Thread loosening mechanism of sewing machine

Abstract

The utility model relates to the field of thread loosening control of sewing machines, and discloses a thread loosening mechanism of a sewing machine, which comprises a fixed seat, a control line, a thread pulling part and a control part, one end of the control line is connected to the line loosening end, and the other end is a line pulling end connected to the line pulling part; the inner side part of the wire pulling part is connected with the wire pulling end, the outer side part is matched with the control part, and the wire pulling part moves to drive the wire pulling end to move and the outer side part is matched with the control part; the control part comprises a swing arm which acts on the wire pulling part and can do reciprocating motion, the swing arm comprises an arm body and an abutting part connected to the arm body, and the abutting part acts on the wire pulling part; the wire pulling part is installed on the fixing base and can rotate under the action of the abutting part, and the wire pulling end of the control wire is driven to move in the rotating process. The device has the advantages of reliable control and long service life.

Description

Technical Field

[0001] The utility model relates to the field of sewing machines, in particular to a thread loosening mechanism of a sewing machine. Background Art

[0002] Chinese patent CN202220474368.1 discloses a thread trimming and loosening mechanism of a sewing machine and a sewing machine with the mechanism, wherein the thread trimming mechanism and the thread loosening mechanism use a motor to drive a cam mechanism, and then drive a thread loosening seat and a thread trimming shaft to rotate to achieve thread loosening and thread trimming. In this solution, the thread loosening seat is installed at the cam end and connected to the loosening and trimming crank. At the same time, a thread trimming mounting seat is also provided in this area. The space in this part is small and installation and maintenance are inconvenient. This solution provides a sewing machine thread loosening mechanism based on the existing design. Utility Model Content

[0003] The utility model aims at the shortcomings of the prior art and provides a thread loosening mechanism for a sewing machine.

[0004] In order to solve the above technical problems, the utility model is solved by the following technical solutions:

[0005] A thread loosening mechanism for a sewing machine comprises a fixing seat, a control line, a thread pulling part and a control part;

[0006] One end of the control line is used to be connected to the loose wire end, and the other end is the pull wire end connected to the pull wire part;

[0007] The inner part of the wire pulling part is connected to the wire pulling end, and the outer part cooperates with the control part. The movement of the wire pulling part drives the movement of the wire pulling end, and the outer part cooperates with the control part.

[0008] The control part includes a swing arm that can reciprocate and act on the wire pulling part. The swing arm includes an arm body and a resistance part connected to the arm body. The resistance part acts on the wire pulling part. The wire pulling part is installed on a fixed seat and can rotate under the action of the resistance part, driving the wire pulling end of the control line to move during the rotation.

[0009] Preferably, the fixed seat includes a connecting shaft, and the wire pulling part is sleeved on the connecting shaft and can rotate around the connecting shaft; it also includes an elastic return part, which is connected to the wire pulling part to provide a circumferential force for the wire pulling part; during the swinging process of the resistance part, the wire pulling part can be driven to overcome the force of the elastic return part to rotate the wire pulling part, and while the wire pulling part rotates, the wire pulling part drives the control line to extend out, and when the resistance part moves in the opposite direction, the elastic return part releases the elastic potential energy to act on the wire pulling part to rotate in the opposite direction and drive the control line to retract.

[0010] Preferably, the elastic return member is a torsion spring, which is sleeved on the connecting shaft, with one end of the torsion spring being restricted on the wire pulling part and the other end being used to be restricted on the fixing seat.

[0011] Preferably, the wire pulling part includes a mounting base installed on the fixed base and rotatable relative to the fixed base, and also includes a contact plate fixedly connected to the mounting base, the inner end of the side surface of the contact plate is connected to the wire pulling end of the control line, the contact part acts on the outer end of the side surface of the contact plate, and the contact plate forms an acute angle with the swing arm in the initial state.

[0012] Preferably, the abutment plate is arranged in a vertical direction.

[0013] Preferably, the connecting line formed by the points on the wire pulling part through which the interference part passes is defined as a control trajectory, and when the wire pulling part passes through each point on the control trajectory, the distance between each point and the root of the interference part is less than or equal to the length of the interference part, and the distance between each point and the root of the interference part gradually decreases from one end to the other end of the control trajectory.

[0014] Preferably, the mounting seat includes an upper ear and a lower ear, the abutment plate is fixedly connected to the lower ear or the upper ear through a connecting arm, the elastic return member is sleeved on the connecting shaft and located between the upper ear and the lower ear, one end of the elastic return member is connected to the connecting arm, and the other end is used to abut against the fixed seat.

[0015] Preferably, the wire pulling end includes a locking sleeve locked on the control line and a limiting part 1 and a limiting part 2 fixed on the locking sleeve, the control line passes through the inner end of the wire pulling part, and the wire pulling part is located between the limiting part 1 and the limiting part 2.

[0016] Preferably, the control part includes a rotating shaft, and the swing arm is fixedly installed on the rotating shaft, and when the rotating shaft rotates, the swing arm is driven to swing synchronously; the resistance part swings inward to push the wire pulling part to rotate inward, and the inner end of the wire pulling part pulls the control line to the left; the resistance part swings outward, and the wire pulling part rotates outward under the action of the elastic return part, and the inner end of the wire pulling part pushes the control line to the right.

[0017] Preferably, the abutment portion is a columnar member with an arc-shaped end, and the surface of the wire pulling portion that is in contact with the abutment portion is a flat surface.

[0018] The utility model adopts the above technical solution, and has the following significant technical effects:

[0019] The wire loosening mechanism designed in the utility model adopts the method of pulling and retracting to loosen the wire. During the loosening process, the wire will not form obvious bending creases, which improves the life of the wire and optimizes the loosening effect. At the same time, the loosening action is performed by swinging and resisting rotation, and the whole control process is smoother, and the torsion spring can cooperate with the loosening end to make the wire return quickly. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the overall structure of the device.

[0021] Figure 2 It is a schematic diagram of the overall structure of the device.

[0022] Figure 3 It is a schematic diagram of the structure of the device with the fixing seat removed.

[0023] Figure 4 It is a schematic diagram of the coordination between the control line, the wire pulling part and the control part.

[0024] The technical names of the accompanying drawings are: 1-fixed seat, 2-control line, 3-pull wire part, 4-control part, 5-loose wire end, 6-swing arm, 7-arm body, 8-contact part, 9-connecting shaft, 10-elastic return member, 11-mounting seat, 12-contact plate, 13-upper ear, 14-lower ear, 15-locking sleeve, 16-connecting arm, 17-limiting part one, 18-limiting part two, 19-rotating shaft. DETAILED DESCRIPTION

[0025] The utility model is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0026] Example 1

[0027] A thread loosening mechanism for a sewing machine comprises a fixing seat 1, a control line 2, a thread pulling part 3 and a control part 4;

[0028] One end of the control line 2 is used to connect to the loosening end 5, and the other end is the pulling end connected to the pulling part 3; the control line 2 is a pulling line, which can act on the loosening end 5 to loosen the line by pulling the pulling line. The prior art generally also uses the method of controlling the pulling line to control the loosening end 5.

[0029] The inner part of the wire pulling part 3 is connected to the wire pulling end, and the outer part cooperates with the control part 4. The movement of the wire pulling part 3 drives the movement of the wire pulling end, and the outer part cooperates with the control part 4; the specific connection method between the wire pulling part 3 and the wire pulling end is not limited to a certain method, and all connection methods that can drive the movement of the wire pulling end when the wire pulling part 3 moves should belong to the protection scope of this scheme.

[0030] As for the way in which the outer part of the wire pulling part 3 cooperates with the control part 4 in this embodiment, the two are in a resistance cooperation and can be separated from each other. When the control part 4 moves, it will drive the wire pulling part 3 to move through the resistance, thereby driving the wire pulling end to move to realize the control of the control line 2.

[0031] The control part 4 includes a swing arm 6 that acts on the wire pulling part 3 and can reciprocate. The swing arm 6 includes an arm body 7 and a resistance part 8 connected to the arm body 7. The resistance part 8 acts on the wire pulling part 3. The wire pulling part 3 is installed on the fixed seat 1 and can rotate under the action of the resistance part 8, and the wire pulling end of the control line 2 is driven to move during the rotation. In this scheme, the reciprocating swing of the resistance part 8 is achieved by using the rotating shaft 19 to drive the swing arm 6 to swing back and forth.

[0032] In this embodiment, the fixed seat 1 includes a body and a connecting shaft 9, and the wire pulling part 3 is sleeved on the connecting shaft 9 and can rotate around the connecting shaft 9; in this embodiment, the connecting shaft 9 is fixed on the body of the sewing machine, the upper end of the connecting shaft 9 is fixedly connected to the body, and the lower end has a supporting head for supporting the wire pulling part 3, and the wire pulling part 3 is sleeved on the connecting shaft 9 and sits on the supporting head.

[0033] This embodiment also includes an elastic return member 10, which is connected to the wire pulling part 3 to provide a circumferential force to the wire pulling part 3. This is because the movement of the wire pulling part 3 in this solution is a rotational movement. In order to ensure the return of the wire pulling part 3, it is necessary to use the elastic return member 10 that provides a circumferential force to assist.

[0034] In this embodiment, the elastic return member 10 is a torsion spring. The torsion spring is sleeved on the connecting shaft 9, one end of the torsion spring is limited on the wire pulling part 3, and the other end is used to be limited on the fixing seat 1, and the fixing seat 1 includes a limiting boss 20, and the end of the torsion spring limited on the fixing seat 1 is specifically limited on the limiting boss 20, and the limiting boss 20 is located on the lower side of the body.

[0035] During the swinging process of the resistance part 8, the wire pulling part 3 can be driven to overcome the force of the elastic return part 10 to rotate the wire pulling part 3. While the wire pulling part 3 rotates, the wire pulling part 3 drives the control line 2 to extend. When the resistance part 8 moves in the opposite direction, the elastic return part 10 releases the elastic potential energy to act on the wire pulling part 3 to rotate in the opposite direction and drive the control line 2 to retract.

[0036] The line formed by the points on the wire drawing part 3 through which the interference part 8 passes is defined as a control trajectory. In the present embodiment, the control trajectory falls on the side of the interference plate 12. When the wire drawing part 3 passes through each point on the control trajectory, the distance between each point and the root of the interference part 8 is less than or equal to the length of the interference part 8, and the distance between each point and the root of the interference part 8 gradually decreases from one end to the other end of the control trajectory. Since the length of the interference part 8 is fixed, the interference part 8 will push the interference plate 12 outward when passing through each point on the control trajectory. Since the interference plate 12 is restricted by the mounting seat 11, the movement of the interference plate 12 is rotation. In order to ensure that the interference plate 12 can be gradually pushed during the movement, a design is selected in which the distance between each point and the root of the interference part 8 gradually decreases from one end to the other end of the control trajectory.

[0037] In this embodiment, the wire pulling end includes a locking sleeve 15 locked on the control line 2 and a limiting part 17 and a limiting part 2 18 fixed on the locking sleeve 15. The control line 2 passes through the inner end of the wire pulling part 3, and the wire pulling part 3 is located between the limiting part 17 and the limiting part 2 18. The wire pulling end includes a locking sleeve 15 for locking the end of the wire pulling, and the limiting parts 1 and 2 18 are fixedly connected to the locking sleeve 15. The locking sleeve 15 can include the wire pulling part 3 to act on the wire pulling to protect the wire, and the locking sleeve 15 is straighter and has a larger diameter than the wire pulling.

[0038] In this embodiment, the control part 4 includes a rotating shaft 19, and the swing arm 6 is fixedly installed on the rotating shaft 19. When the rotating shaft 19 rotates, the swing arm 6 is driven to swing synchronously; the resistance part 8 swings inward to push the wire pulling part 3 to rotate inward, and the inner end of the wire pulling part 3 pulls the control line 2 to the left; the resistance part 8 swings outward, and the wire pulling part 3 rotates outward under the action of the elastic return member 10, and the inner end of the wire pulling part 3 pushes the control line 2 to the right.

[0039] The abutment portion 8 is a columnar member with an arc-shaped end, and the surface of the wire pulling portion 3 that contacts the abutment portion 8 is a flat surface.

[0040] The scheme works as follows:

[0041] When it is necessary to loosen the line, the rotating shaft 19 rotates to drive the swing arm 6 and the contact part 8 on the swing arm 6 to rotate synchronously, and the contact part 8 contacts the contact plate 12. Since the distance between the root of the contact part 8 and the contact plate 12 becomes smaller as it moves inward, the contact part 8 will push the contact plate 12 to rotate during the inward swinging process. While the contact plate 12 rotates, the torsion spring accumulates force, and the inner end of the contact plate 12 drives the pulling wire end to pull the control wire 2, and the other end of the control wire 2 drives the mechanism of the loosening wire end 5 to loosen the line; after the loosening of the line is completed, the rotating shaft 19 reverses to drive the swing arm 6 and the contact part 8 on the swing arm 6 to rotate synchronously. Since the distance between the root of the contact part 8 and the contact plate 12 becomes larger as it moves outward, the torsion spring releases the continued elastic potential energy when the contact part 8 swings outward, causing the contact plate 12 to rotate and drive the pulling wire end and the pulling wire to return to complete a loosening control action.

[0042] Example 2

[0043] The difference from the embodiment 1 is that: the present embodiment discloses that the wire pulling part 3 in the present embodiment includes a mounting seat 11 mounted on the fixing seat 1 and rotatable relative to the fixing seat 1, and also includes a contact plate 12 fixedly connected to the mounting seat 11, the inner end of the side surface of the contact plate 12 is connected to the wire pulling end of the control line 2, the contact part 8 acts on the outer end of the side surface of the contact plate 12, and the contact plate 12 forms an acute angle with the swing arm 6 in the initial state. Due to the design of the angle structure, the closer the distance between the two side surfaces is to the intersection point, the greater the distance pushed by the contact part 8; therefore, this structural design can meet the requirement that the contact part 8 gradually pushes the wire pulling part 3 to rotate inward during the inward swinging process, and the inner end of the wire pulling part 3 pulls the control line 2 to the left; the contact part 8 swings outward, and the wire pulling part 3 rotates outward under the action of the elastic return member 10, and the inner end of the wire pulling part 3 pushes the control line 2 to the right.

[0044] The mounting seat 11 includes an upper ear 13 and a lower ear 14, the abutment plate 12 is fixedly connected to the lower ear 14 or the upper ear 13 through a connecting arm 16, the elastic return member 10 is sleeved on the connecting shaft 9 and located between the upper ear 13 and the lower ear 14, one end of the elastic return member 10 is connected to the connecting arm 16, and the other end is used to abut on the fixing seat 1. Specifically in this embodiment, the connecting arm 16 is fixedly connected to the lower ear 14. Specifically in this embodiment, the abutment plate 12 is arranged in a vertical direction.

[0045] Example 3

[0046] On the basis of Example 1 and Example 2, this example further describes the control line 2, which includes an internal wire core and an external wire sheath. A support bracket for supporting and guiding the control line 2 is also provided on the machine body.

Claims

1. A thread loosening mechanism for a sewing machine, characterized in that: It comprises a fixing seat (1), a control line (2), a wire pulling part (3) and a control part (4); One end of the control line (2) is used to be connected to the loose wire end (5), and the other end is the pulling wire end connected to the pulling wire part (3); The inner part of the wire pulling part (3) is connected to the wire pulling end, and the outer part cooperates with the control part (4). The movement of the wire pulling part (3) drives the movement of the wire pulling end, and the outer part cooperates with the control part (4). The control part (4) comprises a swing arm (6) which acts on the wire pulling part (3) and can reciprocate, the swing arm (6) comprises an arm body (7) and a resistance part (8) connected to the arm body (7), the resistance part (8) acts on the wire pulling part (3); the wire pulling part (3) is mounted on the fixed seat (1) and can rotate under the action of the resistance part (8), and the wire pulling end of the control line (2) is driven to move during the rotation process.

2. A thread loosening mechanism for a sewing machine according to claim 1, characterized in that: The fixing seat (1) comprises a connecting shaft (9), and the wire pulling part (3) is sleeved on the connecting shaft (9) and can rotate around the connecting shaft (9); and also comprises an elastic return member (10), and the elastic return member (10) is connected to the wire pulling part (3) to provide a circumferential force for the wire pulling part (3); during the swinging process of the resistance part (8), the wire pulling part (3) can be driven to overcome the force of the elastic return member (10) to rotate the wire pulling part (3), and while the wire pulling part (3) rotates, the wire pulling part (3) drives the control line (2) to extend; when the resistance part (8) moves in the reverse direction, the elastic return member (10) releases the elastic potential energy to act on the wire pulling part (3) to rotate in the reverse direction and drives the control line (2) to retract.

3. A thread loosening mechanism for a sewing machine according to claim 2, characterized in that: The elastic return member (10) is a torsion spring, which is sleeved on the connecting shaft (9), one end of which is restricted on the wire pulling part (3), and the other end of which is used to be restricted on the fixing seat (1).

4. A thread loosening mechanism for a sewing machine according to claim 1, 2 or 3, characterized in that: The wire pulling part (3) comprises a mounting seat (11) mounted on a fixing seat (1) and rotatable relative to the fixing seat (1), and also comprises a contact plate (12) fixedly connected to the mounting seat (11), wherein the inner end of the side surface of the contact plate (12) is connected to the wire pulling end of the control line (2), the contact part (8) acts on the outer end of the side surface of the contact plate (12), and the contact plate (12) forms an acute angle with the swing arm (6) in an initial state.

5. A thread loosening mechanism for a sewing machine according to claim 4, characterized in that: The abutment plate (12) is arranged in a vertical direction.

6. A thread loosening mechanism for a sewing machine according to claim 1, 2 or 3, characterized in that: A line formed by points on the wire drawing part (3) through which the interference part (8) passes is defined as a control trajectory. When the wire drawing part (3) passes through each point on the control trajectory, the distance between each point and the root of the interference part (8) is less than or equal to the length of the interference part (8), and the distance between each point and the root of the interference part (8) gradually decreases from one end to the other end of the control trajectory.

7. The thread loosening mechanism for a sewing machine according to claim 4, characterized in that: The mounting seat (11) comprises an upper ear (13) and a lower ear (14); the abutment plate (12) is fixedly connected to the lower ear (14) or the upper ear (13) via a connecting arm (16); an elastic return member (10) is sleeved on the connecting shaft (9) and is located between the upper ear (13) and the lower ear (14); one end of the elastic return member (10) is connected to the connecting arm (16), and the other end is used to abut against the fixing seat (1).

8. A thread loosening mechanism for a sewing machine according to claim 1, 2 or 3, characterized in that: The wire pulling end comprises a locking sleeve (15) locked on the control line (2) and a limiting part 1 (17) and a limiting part 2 (18) fixed on the locking sleeve (15); the control line (2) passes through the inner end of the wire pulling part (3), and the wire pulling part (3) is located between the limiting part 1 (17) and the limiting part 2 (18).

9. A thread loosening mechanism for a sewing machine according to claim 1, 2 or 3, characterized in that: The control part (4) comprises a rotating shaft (19), and the swing arm (6) is fixedly mounted on the rotating shaft (19). When the rotating shaft (19) rotates, the swing arm (6) is driven to swing synchronously; the abutment part (8) swings inwards to push the wire pulling part (3) to rotate inwards, and the inner end of the wire pulling part (3) pulls the control line (2) to the left; the abutment part (8) swings outwards, and under the action of the elastic return member (10), the wire pulling part (3) rotates outwards, and the inner end of the wire pulling part (3) pushes the control line (2) to the right.

10. A thread loosening mechanism for a sewing machine according to claim 1, 2 or 3, characterized in that: The abutment portion (8) is a columnar member with an arc-shaped end, and the surface of the wire pulling portion (3) that is in contact with the abutment portion (8) is a flat surface.

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