JPH06126068A - Sewing machine - Google Patents

Abstract

PURPOSE:To prevent a sewing thread from dropping off at a time of start of sewing, by a method wherein a sewing machine motor is continued to rotate after a needlebar separating device is operated so that a thread cutting device can cut a needle thread, and the sewing machine motor is stopped when a sewing-pressing member moves to a retreating end position after a balance passes an upper dead point. CONSTITUTION:A sewing-pressing member motion changing device and a needlebar motion changing device are connected to a main shaft 110 in parallel with each other. At a time of finish of sewing, before a sewing machine motor is stopped, not only needle thread 76 and bobbin thread are cut, but also a thread end 252 of the needle thread 76 is swept away by a thread sweeping member. At this time, a needlebar 70 has not moved from its upper dead point, and stops only after a balance 130 passes its upper dead point. By this, a loosened part is generated in the needle thread which is hung over the balance 130, and therefore, when the balance 130 has passed over its upper dead point, the needle thread is drawn out from a spool by a sufficient amount. Therefore, in the case that the balance 130 moves again up to its upper dead point, the needle thread 76 does not come out of a sewing needle.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sewing machine, and more particularly, to stop control of a sewing machine motor.

[0002]

2. Description of the Related Art A sewing machine generally has a needle bar, a spindle, a balance,
It is configured to include a needle bar motion conversion device, a balance motion conversion device, a thread cutting device, and control means. The needle bar holds the sewing needle and can reciprocate in the axial direction.The motion converting device for the needle bar is provided between the main shaft and the needle bar rotated by the sewing machine motor, and the rotation of the main shaft is controlled by the upper side of the needle bar. The needle bar is moved up and down by converting it into a reciprocating motion between the dead center and the bottom dead center. In addition, the balance is provided so as to be rotatable about an axis, pulling out the upper thread from the spool and tightening the upper thread to form a stitch,
The motion converting device for the balance is provided between the main shaft and the balance,
The rotation of the spindle is converted into a reciprocating motion between the top dead center and the bottom dead center of the balance. Further, the thread cutting device cuts the upper thread connected to the sewing material through the balance and the sewing needle, and the control means
The sewing machine motor and the thread cutting device are controlled to operate the needle bar and the balance, and the thread cutting device is caused to cut the thread.

When forming a stitch in such a sewing machine, it is usual to provide a sewing material pressing member and press the sewing material. The sewing material pressing member has a forward end position for pressing the sewing material, Some sewing machines are reciprocally moved between the forward end position and the farthest end position. In this case, the motion converting device for the sewing material pressing member is provided between the main shaft and the sewing material pressing member, and the rotation of the main shaft is converted into the reciprocating motion between the forward end position and the backward end position to thereby change the sewing material. The pressing member is moved.

For example, the needle bar holds the sewing material pressing member so as to be movable in the axial direction, and the spring is pressed against the receiving member fixed to the needle bar so that the sewing material pressing member moves together with the needle bar. A stopper is provided while the material pressing member moves forward together with the needle bar, and only the needle bar moves forward after the sewing material pressing member contacts the stopper. In this case, the receiving member for converting the rotation of the main shaft into the motion of the needle bar, the spring and the stopper together with the motion converting device for the needle bar constitute the motion converting device for the sewing material pressing member. A sewing material pressing member is provided separately from the needle bar, and a cam device that converts the movement of the needle bar into the movement of the sewing material pressing member is provided between the sewing material pressing member and the needle bar to move the sewing material pressing member. Has also been done. In this case, the cam device constitutes the motion converting device for the sewing material pressing member together with the motion converting device for the needle bar.

Further, in the sewing machine, a needle bar separating device is provided which cuts off the motion transmission to the needle bar by the motion converting device for the needle bar and allows the needle bar to stay at the top dead center even when the sewing machine motor is rotating. May be For example, in the sewing machine described in the specification of Japanese Patent Application No. 3-122036 of the present applicant, when a stitch longer than the longest stitch that can be formed by one rotation of the main shaft is formed, the needle bar is top-dead. The sewing material is fed in a state where it stays at the point, and the needle bar disconnection device releases the needle bar disconnection at the timing when the stitch of the desired length is formed, so that a long stitch is formed. In this sewing machine, the sewing material pressing member is held by the needle bar and moves together with the needle bar. This needle bar separating device is also controlled by the control means to separate the needle bar.

In a sewing machine having this needle bar separating device, at the end of sewing, the needle bar is kept at the top dead center of the needle bar by the needle bar separating device, and the sewing machine motor is moved in the state where the balance is moved to the balance top dead center. It was supposed to stop. If the balance stops before the top dead center, when the balance moves from the stop position to the top dead center at the start of sewing, the upper thread may be pulled and the upper thread may come out of the sewing needle. It is necessary to stop the thread as close as possible to the top dead center to prevent the thread from being pulled out from the sewing needle.If the needle bar is moving, determine the stop position of the balance in consideration of the needle bar position. Is required and the balance cannot be stopped at the top dead center. Therefore, the needle bar is allowed to stay at the needle bar top dead center by the needle bar separating device, and the balance can be stopped at the balance top dead center.

In this case, in the sewing machine of the type in which the needle bar holds the sewing material pressing member, the sewing material pressing member moves together with the needle bar to the top dead center position by the operation of the needle bar separating device. On the other hand, in the sewing machine of the type in which the motion of the needle bar is transmitted to the sewing material pressing member by the cam device,
When the needle bar is stopped at the needle bar top dead center by the needle bar separating device, the sewing material pressing member does not stop at the retracted end position.

[0008]

In the former case, since the needle bar and the sewing material pressing member both stop at the position farthest from the sewing material, the sewing material can be replaced easily. Sometimes, there is a problem that a collision sound is generated and durability is reduced each time the sewing material pressing member comes into contact with the stopper. Further, in the case of a multi-needle sewing machine having a plurality of sewing needles, the same number of sewing material pressing members as needle bars are required, which causes a problem of increased cost. On the other hand, in the latter case, since the sewing material pressing member is not at the retracted end position when the needle bar is at the top dead center of the needle bar, the sewing material replacement space is insufficient and the replacement work becomes difficult. . An object of the present invention is to provide a sewing machine which does not come off from a sewing needle at the start of sewing, can stop both a needle bar and a sewing material pressing member at positions suitable for sewing material replacement, and has excellent durability. It was done.

[0009]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides a needle bar, a sewing material pressing member, a balance,
In a sewing machine including a spindle, a motion converting device for a needle bar, a motion converting device for a sewing material pressing member, a motion converting device for a balance, a needle bar separating device, a thread trimming device, and a control means, a motion converting device for a sewing material pressing member and a needle. The rod motion converting device is connected to the main shaft in parallel with each other, and the control means causes the sewing machine motor to rotate even after the needle bar separating device is operated, the thread cutting device cuts the upper thread, and the balance The gist of the invention is to provide sewing machine motor control means for stopping the sewing machine motor when the sewing material pressing member moves to the retracted end position after passing through the top dead center.

[0010]

[Function] When the balance passes the top dead center of the balance, the upper thread is sufficiently pulled out from the spool, so that the upper thread can be removed from the needle even when the balance moves to the top dead center of the balance again. There is no. In particular, if the balance passes the balance top dead center in the state where the needle bar is retained at the needle bar top dead center by the needle bar separating device, the needle thread pulled out from the spool is not used for forming the stitch. As a result, the allowance for the upper thread increases. Also,
Since the motion converting device for the sewing material pressing member and the motion converting device for the needle bar are connected to the main shaft in parallel with each other, the sewing material pressing member is moved even when the needle bar remains at the top dead center of the needle bar. Therefore, the sewing material pressing member can be stopped at a position suitable for exchanging the sewing material without being restricted by the position of the needle bar. Moreover, since the balance can be stopped at any position after passing the top dead center of the balance, the sewing material pressing member can be stopped at a desired position without being constrained by either the balance or the needle bar. The material pressing member moves to the retracted end position, and the sewing machine motor can be stopped in the state where the sewing material replacement space is secured.

[0011]

As described above, according to the present invention, the needle thread does not come off from the sewing needle at the start of sewing, the sewing material replacement work can be easily performed, and the needle bar serves as the sewing material pressing member. A collision sound is not generated as in the case of holding the sewing machine, and a sewing machine having high durability can be obtained. In the case of a multi-needle sewing machine, only one sewing material pressing member is required for a plurality of needle bars, and the sewing machine can be constructed at low cost.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. In FIG. 3, 10 is a sewing machine table, and a sewing machine frame 12 is fixed to the sewing machine table 10. The sewing machine frame 12 includes a pedestal portion 14 standing up from the sewing machine table 10, an upper arm 16 horizontally extending in a cantilever manner from an upper end of the pedestal portion 14, and a lower end of the pedestal portion 14 in parallel with the upper arm 16. And an extended bed 18.

Between the upper arm 16 and the bed 18,
A cloth holding frame 22 for holding the work cloth 20 as the sewing material of the present invention is provided so as to be movable in the X-axis direction and the Y-axis direction. A pair of guides (not shown) extending in the Y-axis direction are fixed to the sewing machine table 10, and a pair of Y-direction moving frames 26 (only one of which is shown in each figure) is movably attached thereto. , Y direction drive motor 28
(See FIG. 12). In addition, the pair of Y-direction moving frames 26 support the support plate 30 extending in the X-axis direction.
Both ends are fixed, and guides (not shown) are fixed to the support plate 30. An X-direction moving frame 32 is movably attached to this guide, and an X-direction drive motor 34 is attached.
(See FIG. 12). The support plate 36 is attached to the X-direction moving frame 32, and the cloth holding frame 22 is attached to the projecting end portion thereof. The work cloth 20 held by the cloth holding frame 22 is the X-direction moving frame 32.
By moving the Y-direction moving frame 26, the sewing machine table 1
It can be moved in any direction in the plane parallel to 0. In the present embodiment, the Y-direction moving frame 26 and the Y-direction drive motor 2
8, the X-direction moving frame 32, the X-direction drive motor 34, the cloth holding frame 22 and the like are the work cloth feeding device 38 as the sewing material feeding device.
Is configured.

A needle bar support case 40 as a movable case is attached to the protruding end of the upper arm 16 so as to be movable in the X-axis direction. As shown in FIG. 4, a guide plate 42 is fixed to the lower part of the back surface of the needle bar support case 40 on the upper arm 16 side. Guide plate 4
2 has a length substantially equal to the length of the needle bar support case 40 in the X-axis direction, and is made to extend forward from the upper arm 16 with a roller 43 rotatably attached to the lower surface of the front part of the upper arm 16. The roller 43 and the guide plate 42 guide the movement of the needle bar support case 40. A linear guide 48 is provided between the bottom plate 46 of the frame 44 integrally attached to the upper rear portion of the needle bar support case 40 and the upper surface of the upper arm 16. Linear guide 4
8 is a guide plate that is attached to the bottom plate 46 and has a length substantially equal to the length of the needle bar support case 40 in the X-axis direction;
A guide block attached to the upper surface of the upper arm 16 and fitted with a guide plate guides the movement of the needle bar support case 40.

The bottom plate 46 of the frame 44 has a length approximately equal to the dimension of the needle bar support case 40 in the X-axis direction and extends toward the base end side of the upper arm 16 and its protruding end. A plurality of rollers 56 are rotatably attached to the section so as to be spaced apart in the X-axis direction, and are engaged with the cam grooves 60 of the cam 58. The cam 58 is rotatably supported on the upper arm 16 by a bracket 62, and is rotated by rotation of a needle bar support case moving motor 68 transmitted via bevel gears 64 and 66. As the cam 58 rotates, the plurality of rollers 5
6 are sequentially fitted in the cam groove 60, and the needle bar support case 40 is X-shaped.
The twelve needle bars 70 (only a part of which are shown in FIG. 3) supported by the needle bar support case 40 are moved in the axial direction, and the needle bars 70 are rotated and positioned at the sewing position. The roller 56, the cam 58, the bevel gears 64 and 66, the needle bar supporting case moving motor 68 and the like constitute a needle bar supporting case moving device as a movable case moving device.

At the lower end of each of these 12 needle bars 70,
A sewing needle 72 is detachably attached by a sewing needle holder 73 as shown in FIG. 4 as a representative one, and the needle bar 70 and the sewing needle holder 73 constitute a sewing needle holding member. The needle threads 76 of different colors are passed through the threading holes 74 of the twelve sewing needles 72. The needle bar 70 includes two guide blocks 78 attached to the needle bar support case 40,
A needle bar holder 82 fixed to a portion of the needle bar 70 between the two guide blocks 78, 80 while being movably supported in the vertical direction, and a needle bar support case 40.
The spring 8 disposed between the spring receiver 84 fixed to the
It is biased upward by 6.

The needle bar top dead center, which is the rising end position of the needle bar 70, is defined by the needle bar stopper 88 contacting the upper guide block 78 via a cushion 89.
The needle bar stopper 88 is attached to the needle bar 70 so that its position can be adjusted, and the top dead center of the needle bar can be adjusted by adjusting the position.

The needle bar 70 is moved up and down using a sewing machine motor 90 (see FIG. 3) as a drive source. A guide rod 92 is fixed to the protruding end portion of the upper arm 16, an elevating body 94 is fitted in a vertically movable manner, and an engaging body 96 fitted in the guide rod 92 so as to be movable is rotatably fitted. ing. As shown in FIG. 5, an engaging groove 102 extending in the X-axis direction is formed in the engaging body 96 by a pair of engaging pieces 98, 100 provided at a distance in the vertical direction. This engaging groove 10
An engaging protrusion 104 provided on a needle bar holder 82 fixed to the needle bar 70 can be engaged with the needle bar 2, and the needle bar 70 can be moved up and down integrally with the engaging body 96 by the engagement. It has become. Further, the engagement body 96 is urged by a spring (not shown) in a direction to rotate clockwise when viewed from above in FIG.

As shown in FIG. 4, the elevating body 94 has
One end of the connecting rod 106 is connected by a pin 108. In the upper arm 16, the main shaft 110
Is rotatably arranged and the drive cam 1 is provided at the front end.
12 is fixed, and the other end of the connecting rod 106 is rotatably connected to a crank lever 114 fixed to the front end surface of the drive cam 112 by a pin (not shown). Therefore, the main shaft 110 is the sewing machine motor 9
Crank lever 114 when rotated by 0
Of the lifting body 94 by the connecting rod 106.
And the linear reciprocating motion of the engagement body 96 is converted to the needle bar 70.
Is moved up and down between the needle bar top dead center and the needle bar bottom dead center. The needle bar holder 82, the lifting body 94, the engaging body 96, the connecting rod 106 and the crank lever 114 are the main shaft 110.
That is, the motion converting device for a needle bar of the present invention that converts the rotation of the above into a reciprocating motion of the needle bar 70 in the axial direction is constituted.

Engagement projection 104 projecting from needle bar holder 82
Is disengaged from the engagement groove 102 by a jump device 120 as the needle bar separating device of the present invention shown in FIG. An inclined surface 122 is formed on a portion of the engagement body 96 on the side opposite to the needle bar 70 so as to incline in a direction further away from the needle bar 70. A jump solenoid 124 is arranged on the upper arm 16 in the X-axis direction. When the jump solenoid 124 is demagnetized, the plunger 126 is at the retracted position where it does not engage the inclined surface 122.
When the jump solenoid 124 is excited, the inclined surface 12
It is made to project to the engagement position which engages with 2.

The jump solenoid 124 is always demagnetized, and is excited in a state where the engaging body 96 is located below the plunger 126, as will be described later. Therefore, as the engaging body 96 moves up, the plunger 126 engages with the inclined surface 122, the engaging body 96 is rotated counterclockwise when viewed from above against the biasing force of the spring, and the engaging groove 102 Is disengaged from the engaging protrusion 104, and the needle bar 70 is urged by the spring 86 to jump to the needle bar top dead center. The vertical movement obtained by the motion converting device for the needle bar is not transmitted to the needle bar 70, and is kept in the state of staying at the top dead center of the needle bar.

When the jump solenoid 124 is demagnetized,
When the plunger 126 is retracted, the engagement body 96 is urged by a spring (not shown) to be rotated clockwise when viewed from above, and returns to a position where it engages with the engagement protrusion 104. If the jumping solenoid 124 is demagnetized and the engaging body 96 is raised while the engaging body 96 is at a position lower than the position at which the needle bar 70 is moved to the needle bar top dead center,
The engagement protrusion 104 engages with the engagement groove 102. Engagement groove 10
The upper engaging piece 98 forming 2 has an inclined surface 128, and the engaging projection 104 first engages with the inclined surface 128 and resists the biasing force of the spring as the engaging body 96 moves upward. To rotate the engaging body 96. Then, when the engagement groove 102 reaches the engagement protrusion 104, the engagement body 9
6 is rotated by the urging force of the spring, and the engaging groove 1
02 and the engagement protrusion 104 are engaged with each other.

Although the engaging body 96 is slightly raised even after the engagement groove 102 and the engagement protrusion 104 are engaged, the needle bar stopper 88 contacts the guide block 78 via the cushion 89 as described above. Since they are in contact with each other, the engagement protrusion 104 does not rise. Therefore, the engagement groove 102 is made slightly wider than the engagement protrusion 104 to allow the slight increase of the engagement body 96. The needle bar top dead center is the engaging body 96.
It is set to a position slightly lower than the rising end position of.

The needle bar support case 40 includes 12 needle bars 7
Twelve balances 130 are attached corresponding to 0 respectively. The upper thread 76 fed from a spool (not shown) provided on the upper arm 16 is threaded by the thread tension device 134.
(See FIG. 3) and then as shown in FIG.
The thread hooking member 136 attached to the front surface of the sewing machine 0 is passed through the thread balance 130, the thread hooking member 136 again, and then the guide member 138 to reach the threading hole 74 of the sewing needle 72. . Further, a hook 140 for hooking the thread end portion of the upper thread 76 is attached to the front surface of the guide member 138.

As shown in FIG. 4, the balance 130 is rotatably attached to a shaft 142 supported by the frame 44 fixed to the needle bar support case 40, and each balance 130 is attached.
A yoke-shaped member 144 is fixed to the. These yoke members 144 are engageable with a roller 149 held at the tip of a lever 148 rotatably attached to the upper arm 16 by a shaft 146. A base end of another lever 150 is fixed to the shaft 146, and a roller 152 rotatably attached to a free end of the lever 150 is
Balance drive cam groove 15 formed on the drive cam 112
4 and the balance 130 engaged with the roller 149 via the yoke-shaped member 144 when the drive cam 112 is rotated by the main shaft 110 is between the balance top dead center and the balance bottom dead center. Can be rotated back and forth. Drive cam 11
The portion in which the balance driving cam groove 154 of 2 constitutes the balance driving cam, and the yoke-shaped member 144 and the lever 1 are provided.
Together with 48, 150, etc., they constitute the motion converting device for the balance of the present invention which converts the rotation of the main shaft 110 into the reciprocating rotary motion of the balance 130.

The shaft 160 supported by the frame 44
Further, as many balance supports 162 as the balances 130 are rotatably attached, and are biased by the torsion springs 164 corresponding to the balance supports 162 so as to engage with the respective balances 130.
Therefore, the balance 1 to which each balance support 162 always corresponds.
Although each of the needle bars 30 is kept at the position near the top dead center, when the needle bar 70 is moved to the sewing position by the movement of the needle bar support case 40, the yoke-shaped member 144 corresponding to the needle bar 70 moves the roller 149. By engaging
After the balance 130 corresponding to the needle bar 70 is driven by the drive cam 112, the balance support 162 corresponding to the balance 130 is protruded upward from the upper arm 16 on the cam surface 168. Engages with the protruding end of the balance and rotates in a direction away from the balance 130.
It is in a state in which the rotation of 0 is permitted.

The rotation of the main shaft 110 causes the needle bar 70 to be moved up and down and the balance 130 to be rotated at the same time. The balance drive cam groove 154 has a predetermined movement as shown in the timing chart of FIG. Is formed at the timing of This timing chart will be described later. The rotation of the balance 130 draws the upper thread 76 from a spool (not shown) and tightens the upper thread 76 entwined with the lower thread to form a stitch. The needle bar 70, the sewing needle 72, the balance 130, the motion converting device for the needle bar, the motion converting device for the balance, the shuttle (not shown), the main shaft 110 and the sewing machine motor 90 constitute a stitch forming device.

The upper arm 16 is also shown in FIGS.
As shown in, a cloth pressing device 170 as a sewing material pressing device is provided. A presser foot bar 172 of the present invention is fitted to the front end portion of the upper arm 16 so as to be able to move up and down, and a cloth presser foot 174 as a sewing material pressing member is detachably attached to the lower end portion protruding from the upper arm 16. Has been. The lower end portion of the cloth pressing foot 174 is extended to the sewing needle 72 side of the needle bar 70 positioned at the sewing position, and a needle hole 180 is formed in the pressing portion 176 of the cloth pressing foot 174 parallel to the bed 18. There is. Further, the cloth presser foot 174 includes the presser foot bar 172, the needle bar support case 4
0 and the upper arm 16 and the like are colored in a conspicuous color different from the colors of the peripheral members.

An elevating member 184 is fitted to the holding foot bar 172 so as to be relatively movable. The elevating member 184 has a frame shape, and a piece 186 fixed to the pressing foot bar 172 is fitted so as to be relatively movable.
4 is urged downward by a spring 190 arranged between the upper wall 188 and the upper wall 188 of the upper and lower walls 188 and abutted against a rubber stopper 194 provided on the lower wall 192 of the elevating member 184. An engaging protrusion 198 is provided on the front surface of the piece 186, and a plate 200 fixed to the front surface of the upper arm 16 is provided.
Is fitted into the long hole 202 formed in the
It is supposed to guide the movement of.

A shaft 208 is projectingly provided on the elevating member 184, one end of a link 210 is rotatably fitted, and the other end of the link 210 is rotated by a connecting pin 212 to an arm 216 of a lever 214. It is movably connected. The lever 214 has an L shape and is rotatably attached to the upper arm 16 by a shaft 218.
An arc-shaped elongated hole 220 is formed at the tip of the. The connecting pin 212 includes a shaft portion 222 shown in FIG. 7, an oval fitting portion 224 as shown in FIG. 6, and a male screw portion 226 protruding from the fitting portion 224. In the arm portion 216, the link portion 210 is rotatably fitted, the fitting portion 224 is fitted in the elongated hole 220, and the male screw portion 226 is screwed with the nut 228.
It is fixed to.

An elongated hole 232 is formed in an arc around the shaft center of the shaft 218 at the tip of the other arm 230 of the lever 214, and a roller 234 as a cam follower is provided as shown in FIG. It is rotatably attached by a support pin 236 and is engaged with a cloth presser foot drive cam groove 240 formed in the drive cam 112.
The support pin 236 is fitted into the elongated hole 232 in the oval fitting portion 242, the roller 234 is rotatably attached to the shaft portion 244 projecting from one end surface of the fitting portion 242, and the other end surface thereof is attached. The nut 2 is attached to the male screw portion 246 protruding from the
The screw 48 is fixed to the arm portion 230, and the rotation position of the lever 214 can be adjusted by adjusting the relative position between the fitting portion 242 and the elongated hole 232.

When the main shaft 110 is rotated by the sewing machine motor 90, the lever 214 is rotated and the link 210 is moved up and down by the rotation of the cloth presser foot driving cam groove 240. Thereby, the lifting member 184
Is moved up and down, and the presser foot bar 172 is integrally moved up and down, and the cloth presser foot 174 is moved to the forward end position where the work cloth 20 is pressed and the backward end position where the cloth retracting foot 174 is most retracted from the forward end position. At this time, the spring 190 remains extended, and the lifting member 184 and the pressing foot bar 17 are
2 (cloth presser foot 174) is integrally raised and lowered.

The portion of the drive cam 112 in which the cloth presser foot drive cam groove 240 is formed constitutes a cloth presser foot drive cam, and the lifting member 184, the link 210 and the lever 214.
Together with the link mechanism, roller 234, etc.
The motion converting device for the fabric pressing foot is constituted as the motion converting device for the sewing material pressing member of the present invention which converts the rotation of the main shaft 110 into the vertical movement of the cloth pressing foot 174. In addition, the cam groove 240 for driving the presser foot is integrally formed with the crank lever 114 for moving the needle bar 70 up and down.
No. 0, and the motion converting device for the needle bar and the motion converting device for the presser foot are connected to the main shaft 110 in parallel with each other.

The forward end position of the cloth pressing foot 174 can be changed by adjusting the connecting position of the link 210 to the lever 214. In the present embodiment, the forward end position of the cloth pressing foot 174 is set to a position that does not press the work cloth 20 and faces the work cloth 20 with a slight distance therebetween.
It is adjusted according to the thickness of the work cloth 20. At the time of adjustment, the lever 214 is stopped at a position where the cloth pressing foot 174 is moved to the forward end position, and the operator loosens the nut 228 from the opening 249 (see FIG. 7) formed on the right side surface of the upper arm 16 and the connecting pin The position of the fitting portion 224 of the 212 in the elongated hole 220 is changed, and the connecting pin 212 is fixed to the lever 214 at a position where an appropriate gap is obtained between the cloth pressing foot 174 and the work cloth 20.

The elongated hole 220 is formed along an arc centered on the axis of the shaft 208 when the cloth presser foot 174 is at the retracted end position. Therefore, as described above, even if the connecting pin 212 is fixed at any position within the elongated hole 220 in order to adjust the forward end position of the cloth pressing foot 174, the lever 214 moves to the backward end position side turning end. When rotated, the shaft 208 always moves to the center of the arc defining the elongated hole 220, and the retracted end position of the cloth presser foot 174 becomes constant.

However, in order to keep the retracted end position of the cloth presser foot 174 constant in this way, the elongated hole 220 is centered on the shaft 208 while the lever 214 is at the pivoted end on the retracted end position side. It must be exactly along the arc.
If this condition is not met, roller 2
34 to the lever 214 to release the lever 214
Is moved with respect to the roller 234, and the position of the lever 214 is adjusted so that the slot 220 is positioned on an arc centered on the axis of the shaft 208. The link 210 and the lever 214 which constitute the motion converting device for the presser foot are elongated holes 220.
And the connecting hole 212 so as to adjust the position, and the long hole 220 moves the shaft 208 in the retracted end position.
Since the portion formed so as to be located on the arc centered on the axis center of is the position adjusting device for maintaining the retracted end position of the cloth pressing foot 174 constant and adjusting the advanced end position, is there.

A thread wiping device 250 is attached to the left side surface of the upper arm 16 as shown in FIG. The thread wiping device 250 is a device for grasping the thread end 252 of the upper thread 76 extending from the sewing needle 72 to the work cloth 20, and is fixed to the left side surface of the upper arm 16 as shown in FIGS. 9 and 10. It has a support plate 254. A thread wiping solenoid 256 is attached to the support plate 254. The thread wiping solenoid 256 is a rotary solenoid,
The demagnetization causes the drive shaft 260 to rotate in both forward and reverse directions by a fixed angle. A base end portion of a lever 262 is fixed to the drive shaft 260, and a link 26 is attached to a free portion of the lever 262.
One end of No. 4 is rotatably connected by a shaft 266, and the other end of the link 264 is connected with a thread wiping member 268.

A shaft 270 is provided at the other end of the link 264.
Is erected and protrudes into the upper arm 16 through an elongated hole 272 formed in the support plate 252, and the thread wiper member 268 is rotatably connected to the protruding end portion. The thread wiping member 268 has a plate shape as shown in FIG. 10, is extended in a direction intersecting with the axis of the needle bar 70 positioned at the sewing position, and has a thread end 252 at the tip thereof. Hooks 274 that engage are provided.

As shown in FIG. 10, the needle bar support case 40 has a guide 2 for guiding the movement of the thread wiping member 268.
84 is provided. The guide 284 includes two thin plates 288, 2 whose both ends are fixed to brackets 286 which are fixed to both side surfaces of the needle bar support case 40 parallel to the X-axis direction.
It is composed of 90. These thin plates 288, 290
Are arranged in parallel with each other with a slight gap, and the thread wiper member 268 is inserted between the thin plates 288 and 290.
The movement is guided, and the movement of the needle bar support case 40 is allowed by the relative movement with the guide 284. A gap is provided between the thread wiping member 268 and the thin plate 288 so that the thread wiping member 268 does not float above the thin plate 290.

The lever 262 is the solenoid 256 for thread removal.
The shaft 270 is reciprocally moved along the elongated hole 272 via the link 264 by being rotated in both forward and reverse directions by the excitation and demagnetization of the thread guide member 268.
It is guided by 84 and moves linearly to the retracted position shown by the solid line in FIG. 9 and the projecting position shown by the chain double-dashed line. The retracted position and the protruding position are on opposite sides of each other with the axis of the needle bar 70 interposed therebetween. The thread wiping solenoid 256, the lever 262 and the link 264 form a thread wiping member moving device. Note that reference numerals 292 and 294 denote stoppers fixed to the support plate 254. By defining the rotation range of the lever 262, the retracted position and the projected position of the thread wiping member 268 are defined.

A portion of the bed 18 covered with the needle plate 298 is provided with a thread cutting device 300 as shown in FIG. The thread cutting device 300 has a fixed blade 304 fixed to the bed 18 and a movable blade 308 attached by a shaft 306 so as to be rotatable about a vertical axis. The movable blade 308 is provided below the fixed blade 304, and a hook 310 for catching the upper thread 76 and a lower thread (not shown), and a cutting edge 312 for cutting the upper thread 76 and the lower thread in cooperation with the fixed blade 304. have. Movable blade 308 and spindle 11
Between 0 and 0, a link 316 connected to the movable blade 308 by a shaft 314, a thread cutting solenoid 318 (see FIG. 12).
(See) and a motion converting device for a movable blade, which is configured by a cam or the like (not shown).

The cam of the motion converting device for the movable blade is the main shaft 110.
The roller is engaged with the cam groove by the excitation of the thread cutting solenoid 318 and the link 316 is moved only when the thread is cut, and the movable blade 30 is moved.
8 is rotated to a first position shown by a solid line in FIG. 11 and a second position shown by a chain double-dashed line. The first position and the second position are on opposite sides of the needle hole 322 formed in the needle plate 298. The thread cutting solenoid 318 is demagnetized after being excited for a certain period of time, and the roller is disengaged from the cam groove after the movable blade 308 returns to the first position. Even if the thread cutting solenoid 318 is demagnetized, the roller is kept engaged with the cam groove, and after the movable blade 308 returns to the first position,
A mechanism is provided which allows the cam to be disengaged from the cam groove.

This sewing machine has a control device 330 shown in FIG.
Controlled by. The control device 330 has a CPU 33.
2, a computer having a ROM 334, a RAM 336, and a bus 338 for connecting them. An input port 340 is connected to the bus 338, an external storage device 342 including a magnetic disk and a disk drive device is connected to the bus 338, and sewing data is supplied. An output port 344 is also connected to the bus 338, and drive circuits 346, 348, 3 are connected.
50, 352, 354, 356, 358 and the control circuit 360, the X-direction drive motor 34, the Y-direction drive motor 28, the needle bar support case moving motor 68, the sewing machine motor 90, the jump solenoid 124, the thread wiping solenoid 256. The thread cutting solenoid 318 and the display 364 are connected. Further, the ROM 334 stores various programs necessary for sewing.

Next, the operation of the sewing machine thus constructed will be described. When forming a stitch on the work cloth 20 by this sewing machine, the work cloth 20 is held by the cloth holding frame 22 and moved in an arbitrary direction by the work cloth feeding device 38, and the needle bar 70 is moved by the sewing machine motor 90. Is moved up and down, and the balance 130 is rotated. Further, the cloth pressing foot 174 is moved up and down in synchronization with the lifting and lowering of the needle bar 70 and the rotation of the balance 130 by the rotation of the cam groove 240 for driving the cloth pressing foot. As shown in the timing chart of FIG. 1, the cloth presser foot 174 is stopped for a certain period of time while moving from the backward end position to the forward end position, and when the sewing needle 72 comes out of the work cloth 20, it is at the forward end position and the sewing needle 72
Of the work cloth 20 from the work cloth 20 and then move to the backward end position.

The balance thread amount shown in the timing chart of FIG. 1 is the amount of the upper thread 76 pulled up by the balance 130, and the hook thread amount at the time of thread cutting is the case when the upper thread 76 and the lower thread are cut. Is the thread amount required to pass the shuttle through the loop of the upper thread 76, and the non-thread-cutting loop thread amount is for passing the shuttle through the loop of the upper thread 76 when the upper thread 76 and the bobbin thread are not cut. The amount of thread required for

As described above, the forward end position of the cloth presser foot 174 is set to a position slightly above the work cloth 20, and the work cloth 20 does not come into contact with the work cloth 20 at the time of sewing. When there are obstacles such as a hook, a hook, a thick portion, and the like, the cloth presser foot 174 hits those obstacles, and when the obstacle exerts a drag force of a set value or more, the spring 190 is pressed. Is compressed, the presser foot bar 172 rises relative to the elevating member 184, the cloth presser foot 174 gets over the obstacle, and damage to the cloth presser foot 174, buttons, etc. is avoided. Needle bar 1
The structure that allows the 72 and the elevating member 184 to move relative to each other and the spring 190 disposed between them are always in a state of integrally moving the elevating member 184 and the needle bar 172. A relative movement permitting device that permits relative movement of the needle bar 172 with respect to the elevating member 184 when a drag force of 174 or more is applied is configured. The set value can be adjusted by changing the set load of the spring 190.

As described above, the cloth pressing foot 174 can get over the obstacle by compressing the spring 190, but normally, the cloth pressing foot 174 does not contact the work cloth 20, and the lifting member 184 and the support rod 172 are not contacted. Move together and the spring 190 is not compressed. Conventionally, it was necessary to compress the spring in order to raise and lower the cloth presser foot, so there was a problem that load fluctuations occurred on the main shaft based on the reaction force from the springs, causing uneven rotation of the main shaft. In the present embodiment, the cloth presser foot 174
Since it is not necessary to compress the spring 190 in order to move up and down, the rotation unevenness of the main shaft 110 can be reduced.

At the end of sewing, the upper thread 76 and the lower thread are cut and the thread end 252 of the upper thread 76 is wiped by the thread wiping member 268 before the sewing machine motor 90 is stopped. As shown in the timing chart of FIG. 1, first, the thread cutting solenoid 318 is excited (ON) to move the movable blade 308 from the first position to the second position. The movable blade 308 actually starts its forward movement a little later, and the jump solenoid 12 is started before the forward movement starts.
4 is excited and the needle bar 70 is made to jump.

At approximately the same time as the jump of the needle bar 70, the movable blade 308 starts to move forward and rotates from the first position to the second position. Then, the hook 310 catches the lower thread and the upper thread 76 when the movable blade 308 retreats, and the cutting edge 312 and the fixed blade 30.
4 cuts the upper thread 76 and the lower thread in cooperation with each other.

During this time, the sewing machine motor 90 is rotating, but the needle bar 70 jumps and remains at the top dead center of the needle bar, and only the cloth presser foot 174 and the balance 130 are moved up and down. Therefore, when the cloth presser foot 174 is moved to the forward end position, the sewing needle 72 and the cloth presser foot 174 are moved.
A wide space is created between the thread and the thread, and the thread wiping member 268 brushes the thread end 252 in the space.

At the time of thread wiping, the thread wiping solenoid 256 is excited, the thread wiping member 268 is projected to the projecting position, the thread wiping solenoid 256 is demagnetized, and the thread wiping member 268 is moved to the retracted position. Thread clearing member 26
When 8 is moved from the projecting position to the retracted position, the work cloth feeding device 38 moves the cloth holding frame 22,
Work cloth 20 is moved in a direction that helps hook 274 capture thread end 252, ie, to the left in FIG. Even if the upper thread 76 is cut, it sticks in the work cloth 20, and if the work cloth 20 is moved, the thread end 252 can be moved, whereby the thread end 252 is reliably caught by the hook 274. To be done. Thread wiper 2
When 68 moves from the retracted position to the projecting position, the yarn end 25
2 and bend it to the right in FIG.
Even if 52 is out of the movement path of the thread wiping member 268, the thread end 252 is moved to the left as the work cloth 20 moves, and is reliably caught by the hook 274.

Before moving the work cloth 20, the thread end 252 is moved.
May already be in contact with the side surface of the thread wiping member 268. In that case, as the work cloth 20 moves, the thread end 2
There is no problem as 52 is only deflected by the thread wiping member 268.

After the thread end 252 has been wiped by the thread wiping member 268, the sewing machine motor 90 is stopped. This stop time is a time when the upper thread 76 and the lower thread are cut, the cloth presser foot 174 is moved to the retracted end position, and the balance 130 is slightly lowered beyond the balance top dead center. If the needle bar 70
If is not jumped, it should descend a certain distance from the needle bar top dead center at this time, but it does not actually descend.

As described above, the sewing machine motor 90 is operated by the needle bar 70.
Is at the needle bar top dead center and has not moved, and the balance 130 is stopped after the balance top dead center once, the balance 13
A slack is generated in the upper thread 76 hung on 0. Balance 130
Since the upper thread 76 is sufficiently pulled out from the spool when the thread passes the balance top dead center, the upper thread 76 can be removed from the sewing needle 72 even when the balance 130 moves to the balance top dead center again. There is no. In particular, the needle bar 70 is the jump device 12
If the balance 130 passes through the balance top dead center while being retained at the needle bar top dead center by 0, the upper thread 76 pulled out from the spool is not used for forming the stitch, and accordingly, the upper thread 76 You can afford more. Therefore, the balance 1 at the start of sewing
Even when 30 moves to the balance top dead center, the upper thread 76 does not come out from the sewing needle 72. If the balance 130 is stopped without crossing the balance top dead center, the upper thread 76 may be pulled when the sewing machine moves to the balance top dead center at the start of sewing and may be pulled out from the sewing needle 72. Is moved to the balance top dead center and the upper thread 76 is slackened, the upper thread 76 will not come out of the sewing needle 72 even if the balance 130 is moved to the balance top dead center next.

When the sewing machine motor 90 is stopped, the cloth presser foot 174 is at the retracted end position, and there is a large space between the cloth presser foot 174 and the work cloth 20, so that the work cloth 20 must be replaced. It can be done easily. The motion converting device for the needle bar and the motion converting device for the presser foot are connected to the main shaft 110 in parallel with each other, and only the presser foot 174 can be moved while the needle bar 70 is jumped. Since the balance 130 has once slackened the upper thread 76 beyond the top dead center of the balance, the cloth presser foot 174
Regardless of the position of the needle bar 70 or the balance 130, the work cloth 20
This is because it can be stopped at a position suitable for replacement.

As in the conventional case, the cloth pressing foot 174 has the needle bar 70.
Sewing machine motor 90
Is stopped in a state in which both the needle bar 70 and the balance 130 are located as close to the top dead center as possible, a space is secured between the sewing needle 72 and the work cloth 20, and the upper thread 76 is removed from the balance 130. It is necessary to prevent it from coming off, and the cloth presser foot 174 has the needle bar 70 and the balance 130.
Will be stopped at the position determined by the position of
It is difficult to secure a work cloth replacement space. However, in the present embodiment, the needle bar 70 remains at the top dead center of the needle bar, and the balance 130 once slackens the upper thread 76 beyond the top dead center so that the upper thread 76 is sewn at the start of sewing. Since there is no danger of slipping out, it may be stopped at any position between the top dead center and the bottom dead center of the balance, and the cloth presser foot 174 can be stopped at the most suitable position for work cloth replacement. is there.

Further, although the forward end position of the cloth pressing foot 174 can be adjusted according to the thickness of the work cloth 20, it can be adjusted by changing the connecting position of the link 216 to the lever 214. Therefore, unlike the case where the forward end position is defined by the stopper, no collision noise is produced, the operation is quiet, and the cloth presser foot 174 and the like are not impacted, so that the life can be improved.

Further, since the retracting end position does not change even if the advancing end position of the cloth pressing foot 174 is adjusted, the relative position in the vertical direction between the cloth pressing foot 174 and the sewing needle 72 at the retracting end position. The relationship is constant, and the cloth presser foot 174 does not interfere with the threading operation to the sewing needle 72, and the threading can always be performed in the same state.

Further, when the forward end position and the backward end position are changed together without changing the movement amount of the cloth pressing foot 174, the space to be secured for moving the cloth pressing foot 174 becomes large and the sewing machine Becomes larger, and if the forward end position is moved closer to the work cloth 20 side, the retreat end position will also be closer to the work cloth 20 side, and the space for work cloth replacement work will be reduced accordingly, and the replacement work Although it is difficult to remove, such a problem does not occur if the backward end position is not changed.

Further, since the motion converting device for the needle bar and the motion converting device for the sewing material pressing member are connected to the main shaft 110 in parallel with each other, one full rotation of the main shaft 110 can be freely lifted and lowered by the cloth pressing foot 174. It has a high degree of freedom in design. Conventionally, the needle bar holds the cloth presser foot, or the needle bar drives the cam device for raising and lowering the cloth presser foot, but in this case, it is restricted by the movement of the needle bar. Cloth pressing foot 174 for one full rotation of main shaft 110
It cannot be freely used to lift or lower the
4, the movement control device for the needle bar and the movement conversion device for the presser foot are connected to the main shaft 110 in parallel with each other, as in the present embodiment. Since the shape of the foot drive cam groove 240 allows the cloth pressing foot 174 to be temporarily stopped at the forward end position, the degree of freedom in design is high, and the cloth pressing device 170 having excellent usability can be obtained. is there.

Also, the foot support rod 172 is held down while suppressing the movement of the needle bar.
When converting to raising and lowering, it is necessary to install a motion conversion device near the needle bar, but around the needle bar, a balance etc.
Since there are other members, the space is limited, and it is difficult to increase the stroke of the presser foot. On the other hand, if the motion converting device for the cloth pressing foot is connected to the main shaft 110 in parallel with the motion converting device for the needle bar, it is not necessary to provide it in the vicinity of the needle bar, so that the stroke of the cloth pressing foot 174 should be increased. Will be easier.

Further, the thread end portion 252 of the upper thread 76 is adapted to be removed by inserting the thread removing member 268 between the cloth presser foot 174 and the sewing needle 72, which has a thread removing function and is processed. It is possible to obtain a sewing machine at a low cost that allows easy cloth replacement work. The cloth presser foot 174 is moved to the retracted end position, and the thread wiper member 268 is moved to the cloth presser foot 174 and the work cloth 2.
When the needle end support 252 is moved to move the needle bar support case 40 to change the needle bar, the yarn end 252 slips out of the thread wiping member 268. There is. The thread end 252 has the cloth presser foot 17
This is because the thread is wiped by the thread wiper member 268 via 4 and the path becomes longer than in the case where it directly reaches the thread wiper member 268, and the length of the thread end portion 252 is insufficient. Again, it is necessary to provide the cloth presser foot 174 for each of the plurality of needle bars 70. Further, the cloth presser foot 174 is stopped at the forward end position, and the thread wiping member 2
Even when 68 is inserted between the sewing needle 72 and the cloth presser foot 174 to disengage the thread end portion 252, the cloth presser foot motion converting device and the needle bar motion converting device are parallel to each other on the main shaft 110.
If the cloth presser foot 174 is not configured to move even when the needle bar 70 is jumped, the cloth presser foot 1
In order to move 74 to the retracted end position, it is necessary to provide a dedicated cloth pressing foot moving device, which increases the cost.
However, in the present embodiment, the motion converting device for the cloth pressing foot and the motion converting device for the needle bar are connected to the main shaft 110 in parallel with each other, and the cloth pressing foot 174 is moved even when the needle bar 70 is jumped. Since the thread wiper member 268 is made to enter between the cloth pressing foot 174 and the sewing needle 72 to brush the thread end 252, the cloth pressing member is pressed against the plurality of needle bars 70. It is only necessary to provide one foot 174, and a space for exchanging the work cloth can be secured, and an inexpensive sewing machine can be obtained.

When the color of the upper thread 76 is changed next to the replacement of the work cloth 20, as shown in FIG. 2, the sewing machine motor 90 is further rotated once and then the needle bar 70 is rotated.
Are replaced. The needle bar support case 40 is moved and the needle bar 70 is replaced, but at that time, if the cloth pressing foot 174 is at the retracted end position, the sewing needle 72 is in the needle hole 180 of the cloth pressing foot 174. , Needle bar support case 4
Prevents 0 from moving. Therefore, at the time of color change, the sewing machine motor 90 is stopped at the position where the cloth presser foot 174 is between the forward end position and the backward end position and the sewing needle 72 comes out of the needle hole 180 of the cloth presser foot 174, and the cloth presser foot 17
4 does not hinder the movement of the needle bar support case 40.

After the sewing machine motor 90 is stopped, the needle bar support case 40 is moved and the needle bar 70 to be used next is positioned at the sewing position. As described above, the cloth presser foot 174 is colored in a conspicuous color different from that of the peripheral members, so that the sewing position can be clearly recognized by the operator, and the needle bar 70 moved to the sewing position can be easily recognized. The needle bar support case 40 has a number at a position corresponding to each needle bar 70, recognizes the needle bar 70 that has been moved to the sewing position, and based on that, the needle bar 70 of the needle bar support case 40 is identified. By observing the number attached to the corresponding position, it is easy to know what number of the needle bar 70 is moved to the sewing position without counting the needle bar 70, and thus the color of the upper thread 76 is selected. It is possible to easily determine whether or not the needle bar 70 is in the opened state or the needle bar 70 to be used next is located from the needle bar 70 in the sewing position. After the replacement, the sewing machine motor 90 is rotated again, and the cloth presser foot 174 is stopped at the position moved to the retracted end position.

The work cloth 20 is not replaced, and the upper thread 76
When only the color of is changed, the sewing machine motor 90 causes the sewing needle 72 to move from the needle hole 180 of the cloth presser foot 174 after the needle bar 70 is jumped, the thread is cut and the thread is wiped as in the case of changing the work cloth. The needle bar support case 40 is stopped when the needle bar support case 40 is moved out.

In this way, when changing colors, the cloth presser foot 174
Is between the forward end position and the backward end position, and the sewing needle 72
Is stopped at the position where it comes out of the needle hole 180,
It does not hinder the movement of the needle bar support case 40, and
As described above, when the cloth is replaced, the cloth is stopped at the retracted end position, so that a sufficient replacement work space can be secured between the cloth presser foot 174 and the work cloth 20.

By controlling the stop position of the sewing machine motor 90, the cloth presser foot 174 is moved between the backward end position and the forward end position.
The needle bar support case 40 can be stopped at a certain position to allow the needle bar support case 40 to move, and the workability of the work cloth replacement can be ensured.
4 is provided so that when the needle bar support case 40 moves, it moves together with the needle bar 70, and moves with the needle bar 70 to the retracted end position to secure a work cloth replacement space. It is not necessary to provide a plurality of 174, and it is possible to obtain at low cost a sewing machine that can replace the work cloth 20 with good workability.

As is apparent from the above description, in this embodiment, the sewing machine motor 90, the thread trimming device 300 and the jump device 120 of the computer of the control device 330 are used.
The portion for controlling the sewing machine constitutes the control means of the present invention, the sewing machine motor 90 is rotated even after the jump device 120 of the computer is operated, the thread cutting device 300 cuts the upper thread 76, and the balance 130 is placed on top of it. After passing through the dead point,
The portion that stops the sewing machine motor 90 after the cloth presser foot 174 has moved to the retracted end position constitutes the sewing machine motor control means of the present invention.

In the above embodiment, the thread wiping member 26 is used.
Although the yarn end portion 252 of 8 is moved by linearly reciprocating, the yarn end 252 may be moved by reciprocating movement by rotation or unidirectional movement.

Further, in the above embodiment, a large number of sewing needles 72
Each one was attached to the needle bar 70 by the needle hook 73, but only one needle bar was provided for many sewing needles, and the sewing needle used for sewing was provided for the needle bar provided at the sewing position. The present invention can be applied to a sewing machine that is rotated. In this case, the sewing needle holding member such as the sewing needle holder 73 is easily attached to and detached from the needle bar, and the sewing needle holding member is moved with respect to the needle bar.

Further, the present invention can be applied to a sewing machine having only one sewing needle.

Further, in the above-described embodiment, the needle bar separating device is adapted to cause the needle bar 70 to jump from the position disengaged from the engagement body 96 to the needle bar top dead center by the biasing force of the spring 86. However, the needle bar 70 may be separated at the needle bar top dead center.

In addition, the present invention can be implemented in various modified and improved modes based on the knowledge of those skilled in the art without departing from the scope of the claims.

[Brief description of drawings]

FIG. 1 is a timing chart illustrating the operation of a sewing machine that is an embodiment of the present invention.

FIG. 2 is a timing chart for explaining the operation of the sewing machine when changing colors.

FIG. 3 is a perspective view schematically showing an appearance of the sewing machine.

FIG. 4 is a side sectional view showing a protruding end portion of an upper arm of the sewing machine.

FIG. 5 is a perspective view showing a jump device of the sewing machine.

FIG. 6 is a side view showing a cloth pressing device of the sewing machine.

FIG. 7 is a front view showing the cloth pressing device.

FIG. 8 is a view showing a thread wiping device of the sewing machine.

FIG. 9 is a side view showing the yarn wiping device.

FIG. 10 is a front view showing the yarn wiping device.

FIG. 11 is a plan view showing a thread cutting device of the sewing machine.

FIG. 12 is a diagram showing a control device for controlling the sewing machine.

[Explanation of symbols]

 20 Work cloth 38 Work cloth feeding device 70 Needle bar 72 Sewing needle 76 Upper thread 82 Needle bar hug 90 Sewing machine motor 94 Elevating body 96 Engaging body 106 Connecting rod 110 Main shaft 114 Crank lever 130 Balance 144 Yoke-shaped member 148, 150 Lever 154 Balance drive Cam groove 170 Cloth pressing device 174 Cloth pressing foot 184 Elevating member 210 Link 214 Lever 234 Roller 240 Cloth pressing foot driving cam groove 300 Thread cutting device 250 Thread wiping device 252 Thread end portion 256 Thread wiping solenoid 262 Lever 264 link 268 Thread clearing member 330 Control device

Claims (1)

[Claims] 1. A needle bar that holds a sewing needle and can reciprocate in the axial direction, a sewing material pressing member that presses the sewing material, a balance that is rotatable about one axis, and a main shaft that is rotated by a sewing machine motor. , Provided between the main shaft and the needle bar to rotate the main shaft,
A needle bar motion conversion device that converts reciprocating motion between the top dead center and the bottom dead center of the needle bar, and is provided between the main shaft and the sewing material pressing member, and rotates the main shaft by pressing the sewing material. A motion converting device for a sewing material pressing member, which converts the reciprocating motion between an advancing end position for pressing the sewing material of the member and a retracting end position farthest from the advancing end position, and is provided between the spindle and the balance. And a motion converting device for the balance that converts the rotation of the main shaft into a reciprocating motion between the top dead center and the bottom dead center of the balance, and cuts off the motion transmission to the needle bar by the motion converting device for the needle bar, A needle bar separating device that allows the needle bar to stay at the top dead center despite the operation of the motor; and a thread cutting device that cuts an upper thread connected to the sewing material via the balance and the sewing needle, The sewing machine motor, the thread trimming device, and the needle bar In a sewing machine and a control means for controlling the release device, while connected to the main shaft of said sewing material holding member for motion converter and the needle bar for motion converter each other in parallel,
In the control means, after rotating the sewing machine motor even after operating the needle bar separating device, after the thread cutting device cuts the upper thread, the balance has passed through its top dead center, A sewing machine including a sewing machine motor control means for stopping the sewing machine motor when the sewing material pressing member moves to the retracted end position.