JP2678221B2 - Condensation device for sewing machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a condensing device for a sewing machine, and more particularly to a condensing device for a sewing machine for finely sewing a cloth on a needle plate at the end of sewing the cloth.

[0002]

2. Description of the Related Art Conventionally, as a sewing machine, for example, a chain stitch sewing machine as shown in FIG. 4 and FIG. 5 is known, which is provided with a base 2 supported by a sewing machine main body 1 in a cantilever manner.
The cloth is supported on the needle plate 3 provided on the base 2, the cloth is pressed by the presser foot 4, and the head 5 located above the base 2
The sewing needle 6 is moved back and forth toward the cloth on the needle plate 3, and the feed dog 7 is attached to the sewing needle 6 through the opening 3a provided in the needle plate 3.
The sewing is performed at a predetermined sewing pitch while feeding the cloth on the needle plate 3 by driving the cloth to project in synchronization with the above. The feed dog 7 is moved in a substantially elliptical motion by a well-known drive mechanism 8 which is interlocked with the main shaft 9.

Meanwhile, some sewing machines use a condensation device for making the above-mentioned sewing pitch finer to prevent fraying at the end of sewing of cloth in the sewing process. As a conventional condensation device, for example, the driving mechanism 8 is mechanically changed at the end of the sewing process so that the feed pitch of the feed dog 7 is reduced to make the sewing pitch finer. is there.

[0004]

However, in the above-mentioned conventional condensation device for a sewing machine, the feed dog 7 is used.
Since the drive mechanism 8 of is mechanically adjusted,
There is a problem that the structure becomes complicated and large, and the cost becomes high. In particular, in the case of a small sewing machine in which a small cylindrical cloth such as a hem of pants is inserted into a base and sewn, there is not enough space, and it is difficult to provide a condensation device. .

The present invention has been made in view of the above problems, and provides a condensation device for a sewing machine, which can be easily installed without complicating the device and making it compact. There is a point to do.

[0006]

SUMMARY OF THE INVENTION The technical means of the present invention for solving the above problems is to support cloth on a needle plate provided on a base and to move the needle plate from a head located above the base. While moving the sewing needle back and forth toward the upper cloth and driving the feed dog from the opening provided in the needle plate to feed the cloth on the needle plate, the cloth is sewn at a predetermined sewing pitch. In the condensation device for a sewing machine that makes the sewing pitch finer, the throat plate is based on one of its front side ends.
It is rotatably supported and floats on the needle side when it is rotated from its normal position.
To rotatably, floated the needle plate to the required height by providing floating mechanism that reduces the amount of projection of the needle plate of the feed dog, the該浮moving mechanism, the rear side of the provided in the base needle plate Possession
Lifting stroke adjustable piston rod
It is composed of a Linda device .

[0007]

[0008]

[0009]

According to the condensation device for a sewing machine configured as described above, during normal sewing, the needle plate is positioned at a steady position, the sewing needle is advanced and retracted toward the cloth on the needle plate, and The feed dog is driven to project from the opening provided in the plate in synchronization with the sewing needle, whereby the cloth on the needle plate is sequentially sewn to the rear side while being sewn at a predetermined sewing pitch. In the required sewing process such as the end time of sewing,
When the stitch pitch is made fine, the floating mechanism is driven and the needle plate is floated to the required height position. This reduces the amount of protrusion of the feed dog from the needle plate,
Since the time during which the feed dog protrudes from the needle plate is shortened and the time during which the cloth is fed is shortened, the cloth feed amount is reduced. Therefore, the sewing needle moves back and forth in a normal cycle, and the sewing pitch becomes fine.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A condensation device for a sewing machine according to an embodiment of the present invention will be described in detail below with reference to the accompanying drawings.
The sewing machine condensation device according to the embodiment shown in FIGS. 1 and 2 is applied to the chain stitch sewing machine shown in FIG. 4 as described above. Note that the same components as described above are denoted by the same reference numerals and described.

In the embodiment, 2 is a cylindrical base extending in a direction orthogonal to the cloth advancing direction and cantilevered by the sewing machine body 1 (FIG. 4), and 10 is a needle provided in the upper opening 2a of the base 2. It is a plate. The needle plate 10 has one front side end rotatably supported by a support member 11 fixed to the opening 2a of the base 2 by a shaft 12 and can be floated by rotating from a steady position A. There is. Reference numeral 16 is a bearing portion of the support member 11 that receives the shaft 12. The other end of the needle plate 10 is supported by a step portion 13 provided on the rear side of the opening 2a of the base 2. Reference numeral 14 is an opening provided in the needle plate 10 through which the feed dog 7 can project, and 15 is an insertion hole through which the sewing needle 6 is inserted.

The sewing needle 6 is moved back and forth toward the cloth on the needle plate 10 by a drive mechanism (not shown) provided on the head 5 (FIG. 4). Reference numeral 4 is a presser foot that presses the cloth with a spring (not shown). The feed dog 7 is driven to project from the opening 14 provided in the needle plate 10 in synchronization with the sewing needle 6, and feeds the cloth on the needle plate 10. Feed dog 7 is spindle 9
A known drive mechanism 8 interlocked with the drive mechanism 8 causes the elliptical movement.

Reference numeral 20 denotes a floating mechanism for floating the needle plate 10 to a required height position (floating position) B, which is composed of an air cylinder device for lifting the lower rear side of the needle plate 10 provided on the base 2. There is. The cylinder device 20 has a mounting bracket 2
1, a cylinder 22 mounted inside the base 2 and a piston rod 23 that is provided in the cylinder 22 so as to be movable back and forth. The piston rod 23 is provided with a bolt 25 whose tip 23a abuts the needle plate 10 and is screwed into the base end 24 to adjust the upper limit position of the tip 23a. Reference numeral 26 is a nut for positioning the bolt 25.

Then, in the cylinder device 20, when air is supplied to the cylinder 22, the needle plate 10 is floated to a required floating position B, the amount of protrusion of the feed dog 7 from the needle plate 10 is decreased, and the steady state is achieved. The protrusion amount D is changed to the floating protrusion amount d.
This floating protrusion amount d is determined by the bolt 25 of the piston rod 23.
Adjust the appropriate amount in advance by adjusting the screwing in.

Further, the cylinder device 20 is preprogrammed so that air is supplied when the main shaft 9 rotates at a predetermined time so that the needle plate 10 floats at the end of the sewing of the cloth during the sewing process. It should be noted that the cylinder device 20 may be supplied with air at a proper time by a manual valve or the like, and may be appropriately set.

Therefore, when assembling the condensation device for a sewing machine according to this embodiment, the support member 11 pivotally supporting the needle plate 10 is attached to the opening 2a of the base 2 and the cylinder device 20 is attached to the base 2. In this case, the number of cylinder devices 20 is increased as compared with the conventional parts, and since the cylinder devices 20 are provided in the space of the base 2, the existing sewing machine can be easily attached and the mechanism is simple. It doesn't get complicated. Moreover, since one end of the needle plate 10 is attached by the hinge of the shaft 12, it is not necessary to provide a special mechanism on this one end side.
Since it does not take up space, the size can be reduced.

Next, the operation of the condensation device for the sewing machine according to the embodiment will be described. During normal suturing, the cylinder device 20 is retracted and the needle plate 10 is positioned at the steady position A. In this state, the sewing needle 6 is moved back and forth toward the cloth on the needle plate 10, and the feed dog 7 is driven to project from the opening 14 provided in the needle plate 10 in synchronization with the sewing needle 6, thereby, The cloth on the needle plate 10 is sewn at a predetermined sewing pitch while being fed to the rear side in order.

When the end of sewing arrives, air is supplied to the cylinder device 20 automatically or manually,
The piston rod 23 of the cylinder device 20 projects and the throat plate 10 is floated to a required height position B. As a result, the protrusion amount of the feed dog 7 from the needle plate 10 becomes the steady protrusion amount D.
To the floating protrusion amount d. In this case, since the amount of protrusion of the feed dog 7 from the needle plate 10 decreases, the time during which the feed tooth 7 projects from the needle plate 10 becomes shorter, that is, the time during which the cloth is fed becomes shorter, The feeding amount of cloth decreases. Therefore, since the sewing needle 6 moves back and forth at a normal cycle, the sewing pitch becomes fine. When the sewing is completed, the piston rod 23 of the cylinder device 20 is retracted, the needle plate 10 is positioned at the steady position A, and the next cloth is sewn. In this way, the suturing is repeated.

When adjusting the sewing pitch at the end of sewing, the screwing amount of the bolt 25 of the piston rod 23 of the cylinder device 20 may be changed appropriately. As a result, the height position B of the needle plate 10 changes, so that the amount of protrusion of the feed dog 7 from the needle plate 10 is adjusted. In this case, since the sewing pitch can be easily adjusted only by adjusting the stroke of the cylinder device 20, the work is easily performed.

FIG. 3 was considered during the development stage of the present invention.
The condensation device for the sewing machine is shown and opened for reference.
Show. In this, the entire needle plate 30 is rotatably supported in the opening 14 of the base 2, and a pair of cylinder devices 20 are provided in front of and behind the needle plate 30 via mounting fittings 31 to horizontally float the needle plate 30. It is the one .

The sewing machine to which the present invention is applied is not limited to the chain stitch type sewing machine described above, and may be a lock stitch type sewing machine.
Needless to say, the present invention may be applied to any type of sewing machine, large or small, as long as it is a type of sewing machine that feeds cloth.

[0022]

As described above, according to the condensation device for a sewing machine according to the present invention, the protrusion amount of the feed dog is reduced and the feed amount of the cloth is reduced only by floating the needle plate by the floating mechanism. Since the sewing pitch can be made fine, a simple structure can be achieved without complicating the device. Further, since it has a simple structure, it can be easily attached to a small sewing machine, the cost can be reduced, and the versatility can be improved.

Further, since one end of the throat plate is rotatably supported by the base and is made to float , the throat plate is moved in parallel.
Operation is much smoother and easier.
And the floating mechanism can be simplified.
You. Further, since it is not necessary to provide a special mechanism on one end side of the needle plate, the structure can be simpler and space is not taken up, so that the size can be further reduced. Also, one end of the needle plate is supported by the shaft.
Since it has, share the load of the needle plate with the cylinder device.
It can be supported, and the load on the cylinder device is reduced accordingly.
That the cylinder device can be made smaller.
effective.

Further, since the floating mechanism is composed of the cylinder device for lifting the needle plate , the cylinder device can be easily installed in the space of the base and so on.
Simple structure and easy installation. Moreover, since the sewing pitch can be adjusted only by adjusting the stroke of the cylinder device, there is an effect that the adjustment work can be easily performed.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a condensation device for a sewing machine according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a main part of a condensation device for a sewing machine according to an embodiment of the present invention.

FIG. 3 is a cross-sectional view showing a condensation device for a sewing machine, which was conceived at the development stage of the present invention .

FIG. 4 is a perspective view showing an example of a sewing machine to which an embodiment of the present invention is applied.

FIG. 5 is a sectional view showing the structure of a conventional sewing machine.

[Explanation of symbols]

 1 sewing machine main body 2 base 3 needle plate (conventional example) 5 head 6 sewing needle 7 feed dog 8 drive mechanism 10 needle plate 11 support member 12 shaft 14 opening 15 insertion hole A steady position B floating position 20 cylinder device 22 cylinder 23 piston rod 25 Bolt 30 needle plate

Claims (1)

(57) [Claims] 1. A cloth is supported on a needle plate provided on a base, a sewing needle is moved forward and backward from a head located above the base toward the cloth on the needle plate, and an opening provided on the needle plate is used. In the condensation device for the sewing machine, in which the feed dog is driven to protrude so as to feed the cloth on the needle plate, the cloth is sewn at a predetermined sewing pitch, and the needle plate is fixed to the front end of the needle plate in the condensation device for sewing in the sewing process. Axis pivotable on the base
It can be floated to the needle side by rotating from a steady position by supporting it.
A floating mechanism is provided for floating the needle plate to a required height position to reduce the amount of protrusion of the feed dog from the needle plate.
A straw that is attached to the base and lifts the rear side of the needle plate.
Cylinder device with adjustable piston rod
Condensation device for sewing machines characterized by being made.