JPH0424058A - Upper feed gear driving mechanism for sewing machine - Google Patents

Abstract

PURPOSE:To reduce the moving-upward driving force of an upper feed gear and the operating force of a pedal by connecting an input bearing shaft to the front end section of an oscillation bearing member, and a pivotally bearing shaft to the rear end section of the bearing member, and by supporting a guide member between the pivotally bearing shaft and the input bearing shaft, on the oscillation bearing member, rotatably. CONSTITUTION:In the upper feed gear driving mechanism 1 of a sewing machine, under stitching execution, on an oscillation bearing member 41, via an input bearing shaft 42 with a vertically driving means 30 and via a link 40 with the rotatable centers of the pivotally bearing shafts 47, 48 of the one-end section of an upper feed base bearing arm 44, reciprocating driving-motion is performed in the vertical direction. In this case, on a guide member 20, the reciprocating driving-motion is performed, and so on an upper feed base 18 and an upper feed gear 24, the reciprocating driving-motion is performed in the vertical direction. Besides, on the upper feed base 18, the reciprocating driving-motion is performed in the front and rear directions with a front and rear driving means 2 in a state that the base 18 is supported by the guide member 20. Accordingly, on the upper feed gear 24, cloth piece feeding motion is performed with the reciprocating driving-motion in the vertical direction combined with the reciprocating driving-motion in the front and rear direction. In the meantime, when a pedal is operated at the time of stopping the stitching, then the oscillation bearing member is rotationally moved upward with the oscillating-upward of the pivotally bearing shafts of the one-end section of the upper feed base bearing arm 44 with the rotational center of the input bearing shaft 42.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an upper feed dog drive mechanism of a sewing machine, and in particular, a mechanism that can reduce the driving force of the vertical drive means for vertically moving the upper feed dog and the operating force of the pedal. related to what was done.

[Prior art]

In general, it includes a needle bar up and down drive mechanism that moves the needle bar up and down, a feed dog up and down drive mechanism that moves the feed dog (lower feed dog) up and down, and a feed back and forth drive mechanism that moves it back and forth.
Equipped with an upper feed dog drive mechanism consisting of an upper feed dog, an upper feed dog vertical drive mechanism that moves the upper feed dog up and down, and an upper feed back and forth drive mechanism that moves the upper feed dog back and forth, improving the accuracy of feeding the work cloth. Various sewing machines such as overlock sewing machines have been put into practical use.

The upper feed dog drive mechanism of this overlock sewing machine is configured as shown in FIG. 5, for example.

Drive shaft 103 rotationally driven by a sewing machine motor (path shown)
The front end of a link 101 is rotatably fitted onto an eccentric cam 100 fixed to the eccentric cam 100, and the rear end of this link 101 is rotatably connected to an L-shaped swing support member 141 by an input support shaft 142. Further, a guide member 120 is pivotally attached to the front end of the swing support member 141 with a pin 122. An upper feed table 118 having an upper feed dog 124 fixed to its front end is mounted in a groove 121 formed in the guide member 120 so as to be movable back and forth.

On the other hand, the base end of the swing support member 141 is rotatably supported by a pivot shaft 147 at the front end of the upper feed base support arm 144, which is rotatably supported by a support shaft 143 extending in the left-right direction. A drive plate 149 connected to a pedal (not shown) is fixed to the section. By bringing the upper end of this drive plate 149 into contact with a bolt 151 screwed into the machine frame 150, the rotation of the upper feed table support arm 144 in the clockwise direction in FIG. 5 is restricted. The lower end of a link 117 is fixed to a swing shaft 114 that is reciprocated by the drive of the drive shaft 103 via an eccentric cam (not shown), and the upper end of this link 117 is rotated in the front-rear direction by a pin 119. It is connected to the rear end of the extending upper feed table 118.

Furthermore, even when the sewing speed is operated at high speed, the upper feed dog 124
In order to ensure vertical movement, the guide member 120 is elastically urged downward by a pressing force P by a pressing member 161.

Therefore, as the drive shaft 103 rotates, the lower end of the swing support member 141 swings back and forth about the pivot shaft 147 via the eccentric cam 100 and the link 101, and its front end moves up and down. Therefore, the guide member 120 moves up and down,
The upper feed dog 124 moves up and down. Furthermore, the upper feed table 118 moves back and forth while being supported by the guide member 120 due to the back and forth swinging of the link 117. As a result, the upper feed table 118
performs cloth feeding motion that combines up-and-down movement and back-and-forth movement.

[Problem to be solved by the invention]

As mentioned above, in an overlock sewing machine or the like equipped with an upper feed dog drive mechanism, in order to move the upper feed dog 124 upward against the pressing force P during sewing by the vertical drive mechanism, the dimensions 11 and 124 shown in the figure are required. , an upward driving force corresponding to the ratio of the illustrated dimension i2 is required.

By the way, the dimensions I! , 1 is set longer than the dimension I12, the upper drive force becomes smaller, but the upper feed dog 1
In order to obtain a predetermined vertical movement amount of 24, the vertical drive mechanism 13
The amount of oscillation at 0 must be increased. On the other hand, dimension 1
2 is set longer than the dimension 11, the amount of rocking becomes smaller, but the upward driving force of the vertical driving mechanism 130 becomes larger.

Therefore, in order to make both the upward driving force and the amount of swing of the vertical drive mechanism 130 small, it is desirable to set dimension 21 and dimension !2 to be approximately the same dimension.

In this case, especially during high-speed operation, in order to ensure the cloth feeding movement of the upper feed dog 124, the pressing force P is set to, for example, about 15 to
Since it is set to a large value of 20 kg/aa, the vertical drive mechanism 130 has a pressing force P in order to resist this pressing force P.
There are problems such as the need for a large upward drive force such as between the road and the road or the like, and the vertical drive mechanism 130 becoming larger.

Furthermore, when sewing is stopped and the upper feed table support arm 144 is rotated in the direction of arrow C by operating the pedal via the drive plate 149 to raise the upper feed dog 124, the size is too high. 2 with support shaft 14
3 and the dimensions of the pivot shaft 147! Since the pedal is operated against a pressing force P that is applied at a position that is separated by a distance of 3, the operating force becomes very large, and there is a problem that the pedal lacks operability.

SUMMARY OF THE INVENTION An object of the present invention is to provide an upper feed dog drive mechanism for a sewing machine that can reduce the upward drive force of a vertical drive means for upward movement of the upper feed dog and the operating force of the pedal.

[Means to solve the problem]

The upper feed dog drive mechanism of the sewing machine according to the present invention includes an upper feed table to which the upper feed dog is attached, a guide member that supports the upper feed table so as to be movable back and forth, and a rocking mechanism that rotatably supports the guide member. A support member, and an upper feed base support which is rotatably pivoted to the machine frame, supports the swing support member so as to be able to swing up and down via a link to a pivot shaft at one end, and has a pedal connected to the other end. a back-and-forth drive means for reciprocating the arm and the upper feed table in the front-back direction; and a vertical drive means for reciprocating the swing support member in the up-down direction via an input support shaft connected to an end of the swing support member; , an upper feed drive mechanism for a sewing machine including a biasing mechanism that elastically biases a guide member downward; an input support shaft is connected to a front end of the swing support member; and a pivot shaft is connected to a rear end of the swing support member. The guide member is rotatably supported by the swing support member between the pivot shaft and the input support shaft.

[Function] In the upper feed dog drive mechanism of the sewing machine according to the present invention, during sewing, the swing support member is reciprocated in the vertical direction via the input support shaft by the vertical drive means, and the swing support member The upper feed table is reciprocated in the vertical direction via a link with the pivot shaft at one end of the upper feed table support arm as the center of rotation. At this time, the guide member rotatably supported by the swing support member reciprocates in the vertical direction, so the upper feed table and the upper feed dog attached to the upper feed table are reciprocated in the vertical direction. . Further, the upper feed table is reciprocated in the front-back direction by the front-back drive means while being supported by the guide member. Therefore, the upper feed dog performs cloth feed movement by a combination of reciprocating drive in the up-down direction and the front-back direction.

On the other hand, when the pedal is operated when sewing is stopped, the swinging support member is pivoted upward about the input support shaft by the upward swing of the pivot shaft at one end of the upper feed table support arm. Therefore, the upper feed dog is driven upward via the guide member and the upper feed table.

Here, a manual support shaft is connected to the front end of the swing support member, and a pivot shaft is connected to the rear end of the swing support member, and the guide member that is elastically biased downward by the pressing force of the biasing mechanism is the pivot shaft. Since it is supported by the swinging support member between the input support shaft and the input support shaft, the up-and-down drive means moves upward against the pressing force about the pivot shaft during sewing. The driving force may be much smaller than the pressing force due to the "lever principle."

Furthermore, when sewing is stopped, the operating force of the pedal that drives the swinging support member upwardly against the pressing force about the input support shaft may be much smaller than the pressing force due to the "lever principle."

〔Effect of the invention〕

According to the upper feed dog drive mechanism of the sewing machine according to the present invention, as explained in the [Operation] section, the input support shaft is connected to the front end of the swing support member, and the pivot shaft is connected to the rear end of the swing support member. connected,
Since the guide member is supported by the swinging support member between the pivot shaft and the input support shaft, the swinging support member rotates around the pivot shaft during sewing against the pressing force of the biasing mechanism. The upward driving force of the vertical drive means for upwardly driving the can be significantly reduced, and the vertical drive mechanism can be downsized.

Furthermore, when sewing is stopped, the operating force of the pedal that drives the swinging support member upward about the input support shaft can be reduced, and the operability of the pedal can be greatly improved.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

This embodiment is a case where the present invention is applied to an overlock sewing machine (overlock sewing machine) equipped with an upper feed dog for improving the feed accuracy of work cloth.

As shown in FIG. 1, the overlock sewing machine M includes a needle bar vertical drive mechanism that moves the needle bar 66 vertically, a looper drive mechanism that drives the upper looper and the lower louver, and a lower feed dog 67 that moves the needle bar 66 vertically and longitudinally. an upper feed dog rear drive mechanism 2 that reciprocates the upper feed dog 24 in the front-rear direction; and an upper feed dog vertical drive mechanism 30 that reciprocates the upper feed dog 24 in the up-down direction. A drive mechanism 1 and the like are provided.

Since the needle bar vertical drive mechanism, looper drive mechanism, lower feed dog drive mechanism, etc. are similar to existing ones, their explanations will be omitted, and the upper feed dog drive mechanism 1 will be explained based on FIGS. 1 to 4.

First, the upper feed dog rear drive mechanism 2 will be explained. The front end of a longitudinal swing arm 5 is rotatably fitted onto an eccentric cam 4 fixed to a drive shaft 3 which is rotationally driven by a sewing machine motor (path shown). The rear end of the longitudinal swing arm 5 is rotatably connected to a first link 7 fixed to the longitudinal swing shaft 6 with a pin 8, and the longitudinal swing shaft 6 is provided with an arcuate groove 10. The formed longitudinal swing adjustment member 9 is fixed. A square piece 12 provided with a pin 11 is movably mounted in this groove 10, and a lower end portion of a second link 13 is rotatably connected to this pin 11. The upper end of the second link 13 is rotatably connected to the first arm 15 fixed to the swing shaft 14 by a pin 16, and the lower end of the third link 17, whose upper end is fixed to the swing shaft 14, is A plate-shaped upper feed table 1 extending in the front-rear direction
8 is rotatably connected by a pin 19, and this upper feed table 18 can be moved back and forth by fitting from the left into a groove 21 formed in a guide member 20 at approximately the center in the front and back direction. The upper feed dog 24 is attached to the front end of the upper feed dog with a screw 23.

On the other hand, in order to adjust the amount of movement of the upper feed dog 24 in the front-rear direction, a fourth
The rear end of the link 25 is connected to the lower end of an adjustment link 26, and the upper end of the adjustment link 26 is connected to the lower end of an adjustment lever 28 via a support shaft 27.

Next, the upper feed dog vertical drive mechanism 30 will be explained.
A vertical swing adjustment member 32 having an arcuate groove 33 is fixed to a vertical swing shaft 31 that is swing-driven via an eccentric cam (as shown) fixed to the drive shaft 3 or a link mechanism. has been done. A square piece 3 with a pin 34 provided in this groove 33
5 is movably fitted into this pin 34.
The lower end of the link 36 is rotatably connected. Fifth
The upper end of the link 36 is rotatably connected by a pin 39 to a second arm 38 fixed to a swing shaft 37.
At the lower end of the sixth link 40, the upper end of which is fixed to It is rotatably supported at 42. The central part of the swing support member 41 in the front-rear direction is pivotally connected to a pin 22 protruding from the guide member 20, and the swing support member 41 rotatably supports the guide member 20 via the pin 22. There is.

An upper feed table support arm 44 is rotatably supported on a support shaft 43 extending in the left-right direction on the rear side of the swing shaft 14, and a bifurcated portion 45 is formed at the front end portion of the upper feed table support arm 44. The upper end of the seventh link 46 is rotatably connected to the forked portion 45 by a first pivot shaft 47, and the seventh link 46
The rear end of the swing support member 41 is rotatably connected to the lower end of the swing support member 6 by a second pivot shaft 48 . That is, the guide member 20 is supported by the swing support member 41 at an intermediate position between the second pivot shaft 48 and the input support shaft 42 .

A drive plate 49 connected to a pedal (path shown) for forcibly moving the upper feed dog 24 upward is fixed to the rear end of the upper feed table support arm 44, and the upper end of this drive plate 49 is connected to a motor. frame 50
By making contact with the port 51 screwed into the upper carriage support arm 44, rotation in the clockwise direction in FIG. 2 is restricted.

On the other hand, in order to adjust the amount of movement of the upper feed dog 24 in the vertical direction, an eighth
The rear end of the link 52 is connected to the lower end of an adjustment arm 53, and the adjustment arm 53 is connected to an adjustment lever 55 via a support shaft 54.

Next, even when the sewing speed is operated at high speed, the upper feed dog 24
A biasing mechanism 60 that elastically biases the guide member 20 downward in order to ensure vertical movement of the guide member 20 will be described.

The lower end of a cylindrical pressing member 61 supported by the machine frame 50 so as to be vertically movable contacts the guide member 20 from above, and a compression spring 62 is inserted into the spring housing hole formed inside the pressing member 61 .
is accommodated. Further, an adjusting member 63 having a spring receiving hole is fitted onto the upper end portion of the pressing member 61 from above.

This adjustment member 63 is screwed into the machine frame 50 by a screw formed on the outer periphery of its substantially lower half portion. Therefore, the adjustment member 63
When the operating section 64 is rotated clockwise, the elastic force of the compression spring 62 increases, and a strong pressing force P elastically urges the guide member 20 downward, and the operating section 64 is rotated counterclockwise. When rotated, the elastic force of the compression spring 62 becomes smaller, and the guide member 20 is elastically urged downward by a weak pressing force P. In addition, the reference numeral 66 is a needle bar with the sewing needle 65 attached to its lower end, the reference numeral 67 is a lower feed dog, the reference numeral 68 is a lever that drives the lower feed dog 67 in the vertical and longitudinal directions, and the reference numeral 69 is a throat plate.

Next, the operation of the upper feed dog drive mechanism 1 will be explained based on FIGS. 2 to 4.

The rotation of the drive shaft 3 causes the first link 7 to open via the eccentric cam 4.
Since the longitudinal swing shaft 6, the longitudinal swing adjustment member 9, and the square piece 12 swing, the upward feed is caused by the swing of the second link 13, the first arm 15, the swing shaft 14, and the third link 17. The table 18 is reciprocated in the front-rear direction while being supported by the groove 21, and at the same time, the upper feed dog 24 is also reciprocated in the front-rear direction. and,
By operating the adjustment lever 28 in the direction shown by arrow A, the distance between the square piece 12 and the longitudinal swing shaft 6 is changed, and the amount of swing of the second link 13, that is, the amount of movement of the upper feed dog 24 in the longitudinal direction is changed. is changed. Furthermore, the rotation of the drive shaft 3 causes the vertical swing shaft 31, the vertical swing adjustment member 32, and the square piece 35 to swing, so that the fifth link 36, the second arm 38, the swing shaft 37, and the sixth link 40 Due to the swinging, the swinging support member 41 swings vertically about the second pivot shaft 48, and the guide member 20 also swings vertically, and at the same time, the upper feed table 18 moves the bin 19. Since the upper feed dog 24 swings in the vertical direction as the center of rotation, the upper feed dog 24 reciprocates in the vertical direction. and,
By operating the adjustment lever 55 in the direction shown by arrow B, the vertical swing shaft 31 of the square piece 35 is adjusted via the adjustment arm 53.
The amount of swing of the fifth link 36, that is, the amount of vertical movement of the upper feed dog 24 is changed by changing the distance from the upper feed dog 36. Therefore, the upper feed dog 24 performs a cloth feeding motion that combines forward and backward movement and up and down movement.

Here, the guide member 20, which is elastically urged downward by the pressing force P of the pressing member 61, is supported by the swing support member 41 at an intermediate position between the second pivot shaft 48 and the input support shaft 42. The dimension from the second pivot shaft 48 to the input support shaft 42 is approximately twice the dimension from the second pivot shaft 48 to the position where the pressing force P acting on the swing support member 41 via the guide member 20 is applied. The upward driving force that drives the swing support member 41 upward against the pressing force P about the second pivot shaft 48 during sewing is as follows:
Due to the "lever principle", the pressing force P can be significantly reduced to about half, and the upper feed dog vertical drive mechanism 30 can be downsized.

Furthermore, when the pedal is operated to forcibly raise the upper feed dog 24 above the throat plate 69 when sewing is stopped,
The upper feed table support arm 44 rotates in the direction of arrow C via the drive plate 49. At this time, the swing support member 41 is connected to the input support shaft 42.
The guide member 20 and the upper feed table 18 rotate counterclockwise in FIG. 2 via the seventh link 46 with
The upper feed dog 24 is raised via the upper feed dog 24. That is, in this case as well, the dimension from the input support shaft 42 to the second pivot shaft 48 is approximately twice the dimension from the input support shaft 42 to the position where the pressing force P acting on the swing support member 41 is applied. The operating force for operating the pedal to move the swinging support member 41 upward against the pressing force P can be significantly reduced to about half of the pressing force P due to the "lever principle", improving the operability of the pedal. can be significantly improved.

Note that the upper feed dog drive mechanism 1 is merely an example.
It goes without saying that the present invention can be applied to various upper feed dog drive mechanisms, and can also be applied to various sewing machines equipped with the upper feed dog 24 and the upper feed dog drive mechanism 1. be.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, in which Fig. 1 is a perspective view of an overlock sewing machine, Fig. 2 is a side view of the upper feed dog drive mechanism incorporated in the sewing machine, and Fig. 3 is the upper feed dog drive mechanism. FIG. 4 is a perspective view of the main part of the upper feed dog drive mechanism, and FIG. 5 is a view corresponding to FIG. 2 according to the prior art. M...Overlock sewing machine, 1...Upper feed dog drive mechanism, 2...Upper feed dog vertical drive mechanism, 3...Drive shaft, 4...Eccentric cam, 5...Back and forth swing arm, 6...
・Fore-and-aft swing axis, 9... Fore-and-aft swing adjustment member, 12.
- Square piece, 13... Second link, 14... Swing shaft, 18... Upper feed base, 20... Guide member, 24...
- Upper feed dog, 30... Upper feed dog vertical drive mechanism, 32
・・Vertical swing adjustment member, 35・・Square piece, 37・・Swing axis, 40・・6th link, 42・・Input support shaft, 4 47・・・1st pivot shaft, 60・・・Biasing Mechanism, 6. Compression spring, 63. 41. Swing support member, 4. Upper feed base support arm, 48. Second pivot shaft, 1. Pressing member, 62. Adjustment member.

Claims (1)

[Claims] (1) An upper feed base to which the upper feed dog is attached, a guide member that supports the upper feed base so as to be able to move forward and backward, a swing support member that rotatably supports the guide member, and a swing support member that is rotatable on the machine frame. an upper feed table support arm which is pivotally connected to the upper feed table, supports the swing support member vertically swingably through a link to a pivot shaft at one end, and has a pedal connected to the other end; A longitudinal drive means for reciprocating, a vertical drive means for reciprocating the swing support member in the vertical direction via an input support shaft connected to an end of the swing support member, and an elastic biasing guide member downward. In the upper feed drive mechanism of the sewing machine, the input support shaft is connected to the front end of the swing support member, and the pivot shaft is connected to the rear end of the swing support member, and the guide member is connected to the pivot shaft. An upper feed dog drive mechanism for a sewing machine, characterized in that the upper feed dog drive mechanism is rotatably supported by a swing support member between an input support shaft.