JPH0570481U - Sewing machine bobbin bobbin slip prevention device - Google Patents

Abstract

(57) [Summary] [Object] The present invention is capable of reliably preventing the idle thread of the bobbin bobbin during the thread cutting operation without adversely affecting the stitch forming operation during the sewing operation. The purpose is to provide a prevention device. According to the present invention, the picker 12 and the picker stopper 13 which constitute the bobbin pressing mechanism 16 are advanced in conjunction with the movable blade 11 of the thread trimming mechanism, and the lower thread bobbin 5 housed in the bobbin case 4 is braked. The holding member moving mechanism (20 to 25, 20 to 25, which operates in conjunction with the thread cutting mechanism until the movable blade moves back and cuts the thread
41, 41a, 42) so that the holding member 17 is projected to keep the picker stopper and the picker constituting the bobbin pressing member in the advanced position, and after the thread cutting operation is completed, the holding member is retracted to return the bobbin pressing member. The lower thread bobbin is released from the braking operation.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a bobbin thread bobbin idling prevention device mounted on a sewing machine hook, and more particularly to a bobbin thread bobbin idling prevention device that prevents a bobbin thread bobbin from idling during a thread cutting operation of a thread cutting mechanism provided in a sewing machine. ..

[0002]

[Prior Art]

 Currently, the sewing machine is equipped with a thread trimming mechanism that automatically cuts the sewing thread (upper thread and bobbin thread) according to the thread trimming command output from the synchronizer attached to the sewing machine spindle at the end of the sewing operation. It has been known. As a thread trimming mechanism, generally, a movable blade provided below the needle plate reciprocates horizontally in response to a thread trimming command, and catches the thread that is vertically threaded from the needle plate across the sewing machine hook. The needle is pulled out to a cutting position lateral to the needle drop position, and both yarns are cut between the fixed blade provided at this cutting position.

Of the sewing thread thus cut, the lower thread is wound around a lower thread bobbin that is rotatably mounted on a sewing machine via a bobbin case, as is well known. During the thread pulling operation of the blade, the lower thread is fed by the rotation of the lower thread bobbin. At this time, it is desirable that the bobbin thread be fed from the bobbin thread bobbin without excess or deficiency in accordance with the stroke of the drawing operation of the movable blade. However, the bobbin thread bobbin may rotate more than necessary due to inertia force during rotation. In other words, there is a possibility that the bobbin may spin idly, and in that case, the bobbin thread that is unnecessarily fed out may get entangled in the bobbin case, or the bobbin thread may loosen during cutting, resulting in poor sharpness. Occurs.

In order to prevent such a bobbin thread bobbin from spinning, a spinning prevention device as shown in FIG. 13A is currently proposed and implemented. In this device, an annular leaf spring b as shown in FIG. 2B is provided at the bottom of the inner hook a, and the leaf spring is attached to the collar of the bobbin thread bobbin d attached to the inner hook a together with the bobbin case c. The lower thread bobbin d is braked by pressing b.

[0005]

[Problems to be solved by the device]

 However, in the above-described conventional slip prevention device, the leaf spring b is configured to constantly brake the bobbin thread bobbin d housed in the bobbin case c, so that the thread tension is weakened and sewing is performed with low tension. However, there was a problem that good seams were not formed. That is, low-tension sewing is performed by weakening the needle thread tension with a thread tensioner or the like, but in this case as well, a certain amount of braking is applied to the bobbin thread bobbin, which acts as bobbin thread feeding resistance. A tension imbalance occurs between the thread and the bobbin thread, and the problem arises that the connection point of both threads is exposed from the bottom surface of the cloth and the quality of the sewn product is significantly degraded.

This invention has been made in view of the above problems, and in a sewing machine capable of reliably preventing idling of a bobbin thread bobbin during a thread cutting operation without adversely affecting a stitch forming operation during a sewing operation. An object of the present invention is to provide a bobbin bobbin idling prevention device.

[0007]

[Means for Solving the Problems]

 This invention is a sewing machine in which a reciprocating movable blade captures and pulls out the sewing machine thread to cut the thread, which is detachably attached to the sewing machine hook and internally rotates a bobbin thread bobbin. A hollow cylindrical bobbin case for movably housing, an opening formed in this bobbin case, and an opening / removal provided for the opening of the bobbin case, and when the movable blade moves forward, it moves to the advanced position. Bobbin pressing mechanism that has a bobbin pressing member that presses the bobbin pressing bobbin with pressure, a biasing means that biases the bobbin pressing member toward the retracted position, and the bobbin pressing member can be retracted in and out of the forward / backward movement path. A holding member for holding the bobbin pressing member in the advanced position against the biasing means when protruding, and a holding member moving mechanism for retracting the holding member in conjunction with the reciprocating movement of the movable blade. , In which at least the movable blades are so as to hold the holding member until the return to the forward position or disconnected from the position to the protruding position by the holding member movement mechanism.

[0008]

[Action]

 In this invention, when the movable blade starts to move forward, the movable blade comes into contact with the movable blade to move the bobbin pressing member to the advanced position, and the rotation of the bobbin thread bobbin housed in the bobbin case is restricted. After that, the movable blade starts to move back to perform the operation of catching / pulling out / thread cutting the sewing machine thread, and then the contact state with the bobbin pressing member is released. At this time, when the movable blade is returned, the holding member moving mechanism holds the bobbin pressing member in the advanced position by projecting the holding member in the forward / backward movement path of the bobbin pressing member. It is released by returning to the position and cutting the thread. For this reason, the bobbin thread bobbin does not idle during the bobbin thread catching / pulling-out operation by the movable blade, and the braking force is not unnecessarily applied during the sewing operation. It is possible to form good seams.

[0009]

【Example】

 An embodiment of the invention will be described below with reference to FIGS. FIG. 1 is a plan view showing the peripheral construction of a sewing machine hook in this embodiment, and FIG. 2 is a side view of the one shown in FIG. In the figure, 1 is a hook base fixed to a sewing machine frame in a sewing machine bed, and 2 is a horizontal hook as a sewing hook supported by the hook base 1. The horizontal hook 2 comprises an outer hook 2a having a sword tip 2a1 for catching a needle thread loop, and an inner hook 2b fitted in the outer hook 2a. The outer hook 2a is supported vertically on the hook base 1. It is fixed to a rotary hook shaft (not shown), which rotates in conjunction with the lower shaft 3 of the sewing machine that is horizontally supported by the rotary hook 1 so that it rotates on a horizontal plane together with the lower hook shaft 2a1. The needle thread loop is captured by and the binding between the upper thread and the lower thread is formed.

Reference numeral 4 denotes a bobbin case detachably attached to the inner hook 2b of the horizontal hook 2. The bobbin case 4 has a hollow cylindrical shape, and a bobbin thread 5 around which a bobbin thread is wound can be rotatably housed therein (see FIG. 4). An opening 4a is formed on the peripheral surface of the bobbin case 4, and a pressing piece 6 fixed to the peripheral surface of the bobbin case 4 in a cantilever spring shape is inserted into the opening 4a. (See FIGS. 3 and 4). Due to its own elastic force, the pressing piece 6 always has the pressing portion 6a provided on the free end side in pressure contact with the groove portion 4b formed on the inner peripheral surface of the bobbin case 4, and the intermediate portion 6b. It is designed to project from the outer peripheral surface of. A fixed blade mounting base 7 is fixed to the pot base 1, and a fixed blade 8 having a blade portion 8a is fixed to the fixed blade mounting base 7. The fixed blade 8 is provided at a position where it does not interfere with a sewing needle that moves up and down, and its blade portion 8a is arranged at a predetermined thread cutting position.

Reference numeral 9 denotes a movable blade drive shaft that is rotatably supported in a state perpendicular to the pot base 1. The base end of the movable blade 11 is fixed to the movable blade drive shaft 9 via a movable blade mount 10 as shown in FIG. The movable blade drive shaft 9 is interlocked with a thread cutting drive mechanism (shown in FIG. 10), which will be described later, which operates according to a thread cutting command. Is becoming Further, the movable blade 11 is formed with a thread catching portion 11a and a blade portion 11b at its tip (in the figure, a pair of thread catching portion 11a for the upper thread and lower thread for the lower thread 11b and the blade portion 11b). , But each may be one.) When the movable blade 11 is in the initial position, the thread cutting drive mechanism is inoperative. When the movable blade drive shaft 9 rotates, the movable blade 11 rotates counterclockwise, and the tip of the movable blade 11 crosses between the horizontal hook 2 and the needle plate located above it. When the machine moves forward horizontally, it separates the sewing thread (bobbin thread and upper thread) from the needle plate to the horizontal hook at the time of the forward movement, and catches it by the thread catching section 11a when returning in the clockwise direction. The sewing machine thread is cut out by the cooperation of the blade portion 8a of the fixed blade 8 and the blade portion 11b of the movable blade 11 at the cutting position. A thread cutting mechanism is constituted by the above 7 to 11 and a thread cutting driving mechanism 30 described later.

A picker 12 is supported by the movable blade drive shaft 9 so as to be rotatable in the horizontal direction, and has a vertically bent shape. By rotating the picker 12 about the movable blade driving shaft 9, the tip portion 12a moves forward and backward with respect to the pressing piece 6 provided on the peripheral surface of the bobbin case, and presses and releases the intermediate portion 6b. (See FIGS. 3 and 4). Reference numeral 13 denotes a picker stopper which is bent upward and downward, is supported by the movable blade drive shaft 9 so as to be rotatable in the horizontal direction, and is positioned between the upper and lower surfaces of the picker 12. An abutting portion 13a and a locking portion 13b which are bent upward are formed at the side end of the picker stopper 13, and the picker stopper 13 is stretched between the picker stopper 13 and the picker stopper 13. The urging force of the pulling spring 14 opposes the side surface of the picker 12.

Reference numeral 15 is a pulling spring stretched between the picker stopper 13 and the hook base 1, and the abutting portion 13a of the picker stopper 13 of the movable blade mounting base 10 is shown in FIG. The picker stopper 13 is biased so as to come into contact with the side surface. The picker 12 and the picker stopper 13 compose a bobbin pressing member, and the pickers 12 to 15 compose a bobbin pressing mechanism 16.

Reference numeral 17 denotes a picker holding plate as a holding member provided on the side of the bobbin pressing mechanism 16, and has a pair of bent locking arms 17a and 17b. This picker holding plate 17 is rotatably attached to the side surface of a support base 18 fixed to the pot base 1 by a step screw 19, and the range of rotation is such that the engaging arm 17b and the support base 18 contact each other. The pulling bar 20 stretched between the hook base 1 and the hook base 1 always urges the locking arm 17b against the side of the support base 18 in the direction of pressure contact. (See Figure 9). When the locking arm 17b and the support base 18 are in contact with each other, one locking arm 17a projects into the horizontal movement path of the locking portion 13b of the picker stopper 13, and vice versa. When one of the locking arms 17a is in contact with the upper surface of the support base 18 (see FIG. 8), the locking arm 17a is located at the non-interference position below the locking portion 13b of the picker topper 13. It is supposed to be retained. Then, the movable blade 11 and the bobbin pressing members 12 and 13 are rotated by the counterclockwise rotation of the movable blade drive shaft 9, and the picker holding plate 17 is also rotated.

Reference numeral 21 denotes an actuating rod for rotating the picker holding plate 17, which is supported by a guide member 22 fixed to the pot base 1 so as to be vertically movable below the locking arm 17b of the picker holding plate 17. .. Reference numeral 23 denotes a push spring interposed between the upper end portion 21a of the operating rod 21 and the guide member 22, and applies an upward biasing force to the operating rod 21 to lock the upper end portion 21a of the picker holding plate 17. It is designed to be pressed against the arm 17b. Further, since the upward biasing force applied from the push spring 23 to the locking arm 17b via the actuating rod 21 is set to be larger than the biasing force applied by the pulling spring 20, The stop arm 17b is always pushed upward against the pulling spring 20, and the other locking arm 17a is pressed against the upper surface of the support base 18 as shown in FIG.

Reference numeral 24 denotes an operating rod arm fixed to the lower end portion of the operating rod 21, to which the inner wire 41 a of the arm moving double wire 41 held by the wire mounting plate 25 is fixed. There is. The double wire 41 for arm movement is arranged from the wire mounting plate 25 to a wire actuating arm 42 described later, and the inner wire 41a is moved in the double wire 41 by the actuation of the wire actuating arm 42. However, the operating rod arm 24 is moved up and down. The holding member moving mechanism is composed of the above 20 to 25 and 41, 41a and 42.

By the way, various types of thread trimming drive mechanisms for rotating the movable blade drive shaft 9 described above have been proposed and implemented at present, and any device can be applied to the present invention. Then, the one shown in FIG. 10 is used. The thread trimming drive mechanism 30 shown here has substantially the same configuration as that shown in Japanese Patent Publication No. 58-11239, and the movable blade drive shaft 9 is rotated as follows. ing.

That is, a thread cutting cam 32 having a cam groove 32a formed on its peripheral surface and a connecting cam 33 are fixed to the lower shaft 3 which rotates in conjunction with the sewing machine main shaft 3. Further, a follower 35 is supported on a support shaft 34a supported by a support 34 fixed to the lower surface of the bed so as to be vertically movable and rotatable, and is constantly urged downward by a push spring 35s (FIG. 11). reference). A roller 35c which can be inserted into and removed from the cam groove 32a is pivotally attached to a roller shaft 35d on one arm portion 35a of the driven body 35. By moving the driven body 35 up and down, the roller 35c is moved. It is designed to be inserted into and removed from the cam groove 32. Then, the other arm portion 35b of the driven body 35 is connected to one end portion of an L-shaped link 37 fixed to the movable blade drive shaft 9 via ball connecting rods 36a and 36b.

Further, a solenoid 39 is provided on the side of the thread trimming cam 32, and when a predetermined thread trimming command is output, the plunger 39a moves in the direction A in the figure. .. When the plunger 39a moves in the direction A, the bifurcated connecting body 38 attached thereto moves in the same direction, and the connecting roller 38a1 provided on the leg portion 38a above the connecting body 38 is connected to the connecting roller 38a1. It is located in the movement path of the cam 33. Here, when the rotation of the lower shaft 3 is started in conjunction with the main shaft of the sewing machine, the connecting cam 33 rotates accordingly, and the end face pushes up the connecting roller 38a1 to move the connecting body 38 to the shaft of the plunger 39a. Rotate to the center. As a result, the leg portion 38a of the connecting body 38 pushes up the driven body 35 upward against the biasing force of the push spring 35s, and the roller 35c provided on the driven body 35 is fitted into the cam groove 32a of the thread cutting cam 32. Let

When the thread cutting cam 32 further rotates in this state, the roller 35c is first pushed out to the left according to the shape of the cam groove 32a, and the driven body 35 rotates clockwise in the figure. As a result, the L-shaped link 37 and the movable blade drive shaft 9 are both rotated in the counterclockwise direction by being pulled by the arm portions 35a and 35b, and the movable blade 11 moves forward horizontally from the initial position to the forward movement start position. To do.

Thereafter, when the thread cutting cam 32 further rotates, the roller 35c is pressed to the right by the cam groove 32a, and the driven body 35 rotates counterclockwise. As a result, the L-shaped link 37 is pressed via the arms 35a and 35b, and is rotated clockwise with the movable blade drive shaft 9 to move the movable blade 11 back. The movable blade 11 returns to the cutting position immediately before the lower shaft 3 rotates once, and the driven body 35 moves downward at the time of one rotation. As a result, the roller 35c is removed from the cam groove 32a and returns to the initial state. As described above, in the thread trimming mechanism applied to this embodiment, the rotation of the lower shaft 3 is used to rotate the movable blade drive shaft 9.

Further, the thread cutting drive mechanism 30 is interlocked with a wire operation arm 42 for moving the above-mentioned double wire 41 for arm movement. That is, a wire actuating arm 42 as shown in FIGS. 11 and 12 is fixed to the support shaft 34a of the thread cutting drive mechanism 30, and the inner wire 41a of the double wire 41 is fixed to this arm 42. Is fixed. A locking body 43 is rotatably supported by a step screw 44 on a support body 34 that supports the arm 42. The locking body 43 is formed with a protruding portion 43a and a locking step portion 43b that bend upward, and the upper end 43b1 of the locking step portion 43b is always fixed by the pulling spring 43s. It is urged to press against the lower surface. In addition to the arm moving double wire 41, a thread tension double wire 50 for opening and closing a known thread tension device (not shown) is connected to the wire actuating arm 42 (see FIG. 12). ).

Next, the operation will be described based on the above configuration. In the initial state before the thread cutting operation, the tip portion 12a of the picker 12 is separated from the peripheral surface of the bobbin case 4 held by the horizontal hook 2 as shown in FIG. 8, and the picker holding plate 17 is , The locking arm 17a is held at a position where it does not interfere with the picker stopper 13.

Here, when the thread trimming drive mechanism 30 operates as described above by the thread trimming command output after the end of the sewing operation and the movable blade drive shaft 9 rotates in the forward direction (counterclockwise direction), Along with this, the movable blade mount 10 and the movable blade 11 start moving forward. At this time, since the contact portion 13a of the picker stopper 13 is pressed against the movable blade mounting base 10 by the action of the pulling spring 15, it is pressed by the mounting base 10 and the picker topper 13 also resists the pulling spring 15. The movable blade drive shaft 9 as a center, and the forward movement is also transmitted to the picker 12 via the pulling spring 14, so that both the pickers 12 also move about the movable blade drive shaft 9. Move. Immediately before the movable blade 11 reaches the most forward movement position, the tip portion 12a of the picker 12 abuts on the intermediate portion 6b of the pressing piece 6 and then presses it to move the pressing portion 6a of the pressing piece 6 onto the bobbin. The lower thread bobbin 5 housed in the case 4 is pressed against the collar portion. As a result, the rotation of the lower thread bobbin 5 is braked.

On the other hand, the forward movement of the movable blade 11 is performed by moving the roller 35c leftward in FIG. 10 as described above. In this movement, the roller shaft 35d supporting the roller 35c is moved. It moves from the position shown by the solid line in FIG. 12 to the position shown by the chain double-dashed line, during which it abuts against the wire working arm 42 and presses it, moving the wire working arm 42 to the position shown by the chain double-dashed line. Rotate. Therefore, the inner wires 41a and 50a of the two double wires 41 and 50 are pulled by the wire actuating arm 42 to move, and the actuating rod 21 fixed to the actuating rod arm 24 connected to the wire 41 is It is pulled down against the push spring 23. As a result, the upward pushing force applied to the locking arm 17a of the picker holding plate 17 by the operating rod 21 is released, and the picker holding plate 17 is rotated by the urging force of the pulling spring 20 to lock the locking arm 17a. Comes into contact with the lower surface of the picker stopper 13 located above it.

After that, when the picker stopper 13 together with the movable blade 11 reaches the forward movement position and retracts from above the locking arm 17a, the locking arm 17b moves further upward and the locking portion 13b of the picker topper 13 is moved. Project into the horizontal movement path of. That is, the picker topper 13 is held at a position that prevents the backward movement of the picker topper 13 (see the chain double-dashed line in FIG. 2; Further, when the wire operating arm 42 moves to the position shown by the chain double-dashed line in FIG. 12, the contact state between the lower surface of the wire operating arm 42 and the upper end portion 43b1 of the locking body 43 is released, and the pulling operation is performed. The upper end portion 43b1 of the locking body 43 is engaged with the end portion of the wire operating arm 42 by the biasing force of the spring 43s. By this engagement, the wire actuating arm 42 is locked at the position shown by the chain double-dashed line in FIG. At this time, in the thread tension regulator, since the wire tension double wire 50 is pulled by the wire actuating arm 42, the upper thread is in the open state.

After that, the roller shaft 35d starts the backward movement from the position shown by the alternate long and short dash line in FIG. 12 to the position shown by the solid line, and the movable blade 11 also starts the backward movement at this time. As described above, since the locking portion 13b of the picker stopper 13 is locked by the locking arm 17a of the picker holding plate 17, the picker 12 is also prevented from returning, and the picker 12 presses the pressing piece 6, Continue braking the bobbin thread bobbin 4. Immediately before the lower shaft 3 makes one revolution along with the main shaft of the sewing machine, the movable blade 11 returns to the cutting position, and cuts the drawn and drawn lower thread and upper thread in cooperation with the fixed blade 8. .. In this way, by braking the lower thread bobbin 5 during the thread cutting operation, the inertial force of the lower thread bobbin 5 that rotates with the thread withdrawing operation of the movable blade 11 is suppressed, and the idle thread of the lower thread bobbin 5 rotates. Is prevented.

Further, when the lower shaft 3 makes one rotation, the driven body 35 descends, and the roller 35c of the driven body 35 is withdrawn from the cam groove 32a of the thread cutting cam 32, while the driven body 35 of the locking body 43 is removed. The protrusion 43a is pushed downward to release the engagement between the locking step 43b and the wire operating arm 42. As a result, the operating rod 21 held in the lowered position via the inner wire 41a is pushed up by the urging force of the push spring 23, and the upper end portion 21a thereof pushes up the locking arm 17b of the picker holding plate 17. .. As a result, the one locking arm 17a of the picker holding plate 17 is released from the locking portion 13b of the picker stopper 13, and the locked state with respect to the picker stopper 13 is released.

When the locked state with respect to the picker stopper 13 is released, the picker topper 13 returns to the initial position by the urging force of the pulling spring 15, and the picker 12 also returns to the initial position with the pressing piece. Release the pressure on 6. As a result, the braking applied to the lower thread bobbin 5 is released. As described above, in this embodiment, the bobbin thread bobbin is braked only during the thread trimming operation period and released at the time of sewing, so that the bobbin thread tension is maintained even when low tension sewing is performed. It is possible to form a contact at an appropriate place of cloth pressure without becoming excessive.

In the above-described embodiment, the picker 12 brakes the bobbin thread bobbin 5 via the pressing piece 6 provided on the bobbin case 4, but the pressing piece 6 is removed and the picker 12 is removed. It is also possible that the bobbin case 4 is inserted through the opening 4a and the picker 12 is directly brought into pressure contact with the bobbin bobbin for braking. Further, in this embodiment, the bobbin pressing mechanism 16 is composed of the picker 12 and the picker stopper 13 which are connected by the pulling spring 14 so as to absorb the impact at the time of contact with the pressing plate 6. It is also possible to integrally configure 12 and the picker stopper 13 by a single member. In this case as well, the intended purpose of applying and releasing the braking force to the bobbin bobbin can be achieved, and as a bobbin pressing member. It is not limited to those shown in the above embodiments.

The present invention can also be applied to a two-needle sewing machine in which two horizontal hooks are arranged side by side. That is, when applied to a two-needle sewing machine, members such as the bobbin pressing mechanism 16 and the holding member 17 are symmetrically provided corresponding to each horizontal hook, and the double wire connected to each holding member is used as described above. It may be connected to the wire actuating arm 42 in the same manner as in the embodiment. That is, in this case, three wires are connected to the single wire actuating arm 42 in addition to the wires connected to the thread tension regulator. Further, the present invention can be applied not only to a sewing machine using a horizontal hook but also to a sewing machine having a vertical hook, and the present invention is not limited to the above embodiment.

[0032]

As described above, in the lower thread bobbin idling prevention device of the sewing machine according to the present invention, the bobbin pressing member is advanced in association with the movable blade of the thread trimming mechanism, and is stored in the bobbin case. In addition to braking the bobbin thread bobbin, the bobbin pressing member is kept in the advanced position by the holding member until the movable blade retreats and cuts the thread. The inertial force generated in the bobbin bobbin is suppressed by the braking force of the bobbin pressing member, and the bobbin thread can be reliably prevented from idling. After the thread trimming operation, the holding member releases the bobbin pressing member and the bobbin pressing member retracts to release the braking applied to the bobbin thread bobbin, so that the bobbin thread tension becomes excessive during the sewing operation. Moreover, the connecting point between the upper thread and the lower thread can be formed at an appropriate position within the cloth thickness. Further, the holding member moving mechanism for moving the holding member is configured to be interlocked with the thread trimming mechanism, and since it does not require an actuator or a control device, it can be made compact and inexpensive. The operation is also reliable.

[Brief description of drawings]

FIG. 1 is a schematic plan view showing an embodiment of the present invention.

FIG. 2 is a side view of what is shown in FIG.

FIG. 3 is a perspective view showing a bobbin case and a pressing piece in the embodiment.

4 is a perspective view showing a bobbin case, a pressing piece and a bobbin thread bobbin shown in FIG. 3. FIG.

FIG. 5 is a plan view showing a mounting state of the bobbin pressing mechanism and the movable blade in the above embodiment.

6 is an X-ray arrow view of what is shown in FIG. 5. FIG.

7A is a perspective view of the bobbin pressing mechanism shown in FIG. 5, FIG. 7B is a perspective view showing a picker in FIG. 7A, and FIG. 7C is a picker shown in FIG. It is a perspective view showing a stopper.

8 is a perspective view showing an initial state of the picker holding plate shown in FIG. 7 and FIG.

9 is a perspective view showing a state of each member shown in FIG. 8 at the time of forward movement.

FIG. 10 is a plan view of the thread trimming drive mechanism according to the above embodiment as seen from the top surface of the bed.

11 is a partial vertical cross-sectional side view showing an attached state of the driven body shown in FIG. 10, a wire operation arm, and the like.

12 is a plan view of the wire actuating arm and the like shown in FIG.

13 (a) is a vertical sectional side view showing a conventional bobbin thread idling prevention device for a sewing machine, and FIG. 13 (b) is a plan view showing the leaf spring shown in FIG. 13 (a).

[Explanation of symbols]

 2 horizontal hook (sewing hook) 4 bobbin case 5 bobbin thread bobbin 6 pressing piece 8 fixed blade 11 movable blade 30 thread cutting drive mechanism 12 picker 13 picker stopper 16 bobbin pressing mechanism 15 tension spring (biasing means) 17 picker holding plate ( Holding member) 42 wire operation arm

Claims (1)

[Scope of utility model registration request] 1. A fixed blade provided at a predetermined sewing thread cutting position below the throat plate and a sewing thread positioned between the throat plate and the sewing hook to reciprocate from an initial position in response to a predetermined thread cutting command. A sewing machine having a thread cutting mechanism having a movable blade that captures and pulls out and cuts a sewing thread in cooperation with the fixed blade, the sewing machine being detachably provided to the sewing machine hook and having a bobbin bobbin inside thereof. A hollow cylindrical bobbin case that is movably accommodated, an opening formed in the bobbin case, and a movable blade that moves forward and backward with respect to the opening of the bobbin case and moves to an advanced position when the movable blade moves forward. A bobbin pressing mechanism having a bobbin pressing member that presses the bobbin bobbin, an urging unit that urges the bobbin pressing member toward a retracted position, and a bobbin pressing member that is retractable with respect to an advancing and retracting movement path of the bobbin pressing member. Be A holding member for holding the bobbin pressing member in the advanced position against the biasing means at the time of protrusion and a holding member moving mechanism for moving the holding member in and out in association with the reciprocating movement of the movable blade are provided. A mechanism interlocks with the thread cutting mechanism, and holds the holding member in the protruding position at least until the movable blade returns from the forward movement position to the cutting position, and a lower thread bobbin idling prevention device for a sewing machine. ..