Thread guide mechanism and sewing machine

Abstract

The technical scheme of the application provides a thread guide mechanism and a sewing machine. The thread guide mechanism comprises a first guide roller, which is rotationally arranged around a fixed shaft; a second guide roller, which is rotationally arranged around a moving shaft, the moving shaft is parallel to the fixed shaft and can float in a plane perpendicular to the fixed shaft, and the second guide roller elastically presses the first guide roller; a transmission belt, one of the first guide roller and the second guide roller is in contact with the inner surface of the transmission belt for transmission, and the other is in contact with the outer surface of the transmission belt for transmission; and the first guide roller and the second guide roller are driven by the transmission belt to rotate in opposite directions at the same speed. The thread guide mechanism driven by the inner and outer surfaces of the transmission belt realizes the design scheme of the front and back transmission of the thread guide mechanism in different rotation directions of the first guide roller and the second guide roller, which simplifies the mechanism design, reduces the installation space of the thread guide mechanism, and simplifies the maintenance requirement of the thread guide mechanism.

Description

Technical Field

[0001] This application relates to the field of sewing equipment technology, specifically to a fabric guiding mechanism and a sewing machine. Background Technology

[0002] To improve production efficiency, ensure the movement trajectory of the fabric before and after the sewing head, and guarantee the appearance quality of the sewing, sewing machines, especially industrial stitching machines, usually have specific fabric guiding mechanisms installed before and after the sewing head.

[0003] Taking the sewing machine as an example again, Figure 1 This is a simplified diagram of a fabric guiding mechanism in the prior art. The fabric guiding mechanism 2 is located on one side of the fabric W flowing out of the sewing head 1. After the fabric is sewn, it is guided out in a specific direction by the fabric guiding mechanism 2. The fabric guiding mechanism 2 generally includes two elastically clamped guide rollers 21. During fabric guiding, the fabric W is positioned between the two guide rollers 21, and the two guide rollers 21 push the fabric to achieve feeding motion. In reality, since the fabric W is formed by overlapping two opposing pieces of fabric during the sewing process, both guide rollers 21 are drive wheels to ensure consistent material guidance. In the prior art, the synchronous drive of the guide rollers 21 is achieved by a set of transmission gears, specifically by a gear set driven by a drive shaft. Furthermore, to achieve initial fabric positioning, the rotation axis of one set of guide rollers 21 needs to be configured to translate within a plane perpendicular to the axis to open the space between the two guide rollers 21. For this purpose, a handle 211 can be provided on the support of the movable guide roller 21 for manually opening the gap between the two guide rollers 21.

[0004] The main problem with using a wheel train 22 to drive the two guide wheels 21 is that the wheel train 22 is relatively bulky, limiting the space on the side of the sewing machine head. Furthermore, maintaining the wheel train 22 in good working order typically requires lubrication. In the prior art, this is achieved by supplying lubricating oil to the housing containing the wheel train 22. This places high demands on the sealing performance of the guide mechanism 2. Under poor maintenance conditions, the wheel train 22 must be positioned above the guide wheels 21 due to operational constraints. Oil leakage caused by poor sealing of the guide mechanism 2 may contaminate the fabric W. Utility Model Content

[0005] To address the problem of limited space and impaired fabric cleaning caused by the transmission mechanism design of the existing fabric guiding mechanism 2, this application provides a fabric guiding mechanism and a sewing machine.

[0006] This application provides a guiding mechanism, including:

[0007] The first guide wheel is set to rotate around a fixed axis;

[0008] The second guide wheel is rotatably arranged around the movable axis, which is parallel to the fixed axis and can float in a plane perpendicular to the fixed axis. The second guide wheel elastically presses against the first guide wheel.

[0009] The transmission belt has one of the first guide pulley and the second guide pulley in contact with the inner surface of the transmission belt for transmission, and the other of the two in contact with the outer surface of the transmission belt for transmission.

[0010] The first guide wheel and the second guide wheel are driven by a transmission belt to rotate in opposite directions at the same speed.

[0011] Preferably, it further includes a swing arm, wherein the moving axis of the second guide wheel is disposed on the swing arm offset from the swing axis; when the swing arm swings about the swing axis, the moving axis moves in a plane perpendicular to the fixed axis.

[0012] Preferably, the swing arm is elastically stretched by an elastic element connected to the housing at one end, and the elastic element causes the second guide wheel to elastically press against the surface of the first guide wheel.

[0013] Preferably, the swing arm is also provided with a handle, which forms a force-saving lever that drives the second guide wheel to swing around the swing axis.

[0014] Preferably, the wrap angle of the transmission belt at the first guide pulley and the second guide pulley is less than 180 degrees.

[0015] Preferably, the wrap angle of the transmission belt at the first guide pulley and the second guide pulley is less than 120 degrees.

[0016] Preferably, it further includes an idler pulley, which is used to spread the running path of the transmission belt so that the wrap angle of the transmission belt at the first guide pulley and the second guide pulley is less than 120 degrees.

[0017] Preferably, the first supporting components that appear when the transmission belt passes upstream and downstream of the second guide pulley are the first supporting component and the second supporting component, respectively; then one of the first supporting component and the second supporting component is the first guide pulley;

[0018] The swing range of the swing arm is limited to a preset range around the perpendicular line connecting the first support and the second support.

[0019] Preferably, the swing axis of the swing arm is located on the perpendicular bisector of the line connecting the first support member and the second support member.

[0020] Alternatively, the swing arm may swing at an angle of no more than 20 degrees on one side around the vertical line.

[0021] Preferably, the idler wheel floats elastically in a plane perpendicular to the fixed axis.

[0022] This application also provides a sewing machine that includes the fabric guide mechanism described in any of the above claims.

[0023] This application provides a fabric guiding mechanism that achieves different rotation directions for the first and second guide wheels through the inner and outer surfaces of a transmission belt. Its transmission mechanism employs a flexible belt drive, avoiding the use of gear trains. The forward and reverse transmission design further simplifies the mechanism design, reducing installation space and simplifying maintenance. Since belt drives generally do not require lubrication with oil or grease, fabric contamination is effectively avoided, ensuring fabric cleanliness. Attached Figure Description

[0024] Figure 1 A simplified diagram of a guide fabric mechanism in the prior art;

[0025] Figure 2 This is a schematic diagram of the guiding mechanism of this application;

[0026] Figure 3 Some embodiments of the path of the drive belt 43 of the guide cloth mechanism of this application;

[0027] Figure 4 A schematic diagram showing the guide fabric mechanism of this application after partially obstructing the area;

[0028] Figure 5 This is a schematic diagram of the fabric guide mechanism of this application applied to a sewing machine.

[0029] In the picture:

[0030] 1: Machine head; 2: Fabric guiding mechanism; 21: Fabric guiding wheel; 211: Handle; 22: Gear train; 41: First guide wheel; 42: Second guide wheel; 421: Swing arm; 422: Elastic element; 43: Transmission belt; 431: Handle; 44: Drive wheel; 45: Idler wheel; 46: Machine housing; 461: Opening; 51: First support member; 52: Second support member; 53: Vertical line; O: Fixed shaft; O1: Moving shaft; O2: Swing shaft; W: Fabric. Detailed Implementation

[0031] The technical solution of this application will be described in detail below with reference to the accompanying drawings and specific embodiments. In this specification, the dimensions of the drawings do not represent the actual size ratio. The drawings are only used to illustrate the relative positional relationship and connection relationship between the components. Components with the same name or the same reference numeral represent similar or the same structure, and are limited to illustrative purposes.

[0032] Figure 2This is a schematic diagram of the fabric guiding mechanism 2 of this application. The technical solution of this application includes a first guide wheel 41 rotatably arranged around a fixed axis O and a second guide wheel 42 elastically pressed against the first guide wheel 41. The second guide wheel 42 is rotatably arranged around a moving axis O1, and the moving axis O1 is parallel to the fixed axis O, allowing the moving axis O1 to float in a plane perpendicular to the fixed axis O. The first guide wheel 41 and the second guide wheel 42 are driven to rotate in opposite directions at equal speeds by a transmission belt 43, which is driven by a drive wheel 44. As shown in the figure, the first guide wheel 41 and the second guide wheel 42 have different rotation directions but equal rotation speeds. Therefore, when the fabric is being unloaded, the multiple layers of fabric sewn together can each be pushed by the first guide wheel 41 and the second guide wheel 42, ensuring synchronous movement of the multiple layers of fabric and avoiding the problem of fabric misalignment at the machine head caused by the gradual difference in fabric forward speed when driven from one side. To achieve the opposite rotation of the first guide wheel 41 and the second guide wheel 42 with the simplest structure, one of the first guide wheel 41 and the second guide wheel 42 meshes with the inner surface of the transmission belt 43 and rotates, while the other meshes with the outer surface of the transmission belt 43 and rotates. The equal rotational speeds of the two are achieved by designing the meshing points of the first guide wheel 41 and the second guide wheel 42 with the transmission belt 43 to have the same circumferential size.

[0033] In practical applications, the transmission belt 43 is preferably a synchronous belt with double-sided meshing teeth. Both the second guide pulley 42 and the first guide pulley 41 are coaxially equipped with synchronous pulleys of the same number of teeth. Because they mesh internally and externally and have equal tooth counts, under the drive of the same transmission belt 43, the first guide pulley 41 and the second guide pulley 42 can maintain equal rotational speeds even when rotating in opposite directions. With this design, the use of the transmission belt 43 instead of a gear train simplifies the design of the drive mechanism, avoiding the need for multiple gears in the drive mechanism of 2. Using a synchronous belt drive compresses the volume of the rotating mechanism, leaving more space for the layout of other mechanisms in the machine head. Furthermore, the synchronous belt rotation has a certain degree of flexibility, resulting in less impact during movement and smoother operation. In this case, the operating noise of the mechanism is lower, and lubrication is usually unnecessary, thus ensuring the cleanliness of the fabric guide mechanism 2 and completely avoiding the problem of potential fabric contamination W.

[0034] like Figure 1As shown in the schematic diagram, to ensure the stability of the transmission system and prevent slippage of the transmission belt 43, the wrap angle of the transmission belt 43 at both the first guide pulley 41 and the second guide pulley 42 should be less than 180 degrees, more preferably less than 120 degrees. To achieve this, an idler pulley 45 may be provided to spread the transmission belt 43. The purpose of the idler pulley 45 is to ensure that, by fixing the running path of the transmission belt 43, the wrap angle of the transmission belt 43 with both the first guide pulley 41 and the second guide pulley 42 meets the requirement of being within 120 degrees. Figure 3 This is a schematic diagram of several transmission structures of the guide belt mechanism 2. When the radius of the drive wheel 44 is significantly larger than the radii of the first guide wheel 41 and the second guide wheel 42, there is a situation where it is not necessary to set an idler wheel 45, but the appropriate positional arrangement of the first guide wheel 41 and the second guide wheel 42 can ensure that the wrap angle of the transmission belt 43 at the first guide wheel 41 and the second guide wheel 42 meets the above conditions. More generally, it is necessary to... Figure 3 The idler pulley 45 is set to change the motion path of the transmission belt 43 so that the wrap angle of the transmission belt 43 meets the requirements.

[0035] Figure 4 This is a schematic diagram of the fabric guiding mechanism 2 after partially obscuring the area. The surfaces of the first guide wheel 41 and the second guide wheel 42 mesh with each other to ensure the pressing output of the fabric and prevent slippage between them. For this purpose, the rotating surfaces of the first guide wheel 41 and the second guide wheel 42 that press the fabric have interlocking undulating features, such as straight or helical teeth with lower tooth height as shown in the figure, or other surface knurling features in the design. The moving axis O1 of the second guide wheel 42 is eccentrically (offset from the swing axis O2) on the swing arm 421. When the swing arm swings about its swing axis O2, the moving axis O1 moves in a plane perpendicular to the fixed axis O, thereby realizing the contact and separation between the first guide wheel 41 and the second guide wheel 42.

[0036] like Figure 4 As shown in the schematic diagram, the swing arm 421 is elastically tightened by an elastic element 422 fixed at one end to the housing 46. The elastic element 422 causes the second guide wheel 42 to elastically press against the surface of the first guide wheel 41. A handle 431 extending along the length of the swing arm 421 is also provided, forming a lever that saves effort. In this case, turning the handle 431 causes the swing arm 421 to overcome the elastic force of the elastic element 422 and move away from the first guide wheel 41, thereby opening the space between the first guide wheel 41 and the second guide wheel 42. At this time, fabric can be placed between the first guide wheel 41 and the second guide wheel 42.

[0037] like Figure 4The top view of the housing 46 shows an opening 461 on the housing 46 for the second guide wheel 42 to swing. Finally, it should be noted that during the movement of the moving shaft O1 containing the second guide wheel 42, it is generally impossible to precisely guarantee that the travel of the transmission belt 43 remains constant. This will cause variations in the tension of the transmission belt 43, potentially leading to slippage or other problems. To avoid this, such as... Figure 4 As shown, the first supporting components that appear upstream and downstream of the transmission belt 43 after passing the second guide pulley 42 are the first support member 51 and the second support member 52, respectively. Clearly, one of them is the first guide pulley 41, and the other may be an idler pulley 45 or a drive pulley 44. To avoid the swing of the swing arm 421 significantly affecting the tension of the transmission belt 43, the swing range of the swing arm 421 is limited to a preset range of left and right floating within the vertical line 53 connecting the first support member 51 and the second support member 52. The angle of the swing arm 421 floating to the left and right of this vertical line 53 generally does not exceed 20 degrees. Furthermore, the swing axis O2 of the swing arm 421 can be set on the vertical line of the line connecting the first support member 51 and the second support member 52, thereby balancing the influence of the swing of the swing arm 421 on the wrap angle of the transmission belt 43 at the first support member 51 and the second support member 52 on both sides, and improving the reliability of the transmission belt 43 operation. Figure 5 This is a schematic diagram of the fabric guide mechanism 2 in this application applied to a sewing machine.

[0038] The above description is merely a preferred embodiment of this application and is not intended to limit the scope of this application. Any modifications and improvements made by those skilled in the art to the technical solutions of this application without departing from the spirit of this application shall fall within the protection scope defined by the claims of this application.

Claims

1. A fabric guiding mechanism, characterized in that, include: The first guide wheel (41) is rotatably set around a fixed axis (O); The second guide wheel (42) is rotatably arranged around the movable shaft (O1), the movable shaft (O1) is parallel to the fixed shaft (O) and can float in a plane perpendicular to the fixed shaft (O), and the second guide wheel (42) elastically presses against the first guide wheel (41); The transmission belt (43) has one of the first guide pulley (41) and the second guide pulley (42) in contact with the inner surface of the transmission belt (43) for transmission, and the other of the two in contact with the outer surface of the transmission belt (43) for transmission. The first guide wheel (41) and the second guide wheel (42) are driven to rotate in opposite directions at the same speed by a transmission belt (43).

2. The guiding mechanism as described in claim 1, characterized in that, It also includes a swing arm (421), and the moving axis (O1) of the second guide wheel (42) is set on the swing arm (421) offset from the swing axis (O2); when the swing arm (421) swings around the swing axis (O2), the moving axis (O1) moves in a plane perpendicular to the fixed axis (O).

3. The guiding mechanism as described in claim 2, characterized in that, The swing arm (421) is elastically tightened by an elastic element (422) connected to the housing (46) at one end, and the elastic element (422) causes the second guide wheel (42) to elastically press against the surface of the first guide wheel (41).

4. The guiding mechanism as described in claim 2, characterized in that, The swing arm (421) is also provided with a handle (431), which forms a force-saving lever that drives the second guide wheel (42) to swing around the swing axis (O2).

5. The guiding mechanism as described in any one of claims 1-4, characterized in that, The wrap angle of the transmission belt (43) at the first guide wheel (41) and the second guide wheel (42) is less than 180 degrees, and the wrap angle of the transmission belt (43) at the first guide wheel (41) and the second guide wheel (42) is less than 120 degrees.

6. The guiding mechanism as described in claim 1, characterized in that, It also includes an idler pulley (45), which is used to spread the running path of the transmission belt (43) so that the wrap angle of the transmission belt (43) at the first guide pulley (41) and the second guide pulley (42) is less than 120 degrees.

7. The guiding mechanism as described in claim 2 or 4, characterized in that, When the transmission belt (43) passes upstream and downstream of the second guide wheel (42), the first supporting components that appear first are the first support member (51) and the second support member (52), respectively; then one of the first support member (51) and the second support member (52) is the first guide wheel (41); The swing range of the swing arm (421) is limited to a predetermined range around the perpendicular line (53) connecting the first support (51) and the second support (52).

8. The guiding mechanism as described in claim 7, characterized in that, The swing axis (O2) of the swing arm (421) is located on the perpendicular bisector of the line connecting the first support member (51) and the second support member (52). Alternatively, the swing arm (421) swings at an angle of no more than 20 degrees on one side around the vertical line (53).

9. The guiding mechanism as described in claim 6, characterized in that, The idler wheel (45) floats elastically in a plane perpendicular to the fixed axis (O).

10. A sewing machine, characterized in that, Includes the guide fabric mechanism as described in any one of claims 1-9.

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