Automatic thread trimming device
By using the relative rotation between the positioning sheet and the movable knife in the automatic thread cutting device of the computer sewing machine, combined with the contact between the wire sheet and the wire guard sheet, the problem of the thread head of the bottom line is solved, and the effective lengthening of the bottom line and the convenience of going online is achieved.
Patent Information
- Application Number
- CN202421829929.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-30
- Publication Date
- 2025-04-25
- Estimated Expiration
- 2034-07-30
AI Technical Summary
During the thread cutting process of existing computer sewing machines, the bottom thread head is too short, making it inconvenient to start the needle and thread it again.
By introducing the relative rotation between the positioning sheet and the movable knife in the thread-cutting device, the contact between the wire-cutting sheet and the wire-guarding sheet forms winding and positioning the bottom line, effectively elongating the bottom line.
It realizes effective lengthening of the bottom line, which facilitates the next needle lifting and threading, ensuring that the coil of the surface line can once again cover the thread end of the bottom line, and completes the line again.
Smart Images
Figure CN222795931U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of automatic thread trimmers for computer sewing machines, in particular to an automatic thread trimmer that facilitates the rethreading of the bottom thread. Background Art
[0002] The computer high sewing machine is an automatic sewing equipment suitable for sewing general leather materials such as shoe uppers, leather bags, hats, etc. During the sewing process, when the upper needle passes through the leather downward, the upper thread is pulled out by the rotary shuttle to form a coil that wraps the bottom thread to form a stitch. In the actual sewing process, the completion of a pattern is accompanied by one thread cutting and one threading.
[0003] The utility model patent CN217127728U discloses an automatic thread trimming device for a computer sewing machine. When trimming the thread, under the drive of the driving member, the thread trimming driving mechanism axially squeezes the reset spring along the thread trimming driving shaft, the roller approaches the thread trimming cam, and the shuttle bed transmission shaft drives the cam assembly to rotate synchronously, so that the roller contacts the thread trimming contact part of the thread trimming cam, and drives the thread trimming driving mechanism and the connecting rod transmission mechanism to swing, thereby driving the thread trimming transmission shaft and the moving knife to rotate, and the moving knife and the blade bite to cut the thread; the cam assembly continues to rotate with the shuttle bed transmission shaft, so that the roller contacts the reset contact part of the thread trimming cam, and resets the thread trimming driving mechanism, the connecting rod transmission mechanism, the thread trimming transmission shaft and the moving knife under the action of the reset spring. At this time, the moving knife is separated from the blade, and a complete automatic thread trimming cycle is completed. However, the technical solution still has the problem that the bottom line head is too short during the thread trimming process, which is inconvenient to start the needle again, that is, the surface coil wraps the bottom line again. Summary of the invention
[0004] The utility model aims to provide an automatic thread trimming device. The utility model utilizes the relative rotation between the positioning piece and the movable knife during the thread trimming process to complete the thread trimming and utilizes the contact between the guide wire piece and the wire protection piece to form the winding and positioning of the bottom line, effectively lengthening the bottom line and facilitating the next needle threading.
[0005] To solve this technical problem, the technical solution of the utility model is: an automatic thread trimming device, comprising a driving assembly and a shearing assembly installed on the shuttle bed transmission shaft, wherein the shearing assembly includes a fixed knife fixed to a mounting seat and having a certain length along the circumferential direction, a movable knife installed on the shuttle bed transmission shaft through a movable knife seat, and a wire guard fixed to the mounting seat in sequence along the radial direction of the shuttle bed transmission shaft from the circumference to the center of the circle; the movable knife extends into between the fixed knife and the wire guard or moves away from the fixed knife and the wire guard along with the driving assembly;
[0006] A wire dividing piece is fixed on the side of the movable knife facing the rotary hook. When the movable knife and the fixed knife are shearing, the wire dividing piece contacts the wire protecting piece to form a bottom line elongated structure.
[0007] As a further improvement, the wire splitting piece protrudes from the movable knife toward the fixed knife along the circumferential direction, and the width of the portion of the wire splitting piece protruding from the movable knife gradually decreases toward the wire protection piece. The utility model uses the portion of the wire splitting piece protruding from the movable knife to guide the bottom line into the movable knife, thereby achieving effective cutting.
[0008] As a further improvement, the line dividing piece includes a connecting portion which is arranged in close contact with the movable knife. The utility model ensures the effectiveness of guiding the bottom thread and the top thread by tightly connecting the line dividing piece and the movable knife.
[0009] As a further improvement, the movable knife is provided with a guide notch on one side facing the fixed knife, and a wire storage groove extending from the guide notch and distributed along the circumferential direction; the guide notch has an open structure along the wire cutting direction, and the bottom end of the guide notch is connected to the wire storage groove; the fixed knife and the movable knife rotating along the wire cutting direction form a surface contact until the blade of the fixed knife moves to the wire cutting protrusion of the movable knife. The utility model effectively ensures the shearing of the bottom line while protecting the extension and positioning of the bottom line. When the movable knife is reset to the non-shearing position, the bent thread head supported by the movable knife and the wire dividing sheet is in the moving path of the surface line, which effectively ensures the upper line.
[0010] As a further improvement, the wire protection sheet includes a fixed section fixed to the mounting seat, an interference section for contacting with the wire dividing sheet to form a bottom line elongated structure, and a limiting section arranged parallel to the fixed knife.
[0011] As a further improvement, the movable knife is fixedly connected to a thread trimmer transmission sleeve coaxially nested with the shuttle bed transmission shaft through a movable knife seat, and both ends of the thread trimmer transmission sleeve are respectively installed on the shuttle bed transmission shaft through needle bearings.
[0012] The utility model effectively reduces noise.
[0013] As a further improvement, the thread trimmer transmission shaft sleeve drives the thread trimmer transmission shaft sleeve and the movable knife to rotate relative to the fixed knife through the driving assembly.
[0014] By adopting the above technical solution, the beneficial effects of the utility model are:
[0015] When the movable blade is relatively rotated to the cutting position with the driving component relative to the wire dividing piece and the fixed knife, that is, the wire cutting protrusion on the surface of the movable knife contacts the blade of the fixed knife, the bottom line of the shuttle core is elongated and fixed as the wire dividing piece of the wire protecting piece contacts. Since the length of the bottom line thread end is guaranteed and supported and guided by the movable knife, when the needle passing through the surface thread is inserted into the shuttle again, the edge of the shuttle rotates with the shuttle bed rotating shaft to ensure that the coil of the surface thread once again covers the thread end of the bottom line, and the thread is put on again. The utility model utilizes the relative rotation between the positioning piece and the movable knife during the thread cutting process to complete the thread cutting and utilizes the contact between the guide wire piece and the wire protecting piece to form the winding and positioning of the bottom line, effectively elongating the bottom line, and facilitating the next needle and threading. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Figure 1 It is a stereoscopic diagram of an automatic thread trimming device involved in the utility model;
[0017] Figure 2 This is a schematic diagram of the split structure of the small nozzle seat and the thread cutting device of the utility model;
[0018] Figure 3 A three-dimensional diagram of the movable knife in the utility model;
[0019] Figure 4 This is the front view of the hidden small mouth seat of the utility model;
[0020] Figure 5 It is a schematic diagram of the state in which the small mouth seat is hidden and the shearing component forms a bottom line elongated structure of the utility model.
[0021] In the figure:
[0022] Shuttle bed transmission shaft 1; drive assembly 2; shearing assembly 3; fixed knife 31; moving knife seat 32; movable knife 33; guide notch 331; wire storage groove 332; wire cutting protrusion 333; wire protection piece 34; fixed section 341; abutment section 342; limit section 343; wire dividing piece 35; mounting seat 4; rotary hook 5; wire cutting transmission shaft sleeve 6 。 DETAILED DESCRIPTION
[0023] In order to further explain the technical solution of the present utility model, the present utility model is described in detail below through specific embodiments.
[0024] This embodiment discloses an automatic thread trimming device, such as Figures 1 to 5As shown, it comprises a driving assembly 2 and a shearing assembly 3 mounted on the shuttle bed transmission shaft 1, wherein the shearing assembly 3 comprises a fixed knife 31 having a certain length along the circumferential direction fixed to a mounting seat 4, a movable knife 33 mounted on the shuttle bed transmission shaft 1 through a movable knife seat 32, and a wire guard 34 fixed to the mounting seat 4 in sequence from the circumference to the center of the shuttle bed transmission shaft 1 in the radial direction; the movable knife 33 extends into between the fixed knife 31 and the wire guard 34 or away from the fixed knife 31 and the wire guard 34 along with the driving assembly 2;
[0025] A wire dividing piece 35 is fixed to the side of the movable knife 33 facing the rotary hook 5. When the movable knife 33 and the fixed knife 31 are shearing, the wire dividing piece 35 contacts the wire protecting piece 34 to form a bottom line elongated structure.
[0026] In this embodiment, the wire dividing piece 35 protrudes from the movable knife 33 toward the fixed knife 31 along the circumferential direction, and the portion of the wire dividing piece 35 protruding from the movable knife 33 gradually decreases in width toward the wire protecting piece 34. In this embodiment, the portion of the wire dividing piece 35 protruding from the movable knife 33 is used to guide the bottom line into the movable knife 33, thereby achieving effective cutting.
[0027] In this embodiment, the line dividing piece 35 includes a connecting portion that is arranged in close contact with the movable knife 33. In this embodiment, the line dividing piece 35 and the movable knife 33 are tightly connected to ensure the effectiveness of the bottom line guide.
[0028] In this embodiment, the movable knife 33 is provided with a guide notch 331 and a wire storage groove 332 extending from the guide notch 331 and distributed along the circumferential direction; the guide notch 331 has an open structure along the wire cutting direction, and the bottom end of the guide notch 331 is connected to the wire storage groove 332; the fixed knife 31 and the movable knife 33 rotating along the wire cutting direction form a surface contact until the blade of the fixed knife 31 moves to the wire cutting protrusion 333 of the movable knife 33. This embodiment effectively ensures the shearing of the bottom line while protecting the extension and positioning of the bottom line. When the movable knife 33 is reset to the non-shearing position, the bent thread head supported by the movable knife 33 and the wire dividing sheet 35 is in the moving path of the surface thread, which effectively ensures the upper thread.
[0029] In this embodiment, the wire protection piece 34 includes a fixing section 341 fixed to the mounting seat 4 , an abutting section 342 for contacting with the wire dividing piece 35 to form a bottom line elongated structure, and a limiting section 343 arranged parallel to the fixed knife 31 .
[0030] In this embodiment, the movable knife 33 is fixedly connected to the thread trimming transmission sleeve 6 coaxially nested with the shuttle bed transmission shaft 1 through the movable knife seat 32, and both ends of the thread trimming transmission sleeve 6 are respectively installed on the shuttle bed transmission shaft 1 through needle bearings. This embodiment effectively reduces noise.
[0031] In this embodiment, the thread trimmer transmission shaft sleeve 6 drives the thread trimmer transmission shaft sleeve 6 and the movable knife 33 to rotate relative to the fixed knife 31 through the driving assembly 2.
[0032] The working process of this embodiment is as follows:
[0033] In this embodiment, when the movable blade rotates relative to the wire dividing piece 35 and the fixed knife 31 with the driving assembly 2 to the cutting position, that is, the wire cutting protrusion 333 on the surface of the movable knife 33 contacts the blade of the fixed knife 31, the bottom line of the shuttle core of the active rotary hook 5 is elongated and fixed as the wire dividing piece 35 contacts the wire protecting piece 34. Since the length of the bottom line thread end is guaranteed and supported and guided by the movable knife 33, when the needle passing through the surface thread is inserted into the rotary hook 5 again, the edge of the rotary hook 5 rotates with the shuttle bed rotation axis to ensure that the coil of the surface thread once again wraps the thread end of the bottom line, completing the threading again. In this embodiment, the relative rotation between the positioning piece and the movable knife 33 during the thread cutting process is used to complete the thread cutting and at the same time utilize the contact between the guide wire piece and the wire protecting piece 34 to form the winding and positioning of the bottom line, effectively elongating the bottom line and facilitating the next needle and threading.
Claims
1. An automatic thread trimming device, characterized in that: The invention comprises a driving assembly and a shearing assembly installed on the shuttle bed transmission shaft, wherein the shearing assembly comprises a fixed knife fixed to a mounting seat and having a certain length along the circumferential direction, a movable knife installed on the shuttle bed transmission shaft through a movable knife seat, and a wire guard fixed to the mounting seat in sequence from the circumference to the center of the circle along the radial direction of the shuttle bed transmission shaft; the movable knife extends into between the fixed knife and the wire guard or moves away from the fixed knife and the wire guard along with the driving assembly; A wire dividing piece is fixed on the side of the movable knife facing the rotary hook. When the movable knife and the fixed knife are shearing, the wire dividing piece contacts the wire protecting piece to form a bottom line elongated structure.
2. An automatic thread trimming device according to claim 1, characterized in that: The wire dividing piece protrudes from the movable knife toward the fixed knife along the circumferential direction, and the width of the portion of the wire dividing piece protruding from the movable knife gradually decreases toward the wire protecting piece.
3. An automatic thread trimming device as claimed in claim 2, characterized in that: The wire dividing piece comprises a connecting portion which is arranged in close contact with the movable knife.
4. An automatic thread trimming device according to claim 1, characterized in that: The movable knife is provided with a guide notch on one side facing the fixed knife and a wire storage groove extending from the guide notch and distributed along the circumferential direction; the guide notch has an open structure along the wire cutting direction, and the bottom end of the guide notch is connected to the wire storage groove; the fixed knife forms a surface contact with the movable knife rotating along the wire cutting direction until the blade of the fixed knife moves to the wire cutting protrusion of the movable knife.
5. The automatic thread trimming device according to claim 1, characterized in that: The wire protection piece comprises a fixed section fixed to the mounting seat, an interference section for contacting with the wire dividing piece to form a bottom line elongated structure, and a limiting section arranged parallel to the fixed knife.
6. An automatic thread trimming device according to claim 1, characterized in that: The movable knife is fixedly connected to a thread trimming transmission shaft sleeve coaxially nested with the shuttle bed transmission shaft through a movable knife seat, and both ends of the thread trimming transmission shaft sleeve are respectively installed on the shuttle bed transmission shaft through needle bearings.
7. An automatic thread trimming device according to claim 6, characterized in that: The thread trimmer transmission shaft sleeve drives the thread trimmer transmission shaft sleeve and the movable knife to rotate relative to the fixed knife through the driving assembly.