CN101709537A - Line cutting structure for sewing machines - Google Patents

Abstract

The invention relates to a thread cutting structure for a sewing machine. The existing tangent structure is complicated, the installation and adjustment are difficult, the cost is high, and the reset assembly is complicated, so the operation noise is relatively large. The invention provides a thread tangent structure for sewing machines. The electromagnet in the electromagnet assembly is vertically and fixedly connected to the installation frame, and its action end is located at the lower part; The driven end is spherically connected with one end of the cutter connecting rod in the cutter assembly through a spherical long pin, and the other end of the cutter connecting rod is spherically connected with a spherical short pin; It is fixedly arranged on the lower shaft, and the spring of the reset assembly is arranged between the mounting frame in the electromagnet assembly and the driving end of the driving rod. The invention adjusts the action direction of the original electromagnet assembly from the principle of action, so the structure is simple and the action is more stable and reliable.

Description

Thread tangent structure for sewing machine

technical field

The invention relates to the technical field of sewing machine equipment, in particular to a thread cutting structure for a sewing machine.

Background technique

The thread cutting structure for existing sewing machines usually consists of an electromagnet assembly, a thread cutting assembly, a cam action assembly and a reset assembly. The electromagnet assembly is composed of an electromagnet moving in the horizontal direction and a mounting frame; The driving rod, the disc-shaped tangent cam and the cam crank assembly, the tangent cam is arranged on the lower shaft, and the tangent roller is arranged on the cam crank assembly; the tangent assembly includes a cutter shaft, a cutter connecting rod, and a cutter drive crank and the cutter frame, the cutter connecting rod and the cutter frame are connected by short pins, and the cam crank assembly is arranged on the cutter shaft; a reset assembly is also arranged on the cutter shaft. When working, the thread tangent electromagnet acts horizontally, and the driving frame moves vertically to push the tangent roller on the cam crank assembly to engage with the tangent cam, which drives the cam crank assembly to rotate, and then drives the cutter shaft to rotate, and the cutter shaft drives the thread tangent assembly The cutter drives the crank, and the cutter drives the crank and then drives the cutter connecting rod to move linearly to complete the tangent action. After finishing the thread cutting, after the thread cutting electromagnet release signal is given, the cam crank assembly resets it through the resetting device, and the thread cutting assembly returns to its original position at the same time.

It can be seen that the existing structural mechanism is complicated, installation and adjustment are difficult, and the cost is high. At the same time, because complex reset components are required, relatively large noise is generated during operation, which affects the environment.

Contents of the invention

The present invention provides a thread tangent structure for sewing machines to overcome the problems of complex mechanism, difficult installation and adjustment, high cost and high noise in the prior art.

In order to overcome the problems existing in the prior art, the technical solution of the present invention is: a thread cutting structure for a sewing machine, comprising a lower shaft, an electromagnet assembly, a cam action assembly, a thread cutting assembly and a reset assembly, and the electromagnet assembly is fixed by a mounting frame and a vertical It consists of an electromagnet connected to the mounting frame. The thread cutting assembly includes a cutter link and a cutter frame connected by a short pin. The cam action assembly includes a thread cutting cam, a driving rod and a thread cutting roller. The special feature is that :

The electromagnet in the electromagnet assembly is vertically fixedly connected to the mounting frame, and its action end is located at the lower part; the driving rod in the cam action assembly is arranged horizontally, and the driving end of the driving rod is hinged with the action end of the tangent electromagnet through a spherical connecting pin. The moving end is spherically connected with one end of the cutter connecting rod in the cutter assembly through a spherical long pin, and the other end of the cutter connecting rod is spherically connected with a spherical short pin; Cylindrical cam mechanism, the tangent cam is fixedly arranged on the lower shaft, and the motion trajectory of the tangent roller matches the tangent cam; the reset assembly includes a spring, and the spring is arranged between the mounting bracket in the electromagnet assembly and the driving end of the drive rod.

The thread cutting structure for the sewing machine further includes a thread releasing mechanism, and the thread releasing mechanism includes a thread releasing steel rope fixed on the driving end of the driving rod.

Above-mentioned slack wire steel rope can be fixed on the driving bar by steel rope pressing plate.

Compared with the prior art, the present invention adjusts the action direction of the original electromagnet assembly from the principle of action, and at the same time, the action of the cutter connecting rod is changed from linear motion to arc motion, so it has the following advantages:

1. Simple structure: the cutter driving crank is reduced in the thread cutting assembly, and the cam action assembly is directly connected with the cutter connecting rod in the thread cutting assembly, which reduces the number of transmission parts and makes the action more reliable; the cam action assembly uses a cylindrical cam The mechanism is the main structure. Compared with the original structure, the complex cam crank assembly is reduced, and the installation and adjustment are more convenient; the simplification of the reset mechanism is more prominent, and the complex mechanism is replaced by a spring, and the action is more reliable.

2. The thread trimming action is more stable and reliable: the thread trimming cam is designed as a cylindrical cam mechanism, and when the roller meshes with the thread trimming cam 5 (the thread trimming roller enters the cam groove of the thread trimming cam 5), it can provide greater torque and simultaneously cut the knife The connection between the connecting rod and both ends is connected by a ball, which reduces the resistance of the mechanism itself and provides more sufficient force when cutting the thread. While the thread tangent is stable and reliable, it also improves the success rate of thick thread cutting.

3. Low noise: The ball connection structure at both ends of the cutter link can effectively reduce vibration and noise. At the same time, the reset device of the thread cutting mechanism is very simple. Only one spring is needed to complete the reset, and the sound is also greatly reduced.

4. Low cost: the cost is reduced by about 20%.

Description of drawings

Fig. 1 is the schematic diagram of original structure;

Fig. 2 is the A direction view of Fig. 1;

Fig. 3 is a structural representation of the present invention;

Fig. 4 is the B direction view of Fig. 3;

Fig. 5 is a view from the direction C of Fig. 3 .

The reference signs are explained as follows:

1-mounting frame, 2-spring pin, 3-spring, 4-electromagnet, 5-tangent cam, 6-cutter link, 7-spherical short pin, 8-cutter holder, 9-spherical long pin, 10 -drive frame, 11-steel rope pressing plate, 12-spherical connecting pin, 13-tangential roller, 14-loose wire rope, 15-lower shaft, 16-resetting assembly, 17-cutter shaft.

Detailed ways

The present invention will be described in detail below in conjunction with the accompanying drawings.

See Figures 1 and 2. The thread cutting structure of the existing sewing machine usually consists of an electromagnet assembly, a thread cutting assembly, a cam action assembly and a reset assembly.

Among them: the electromagnet assembly is composed of an electromagnet 4 moving in the horizontal direction and a mounting frame 1; the cam action assembly includes a drive rod 10 arranged in a vertical direction, a disc-shaped tangent cam 5 and a cam crank assembly, and the tangent cam 5 is arranged on the lower shaft 15, the cam crank assembly is provided with a tangent roller 13; the wire assembly includes a cutter shaft 17, a cutter connecting rod 6, a cutter driving crank and a cutting knife holder 8, and the cutter connecting rod 6 and the cutter holder 8 pass through a short Pin connection, the cam crank assembly is arranged on the cutter shaft 17, meanwhile, the reset assembly 16 is also arranged on the cutter shaft 17.

See Figure 3 to Figure 5. A thread cutting structure for a sewing machine provided by the present invention includes a lower shaft 15, an electromagnet assembly, a cam action assembly, a thread cutting assembly, a reset assembly and a thread loosening mechanism.

Among them: the electromagnet assembly is composed of a mounting frame 1 and an electromagnet 4 vertically fixedly connected to the mounting frame 1. The cutter connecting rod 6 and the cutter frame 8 connected by the short pin 7; the cam action assembly includes the tangent cam 5, the tangent roller 13 and the driving rod 10, the driving rod 10 is arranged horizontally, and its driving end is connected with the tangential solenoid through the spherical connecting pin 12. The action end of iron 4 is hinged, and its driven end is spherically connected with one end of the cutter connecting rod 6 in the cutter assembly by the spherical long pin 9, and the other end of the cutter connecting rod 6 is connected spherically with the spherical short pin 11; The tangent roller 13 is arranged on the driving end of the driving rod 10, the tangent cam 5 is a cylindrical cam mechanism, and the tangent cam 5 is fixedly arranged on the lower shaft 15, and the movement track of the tangent roller 13 is matched with the tangent cam 5; the reset assembly includes Spring 3, spring 3 is arranged between mounting frame 1 and the driving end of driving rod 10 in the electromagnet assembly; The steel rope pressing plate 11 is fixed on the driving rod 10 .

When the present invention worked: the lower shaft 15 rotated, and the tangent cam 5 followed the rotation. When it is necessary to cut the thread, after the system gives the ferromagnetic signal, the electromagnet 4 fixed on the mounting frame 1 is attracted, and the driving rod 10 is driven to swing, and the driving rod 10 drives the thread cutting roller 13 to move into the thread cutting cam 5, and the thread cutting roller 13 follows the movement of the thread-cutting cam 5 and transmits the action to the drive rod 10, the drive rod 10 drives the cutter connecting rod 6 to swing through the spherical long pin 9, and the cutter connecting rod 6 drives the cutter frame 8 to rotate through the spherical short pin 7. Rotary movement of the lower shaft 15. While the electromagnet 4 is sucked in, the active end of the driving rod 10 moves to stretch the spring 3;

After the cutter frame 8 drives the cutter to complete the thread-cutting action, the thread-cutting electromagnet 4 is released. At this time, the thread-cutting roller 13 returns and exits from the thread-cutting cam 5, and the stretched spring 3 drives the driving rod 10 to swing counterclockwise due to the elastic force. Immediately passed to the cutter connecting rod 6 and the cutter frame 8 to return to the original position, completing a thread cutting action;

When tangent, will cooperate with tangent timing to give thread loosening, when drive rod 10 swings anticlockwise, drive thread loosening steel rope 14 action, realize thread loosening function.

Claims (3)

1. line cutting structure for sewing machines, comprise lower shaft, electromagnet assembly, cam action assembly, tangent line assembly and reset assembly, electromagnet assembly is made up of the electromagnet (4) that installing rack (1) and vertical fixing are connected on the installing rack (1), described tangent line assembly comprises cutter connecting rod (6) and the cutoff knife rack (8) that connects by short pin, described cam action assembly comprises tangential cam (5), drive rod and tangent line roller (13), it is characterized in that:

Electromagnet in the described electromagnet assembly (4) vertical fixing is connected on the installing rack (1), and its motion end is positioned at the bottom;

Drive rod in the described cam action assembly is horizontally disposed with, the drive end of drive rod is hinged by the motion end of spherical connecting pin and tangent line electromagnet (4), its driven end is connected by have strong market potential an end sphere of the cutter connecting rod (6) in (9) and the cutter assembly of sphere, and the other end of cutter connecting rod (6) is connected with spherical short pin (7) sphere;

Described tangent line roller (13) is arranged on the drive end of drive rod, and tangential cam (5) is a cylindrical cam mechanism, and tangential cam (5) is fixedly set on the lower shaft, and the movement locus of tangent line roller (13) matches with tangential cam (5);

Described reset assembly comprises spring (3), and spring (3) is arranged between the drive end of installing rack in the electromagnet assembly (1) and drive rod.

2. a kind of line cutting structure for sewing machines according to claim 1 is characterized in that: comprise that also thread releasing mechanism, thread releasing mechanism comprise the loose ends steel cable (14) on the drive end that is fixed in drive rod.

3. a kind of line cutting structure for sewing machines according to claim 2 is characterized in that: described loose ends steel cable (14) is fixed on the drive rod by steel cable pressing plate (11).

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