JP2001049568A - Multi-colored sewing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multi-colored sewing machine capable of surely detecting an end breakage during sewing and preventing an improper detection during changing yarns. SOLUTION: In this multi-colored sewing machine in which a base frame A is horizontally rotatably equipped with a driving gear 37 for driving loopers 15 positioned on a needle drop location, on the other hand, a looper stand 7 attached transversely movably to the base frame A is integrally equipped with passive gears 18 for engaging with the driving gear 37 and the plural horizontally rotatable loopers 15 are arranged so as to be selectively positioned on needle locations by lateral movement of the looper stand 7, end breakage can be surely detected during sewing and an improper detection can be prevented during changing yarns to constitute an end breakage detector.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a needle for selectively sewing one of a plurality of loopers provided for sewing threads of each color in order to sew an embroidery pattern in which a plurality of colors are mixed with a plurality of sewing threads. The present invention relates to a thread holding device in a multicolor sewing machine that is brought to a drop position to perform sewing.

[0002]

2. Description of the Related Art A drive gear for driving a looper located at a needle drop position is provided on a base frame so as to be horizontally rotatable. On the other hand, a looper base is provided so as to be laterally movable with respect to the base frame, a plurality of loopers each having a passive gear are rotatably mounted on the looper base, and the looper base is selectively moved to a needle drop position by the lateral movement of the looper base. So that it can arrive. The base frame is provided with a rack for meshing with a passive gear separated from the drive gear.When the looper moves away from the needle drop position with the lateral movement of the looper table, the passive gear replaces the drive gear. (For example, Japanese Patent Publication No. 61-2)
7075).

In the above-described configuration, even if the looper once leaves the needle drop position and then returns to the needle drop position, the position of the looper in the rotation direction is the same as that when the looper is separated from the needle drop position. Return to position. Therefore, the looper that has reached the needle drop position can immediately start the sewing operation at the same position.

[0004]

However, in the above-described structure, when the looper table is moved laterally, the passive gear always meshes with the rack and turns around, so that all the passive gears need to be moved laterally. However, there is a problem that an extra force is required to rotate the looper, and a strong lateral driving device is required.

The present invention has been made to solve the above-mentioned problems (technical problems) of the prior art, and it is possible to bring a plurality of loopers to the needle drop position with high reproducibility of the rotational direction position. Further, it is an object of the present invention to provide a multicolor sewing machine capable of changing a looper with a light force. Further, the present invention is intended to prevent the cut yarn from falling off the looper when the yarn holding device cuts the yarn, and to prevent the yarn from entering at the entrance side or the back side of the sandwiching surfaces 92b, 93b. The purpose is to be able to securely hold it when it comes to the position.

[0006]

In order to achieve the above object, a multicolor sewing machine according to the present invention has a base frame in which a driving gear for driving a looper located at a needle drop position can be horizontally rotated. On the other hand, the looper base mounted on the base frame so as to be able to move laterally is provided with passive gears for meshing with drive gears, respectively, and includes a plurality of horizontally rotatable loopers. In the multicolor sewing machine which is disposed so as to be selectively positioned at the needle drop position by lateral movement, the plurality of loopers include a passive gear in each of an operating position where the passive gear meshes with the drive gear and a non-meshing retracting position. It is configured to be freely repositionable in each axial direction so that it can be selectively positioned, and furthermore, an elevating mechanism for repositioning the looper positioned at the needle drop position in the axial direction, and a looper positioned at the retracted position. In the direction of rotation It is obtained by a holding mechanism for holding in position.

[0007]

When the looper is replaced, the looper is moved in the axial direction to move the passive gear from the drive gear to the guide gear, and the guide gear is further rotated to move the passive gear to the toothless portion of the guide gear. The edges of the drive gear and the passive gear are cut off. In this case, the position of the looper in the rotation direction is held at a predetermined position by the holding mechanism. The horizontal movement of the looper table is performed in the above state. When the passive gear of the looper newly arrived at the needle drop position meshes with the drive gear, the toothed portion of the guide gear first meshes with the passive gear by the rotation of the guide gear, and then the looper is moved in the axial direction. As a result, the passive gear shifts from the guide gear to the drive gear and meshes therewith.

[0008]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 to 4 show one bed A in a multi-head multi-color sewing embroidery sewing machine. A plurality of such beds A are juxtaposed in the left-right direction in FIG. Although not shown, a sewing head is provided at a spatially upper position of each bed A. FIG. 3 shows a hook B for sewing, which is provided on the sewing machine head and is movable up and down. C indicates a base frame in the bed A, and D indicates a looper device.

The base frame C will be described. Reference numeral 1 denotes a frame, and 2 denotes a top plate for supporting an object to be sewn or an embroidery frame. The top plate is detachably attached (for example, bolted) to the frame 1 for maintenance of various members attached to the frame. A needle plate 3 has a needle drop hole 4 and a thread pull-up hole, and is detachably attached to the top plate.

Next, the looper device D will be described. Reference numeral 6 denotes a rail attached to the frame 1, which is formed to be long in a direction perpendicular to the paper surface of FIG. Reference numeral 7 denotes a looper base which can be moved horizontally along the rail 6 by a slide body 8 attached to the lower surface. The moving direction may be a direction in which an arc trajectory is drawn in a horizontal plane. Reference numeral 9 denotes a looper assembly which is juxtaposed in the moving direction of the looper base 7 so as to selectively reach the needle drop position by the lateral movement of the looper base 7. FIG.
Reference numeral 10 denotes a member for moving the looper base 7 in a lateral direction. In this example, a member for laterally moving through the frame 1 is shown. The looper base 7 is fixed to the horizontal moving rod 10, and an end (not shown) of the horizontal moving rod 10 is connected to a driving device for moving the looper base 7 laterally. 11
Is a driving device for rotating and driving the looper at the needle drop position, 12 is an elevating device for moving the looper at the needle drop position up and down between an upper operating position and a lower retract position, and 13 is a retract position. Each of the holding mechanisms for holding the looper at a predetermined preparation position in the rotation direction thereof is shown.

FIG. 6 showing the looper assembly 9 will be described. Reference numeral 14 denotes a looper shaft for rotatably and vertically moving the looper, and is attached to the looper table 7 so as to be freely rotatable and vertically movable. The looper shaft 14 is hollow for thread insertion.
Reference numeral 15 denotes a well-known looper fixed to a looper shaft 14, which has a needle drop hole 16 and a thread lead-out hole 17 communicating with the hollow portion. 18 is a looper
15 is a passive gear for transmitting the rotational driving force to 15 and is attached to the looper shaft 14. Reference numeral 19 denotes a cam for determining the position of the looper 15 in the rotating direction, which is provided with an engaging recess 20 and is attached to the looper shaft 14 with a mounting screw 19a as shown in FIG. Reference numeral 21 shown in FIG. 3 is a connecting body for transmitting the lifting drive force from the lifting device 12 to the looper 15, and an engagement piece 22 with the lifting device is provided at a distal end thereof.
Bearings 24 are provided at the bases of the rotation stoppers 23 so as to be rotatable relative to the looper shaft 14 and integrated in the axial direction.
Installed in.

The driving device 11 will be described. Reference numeral 31 denotes a housing for accommodating the connecting gear, which is attached to the frame 1. 32 is a lid of the housing 31. 33 is the main shaft,
The frame 1 is laid horizontally so as to penetrate the housing 31,
A drive source, for example, a motor is connected to one end not shown. Reference numeral 35 denotes a drive shaft for driving the looper, which is connected to the main shaft 33 in the housing 31 via connection gears 34 and 36. Reference numeral 37 denotes a drive gear for rotating the looper, which is fixed to the shaft 35. Reference numeral 38 denotes a guide gear for guiding the engagement of the passive gear 18 with the drive gear 37, and has a toothed portion 39 and a toothless portion 40 as shown in FIG. The toothed portion 39 has the same diameter as the drive gear 37,
They are formed at the same pitch. The range of the toothless portion 40 is set to be large enough to prevent the passive gear from meshing with the lateral gear as described later. The guide gear 38 is attached to the drive shaft 35 with the teeth of the drive gear 37 and the teeth of the toothed portion 39 continuing. In this example, the guide gear 38 and the drive gear 37 are integrally formed.

The holding mechanism 13 will be described. Reference numeral 41 denotes a substrate fixed to the looper base 7, and reference numeral 42 denotes a detent piece for engagement with the cam 19, which is provided with a number corresponding to the number of the cams 19 of each looper assembly 9 as shown in FIG. Then, it is attached to the substrate 41. Reference numeral 43 denotes an operation window for operating the mounting screw 19a, which is formed at a position and a size opposite to the mounting screw 19a of the cam 19 in the entire looper assembly 9 at the retracted position as shown in FIG. Reference numeral 44 denotes a member for guiding the connecting body 21 up and down without rotating, and is engaged with the rotation stopper 23. Reference numeral 45 shown in FIGS. 1 and 8 is a detachment restricting member for preventing the concave portion 20 of the cam 19 from coming off from the above-mentioned detent piece 42. As is clear from FIG. The gap between the upper surface of the passive gear 18 at
As shown in FIG. 2, it is provided at a position smaller than the fitting depth of the rotation preventing piece 42 to the concave portion 20 and, as shown in FIG. 2, overlaps with the passive gear 18 related to the looper 15 other than the looper 15 at the needle drop position. And is attached to the housing 31 for fixing to the frame 1.

Next, the operation of the embroidery sewing machine will be described. During normal sewing, the looper assembly 9 at the needle drop position, that is, the looper assembly 9 at the position where the needle drop hole 16 of the looper 15 overlaps with the needle drop hole 4 of the needle plate 3 is moved by the lifting mechanism 12. In the actuated position, as shown in FIG. 3, the passive gear 18 is engaged with the drive gear 37. The main shaft 33 is reciprocated, and the looper 15 is reciprocated via the gears 34 and 36, the drive shaft 35, the drive gear 37, and the passive gear 18 as is well known. This rotation is performed in synchronization with the vertical movement of the sewing hook B as is well known. On the top plate 2, the cloth spread over the embroidery frame is intermittently moved laterally in synchronization with the vertical movement of the hook B. As a result, the sewing is performed on the needle plate 3 with the sewing thread 46 supplied through the thread lead-out hole 17 of the looper 15. In the case of the sewing described above, the direction of the hook portion of the hook B is determined according to the sewing method and the moving direction of the cloth, as is well known. In the case of a sewing method in which the thread is simply pulled up from the cloth for each stitch (a sewing method referred to as a loop sewing), the direction is the same as that in which the thread can be easily detached. The direction of the starting point at which the looper 15 rotates, for example, the direction of the thread lead-out hole 17 with respect to the needle drop hole 16 is
As is well known, it is determined according to the direction of the hook so that hooking of the thread to the hook is ensured. For example, a state in which the thread lead-out hole 17 faces the needle drop hole 16 on the opposite side to the direction of the hook. To be.

Next, a looper 15 for changing a thread used for sewing is provided.
Explain the exchange. The state where the needle B is located at the top dead center and the looper 15 is located at the origin in the rotating direction, for example, the thread leading-out hole 17 is in the needle dropping position in FIG. 2 (the position where it is connected to the driving gear 37).
The sewing machine is stopped when the clock arrives at the 9 o'clock position as indicated by the looper 15 in FIG. Next, the thread after sewing is cut manually or by a thread cutting device described later. Next, the lifting device 12
As a result, the looper assembly 9 at the needle drop position is lowered to the retracted position as shown in FIG.

In this state, the passive gear 18 is shown in FIG.
As shown in the middle diagram (this diagram is a diagram as viewed from the bottom side), the toothed portion 39 of the guide gear 38
19 is on the detent piece 42. Next, in this state, the guide gear 38 is rotated in the arrow X direction by the main shaft 33. In the turning process, when the passive gear 18 is engaged with the toothed portion 39 of the guide gear 38 as shown in FIG. 9A, the passive gear 18 is interlocked with the rotation of the guide gear 38 in the arrow X direction. To rotate. Eventually, as shown in FIG. 9B, when the passive gear 18 comes out of the toothed portion 39 of the guide gear 38 to the toothless portion 40,
Then, the rotation of the passive gear 18 stops. At the time of this stop, as shown in FIG.
20 fits with the rotation stopper 42. As a result, the position of the looper 15 in the rotation direction is such that the passive gear 18
The thread lead-out hole 17 like the looper 15 located at a position other than the needle drop position in FIG. In order to achieve such a state, the positional relationship between the cam 19 and the passive gear 18 in the rotational direction is adjusted in advance. The adjustment is
When the 20 is engaged with the rotation stopper 42, the mounting screw
This is performed by loosening the loop 19a, turning the looper 15 together with the shaft 14 to a predetermined preparation position, and then tightening the screw 19a. The work is performed through the window 43 from the front side of the sewing machine.

The guide gear 38 continues to move in the direction indicated by the arrow X in FIG.
In the direction shown in FIG. 9 (C). In this state, the horizontal moving rod 10 is used to move the looper base 7.
Is laterally moved, for example, in the direction of arrow 47 in FIG. In the case of the lateral movement, all the passive gears 18 move laterally through the toothless portion 40 as shown in FIGS. 10 and 11, so that the looper 15 does not rotate at all. The horizontal movement of the looper base 7 causes the next operation of the looper 15 as shown in FIG.
(The looper 15 is pre-loaded with a different color or type of thread from the previously operated looper) is brought to the needle drop position. The position of the looper 15 in the rotation direction is held at a predetermined preparation position by the holding mechanism 13 in the same manner as described above.

When the new looper 15 comes to the needle drop position,
Next, the rotation of the main shaft 33 causes the guide gear 38 to rotate in the direction of the arrow Y in FIG. 9C. When the toothed portion 39 of the guide gear 38 reaches a position as shown in FIG.
Starts rotating by meshing with the toothed portion 39. The cam 19 rotates with the rotation of the passive gear 18. Then, the cam 19 has the fitting recess 20 disengaged from the detent piece 42 and rides on the detent piece 42 as shown in FIG. When the toothed portion 39 starts engaging with the passive gear 18, the passive gear 18 is held by the holding mechanism 13 in a state where the passive gear 18 has previously been disengaged from the toothed portion 39. The tooth tip of the passive gear 18 and the tooth tip of the toothed portion 39 are extremely smoothly processed without collision. When the passive gear 18 engages with the toothed portion 39 of the guide gear 38 as described above, the elevating device 12 causes the looper assembly 9 that has newly reached the needle drop position.
Is raised. As a result, the passive gear 18 reaches the drive gear 37 using the teeth of the guide gear 38 as a guide, and the looper 15 reaches the operating position during sewing as shown in FIG.

In the above-mentioned sewing machine, maintenance of various members attached to the frame 1 can be performed by removing the top plate 2 from the frame 1, leaving the upper surface open, and performing maintenance therefrom. In this case, even if the operator accidentally touches the looper assembly 9 at a position other than the standby position, that is, the needle drop position, the detachment restricting member 45 prevents the looper assembly 9 from rising, and the concave portion 20 of the cam 19 is prevented from rotating. It is kept fitted to 42. Therefore, the position of the looper 15 in the rotation direction is maintained at the preparation position.

Next, the elevating device 12 shown in FIGS.
Will be described. This elevating device 12 moves a number of loopers sideways for thread change and selectively positions them at the needle dropping position, and the looper is moved to an upper operating position for the sewing operation at the needle dropping position. In a multicolor sewing embroidery sewing machine which is to be repositioned between a lower retreat position for the horizontal movement and a position where the upper and lower loopers are moved up and down a thread supply path defined at a position directly below the looper. From the other position so as to be able to perform smoothly.

The drawings will be described below. Symbols A to D,
The structures indicated by 1 to 45 and their functions are as described above. Next, the lifting device 12 will be described in detail. Reference numeral 51 denotes a thread 46 directly below the looper 15 at the needle drop position.
A support frame for supporting at a lateral position avoiding the supply path P of the sewing machine, and a support frame behind the path P (a side where the operator of the sewing machine is located, that is, a left side in FIG. 3) to avoid various other mechanisms. (A rear side as viewed from above), and a vertically long rotation stopper 52 is provided on the front surface, and attached to the frame 1 with bolts 51a.
53 is a guide rod. Numeral 54 denotes an elevating body for vertically moving the looper assembly 9, which is vertically movably mounted on a guide rod 53, and which is provided with a fitting body 55 provided at a rear portion for preventing rotation.
52 so that it can move up and down freely.
An engaging portion 56 for engaging with the motor 22 is provided. The side surface of the engaging portion 56 is formed in a U-shape so that the engaging piece 22 can freely enter and exit in the left-right direction with the lateral movement of the looper base 7. The engaging portion 56 includes a push-up body 57 for raising the engaging piece 22 and a pressing body 58 for lowering the same. Reference numeral 59 in the pressing body 58 is a pressing piece for urging the engaging piece 22 downward, and is provided to be vertically movable with respect to the base member 58a of the pressing body, and is urged downward by a spring 60. is there. Next, reference numerals 61 to 63 denote structures for moving the elevating body 54 up and down. Reference numeral 61 denotes a driving shaft for elevating and lowering, which is rotatably mounted on the support frame 51. The shaft 61 is provided horizontally across other beds, and one end is connected to a drive device for lifting operation. Reference numerals 62 and 63 denote members for converting the reciprocating rotational movement of the shaft 61 into a vertical movement of the elevating body 54. Reference numeral 62 denotes a lever, and reference numeral 63 denotes a link. The link 63 is connected to the elevating body 54 at a substantially intermediate position between the penetrating part of the guide rod 53 and the engaging part 56 in order to move the elevating body 54 up and down smoothly without undulation.

The operation of the lifting device 12 will be described. During the sewing operation of the sewing machine, the lifting body 54 is at the raised position as shown in FIGS. 3 and 12A, and the looper 15 is at the operating position.
When the looper 15 is moved to the evacuation position, the drive shaft 61 rotates counterclockwise in the drawing, and the elevating body 54 descends to the descending position through the members 62 and 63 as shown in FIGS. In the case of this lowering, the engagement piece 22 is pushed down by the spring-biased push piece 59, so that the lower surface of the cam 19 is located at a place other than the concave portion 20.
And there is no trouble even if the lowering of the engagement piece 22 stops there. As described above, when the looper 15 rotates to the ready position, the concave portion 20 faces the detent piece 42, so that the engaging piece 22 is lowered by the pressing force of the pressing piece 59, and the concave portion 20 and the detent piece 42 are fitted. Is achieved.

Next, in FIGS. 1-4 and 13-18, E indicates a yarn cutting device. This thread cutting device E is a sewing machine which is capable of performing sewing while exchanging various kinds of threads by interchangeably using a large number of loopers. Is held to prevent it from falling out of the looper, and cutting is performed in the holding state, and even if it is configured as such,
It is an object of the present invention to make it possible to easily perform operations of assembling, adjusting, and maintaining the thread cutting device.

The drawings will be described below. Symbols A to D,
Structures 1 to 45 and their functions are as described above. Next, the yarn cutting device E will be described. The device E includes a cutting mechanism E1 for cutting the yarn at a position off the side of the vertical movement locus so as not to hinder the vertical movement of the looper 15, and an operation mechanism E2 thereof. The cutting mechanism E1 only slightly avoids the vertical movement of the looper 15 in order to shorten the thread remaining on the side following the cloth after cutting and the thread remaining on the side of the looper 15 as short as possible. It is provided at a position as close to the looper 15 as possible. The cutting device E also includes a yarn shifting mechanism E3 for bringing the yarn between the needle hole 4 and the looper 15 to the cutting mechanism E1, and an operating mechanism E4 thereof.

First, the cutting mechanism E1 will be described. FIG.
Reference numeral 66 denotes a support for supporting each member of the cutting mechanism E1, and a substrate 66a located close to the lower surface of the top plate 2 and a substrate 66a.
And a supporting portion 66b for supporting the
b is bolted to the frame 1. Reference numeral 67 denotes a cutter, and a fixed knife fixed to the substrate 66a so that the yarn brought toward the cutter can be cut at the given position.
68, and a movable knife 70 pivotally attached to the fixed knife 68. 68a and 70a show each blade. 69 is a fixing screw, and 71 is a pivotally mounted pin. 72 is a movable knife 70
Arm for actuation.

Next, the operation mechanism E2 will be described. FIG.
The reference numeral 74 denotes an operation shaft, which is provided laterally so as to penetrate the frame 1 at a position immediately below the top plate 2 and connected to a drive source (not shown). Reference numeral 75 denotes a scalpel cam, which is a cylindrical cam used to fit in a small space below the top plate 2. Reference numeral 76 denotes a transmission piece for transmitting the operation of the cam 75 to the movable knife 70. The transmission piece has a height such that it can be located in a narrow space between the top plate 2 and the looper 15 traversing therebelow or a thread holding mechanism described later. Formed in a flat shape with small dimensions in the direction
The pin c is pivotally attached to the substrate 66a with a pin, a driven piece 76a attached to one end is fitted into the cam groove 75a of the cam 75, and the other end is connected to the arm 72 by a pin 76b. Reference numeral 77 denotes a member for preventing the driven piece 76a from coming off (floating) from the cam groove 75a, and is constituted by a pin fixed to a support 80 described later through an elongated hole 76d formed in the transmission piece 76.

Next, the yarn deviation mechanism E3 will be described. Reference numeral 80 denotes a support for supporting each member of the yarn deviation mechanism E3, which is provided near the lower surface of the top plate 2 and is bolted to the frame 1.
Numerals 81 and 82 denote upper and lower thread pieces, respectively, which are provided at the front end of a reciprocating member 85 which can be freely reciprocated in the horizontal direction by guides 83 and 84 bolted to the support 80. The lower thread piece 82 is formed of one piece with the reciprocating member 85, and the upper thread piece 81 is welded to the reciprocating member 85.

The operation mechanism E4 will be described. 86 in FIG.
Is a cam for moving the yarn pieces 81 and 82 forward and backward.
When mounting the cams 75 and 86 on the operation shaft 74 in assembling the E4 and E4, the relationship between the operation timing of the movable knife 70 and the thread pieces 81 and 82 can be obtained without taking into account the positional relationship between the cams 75 and 86. Are formed integrally with the cam 75 so as to be as designed. 87 is a cam
A transmission piece that transmits the movement of 86 to the thread pieces 81 and 82.
It is formed in a flat shape from the same consideration as 76. 87a
Is a driven piece for the cam groove 86a, 87b is a pin for linking with the advance / retreat member 85, and 87c is a pin for pivotally connecting the intermediate portion to the support 80.

Next, FIG. 1F and FIG.
2 shows a yarn holding device provided in connection with the present invention. The device F is for preventing the cut yarn from falling off the looper 15 when cutting the yarn, and will be described below with reference to FIGS. 1, 2, 15 and 16. Numerals 90 in FIGS. 1 and 2 denote yarn holding means individually provided for each looper 15. Each thread holding means 90 is provided as close as possible to each looper 15 for the same purpose as the cutting mechanism E1. The thread holding means 90 has a pair of gripping pieces 92 and 93. The gripping piece 92 is formed integrally with a base 91 common to all the yarn holding means 90 to facilitate assembly. The gripping piece 93 is pivotally attached to the base 91 so as to be able to adjust the position in the lateral direction (left and right direction in FIG. 2) with respect to the base 91 in order to adjust the contact between the gripping piece 92 and the gripping surface 92b. I have. That is, as shown in FIG.
Is rotatably fitted to the holding cylinder 94, and the holding cylinder 94 is attached to the base 91 by a stopper (for example, a bolt) 95 having a smaller diameter than its inner diameter. Reference numeral 96 denotes a washer for preventing the holding piece 93 from coming off. In this configuration, the position of the base 93a of the gripping piece 93 can be determined so that the sandwiching surfaces 93b, 92b of the gripping piece 93 and the gripping piece 92 are in close contact with each other in the entire area. Then, the stopper 95 is fixed. In this way, even when the yarn comes to any position, such as the entrance side or the back side of the sandwiching surfaces 92b, 93b, it can be reliably sandwiched and held. 97 is a gripping piece
An operation piece 93, 97a is a recess for receiving a spring. Reference numeral 98 denotes a spring holding piece which is attached to the base 91. 99 is the gripping piece 92,
A compression coil spring 93 for closing each other with a predetermined clamping force, and 100 is a washer for receiving a spring.

FIG. 17A shows a yarn holding device F having such a structure as shown in FIG. 17A in order to reliably hold the yarn brought to the yarn holding means 90 by the yarn shifting mechanism E3 from the looper 15 stopped at the position of the origin. As shown, the clamping surface 92b of the gripping piece 92
Of the looper 15 whose extension line 92c is at the position of the origin.
Is mounted on the looper table 7 in a positional relationship of passing through the position.

Next, G shown in FIGS. 1 to 4 is a release mechanism for releasing the thread holding means 90 associated with the looper 15 located at the needle drop position. The mechanism G is mounted on the frame 1 with a bracket.
It is constituted by a solenoid 102 mounted via 101. The plunger 103 of the solenoid 102 faces the operation piece 97 of the thread holding means 90. When power is supplied to the solenoid 102, the plunger 103 projects. Then, the operation piece 97 is pushed to open between the grip pieces 92 and 93.

Next, the operation of the above-described yarn cutting device E and the structure related thereto will be described. The thread cutting device E is used, for example, in a case where sewing using one thread is completed and then the thread is changed and sewing is performed using another thread. The operation will be described with reference to FIGS. After sewing at a normal spindle speed of about 500 revolutions per minute, the spindle speed is reduced to, for example, about 200 revolutions for stopping.
When the sewing of the cloth to the predetermined position is completed, as shown by reference numeral 201 in FIG. 19, first, the vertical movement of the hook B is stopped, and the rotation of the main shaft 33 is stopped. in this case,
The looper 15 is positioned at the origin in the rotation direction, for example, FIG.
The rotation of the thread lead-out hole 17 stops at 9 o'clock on the timepiece as shown in FIG. Next, the looper assembly 9 is moved by the lifting device 12.
4 and FIG. 17B, the looper 15 retreats downward from the advance / retreat path of the yarn pieces 81 and 82 (see reference numeral 202 in FIG. 19). Also, the gripping pieces 92 and 93 are released by the release mechanism G.
Are opened as shown in FIG. 17C (reference numeral 20 in FIG. 19).
3). Next, the yarn pieces 81 and 82 are shown in FIGS.
19, the thread 46 between the needle hole 4 and the thread outlet hole 17 of the looper 15 is brought between the gripping pieces 92 and 93 and between the scalpels 68 and 70 (FIG. 19). Reference numeral 204). Next, when the release mechanism G is restored, FIG.
The space between the gripping pieces 92 and 93 is closed as shown in FIG.
Is held. Next, as shown in FIGS. 18G and 18H, the sewing thread 46 is cut by the operation of the movable knife 70 (see reference numeral 205 in FIG. 19). In the case of this cutting, the cloth 104 and the holding piece
One end of the sewing thread 46 between the threads 92 and 93 is fixed to the cloth 104, and the other end is gripped by gripping pieces 92 and 93. That is, both ends of the sewing thread 46 between them are fixed in a constant tension state. Therefore, when the scalpel 70 is operated, the sewing thread 46 does not enter between the overlapping surfaces of the scalpels 68 and 70 without being cut, and is reliably cut by the scalpels 68 and 70. After the cutting, the thread pieces 81 and 82 are returned to their original positions (see reference numeral 206 in FIG. 19).

When the cutting of the thread is completed as described above, the looper 15 is replaced as described above. When the looper 15 provided with the next thread to be used in the looper replacement process comes to the needle drop position, the looper 15 is raised as shown in FIG. 3 (see reference numeral 207 in FIG. 19). When the looper replacement is completed, the vertical movement of the hook B is started (see reference numeral 208 in FIG. 19), and the spindle 3 is moved.
The rotation of 3 is started at a low speed, the horizontal movement of the embroidery frame is also started, and the sewing of the embroidery pattern is started. In the case of this start, the leading end of the sewing thread is held by the gripping pieces 92 and 93. Therefore, when the hook B descends into the needle drop hole 16 of the looper 15 and the looper 15 rotates, the thread supplied through the thread lead-out hole 17 of the looper 15 is securely hooked on the hook portion of the hook B. Therefore, sewing is started properly without skipping. The holding of the leading end of the sewing thread is released as indicated by reference numeral 209 in FIG. 19 after the sewing at the start of the sewing is ensured. Then, the number of revolutions of the main shaft is also increased, and a normal sewing state is set.

Next, as another application example, the cutting device E finishes sewing of embroidery at one place in a cloth,
Used to sew another embroidery at another location. In this case, at the time point indicated by reference numeral 210 in FIG. 19, the frame is moved so that the place where sewing is newly performed reaches the needle drop position. Other operations are the same as those in the case of the thread change.

Next, in FIGS. 1, 3, 20, and 21, H indicates a thread entanglement preventing mechanism. The thread entanglement preventing mechanism H is used for a sewing machine that cuts a thread after the sewing operation is completed, and in the case of the cutting, cuts the thread in a state of being held in advance so that the cut thread does not fall off the looper 15. An object of the present invention is to prevent the thread from being wound around the rotating looper 15 when sewing is started again using the held thread.

The drawings will be described below. Symbols A to G,
The structure of 1 to 103 and the operation thereof are as described above. Next, the thread entanglement prevention mechanism H will be described. 110 is the thread holding means 9
This is a lifting member for lifting the thread 46 held by 0 near the looper 15. Lifting height is looper
For example, the upper surface of the looper 15 to prevent entanglement with 15
It is the same height as 15a. A smooth radius is formed at the corner 15b between the upper surface and the side surface of the looper 15 so that the yarn slides well there, and even if the yarn slightly hits the side surface of the looper 15, it is guided to the upper surface side. in case of,
The lifting height may be lower. 111 is the lifting member 1
10 shows an elevating mechanism for lifting the 10 to a position where it functions as described above and lowering it so as not to obstruct thread cutting. Numeral 112 denotes an elevating member of the mechanism 111, which extends along the frame 1 so as not to obstruct the lateral movement of the looper table 7 and avoids the lateral movement range.
Guided by three. Reference numeral 114 denotes a member for supporting the lifting member 110, which is attached to the left and right elevating members 112 in a bridge shape. 115 is a member for vertically moving the elevating member 112,
The looper elevating drive shaft 61 for simultaneous operation with the vertical movement of the looper 15
The tip of the lever 115
a is engaged with the connecting portion 112a of the elevating member 112.

Next, the operation of the thread entanglement prevention mechanism H will be described. When the looper 15 is lowered to the retracted position as shown in FIG. 4 for the operation of the thread cutting device E, the lifting member 110 is also lowered. Thereafter, when a new embroidery sewing operation is started, when the looper 15 is raised to the operating position as shown in FIG. 3, the lifting member 110 is also raised by the lifting mechanism 111 as shown in FIG.
The thread 46 whose leading end is held is lifted as shown in FIG. In this state, the operation of the looper 15 is started as shown in FIG. Therefore, the lifted thread 46 does not become entangled with the rotating looper 15, and the sewing starts smoothly.

Next, in FIGS. 3, 5, 22 to 24, J indicates a thread tension device. This thread tension device J includes a plurality of loopers.
By moving the looper stand 7 holding 15 the loopers
By selectively positioning the 15 at the needle drop position, in a sewing machine that can sew a cloth using a different color thread attached to each looper selectively, even when performing sewing with any looper, It is an object of the present invention to be able to always perform sewing with a good thread tension from the start of sewing.

The drawings will be described below. Symbols A to G,
The structure of 1 to 103 and the operation thereof are as described above. Next, the thread tension device J will be described. Reference numeral 120 denotes a frame for holding the thread tension mechanism, which is attached to the looper base 7 via the substrate 41. 120a is a thread insertion window. 121 is each looper 1
A plurality of thread tension mechanisms for individually adjusting the tension of the thread leading to 5 are attached to the above-mentioned lumber frame 120 in order to maintain a constant positional relationship with each looper 15 even when the looper base 7 moves laterally. is there. Reference numeral 122 denotes a change mechanism for changing the tension of each thread tension mechanism 121.

Next, the thread tension mechanism 121 will be described with reference to FIGS.
It will be described based on. 123 and 124 are thread tensioners for giving a resistance to the thread 46 pulled by the hook B, and 125 is a tension device for giving tension to the thread drawn through the thread tensioner 124. The thread tension controller 123 is a known thread tensioner that applies a certain resistance to the yarn, and 124 is a known thread tension regulator capable of changing the strength of the thread (for example, Japanese Utility Model Publication No. Sho 53-6611). In these figures, 126 and 127 are thread tension discs, 128 is a spring for pressing the thread tension disc 127 against the thread tension disc 126, and 129 is a knob for adjusting the pressing force. Reference numeral 130 in the thread tensioner 124 is a member for changing the drag, and an example of a loosening bar that weakens the drag by separating the thread tension tray 127 from the thread tension tray 126 is exemplified.

Next, the tension device 125 will be described. Reference numeral 131 denotes a spring arm for giving a resilient pulling force to the thread, which is also called a thread take-up spring, and has a threading ring 132 at a free end. The base portion 133 of the spring arm 131 is pivotally attached to the frame 120 by a pivot piece, for example, a pin 134, for integrally changing the pulling force, and is integrally provided with an operation arm 135. The operation arm 135 projects from the rear side of the frame 120 for operation by the change mechanism 122 through the long hole 136. 1
Reference numeral 37 denotes a member for positioning the operation arm 135 on one side of the repositionable range. A spring is used to enable the operation arm 135 to move to the other side.
It is attached to a holding pin 138 attached to 0. Spring 137
One end 139 is engaged with the through hole 140 of the frame 120, and the other end 141
Is engaged with the operation arm 135, and the operation arm 135 is pressed against the lower end 136a of the long hole 136 as a positioning part thereof. Reference numerals 142 and 143 denote thread guides for adjusting the direction of the thread passing through the threading ring 132 to an appropriate direction for applying tension, and are attached to the frame 120.

Next, the change mechanism 122 will be described. 145 is a change operation axis, which is commonly provided on other beds,
An operating device is attached to one end. 146 is an operation member,
An operating unit 147 for operating the member 130 and an operating unit 148 for operating the operating arm 135 are provided, and only the thread tension mechanism 121 related to the looper 15 located at the needle drop position is operated. The position is selected and attached to the operation shaft 145.

Next, the setting of the thread tension and the operation of the thread tension mechanism 121 in the case of the sewing will be described. When the sewing is the chain stitch, the drag and the tension applied to the thread 46 are increased. That is, the operation member 146 is placed at the position indicated by the solid line in FIG. 22, the thread tension plate 127 of the thread tensioner 124 is placed in the state shown by the solid line in FIG. 22, and the spring arm 131 of the tension device 125 is placed in the state shown by the solid line in FIG. When sewing is performed in this state, the tightening force of the thread against the cloth during sewing is large, and a properly tightened and appropriate chain stitch can be performed.

On the other hand, when the sewing is a known loop sewing (for example, JP-A-4-34062), the drag and tension applied to the thread 46 are reduced. That is, by turning the operation shaft 145, the operation member 4
22 is placed at the position indicated by the two-dot chain line in FIG. 22, and the thread tension plate 127 of the thread tensioner 124 is set to the state indicated by the two-dot chain line in FIG.
The 25 spring arms 131 are in the state of the two-dot chain line in FIG. When sewing is performed in this state, the thread can be smoothly pulled from the cloth on the needle plate 3, and loop sewing at a predetermined height can be properly performed.

Next, in the case of changing the thread used for sewing, since the thread tension device J is mounted on the looper table 7, even if the looper table 7 moves laterally, each looper 15 and the thread tension mechanism associated with each looper 15 are associated. The positional relationship with 121 is unchanged. Therefore, even if the looper 15 is replaced by the horizontal movement of the looper base 7, each looper 15 is replaced.
The thread between the thread tension mechanism 121 and the thread tension mechanism 121 associated with each thread is always kept in a taut state (there is no unnecessary slack). Therefore, regardless of which looper 15 is used for sewing, the thread reaching the looper 15 is sewn from the start of the sewing with the appropriate drag by the thread tensioners 123 and 124 and the appropriate tension by the tension device 125 applied. It can be performed.

Next, in FIGS. 3, 5, and 25, K indicates a yarn breakage detecting device. The yarn breakage detecting device K selectively moves the loopers 15 to the needle drop position by laterally moving the looper base 7 holding the plurality of loopers 15, thereby detecting the different color yarns attached to each looper. SUMMARY OF THE INVENTION It is an object of the present invention to provide a sewing machine that can selectively use a sewing machine to perform sewing on a cloth, so that a thread break can be reliably detected during sewing, and an erroneous detection can be prevented during a thread change.

Hereinafter, the drawings will be described. Symbols A to D,
The structures of J, 1 to 62 and 121 to 148 and the operation thereof are as described above. Next, the yarn breakage detecting device K will be described. 151
Is a detector main body, for the purpose of enabling operation with extremely light force and for the purpose of simplifying the configuration of the detection piece described below, a rotary operation type micro switch in which the movable portion 152 rotates is used, It is attached to the support frame 51. Reference numeral 153 denotes a detection piece for detecting the presence or absence of a thread break. The detection piece 153 is provided so as to freely move along the path P of the thread relating to the looper at the needle drop position and in the direction crossing the path. If there is tension and tension is applied to the yarn, the movement in the above direction is interrupted by the yarn, and if the yarn breaks and the tension is lost, push the yarn and move in the above direction (there is no yarn In this case, the urging force is applied in the above direction so as to move as it is. In this example, the above-mentioned movement is enabled by attaching to the movable portion 152 of the microswitch, and the urging force of the movable portion 152 is used. FIG.
As shown in FIG.
“a” is V-shaped in order to prevent lateral deviation from the yarn. Reference numeral 154 denotes an evacuation lever for disabling the detection piece 153, and reference numeral 155 denotes an operation piece for operating the lever 154. Mounted on lever 62.

In the thread breakage detecting device K, during normal sewing, the detecting piece 153 contacts the thread 46 as shown in FIG. 25 (A), and the detector main body 151 keeps the thread in an appropriate state. It emits a signal indicating the presence, for example, a conduction signal. On the other hand, when the yarn 46 breaks, the detecting piece 153 moves as shown in FIG. 3B, and the detector main body 151 issues a signal indicating that the yarn has broken, for example, a non-conduction signal. At the time of looper replacement for thread change, when the looper elevating drive shaft 61 rotates to lower the looper, the lever 154 is pushed by the operation piece 155 as shown in FIG. Therefore, even if the thread 46 does not exist before the detection piece 153 for the reason of the looper replacement,
This prevents the detector main body 151 from erroneously issuing a thread break signal.

[0049]

As described above, according to the present invention, when the looper table 7 is to be moved laterally for switching the looper 15, the passive gear 18 is driven by changing the position of the looper 15 in the axial direction. By moving the gear 37 to the guide gear 38 and turning the guide gear 38 to expose the passive gear 18 to the toothless portion 40, the edge of the looper 15 can be cut off from the drive gear 37. There is an effect that can be performed with light power.

Further, as described above, the driving gear 37 and the looper 15
Even if the edge of the looper 15 is cut off, the position of the looper 15 in the rotation direction is maintained at a predetermined position by the holding mechanism 13, so that the looper 15 that has reached the needle drop position after the lateral movement is driven again. When the looper 15 is connected to the gear 37, the position of the looper 15 in the rotation direction is an appropriate position, and the sewing operation can be immediately started.

[Brief description of the drawings]

FIG. 1 is a plan view of a bed with a top plate removed.

FIG. 2 is a plan view of the bed in a state where a top plate and a yarn cutting device are removed.

FIG. 3 is a longitudinal sectional view.

FIG. 4 is a partial vertical cross-sectional view showing a state where the looper assembly is lowered.

FIG. 5 is a front view of the looper device.

FIG. 6 is a partially broken perspective view showing a structure related to a drive gear and a looper.

FIG. 7 is a bottom view showing a looper holding mechanism.

FIG. 8 is a partially omitted side view showing the looper assembly and its holding mechanism.

FIG. 9 is a diagram illustrating an operation order of looper switching.

FIG. 10 is a front view showing the relationship between the passive gear, the drive gear, and the guide gear when the looper is switched.

FIGS. 11A and 11B are horizontal sectional views showing the relationship between a passive gear and a guide gear at the time of looper switching.

FIG. 12 is an explanatory diagram of the operation of the looper elevating mechanism.

FIG. 13 is a perspective view of a yarn cutting device.

FIG. 14 is a mechanism diagram of a yarn cutting device.

FIG. 15 is an exploded perspective view of the yarn holding device.

FIG. 16 is a cross-sectional view showing an attachment structure of a movable gripping piece base.

FIGS. 17A to 17D are explanatory diagrams illustrating the operation of a thread pulling mechanism, a thread holding unit, and a thread cutting mechanism.

18 (E) to (H) are explanatory views of the operation of the yarn pulling mechanism, the yarn holding means, and the yarn cutting mechanism.

FIG. 19 is a time chart for explaining the operation.

FIG. 20 is a mechanism diagram of a thread entanglement prevention mechanism.

FIGS. 21A and 21B are explanatory diagrams of the operation of a thread entanglement prevention mechanism.

FIG. 22 is a partial longitudinal sectional view of a thread tension mechanism.

FIG. 23 is a front view of the tension mechanism.

24A is a rear view of the tension mechanism when the tension is high, and FIG. 24B is a rear view of the tension mechanism when the tension is low.

FIGS. 25A to 25C are diagrams for explaining the yarn detecting device and its operation.

[Description of Signs] A Base frame 7 Looper base 13 Holding mechanism 15 Looper 18 Passive gear 37 Drive gear 38 Guide gear

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[Procedure amendment]

[Submission date] August 17, 2000 (2008.1.
7)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Full text

[Correction method] Change

[Correction contents]

[Document Name] Statement

[Title of the Invention] Multicolor sewing machine

[Claims]

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a needle for selectively sewing one of a plurality of loopers provided for sewing threads of each color in order to sew an embroidery pattern in which a plurality of colors are mixed with a plurality of sewing threads. The present invention relates to a multicolor sewing machine which is brought to a drop position to perform sewing.

[0002]

2. Description of the Related Art A drive gear for driving a looper located at a needle drop position is provided on a base frame so as to be horizontally rotatable. On the other hand, a looper base is provided so as to be laterally movable with respect to the base frame, a plurality of loopers each having a passive gear are rotatably mounted on the looper base, and the looper base is selectively moved to a needle drop position by the lateral movement of the looper base. So that it can arrive. The base frame is provided with a rack for meshing with a passive gear separated from the drive gear.When the looper moves away from the needle drop position with the lateral movement of the looper table, the passive gear replaces the drive gear. (For example, Japanese Patent Publication No. 61-2)
7075).

In the above-described configuration, even if the looper once leaves the needle drop position and then returns to the needle drop position, the position of the looper in the rotation direction is the same as that when the looper is separated from the needle drop position. Return to position. Therefore, the looper that has reached the needle drop position can immediately start the sewing operation at the same position.

[0004]

However, the above structure has a problem that when the looper base is moved laterally, the threads attached to the looper are cut off and fall off from the looper. In order to prevent this, it is considered to attach a yarn holding means to each looper. However, there has been a problem that the reliability of the yarn holding is low and the yarn sometimes comes off.

The present invention has been made to solve the above-mentioned problems (technical problems) of the prior art, and prevents the cut yarn from falling off the looper when the yarn holding device cuts the yarn. It is an object of the present invention to ensure that the yarn can be reliably sandwiched and held at any position such as the entrance side or the back side of the clamping surface.

[0006]

The multicolor sewing machine according to the present invention is provided with a drive gear for driving a looper located at a needle drop position on a base frame so as to be horizontally rotatable, while the base frame is provided with a drive gear. On the other hand, the looper table which is mounted so as to be able to move laterally is equipped with passive gears for meshing with the driving gears, respectively, and a plurality of loopers which can rotate horizontally are selectively needle-dropped by the lateral movement of the looper table. In the multicolor sewing machine arranged so as to be positioned at the position, the looper base is provided so as to correspond to each of the plurality of loopers so as to prevent the thread from falling out of the looper by being clamped by the clamping surface. The yarn holding means having a pair of gripping pieces are provided in correspondence with each other, and at least one of the pair of gripping pieces in each yarn holding means is provided with a looper base so that a sandwiching surface between the gripping pieces can be freely separated. Pivotally attached to the Its pivot state is one in which the base portion of the grip piece against the fixture so that both the inlet side and the rear side of the clamping surfaces in contact are both positioned adjustable configured in the lateral direction.

[0007]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 to 4 show one bed A in a multi-head multi-color sewing embroidery sewing machine. A plurality of such beds A are juxtaposed in the left-right direction in FIG. Although not shown, a sewing head is provided at a spatially upper position of each bed A. FIG. 3 shows a hook B for sewing, which is provided on the sewing machine head and is movable up and down. C indicates a base frame in the bed A, and D indicates a looper device.

[0008] The base frame C will be described. Reference numeral 1 denotes a frame, and 2 denotes a top plate for supporting an object to be sewn or an embroidery frame. The top plate is detachably attached (for example, bolted) to the frame 1 for maintenance of various members attached to the frame. A needle plate 3 has a needle drop hole 4 and a thread pull-up hole, and is detachably attached to the top plate.

The looper device D will be described. Reference numeral 6 denotes a rail attached to the frame 1, which is formed to be long in a direction perpendicular to the paper surface of FIG. Reference numeral 7 denotes a looper base which can be moved horizontally along the rail 6 by a slide body 8 attached to the lower surface. The moving direction may be a direction in which an arc trajectory is drawn in a horizontal plane. Reference numeral 9 denotes a looper assembly which is juxtaposed in the moving direction of the looper base 7 so as to selectively reach the needle drop position by the lateral movement of the looper base 7.

In FIG. 1, reference numeral 10 denotes a member for moving the looper base 7 in a lateral direction. In this embodiment, a laterally moving rod inserted through the frame 1 is shown. The looper base 7 is fixed to the laterally moving rod 10.
Is connected to a driving device for moving the looper table 7 laterally. 11 is a driving device for rotating and driving the looper at the needle drop position, 12 is an elevating device for vertically moving the looper at the needle drop position between the upper operating position and the lower retracted position,
Reference numeral 13 denotes a holding mechanism for holding the looper at the retracted position at a predetermined preparation position in the rotation direction.

FIG. 6 showing the looper assembly 9 will be described. Reference numeral 14 denotes a looper shaft for rotatably and vertically moving the looper, and is attached to the looper table 7 so as to be freely rotatable and vertically movable. The looper shaft 14 is hollow for thread insertion.
Reference numeral 15 denotes a well-known looper fixed to a looper shaft 14, which has a needle drop hole 16 and a thread lead-out hole 17 communicating with the hollow portion. 18 is a looper
15 is a passive gear for transmitting the rotational driving force to 15 and is attached to the looper shaft 14. Reference numeral 19 denotes a cam for determining the position of the looper 15 in the rotating direction, which is provided with an engaging recess 20 and is attached to the looper shaft 14 with a mounting screw 19a as shown in FIG. Reference numeral 21 shown in FIG. 3 is a connecting body for transmitting the lifting drive force from the lifting device 12 to the looper 15, and an engagement piece 22 with the lifting device is provided at a distal end thereof.
Bearings 24 are provided at the bases of the rotation stoppers 23 so as to be rotatable relative to the looper shaft 14 and integrated in the axial direction.
Installed in.

The driving device 11 will be described. Reference numeral 31 denotes a housing for accommodating the connecting gear, which is attached to the frame 1. 32 is a lid of the housing 31. 33 is the main shaft,
The frame 1 is laid horizontally so as to penetrate the housing 31,
A drive source, for example, a motor is connected to one end not shown. Reference numeral 35 denotes a drive shaft for driving the looper, which is connected to the main shaft 33 in the housing 31 via connection gears 34 and 36. Reference numeral 37 denotes a drive gear for rotating the looper, which is fixed to the shaft 35. Reference numeral 38 denotes a guide gear for guiding the engagement of the passive gear 18 with the drive gear 37, and has a toothed portion 39 and a toothless portion 40 as shown in FIG. The toothed portion 39 has the same diameter as the drive gear 37,
They are formed at the same pitch. The range of the toothless portion 40 is set to be large enough to prevent the passive gear from meshing with the lateral gear as described later. The guide gear 38 is attached to the drive shaft 35 with the teeth of the drive gear 37 and the teeth of the toothed portion 39 continuing. In this example, the guide gear 38 and the drive gear 37 are integrally formed.

The holding mechanism 13 will be described. Reference numeral 41 denotes a substrate fixed to the looper base 7, and reference numeral 42 denotes a detent piece for engagement with the cam 19, which is provided with a number corresponding to the number of the cams 19 of each looper assembly 9 as shown in FIG. Then, it is attached to the substrate 41. Reference numeral 43 denotes an operation window for operating the mounting screw 19a, which is formed at a position and a size opposite to the mounting screw 19a of the cam 19 in the entire looper assembly 9 at the retracted position as shown in FIG. Reference numeral 44 denotes a member for guiding the connecting body 21 up and down without rotating, and is engaged with the rotation stopper 23. Reference numeral 45 shown in FIGS. 1 and 8 is a detachment restricting member for preventing the concave portion 20 of the cam 19 from coming off from the above-mentioned detent piece 42. As is clear from FIG. The gap between the upper surface of the passive gear 18 at
As shown in FIG. 2, it is provided at a position smaller than the fitting depth of the rotation preventing piece 42 to the concave portion 20 and, as shown in FIG. 2, overlaps with the passive gear 18 related to the looper 15 other than the looper 15 at the needle drop position. And is attached to the housing 31 for fixing to the frame 1.

Next, the operation of the embroidery sewing machine will be described. During normal sewing, the looper assembly 9 at the needle drop position, that is, the looper assembly 9 at the position where the needle drop hole 16 of the looper 15 overlaps with the needle drop hole 4 of the needle plate 3 is moved by the lifting mechanism 12. In the actuated position, as shown in FIG. 3, the passive gear 18 is engaged with the drive gear 37. The main shaft 33 is reciprocated, and the looper 15 is reciprocated via the gears 34 and 36, the drive shaft 35, the drive gear 37, and the passive gear 18 as is well known. This rotation is performed in synchronization with the vertical movement of the sewing hook B as is well known. On the top plate 2, the cloth spread over the embroidery frame is intermittently moved laterally in synchronization with the vertical movement of the hook B. As a result, the sewing is performed on the needle plate 3 with the sewing thread 46 supplied through the thread lead-out hole 17 of the looper 15. In the case of the sewing described above, the direction of the hook portion of the hook B is determined according to the sewing method and the moving direction of the cloth, as is well known. In the case of a sewing method in which the thread is simply pulled up from the cloth for each stitch (a sewing method referred to as a loop sewing), the direction is the same as that in which the thread can be easily detached. The direction of the starting point at which the looper 15 rotates, for example, the direction of the thread lead-out hole 17 with respect to the
As is well known, it is determined according to the direction of the hook so that hooking of the thread to the hook is ensured. For example, a state in which the thread lead-out hole 17 faces the needle drop hole 16 on the opposite side to the direction of the hook. To be.

Next, a looper 15 for changing a thread used for sewing is provided.
Explain the exchange. The state where the needle B is located at the top dead center and the looper 15 is located at the origin in the rotating direction, for example, the thread leading-out hole 17 is in the needle dropping position in FIG. 2 (the position where it is connected to the driving gear 37).
The sewing machine is stopped when the clock arrives at the 9 o'clock position as indicated by the looper 15 in FIG. Next, the thread after sewing is cut manually or by a thread cutting device described later. Next, the lifting device 12
As a result, the looper assembly 9 at the needle drop position is lowered to the retracted position as shown in FIG.

In this state, the passive gear 18 is shown in FIG.
As shown in the middle diagram (this diagram is a diagram as viewed from the bottom side), the toothed portion 39 of the guide gear 38
19 is on the detent piece 42. Next, in this state, the guide gear 38 is rotated in the arrow X direction by the main shaft 33. In the turning process, when the passive gear 18 is engaged with the toothed portion 39 of the guide gear 38 as shown in FIG. 9A, the passive gear 18 is interlocked with the rotation of the guide gear 38 in the arrow X direction. To rotate. Eventually, as shown in FIG. 9B, when the passive gear 18 comes out of the toothed portion 39 of the guide gear 38 to the toothless portion 40,
Then, the rotation of the passive gear 18 stops. At the time of this stop, as shown in FIG.
20 fits with the rotation stopper 42. As a result, the position of the looper 15 in the rotation direction is such that the passive gear 18
The thread lead-out hole 17 like the looper 15 located at a position other than the needle drop position in FIG. In order to achieve such a state, the positional relationship between the cam 19 and the passive gear 18 in the rotational direction is adjusted in advance. The adjustment is
When the 20 is engaged with the rotation stopper 42, the mounting screw
This is performed by loosening the loop 19a, turning the looper 15 together with the shaft 14 to a predetermined preparation position, and then tightening the screw 19a. The work is performed through the window 43 from the front side of the sewing machine.

The guide gear 38 continues to move in the direction indicated by the arrow X in FIG.
In the direction shown in FIG. 9 (C). In this state, the horizontal moving rod 10 is used to move the looper base 7.
Is laterally moved, for example, in the direction of arrow 47 in FIG. In the case of the lateral movement, all the passive gears 18 move laterally through the toothless portion 40 as shown in FIGS. 10 and 11, so that the looper 15 does not rotate at all. The horizontal movement of the looper base 7 causes the next operation of the looper 15 as shown in FIG.
(The looper 15 is pre-loaded with a different color or type of thread from the previously operated looper) is brought to the needle drop position. The position of the looper 15 in the rotation direction is held at a predetermined preparation position by the holding mechanism 13 in the same manner as described above.

When the new looper 15 comes to the needle drop position,
Next, the rotation of the main shaft 33 causes the guide gear 38 to rotate in the direction of the arrow Y in FIG. 9C. When the toothed portion 39 of the guide gear 38 reaches a position as shown in FIG.
Starts rotating by meshing with the toothed portion 39. The cam 19 rotates with the rotation of the passive gear 18. Then, the cam 19 has the fitting recess 20 disengaged from the detent piece 42 and rides on the detent piece 42 as shown in FIG. When the toothed portion 39 starts engaging with the passive gear 18, the passive gear 18 is held by the holding mechanism 13 in a state where the passive gear 18 has previously been disengaged from the toothed portion 39. The tooth tip of the passive gear 18 and the tooth tip of the toothed portion 39 are extremely smoothly processed without collision. When the passive gear 18 engages with the toothed portion 39 of the guide gear 38 as described above, the elevating device 12 causes the looper assembly 9 that has newly reached the needle drop position.
Is raised. As a result, the passive gear 18 reaches the drive gear 37 using the teeth of the guide gear 38 as a guide, and the looper 15 reaches the operating position during sewing as shown in FIG.

In the above-mentioned sewing machine, maintenance of various members attached to the frame 1 can be performed by removing the top plate 2 from the frame 1, leaving the upper surface open, and performing maintenance therefrom. In this case, even if the operator accidentally touches the looper assembly 9 at a position other than the standby position, that is, the needle drop position, the detachment restricting member 45 prevents the looper assembly 9 from rising, and the concave portion 20 of the cam 19 is prevented from rotating. It is kept fitted to 42. Therefore, the position of the looper 15 in the rotation direction is maintained at the preparation position.

Next, the elevating device 12 shown in FIGS.
Will be described. This elevating device 12 moves a number of loopers sideways for thread change and selectively positions them at the needle dropping position, and the looper is moved to an upper operating position for the sewing operation at the needle dropping position. In a multicolor sewing embroidery sewing machine which is to be repositioned between a lower retreat position for the horizontal movement and a position where the upper and lower loopers are moved up and down a thread supply path defined at a position directly below the looper. From the other position so as to be able to perform smoothly.

The drawings will be described below. Symbols A to D,
The structures indicated by 1 to 45 and their functions are as described above. Next, the lifting device 12 will be described in detail. Reference numeral 51 denotes a thread 46 directly below the looper 15 at the needle drop position.
A support frame for supporting at a lateral position avoiding the supply path P of the sewing machine, and a support frame behind the path P (a side where the operator of the sewing machine is located, that is, a left side in FIG. 3) to avoid various other mechanisms. (A rear side as viewed from above), and a vertically long rotation stopper 52 is provided on the front surface, and attached to the frame 1 with bolts 51a.
53 is a guide rod. Numeral 54 denotes an elevating body for vertically moving the looper assembly 9, which is vertically movably mounted on a guide rod 53, and which is provided with a fitting body 55 provided at a rear portion for preventing rotation.
52 so that it can move up and down freely.
An engaging portion 56 for engaging with the motor 22 is provided. The side surface of the engaging portion 56 is formed in a U-shape so that the engaging piece 22 can freely enter and exit in the left-right direction with the lateral movement of the looper base 7. The engaging portion 56 includes a push-up body 57 for raising the engaging piece 22 and a pressing body 58 for lowering the same. Reference numeral 59 in the pressing body 58 is a pressing piece for urging the engaging piece 22 downward, and is provided to be vertically movable with respect to the base member 58a of the pressing body, and is urged downward by a spring 60. is there. Next, reference numerals 61 to 63 denote structures for moving the elevating body 54 up and down. Reference numeral 61 denotes a driving shaft for elevating and lowering, which is rotatably mounted on the support frame 51. The shaft 61 is provided horizontally across other beds, and one end is connected to a drive device for lifting operation. Reference numerals 62 and 63 denote members for converting the reciprocating rotational movement of the shaft 61 into a vertical movement of the elevating body 54. Reference numeral 62 denotes a lever, and reference numeral 63 denotes a link. The link 63 is connected to the elevating body 54 at a substantially intermediate position between the penetrating part of the guide rod 53 and the engaging part 56 in order to move the elevating body 54 up and down smoothly without undulation.

The operation of the lifting device 12 will be described. During the sewing operation of the sewing machine, the lifting body 54 is at the raised position as shown in FIGS. 3 and 12A, and the looper 15 is at the operating position.
When the looper 15 is moved to the evacuation position, the drive shaft 61 rotates counterclockwise in the drawing, and the elevating body 54 descends to the descending position through the members 62 and 63 as shown in FIGS. In the case of this lowering, the engagement piece 22 is pushed down by the spring-biased push piece 59, so that the lower surface of the cam 19 is located at a place other than the concave portion 20.
And there is no trouble even if the lowering of the engagement piece 22 stops there. As described above, when the looper 15 rotates to the ready position, the concave portion 20 faces the detent piece 42, so that the engaging piece 22 is lowered by the pressing force of the pressing piece 59, and the concave portion 20 and the detent piece 42 are fitted. Is achieved.

Next, in FIGS. 1-4 and 13-18, E indicates a yarn cutting device. This thread cutting device E is a sewing machine which is capable of performing sewing while exchanging various kinds of threads by interchangeably using a large number of loopers. Is held to prevent it from falling out of the looper, and cutting is performed in the holding state, and even if it is configured as such,
It is an object of the present invention to make it possible to easily perform operations of assembling, adjusting, and maintaining the thread cutting device.

The drawings will be described below. Symbols A to D,
Structures 1 to 45 and their functions are as described above. Next, the yarn cutting device E will be described. The device E includes a cutting mechanism E1 for cutting the yarn at a position off the side of the vertical movement locus so as not to hinder the vertical movement of the looper 15, and an operation mechanism E2 thereof. The cutting mechanism E1 only slightly avoids the vertical movement of the looper 15 in order to shorten the thread remaining on the side following the cloth after cutting and the thread remaining on the side of the looper 15 as short as possible. It is provided at a position as close to the looper 15 as possible. The cutting device E also includes a yarn shifting mechanism E3 for bringing the yarn between the needle hole 4 and the looper 15 to the cutting mechanism E1, and an operating mechanism E4 thereof.

First, the cutting mechanism E1 will be described. FIG.
Reference numeral 66 denotes a support for supporting each member of the cutting mechanism E1, and a substrate 66a located close to the lower surface of the top plate 2 and a substrate 66a.
And a supporting portion 66b for supporting the
b is bolted to the frame 1. Reference numeral 67 denotes a cutter, and a fixed knife fixed to the substrate 66a so that the yarn brought toward the cutter can be cut at the given position.
68, and a movable knife 70 pivotally attached to the fixed knife 68. 68a and 70a show each blade. 69 is a fixing screw, and 71 is a pivotally mounted pin. 72 is a movable knife 70
Arm for actuation.

Next, the operation mechanism E2 will be described. FIG.
The reference numeral 74 denotes an operation shaft, which is provided laterally so as to penetrate the frame 1 at a position immediately below the top plate 2 and connected to a drive source (not shown). Reference numeral 75 denotes a scalpel cam, which is a cylindrical cam used to fit in a small space below the top plate 2. Reference numeral 76 denotes a transmission piece for transmitting the operation of the cam 75 to the movable knife 70. The transmission piece has a height such that it can be located in a narrow space between the top plate 2 and the looper 15 traversing therebelow or a thread holding mechanism described later. Formed in a flat shape with small dimensions in the direction
The pin c is pivotally attached to the substrate 66a with a pin, a driven piece 76a attached to one end is fitted into the cam groove 75a of the cam 75, and the other end is connected to the arm 72 by a pin 76b. Reference numeral 77 denotes a member for preventing the driven piece 76a from coming off (floating) from the cam groove 75a, and is constituted by a pin fixed to a support 80 described later through an elongated hole 76d formed in the transmission piece 76.

Next, the yarn deviation mechanism E3 will be described. Reference numeral 80 denotes a support for supporting each member of the yarn deviation mechanism E3, which is provided near the lower surface of the top plate 2 and is bolted to the frame 1.
Numerals 81 and 82 denote upper and lower thread pieces, respectively, which are provided at the front end of a reciprocating member 85 which can be freely reciprocated in the horizontal direction by guides 83 and 84 bolted to the support 80. The lower thread piece 82 is formed of one piece with the reciprocating member 85, and the upper thread piece 81 is welded to the reciprocating member 85.

The operation mechanism E4 will be described. 86 in FIG.
Is a cam for moving the yarn pieces 81 and 82 forward and backward.
When mounting the cams 75 and 86 on the operation shaft 74 in assembling the E4 and E4, the relationship between the operation timing of the movable knife 70 and the thread pieces 81 and 82 can be obtained without taking into account the positional relationship between the cams 75 and 86. Are formed integrally with the cam 75 so as to be as designed. 87 is a cam
A transmission piece that transmits the movement of 86 to the thread pieces 81 and 82.
It is formed in a flat shape from the same consideration as 76. 87a
Is a driven piece for the cam groove 86a, 87b is a pin for linking with the advance / retreat member 85, and 87c is a pin for pivotally connecting the intermediate portion to the support 80.

Next, FIG. 1F and FIG.
2 shows a yarn holding device provided in connection with the present invention. The device F is for preventing the cut yarn from falling off the looper 15 when cutting the yarn, and will be described below with reference to FIGS. 1, 2, 15 and 16. Numerals 90 in FIGS. 1 and 2 denote yarn holding means individually provided for each looper 15. Each thread holding means 90 is provided as close as possible to each looper 15 for the same purpose as the cutting mechanism E1. The thread holding means 90 has a pair of gripping pieces 92 and 93. The gripping piece 92 is formed integrally with a base 91 common to all the yarn holding means 90 to facilitate assembly. The gripping piece 93 is pivotally attached to the base 91 so as to be able to adjust the position in the lateral direction (left and right direction in FIG. 2) with respect to the base 91 in order to adjust the contact between the gripping pieces 92 and the holding surfaces 92b and 93b. I have. That is, as shown in FIG.
Is rotatably loosely fitted to the holding cylinder 94, and the holding cylinder 94 is attached to the base 91 by a fixing tool (for example, a bolt) 95 having a diameter smaller than the inner diameter thereof. Reference numeral 96 denotes a washer for preventing the holding piece 93 from coming off. In this configuration, the position of the base 93a of the gripping piece 93 can be determined so that the sandwiching surfaces 93b, 92b of the gripping piece 93 and the gripping piece 92 are in close contact with each other in the entire area. Then, the fixing tool 95 is fixed. In this way, even when the yarn comes to any position, such as the entrance side or the back side of the sandwiching surfaces 92b, 93b, it can be reliably sandwiched and held. 97 is a gripping piece
An operation piece 93, 97a is a recess for receiving a spring. Reference numeral 98 denotes a spring holding piece which is attached to the base 91. 99 is the gripping piece 92,
A compression coil spring for urging 93 to close each other with a predetermined clamping force, and 100 is a washer for receiving a spring.

FIG. 17A shows a yarn holding device F having such a structure as shown in FIG. 17A in order to reliably hold the yarn brought to the yarn holding means 90 by the yarn shifting mechanism E3 from the looper 15 stopped at the position of the origin. As shown, the clamping surface 92b of the gripping piece 92
Of the looper 15 whose extension line 92c is at the position of the origin.
Is mounted on the looper table 7 in a positional relationship of passing through the position.

Next, G shown in FIGS. 1 to 4 is a release mechanism for releasing the thread holding means 90 associated with the looper 15 located at the needle drop position. The mechanism G is mounted on the frame 1 with a bracket.
It is constituted by a solenoid 102 mounted via 101. The plunger 103 of the solenoid 102 faces the operation piece 97 of the thread holding means 90. When power is supplied to the solenoid 102, the plunger 103 projects. Then, the operation piece 97 is pushed to open between the grip pieces 92 and 93.

Next, the operation of the above-described yarn cutting device E and the structure related thereto will be described. The thread cutting device E is used, for example, in a case where sewing using one thread is completed and then the thread is changed and sewing is performed using another thread. The operation will be described with reference to FIGS. After sewing at a normal spindle speed of about 500 revolutions per minute, the spindle speed is reduced to, for example, about 200 revolutions for stopping.
When the sewing of the cloth to the predetermined position is completed, as shown by reference numeral 201 in FIG. 19, first, the vertical movement of the hook B is stopped, and the rotation of the main shaft 33 is stopped. in this case,
The looper 15 is positioned at the origin in the rotation direction, for example, FIG.
The rotation of the thread lead-out hole 17 stops at 9 o'clock on the timepiece as shown in FIG. Next, the looper assembly 9 is moved by the lifting device 12.
4 and FIG. 17B, the looper 15 retreats downward from the advance / retreat path of the yarn pieces 81 and 82 (see reference numeral 202 in FIG. 19). Also, the gripping pieces 92 and 93 are released by the release mechanism G.
Are opened as shown in FIG. 17C (reference numeral 20 in FIG. 19).
3). Next, the yarn pieces 81 and 82 are shown in FIGS.
19, the thread 46 between the needle hole 4 and the thread outlet hole 17 of the looper 15 is brought between the gripping pieces 92 and 93 and between the scalpels 68 and 70 (FIG. 19). Reference numeral 204). Next, when the release mechanism G is restored, FIG.
The space between the gripping pieces 92 and 93 is closed as shown in FIG.
Is held. Next, as shown in FIGS. 18G and 18H, the sewing thread 46 is cut by the operation of the movable knife 70 (see reference numeral 205 in FIG. 19). In the case of this cutting, the cloth 104 and the holding piece
One end of the sewing thread 46 between the threads 92 and 93 is fixed to the cloth 104, and the other end is gripped by gripping pieces 92 and 93. That is, both ends of the sewing thread 46 between them are fixed in a constant tension state. Therefore, when the scalpel 70 is operated, the sewing thread 46 does not enter between the overlapping surfaces of the scalpels 68 and 70 without being cut, and is reliably cut by the scalpels 68 and 70. After the cutting, the thread pieces 81 and 82 are returned to their original positions (see reference numeral 206 in FIG. 19).

When the cutting of the thread is completed as described above, the looper 15 is replaced as described above. When the looper 15 provided with the next thread to be used in the looper replacement process comes to the needle drop position, the looper 15 is raised as shown in FIG. 3 (see reference numeral 207 in FIG. 19). When the looper replacement is completed, the vertical movement of the hook B is started (see reference numeral 208 in FIG. 19), and the spindle 3 is moved.
The rotation of 3 is started at a low speed, the horizontal movement of the embroidery frame is also started, and the sewing of the embroidery pattern is started. In the case of this start, the leading end of the sewing thread is held by the gripping pieces 92 and 93. Therefore, when the hook B descends into the needle drop hole 16 of the looper 15 and the looper 15 rotates, the thread supplied through the thread lead-out hole 17 of the looper 15 is securely hooked on the hook portion of the hook B. Therefore, sewing is started properly without skipping. The holding of the leading end of the sewing thread is released as indicated by reference numeral 209 in FIG. 19 after the sewing at the start of the sewing is ensured. Then, the number of revolutions of the main shaft is also increased, and a normal sewing state is set.

Next, as another application example, the cutting device E finishes sewing of embroidery at one place in a cloth,
Used to sew another embroidery at another location. In this case, at the time point indicated by reference numeral 210 in FIG. 19, the frame is moved so that the place where sewing is newly performed reaches the needle drop position. Other operations are the same as those in the case of the thread change.

Next, in FIGS. 1, 3, 20, and 21, H indicates a thread entanglement preventing mechanism. The thread entanglement preventing mechanism H is used for a sewing machine that cuts a thread after the sewing operation is completed, and in the case of the cutting, cuts the thread in a state of being held in advance so that the cut thread does not fall off the looper 15. An object of the present invention is to prevent the thread from being wound around the rotating looper 15 when sewing is started again using the held thread.

The drawings will be described below. Symbols A to G,
The structure of 1 to 103 and the operation thereof are as described above. Next, the thread entanglement prevention mechanism H will be described. 110 is the thread holding means 9
This is a lifting member for lifting the thread 46 held by 0 near the looper 15. Lifting height is looper
For example, the upper surface of the looper 15 to prevent entanglement with 15
It is the same height as 15a. A smooth radius is formed at the corner 15b between the upper surface and the side surface of the looper 15 so that the yarn slides well there, and even if the yarn slightly hits the side surface of the looper 15, it is guided to the upper surface side. in case of,
The lifting height may be lower. 111 is the lifting member 1
10 shows an elevating mechanism for lifting the 10 to a position where it functions as described above and lowering it so as not to obstruct thread cutting. Numeral 112 denotes an elevating member of the mechanism 111, which extends along the frame 1 so as not to obstruct the lateral movement of the looper table 7 and avoids the lateral movement range.
Guided by three. Reference numeral 114 denotes a member for supporting the lifting member 110, which is attached to the left and right elevating members 112 in a bridge shape. 115 is a member for vertically moving the elevating member 112,
The looper elevating drive shaft 61 for simultaneous operation with the vertical movement of the looper 15
The tip of the lever 115
a is engaged with the connecting portion 112a of the elevating member 112.

Next, the operation of the thread entanglement prevention mechanism H will be described. When the looper 15 is lowered to the retracted position as shown in FIG. 4 for the operation of the thread cutting device E, the lifting member 110 is also lowered. Thereafter, when a new embroidery sewing operation is started, when the looper 15 is raised to the operating position as shown in FIG. 3, the lifting member 110 is also raised by the lifting mechanism 111 as shown in FIG.
The thread 46 whose leading end is held is lifted as shown in FIG. In this state, the operation of the looper 15 is started as shown in FIG. Therefore, the lifted thread 46 does not become entangled with the rotating looper 15, and the sewing starts smoothly.

Next, in FIGS. 3, 5, 22 to 24, J indicates a thread tension device. This thread tension device J includes a plurality of loopers.
By moving the looper stand 7 holding 15 the loopers
By selectively positioning the 15 at the needle drop position, in a sewing machine that can sew a cloth using a different color thread attached to each looper selectively, even when performing sewing with any looper, It is an object of the present invention to be able to always perform sewing with a good thread tension from the start of sewing.

The drawings will be described below. Symbols A to G,
The structure of 1 to 103 and the operation thereof are as described above. Next, the thread tension device J will be described. Reference numeral 120 denotes a frame for holding the thread tension mechanism, which is attached to the looper base 7 via the substrate 41. 120a is a thread insertion window. 121 is each looper 1
A plurality of thread tension mechanisms for individually adjusting the tension of the thread leading to 5 are attached to the above-mentioned lumber frame 120 in order to maintain a constant positional relationship with each looper 15 even when the looper base 7 moves laterally. is there. Reference numeral 122 denotes a change mechanism for changing the tension of each thread tension mechanism 121.

Next, the thread tension mechanism 121 will be described with reference to FIGS.
It will be described based on. 123 and 124 are thread tensioners for giving a resistance to the thread 46 pulled by the hook B, and 125 is a tension device for giving tension to the thread drawn through the thread tensioner 124. The thread tension controller 123 is a known thread tensioner that applies a certain resistance to the yarn, and 124 is a known thread tension regulator capable of changing the strength of the thread (for example, Japanese Utility Model Publication No. Sho 53-6611). In these figures, 126 and 127 are thread tension discs, 128 is a spring for pressing the thread tension disc 127 against the thread tension disc 126, and 129 is a knob for adjusting the pressing force. Reference numeral 130 in the thread tensioner 124 is a member for changing the drag, and an example of a loosening bar that weakens the drag by separating the thread tension tray 127 from the thread tension tray 126 is exemplified.

Next, the tension device 125 will be described. Reference numeral 131 denotes a spring arm for giving a resilient pulling force to the thread, which is also called a thread take-up spring, and has a threading ring 132 at a free end. The base portion 133 of the spring arm 131 is pivotally attached to the frame 120 by a pivot piece, for example, a pin 134, for integrally changing the pulling force, and is integrally provided with an operation arm 135. The operation arm 135 projects from the rear side of the frame 120 for operation by the change mechanism 122 through the long hole 136. 1
Reference numeral 37 denotes a member for positioning the operation arm 135 on one side of the repositionable range. A spring is used to enable the operation arm 135 to move to the other side.
It is attached to a holding pin 138 attached to 0. Spring 137
One end 139 is engaged with the through hole 140 of the frame 120, and the other end 141
Is engaged with the operation arm 135, and the operation arm 135 is pressed against the lower end 136a of the long hole 136 as a positioning part thereof. Reference numerals 142 and 143 denote thread guides for adjusting the direction of the thread passing through the threading ring 132 to an appropriate direction for applying tension, and are attached to the frame 120.

Next, the change mechanism 122 will be described. 145 is a change operation axis, which is commonly provided on other beds,
An operating device is attached to one end. 146 is an operation member,
An operating unit 147 for operating the member 130 and an operating unit 148 for operating the operating arm 135 are provided, and only the thread tension mechanism 121 related to the looper 15 located at the needle drop position is operated. The position is selected and attached to the operation shaft 145.

Next, the setting of the thread tension and the operation of the thread tension mechanism 121 in the case of the sewing will be described. When the sewing is the chain stitch, the drag and the tension applied to the thread 46 are increased. That is, the operation member 146 is placed at the position indicated by the solid line in FIG. 22, the thread tension plate 127 of the thread tensioner 124 is placed in the state shown by the solid line in FIG. 22, and the spring arm 131 of the tension device 125 is placed in the state shown by the solid line in FIG. When sewing is performed in this state, the tightening force of the thread against the cloth during sewing is large, and a properly tightened and appropriate chain stitch can be performed.

On the other hand, when the sewing is a known loop sewing (for example, JP-A-4-34062), the drag and tension applied to the thread 46 are reduced. That is, by turning the operation shaft 145, the operation member 4
22 is placed at the position indicated by the two-dot chain line in FIG. 22, and the thread tension plate 127 of the thread tensioner 124 is set to the state indicated by the two-dot chain line in FIG.
The 25 spring arms 131 are in the state of the two-dot chain line in FIG. When sewing is performed in this state, the thread can be smoothly pulled from the cloth on the needle plate 3, and loop sewing at a predetermined height can be properly performed.

Next, in the case of changing the thread used for sewing, since the thread tension device J is mounted on the looper table 7, even if the looper table 7 moves laterally, each looper 15 and the thread tension mechanism associated with each looper 15 are associated. The positional relationship with 121 is unchanged. Therefore, even if the looper 15 is replaced by the horizontal movement of the looper base 7, each looper 15 is replaced.
The thread between the thread tension mechanism 121 and the thread tension mechanism 121 associated with each thread is always kept in a taut state (there is no unnecessary slack). Therefore, regardless of which looper 15 is used for sewing, the thread reaching the looper 15 is sewn from the start of the sewing with the appropriate drag by the thread tensioners 123 and 124 and the appropriate tension by the tension device 125 applied. It can be performed.

Next, in FIGS. 3, 5, and 25, K indicates a yarn breakage detecting device. The yarn breakage detecting device K selectively moves the loopers 15 to the needle drop position by laterally moving the looper base 7 holding the plurality of loopers 15, thereby detecting the different color yarns attached to each looper. SUMMARY OF THE INVENTION It is an object of the present invention to provide a sewing machine that can selectively use a sewing machine to perform sewing on a cloth, so that a thread break can be reliably detected during sewing, and an erroneous detection can be prevented during a thread change.

Hereinafter, the drawings will be described. Symbols A to D,
The structures of J, 1 to 62 and 121 to 148 and the operation thereof are as described above. Next, the yarn breakage detecting device K will be described. 151
Is a detector main body, for the purpose of enabling operation with extremely light force and for the purpose of simplifying the configuration of the detection piece described below, a rotary operation type micro switch in which the movable portion 152 rotates is used, It is attached to the support frame 51. Reference numeral 153 denotes a detection piece for detecting the presence or absence of a thread break. The detection piece 153 is provided so as to freely move along the path P of the thread relating to the looper at the needle drop position and in the direction crossing the path. If there is tension and tension is applied to the yarn, the movement in the above direction is interrupted by the yarn, and if the yarn breaks and the tension is lost, push the yarn and move in the above direction (there is no yarn In this case, the urging force is applied in the above direction so as to move as it is. In this example, the above-mentioned movement is enabled by attaching to the movable portion 152 of the microswitch, and the urging force of the movable portion 152 is used. FIG.
As shown in FIG.
“a” is V-shaped in order to prevent lateral deviation from the yarn. Reference numeral 154 denotes an evacuation lever for disabling the detection piece 153, and reference numeral 155 denotes an operation piece for operating the lever 154. Mounted on lever 62.

In the thread breakage detecting device K, during normal sewing, the detecting piece 153 contacts the thread 46 as shown in FIG. 25 (A), and the detector main body 151 keeps the thread in an appropriate state. It emits a signal indicating the presence, for example, a conduction signal. On the other hand, when the yarn 46 breaks, the detecting piece 153 moves as shown in FIG. 3B, and the detector main body 151 issues a signal indicating that the yarn has broken, for example, a non-conduction signal. At the time of looper replacement for thread change, when the looper elevating drive shaft 61 rotates to lower the looper, the lever 154 is pushed by the operation piece 155 as shown in FIG. Therefore, even if the thread 46 does not exist before the detection piece 153 for the reason of the looper replacement,
This prevents the detector main body 151 from erroneously issuing a thread break signal.

[0049]

As described above, according to the present invention, when the looper base 7 is to be moved laterally for switching the looper 15, the effect of preventing the cut thread from falling off the looper 15 can be obtained. is there.

Further, in the present invention, at least one of the pair of gripping pieces 92, 93 of each thread holding means 90 is provided with a looper so that the sandwiching surfaces 92b, 93b can be freely separated from each other. It is pivotally attached to the table side, and the pivoted state is such that the base of the gripping piece is fixed to the fixture 95 so that both the entrance side and the back side of the clamping surface are in contact with each other. Since it is configured so that the position in the horizontal direction can be freely adjusted, the yarn cut in each of the loopers can be securely pinched no matter where it comes, such as the entrance side or the back side of the clamping surfaces 92b, 93b. There is an effect that can be maintained.

[Brief description of the drawings]

FIG. 1 is a plan view of a bed with a top plate removed.

FIG. 2 is a plan view of the bed in a state where a top plate and a yarn cutting device are removed.

FIG. 3 is a longitudinal sectional view.

FIG. 4 is a partial vertical cross-sectional view showing a state where the looper assembly is lowered.

FIG. 5 is a front view of the looper device.

FIG. 6 is a partially broken perspective view showing a structure related to a drive gear and a looper.

FIG. 7 is a bottom view showing a looper holding mechanism.

FIG. 8 is a partially omitted side view showing the looper assembly and its holding mechanism.

FIG. 9 is a diagram illustrating an operation order of looper switching.

FIG. 10 is a front view showing the relationship between the passive gear, the drive gear, and the guide gear when the looper is switched.

FIGS. 11A and 11B are horizontal sectional views showing the relationship between a passive gear and a guide gear at the time of looper switching.

FIG. 12 is an explanatory diagram of the operation of the looper elevating mechanism.

FIG. 13 is a perspective view of a yarn cutting device.

FIG. 14 is a mechanism diagram of a yarn cutting device.

FIG. 15 is an exploded perspective view of the yarn holding device.

FIG. 16 is a cross-sectional view showing an attachment structure of a movable gripping piece base.

FIGS. 17A to 17D are explanatory diagrams illustrating the operation of a thread pulling mechanism, a thread holding unit, and a thread cutting mechanism.

18 (E) to (H) are explanatory views of the operation of the yarn pulling mechanism, the yarn holding means, and the yarn cutting mechanism.

FIG. 19 is a time chart for explaining the operation.

FIG. 20 is a mechanism diagram of a thread entanglement prevention mechanism.

FIGS. 21A and 21B are explanatory diagrams of the operation of a thread entanglement prevention mechanism.

FIG. 22 is a partial longitudinal sectional view of a thread tension mechanism.

FIG. 23 is a front view of the tension mechanism.

24A is a rear view of the tension mechanism when the tension is high, and FIG. 24B is a rear view of the tension mechanism when the tension is low.

FIGS. 25A to 25C are diagrams for explaining the yarn detecting device and its operation.

[Description of Signs] A Base frame 7 Looper base 13 Holding mechanism 15 Looper 18 Passive gear 37 Drive gear 38 Guide gear

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) D05C 15/34 D05C 15/34

Claims (1)

[Claims] 1. A base frame is provided with a drive gear for driving a looper located at a needle drop position so as to be horizontally rotatable, while a looper base mounted on the base frame so as to be laterally movable is provided with a drive gear. Multicolor sewing in which a passive gear for meshing with a drive gear is integrally provided, and a plurality of loopers rotatable in a horizontal direction are arranged so as to be selectively positioned at the needle drop position by laterally moving the looper table. A thread holding device for a multicolor sewing machine, comprising a pair of gripping pieces.