JPS6135876B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a single thread chainstitch cycle sewing machine, such as an industrial button sewing machine.

Conventionally, in industrial button-equipped sewing machines, at the end of one sewing cycle, a single cam body that interlocks with the main shaft of the sewing machine operates, and a thread cutting mechanism located below the bed surface is activated to cut the thread as the needle moves up and down. The presser arm, which has a holding arm at the tip for holding a button, is raised relative to the feed plate. More specifically, the lifting of the presser arm is caused by an actuation lever whose intermediate portion is rotatably supported by the arm of the sewing machine and whose one end is connected to the cam body connected to the other end of the presser arm. This was accomplished by attaching an adjustable lifting arm that engaged the stationary arm and raised the presser arm.

In a single-thread chainstitch cycle sewing machine with such a configuration, by adjusting the mounting position of the lifting arm relative to the operating lever and adjusting the timing of raising the presser arm, the thread can be tightened at the last needle at the end of one sewing cycle. Furthermore, the amount of thread remaining on the needle side after cutting by the thread cutting mechanism can be adjusted. In other words, if the presser arm lifts quickly, the thread will be tight and the amount of thread remaining after cutting will be long.On the other hand, if the presser arm lifts late, the thread will not be tight and the amount of thread remaining after cutting will be longer. becomes shorter.

Adjustment of the thread tension and the amount of thread remaining after cutting is performed according to various sewing conditions such as the type and thickness of the fabric to be processed. If the timing of engagement of the lifting arm with the arm fixed to the presser arm changes, the upward stroke of the article holding arm such as a button at the tip of the presser arm changes, and if the upward stroke becomes smaller, it may be necessary to This makes it difficult to insert a button or the like into the holding arm at the tip of the presser arm and to insert cloth between the holding arm and the feed plate, resulting in a decrease in work efficiency.

In view of such circumstances, the present invention solves the conventional drawbacks by making it possible to adjust the timing of raising the presser arm and to raise the presser arm to a substantially constant height regardless of the adjustment. were eliminated all at once.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An example in which the present invention is embodied in an industrial button-equipped sewing machine, which is one type of single-thread chainstitch cycle sewing machine, will be described below.

In the figure, 1 is the frame of an industrial button sewing machine, which includes an arm 1a and a bed 1b. Reference numeral 2 denotes a main shaft of the sewing machine rotatably supported on the machine frame 1, on which a cam disk 3 is fixed and a rotating body 5 which is constantly rotated by a belt 4 in conjunction with a motor (not shown) is loosely fitted. There is. The rotating body 5 and the cam disk 3 are interlocked by a clutch lever 7 fixed to one end of a swing shaft 6 rotatably supported on the machine frame 1.
Shutdown is now controlled,
In the state shown in FIG. 1, the interlock between the two is cut off, and when the clutch lever 7 is rotated clockwise from that state, the two are interlocked.
Reference numeral 8 denotes a stop lever fixed to the swing shaft 6, the tip of which engages with a locking portion 3a formed on the cam disk 3 to lock the sewing machine main shaft 2 at a position above the needle. It has a piece 8a. A spring 9 is stretched between the stop lever 8 and the machine frame 1, and normally biases the stop lever 8 in the counterclockwise direction in FIG. 10 is a driving solenoid for the sewing machine attached to the machine frame 1, and when it is energized, its armature 10a protrudes and rotates the stop lever 8 against the action of the spring 9; It is energized based on the operator's foot switch operation.

Reference numeral 11 denotes a needle bar supported by the arm 1a so as to be movable up and down, with a needle bar take-up 12 at the upper end and a needle 13 at the lower end.
is installed. Reference numeral 14 denotes a needle drive arm whose intermediate portion is swingably supported by a support shaft 15 fixed to the arm 1a, one end operatively connected to the needle bar 11 and the other end fixed to the sewing machine main shaft 2. It is connected to a cam holder 17 that holds the eccentric cam 16. A looper 18 cooperates with the needle 13 to form a single thread chainstitch, and is disposed below the bed surface of the bed 1b.

19 is a throat plate attached to the bed 1b;
A needle hole 20 is formed. A thread cutting mechanism is disposed between the throat plate 19 and the looper 18 for cutting the inner fabric side limb t1 of the thread ring T formed as the needle 13 moves up and down. That is, 21 is a step screw 2 whose base end is attached to the lower surface of the throat plate 19.
a first movable blade rotatably supported by 2;
A cutting edge 21a is formed. Reference numeral 23 denotes a thread handling plate fixed to the back surface of the first movable blade 21 by screws 24, 24, the tip of which is located below the first movable blade 51 with a space therebetween. Enter into the ring T and cut the cloth side limb t1 into the cutting blade 21a.
lead to. A second movable blade 25 has an intermediate portion rotatably supported on the lower surface of the throat plate 19 by a step screw 26, and has a cutting blade 2 at one end that cooperates with the cutting blade 21a.
5a is formed, and its cutting edge 25a enters between the first movable blade 21 and the yarn handling plate 23. Reference numeral 27 denotes a link, one end of which is rotatably connected to the other end of the second movable blade 25 by a pin 28, and the other end rotatably connected to the first movable blade 21 by a pin 29. There is. Reference numeral 30 denotes an operating rod of the thread cutting mechanism disposed in the bed 1b, one end of which is connected to the first movable blade 21 by a pin 31.
is connected to.

Reference numeral 32 denotes a feed plate disposed on the surface of the bed 1b, which is moved back and forth and left and right across the vertical movement path of the needle 13 by a cam body (not shown) that interlocks with the main shaft 2 of the sewing machine. Processed cloth 3 on top
3 is placed. Reference numeral 34 denotes a presser arm whose base end is rotatably supported by a pin 35 on the feed plate 33, and whose tip end holds the work cloth 3 placed on the feed plate 32.
A pair of holding arms 37, 3 for pressing the button 3 and holding the button 36 sewn to the cloth 33.
7 is provided. Also, 38 is the presser arm 3
It is an L-shaped arm attached to 4, and a roller 39 is provided at the tip. A coil spring 40 is stretched between a spring receiver 41 fixed to the presser arm 34 and the arm 1a, and normally urges the presser arm 34 downward.

42 is a triangular cam fixed to the main shaft of the sewing machine;
Reference numeral 43 denotes a forked swinging arm whose base end is rotatably supported on the machine frame 1 by a pin 44, the forked part of which holds the triangular cam 42, and swings according to the rotation of the triangular cam 42. be done. In addition, the bifurcated swinging arm 4
3 is formed with a bent portion 43a. 45 is a link in which a notch 45a that can be engaged with the bent portion 43a is formed; The upper end is rotatably supported by a pin 48. 49 is a bell crank lever whose intermediate portion is rotatably supported by a step screw 51 on a leg portion 50 fixed to the machine frame 1; one end is connected to the lower end of the link 47, and the other end is connected to the operating link. It is connected to the other end of the rod 30. 49a
is a tension spring stretched between the bell crank lever 49 and the machine frame 1.

Reference numeral 52 is arranged below the operating lever 46 and is fixed to the arm 1a.
A lifting lever rotatably supported by 4.
Roller 3 of L-shaped arm 38 whose free end is fixed to presser arm 34
It extends so that it can be engaged with 9 from below. 55
is a link whose upper end is rotatably supported by a shoulder screw 56 at the other end of the operating lever 46 and whose lower end is rotatably supported by a shoulder screw 57 at the intermediate portion of the lifting lever 52; Along with the rotation, the lifting lever 52 is rotated upward to raise the presser arm 34. Further, as is clear from FIG. 6, the stepped screw 57 has a head 57a.
, a shaft portion 57b into which the lower end of the link 55 is rotatably inserted, a stepped portion 57c, and a threaded portion 57d. 58 is Natsu. Reference numeral 59 denotes a long hole formed in the lifting lever 52, through which the step screw 5
7 through which the threaded portion 57d passes. The long hole 59
is formed to extend in a tangential direction to a circular arc centered on the step screw 56 for attaching the link 55 to the operating lever 46 in the upward rotational position of the lifting lever 52. Ideally, this elongated hole 59 extends along the circular arc, but it is easier to process it if it extends linearly, and there is no practical problem in terms of functionality.

A camshaft 60 is rotatably supported by the machine frame 1, and is interlocked with the main shaft 2 of the sewing machine and rotates once for every 16 revolutions of the main shaft 2 of the sewing machine. A control cam 61 is fixed to the camshaft 60, and two recesses 62 and 63 are formed around the control cam. Reference numeral 64 denotes a follower whose base end is fixed to the swing shaft 6, and a roller 65 that contacts the outer periphery of the control cam 61 is provided at the tip. Further, 66 is an arm whose upper end is fixed to the swing shaft 6, and is connected to the lower end of the link 45 via a link 67.

Next, the effect will be explained. Figures 1, 2, 4 and 5 show the state when the sewing machine is stopped.

In this state, the stop lever 8 and the clutch lever 7 are rotated counterclockwise in FIG. The rotation of the main shaft 2 of the sewing machine is stopped and the needle 13 is positioned at an upper position.
At the same time, the clutch lever 7 acts to interrupt the interlock between the rotating body 5 and the cam disk 3, and the rotation of the motor is not transmitted to the main shaft 2 of the sewing machine.

At this time, the roller 65 of the follower 64 is moved by the control cam 61.
The link 45 is rotated clockwise in FIG. The triangular cam 42
The link 45 is pulled downward by the action of . Therefore, the actuating link 3 is moved through the link 47 and the bell crank 49 against the action of the tension spring 49a.
0 is moved to the right in FIG. 2, that is, in the direction of arrow A in FIG. 4, the first movable blade 21 is moved, and the second movable blade 25 is moved via the link 27.
Both cutting edges 21a and 25a are in the cutting position.

On the other hand, the downward movement of the link 45 causes the operating lever 46 to be moved counterclockwise in FIG. 2, or clockwise in FIG. pin 3
5 as the center and resisting the action of the coil spring 46, the first,
It is rotated clockwise in FIG. 5, or counterclockwise in FIG. 2, and the pair of holding arms 37, 37 at the tip are raised.

When starting sewing in such a state, first, the presser arm 34 and the feed plate 3, which have been raised, are
2, the button 36 to be sewn to the holding arms 37, 37 at the tip of the presser arm 34, and the foot switch to start the sewing machine are stepped on.

As a result, the drive solenoid 10 is energized and its armature 10 is operated to protrude, and the stop lever 8,
The clutch lever 7 is rotated against the action of the spring 9, and as a result, the main shaft 2 of the sewing machine begins to rotate and the needle 13 is rotated.
is moved up and down and one sewing cycle is started. On the other hand, the roller 65 of the follower 64 is connected to the control cam 6 via the swing shaft 6 which is integrated with the stop lever 8 and the clutch lever 7.
1 and comes to be located on the circumferential surface of the recess 62 (because the control cam 61 also begins to move).
Therefore, at this point, the drive solenoid 1
Even if the sewing machine 0 is castrated, the stop lever 8 and the clutch lever 7 continue to maintain their previous states, so that the sewing machine remains in operation.

As the follower 64 rotates counterclockwise in FIG.
5 is rotated counterclockwise around the pin 48, and the notch 45a and the bent portion 43a of the forked swing arm 43
The engagement with is released. As a result, the coil spring 4
0, the presser arm 34 is rotated downward, and the holding arms 37, 37 come to press down the work cloth 33. By moving the presser arm 34 downward, L
The lifting lever 52 is moved downward via the mold arm 38, and the actuating bar is moved via the link 55 counterclockwise in FIG. 5 or clockwise in FIG. The action link 30 is moved to the left (arrow A) via the lever 49.
direction), the first movable blade 21 is retracted, and the second movable blade 25 is also retracted via the link 27.

Therefore, when one sewing cycle progresses and one stitch is before the end of the cycle, the roller 65 of the follower 64
falls into another recess 63 of the control disk 61 by the action of the spring 9, and the link 4
5 is rotated around the pin 48 and the notch 45
a engages with the bent portion 43a of the bifurcated swinging arm 43.
As a result, the triangular cam 42 causes the bifurcated swing arm 4 to
3 is rotated counterclockwise in FIG. 2 about pin 44, link 45 is pulled downward. As a result, the actuation link 30 is moved to the right via the link 47 and the bell crank 49, and the first and second movable blades 21 and 25 are moved so that their cutting blades 21a and 25a approach each other. With this movement, first, the yarn handling plate 23 of the first movable blade 21 guides the cloth side limb t1 of the yarn ring T expanded by the looper 18 toward the cutting blade 25a side, and then the double blade 2
The cloth side limb t1 is cut by 1a and 25a.

At the same time, the downward movement of the link 45 rotates the operating lever 46, and the lifting lever 52 is rotated upward via the link 55, and the lifting lever 52 engages with the roller 39 of the L-shaped arm 38. The presser arm 34 is raised.

The roller 65 of the follower 64 is connected to the recess 6 of the control cam 61.
3, at the same time, the stop piece 8a of the stop lever 8 comes to engage with the circumferential surface of the cam disk 3, and at the same time the clutch lever 7 comes to push the rotating body 5 toward the cam disk 3. Immediately after thread cutting and lifting of the presser arm 34 are completed, the stop piece 8a of the stop lever 8 engages with the locking portion 3a of the cam disk 3, and the sewing machine is in a state where the needle 13 is positioned upward. It will be stopped at
In the case of a two-hole button, sewing is completed at this point; in the case of a four-hole button, the drive solenoid 10 is turned on again after one stitch is formed, regardless of whether the foot switch is operated once. Then, the second seam is formed. This second operation is exactly the same as described above.

The amount of thread remaining on the needle side after the thread is tightened and cut on the final needle of one sewing cycle can be adjusted by adjusting the connection point of the link 55 to the lifting lever 52. To make this adjustment, first use the nut 58
is loosened, the link 55 is rotated around the step screw 56, the position of the step screw 57 at the lower end of the link 55 on the elongated hole 59 of the lifting lever 52 is changed, and the nut 58 is tightened again. As a result, the lifting lever 52 is tightened by the stepped portion 57c of the stepped screw 57 and the nut 58, so that the stepped screw 57 is fixed onto the lifting lever 52.

FIG. 7 diagrammatically explains this situation, and the solid line shows the positional relationship of each part when the operating lever 46 is rotated counterclockwise in FIG. 5 and the presser arm 34 is lowered. The broken lines indicate the positional relationship of the respective parts when the operating lever is rotated clockwise and the presser arm 34 is raised. In addition, in the figure, A indicates that the connection point is the fifth
This is the case where the adjustment is to the leftmost side in the figure, B is the case where it is adjusted to the middle, and C is the case where it is adjusted to the right.

As can be seen from this figure, when the presser arm 34 is in the lowered state, the lifting lever 5 is in the state indicated by A.
The tip of the lifting lever 52 is located at the lowest position, and as the states shown by B and C are reached, the tip of the lifting lever 52 is positioned upward. That is, when the connection point is adjusted to the leftmost position in FIG.
The roller 39 is disposed separately below the roller 39 of the roller 39. Further, the distance between the roller 39 and the lifting lever 52 at this time becomes smaller as the connection point is moved from the leftmost position in FIG. 5 to the right. This means that even when the operating lever 52 is rotated and the presser arm 34 is raised in the same way, the more the connection point is adjusted to the left in FIG. This means that the thread tension is weak and the remaining thread t1 remaining on the needle side after cutting is shortened.The more you adjust it to the right, the faster the presser arm 34 will rise, and the thread tightening at the final needle will be better, leading to cutting. This means that the thread limb t1 remaining on the later needle side becomes longer. This is because the timing of raising the presser arm 34 is different from the timing of thread cutting by the thread cutting mechanism. Then, the connection point is set to the fifth point.
When set to the leftmost position in the figure, the presser arm 34 is raised only after thread cutting is actually completed. Such adjustments need to be made as appropriate depending on sewing conditions such as the thickness and type of cloth.

Regardless of such adjustment, the amount of rise of the presser arm 34 remains approximately constant. This means that in the upward rotation position of the lifting lever 52, the attachment position of the link 55 to the lifting lever 52 is tangential to the circular arc centered on the step screw 56, which is the connection point of the link 55 to the operating lever 46. Extending long hole 59
This is because the position above the lifting lever 52 hardly changes even if the connecting point is adjusted because the adjustment is made along the vertical axis. For this reason, the holding arms 37, 37 of the presser arm 34 rise to a substantially constant height regardless of the adjustment of the connection points, so that the button 36 and the workpiece cloth 33 can be inserted very easily.

In addition to the structure shown in the above embodiment, there are various mechanisms that can adjust the timing at which the presser arm 34 starts to rise and raise the presser arm 34 to a substantially constant height regardless of the adjustment. Possible variations are as follows. Further, the present invention can be applied to other similar sewing machines other than industrial sewing machines with buttons.

As described in detail above, the present invention is able to adjust the timing at which the presser arm 34 starts to rise and to raise the presser arm 34 to a substantially constant height regardless of the adjustment. Not only can the tension of the thread at the final needle and the amount of thread remaining on the needle side after cutting the thread be adjusted, but also the insertion and retention of objects such as buttons 6 into the tip holding arms 37, 37 of the presser arm 34 is possible. Excellent effects such as easy insertion of the work cloth 33 between the arms 37, 37 and the feed plate 32 are achieved.

[Brief explanation of the drawing]

Figure 1 is a perspective view of the thread cutting mechanism, Figure 5 is a perspective view of the presser arm, and Figure 2 is a left side view of Figure 2. Figure 4 is a perspective view of the thread cutting mechanism. FIG. 6 is an enlarged sectional view taken along the line -- in FIG. 5, and FIG. 7 is an explanatory diagram of the operation. In the figure, 1 is a machine frame, 2 is a sewing machine main shaft, 3 is a cam disk, 5 is a rotating body, 6 is a swing shaft, 7 is a clutch lever, 8 is a stop lever, 10 is a drive solenoid, 1
3 is a needle, 18 is a looper, 19 is a throat plate, 21 is a first movable blade, 23 is a thread handling plate, 25 is a second movable blade, 27 is a link, 30 is an operating link, 32 is a feed plate, 33 is a work cloth, 34 is a presser arm, 36 is a button, 34 and 37 are holding arms, 40 is a coil spring, 4
2 is a triangular cam, 43 is a bifurcated swing arm, 45 is a link, 46 is an operating lever, 47 is a link, 49 is a bell crank lever, 52 is a lifting lever, 55 is a link, 56 and 57 are step screws, 59 is a Long hole, 61
is a control cam, and 64 is a follower.

Claims (1)

[Scope of Claims] 1. A needle that moves up and down in conjunction with the main shaft of the sewing machine, a looper disposed below the bed surface to form a single-thread chain stitch in cooperation with the needle, and the looper. a thread cutting mechanism for cutting an inner fabric side limb of a thread ring formed as the needle moves up and down, the thread being disposed between the thread cutting mechanism and the thread cutting mechanism; A moving feed plate, which moves together with the feed plate and is attached to the feed plate so that it can be raised and lowered, and whose tip presses the work cloth placed on the feed plate and holds the article to be sewn onto the work cloth. a cam body that rotates in conjunction with the main shaft of the sewing machine; a first motion transmission means for operating the thread cutting mechanism in accordance with the rotation of the cam body; and the cam body. a second motion transmitting means for raising the presser arm according to the rotation of the cam; and a second motion transmitting means that is interlocked with the main shaft of the sewing machine and interrupts interlocking between the cam and the first and second motion transmitting means during one sewing cycle. In a single-thread chainstitch cycle sewing machine provided with a control means for interlocking the two at the end of a sewing cycle, the second movement transmission means has an intermediate portion rotatably supported on the arm of the sewing machine. an actuating lever having one end linked to the cam body; and a lifting lever disposed below the actuating bar, a base end rotatably supported by the arm, and a free end capable of engaging and disengaging from the presser arm. , an upper end is rotatably supported by the other end of the operating lever, and a lower end is rotatably attached to the lifting lever, so that the lifting lever is rotated upward as the operating lever rotates; a link for raising the presser arm by engagement of the lifting lever with the presser arm; the attachment position of the link relative to the lifting lever is such that the link is activated when the lifting lever is rotated upward; A single-thread chainstitch cycle sewing machine characterized in that adjustment is possible along an arc or along a tangential direction of a circular arc centered on the attachment position to the other end of the lever.