JPH0137584Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) This invention relates to a button sewing machine, and in detail, it has a configuration that allows sewing button sewing stitches with a crossover thread and button sewing stitches without a crossover thread. It is related to.

(Prior art) In general, as shown in Fig. 4, the stitches for attaching four-hole buttons are sewn between the buttonholes 1 of one set, and then the stitches are sewn through the crossover thread 2 without cutting the thread. A stitch 4 with a crossover thread is formed by sewing continuously between the buttonholes 3 of the other set, and after sewing between the buttonholes 1 of one set, as shown in Fig. 5. There is a stitch 5 without a crossover thread, which is formed by cutting the thread and sewing it discontinuously between the buttonholes 3 of the other set. By the way, when sewing the stitch 5 without a crossover thread, the thread is cut in the middle, so if the thread cutting means and the presser foot equipped with the button clamp are configured to operate at the same time,
When the thread is cut, the button is released when the presser foot is released, and when sewing between the other set of buttonholes 3, the position of the buttonhole 3 is shifted from the predetermined needle drop point, which is an inconvenience.

Therefore, in conventional button sewing machines, the sewing machine start pedal, the presser foot, and the button grip are moved up and down together to cause the thread cutting device to perform the thread cutting operation continuously after the sewing operation using the needle. When sewing stitch 4 with a crossover thread by separately providing a presser foot operation pedal, operate the former pedal to sew continuously between buttonholes 1 and 3 of both sets. The thread is cut, and then the latter pedal is operated to raise the presser foot and button clamp to release the work cloth and button B.
When sewing stitch 5 without a crossing thread, first operate the former pedal once to sew between the buttonholes 1 of one set, cut that thread, and then sew the thread between the buttonholes 1 of one set. Operate the same pedal and press button hole 3 of the other set.
After sewing the gap, the thread is cut, and then the latter pedal is operated to release the work cloth and button B.

(Problem to be solved by the invention) However, in this conventional configuration, it is necessary to operate two pedals, the pedal for starting the sewing machine and the pedal for operating the presser foot, which not only deteriorates the operability but also makes it difficult to When sewing a stitch 5 without a thread, the operation of both pedals is repeated twice, once, twice, once, causing a problem in that the operator's operating rhythm is disrupted and erroneous operations are likely to occur.

This invention was made in view of the above-mentioned problems, and its purpose is to improve operability by making it possible to switch between stitches with a crossover thread and stitches without a crossover thread using a simple configuration. The purpose of the present invention is to provide a new button sewing machine capable of sewing buttons.

(Means for Solving the Problems) In order to solve the above-mentioned problems, in this invention, as shown in FIG. A needle 27 that moves up and down accordingly, a presser foot 35 that is movably disposed on the bed surface 9 of the sewing machine across the vertical movement path of the needle 27 and is always biased toward the bed surface 9, and the presser foot 35. 35, a presser foot lifting member 49 supported by the sewing machine frame 8, and thread cutting means 86, 8 for cutting the thread connected to the needle 27 after forming a series of stitches.
7, and drive means 61, 63, 65, etc., which are operated in accordance with the rotation of the main shaft 12 in order to drive the thread cutting means 86, 87, etc., and the drive means 6.
1, 63, 65, etc. and the presser foot lifting member 49;
The presser foot actuating means 90 is configured to be movable between the presser foot actuating means 90 and a non-operating position where no transmission occurs, and position changing means 98, 104 for selectively moving the presser foot actuating means 90 to the actuating position or the non-operating position. ing.

(Function) The position converting means 104 and 98 are the presser foot actuating means 9
When the thread cutting means 86, 87 and the presser foot lifting member 49 are operated together with the operation of the drive means 61, 63, 65, etc.

On the other hand, when the position converting means 104, 98 drives the presser foot actuating means 90 and places it in the non-operating position, only the thread cutting means 86, 87 are operated and the presser foot lifting member 49 is not operated.

(Example) An example embodying this invention will be described below with reference to the drawings.

As shown in FIG. 1, a main shaft 12 is rotatably supported within the bed portion 9 of the sewing machine frame 8, and the main shaft 12 is provided with main shaft drive control means, which is a known mechanism. This main shaft drive control means is constructed as follows. As shown in Figure 2,
A pulley 11 is attached to one end of the main shaft 12 so as to be freely rotatable and slidable in the axial direction, and is connected via a belt 13 to a sewing machine driving motor (not shown). A control disk 14 having a step-like locking portion 15 on the circumferential surface is fixed to the main shaft 12 adjacent to the pulley 11, and a clutch mechanism (not shown) is interposed between the control disk 14 and the pulley 11. There is.

A control lever 16 is fixed to a support shaft 17 rotatably supported within the sewing machine frame 8 so as to extend parallel to the main shaft 12, and a locking protrusion 16b is provided protruding from the lower base end of the control lever 16. A locking shaft 18 is supported on the upper side so as to be slidable in the axial direction.
A locking portion 15 of the control disk 14 is attached to one end of the locking shaft 18.
A locking piece 19 that engages with is attached. In FIG. 2, 20 is a spring that biases the locking piece 19 in the engaging direction, and 21 is a spring that biases the control lever 16 in the counterclockwise direction in the figure. Further, a pressing lever 24 having a cam member (not shown) at its tip that engages with the pulley 11 is fixed to one end of the support shaft 17, and the lever 24 is swung as the support shaft 17 reciprocates. At times, the pulley 11 is moved toward and away from the control disk 14 on the main shaft 12 by the action of the cam member.

A control solenoid 22 is installed on the outer surface of the bed portion 9 of the sewing machine frame 8, and its plunger 23 is brought into contact with the locking protrusion 16b of the control lever 16. When the control solenoid 22 is energized by a start switch (not shown) that is turned on and off by the operator's foot operation, the plunger 23 protrudes and the control lever 16 resists the action of the spring 21, and together with the support shaft 17, the plunger 23 protrudes. is rotated clockwise, the locking piece 19 is disengaged from the locking portion 15 of the control disk 14, and the pulley 11 is moved in the direction away from the control disk 14 through the swinging of the press lever 24. . For this reason, the clutch mechanism is activated, and the rotation of the pulley 11 is controlled by the control disk 14.
is transmitted to rotate the main shaft 12. Further, as will be described later, when the main shaft 12 is rotated a predetermined number of times, the support shaft 17 is rotated counterclockwise in the figure from the above state, and the locking piece 19 is locked to the locking portion 15. The pulley 11 is moved via the push lever 24 to the side closer to the control disk 14 . Therefore, the clutch mechanism becomes inactive, and even though the pulley 11 is being rotated by the sewing machine drive motor, the rotation of the main shaft 12 is blocked and momentarily stopped, and the needle 27 (described later) reaches the top dead center. held still.

As shown in FIG. 1, a needle bar 28 having a needle 27 at the lower end is provided at the tip of the arm portion 10 of the sewing machine frame 8.
is supported to be movable up and down as the main shaft 12 rotates, and a looper (not shown) for forming stitches in cooperation with the needle 27 is rotatable in the bed portion 9 opposite to the needle bar 28. Possibly supported. A feed plate 29 is provided on the top surface of the bed portion 9 of the sewing machine frame 8.
is supported so as to be movable in the front-rear direction and left-right direction in conjunction with the main shaft 12, and a forward-extending feed plate 30 is attached to its tip. This feed plate 30
A needle plate 31 having a needle hole 32 is mounted on the upper surface of the bed portion 9 so as to be located below the needle hole 32.

A shaft 34 provided almost on the top surface of the feed table 29
A presser foot 35 is rotatably supported at its rear end, and an engaging piece 37 having an engaging protrusion 36 at its upper end is erected and fixed substantially on the upper surface of the presser foot 35 . Further, a button holding device 40 having a pair of button holding arms 39 that can be opened and closed is attached to the lower surface of the front end of the presser foot 35.

A presser bar 43 extending vertically is supported at the upper end of the front protrusion 42 of the bracket 41 fixed to the lower surface of the arm portion 10 so as to be movable up and down, and its lower end abuts the upper surface of the presser foot 35. has been done. A spring 46 is fitted into the presser bar 43, and the presser foot 35 is pressed downward based on the spring force adjusted by the adjusting nut 45.

On the other hand, a support shaft 48 provided at the lower end of the bracket 41 has a presser foot lifting lever 4 as a presser foot lifting member.
9 is rotatably supported, and an arm 50 is formed protruding from the lower side of the front end thereof and extends toward the lower side of the engagement protrusion 36 of the engagement piece 37. Further, an inverted L-shaped operating lever 51 is rotatably attached to the support shaft 48, and the presser foot lifting lever 4 is rotated by a screw 52.
It is integrated into 9. A connecting rod 5 is connected between the lower end of the operating lever 51 and the button holding device 40.
3 is interposed.

When the presser foot lifting lever 49 is rotated clockwise in FIG. The button holding device 40 is separated from the upper surface of the bed portion 9. Also, at this time, both button clamping arms 39 of the button clamping device 40 are opened via the actuating lever 51 and the connecting rod 53, and in this state, the operator's hand or a button feeding robot (not shown) is placed between the tip ends of the button clamping arms 39 of the button clamping device 40. The button is now supplied by the button. In addition,
The structure and operation of the button clamping device 40 and its opening/closing mechanism are disclosed in detail in the specification and drawings of Japanese Patent Application No. 160113/1982 filed on August 31, 1988 by the same applicant as this application. Please refer to this.

A shaft 60 is disposed between the main shaft 12 and the support shaft 17 and extends parallel to the main shaft 12 and rotates at a reduced speed in conjunction with the main shaft 12. A control cam 61 is mounted on the shaft 60.
is fixed. The outer periphery of the control cam 61 is formed with an equal radius portion 62a and a pair of recesses 62b separated by 180 degrees. The control cam 61 is rotated half a turn every eight reciprocations of the needle 27 (eight rotations of the main shaft 12). Further, the shaft pin 55 provided in the control cam 61 near one of the recesses 62b has the recess 62b.
An opening/closing lever 56 that can open and close the opening/closing lever 2b is rotatably supported, and an operating pin 58 that is guided and fitted into a long hole 57 whose part abuts on the control cam 61 is protruded from its tip. Further, a cam contact lever 63 is fixed to the support shaft 17 at approximately the center thereof;
A cam contactor 64 that engages with the outer peripheral surface of the control cam 61 is pivotally attached to its upper end.

On the other hand, a rotary lever 59 is supported by a shaft 66 in the sewing machine frame 8 above the control cam 61, and a reciprocating lever 65 that extends vertically via a connecting pin 69 is rotatable at the upper end of the forward protrusion 59a. movably supported. This reciprocating rod 65
The lower end portion and the lower end portion of the cam contact lever 63 are connected to each other by a connecting rod 67.
7 is movable relative to the cam contact lever 63 by the length of an elongated hole 68 formed at the lower end of the cam contact lever 63. Further, a tension spring 72 is disposed between a spring hook pin 70 protruding from the connecting rod 67 and a locking pin 71 fixed to the sewing machine frame 8.
is tensioned, and the spring force urges the connecting rod 67 to move rearward, and the reciprocating rod 65 is urged to rotate counterclockwise in FIG. 1 about the connecting pin 69.

A rocking body 75 is supported on a shaft 74 provided in the vicinity of the main shaft 12 so as to be rotatable back and forth, and an eccentric cam 73 fixed on the main shaft 12 is held by its forked portion 76 . A locking pawl 77 that can be engaged with a locking recess 78 cut out in the lower end of the reciprocating rod 65 is bent on the rearward protrusion of the rocking body 75 . Then, while the eccentric cam 73 rotates once, the rocking body 75 is rotated back and forth, and the rocking body 75 is rocked clockwise in the figure with the locking pawl 77 and the locking recess 78 engaged. When the locking claw 77 moves downward, the reciprocating lever 65 is lowered and the rotating lever 59 is rotated counterclockwise in the figure.

A link 81 is connected at one end to the connecting pin 69 of the rotating lever 59, and the other end is connected to one end of a connecting lever 83 rotatably supported within the sewing machine frame 8 via a shaft screw 82. has been done. A slide lever 84 extending back and forth is connected to the other end of the connecting lever 83, and a movable blade operating body 85 is provided at the front end of the slide lever 84. The throat plate 31 is located at the front end of the movable blade operating body 85.
A rotatable movable blade 86 is connected to the lower side of the needle hole 32. When the reciprocating rod 65 is lowered, the rotating lever 59, the link 81,
The movable blade 86 is rotated via the connecting lever 83, the slide lever 84, and the movable blade operating body 85 so as to cross the vertical movement path of the needle 27, and the limb on the fabric side of the needle thread loop captured by the looper The needle 27 can be cut in cooperation with a fixed blade 87 placed at an opposite position across the vertical movement path of the needle 27.

On the other hand, the downward protrusion 59b of the rotary lever 59
A presser foot lifting lever 90 extending back and forth via a support shaft 89 is rotatably supported at its rear end, and at its front end is connected to an engaging pin 91 protruding from the upper end of the presser foot lifting lever 49. An engagement recess 92 that can be fitted from below is formed, and a long hole 9 extending in the longitudinal direction is formed on the rear side of the engagement recess 92.
3 is transparent. A support plate 96 is fixed to the outer surface of the arm portion 10 above the presser foot lifting lever 90 by a pair of mounting screws 95, and a letter-shaped lever 98 is attached to the front protruding end of the support plate 96 via a shaft 97.
is rotatably supported at its intermediate portion. An oval hole 99 is formed through the upper end of the dogleg-shaped lever 98, and a support pin 100 that fits into the elongated hole 93 of the presser foot lifting lever 90 is protruded from the lower end. The holes 101 corresponding to the pair of mounting screws 95 extend back and forth, so that the longitudinal position of the support plate 96 can be finely adjusted depending on the relationship between the holes 101 and the mounting screws 95.

An air cylinder 104 that extends back and forth is attached to the upper protrusion 102 of the support plate 96 by a mounting nut 103, and a pin 107 that fits into the oval hole 99 of the dog-shaped lever 98 projects from the tip of the piston rod 105. has been done. As shown in FIG. 1, when the piston rod 105 of the air cylinder 104 is retracted, the dogleg-shaped lever 9
8, the presser foot lifting lever 90 is placed in a substantially horizontal operating position, and its engagement recess 92 is fitted into the engaging pin 91 of the presser foot lifting lever 49 from below. The movement of the reciprocating rod 65 is transmitted to the presser foot lifting lever 49 through the presser foot lifting lever 49. Also, the piston rod 1 of the air cylinder 104
05, as shown in FIG. 3, the dog-shaped lever 98 is rotated counterclockwise from the above-mentioned state, and the presser foot lifting lever 90 is moved by fitting the support pin 100 into the elongated hole 93. It is rotated downward by a predetermined angle. Therefore, at this time, the engagement recess 92 of the presser foot lifting lever 90 is disengaged from the engagement pin 91 of the presser foot lifting lever 49, the presser foot lifting lever 90 is placed in the non-operating position, and the movement of the reciprocating lever 65 is controlled by the presser foot. The signal is not transmitted to the raising lever 49.

As shown in FIG. 1, a thread removal solenoid 110 is attached to a mounting plate 109 fixed to the outer surface of the front end of the arm section 10, and its plunger 1
11 includes a connecting rod 112, a link 113, and a rotating shaft 1.
14, the thread removing arm 115 is operatively connected, and by energizing the thread removing solenoid 110 after completing a series of stitches, the thread removing arm 115 is swung across the vertical movement path of the needle 27. Said movable blade 8
Needle 2 cut by cooperation with 6 and fixed blade 87
It is designed to sweep the threads connected to 7 to the side.

Next, the operation of the button sewing machine configured as described above will be explained.

First, a case will be described in which a four-hole button B is sewn onto a workpiece cloth using stitch 4 with a crossover thread.In this case, the air cylinder 104 is set to a non-operating state. When the air cylinder 104 is in the non-operating state, as shown in FIG. It is engaged with the engagement pin 91 of the presser foot lifting lever 49. Also, the opening/closing lever 56
The operating pin 58 is operated to place the lever 56 in the closed position, and one recess 62b of the control cam 61 is closed.

Now, when the sewing machine is stopped, the cam contact lever 63
is located at the chain line position in FIG. 1, and the cam contactor 64
is engaged with one recess 62b of the control cam 61. The cam contact lever 63 is located behind the long hole 68 of the cam contact lever 63, and is connected to the reciprocating rod 65 via the connecting rod 67.
The lower end of the locking recess 7 is located at the rear position.
A locking pawl 77 of a rocking body 75 is locked to 8, and the locking pawl 77 is in a lower position, and the reciprocating rod 65 is lowered.

Therefore, the rotary lever 59 is at the chain line position in FIG. 1, and the presser foot lifting lever 49 is positioned at the chain line position in FIG. The arm 50 is rotated to the chain line position, and the engagement of the arm 50 with the engagement protrusion 36 of the engagement piece 37 causes the presser foot 35 and button holding device 40 to integrally resist the action of the spring 46 of the presser bar 43. and is rotated to the upper position. In this state, the button B is held between the distal ends of both button holding arms 39.

When the control solenoid 22 is excited in this state, the rotation of the pulley 11 is transmitted to the main shaft 12. Further, the support shaft 17 is rotated by the excitation of the control solenoid 22, and the cam contact lever 63 is swung to the solid line position in FIG. This brings the state of engagement with the equal radius cam portion 62a. As the cam contact lever 63 swings, its elongated hole 68 is moved forward, and the lower end of the reciprocating rod 65 is moved forward via the connecting rod 67, and the locking recess 78 and the rocking body 75 are moved forward. The locking with the locking pawl 77 is released. Therefore, the reciprocating lever 65, the rotating lever 59, the presser foot lifting lever 90, and the presser foot lifting lever 49 are each in a movable state, so that the presser foot 35 is rotated downward by the action of the spring 46 of the presser rod 43. The button holding arm 39 presses the work cloth against the upper surface of the bed portion 9, and the presser foot lifting lever 49 and the presser foot lifting operating rod 9
0, the rotary lever 59 is moved in the opposite direction to the above case, and the reciprocating lever 65 is raised.

While the cam contact 64 of the cam contact lever 63 is engaged with the equal radius cam portion 62a of the control cam 61, the support shaft 17 is not rotated counterclockwise.
The main shaft 12 is held in a driving state, and as the main shaft 12 rotates, the needle 27 is reciprocated up and down eight times, and in synchronization with this, the feed base 29 is reciprocated left and right, so that the needle 27 and the looper cooperate with each other. A seam between holes 1 of one set shown in FIG. 4 is formed on the button B held by the button holding arm 39. Subsequently, as the control cam 61 rotates, the cam contact lever 6
The third cam contactor 64 faces the other recess 62b, but since the recess 62b is closed by the opening/closing lever 56, the cam contact lever 63 is held at the solid line position in FIG. Therefore, even if the cam contactor 64 comes into contact with the recess 62b, the reciprocating rod 65 will not be lowered, and the thread will not be cut by the movable blade 86. Then, with the presser foot 35 pressing the work cloth, feed is applied to the work cloth of the button B via the feed table 29 so that the holes 3 of the other set face the needle drop points.

Subsequently, the control cam 61 is further rotated, and the cam contactor 64 of the cam contact lever 63 is brought into contact with the control cam 6.
When the needle 27 is engaged with the other equal radius cam portion 62a of the button B, the needle 27 is reciprocated eight more times as the main shaft 12 rotates, and as shown in FIG. A stitch is formed which is continuous with the stitch 2 through the stitch 2, and the button B is sewn onto the work cloth through the stitch 4 with a crossover thread.

When the control cam 61 rotates once in this manner and the cam contactor 64 faces one of the recesses 62b,
The cam contact lever 63 is activated by the action of the spring 21.
is swung to the chain line position in FIG.
is engaged with the recess 62b, and the support shaft 17
The control lever 16 is integrally rotated counterclockwise in FIGS. 1 and 2, and the locking piece 19 is locked with the locking portion 15 of the control disk 14, and the pulley 11 The connection between the main shaft 12 and the control disk 14 is dissociated, and the rotation of the main shaft 12 is stopped. At this time,
As the cam contact lever 63 swings, its elongated hole 68 is moved rearward, so that the lower end of the reciprocating rod 65 is placed at the rear position via the connecting rod 67 due to the spring force of the tension spring 72. Therefore, the reciprocating rod 6
A locking claw 77 disposed at an upper position by the action of an eccentric cam 73 is locked in the locking recess 78 of No. 5 in synchronization with the movement of the needle 27 from the top dead center to the bottom dead center in the final needle. will be stopped. When the needle 27 is moved from the bottom dead center to the top dead center in this locked state, the locking pawl 77 is moved downward in synchronization with the movement, and the reciprocating rod 65 is lowered.

Therefore, the rotating lever 59, the presser foot lifting operation lever 9
0, the presser foot lifting lever 49 is rotated clockwise in FIG. 1, and the presser foot 35 is placed in the upper position. At the same time, as the reciprocating rod 65 descends, the movable blade 8
6 is rotated to cross the vertical path of the needle 27, and the thread connected to the needle 27 is cut by the cooperation of the movable blade 86 and the fixed blade 87. Further, in synchronization with this, the thread removing solenoid 110 is energized, the thread removing arm 115 is swung across the vertical movement path of the needle 27, and the cut thread is removed to the side.

With this, the one button sewing cycle using stitch 4 of the crossover thread is completed, and the next button B is supplied between the distal ends of the button holding arms 39 located at the upper position.

Next, to explain the case of sewing the four-hole button B onto the workpiece fabric using stitch 5 without a crossover thread, first, the air cylinder 104 is set to the operating state, and the opening/closing lever 56 is placed in the open position. Then, one recess 62b of the control cam 61 is opened to start the sewing machine. The seam between the holes 1 of one set of buttons B is the seam 4 with the crossover thread described above.
It is formed in the same way. However, just before the cam contactor 64 engages one of the equal radius cam portions 62a, the air cylinder 104 is actuated based on an electric signal from the control device, the piston rod 105 is protruded, and the dogleg-shaped lever 98 is moved to the first position. It is rotated counterclockwise from the state shown in the figure. Therefore, as shown in FIG. 3, the presser foot lifter lever 90 is rotated downward about the support shaft 89 to the non-operating position, and its engagement recess 92 engages with the engagement pin 91 of the presser foot lifter lever 49.
dissociated from.

In this state, the control cam 61 is further rotated, and the cam contact 64 of the cam contact lever 63 is inserted into the recess 62b.
When the opening/closing lever 56 is open, the cam contact lever 63 is swung to the chain line position by the spring force of the spring 21, and the cam contact 64
engages with the recess 62b. This cam contact lever 6
3, the lower end of the reciprocating rod 65 is placed in the rear position through the backward movement of the elongated hole 68 and the connecting rod 67, and the locking claw of the rocking body 75 is inserted into the locking recess 78 in the same manner as described above. 77 is locked. As the rocking body 75 swings clockwise, the reciprocating rod 65
is lowered and the rotating lever 59 is placed at the chain line position. Therefore, the movable blade 86 is rotated via the link 81 and the like to cut the thread connected to the needle 27, and the thread removing arm 11 is cut by the excitation of the thread removing solenoid 110.
5 is swung to remove the cut end of the thread. At the same time, the presser foot lifting lever 90 is moved rearward, but since the presser foot lifting lever 90 is placed in the non-operating position, the movement is not transmitted to the presser foot lifting lever 49, and the presser foot 35 is moved backward to remove the workpiece. is held in a pressed state.

When the seam between the holes 1 of one set of buttons B is formed and the thread is cut, the control solenoid 22 is energized again based on an electric signal from the control device, causing the main shaft 12 to rotate and contacting the cam. Lever 6
3 is swung, and the cam contactor 64 is removed from the recess 62b and engaged with the other equal radius cam portion 62a. Therefore, the lower end of the reciprocating rod 65 is moved forward via the connecting rod 67, the locking recess 78 and the locking pawl 77 are disengaged, and the reciprocating rod 65 is raised. Then, the presser foot lifting lever 90 is moved forward, and its engagement recess 92 is disposed below the locking pin 91 of the presser foot lifting lever 49.

Therefore, the cam contactor 64 of the cam contact lever 63
is engaged with the other equal radius cam portion 62a of the control cam 61, the needle 27 is reciprocated eight times, and the button B is pressed.
A seam is formed between the holes 3 of the other set, which is discontinuous with the seam between the holes 1 of one set. Also, during this eight-stitch sewing, the piston rod 105 of the cylinder 104 is retracted, and the doglegged lever 98 is rotated back to the position shown in FIG. As a result, the presser foot lifting operation lever 9
0 is rotated to the operating position, and its engagement recess 92 is fitted into the engagement pin 91 of the presser foot lifting lever 49 from below.

Then, when the cam contactor 64 engages with the recess 62b, the main shaft 12 moves as the cam contact lever 63 swings.
After the rotation of the reciprocating lever 65 is lowered and the thread is cut by the movable blade 86,
The thread is removed by the thread removal arm 115. Also,
At the same time, the presser foot lifting lever 90 is moved rearward, and the presser foot 35 is rotated upward together with the button holding device 40 via the presser foot lifting lever 49.

With the above, sewing of the four-hole hodder using stitch 5 without a crossover thread is completed.

Effects of the invention As detailed above, according to this invention, the presser foot lifter is configured so that it can be switched between the working position and the non-working position, so that it can be used for stitches with and without crossing threads. This has the effect that the switching operation can be easily performed.

Furthermore, in this invention, when attaching buttons without a crossover thread, the position changing means drives the presser foot actuating means and places it in the non-operating position, so only the thread trimming means is activated and the presser foot lifting member is not activated. . Therefore, the presser foot does not go up and continues to press the workpiece cloth, so the workpiece cloth to be buttoned does not move inadvertently, making it possible to reliably attach buttons without jumping threads. play.

[Brief explanation of the drawing]

Fig. 1 is a front view of a button sewing machine showing an embodiment of this invention, Fig. 2 is a perspective view showing the main shaft drive control means, and Fig. 3 is a main view showing different operating states of the presser foot operating means. FIG. 4 is a plan view of the button showing a stitch with a crossing thread, and FIG. 5 is a plan view of the button showing a stitch without a crossing thread. In the figure, 8 is the sewing machine frame, 12 is the main shaft,
27 is a needle, 35 is a presser foot, 49 is a presser foot lifting lever as a presser foot lifting member, 61, 63, and 65 are control cams, cam contact levers, and reciprocating rods constituting drive means, respectively, and 86 and 87 are thread cutting means. 90 is a presser foot lifting lever as a presser foot actuating means, 98 is a dog-shaped lever constituting a position changing means, 104 is an air cylinder constituting a position changing means, and B is a button. .

Claims (1)

[Claims for Utility Model Registration] A main shaft 12 rotatably supported by the sewing machine frame 8, and a needle 27 that moves up and down as the main shaft 12 rotates.
, a presser foot 35 which is movably disposed on the bed surface 9 of the sewing machine across the vertical movement path of the needle 27 and is always biased toward the bed surface 9; To drive the presser foot lifting member 49 supported by the sewing machine frame 8, thread cutting means 86, 87 for cutting the thread connected to the needle 27 after forming a series of stitches, and the thread cutting means 86, 87, etc. , drive means 61, 63, 65, etc., which are operated in accordance with the rotation of the main shaft 12;
63, 65, etc. to the presser foot lifting member 49, and a non-operating position where the movement is not transmitted to the presser foot lifting member 49. position changing means 98, 104 for selectively moving the presser foot to a non-operating position; Both the means 86 and 87 and the presser foot lifting member 49 are operated, and the presser foot operating means 90
is placed in the non-operating position, only the thread trimming means 86 and 87 are operated, and the presser foot lifting member 49
A button sewing machine characterized by being configured such that the button is not activated.