RU1807137C - Modular shuttle sewing machine accessory for overseam stitch forming - Google Patents

Abstract

The invention relates to the clothing industry, and in particular to sewing equipment used in the manufacturing process of garments. The proposed modular attachment can be used in combination with shuttle stitch sewing machines of various designs. The prefix is characterized by advanced technological capabilities, ensures stable operation of sewing equipment with high quality stitches. The modular attachment to the shuttle stitch sewing machine is equipped with a thread feeder of the upper looper thread. The latter is mounted on the transmission link of the looper movement mechanism. Said mechanism has additional means for adjusting the stroke of the loopers. It is made in the form of an arcuate groove formed on a vertical rack of the housing. In this case, the groove curvature depends on the magnitude of the strokes of the needle bar of the sewing machines. The thread guide holder is additionally equipped with a movable locking sleeve, 1 zp f-ly, 6 ill. Yo

Description

The invention relates to sewing equipment, namely, sewing devices and devices that can be used in the manufacture of various garments.

The aim of the invention is to expand the technological capabilities of the set-top box and to enable its stable operation with sewing machines of various designs.

Figure 1 shows a machine with a modular console; figure 2,3 is the same side view and top: figure 4 is a relative position

looper attachments and machine needles; Figures 5 and 6 show the interaction of loopers and needles during the formation of overcasting stitches.

A modular attachment 1 for forming overcasting stitches is mounted on the platform 2 of the known shuttle stitch machine having a pad holder 3 and a needle bar 4.

The attachment body has fastening means 5 for mounting it on the end of the presser foot 3 after removing the presser tray,

00

about

4

SB VI

which can be made in the form of a grip and screw clamp.

The attachment includes lever mechanisms for moving the loopers, which receive movement from the needle bar 4. The two-arm lever 6 is connected to the latter, the roll end of which covers the needle retainer. The lever 6 is mounted on the axis 7, equipped with fixing elements, and one of its ends is kinematically connected to the transmission link 8, which informs the movement of the rotary disk 9, mounted in the console body on the vertical axis 10. On the disk 9 there is a hinge 11 on which the link is mounted 12 kinematically associated with a rotatable holder 13 on which the upper looper is mounted

14 consoles.

Disc 9 via articulated link

15 is connected to the disk 16, on which the guide groove 17 is made. On the disk 16, a hinge 18 is fixed connected to the link 19, which is kinematically connected to the holder 20 of the lower looper 21.

A hinge 22 is also installed on the disk 16, which is kinematically connected through the movable lever 23 to the thread take-up device 24.

A guide 25 is also mounted on the body of the set-top box 25 supporting the workable sewing part 26 in the required position relative to the needle 27 and the needle plate 28 of the sewing machine.

A rotating transport roller 29 is placed above the needle plate 28 of the sewing machine and the gear rack of the material transport mechanism included in the machine.

Thread 30 is threaded into looper 14, and thread 31 is looped 21. These threads are supplied from bobbins mounted on racks in the lower part of the composite thread guide holder 32, Thread 30 is fed from bobbin 33 to thread guide 32 mounted on the upper part 34 of the holder the connection of which with the lower part 35 is made using the hinge axis 36, which allows the holder to fold when the attachment is in the idle position. The parts 34 and 35 are locked in the working position by means of a movable locking sleeve 37, which, during these operations, moves along the longitudinal axis of the holder to the desired position.

The path of the thread 30 is determined by the positions of the additional thread feeder 38, which is mounted on the transfer link 8, the fixed thread guide 39, the thread tension controller

40 and hole 41 for threading the looper 14, An arcuate groove 43 is made on the vertical stand 42 of the housing 1, the width of which is equal to the diameter of the axis 7. The curvature of the groove 43 is determined by the possible differences in the needle strokes 5 and 5 for different classes of sewing machines with which used modular prefix. This provides education conditions.

stitch (moments of capture of threads) at different thicknesses of the fabric of the processed sewing part 26. Angle A) / determining the size of the groove 43 is determined from the need to offset the axis 7 when using

consoles with various sewing machines.

A arctg (R

2 -tg

where R ZITach - SHmin

a Snmaxi 5it | P - maximum and minimum needle strokes.

The coordinates of the center C of the curvature of the groove relative to the needle plate (axis OZ, coinciding with the direction of movement of the material) and the axis of the needle (axis OY) are determined from the expressions:

Yc YBmax - () + R

Zc SHmin / 2 - tg% L

0

where Uvtax is the maximum rise of the needle holder (needle fixing screw) under the needle plate with the minimum needle stroke Si / imin, op t is the value of the angle of rotation of the double lever for the case when the looper stitches are caught by the needle and the lower looper thread by the upper looper blade.

When changing the position of the axis 7 in the groove

5 to 43, the shoulder ratio of the two shoulders of the arm 6 is changed.

The operation of the modular set-top box is as follows. Before turning on the sewing machine, the presser foot is removed from the presser foot 3 and installed at the end of the last modular attachment. In this case, the attachment body is based on the surface of the platform 2 of the sewing machine, and the fork end of the lever 6

5 is connected to the needle bar 4. After turning on the sewing machine, when the needle bar 4 is shifted with the needle 27 in the vertical plane, the two-arm lever 6, which, via link 8,

reports oscillatory motion about axis 10 to disk 9.

From the disk 9 through the hinge 11 and the link 12, the holder 13 with the upper looper 14 receives the reciprocating movement. By means of the pivot link 15, which is located in the groove 17 of the rotary disk 16 and moves along this groove, the reverse-rotational movement is also communicated to the disk 16. The last the oscillating movement of the holder 20, on which the lower looper 21.0t of the disk 16 is fixed, oscillating movement is also communicated to the thread winder 24, which, together with the looper 14 and 21, is involved in the formation of three-thread overcasting stitches. The latter is filled under the needle plate 28 of the sewing machine, and the processed sewing part 26 is located neither on the surface of the guide 25. The latter is positioned so that there is a gap between the opposite surfaces of the guide 25 and the needle plate to move the looper 21.

In the stitching process, the upper looper 14 biases the thread 30 along the path of the needle 27 with the needle thread, placing the thread 30 above the surface of the sewing part 26. The lower looper 21 biases the thread 31 along the path of the needle 27, placing this thread under the guide 25, In the process the filing of the thread 31 of the lower looper presses the participation of the swinging thread take-up unit 24.

After the loopers 14, 21 have reached the extreme right position (see Fig. 6) and the reverse bias has begun, the thread 31 is grasped by the upper looper 14. To ensure this grasp, the protruding lower looper 21 in the extreme right position is necessary.

To ensure exact coincidence of the values of the working strokes of the needle 27 of the sewing machine and the loopers 14, 21, the design of the set-top box additionally provides a means for adjusting the values of the working strokes of the loopers, which provides the expansion of technological capabilities and creates conditions for using the machine with sewing machines having needle mechanisms with different working sizes move

The adjustment is performed by displacing the axis 7 along the arcuate groove 43 in the vertical strut 42 of the console body 1. When setting up the set-top box, the orientation angle tf of the axis 7 of the two shoulders lever in the groove 43 (see Fig. 2) is determined from the expression:

and,

Jhmin

arctg (.--).

2 -tg

2

where 5i is the needle stroke of the sewing machine on which the attachment is mounted.

To ensure the stability of the stitch-formation with different stroke sizes of the upper looper, various sizes of bobbins (diameter, height), winding density of the thread on bobbins, etc. This thread is wound from bobbin 33 using the thread feeder 38 of this thread, which is mounted on link 8. The progress of this link, and consequently the shift 5 of the thread picker 38, changes when the ratio of the arms of the lever 6 changes after adjusting the position of the axis 7 relative to the groove 43. The thread picker 38 holds the thread 30 while the needle is offset 27 up and

0 shifts it to the tension regulator 10. When winding the thread 30 with the thread feeder 38, the tension of Th-t in the branch of thread feeder 38 is 39 higher, the tension of Th-b in the branch of thread feeder 38 is reel 35. Stability of stitching is ensured precisely with this ratio Tn-t Tn-b, which leads to the fact that the length of the released thread 30 is equal to the consumption of this thread when the stitch is formed by looper 14.

0In addition to installing a modular attachment on the machine platform and connecting it to the presser foot and needle bar of the latter, parts are transferred before the work process begins

5 34 and 35 of the thread holder to the working position. This is accomplished by rotating part 34 relative to the hinge axis 36, aligning these parts relative to the vertical axis and fixing them in such

0 position of the movable locking sleeve 37, which is biased toward the location of the pivot axis 36.

The design of the modular attachment makes it possible to use it5 to form the overcasting stitch with shuttle stitch sewing machines and creates the necessary conditions for a stable sewing process, regardless of the size of the sewing needle stroke

0 cars.

Claims (2)

SUMMARY OF THE INVENTION 1. A modular attachment for forming overcast stitches to various shuttle stitch sewing machines having a needle bar, movable in a vertical plane, a foot holder and a platform comprising a housing with fastening means on the foot holder and a vertical stand, upper and lower loopers, a lever mechanism for moving loops, having a two-arm lever with an axis of attachment connected to a vertical strut, and a transmission link, a low-detachable thread of the lower looper, elements for tensioning the threads and an integral holder of thread guides, characterized in that In order to expand the technological capabilities and stabilize the quality of the stitch, it is additionally equipped with a thread feeder for the upper looper thread mounted on the gear the loop link of the looper movement mechanism, and the latter has an additional means for adjusting the working stroke of the loopers, made in the form of an arcuate groove formed on a vertical stand of the body, the radius of curvature of this groove depending on the stroke size of the needle bar of the sewing machines. 2. The prefix according to claim 1, characterized by the fact that the holder of the thread guide is additionally equipped with a movable locking sleeve. s Figure 5.