JPH0515678A - Thread take-up lever device for multi-needle type sewing machine - Google Patents

Abstract

PURPOSE:To reduce a driving noise by transferring directly driving force from a thread take-up lever driving mechanism to a thread take-up lever, and also, to curtail the number of parts, and to simplify the structure by eliminating the need of selection of the thread take-up lever at the time of changing a thread. CONSTITUTION:The device is provided with a single thread take-up lever 90 assembled so that a reciprocating turn can be executed to a sewing machine arm of a multi-needle type sewing machine for executing sewing by driving vertically one piece of needle bar selected by a moving operation of a needlebar case 50 in which plural pieces of needle bars 60 are provided a thread take-up lever driving mechanism B which is positioned on the sewing machine arm 12 side in the same way and allows the thread take-up lever 90 to execute a reciprocating turn, a thread selecting part 70 which can hold separately a throat allowed to pass through a sewing needle 68 of each needle bar, respectively on the needlebar case 50 side, and a thread holding part 96 which hooks a thread allowed to pass through the sewing needle of the needlebar selected by the moving operation of the needlebar case 50 formed in the thread take-up lever 90, in the thread selecting part 70 and can give a thread take-up operation to this thread.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a balance device for a multi-needle sewing machine in which a sewing machine head is provided with a plurality of needle bars for the purpose of changing colors of sewing threads.

[0002]

2. Description of the Related Art A sewing machine head 510 of a conventional multi-needle type sewing machine is shown in FIGS. In these drawings, the needle bar case 550 is provided on the front surface of the sewing machine arm 512.
Is assembled slidably in the width direction of the sewing machine head 510. This needle bar case 550 has a plurality of needle bars 5.
60 and the balance 590 of the same number as this are respectively provided. The needle bar case 550 is slid by a signal for thread change based on the control data of the sewing operation. As a result, the selected one needle bar 560 receives the driving force from the needle bar drive mechanism, and thus the needle bar 560 is vertically driven together with the sewing needle 568 attached to the lower end thereof. At the same time that the needle bar 560 is selected, the balance 590 corresponding to the needle bar 560 receives the driving force from the balance driving mechanism. Therefore, the selected balance 590 also reciprocally rotates in synchronization with the vertical driving of the needle bar 560, and the thread passing through the sewing needle 568 of the needle bar 560 is given the balance operation. The transmission of the driving force from the balance drive mechanism to the balance 590 is realized by meshing the gear Y of the balance 590 with the drive gear X of the drive lever 528 of the balance drive mechanism by sliding the needle bar case 550. (Figs. 8 and 10
See).

[0003]

In the above conventional technique, the balance 590 must be selected at the same time as the selection of the needle bar 560 at the time of thread change. For that purpose, the driving force from the balance driving mechanism to the balance 590 is required. The transmission system has the gears X and Y.
Is required. Such a gear mesh portion has a certain backlash, and a larger backlash is required to selectively mesh the drive gear X of the drive lever 528 with the gear Y of the balance 590. Note that there is a type in which the engagement between the hook and the pin is used instead of the meshing of the gears X and Y, but it is the same in that a backlash is required. As a result, the generation of noise accompanying the driving of the balance 590 becomes a problem, and since the balance 590 having the number of the needle bars 560 is required, the number of parts of the balance device is increased and its structure is complicated. Become.

The technical problem of the present invention is that the selection of the balance is not required at the time of thread change, the driving force from the balance driving mechanism is directly transmitted to the balance, the driving noise is reduced, and the number of parts is reduced. It is to realize reduction and simplification of the structure.

[0005]

In order to solve the above-mentioned problems, the multi-needle sewing machine balance device of the present invention is constructed as follows. That is, the sewing machine head includes a sewing machine arm fixed to the frame and a needle bar case movably assembled to the front surface of the sewing machine arm.
This needle bar case is provided with a plurality of needle bars each having a sewing needle attached to its lower end so as to be movable up and down, and one needle bar selected by moving the needle bar case is used as a needle bar drive mechanism. In a multi-needle sewing machine that is driven up and down by means of a sewing machine, a single balance that is reciprocally rotatable with respect to the sewing machine arm and a sewing machine arm that is also located on the sewing machine arm side and is used to drive the needle bar up and down. Formed on the balance, a balance drive mechanism for rotating the balance in a reciprocating manner, a thread selection unit capable of individually retaining threads threaded through the sewing needles of the needle bars on the needle bar case side. And a thread holding section capable of hooking a thread threaded through the sewing needle of the needle bar selected by moving the needle bar case in the thread selection section and imparting a balance operation to the thread.

[0006]

According to the above construction, when the needle bar case is moved and the needle bar is selected at the time of changing the thread, the sewing needle of the needle bar selected from among the threads of the thread selecting section of the needle bar case is selected. The thread being threaded comes to a position corresponding to the thread holding portion of the balance provided on the sewing machine arm side. The needle bar selected in this state is vertically driven by the needle bar drive mechanism,
In synchronization with this, the balance is also reciprocally rotated by the balance driving mechanism. By the rotation of the balance, the thread passed through the sewing needle of the selected needle bar is hooked by the thread holding portion, and the thread is given a balance operation. In this way, when the needle bar is selected when changing the thread of the multi-needle sewing machine, the balance is driven by selecting the thread passed through the sewing needle of each needle bar instead of selecting the balance in accordance with this. It can be driven directly without using a gear or the like for the drive transmission from the mechanism to the balance.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. In the following examples, the balance device of the present invention is applied to a multi-head / multi-needle sewing machine. FIG. 7 shows a perspective view of the entire multi-head / multi-needle sewing machine. In this drawing, a sewing machine frame 2 is located on the upper surface of a sewing machine table 1, and a plurality of sewing machine heads 10 are provided on the front surface of the sewing machine frame 2. Further, on the upper surface of the sewing machine frame 2, there is arranged an adjusting table 4 having a member for applying a constant tension to the needle thread passed through each sewing needle 68 of each sewing machine head 10.

1 and 2 are side sectional views showing one of the sewing machine heads 10, FIGS. 3 and 4 are front views thereof, and FIG. 5 is a side sectional view on the side opposite to FIGS. The figure is shown. In these drawings, the sewing machine head 10 has a sewing machine arm 12 fixed to the sewing machine frame 2. A sewing machine spindle 14 penetrates the sewing machine arm 12, and the sewing machine spindle 14 has a single drive source (motor).
Thus, the driving force is transmitted to each sewing machine head 10. The needle bar drive cam 16, the balance drive cam 26 (see FIG. 1), and the cloth presser drive cam 32 (see FIG. 5) are fixed inside the sewing machine arm 12 on the axis of the sewing machine main shaft 14.

A needle bar case 50 is attached to the front surface of the sewing machine arm 12 so as to be slidable in the width direction of the sewing machine head 10. The needle bar case 50 is provided with a plurality of needle bars 60 arranged along the sliding direction so as to be vertically movable. Each of these needle bars 60
The sewing needles 68 are attached to the lower ends of the respective. Further, on the axis of each needle bar 60, a needle bar holder 62 is fixed between the upper and lower horizontal frames 52, 53 of the needle bar case 50. A projecting pin 64 is fixed to the needle bar holder 62 on the side of the sewing machine arm 12. By sliding the needle bar case 50, one needle bar 6
0 is selected, and the projecting pin 64 of the needle bar 60 engages with the vertical drive member 44 of the needle bar drive mechanism A, which will be described later, and receives the vertical motion. A coil spring 66 is provided between each head 61 and the upper horizontal frame 52 of the needle bar case 50 on the axis of each needle bar 60. Due to the elasticity of this coil spring 66, each needle bar 6
0 is always biased upward.

A support plate 72 is fixed to the upper surface of the needle bar case 50. The plate 72 extends horizontally so as to cover the upper surface of the sewing machine arm 12, and is bent vertically upward from there. The upper end of the vertical portion is a horizontal support surface 73, and another plate 78 is fixed on the support surface 73 via a pair of left and right spacers 76. Each of the plate 78 and the support surface 73 has a needle bar case 50 at a position corresponding to each other.
The same number of thread holes as those of the needle bar 60 of

That is, the plate 78 and the supporting surface 7
3 is a thread selecting section 70 in which the upper thread guided from the upper thread adjusting base 4 to the sewing needle 68 of each needle bar 60 is individually held at a constant interval. Moreover, in the thread selection section 70, the needle bar case 5 is attached to the support plate 72.
The same number of slits 74 as the upper thread is formed along the sliding direction of 0. These slits 74 are for allowing the operation of the balance 90 described below at each slide position of the needle bar case 50. Further, as shown in FIGS. 2 and 4, in the needle thread adjusting base 4, the needle thread of each sewing needle 68 is individually tensioned by the respective tension devices 5, 5.
6 and the thread take-up spring 7 are passed through in this order and guided to the thread selecting section 70. The thread take-up spring 7 prevents loosening of each upper thread located between the support surface 73 of the thread selection section 70 and the plate 78 at the time of thread change, which will be described later, and the thread of the thread balance 90 described next. This functions so that the yarn can be accurately selected by the holding unit 96.

FIG. 6 shows the sewing machine head 10 in a plan view. As is clear from this drawing, a single balance 90 is provided at a position near the upper side of the sewing machine arm 12. The boss portion 94 of the balance 90 is mounted so as to be reciprocally rotatable with respect to a balance shaft 92 whose both ends are supported on both side walls of the sewing machine arm 12. At the tip of the balance 90, as shown in FIG. 6, a thread holding portion 96 is formed by fixing one end of a hook member 96a bent in a "dogleg" shape. This thread holding portion 96
It is possible to hook one of the upper threads positioned in the thread selection section 70 of the needle bar case 50 with the rotation of the balance 90 and give the thread a balance operation.

Mainly as is clear from FIG. 5, a cloth presser guide shaft 82 having a cloth presser 80 at the lower end is attached to the sewing machine arm 12 so as to be parallel to the needle bars 60 and movable up and down. Has been. This guide shaft 8
A locking member 84 is fixed to a substantially intermediate portion on the axis of No. 2, and the guide shaft 82 is positioned on the axis of the guide shaft 82 between the locking member 84 and the lower surface of the upper wall of the sewing machine arm 12. Coil spring 86 that urges downward
Is provided.

Next, the needle bar 60, the balance 90 and the presser foot 8
The structure of each drive mechanism of No. 0 will be briefly described. First, as shown in FIG. 1, the needle bar drive mechanism A has a structure in which the rotation of the needle bar drive cam 16 on the axis of the sewing machine main shaft 14 is transmitted to the needle bar drive lever 20 through the connecting rod 18. There is. One end of the needle bar drive lever 20 is rotatably supported by a support shaft 22 with respect to a part of the sewing machine arm 12. The connecting rod 18 is connected to a substantially intermediate portion of the needle bar drive lever 20. Therefore, the rotation of the needle bar drive cam 16 is converted into the rotation operation of the needle bar drive lever 20 through the reciprocating motion of the connecting rod 18. Needle bar drive lever 2
An engaging recess 21 is formed at the tip of 0.

The needle bar drive mechanism A also has a single base needle bar 40. The base needle bar 40 is arranged in parallel to each needle bar 60 with respect to the sewing machine arm 12, and an up-and-down drive member 44 is assembled on the shaft so as to be vertically movable along the base needle bar 40. The engaging recess 21 of the needle bar drive lever 20 is engaged with the pin 46 protruding from the vertical drive member 44. Therefore, the vertical drive member 44 is driven up and down in conjunction with the rotation of the needle bar drive lever 20. Moreover, the vertical drive member 44 includes a pair of upper and lower engaging protrusions 48 on the side (front surface side) of the needle bar case 50 facing each needle bar 60. Based on the slide of the needle bar case 50 described above, the projecting pin 64 of each needle bar 60 is selectively engaged with the engaging protrusion 48. That is, the selected one needle bar 60 is vertically driven in association with the vertical movement of the vertical drive member 44. The sewing machine head 10
When a jump signal is input to the needle bar drive lever 20, the needle bar drive lever 20 is controlled to rotate about the vertical axis 24 in FIG. Is disengaged from the pin 46 of the vertical drive member 44. As a result, the transmission of the driving force from the needle bar drive mechanism A to the needle bar 60 is blocked.

As is apparent from FIGS. 1 and 6, the balance drive mechanism B includes a balance drive lever 28 rotatably supported by the support shaft 30 with respect to the sewing machine arm 12. A cam follower 29 that is in contact with the outer circumference of the balance drive cam 26 that rotates together with the sewing machine main shaft 14 is provided at a part of the balance drive lever 28. In addition, the balance drive lever 28
The tip end of is connected to a portion of the balance 90 which extends outward from the boss portion 94 via a link 31.
The force of the spring 98 acts on the balance 90 in a direction to return the balance 90 to the solid line state of FIG. 1, for example.
As a result, the force of the spring 98 acts so as to press the cam follower 29 of the balance drive lever 28 against the outer circumference of the balance drive cam 26. Therefore, when the balance drive cam 26 rotates, the balance drive lever 28 rotates about its support shaft 30 as a fulcrum, and in conjunction with this, the balance 90 moves between the solid line position and the imaginary line position in FIG. 1 on the axis of the balance shaft 92. Reciprocating between.

As shown in FIG. 5, the presser foot drive mechanism C has a support shaft 3 at a substantially middle portion with respect to the sewing machine arm 12.
A cloth pressing drive lever 34 rotatably supported by 6 is provided. A cam follower 35 that is in contact with the outer circumference of the cloth pressing drive cam 32 that rotates together with the sewing machine main shaft 14 is provided at one end of the cloth pressing drive lever 34. Further, the other end of the presser foot drive lever 34 has an engaging member 8 fixed to the guide shaft 82 of the presser foot 80.
It is locked to the lower surface of No. 4. Therefore, the presser foot drive cam 32
When is rotated, the presser foot drive lever 34 is rotated about the support shaft 36 as a fulcrum, and in conjunction with this, the guide shaft 82 is driven up and down together with the presser foot 80.

As shown in FIG. 5, an air cylinder 3 for retracting the cloth presser is provided below the cloth presser drive lever 34.
8 are provided. Rod 3 of this air cylinder 38
5 is always in the solid line state of FIG. 5 due to the force of the built-in spring, and when air is supplied to the air cylinder 38 in response to the retract signal, 9 projects to the state of the imaginary line. As a result, the cloth presser drive lever 34 is rotated beyond the range of rotation associated with the rotation of the cloth presser drive cam 32, and the guide shaft 82 is largely pushed upward together with the cloth presser 80 to be in a retracted state.

Next, a structure for regulating the top dead center of the needle bar 60 selected by sliding the needle bar case 50 will be described. As is clear from FIGS. 1, 5 and 6, the top dead center stopper 1 is provided on the shaft near the upper end of the base needle bar 40.
The sleeve portion 101 of No. 00 is assembled so as to be vertically movable along the base needle bar 40. The top dead center stopper 100 is a needle bar 6 driven by a needle bar drive mechanism A.
It is positioned so that it can receive the head 61 of 0. A pin 102 is projected on the outer circumference of the sleeve portion 101.

On the other hand, the lever 1 is mounted on the balance shaft 92.
04 is rotatably supported. The tip portion of the lever 104 is engaged with the pin 102 of the sleeve portion 101. Moreover, an end of the rod 108 of the air cylinder 106 is connected to a part of the lever 104. When the supply of air to the air cylinder 106 is stopped, the rod 108 is moved by the force of the built-in spring as shown in FIG.
Is drawn into the state of the virtual line. This causes the lever 104 to rotate on the axis of the balance shaft 92, and in conjunction with this, the top dead center stopper 100 moves upward along the base needle bar 40.

Finally, the structure for pulling the end of the thread-cut upper thread into the needle bar case 50 after finishing the sewing will be described. As shown in FIGS. 1, 3 and 5. An air cylinder 202 is attached to the inclined lower surface of the sewing machine arm 12. The hook 200 is fixed to the rod 204 of the air cylinder 202. A lateral plate 54 is provided on the lower surface of the needle bar case 50 over the same range as the width of the case 50. The lateral plate 54 is provided with a slit-shaped window 54a through which the hook 200 can pass.

After the sewing is finished and the upper thread is cut under the needle plate, air is supplied to the air cylinder 202, and the rod 204 thereof projects with the hook 200. At this time,
The hook 200 passes through the window 54a of the lateral plate 54 and projects directly below the sewing needle 68 of the needle bar 60 retracted upward. Therefore, the hook 200 is passed through the sewing needle 68 and hooks the thread continuing to the needle plate side, and when the air supply to the air cylinder 202 is stopped thereafter, the rod 204 is pulled back to the original position together with the hook 200. As a result, the end of the upper thread passes through the window 54a of the horizontal plate 54 and is drawn to the back side thereof. The drawn yarn ends are entangled and held by a plurality of loop-shaped fibers on the tape surface attached to the back surface of the horizontal plate 54.

When the sewing machine having the above-mentioned construction receives a signal for thread change, the needle thread passed through the sewing needle 68 of the needle bar 60 which has been sewn is thread-cut, and its thread end is crossed by the hook 200. It is held on the back side of the plate 54. At this time, the jump signal already described enters the sewing machine head 10, and the engagement recess 21 of the needle bar drive lever 20 in the needle bar drive mechanism A and the pin 46 of the vertical drive member 44 are released. At the same time, the top dead center stopper 100 is raised to the position shown by the phantom line in FIG. 1 or 5 by the control of the air cylinder 106. For this reason, the needle bar 60 after being sewn is pushed up by the spring 66 to the retracted position where the needle bar holder 62 is received by the lower surface of the upper horizontal frame 52 of the needle bar case 50. That is, this needle bar 60 is at the same position as the other needle bar 60 in standby. As the needle bar 60 moves up, the vertical drive member 44, which is disengaged from the needle bar drive lever 20, also moves up.

The rotation of the sewing machine main shaft 14 is temporarily stopped on the basis of the signal for thread change, but the balance 90 at this time is at the most retracted position as shown by the solid line in FIG. 1, for example. It has stopped. Therefore, as already described, the needle bar case 50 is slid along the front surface of the sewing machine arm 12, whereby a new needle bar 60 is selected, and the protruding pin 64 of the needle bar holder 62 is moved to the vertical drive member 44. Engages with the engaging protrusion 48. Also needle bar case 5
With the slide of 0, the yarn selection unit 70 moves relative to the yarn holding unit 96 of the thread balance 90. Then, among the respective upper threads held by the thread selection section 70, the upper thread passed through the sewing needle 68 of the selected needle bar 60 comes to a position corresponding to the thread holding section 96 of the thread balance 90.

Subsequently, the top dead center stopper 100 is lowered again to the solid line state in the drawing by the control of the air cylinder 106 thereof. This newly selected needle bar 60
Together with the vertical drive member 44 are pushed down to the top dead center position during normal sewing work. And this vertical drive member 44
During the lowering of the
The lever 20 is once rotated about the vertical axis 24 so that the lever 20 is pushed back by interfering with the front end of 0. However, the rotation of the needle bar drive lever 20 at this time is immediately returned by the force of the return spring, so that the pin 46 of the vertical drive member 44 engages with the engagement recess 21 of the needle bar drive lever 20. .. After that, the sewing machine main shaft 14 starts to rotate again, the selected needle bar 60 is vertically driven, and the balance 90 and the cloth presser 80 are also driven in synchronization with this. Now, when the balance 90 starts reciprocating rotation about the axis of the balance shaft 92, the needle thread passed through the sewing needle 68 of the selected needle bar 60 is hooked in the thread selection section 70, and this thread is balanced. Action is given. That is, for the balance 90, the upper thread itself is selected when changing the thread.

[0026]

As described above, according to the present invention, in a multi-needle type sewing machine, a single balance is provided, and at the same time as selecting a needle bar for thread change, selecting a thread passed through a sewing needle of each needle bar. Thus, the transmission of the driving force from the balance driving mechanism to the balance can be directly transmitted, so that the noise associated with the balance driving can be reduced, the number of parts can be reduced, and the structure can be simplified.

[Brief description of drawings]

FIG. 1 is a side sectional view showing a sewing machine head.

FIG. 2 is a side view showing a needle thread adjustment base above the upper side in FIG.

FIG. 3 is a front view showing a cutaway part of the sewing machine head.

FIG. 4 is a front view showing an upper thread adjusting stand above the upper side in FIG.

5 is a side sectional view of the sewing machine head as viewed from the side opposite to FIG.

FIG. 6 is a plan view of the sewing machine head.

FIG. 7 is a perspective view showing the entire sewing machine.

FIG. 8 is a side sectional view showing a conventional sewing machine head.

9 is a front view of FIG. 8. FIG.

FIG. 10 is a plan view of a conventional sewing machine head.

[Explanation of symbols]

 2 Sewing machine frame 10 Sewing machine head 12 Sewing machine arm 50 Needle bar case 60 Needle bar 68 Sewing needle 70 Thread selection section 90 Thread balance 96 Thread holding section A Needle bar drive mechanism B Balance drive mechanism

Claims (1)

Claims: 1. A sewing machine head includes a sewing machine arm fixed to a frame and a needle bar case movably attached to a front surface of the sewing machine arm. A plurality of needle bars with sewing needles attached to the lower end are provided so that they can be moved up and down, and one needle bar selected by moving the needle bar case is moved up and down by the needle bar drive mechanism to perform sewing. In a multi-needle type sewing machine to be performed, a single balance that is assembled so as to be capable of reciprocating rotation with respect to the sewing machine arm and a reciprocating balance that is also located on the sewing machine arm side and is synchronized with the vertical drive of the needle bar. A balance driving mechanism that rotates, a thread selection unit that can individually hold threads that are passed through the sewing needles of the needle bars on the needle bar case side, and a needle bar case that is formed on the balance and moves the needle bar case. Selected by operation Balance device Taharishiki sewing machine and a yarn holding portion capable imparting balance operation to the yarn hooking in the yarn selecting portion yarns are threaded through the needle of the needle bar was.