JP3464158B2 - Multi-needle sewing machine - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-needle type sewing machine which is provided with a plurality of needle bars and a balance on one head and is capable of forming a sewing pattern of a plurality of colors by switching these.

[0002]

2. Description of the Related Art Conventionally, there is a sewing machine in which one head is provided with a plurality of needle bars and a balance and these are switched to continuously perform a sewing operation. The sewing machines illustrated in JP-A-9-38367 and JP-A-9-75569 are examples.

When such a sewing machine is used, a sewing operation using threads of a plurality of colors can be continuously performed while the operator automatically changes the threads without changing the threads one by one. The thread change is performed by moving the box holding the needle bar or the balance to the left or right with respect to the main body frame, and making the specific balance corresponding to the moving position and the needle bar corresponding to this balance move up and down. .

In order to smoothly feed the upper thread during sewing, the vertical movements of the balance and the needle bar are in phase with each other, although their cycles are coincident with each other. For example, when the balance is at top dead center, the needle bar is not located at top dead center. On the other hand, it is desirable to keep both the balance and the needle bar in standby at top dead center. By doing so, the upper thread is tensioned, and it is possible to prevent the upper thread from being entangled with the surroundings. On the other hand, by setting the needle bar at the top dead center, it is possible to prevent the needle from easily hitting the work cloth or the presser foot when the needle bar is moved to the left or right.

Therefore, such a multi-needle type sewing machine has a needle bar jump mechanism. When changing the thread, the balance and the needle bar are temporarily stopped at the top dead center of the balance (as described above, the needle bar is not at the top dead center), and the needle bar is moved from its driving means. Free it and move (jump) to top dead center at once. A biasing force such as a coil spring is often used as the driving force for this jump. Then, with both the balance and the needle bar at the top dead center, the box is moved left and right.

By the way, in order to meet the demand for higher efficiency in sewing work, attempts have been made to increase the speed of such sewing machines. For example, in the case of an embroidery sewing machine, there has been a demand for further speeding up, although the upper limit of the rotational speed of the upper shaft was conventionally 1000 to 1200 rpm.

[0007]

However, when the sewing machine is operated at high speed, higher precision is required for the operation of the needle bar jump mechanism. If the jump timing is deviated, the biasing force may not reach a desired value, noise may be generated, or the jump may not be performed reliably and quickly.

The present invention has been made in view of the above problems, and the present invention as set forth in claim 1 is, as a basic technique for solving this problem, prevents the upper thread of the balance from being entangled around. At the same time, it proposes a technique for changing the thread of the balance in a posture other than the top dead center.

It is another object of the present invention to provide a multi-needle sewing machine capable of suppressing the generation of noise even when the needle bar and the balance operate at high speed. The present invention according to claim 3 is intended to realize the multi-needle sewing machine according to claim 1 or 2 with a simple configuration.

The present invention according to claims 4 and 5 proposes each example of the balance attitude regulating means.

[0011]

Means for Solving the Problems and Effects of the Invention According to the present invention as set forth in claim 1 for achieving the above object, a plurality of balances arranged in the left-right direction are moved in the left-right direction and desired. In the multi-needle sewing machine in which only the balance is arranged so that the driving force from the drive mechanism fixed in the left-right direction can be transmitted, and the balance is rocked around the axis along the left-right direction. Instead, the balance in a standby state is set to a posture of a substantially top dead center in the swing of the balance, and when the balance is arranged so that the driving force from the drive mechanism can be transmitted, the balance is provided with the balance follower. And a balance posture regulating means for setting a switching posture in which the positions of the balance drive body and the balance drive body provided in the drive mechanism are matched.

In this multi-needle type sewing machine, the balance posture regulating means sets the posture of the stand-by balance to the posture of the top dead center of the balance. Here, the “substantially top dead center” is preferably the top dead center of the balance, but if the posture is such that the upper thread can be stretched to the extent that it is not entangled with the surroundings, it may be slightly offset from the top dead center. good.

On the other hand, the balance posture regulating means sets the posture of the balance at the time of changing the thread to a posture (switching posture) in which the positions of the balance follower provided in this balance and the balance driving body for driving the balance are aligned with each other. . This switching posture is a position different from the top dead center. That is, conventionally, the thread was changed while the balance was at the top dead center, but in the multi-needle sewing machine of the present invention, the thread is changed after the balance is in the switching posture.

Therefore, according to the multi-needle type sewing machine of the first aspect, the thread of the balance is changed in a posture other than the top dead center while preventing the upper thread of the standby balance from being entangled with the surroundings. be able to. According to a second aspect of the present invention, in the multi-needle sewing machine according to the first aspect, needle bars that are arranged in parallel corresponding to the respective balances and that are vertically moved in synchronization with the swing of the corresponding balances are provided. When it is located at approximately the top dead center of the vertical movement, it is moved in the left-right direction together with the balance corresponding to the needle bar.

That is, the balance switching posture of this multi-needle sewing machine is the posture that the balance takes when the needle bar is located at the top dead center during sewing. Therefore, the balance and the needle bar are switched at the position where the needle bar reaches the top dead center, and the balance to be driven is switched by the balance attitude regulating means from the above-mentioned approximately top dead center. To be

Therefore, according to the multi-needle type sewing machine of the second aspect, the needle bar jump mechanism is unnecessary, and the generation of noise can be suppressed even when the needle bar and the balance operate at high speed. The present invention according to claim 3 provides the invention according to claim 1 or 2.
In the multi-needle type sewing machine according to the item (1), the balance posture restricting means releases the restriction of the posture of the balance arranged so that the driving force from the drive mechanism can be transmitted.

That is, in this multi-needle type sewing machine, the balance used for sewing is not regulated by the balance attitude regulating means and is only driven by the balance driving body. As a mode contrary to this, there is a configuration in which the balance attitude regulating means is driven by the swing of the balance while the balance is being driven by the balance driving body. However, this is likely to complicate the structure of the balance posture regulating means.

In this respect, according to the multi-needle type sewing machine of the third aspect, since the balance attitude regulating means does not have to restrict the attitude of the balance when the balance is in operation, it has a simple structure. It is possible to realize the balance attitude regulating means. As for the structure of the balance attitude regulating means, the balance attitude regulating means may be the same as the multi-needle sewing machine according to claim 4.
The multi-needle sewing machine according to claim 5, further comprising: an actuator that is driven during the movement in the left-right direction and swings the balance in standby to bring the balance into the switching posture. The balance posture regulating means is provided corresponding to each of the plate cams fixed in the left-right direction and each of the balances. When the balance is moved in the left-right direction, the balance cams follow the plate cams and shake the balance. It is conceivable that the balance is provided with a plate cam follower that moves the balance to the switching posture.

In particular, in the fifth aspect of the invention, the posture of the balance is set to the top dead center during standby and to the switching posture when switching by simply moving the plate cam follower together with the balance to the left and right. Can be very simple.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. First, FIG. 1 is a front view of a multi-needle sewing machine 1 to which the present invention is applied. As shown in the figure, the multi-needle sewing machine 1 includes five needle bars 3, and correspondingly five balances 5 are arranged side by side on the front side. Then, the box 6 including the needle bar 3 and the balance 5 is moved in the left-right direction in the drawing, and the needle bar 3 and the balance 5 corresponding to the moving position are used to perform the sewing operation.

FIG. 2 shows a state in which the casing of the box 6 is removed from the front view shown in FIG. The lower part, on which the needle bar 3 and the like are arranged, is not shown. As shown in the figure, five balances 5 are arranged in the box 6 at equal intervals, and plate cam followers 41 are provided corresponding to the respective balances 5. The plate cam follower 41 is arranged on the front side of each corresponding balance 5 in this figure. On the other hand, a shaft 43 is provided at the back of the balance 5, and can be swung on the same axis as the balance 5 via arms 45 on both the left and right sides thereof. Actuator 47 provided at the left end of this shaft
Is for swinging only the shaft 43, and this swing indirectly swings the balance 5 (details will be described later).

FIG. 3 shows a drive mechanism of the balance 5. Figure 3
(A) is the figure which looked at the inside of the multi-needle type sewing machine 1 from the right side of FIG. The balance 5 is rotatable about a point P as an axis, and a first cylindrical portion 11 sandwiched by a second forked portion 9 formed at a position substantially symmetrical to the tip portion 7 with respect to this point P is moved up and down. This causes it to swing. The second forked portion 9 corresponds to the balance follower of the present invention, and the first cylindrical portion 11 corresponds to the balance driver. The first cylindrical portion 11 extends in the depth direction of the drawing, and the diameter of the first cylindrical portion 11 is such that there is a slight gap with the second forked portion 9. When switching the balance 5 to another balance 5, the balance 5 is stopped in a posture in which the needle bar 3 corresponds to the top dead center, and the box 6 is placed in a direction perpendicular to the drawing.
(The left part of the figure) is moved, and the second forked part 9 of another balance 5 holds the first cylindrical part 11 therebetween.

The first cylindrical portion 11 is fixed to the rod 13, and the second cylindrical portion 15 projecting rearward (rightward in the figure) from slightly below the center of the rod 13 is moved up and down. Driven by. It is the swing shaft 17 that moves the second cylindrical portion 15 up and down, and the first forked portion 19 formed at the front end (the left end in this figure) of the swing shaft 17 holds the second cylindrical portion 15 between them. By swinging, the second cylindrical portion 15, the rod 13, and the first cylindrical portion 11 are moved up and down, and the balance 5 is swung.

The mechanism for oscillating the oscillating shaft 17 includes the arm portion 21.
The sliding body 23, the crank 25, and the upper shaft 27. Upper shaft 2
7 is rotated at a constant speed by a motor (not shown), and the rotation is transmitted to the crank 25 via gears 29 and 31.
A sliding body 23 is provided on the crank 25 so as to be rotatable about an axis parallel to the upper shaft 27, and an arm portion 21 is inserted through the sliding body 23. The arm portion 21 is provided perpendicular to the swing shaft 17, and when the upper shaft 27 is rotated at a constant speed in this state, the swing shaft 17 swings.

The plate cam follower 41 is swingably provided about the point Q, and is biased counterclockwise in the figure by a spring 49. The plate cam 51 is provided on the body frame 39 side, and its cam surface is shown in FIG.
As shown in (b). 3B is a plan view showing the vicinity of the center of the plate cam 51, and the left-right direction of FIG. 3B is the left-right direction of the multi-needle sewing machine 1 (direction perpendicular to FIG. 3A).
Has become. The upper surface of this figure is a cam surface with which the tip of the plate cam follower 41 abuts, and A is the tip of the plate cam follower 41 (hereinafter simply referred to as the plate cam follower 4) corresponding to the balance 5 in standby.
1) is a contact surface, and C is a surface with which the plate cam follower 41 contacts when the sewing operation is performed using the balance 5. When the plate cam follower 41 is moved by the lateral movement of the box 6, the tip end of the plate cam follower 41 comes into contact with these cam surfaces one after another.

The needle bar 3 is moved up and down by the rotational force of the upper shaft 27 transmitted by the needle bar drive mechanism 33, only a part of which is shown in the figure. The needle bar holder 81 is a portion that receives vertical movement. The pin 77 is used to hold the waiting needle bar 3 at the top dead center, and the pin 79 is
It is lowered when the needle bar 3 is moved up and down (details will be described later).

FIG. 4 shows how the balance 5 is swung by the balance mechanism described above. First, FIG. 4A shows a state where the balance 5 is on standby, FIG. 4B shows a state when the balance 5 is switched, and FIG. 4C shows a state when the balance 5 is in operation. It represents. First, in the standby state shown in FIG. 4A, since the balance 5 shown in this figure is moved to the left and right of the position where the sewing operation is performed, the tip end of the plate cam follower 41 is the surface of the plate cam 51. Abuts A. At this time, the arm portion 41a protruding in the middle of the plate cam follower 41
Pushes up the lower surface of the balance 5 and holds the balance 5 in the posture of its top dead center. At this time, the arm 45 is positioned as shown in this figure, and the shaft 43 is separated from the balance 5. In addition, the needle bar 3 standing by with the balance 5 has the arm 53
The needle bar 3 is lifted up and is located at the top dead center of the needle bar 3. The arm 53 is urged by a spring 55 counterclockwise in the figure.

In the state in which the balance 5 shown in FIG. 4B is switched, the arm 45 is swung counterclockwise by the actuator 47 (see FIG. 2), and the shaft 43 presses the standby balance 5. Causes the balance 5 to swing. Then, the position of the balance 5 in the standby state and the position of the balance 5 connected to the first cylindrical portion 11 are matched.
On the other hand, the arm portion 41a of the plate cam follower 41 abuts on the lower surface of the balance 5, and holds the balance 5 in the posture shown in the figure against the pressing force of the shaft 43. At this time, the balance 5 is in a posture corresponding to the needle bar 3 located at the top dead center during sewing. This posture is called a switching posture. In this state, the box 6 can be moved left and right.

In the operating state shown in FIG. 4C, the tip end of the plate cam follower 41 is in contact with the surface C of the plate cam 51. As a result, the plate cam follower 41 is swung to the greatest extent in the clockwise direction, and the arm portion 41 a is completely detached from the balance 5. On the other hand, the arm 45 is swung clockwise before the balance 5 starts the sewing operation, and the shaft 43 is rotated.
Is positioned so as not to contact the balance 5 even at the top dead center of the balance 5. In this way, the balance 5 is brought into a driven state by vertically moving the first cylindrical portion 11. The needle bar 3, which is not shown in FIG. 4C, can be moved up and down by the pin 79 pushing down the arm 53, and is moved up and down by the needle bar drive mechanism 33 (see FIG. 3).

In the multi-needle type sewing machine 1 thus constructed, the switching posture of the balance 5 (the posture shown in FIG. 4B) is set to the posture corresponding to the top dead center of the needle bar 3. Therefore, the thread change is performed at the position where the needle bar 3 reaches the top dead center, and the balance 5 to be driven by the thread change changes the shaft 43.
Pushes down the balance 5, and the pushing down amount is set to the first cylindrical portion 11
By taking the position of the balance 5 which is connected to the switch 5, the switching posture is set. On the contrary, when the balance 5 in operation is on standby, by moving the box 6 left and right, the balance 5
When the plate cam follower 41 is driven from the surface C to the surface A of the plate cam 51 while the connection between the plate cam follower 41 and the first cylindrical portion 11 is released, the plate cam follower 41 pushes up the balance 5 and the balance 5 It is held at the top dead center position.

Therefore, according to the multi-needle type sewing machine 1, the needle bar jump mechanism, which is required in the conventional multi-needle type sewing machine, becomes unnecessary, and noise is generated even when the needle bar 3 and the balance 5 operate at high speed. Occurrence can be suppressed. Also, FIG. 4 (c)
In the state shown in, the shaft 43 and the plate cam follower 41 corresponding to the operating balance 5 are completely separated from the balance 5, and the balance 5 is driven by the first cylindrical portion 11. It will be just a state. Therefore, the multi-needle type sewing machine 1 which does not require the needle bar jump mechanism can be realized with a simple structure.

Although the multi-needle type sewing machine 1 has been described as one embodiment of the present invention, the present invention is not limited to this embodiment and can be implemented in various modes. For example, it may be applied to a multi-needle type sewing machine having six or more needle bars 3 or a multi-needle type sewing machine having 2 to 4 needle bars 3. Further, a configuration in which the balance is set to the switching posture or the top dead center posture may be realized as shown in FIGS. Figure 5
FIG. 5A shows a state in which the balance 5'is on standby, and FIG.
Is the state when switching the balance 5 ′, and FIG.
The state is shown when the balance 5'is in operation. The same components as those shown in FIG. 4 are designated by the same reference numerals.

In this embodiment, the shaft 43 and the arm 45 are
Without using the plate cam follower 41 and the plate cam 51 'shown in FIG.
By means of and, swinging from the top dead center to the switching posture is also performed. In order to make this possible, a groove cam 57 is formed in the lower portion of the balance 5 ', and the tip of the arm portion 41a moves inside the groove cam 57, whereby the balance 5'is swung, and The balance 5'can be swung clockwise or counterclockwise depending on the moving direction of the portion 41a.

That is, in the standby state shown in FIG. 5A, the tip of the plate cam follower 41 contacts the surface A, and the arm 4
1a fits into the groove cam 57 and holds the balance 5'at the top dead center position. In the state in which the balance 5'is switched as shown in FIG. 5B, the tip of the plate cam follower 41 is in contact with the surface B of the plate cam 51 '. At this time,
Since the arm portion 41a moves in the groove cam 57,
Unlike the case shown in FIG. 4B, the balance 5 ′ swings counterclockwise even if it is not pressed by the shaft 43, and assumes the switching posture. This switching posture is a posture corresponding to the top dead center position of the needle bar 3 during operation, as in the embodiment shown in FIG. In the operating state shown in FIG. 5C, the tip of the plate cam follower 41 contacts the surface C of the plate cam 51 ',
The arm portion 41a is completely removed from the groove cam 57. As a result, the balance 5'is driven by vertically moving the first cylindrical portion 11.

When the balance 5'which has been operating is put on standby, the box 6 is moved to disconnect the balance 5'and the first cylindrical portion 11 as in the embodiment shown in FIG. The arm 41a pushes up the balance 5'to bring it to the switching posture and then to the top dead center posture.

With this structure, the shaft 43, the arm 45, and the actuator 47 are unnecessary, so that the multi-needle sewing machine 1 can be realized in a simpler manner.

[Brief description of drawings]

FIG. 1 is a front view of a multi-needle sewing machine 1 according to an embodiment of the present invention.

FIG. 2 is a side view showing a balance mechanism of the multi-needle sewing machine 1.

FIG. 3 is a front view of a balance mechanism of the multi-needle sewing machine 1.

FIG. 4 is an explanatory diagram showing how the balance 5 is swung by moving the box 6 in the multi-needle type sewing machine 1.

FIG. 5 is an explanatory view showing another mode in which the balance 5 ′ is swung by moving the box 6.

FIG. 6 is a plan view of a plate cam 51 ′ that swings the balance 5 ′.

[Explanation of symbols]

1 ... Multi-needle sewing machine 3 ... Needle bar 5 ... Balance 6 ... Box 11 ... 1st cylindrical part 13 ... Balance drive rod 33 ... Needle bar drive mechanism 39 ... Body frame 41 ... Plate cam follower 41a ... Arm 43 ... Shaft 45 ... Arm 47 ... Actuator 51 ... Plate cam 57 ... Groove cam

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hitomi Otoshi 15-1, Naesehiro-cho, Mizuho-ku, Nagoya, Aichi Prefecture, Brother Industries, Ltd. (56) Reference JP-A-9-38367 Flat 9-75569 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) D05B 49/00-49/02 D05B 55/14-55/16 D05C 11/16

Claims (5)

(57) [Claims] 1. A plurality of balances arranged in parallel in the left-right direction are moved in the left-right direction, and only a desired balance is arranged so that a driving force from a drive mechanism fixed in the left-right direction can be transmitted. In a multi-needle sewing machine that swings the balance around an axis along a line, a balance that is not rocked and is on standby is brought to a posture of approximately top dead center when the balance is rocked, and the balance is driven by the drive mechanism. When the balance is arranged so that the driving force from the balance can be transmitted, the balance attitude regulating means is provided to bring the balance into a switching attitude in which the positions of the balance follower provided in the balance and the balance drive provided in the drive mechanism are aligned. A multi-needle sewing machine characterized by. 2. The needle bar, which is arranged in parallel to each of the balances and is vertically moved in synchronization with the oscillation of the corresponding balance, is located at a substantially top dead center of the vertical movement. The multi-needle sewing machine according to claim 1, wherein the multi-needle sewing machine is moved in the left-right direction together with a balance corresponding to a rod. 3. The balance posture regulating means releases the regulation of the posture of the balance arranged so that the driving force from the drive mechanism can be transmitted. The described multi-needle sewing machine. 4. The balance posture regulating means is provided with an actuator which is driven when the balance is moved in the left-right direction and swings the standby balance to bring the balance into the switching posture. The multi-needle sewing machine according to any one of claims 1 to 3, which is characterized in that. 5. The balance posture regulating means is provided corresponding to each of the plate cams fixed in the left-right direction, and each balance, and the balance is moved in the left-right direction to follow the plate cams, 4. The multi-needle sewing machine according to claim 1, further comprising: a plate cam follower that swings the balance to bring the balance into the switching posture.