Driving device capable of adjusting height of feed dog

Abstract

The invention relates to a driving device capable of adjusting the height of a feed dog, which comprises a driving connecting rod, an eccentric connecting rod, a pushing connecting rod, a connecting rod and a feed dog bracket, and further comprises an eccentric cam, the eccentric cam consists of an outer eccentric cam and an inner eccentric cam, the outer eccentric cam is fixedly connected with a bearing, and the inner eccentric cam is eccentrically arranged in the outer eccentric cam; the inner eccentric cam is connected with the driving shaft; different heights of the cloth feeding teeth are achieved by adjusting different angles through the inner eccentric cam, and the problem that in the prior art, sewing and take-up of fabric with different thicknesses are difficult is solved.

Description

Technical Field

[0001] The invention relates to the technical field of sewing machines, and in particular to a driving device capable of adjusting the height of a feed tooth. Background Art

[0002] When the sewing machine is working, the fabric is lifted and pulled rhythmically by the presser foot and the feed dog, so as to achieve uniform and equidistant movement of the fabric. Generally, the height of the feed dog is set when the sewing machine leaves the factory. The height of the feed dog is fixed and often cannot be adjusted by itself. To adjust the height of the feed dog by itself, corresponding adjustment tools are required, and the adjustment process is time-consuming and labor-intensive, and the height of the feed dog is difficult to control. When sewing thick materials, the sewing machine that has not adjusted the height of the feed dog will have insufficient feed dog stroke height, poor thread collection effect, and even the height of the feed dog will fall into the deformation range of the fabric, which will eventually lead to the upper layer of the thicker fabric in multiple layers being delaminated due to insufficient dragging force. Therefore, under normal circumstances, different sewing machines are generally selected for fabrics of different thicknesses.

[0003] How to overcome the aforementioned sewing quality problems such as insufficient feed tooth height, poor thread collection and delamination is a technical problem to be solved by the present invention. Summary of the invention

[0004] The purpose of the present invention is to provide a driving device capable of adjusting the height of a feed tooth, thereby solving the sewing quality problems of insufficient feed tooth height, poor thread collection and delamination in the prior art.

[0005] To achieve the above object, the technical solution of the present invention is:

[0006] A driving device capable of adjusting the height of a feed dog, comprising a driving connecting rod, an eccentric connecting rod, a pushing connecting rod, a connecting rod and a feed dog bracket, wherein the driving connecting rod is rotatably connected to the eccentric connecting rod, the eccentric connecting rod is rotatably connected to the pushing connecting rod, the pushing connecting rod is rotatably connected to the connecting rod, and the connecting rod is rotatably connected to the feed dog bracket;

[0007] It also includes a cam, which is eccentrically connected to the drive shaft and is also connected to the drive connecting rod through a bearing;

[0008] The driving shaft drives the cam to rotate eccentrically, so that the driving connecting rod periodically drives the eccentric connecting rod, the pushing connecting rod and the connecting rod to perform periodic linkage, and the connecting rod drives the feed dog bracket to perform periodic movement in the horizontal direction and the vertical direction;

[0009] The cam is composed of an outer eccentric cam and an inner eccentric cam, the outer eccentric cam is fixedly connected to the bearing, the inner eccentric cam is eccentrically arranged inside the outer eccentric cam, and the inner eccentric cam is eccentrically connected to the drive shaft;

[0010] The outer eccentric cam and the inner eccentric cam are both circular, the outer eccentric cam is provided with a circular mounting cavity, the center of the mounting cavity deviates from the center of the outer eccentric cam, and the center of the mounting cavity is the eccentricity of the outer eccentric cam; the inner eccentric cam is arranged in the mounting cavity; the center of the eccentric connection between the inner eccentric cam and the drive shaft is the eccentricity of the inner eccentric cam;

[0011] A first eccentric position and a second eccentric position of the inner eccentric cam are fixed in the outer eccentric cam, and when the inner eccentric cam is fixed at the first eccentric position, the vertical movement of the feed dog bracket is limited within a first stroke height, and when the inner eccentric cam is fixed at the second eccentric position, the vertical movement of the feed dog bracket is limited within a second stroke height;

[0012] When the inner eccentric cam is in the first eccentric position, the eccentricity of the inner eccentric cam coincides with the eccentricity of the outer eccentric cam; when the inner eccentric cam is in the second eccentric position, the eccentricity of the inner eccentric cam does not coincide with the eccentricity of the outer eccentric cam, and the distance between the two is the difference between the second stroke height and the first stroke height of the vertical movement of the feed dog bracket.

[0013] The driving connecting rod comprises a bearing mounting part and a driving arm, a bearing is arranged in the bearing mounting part, an eccentric cam is arranged in the bearing, and the driving arm is connected with the eccentric connecting rod.

[0014] The inner eccentric cam comprises a circular wheel body and a wheel shaft protruding from the surface of the wheel body, the center of the wheel shaft deviates from the center of the wheel body, and the center of the wheel shaft is the eccentricity of the inner eccentric cam; the wheel shaft is connected to the driving shaft.

[0015] The inner eccentric cam rotates 90°, 180° or 270° from the first eccentric position to the second eccentric position.

[0016] The edge of the outer eccentric cam is provided with a screw hole which penetrates to the installation cavity, and the bolt passes through the screw hole to fix the inner eccentric cam in the installation cavity.

[0017] The screw holes are evenly arranged on the edge of the outer eccentric cam, and two screw holes are arranged.

[0018] The advantages of the present invention are: 1. The main structure of the existing sewing machine is not changed, and the feed dog height can be adjusted to ensure the thread collection effect; 2. An inner eccentric cam is arranged in the outer eccentric cam of the prior art, and the feed dog height can be adjusted by changing the position of the inner eccentric cam; 3. The position change of the inner eccentric cam is convenient and easy to operate; 4. On the basis of the existing sewing machine structure, only the outer eccentric cam is changed, the technical transformation cost is low, and one sewing machine can be suitable for processing fabrics of different thicknesses. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of the inner eccentric cam of the present invention being located at a first eccentric position;

[0020] Figure 2 It is a structural schematic diagram of the inner eccentric cam of the present invention being located at a second eccentric position;

[0021] Figure 3 is a planar cross-sectional view of the external eccentric cam of the present invention;

[0022] Figure 4 is a longitudinal sectional view of the inner eccentric cam of the present invention;

[0023] Figure 5 It is a structural schematic diagram of the driving connecting rod of the present invention.

[0024] In the figure: 1-driving connecting rod; 11-bearing mounting part; 12-driving arm; 2-eccentric connecting rod; 3-pushing connecting rod; 4-connecting rod; 5-feed dog bracket; 6-external eccentric cam; 61-mounting cavity; 62-screw hole; 7-inner eccentric cam; 71-wheel body; 72-wheel axle; 8-bearing. DETAILED DESCRIPTION

[0025] The present invention is further described below in conjunction with the accompanying drawings, which are only used for exemplary description and cannot be understood as limiting the present invention.

[0026] In order to more concisely describe the present embodiment, some parts known to those skilled in the art but not related to the main content of the present invention are omitted in the drawings or descriptions. In addition, for the convenience of description, some parts in the drawings are omitted, enlarged or reduced, but they do not represent the size or entire structure of the actual product.

[0027] The present invention discloses a driving device capable of adjusting the height of a feed dog. Figure 1-5 As shown, it includes a driving connecting rod 1, an eccentric connecting rod 2, a pushing connecting rod 3, a connecting rod 4 and a feed dog bracket 5. The driving connecting rod 1 is rotatably connected to the eccentric connecting rod 2, the eccentric connecting rod 2 is rotatably connected to the pushing connecting rod 3, the pushing connecting rod 3 is rotatably connected to the connecting rod 4, and the connecting rod 4 is rotatably connected to the feed dog bracket 5; it also includes a cam, which is eccentrically connected to the driving shaft, so that the rotation of the cam is eccentric rotation, and the cam is also connected to the driving connecting rod 1 through a bearing 8.

[0028] The driving shaft drives the cam to rotate eccentrically, so that the driving connecting rod 1 periodically drives the eccentric connecting rod 2, the pushing connecting rod 3 and the connecting rod 4 to perform periodic linkage, and the connecting rod 4 drives the feed dog bracket 5 to perform periodic movement in the horizontal and vertical directions.

[0029] Preferably, if Figure 5As shown, the driving connecting rod 1 comprises a bearing mounting portion 11 and a driving arm 12, a bearing 8 is arranged in the bearing mounting portion 11, a cam is arranged in the bearing 8, and the driving arm 12 is connected to the eccentric connecting rod 2. The above is the prior art in the existing sewing machine.

[0030] In the device, the eccentric rotation of the cam determines the horizontal movement distance of the driving link 1, and the horizontal movement distance of the driving link 1 determines the height of the feed dog bracket 5 in the vertical direction through linkage, that is, the height of the feed dog bracket 5 in the vertical direction depends on the distance that the eccentric rotation of the cam can make the driving link 1 move in the horizontal direction. Therefore, adjusting the height of the feed dog bracket 5 is to adjust the eccentric connection position of the driving shaft and the cam to adjust the horizontal movement distance of the driving link 1.

[0031] Based on this, the present invention creatively sets an eccentric cam in the existing cam, so as to adjust the horizontal movement distance of the driving connecting rod 1 and then adjust the height of the feed dog bracket 5 in the vertical direction at the lowest cost without changing other structures of the sewing machine.

[0032] like Figure 1 , Figure 2 As shown, the cam is composed of an outer eccentric cam 6 and an inner eccentric cam 7. The outer eccentric cam 6 is fixedly connected to a bearing 8, and the inner eccentric cam 7 is eccentrically arranged inside the outer eccentric cam 6. The inner eccentric cam 7 is connected to a drive shaft.

[0033] The first eccentric position and the second eccentric position of the fixed inner eccentric cam 7 are set in the outer eccentric cam 6. The inner eccentric cam 7 is at the second eccentric position when it rotates 90°, 180° or 270° from the first eccentric position.

[0034] like Figure 1 , Figure 3 As shown, the outer eccentric cam 6 and the inner eccentric cam 7 are both circular. The outer eccentric cam 6 is provided with a circular mounting cavity 61. The center of the mounting cavity 61 deviates from the center of the outer eccentric cam 6. The center of the mounting cavity 61 is the eccentricity of the outer eccentric cam 6. The inner eccentric cam 7 is arranged in the mounting cavity 61.

[0035] like Figure 4 As shown, the inner eccentric cam 7 includes a circular wheel body 71 and a wheel shaft 72 protruding from the surface of the wheel body 71, the center of the wheel shaft 72 deviates from the center of the wheel body 71, and the center of the wheel shaft 72 is the eccentricity of the inner eccentric cam 7; the wheel shaft 72 is connected to the drive shaft.

[0036] When the inner eccentric cam 7 is in the first eccentric position, the eccentricity of the inner eccentric cam 7 coincides with the eccentricity of the outer eccentric cam 6; when the inner eccentric cam 7 is in the second eccentric position, the eccentricity of the inner eccentric cam 7 does not coincide with the eccentricity of the outer eccentric cam 6; when the inner eccentric cam 7 is fixed at the first eccentric position, the vertical movement of the feed dog bracket 5 is limited to the first stroke height, and when the inner eccentric cam 7 is fixed at the second eccentric position, the drive shaft rotates to lengthen the horizontal movement distance of the drive connecting rod 1, and the vertical movement of the feed dog bracket 5 is limited to the second stroke height; the distance between the eccentricity of the inner eccentric cam 7 and the eccentricity of the outer eccentric cam 6 is the difference between the second stroke height of the vertical movement of the feed dog bracket 5 and the first stroke height.

[0037] like Figure 1-3 As shown, the edge of the outer eccentric cam 6 is provided with a screw hole 62 penetrating to the mounting cavity 61 , and a bolt passes through the screw hole 62 to fix the inner eccentric cam 7 in the mounting cavity 61 .

[0038] Furthermore, the screw holes 62 are evenly arranged on the edge of the outer eccentric cam 6 , and two screw holes 62 are arranged.

[0039] The above description is only a preferred embodiment of the present invention and is not intended to limit the scope of the present invention. That is, any equivalent changes and modifications made according to the content of the patent application scope of the present invention should be within the technical scope of the present invention.

Claims

1. A driving device capable of adjusting the height of a feed dog, comprising a driving connecting rod (1), an eccentric connecting rod (2), a pushing connecting rod (3), a connecting rod (4) and a feed dog bracket (5), wherein the driving connecting rod (1) is rotatably connected to the eccentric connecting rod (2), the eccentric connecting rod (2) is rotatably connected to the pushing connecting rod (3), the pushing connecting rod (3) is rotatably connected to the connecting rod (4), and the connecting rod (4) is rotatably connected to the feed dog bracket (5); It also includes a cam, which is eccentrically connected to the drive shaft and is also connected to the drive connecting rod (1) via a bearing (8); The driving shaft drives the cam to rotate eccentrically, so that the driving connecting rod (1) periodically drives the eccentric connecting rod (2), the pushing connecting rod (3) and the connecting rod (4) to perform periodic linkage, and the connecting rod (4) drives the feed dog bracket (5) to perform periodic movement in the horizontal direction and the vertical direction; Features: The cam is composed of an outer eccentric cam (6) and an inner eccentric cam (7), the outer eccentric cam (6) is fixedly connected to a bearing (8), the inner eccentric cam (7) is eccentrically arranged inside the outer eccentric cam (6), and the inner eccentric cam (7) is eccentrically connected to a drive shaft; The outer eccentric cam (6) and the inner eccentric cam (7) are both circular; the outer eccentric cam (6) is provided with a circular mounting cavity (61); the center of the mounting cavity (61) deviates from the center of the outer eccentric cam (6); the center of the mounting cavity (61) is the eccentricity of the outer eccentric cam (6); the inner eccentric cam (7) is arranged in the mounting cavity (61); the center of the eccentric connection between the inner eccentric cam (7) and the drive shaft is the eccentricity of the inner eccentric cam (7); A first eccentric position and a second eccentric position of a fixed inner eccentric cam (7) are arranged inside the outer eccentric cam (6); when the inner eccentric cam (7) is fixed at the first eccentric position, the vertical movement of the feed dog bracket (5) is limited within a first stroke height; and when the inner eccentric cam (7) is fixed at the second eccentric position, the vertical movement of the feed dog bracket (5) is limited within a second stroke height; When the inner eccentric cam (7) is in a first eccentric position, the eccentricity of the inner eccentric cam (7) coincides with the eccentricity of the outer eccentric cam (6); when the inner eccentric cam (7) is in a second eccentric position, the eccentricity of the inner eccentric cam (7) does not coincide with the eccentricity of the outer eccentric cam (6), and the distance between the two is the difference between the second stroke height and the first stroke height of the vertical movement of the feed dog bracket (5).

2. The driving device capable of adjusting the height of the feed dog according to claim 1, characterized in that: The driving connecting rod (1) comprises a bearing mounting portion (11) and a driving arm (12); a bearing (8) is arranged in the bearing mounting portion (11); an eccentric cam is arranged in the bearing (8); and the driving arm (12) is connected to the eccentric connecting rod (2).

3. The driving device capable of adjusting the height of the feed dog according to claim 1, characterized in that: The inner eccentric cam (7) comprises a circular wheel body (71) and a wheel shaft (72) protruding from the surface of the wheel body (71); the center of the wheel shaft (72) deviates from the center of the wheel body (71); the center of the wheel shaft (72) is the eccentricity of the inner eccentric cam (7); and the wheel shaft (72) is connected to a driving shaft.

4. The driving device capable of adjusting the height of the feed dog according to claim 1, characterized in that: The inner eccentric cam (7) is rotated 90°, 180° or 270° from the first eccentric position to the second eccentric position.

5. The driving device capable of adjusting the height of the feed dog according to claim 1, characterized in that: The edge of the outer eccentric cam (6) is provided with a screw hole (62) penetrating to the mounting cavity (61), and a bolt passes through the screw hole (62) to fix the inner eccentric cam (7) in the mounting cavity (61).

6. The driving device capable of adjusting the height of the feed dog according to claim 5, characterized in that: The screw holes (62) are evenly arranged on the edge of the outer eccentric cam (6), and two screw holes (62) are arranged.

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