Mechanical thread winding device for a sewing machine and sewing machine

Abstract

A mechanical winding device for sewing machine, comprising an electric motor, a swing arm, a rotating shaft, a housing, a mounting bracket, a cover, a switch, a cam, a tension spring and a push rod, the cover and the housing cooperate to form a mounting cavity, the electric motor and the mounting bracket are installed in the mounting cavity and protected by the cover, the switch, the cam, the tension spring and the push rod are installed on the mounting bracket, one end of the push rod is located between the cam and the switch, the cam is connected with a transmission shaft, the transmission shaft is connected with the swing arm through the cover, and the rotating shaft is connected with the electric motor through the cover; when winding, the swing arm drives the cam to rotate to drive the push rod to turn on the switch to start the electric motor to wind, the increased thread pushes the swing arm to drive the cam to rotate, when reaching the set winding thickness, the relief surface on the cam makes the push rod be pulled open under the action of the tension spring to turn off the switch to shut down the electric motor; the mechanical winding device is beneficial to prevent pollution and has good winding consistency; a sewing machine adopting the winding device is also proposed.

Description

Technical Field

[0001] This invention relates to the field of sewing machine technology, and more specifically to a mechanical thread winding device for a sewing machine and a sewing machine. Background Technology

[0002] Bottom thread is an important thread required for sewing, and it is used in large quantities. It is of great significance for ensuring the quality of sewing. When using bottom thread, it is necessary to first wind it around the bobbin. Therefore, how to set up the winding device needs to be studied. The original design proposed a mechanical winding device (commonly known as a thread winder). This device includes a swing arm, a rotating shaft, and a transmission wheel system. The swing arm is positioned around the circumference of the rotating shaft. When winding is required, the bobbin is first mounted on the rotating shaft. Then, the swing arm swings towards the circumference of the bobbin, simultaneously pushing the part of the rotating shaft to engage with the driving wheel of the transmission wheel system. Specifically, a driven wheel is located at the lower end of the rotating shaft, moving towards the driving wheel along with the rotating shaft. This allows the driven wheel to engage with the driving wheel. When the thread on the bobbin reaches a certain thickness, the swing arm is pushed away from the bobbin due to the thickness. Upon reaching a certain thickness, the rotating shaft is reset, separating the driven wheel from the driving wheel to complete the winding. The driving wheel is operated by a sewing machine, typically controlled by the user's foot pedal. The winding speed varies depending on the speed of the driving wheel.

[0003] As can be seen from the above, current mechanical winding devices, due to their reliance on transmission gear systems and the sewing machine's own electric motor, are susceptible to oil and dust contamination, and the winding consistency is poor.

[0004] Therefore, this disclosure proposes a mechanical winding device for sewing machines that is beneficial for preventing contamination and ensuring good winding consistency. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a mechanical winding device for a sewing machine, which is beneficial for preventing pollution and has good winding consistency; and to propose a sewing machine that uses the aforementioned winding device.

[0006] The technical solution of the present invention is: a mechanical winding device for a sewing machine, comprising an electric motor, a swing arm, and a rotating shaft. The rotating shaft is used to mount the bobbin. The device also includes a housing, a mounting bracket, a cover, a switch, a cam, a tension spring, and a push rod. The cover and the housing cooperate to form a mounting cavity. The electric motor and the mounting bracket are installed in the mounting cavity and protected by the cover. The switch, the cam, the tension spring, and the push rod are mounted on the mounting bracket. One end of the push rod is located between the cam and the switch. The cam is connected to a transmission shaft, which passes through the cover and is connected to the swing arm. The rotating shaft passes through the cover and is connected to the electric motor.

[0007] When winding, the bobbin is first mounted on the rotating shaft. Then, the swing arm moves towards the circumference of the bobbin. The swing arm drives the cam to rotate through the transmission shaft. The rotation of the cam drives one end of the push rod to move towards the switch, turning on the switch and starting the electric motor to drive the rotating shaft to rotate and wind the bobbin. As winding continues, the added thread will push the swing arm away from the bobbin. The swing arm will simultaneously drive the cam to rotate. When the set winding thickness is reached, the clearance surface on the cam causes the push rod to be pulled away by the tension spring, so that one end is disengaged from the switch, thereby turning off the switch and stopping the electric motor.

[0008] With the above structure, the present invention has the following advantages: This disclosure adopts a completely different structural scheme and working principle compared with the prior art. Specifically, the winding is controlled by the swing arm to control whether the switch is on or off. There is no original transmission wheel system, so there are no problems such as wear and contamination. In the specific structure, the electric motor and the mounting bracket are installed in the mounting cavity and protected by the cover. The switch, cam, tension spring and push rod are installed on the mounting bracket. That is to say, the electric motor, the mounting bracket and the various components installed on the mounting bracket are contained in the mounting cavity and protected by the cover. Therefore, it is beneficial to prevent contamination and has better winding consistency.

[0009] In addition, since the electric motor can be started simply by moving the swing arm towards the bobbin, there is no need for the user to use the sewing machine pedal to control the speed of the drive wheel, making it more efficient and also conducive to better thread winding consistency.

[0010] In some embodiments, the cover is provided with a first limiting part and a second limiting part, and the swing arm is provided with a mating protrusion. The mating protrusion is movably fitted between the first limiting part and the second limiting part, and the swing range of the swing arm is defined by the first limiting part and the second limiting part.

[0011] In some embodiments, an electric motor is mounted on the lower side of the mounting bracket, and a rotating shaft passes sequentially through the mounting bracket and the cover, protruding from the upper side of the cover. A switch, a cam, a tension spring, and a push rod are all mounted on the upper side of the mounting bracket and located between the mounting bracket and the cover.

[0012] In some embodiments, the electric motor, switch, cam, tension spring, and push rod are all mounted on a mounting bracket to form a separate assembly, which is then installed in the housing, and a cover is installed to close the opening of the housing; the drive shaft is installed with the separate assembly first and then the cover is installed, or the drive shaft is installed after the cover is installed.

[0013] In some embodiments, the mounting bracket is provided with hooks in the circumferential direction, and the mounting bracket is mounted at the opening of the housing via the hooks.

[0014] In some embodiments, the swing arm includes a first arm and a second arm arranged side by side, the first arm and the second arm being connected at the same end to form a U-shaped structure, and an adjusting screw is provided to change the interval between the first arm and the second arm, thereby changing the winding thickness.

[0015] In some embodiments, the device further includes a mounting base and a support base. The mounting base is located on the upper side of the cover and is fixedly mounted on the rotating shaft. The support base is axially movably fitted onto the rotating shaft. The top surface of the support base serves as a support surface for the bottom surface of the bobbin. An elastic structure is provided between the support base and the mounting base. This elastic structure is used to provide upward elastic support to the support base when the bobbin is fitted onto the rotating shaft and pressed against the support base, thereby clamping the thread end between the bottom surface and the support surface to achieve the purpose of pressing the thread end. The rotating shaft drives the mounting base, the elastic structure, the support base, and the bobbin to rotate together for winding.

[0016] In some embodiments, the support base and the mounting base are fitted together axially, and a guide post and a guide groove are provided between the support base and the mounting base to achieve axial guidance and circumferential transmission.

[0017] In some embodiments, the top surface has a recess that engages with the bottom of the bobbin, and the inner bottom surface of the recess serves as a support surface. Attached image description: Figure 1 This is a three-dimensional schematic diagram of a mechanical winding device for a sewing machine disclosed herein.

[0018] Figure 2 In order to be in Figure 1 A three-dimensional diagram of the bobbin after it has been fitted onto the base.

[0019] Figure 3 In order to be in Figure 1 A three-dimensional diagram after removing the cover.

[0020] Figure 4 In order to be in Figure 3 A three-dimensional schematic diagram after removing the support base from the original structure.

[0021] Figure 5 In order to be in Figure 4 A three-dimensional schematic diagram after removing the mounting base and spring from the original design.

[0022] Figure 6 In order to be in Figure 5 A 3D schematic diagram after removing the outer shell from the base.

[0023] Figure 7 In order to be in Figure 6 A three-dimensional schematic diagram after removing the drive shaft and swing arm from the original design.

[0024] Figure 8 This is a three-dimensional schematic diagram of a mounting base disclosed herein.

[0025] Figure 9 This is a three-dimensional schematic diagram of a support base from a top view.

[0026] Figure 10 This is a three-dimensional schematic diagram of a support base from a bottom view.

[0027] Figure 11 This is a three-dimensional schematic diagram of a bobbin.

[0028] The diagram shows: 1-Electric motor, 2-Rotating shaft, 3-Boob core, 3.1-Bottom surface, 3.2-Matching groove, 4-Mounting base, 4.1-Guide groove, 5-Support base, 5.1-Supporting surface, 5.2-Guide post, 5.3-Recess, 6-Spring, 7-Snap ring, 8-Machine base, 9-Outer shell, 10-Mounting bracket, 10.1-Switch, 10.2-Cam, 10.3-Tension spring, 10.4-Push rod, 10.5-Drive shaft, 10.6-Hook, 10.7-Allowing surface, 11-Cover, 11.1-First limiting part, 11.2-Second limiting part, 12-Swing arm, 12.1-Matching protrusion, 12.2-First arm, 12.3-Second arm, 12.4-Adjusting screw. Detailed Implementation

[0029] To better understand this application, various aspects of this application will be described in more detail below with reference to the accompanying drawings. It should be understood that these detailed descriptions are merely illustrative of exemplary embodiments of this application and are not intended to limit the scope of this application in any way. Throughout the specification, the same reference numerals refer to the same elements.

[0030] like Figures 1 to 10 As shown, this disclosure proposes a mechanical winding device for a sewing machine and a sewing machine, including an electric motor 1, a swing arm 12, and a rotating shaft 2. The rotating shaft 2 is used to mount the bobbin 3. It also includes a housing 9, a mounting bracket 10, a cover 11, a switch 10.1, a cam 10.2, a tension spring 10.3, and a push rod 10.4. The cover 11 cooperates with the housing 9 to form a mounting cavity. The electric motor 1 and the mounting bracket 10 are installed in this mounting cavity and protected by the cover 11. A switch 10.1, a cam 10.2, a tension spring 10.3, and a push rod 10.4 are installed on the mounting bracket 10. One end of the tension spring 10.3 is connected to the mounting bracket 10, and the other end of the tension spring 10.3 is connected to the push rod 10.4. One end of the push rod 10.4 is located between the cam 10.2 and the switch 10.1. The cam 10.2 is connected to a drive shaft 10.5, which passes through the cover 11 and is connected to the swing arm 12. The rotating shaft 2 passes through the cover 11 and is connected to the electric motor 1.

[0031] When winding, the bobbin 3 is first mounted on the rotating shaft 2. Then, the swing arm 12 moves towards the circumference of the bobbin 3. The swing arm 12 drives the cam 10.2 to rotate through the transmission shaft 10.5. The rotation of the cam 10.2 drives one end of the push rod 10.4 to move towards the side of the switch 10.1, thus turning on the switch 10.1 and starting the electric motor 1 to drive the rotating shaft 2 to rotate and wind the bobbin. As winding progresses, the added thread will push the swing arm 12 away from the bobbin 3. The swing arm 12 will simultaneously drive the cam 10.2 to rotate. When the set winding thickness is reached, the clearance surface 10.7 on the cam 10.2 causes the push rod 10.4 to be pulled open under the action of the tension spring 10.3, so that one end of the push rod is disengaged from the switch 10.1, thereby turning off the switch 10.1 and stopping the electric motor 1.

[0032] The power supply cable can be inserted into the mounting cavity through the outer casing 9 or the cover 11, thereby controlling whether the electric motor 1 is powered and rotated by the switch 10.1. The switch 10.1 is preferably a micro switch.

[0033] like Figure 1 As shown, the cover 11 and the outer shell 9 can be directly connected to form a mounting cavity, or other structures can be used, such as an indirect connection between the cover 11 and the outer shell 9 via a mounting bracket 10 to form a mounting cavity. Any structural scheme that allows the cover 11 and the outer shell 9 to mate to form a mounting cavity, applicable to this disclosure, can be used in this disclosure.

[0034] In some embodiments, such as Figure 1 , 2 As shown, the cover 11 is provided with a first limiting part 11.1 and a second limiting part 11.2, and the swing arm 12 is provided with a mating protrusion 12.1. The mating protrusion 12.1 is movably mated between the first limiting part 11.1 and the second limiting part 11.2, and the swing range of the swing arm 12 is limited by the first limiting part 11.1 and the second limiting part 11.2.

[0035] In some embodiments, such as Figure 6 As shown, the electric motor 1 is mounted on the lower side of the mounting bracket 10, and the rotating shaft 2 passes through the mounting bracket 10 and the cover 11 in sequence, protruding from the upper side of the cover 11. The switch 10.1, cam 10.2, tension spring 10.3, and push rod 10.4 are all mounted on the upper side of the mounting bracket 10 and located between the mounting bracket 10 and the cover 11. In this way, the structure is more compact. In addition, the axial limit switch 10.1, cam 10.2, tension spring 10.3, and push rod 10.4 of the cover 11 can also be used.

[0036] In some embodiments, such as Figure 6As shown, the electric motor 1, switch 10.1, cam 10.2, tension spring 10.3 and push rod 10.4 are all mounted on the mounting bracket 10 to form an independent assembly. This independent assembly is then installed in the housing 9, and then the cover 11 is installed to close the opening of the housing 9. The drive shaft 10.5 is installed with the independent assembly first and then the cover 11 is installed, or the drive shaft 10.5 is installed after the cover 11 is installed.

[0037] In this example, the drive shaft 10.5 is installed after the cover 11 is installed. The drive shaft 10.5 can be installed with the swing arm 12 first and then connected to the cam 10.2, or the drive shaft 10.5 can be connected to the cam 10.2 first and then the swing arm 12 is installed.

[0038] In some embodiments, such as Figure 5 , 6 As shown, the mounting bracket 10 is provided with hooks 10.6 around its circumference, and the mounting bracket 10 is installed at the opening of the housing 9 through the hooks 10.6. In this way, the structure is simple and compact, and the installation is more convenient.

[0039] In some embodiments, such as Figure 1 As shown, the swing arm 12 includes a first arm 12.2 and a second arm 12.3 arranged side by side. The first arm 12.2 and the second arm 12.3 are connected at the same end to form a U-shaped structure. An adjusting screw 12.4 is also provided to change the interval between the first arm 12.2 and the second arm 12.3, thereby changing the winding thickness.

[0040] In some embodiments, such as Figures 1 to 10 As shown, it also includes a mounting base 4 and a support base 5. The mounting base 4 is fixedly mounted on the rotating shaft 2. This fixed mounting can adopt existing fixed mounting structures such as screw connection, snap connection, or tight fit, which will not be described in detail. The support base 5 is axially movably fitted on the rotating shaft 2. The top surface of the support base 5 serves as the support surface 5.1 for the bottom surface 3.1 of the bobbin 3. An elastic structure is provided between the support base 5 and the mounting base 4. This elastic structure is used to provide upward elastic support to the support base 5 when the bobbin 3 is fitted on the rotating shaft 2 and pressed against the support base 5. This allows the thread end to be clamped between the bottom surface 3.1 and the support surface 5.1 to achieve the purpose of pressing the thread end. The rotating shaft 2 drives the mounting base 4, the elastic structure, the support base 5, and the bobbin 3 to rotate together for winding. After winding is completed, the bobbin 3 is pulled off the rotating shaft 2.

[0041] In this way, compared with the current technology, this disclosure eliminates the pressure plate and the pressure arm that extends radially outward. Instead, it adopts a completely different structural scheme and working principle. Specifically, by making the support seat 5 generate upward elastic support after being pressed, the thread end is clamped between the bottom surface 3.1 and the support surface 5.1 to achieve the purpose of pressing the thread end. Meanwhile, the rotating shaft 2 drives the mounting seat 4, the elastic structure, the support seat 5, and the bobbin 3 to rotate together to wind the thread. This facilitates the winding of the bobbin 3, makes it convenient for users to use, and eliminates the risk of cuts.

[0042] The bobbin 3 can be tightly fitted onto the rotating shaft 2, so that when the bobbin 3 presses against the support base 5, the support base 5 generates upward elastic support under pressure. Alternatively, other structures can be used, such as... Figure 9 and 10 As shown, a retaining ring 7 is provided on the rotating shaft 2. This retaining ring 7 is used to axially lock and limit the bobbin 3. The principle is that the retaining ring 7 can move elastically in the radial direction. When the bobbin 3 is installed, the mating groove 3.2 on the inner wall of the bobbin 3 engages with the retaining ring 7 and is elastically tight. In this way, the axial movement has a certain resistance to meet the elastic support requirement. At the same time, the mating groove 3.2 and the retaining ring 7 cooperate to form circumferential transmission. Of course, other structures are also possible. Any structural scheme that is suitable for the bobbin 3 being installed on the rotating shaft 2 in this disclosure can be applied to this disclosure.

[0043] In some embodiments, such as Figure 1 , 2 As shown in Figures 8 and 9, the support base 5 and the mounting base 4 are fitted together axially, and a guide post 5.2 and a guide part are provided between the support base 5 and the mounting base 4. The guide post 5.2 and the guide part cooperate to achieve axial guidance and circumferential transmission. The guide part is, for example, a guide hole, and the guide post 5.2 cooperates with the guide hole. The guide post 5.2 can be set on the support base 5 and the guide part can be set on the mounting base 4, or the guide post 5.2 can be set on the mounting base 4 and the guide part can be set on the support base 5. In this way, the structure is compact, simple and reliable.

[0044] Furthermore, such as Figure 1 , 2 As shown in Figures 8 and 9, a concave-convex fitting guide structure is provided between the outer periphery of the support base 5 and the inner periphery of the mounting base 4. This concave-convex fitting guide structure includes a concave portion and a convex portion. The concave portion serves as a guide portion, which is the guide groove 4.1, and the convex portion serves as a guide post 5.2. In this way, the structure is not only simple, but also conducive to a more compact radial dimension.

[0045] like Figure 4 As shown, the elastic structure uses spring 6. In this example, spring 6 is a wave spring, which makes the structure simple and the size small.

[0046] In some embodiments, such as Figure 2 , 3 As shown, the top surface has a recess 5.3 that fits into the bottom of the bobbin 3, and the inner bottom surface of the recess 5.3 serves as a support surface 5.1. This better clamps the thread end. Specifically, because it is a recess 5.3, when the bobbin 3 is fitted onto the rotating shaft 2 and pressed against the support seat 5, an angle is formed between the outer periphery of the bottom of the bobbin 3 and the inner periphery of the recess 5.3, thus pressing the thread end at the angle, which is beneficial for pressing the thread end.

[0047] The sewing machine disclosed herein includes a machine base 8, on which a winding device is provided, which employs the aforementioned mechanical winding device for sewing machines.

[0048] When understanding this invention, the above structure may be referred to other embodiments / appendices if necessary. Figure 1 And that's understood, so I won't go into details here.

[0049] The above description is merely an illustrative embodiment of the present invention. Therefore, all equivalent changes or modifications made to the structure, features, and principles described in the scope of protection of the present invention are included within the scope of protection of the present invention.

Claims

1. A mechanical winding device for a sewing machine, comprising an electric motor (1), a swing arm (12), and a rotating shaft (2), the rotating shaft (2) being used to mount a bobbin (3), characterized in that, It also includes a housing (9), a mounting bracket (10), a cover (11), a switch (10.1), a cam (10.2), a tension spring (10.3), and a push rod (10.4). The cover (11) and the housing (9) cooperate to form a mounting cavity. The electric motor (1) and the mounting bracket (10) are installed in the mounting cavity and protected by the cover (11). The switch (10.1), the cam (10.2), the tension spring (10.3), and the push rod (10.4) are installed on the mounting bracket (10). One end of the push rod (10.4) is located between the cam (10.2) and the switch (10.1). The cam (10.2) is connected to a drive shaft (10.5). The drive shaft (10.5) passes through the cover (11) and is connected to the swing arm (12). The rotating shaft (2) passes through the cover (11) and is connected to the electric motor (1). When winding, first, a bobbin (3) is mounted on the rotating shaft (2), and then the swing arm (12) moves towards the circumference of the bobbin (3). The swing arm (12) drives the cam (10.2) to rotate through the transmission shaft (10.5). The rotation of the cam (10.2) drives one end of the push rod (10.4) to move towards the side of the switch (10.1) to turn on the switch (10.1), thereby starting the electric motor (1) to drive the rotating shaft (2) to rotate and wind the bobbin. As the winding progresses, the increased thread will push the swing arm (12) to gradually move away from the bobbin (3). The swing arm (12) will simultaneously drive the cam (10.2) to rotate. When the set winding thickness is reached, the clearance surface (10.7) on the cam (10.2) causes the push rod (10.4) to be pulled open under the action of the tension spring (10.3) so that one end is disengaged from the switch (10.1), thereby disconnecting the switch (10.1) and turning off the electric motor (1).

2. The mechanical winding device for a sewing machine according to claim 1, characterized in that, The cover (11) is provided with a first limiting part (11.1) and a second limiting part (11.2), and the swing arm (12) is provided with a mating protrusion (12.1). The mating protrusion (12.1) is movably mated between the first limiting part (11.1) and the second limiting part (11.2), and the swing range of the swing arm (12) is limited by the first limiting part (11.1) and the second limiting part (11.2).

3. A mechanical winding device for a sewing machine according to claim 1 or 2, characterized in that, An electric motor (1) is installed on the lower side of the mounting bracket (10), and a rotating shaft (2) passes through the mounting bracket (10) and the cover (11) in sequence and protrudes from the upper side of the cover (11). A switch (10.1), a cam (10.2), a tension spring (10.3) and a push rod (10.4) are all installed on the upper side of the mounting bracket (10) and located between the mounting bracket (10) and the cover (11).

4. A mechanical winding device for a sewing machine according to claim 3, characterized in that, The electric motor (1), switch (10.1), cam (10.2), tension spring (10.3) and push rod (10.4) are all mounted on the mounting bracket (10) to form an independent assembly, which is then installed in the housing (9), and then the cover (11) is installed to close the opening of the housing (9); the drive shaft (10.5) is installed with the independent assembly first and then the cover (11) is installed, or the cover (11) is installed and then the drive shaft (10.5) is installed.

5. A mechanical winding device for a sewing machine according to claim 3, characterized in that, The mounting bracket (10) is provided with hooks (10.6) in the circumference, and the mounting bracket (10) is installed at the opening of the outer shell (9) by means of the hooks (10.6).

6. A mechanical winding device for a sewing machine according to claim 1, characterized in that, The swing arm (12) includes a first arm (12.2) and a second arm (12.3) arranged side by side. The first arm (12.2) and the second arm (12.3) are connected at the same end to form a U-shaped structure. An adjusting screw (12.4) is also provided to change the interval between the first arm (12.2) and the second arm (12.3), thereby changing the winding thickness.

7. A mechanical winding device for a sewing machine according to claim 1, characterized in that, It also includes a mounting base (4) and a support base (5). The mounting base (4) is located on the upper side of the cover (11) and is fixedly mounted on the rotating shaft (2). The support base (5) is axially mounted on the rotating shaft (2). The top surface of the support base (5) serves as the support surface (5.1) for the bottom surface (3.1) of the bobbin (3). An elastic structure is provided between the support base (5) and the mounting base (4). This elastic structure is used to provide upward elastic support to the support base (5) when the bobbin (3) is mounted on the rotating shaft (2) and pressed on the support base (5), so that the thread end is clamped between the bottom surface (3.1) and the support surface (5.1) to achieve the purpose of pressing the thread end. The rotating shaft (2) drives the mounting base (4), the elastic structure, the support base (5), and the bobbin (3) to rotate together to wind the thread.

8. A mechanical winding device for a sewing machine according to claim 7, characterized in that, The support base (5) and the mounting base (4) are fitted together axially, and a guide post (5.2) and a guide part are provided between the support base (5) and the mounting base (4). The guide post (5.2) and the guide part cooperate to achieve axial guidance and circumferential transmission.

9. A mechanical winding device for a sewing machine according to claim 7, characterized in that, The top surface is provided with a recess (5.3) that fits into the bottom of the bobbin (3), and the inner bottom surface of the recess (5.3) serves as a support surface (5.1).

10. A sewing machine, comprising a machine base (8), wherein a winding device is provided on the machine base (8), characterized in that, The winding device employs the mechanical winding device described in any one of claims 1 to 9.

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