JPS6042745B2 - Bobbin thread replenishment device for lockstitch sewing machines - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a lockstitch sewing machine, and more particularly to a bobbin thread replenishing device for replenishing the bobbin with thread from the needle side.

Prior Art Conventionally, as this type of device, for example,
There is one described in the 0876 publication.

When refilling the bobbin with thread in this device,
When the selection member is manually operated, the protrusion of the selection member is placed adjacent to the passageway between one end of the spring support arm on the bobbin case and the inner edge of the cutout hole. When the sewing machine is operated in this state, the thread carried on the needle is caught by the thread ring catching beak of the thread ring catcher, and the fixed end side limb of the needle thread ring is forcibly bent by the protrusion. Later, the needle thread loop is introduced into the bobbin case via the thread inlet on the spring support arm. However, in this conventional configuration, the needle thread ring is forcibly bent, which not only applies more contact resistance than necessary to the needle thread ring, but also causes the spring support arm, notch hole, and selection Since the protrusions of the members are arranged close to each other to form a path for introducing the needle thread ring into the bobbin case, the machining accuracy and assembly accuracy of these parts is high, and each part is accurately placed in a predetermined position. The drawback was that the need arose and manufacturing costs rose. Purpose This invention was made in order to eliminate the above-mentioned defects, and its purpose is to provide a cover on the bobbin case to allow the needle thread ring to enter the bobbin case when performing a bobbin thread replenishment operation. It is an object of the present invention to provide a bobbin thread replenishing device for a lockstitch sewing machine that can be manufactured at low cost and allows the needle thread ring to enter the bobbin case reliably and smoothly by opening the notch.

EXAMPLE Below, a first example embodying this invention is shown in FIGS. 1A and b.
- Explaining according to FIG. 5, as shown in FIGS. 1A, b and 2, a throat plate 2 and a slide plate (not shown) are respectively attached to the upper surface of the bed portion 1a of the sewing machine frame 1. It is worn.

A support tube 4 extending in the vertical direction is fixed to the center of a bracket 3 fixed in the bed portion 1a below the throat plate 2, and an operating shaft 6 having a disk 5 at the upper end is attached to the support tube 4 for vertical movement and vertical movement. It is rotatably penetrated. Engagement protrusions 7 and 8 are provided on the outer periphery and upper surface of the disk 5, respectively. The thread ring catcher 9 is formed into a substantially short cylindrical shape with an open bottom, and a lace portion 10 and a thread ring catching beak 11 are formed on the inner surface of the annular peripheral wall thereof. A screw gear 12 is located at the center of the lower surface of the thread ring catcher 9.
The screw gear 12 has a center hole 1 which is formed in a protruding manner and opens at the center of the bottom of the thread ring catcher 9 at the axis of the screw gear 12.
3 is provided through the support cylinder 4, and the screw gear 12 is fitted to the outer peripheral surface of the shaft cylinder of the support cylinder 4 through the center hole 13 thereof.

A locking groove 14 extending in the vertical direction is formed in the upper part of the inner wall of the center hole 13 of the screw gear 12, and the engagement protrusion 7 on the outer periphery of the disk 5 engages with the locking groove 14 so as to be able to move up and down. In this state, the operating shaft 6 rotates integrally with the thread ring catcher 9. A lower shaft 16 having a screw gear 15 is rotatably supported in front of the bracket 3, and the screw gear 15 is meshed with the screw gear 12). When the lower shaft 16 rotates, the thread ring catcher 9 and the operating shaft 6 are moved in synchronization with the vertical reciprocating movement of the needle 17 attached to a needle bar (not shown) via the screw gears 15 and 12. It is designed to be rotated counterclockwise as shown in Figures 1A and 1B. A flange portion 19 is formed on the outer periphery of the bobbin case 18 having a substantially cylindrical shape.
The bobbin case 18 is housed in the thread ring catcher 9) in a state where it is engaged with the thread ring catcher 9) from above.

A needle drop groove 19a is formed in this flange portion 19. A thread carrying bobbin 20 is rotatably accommodated in a bobbin accommodating portion 18a formed at the center of the bobbin case 18. A plurality of recesses 21a are formed in the lower surface of the lower flange 21 of the bobbin 20, and a recess 22a is formed in the center of the upper flange 22 of the bobbin 20. A slit 22b is formed for introducing the yarn. Then, as shown by the solid line in FIG. 2, the operating shaft 6 was moved upward, and the lower shaft 16 was rotated with the engaging protrusion 8 on the disc 5 disposed within the recess 21a. Sometimes, the operating shaft 6 is rotated via the screw gears 15, 12, the thread ring catcher 9, the locking groove 14, and the engagement protrusion 7 on the outer periphery of the disc 5, and the engagement protrusion 8 on the disc 5 is moved into the recess. The bobbin 20 is rotated integrally with the thread ring catcher 9 by engaging with the inner wall of the bobbin 21a. Further, a bobbin rotation mechanism is constituted by the operating shaft 6, the thread ring catcher 9, the screw gears 12, 15, and the like. Below the throat plate 2, a support plate 23 is fixed on the boss 3b of the bracket 3, and three anti-floating pieces 24 screwed onto the support plate 23 fit into the locking groove of the bobbin case 18. 25 is loosely fitted. This prevents the bobbin case 18 from floating during operation of the sewing machine. Further, on the bracket 3 at the rear of the screw gear 12, a regulating member body 27 having a pair of regulating pieces 26 is provided.
is swingably supported in a horizontal plane by a shaft 27a. As the thread ring catcher 9 rotates, the regulating member 27 swings, and the regulating pieces 26 alternately engage with the locking grooves 28 of the bobbin case 18, thereby regulating the rotation of the bobbin case 18. be done. A rotating shaft 29 is rotatably inserted into the right side extension 3a of the bracket 3, and a substantially L-shaped selection member 30 is fixed at its base end to its upper end. The selection member 30 is located between a first position for the stitch forming operation shown in FIG. It is designed so that it can be rotated. A protrusion 31 that can enter the recess 22a of the bobbin 20 at a small distance is formed at the tip of the selection member 30.
1 is provided with a thread cutting section 31a. At approximately the center of the selection member 30, a pin 32 serving as an operating member is provided to protrude downward. On the lower surface of the bracket 3, a member 33 is fixed to the lower end of the rotation shaft 29 and is rotatable integrally with the selection member 30, and a pair of engagement recesses 33a and 33b are formed on the side edges of the member 33, and a pair of engagement recesses 33a and 33b are formed on the side edges of the member 33, and The cam surface 33c located between the recesses 33a and 33b, the continuous equal radius surface 33d of one engagement recess 33a, and the arcuate groove 3 on the lower surface of the bracket 3
4 are respectively formed with locking protrusions 35 that can be engaged with each other.

Adjacent to this cam body 33, on the lower surface of the small bracket 3, a linking member 36 formed by bending a plate spring material is rotatably supported, and is supported by a tension spring 37 counterclockwise in FIGS. 3A and 3B. It is urged to rotate in the direction. A V-shaped bent piece 38 that engages with the side edge of the cam body 33 is formed at one end of the linking member 36, and an extending piece 39 having an inclined surface 39a is formed at the other end. This extending piece 39 has a round hole 39b through which the large-diameter portion 6a of the operating shaft 6 is inserted, and the round hole 39b.
b, and is formed in an arc shape around the rotation center of the linking member 36, and has an elongated hole 39c through which the small diameter portion 6b of the operating shaft 6 is inserted, and follows the cam surface 33c of the cam body 33. The linking member 36 is arranged so that the small diameter portion 6b of the operating shaft 6 is always inserted into the elongated hole 39c within the rotation range of the linking member 36. Further, the rotation shaft 29, the cam body 33, the linking member 36, and the like constitute a linking mechanism that links the bobbin rotation mechanism and the selection member 30. When the selection member 30 is placed in the first position shown in FIG. 1a, the bending piece 38 of the linking member 36 is aligned with the equiradial surface of the cam body 33, as shown in FIG. 3a.
3d, the linkage mechanism is placed in the inactive position. As a result, the actuating shaft 6 extends its small diameter portion 6b through the elongated hole 39c.
The connecting member 36 is moved downwardly along the inclined surface 39a of the connecting member 36, and its operating shaft 6 is set to the inactive state shown by the chain line in FIG. Further, when the selection member 30 is rotated clockwise in FIG. 1a and the selection member 30 is placed in the second position shown in FIG. 1b, the linking member is rotated as shown in FIG. 36 bent pieces 38 are engaged with the other engagement recess 33b of the cam body 33, and the linkage mechanism is placed in the operating position. As a result, the small diameter portion 6b of the actuating shaft 6 is connected to the linking member 3.
6, the operating shaft 6 is moved upward along the inclined surface 39a, and the operating shaft 6 is inserted into the second long hole 39c.
The operating state is set as shown by the solid line in the figure. As shown in FIGS. 2 and 5, a connecting member 40 is fixed to the rotating shaft 29 below the right side extending portion 3a of the bracket 3, and the connecting member 40, connecting rod 41, rotating arm 42 and The selection member 30 is connected to a needle bar release mechanism (not shown) via a connecting rod 43.

As shown in FIGS. 1A and 1B and 4 and 5, the needle drop groove 19a is located on the flange portion 19 of the bobbin case 18.
There is a lever storage section 44 on the opposite side separated by approximately 180 degrees from the
are formed, and a notch 45 and a communication groove 46 that communicate with the lever accommodating portion 44 and the bobbin accommodating portion 18a are respectively formed at predetermined intervals. As shown in FIG. 4, a portion of the needle thread loop captured and pulled out by the thread loop catcher 9 can smoothly enter the inside of the bobbin case 18 through the notch 45. It's becoming like that. In the lever storage portion 44, a thread tension adjusting plate spring 48 is attached to the notch 45 side, which is held between a pair of plate members 47a and 47b and has a guide portion 48a at its tip. An arcuate control lever 4 as a control member is disposed within the lever storage portion 44 so as to be located on the rotation locus of the pin 32 on the selection member 30.
9 is rotatably supported almost at the center.

A projecting piece 50 projecting toward the bobbin case 18 side and a guide piece 51 for guiding the needle thread ring into the bobbin case 18 are formed at one end of the control lever 49, and both 50 and 51 form the notch. Inner wall of section 45 and plate spring 48
The guide portion 48a can be opened and closed.
A detection portion 52 is bent at the other end of the control lever 49 and can enter between the upper and lower flanges 21 and 22 of the bobbin 20 via the communication groove 46. A compression spring 53 serving as a spring means is interposed between the control lever 49 and the side wall of the lever storage portion 44 in the vicinity of the detection portion 52 . During normal sewing operation, the detection section 52 is locked to the inner wall of the bobbin accommodating section 18a by the spring force of the compression spring 53, and the protrusion piece 50 and the guide piece 51
The inner wall of the notch 45 and the guide portion 4 of the leaf spring 48
8a is closed, and the control lever 49 is placed in the first position shown in FIG. 1a. When replenishing bobbin thread, the pin 32 and the control lever 49 engage with each other as the selection member 30 rotates, and the control lever 49 moves counterclockwise in FIG. 1A against the spring force of the compression spring 53. rotated to
The detection unit 52 detects both the upper and lower flanges 21 and 2 of the bobbin 20.
2, and the protrusion piece 50 and the guide piece 5
1, the space between the inner wall of the notch 45 and the guide portion 48a of the leaf spring 48 is opened, and the control lever 49 is moved to the position shown in FIG.
is placed in the second position shown in . Next, the operation of the sewing machine configured as described above will be explained.

Now, in FIG. 1a, the selection member 30 is placed in the first position, the pin 32 on the selection member 30 is separated from the control lever 49, and the control lever 49 is moved to the first position by the spring force of the compression spring 53. This shows the arranged state.

As a result, as shown in FIG. 3a, the cam body 33 is placed in the non-active position, and the bent piece 38 of the linking member 36 is engaged with the equal radius surface 33d of the cam body 33. Therefore, the small diameter portion 6b of the actuating shaft 6 is inserted into the lower part of the elongated hole 39c adjacent to the round hole 39b of the linking member 36, and the actuating shaft 6 is placed at the chain line position in FIG. 8 is bobbin 20
The bobbin rotation mechanism is set in an inactive state at a distance from the recess 21a. If you operate the sewing machine in this condition, the lower shaft 1
6 and screw gears 15 and 12, the thread ring catcher 9
is rotated counterclockwise in FIG. 1a for each reciprocating movement of the hand 17.

Then, the needle thread Y carried by the needle 17 is captured by the thread ring catching beak 11, and the needle thread Y passes through the bobbin case 18 to form a needle thread ring, and the bobbin thread wound around the bobbin 20 is fed out by the needle thread loop. As a result, a lock stitch is formed on the work cloth (not shown) on the bed portion 1a, and the feed dog 54a on the feed table 54 and the presser foot (not shown) cooperate to feed the work cloth. will be granted. At this time, since the space between the inner wall of the notch 45 and the leaf spring 48 is closed by the protruding piece 50 and the guide piece 51 of the control lever 49, the needle thread ring is moved to the bobbin case 18.
It will not be introduced internally. When all the bobbin thread is consumed by the sewing operation of the sewing machine, in order to replenish the bobbin thread, after stopping the operation of the sewing machine, the needle 17 is placed above the throat plate 2 at a predetermined position. One end of the needle thread Y is fixed to the fixed part (near the needle), and the upper surface of the thread loop catcher 9 is opened by manually operating a sliding plate (not shown).

In this state, the selection member 30 is manually rotated clockwise in FIG. 1a, so that the protrusion 31 of the selection member 30 enters the recess 22a of the bobbin 20, as shown in FIG. 1b. This rotation of the selection member 30 causes the pin 32 to move to the control lever 49.
The control lever 49 is rotated counterclockwise in FIG.
The space between the inner wall of the bobbin 20 and the leaf spring 48 is opened, and the detection portion 52 of the control lever 49 enters between the upper and lower flanges 21 and 22 of the bobbin 20. On the other hand, as the selection member 30 is rotated, the cam body 33 is rotated clockwise from the state shown in FIG. The linking member 36 is rotated clockwise by the action of the cam surface 33c. Then, when the protrusion 31 of the selection member 30 enters the recess 22a of the bobbin 20, the bent piece 38 of the linking member 36 engages with the engagement recess 33b of the cam body 33, and the cam body 33 and linkage are engaged. Part 3
6 is held in the operating state shown in FIG. 3b, and the selection member 30
is blocked in the second position shown in FIG. 1b. Also,
As the linking member 36 rotates, the operating shaft 6 is moved upward along the inclined surface 39a of the linking member 36.

Then, as shown by the solid line in FIG. 2, the engaging protrusion 8 on the operating shaft 6 is arranged in the recess 21a of the bobbin 20, and the operating shaft 6 is held in the operating state by the spring force of the linking member 36 itself. . When you restart the sewing machine in this state, needle 17
During one reciprocating movement, the bobbin 20 and thread loop catcher 9 are rotated together based on the engagement between the engagement protrusion 8 and the inner edge of the recess 21a, and the first needle thread loop is rotated. Once formed, the needle bar release mechanism is actuated by a predetermined cam action, and the reciprocating movement of the needle 17 is stopped. Then, the thread ring capturing beak 11 that captured the needle thread Y when forming the first needle thread loop moves to the control lever 49.
When passing near the protruding piece 50, the fixed side limb Y1 of the needle thread Y passes through the notch 45 and is bent along the guide piece 51, the protruding piece 50, and the guide part 48a of the leaf spring 48. After being smoothly introduced into the bobbin case 18 without any friction, it is held between the leaf spring 48 and the lower plate member 47b.

Then, as the bobbin 20 is continuously rotated, the needle thread Y is wound around the shaft portion of the bobbin 20. During this bobbin thread replenishment operation, the fixed side limb Y1 of the needle thread Y is connected to the recess 22a of the upper flange 22 of the bobbin 20 and the selection member 30.
As the bobbin 20 rotates, the fixed side limb Y1 is cut by the thread cutting part 31a of the protrusion 31 so as to be worn out. When the thread is sufficiently refilled around the bobbin 20, the detecting section 52 of the control lever 49 engages with the thread, and when the winding diameter of the bobbin thread increases due to the subsequent bobbin thread replenishment operation, the thread is compressed. With the aid of the spring 53, the control lever 49 is rotated clockwise in FIG. 1b, and the selection member 30 is moved from the second position shown in FIG. 1b to the second position shown in FIG. The selection member 30 is rotated to an intermediate position between the first position and the second position. In response to the rotation of the selection member 30 to the intermediate position,
The cam body 33 and the linking member 36 are each rotated back, and as is clear from FIGS. 3A and 3B, the cam body 33
The bent piece 38 of the linking member 36 engages with the engagement recess 33a. Further, with the return rotation of the linking member 36, the operating shaft 6 is moved down along the inclined surface 39a, and the engaging protrusion 8 of the operating shaft 6 is separated from the recess 21a of the bobbin 20. The rotation is surely stopped and the bobbin thread replenishment operation is completed. After cutting the needle thread Y and placing the winding end of the bobbin thread on the bobbin case 18, when the upper surface of the rivet portion 1a is closed by the sliding plate, the cam portion formed on the lower surface of the sliding plate The selection member 30 is rotated back to the first position shown in FIG. 1a by cooperation with an engaging piece (not shown) provided protruding from the selection member 30, and the needle bar release mechanism becomes inactive. Set. Thereby, the next stitch forming operation can be performed continuously. Further, when the operating shaft 6 moves upward, the engaging protrusion 8 on the operating shaft 6 is inserted into the recess 20 of the bobbin 20.
When the extending piece 39 of the linking member 36 is once bent downward against its own spring force, the engaging protrusion 8 is bent by the subsequent rotation of the operating shaft 6. Since it is disposed within the recess 21a of the bobbin 20, the bobbin 20 can be smoothly rotated without any support.

Another Embodiment Hereinafter, a second embodiment of the present invention will be described with reference to FIGS. 6A, b to 1.
According to Figures 1a-d, Figures 7, 8 and 11
As shown in Figures a to d, a needle plate 102 is attached to the upper surface of the bed portion 1a of the sewing machine frame 1, and the needle plate 102 is attached to the bed portion 1a adjacent to the throat plate 102 to expose the inside of the bed portion 1a. An opening/closing plate 102a is attached so as to be openable and closable.

Below this opening/closing plate 102a, a support cylinder 104 is located approximately in the center of the bracket 103 provided in the bed portion 1a.
is inserted and fixed. An operating shaft 106 is inserted into the support tube 104 so as to be able to move up and down and rotate, and a disk 105 located above the support tube 104 is fixed to the upper end of the operation shaft 106 . A pair of protrusions 105a are formed on the upper surface of this disc 105, and a connecting pin 105b is provided protruding from the lower surface. The thread ring catcher 109 is formed into a substantially short cylindrical shape with an open bottom, and a lace portion 110 and a thread ring catching beak 111 are formed on the inner surface of the annular peripheral wall. A shaft cylinder portion 109a is protruded from the center of the lower surface of the thread ring catcher 109, and the support cylinder 104 is inserted into the shaft cylinder portion 109a.
A screw gear 112 is fixed to the outer periphery of the cylindrical shaft portion 109a, and a disc-shaped cam member 113 is fixed to the upper end of the cylindrical shaft portion 109a. The disc 105 is housed in the thread ring catcher 109, and the connecting pin 105b is loosely fitted into a through hole 114 formed through the bottom of the thread ring catcher 109 and the cam member 113. Further, the shaft cylindrical portion 109a is connected to the screw gear 1.
12 to a lower shaft (not shown). When the lower shaft rotates, the thread ring catcher 109 and the operating shaft 106 are moved in synchronization with the longitudinal reciprocating movement of the needle 17 attached to the needle bar (not shown) via the screw gear 112 as shown in FIG. A and b are physically rotated clockwise. Inside the thread ring catcher 109 is an upper member 118a.
and a lower member 118b, and the bobbin case 118 includes both the members 118a
, 118b is attached to the lace portion 110 of the yarn ring catcher 109 at a groove portion 119 formed on the outer peripheral edge of the joint portion of the yarn ring catcher 109.

A bobbin accommodating portion 120 defined by an annular peripheral wall 120a is provided at the center of the bobbin case 118. As shown in FIGS. 6A, BL and FIGS. 11a-b, a slit 121 and a notch groove 122 as a notch communicating with the bobbin accommodating portion 120 are provided at mutually opposing positions on the annular peripheral wall 120a of the bobbin case 118. each formed. Then, a portion of the needle thread loop captured by the thread loop catcher 109 and pulled out is inserted into the slit 121.
It is adapted to enter inside the bobbin case 118 via the. On the annular peripheral wall 120a, a bent portion 123 is provided at the tip near the bobbin thread introduction side of the slit 121.
A leaf spring 123 having a shape is fixed, and the slit 12
Tension is applied between the leaf spring 123 and the annular peripheral wall 120a to the needle thread ring passing through the needle thread ring 1.
Adjacent to the bending portion 123a and on the upper member 118a, a control member 124 for covering the bobbin thread introduction side of the slit 121 from the outside is located at the first position shown in FIG. 6a and in the first position shown in FIG. 6b. It is rotatably supported between the second position shown in FIG. Further, this control member 124 is provided with a connecting pin 124a that projects downward, and the inclined guide surface 1
24b is formed.

A first operating lever 125 is rotatably supported near its base end on the upper member 118a, and an elongated hole 125a into which the connecting pin 124a is loosely fitted is formed at its tip. A bent portion 125b having a substantially arcuate planar shape is formed upright on the inner edge of the first operating lever 125. A leaf spring 126 that engages with the bent portion 125b is fixed to the annular peripheral wall 120a so as to face the bent portion 125b, and its spring force causes the elongated hole 125a to
The control member 12 through fitting with the connecting pin 124a.
4 is biased to rotate toward the first position. A thread carrying bobbin 127 is accommodated in the bobbin accommodating portion 120 of the bobbin case 118, and a pair of recesses 128a into which the protrusions 105a of the disc 105 can be fitted are formed in the lower flange 128 of the bobbin 127.

When the disk 105 is moved upward together with the operating shaft 106 as shown by the chain line in FIG. 7, the protrusion 105a is loosely fitted into the recess 128a. In this state, when the thread ring catcher 109 and the operating shaft 106 are rotated by the lower shaft via the screw gear 112, the protrusion 105a engages with the inner edge of the recess 128a of the bobbin 127, and the bobbin 127 is rotated.
7 is rotated. Then, the lower shaft, screw gear 1
12, thread ring catcher 109, disk 105 and operating shaft 106
A bobbin rotation mechanism is constructed by the above. Further, a recess 129 is provided at the center of the upper flanges 12 and 9 of the bobbin 127.
A is formed in the upper flange 129, and a slit 129b is formed in the upper flange 129 as a locking means for locking a part of the needle thread ring introduced into the bobbin 127. As shown in FIGS. 7 and 8, the yarn loop catcher 10
A support plate 130 having an opening at the center is fixed on the bracket 103 below the bracket 9, and upright portions 131 and 132 extending upward are formed on the front and right edges of the support plate 130, respectively. Figure 6A, b and Figure 11 a-d
, the upper member 118a of the bobbin case 118 is disposed adjacent to one of the upright portions 131 of the support plate 130.
A regulation plate 133 is fixed on the top. Also, Figure 6A
, b, a regulating body 134 having a regulating piece 134a is supported by a shaft 134b in the bed portion 1a, and the regulating body 134 is engaged with the cam member 113, and the cam member 134 is engaged with the cam member 113. Due to the action of 113, the thread ring catcher 1
It is oscillated in time with the rotation of 09. The rotation of the bobbin case 118 is regulated by the one standing portion 131, the regulating plate 133, and the regulating member 134. As shown in FIG. 9, the other upright portion 132 has a guide groove 135 having a predetermined width and four recesses 135a.
is formed.

This guide groove 135 has a selection lever 13 as a selection member.
The small diameter portions of a pair of pins 137 fixed to the pins 6 are respectively inserted and fitted. An operating knob 138 is provided on the upper edge of the selection lever 136, and a bent piece 139 having a long hole 139a is formed. Selection lever 13
6 is below, a leaf spring 141 is attached to the support plate 130 at its center with a screw 140, and the vicinity of both ends of the leaf spring 141 are engaged with the lower corners of the selection lever 136, and the selection lever 136 is pushed upward. It is strong. Then, based on manual operation of the operation knob 138, the selection lever 136 is moved to the ninth position.
It can be selectively placed in a first selection position shown by a solid line in the figure and a second selection position shown by a chain line in the same figure,
In both positions, the spring force of the leaf spring 141 causes the pin 137 on the selection lever 136. The small diameter portions of the guide grooves 135 are engaged with every other recess 135a of the guide groove 135. As shown in FIGS. 6A and 6B and FIG. 7, a shaft 142 is inserted and supported by the boss portion 103a of the bracket 103 in the front notch 130a of the support plate 130. As shown in FIGS.

As shown in FIG. 8, a second operating lever 143 is supported at the upper half of this shaft 142 at its U-shaped base end so as to be rotatable and movable up and down, and is wound around the shaft 142. A compression spring 144 urges the U-shaped base end to move on the shaft 142 in a direction in which it engages with a retaining ring 142a, that is, downward. A connecting pin 145 extending downward is fixed near the base end of the second operating lever 143, and the connecting pin 145 connects to the elongated hole 136 of the selection lever 136.
It is inserted into a. Further, a thread cutting member 146 having a cutting edge 146a directed downward is attached to the tip of the second actuating lever 143, and can enter into the recess 129a of the bobbin 127 through a slight gap. There is.
Furthermore, as shown in FIG. 6b, the tip of the second operating lever 143 is provided with an annular peripheral wall 120 of the bobbin case 118.
An arc-shaped thread guide portion 147 that can be placed on the bending portion 12 of the first operating lever 125 is formed.
A pin 148 as an actuating member that can be engaged with 5b from the outside.
is installed protrudingly. A hanging piece 149 is bent at one side edge of the second operating lever 143. When the selection lever 136 is placed in the first selection position to perform a normal seam forming operation, as shown by the solid line in FIG. 9 and shown in FIG. 6a, the selection lever 136 is Based on the engagement between the elongated hole 139a and the connecting pin 145 of the second operating lever 143, the second operating lever 143 is rotated to one position, and the thread cutting member 146 of the second operating lever 143 is rotated to one position. , the thread guide portion 147 and the pin 148 are retracted from above the bobbin case 118, and the pin 148 is separated from the bent portion 125b of the first operating lever 125.

Therefore, the first operating lever 125 is rotated by the spring force of the leaf spring 126, and the elongated hole 125a and the pin 12 are rotated.
The control member 124 is placed in the first position via 4a. In addition, as shown by the chain line in FIG. 9 and shown in FIG. 6b,
When the selection lever 136 is placed in the second selection position to perform the bobbin thread replenishment operation, the second operating lever 14
3 is rotated to the other position, the thread cutting member 146 enters into the recess 129a of the bobbin 127, and the thread guide part 14
7 is disposed on the annular peripheral wall 120a, and the pin 148 engages with the bent portion 125b of the first actuation lever 125.
Thereby, the first actuating lever 125 is rotated against the spring force of the leaf spring 126, and the control member 124 is placed in the second position. Further, based on the movement of the selection lever 136 from the first selection position to the second selection position, the needle 17 is moved to the first position via the protrusion 137a1 of one pin 137, the rotation lever 150, the connecting rod 151, etc. A needle bar release mechanism (not shown) for stopping the needle bar at a position above the throat plate 102 after two vertical reciprocations is set to a ready state for operation. As shown in FIG. 9, a two-armed lever 152 is rotatably supported at its center by the screw 140 via a support member 152c on the support plate 130 below the selection lever 136, and one end of the two-armed lever 152 is is the selection lever 1.
An engagement pin 152a that can be engaged with the lower edge of the second operating lever 143 is provided protruding from the other end, and an engagement pin 152b that can be engaged with the lower surface of the base end of the second operating lever 143 is provided on the other end. ing.

As shown in FIG. 7, a block body 153 having an annular groove 153a on its outer periphery is attached to the lower end of the shaft 142 and can be moved up and down between an inactive position shown by a solid line in the figure and an active position shown by a chain line in the same figure. Possibly inserted. A connecting plate 154 is rotatably supported at one end of the block body 153 by a step screw 155, and an engaging pin 152b of the two-armed lever 152 is inserted into a long hole 154a formed at the other end. There is. Therefore, the two-armed lever 152 and the block body 1
53 are connected to each other via a connecting plate 154. A linking member 156 made of a plate spring material is installed between the lower end of this block body 153 and the lower end of the operating shaft 106. The two-armed lever 152 and the block body 153
, the connecting plate 154, the connecting member 156, and the like constitute a linking mechanism that links the selection lever 136 and the operating shaft 106. As shown in FIGS. 6 to 8, below the screw gear 112, a two-armed intermediate lever 157 is rotatably supported at the center of the bracket 103 around a support shaft 158, and is provided with a protrusion at one end. The connecting pin 157a is loosely fitted into the annular groove 153a of the block body 153.

Further, the other end engaging portion 157b of the intermediate lever 157 projects onto the support plate 130 through the square hole 130b of the support plate 130. This intermediate lever 1 is attached to the support shaft 158.
Torsion coil spring 1 for biasing rotation of 57 in one direction
59 is wound around the connecting pin 15, and its spring force always keeps the connecting pin 15
7a, the block body 153 is urged to move toward the inactive position shown by the solid line in FIG. Then, as shown by the solid line in FIG. 9, the operating knob 138 disposed at the first selection position is pressed down to
When the small diameter portion of the upper pin 137 is engaged with the inner bottom edge of the guide portion 135, the selection lever 136 rotates the two-armed lever 152 in one direction, and the second operating lever 1
43 is moved upward against the spring force of the compression spring 144, and the block body 153 is moved upward via the connecting plate 154 against the spring force of the torsion coil spring 159.

As a result, the operating shaft 106 is
At the same time, the disk 105 is moved up to the position indicated by the chain line in FIG.
The protrusion 105a of the disc 105 is located in the recess 1 of the bobbin 127.
28a, and the bobbin rotation mechanism is set to the operating state. Further, due to the upward movement of the block body 153, the intermediate lever 157 resists the spring force of the torsion coil spring 159.
is rotated from the solid line position to the chain line position in FIG. As shown in Fig. 6A, b and Fig. 8,
The support plate 1 is located at the rear right side of the thread loop catcher 109.
A detection lever 161 as a thread amount detection means is rotatably supported at the base end of a support shaft 160 on the spindle 30, and the tip thereof passes through the cutout groove 122 of the bobbin case 118 and connects to the upper and lower flanges of the bobbin 127. A detection part 161a that can enter between 128 and 129 is formed protrudingly.

An upright piece 161b that can be engaged with the hanging piece 149 of the second operating lever 143 is bent and formed on the detection lever 161 in the vicinity of the detection portion 161a. Detection lever 1
A locking lever 162 is rotatably supported on a support shaft 160 below 61, and the intermediate lever 15 is attached to the tip of the locking lever 162.
A locking portion 162a that can be engaged with the locking portion 157b of No. 7 is formed in a protruding manner. The detection lever 161 and the locking lever 1
A sleeve 163 as a connecting means is attached to the support shaft 160 between the support shaft 160 and the support shaft 62, and the base ends of the levers 161 and 162 are fixed to both upper and lower ends of the sleeve 163. of
A torsion coil spring 164 as a spring means is wound around the sleeve 163, and one end of the torsion coil spring 164 is fixed to the support plate 130 and the other end to the locking lever 162.

Due to the spring force of this torsion coil spring 164, the locking lever 162 and the detection lever 161 are moved to the sleeve 163.
is biased to rotate clockwise in FIGS. 6A and 6B. Furthermore, when the second operating lever 143 is placed in the position shown in FIG. 6a, the torsion coil spring 1
The hanging piece 1 of the second operating lever 143 is
49 is engaged with the upright piece 161b of the detection lever 161,
The detection portion 16 of the detection lever 161 via the sleeve 163
1a and the locking portion 162a of the locking lever 162 are respectively arranged at the retracted position. Then, the selection lever 136
With the small diameter portion of the upper pin 137 disposed within the guide groove 135 and the intermediate lever 157 positioned at the chain line position in FIG. 8 through the block body 153, the selection lever 136 is moved upward in FIG. 6a. When the detection lever 161 and the locking lever 162 are physically rotated in one direction via the second operating lever 143 based on the spring force of the torsion coil spring 164, the detection portion 161 of the detection lever 161
a enters between the upper and lower flanges 128 and 129 of the bobbin 127 through the notch groove 122 of the bobbin case 118, and the locking portion 162a of the locking lever 162 engages with the engaging portion 157b of the intermediate lever 157, The intermediate lever 157 prevents the block body 153 and the like from moving downward. Further, the intermediate lever 157 and the locking lever 162 constitute a holding mechanism for holding the interlocking mechanism such as the block body 153 in the operating position shown by the chain line in FIG. 7. Next, the operation of the sewing machine configured as described above will be explained. Now, when performing a normal seam forming operation, when the selection lever 136 is placed in the first selection position as shown by the solid line in FIG. The lever 143 is rotated to the position shown in FIG. 6a,
The pin 148 on the second actuation lever 143 is separated from the bent portion 125b of the first actuation lever 125.

Therefore, the control member 124 is placed in the first position via the first operating lever 125 based on the spring force of the leaf spring 126, and the bobbin thread introduction side of the slit 121 of the bobbin case 118 is closed. On the other hand, the hanging piece 149 of the second operating lever 143 and the upright piece 16 of the detection lever 161
1b, and based on the engagement, the detection lever 1
61 and the locking lever 162 are placed in the retracted position shown in FIG. 6a. Further, as shown in FIGS. 7 and 8, since the intermediate lever 157 is biased to rotate in the counterclockwise direction in FIG. 8 by the torsion coil spring 159, the block body 153 is biased to move downward. .

When the selection lever 136 is placed at the solid line position in FIG. is engaged with. Therefore,
The interlocking mechanism consisting of the block body 153 and the like is allowed to move to the non-operating position, and as shown by the solid line in FIG. 7, the interlocking mechanism is placed and maintained at the non-operating position. Further, as the block body 153 moves to the inactive position, the operating shaft 106 is placed at the solid line position in FIG. The bobbin rotation mechanism is set to an inactive state by being separated from the bobbin 127, and rotation transmission to the bobbin 127 is cut off, so that the bobbin 127 can freely rotate as the bobbin thread is paid out. Therefore, when the sewing machine is operated in this state, the thread ring catcher 109 is rotated clockwise in FIG. 6a for each reciprocating movement of the needle 17 via the lower shaft and screw gear 112.

Then, the needle thread Y carried by the needle 17 passes through the thread ring catching beak 111.
The needle thread Y passes through the bobbin case 118 to form a needle thread loop, and the needle thread Y passes through the bobbin case 118 to form a needle thread loop.
The bobbin thread wound on the needle is let out by the needle thread loop. Thereby, the processed cloth (not shown) on the bed portion 1a
A lock stitch is formed on the feed dog 5 on the feed table 54.
Feed is applied to the workpiece cloth through cooperation between the presser foot 4a and a presser foot (not shown). At this time, since the bobbin thread introduction side of the slit 121 is closed by the control member 124, the needle thread ring is not introduced into the bobbin case 118. When all the bobbin thread is consumed by the sewing operation of the sewing machine, in order to replenish the bobbin thread, after stopping the operation of the sewing machine, the needle 17 is placed above the throat plate 102 at a predetermined position. Needle thread Y on the fixed part (near the needle)
One end of the thread loop catcher 109 is fixed, and the opening/closing plate 102a is manually operated to open the top surface of the thread loop catcher 109.

If the operation knob 138 is pressed down in this state, the eighth
, 9, the two-armed lever 152 is rotated clockwise and the compression spring 14 is rotated by the engagement pin 152b.
The second operating lever 143 is moved upward against the spring force of 4. Also, based on the rotation of the two-armed lever 152, the plate 15
4, the block body 15 resists the force of the torsion coil spring.
3 is moved upward, and the intermediate lever 157 is rotated, so that the intermediate lever 157 is placed at the chain line position in FIG. Further, with the upward movement of the block body 153, the operating shaft 106 and the disk 105 are moved upward via the linking member 156, and the protrusion 105a is moved upwardly toward the bobbin 1, as shown by the chain line in FIG.
27, and the bobbin rotation mechanism is set to the operating state. Then, with the selection lever 136 pressed down, move the selection lever 136 into the guide groove 136.
When moved along the elongated hole 139a and the connecting pin 14
5, the second operating lever 143 is rotated counterclockwise from the state shown in FIG.
The thread guide section 147 is connected to the annular peripheral wall 120 of the bobbin case 118.
a, and the pin 148 engages with the bent portion 125b of the first actuating lever 125 so that the actuating lever 12
5 is rotated clockwise from the state shown in FIG. 6a, and the closing of the bobbin thread introduction side of the slit 121 by the control member 124 is released.

Further, the detection lever 161 and the locking lever 162 are rotated clockwise from the position shown in FIG. 6a following the second operating lever 143 due to the spring force of the torsion coil spring 164, and are moved to the position shown in FIG. 6b. As shown, the detection portion 161a of the detection lever 161 enters between the upper and lower flanges 128, 129 of the bobbin 127 through the notch groove 122 of the bobbin case 118, and the locking portion 162a of the locking lever 162 engages with the intermediate lever. 157 is engaged with the engaging portion 157b. Based on this engagement, the return rotation of the intermediate lever 157 is prevented, and the block body 153 and the linking member 156 are held in the operating position shown by the chain line in FIG. The disk 105 is held at the position indicated by the chain line in FIG.

Subsequently, when the selection lever 136 is released from the depression operation, the selection lever 136 is moved upward by the spring force of the leaf spring 141 and is held at the second selection position shown by the chain line in FIG. When the selection lever 136 is moved upward,
Along with the upward movement, the second operating lever 143 is moved downward by the spring force of the compression spring 144, and the thread cutting member 146 is moved into the recess 129a of the bobbin 127 at a slight interval as shown by the chain line in FIG. enter. Further, as is clear from FIG. 7, the downward movement of the second actuating lever 143 causes the two-armed lever 152 to rotate counterclockwise in FIG. 9, but the engagement pin 152b is It only moves within the elongated hole 154a of the plate 154. When the sewing machine is restarted in this state, the bobbin 127 and the thread loop catcher 109 are connected to each other due to the engagement between the protrusion 105a on the disc 105 and the recess 128a of the bobbin 127 while the needle 17 is reciprocating. When the needles 17 are rotated together and the first needle thread loop is formed, the needle bar release mechanism is actuated by a predetermined cam action, and the reciprocating movement of the needle 17 is stopped.

As shown in FIG. 11a, when the needle thread loop is formed for the first time, when the thread loop capturing beak 111 that has captured the needle thread Y passes near the shaft attachment part of the first actuating lever 125, the needle The needle side limb Y2 of the thread Y is connected to the inclined guide surface 124 of the control member 124.
b, as shown in FIG. 11b, its limb Y2
The bent portion 123a of the leaf spring 123 and the bobbin case 118
It is held between the annular peripheral wall 120a. Then the first
As shown in FIGS. 1B and 1C, when the thread ring catching beak 111 passes near the pin 148 on the second actuating lever 143, the needle side limb Y2 is not bent and the bobbin case 118 is closed. It is smoothly and reliably introduced between the upper and lower flanges 128 and 129 of the bobbin 127 through the slit 121, and a part of the needle side limb Y2 rides on the thread guide part 147 of the second operating lever 143, Needle side limb Y
2 is bent between the outer peripheral edge of the upper flange 129 of the bobbin 127 and the thread guide section 147. Then, as shown in FIG. 11c, after the needle thread Y detaches from the thread ring catching beak 111 and passes through the bobbin case 118, the fixed side limb Y1 of the needle thread Y is bent by the pin 148, and the bobbin thread Y is bent by the pin 148. It is arranged on the upper member 118a of the case 118.

Further, as the bobbinon 127 rotates, the bent portion of the needle side limb Y2 between the outer peripheral edge of the upper flange 129 and the thread guide portion 147 is locked in the slit 129b of the bobbin 127, and enter. As shown in FIG. 11d, when the bobbin 127 is further rotated,
Since the needle side limb Y2 is locked at the innermost part of the slit 129b, the needle thread Y is wound around the shaft of the bobbin 127, and the fixed side limb Y1 is connected to the thread guide part 147. The bobbin 127 is stretched between the slit 129b and
The thread enters between the recess 129a and the thread cutting member 146, and is cut by being worn out as the bobbin 127 rotates. When the thread is sufficiently refilled around the bobbin 127, the detecting portion 161a of the detection lever 161 engages with the thread, as is clear from FIG. When the winding diameter of the bobbin thread increases,
The detection lever 1 resists the spring force of the torsion coil spring 164.
61 and the locking lever 162 are physically rotated counterclockwise from the position shown in FIG. 6b, and the locking portion 1 of the locking lever 162
62a is disengaged from the engaging portion 157b of the intermediate lever 157. As a result, based on the spring force of the torsion spring 159, the intermediate lever 157 is rotated back to the solid line position in FIG. The actuating shaft 106 and the disc 105 are moved down through the linking member 156 and the protrusion 1
05a is separated from the recess 128a of the bobbin 127, the rotation of the bobbin 127 is reliably stopped, and the bobbin thread replenishment operation is completed.

Then, the operation of the sewing machine is stopped, the needle thread Y is cut, and the winding end of the bobbin thread is placed on the bobbin case 118, and then the selection lever 136 is moved to the first selection position shown by the solid line in FIG. When the second operating lever 143, the detection lever 161, and the locking lever 162 are rotated back to the position shown in FIG. 6a, the needle bar release mechanism is set to the inactive state. Ru.

After that, if the thread loop catcher 109 is covered with the opening/closing plate 102a, the next sewing starts. Eye forming operations can be performed continuously. Further, when the operating shaft 106 moves upward, the protrusion 105a on the disk 105 moves into the recess 128a of the bobbin 127.
When the linking member 156 is engaged with a portion other than the bobbin 1, the linking member 156 is once bent downward against its own spring, and then the projection 105a is moved to the bobbin 1 by the subsequent rotation of the operating shaft 106.
27, the bobbin 127 can be smoothly rotated without any support.

Note that this invention is not limited to the above-mentioned embodiments, and the configuration of each part may be arbitrarily changed without departing from the spirit of this invention, for example, by using electromagnetic means such as a solenoid as an operating member. is also possible.

Effects As described in detail above, the present invention has a structure in which a needle thread ring is fixed on the bobbin case so as to allow a portion of the needle thread ring to be caught and pulled out by the thread ring catcher to enter the inside of the bobbin case. a first position in which a notch is formed in the needle thread ring, and the notch is closed so as to prevent the needle thread ring from entering inside the bobbin case and pass around the bobbin case;
A control member is rotatably mounted on the bobbin case and can take a second position in which the notch is opened so that a portion of the needle thread ring enters the inside of the bobbin case, and the control member is always in an off position. Spring means are provided for biasing the selection member to a first position and for moving said control member to a second position against the action of the spring means in conjunction with operation of the selection member to perform a bobbin thread replenishment operation. By providing the actuating member, when performing the bobbin thread replenishment operation, by opening the notch with the control member, a part of the needle thread ring can be reliably and smoothly inserted into the bobbin case without being bent. It has the excellent effect of being able to penetrate into the surrounding area and being manufactured at low cost.

[Brief explanation of the drawing]

1A and 1B to FIG. 5 show a first embodiment of the present invention, and FIG. 1A is a plan view of the sewing machine when performing a stitch forming operation, and FIG. 1B is a bobbin thread of the sewing machine. FIG. 2 is a sectional view taken along the line ■-■ in FIG. 1b, and FIGS. 3A and 3b are cross-sectional views taken along the line ■-■ in FIG. FIG. 4 is a partial perspective view of the sewing machine at the initial stage of bobbin thread replenishment operation, and FIG. 5 is an exploded perspective view showing the bobbin thread replenishment device and its related components. 6A and 6B to FIGS. 11A to 11D show a second embodiment of the present invention, in which FIG. 6A is a plan view of the sewing machine when performing a seam forming operation, and FIG. 6B is the same. 7 is a sectional view taken along line 1--2 in FIG. 6a, FIG. 8 is a sectional view taken along line 6--2 in FIG. Fig. 10 is a side view of the thread ring catcher during bobbin thread replenishment operation, and Fig. 11 ad shows the operating state of the bobbin thread replenishment device during bobbin thread replenishment operation. FIG. disk·
...5,105, operating axis ...6,106,
Thread ring catcher...9,109, Thread ring catcher beak...
...11,111, Screw gear ...12,
15,112 (said 5, 6, 9, 12, 15, 105,
106, 109, 112, etc. constitute a bobbin rotation mechanism), needle...17, bobbin case...
...18,118, thread carrying bobbin ...2
0,127, Selected member...30,136, Pin as special member...32,148, Notch
...45, slit as a notch part...
1211 Control lever as control member...49
, control member...12 male detection section...52
, compression spring as spring means...53 and leaf spring...126, bobbin housing section...12
0, Annular peripheral wall...120a, Needle thread...
Y.

Claims (1)

[Scope of Claims] 1. A thread ring catcher 9, 109 having a thread ring catching beak 11, 111 and rotatable in synchronization with the vertical reciprocating movement of the needle 17, and a thread ring catcher 9, 109 inside the thread ring catcher 9, 109. bobbin case 1 held in
In a lockstitch sewing machine equipped with a thread carrying bobbin 20, 127 that is rotatable within the bobbin case 18, 118, the needle thread is caught and pulled out by the thread ring catcher 9, 109. Part of the ring is bobbin case 1
Notches 45, 12 formed on the bobbin cases 18, 118 to allow the cutouts 45, 12 to enter inside the bobbin cases 18, 118.
1, and the notch is rotatably mounted on the bobbin case 18, 118 to prevent the needle thread ring from entering inside the bobbin case 18, 118 and to pass around the bobbin case 18, 118. 45, 121 and a portion of the needle thread ring is in the bobbin case 1.
8,118 so that the notch 45,1
a control member 49 capable of assuming a second position in which it opens 21;
124, spring means 53, 126 for normally biasing the control members 49, 124 to the first position, and a selection member operable to selectively perform stitch forming operations and bobbin thread replenishment operations. 30, 136 and its selection member 30, 136
an actuating member 32, 148 for moving said control member 49, 124 into a second position against the action of spring means 53, 126 in connection with the operation for performing a bobbin thread replenishment operation; locking means 22b for locking a portion of the needle thread ring that enters inside the bobbin case 18, 118 at the second position of 49, 124 to the bobbin 20, 127;
129b, and a bobbin rotation mechanism 5, 6, 9, 12, 15, 105, 106 for winding the thread Y onto the bobbin 20, 127 at the second position of the control member 49, 124,
112, etc.). 2 The bobbin rotation mechanism includes the selection member 30, 136.
A bobbin thread replenishing device in a lockstitch sewing machine according to claim 1, wherein the bobbin thread replenishing device in a lockstitch sewing machine is set to an operating state in connection with an operation for performing bobbin thread replenishment. 3. The control member includes a control lever 49, which has a portion formed at one end for opening and closing the notch 45 on the bobbin case 18, and a detection portion 52 capable of entering into the bobbin 18 formed at the other end; When the bobbin 20 is sufficiently replenished with yarn Y at the second position of the control member, the detecting portion 52 of the control lever 49 engages with the yarn Y, thereby causing the control lever 49 to move toward the first position. Claim 2, in which the selection member 30 is once moved, thereby releasing the operation of the selection member 30 for performing bobbin thread replenishment via the actuating member 32.
A bobbin thread replenishing device for a lockstitch sewing machine as described in 2. 4. The notch on the bobbin case 118 is composed of a slit 121 formed in the annular peripheral wall 120a constituting the bobbin accommodating section 120, and the control member 124 covers at least the bobbin thread introduction side of the slit 121 from the outside. A bobbin thread replenishing device in a lockstitch sewing machine according to claim 1 or 2, which is installed to obtain a bobbin thread.