JP3136964U - Automatic thread trimming machine - Google Patents

Abstract

An automatic thread trimming device for a sewing machine capable of maintaining a stable linear motion when a movable knife is extended and capable of accurately capturing and cutting a thread.
A first sliding groove including a linear sliding groove and an arc-shaped sliding groove is provided at the rear stage of the knife board, and one end of a rotatable swing arm is coupled to the first sliding groove with a bottom pin and supported. One end of the rack is pivotally connected to the swing arm, the other end is pivotally connected to the middle stage of the scalpel board, and a trap is movably coupled above the scalpel, and one end of the swing arm is connected to the rear end of the trap. Is provided, and is moved by being pushed by a swing arm. After the knife is rotationally shifted around the pivot of the middle stage by installing a support frame, the center of the arc of the arc-shaped sliding groove and the rotation fulcrum of the swing arm are concentric and straight when extended to the movable knife. Maintain the movement and stabilize the yarn catching action.
[Selection] Figure 1

Description

  The present invention relates to a kind of automatic thread trimming apparatus, and more particularly to a thread catching and cutting apparatus applied to a sewing machine.

  Generally, in an automatic thread trimming device of a sewing machine, an actuator drives a catcher to extend it to a sewing needle part, catches the thread, returns the catcher to a female part, and cuts the thread. The stability and accuracy of the thread catching and cutting operations are greatly related to the quality and work efficiency of the sewing, and also affect the service life of the sewing machine and its parts.

  As a known automatic thread trimmer for a sewing machine, there is, for example, Patent Document 1, which is a combination of a plate body, a female arm, a capture arm, a suspension arm set, and a known clamp sheet, a knife, a capture rod, and a swing arm assembly. The main feature is that a suspension arm set consisting of left and right suspension arms is fixed to the plate, and a downward convex column of the left suspension arm is inserted into the left long hole of the capture arm, The convex column is inserted into the hole of the convex ear of the female arm, the female arm is swung around the convex column as a fulcrum, and a long hole is provided at the rear end of the female arm to insert the convex column below the rear end of the capture arm.

  During the swing arm operation, the capture arm is pushed, and the capture arm and the female arm are rotated with the convex column below the right suspension arm as a fulcrum, and then the capture arm is a convex hole under the rear end with a slot at the rear end of the female arm. Is moved to a straight line along the thread catching position. However, the catch arm is driven and moved by rotating the swing arm, and the swing arm exhibits an arc motion. Therefore, when the catch arm moves linearly and extends to catch the yarn, the female arm restrains other guide parts. In this state, it is easy to rotate, does not reach a stable thread trimming position, and the extension operation of the catching arm is unstable. When it becomes impossible to move to the position and the problem of inaccurate bias occurs, there may be a defect that the yarn cannot be caught or cut. In addition, the lever proportional to the distance from the swinging fulcrum of the female arm to the female arm of the female arm and the distance of the swing arm is too large. When the swing arm drives the capture arm, a relatively large force is applied and the frictional force of the capture arm movement is reduced. Large, prone to noise and wear, and prone to equipment failure. This is another drawback.

Taiwan Utility Model Notice 494927

  The main object of the present invention is to provide an automatic thread trimming device for a sewing machine that can maintain a stable linear motion when a movable knife is extended, and that can accurately perform thread capturing and cutting operations.

  Another object of the present invention is to provide an automatic thread trimming device for a sewing machine which can maintain a relative angle between a knife moving direction and a catcher and is stable and can perform a stable thread catching operation.

  Another object of the present invention is to provide an automatic thread trimmer for a sewing machine that reduces the resistance during movement, thereby reducing the output required for the actuator and reducing wear.

The device of claim 1 is an automatic thread trimmer for a sewing machine.
A base, a receiving groove, a swing arm pivoted on the base, the swing arm rotatable about a pivot contact, and a pin provided on one bottom of the swing arm; Base and
A female disc, provided in a receiving groove of the base, provided with a first sliding groove behind the first sliding groove, including a linear sliding groove and an arc-shaped sliding groove, and the swing arm The pin is slidably coupled into the first sliding groove, a pivot hole is provided in the middle part of the knife board, and a step-like partition plate is provided above the front stage, and above the partition plate. A female knife provided with a fixed knife, and an accommodating space formed between the partition plate and the fixed knife;
A catcher, operatively coupled above the scalpel, which includes a movable scalpel frame and a scalpel, and is provided with a concave groove in the rear stage of the movable scalpel frame, the concave groove being provided on the swing arm; The movable knife is fixed to the front end of the movable knife frame, and the movable knife is operatively sandwiched between the stationary knife and the space between the partition plates. A trap,
A support frame, one end of which is pivotally connected to the pivot contact of the swing arm, and the other end is pivoted to the pivot hole of the female board;
Is an automatic thread trimming device for a sewing machine.
According to a second aspect of the present invention, in the automatic thread trimmer for the sewing machine according to the first aspect, a screw hole is provided at the rear of the knife, a linear sliding groove is provided at the rear stage of the movable knife frame, The automatic thread trimmer for a sewing machine is characterized in that it passes through a linear sliding groove at the rear stage of the movable knife frame and is screwed into the screw hole of the knife board.
The invention according to claim 3 is the automatic thread trimmer for the sewing machine according to claim 1, wherein a second linear sliding groove is provided in the middle portion of the scalpel, and a convex projecting downward at the front end of the movable scalpel frame. An automatic thread trimmer for a sewing machine is provided, wherein a column is provided, and the convex column is slidably coupled into the second sliding groove.
According to a fourth aspect of the present invention, there is provided the automatic thread trimmer for a sewing machine according to the first aspect, wherein a compression spring is provided beside the receiving groove of the base, one end of which is fixed on the base, and the other end is the female disk. It is an automatic thread trimmer for a sewing machine, characterized by being placed in
The invention according to claim 5 is the automatic thread trimmer for the sewing machine according to claim 1, wherein a pivot is provided at the bottom of one end of the support frame, and the pivot is pivotally connected to a pivot hole of the female plate through a corrugated washer. This is a sewing machine automatic thread trimmer.
The invention of claim 6 is the automatic thread trimmer for a sewing machine according to claim 1, wherein a positioning pin and a screw hole are provided on the base, and a plurality of positioning holes are provided on the support frame. The automatic thread trimmer for a sewing machine is characterized in that it is fitted with a positioning pin, and a screw is passed through to fix the support frame to a screw hole of the base.
The invention according to claim 7 is the automatic thread trimmer for a sewing machine according to claim 1, wherein the center of the arc of the arc-shaped sliding groove and the pivot contact of the swing arm are rotated after the knife disk rotates at an angle with the pivot as a fulcrum. Is an automatic thread trimmer for a sewing machine, characterized in that

  In the present invention, a first sliding groove including a linear sliding groove and an arc-shaped sliding groove is provided at the rear stage of the knife board, and one end of a rotatable swing arm is coupled to the first sliding groove with a pin at the bottom, and supported. One end of the rack is pivotally connected to the swing arm, the other end is pivotally connected to the middle of the knife board, and a trap is movably coupled above the knife board, and one end of the swing arm is connected to the rear end of the trap. Is provided, and is moved by being pushed by a swing arm. After the knife is rotationally shifted around the pivot of the middle stage by installing a support frame, the center of the arc of the arc-shaped sliding groove and the rotation fulcrum of the swing arm are concentric and straight when extended to the movable knife. Maintains movement and stabilizes and secures the yarn catching action. In addition, the rotating fulcrum of the knife board is provided between the knife and the arc-shaped sliding groove to reduce the lever ratio between the knife end and the swing arm end, reduce the resistance force between the pin and the first sliding groove wall surface, and is required for the actuator. Reduce output as well as pin wear.

  In the present invention, a swing arm is pivotally mounted on a base, the swing arm is capable of rotating and swinging with a pivot contact as a fulcrum, and a pin is provided at one bottom of the swing arm. A knife plate is provided on the base, a first sliding groove is provided behind the knife plate, the first sliding groove includes a linear sliding groove and an arc-shaped sliding groove, and the pin of the swing arm is the first. Actively coupled in one sliding groove. A step-like partition plate is provided above the knife plate, a fixed knife is provided above the partition plate, and an accommodation space is formed between the partition plate and the fixed knife. The catcher is movably coupled to the upper part of the knife board, and includes a movable knife frame and a movable knife, and is provided with a concave groove at the rear stage of the movable knife frame, and the concave groove is provided with one end of the swing arm pin. The movable knife is fixed to the front end of the movable knife holder, and the movable knife is operatively sandwiched in a storage space between the fixed knife and the partition plate. A pivot hole is provided in the middle part of the scalpel, and the support frame is pivoted to the pivot hole at the pivot of one end thereof, and the other end is pivoted to the pivot contact of the swing arm.

  In addition, a screw hole is provided at the rear of the knife, a linear sliding groove is provided at the rear stage of the movable knife frame, and a position limiting screw is screwed into the screw hole of the knife through the linear sliding groove, The linear sliding groove is movable along the position limiting screw. A straight second sliding groove is provided in the middle part of the knife plate, a convex column extending downward is provided at the front end of the movable knife frame, and the convex column is slidably coupled into the second sliding groove. Thus, it can be moved along the second sliding groove.

  Since the support frame is pivotally connected to the swing arm and knife board, when the swing arm rotates under the drive of the actuator, the movable knife frame is pushed and moved forward, and is rotated with the knife board to cut the thread. Make an angle. At this time, the center of the arc of the arc-shaped sliding groove of the scalpel plate is concentric with the pivot contact of the swing arm, so that when the swing arm continues to move forward, the scalpel plate and the fixed scalpel remain stationary. In addition, the linear movement can be maintained when the movable knife is extended, and the movable knife can be stably and accurately moved to the yarn catching position.

  In addition, a positioning pin is provided on the base, a positioning hole is provided in the support frame, and the pivot position of the support frame is fixed by being fitted to the positioning pin. The relative angle of the needle is maintained and unchanged, and the yarn catching operation is further stabilized.

  Furthermore, the knife plate rotates around the pivot of the middle support frame, and the fulcrum is provided between the fixed knife and the arc-shaped sliding groove, thereby reducing the lever proportionality between the knife end and the transmission pin end. The resistance force between the pin and the wall surface of the first sliding groove is reduced, and the movement of the pin is made smoother, thereby reducing the output required for the actuator and reducing the wear of the pin.

  Please refer to FIG. The present invention includes a base 1, a knife board 2, a trap 3 and a support rack 4.

  A plurality of coupling holes are provided in the periphery of the base 1 and used for attaching the base 1 to a sewing machine base. A housing groove 10 is provided in the middle stage, and a knife board 2 and a catcher 3 are installed. A compression spring 16 is provided beside 10, and one end of the compression spring 16 is fixed to the base 1 with a screw, and the other end is placed on the knife board 2 to control the knife board 2. A swing arm 11 is pivoted above the base 1, and one end of the swing arm 11 is driven by an actuator (not shown) and can be rotated with the pivot contact 12 as a fulcrum. A pin 13 is provided at the bottom of the knife and is operatively coupled to the scalpel 2. Further, two screw holes 14 and a projecting positioning pin 15 are provided at the front position of the base 1.

  The female plate 2 is provided in the receiving groove 10 of the base 1, and a first sliding groove 20 is provided at the rear thereof. The first sliding groove 20 includes a rear linear sliding groove 201 and a front arc-shaped sliding groove 202. Consists of. The first sliding groove 20 accommodates the pin 13 of the swing arm 11 and moves the pin 13 in the first sliding groove 20. A screw hole 21 is provided behind the knife board 2. A pivot hole 22 and a second sliding groove 23 in a straight state are provided in the middle part of the knife board 2, and the support frame 4 is pivoted in the pivot hole 22. A partition plate 24 is provided above the front of the knife plate 2, a fixed knife 25 is provided above the partition plate 24, and the partition plate 24 and the fixed knife 25 are fixed to the knife plate 2 with screws and the partition plate 24. Is formed in a staircase plate shape, and an accommodation space is formed between the partition plate 24 and the fixed knife 25. Two thread clamping leaf springs 26, leaf spring pushing plates 27, and contact plates 28 are separately provided below the knife board 2.

  The catcher 3 includes a movable knife frame 31 and a movable knife 32, and the catcher 3 is provided above the knife board 2. A concave groove 311 and a linear sliding groove 312 are provided at the rear stage of the movable knife frame 31, and the concave groove 311 accommodates one end of the swing arm 11, and the movable knife frame 31 moves in response to the push of the swing arm 11. The position limiting screw 29 passes through the linear sliding groove 312 and is screwed into the screw hole 21 at the rear stage of the scalpel 2, the movable scalpel frame 31 is operatively coupled to the scalpel 2, and protrudes downward at the front end of the scalpel frame 31. An extending convex column 313 is provided, and the convex column 313 is operatively coupled into the second sliding groove 23 in the middle position of the knife board 2. The movable knife 32 is fixed to the front end of the movable knife frame 31 with two screws, and the movable knife 32 is movably sandwiched between the fixed knife 25 and the partition plate 24.

  One end of the support frame 4 is pivotally connected to the pivot contact 12 of the swing arm 11, and the other end is pivotally connected to the pivot hole 22 of the scalpel board 2 through the corrugated washer 41. Four positioning holes 42 are provided in the support rack 4, and two positioning pins 15 of the base 1 are fitted into two intermediate positioning holes 42, and the two outer positioning holes 42 are formed on the support rack 4 with screws. The first screw hole 14 is fixed.

  With the above-described structure, as shown in FIG. 2, when the movable knife 32 is in the standby position and is not extended, the pin 13 of the swing arm 11 is located at the rear end of the linear sliding groove 201 of the knife board 2, The position limiting screw 29 is located at the front end of the linear sliding groove 312 of the movable knife frame 31, and the convex column 313 of the movable knife frame 31 is located at the rear end of the second sliding groove 23 of the knife board 2.

  When it is necessary to perform the thread catching and cutting operations, as shown in FIG. 3, the fixed knife 25 rotates by a certain angle to reach the thread trimming position, and the movable knife 32 extends by a certain distance. When the actuator drives the swing arm 11 and rotates the pivot contact 12 as a fulcrum, the swing arm 11 rotates forward and pushes the movable knife frame 31 to move it forward, and the movable knife 32 moves forward. Extend a certain distance. The pin 13 of the swing arm 11 is slidably coupled in the first sliding groove 20 of the knife board 2, and the support rack 4 is positioned and fixed by the positioning pin 15, so that the knife board 2 is driven and supported thereby. The pivot 4 is rotated about the pivot 40 as a fulcrum, shifted by an angle, and the fixed knife 25 is also rotated by an angle to reach the thread trimming position. At the same time, the pin 13 of the swing arm 11 moves to the arc-shaped sliding groove 202 along the linear sliding groove 201. At this time, the angle after the rotational movement of the knife board 2 is concentric with the center of the circle of the arc-shaped sliding groove 202 and the pivot contact 12 of the swing arm 11. The movable knife frame 31 moves forward, rotates at a certain angle simultaneously with the knife board 2, and the linear sliding groove 312 moves along the position limiting screw 29 at the same time, and the position limiting screw 29 moves to the front end of the linear sliding groove 312. Further away, the convex column 313 of the movable knife frame 31 also moves a certain distance forward along the second sliding groove 23 of the knife board 2.

  As shown in FIG. 4, when the swing arm 11 continues to rotate and reaches the front end of the arc-shaped slide groove 202, the center of the arc of the arc-shaped slide groove 202 and the pivot contact 12 of the swing arm 11 are concentric. Therefore, the pin 13 moves along the arc-shaped sliding groove 202 of the knife board 2, the knife board 2 maintains the same angle and does not move any more, the stationary knife 25 is also fixed and immovable, The movable knife frame 31 moves forward in response to the push of the swing arm 11. The linear sliding groove 312 of the movable knife frame 31 continues to move forward at the same angle along the position limiting screw 29 of the knife board 2 so that the position limiting screw 29 reaches the rear end of the linear sliding groove 312 and the convex of the front end. The column 313 also drives the movable knife frame 31 to move forward along the second sliding groove 23 to the front end of the second sliding groove 23, and drives the movable knife 32 to advance linearly at the same angle. The yarn 5 is captured accurately by reaching the capturing position. When the swing arm 11 is pushed in the opposite direction, the movable knife 32 captures the thread 5 and pulls it to the fixed knife 25 to cut the thread 5.

As can be seen from the above, the present invention has the following advantages:
1. Since the support frame 4 is pivotally connected to the swing arm 11 and the knife disk 2, when the knife disk 2 rotates to the thread trimming angle, the center of the arc of the arc-shaped sliding groove 202 is the pivot of the swing arm 11. The concentricity with the contact point 12 can be maintained, so that when the swing arm 11 continues to move forward, the scalpel 2 and the fixed scalpel 25 hold the immovable state, and when the movable scalpel 32 extends, the linear motion is performed. It can be maintained and moved to the yarn catching position stably and accurately.
2. The knife disk 2 rotates with the pivot 40 of the support frame 4 as a fulcrum, and the fulcrum is provided between the fixed knife 25 and the arc-shaped sliding groove 202 to reduce the leverage of the knife end and the transmission pin 13 end. This reduces the resistance between the pin 13 and the wall surface of the first sliding groove 20 and makes the movement of the pin 13 smoother, thereby reducing the required output of the actuator and reducing pin wear.

It is an exploded view of the present invention. It is a thread trimming operation | movement display figure (1) of this invention. It is a thread trimming operation | movement display figure (2) of this invention. It is a thread trimming operation | movement display figure (3) of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base 10 Accommodating groove 11 Swing arm 12 Pivoting contact 13 Pin 14 Screw hole 15 Positioning pin 16 Compression spring 2 Female board 20 First sliding groove 201 Linear sliding groove 202 Arc shaped sliding groove 21 Screw hole 22 Pivoting hole 23 Second Slide groove 24 Separator plate 25 Fixed knife 26 Thread pinching plate spring 27 Plate spring push plate 28 Contact plate 29 Position limit screw 3 Trap 31 Movable frame 311 Concave groove 312 Straight slide groove 313 Convex column 32 Movable knife 4 Support frame 40 Axis 41 Corrugated washer 42 Positioning hole 5 Thread

Claims (7)

In the automatic thread trimmer of the sewing machine,
A base, a receiving groove, a swing arm pivoted on the base, the swing arm rotatable about a pivot contact, and a pin provided on one bottom of the swing arm; Base and
A female disc, provided in a receiving groove of the base, provided with a first sliding groove behind the first sliding groove, including a linear sliding groove and an arc-shaped sliding groove, and the swing arm The pin is slidably coupled into the first sliding groove, a pivot hole is provided in the middle part of the knife board, and a step-like partition plate is provided above the front stage, and above the partition plate. A female knife provided with a fixed knife, and an accommodating space formed between the partition plate and the fixed knife;
A catcher, operatively coupled above the scalpel, which includes a movable scalpel frame and a scalpel, and is provided with a concave groove in the rear stage of the movable scalpel frame, the concave groove being provided on the swing arm; The movable knife is fixed to the front end of the movable knife frame, and the movable knife is operatively sandwiched between the stationary knife and the space between the partition plates. A trap,
A support frame, one end of which is pivotally connected to the pivot contact of the swing arm, and the other end is pivoted to the pivot hole of the female board;
An automatic thread trimmer for a sewing machine, characterized by comprising   2. The automatic thread trimmer for a sewing machine according to claim 1, wherein a screw hole is provided at the rear of the knife, a linear sliding groove is provided at the rear stage of the movable knife frame, and the position limiting screw is arranged at a linear slip at the latter stage of the movable knife frame. An automatic thread trimmer for a sewing machine, wherein the automatic thread trimmer is threaded into a screw hole of the knife board through a groove.   2. The automatic thread trimmer for a sewing machine according to claim 1, wherein a second linear sliding groove is provided in the middle portion of the knife plate, and a convex column protruding downward is provided at the front end of the movable knife frame. An automatic thread trimmer device for a sewing machine, wherein a column is slidably coupled in the second sliding groove.   2. The automatic thread trimmer for a sewing machine according to claim 1, wherein a compression spring is provided beside the receiving groove of the base, one end of which is fixed on the base, and the other end is placed on the knife board. An automatic thread trimmer for sewing machines.   2. The automatic thread trimmer for a sewing machine according to claim 1, wherein a pivot is provided at the bottom of one end of the support frame, and the pivot is pivotally connected to a pivot hole of the female plate through a corrugated washer. Automatic thread trimmer for sewing machine.   The automatic thread trimmer for a sewing machine according to claim 1, wherein positioning pins and screw holes are provided on the base, a plurality of positioning holes are provided on the support frame, and the positioning holes are respectively fitted with the positioning pins. And an automatic thread trimmer for a sewing machine, wherein the screw is passed through and the support frame is fixed to the screw hole of the base.   2. The automatic thread trimmer for a sewing machine according to claim 1, wherein the center of the arc of the arc-shaped sliding groove and the pivot contact of the swing arm are concentric after the knife disk rotates at an angle with the pivot as a fulcrum. An automatic thread trimmer for sewing machines.

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