Lapping machine feeding mechanism with stable sewing needle pitch

Abstract

The feeding mechanism of the lacing machine with the stable sewing needle pitch comprises a machine shell, a movable frame, a main feeding gear, a differential feeding gear, a main driving assembly and a differential driving assembly, the differential driving assembly comprises a support, a first motor, a first gear, a gear transmission shaft and an intermediate gear, and the first motor, the first gear, the gear transmission shaft and the intermediate gear are arranged on the support. An output shaft of the first motor is sleeved with the first gear, the upper end of the gear transmission shaft is sleeved with an upper gear meshed with the first gear, a lower gear is arranged at the lower end of the gear transmission shaft, and the intermediate gear is meshed with the lower gear and the differential feeding gear; when the first motor rotates, power of the first motor can be transmitted to the differential feeding gear through the first gear via the upper gear, the gear transmission shaft, the lower gear and the intermediate gear, so that the differential feeding gear rotates according to 20%-50% of the rotating speed of the first gear, transmission is achieved through meshing of the multiple sets of gears, a large transmission ratio is formed, and distances are consistent during high-speed sewing and low-speed sewing; the stability of the sewing needle pitch is enhanced.

Description

A feeding mechanism for a sewing machine with stable stitch length Technical Field

[0001] This utility model belongs to the field of sewing machine technology, specifically relating to a feeding mechanism for a sewing machine with stable stitch spacing. Background Technology

[0002] Lasting machines are used for sewing footwear and leather goods. Existing lasting machines employ a feeding mechanism driven by dual stepper motors and a single-needle, single-thread, bottomless design to achieve high-precision sewing and stable material feeding. Specifically, the lasting machine uses dual stepper motors to drive the main feed wheel and a differential feed wheel respectively. The main feed wheel is driven by a synchronous belt, while the differential feed wheel is driven by gears. The feed amount of sewing material is controlled by adjusting the speed and direction of the two motors. However, with this type of design, it is difficult to completely prevent sewing material debris from embedding in the tooth grooves of the synchronous belt pulley or between the teeth of the synchronous belt during sewing. This leads to unstable transmission, accelerated component wear, and even timing belt delamination. The installation of the timing belt requires a high degree of parallelism between the two shafts, and the belt tension must be appropriate. Improper installation can cause the timing belt to over-stretch. Premature wear occurs because the synchronous belt becomes looser during prolonged transmission, leading to slippage and unstable stitch length. In a loose state, relative sliding and impact accelerate wear and shorten the belt's lifespan. Furthermore, the small transmission ratio between the differential feed wheel and the motor means that even slight changes in motor speed affect the sewing speed, making precise speed adjustment difficult. This hinders accurate speed control for different fabrics and makes stable stitch length control challenging. The small transmission ratio also limits the amplification of motor torque after gear transmission, resulting in insufficient torque to overcome resistance in complex sewing movements, such as thick fabrics or special patterns. This can lead to insufficient power, decreased sewing quality, or even machine jamming. Summary of the Invention

[0003] The purpose of this invention is to overcome one or more shortcomings in the prior art and provide a feeding mechanism for a sewing machine with stable stitch spacing.

[0004] To achieve the above objectives, the technical solution provided by this utility model is a feeding mechanism for a sewing machine with stable stitch spacing, comprising:

[0005] The housing contains a rotatable pressure foot shaft;

[0006] A movable frame is located on the outside of the housing and extends vertically. The lower end of the movable frame is connected to the end of the presser foot shaft that passes through the housing, and the upper end of the movable frame is provided with a mounting block.

[0007] The main feed gear, the differential feed gear, the main drive assembly for driving the main feed gear to rotate, and the differential drive assembly for driving the differential feed gear to rotate;

[0008] The differential drive assembly includes a support and a first motor, a first gear, a gear transmission shaft, and an intermediate gear mounted on the support. The support is connected to the mounting block. The first motor is fixedly mounted. The first gear is sleeved on the output shaft of the first motor. The gear transmission shaft is rotatably mounted, with an upper gear meshing with the first gear at its upper end and a lower gear at its lower end. The intermediate gear is rotatably mounted and meshes with the lower gear and the differential feeding gear. When the first motor rotates, the first gear transmits the power provided by the first motor to the differential feeding gear through the upper gear, the gear transmission shaft, the lower gear, and the intermediate gear, causing the differential feeding gear to rotate at 20% to 50% of the rotational speed of the first gear.

[0009] Preferably, the support includes a first motor base and a bushing base. The first motor base is L-shaped and has a horizontal plate and a vertical plate connected vertically. The horizontal plate is fixed to the mounting block, and the first motor is fixed to the side of the vertical plate away from the horizontal plate. The bushing base is connected to the middle of the bottom surface of the horizontal plate and extends downward. The bushing base has a through hole that extends through the bushing base in the vertical direction. The gear drive shaft is rotatably inserted through the through hole. The bottom of the bushing base also has a mounting hole for installing the intermediate gear. The mounting hole is located on one side of the through hole and communicates with the through hole.

[0010] More preferably, the side wall of the bushing seat is connected to a support plate that extends horizontally outward, and the lower end face of the support plate is provided with a downwardly protruding cylindrical protrusion, and the differential feeding gear is rotatably sleeved on the cylindrical protrusion.

[0011] More preferably, the bushing seat includes a seat body and a side cover plate, the side cover plate being connected to the seat body and sealing the lateral opening on the seat body, the surface of the side cover plate facing the lateral opening having a groove, the groove forming part of the mounting hole.

[0012] More preferably, a step is provided above the groove, and an insertion hole is provided on the bottom wall of the step. The end face of the side cover plate away from the seat body is also provided with a set screw hole. The set screw hole is perpendicularly connected to the insertion hole. The intermediate gear is rotatably sleeved on the central shaft. The upper end of the central shaft is inserted into the insertion hole and locked in the insertion hole by a set screw threaded in the set screw hole.

[0013] More preferably, the bottom wall of the bushing seat is connected to a cover plate, and the cover plate has a notch to expose the mounting hole so as to disassemble the intermediate gear.

[0014] More preferably, the intermediate gear is a low-strength gear, and when the maximum torque output by the first motor is still insufficient to drive the differential feeding gear to rotate, the intermediate gear breaks and disengages from the differential feeding gear and / or the lower gear.

[0015] Preferably, the upper gear and the first gear mesh perpendicularly, both the upper gear and the first gear are bevel gears, and the lower gear is integrally formed with the gear drive shaft.

[0016] Preferably, the main drive assembly includes a second motor, a second gear, a drive shaft, and a transmission gear. The second motor is vertically connected to the housing via a second motor mount. The second gear is mounted on the output shaft of the second motor. The drive shaft extends vertically. The transmission gear is mounted on the bottom of the drive shaft and meshes with the second gear. The main feeding gear is mounted on the upper end of the drive shaft and rotates synchronously with the transmission gear.

[0017] More preferably, the transmission gear and the differential feeding gear are located on opposite sides of the rotation axis of the main feeding gear.

[0018] Due to the application of the above technical solution, this utility model has the following advantages compared with the prior art:

[0019] The sewing machine feeding mechanism with stable stitch length provided by this utility model includes a machine housing, a movable frame, a main feeding gear, a differential feeding gear, a main drive assembly, and a differential drive assembly. The differential drive assembly includes a support and a first motor, a first gear, a gear transmission shaft, and an intermediate gear mounted on the support. The support is connected to a mounting block on one side of the machine housing. The first motor is fixedly mounted, and the first gear is sleeved on the output shaft of the first motor. The gear transmission shaft is rotatably mounted, with an upper gear meshing with the first gear at its upper end and a lower gear at its lower end. The intermediate gear is rotatably mounted and meshes with the lower gear and the differential feeding gear. When the first motor rotates, the first gear transmits the power provided by the first motor to the differential feeding gear via the upper gear, gear transmission shaft, lower gear, and intermediate gear. The differential feeding gear rotates at 20% to 50% of the speed of the first gear. Through the meshing of multiple gears, transmission can be achieved and a large transmission ratio can be formed. When the differential feeding gear rotates at low speed, the first motor has a higher speed, greatly reducing the impact of small changes in the first motor speed on the sewing speed and facilitating fine adjustment of the sewing speed. This enhances the stability of the stitch length. During toe closure, stitching can be performed according to preset dimensions and shapes, ensuring uniform spacing between each stitch, thereby improving the quality and aesthetics of the toe closure. Utilizing an advanced control system and high-quality mechanical components, it maintains stable operation even at high speeds. During toe closure, it effectively reduces sewing defects caused by machine vibration or jamming, ensuring the stability of the closure quality and reducing the defect rate. Attached Figure Description

[0020] Figure 1 is a perspective view of a preferred embodiment of the present invention.

[0021] Figure 2 is a three-dimensional enlarged schematic diagram of Figure 1 with the casing hidden.

[0022] Figure 3 is an exploded view of the assembly of the main feed gear and the main drive assembly in Figure 2.

[0023] Figure 4 is an exploded view of the assembly of the differential feeding gear and differential feeding assembly in Figure 2.

[0024] Figure 5 is a front view schematic diagram of the differential feeding gear and differential feeding assembly in Figure 2.

[0025] Figure 6 is a cross-sectional view along the AA direction in Figure 5.

[0026] Figure 7 is a cross-sectional view along the BB direction in Figure 5.

[0027] Figure 8 is a cross-sectional view along the CC direction in Figure 5.

[0028] Wherein: 10. Housing; 11. Presser foot shaft; 20. Moving frame; 21. Mounting block; 30. Main feeding gear; 40. Differential feeding gear; 50. Main drive assembly; 51. Second motor; 52. Second gear; 53. Transmission shaft; 54. Transmission gear; 55. Second motor base; 60. Differential drive assembly; 61. Support; 611. First motor base; 611a. Horizontal plate; 611b. Vertical plate; 612. Bushing base; 613. 614. Through hole; 615. Mounting hole; 616. Support plate; 617. Cylindrical protrusion; 618. Seat body; 619. Side cover plate; 620. Groove; 621. Step; 622. Insertion hole; 623. Set screw hole; 624. Set screw; 625. Cover plate; 626. Notch; 62. First motor; 63. First gear; 64. Gear drive shaft; 641. Upper gear; 642. Lower gear; 65. Intermediate gear; 651. Central shaft. Detailed Implementation

[0029] As shown in Figures 1 to 8, the feeding mechanism for a sewing machine with stable stitch length provided by this utility model includes: a machine housing 10, a movable frame 20, a main feeding gear 30, a differential feeding gear 40, a main drive assembly 50, and a differential drive assembly 60. The machine housing 10 contains a rotatable presser foot shaft 11. The movable frame 20 is located outside the machine housing 10 and extends vertically. The lower end of the movable frame 20 is connected to the end of the presser foot shaft 11 that penetrates the machine housing 10, and the upper end of the movable frame 20 is provided with a mounting block 21. The main feeding gear 30 and the differential feeding gear 40 are used for feeding. During feeding, the rotational speed of the differential feeding gear 40 can be the same as or different from that of the main feeding gear 30 to achieve differential feeding. The main drive assembly 50 drives the main feeding gear 30 to rotate, and the differential drive assembly 60 drives the differential feeding gear 40 to rotate. The drive assembly 60 includes a support 61 and a first motor 62, a first gear 63, a gear drive shaft 64, and an intermediate gear 65 mounted on the support 61. The support 61 is connected to the mounting block 21. The first motor 62 is fixedly mounted. The first gear 63 is sleeved on the output shaft of the first motor 62. The gear drive shaft 64 is rotatably mounted. Its upper end is sleeved with an upper gear 641 that meshes with the first gear 63, and its lower end is provided with a lower gear 642. The intermediate gear 65 is rotatably mounted and meshes with the lower gear 642 and the differential feeding gear 40. When the first motor 62 rotates, the first gear 63 transmits the power provided by the first motor 62 to the differential feeding gear 40 through the upper gear 641, the gear drive shaft 64, the lower gear 642, and the intermediate gear 65, so that the differential feeding gear 40 rotates at 20% to 50% of the rotational speed of the first gear 63.

[0030] The advantages of this setup are that it enables transmission through multiple sets of meshing gears and forms a large transmission ratio. When the differential feeding gear rotates at low speed, the first motor has a higher speed, greatly reducing the impact of small changes in the first motor speed on the sewing speed. It also facilitates fine adjustment of the sewing speed, enhances the stability of the stitch length, and reduces the torque requirement of the first motor, thereby reducing costs. When the toe is gathered, it can be sewn according to the preset size and shape, ensuring that the spacing of each stitch is uniform, thus improving the quality and aesthetics of the toe gathering. It adopts an advanced control system and high-quality mechanical components, maintaining a stable working state even at high speeds. When gathering the toe, it effectively reduces sewing defects caused by machine vibration or jamming, ensuring the stability of the gathering quality and reducing the defect rate.

[0031] To facilitate processing and assembly, in this embodiment, the upper gear 641 and the first gear 63 mesh vertically, both of which are bevel gears, and the lower gear 642 is integrally formed with the gear drive shaft 64.

[0032] For ease of setup, in this embodiment, the support 61 includes a first motor base 611 and a bushing base 612. The first motor base 611 is L-shaped and has a horizontal plate 611a and a vertical plate 611b connected vertically. The horizontal plate 611a is fixed on the mounting block 21, and the first motor 62 is fixed on the side of the vertical plate 611b away from the horizontal plate 611a. The bushing base 612 is connected to the middle of the bottom surface of the horizontal plate 611a and extends downward. The bushing base 612 has a through hole 613 that runs through the bushing base 612 in the vertical direction. The gear drive shaft 63 is rotatably inserted in the through hole 613. The bottom of the bushing base 612 also has a mounting hole 614 for mounting an intermediate gear 65. The mounting hole 614 is located on one side of the through hole 613 and communicates with the through hole 613.

[0033] Furthermore, the side wall of the bushing seat 612 is connected to a support plate 615 extending horizontally outward. The lower end face of the support plate 615 is provided with a downwardly protruding cylindrical protrusion 616. The differential feeding gear 40 is rotatably sleeved on the cylindrical protrusion 616. Furthermore, the bushing seat 612 includes a seat body 617 and a side cover plate 618. A through hole 613 and a portion of the mounting holes 614 are provided in the seat body 617. The side cover plate 618 is connected to the seat body 617 and blocks the lateral opening on the seat body 617. The surface of the side cover plate 618 facing the lateral opening is provided with a groove 619. The groove 619 constitutes another portion of the mounting holes 614. The support plate 615 is connected to the end face of the side cover plate 618 away from the seat body 617.

[0034] To facilitate the disassembly of the intermediate gear 65, a step 620 is provided above the groove 619. The bottom wall of the step 620 has an insertion hole 621. The end face of the side cover plate 618 away from the seat body 617 is also provided with a set screw hole 622. The set screw hole 622 is perpendicular to the insertion hole 621. The intermediate gear 65 is rotatably sleeved on the central shaft 651. The upper end of the central shaft 651 is inserted into the insertion hole 621 and locked in the insertion hole 621 by the set screw 623 connected by the internal thread of the set screw hole 622. Furthermore, a cover plate 624 is connected to the bottom wall of the bushing seat 612. The cover plate 624 has a notch 625 that exposes the mounting hole 614 so that the intermediate gear 65 can be disassembled from below.

[0035] The intermediate gear 65 is a low-strength gear, such as a plastic or plastic-steel gear. The strength of the intermediate gear 65 is less than that of the differential feeding gear 40 and the lower gear 642. When the maximum torque output of the first motor 62 is still insufficient to drive the differential feeding gear 40 to rotate (when the material is jammed), the intermediate gear 65 breaks, thereby disconnecting from the meshing with the differential feeding gear 40 and / or the lower gear 642, so as to protect the differential feeding gear 40, the lower gear 642, and the gear drive shaft 64. At the same time, since the intermediate gear 65 can be quickly replaced, subsequent maintenance is also relatively convenient.

[0036] In this embodiment, the main drive assembly 50 includes a second motor 51, a second gear 52, a drive shaft 53, and a drive gear 54. The second motor 51 is vertically connected to the housing 10 via a second motor mount 55. The second gear 52 is mounted on the output shaft of the second motor 51. The drive shaft 53 extends vertically. The drive gear 54 is mounted on the bottom of the drive shaft 53 and meshes with the second gear 52. The main feeding gear 30 is mounted on the upper end of the drive shaft 53 and rotates synchronously with the drive gear 54. This configuration avoids unstable transmission caused by foreign objects embedding, thereby improving transmission performance.

[0037] To save space and facilitate installation, the transmission gear 54 and the differential feeding gear 40 are located on opposite sides of the rotation axis of the main feeding gear 30.

[0038] The above embodiments are only for illustrating the technical concept and features of this utility model. Their purpose is to enable those skilled in the art to understand the content of this utility model and implement it accordingly. They should not be used to limit the protection scope of this utility model. All equivalent changes or modifications made in accordance with the spirit and essence of this utility model should be included within the protection scope of this utility model.

Claims

1. A feeding mechanism for a sewing machine with stable stitch spacing, comprising: The housing contains a rotatable pressure foot shaft; A movable frame is located outside the machine housing and extends vertically. The lower end of the movable frame is connected to the end of the presser foot shaft that passes through the machine housing, and the upper end of the movable frame is provided with a mounting block. The system includes a main feeding gear, a differential feeding gear, a main drive assembly for driving the main feeding gear to rotate, and a differential drive assembly for driving the differential feeding gear to rotate. The differential drive assembly comprises a support and a first motor, a first gear, a gear transmission shaft, and an intermediate gear mounted on the support. The support is connected to the mounting block, and the first motor is fixed. The configuration includes a first gear mounted on the output shaft of the first motor, a rotatable gear drive shaft with an upper gear meshing with the first gear at its upper end and a lower gear at its lower end, and an intermediate gear rotatably mounted and meshing with the lower gear and the differential feeding gear. When the first motor rotates, the first gear transmits the power provided by the first motor to the differential feeding gear through the upper gear, the gear drive shaft, the lower gear, and the intermediate gear, causing the differential feeding gear to rotate at 20% to 50% of the rotational speed of the first gear.

2. The feeding mechanism for a sewing machine with stable stitch length as described in claim 1, characterized in that: The support includes a first motor base and a bushing base. The first motor base is L-shaped and has a horizontal plate and a vertical plate connected vertically. The horizontal plate is fixed to the mounting block, and the first motor is fixed to the side of the vertical plate away from the horizontal plate. The bushing base is connected to the middle of the bottom surface of the horizontal plate and extends downward. The bushing base has a through hole that runs through the bushing base in the vertical direction. The gear drive shaft is rotatably inserted through the through hole. The bottom of the bushing base also has a mounting hole for installing the intermediate gear. The mounting hole is located on one side of the through hole and communicates with the through hole.

3. The feeding mechanism for a sewing machine with stable stitch length as described in claim 2, characterized in that: The side wall of the bushing seat is connected to a support plate that extends horizontally outward. The lower end face of the support plate is provided with a downward protruding cylindrical protrusion. The differential feeding gear is rotatably sleeved on the cylindrical protrusion.

4. The feeding mechanism for a sewing machine with stable stitch length as described in claim 3, characterized in that: The bushing seat includes a seat body and a side cover plate. The side cover plate is connected to the seat body and blocks the lateral opening on the seat body. The surface of the side cover plate facing the lateral opening has a groove, which forms part of the mounting hole.

5. The feeding mechanism for a sewing machine with stable stitch length as described in claim 4, characterized in that: A step is provided above the groove, and a insertion hole is provided on the bottom wall of the step. A set screw hole is also provided on the end face of the side cover plate away from the seat body. The set screw hole is perpendicular to the insertion hole. The intermediate gear is rotatably sleeved on the central shaft. The upper end of the central shaft is inserted into the insertion hole and locked in the insertion hole by a set screw threaded in the set screw hole.

6. The feeding mechanism for a sewing machine with stable stitch length as described in claim 2, characterized in that: The bottom wall of the bushing seat is connected to a cover plate, and the cover plate has a notch that exposes the mounting hole so as to disassemble the intermediate gear.

7. The feeding mechanism for a sewing machine with stable stitch length as described in claim 6, characterized in that: The intermediate gear is a low-strength gear. When the maximum torque output by the first motor is still insufficient to drive the differential feeding gear to rotate, the intermediate gear breaks and disengages from the differential feeding gear and / or the lower gear.

8. The feeding mechanism for a sewing machine with stable stitch length according to claim 1, characterized in that: The upper gear meshes perpendicularly with the first gear, and both the upper gear and the first gear are bevel gears. The lower gear is integrally formed with the gear drive shaft.

9. The feeding mechanism for a sewing machine with stable stitch length according to claim 1, characterized in that: The main drive assembly includes a second motor, a second gear, a drive shaft, and a transmission gear. The second motor is vertically connected to the housing via a second motor mount. The second gear is mounted on the output shaft of the second motor. The drive shaft extends vertically. The transmission gear is mounted on the bottom of the drive shaft and meshes with the second gear. The main feeding gear is mounted on the upper end of the drive shaft and rotates synchronously with the transmission gear.

10. The feeding mechanism for a sewing machine with stable stitch length according to claim 9, characterized in that: The transmission gear and the differential feeding gear are located on opposite sides of the rotation axis of the main feeding gear.

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