CN111663250A - Handheld sewing machine with flying shuttle bobbin thread and motion mode thereof - Google Patents

Abstract

The invention discloses a hand-held sewing machine with a shuttle bobbin thread and its movement method, comprising a linkage mechanism, a base and a pressure beam, wherein a sewing machine needle is installed at one end of the pressure beam to be screwed into a needle-fixing bolt for fixing, and a side of the pressure beam is provided with an adjusting beam. The line button, the line adjustment button is connected to the wire wheel in the pressure beam, the abdomen of the pressure beam is connected to one end of the compression spring, the other end of the compression spring is connected to the base, the pressure beam is inserted into the base and the shaft is hinged, and a linkage mechanism is installed in the base, and the linkage mechanism is connected to the pressure beam , the presser beam is fixedly connected to the presser foot. The movement mode is that the pressing beam drives the linkage mechanism, and the present invention has upper and lower double threads, flexible operation, good sewing effect, and easy portability.

Description

A hand-held sewing machine with shuttle bottom thread and its movement mode

technical field

The invention belongs to the technical field of machinery, and in particular relates to a hand-held sewing machine with a shuttle bottom thread, and also relates to a movement mode of the sewing machine.

Background technique

Sewing machine is the most basic sewing equipment in garment production and is used in almost all garment production. A sewing machine is mainly a machine that uses one or more sewing threads to form one or more stitches on the sewing material to interweave or sew one or more layers of sewing material. Sewing machines are mainly used in clothing, luggage, leather, shoemaking and other industries. They can also sew cotton, linen, silk, wool, man-made fibers and other fabrics, plastics, paper and other products. With the simplest stitches, they can be sewn neatly and beautifully. , uniform, flat and firm stitches, fast sewing speed, easy operation and easy to understand.

At present, in the sewing machine industry, sewing machines have been very developed, with a wide variety of models and styles. But the general classification is divided into two categories, namely, household sewing machines and industrial sewing machines. The popularity of home sewing machines can be said to be unprecedented, and it has become a necessary daily necessities for people to sew clothes. Home sewing machines are generally composed of a head part, a platen part, and a frame part. This type of sewing machine has a complex structure, many parts, large volume and high cost. In use, for the user, although it is not too advanced technology, but also must have certain basic knowledge and skills to operate. Especially before each use, it is necessary to select the type of thread and sewing needle to be used according to the properties of the item to be sewn, such as the material, hardness and thickness of the item, and then according to the mentioned situation, and then accurately Install and debug, so that it is in a relatively fixed position, and then the sewing operation can be carried out.

General household sewing machines, although some have been made very small, exquisite and lightweight, are also operated in a relatively fixed location during use, which is still inconvenient to carry, let alone operate and use in the process of carrying. Therefore, for simple sewing, people often prefer to sew by hand rather than use a sewing machine, especially for people who do not understand the operation method of the sewing machine, or people who mail small items, travel, and simple sewing for small families. . Hand-stitching is obviously inefficient, time-consuming and labor-intensive, and the quality of the sewing is poor, very irregular, and unreliable.

In order to minimize the inconvenience caused by this pure manual labor, many people with lofty ideals have proposed various manual micro-sewing machines and made products popular in the market. The structural style of its door is composed of the body, the upper bridge, the force rod, the lever, the spring, etc., and the combined swinging cam hook and hook realizes bottomless sewing. The simplest one is that there is no combined swinging cam hook. Hooking is done with a stationary snap hook. But these products are all single-thread sewing. The stitches of single-thread sewing are in the form of continuous sleeves, and once the thread ends are pulled out, it is easy to be detached, which is the biggest disadvantage of single-thread sewing. In addition, during the operation of these manual micro-sewing machines, some of them are inflexible in operation, and thread jamming often occurs, and the sewing effect is rough.

SUMMARY OF THE INVENTION

The purpose of the present invention is to overcome the above shortcomings and provide a hand-held sewing machine with a shuttle bottom thread, which is flexible in operation, good in sewing effect and easy to carry.

Purpose of the present invention and solving its main technical problem are to adopt following technical scheme to realize:

A hand-held sewing machine with a flying shuttle bottom thread of the present invention includes a linkage mechanism, a base, and a pressure beam, wherein a sewing machine needle is installed at one end of the pressure beam to be screwed into a fixed needle bolt for fixing, and a thread adjustment button is installed on the side of the pressure beam to adjust the thread. The button is connected to the wire wheel in the pressure beam, the abdomen of the pressure beam is connected to one end of the compression spring, the other end of the compression spring is connected to the base, the pressure beam is clamped into the base and inserted into the shaft to be hinged, a linkage mechanism is installed in the base, the linkage mechanism is connected to the pressure beam, and the pressure beam is fixedly connected presser foot.

The linkage mechanism is composed of a fork, a splint A, a crank A, a branch lever A, a feed dog seat, a cloth feed dog, a splint B, a branch lever B, a cam, a shuttle, a shuttle seat, a crank B, The power rod, crank C, branch-tie rod B, crank-turn D are composed. The power rod and crank C are respectively clamped between the splint A and the splint B. The upper end of the crank C is hinged to one end of the branch-tie rod B, and the other end of the branch-tie rod B is hinged One end of the crank A, the crank A is inserted into the pin to connect the splint A and the splint B, the other end of the crank A is hinged to one end of the branch pull rod A, and the other end of the branch pull rod A is hinged to the feeder seat. For the cloth teeth, there are two cams placed under the feed dog seat. The two cams are inserted into the pins to connect the splint A and the splint B respectively. The two cams are hinged on the two ends of the branch and tie rod B, and one end of the branch tie rod B is hinged with the crank D. , the crank D is inserted into the pin to connect the splint A and the splint B. The convex strips set on the splint A and the splint B are placed with a shuttle seat, a shuttle is placed in the shuttle seat, and one end of the crank B is inserted under the shuttle seat. , the other end of the crank B is inserted into the pin to connect the splint A and splint B, the lower end of the power rod is inserted into the pin to connect to one end of the fork, the middle of the fork is inserted into the pin to connect the splint A and the splint B, and the other end of the fork is set to rotate The lever provided at the lower end of the pressure beam is inserted into the sleeve.

A movement mode of a hand-held sewing machine with a shuttle bottom thread, wherein;

1) When the feed dog is in the highest position, the cam is in an upright state, the shuttle is in the right position, and the shuttle seat is in the right position. When the sewing work is performed, when the beam is pressed down by hand, the shifting fork drives the power rod to move down, and the power rod The contact shoulder i touches the contact h of the crank D, so that the crank D moves the branch rod B to the right, and the cam rotates clockwise around its own axis under the drive of the branch rod B until it rotates to its lowest position, so that The feed dog seat shown falls vertically below the sewing plane, and the presser foot and cloth at this time also fall with the feed dog seat, and finally land on the base plane;

2) When the power rod continues to move downward, the contact shoulder f of the power rod touches the contact point e, the contact point e drives the crank C to move, the crank C drives the branch rod B to move, and the branch rod B drives the crank A, The crank A drives the branch rod A to push the feed dog seat to the right end point, and wait for the next rise;

3) At the same time, the contact shoulder b of the power lever touches the contact point a, and the contact point a drives the crank B to rotate counterclockwise, and the crank B drives the shuttle seat to make the shuttle fly from the right position to the left position shown;

4) When the needle tip of the sewing machine needle starts to move downward from the top dead center until the needle tip of the sewing machine is 1 mm away from the presser foot shown, the actions 1), 2) and 3) have been completed. This state is always the case until the needle tip of the sewing machine reaches the bottom dead center.

5) When the hand releases the pressure beam, the sewing machine will perform the lower half sewing work by the elastic force of the compression spring. Under the action of the compression spring, the fork moves the power rod to move upward, and the contact on the power rod c is already below the contact point a, when the power lever moves upward, the contact point c will touch the contact point a, and the crank B will drive the shuttle seat to make the shuttle fly from the left position to the right position as shown in the figure, and the flying is completed. The purpose of the shuttle passing through the line;

6) When the contact shoulder i on the power rod has been below the contact h, and the power rod moves upward, the contact shoulder g will touch the contact h, driving the crank D to rotate in the counterclockwise direction, thereby pulling the branch rod B to the Move to the right to make the cam rotate to the left according to its own axis to become an upright state, and lift the presser foot and the feed dog seat vertically upward to prepare for the horizontal feeding;

7) When the feed dog seat is in an upright state, the contact shoulder d on the power rod just touches the contact point e from the bottom to the top, thereby driving the crank C to drive the branch rod B to move, and the branch rod B drives the crank A. The crank A drives the branch rod A to move the feed dog seat horizontally to the left to complete the work of feeding the cloth forward;

8) When the sewing machine needle starts to lift up at the bottom dead center, when the needle tip of the sewing machine needle rises by 1.5 mm, the upper thread on the sewing machine needle forms a thread sleeve, which is the action of shuttle threading. At this time, the sewing machine needle continues to rise, When the height of the needle tip of the sewing machine exceeds the upper plane of the sewing machine needle presser foot by 2 mm, it is the vertical upward movement of the feed dog seat and the horizontal left feed movement.

The shuttle is olive-shaped, and can move left and right on the groove set on the shuttle seat.

The shuttle seat can move left and right.

The power rod has several convex curved shapes and can move up and down.

Compared with the prior art, the present invention has obvious beneficial effects; it can be seen from the above technical solutions that a sewing machine needle is installed at one end of the pressure beam to be screwed into a needle-fixing bolt, and a thread adjustment button is installed on the side of the pressure beam, and the thread adjustment button is connected The wire wheel in the pressure beam, the belly of the pressure beam is connected to one end of the compression spring, the other end of the compression spring is connected to the base, the pressure beam is inserted into the base and inserted into the shaft to be hinged, a linkage mechanism is installed in the base, the linkage mechanism is connected to the pressure beam, and the pressure beam is fixedly connected to the presser foot . When the feed dog is in the highest position, the cam is in the upright state, the shuttle is in the upright state, and the shuttle seat is in the right position. When the sewing work is performed, when the beam is pressed down by hand, the shifting fork drives the power rod to move down, and the power rod touches the shoulder i touches the contact h of the crank D, so that the crank D moves the branch and tie rod B to the right, and the cam rotates clockwise around its own axis under the drive of the branch and tie rod B until it rotates to its lowest position, so that the shown The feed dog seat falls vertically below the sewing plane, and the presser foot and cloth at this time also fall with the feed dog seat, and finally land on the base plane;

When the power rod continues to move downward, the contact shoulder f of the power rod touches the contact point e, the contact point e drives the crank C to move, the crank C drives the branch rod B to move, the branch rod B drives the crank A, and the crank A moves Drive the branch pull rod A to push the feed dog seat to the right end point, and wait for the next rise; at the same time, the contact shoulder b of the power rod touches the contact point a, and the contact point a drives the crank B to rotate counterclockwise, and the crank B Drive the shuttle seat to make the shuttle fly from the right position to the left position shown; when the needle tip of the sewing machine starts to move downward from the top dead center, until the needle tip of the sewing machine is 1 mm away from the presser foot shown, 1) , 2), 3), the action has been completed, until the needle tip of the sewing machine reaches the bottom dead center, all in this state. When the hand releases the pressure beam, the sewing machine will perform the lower half sewing work by the elastic force of the compression spring. Under the action of the compression spring, the shift fork moves the power rod upward, and the contact c on the power rod is already in Below the contact point a, when the power lever moves upward, the contact point c will touch the contact point a, and the crank B will drive the shuttle seat to make the shuttle fly from the left position to the right position as shown in the figure, completing the shuttle passing through. The purpose of going on line; when the contact shoulder i on the power rod is below the contact h and the power rod moves upward, the contact shoulder g will touch the contact h, driving the crank D to rotate in the counterclockwise direction, thereby pulling the branch rod B Move to the right, make the cam rotate to the left according to its own axis and become an upright state, and lift the presser foot and the feed dog seat vertically upward to prepare for the horizontal feeding; when the feed dog seat is in an upright state, the power The contact shoulder d on the rod just touches the contact point e from the bottom to the top, so as to drive the crank C to drive the branch tie rod B to move, the branch tie rod B drives the crank crank A, and the crank crank A drives the branch tie rod A to move the feed dog seat horizontally to the left When the sewing machine needle starts to lift upward at the bottom dead center, when the needle tip of the sewing machine needle rises by 1.5 mm, the upper thread on the sewing machine needle forms a thread cover, which is the action of shuttle threading. At this time, the sewing machine needle continues to rise, and when the height of the needle tip of the sewing machine needle exceeds the upper plane of the sewing machine needle presser foot by 2 mm, it is the vertical rising action of the feed dog seat and the horizontal left feeding action. The upper and lower double lines are realized, the operation is flexible, the sewing effect is good, and it is easy to carry.

Description of drawings

Fig. 1 is the structural representation 1 of the present invention;

Fig. 2 is the structural representation 2 of the present invention;

Fig. 3 is the structural representation of the linkage mechanism of the present invention;

Fig. 4 is the structural representation that the linkage mechanism of the present invention removes the splint B;

Fig. 5 is the front view that the linkage mechanism of the present invention removes the splint B;

Fig. 6 is the structural schematic diagram of the feed dog seat and the feed dog of the present invention;

Fig. 7 is the top view of the feed dog seat and the feed dog of the present invention;

Fig. 8 is the structural representation of the branch tie rod B and the cam of the present invention;

Fig. 9 is the structural representation of the shuttle and shuttle seat of the present invention;

FIG. 10 is a top view of the shuttle and the shuttle seat of the present invention.

Reference number:

1. Linkage mechanism, 2. Base, 3. Indenter, 4. Needle, 5. Bolt, 6. Presser foot, 7. Adjustment wheel, 8. Spring, 9. Fork, 10. Plywood A, 11. Crank A, 12, branch pull rod A, 13, feed dog seat, 14, feed dog, 15, splint B, 16, branch pull rod B, 17, cam, 18, shuttle, 19, shuttle seat, 20, curved Knee B, 21, power rod, 22, crank C, 23, tie rod B, 24, crank D, 25, contact c, 26, shoulder b, 27, contact a, 28, shoulder f, 29, contact e, 30, contact shoulder d, 31, contact h, 32, contact shoulder i, 33, contact shoulder g.

Detailed ways

The specific embodiments, structures, features and effects of the present invention will be described in detail below with reference to the accompanying drawings and preferred embodiments.

A hand-held sewing machine with a shuttle bottom thread of the present invention includes a linkage mechanism 1, a base 2, and a pressure beam 3, wherein a sewing machine needle 4 is installed at one end of the pressure beam 3 and is screwed into a needle-fixing bolt 5 to fix, and the side of the pressure beam 3 is installed There is a wire adjustment button 7, the wire adjustment button 7 is connected to the wire wheel in the pressure beam 3, the abdomen of the pressure beam 3 is connected to one end of the compression spring 8, the other end of the compression spring 8 is connected to the base 2, the pressure beam 3 is inserted into the base 2 and inserted into the shaft to hinge, and the base A linkage mechanism 1 is installed inside 2 , the linkage mechanism 1 is connected to the press beam 3 , and the press beam 3 is fixedly connected to the presser foot 6 .

The linkage mechanism 1 consists of a shifting fork 9, a splint A10, a crank A11, a branch pull rod A12, a feed dog seat 13, a cloth feed dog 14, a splint B15, a branch pull rod B16, a cam 17, a flying shuttle 18, and a flying shuttle. Seat 19, crank B20, power rod 21, crank C22, tie rod B23, crank D24, power rod 21, crank C22 are respectively clamped between the splint A10 and splint B15, and the upper end of crank C22 is hinged with a branch tie rod One end of B23, the other end of branch lever B23 is hinged to one end of crank A11, crank A11 is inserted into the pin to connect splint A10 and splint B15, the other end of crank A11 is hinged to one end of branch draw bar A12, and the other end of branch draw bar A12 is hinged to the cloth feeder seat 13. The feed dog seat 13 is provided with a cloth feed dog 14, and two cams 17 are placed under the cloth feed dog seat 13. Both ends of the branch lever B16, one end of the branch lever B16 is hinged to the crank D24, and the crank D24 is inserted into the pin to connect the splint A10 and the splint B15. A shuttle 18 is placed in the seat 19, one end of the crank B20 is inserted under the shuttle seat 19, the other end of the crank B20 is inserted into a pin to connect the splint A10 and the splint B15, and the lower end of the power rod 21 is inserted into the pin to connect one end of the fork 9. , the middle of the shift fork 9 is inserted into the pin to connect the splint A10, the splint B15, and the lever provided at the lower end of the pressure beam 3 is inserted into the rotating sleeve provided at the other end of the shift fork 9.

A movement method of a hand-held sewing machine with a shuttle bottom thread, wherein;

1) When the feed dog 14 is in the highest position, the cam 17 is in an upright state, the shuttle 18 and the shuttle seat 19 are in the right position. When sewing work, when the beam 3 is pressed down by hand, the shifting fork 9 drives the power rod 21 moves downward, the contact shoulder i32 of the power rod 21 touches the contact h31 of the crank D24, so that the crank D24 moves the branch and tie rod B16 to the right, and the cam 17 rotates clockwise around its own axis under the drive of the branch and tie rod B16 Rotate to its lowest position, so that the shown feed dog seat 13 falls vertically below the sewing plane, and the presser foot 6 and the cloth at this time also fall with the feed dog seat 13, and finally fall on the plane of the base 2;

2) When the power rod 21 continues to move downward, the contact shoulder f28 of the power rod 21 touches the contact e29, the contact e29 drives the crank C22 to move, the crank C22 drives the branch and pull rod B23 to move, and the branch and pull rod B23 drives the crank crank A11, the crank A11 drives the branch rod A12 to push the feed dog seat 13 to the right end point, and wait for the next rise;

3) At the same time, the contact shoulder b26 of the power lever 21 touches the contact point a27, the contact point a27 drives the crank B20 to rotate counterclockwise, and the crank B20 drives the shuttle seat 19 to make the shuttle 18 fly from the right position to the shown left position;

4) When the needle tip of sewing machine needle 4 starts to move downward from the top dead center, until the needle tip of sewing machine needle 4 is still 1 mm away from the presser foot 6 shown, the actions 1, 2, and 3 have been completed. It is in this state until the needle tip of the 4th needle of the sewing machine reaches the bottom dead center.

5) When the hand releases the pressure beam 3, the sewing machine will perform the lower half sewing work by the elastic force of the compression spring 8. The contact c25 on the lever 21 is already below the contact a27. When the power lever 21 moves upward, the contact c25 will touch the contact a27, and the crank B20 will drive the shuttle seat 19 to make the shuttle 18 fly from the left position. To the right position of the picture, complete the purpose of the shuttle passing through the upper line;

6) When the contact shoulder i32 on the power rod 21 is below the contact h31 and the power rod 21 moves upward, the contact shoulder g33 will touch the contact h31, driving the crank D24 to rotate in the counterclockwise direction, thereby pulling the branch rod. B16 moves to the right, so that the cam 17 rotates to the left according to its own axis and becomes an upright state, and lifts the presser foot 6 and the feed dog seat 13 vertically upwards to prepare for the horizontal feeding;

7) When the feed dog seat 13 is in an upright state, the contact shoulder d30 on the power rod 21 just touches the contact point e29 from the bottom to the top, thereby driving the crank C22 to drive the branch rod B23 to move, and the branch rod B23 drives the crank crank A11, the crank A11 drives the branch pull rod A12 to horizontally move the feed dog seat 13 to the left to complete the work of feeding the cloth forward;

8) When the needle 4 of the sewing machine starts to lift up at the bottom dead center, when the needle tip of the needle 4 of the sewing machine rises by 1.5 mm, the upper thread on the needle 4 of the sewing machine forms a thread sleeve, and this is the threading action of the shuttle 11. At this time, the sewing machine The needle 4 continues to rise. When the height of the needle tip of the sewing machine needle 4 exceeds the upper plane of the sewing machine needle 4 presser foot 6 by 2 mm, it is the vertical upward movement of the feed dog seat 13 and the horizontal leftward feed movement.

The shuttle 18 is olive-shaped, and can move left and right on the groove provided on the shuttle seat 19 .

The shuttle seat 19 can move left and right.

The power rod 21 has several convex and curved shapes and can move up and down.

The above content is a further detailed description of the present invention in combination with specific preferred embodiments, and it cannot be considered that the specific implementation of the present invention is limited to these descriptions. For those of ordinary skill in the technical field of the present invention, without departing from the concept of the present invention, some simple deductions or substitutions can be made, which should be regarded as belonging to the protection scope of the present invention.

Claims (6)

1. A hand-held sewing machine with a shuttle bottom thread comprises a linkage mechanism (1), a base (2) and a pressing beam (3), and is characterized in that; install sewing machine needle (4) at press beam (3) one end and twist and decide needle bolt (5) fixed, be equipped with on press beam (3) side and transfer line button (7), transfer line button (7) and connect the line wheel in press beam (3), press beam (3) belly connection compression spring (8) one end, base (2) are connected to compression spring (8) other end, press beam (3) card is gone into base (2) and is inserted the axle and articulate, install linkage (1) in base (2), press beam (3) are connected to linkage (1), press beam (3) fixed connection presser foot (6).

2. The hand-held sewing machine with a fly shuttle bobbin thread according to claim 1, wherein the linkage mechanism (1) is composed of a shifting fork (9), a clamping plate A (10), a crank throw A (11), a branch pull rod A (12), a feed dog seat (13), a feed dog (14), a clamping plate B (15), a branch pull rod B (16), a cam (17), a fly shuttle (18), a fly shuttle seat (19), a crank throw B (20), a power rod (21), a crank throw C (22), a branch pull rod B (23) and a crank throw D (24), the power rod (21) and the crank throw C (22) are respectively clamped between the clamping plate A (10) and the clamping plate B (15), one end of the branch pull rod B (23) is hinged at the upper end of the crank throw C (22), one end of the crank throw A (11) is hinged at the other end of the crank throw B (23), and the crank A (11) is inserted into a pin to connect the clamping plate A (10) and the clamping plate B (15), one end of a branch pull rod A (12) is hinged to the other end of a crank throw A (11), the other end of the branch pull rod A (12) is hinged to a cloth feeding tooth seat (13), cloth feeding teeth (14) are arranged on the cloth feeding tooth seat (13), two cams (17) are placed below the cloth feeding tooth seat (13), the two cams (17) are respectively inserted into a pin to connect a clamping plate A (10) and a clamping plate B (15), the two cams (17) are respectively hinged to two ends of the branch pull rod B (16), one end of the branch pull rod B (16) is hinged to a crank throw D (24), the crank throw D (24) is inserted into a pin to connect the clamping plate A (10) and the clamping plate B (15), flying shuttle seats (19) are placed on raised lines arranged on the clamping plate A (10) and the clamping plate B (15), flying shuttles (18) are placed in the flying shuttle seats (19), one end of the crank throw B (20) is inserted into the lower portion of the flying shuttle seats (19), and the other end of, The lower end of the power rod (21) is inserted into one end of a pin connecting shifting fork (9), the middle part of the shifting fork (9) is inserted into a pin connecting clamping plate A (10) and a clamping plate B (15), and a lever arranged at the lower end of the pressing beam (3) is inserted into a rotating sleeve arranged at the other end of the shifting fork (9).

3. A movement mode of a hand-held sewing machine with a fly shuttle bobbin thread is characterized in that;

1) the cloth feeding tooth (14) is located at the highest position, the cam (17) is located at the vertical state flying shuttle (18), the flying shuttle seat (19) is located at the right position, when sewing is carried out, when the beam (3) is pressed downwards by hand, the shifting fork (9) drives the power rod (21) to move downwards, a contact shoulder i (32) of the power rod (21) is pressed against a contact point h (31) of the crank D (24) to enable the crank D (24) to shift the branch pull rod B (16) rightwards, the cam (17) is driven by the branch pull rod B (16) to rotate around the axis of the cam in the clockwise direction until the cam rotates to the lowest position of the cam, so that the cloth feeding tooth seat (13) is vertically dropped below a sewing plane, and the presser foot (6) and the cloth at the moment also drop along with the cloth feeding tooth seat (13), and finally the cam is located on the plane of the base (2);

2) when the power rod (21) continues to move downwards, the contact shoulder f (28) of the power rod (21) pushes against a contact e (29), the contact e (29) drives a crank throw C (22) to move, the crank throw C (22) drives a branch pull rod B (23) to move, the branch pull rod B (23) drives a crank throw A (11), the crank throw A (11) drives a branch pull rod A (12) to push the cloth feeding tooth seat (13) to a right terminal point, and the cloth feeding tooth seat is waited to rise again next time;

3) meanwhile, a contact shoulder B (26) of the power rod (21) is abutted against a contact a (27), the contact a (27) drives a crank throw B (20) to rotate in the anticlockwise direction, and the crank throw B (20) drives a shuttle flying seat (19) to fly a shuttle (18) from the right position to the left position;

4) when the needle point of the sewing machine needle (4) starts to move downwards from the upper dead point until the needle point of the sewing machine needle (4) is 1 mm away from the shown presser foot (6), the actions of 1), 2) and 3) are finished until the needle point of the sewing machine needle (4) reaches the lower dead point, and the actions are all in the state;

5) when the pressing beam (3) is released by a hand, the sewing machine performs lower half part sewing work under the action of the elastic force of the compression spring (8), the shifting fork (9) shifts the power rod (21) to move upwards under the action of the compression spring (8), the contact c (25) on the power rod (21) is positioned below the contact a (27), when the power rod (21) moves upwards, the contact c (25) pushes against the contact a (27), and the crank B (20) drives the fly shuttle seat (19) to fly the fly shuttle (18) from the left position to the right position of the figure, so that the aim of enabling the fly shuttle to pass through the upper thread is fulfilled;

6) when a contact shoulder i (32) on the power rod (21) reaches the position below a contact point h (31), and the power rod (21) moves upwards, a contact shoulder g (33) pushes the contact point h (31) to drive a crank D (24) to rotate in the anticlockwise direction, so that a branch traction rod B (16) is pulled to move rightwards, a cam (17) rotates leftwards according to the axis of the cam to become an upright state, and a presser foot (6) and a cloth feeding tooth seat (13) are lifted vertically upwards to prepare for horizontal cloth feeding;

7) when the cloth feeding tooth holder (13) is in an upright state, the contact shoulder d (30) on the power rod (21) just pushes the contact point e (29) upwards from the lower direction, so that the crank C (22) is driven to drive the branch pull rod B (23) to move, the branch pull rod B (23) drives the crank A (11), and the crank A (11) drives the branch pull rod A (12) to horizontally move the cloth feeding tooth holder (13) leftwards, so that the work of feeding cloth forwards is completed;

8) when the sewing machine needle (4) starts to lift upwards at the bottom dead center, when the needle point of the sewing machine needle (4) rises by 1.5 mm, the upper thread on the sewing machine needle (4) forms a thread sleeve, the threading action of the shuttle (11) is performed at the moment, the sewing machine needle (4) continues to rise at the moment, and when the height of the needle point of the sewing machine needle (4) exceeds the upper plane of the presser foot (6) of the sewing machine needle (4) by 2 mm, the vertical rising action and the horizontal leftward cloth feeding action of the cloth feeding tooth seat (13) are performed.

4. A hand-held sewing machine with a fly bobbin thread as claimed in claim 1, characterised in that the fly (18) is olive shaped and moves side to side over a recess provided in the fly seat (19).

5. A hand-held sewing machine with a fly bobbin thread as claimed in claim 1 wherein the fly base (19) is movable to the left and right.

6. A hand-held sewing machine with a fly bobbin thread according to claim 1 wherein the power bar (21) is of a convex curved type and is movable up and down.

Images