JPH0368716B2 - - Google Patents

Description

Detailed Description of the Invention Technical Field The present invention relates to a needle sewing machine in which a needle bar is moved up and down through a crank mechanism by rotation of an upper shaft, and in which the connection between the upper shaft and the needle bar is released and the upper shaft is rotated. The present invention relates to a needle bar drive device that stops the needle bar at an upper end position while the needle bar remains in the upper end position.

Prior Art Stitch sewing machines having the following structure have been known so far. That is, an upper shaft with a crank at the tip is provided in the arm along the arm's axial direction, and a needle bar is provided at the tip of the arm so as to be movable up and down in the vertical direction, and the needle bar holder provided on the needle bar and The needle bar is connected to a crank by a crank rod, and the needle bar is moved up and down by the rotation of the upper shaft, thereby driving the pricking needle at the lower end of the needle bar.

By the way, when using the sewing machine mentioned above, when creating a long stitch with one stitch, or when a fabric frame holding the fabric to be stitched passes under the needle, the lower end of the needle and the arm should be It is necessary to stop the needle bar at the upper end position in order to make the distance between the needle bar and the bed equal to or higher than the height of the cloth frame.

However, with the above structure, it is necessary to stop the upper shaft at the upper end position of the needle bar, but since the rotation angle of the upper shaft with respect to the upper end position of the needle bar is almost 0 degrees, the needle bar is stopped at the upper end position. There was a problem that it was complicated to adjust the timing of the upper axis to make the

OBJECT OF THE INVENTION An object of the present invention is to solve the above-mentioned problem, and to fix the needle bar and the upper shaft at any position on the needle bar without stopping the rotation of the upper shaft or reducing the rotational speed of the upper shaft. To provide a needle bar drive device for a needle bar sewing machine that can easily release the connection between the needle bars and reliably stop the needle bar at the upper end position.

Structure of the Invention In order to achieve the above object, the present invention provides an upper shaft with a crank at the tip in the arm along the arm axis direction, and a guide rod is provided in the arm tip so as to be rotatable in the arm vertical direction. , the guide rod is provided with a vertically moving member that moves up and down along the guide rod, the crank and the vertically moving member are connected by a crank rod, and the vertically moving member is moved up and down along the guide rod by rotation of the upper shaft. and an engaging member that rotates in a predetermined direction is provided on the vertically movable member, and the engaging member includes an engaging portion that connects to the inclined surface and a first spring that biases the engaging portion to the engaging position. On the other hand, a needle bar is provided on the distal end side of the arm from the guide rod and is movable up and down along the vertical direction separately from the engagement member, and is biased toward the upper end position by a second spring, so that the needle bar A needle bar holder having an engaging portion connected to the inclined surface is provided at the needle bar holder, and the inclined surface of the engaging member is slid on the inclined surface of the needle bar holder to releasably engage both the engaging portions. The arm is provided with a drive device that moves the needle bar holder up and down together with the engagement member and rotates the guide rod, and rotation of the guide rod by the drive device rotates the engagement portion of the engagement member in a predetermined direction. The guide rod is provided with a release member for releasing the engagement with the needle bar holder.

Effects of the Invention As described above, the present invention provides a needle bar with a simple needle bar holder, and an engagement member that engages with the needle bar holder on the upper shaft side of the arm and separately from the needle bar. The needle bar holder is configured to be engaged or disengaged by the engaging member. Therefore, for example, when using a large number of needle bars to perform stitching with a large number of colored threads, it is necessary to alternately connect the large number of needle bars to one upper shaft. case,
Each needle bar only needs to be provided with a needle bar holder, and only one engaging member needs to be provided on the upper shaft side, resulting in a simple structure as a whole. Further, in the present invention, the drive device disengages the engagement member from the needle bar holder at an arbitrary position of the needle bar, and the second spring stops the needle bar at the upper end position, and only the engagement member is moved up and down along the guide rod by rotation of the upper shaft, and at the upper end position of the engaging member, the inclined surface of the engaging member slides on the inclined surface of the needle bar holder, causing the engaging member to resist the first spring. After the needle bar holder rotates slightly in a predetermined direction, the engaging part of the engaging member engages with the engaging part of the needle bar holder, and the needle bar holder moves up and down together with the engaging member.
The upper shaft can be easily rotated while the upper shaft is rotating, that is, without stopping the rotation of the upper shaft or reducing its rotational speed, and even if the rotation angle of the upper shaft with respect to the upper end position of the needle bar is almost 0°. With this structure, the connection between the needle bar and the upper shaft can be easily released at any position on the needle bar, and the needle bar can be reliably stopped at the upper end position. Therefore, the efficiency of sewing work can be further improved.

EXAMPLES The present invention will be specifically described below based on illustrated examples.

As shown in Figures 1 and 2, 1 is an arm, 2 is an upper shaft that extends in the axial direction of the arm and whose tip is supported by a bearing 3 on the arm 1, and 4 is provided at the tip of the upper shaft 2. A crank 8 rotates integrally with the upper shaft 2, and a bearing 1 is attached to the tip of the arm along the arm vertical direction.
5 and 15 are a guide rod rotatably provided with respect to the arm 1; 7 is a vertically moving member provided on the guide rod 8 and moves up and down; 5 has one end pivotally connected to the crank 4 with a pin 6; A crank rod whose end is loosely fitted into a rear end shaft portion 7c of a platform 7a (to be described later) of the vertically movable member 7, 9 an engagement member supported rotatably in a predetermined direction by the vertically movable member 7, and 23 an arm. A needle bar 26 provided at the tip of the arm so as to be vertically movable along the vertical direction of the arm is a needle bar holder that is engaged with the center portion of the needle bar 23 and is detachable from the engaging member 9, and is attached to the upper shaft. 2, the vertically movable member 7 is moved up and down along the guide rod 8 via the crank 4 and crank rod 5, and further, the needle bar 23 is moved up and down by the engagement between the engaging member 7 and the needle bar holder 26. I try to do some sewing work.

As shown in FIG. 3, the vertically movable member 7 includes a cylindrical portion 7b vertically disposed on a base portion 7a, and a hole 7f penetrating in the vertical direction from the cylindrical portion 7b to the base portion 7a. The guide rod 8 is loosely fitted. At the distal end of the platform 7a, there is a through hole 7g for supporting an engagement member that penetrates in the lateral direction, and a locking protrusion 7e that projects laterally from one side and locks the engagement member 9 in the engagement position B.
In addition, a spring seat recess 7d for a first spring 11, which will be described later, is provided at the lower part of the side surface of the tip end of the cylindrical portion 7b.

Further, the engagement member 9 includes substantially U-shaped side plates 9a,
9a are connected to each other by an inclined portion 9b serving as an inclined surface on the top end side. This inclined part 9
b has a slope downward to the left in FIG. 3, and
The lower surface of the inclined portion 9b is a flat surface to form an engaging surface 9d serving as an engaging portion. A through hole 9f is provided at the lower end of each side plate 9a, and each through hole 9f, 9
The through hole 7g of the base portion 7a of the vertically movable member 7 is located between the holes 7a and 7f, and the two members are pivotally connected to each other by the rotation shaft 10. A spring seat recess 7 of the cylindrical portion 7b of the vertically movable member 7 is provided on the rear surface of the inclined portion 9b of the engaging member 9.
A spring seat recess 9g corresponding to d is provided, and both recesses 7
A first spring 11 is compressed between d and 9g, and urges the engaging member 9 to rotate counterclockwise in FIG. The corner portion 9 inside the lower bent portion of one side plate 9a of the engaging member 9 is attached to the locking protrusion 7e of the base portion 7a of the movable member 7.
e is locked, and the engaging member 9 is held at the engaging position B. Also, one side surface 9a of the engaging member 9
A pin 9c is provided on the rear side of the upper part thereof to protrude perpendicularly to the side surface 9a.

Further, the guide rod 8 is provided with arm members 12 and 13 at the upper and lower portion thereof in a direction perpendicular to the axis of the guide rod 8, and both arm members 12 and 1 are integrally provided with the guide rod 8.
3 also rotates. This both arm members 1
2 and 13, a rod 14 that can contact the pin 9c of the engaging member 9 supported by the vertically movable member 7 provided on the guide rod 8 is installed coaxially with the guide rod 8, as shown in FIG. I support it. Therefore, as the guide rod 8 rotates, the rod 14 is rotated together with both arm members 12 and 13 around the axis of the guide rod 8, and the engaging member 9 is rotated.
the pin 9c is moved rearward in the arm axis direction. Therefore, the engagement member 9 is aligned with the rotation axis 1 relative to the vertically movable member 7.
It rotates clockwise in FIG. 1 with the center at 0.

The lower end of the guide rod 8 is provided with a bracket 16 that projects downward from the lower end of the arm and rotates integrally with the guide rod 8. An electromagnet 19 is provided on the lower surface of the arm tip. This electromagnet 19 uses magnetic force to move the movable piece 18 back and forth along the arm axis direction.
Each end of the link 17 is pivotally connected to the bracket 16 and the bracket 16 by pins 20 and 21. Therefore,
The electromagnet 19 is driven to move the movable piece 18 backward in the arm axis direction, and the link 17 and bracket 16
The guide rod 8 is rotated counterclockwise in FIG. 4 via . In FIG. 1, reference numeral 25 denotes a torsion spring provided between the arm 1 and the upper arm member 12, which urges the guide rod 8 to rotate clockwise in FIG.

Further, reference numeral 22 denotes a guide plate provided within the tip of the arm in a direction perpendicular to the arm axis, and has a long hole extending in the vertical direction in the center.

The needle bar 23 provided at the tip of the arm has a second spring 24 compressed in its upper portion to bias the needle bar 23 to the upper end position with respect to the arm 1. This needle bar 2
A needle 28 is attached to the lower end of 3 through a needle holder 27.
It is equipped with The needle bar holder 26, which is fixed to the central part of the needle bar 23, is attached to the needle bar holder 26, which passes through the elongated hole 22a of the guide plate 22 and extends toward the rear in the arm axis direction, that is, toward the inclined portion 9b of the engaging member 9. A protruding engaging portion 26a is provided, and an inclined surface 26b on which the inclined portion 9b of the engaging member 9 slides is formed at the rear end of the engaging portion 26a. The engaging portion 26a is biased upward by the second spring 24, while the engaging member 9
The engaging surface 9d is biased to rotate counterclockwise in FIG. 1 by the first spring 11, so that the engaging portion 26a and the engaging surface 9d are removably engaged.

The needle bar drive device configured as described above lowers the vertically movable member 7 along the guide rod 8 via the crank rod 5 by the rotation of the upper shaft 2 and the crank 4. As the vertically movable member 7 descends, as shown in FIG.
The needle bar 23 is lowered by the engagement of the engagement portion 26a of No. 6. Then, the electromagnet 1 is placed at an arbitrary position on the needle bar 23.
When the guide rod 8 is rotated counterclockwise in FIG. 6 by driving the arm members 12 and 13, the rod 1
4 rotates counterclockwise around the guide rod 8 (direction a in FIG. 6), and the rod 14 contacts the pin 9c of the engaging member 9 as shown in FIG. (direction b in Fig. 6). Therefore, the engaging member 9 is rotated clockwise in FIG. 7 about the rotation shaft 10 relative to the vertically movable member 7, and the engagement between the engaging member 9 and the needle bar holder 26 is released. Immediately after the engagement is released, the needle bar 23 is raised by the biasing force of the second spring 24. The needle bar 23 has an engaging portion 26a of the needle bar holder 26 that is connected to the elongated hole 22a of the guide plate 22.
The needle bar holder 26 moves upward while being guided by the guide plate 22, and stops at the position where the engaging portion 26a of the needle bar holder 26 abuts against the upper end of the elongated hole 22a of the guide plate 22, that is, at the upper end position of the needle bar 23. The needle bar holder 26 of the needle bar 23 that has stopped at this upper end position engages with the engaging member 9 again at the upper end position. That is, when the driven electromagnet 19 is turned off, the guide rod 8 is reversely rotated by the biasing force of the torsion spring 25, returning the rod 14 to its original position (fourth,
5), and at the same time, the engaging member 9 is also returned to the engaging position B where it is locked to the locking protrusion 7e of the vertically movable member 7 by the biasing force of the first spring 11. In this state, when the engaging member 9 rises together with the vertically movable member 7 as the upper shaft 2 rotates, the inclined surface 26b of the engaging portion 26a of the needle bar holder 26 held at the upper end position and the inclined surface 26b of the engaging member 9 The portion 9b is in contact with the portion 9b. And the eighth
As shown in the figure, as the inclined portion 9b of the engaging member 9 slides on the inclined surface 26b of the needle bar holder 26, the engaging member 9 rotates around the rotating shaft 10 against the spring 11. It rotates slightly clockwise in FIG. 8, and then the engaging portion 26a of the needle bar holder 26 and the engaging surface 9d of the engaging member 9
The two are re-engaged by the force of the spring 11.

According to this embodiment, the connection between the needle bar and the upper shaft can be automatically released at any position on the needle bar using the electromagnet.

Note that the present invention is not limited to this example, and can be implemented in various other ways. for example,
Instead of separately providing an arm member and a rod on the guide rod as a release member, they may be provided integrally.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional side view of the tip of an arm according to an embodiment of the present invention, FIG. 2 is a cross-sectional view taken along line A-A in FIG. 1, and FIG. 4,5
The figures are a plan view and a side view, respectively, showing the engaged state of the engaging member and the needle bar holder, and FIGS. 6 and 7 are a plan view and side view, respectively, showing the disengaged state of the engaging member and the needle bar holder. , FIG. 8 is a side view showing a state in which the engaging member is engaged with the needle bar holder. DESCRIPTION OF SYMBOLS 1... Arm, 2... Upper shaft, 4... Crank, 5... Crank rod, 7... Vertical moving member, 8... Guide rod, 9
...Engagement member, 11...First spring, 14...Rod, 1
9... Electromagnet, 23... Needle bar, 24... Second spring, 26
...Holding the needle bar.

Claims (1)

[Scope of Claims] 1. An upper shaft 2 having a crank 4 at its tip is provided in the arm 1 along the axial direction, and a guide rod 8 is provided at the tip of the arm so as to be rotatable along the arm vertical direction, The guide rod 8 is provided with a vertically movable member 7 that moves up and down along the guide rod 8, the crank 4 and the vertically movable member 7 are connected by a crank rod 5, and the vertically movable member 7 is moved by the rotation of the upper shaft 2. The vertically movable member 7 is provided with an engaging member 9 that rotates in a predetermined direction along the guide rod, and the engaging member 9 has an engaging portion 9d connected to the inclined surface 9b and the engaging portion. 9d to the engagement position, and a needle bar 23 is provided on the arm distal end side of the guide rod 8 and separately from the engagement member 9 and is movable up and down along the vertical direction. , and is biased toward the upper end position by a second spring 24, and is provided with a needle bar holder 26 having an engaging portion 26a connected to the inclined surface 26b of the needle bar 23, and the inclined surface 26b of the needle bar holder 26 is By sliding the inclined surface 9b of the engaging member 9, both the engaging parts 26a and 9b are removably engaged, and the needle bar holder 2 is moved together with the engaging member 9.
6 and rotating the guide rod 8,
21 is provided on the arm 1, and the drive devices 16, 17,
Release members 12, 13, 14 rotate the engaging portion 9b of the engaging member 9 in a predetermined direction by rotation of the guide rod 8 by the guide rods 8, 18, 19, 20, 21 to release the engagement with the needle bar holder 9. A needle bar drive device for a needle bar sewing machine, characterized in that the guide bar 8 is provided with a needle bar drive device.