JP2806001B2 - Sewing machine threading device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial application field) The present invention relates to a threading device for a sewing machine provided in the sewing machine and capable of passing a thread through an eye of a sewing needle by a simple operation. .

(Prior Art) In recent years, for example, in the case of a household sewing machine, a ninth arm is provided on an arm portion in order to facilitate an operation of passing a thread through an eye of a sewing needle.
A device provided with a threading device 1 as shown in the figure is provided. The threading device 1 includes a needle bar base 3 that supports a needle bar 2 movably up and down, and includes an operating body 4 and a threading shaft 5. The cam groove 6 is provided at the upper end of the operating body 4.
Are formed integrally with each other.
Are fitted on the outer periphery of the upper end of the threading shaft 5. A hook 8 (see FIG. 8), a guide piece 9 and the like are provided at a lower end of the threading shaft 5, and pins 10 are provided at an upper portion thereof to protrude to both sides in the diameter direction. One side of the pin 10 is engaged with the cam groove 6 of the cylindrical portion 7, and in this state, a coil spring 11 is provided between the cylindrical portion 7 and the pin 10. On the other hand, the needle bar 2 is provided with a sewing needle 12 at a lower end, and is connected to a needle bar crank at an intermediate portion by a needle bar holding member 13. Further, a positioning member 14 is attached to the needle bar 2 so as to be positioned slightly above the needle bar holder 13 so as to be vertically adjustable with respect to the needle bar 2.

In this configuration, in order for the user to perform the threading operation, first, the operating body 4 that is urged upward against the needle bar base 3 by a spring (not shown) and is always in the retracted position shown in FIG.
Is pressed down by pressing the finger hook 4a at the lower end thereof downward. Then, the threading shaft 5 moves down integrally with the pin 10 being pressed against the lower end of the cam groove 6 by the spring force of the coil spring 11. The threading shaft 5 has a needle bar 2 on the other side of the pin 10.
The hook 8 is lowered to a position where the hook 8 is locked to the upper surface of the positioning member 14 fixed at this time. At this time, as shown in FIG. In this state, it is positioned behind the sewing needle 12. Here, when the operating body 4 is further depressed, the coil spring
Only the operating body 4 descends against the spring force of 11, and at this time,
When the pin 10 latched in the cam groove 6 relatively rises in the cam groove 6 in the oblique direction, the threading shaft 5 rotates in the direction of arrow A and the hook 8 enters the eye hole 12a. . In this state, as shown in FIG. 8 (b), the user hooks the thread 15 on the hook 8, and thereafter gradually releases the pressing force on the operating body 4, the operating body 4 The hook 8 (threading shaft 5) is hooked with the thread 15 in the direction opposite to the arrow A, as shown in FIG. 8 (c). And rotate. Thus, the thread 15 can be passed through the eye 12a of the sewing needle 12 with a simple operation.

(Problems to be Solved by the Invention) In the conventional threading device 1 described above, the dimension of the threading shaft 5 in the height direction from the lower end of the needle bar base 3 is ninth.
As shown in the figure, a dimension a corresponding to the width of the needle bar holder 13 moving up and down, a length dimension b from the needle bar holder 13 to the positioning member 14, and a length dimension c from the pin 10 to the positioning member 14 (this Is the height from the hook 8 to the eye 12a of the sewing needle 12), the dimension d in the height direction of the cam groove 6, and the length e from the upper end of the cam groove 6 to the upper end of the threading shaft 5. Only the minimum was necessary.

However, as described above, (a + b + c)
In the structure requiring the size of (+ d + e), the overall height of the threading device 1 is relatively large, and the size of the arm in the height direction is also relatively large. For this reason,
In the threading device 1 having the conventional structure, for example, it is difficult to install the threading device 1 in a small-sized sewing machine. Therefore, the space saving of the entire threading device 1 has been demanded.

The present invention has been made in view of the above circumstances, and an object thereof is to allow a thread to pass through an eye of a sewing needle with a simple operation, and to reduce the overall height. To provide a possible sewing machine threading device.

[Structure of the Invention] (Means for Solving the Problems) A threading device for a sewing machine according to the present invention is an operation that is vertically movable on a machine frame that supports a needle bar that is driven up and down via a needle bar holder. Body, a threading shaft provided on the machine frame so as to be rotatable and movable up and down, and a hook provided at a lower end portion of the threading shaft, and a descent of the threading shaft. A positioning mechanism for regulating the limit position to a position where the height of the hook and the eye of the sewing needle coincide with each other, and a needle for turning the hook by rotating the threading shaft at the lower end position according to the operation of the operating body. And a cam mechanism for entering the eye hole of the needle, wherein the positioning mechanism is located above the cam mechanism on the needle bar or the hooked portion provided on the needle bar holder and the threading shaft. And a positioning member to be locked to the locked portion provided by It is intended.

(Operation) According to the above means, the hook provided at the lower end of the threading shaft descends in response to the operation of the operating body, and the height of the hook and the eye of the sewing needle is lowered by the positioning mechanism. It is regulated at the same position. Then, in response to the operation of the operating body, the hook rotates by the cam mechanism and enters the eye of the sewing needle. Thereby, the user can easily perform the operation of passing the thread through the eye hole.

In this case, unlike a member that is located at the lower end of the normal cam mechanism, a member that locks to a predetermined position of the needle bar
Since the positioning member is located above the cam mechanism, it is not necessary to secure a length dimension for the cam mechanism above the positioning member on the threading shaft. Therefore, the height can be reduced accordingly.

Example An example of the present invention will be described below with reference to FIGS. The hook 8 and the sewing needle 12 shown in FIG.
Since the thread 15 is the same as that described in the conventional example, a new illustration thereof is omitted, and the same reference numeral is used.

Although not shown in detail, the sewing machine includes a bed portion and an arm portion, and a needle bar 21 having the sewing needle 12 is provided at a distal end of the arm portion. The needle bar 21 is supported by a machine frame 22 (see FIG. 5) of the arm portion via a needle bar base 23 so as to be vertically movable. The needle bar base 23 has a vertically long plate shape integrally having a side plate portion 23a. In this case, an upper end portion of the needle bar base 23 is pivotally supported by the machine frame 22 by a support shaft 24. It is movably provided. As shown in FIGS. 1 to 4, the needle bar 21 is provided on a support piece 25 and a support piece 26 provided at the lower end and the upper portion of the needle bar base 23, respectively, by being bent rearward. It is vertically movably inserted and supported, and in this state, it is connected to a needle bar crank (not shown) by a needle bar holding member 27 between the support piece 25 and the support piece 26, and is vertically moved. As a result, the needle bar 21 is moved up and down within a predetermined moving range (the position of the lower end of the needle bar holder 27 is indicated by a two-dot chain line in FIG. 1) via a needle bar crank by driving a motor (not shown). It has become. Further, by a swing mechanism (not shown), it is possible to swing the needle bar base 23 in synchronization with the vertical movement of the needle bar 21, whereby the needle bar 21 swings left and right while moving up and down. That is, a so-called zigzag sewing can be performed. In the state where the sewing machine is stopped, as shown in FIGS. 1 to 4,
The needle bar 21 is stopped at the upper end position (hereinafter referred to as a needle upper position) in the vertical movement range.

In the vicinity of the needle bar 21, an eye hole of the sewing needle 12 is provided.
A threading device 28 according to the present embodiment for passing the thread 15 through 12a is provided. Hereinafter, the threading device 28 will be described in detail.

The threading device 28 includes an operating body 29, a threading shaft 30, and the like. In this case, the threading device 28 is provided on the machine frame 22 via the needle bar base 23. As shown in FIGS. 1 to 4, the operating body 29 is a finger-holding portion for a user to put a finger on a lower end portion.
It has a semi-cylindrical tubular portion 31 surrounding the threading shaft 30 at the top. A cam groove 32 extending in an oblique direction is formed in the cylindrical portion 31. The operating body 29 has a long hole 23b (fifth fifth end) formed by extending the upper end protrusion 29b in the side plate portion 23a of the needle bar base 23 in the vertical direction.
(See FIG.), And is provided on the left side of the needle bar base 23 so as to be vertically movable. Further, protruding pieces 29c and 29d having extending holes to the right are provided at the upper end and lower part of the operating body 29, respectively, and a threading shaft 30 described later is inserted into these protruding pieces 29c and 29d. It has become so. As shown in FIG. 5, a spring 33 is provided between the operating body 29 and the needle bar base 23. Therefore, in a normal state, as shown in FIG. 1, FIG. 2 and FIG. The operating body 29 is urged upward by a spring 33, and the operating body 29
Is located at a position where it comes into contact with the lower surface of the support piece 25. Although not shown, in this state, the finger hook 29a of the operating body 29 is located at the lower part of the distal end of the arm of the sewing machine and can be pressed down by the user from the outside.

On the other hand, the threading shaft 30 has a shaft portion 30a extending vertically.
A hook 8 (see FIG. 8), auxiliary guides 34, 34 provided on both sides of the hook 8, and a guide piece 35 provided on the opposite side to the hook 8 are provided on the large diameter portion 30b at the lower end of the hook 8. It is configured. Further, a pin 36 protruding in one direction in the diameter direction is provided on an upper portion of the shaft portion 30a. This threading shaft 30
The lower portion of the shaft portion 30a is inserted through the support piece portion 25 of the needle bar base 23 and the protruding piece portion 29d of the operating body 29, and the upper portion of the shaft portion 30a is protruding piece portion of the operating body 29 described above. The needle bar 21 is provided so as to be rotatable and vertically movable along the left side of the needle bar 21. Then, at this time, the operating body
The 29 cylindrical portion 31 surrounds the upper portion of the shaft portion 30a, and the pin 36 is engaged with the cam groove 32, whereby the cam mechanism 37 for rotating the threading shaft 30 is provided. It is configured. Further, the pin 36 and the projecting piece 29c at the upper end of the operating body 29 are provided.
A coil spring 38 is disposed between the pin 36 and the pin 36. Normally, the pin 36 is pressed against the lower end of the cam groove 32 by this spring force.

Accordingly, when the pressing force is not applied to the operating body 29, the threading shaft 30 is moved together with the operating body 29 to the uppermost position by the spring force of the spring 33 as shown in FIGS. 1, 2 and 5. (Hereinafter, this position is referred to as a retreat position). Also,
When the downward movement of the threading shaft 30 is permitted,
In a state where the pin 36 is pressed against the lower end of the cam groove 32 by the spring force of the coil spring 38, the threading shaft 30 moves down integrally with the operating body 29. At this time, the hook 8 is located slightly to the left rear of the sewing needle 12 and moves up and down. When the lowering position of the threading shaft 30 is regulated by a positioning mechanism 39 described later and the operation body 29 is further pushed down in a state where the threading shaft 30 is at the lowest position (hereinafter, this position is referred to as a threading position), the cam By the action of the mechanism 37, the threading shaft 30 is rotated in the direction of the arrow A at the same height position, and the hook 8 is turned into the eye of the sewing needle 12.
It is designed to enter 12a.

A positioning mechanism 39 for regulating the lower limit position of the threading shaft 30 to a position where the height of the hook 8 and the height of the eye 12a of the sewing needle 12 match will be described.

The upper end of the shaft portion 30a of the threading shaft 30 is set so as to protrude slightly above the protruding piece portion 29c of the operating body 29, and a positioning member 40 is provided at the upper end portion of the shaft portion 30a. Have been. Accordingly, the positioning member 40 is provided above the cam mechanism 37. As shown in FIG. 7, the positioning member 40 is fitted and fixed to the threading shaft 30 so that the vertical position can be adjusted by screws 41.
On the other hand, as shown in FIG. 6, the needle bar holder 27 is integrally provided with a locked portion 42 projecting leftward. Thus, the positioning member 40 is locked to the locked portion 42, whereby the lowering limit position of the threading shaft 30 is regulated, and thus the positioning mechanism 39 is configured. In this case, the vertical position of the positioning member 40 is adjusted, for example, at the time of shipment, in consideration of the variation of each part, and the height of the hook 8 and the eye 12a of the sewing needle 12 surely match at the threading position. It is made to do. When the threading shaft 30 is rotated at the threading position, the positioning member 40 slides on the locked portion 42.

The lower surface of the positioning member 40 on the front side has a seventh
As shown in the figure, a notch 40a is formed, while the needle bar base 23 is provided with a projection 43. This projection 43
As shown in FIGS. 1 and 2, the needle bar at the needle position
It is provided slightly below the locked portion 42 of the 21.
The notch 40a and the projection 43 constitute a rotation inhibiting mechanism 44 as described later, and protect the hook 8 when the user uses the threading device 28 while the needle bar 21 is lowered by mistake. Is to be planned.

Next, a procedure for passing the thread 15 through the eye 12a of the sewing needle 12 using the threading device 28 configured as described above will be described.

Normally, as described above, the needle bar 21 is stopped at the needle-up position, and the threading shaft 30 is located at the retracted position (see FIGS. 1 and 2). When passing the thread 15, the user first grasps the tip of the thread 15 guided from the upper thread supply source (not shown) to the vicinity of the sewing needle 12 through a predetermined balance mechanism or the like of the arm portion with the finger of the right hand. While lightly holding, the finger of the left hand is hung on the finger hook 29a, and the operating body 29 is pressed down by a force opposing the spring force of the spring 33. Then pin 36
Is pressed against the lower end of the cam groove 32 by the spring force of the coil spring 38, and the threading shaft 30 moves down integrally with the operating body 29 straight through these. The lowering of the threading shaft 30 is stopped at the threading position where the positioning member 40 is locked by the locked portion 42 of the needle bar 21 (see FIGS. 3 and 8A). . Here, in a state where the height of the hook 8 matches the height of the eye 12a of the sewing needle 12, the hook 8 is located on the left rear side of the eye 12a. And, from this state, the operating tool
When the 29 is pushed down, the pin 36, that is, the threading shaft 30 remains at the same height position, and only the operating body 29 descends against the spring force of the coil spring 38. The pin 36 comes to move relatively obliquely up the 32,
Thus, the threading shaft 30 is rotated by the cam mechanism 37. As a result, as described above, the hook 8 enters the eye 12a of the sewing needle 12 (see FIGS. 4 and 8 (b)), and the user releases the thread 15 held by the right hand. After hanging on the guide piece 35, the hook 8 is hooked.

Thereafter, when the pressing force on the operating body 29 is gradually released, first, the pin 36 moves downward in the cam groove 32 relatively obliquely by the spring force of the coil spring 38, and the threading is performed. axis
30 rotates in the direction opposite to arrow A. Thus, as shown in FIG. 8 (c), the hook 8 comes out of the eye hole 12a and the thread 15 is passed therethrough. Thereafter, when the pressing force on the operating body 29 is further released, the threading shaft 30 is
And the operation body 29 moves upward and moves again, and FIGS.
It is returned to the retracted position shown in the figure. Thus, the user can easily perform the operation of passing the thread 15 through the eye holes 12a.

In addition, by providing the rotation prohibiting mechanism 44, the position where the needle bar 21 is lowered instead of the needle upper position due to, for example, the user turning the pulley by hand, that is, the locked portion 42 of the needle bar holder 27 is projected. 43
If the user attempts to perform the above-described threading operation in a state where the threading operation is stopped at a position lower than the lower position, as shown in FIG. Before the positioning member 40 is locked by the locked portion 42, the positioning member 40 is locked by the projection 43, so that downward movement and rotation in the direction of arrow A are prohibited. With this, for example, when the tip of the sewing needle 12 is stuck in a needle plate (not shown),
Even if the user tries to use the threading device 28 by mistake, it is possible to prevent the hook 8 from hitting the sewing needle 12 due to the rotation of the threading shaft 30 and to protect the hook 8. is there.

In this embodiment, the positioning member 40 constituting the positioning mechanism 39 is provided at the upper end of the threading shaft 30 at a position higher than the cam mechanism 37, as in the conventional example shown in FIG. Unlike the configuration in which the cam mechanism is disposed above the pin 10 for regulating the lower limit position of the needle bar 2, the length of the threading shaft 30 for the cam mechanism 37 above the positioning member 40. There is no need to secure Accordingly, as shown in FIG. 1, the dimension d in the height direction of the cam groove 32 is set to the length dimension c from the positioning member 40 to the locked portion 42 (this corresponds to the eye 12a of the sewing needle 12 from the hook 8). Up to the height). In addition, in the present embodiment, the positioning member 40 is provided so as to be position-adjustable.
Is formed integrally with the needle bar holder 27, so that the length b required from the needle bar holder 13 to the positioning member 14, which is conventionally required, is unnecessary.

Accordingly, the height dimension of the threading shaft 30 of the present embodiment from the lower end of the needle bar base 23 is, as shown in FIG. The dimension c and the length e ′ from the lower surface to the upper end of the positioning member 40 are added (a
+ C + e '), and the height could be reduced by at least (b + d) compared to the conventional one. As a result, the entire threading device 28 can be saved in space, and can also be incorporated in a small sewing machine having a relatively small height of the arm portion.

Particularly, in the present embodiment, the notch 40
a and the projection 43 is provided on the needle bar base 23 to form the rotation inhibiting mechanism 44, so that when the user accidentally tries to use the threading device 28 with the needle bar 21 being lowered. Also, the effect that the hook 8 can be protected can be obtained.

In the above embodiment, the locked portion 42 is provided integrally with the needle bar holder 27. However, even if the locked portion 42 is provided as a separate member on the needle bar 21 slightly above the needle bar holder 27, Only for d, the height dimension can be reduced, and the intended purpose can be achieved.

In addition, the rotation prohibiting mechanism 44 may not be necessarily provided, and the present invention can be applied to not only a zigzag sewing machine but also a straight stitch sewing machine. It is.

[Effects of the Invention] As is clear from the above description, according to the threading device of the sewing machine of the present invention, the thread can be passed through the eye of the sewing needle with a simple operation, and This provides an excellent effect that the height can be reduced.

[Brief description of the drawings]

1 to 8 show an embodiment of the present invention. FIG. 1 is a front view of a main part shown through a needle bar base, FIG. 2 is a rear view of the main part, and FIG. And FIG. 4 is a view corresponding to FIG. 1 showing different states during the threading operation, FIG. 5 is a longitudinal sectional side view of a main part, FIG. 6 is a cross-sectional top view of a positioning mechanism portion, and FIG. 8B and 8B are enlarged top and front views, respectively, showing the rotation prohibiting mechanism, and FIGS. 8A to 8C are diagrams showing the states of the sewing needle and the hook at the time of the threading operation in order. It is an expansion perspective view of a part. FIG. 9 is a diagram corresponding to FIG. 1 showing a conventional example. In the drawing, 8 is a hook, 12 is a sewing needle, 12a is an eye hole, 15 is a thread, 21 is a needle bar, 22 is a machine frame, 23 is a needle bar stand, 27 is a needle bar holder,
28 is a threading device, 29 is an operating body, 30 is a threading shaft, 31 is a cylindrical portion, 32 is a cam groove, 36 is a pin, 37 is a cam mechanism, 38 is a coil spring, 39 is a positioning mechanism, and 40 is positioning. Reference numeral 40a denotes a cutout portion, 42 denotes a locked portion, 43 denotes a projection, and 44 denotes a rotation inhibiting mechanism.

Claims (1)

(57) [Claims] An apparatus for passing a thread guided from an upper thread supply source through an eye of a sewing needle provided on a needle bar, wherein the device supports the needle bar which is driven up and down through a needle bar holder. An operating body provided on the machine frame so as to be vertically movable, a threading shaft provided on the machine frame so as to be rotatable and vertically movable and moved up and down in response to the operation of the operating body, and a lower end of the threading shaft A hook provided in the section, a positioning mechanism for regulating a lower limit position of the threading shaft to a position where the height of the hook and the eye of the sewing needle coincide with each other, according to an operation of the operating body. A cam mechanism for rotating the threading shaft at the lower end position to allow the hook to enter the eye of the sewing needle, wherein the positioning mechanism is provided on the needle bar or the needle bar holder. A locking portion provided, and the threading shaft is positioned above the cam mechanism. And threading device of a sewing machine, characterized in that is composed of a positioning member to be engaged with the engaged portion provided.