Needle bar linkage

Abstract

The utility model provides a needle bar connecting rod mechanism belongs to sewing machine technical field. It has solved the problem of inconvenient assembly on the whole machine caused by complex structure. It includes lifting seat, swing seat which is annular and is hinged on lifting seat and needle bar which passes through swing seat, two abutting pieces are fixed on needle bar, two blocky action parts are integrally arranged on swing seat, two action parts are symmetrically arranged about the hinge center line of swing seat and lifting seat, the upper end and lower end of action part are projected on swing seat outside along the axial direction of needle bar, the upper end and lower end of action part have the outer convex arc action surface, two arc action surfaces on the same action part are concentrically arranged and have the same radius, the arc action surfaces on two action parts are parallel, the upper abutting piece abuts on the arc action surface of two upper ends of action part, the lower abutting piece abuts on the arc action surface of two lower ends of action part. It has the advantages of simple structure, convenient assembly on the whole machine and the like.

Description

Technical Field

[0001] This utility model belongs to the field of sewing machine technology and relates to needle bar linkage mechanism. Background Technology

[0002] A buttonhole machine is a type of sewing machine. Its needle bar needs to move up and down and swing back and forth and left and right during use. Therefore, a needle bar linkage mechanism needs to be installed at the head of the buttonhole machine to enable the needle bar to move up and down or swing back and forth and left and right under the drive of other driving mechanisms. For example, a needle bar linkage device disclosed in patent application number 201310085277.4 includes a needle swing frame, a needle swing fork arm, and a needle bar passing through the needle swing frame. The needle swing frame is connected to the needle swing fork arm. Fixed rings are provided on both the upper and lower sides of the needle swing frame, and the fixed rings are sleeved and fixed to the needle bar. The needle swing frame includes a main swing frame, a main swing block located on the upper side of the main swing frame, and a lower swing block located on the lower side of the main swing frame. The upper and lower swing blocks respectively abut against corresponding fixed rings. The upper swing block and the corresponding fixed ring... A gasket is provided between the upper and lower swing blocks, and a gasket is provided between the lower swing block and the corresponding fixed ring. The needle rod passes through the upper swing block, the main swing frame and the lower swing block in sequence, and the needle rod can swing relative to the main swing frame. The upper and lower surfaces of the main swing frame have an arc-shaped contact surface two and an arc-shaped contact surface three, respectively. The lower surface of the upper swing block has a contact surface one that is in contact with contact surface two, and the upper surface of the lower swing block has a contact surface four that is in contact with contact surface three. Contact surfaces one, two, three and four are all spherical or cylindrical.

[0003] Other drive mechanisms in the buttonhole machine drive the needle bar to move up and down and / or swing. Assuming the initial state of the needle bar is vertical, when the needle bar swings to the left, the position of shim one also tilts to the left. The plane where shim one is located is always perpendicular to the needle bar, so the upper swing block, which is in contact with shim one, swings to the left relative to the main swing frame, and shim one slides relative to the upper swing block. At the same time, the lower swing block swings to the right relative to the main swing frame, and shim two slides relative to the lower swing block. The connection between the main swing frame, the upper swing block, and the lower swing block is a surface contact. No matter how the needle bar swings, the distance between the upper swing block and the lower swing block along the needle bar axis will not change, thus preventing gaps and noise between the upper swing block and the main swing frame, and between the lower swing block and the main swing frame.

[0004] However, the addition of the main swing block and the lower swing block also makes the structure of the entire needle bar linkage device more complicated. In particular, the needle bar linkage device is set at the head of the buttonhole machine, and the space at the head is very small, which makes the assembly of the whole machine very inconvenient. Utility Model Content

[0005] The purpose of this invention is to address the aforementioned problems in the existing technology by proposing a needle bar linkage mechanism, which solves the problem of inconvenient assembly on the whole machine due to complex structure.

[0006] The objective of this utility model can be achieved through the following technical solutions:

[0007] A needle bar linkage mechanism includes a lifting seat, a ring-shaped swing seat hinged to the lifting seat, and a needle bar passing through the swing seat. Two abutment members are fixed on the needle bar, and the two abutment members are respectively located on the upper and lower sides of the swing seat. The swing seat is characterized by having two block-shaped action parts integrally provided on it. The two action parts are symmetrically arranged about the hinge center line between the swing seat and the lifting seat. The action parts have an upper end and a lower end that protrude outward from the swing seat along the axial direction of the needle bar. The upper end and the lower end of the action part both have outwardly convex arc action surfaces. The two arc action surfaces on the same action part are concentric and have the same radius. The arc action surfaces on the two action parts are parallel. The abutment member located above abuts against the arc action surface at the upper end of the two action parts, and the abutment member located below abuts against the arc action surface at the lower end of the two action parts.

[0008] With the needle bar initially vertical, two abutting parts fixed to the needle bar simultaneously abut against the upper and lower ends of the two action parts. Since the two action parts are symmetrically arranged about the hinge center line of the swing seat, both the upper and lower ends of the action parts have outwardly convex arc action surfaces. These two arc action surfaces are concentric and have the same radius. The arc action surfaces on the two action parts are parallel, which means that the line connecting the centers of the arc action surfaces on the two action parts is perpendicular to the hinge center line of the swing seat. The two abutting parts are tangent to the circles containing these two arc action surfaces. Therefore, when the needle bar swings to the left or right (here, the left and right directions are the extension directions of the hinge center line of the swing seat), the distance between the two abutting parts along the needle bar axis remains unchanged. This ensures that there is never a gap between the two abutting parts and the swing seat, thus ensuring that this needle bar linkage mechanism can also have the same noise reduction effect as the prior art. When the needle bar swings back and forth, it is held in place by two abutments that swing around the hinge point between the needle bar and the lifting seat. During this process, the distance between the two abutments along the needle bar axis remains constant, so there is no gap between the two abutments and the swing seat, which reduces noise.

[0009] Building upon this, the needle bar linkage mechanism eliminates the upper and lower swing blocks found in existing technologies, thus simplifying the structure and reducing costs compared to current technologies. In particular, needle bar linkage mechanisms are typically installed at the sewing machine head, where the internal space is already quite limited. This simplified mechanism simplifies assembly within the machine and reduces the number of mating points, resulting in less noise during operation. Furthermore, in practice, only a single swing seat with two active parts needs to be cut using wire cutting, eliminating the need for machining spherical or arc-shaped surfaces as required by existing technologies, significantly reducing the precision requirements for machining.

[0010] In the aforementioned needle bar linkage mechanism, both active parts extend radially along the swing seat to the outer periphery of the swing seat.

[0011] With the above settings, the active part has sufficient thickness in the front-to-back direction, so that the weight of the entire swing seat is not too heavy.

[0012] In the above-mentioned needle bar linkage mechanism, both abutment components include a washer and a locking block. The washer is sleeved on the needle bar, and the locking block is fixedly connected to the needle bar. The two washers abut against the upper and lower ends of the two action parts respectively, and the two locking blocks abut against the side of the two washers facing away from the swing seat respectively.

[0013] By using a pad to abut against the swing seat, the pad moves more smoothly along the arc-shaped action surface when the needle bar swings to the left or right, making it less prone to jamming. The pad is also more wear-resistant, thus extending its service life.

[0014] In the aforementioned needle bar linkage mechanism, the distance between the opposite sides of the two action parts is greater than the outer diameter of the gasket.

[0015] Since the needle bar swings back and forth by two abutments clamping the swing seat around the hinge point between it and the lifting seat, the distance between the opposite sides of the two action parts is set to be greater than the outer diameter of the gasket. In this way, the gasket does not protrude beyond the two action parts along the radial direction of the swing seat, thereby reducing the wear of the upper gasket on the upper end of the action part and the wear of the lower gasket on the lower end of the action part, and extending the service life.

[0016] In the aforementioned needle bar linkage mechanism, the inner surfaces of the two action parts are flush with the central hole wall of the swing seat.

[0017] The inner surface of the actuating part is flush with the wall of the central hole of the swing seat, which makes the machining process easier.

[0018] Compared with existing technologies, this needle bar linkage mechanism has two symmetrically positioned action parts on the swing seat, with their hinge center lines aligned about the swing seat. Each action part has an upper and lower end that protrude out of the swing seat along the axial direction of the needle bar. Both the upper and lower ends of the action parts have concentric arc action surfaces with the same radius. Two abutting members abut against the upper and lower ends of the two action parts respectively. This means that the two abutting members are tangent to the circles containing the two arc action surfaces. As a result, when the needle bar swings to the left or right, the distance between the two abutting members along the axial direction of the needle bar remains constant. This ensures that there is no gap between the two abutting members and the swing seat, thus reducing noise. Furthermore, this structure eliminates the need for upper and lower swing blocks, simplifying the structure and reducing costs. The simplification of the structure also makes assembly on the machine more convenient. Attached Figure Description

[0019] Figure 1 This is a three-dimensional schematic diagram of the needle bar linkage mechanism.

[0020] Figure 2 This is a planar schematic diagram of the needle bar linkage mechanism.

[0021] Figure 3 This is a schematic diagram of the needle bar and the swing seat from another angle.

[0022] Figure 4 This is a three-dimensional schematic diagram of the swing seat.

[0023] In the diagram, 1 is the lifting seat; 1a is the main body; 1b is the connecting arm; 2 is the swing seat; 2a is the connecting part; 2b is the action part; 2b1 is the arc action surface; 3 is the needle bar; 4 is the pivot shaft; 5 is the bearing; 6 is the connecting rod; 7 is the abutment; 7a is the gasket; and 7b is the locking block. Detailed Implementation

[0024] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments.

[0025] like Figure 1 and Figure 2As shown, the needle bar linkage mechanism includes a lifting seat 1, a ring-shaped swing seat 2 hinged to the lifting seat 1, and a needle bar 3 passing through the swing seat 2. The outer diameter of the needle bar 3 is smaller than the central hole diameter of the swing seat 2, creating a space between them for the needle bar 3 to swing relative to the swing seat 2. Specifically, the lifting seat 1 has a main body 1a that is roughly U-shaped in the horizontal direction and a connecting arm 1b integrally disposed at one end of the main body 1a and facing upward. Pivot shafts 4 are respectively provided at both ends of the main body 1a. Two cylindrical connecting parts 2a protrude from the outer periphery of the swing seat 2. Both connecting parts 2a have connecting holes along the radial direction of the swing seat 2. The two pivot shafts 4 are respectively inserted into the two connecting holes to hinge the swing seat 2 to the lifting seat 1. The connecting arm 1b has a mounting hole, the central axis of which is parallel to the hinge center line of the swing seat 2. A bearing 5 is provided in the mounting hole. This needle bar linkage mechanism also includes a Z-shaped connecting rod 6, one end of which is inserted into the bearing 5.

[0026] like Figure 2 , Figure 3 and Figure 4 As shown, two abutment members 7 are fixed on the needle bar 3, and the two abutment members 7 are located on the upper and lower sides of the swing seat 2 respectively. The swing seat 2 is integrally provided with two block-shaped working parts 2b. The two working parts 2b are symmetrically arranged about the hinge center line between the swing seat 2 and the lifting seat 1. The working parts 2b have an upper end and a lower end that protrude outward from the swing seat 2 along the axial direction of the needle bar 3. The upper end and the lower end of the working parts 2b each have an outwardly convex arc working surface 2b1. The two arc working surfaces 2b1 on the same working part 2b are concentric and have the same radius. The arc working surfaces 2b1 on the two working parts 2b are parallel, that is, the line connecting the centers of the arc working surfaces 2b1 of the two working parts 2b is perpendicular to the hinge center line of the swing seat 2. The abutment member 7 located above abuts against the arc working surface 2b1 at the upper end of the two working parts 2b, and the abutment member 7 located below abuts against the arc working surface 2b1 at the lower end of the two working parts 2b. In this embodiment, both actuating parts 2b extend radially along the swing seat 2 to the outer periphery of the swing action, and the inner surfaces of the two actuating parts 2b are flush with the central hole wall of the swing seat 2. The abutting member 7 includes a gasket 7a and a locking block 7b. The gasket 7a is sleeved on the needle bar 3, and the locking block 7b is fixedly connected to the needle bar 3. The two gaskets 7a abut against the upper and lower ends of the two actuating parts 2b respectively. The distance between the opposite sides of the two actuating parts 2b is greater than the outer diameter of the gasket 7a. The two locking blocks 7b abut against the side of the two gaskets 7a facing away from the swing seat 2 respectively.

[0027] With the needle bar 3 initially vertical, two abutting pieces 7 fixed to the needle bar 3 simultaneously abut against the upper and lower ends of the two abutting parts 2b. Since the two abutting parts 2b are symmetrically arranged about the hinge center line of the swing seat 2, both the upper and lower ends of the abutting parts 2b have arc-shaped abutting surfaces 2b1, and these two arc-shaped abutting surfaces 2b1 are concentrically arranged. This means that the two abutting pieces 7 are tangent to the circles containing these two arc-shaped abutting surfaces 2b1. Therefore, when the needle bar 3 is in a vertical position... Figure 2 When the needle bar swings left or right as shown, the distance between the two abutment pieces 7 along the axial direction of the needle bar 3 remains constant. This ensures that there is never a gap between the two abutment pieces 7 and the swing seat 2, thus guaranteeing that this needle bar linkage mechanism can achieve the same noise reduction effect as existing technologies. Furthermore, this needle bar linkage mechanism eliminates the upper and lower swing blocks found in existing technologies, thereby simplifying the structure and reducing costs compared to existing technologies. In particular, needle bar linkage mechanisms are installed at the sewing machine head, where the internal space is relatively narrow. This simplified needle bar linkage mechanism makes assembly on the entire machine more convenient, and the reduced number of mating points further reduces noise generation during sewing machine operation.

[0028] When the needle bar 3 swings back and forth, it is clamped by two abutment pieces 7 and swings together around the hinge point between the needle bar 3 and the lifting seat 1. During this process, the distance between the two abutment pieces 7 along the axis of the needle bar 3 remains constant. Therefore, there is no gap between the two abutment pieces 7 and the swing seat 2, which can reduce noise.

[0029] The specific embodiments described herein are merely illustrative examples illustrating the spirit of this utility model. Those skilled in the art to which this utility model pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of this utility model or exceeding the scope defined by the appended claims.

Claims

1. A needle bar linkage mechanism, comprising a lifting seat (1), a ring-shaped swing seat (2) hinged to the lifting seat (1), and a needle bar (3) passing through the swing seat (2), wherein two abutment members (7) are fixed on the needle bar (3), the two abutment members (7) being located on the upper and lower sides of the swing seat (2), characterized in that, The swing seat (2) is integrally provided with two block-shaped action parts (2b). The two action parts (2b) are symmetrically arranged about the hinge center line of the swing seat (2) and the lifting seat (1). The action parts (2b) have an upper end and a lower end that protrude out of the swing seat (2) along the axial direction of the needle bar (3). The upper end and the lower end of the action parts (2b) both have outwardly protruding arc action surfaces (2b1). The two arc action surfaces (2b1) on the same action part (2b) are concentrically arranged and have the same radius. The arc action surfaces (2b1) on the two action parts (2b) are parallel. The upper abutment (7) abuts against the arc action surfaces (2b1) at the upper end of the two action parts (2b), and the lower abutment (7) abuts against the arc action surfaces (2b1) at the lower end of the two action parts (2b).

2. The needle bar linkage mechanism according to claim 1, characterized in that, Both actuating parts (2b) extend radially along the swing seat (2) to the outer periphery of the swing seat (2).

3. The needle bar linkage mechanism according to claim 2, characterized in that, Both abutment parts (7) include a gasket (7a) and a locking block (7b). The gasket (7a) is sleeved on the needle bar (3), and the locking block (7b) is fixedly connected to the needle bar (3). The two gaskets (7a) abut against the upper and lower ends of the two action parts (2b) respectively, and the two locking blocks (7b) abut against the side of the two gaskets (7a) facing away from the swing seat (2) respectively.

4. The needle bar linkage mechanism according to claim 3, characterized in that, The distance between the opposite sides of the two working parts (2b) is greater than the outer diameter of the gasket (7a).

5. The needle bar linkage mechanism according to claim 1, 2, 3, or 4, characterized in that, The inner surfaces of the two action parts (2b) are flush with the central hole wall of the swing seat (2).

Images