Automatic switching mechanism of thread trapper and sewing machine

Abstract

The utility model discloses an automatic switching mechanism of a thread trapper and a sewing machine in the technical field of sewing machines. The switching shaft is mounted on one side of the mounting frame, and the switching shaft is rotationally connected with the mounting frame; the switching cam is fixedly mounted on the switching shaft; the trigger plate is mounted above the mounting frame, one end of the trigger plate is in transmission connection with the switching cam, and when the switching cam rotates, the trigger plate can move in the axis direction of the switching shaft; and the switching plate is installed on the other side of the installation frame, the top end of the switching plate is fixedly connected with the other end of the trigger plate, and a thread loosening claw is arranged at the bottom end of the switching plate. According to the utility model, a cam transmission mode is adopted, so that automatic switching of freely-adjusted yarn trappers is realized.

Description

Technical Field

[0001] This utility model relates to the field of sewing machine technology, specifically to an automatic switching mechanism for a thread clamp and a sewing machine. Background Technology

[0002] Existing sewing machines use a thread clamp (with a built-in spring providing elastic pressure) to grip the thread, creating tension at the other end of the thread as it's sewn onto the fabric, resulting in neat stitches. However, different fabrics require different tension levels during sewing, necessitating manual adjustment of the thread clamp's tightness.

[0003] To accommodate the tension requirements of sewing different fabrics, the existing thread clamps have a large adjustment range for the thread insertion length. When changing to different fabrics, it is necessary to repeatedly experiment and make multiple adjustments until a neat stitch is achieved. In particular, when changing to fabrics with a large range of characteristics, it often takes a lot of time to try and adjust the clamping degree, which is not only inefficient but also requires a high level of experience from the technicians.

[0004] Patent document CN216075297U discloses a double-row thread clamping device. This device has a first thread clamp and a second thread clamp mounted on a base plate. By controlling the first and second thread clamps to apply different clamping forces sequentially to the thread, different sewing stitch requirements can be achieved. Based on this, it has been proposed that if the first thread clamp applies a preset clamping force to the thread for sewing common fabrics, and the second thread clamp applies an adjustable clamping force for sewing less common fabrics, the efficiency of adjusting the thread clamping force can be greatly improved.

[0005] Therefore, how to achieve rapid cutting of two thread clamps under different sewing requirements has become a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0006] In view of this, the purpose of this utility model is to provide an automatic switching mechanism for a wire clamp to address the above-mentioned technical problems.

[0007] The technical solution adopted by this utility model is: an automatic switching mechanism for a wire clamp, the automatic switching mechanism comprising:

[0008] Mounting rack;

[0009] A switching shaft is mounted on one side of the mounting bracket, and the switching shaft is rotatably connected to the mounting bracket;

[0010] A switching cam, which is fixedly mounted on a switching shaft;

[0011] A trigger plate is mounted on top of the mounting bracket. One end of the trigger plate is connected to the switching cam drive, and the trigger plate can move along the axis of the switching shaft when the switching cam rotates.

[0012] A switching plate is installed on the other side of the mounting bracket, and the top end of the switching plate is fixedly connected to the other end of the trigger plate. A wire release claw is provided at the bottom end of the switching plate.

[0013] Preferably, the switching cam is an end face cam, and a roller is installed at one end of the trigger plate, with the outer circumferential surface of the roller abutting against the working end face of the switching cam.

[0014] Preferably, a guide shaft is installed on the other side of the mounting bracket. The guide shaft is arranged parallel to the switching shaft and is slidably connected to the mounting bracket. The other end of the trigger plate is fixedly connected to the guide shaft, and the top end of the switching plate is fixedly connected to the guide shaft.

[0015] Preferably, a return spring is sleeved on the guide shaft, one end of the return spring abuts against the mounting bracket, and the other end of the return spring abuts against the switching plate.

[0016] Preferably, a wire guide plate is installed on the other side of the mounting bracket, the guide shaft is located between the wire guide plate and the switching shaft, the wire guide plate is formed with an elongated slot, the elongated slot is arranged along the axial direction of the guide shaft, and a switching limit pin is accommodated in the elongated slot, one end of the switching limit pin is fixedly connected to the guide shaft.

[0017] Preferably, there are multiple loosening claws, and the multiple loosening claws are staggered in the horizontal and / or vertical directions.

[0018] Preferably, the switching cam is coaxially mounted on the switching shaft, and in the circumferential direction, the working end face of the switching cam includes a loose section and a clamping section.

[0019] The second objective of this utility model is to provide a sewing machine, including the above-mentioned automatic switching mechanism for a thread clamp, and further including a frame, a preset gear thread clamp, and a freely adjustable thread clamp. The automatic switching mechanism is installed on the top of the frame, the preset gear thread clamp is installed on the thread guide plate of the automatic switching mechanism, the freely adjustable thread clamp is installed on the frame and is located below the preset gear thread clamp, and the thread release claw of the automatic switching mechanism is located on one side of the freely adjustable thread clamp.

[0020] The beneficial effects of this utility model are:

[0021] This invention employs a cam drive system. A switching cam is fixedly mounted on the switching shaft. One end of a trigger plate located above the frame is connected to the switching cam drive, and the other end of the trigger plate is fixedly connected to the top of the switching plate. A loosening claw capable of inserting between two clamping plates is fixedly connected to the bottom of the switching plate. During the rotation of the switching shaft, the switching cam drives the trigger plate to reciprocate along the axis of the switching shaft, allowing the loosening claw at the bottom of the switching plate to insert between or withdraw from between the two clamping plates. This enables the two clamping plates to clamp or loosen the thread, achieving automatic switching of the freely adjustable clamping device. Attached Figure Description

[0022] Figure 1 This is one of the structural schematic diagrams of the automatic switching mechanism of the wire clamp of this utility model;

[0023] Figure 2 This is the second structural schematic diagram of the automatic switching mechanism of the wire clamp of this utility model;

[0024] Figure 3 A three-dimensional schematic diagram of the switching cam;

[0025] Figure 4 This is a schematic diagram of a sewing machine.

[0026] Explanation of the reference numerals in the figure:

[0027] 100. Automatic switching mechanism;

[0028] 110. Mounting bracket;

[0029] 120. Switch axis;

[0030] 130. Switching cam; 131. Loosening line segment; 132. Clamping line segment;

[0031] 140. Trigger plate;

[0032] 150. Switching board; 151. Cable release claw;

[0033] 160. Rollers;

[0034] 170. Guide shaft; 171. Switching limit pin;

[0035] 180. Return spring;

[0036] 190. Wiring guide plate; 191. Long slot hole;

[0037] 200. Rack;

[0038] 300. Preset gear cable clamp;

[0039] 400. Adjustable wire clamp. Detailed Implementation

[0040] The specific embodiments of this utility model will be further described in detail below with reference to the accompanying drawings. These embodiments are only used to illustrate this utility model and are not intended to limit it.

[0041] In the description of this utility model, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this utility model. In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0042] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0043] Furthermore, in the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0044] Examples, such as Figures 1-4 As shown, an automatic switching mechanism for a wire clamp is disclosed. The automatic switching mechanism 100 includes: a mounting bracket 110, a switching shaft 120, a switching cam 130, a trigger plate 140, and a switching plate 150.

[0045] The switching shaft 120 is mounted on one side of the mounting bracket 110, and both ends of the switching shaft 120 are rotatably connected to the mounting bracket 110.

[0046] The switching cam 130 is fixedly mounted on the switching shaft 120 so that the switching cam 130 rotates synchronously with the switching shaft 120.

[0047] The trigger plate 140 is mounted above the mounting bracket 110. One end of the trigger plate 140 is connected to the switching cam 130 for transmission, and when the switching cam 130 rotates, the trigger plate 140 can move along the axis of the switching shaft 120.

[0048] The switching plate 150 is installed on the other side of the mounting bracket 110, and the top of the switching plate 150 is fixedly connected to the other end of the trigger plate 140. The bottom of the switching plate 150 is fixedly connected to the wire release claw 151.

[0049] This utility model adopts a cam transmission structure. A switching cam 130 is fixedly installed on the switching shaft 120. One end of the trigger plate 140 located above the mounting bracket 110 is connected to the switching cam 130, and the other end of the trigger plate 140 is fixedly connected to the top of the switching plate 150. A loosening claw 151 that can be inserted between two clamping plates is fixedly connected to the bottom of the switching plate 150. During the rotation of the switching shaft 120, the switching cam 130 can drive the trigger plate 140 to move back and forth along the axis of the switching shaft 120 through cam transmission, so that the loosening claw 151 at the bottom of the switching plate 150 can be inserted between two clamping plates or pulled out from between two clamping plates, thereby clamping or loosening the two clamping plates to achieve automatic switching of the freely adjustable clamping device.

[0050] It should be noted that the lateral direction in this utility model refers to... Figure 1 In this context, the X-axis direction and the longitudinal direction refer to... Figure 1 The Y-axis direction, the vertical direction refers to Figure 1 The Z-axis direction in the equation.

[0051] Specific embodiment 1, such as Figure 1 and Figure 2 As shown, an automatic switching mechanism for a wire clamp is disclosed. The automatic switching mechanism 100 includes: a mounting bracket 110, a switching shaft 120, a switching cam 130, a trigger plate 140, a switching plate 150, and a roller 160.

[0052] The switching shaft 120 is installed on the longitudinal side of the mounting bracket 110. The switching shaft 120 is arranged in the transverse direction, and both ends of the switching shaft 120 are rotatably connected to the mounting bracket 110 through bearings.

[0053] The switching cam 130 is fixedly mounted on the switching shaft 120 so that the switching cam 130 rotates synchronously with the switching shaft 120.

[0054] Preferably, the switching cam 130 is an end face cam. The switching cam 130 is coaxially mounted in the middle of the switching shaft 120. In the circumferential direction of the switching cam 130, the working end face of the switching cam 130 includes a loosening segment 131 and a clamping segment 132. That is, the left end face of the switching cam 130 includes a loosening segment 131 and a clamping segment 132, and the beginning and end ends of the loosening segment 131 and the clamping segment 132 are fixedly connected.

[0055] It should be noted that the axial dimensions of the switching cam 130 corresponding to the loose segment 131 and the clamping segment 132 are different. For example, in Figure 1 In this case, the axial dimension of the switching cam 130 corresponding to the loose segment 131 is greater than the axial dimension of the switching cam 130 corresponding to the clamping segment 132.

[0056] The trigger plate 140 is mounted on top of the mounting bracket 110 in the longitudinal direction, and the trigger plate 140 is slidably connected to the mounting bracket 110 in the transverse direction. One longitudinal end of the trigger plate 140 abuts against the working end face of the switching cam 130 so that when the switching cam 130 rotates, it can drive the trigger plate 140 to move along the axis of the switching shaft 120.

[0057] Specifically, a roller 160 is installed at one end of the trigger plate 140. The roller 160 is rotatably mounted above the trigger plate 140, and the axis of the roller 160 is spatially perpendicular to the axis of the switching cam 130. The outer circumferential surface of the roller 160 abuts against the working end face of the switching cam 130. That is, during the rotation of the switching shaft 120, the outer circumferential surface of the roller 160 can abut against the loose section 131 and the clamping section 132 of the switching cam 130 in succession, so that the switching cam 130 can smoothly drive the trigger plate to move along the axis of the switching shaft 120.

[0058] Preferably, the sliding connection between the trigger plate 140 and the mounting bracket 110 is achieved as follows:

[0059] A guide shaft 170 is installed on the other longitudinal side of the mounting bracket 110. The guide shaft 170 is arranged parallel to the switching shaft 120, and both ends of the guide shaft 170 are slidably connected to the mounting bracket 110 in the lateral direction. The other longitudinal end of the trigger plate 140 is fixedly connected to the guide shaft 170.

[0060] A return spring 180 is fitted on the guide shaft 170. One end of the return spring 180 abuts against the mounting bracket 110, and the other end of the return spring 180 abuts against the switching plate 150. The return spring 180 applies a lateral force to the guide shaft 170, which, together with the lateral pushing action of the switching cam 130 on the trigger plate 140, allows the trigger plate 140 to reciprocate in the lateral direction during the rotation of the switching shaft 120.

[0061] The switching plate 150 is installed on the other side of the longitudinal direction of the mounting bracket 110, and the top end of the switching plate 150 is fixedly connected to the other end of the trigger plate 140, that is, the top end of the switching plate 150 is fixedly connected to the guide shaft 170, and a wire release claw 151 is fixedly connected to the bottom end of the switching plate 150.

[0062] Specific embodiment 2, such as Figure 1 , Figure 2 and Figure 3As shown, an automatic switching mechanism for a wire clamp is disclosed. The automatic switching mechanism 100 includes: a mounting bracket 110, a switching shaft 120, a switching cam 130, a trigger plate 140, a switching plate 150, a roller 160, a guide shaft 170, and a wire guide plate 190.

[0063] The switching shaft 120 is installed on the longitudinal side of the mounting bracket 110. The switching shaft 120 is arranged in the transverse direction, and both ends of the switching shaft 120 are rotatably connected to the mounting bracket 110 through bearings.

[0064] The switching cam 130 is an end face cam. The switching cam 130 is coaxially mounted in the middle of the switching shaft 120. In the circumferential direction of the switching cam 130, the working end face of the switching cam 130 includes a loose section 131 and a clamping section 132.

[0065] The trigger plate 140 is mounted vertically above the mounting bracket 110, and the trigger plate 140 is slidably connected to the mounting bracket 110 in the transverse direction. One longitudinal end of the trigger plate 140 abuts against the working end face of the switching cam 130. A guide shaft 170 is mounted on the other longitudinal side of the mounting bracket 110. The guide shaft 170 is parallel to the switching shaft 120, and both ends of the guide shaft 170 are slidably connected to the mounting bracket 110 in the transverse direction. The other longitudinal end of the trigger plate 140 is fixedly connected to the guide shaft 170.

[0066] A return spring 180 is fitted on the guide shaft 170. One end of the return spring 180 abuts against the mounting bracket 110, and the other end of the return spring 180 abuts against the switching plate 150. The return spring 180 applies a lateral force to the guide shaft 170, which, together with the lateral pushing action of the switching cam 130 on the trigger plate 140, allows the trigger plate 140 to reciprocate in the lateral direction during the rotation of the switching shaft 120.

[0067] A wire guide plate 190 is installed on the other longitudinal side of the mounting bracket 110. The wire guide plate 190 is arranged in the transverse direction, and both ends of the wire guide plate 190 are fixedly connected to the mounting bracket 110. The guide shaft 170 is located between the wire guide plate 190 and the switching shaft 120. A long slot 191 is formed on the wire guide plate 190. The long slot 191 is arranged along the axial direction of the guide shaft 170, that is, the length of the slot 191 is parallel to the axial direction of the guide shaft 170. A switching limit pin 171 is accommodated in the long slot 191. One end of the switching limit pin 171 is fixedly connected to the guide shaft 170 and is used to limit the transverse movement of the guide shaft 170.

[0068] The switching plate 150 is installed on the other side of the longitudinal direction of the mounting bracket 110, and the top of the switching plate 150 is fixedly connected to the guide shaft 170, and the bottom of the switching plate 150 is fixedly connected to the wire release claw 151.

[0069] Preferably, there are multiple loosening claws 151, and the multiple loosening claws 151 are staggered in the lateral direction, that is, the multiple loosening claws 151 are spaced apart in the lateral direction.

[0070] Preferably, there are multiple loosening claws 151, and the multiple loosening claws 151 are staggered in the vertical direction, that is, the multiple loosening claws 151 are spaced apart in the vertical direction.

[0071] More preferably, there are multiple loosening claws 151, and the multiple loosening claws 151 are staggered in the horizontal and vertical directions. That is, the multiple loosening claws 151 are spaced apart in the vertical direction, and at the same time, the multiple loosening claws 151 are also spaced apart in the vertical direction, so that the multiple loosening claws 151 can be inserted into the two clamping plates of the multiple clamping wires at the same time.

[0072] Examples, such as Figure 4 As shown, a sewing machine includes the aforementioned automatic switching mechanism for the thread clamp, and further includes a frame 200, a preset-position thread clamp 300, and a freely adjustable thread clamp 400. The automatic switching mechanism 100 is fixedly installed on the top of the frame 200. There are multiple preset-position thread clamps 300, and these multiple preset-position thread clamps 300 are installed on the thread guide plate 190 of the automatic switching mechanism 100. There are multiple freely adjustable thread clamps 400, and these multiple freely adjustable thread clamps 400 are installed in a staggered manner on the frame 200, and the freely adjustable thread clamps 400 are located below the preset-position thread clamps 300. The thread release claws 151 of the automatic switching mechanism 100 are located one-to-one on one side of the freely adjustable thread clamps 400.

[0073] The working process of the automatic switching mechanism of this utility model is as follows:

[0074] When the thread clamp 300 is used to clamp the thread, the switching shaft 120 rotates to the point where the loosening segment 131 of the switching cam 130 contacts the roller 160. The rotation from the point where the clamping segment 132 contacts the roller 160 to the point where the loosening segment 131 contacts the roller 160 causes the switching cam 130 to push the roller 160 to the left along the axial direction. This causes the trigger plate 140 to drive the switching plate 150 and the loosening claw 151 to move to the left. The loosening claw 151 is located on the right side of the two clamping plates of the freely adjustable thread clamp 400. When the loosening claw 151 moves to the left, it inserts between the two clamping plates of the freely adjustable thread clamp 400, thereby causing the two clamping plates to loosen the thread, which means that the freely adjustable thread clamp 400 is ineffective.

[0075] When the freely adjustable thread clamp 400 is used to clamp the thread (the preset position thread clamp 300 is disabled), the switching shaft 120 rotates accordingly until the clamping section 132 of the switching cam 130 contacts the roller. The thread loosening section 131 contacts the roller 160, and the rotation to the point where the clamping section 132 contacts the roller 160 will cause a gap to appear between the switching cam 130 and the roller 160. Under the elastic force of the return spring 180, the guide shaft 170 will move to the right along the axial direction, thereby causing the switching plate 150 and the thread loosening claw 151 to move to the right. The thread loosening claw 151 is located on the right side of the two clamping plates of the freely adjustable thread clamp 400. The movement of the thread loosening claw 151 to the right will pull it out from between the two clamping plates of the freely adjustable thread clamp 400, thereby causing the two clamping plates to clamp the thread.

[0076] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present utility model, and these improvements and substitutions should also be considered within the protection scope of the present utility model.

Claims

1. An automatic switching mechanism for a wire clamp, characterized in that, The automatic switching mechanism (100) includes: Mounting bracket (110); A switching shaft (120) is mounted on one side of a mounting bracket (110) and is rotatably connected to the mounting bracket (110); A switching cam (130) is fixedly mounted on a switching shaft (120); A trigger plate (140) is mounted on top of a mounting bracket (110). One end of the trigger plate (140) is connected to a switching cam (130) for transmission. When the switching cam (130) rotates, the trigger plate (140) can move along the axis of the switching shaft (120). A switching plate (150) is installed on the other side of the mounting bracket (110), and the top end of the switching plate (150) is fixedly connected to the other end of the trigger plate (140). A wire release claw (151) is connected to the bottom end of the switching plate (150).

2. The automatic switching mechanism for a wire clamp according to claim 1, characterized in that, The switching cam (130) is an end face cam, and a roller (160) is installed at one end of the trigger plate (140). The outer circumferential surface of the roller (160) abuts against the working end face of the switching cam (130).

3. The automatic switching mechanism for a wire clamp according to claim 2, characterized in that, A guide shaft (170) is installed on the other side of the mounting bracket (110). The guide shaft (170) is parallel to the switching shaft (120) and is slidably connected to the mounting bracket (110). The other end of the trigger plate (140) is fixedly connected to the guide shaft (170), and the top end of the switching plate (150) is fixedly connected to the guide shaft (170).

4. The automatic switching mechanism for a wire clamp according to claim 3, characterized in that, A reset spring (180) is sleeved on the guide shaft (170). One end of the reset spring (180) abuts against the mounting bracket (110), and the other end of the reset spring (180) abuts against the switching plate (150).

5. The automatic switching mechanism for a wire clamp according to claim 4, characterized in that, A wire guide plate (190) is installed on the other side of the mounting bracket (110). The guide shaft (170) is located between the wire guide plate (190) and the switching shaft (120). A long slot (191) is formed on the wire guide plate (190). The long slot (191) is arranged along the axial direction of the guide shaft (170), and a switching limit pin (171) is accommodated in the long slot (191). One end of the switching limit pin (171) is fixedly connected to the guide shaft (170).

6. The automatic switching mechanism for a wire clamp according to claim 1, characterized in that, The number of the loosening claws (151) is multiple, and the multiple loosening claws (151) are staggered in the horizontal direction and / or vertical direction.

7. The automatic switching mechanism for a wire clamp according to claim 2, characterized in that, The switching cam (130) is coaxially mounted on the switching shaft (120), and in the circumferential direction, the working end face of the switching cam (130) includes a loose section (131) and a clamping section (132).

8. A sewing machine, characterized in that, The automatic switching mechanism for a wire clamp according to any one of claims 1-7 further includes a frame (200), a preset gear wire clamp (300), and a freely adjustable wire clamp (400). The automatic switching mechanism (100) is mounted on the top of the frame (200), the preset gear wire clamp (300) is mounted on the wire guide plate (190) of the automatic switching mechanism (100), the freely adjustable wire clamp (400) is mounted on the frame (200) and is located below the preset gear wire clamp (300), and the wire release claw (151) of the automatic switching mechanism (100) is located on one side of the freely adjustable wire clamp (400).

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