阅读说明：本技术 一种裤襻机用压脚装置及裤襻机 (Presser foot device for belt loop machine and belt loop machine ) 是由 阮积祥 马颖 于 2019-09-04 设计创作，主要内容包括：本发明提供一种裤襻机用压脚装置及裤襻机,裤襻机用压脚装置包括固定座、以及两个相对于固定座都可上下移动的裤襻压脚,每个裤襻压脚都包括两个并排的压脚板、以及形成在两个压脚板之间且允许裤襻机中机针穿过的缝制区,每个裤襻压脚的两个压脚板具有独立的下移行程。本申请将裤襻压脚分成两个具有独立的下移行程的压脚板,故两个压脚板能够根据各自下方缝料的厚度来控制各自的下移行程、自适应各自下方缝料的厚度,从而在裤襻厚度不一样时,各裤襻压脚中的两个压脚板能够给出不同的压力,避免压脚板与缝料之间出现夹角,从而使保证压脚板与缝料之间的接触面积,也即保证压脚板能够有效地压牢缝料,由此避免出现缝制歪斜现象,保证缝制效果。(The invention provides a presser foot device for a belt loop and a belt loop machine, wherein the presser foot device for the belt loop comprises a fixed seat and two belt loop presser feet which can move up and down relative to the fixed seat, each belt loop presser foot comprises two side-by-side presser foot plates and a sewing area which is formed between the two presser foot plates and allows a machine needle in the belt loop machine to pass through, and the two presser foot plates of each belt loop presser foot have independent downward moving strokes. This application falls into two presser foot boards that have independent stroke that moves down with the belt loop presser foot, so two presser foot boards can come control respective stroke that moves down according to the thickness of the sewing material of below separately, the thickness of the sewing material of below separately of self-adaptation, thereby when belt loop thickness is different, two presser foot boards in each belt loop presser foot can give different pressure, avoid appearing the contained angle between presser foot board and the sewing material, thereby make the area of contact who guarantees between presser foot board and the sewing material, also guarantee that the presser foot board can press the sewing material firmly effectively, avoid appearing making up crooked phenomenon from this, guarantee to make up the effect.)

1. A presser foot device for a loop machine comprises a fixed seat (10) and two loop presser feet (20) which can move up and down relative to the fixed seat (10), and is characterized in that: each loop presser foot (20) comprises two side-by-side presser foot plates (21) and a sewing area (22) which is formed between the two presser foot plates (21) and allows a needle in the loop machine to pass through, and the two presser foot plates (21) of each loop presser foot (20) have independent downward moving strokes.

2. A presser foot device for a loop machine as claimed in claim 1, wherein: the trousers loop pressing device also comprises two driving cylinders (30) which are arranged on the fixed seat (10) and correspond to the two trousers loop pressing feet (20) one by one; each driving cylinder (30) is provided with a cylinder body (31), two main air cavities (32) which are arranged in the cylinder body (31) and are independent of each other, a cylinder rod (33) which can be installed in each main air cavity (32) in a vertically moving mode, and a main air pipe joint (34) which is installed at the upper end of each main air cavity (32), wherein the lower ends of the two cylinder rods (33) in each driving cylinder (30) are respectively connected with two presser foot plates (21) in each belt loop presser foot (20).

3. A presser foot device for a loop machine as claimed in claim 2, wherein: the lower end of the cylinder rod (33) is connected with the foot pressing plate (21) through a foot pressing fixing block (23), the foot pressing fixing block (23) is installed below the cylinder body (31) in a vertically movable mode, the lower end of the cylinder rod (33) can abut against the foot pressing fixing block (23), and the foot pressing fixing block (23) is fixed with the foot pressing plate (21).

4. A presser foot device for a loop machine as claimed in claim 3, wherein: the presser foot fixing block (23) is fixed with a guide rod (35) extending up and down, and a guide hole (311) matched with the guide rod (35) is formed in the cylinder body (31).

5. A presser foot device for a loop machine as claimed in claim 3, wherein: the trousers loop presser foot assembly is characterized by further comprising a reset tension spring (41), a limiting shaft (42) connected to the upper end of the reset tension spring (41) and a limiting clamping head (43) connected to the lower end of the reset tension spring (41), a mounting hole (36) is formed in the cylinder body (31), the reset tension spring (41) is located in the mounting hole (36), the limiting shaft (42) can be abutted to the upper end of the cylinder body (31), the limiting clamping head (43) comprises a sliding shaft portion (431) and a limiting flange portion (432) arranged at the lower end of the sliding shaft portion (431), sliding holes (24) matched with the sliding shaft portion (431) are formed in two presser foot fixing blocks (23) in the trousers loop presser foot (20) together, and the limiting flange portion (432) is located below the two presser foot fixing blocks (23) in the trousers loop presser foot (20) and can be abutted to the presser foot fixing.

6. A presser foot device for a loop machine as claimed in claim 3, wherein: each driving cylinder (30) further comprises an auxiliary air chamber (37) opened in the cylinder block (31), an auxiliary pressure rod (38) movably installed in the auxiliary air chamber (37) up and down, and an auxiliary air pipe joint (39) installed at the upper end of each auxiliary air chamber (37), the lower end of the auxiliary pressure rod (38) can abut against two presser foot fixing blocks (23) in the belt loop presser foot (20).

7. A belt loop machine comprises a machine shell, and is characterized in that: further comprising a presser foot device for a loop machine as claimed in any one of claims 1 to 6, said holder (10) being fixed to the casing.

Technical Field

The invention relates to a presser foot device for a belt loop machine.

The invention also relates to a belt loop machine comprising the belt loop machine presser foot device.

Background

In the clothing industry, there are currently various types of loop machines that are capable of automatically stapling loops. Generally, a belt loop machine is provided with a presser foot device, the presser foot device comprises two presser feet, and two sides of a folded belt loop are pressed by the presser feet; such as the one disclosed in chinese utility model application No. 200720110843.2. Fig. 1 shows a presser foot 100 of a loop machine pressing folded loops 200. In the actual sewing process, the above-mentioned loop machines generally have the following drawbacks: when the thicknesses of the folded belt loops 200 are not consistent, an angle is formed between the presser foot 100 and the belt loops 200, so that the contact area between the presser foot 100 and the belt loops 200 is small, the presser foot 100 cannot press the belt loops 200 well, the belt loops 200 are not pressed firmly easily, the phenomenon of inclined sewing occurs in the sewing process, and the sewing effect is affected.

Disclosure of Invention

In view of the above-mentioned shortcomings of the prior art, the present invention provides a presser foot device for a belt loop, which can adapt to the thickness of the belt loop to ensure the pressing effect.

In order to achieve the purpose, the invention provides a presser foot device for a belt loop machine, which comprises a fixed seat and two belt loop presser feet capable of moving up and down relative to the fixed seat, wherein each belt loop presser foot comprises two side-by-side presser foot plates and a sewing area formed between the two presser foot plates and allowing a needle in the belt loop machine to pass through, and the two presser foot plates of each belt loop presser foot have independent downward moving strokes.

Furthermore, the presser foot device for the belt loop machine further comprises two driving cylinders which are arranged on the fixed seat and correspond to the two belt loop presser feet one to one; each driving cylinder is provided with a cylinder body, two mutually independent main air cavities arranged in the cylinder body, a cylinder rod which can be installed in each main air cavity in a vertically moving mode, and a main air pipe joint installed at the upper end of each main air cavity, and the lower ends of the two cylinder rods in each driving cylinder are respectively connected with two presser foot plates in each belt loop presser foot.

Further, the lower end of the air cylinder rod is connected with the foot pressing plate through a foot pressing fixing block, the foot pressing fixing block is mounted below the air cylinder body in a vertically movable mode, the lower end of the air cylinder rod can be abutted against the foot pressing fixing block, and the foot pressing fixing block and the foot pressing plate are fixed.

Furthermore, a guide rod extending up and down is fixed on the presser foot fixing block, and a guide hole matched with the guide rod is formed in the cylinder body.

Further, the presser foot device for the belt loop presser foot further comprises a reset tension spring, a limiting shaft connected to the upper end of the reset tension spring and a limiting chuck connected to the lower end of the reset tension spring, a mounting hole is formed in the cylinder body, the reset tension spring is located in the mounting hole, the limiting shaft can be abutted to the upper end of the cylinder body, the limiting chuck comprises a sliding shaft portion and a limiting flange portion arranged at the lower end of the sliding shaft portion, two presser foot fixing blocks in the belt loop presser foot are jointly provided with sliding holes matched with the sliding shaft portion, and the limiting flange portion is located below the two presser foot fixing blocks in the belt loop presser foot and can be abutted to the presser foot fixing blocks.

Furthermore, each driving cylinder also comprises an auxiliary air cavity arranged in the cylinder body, an auxiliary pressure rod which can be installed in the auxiliary air cavity in a vertically moving mode, and an auxiliary air pipe connector installed at the upper end of each auxiliary air cavity, and the lower end of the auxiliary pressure rod can be abutted against two presser foot fixing blocks in the belt loop presser foot.

The invention also provides a belt loop machine, which comprises a machine shell and the belt loop machine presser foot device, wherein the fixed seat is fixed on the machine shell.

As described above, the presser foot device for a loop machine and the loop machine according to the present invention have the following advantageous effects:

this application falls into two presser foot boards that have independent stroke that moves down with the belt loop presser foot, so two presser foot boards can come control respective stroke that moves down according to the thickness of the sewing material of below separately, the thickness of the sewing material of below separately of self-adaptation, thereby when belt loop thickness is different, two presser foot boards in each belt loop presser foot can give different pressure, avoid appearing the contained angle between presser foot board and the sewing material, thereby make the area of contact who guarantees between presser foot board and the sewing material, also guarantee that the presser foot board can press the sewing material firmly effectively, avoid appearing making up crooked phenomenon from this, guarantee to make up the effect.

Drawings

FIG. 1 is a view showing the operation of a presser foot in a conventional belt loop machine.

Fig. 2 and 3 are schematic structural views of a presser foot device for a belt loop in the present application at different viewing angles.

FIG. 4 is an exploded view of the left drive cylinder and left loop presser foot of FIG. 2.

Fig. 5 and 6 are schematic views of the connection between the reset assembly and two presser foot fixing blocks in the loop presser foot of the present application.

(wherein, FIG. 6 is a cross-sectional view of FIG. 5 at the center axis of the return tension spring.)

Fig. 7 is an operation state diagram of a presser foot device for a loop machine in the present application.

Fig. 8 is a schematic structural view of a footpad in the present application.

Description of the element reference numerals

10 fixed seat

11 fixed beam

12 fixed pressing plate

20 belt loop presser foot

21 presser foot plate

21L left foot pressing plate

21R right foot pressing plate

211 connecting part

212 pressing part

213 guide slider part

214 pressing noodles

22 sewing area

23 presser foot fixing block

23L left presser foot fixing block

23R right presser foot fixing block

231 mounting groove portion

24 sliding hole

30 driving cylinder

31 cylinder block

32 main gas chamber

32L left main air cavity

32R Right main air cavity

33 Cylinder rod

33L left cylinder rod

33R right cylinder rod

34 main gas pipe joint

34L left main air pipe joint

34R right main air pipe joint

35 guide bar

36 mounting hole

37 auxiliary air cavity

38 auxiliary pressure lever

39 auxiliary gas pipe joint

311 pilot hole

41 reset tension spring

42 limit shaft

43 position-limiting chuck

431 sliding shaft part

432 limit flange part

51 stopper

52 limit pin shaft

53 limiting clamp

Detailed Description

The following description of the embodiments of the present invention is provided for illustrative purposes, and other advantages and effects of the present invention will become apparent to those skilled in the art from the present disclosure.

It should be understood that the structures, proportions, and dimensions shown in the drawings and described herein are for illustrative purposes only and are not intended to limit the scope of the present invention, which is defined by the claims, but rather by the claims. In addition, the terms such as "upper", "lower", "left", "right", "middle" and "one" used in the present specification are for convenience of description only and are not intended to limit the scope of the present invention, and changes or modifications of the relative relationship thereof may be made without substantial technical changes and modifications.

The application provides a belt loop machine, which comprises a machine shell and a presser foot device for the belt loop machine. As shown in fig. 2 to 4, the presser foot device for a loop machine includes a fixing base 10 and two loop presser feet 20 capable of moving up and down relative to the fixing base 10, the fixing base 10 is fixed to a casing of the loop machine, and the presser foot device for a loop machine is integrally mounted on the casing of the loop machine. For convenience of description, in the following embodiments, the side-by-side direction of the two loop presser feet 20 in the presser foot device is defined as the left-right direction, i.e., the two loop presser feet 20 are arranged left and right.

Further, as shown in fig. 2 to 4, each of the loop presser feet 20 includes two presser foot plates 21 arranged side by side in the left-right direction, and a sewing area 22 formed between the two presser foot plates 21 and allowing a needle in the loop machine to pass through, the center of the sewing area 22 in the left-right direction being a center line L of the needle in the loop machine; the parallel direction of the two presser foot plates 21 in each belt loop presser foot 20 is the same as the parallel direction of the two belt loop presser feet 20 in the presser foot device, and the two belt loop presser feet are arranged in parallel left and right; in particular, the two presser feet 21 of each loop presser foot 20 have independent downward moving strokes, that is, the downward moving strokes of the two presser feet 21 of each loop presser foot 20 may be the same or different, or alternatively, the two presser feet 21 may be flush or high when the loop presser foot 20 presses the loops. When the loop sewing machine is used for sewing loops, loop presser feet 20 in the presser foot device move downwards, and two presser feet 21 forming each loop presser foot 20 move downwards to press and stick sewing materials, as shown in fig. 7; when the two presser feet 21 of each belt loop presser foot 20 move downwards, the respective downward movement stroke can be controlled according to the thickness of the sewing material below the presser foot: when the adhered seam material is thick, the downward movement stroke of the foot pressing plate 21 is small, and the height is high; when the attached sewing material is thin, the downward moving strokes of the presser foot plates 21 are more and the height is lower, so that the downward moving strokes of the two presser foot plates 21 of the loop presser foot 20 are mutually independent and do not interfere with each other, and the thickness of the sewing material below each presser foot can be self-adapted. Therefore, when the thickness of the belt loops is different, the two presser feet 21 in each belt loop presser foot 20 can give different pressures according to the thickness of the sewing material below the presser foot 21, so that an included angle between the presser foot 21 and the sewing material is avoided, and the two presser feet 21 can reliably press and stick the sewing material, thereby ensuring the contact area between the presser feet 21 and the sewing material, namely ensuring that the presser feet 21 can effectively press and stick the sewing material, avoiding the phenomenon of oblique sewing and ensuring the sewing effect.

In the presser foot device for a belt loop machine, in order to realize that two presser foot plates 21 in each belt loop presser foot 20 have independent downward moving strokes, the two presser foot plates 21 can be respectively and independently driven, or the two presser foot plates 21 can be set to be in an angle self-adjusting structure through a joint assembly. Preferably, the present application uses two presser foot plates 21 in each loop presser foot 20 to be driven independently to realize independent downward movement of the two presser foot plates 21. Based on this, as shown in fig. 2 to fig. 4, the presser foot device for a loop machine further includes two driving cylinders 30 which are both mounted on the fixing base 10 and correspond to the two loop presser feet 20 one by one, so that the driving cylinders 30 are also arranged in two and left and right directions, the left driving cylinder 30 corresponds to the left loop presser foot 20, and the right driving cylinder 30 corresponds to the right loop presser foot 20. Further, the two driving cylinders 30 have the same structure, and the two loop presser feet 20 have the same structure, and based on this, the structure of the driving cylinder 30, the structure of the loop presser foot 20, and the connection structure between the driving cylinder 30 and the loop presser foot 20 will be described below by taking the left driving cylinder 30 and the left loop presser foot 20 as an example.

As shown in fig. 2 to 4, two presser feet 21 in the loop presser foot 20 are a left presser foot 21L and a right presser foot 21R, respectively; the driving cylinder 30 includes a cylinder block 31 mounted on the fixing base 10, two main air chambers 32 provided in the cylinder block 31 and independent from each other, a cylinder rod 33 installed in each main air chamber 32 to be movable up and down, and a main air pipe joint 34 installed at an upper end of each main air chamber 32, the two main air chambers 32 are a left main air chamber 32L and a right main air chamber 32R, the two cylinder rods 33 are a left cylinder rod 33L inserted in the left main air chamber 32L and a right cylinder rod 33R inserted in the right main air chamber 32R, a lower end of the left cylinder rod 33L is connected to the left footpad 21L, a lower end of the right cylinder rod 33R is connected to the right footpad 21R, and the two main air pipe joints 34 are a left main air pipe joint 34L installed at an upper end of the left main air chamber 32L and a right main air pipe joint 34R installed at an upper end of the right main air chamber 32R, respectively. Preferably, the belt loop presser foot 20 further comprises a presser foot fixing block 23, and the lower end of the cylinder rod 33 is connected with the presser foot plate 21 through the presser foot fixing block 23, so that there are two presser foot fixing blocks 23 in the belt loop presser foot 20, namely a left presser foot fixing block 23L connected between the lower end of the left cylinder rod 33L and the left presser foot plate 21L, and a right presser foot fixing block 23R connected between the lower end of the right cylinder rod 33R and the right presser foot plate 21R. The left presser foot fixing block 23L and the right presser foot fixing block 23R are arranged side by side in the left-right direction and are both mounted below the cylinder block 31 so as to be movable up and down; the lower end of the left cylinder rod 33L can abut against the upper end face of the left presser foot fixing block 23L, and the left presser foot plate 21L is fixed to the left presser foot fixing block 23L through a screw; similarly, the lower end of the right cylinder rod 33R can abut against the upper end surface of the right presser foot fixing block 23R, and the right presser foot plate 21R is fixed to the right presser foot fixing block 23R by a screw.

When the folded trouser loops are sent to the lower part of the presser foot device, the left main air pipe joint 34L and the right main air pipe joint 34R in the driving air cylinder 30 are ventilated, a left air cylinder rod 33L and a right air cylinder rod 33R both extend downwards from the air cylinder body 31, the left air cylinder rod 33L presses the left presser foot fixing block 23L, and then the left presser foot plate 21L is driven to move downwards, so that the left presser foot plate 21L presses and sticks to the sewing material positioned on the left side of the central line L of the machine needle, as shown in fig. 7; meanwhile, the right cylinder rod 33R presses the right presser foot fixing block 23R, and then the right presser foot plate 21R is driven to move downwards, so that the right presser foot plate 21R presses and adheres to the sewing material on the right side of the machine needle center line L. When the sewing material on the left presser foot plate 21L side is thick, the downward movement stroke of the left cylinder rod 33L, the left presser foot fixing block 23L and the left presser foot plate 21L is small, the downward movement stroke of the right cylinder rod 33R, the right presser foot fixing block 23R and the right presser foot plate 21R is large, the position of the left presser foot fixing block 23L is higher than that of the right presser foot fixing block 23R, and the position of the left presser foot plate 21L is higher than that of the right presser foot plate 21R, so that the left presser foot plate 21L and the right presser foot plate 21R can be well contacted with the sewing material and firmly press the sewing material. When the sewing material on the left presser foot plate 21L side is thin, the downward movement stroke of the left cylinder rod 33L, the left presser foot fixing block 23L and the left presser foot plate 21L is large, the downward movement stroke of the right cylinder rod 33R, the right presser foot fixing block 23R and the right presser foot plate 21R is small, the position of the left presser foot fixing block 23L is lower than that of the right presser foot fixing block 23R, and the position of the left presser foot plate 21L is lower than that of the right presser foot plate 21R, so that the left presser foot plate 21L and the right presser foot plate 21R can be well contacted with the sewing material and firmly press the sewing material.

As shown in fig. 2 to 4, the driving cylinder 30 further includes an auxiliary air chamber 37 opened in the cylinder block 31, an auxiliary pressure rod 38 installed in the auxiliary air chamber 37 to be movable up and down, and an auxiliary air pipe joint 39 installed at an upper end of each auxiliary air chamber 37, the auxiliary air chamber 37 is an air chamber independent of the left main air chamber 32L and the right main air chamber 32R, a lower end of the auxiliary pressure rod 38 is capable of abutting against the two presser foot fixing blocks 23 in the belt loop presser foot 20, that is, the auxiliary pressure rod 38 is provided on an inner edge side of the left presser foot fixing block 23L and an inner edge side of the right presser foot fixing block 23R, and a projection of the auxiliary pressure rod 38 has a portion on the left presser foot fixing block 23L and another portion on the right presser foot fixing block. After the left main air pipe joint 34L and the right main air pipe joint 34R in the cylinder 30 to be driven are ventilated and the left foot pressing plate 21L and the right foot pressing plate 21R are pressed to joint material, the auxiliary air pipe joint 39 in the cylinder 30 is driven to be ventilated, and the auxiliary pressure rod 38 extends downwards from the cylinder body 31; when the sewing material on the left presser foot plate 21L side is thick, the position of the left presser foot fixing block 23L is higher than the position of the right presser foot fixing block 23R, so that the lower end of the auxiliary pressure lever 38 is only pressed on the left presser foot fixing block 23L to provide auxiliary pressure for the left presser foot fixing block 23L, and the left presser foot plate 21L can be better pressed against the thick sewing material; when the sewing material on the right presser foot plate 21R side is thick, the position of the right presser foot fixing block 23R is higher than the position of the left presser foot fixing block 23L, so that the lower end of the auxiliary pressure lever 38 is only pressed on the right presser foot fixing block 23R to give an auxiliary pressure to the right presser foot fixing block 23R, thereby enabling the right presser foot plate 21R to better press and stick the thick sewing material; when the thickness of the sewing material on the left presser foot plate 21L side is the same as the thickness of the sewing material on the right presser foot plate 21R side, the left presser foot fixing block 23L is flush with the right presser foot fixing block 23R, the lower end of the auxiliary pressure lever 38 can be pressed on the left presser foot fixing block 23L and the right presser foot fixing block 23R at the same time, and an auxiliary pressure is provided for the left presser foot fixing block 23L and the right presser foot fixing block 23R at the same time, so that the left presser foot plate 21L and the right presser foot plate 21R can be better pressed against the thick sewing material. After that, the sewing is performed, and the left main air pipe joint 34L, the right main air pipe joint 34R, and the auxiliary air pipe joint 39 are all in the air-passing state during the sewing.

Further, as shown in fig. 2 and 3, the fixing base 10 includes a fixing beam 11 extending left and right and a concave fixing pressure plate 12, the fixing pressure plate 12 is clamped on the fixing beam 11 and fixed therebetween by screws, the fixing pressure plate 12 is fixed to the cylinder block 31 of the driving cylinder 30 by screws, so that the driving cylinder 30 is mounted on the fixing base 10, the fixing beam 11 is fixed to the housing of the loop machine, and the presser foot device is integrally mounted in the loop machine. In addition, as shown in fig. 3 and 8, the presser foot plate 21 includes a connecting portion 211 extending by bending, and a presser portion 212 horizontally extending from one end of the connecting portion 211, a lower end surface of the presser portion 212 is an uneven presser surface 214 and contacts with the sewing material, and the presser surface 214 is preferably a sawtooth surface to improve the friction force with the sewing material and ensure the pressing effect; the connecting portion 211 and the presser foot fixing block 23 are fixed by screws. Preferably, as shown in fig. 3, the upper end of the connecting portion 211 is provided with a guide slider portion 213 protruding upward, the lower end of the presser foot fixing block 23 is provided with a mounting groove portion 231 extending leftward and rightward, and the guide slider portion 213 is located in the mounting groove portion 231 and fixed to the presser foot fixing block 23 by a screw, whereby the mounting position of the presser foot plate 21 in the leftward and rightward direction can be easily adjusted.

Preferably, as shown in fig. 2 and 4, the left presser foot fixing block 23L and the right presser foot fixing block 23R are both fixed with a guide rod 35 extending up and down, a guide hole (311) matched with the guide rod 35 is opened in the cylinder block 31, and the guide rod 35 is matched with the guide hole (311) to play a role of guiding the downward movement of the presser foot plate 21.

Further, as shown in fig. 4 to 6, the presser foot device for a belt loop machine further includes a reset assembly connected between the driving cylinder 30 and the belt loop presser foot 20, the reset assembly includes a reset tension spring 41 extending up and down, a limit shaft 42 connected to an upper end of the reset tension spring 41, and a limit chuck 43 connected to a lower end of the reset tension spring 41, the cylinder block 31 is provided with a mounting hole 36 extending up and down, the reset tension spring 41 is located in the mounting hole 36, the limit shaft 42 can abut against an upper end of the cylinder block 31, the limit chuck 43 includes a sliding shaft portion 431 extending up and down and a limit flange portion 432 provided at a lower end of the sliding shaft portion 431, an inner side (i.e., a right side) of the left presser foot fixing block 23L and an inner side (i.e., a left side) of the right presser foot fixing block 23R are provided with a sliding hole 24 matching with the sliding shaft portion, The other part is opened inside the right presser fixed block 23R, and the limit flange part 432 is positioned below the left presser fixed block 23L and the right presser fixed block 23R and can abut against the left presser fixed block 23L and the right presser fixed block 23R. When the left main air pipe joint 34L and the right main air pipe joint 34R in the driving air cylinder 30 are ventilated and the left air cylinder rod 33L and the right air cylinder rod 33R are driven to extend downwards, the left presser foot fixing block 23L and the right presser foot fixing block 23R move downwards, the reset tension spring 41 is stretched and in an energy storage state under the action of the limiting shaft 42 and the limiting clamping head 43, and after the subsequent sewing is finished, when the left main air pipe joint 34L, the right main air pipe joint 34R and the auxiliary air pipe joint 39 are not ventilated, the limiting clamping head 43 moves upwards under the action of the reset tension spring 41, the limiting flange part 432 of the limiting clamping head 43 drives the left presser foot fixing block 23L and the right presser foot fixing block 23R to move upwards together, so that the reset presser foot lifting action is.

Further, as shown in fig. 3 and 4, a height difference limiting assembly is further connected between the left presser foot fixing block 23L and the right presser foot fixing block 23R, the height difference limiting assembly includes a limiting block 51 fixed at the lower end of the right presser foot fixing block 23R, a limiting pin 52 penetrating the left presser foot fixing block 23L, and a limiting fastener 53 fixed at the upper end of the limiting pin 52, the lower end of the limiting pin 52 is fixed to the limiting block 51, a movable gap is formed between the limiting block 51 and the left presser foot fixing block 23L in the up-down direction, so as to limit the height difference between the left presser foot fixing block 23L and the right presser foot fixing block 23R, that is, the height difference between the left presser foot plate 21L and the right presser foot plate 21R.

To sum up, the present application divides the belt loop presser foot 20 into two left presser foot plate 21L and right presser foot plate 21R which are respectively located at the left and right sides of the central line L of the machine needle, and adopts the driving cylinder 30 to respectively and independently control the descending of the left presser foot plate 21L and the right presser foot plate 21R, and can independently control the height of the left presser foot plate 21L and the right presser foot plate 21R, and the descending strokes of the left presser foot plate 21L and the right presser foot plate 21R are mutually independent and do not interfere with each other, so that the present application can self-adapt to the thickness of the sewing material below the respective presser foot plate, and relatively increase the contact area between the left presser foot plate 21L and the sewing material, thereby well pressing and sticking the belt loop with inconsistent thickness, and ensuring the sewing effect.

Therefore, the invention effectively overcomes various defects in the prior art and has high industrial utilization value.

The foregoing embodiments are merely illustrative of the principles and utilities of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which can be made by those skilled in the art without departing from the spirit and technical spirit of the present invention be covered by the claims of the present invention.