JPH0638871U - Threading mistake prevention device - Google Patents

Abstract

(57) [Summary] [Purpose] The needle thread is prevented from being accidentally hooked when the needle thread tension mechanism is closed. [Structure] When the presser foot lifting lever 22 is lowered, the connecting member 30 and the mounting member 32 are operated, the tone mechanism 44 is closed, the guide plate 46 is moved above the balance 48, and the top of the balance thread hook is closed. It Therefore, it is possible to reliably prevent the upper thread from being hooked on the upper thread tension mechanism 44 when the upper thread tension mechanism 44 is closed.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a threading mistake preventing device for a sewing machine.

[0002]

[Prior art]

 Conventionally, in sewing machines equipped with a thread loosening mechanism that opens and closes the thread path of the needle thread tension mechanism, when performing needle thread hooking on the needle thread tension mechanism, the operator raises the presser foot lifting lever to The needle thread of the mechanism was opened, and the upper thread was hung on the upper thread tension mechanism.

That is, since the needle thread tension mechanism is closed when the presser foot lifting lever is lowered, the upper thread could not be reliably hooked on the needle thread tension mechanism. For this reason, when hooking the upper thread, the operator lifts the presser foot lifting lever to open the upper thread tension mechanism and hangs the upper thread.

Further, in some sewing machines, as disclosed in Japanese Utility Model Laid-Open No. 2-130574, a yarn path which is specially provided to prevent mistakes in needle thread hooking on a part of the yarn path. In some cases, a plate is provided in the path to prevent a threading mistake.

[0005]

[Problems to be solved by the device]

 However, in the conventional sewing machine, when the operator hooks the upper thread on the sewing machine, the operator applies the upper thread without noticing that the presser foot is lowered and the upper thread tension mechanism is closed. There were times when it ended up. In particular, in a sewing machine in which the needle thread tension mechanism is built into the sewing machine main body, the operator cannot check the open / closed state of the needle thread tension mechanism from the outside. Therefore, the operator does not notice that the upper thread tension mechanism is closed, and even when the upper thread tension mechanism is closed, the operator may hang the upper thread on the outside of the closed upper thread tension mechanism. It was

Further, in the case of a sewing machine in which a part of the above-mentioned yarn path is provided with a yarn path which is specially provided to prevent mistakes in needle thread hooking, and a plate which prevents the thread hooking mistakes is provided in the path. In some cases, the manufacturer did not understand the mechanism and spun on another place.

Therefore, when the upper thread is not accurately applied to the upper thread tension mechanism as described above, sufficient tension cannot be applied to the upper thread. Therefore, the tension of the lower thread becomes higher, the tension of the upper thread and the tension of the lower thread are not adjusted, the upper thread is pulled by the lower thread, and the sewing cannot be satisfactorily performed. Although it is impossible to sew well in this way, there is also a problem that the operator starts sewing without noticing that the needle thread is not hooked on the needle thread tension mechanism.

The present invention has been made to solve the above-mentioned problems, and prevents the threading error of the sewing machine in which the upper thread cannot be hung on the balance when the upper thread tension mechanism is closed. The purpose is to provide a device.

[0009]

[Means for Solving the Problems]

 In order to achieve this purpose, the threading mistake prevention device of the sewing machine of the present invention operates in conjunction with the work clamp mechanism that presses the cloth by raising and lowering the presser foot by the operation of the presser foot lifting lever and the operation of the presser lifting lever. It is equipped with a thread loosening mechanism that opens and closes the upper thread tension mechanism that applies tension to the upper thread. A movable movable thread hooking prevention member and a connecting member which is connected to the presser foot lifting lever to move the thread hooking prevention member from above the thread take-up path when the thread path is opened by the operation of the presser foot lifting lever. Is equipped with.

[0010]

[Action]

 In the threading mistake prevention device of the sewing machine having the above structure, when the thread loosening mechanism is operated and the needle thread mechanism is closed in conjunction with the operation of the presser foot lifting lever, the threading mistake prevention member is located above the balance. Go to and close the thread balance. Further, when the thread loosening mechanism is operated and the upper thread tension mechanism is opened in conjunction with the operation of the presser foot lifting lever, the thread hooking mistake prevention member moves from above the thread take-up and the thread take-up thread path is opened.

[0011]

【Example】

 Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

First, the structure of the sewing machine provided with the threading mistake prevention device of this embodiment will be described with reference to FIG.

The sewing machine according to the present embodiment includes a bed portion 10, a pedestal portion 12 erected from the right end portion of the bed portion 10, and a left side so that the pedestal portion 12 faces the bed portion 10. It is composed of an arm portion 14 extending to the front and a head portion 16 provided at the tip of the arm portion 14. A cover 15 for guiding a needle thread 52, which will be described later, is provided between the arm portion 14 and the head portion 16, and a needle bar 18 having a needle 17 attached thereto and a presser foot 20 thereof are provided at a lower portion of the head portion 16. A presser foot lifting lever 22 for moving the presser foot 20 up and down is provided.

Next, referring to FIGS. 1 and 2, the structure of the yarn hooking mistake prevention device of this embodiment will be described.

The threading mistake prevention device of this embodiment is provided inside the arm portion 14 and the head portion 16. Further, a presser foot lifting lever 22 for moving the presser foot 20 up and down is projected from an operation portion 26 to which a cam 24 is fixed. The operating portion 26 is rotatably supported by a frame (not shown) about a shaft 27. Further, the connecting member 30 that is supported by the cam surface of the cam 24 at the lower end 30a and is rotatably supported about the shaft 28 has the upper end 30b abutted on the right end 32a of the mounting member 32.

The mounting member 32 is rotatably supported by a frame (not shown) about a shaft 34, and the left end portion 32 b is connected to the frame (not shown) by a pulling spring 34, and is moved in the direction of arrow A shown in FIG. Being energized. A roller holding member 38 is rotatably supported by a shaft 36 on the mounting member 32, and two driven rollers 40 are rotatably provided on the roller holding member 38 so as to come into contact with the feeding roller 42. There is. The feeding roller 42 has an upper portion protruding from an opening 38a provided in the roller holding member 38, and a lower portion is connected to a drive motor (not shown) to form an upper thread tension mechanism 44.

Here, a rear end portion 46a of a guide plate 46 described later is fixed to the left end portion 32b of the mounting member 32. Further, as shown in FIG. 3, a balance 48 is provided inside the head 16, and a balance thread hooking port 50 is opened above the head 16. The guide plate 46 rotates integrally with the attachment member 32 about the shaft 34 inside the head portion 16, and when the needle thread tension mechanism 44 is released by the operation of the lever 22, the balance thread hooking port 50 is opened. When the needle thread tension mechanism 44 is opened and is closed, the thread take-up port 50 is movably supported so as to be closed.

The upper thread 52 is sandwiched between the feeding roller 42 and the driven roller 40, supported by the balance 48, and supplied to the needle 17 shown in FIG.

Next, the operation of the yarn hooking mistake prevention device of this embodiment will be described with reference to FIGS. 1 to 3.

First, when the operator rotates the presser foot lifting lever 22 around the shaft 27 in the direction of arrow B shown in FIG. 2, the lower end portion 30 a of the connecting member 30 rides on the cam 24 of the operating portion 26. Thus, the upper end portion 30b of the connecting member 30 rotates in the direction of arrow C shown in FIG. As a result, the right end portion 32a of the attachment member 32 that abuts the upper end portion 30b of the connecting member 30 moves about the shaft 34 in the direction of arrow D shown in FIG. Therefore, the left end portion 32b of the mounting member 32 moves in the clockwise direction about the shaft 34. Therefore, the mounting member 32 moves from the position indicated by the chain double-dashed line in FIG. 3 to the position indicated by the solid line about the shaft 34.

Here, the roller holding member 38 moves in conjunction with the mounting member 32 from the position indicated by the chain double-dashed line to the position indicated by the solid line, as shown in FIG. Therefore, the driven roller 40 is separated from the feeding roller 42, and the needle thread tension mechanism 44 is released.

At this time, the guide plate 46 moves from the position (the position indicated by the chain double-dashed line) covering the balance 48 shown in FIG. 3 to the position indicated by the solid line as the left end portion 32b of the mounting member 32 rotates clockwise. Move to. Therefore, the thread take-up port 50 is opened, and the thread can be hooked on the thread take-up. Therefore, the operator can hang the upper thread 52 on the upper thread tension mechanism 44 and the balance 48 as shown in FIG.

Next, when the worker lowers the presser foot, when the presser foot lifting lever 22 is rotated about the shaft 27 in the direction opposite to the arrow B shown in FIG. 2, the lower end portion 30a of the connecting member 30 is operated. Get off from the cam 24 of the part 26. Since the left end 32b of the mounting member 32 is biased by the pulling spring 34 in the direction of arrow A, the mounting member 32 rotates about the shaft 34 in the counterclockwise direction. Therefore, the mounting member 32 moves from the position indicated by the solid line to the position indicated by the alternate long and two short dashes line about the shaft 34 as shown in FIG.

Here, the roller holding member 38 moves from the position indicated by the solid line to the position indicated by the alternate long and two short dashes line as shown in FIG. 3 in association with the movement of the mounting member 32. 42, the upper thread tension mechanism 44 is closed, and the upper thread 52 is clamped by the upper thread tension mechanism 44. At this time, the guide plate 46 moves from the position shown by the solid line in FIG. 3 to the position shown by the chain double-dashed line (the position covering the balance 48) as the left end portion 32b of the mounting member 32 rotates in the counterclockwise direction. Moving. Therefore, the thread take-up port 50 is blocked, and the thread cannot be hooked on the thread take-up 48.

As described above, when the press-up lever 22 is lowered, since the thread take-up port 50 is closed by the guide plate 46, the thread cannot be hooked on the thread take-up 48. . Therefore, the operator notices that the presser-lifting lever 22 has not been raised to release the needle thread tension mechanism 44, and can prevent the mistaken application of the needle thread to the needle thread tension mechanism with the needle thread closed. .

The present invention can be similarly applied to a sewing machine having a mechanism for adjusting the upper thread by the upper thread tension disc 54 as shown in FIG.

Further, the present invention is not limited to the above-mentioned embodiments, but can be widely applied and can be modified within the scope of the invention.

[0028]

[Effect of device]

 As is clear from the above description, in the threading mistake prevention device of the sewing machine of the present invention, it is possible to prevent the thread from being erroneously hung on the needle thread tension mechanism when the needle thread tension mechanism is closed. It can be surely prevented.

[Brief description of drawings]

FIG. 1 is a front view of a sewing machine provided with a threading mistake prevention device of this embodiment.

FIG. 2 is a perspective view of a mechanism of the yarn hooking mistake prevention device of the present embodiment.

FIG. 3 is a perspective view of a head portion of a sewing machine provided with a threading mistake prevention device of this embodiment.

FIG. 4 is a perspective view of a mechanism of a modified example of the threading error preventing device of the present embodiment.

[Explanation of symbols]

 20 presser foot 22 presser foot lifting lever 30 connecting member 32 mounting member 38 roller holding member 40 driven roller 42 feeding roller 44 upper thread tension mechanism 46 guide plate 48 balance

Claims (1)

[Scope of utility model registration request] 1. A presser foot mechanism for lifting and lowering a presser foot by actuating a presser foot lifting lever, and a needle thread tension mechanism for applying tension to a needle thread in conjunction with the operation of the presser foot lifting lever. A sewing machine that includes a thread loosening mechanism that performs, and a sewing machine that applies an upper thread to the upper thread tension mechanism when the upper thread tension mechanism is opened, and a balance that guides the upper thread that is applied to the upper thread tension mechanism, and a balance of the balance. A movable threading mistake prevention member provided so as to cover the upper part of the yarn path, and the threading mistake prevention member which is connected to the presser foot lifting lever when the yarn path is opened by the operation of the presser foot lifting lever. A yarn hooking device, comprising: a connecting member that is moved from above the yarn path.