Lower differential adjustment device for a sewing machine

Abstract

The utility model provides a kind of sewing machine's lower differential adjusting device, belong to sewing equipment technical field.It solves the problem such as insufficient accuracy of existing lower differential adjusting device adjustment.This sewing machine's lower differential adjusting device, sewing machine includes feeding shaft, differential tooth frame seat is connected on feeding shaft, slide pin slot is set on the side surface of differential tooth frame seat, lower differential adjusting device includes motor and differential adjusting seat, motor can drive differential adjusting seat to move up and down, differential adjusting seat is fixedly connected with differential adjusting pin, the end of differential adjusting pin has the end head of cylindrical shape and coaxially arranged, end head is located at the outside of differential adjusting seat and is embedded into slide pin slot, the outer peripheral surface of end head and the side wall surface of slide pin slot are in close contact, feeding shaft drives differential tooth frame seat to swing around end head.This lower differential adjusting device structure is stable, can improve the accuracy of adjustment.

Description

Technical Field

[0001] This utility model belongs to the field of sewing equipment technology and relates to a differential adjustment device for a sewing machine. Background Technology

[0002] A sewing machine is a machine that sews fabric together using thread. Currently, conventional flatbed sewing machines are equipped with a single feed dog, which feeds the fabric. However, facing increasingly sophisticated garment manufacturing requirements, flatbed sewing machines with a single feed dog cannot meet the high flatness requirements of thin fabrics, knitted fabrics, and elastic fabrics. Therefore, some sewing machines are equipped with a lower differential feeding mechanism. This mechanism has two sets of feed dogs and feeders, allowing for different sewing effects to be achieved through synchronous or asynchronous feeding (i.e., differential feeding). Typically, the differential function of a sewing machine is implemented as follows: the feeding power of one set of feed dogs and feeders comes from the feeding mechanism in the sewing machine, and the feeding power of another set of feed dogs and feeders comes from the lifting mechanism of the sewing machine. That is, the lifting shaft in the lifting mechanism is connected to a feed dog through a differential linkage mechanism and is equipped with a manual adjustment mechanism. The manual adjustment mechanism acts on the differential linkage mechanism to change the transmission efficiency of the differential linkage mechanism, thereby realizing the manual adjustment of the differential stitch pitch (i.e., differential feed amount).

[0003] To avoid downtime for adjustments, manual adjustment is sometimes replaced with motor-driven adjustment. For example, patent document CN219385550U describes a lower differential feeding mechanism for a sewing machine that includes a feeding shaft, a differential tooth holder, and an adjustment assembly. The feeding shaft is movably positioned on the frame, and the differential tooth holder is movably connected to it. A rectangular groove is formed on the side of the differential tooth holder. The adjustment assembly includes an adjustment motor and an adjustment slider. The adjustment slider is located within the rectangular groove and rotates with the differential tooth holder. The adjustment motor drives the adjustment slider to slide along the rectangular groove, and the feeding shaft drives the differential tooth holder to oscillate around the rotation axis of the adjustment slider. During operation, the adjustment motor drives the adjustment slider to slide along the rectangular groove. When the rotation axis of the adjustment slider and the axis of the feeding shaft are at the same horizontal level, the feeding shaft drives the main tooth holder and the differential tooth holder to oscillate synchronously, resulting in synchronous feeding between the main feed tooth and the differential feed tooth. When the horizontal height of the adjusting slider's rotation axis is higher than that of the feed shaft, the feed shaft drives the main feeder seat to swing, which in turn drives the differential feeder seat to swing around the rotation axis of the adjusting slider. The differential swing between the main feeder seat and the differential feeder seat creates the differential feeding required for stretch sewing. When the horizontal height of the adjusting slider's rotation axis is lower than that of the feed shaft, the feed shaft drives the main feeder seat to swing, which in turn drives the differential feeder seat to swing around the rotation axis of the adjusting slider. The differential swing between the main feeder seat and the differential feeder seat creates the differential feeding required for shrinkage sewing.

[0004] However, in the aforementioned differential feeding mechanism, the adjusting slider is merely mounted on the connecting shaft. In order to make the adjusting slider move smoothly and reduce axial interference, the axial depth of the rectangular groove is often greater than the axial thickness of the adjusting slider. Therefore, the adjusting slider is prone to axial displacement during the sliding process in the rectangular groove, resulting in a decrease in adjustment accuracy. Utility Model Content

[0005] The purpose of this invention is to address the aforementioned problems in the existing technology by proposing a differential adjustment device for sewing machines, which solves the technical problem of insufficient adjustment accuracy of existing differential adjustment devices.

[0006] The objective of this utility model can be achieved through the following technical solutions: A differential adjustment device for a sewing machine, the sewing machine including a feed shaft, a differential tooth holder connected to the feed shaft, a sliding pin groove formed on the side of the differential tooth holder, the differential adjustment device including a motor and a differential adjustment seat, the motor capable of driving the differential adjustment seat to move up and down, characterized in that a differential adjustment pin is fixedly connected to the differential adjustment seat, the end of the differential adjustment pin having a cylindrical end coaxially arranged, the end being located outside the differential adjustment seat and embedded in the sliding pin groove, the outer peripheral surface of the end abutting against the side wall surface of the sliding pin groove, the feed shaft driving the differential tooth holder to swing around the end.

[0007] During adjustment, the motor drives the differential adjustment seat to move up and down, and the end of the differential adjustment pin slides up and down in the sliding pin groove, thereby changing the relative height between the feed shaft and the differential adjustment pin to achieve differential adjustment. During sewing, the feed shaft swings, causing the differential tooth holder to swing around its end, achieving differential feeding. Because the differential adjustment pin is fixedly connected to the differential adjustment seat, it does not rotate circumferentially or move axially, ensuring accurate relative positioning between the end of the differential adjustment pin and the sliding pin groove. Furthermore, the cylindrical end of the differential adjustment pin does not interfere with the swinging of the differential tooth holder or the up-and-down movement of the differential adjustment pin, allowing the adjustment process to proceed smoothly. Therefore, the differential adjustment device described below has a stable structure and can improve the accuracy of adjustment.

[0008] In the aforementioned differential adjustment device of the sewing machine, the differential adjustment pin is a stepped shaft structure. The outer diameter of the end of the differential adjustment pin is larger than the outer diameter of the main shaft. The main shaft of the differential adjustment pin is inserted and fixed in the differential adjustment seat, and the end of the differential adjustment pin abuts against the differential adjustment seat. This allows the differential adjustment pin to be axially positioned on the differential adjustment seat, ensuring accurate axial positioning of the end of the differential adjustment pin and improving adjustment accuracy.

[0009] In the aforementioned differential adjustment device of the sewing machine, an annular groove is provided on the outer circumferential surface of the differential adjustment pin. The annular groove is located between the end of the differential adjustment pin and the main body of the differential adjustment pin. The annular groove has a clearance function to avoid installation interference and ensure that the end abuts against the outer side of the differential adjustment seat for axial positioning, so that the end of the differential adjustment pin is installed in an accurate position.

[0010] In the aforementioned differential adjustment device of the sewing machine, a locking screw is threaded onto the differential adjustment seat, and the head of the locking screw abuts against the outer circumferential surface of the differential adjustment pin. The differential adjustment pin is fixed to the differential adjustment seat by tightening the locking screw, and can be easily disassembled by loosening the locking screw. This facilitates the easy replacement of the differential adjustment pin after wear on its end, ensuring the adjustment device maintains good accuracy over long-term operation by replacing the differential adjustment pin.

[0011] In the aforementioned differential adjustment device for a sewing machine, a nut is fixedly connected to the differential adjustment seat. The motor shaft is inserted into the nut and threadedly connected. A motor base is fixedly connected to the motor housing. A guide shaft and a limiting rod, both parallel to the motor shaft, pass through the differential adjustment seat. The guide shaft is located between the limiting rod and the motor shaft, and both the guide shaft and the limiting rod are fixedly connected to the motor base. Thus, the rotation of the motor shaft drives the nut to move up and down, thereby causing the differential adjustment seat to move up and down. The guide shaft and limiting rod provide guidance and limitation, ensuring stable and smooth up-and-down sliding of the differential adjustment seat and facilitating the adjustment process.

[0012] In the aforementioned differential adjustment device for a sewing machine, the motor base has a protruding connecting block. The bottom end of the guide shaft and the bottom end of the limiting rod are both fixedly connected to the connecting block. The motor's rotating shaft is located outside the connecting block. A mounting plate is fixedly connected between the top end of the guide shaft and the top end of the limiting rod. The connecting block and the mounting plate are used to limit the differential adjustment seat, preventing it from moving excessively. Furthermore, the mounting plate is fixedly connected to the base plate of the sewing machine, facilitating the installation of the motor, guide shaft, and limiting rod.

[0013] Compared with the prior art, the present invention has the following advantages: A differential adjustment pin is fixedly connected to the differential adjustment seat. The differential adjustment pin has a cylindrical end that is inserted into the sliding pin groove of the differential gear holder seat. The outer circumferential surface of the end is in contact with the side wall of the sliding pin groove. The differential adjustment pin will not shift axially or rotate circumferentially. At the same time, the end ensures smooth swing of the differential gear holder seat and smooth sliding of the differential adjustment pin, which helps to improve the accuracy of adjustment. Attached Figure Description

[0014] Figure 1 This is a three-dimensional view of the differential adjustment device.

[0015] Figure 2 This is a three-dimensional view of the differential adjustment pin and differential gear holder when the differential adjustment device is disassembled.

[0016] Figure 3 This is a partial sectional view of the differential adjustment pin of the differential adjustment device.

[0017] In the diagram, 1. Base plate; 2. Tooth lifting shaft; 3. Feeding shaft; 4. Differential tooth frame seat; 4a. Sliding pin groove; 5. Main tooth lifting fork crank; 6. Differential tooth lifting fork crank; 7. Main tooth frame seat; 8. Main tooth frame; 9. Differential tooth frame; 10. Differential adjustment seat; 11. Motor; 11a. Rotating shaft; 12. Nut; 13. Motor seat; 13a. Connecting block; 14. Guide shaft; 15. Limiting rod; 16. Mounting plate; 17. Differential adjustment pin; 17a. End; 17b. Main shaft; 17c. Annular groove; 18. Locking screw. Detailed Implementation

[0018] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments.

[0019] like Figure 1 and Figure 2As shown, a lower differential adjustment device for a sewing machine is disclosed. The sewing machine includes a base plate 1, a feed dog shaft 2, a feed shaft 3, and a differential feed dog holder 4. The feed dog shaft 2 and the feed shaft 3 are arranged in parallel and rotatably mounted below the base plate 1. A main feed dog fork-shaped crank 5 and a differential feed dog fork-shaped crank 6 are fixed to the front end of the feed dog shaft 2. A main feed dog holder 7 is fixed to the front end of the feed shaft 3. A main feed dog holder 8 is connected between the upper end of the main feed dog holder 7 and the main feed dog fork-shaped crank 5. The lower end of the differential feed dog holder 4 is hinged to the lower end of the main feed dog holder 7. A differential feed dog holder 9 is connected between the upper end of the differential feed dog holder 4 and the differential feed dog fork-shaped crank 6. A sliding pin groove 4a is provided on the front side of the differential feed dog holder 4. The lower differential adjustment device includes a differential adjustment seat 10 and a motor 11 fixedly connected to the base plate 1. The motor 11 can drive the differential adjustment seat 10 to move up and down. A nut 12 is fixedly connected to the differential adjustment seat 10, and the rotating shaft 11a of the motor 11 is inserted into the nut 12 to form a threaded connection. A motor base 13 is fixedly connected to the housing of the motor 11. A guide shaft 14 and a limiting rod 15, both parallel to the rotating shaft 11a of the motor 11, are passed through the differential adjustment seat 10. The guide shaft 14 is located between the limiting rod 15 and the rotating shaft 11a of the motor 11, and both the guide shaft 14 and the limiting rod 15 are fixedly connected to the motor base 13. The motor base 13 has a protruding connecting block 13a. The bottom ends of the guide shaft 14 and the limiting rod 15 are fixedly connected to the connecting block 13a. The rotating shaft 11a of the motor 11 is located outside the connecting block 13a. A mounting plate 16 is fixedly connected between the top end of the guide shaft 14 and the top end of the limiting rod 15, and the mounting plate 16 is fixedly connected to the base plate 1.

[0020] like Figure 2 and Figure 3 As shown, a differential adjusting pin 17 is fixedly connected to the differential adjusting seat 10. The end of the differential adjusting pin 17 has a cylindrical end head 17a that is coaxially arranged. The end head 17a is located on the outside of the differential adjusting seat 10 and is embedded in the sliding pin groove 4a. The outer peripheral surface of the end head 17a abuts against the side wall surface of the sliding pin groove 4a, and the end head 17a can slide up and down in the sliding pin groove 4a. The feeding shaft 3 drives the differential tooth holder seat 4 to swing around the differential adjusting pin 17. The differential adjusting pin 17 has a stepped shaft structure. The outer diameter of the end head 17a of the differential adjusting pin 17 is larger than the outer diameter of the main body 17b of the differential adjusting pin 17. The main body 17b of the differential adjusting pin 17 is inserted and fixed in the differential adjusting seat 10, and the end head 17a of the differential adjusting pin 17 abuts against the outer surface of the differential adjusting seat 10. An annular groove 17c is provided on the outer peripheral surface of the differential adjusting pin 17, located between the end 17a and the main body 17b of the differential adjusting pin 17. A locking screw 18 is threaded onto the differential adjusting seat 10, with the head of the locking screw 18 abutting against the outer peripheral surface of the main body 17b of the differential adjusting pin 17. If the individual replacement of the differential adjusting pin 17 is not required, the differential adjusting pin 17 can be welded and fixed to the differential adjusting seat 10.

[0021] During adjustment, motor 11 drives differential adjustment seat 10 to move up and down, and end 17a of differential adjustment pin 17 slides up and down in sliding pin groove 4a, thereby changing the relative height between feed shaft 3 and differential adjustment pin 17, that is, changing the swing radius of differential tooth holder 4, thus realizing differential adjustment. During sewing, feed shaft 3 rotates, causing differential tooth holder 4 to swing around end 17a, thus realizing differential feeding. Since differential adjustment pin 17 is fixedly connected to differential adjustment seat 10, differential adjustment pin 17 does not rotate circumferentially or move axially, ensuring accurate relative position between end 17a of differential adjustment pin 17 and sliding pin groove 4a. Furthermore, the cylindrical shape of end 17a of differential adjustment pin 17 does not interfere with the swing of differential tooth holder 4 or the up and down movement of differential adjustment pin 17, allowing the adjustment process to proceed smoothly. Therefore, the differential adjustment device has a stable structure and can improve the accuracy of adjustment. Moreover, the adjustment is made via motor 11, which does not require stopping the machine, making the adjustment quick and accurate.

[0022] The specific embodiments described herein are merely illustrative examples illustrating the spirit of this utility model. Those skilled in the art to which this utility model pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of this utility model or exceeding the scope defined by the appended claims.

Claims

1. A differential adjustment device for a sewing machine, the sewing machine including a feed shaft (3), a differential tooth holder (4) connected to the feed shaft (3), a sliding pin groove (4a) being provided on the side of the differential tooth holder (4), the differential adjustment device including a motor (11) and a differential adjustment seat (10), the motor (11) being capable of driving the differential adjustment seat (10) to move up and down, characterized in that, A differential adjustment pin (17) is fixedly connected to the differential adjustment seat (10). The end of the differential adjustment pin (17) has a cylindrical end (17a) that is coaxially arranged. The end (17a) is located on the outside of the differential adjustment seat (10) and embedded in the sliding pin groove (4a). The outer peripheral surface of the end (17a) is in contact with the side wall of the sliding pin groove (4a). The feeding shaft (3) drives the differential tooth frame seat (4) to swing around the end (17a).

2. The differential adjustment device for a sewing machine according to claim 1, characterized in that, The differential adjustment pin (17) is a stepped shaft structure. The outer diameter of the end (17a) of the differential adjustment pin (17) is larger than the outer diameter of the main body (17b) of the differential adjustment pin (17). The main body (17b) of the differential adjustment pin (17) is inserted and fixed in the differential adjustment seat (10), and the end (17a) of the differential adjustment pin (17) abuts against the differential adjustment seat (10).

3. The differential adjustment device for a sewing machine according to claim 2, characterized in that, An annular groove (17c) is provided on the outer peripheral surface of the differential adjustment pin (17), and the annular groove (17c) is located between the end (17a) of the differential adjustment pin (17) and the main body (17b) of the differential adjustment pin (17).

4. The differential adjustment device for a sewing machine according to claim 2, characterized in that, A locking screw (18) is threaded onto the differential adjustment seat (10), and the head of the locking screw (18) abuts against the outer peripheral surface of the main body (17b) of the differential adjustment pin (17).

5. The differential adjustment device for a sewing machine according to any one of claims 1-4, characterized in that, A nut (12) is fixedly connected to the differential adjustment seat (10). The rotating shaft (11a) of the motor (11) is inserted into the nut (12) and forms a threaded connection. A motor seat (13) is fixedly connected to the housing of the motor (11). A guide shaft (14) and a limiting rod (15) are provided on the differential adjustment seat (10) and are both parallel to the rotating shaft (11a) of the motor (11). The guide shaft (14) is located between the limiting rod (15) and the rotating shaft (11a) of the motor (11). The guide shaft (14) and the limiting rod (15) are both fixedly connected to the motor seat (13).

6. The differential adjustment device for a sewing machine according to claim 5, characterized in that, The motor base (13) has a protruding connecting block (13a). The bottom end of the guide shaft (14) and the bottom end of the limiting rod (15) are both fixedly connected to the connecting block (13a). The rotating shaft (11a) of the motor (11) is located outside the connecting block (13a). A mounting plate (16) is fixedly connected between the top end of the guide shaft (14) and the top end of the limiting rod (15).

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