be finely adjusted. In the above fine adjustment, the stop screw screwed into the frame is loosened with a screwdriver to rotate the eccentric pin 66 to a desired position. After the fine adjustment, the stop screw is tightened to fix the position of the eccentric pin 66. I do.

FIGS. 16, 18 and 19 show the state of the first adjusting mechanism 8 when the movable blade 55 is raised to the upper limit position. For example, the state of the first adjusting mechanism 8 shown in FIG. Rotate the pin portion 66 90 degrees counterclockwise in the figure,
As shown in FIG. 18, the axis 66a of the eccentric pin 66 is eccentric with respect to the axis 61a of the pivot pin 61, and when the height position of the eccentric pin 66 increases by e, the swing transmission member 60
Rotates clockwise in the figure about the axis 57a of the shaft portion 57, and the height of the transmission portion 62 increases by about e / 2.

Although not shown, from the state of the first adjusting mechanism 8 in FIG. 16, for example, the eccentric pin portion 66 is rotated clockwise by 90 degrees in the figure to be eccentric with respect to the axis 61a of the pivot pin 61. When the axis 66a of the pin portion 66 is eccentric and the height position of the eccentric pin portion 66 is increased by e, the swing transmission member 60 is rotated counterclockwise about the axis 57a of the shaft portion 57 substantially. However, the height of the transmission portion 62 is reduced by about e / 2.

Further, from the state of the first adjusting mechanism 8 in FIG. 16, for example, the eccentric pin portion 66 is rotated by 180 degrees in the drawing, and as shown in FIG.
When the axis 66a of the eccentric pin 66 is eccentric and the eccentric pin 66 is moved to the left by 2e, the height position of the axis 66a of the eccentric pin 66 does not change. Accordingly, the distance between the axis 66a of the eccentric pin portion 66 and the axis 57a of the shaft portion 57 is reduced, and the height of the transmission portion 62 is also reduced.

As described above, the height position of the transmission portion 62 is determined not only by the change in the height position of the eccentric pin portion 66 but also by the distance between the axis 66a of the eccentric pin portion 66 and the axis 57a of the shaft portion 57. It is also adjusted by changes. Thus, the eccentric pin portion 66
Is rotated, the height position of the transmission portion 62, that is, the height position of the differential feed dog 3 can be finely adjusted.

The second adjusting mechanism 9 is shown in FIGS.
As shown in FIG. 2, the main feed tooth member 2 has an elevating member 70 which is guided by a mounting member 17 pivotally supported by the pin member 16 of the main feed arm 14 and in which the main feed tooth member 2 is fixed with screws 71.
The elevating member 70 is fastened to the mounting member 17 by a pair of screws 72 so that the fastening can be released.

The mounting member 17 is formed in a U-shaped cross section, and an elevating member 70 is disposed between the mounting members 17. A vertically oriented guide pin 73 is inserted through the elevating member 70 and is fixed by a retaining ring 73a. Guide pin 73
The upper and lower ends are guided through the upper and lower ends of the mounting member 17 so as to be vertically movable. A pair of left and right long holes 75 that are long vertically are formed at the rear end of the mounting member 17, and a pair of screws 72 are inserted into the pair of long holes 75 from the rear side of the mounting member 17.
Is screwed into the elevating member 70. That is, the pair of screws 72 are loosened, the main feed dog member 2 is moved to a desired position between the upper limit position shown in FIG. 21 and the lower limit position shown in FIG. 22, and the pair of screws 72 are tightened. Then, the main feed dog member 2 can be fixed at the height position.

The operation and effect of the lock sewing machine M will be described. In the vertical drive mechanism 7, the swing link member 52 that transmits the vertical drive force to the movable blade 55 is fixed to the pivot shaft 13 that supports the main feed arm 14 of the front-rear drive mechanism 5. However, the structure becomes simple and small with a small number of parts. Therefore, the manufacturing cost of the vertical drive mechanism 7 can be reduced, and the vertical drive mechanism 5 can be used together with the vertical drive mechanism 7.
Is compact, which is very advantageous in forming one end of the bed 83 into a cantilevered free bed 84.

An up-down drive cam 50 provided on the drive shaft 10, and a bifurcated cam follower 54 engaged with the up-down drive cam 50 and having a lower end fixed to the pivot shaft 13. Since the driving force transmission member 51 is provided, the bifurcated cam follower 54 is pushed by the vertical driving cam body 50 that rotates together with the drive shaft 10 to swing the vertical driving force transmission member 51,
By swinging the swing link member 52 together with the pivot shaft 13, the vertical driving force can be reliably transmitted to the movable blade 55 and the differential feed dog member 4.

A modification in which the structure of the vertical driving force transmitting member 51 is changed will be described. As shown in FIG. 23, the forked cam follower 110 of the vertical driving force transmitting member 51A is provided with a first cam driven portion 111 integrated with the vertical driving force transmitting member 51A.
A second cam follower 112 which is pin-coupled to the vertical drive force transmitting member 51A and faces the first cam follower 111 with the vertical drive cam 50 interposed therebetween, and the first and second cam followers 111 and 1
12 is provided with a tension coil spring 113 for urging the coil 12 toward the phase approach side. That is, the vertical drive cam 50 is connected to the bifurcated cam follower 1.
10 can be engaged so as to be in constant contact with it, so that rattling due to manufacturing errors or the like can be reliably absorbed, and the vertical drive transmission member 51 can be swung.

[0046]

According to the movable blade driving device of the sewing machine of the first aspect, the swing link member that transmits the vertical driving force to the movable blade and the feed arm that transmits the front-rear feed driving force to the feed dog are pivotally supported. Since it is fixed to the pivot shaft, the pivot shaft of the swing link member that transmits the vertical driving force to the movable blade can be shared with the pivot shaft that pivotally supports the feed arm. Less simple and compact structure. Therefore, it is very advantageous to reduce the manufacturing cost of the sewing machine and to configure one end of the bed portion of the sewing machine into a cantilevered free bed portion.

According to the movable blade drive device of the sewing machine of the second aspect, the same effect as that of the first aspect is obtained, but a cam body provided on the drive shaft of the sewing machine and a forked cam follower engaged with the cam body are provided. And a vertical drive force transmitting member having a lower end fixed to the pivot shaft. The cam body that rotates together with the drive shaft pushes the bifurcated cam follower to swing the vertical drive force transmitting member. And the vertical drive force can be transmitted to the movable blade via the pivot shaft and the swing link member.

According to the movable blade driving device for a sewing machine of the third aspect, the same effect as that of the second aspect is obtained, but the bifurcated cam follower is provided with a first cam follower integrated with the vertical driving force transmitting member, A second cam follower that is pin-coupled to the vertical drive force transmitting member and faces the first cam follower with the cam interposed therebetween;
A spring member that urges the cam follower to the phase approaching side is provided, so that the cam body is engaged so as to always contact the bifurcated cam follower, to reliably absorb backlash due to manufacturing errors, etc., and drive up and down. The transmission member can be swung.

[Brief description of the drawings]

FIG. 1 is a perspective view of a lock sewing machine according to an embodiment of the present invention.

FIG. 2 is a front view of the lock sewing machine.

FIG. 3 is a left side view of the lock sewing machine.

FIG. 4 is a left side perspective view of the lock sewing machine.

FIG. 5 is a front perspective view of the lock sewing machine.

FIG. 6 is a left side view of a main part inside the lock sewing machine.

FIG. 7 is a right side view of a main part inside the lock sewing machine.

FIG. 8 is a plan view of a main part inside the lock sewing machine.

FIG. 9 is a front view of a main part inside the lock sewing machine.

FIG. 10 is an operation explanatory diagram of the differential feeder (first state).

FIG. 11 is an operation explanatory diagram of the differential feeder (first state).

FIG. 12 is an operation explanatory view of the differential feeder (second state).

FIG. 13 is an operation explanatory view of the differential feeder (second state).

FIG. 14 is a diagram showing feed amounts of a main feed dog member and a differential feed dog member.

FIG. 15 is a diagram showing a height position adjusting mechanism (first and second adjusting mechanisms).

FIG. 16 is a diagram illustrating the operation of the up-down drive mechanism.

FIG. 17 is an explanatory diagram of the operation of the vertical drive mechanism.

FIG. 18 is an operation explanatory view of the first adjusting mechanism.

FIG. 19 is an operation explanatory view of the first adjusting mechanism.

20 is a sectional view taken along line XX-XX in FIG.

FIG. 21 is an operation explanatory view of the second adjusting mechanism.

FIG. 22 is an operation explanatory view of the second adjusting mechanism.

FIG. 23 is a side view of a vertical driving force transmitting member according to a modification.

FIG. 24 is an explanatory diagram of a front-rear drive mechanism and an up-down drive mechanism according to the related art.

[Explanation of symbols]

 M Lock sewing machine 1 Main feed dog 2 Main feed dog member 3 Differential feed dog 4 Differential feed dog member 5 Front / rear drive mechanism 6 Differential feed device 7 Vertical drive mechanism 8 First adjustment mechanism 9 Second adjustment mechanism 10 Drive shaft 11 Front / rear drive cam 12 Front / rear drive force transmitting member 13 Pivot shaft 14 Main feed arm 16 Pin member 20 Slide mechanism 21 Compression coil spring 22 Differential feed connection mechanism 30 Link member 30a Engagement part 31 Switching operation mechanism 40 Knob member 42 Pin member 44 Torsion spring 50 Vertical drive cam 51 Vertical drive force transmission member 52 Swing link member 54 Bifurcated cam follower 55 Movable blade 57 Shaft (pin member) 60 Swing transmission member 61 Pivot pin 62 Transmission unit 63 Length Hole 65 Eccentric mechanism 66 Eccentric pin part 84 Needle plate

Claims (3)

[Claims] A feed dog for feeding a cloth to be sewn on a needle plate;
A feed arm for transmitting a forward / reverse feed driving force to the feed dog, a left-right pivot shaft for rotatably supporting the lower end of the feed arm, and a vertical movement in conjunction with the vertical movement of the feed dog. A movable blade for cutting the cloth in cooperation with the fixed blade, a swing link member for transmitting a vertical driving force to the movable blade, the swing link member being fixed to the pivot shaft at a rear end portion. A movable blade driving device for a sewing machine, further comprising a swing link member. 2. A vertical driving force transmitting member having a cam body provided on a drive shaft of a sewing machine and a bifurcated cam follower engaged with the cam body and having a lower end fixed to the pivot shaft. The movable blade driving device for a sewing machine according to claim 1, wherein: 3. The bifurcated cam follower includes a first cam follower integrated with the vertical drive transmission member, and a second cam follower that is pin-connected to the vertical drive transmission member and faces the first cam follower with a cam interposed therebetween. The movable blade driving device for a sewing machine according to claim 2, further comprising a two-cam follower, and a spring member for urging the first and second cam followers toward each other.