Lower differential feeding mechanism of sewing machine

Abstract

The utility model provides a lower differential feeding mechanism of a sewing machine, which comprises a main feeding shaft, a lower differential feeding shaft, a feed lifting shaft and a differential adjusting structure, and a main feeding tooth structure is arranged between the main feeding shaft and the feed lifting shaft; a lower differential feeding tooth structure is arranged between the lower differential feeding shaft and the feed lifting tooth shaft, the differential adjusting structure comprises a first crank and a second crank which are arranged on the feed lifting tooth shaft, a main feeding transmission assembly is arranged between the main feeding shaft and the feed lifting tooth shaft, and the main feeding transmission assembly comprises a main feeding sliding block which slides on the first crank. A lower differential feeding transmission assembly is arranged between the lower differential feeding shaft and the feed lifting shaft, the lower differential feeding transmission assembly comprises a lower differential feeding sliding block sliding on the second crank and further comprises an adjusting driving structure for adjusting the relative sliding position of the main feeding sliding block and the lower differential feeding sliding block, and the adjusting driving structure is controlled by a motor and a connecting rod. The structure is simple, rapid, accurate and convenient.

Description

Technical Field

[0001] This utility model relates to the field of sewing machine technology, and in particular to a differential feeding mechanism for a sewing machine. Background Technology

[0002] Differential feeding in a sewing machine refers to the independent feeding of the front and rear feed dogs. The feeding speed and distance of the two feed dogs can be adjusted separately, thereby controlling the shrinkage or stretching of the fabric. This mechanism, by adjusting the difference in feeding speed between the front and rear dogs (either forward or reverse), can effectively control the smoothness of the overlock stitch and improve the quality of the finished garment.

[0003] Existing mechanisms for adjusting the feed teeth before and after feeding typically employ mechanical structures, requiring manual adjustment to achieve both forward and reverse states. Furthermore, these mechanisms are complex and inconvenient to adjust. Utility Model Content

[0004] To address the problems of the prior art, this utility model provides a differential feeding mechanism for a sewing machine, which has a simple structure and is quick and convenient to adjust.

[0005] The technical solution adopted is as follows:

[0006] A differential feeding mechanism for a sewing machine includes a lower base plate and a main feeding shaft, a lower differential feeding shaft, and a tooth-lifting shaft rotatably mounted on the lower base plate. The lower differential feeding shaft is movably sleeved on the main feeding shaft, and a main feeding tooth structure is provided between the main feeding shaft and the tooth-lifting shaft. A lower differential feeding tooth structure is provided between the lower differential feeding shaft and the tooth-lifting shaft. The mechanism also includes a differential adjustment structure, comprising a drive crank on the main feeding shaft, a driven crank on the lower differential feeding shaft, and an adjusting crank on the tooth-lifting shaft. A tooth-lifting shaft is provided between the drive crank and the adjusting crank. The system includes a main feeding connecting rod, one end of which is connected to a drive crank, and the other end of which is slidably connected to an adjusting crank via a main feeding slider. The adjusting crank has a first crank for the main feeding slider to slide on. A lower differential feeding connecting rod is provided between the driven crank and the adjusting crank. One end of the lower differential feeding connecting rod is connected to the driven crank, and the other end of which is slidably connected to the adjusting crank via a lower differential feeding slider. The adjusting crank has a second crank for the lower differential feeding slider to slide on. The system also includes an adjusting drive structure for adjusting the relative sliding position of the main feeding slider and the lower differential feeding slider.

[0007] Furthermore, the adjustment drive structure includes a drive motor, an adjustment drive block disposed on the output shaft of the drive motor, a first adjustment rod disposed at one end on the main feeding connecting rod, and a second adjustment rod disposed at one end on the lower differential feeding connecting rod. The adjustment drive block is provided with a first eccentric cam that is connected and cooperates with the other end of the first adjustment rod, and a second eccentric cam that is connected and cooperates with the other end of the second adjustment rod.

[0008] Furthermore, the main feed tooth structure includes a main feed tooth, a main feed tooth holder, a main feed tooth holder seat on the main feed shaft, and a first shift fork that cooperates with the main feed tooth holder on the tooth lifting shaft.

[0009] Furthermore, the lower differential feed tooth structure includes a lower differential feed tooth, a lower differential feed tooth holder, and a lower differential feed tooth holder seat disposed on the lower differential feed shaft. The tooth lifting shaft is provided with a second shift fork that cooperates with the lower differential feed tooth holder.

[0010] Furthermore, the main feeding shaft is provided with a drive structure for driving the main feeding shaft to rotate.

[0011] Furthermore, the first eccentric cam has a first farthest point at its furthest point from the center of the motor output shaft; the second eccentric cam has a second farthest point at its furthest point from the center of the motor output shaft, and the first and second farthest points are on the same straight line and do not overlap.

[0012] Compared with existing technologies, the beneficial effects of this utility model are as follows: This utility model provides a lower differential feeding mechanism for a sewing machine. By adjusting the relative positions of the main feeding slider and the lower differential feeding slider through electronic control of the drive structure, the strokes of the lower differential feeding and the main feeding are adjusted, achieving differential, stretching, and synchronous states. This utility model has a simple structure, uses electronic control for quick and convenient adjustment, and is precise. It can meet different feeding requirements according to different garment processes and fabric characteristics, thereby achieving rapid switching between different sewing positions and adapting to different curvature and tolerance requirements. Attached Figure Description

[0013] Figure 1 , 2 This is a schematic diagram of the feeding mechanism in differential mode;

[0014] Figure 3 , 4 This is a schematic diagram of the feeding mechanism under tension.

[0015] Figure 5 A schematic diagram of the feeding mechanism mounted on the lower base plate;

[0016] Figure 6 This is a front view of a portion of the structure;

[0017] The components include: a lower base plate 1, a main feed shaft 2, a drive crank 201, a lower differential feed shaft 3, a driven crank 301, a lifting shaft 4, an adjusting crank 401, a first crank 4011, a second crank 4012, a main feed tooth structure 5, a main feed tooth 501, a main feed tooth holder 502, a main feed tooth holder seat 503, a first shift fork 504, a lower differential feed tooth structure 6, a lower differential feed tooth 601, a lower differential feed tooth holder 602, and a lower differential feed tooth holder seat. 603, Second shift fork; 604, Differential adjustment structure; 7, Adjustment drive structure; 8, Drive motor; 801, Adjustment drive block; 802, First eccentric cam; 8021, Second eccentric cam; 8022, First adjusting rod; 803, Second adjusting rod; 804, Main feeding link; 9, Main feeding slider; 901, Lower differential feeding link; 10, Lower differential feeding slider; 1001, Drive structure; 11, Output shaft; 12, First farthest point; 13, Second farthest point; 14. Detailed Implementation

[0018] The present invention will be further described below with reference to specific embodiments.

[0019] refer to Figure 1-6 A differential feeding mechanism for a sewing machine includes a lower base plate 1 and a main feeding shaft 2, a lower differential feeding shaft 3, and a lifting tooth shaft 4 rotatably mounted on the lower base plate 1. The lower differential feeding shaft 3 is sleeved on the main feeding shaft 2, and a main feeding tooth structure 5 is provided between the main feeding shaft 2 and the lifting tooth shaft 4. A lower differential feeding tooth structure 6 is provided between the lower differential feeding shaft 3 and the lifting tooth shaft 4.

[0020] It also includes a differential adjustment structure 7, which includes a drive crank 201 on the main feed shaft 2, a driven crank 301 on the lower differential feed shaft 3, and an adjustment crank 401 on the lifting shaft 4. A main feed connecting rod 9 is provided between the drive crank 201 and the adjustment crank 401. One end of the main feed connecting rod 9 is connected to the drive crank 201, and the other end is slidably connected to the adjustment crank 401 through the main feed slider 901. The adjustment crank 401 is provided with a feed slider 901 for the main feed slider 901. 01 The first crank 4011 that slides; a lower differential feeding link 10 is provided between the driven crank 301 and the adjusting crank 401. One end of the lower differential feeding link 10 is connected to the driven crank 301, and the other end is slidably connected to the adjusting crank 401 through the lower differential feeding slider 1001. The adjusting crank 401 is provided with a second crank 4012 for the lower differential feeding slider to slide. It also includes an adjusting drive structure 8 for adjusting the relative sliding position of the main feeding slider 901 and the lower differential feeding slider 1001.

[0021] The lower differential feed shaft 3 is externally mounted on the main feed shaft 2, and the two can rotate independently.

[0022] A main feed tooth structure 5 is provided between the main feed shaft 2 and the tooth lifting shaft 4; a lower differential feed tooth structure 6 is provided between the lower differential feed shaft 3 and the tooth lifting shaft 4. Rotation of the main feed shaft 2 can drive the main feed tooth structure 5 in conjunction, and the rotation angle of the main feed shaft 2 determines the stroke of the main feed tooth structure 5. Similarly, rotation of the lower differential feed shaft 3 can drive the lower differential feed tooth structure 6 in conjunction, and the rotation angle of the lower differential feed shaft 3 determines the stroke of the lower differential feed tooth structure 6.

[0023] The main feeding shaft 2 is equipped with a drive structure 11 for driving the main feeding shaft to rotate. The drive structure 11 can be based entirely on existing technology.

[0024] The adjustment drive structure 8 includes a drive motor 801, an adjustment drive block 802 mounted on the output shaft 12 of the drive motor, a first adjustment rod 803 mounted on the main feeding connecting rod 9 at one end, and a second adjustment rod 804 mounted on the lower differential feeding connecting rod 10 at one end. The adjustment drive block 802 is provided with a first eccentric cam 8021 that is connected and cooperates with the other end of the first adjustment rod 803, and a second eccentric cam 8022 that is connected and cooperates with the other end of the second adjustment rod 804.

[0025] Using electronic control, the relative positions of the main feed slider and the lower differential feed slider can be adjusted more precisely, and the differential amount can be precisely adjusted. Compared with manual adjustment, it is more convenient, faster and more accurate. It is suitable for the lower differential feed mechanism of various machines such as industrial flatbed sewing machines, upper differential feed flatbed sewing machines and chain flatbed sewing machines, so as to solve the sewing of lockstitch and chain stitch on elastic fabrics and knitted fabrics, or for sewing pleats and lace on the lower layer fabrics. It has a wide range of applications.

[0026] The drive motor 801 drives the adjustment drive block 802 to rotate, and the first and second eccentric cams will rotate accordingly. The rotation of the first eccentric cam 8021 will cause the first adjustment rod 803 to swing, thereby causing the main feeding connecting rod 9 to swing up and down, that is, causing the main feeding slider 901 to slide on the first crank 4011. The rotation of the second eccentric cam 8022 will cause the second adjustment rod 804 to swing, thereby causing the lower differential feeding connecting rod 10 to swing up and down, that is, causing the lower differential feeding slider 1001 to slide on the second crank 4012.

[0027] The first eccentric cam 8021 has a first farthest point 13 at the farthest distance from the center of the motor output shaft 12; the second eccentric cam 8022 has a second farthest point 14 at the farthest distance from the center of the motor output shaft 12, and the first and second farthest points do not coincide.

[0028] If the first and second farthest points coincide, when the output shaft 12 of the drive motor 801 rotates, the first and second adjusting rods will swing synchronously. The main feeding slider 901 of the main feeding link 9 and the lower differential feeding slider 1001 of the lower differential feeding link 10 will slide synchronously. Since the main feeding slider 901 and the lower differential feeding slider 1001 have no relative sliding amount, the strokes of the main feeding and differential feeding are the same, and they always maintain a synchronous state, and cannot achieve a forward or reverse state.

[0029] Therefore, preferably, the first and second farthest points are on the same straight line and do not overlap. The greater the distance between the first and second farthest points, the greater the relative sliding amount of the main feeding slider 901 and the lower differential feeding slider 1001 will be when the adjusting drive block 802 rotates.

[0030] The adjustment drive structure 8 can adjust the relative position of the main feeding slider 901 and the lower differential feeding slider 1001. After the main feeding shaft 2 is driven to rotate, the transmission through the main feeding connecting rod 9 will drive the adjusting crank 401 to rotate. The rotation of the adjusting crank 401 will drive the lower differential feeding connecting rod 10 to swing. The lower differential feeding connecting rod 10 will drive the lower differential feeding shaft 3 to rotate through the driven crank 301.

[0031] Taking the figure as an example, when the main feeding slider 901 is at the upper end of the differential feeding slider 1001, and the crank is rotated (the first and second cranks rotate at the same angle), the swing of the lower differential feeding connecting rod 10 is greater than that of the main feeding connecting rod 9, and the rotation angle of the lower differential feeding shaft 3 is greater than that of the main feeding shaft 2. That is, the lower differential feeding stroke is larger, and it is in a differential state. Taking the figure as an example, when the main feeding slider 901 is at the lower end of the differential feeding slider 1001, and the crank is rotated (the first and second cranks rotate at the same angle), the swing of the lower differential feeding connecting rod 10 is less than that of the main feeding connecting rod 9, and the rotation angle of the lower differential feeding shaft 3 is less than that of the main feeding shaft 2. That is, the main feeding stroke is larger, and it is in a stretched state. Similarly, if the main feeding slider 901 and the differential feeding slider 1001 are at the same height, they are in a synchronized state.

[0032] Both the main feed tooth structure 5 and the lower differential feed tooth structure 6 can adopt existing technologies. The main feed tooth structure 5 includes a main feed tooth 501, a main feed tooth holder 502, and a main feed tooth holder seat 503 disposed on the main feed shaft 2. The tooth lifting shaft 4 is provided with a first shift fork 504 that cooperates with the main feed tooth holder 502. The lower differential feed tooth structure 6 includes a lower differential feed tooth 601, a lower differential feed tooth holder 602, and a lower differential feed tooth holder seat 603 disposed on the lower differential feed shaft 3. The tooth lifting shaft 4 is provided with a second shift fork 604 that cooperates with the lower differential feed tooth holder 602.

[0033] The above description is only an optional embodiment of the present utility model and does not limit the patent scope of the present utility model. All equivalent structural transformations made under the inventive concept of the present utility model using the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included in the patent protection scope of the present utility model.

Claims

1. A differential feeding mechanism for a sewing machine, comprising a lower base plate (1) and a main feeding shaft (2), a lower differential feeding shaft (3), and a tooth lifting shaft (4) rotatably mounted on the lower base plate (1), wherein the lower differential feeding shaft (3) is movably sleeved on the main feeding shaft (2), and a main feeding tooth structure (5) is provided between the main feeding shaft (2) and the tooth lifting shaft (4); a lower differential feeding tooth structure (6) is provided between the lower differential feeding shaft (3) and the tooth lifting shaft (4), characterized in that: It also includes a differential adjustment structure (7), which includes a drive crank (201) on the main feed shaft (2), a driven crank (301) on the lower differential feed shaft (3), and an adjustment crank (401) on the tooth lifting shaft (4). A main feed connecting rod (9) is provided between the drive crank (201) and the adjustment crank (401). One end of the main feed connecting rod (9) is connected to the drive crank (201), and the other end is slidably connected to the adjustment crank (401) through the main feed slider (901). The adjustment crank (401) is provided with a main feed slider. The first crank (4011) slides on the block (901); a lower differential feeding link (10) is provided between the driven crank (301) and the adjusting crank (401). One end of the lower differential feeding link (10) is connected to the driven crank (301), and the other end is slidably connected to the adjusting crank (401) through the lower differential feeding slider (1001). The adjusting crank (401) is provided with a second crank (4012) for the lower differential feeding slider to slide. It also includes an adjusting drive structure (8) for adjusting the relative sliding position of the main feeding slider (901) and the lower differential feeding slider (1001).

2. The differential feeding mechanism of the sewing machine as described in claim 1, characterized in that: The adjustment drive structure (8) includes a drive motor (801), an adjustment drive block (802) on the output shaft (12) of the drive motor, a first adjustment rod (803) with one end on the main feeding link (9), and a second adjustment rod (804) with one end on the lower differential feeding link (10). The adjustment drive block (802) is provided with a first eccentric cam (8021) that is connected and cooperates with the other end of the first adjustment rod (803), and a second eccentric cam (8022) that is connected and cooperates with the other end of the second adjustment rod (804).

3. The differential feeding mechanism of the sewing machine as described in claim 1, characterized in that: The main feed tooth structure (5) includes a main feed tooth (501), a main feed tooth holder (502), a main feed tooth holder seat (503) on the main feed shaft (2), and a first shift fork (504) that cooperates with the main feed tooth holder (502) on the tooth lifting shaft (4).

4. The differential feeding mechanism of the sewing machine as described in claim 1, characterized in that: The lower differential feed tooth structure (6) includes a lower differential feed tooth (601), a lower differential feed tooth holder (602), and a lower differential feed tooth holder seat (603) provided on the lower differential feed shaft (3). The tooth lifting shaft (4) is provided with a second shift fork (604) that cooperates with the lower differential feed tooth holder (602).

5. The differential feeding mechanism of the sewing machine as described in claim 1, characterized in that: The main feeding shaft (2) is provided with a drive structure (11) for driving the main feeding shaft to rotate.

6. The differential feeding mechanism of the sewing machine as described in claim 2, characterized in that: The first eccentric cam (8021) has a first farthest point (13) at the farthest distance from the center of the motor output shaft (12); the second eccentric cam (8022) has a second farthest point (14) at the farthest distance from the center of the motor output shaft (12). The first and second farthest points are on the same straight line and do not overlap.

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