Middle presser foot follow-up mechanism and sewing machine

Abstract

The utility model relates to a middle presser foot follow-up mechanism and a sewing machine, and the middle presser foot follow-up mechanism is installed on a rack of the sewing machine and comprises a pressing rod which is installed on the rack in a sliding mode and is provided with a top and a bottom which are opposite; an upper blocking piece and a lower blocking piece are fixed to the top of the pressing rod in a spaced mode, a pressing rod sliding sleeve is arranged between the upper blocking piece and the lower blocking piece in a sliding mode, and a buffer spring arranged on the pressing rod in a sleeving mode is arranged between the pressing rod sliding sleeve and the lower blocking piece. The middle pressing foot is mounted at the bottom of the pressing rod; the motor is installed on the machine frame, and the motor is in linkage with the pressing rod sliding sleeve and drives the pressing rod to move relative to the machine frame through the pressing rod sliding sleeve. According to the middle presser foot follow-up mechanism, follow-up and overall lifting of the middle presser foot can be directly driven, rapid adjustment of the follow-up stroke is achieved, and adaptability is good.

Description

Technical Field

[0001] The present application relates to the field of sewing machines, and in particular to a presser foot follower mechanism and a sewing machine. Background Art

[0002] When sewing denim and other fabrics, the sewing track on the mold is exposed for a long time. When the needle is pulled out of the sewing fabric, the fabric at the needle is easily lifted up, affecting the quality of the sewing stitch. Therefore, it is necessary to use the follow-up middle presser foot to assist in holding the fabric against the fabric, preventing the fabric from being lifted up and ensuring the stability of the stitch.

[0003] In the prior art, the follow-up presser foot structure is generally implemented based on mechanical drive, driven by an eccentric wheel fixed on the upper shaft of the sewing machine, and combined with motor control to achieve the change of the lowest point and the overall lifting and lowering. The overall transmission structure is relatively complex, and it is inconvenient to adjust the follow-up stroke of the presser foot. Utility Model Content

[0004] The present application provides a middle presser foot following mechanism, which can directly drive the following movement of the middle presser foot and the overall lifting and lowering, realize rapid adjustment of the following stroke, and has good adaptability.

[0005] The present application provides a middle presser foot follower mechanism, which is installed on a frame of a sewing machine, and the middle presser foot follower mechanism comprises:

[0006] A pressure rod is slidably mounted on the frame and has a top and a bottom relative to each other; an upper blocking member and a lower blocking member are fixed at intervals on the top of the pressure rod, a pressure rod sliding sleeve is slidably arranged between the upper blocking member and the lower blocking member, and a buffer spring sleeved on the pressure rod is arranged between the pressure rod sliding sleeve and the lower blocking member;

[0007] A middle presser foot, mounted on the bottom of the press rod;

[0008] A motor is installed on the frame. The motor is linked to the pressure rod sliding sleeve and drives the pressure rod to move relative to the frame through the pressure rod sliding sleeve.

[0009] Several optional methods are also provided below, but they are not intended to be additional limitations on the above-mentioned overall solution, but are merely further supplements or preferences. Under the premise that there are no technical or logical contradictions, each optional method can be combined with the above-mentioned overall solution separately, and multiple optional methods can also be combined.

[0010] In one embodiment, a buffer pad sleeved on the pressure rod is provided between the pressure rod sliding sleeve and the upper blocking member.

[0011] In one embodiment, the buffer pad is pressed against the lower end surface of the upper blocking member, and the pressure rod sliding sleeve is driven by the buffer spring to press against the buffer pad in a free state.

[0012] In one embodiment, the lower blocking member is provided with a guide slide block, the frame is provided with a guide groove extending along the movement direction of the pressure rod, and the guide slide block is slidably disposed in the guide groove.

[0013] In one embodiment, a pressure rod bushing is slidably fitted on the outer periphery of the pressure rod, and the pressure rod bushing is vertically fixed to the frame.

[0014] In one embodiment, a transmission assembly is further included, the transmission assembly includes a lever and two sets of connecting rod assemblies connected to both ends of the lever, the two sets of connecting rod assemblies include a first connecting rod assembly connected to the motor and a second connecting rod assembly connected to the pressure rod sliding sleeve;

[0015] The first connecting rod assembly comprises:

[0016] A swing arm, one end of which is fixed to the rotating shaft of the motor and the other end of which is a free end;

[0017] A first connecting rod, one end of which is hinged to the free end of the swing arm, and the other end of which is hinged to the lever;

[0018] The second connecting rod assembly comprises:

[0019] The second connecting rod has one end hinged to the lever and the other end hinged to the pressure rod sliding sleeve.

[0020] In one embodiment, the second connecting rod is vertically disposed above the pressure rod, the second connecting rod has a top end and a bottom end opposite to each other, and the bottom end of the second connecting rod is hinged to the pressure rod sliding sleeve.

[0021] In one embodiment, the lever is L-shaped and has a turning point, and the rotation axis of the lever is located at the turning point of the L-shape;

[0022] The L-shape has a long arm and a short arm relative to each other, wherein the short arm is connected to the first connecting rod assembly, and the long arm is hinged to the top end of the second connecting rod in a transverse arrangement.

[0023] In one embodiment, one end of the long arm and the short arm away from the rotation axis is hinged to the corresponding connecting rod assembly.

[0024] The present application also provides a sewing machine having the middle presser foot follower mechanism described in the present application.

[0025] The middle presser foot follower mechanism of the present application directly drives the pressure rod and the middle presser foot through a motor. The pressure rod and the middle presser foot are directly connected, eliminating an additional connection structure, achieving rapid adjustment of the follower stroke, and having good adaptability. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the conventional technology, the drawings required for use in the embodiments or the conventional technology descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0027] Figure 1 Schematic diagram of the middle presser foot follower mechanism in one embodiment of the present application;

[0028] Figure 2 It is a schematic diagram of the motor and some transmission components of the middle presser foot follower mechanism;

[0029] Figure 3 It is a partial schematic diagram of the pressure rod of the middle presser foot follower mechanism;

[0030] Figure 4 for Figure 1 Schematic diagram of the middle presser foot follower mechanism from another perspective (frame omitted);

[0031] Figure 5 for Figure 2 Schematic diagram of the sensor changing position after the motor rotates.

[0032] The reference numerals of the components are as follows:

[0033] 100, motor; 101, frame; 1011, guide groove; 102, rotating shaft; 103, mounting frame;

[0034] 200, press rod; 201, middle presser foot; 202, press rod sliding sleeve; 203, upper blocking member; 204, lower blocking member; 2041, guide slider; 205, buffer spring; 206, buffer pad; 207, press rod bushing;

[0035] 300, transmission assembly; 301, lever; 3011, turning point; 302, first connecting rod assembly; 303, swing arm; 304, first connecting rod; 305, second connecting rod;

[0036] 401, sensor sheet; 402, sensor; 403, sensor bracket. DETAILED DESCRIPTION

[0037] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0038] It should be noted that when a component is referred to as being "fixed to" or "disposed on" another component, it may be directly on the other component or there may also be a central component. When a component is considered to be "connected to" another component, it may be directly connected to the other component or there may be a central component at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in the specification of this application are for illustrative purposes only and do not represent the only implementation method.

[0039] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0040] In the present application, unless otherwise clearly specified and limited, a first feature being “above” or “below” a second feature may mean that the first feature is directly in contact with the second feature, or the first feature and the second feature are indirectly in contact through an intermediate medium. Moreover, a first feature being “above”, “above”, or “above” a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level (or in a state of use, or from a certain perspective of the drawing) than the second feature. A first feature being “below”, “below”, or “below” a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level (or in a state of use, or from a certain perspective of the drawing) than the second feature.

[0041] Unless otherwise defined, all technical and scientific terms used in the specification of this application have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used in the specification of this application includes any and all combinations of one or more related listed items.

[0042] See also Figure 1 to Figure 5 One embodiment of the present application provides a middle presser foot follower mechanism, which is installed on a frame 101 of a sewing machine. The middle presser foot follower mechanism includes: a pressure rod 200, which is slidably installed on the frame 101 and has a top and a bottom relative to each other; an upper blocking member 203 and a lower blocking member 204 are fixed at intervals on the top of the pressure rod 200, a pressure rod sliding sleeve 202 is slidably arranged between the upper blocking member 203 and the lower blocking member 204, and a buffer spring 205 is arranged between the pressure rod sliding sleeve 202 and the lower blocking member 204 and is sleeved on the pressure rod 200;

[0043] The middle presser foot 201 is installed at the bottom of the press rod 200;

[0044] The motor 100 is mounted on the frame 101 ; the motor 100 is linked to the pressure rod sliding sleeve 202 and drives the pressure rod 200 to move relative to the frame 101 through the pressure rod sliding sleeve 202 .

[0045] The middle presser foot follower mechanism in this embodiment can directly drive the pressure rod 200 and the middle presser foot 201 to follow and lift and lower as a whole through the motor 100. The pressure rod 200 and the middle presser foot 201 are directly connected, eliminating the need for an additional connection structure, thereby achieving rapid adjustment of the follower stroke and having good adaptability.

[0046] In one embodiment, the middle presser foot follower mechanism further includes a transmission assembly 300, which includes a lever 301 and two sets of connecting rod assemblies connected to both ends of the lever 301, and each connecting rod assembly is respectively connected to the motor 100 and the pressure rod 200.

[0047] For the specific configuration of the transmission assembly 300, see Figure 2 The lever 301 is L-shaped and has a turning point 3011, and the rotation axis of the lever 301 is located at the turning point 3011 of the L. Further, the L-shape has a long arm and a short arm relative to each other, wherein the short arm is connected to the first connecting rod assembly 302, and the long arm is connected to the second connecting rod assembly; one end of the long arm and the short arm away from the rotation axis is hinged to the corresponding connecting rod assembly.

[0048] See also Figure 1 , Figure 2 In the illustrated embodiment, of the two sets of connecting rod assemblies, the first connecting rod assembly 302 connected to the motor 100 includes:

[0049] A swing arm 303, one end of which is fixed to the rotating shaft 102 of the motor 100, and the other end of which is a free end;

[0050] The first connecting rod 304 has one end hinged to the free end of the swing arm 303 and the other end hinged to the lever 301 .

[0051] Furthermore, the compression rod sleeve 202 is slidably matched with the top periphery of the compression rod 200. Among the two sets of connecting rod assemblies, the second connecting rod assembly connected to the compression rod 200 includes:

[0052] The second connecting rod 305 has one end hinged to the lever 301 and the other end hinged to the pressure rod sliding sleeve 202 .

[0053] Furthermore, the second connecting rod 305 is vertically placed above the pressure rod 200 , and the second connecting rod 305 has a relative top and bottom, and the bottom end of the second connecting rod 305 is hinged to the pressure rod sliding sleeve 202 ; the long arm of the lever 301 is horizontally hinged to the top of the second connecting rod 305 .

[0054] Furthermore, a buffer pad 206 is provided between the pressure rod sliding sleeve 202 and the upper blocking member 203. The buffer pad 206 is close to the lower end surface of the upper blocking member 203, and the pressure rod sliding sleeve 202 is driven by the buffer spring 205 to be close to the buffer pad 206 in a free state. The design of the buffer pad 206 and the buffer spring 205 can improve the control effect of the middle presser foot 201.

[0055] For example, the control unit sends a signal to the motor 100 for reciprocating swing, which has two endpoints. The actual response angle of the motor 100 will produce overshoot when reaching the two ends of the reciprocating swing. If the overshoot is too large, the buffer pad 206 and the buffer spring 205 can prevent the presser foot from hitting the fabric and the needle plate and causing mechanical damage during the overshoot.

[0056] When the thickness and hardness of the fabric change slightly, and there is a program error or no corresponding change in the height of the presser foot 201, the buffer pad 206 and the buffer spring 205 can also provide protection.

[0057] For example, when the thickness of the cloth changes, an upward force will be generated on the middle presser foot 201, which will be transmitted to the buffer spring 205 through the pressure rod 200. The buffer spring 205 is compressed, which can lift the middle presser foot 201 a little to prevent problems such as mopping the cloth and damaging the mechanical structure.

[0058] The outer periphery of the pressure rod 200 is slidably matched with a pressure rod bushing 207, which is vertically fixed to the frame 101. The pressure rod bushing 207 provides a guide for the movement of the pressure rod 200. In the figure, the lower blocking member 204 is provided with a guide slider 2041 that matches the frame 101, and the frame 101 is provided with a guide groove 1011 extending along the movement direction of the pressure rod 200, and the guide slider 2041 is slidably arranged in the guide groove 1011.

[0059] The movement stroke of the middle presser foot 201 is controlled by the rotation angle of the motor 100. The rotation control of the motor 100 is realized by the sensor 402 and the sensor sheet 401. The sensor sheet 401 itself is L-shaped, and the turning point of the L-shape is fixedly connected to the rotating shaft 102 of the motor 100. The two ends of the L-shape are respectively used to trigger different sensors 402 to correspond to different positions of the middle presser foot 201. Figure 2 The corresponding middle presser foot 201 is at the highest point; see Figure 5 In the middle, the corresponding middle presser foot 201 is located at the lowest point.

[0060] In the figure, the motor 100 is mounted on the frame 101 through the mounting frame 103, and the sensor 402 is mounted on the mounting frame 103 through the induction bracket 403. One of the sensors 402 can adjust its position in the first direction relative to the mounting frame 103, and correspondingly adjust the lowest point position of the middle presser foot 201; the other sensor 402 can adjust its position in the second direction relative to the mounting frame 103, and correspondingly adjust the highest point position of the middle presser foot 201; wherein the first direction and the second direction are perpendicular to each other. The adjustment method can be realized by opening a waist hole on the mounting frame 103 or the induction bracket 403, or setting a plurality of adaptation positions, etc.

[0061] The working process of the middle presser foot follower mechanism in this application is as follows:

[0062] When the rotating shaft 102 of the motor 100 rotates clockwise, the swing arm 303 in the first connecting rod assembly 302 rotates clockwise, driving the lever 301 to rotate clockwise relative to the hinge between the lever 301 and the mounting frame 103. The clockwise rotation of the lever 301 presses the second connecting rod 305 downward to act on the pressure rod sliding sleeve 202. After the pressure rod sliding sleeve 202 is subjected to the downward force, the force acts on the lower blocking member 204 through the buffer spring 205, thereby driving the pressure rod 200 and the middle presser foot 201 at the lower end of the pressure rod 200 to move downward.

[0063] On the contrary, when the rotating shaft 102 of the motor 100 rotates counterclockwise, it acts on the first connecting rod assembly 302, the lever 301, the second connecting rod 305, and the pressure rod sliding sleeve 202 in sequence. The pressure rod sliding sleeve 202 moves upward, directly acts on the buffer pad 206 so that the upper blocking member 203 moves upward, and finally drives the pressure rod 200 and the middle presser foot 201 at the lower end of the pressure rod 200 to move upward.

[0064] In the above process, the pressure rod bushing 207 and the guide slider 2041 of the lower blocking member 204 realize the guiding function to ensure that the angles of the pressure rod 200 and the middle pressure foot 201 are correct.

[0065] When the rotating shaft 102 of the motor 100 rotates to the position corresponding to the lowest point of the middle presser foot 201, one end of the sensor sheet 401 is located above the sensing area of ​​the sensor 402 below, prompting the control unit to have reached the lowest position of the middle presser foot 201; when the rotating shaft 102 of the motor 100 rotates to the position corresponding to the highest point of the middle presser foot 201, the other end of the sensor sheet 401 is above the sensing area of ​​the sensor 402 located on the side, prompting the control unit to have reached the highest position of the middle presser foot 201.

[0066] One embodiment of the present application also provides a sewing machine having the middle presser foot follower mechanism of the present application. By adding the middle presser foot 201 function to the flat-sewing machine head, it can also be applied to thin material scenes, and can be used universally. Other structures of the sewing machine can be implemented in combination with existing technologies.

[0067] During the sewing process, there is synchronization between the movement of the middle presser foot follower mechanism and the needle bar. By adjusting the swing angle of the motor 100 each time, the follower height of the middle presser foot 201 can be adjusted. By controlling the signal given to the motor 100 and the time of giving the signal, the relationship curve between the height of the middle presser foot 201 and the angle of the sewing machine spindle can be adjusted. When the needle enters the cloth and the feeding stops, the middle presser foot 201 is close to the lowest point; when the needle has not left the cloth, the middle presser foot 201 is roughly kept near the lowest point. When the needle moves upward, the middle presser foot 201 can keep against the cloth, which prevents skipped stitches and helps to collect the thread.

[0068] When the needle leaves the cloth and feeding begins, the middle presser foot 201 accelerates to leave the cloth, which is convenient for the feeding action of the pocket sticking machine. When the program setting requires the middle presser foot 201 to change the lowest point of the follow-up, the angle range of the motor 100 can be changed, and then the lowest point of the follow-up of the middle presser foot 201 can be changed. After the sewing is completed, the motor 100 can be directly controlled to rotate counterclockwise to lift the middle presser foot 201 to the required height. Correspondingly, when the next sewing starts, the middle presser foot 201 is put down in advance to ensure synchronization with the needle bar.

[0069] The technical features of the above-mentioned embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification. When the technical features in different embodiments are embodied in the same figure, it can be regarded that the figure also discloses the combination examples of the various embodiments involved.

[0070] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the scope of patent protection of the present application shall be subject to the attached claims.

Claims

1. A presser foot follower mechanism, mounted on a frame of a sewing machine, characterized in that: The middle presser foot follower mechanism comprises: A pressure rod is slidably mounted on the frame and has a top and a bottom relative to each other; an upper blocking member and a lower blocking member are fixed at intervals on the top of the pressure rod, a pressure rod sliding sleeve is slidably arranged between the upper blocking member and the lower blocking member, and a buffer spring sleeved on the pressure rod is arranged between the pressure rod sliding sleeve and the lower blocking member; A middle presser foot, mounted on the bottom of the press rod; A motor is installed on the frame. The motor is linked to the pressure rod sliding sleeve and drives the pressure rod to move relative to the frame through the pressure rod sliding sleeve.

2. The intermediate presser foot follower mechanism according to claim 1, characterized in that: A buffer pad sleeved on the pressure rod is provided between the pressure rod sliding sleeve and the upper blocking member.

3. The intermediate presser foot follower mechanism according to claim 2, characterized in that: The buffer pad is pressed against the lower end surface of the upper blocking member, and the pressure rod sliding sleeve is driven by the buffer spring to be pressed against the buffer pad in a free state.

4. The intermediate presser foot follower mechanism according to claim 1, characterized in that: The lower blocking member is provided with a guide slide block, the frame is provided with a guide groove extending along the moving direction of the pressure rod, and the guide slide block is slidably arranged in the guide groove.

5. The intermediate presser foot follower mechanism according to claim 1, characterized in that: The outer periphery of the pressure rod is slidably matched with a pressure rod bushing, and the pressure rod bushing is vertically fixed to the frame.

6. The intermediate presser foot follower mechanism according to claim 1, characterized in that: It also includes a transmission assembly, which includes a lever and two sets of connecting rod assemblies connected to both ends of the lever, and the two sets of connecting rod assemblies include a first connecting rod assembly connected to the motor and a second connecting rod assembly connected to the pressure rod sliding sleeve; The first connecting rod assembly comprises: A swing arm, one end of which is fixed to the rotating shaft of the motor and the other end of which is a free end; A first connecting rod, one end of which is hinged to the free end of the swing arm, and the other end of which is hinged to the lever; The second connecting rod assembly comprises: The second connecting rod has one end hinged to the lever and the other end hinged to the pressure rod sliding sleeve.

7. The intermediate presser foot follower mechanism according to claim 6, characterized in that: The second connecting rod is vertically arranged above the pressure rod, the second connecting rod has a top end and a bottom end opposite to each other, and the bottom end of the second connecting rod is hinged to the pressure rod sliding sleeve.

8. The intermediate presser foot follower mechanism according to claim 7, characterized in that: The lever is L-shaped and has a turning point, and the rotation axis of the lever is located at the turning point of the L-shape; The L-shape has a long arm and a short arm relative to each other, wherein the short arm is connected to the first connecting rod assembly, and the long arm is hinged to the top end of the second connecting rod in a transverse arrangement.

9. The intermediate presser foot follower mechanism according to claim 8, characterized in that: One end of the long arm and the short arm away from the rotation axis is hinged to the corresponding connecting rod assembly.

10. A sewing machine, characterized in that: The utility model has the intermediate presser foot following mechanism as claimed in any one of claims 1 to 9.

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