JP2000093682A - Sewing machine - Google Patents

Abstract

(57) [Summary] An object of the present invention is to eliminate the uneven winding by optimizing the number of rotations of a bobbin when performing bobbin winding. When the plunger (118) is in a depressed position, the rotation is transmitted to the plunger (118) to rotate the bobbin (12) restrained by the plunger (118).
In the lower thread winding device in which the thread T is supplied from the needle 36 onto the rotating bobbin 12, the rotation speed of the plunger 118 can be adjusted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thread winding device for a sewing machine, and more particularly, to a thread winding device for a sewing machine that supplies a thread to a bobbin accommodated in a thread spooling device.

[0002]

2. Description of the Related Art A conventional thread winding device of this type is disclosed, for example, in Japanese Patent Publication No. 2-34631. Then
In this bobbin winding device, when the plunger is at the depressed position, the rotation of the yarn take-up device is transmitted to the plunger to rotate the bobbin restrained by the plunger, and the thread is supplied from the needle onto the rotating bobbin. It has become.

[0003]

However, in the thread winding device of the sewing machine described in this publication, the rotation speed of the thread take-up device is the same in the case of performing the normal sewing operation and the case of performing the above-described thread winding. Met. Therefore, when performing the bobbin winding, the rotation speed of the bobbin is too fast, and uneven winding has occurred.

Therefore, an object of the present invention is to provide a thread winding device for a sewing machine that eliminates such a problem.

[0005]

In order to solve the above-mentioned problems, the measures taken in claim 1 are: (a) a needle for reciprocating movement; (b) a yarn take-up device rotatable about a vertical rotation axis; (C) a bobbin case that is stably accommodated in the thread take-up device; (d) a bobbin that is stowed in the bobbin case; and (e) a slidable along the axis of the bobbin. A plunger mounted on the bobbin so as to rotatably restrain the bobbin; (f) a spring for urging the plunger upward to position the head of the plunger at a predetermined raised position; A) a sliding plate having a cam and for shifting the plunger to a depressed position when the cam is engaged with the head, and (h) intermittently connecting the plunger and the thread take-up device so that the plunger is depressed. In position An intermittent mechanism for transmitting the rotation of the thread take-up device to the plunger; and (i) activating a sewing mechanism when the plunger is at the depressed position to cause the rotation of the thread take-up device to depend on a set condition. And a control device for supplying a thread from the needle onto the bobbin that rotates with the rotation of the plunger.

[0006]

In the structure (first technical means) according to the first aspect of the present invention, the rotation of the bobbin is adjusted by adjusting the rotation speed of the plunger from the sewing mechanism side so that the thread winding is not uneven. can do. Further, the amount of thread wound can be adjusted according to the sewing mode thereafter.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the accompanying drawings.

Referring to FIG. 1, a sewing machine 200 includes a control device 201 serving as a CPU.
Is connected to a start switch 210, a pattern selection switch 212, a presser position switch 214, and a lower thread position switch 216. When the start switch 210 is closed, the control device 201 informs the user that start of the sewing machine has been instructed.
Recognizes. The presser position switch 214 is interlocked with a not-shown presser foot, and is opened when the presser foot is at the lower position. Also, bobbin thread position switch 2
As described later, when the thread is supplied from the needle 36 to the bobbin 12 by the thread winding device, the cam 16 of the slide plate 24 is simultaneously closed when the head of the plunger is pressed down, as will be described later. Each time the pattern selection switch 212 is pushed, an icon of the sewing pattern and a reference number given to the sewing pattern are displayed on a liquid crystal display 247,
The feed amount of the sewing pattern and the swing width of the needle are read from a storage device (not shown) to a work area in the control device 201, and are appropriately referred to.

The controller 201 also controls the main motor 230, the feed motor 232, and the width motor 234 via the main motor drive circuit 220, the feed motor drive circuit 222, and the width motor drive circuit 224, respectively. Thus, while the main motor 230 is rotating, the rotation is transmitted to the main shaft of the sewing machine, and sewing is performed by reciprocating movement of the needle. The feed motor 232 is driven to drive a feed dog (not shown) by a predetermined angle to feed the cloth by a predetermined amount, and the width motor 234 is controlled to swing by a predetermined amount by the needle bar holding the needle bar. Is done. Further, a rotation speed detection sensor 240 is linked to the main motor 230 that rotates the main shaft, and the rotation speed of the main motor 230 or the main shaft is always transmitted or fed back to the control device 201 as an electric signal.

When a power plug (not shown) of the sewing machine 200 is inserted into an outlet (not shown), the display
The lock stitch pattern icon and its reference number are displayed at the top. If another sewing pattern is desired, until the icon of the desired sewing pattern is displayed on the display 247,
The pattern selection switch 212 is pushed many times.

Next, the start switch 210 is depressed. If the slide plate 24 is fully closed and the presser foot is in the lowered position at this time, it is indicated by a lit lamp. The sewing of the sewing pattern is performed. Otherwise, the cam of the slide plate 24 pushes down on the head of the plunger, indicating that the lower thread position switch 216
When it is recognized by closing, the lower bobbin winding which will be described later is performed. Otherwise, the buzzer 245 is sounded and the operator is notified of an erroneous operation via the display 247. ing.

In the following, the configuration and operation of the lower thread winding device will be specifically described. As shown in FIGS. 2 to 15, the yarn winding device 10 includes a hollow shaft 14 supported in a bush 16.
Is provided. Then, the bush 16 is
The sewing machine bed 18 is formed with a space portion 20 for accommodating the thread take-up device 10. The space 20 is opened and closed by a sliding needle plate 24.

When the sewing machine 200 is in operation, the one-way rotational movement of the thread take-up device 10 is given by a bevel gear 26, which is fixed to the hollow shaft 14 by a set of set screws 28. In addition, it meshes with a bevel gear 30 of a drive bed shaft (not shown). The thread take-up device 10 is configured to make two rotations for each one reciprocating movement of the needle 36 in the vertical direction.
The needle 36 cooperates with the thread take-up device 10 when forming a stitch through a needle hole 38 formed in the needle plate 22.

The yarn take-up device 10 has a cup shape with an upper opening, and includes a rim 40 having a bearing surface 42 extending upward. The rim 40 is further formed with an inwardly extending annular bearing rib 44, a lateral hole 46 is formed on one side of the rib 44, and a point 48 is formed. The needle 36 reciprocates in a passage crossing a plane including the rotary movement passage of the blade point 48. The yarn spooling device 10 includes a base 50 having an arcuate hole 52 formed therein so as to provide a gap to the tip of the needle 36. The thread pulling member 54 supported on the step 55 is attached to the base 50 by screws 56.

A bobbin case 58 is restrained in the yarn take-up device 10 formed in a cup shape. The bobbin case 58 includes a bobbin-compatible cavity 59 opened upward,
An annular base 60 through which a large central control hole 61 passes is formed. A flange 62 is formed on the outside of the bobbin case 58, and the flange 62 is seated on the bearing rib 44 of the yarn spooling device 10, and its radial direction is constrained by the bearing surface 42. . The flange 62 has a thick portion 64 formed along the chord so as to provide a gap between the bobbin case 58 and the thread take-up device 10 with respect to the reciprocating passage of the needle 34. The bobbin case 58 has a thick portion 6
4, recesses 66 and 68 are formed on both sides of the striking member 70. The recesses 66 and 68 receive 72 and 74 of the bobbin case holding member 71, and the holding member 71 is screwed by the screws 76 and 77 and the nut 78 to the sewing machine bed 18.
It is attached to. The arms 72 and 74 limit or suppress the upward movement of the bobbin case 58, and the connecting bridge 80 sandwiches the abutting member 70 and prevents the rotation of the bobbin case 58. As shown in FIG.
The arm 79 pivotally supported by the bed 18 by the bobbin case 5
8 to assist the pressing of the bobbin case 58, and when the bobbin case 58 is removed, the bobbin case 58 is removed.
So that you can take it out of

The thick plate portion 64 of the bobbin case flange 62
A recess 82 is formed in a portion substantially corresponding to the thread tension bracket 8 by a set screw 88.
Six supporting arms 84 are mounted. A radial hole 90 is formed in the flange 62 of the bobbin case adjacent to the recess 82, and a thread tensioner bracket 86 is formed across the hole 90.
Is straddling. The downwardly bent arm 92 on the bracket 86 is arranged in the radial hole 90 of the bobbin case and forms a mounting surface, on which a thread tension spring 94 is mounted by a screw 96. ing.

As shown, the spring 94 is formed with a slot 98 in the form of a U-shaped loop which separates the tongue 100 and through which the bracket 8 extends.
The fastening screw 96 and the positioning pin 102 on the 6 extend. The tongue 100 is surrounded by an outer spring portion 104, and the plank portion 64 frictionally engages the bobbin thread against the downward bracket arm 92 and provides tension to the bobbin thread.

A thread inlet slot 106 is formed in the downward bent arm 92, and the end of the slot 106 is provided with a small hole 108 as shown in FIGS. The spring 94 is guided to a spring plate portion 104. Below this thread tension spring 94, a downward bent arm 92 is provided.
Is formed with a thread guide groove 110, and the bobbin thread extends from the thread tension spring 94 to the stitch forming point through the thread guide groove 110. Therefore, the spring plate portion 104
The tension applied to the bobbin thread by can be controlled by adjusting the tightening screw 96.

The bobbin 12 is provided in the space 5 of the bobbin case 58.
9 can rotate. Bobbin 12 has a top flange 112. An outwardly extending slot 114 is formed in the flange 112.
4 is positioned on top flange 112 so as to be slightly offset from its true radial position. Bobbin 1
2 further comprises a bottom flange 115 having a protruding ring 116 seated on the annular base 60 of the bobbin case 58;
1 and a suspension boss 117 extending inward.

A plunger 118 is mounted in the bobbin 12 so as to be slidable along a rotation axis 120 of the bobbin 12. The plunger 118 includes a top button-shaped screw head 122, a cylindrical portion 124 slidable in a central bobbin hole 126, and a key matching slot 13 in the bobbin 12.
It has a key portion 128 that can slide within the zero. Keyed slot 1 located below top button screw head 122
A spring 136 surrounding the cylindrical portion 124 of the plunger 118 located within 30 is defined by engaging the upper end of the key 128 upwardly with the upper end of the key matching slot 130 (FIG. 4). Energized to the ascending position.

The slide plate 24 is provided with a cam 14 which engages with the plunger 118 when the slide plate 24 is in the partially open position, and causes the plunger 118 to spring 136. The bobbin 12 is driven downward. As shown, the flexible arm 142 of the cam 140 is mounted on the underside of the slide plate 24 and has a recessed surface 14 as shown at 144.
6 and a portion that contacts the surface of the button-shaped head 120. This helps to keep the slide plate 24 stationary when the cam 140 is over the button head 1220. Thus, when the sliding plate 24 is in the partially open position, it is engaged with the plunger 118 and the plunger 118 is driven downward with respect to the spring 136, and at the same time, formed on the lower side of the sliding plate 24. When the lower thread position switch 216 (FIG. 15) of the projection 145 is closed, the
With 45, the user is notified by sound.

The plunger 118 is driven downward by the cam 140 when the sliding plate 24 is partially open, so that the bottom end of the key 128 on the plunger 118 can operate the sewing machine 200. At times, key matching cross slot 14 in the upper end of chuck 150
If 8 or 149 is rotationally aligned to receive the key (FIG. 5), it will be able to enter this slot. At this time, the plunger 118 is connected to the chuck 150 and rotates together with the bobbin 12 and the yarn take-up device 10 and enables the bobbin 12 to be wound.

As shown, the chuck 150 includes a short axis 152 which is mounted within the hollow shaft 14 such that it can rotate about the axis 120, the common axis of the plunger 118 and the hollow shaft 14. It is suspended. The upper end of the chuck 150 having the key fitting slots 148 and 149 is located in the opening 154 of the bobbin thread pull-out member 54, and the bobbin thread pull-out member 54 is attached to the thread take-up device 10 by the screw 56 as described above. .

As is well known (eg, US Pat. No. 3,693,565), the bobbin thread pull-out member 54 pulls out and positions the bobbin thread during a sewing cycle. Chuck 150 is frictionally engaged with annular member 160 by ends 162 and 164 of spring clutch 166, and spring clutch 166 has a tongue 168 extending into slot 170 of the extraction member.
6, the driving member connects the drawer member and the chuck 150 with each other.

The thread guide finger 172 is pivotally mounted in the bed 18 by a pin 174. The pin 174 is connected to one edge 76 of the bobbin case hole 90 and one end of a bracket 86 supporting the thread tensioner spring 94. 178 so as to be substantially opposed to the thread compatible passage (yarn pull-out passage). The thread guide finger 172 is moved to the stopper 18 by the torsion spring 180.
When the sliding plate 24 is at an arbitrary position other than the fully closed position, the spring 180 occupies such a position.

At the position where the finger piece 172 is engaged with the stopper 182, one edge 184 is engaged with the needle thread T,
When the needle thread T is moved around the bobbin case 58 by the yarn take-up device 10, the needle thread T is moved between the edge 176 of the opening 90 and the end 178 of the bracket 86 in the thread matching passage in the bobbin 12. It is arranged to guide inside.

As shown, the finger 172 has an upright tongue 186. The upright tongue piece 186 is used for the sliding plate 2.
When 4 is moved to its fully closed position, it engages a slidably adjustable cam 188 under its slide plate 24. In addition, at this time, the finger piece 172 is
Are no longer guided into the thread matching passage in the bobbin 12 and are held in this position.

When refilling the bobbin 12 with a thread, the free end of the needle thread T extending from the needle 36 on the needle plate 22 is held down, and the sliding plate 24 is moved to its partially closed position. Move the cam 140 at this time
8 comes into engagement with the head 122. At this time, the bobbin thread switch is closed, and the controller 201 recognizes this fact. In this state, when the start switch 210 is pressed, the sewing machine 200 starts operating, and the reciprocating movement of the needle 36 and the thread wheel take-up operation It is in a state where rotation of the container 10 can be performed. As described above, the downward movement of the cam 140 causes the chuck 15 to move.
0 is connected to the spring clutch 166.
And, it is rotated by the pull-out member 54 attached to the yarn spooling device 10 via the chuck 150. Bobbin 12
Is rotated by a plunger 118 acting via a key 128.

When the first downward movement of the needle 36 is performed, both legs of the needle thread T passing through the center of the needle 36 are suspended downward through the needle hole of the needle plate 22, and the point 48 is shown in FIG. The yarn loop of the needle thread T is captured as shown in FIG. When the yarn spooling device 10 further rotates, the yarn loop of the captured needle thread T is divided into an upper yarn loop extending above the bobbin case 58 and a yarn loop extending below the bobbin case 58. The free end of the thread loop of the needle thread T, which comes out of the upper thread loop or needle meddle and is held on the needle plate 22, meets the edge of the finger 172 as shown in FIGS. It is guided into a bobbin thread fitting passage, from where it enters the thread entry slot 106 and small hole 108. At this stage, the needle thread T is attached to the downward bent arm 9 of the bracket 86.
2 and the thread portion 104 of the thread tensioner spring, this thread has not yet been guided into the bobbin 12 and has not yet been released from the sword 48, so that the thread guide groove 11
It isn't even drawn into zero.

When the thread take-up device 10 further rotates and moves beyond the position shown in FIG. 9, the thread thread of the needle thread T is pulled down from the blade point 48. The rotation of the bobbin 12 moves the bobbin slot 114 below the upper leg of the needle thread loop. This upper leg is bobbin slot 1
14 and wound around the hub 192 of the bobbin 12. Since this winding is performed continuously, the slack of the yarn disappears in the yarn and the groove 110 is formed as shown in FIG.
It is drawn into. Also, since the slot 114 is inclined with respect to the radius of the bobbin 12, the upper leg of the thread is
0 and this thread is cut on the cam 140 by the abrasive action of the thread on the bobbin 12 due to the rotation of the bobbin 12 (FIG. 14). Thereafter, the continuous rotation of the bobbin 12 causes a replenishing thread to be wound thereon, which is later used as a bobbin thread when forming a main seam.

After the bobbin 12 is replenished with the thread, the sliding plate 2
4 is moved to the fully closed position (FIG. 3). As a result, the cam 140 is separated from the head of the plunger 118, and the plunger 118 is lifted by the spring 136 and the chuck 15 is moved.
The connection is released from 0, so that the rotation of the bobbin 12 by the yarn winding device 10 is stopped. Movement of the slide plate 24 to the fully closed position causes the cam 188 to engage with the tongue 186 on the finger 172, and the finger 172 is moved from the thread take-up device 10 so that the thread is moved onto the thread matching passage in the bobbin case. And is moved to a position where it is guided to a thread tension device (not shown) (FIG. 13). When the slide plate 24 is completely closed, the lock seam can be formed in a known manner.

The number of rotations of the plunger 118 at the time of winding the bobbin is set at the initial stage, that is, until the state in which the sword tip 48 uniformly wraps the thread T and the thread T is established, is established. The number of rotations is made slower than the number of rotations in normal sewing of a sewing pattern to prevent uneven winding and thread breakage. Therefore, as described above, this rotation speed control
The number of rotations of the main motor 230, which is the driving source of the yarn winding device 10, is determined by using the number-of-rotations detecting sensor 240.

The operation of winding the thread T around the bobbin 12 so that the thread T is supplied from the needle 36 onto the rotating bobbin 12 can be performed even when the sewing operation is interrupted. That is, when the operator recognizes that the bobbin thread has run out from the bobbin 12 during the sewing operation, the operator first presses the start switch 210 to stop the sewing machine drive. Then, after the sliding plate 24 is partially opened and the lower thread position switch 216 is closed, it is confirmed that the presser foot is raised and the pretension of the thread is released, and the lower thread winding switch 2 is turned on.
When the user presses the button 17, the bobbin 12 rotates in the same manner as described above, and the thread T is supplied from the needle 36 to the rotating bobbin 12. If the lower thread winding switch 217 is pressed when a desired amount of thread is wound on the bobbin 12, the rotation of the bobbin 12 is stopped. Then, when the slide plate 24 is closed and the start switch 210 is pressed, sewing of the interrupted sewing pattern is resumed.

If the start switch 210 is pressed by mistake while the presser foot is raised, the sewing mechanism does not operate, and if the lower thread position switch 216 is not closed, the lower thread winding switch 217 is pressed. However, the rotation is not transmitted to the bobbin 12 from the plunger 118.

[Brief description of the drawings]

FIG. 1 is a control block diagram of a sewing machine to which a lower thread winding device according to the present invention is applied.

FIG. 2 is a plan view of the peg when the sliding plate is at an open position.

FIG. 3 is a cross-sectional view taken along line CC of FIG. 2 when the sliding plate is at a fully closed position.

FIG. 4 is a cross-sectional view along the line CC of FIG. 2 when the sliding plate is in a partially open position.

FIG. 5 is an exploded perspective view of the peg.

FIG. 6 is a bottom view of the bobbin.

FIG. 7 is a top view of the yarn take-up device in a position immediately after the point of the sword has taken out the yarn from the needle.

FIG. 8 is a view showing the tip of the blade at a position where the yarn captured by the blade is guided to the bobbin thread tensioner device.

FIG. 9 is a top view of the yarn spooling device in a position where the yarn loop does not fall off from the point of the sword.

FIG. 10 is a top view of the yarn spooling device in a position where the yarn loop has entered a slot of the bobbin flange.

FIG. 11 is an elevation view of a bobbin case.

FIG. 12 is a perspective view of a bobbin case, a thread tensioner device and a thread guide finger, and a diagram showing a thread guided to the thread tensioner device in a partially closed position of a sliding plate.

FIG. 13 is a diagram showing a thread loop of a needle thread passing through a bobbin thread tension spring when the sewing machine is operated.

FIG. 14 is a view showing the state of cutting the yarn position and the end of the yarn after the bobbin has made several rotations along the line NN of FIG. 9 and when refilling the yarn.

FIG. 15 is a side view showing the installation state of the lower thread switch.

[Explanation of symbols]

 Reference Signs List 10 thread take-up device 12 bobbin 24 sliding plate 36 needle 118 plunger 136 spring 150 chuck (intermittent mechanism) 201 controller

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Masanori Tanaka 2-1-1 Asahi-cho, Kariya-shi, Aichi F-term (reference) in Aisin Seiki Co., Ltd. 3B150 AA03 CD00 CD01 FK02 FK04 FK06 LA85 NA72 NB14 NC02 QA06

Claims (6)

[Claims] 1. A needle which reciprocates, (b) a thread take-up device rotatable around a vertical rotation axis, (c) a bobbin case which is stably accommodated in the thread take-up device, (D) a bobbin housed in the bobbin case, (e) a plunger mounted on the bobbin so as to be slidable along the axis of the bobbin and to restrain the bobbin rotatably. (F) a spring for urging the plunger upward to position the head of the plunger at a predetermined raised position; and (g) a cam, and the plunger is disengaged when the cam is engaged with the head. (H) an intermittent mechanism for intermittently connecting the plunger and the yarn take-up device to transfer the rotation of the yarn take-up device to the plunger when the plunger is at the lower position. (I) the said When the plunger is in the depressed position, the sewing mechanism is operated to transmit the rotation of the thread take-up device to the plunger based on a set condition, and the thread is threaded from the needle onto the bobbin which rotates with the rotation of the plunger. A thread winding device for a sewing machine with a control device to be supplied. 2. The thread winding device for a sewing machine according to claim 1, wherein the setting condition is a sewing pattern. 3. The thread winding device for a sewing machine according to claim 1, wherein the setting condition is such that an initial rotation speed of the plunger is lower than a rotation speed of the plunger during normal pattern sewing. 4. The thread winding device for a sewing machine according to claim 1, wherein the control device drives the plunger after electrically confirming that the plunger is at the depressed position. 5. The control device according to claim 1, wherein the thread is supplied from the needle onto the bobbin before sewing is started.
A thread winding device for the sewing machine according to the above. 6. The sewing machine according to claim 1, wherein the controller supplies a thread from the needle onto the bobbin when sewing is interrupted.
A thread winding device for the sewing machine according to the above.