DE102007056132A1 - Sewing machine for sewing processes comprises an upper thread holding unit with a thread holding tool moving along a lower side of a needle plate between a below-the-needle position on a line along which a needle and a stand-by position - Google Patents

Abstract

Sewing machine (100) comprises an upper thread holding unit with a thread holding tool moving along a lower side of a needle plate (108) between a below-the-needle position on a line along which a needle (104) is moved and a stand-by position which is moved away from the below-the-needle position. The machine also has a control unit. Preferred Features: The control unit actuates the needle cutting mechanism (130) whilst the thread holding tool is held in the stand-by position after the last stitch.

Description

TECHNICAL AREA

The The present invention relates to a sewing machine comprising a needle thread holding device for holding a sewing start end part a top thread below a throat plate.

RELATED PRIOR ART

A conventional sewing machine is provided with a top thread holding device for holding a sewing start end portion of a top thread inserted through a needle at a bottom of a needle plate to hold the sewing start end portion of the upper thread on a back side of a sewing material and properly sewed from a first stitch train (see for example JP 2000-279666 A ).

If in the sewing machine a sewing process started a hook of a shuttle captures the upper thread of one Needle out for a first stitch to the sewing start end part to the underside of the throat plate, and a thread holding tool the upper thread holding device holds the sewing start end part and will go backwards (a Side of the vertical drum part) and is in the ready position. When the seam is stabilized after a few stitches, the sewing start end part becomes Approved. As a result, it is possible the sewing start end part of the upper thread to prevent it from the back of the sewing material slip out, whereby a seam is formed, which neatly from the first stitch is.

In a sewing machine, which is provided with a Fadenabschneidemechanismus, in which a moving knife across is twisted a Nadelvertikalbewegungsweg to detect upper and lower threads and cut off, between a needle opening of the needle plate and a gripper mechanism at the bottom of the needle plate be routed to the top and bottom threads at the end of a sewing process the following problem occurs when a button in sewn to the case is to be, in which the upper thread holding device provided is.

More in detail: when a button with two holes is sewn, a needle penetrates alternate through the two holes several times (that is, it will be several stitches executed) and the upper and lower threads, which are passed between the throat plate and the boat, be from the thread trimming mechanism after a last needle penetration cut off. In the case of a button with four holes, the process will continue at each two holes repeated or the sewing process is executed on all two holes and the thread is then cut off.

In the button sewing process is to cause the needle, alternately through the two holes to penetrate a plurality of seams as described above train, the Nähstartendteil the upper thread held by the upper thread holding device, released and hanging several seconds after a sewing start free and is therefore captured in the lower thread, the many times between the two holes runs to to bring about a state in which fine loops with each other be involved. For this reason, a sewing quality, that is a quality of a sewing material deteriorated.

on the other hand the sewing process ends in a state where the sewing start end part is held so that he is about a length, which is pulled out by a thread holding tool, down freely hangs in some cases without tangling with the bobbin thread. The button can not be sewn reliably so that the sewing process be executed again which results in a deterioration in work efficiency. Alternatively, a needle penetration track is left on sewing goods at which the Button sewn on should be, so that the sewing quality deteriorates becomes.

SUMMARY OF THE INVENTION

It It is an object of the invention to provide a seam reliable and fine at a seam start in a button sewing process form, thereby improving a sewing quality or a work efficiency is increased.

According to a first aspect of the invention, a sewing machine ( 100 ):
a top thread holding device ( 10 ) operable to move a sewing start end portion of an upper thread under a throat plate (Fig. 108 ) and let go;
a shuttle mechanism ( 120 ), which grasps the upper thread, so that a lower thread below a needle opening ( 108a ) of the throat plate ( 108 ) to involve;
a thread trimming mechanism ( 130 ), the upper thread and the lower thread between the needle opening ( 108a ) of the throat plate ( 108 ) and the shuttle mechanism ( 120 ), cuts off,
wherein a button (B) is sewn onto a fabric (W) by alternately stitching between at least two openings of the button.

The sewing machine ( 100 ) is characterized in that the upper thread holding device ( 10 ) a thread holding tool ( 20 ) along an underside of the needle plate ( 108 ) between a sub-needle position which is one position is a line along which a needle ( 104 ), and a standby position, which is a position moved from the sub-needle position, is movable, the thread-holding tool ( 20 ) in a thread release state when the thread holding tool is in the under-the-needle position and is brought into a thread holding state while the thread holding tool (FIG. 20 ) is moved from an intermediate position to the standby position, wherein the intermediate position between the sub-needle position and the standby position is, and in that the sewing machine ( 100 ) continue operating control means ( 80 ) which are operable to: 20 ) at the sub-needle position when the needle ( 104 ) penetrates through the sewing material (W) in a first pass; the thread holding tool ( 20 ) at least at the standby position when the needle ( 104 ) penetrates through the fabric (W) in a last stitch; the thread holding tool ( 20 ) to move from the ready position to the intermediate position after the last pass; and then the thread trimming mechanism ( 130 ) to cut off the sewing start end portion of the upper thread.

According to a second aspect of the invention, the operation control means ( 80 ) is still operable to control the needle trimming mechanism ( 130 ) while the thread holding tool ( 20 ) is held after the last stitch at the ready position to the upper and lower threads, which between the needle opening ( 108a ) of the throat plate ( 108 ) and the shuttle mechanism ( 120 ) are guided through, cut off and then the thread holding tool ( 20 ) to the intermediate position to cut off the sewing start end portion of the upper thread.

According to a third aspect of the invention, the operation control means ( 80 ) operable to remove the upper and lower threads between the needle opening ( 108a ), the needle plate ( 108 ) and the shuttle mechanism ( 120 ) and the sewing start end portion of the upper thread after the last stitch by a single operation of the thread cutting mechanism (FIG. 130 ) to cut off.

According to a fourth aspect of the invention, the sewing machine ( 100 ) further comprises a movement mechanism ( 83 . 84 . 140 ), which holds the fabric (W) and moves it around the needle ( 104 ) at a predetermined position, wherein in a case where a puncture point of the first stitch and a puncture point of the last stitch do not coincide with each other, the operation control means (Fig. 80 ) are also operable to control the movement mechanism ( 83 . 84 . 140 ) to position the sewing material (W) such that the needle ( 104 ) after the last stitch, but before moving the thread holding tool ( 20 ), is arranged in the intermediate position at the puncture point of the first stitch.

According to the first Aspect of the invention is the Nähstartendteil held until the last stitch of the upper thread holding device. That's why it's possible the generation of a bird's nest condition due to entanglement effectively with the lower thread, as in the case in which the sewing start end part is released in the middle.

The Thread holding tool is starting from the standby position moved by a predetermined distance in the sub-needle position, after the last stitch, and the thread trimming mechanism is then pressed. Therefore, the upper thread, starting from the needle opening causes the Fadenhaitewerkzeug extends, a thread laxity and hangs below the needle opening down a bit. Therefore, the thread trimming mechanism can the sewing start end part in the same way as in the case in which the Thread between the needle opening and passed through the boat, is cut off. Furthermore, the sewing start end part of the upper thread becomes not released in the upper thread holding device at this time. In contrast to the case in which the freely hanging thread is cut in a free state, therefore, the thread trimming mechanism perform the cut-off well.

Consequently can sew a remaining thread in the workpiece shortened so that the sewing quality improves leaves. Furthermore, a post-treatment for the remaining thread after the sewing process unnecessary be made so that productivity can be improved. Farther allows a special thread trimming process to cut off the residual thread unnecessary be made so that the cost of the sewing process can be reduced can.

According to the second Aspect of the invention will be after the completion of the last stitch the upper and lower threads, between the needle opening and the shuttle mechanism are guided, cut off, and then the sewing start end part becomes of the upper thread cut off. Therefore, it is possible to load the thread trimming device reduce and the threads reliable in comparison with the case in which the Threads collectively be cut off.

According to the third aspect of the invention, after completion of the last stitch, the upper and lower threads formed between the sewing start end portion of the upper thread and the shuttle mechanism become gone, cut off at the same time. Therefore, it is possible to shorten a time required for the cutting operation for each of the threads.

According to the fourth Aspect of the invention set the operation control means, when the puncture point of the first stitch is not the same as the puncture point of the last stitch is the needle at the puncture point of the first stitch then move the thread holding tool to the intermediate position. Therefore, a position that has a base on the fabric side of the sewing start end part of the upper thread should be made to contact the needle opening of the Approach throat plate. When the thread holding tool is moved to the intermediate position, can therefore the Nähstartendteil the upper thread stronger be loosened, and the sewing start end part of the upper thread can be more reliably cut off by the thread trimming mechanism. Furthermore, the Nähstartendteil of the upper thread, which on the sewing material remains after the truncation process, be shortened more.

BRIEF DESCRIPTION OF THE DRAWINGS

1 Fig. 10 is a general side view showing an outline of a sewing machine, a part of which is omitted.

2 is a plan view showing an upper thread guide plate in the direction U in 8th ,

3 FIG. 10 is a front view showing an inner boat of a shuttle mechanism viewed in an X-axis direction. FIG.

4 Fig. 10 is a plan view showing a thread trimming mechanism.

5A to 5C 11 are explanatory views showing an operation of the thread trimming mechanism, wherein FIG

5A shows a standby state of a mobile knife,

5B shows a forward rotation state of the movable blade, and

5C shows a reverse rotation state of the movable knife.

6 is a perspective view showing the upper thread holding device.

7 is an exploded perspective view showing the upper thread holding device.

8th Fig. 12 is an explanatory view showing an operation of the upper thread holding device when seen from a right part in the case where a thread holding tool is placed in a sub-needle position.

9 Fig. 12 is an explanatory view showing the operation of the upper thread holding device when viewed from a lower part in the case where the thread holding tool is placed in the under-the-needle position.

10 Fig. 12 is an explanatory view showing the operation of the upper thread holding device when viewed from a right side in the case where the thread holding tool is placed in a thread bending position.

11 Fig. 12 is an explanatory view showing the operation of the upper thread holding device when viewed from a lower part in the case where the thread holding tool is placed in the thread bending position.

12 Fig. 12 is an explanatory view showing the operation of the upper thread holding device from a right part in the case where the thread holding tool is placed in a standby position.

13 Fig. 12 is an explanatory view showing the operation of the upper thread holding device from a lower part in the case where the thread holding tool is placed in the standby position.

14 Fig. 12 is an explanatory view showing the operation of the upper thread holding device from a right part in the case where the thread holding tool is in a thread releasing position.

15 Fig. 12 is an explanatory view showing the operation of the upper thread holding device seen from a lower part in the case where the thread holding tool is placed in the thread release position.

16 Fig. 12 is an explanatory view showing a relationship between an oscillating operation of a relative position regulating link and a relative position change of a holding member and an intermediate member as viewed from below.

17A to 17D 10 are explanatory views showing an operation, wherein a relationship between a state of a top thread in the standby position and the thread release position and the thread trimming mechanism is illustrated with chanism

17A shows a state of a cutting operation of a movable knife in the standby position of the thread holding tool,

17B shows a state of forward rotation of the movable knife in the thread release position of the thread holding tool,

17C shows a state of reverse rotation of the movable knife in the thread release position of the thread holding tool, and

17D shows the state of the reverse rotation of the movable knife in the thread release position of the thread holding tool and a cutting state of a sewing start end part of the upper thread.

18 Fig. 10 is a block diagram showing a control system of the sewing machine.

19 FIG. 10 is a flowchart showing an operation of the sewing machine. FIG.

DETAILED DESCRIPTION

[Schematic overall structure of the sewing machine]

An embodiment according to the invention will be described in detail below with reference to FIG 1 to 19 described. A sewing machine 100 According to the embodiment, a button and a cloth are relatively moved with respect to a needle in accordance with a predetermined sewing pattern stored in a memory, and a stitching is made a stitching through each hole of the button a set number of times.

1 is a general view showing a summary of the sewing machine 100 according to the embodiment of the invention. The sewing machine 100 has an outer contour comprising a bed section 101 which is positioned in the lower part, a vertical sewing machine column part 102 starting from one end of the bed section 101 protrudes upward, an arm part 103 that stretches along the bed section 101 from the top of the vertical sewing machine column part 102 extends out. The sewing machine 100 corresponds to a so-called Zylinderbettnähmaschine, in which a front end portion of the bed portion 101 is approximately cylindrical, and a width in an X-axis direction is set to be narrower than widths in other parts.

In the following description, a Z-axis direction is a vertical movement direction of a needle 104 , A Y-axis direction is a longitudinal direction of the bed section 101 and the arm part 103 which is perpendicular to the Z-axis direction, and an X-axis direction is a direction that is perpendicular to both the Z-axis direction and the Y-axis direction. Furthermore, if the sewing machine 100 is placed on a horizontal plane, a + (plus) side in the Z-axis direction becomes an upper side of the sewing machine 100 , and a - (minus) side of the Z-axis direction becomes a bottom of the sewing machine 100 , Similarly, a (+) side in the X-axis is a right side, a (-) side in the X-axis is a left side, a (+) side in the Y-axis direction is a front side and a (-) side in the Y-axis direction is a back side.

The sewing machine 100 includes:
a needle 104 placed in a front end part of the arm part 103 is provided and using a sewing machine motor 105 is driven to reciprocate in a vertical direction;
a (not shown) upper thread supply source, which at an upper part of the arm part 103 is provided, and serves to an upper thread of the needle 104 to forward;
a thread tensioner 106 of the upper thread with a predetermined load between the upper thread supply source and the needle 104 sets and generates a resistance to a movement in the feed direction;
a Fadenaufnehmervorrichtung, the upper thread using a thread picker 107 at a predetermined timing between the thread tensioner 106 and the needle 104 pulls up;
a throat plate 108 standing at a top of the bed section 101 arranged and with a needle opening 108 is provided to a front end portion of the needle 104 to put in there;
a shuttle mechanism 120 , which is below the throat plate 108 in the bed section 101 is provided and serves a needle thread loop from the needle 104 which widened down to widen and insert a bobbin thread through the loop;
a top thread holding device 10 which holds an upper thread end when a first stitch of the needle 104 between the needle plate 108 and the shuttle mechanism 120 is pulled up;
a thread trimming mechanism 130 in the bed section 101 is provided and the upper thread and the lower thread is cut, which after a sewing operation between the needle opening 108a the needle plate 108 and the shuttle mechanism 120 passed through;
a material holding mechanism 140 holding a fabric and a button and giving a movement operation for the needle;
a thread wiper mechanism (not shown) that wipes away the upper thread cut above the fabric; and
Operation control means 80 to control an operation each of the structures.

The needle 104 has a thread hole formed near its front end part (a lower end), and the upper thread is inserted through the thread hole. Furthermore, the needle 104 at a lower end of a needle bar 104a held, and a turning and driving force coming from the sewing machine motor 105 is transferred to a vertical, reciprocating force, and the vertical, reciprocating force is by a (not shown) crank mechanism to the needle bar 104a applied, so that the needle bar 104a performs a vertically reciprocating motion in a predetermined cycle. The sewing machine motor 105 is with an encoder 109 (please refer 18 ) for detecting a rotation angle amount thereof. Assuming that an angle of 0 ° is set when the needle 104 is placed in a position of a top dead center, any angular position of 0 ° to 360 °, in which a current output shaft of the sewing machine motor 105 is placed, to the operating tax funds 80 issued.

The thread picker 107 is provided with an upper thread insertion opening (not shown) and performs vertical movement in a state in which the upper thread is inserted therethrough, the upper thread passing through the needle 104 inserted, is pulled up when it is raised. Furthermore, the Fadenaufnehmervorrichtung causes the Fadenaufnehmer 107 in addition, a vertical movement in the same cycle as the needle 105 carry out, and a time at which the thread picker 107 reached its top dead center, lies a little later than a time when the needle 104 reached its top dead center.

The thread tensioner 106 includes thread tensioning discs between which the upper thread is held, and a thread tensioning electromagnet 86 (please refer 18 ) which changes a thrust force for holding the upper thread to control the thread tension. The pushing force of the thread tensioning electromagnet 86 is determined by the operation control means 80 controlled.

[Shuttle mechanism]

As in 3 illustrated, the shuttle mechanism closes 120 a: an inner boat 122 for performing a half reciprocating twist and catching a loop of the upper thread by means of a hook 121 projecting in a rotational circumferential direction, an outer boat 123 for rotatably holding the inner boat 122 , an upper thread guide plate 124 on the outer boat 123 is provided, and a shuttle shaft 125 which is parallel to a longitudinal direction of the bed portion, starting from one side of the vertical pillar portion to the outer boat 123 and that serves to make a half, reciprocating revolution and a driving force to the inner shuttle via a driver (not shown) 122 to apply.

As in 8th shown has the inner boat 122 a rail-shaped protruding part 126 which is formed on an outer circumference so that half a revolution can be repeatedly performed, and running surfaces 127 . 128 who are in conductive contact with a holding groove 123a of the outer boat 123 are on both sides of the projecting part 126 educated. The hook 121 is at one end in a circumferential direction of the rail-shaped protruding part 126 trained, and runs straight through one side of the thread opening of the needle 104 in which it enters a guide opening of the upper thread guide plate 124 occurs, by a half turn of the inner shuttle 122 , whereby the loop of the upper thread is widened. Thus, the catch 121 a front end part inclined to a direction L along a rotation center line of the inner boat 122 runs, and the hook 121 and the above part 126 are on a side of a direction R with respect to a vertical path N of the needle 104 arranged.

The shuttle shaft 125 is with respect to the inner boat 122 positioned on the R side (the direction R side will be referred to as a shuttle shaft side hereinafter) and not directly with the inner shuttle 122 coupled, but is with the inner boat 122 arranged next to it. The shuttle shaft 125 transmits a driving force for half a reciprocating twist on the inner shuttle 122 by a driver to perform a half-round turn.

The shuttle shaft 125 of the shuttle mechanism 120 is parallel to the Y-axis direction and is on the (-) side in the Y-axis direction (backward) with respect to the inner boat 121 arranged and serves to apply half the reciprocating rotation and a driving force in the same direction. A driving force coming from the sewing machine motor 105 is diverted, is converted into a reciprocating revolution, and the reciprocating revolution becomes on the shuttle shaft 125 transferred, so that the vertical reciprocating operation of the needle 104 and half the reciprocating action of the inner shuttle 122 are synchronized with each other in a predetermined phase difference.

The upper thread guide plate 124 is a plate-shaped member for preventing the contact and the entanglement of the upper thread with the treads 127 . 128 of the inner boat 122 , The upper thread guide plate is with a guide opening 124a formed a shape as in 2 has shown if (in a direction U) in 3 seen from above. The guide opening 124a has a thread-splitting section 124b for spreading the upper thread loop, from the hook 121 of the inner boat 122 is widened at an approximately central part on the right side of the same. As in 3 shown, the upper thread loop, which is from the hook 121 is expanded, in a front and rear direction separated into a thread section NF on the needle side and a thread section NB on the Nähgutseite, by adjusting the hook 121 as a boundary with means of the thread part section 124b so that it is possible the contact and the entanglement with the two treads 127 . 128 of the inner boat 122 to prevent.

[Nähguthaltemechanismus]

The material holding mechanism 140 includes: a fabric feed base 141 along the X-axis direction and Y-axis direction above a surface of the bed section 101 using an X-axis motor 83 and a Y-axis motor 84 can be moved and positioned, which are stepper motors, a Nähguthalteglied 142 which is provided so that there is an up-down movement at a front end of the Nähvorschubbasis 141 allows a first swing arm 144 using a cam 143 to be vibrated in an actuating motor 82 is provided, which is to be a stepping motor, a transmission rod 145 for performing a longitudinal movement by the oscillation movement of the first swing arm 144 , an L-shaped second swing arm 146 for performing an oscillation movement by the longitudinal movement of the transmission rod 145 , a pick-me-up 147 , which is a vertical movement process by the second swing arm 146 is granted, and an oscillation rod 148 with two ends, both swingable by the Nähgutschub base 141 are held.

The fabric feed base 141 is mounted so that it is along an XY plane above the bed section 101 is movable by a known construction. By a per se known power transmission structure will continue rotation and driving forces of the X-axis motor 83 and the Y-axis motor 84 are converted into motive forces in the X-axis direction and the Y-axis direction, and the motive forces are applied to the workpiece feed base 141 transfer.

In other words, the material holding mechanism 140 , the X-axis engine 83 and the Y-axis motor 84 function as a moving mechanism that holds a cloth (a workpiece) and a knob and moves the cloth and the knob with respect to a needle so that the needle is located (located) at a predetermined piercing point.

The material holding member 142 is above the throat plate 108 arranged and can hold the button on the fabric in a superimposed state, and its holding state is spent in a downward movement and the holding state is released in an upward movement.

The material holding member 142 is at the fabric feed base 141 held so that it allows an up-down movement, and is at the same time to one end of the oscillating rod 148 coupled. If one end of the oscillating rod 148 is moved vertically by an oscillatory movement, also the Nähguthalteglied 142 moved up and down.

The oscillating rod 148 has the other end to which a tension is applied upward by means of a tension spring (not shown) and the workpiece holding member 142 is constantly pushed down by the voltage. Near the other end of the oscillating rod 148 is an adjoining part 148a intended. Through a lower end of the lifting element 147 gets to the abutment part 148a a pressing force applied downward.

The lifting member 147 is disposed such that a longitudinal direction thereof is set along a vertical direction, and performs an up-down movement in the longitudinal direction. An upper end of the lift element 147 is with the second swing arm 146 coupled, and the vicinity of a lower end thereof is connected to a Betriebsregulierverbindungsglied 149 coupled to a position of the lifting member 147 to stabilize. The coupled end of the second swing arm 146 Performs a vertical oscillation movement such that the lifting member is imparted a vertical movement.

The second swing arm 146 is as described above, approximately L-shaped and is rotatably supported by a sewing machine frame on a bent portion thereof. A lower end of the second swing arm 146 is with the transmission rod 145 coupled, so that an oscillation process is mediated in the longitudinal direction, and the lifting member 147 a vertical movement is given on an upper end side.

The transmission rod 145 has a back End that at one end of the first swing arm 144 is coupled, and the other end of the first swing arm 144 is in contact with the cam 143 ,

The cam 143 is a circumferential cam, which is rotated by the actuating motor in circulation, and the other end of the first swing arm 144 is located on an outer circumference of the cam 143 on, and the first swing arm 144 is vibrated according to the shape of the outer periphery.

The material holding mechanism 140 is set so that the Nähguthalteglied 142 is raised by an engine output shaft, which by the rotation and driving operation of the actuating motor 82 assumes a predetermined angle. In other words, the fabric and the button are controlled by the rotation angle control of the operation motor 82 arrested and released.

In a sewing operation of the button, the operation control means stores 80 plural kinds of sewing data for performing a serial sewing, depending on the number and the arrangement of the thread holes of a button B (see FIG 17A to 17D ), further depending on a gap between the openings, a thread crossing order, or the presence of a thread trimming operation in the middle. A kind of sewing data is selected so that the button sewing operation is performed. In this case, in the material holding mechanism 140 the X-axis motor 83 and the Y-axis motor 84 at each stitch driven by a drive amount determined in the sewing data, whereby the cloth feed base 141 and the Nähguthalteglied 142 be moved and positioned so that the stitch formation is performed by each of the holes of the button B in a predetermined number of times in a predetermined order.

The thread wiper mechanism (not shown) includes a thread wiper member for providing a force through a plurality of links from the second swing arm 146 out, whereby a back and forth rotation is performed. The thread wiping member is provided on a surface side part of the sewing machine so that a front end part thereof passes through a part between a lower end of the needle placed in an upper needle position and the throat plate. The upper thread, between the needle opening 108a the needle plate 108 and the gripper mechanism 120 passed through is cut off and the thread wiper member is then rotated, so that the thus cut end of the upper thread from the fabric can be pulled upwards.

[Thread trimming mechanism]

4 FIG. 10 is a plan view showing a main part of the thread cutting mechanism. FIG 130 and 5A to 5C are explanatory views showing the operation of the same. As in 1 . 4 and 5A to 5C shown, the thread trimming mechanism closes 30 a: a first swing arm 132 that by a cam 131 is pivoted in the actuating motor 82 is provided, a transmission rod 133 for performing a longitudinal movement by the oscillatory movement of the first swing arm 132 , a second swing arm 134 caused by the longitudinal movement of the transmission rod 133 is pivoted, a stationary knife 135 attached to a bottom of the needle plate 108 is attached, a movable knife 136 for performing a reciprocating rotation while slidingly contacting the front end with the blade of the stationary knife, and a link 137 for coupling the movable knife 136 to the second swing arm 134 ,

The cam 131 is a grooved cam by the actuating motor 82 is circulated, and an upper end of the first swing arm 132 is with the cam 131 by a roller (not shown) coupled along a circumferential groove of the cam 131 is moved. Accordingly, the first swing arm leads 132 an oscillating motion corresponding to a shape of the groove of the cam 131 out.

The first swing arm 132 is pivotally rotatably supported on the sewing machine frame in a central part thereof and is arranged approximately in the Z-axis direction. The upper end is with the arm 131 , as described above, and a lower end is connected to a rear end of the transmission rod 133 coupled. When the upper end of the first swing arm 132 through the cam 132 As a result, the transmission rod is pivoted 133 communicated a reciprocating operation.

The second swing arm 134 is pivotally rotatably supported on the outside of the needle plate in a central part in a longitudinal direction thereof, and one of its ends is connected to a front end of the transmission rod 133 coupled. Furthermore, the other end of the second swing arm 134 through the connecting link 137 to the movable knife 136 coupled, and the actuating motor 82 finally gives the reciprocating twist of the moving knife 136 over the first swing arm 132 , the transmission rod 133 , the second swing arm 134 and the link 137 from.

The moving knife 136 is pivotally rotatable on the underside of the throat plate 108 held and performs a reciprocating rotation while it is the surface of the movable knife 136 causes sliding contact with a bottom of the stationary knife 134 to get. The moving knife 136 is retracted to a standby position indicated by a dashed line in FIG 4 and 5A is shown when the cutting operation is not performed, and performs a reciprocating rotation to return to the standby position, after a forward movement in an advancing position, the 4 and 5B is shown with a solid line when the cutting operation is performed.

As described above, the upper thread of the hook 121 of the inner boat 122 is detected to form a needle thread loop, and the thread is separated into the thread portion NF at the needle side and the thread portion NB at the Nähgutseite, by adjusting the hook 121 so that he has a limit through the thread-splitting section 144 the upper thread guide plate 124 is. In this state, the movable knife cuts 136 the upper thread off. In the case where both the thread portion NF on the needle side and the thread portion NB on the cloth side in the needle thread are cut off, the needle thread is cut in two places. In order to avoid the phenomenon, only the thread portion NB on the fabric side is selectively cut off. To perform the selection is the movable knife 136 with a separation tab 136a provided projecting toward a front edge part side.

In the forward twist of the moving knife 136 becomes the separation projection 136a for positioning, to pass through a portion between the thread portion NF on the needle side and the thread portion NB on the Nähgutseite in the upper thread passing through the Fadenaufteilabschnitt 124 be split. When the movable knife 136 performs the forward rotation, only the thread portion NB on the Nähgutseite, which is an outer side of the turning radius, to an outer side in a direction of a turning radius of the movable blade flows 136 and goes to a Fadeneinfangteil 136 around, at a rear edge part side of the movable knife 136 is provided (see 5B ).

Furthermore, an upper side of the movable knife 136 with a blade part 136c provided, which produces a step from the top. By a reverse rotation of the movable knife 136 is the thread portion NB at the Nähgutseite the Fadeneinfangteils 136b between the blade part 136c and a front end portion of the stationary knife 135 placed and cut off in this way (see 5C ).

As described above, the actuating motor 82 an elevation of a Nähgutpressers, a thread wiping operation and an operation of the Fadenabschneidemechanismus 130 run through the cam 143 and the cam 131 , A shape of each cam and a mounting angle thereof are adjusted so that each operation within a non-overlapping angular range in one revolution (0 ° to 360 °) of the actuating motor 82 is performed. In particular, the shape of the cams 131 . 143 set and on the actuating motor 82 fixed, "a downward movement of the workpiece holding part", "a first forward movement of the movable knife", "a first backward movement of the movable knife", "a reciprocating rotation of the thread wiper member", "a second forward movement of the movable knife", "a second backward movement of the movable knife "and" lifting of the material holding member "by a rotation in a predetermined direction of the operation motor 82 be executed in this order.

[Upper thread holding device]

The upper thread holding device 10 At a sewing start, holds the sewing start end portion of the upper thread passing through the needle 104 is inserted through, just below the needle opening 108a the needle plate 108 and moves the end of the upper thread thus held to a position on a back side of the vertical movement path of the needle 104 to prevent the sewing start end portion of the upper thread from slipping out of the sewing material.

The upper thread holding device 10 closes a thread holding tool 20 , Means of movement 40 and relative movement means 60 one. The thread holding tool 20 closes a holding part 21 a holding a Nähstartendteil the upper thread, and a Zwischenlegteil 31 that relates to the holding part 21 relatively moved in a direction in which the Zwischenlegteil 31 moved to the holding part to or from this, to the Nähstartendteil the upper thread together with the holding part 21 to hold on or let go. The moving means 40 move the thread holding tool 20 between a sub-needle position located on the vertical trajectory N of the needle 104 lies (see 8th ), and a standby position located on a back side of the vertical trajectory N of the needle 104 (one side of the vertical drum part) is located. The vertical trajectory N is parallel to the Z-axis direction and is a trajectory representing the tip position of the needle 104 at a top dead center and the Top position of the needle 104 connects to each other at a bottom dead center. The relative resources 60 cause the thread holding tool 20 to be in a release state when the thread holding tool 20 is placed in the under-the-needle position, and switch the thread holding tool 20 from the release state to a hold state between the sub-needle position and the standby position. Each of the positions is described in detail.

[Thread Holding Tool of Upper Thread Holding Device]

6 is a perspective view showing the upper thread holding device 10 and 7 is an exploded perspective view showing the same thing.

As shown in these drawings, the thread holding device closes 20 a holding member 22 with the holding part 21 as well as an intermediate member 32 with the intermediate piece 31 one. Both limbs 22 . 32 have rectangular shapes and are with the Zwischenlegglied 32 superimposed that is placed on an upper side, and are on the relative resources 60 held so that they can slide in the Y-axis direction (the forward and backward directions), wherein the longitudinal direction is parallel to the Y-axis direction ge. In the case where a designation indicating a direction is explained below for each part in the thread holding tool 20 is used, it is assumed to indicate a direction in the state in which the thread holding tool 20 at the relative resources 60 is held without any special notice being given.

The holding member 22 is with rectangular, through openings 23 . 24 at respective end parts (that is, at front and rear sides) in a longitudinal direction thereof. A part that has an inside of the through hole 23 includes at the front, which is a side which is arranged at a front end opposite to the (+) - side of the Y-axis direction, serves as the holding part 21 , Further, the through hole at the front side also functions as a guide hole for guiding a movement in the longitudinal direction of the intermediate piece 31 of the intermediate member 32 ,

A tension spring 62 the relative resource 60 is in the through hole 24 at the back of the holding member 22 and an operating area for performing expansion and contraction is formed. One end of the tension spring 62 is at a front end of the through hole 24 coupled to the back.

An arm part 25 which extends in the (-) side of the X-axis direction is in a slightly rearward position of a central part in the Y-axis direction of the holding member 22 provided and has a front end portion. The holding member 22 gives through the lug 26 a movement force in the longitudinal direction, which by the relative resources 60 is generated.

The intermediate member 32 is divided into two parts, that is a front part 33 and a back part 34 and they are through a coupling link 35 coupled to each other so that a shape of a one-piece and about long plate is obtained. The intermediate piece 31 is at a front end of the front part 33 intended. The intermediate piece 31 indicates: a flat part 30 that is attached to the holding part 21 approach and detach from it, and a curved part 36 that of a front end surface of the retaining member 22 projecting forward, via a lower part of the holding part 21 at the request.

Accordingly, the upper thread passing through the front through the opening 23 of the holding member 22 is inserted from above, between the holding part 21 and the flat part 30 of the intermediate piece 31 held by a relatively approximate most operation of the holding member 22 and the intermediate member 32 , The upper thread thus held by the bent part 36 bent forward, leaving the part 36 forward from a lower end of the flat part 33 extends out. Thus, the upper thread can be moved starting from a front part in a bending down state. Because the end of the upper thread positioned more forward and in this state by the bent part 36 As a result, it becomes from the inner boat 122 of the shuttle mechanism 120 which is arranged underneath, moved forward. Thus, it is possible to contact and tangle with the inner boat 122 to prevent.

The back part 34 has a continuous opening 37 formed in a longitudinal direction. In the case where the intermediate member 32 and the holding member 22 at the relative resources 60 are held in a superimposed state, is the through hole 37 at the back through opening 24 of the holding member 22 superposed arranged, and the tension spring 62 the relative resource 80 is disposed on the inside thereof so as to form an operation area for performing expansion and contraction. The other end of the tension spring 62 is at a rear end of the through opening 37 coupled. Accordingly, the intermediate member 32 and the holding member 22 through the tension spring 62 brought into a coupling state, and it is to the holding part 21 of the holding member 22 and the intermediate piece 31 of the intermediate member 32 an elastic force is applied in such a direction as to constantly approach and abut each other.

In the middle part of the Y-axis direction of the intermediate member 32 is an arm part 38 , which extends to the (+) - side of the X-axis direction, provided, and it has a front end portion to which a Anliegestift 39 fixed, which has a shape of a round bar and is directed downwards. The intermediate leg member 32 gives through the Anliegestift 39 the moving force in the longitudinal direction, which by the relative resources 80 is produced.

[Movement means for the upper thread holding device]

The moving means 40 be related to 6 to 14 described.

The moving means 40 move the thread holding tool 20 between the under-the-needle position, a Fadenbiegeposition, the standby position and a thread release position (an intermediate position).

When the thread holding tool 20 through the moving means 40 is moved backwards and forwards, the opening and closing between the holding part 21 of the holding member 22 and the flat part 30 of the intermediate member 32 switched to the respective positions along the moving direction in accordance with the relative resources.

The under-the-needle position is a position at which the holding part 21 of the holding member 22 and the flat part 30 of the intermediate member 32 are fully open and the front end portion of the thread holding tool 20 under the needle 104 is arranged.

The Fadenabbiegeposition lies on a back of the under-the-needle position. In the Fadenabbiegeposition are the holding part 21 of the holding member 22 and the flat part 30 of the intermediate member 32 almost in the closed state.

The standby position is a position at which the holding part 21 of the holding member 22 and the flat part 30 of the intermediate member 32 are fully closed. The standby position is the furthest backward position among the four positions.

The thread release position is a position at which the holding part 21 of the holding member 22 and the flat part 30 of the intermediate member 32 are fully closed. At the thread release position is the thread holding tool 20 placed between the thread bending position and the standby position.

The moving means 40 close a Y-axis motion mechanism 41 for reciprocating the thread holding tool 20 one at the relative resources 60 is held in the Y-axis direction, and movement position detecting means 46 for detecting whether or not the thread holding tool is held in the sub-needle position or the standby position, respectively. An operation of the Y-axis movement mechanism 41 is determined by the operation control means 80 based on the detection of the movement position detecting means 46 controlled.

As in 7 Shown, the Y-axis motion mechanism closes 41 a: a thread detection motor 42 for outputting a rotational and driving force, a main motion link 43 , whose own Oszillierungszentralposition to an output shaft of the thread detection motor 42 is coupled, a driven link 44 for applying a moving force in the Y-axis direction to a relative position regulating member 63 the relative resource 60 and a transmission link 45 for transmitting a driving force from the main movement link 43 to the driven link 44 out.

The thread detection motor 42 is a stepping motor and is operated at any angle of rotation in the positive and negative directions by the operation control of the operation control means 80 driven.

The main motor link 43 has an end connected to the output shaft of the thread detection motor 42 fixed and coupled there, and has another end that rotatably connected to one end of the transmission link 45 is coupled.

The driven link 44 has an end that pivots on a guide plate 61 the relative resource 60 is held, and the other end of this member is rotatable to the other end of the transmission link 45 coupled. Furthermore, the driven link 44 , which takes about the shape of a bent lever ("dog leg"), with a Anlegevorsprung 52 provided for applying a motive force in the Y-axis direction to the relative position regulating link 63 the relative resource 60 ,

The transmission link 45 is provided approximately in the Y-axis direction and oscillates the driven link 44 with an oscillating motion of the main motion link 43 , which by a drive operation of the thread detection motor 42 is performed.

If through these structures the thread detection motor 42 is driven, the driven link 44 with the oscillating motion of the main motion link 43 vibrated, and the relative position regulating link 63 the relative resource 60 is by the berth 52 moved in the Y-axis direction.

The movement position detecting means 46 be related to 8th to 14 described. In 6 and 7 are the movement position detecting means 46 not shown.

The movement position detecting means 46 close first and second state sensors 47 . 48 with light-emitting units and light-receiving units, and serve to detect the presence of a screen therebetween, and they further close a shielding plate 51 which is connected to the transmission link 45 of the Y-axis movement mechanism 41 is provided, and they have first to third shielding areas 51a . 51b . 51c , The first to third shielding areas 51a . 51b . 51c are in turn starting from a front end of the shielding plate 51 formed backwards.

The first and second state sensors 47 . 48 are along a line of movement of the shielding plate 51 arranged. The first state sensor 47 is arranged on a back side. As a result, the condition sensors 47 . 48 arranged approximately in the Y-axis direction. The light-receiving unit of each of the state sensors 47 . 48 in a power-on state, sets a state in which the screen is present, and in a power-off state, sets a state in which the screen is not present and outputs to the operation control means 80 A signal which is able to identify each of the states.

On the other hand, the shielding plate 51 at the transmission link 45 fixed and held by the light-emitting units and the light-receiving units for both the first and second state sensors 47 . 48 goes through, and is with the first to third shielding areas 51a . 51b . 51c Mistake.

If, as in 8th shown, the thread holding tool 20 is placed at the sub-needle position, the first to third shielding areas 51a . 51b . 51c arranged so that they do not have any of the sensors 47 . 48 shield. In other words, when the transmission link and the abutment protrusion 52 are not moved forward, it is possible to determine that the sub-needle position is reached when the first condition sensor 47 in the off state (a non-shielding state) and the second state sensor 48 also spent in the off state.

If, as in 10 shown, the thread holding tool 20 is placed in the Fadenabbiegeposition, an arrangement is provided, in which the first shielding 51a none of the sensors 47 . 48 shields, the second shielding area 51b the first state sensor 48 and the third shielding area 51c the first sensor 47 shields. In other words, if the transmission link 45 and the berth 52 starting from the under-the-needle position to move backwards, it is possible to determine that the Fadenabbiegeposition is reached when the first state sensor 47 in the on state (a shield state) and the second state sensor 48 also spent in the power-on state.

If, as in 12 shown, the thread holding tool 20 is positioned in the standby position, an arrangement is achieved in which the first shielding area 51a the second sensor 48 shields, the second shielding area 51b none of the sensors 47 . 48 shields and the third shielding area 51c none of the sensors 47 . 48 shields. In other words, if the transmission link 45 and the berth 52 Starting from the Fadenabbiegeposition be moved backwards, it is possible to determine that the standby position is reached when the first state sensor 47 in the off state and the second state sensor 48 is spent in the power-on state.

If, as in 14 shown, the thread holding tool 20 is placed in the thread release position, an arrangement is achieved, in which the first shielding 51a none of the sensors 47 . 48 shields, the second shielding area 51b none of the sensors 47 . 48 shields and the third shielding area 51c the first sensor 47 shields. In other words, if the transmission link 45 and the berth 52 starting from the standby position, it is possible to determine that the thread release position is reached when the first condition sensor 47 in the on state and the second state sensor 48 brought into the off state.

A description will be given of a control performed by the operation control means 80 for the Y-axis movement mechanism 41 to be executed. The operation control means 80 previously store a rotational angle of the thread detection motor 52 for moving the thread holding tool 20 from the under-the-needle position to the standby position as well as a rotation angle amount to Moving the thread holding tool 20 from the standby position to the thread release position, and control the operation of the thread detection motor 42 by referring to a stored angular position when the thread holding tool 20 should be placed in each of the positions.

With respect to the under-the-needle position, the operation control means guide 80 a control as an initial position control part, by using the movement position detecting means 46 if a major source of energy 100 is turned on, and drive the thread detection motor 42 to recover the sub-needle position and stand by in that position.

At a first pass after the sewing start, the operation control means lead 80 as a upper thread holding control part, further comprises a controller for detecting that the needle 104 is pulled up from the fabric to the thread holding tool 20 in the Fadenabbiegeposition, using the encoder 109 of the sewing machine motor 105 , In the Fadenabbiegeposition is between the holding part 21 of the holding member 22 and the flat part 30 of the intermediate member 32 creates a small space. Therefore, the sewing start end part of the upper thread becomes the needle side 14 slid out, while between the holding part 21 of the holding member 22 and the flat part of the intermediate member 32 by the winding force of the Fadenaufnehmers 107 a sliding resistance is generated so that a holding length of the sewing start end portion of the upper thread can be reduced.

If at a second pass through the encoder 109 of the sewing machine motor 105 it is determined that the needle 104 slips up out of the fabric, then a control to place the thread holding tool 20 in the standby position. As a result, the holding part 21 of the holding member 22 and the flat part 30 of the intermediate member 32 closed. Even if subsequently a tension of Fadenaufnehmers 107 As a result, the Nähstartendteil the upper thread is not caused to slip out, but held.

When the upper thread and the lower thread are between the needle opening 108a and the inner boat 122 cut off and wiped off after a final pass, will control the placement of the thread holding tool 20 executed in the thread release position. Unlike the standby position, the thread release position is in a tighter position at the needle opening 108a placed. Therefore, by the movement, the sewing start end portion of the upper thread loosens between the thread holding tool 20 and the needle opening 108a so that the sewing start end portion of the upper thread can be made into a rotation range of the movement meter 136 the thread trimming mechanism 130 enter, and the Nähstartendteil the upper thread can by turning the movable blade 136 be cut off. A detailed description will be given of an arrangement of the sewing start end portion of the upper thread in the thread release position and the movable knife 136 ,

[Relative Resource of Upper Thread Holding Device]

The relative resources 60 be related to 6 to 16 described.

The relative resources 60 include: a guide plate 61 , which is a guide means, for reciprocally supporting the intermediate member 32 and the holding member 22 each in the Y-axis direction, the tension spring 62 , which is a tension energy generating means to constantly a voltage between the intermediate shim 32 and the holding member 22 to lay in such a direction that the intermediate member 31 and the holding member 21 approach each other, the Relativpositionsübulierverbindungsglied 63 engaged with the intermediate member 32 and the holding member 22 is to make it the intermediate piece 31 and the holding part 21 to allow them to approach or separate from each other according to a change in a position caused by its own oscillating motion, and serve each movement position of the thread holding tool 20 a motive force through the means of movement 40 to enter, a first attachment member 64 for oscillating the intermediate piece 31 and the holding part 21 in such a direction as to engage the relative position regulator 63 disconnect each other when the thread holding tool 20 is moved from the thread release position in the under-the-needle position, and a second contact member 65 that with an inclination of Relativpositionsululiergliedes 63 can be moved backwards, which is kept constant to be in sliding contact with the relative position regulating link 63 to arrive, whereby a state is maintained, in which the Zwischenlegteil 31 and the holding part 21 come into close contact with each other when the thread holding tool 20 is moved from the thread release position to the standby position.

The guide plate 61 is at the upper part of the bed section 103 behind the throat plate 108 attached. in the case where a designation indicating a direction is explained in each part of the relative resources 60 is used, it is assumed to indicate a direction in a state in which the guide plate 61 at the bed section 103 is fixed, and without a special Mittei development.

On a surface of the guide plate 61 is a guide groove in an intermediate position in the Y-axis direction 66 provided in the Y-axis direction. The holding member 22 and the intermediate member 32 in the thread holding tool 20 are in the guide groove 66 housed in a superimposed state, wherein the longitudinal directions are aligned with each other. A press plate 67 covers the holding member 22 and the intermediate member 32 from above, allowing a slide out of the guide 66 is prevented. As a result, the holding member 22 and the intermediate member 32 in the guide groove 66 guided and slid in the Y-axis direction in each case. As described above, the retaining member 22 and the intermediate member 32 through the tension spring 62 coupled together. So long as no external force is applied, each of the limbs decreases 22 and 32 a state in which the holding part 21 and the intermediate piece 31 are caused to abut each other. As in 9 . 11 . 13 and 15 are shown, widths in the X-axis direction of the holding member 22 and the intermediate member 32 different from each other. To a relative positional relationship between the respective members 22 and 32 clearly illustrated, they are for convenience shown different from each other, and both the retaining member 22 as well as the intermediate member 32 are currently set to a width in the X-axis direction of the guide groove 66 within such a range are about the same that they can be slid.

Furthermore, there are through openings 68 . 69 provided on both sides, the guide groove 66 the guide plate 61 is arranged between each. The Anliegestift 26 , the holding member 21 is provided is from above into the through hole 68 fitted and inserted, and the Anliegestift 39 the intermediate member 32 is in the through opening 69 fitted and used. Furthermore, both have through openings 68 . 69 Lengths in the Y-axis direction, which are set such that front and rear ends of the respective openings do not interfere with the abutment pins 26 . 39 come into contact, in a movement starting from the under-the-needle position of the thread holding tool 20 to its standby position and a relative movement of the holding member 22 and the intermediate member 32 that is executed with it. Furthermore, the Anliegestifte have 26 . 39 , which in the through openings 68 . 69 are used, front end parts, which is slightly lower surface side of the guide plate 61 stand out and individually engaged with the Relativpositionsübulierverbindungsglied 63 are.

The relative position regulating link 63 is with a turning abutment 70 on the holding member 22 provided, a Drehanliegeteil 71 on the intermediate member 32 and a rotating abutment part on the moving means 40 interposed in an arrangement in a longitudinal direction thereof.

More in detail: the turning abutment 70 with the holding member 22 is a slit-shaped through hole in the longitudinal direction of Relativpo sitionsregulierverbindungsgliedes 63 and the locating pin 26 is inserted into it. The turning abutment part 71 with the intermediate member 32 is a circular through opening and the Anliegestift 39 is inserted into it. The turning abutment part 72 at the movement means 40 is a slit-shaped through hole in the longitudinal direction of the relative position regulating link 63 and the landing pin 52 is inserted into it.

16 Fig. 12 is an explanatory view showing a relationship between an oscillating operation of the relative position regulating link 63 and a relative change in position of the holding member 22 and the intermediate member 32 with a view from above.

Regarding 16 is as long as the holding member 22 and the intermediate member 32 take no external force, the condition of the holding part 21 and the intermediate piece 31 from the tension spring 62 as described above. The state is set to be a top thread holding state. The contact pins 26 . 39 are set so that they are set approximately in the same positions in the Y-axis direction when the holding part 21 and the intermediate piece 31 are held in the resting state. Accordingly, the relative position regulating link becomes 63 that with the Anliegestifte 26 . 39 through the rotating abutment parts 70 and 71 is also held in a state in about the X-axis direction in a normal state by the tension of the tension spring 62 (a state in a solid line in FIG 16 ).

When in this state, a counterclockwise rotational force is applied to the relative position regulating link 63 around the berth 52 is applied around, becomes the relative position regulating link 63 oscillates so that the position is changed. At this time will be about the rotating abutment parts 70 . 71 generates a shift in the Y-axis direction. As a result, an external force is applied in such a direction that the holding part 21 and the intermediate piece 31 between the holding member 22 and the intermediate member 32 separate from each other. Accordingly, the holding part separate 21 and the intermediate piece 31 from each other, against the tension of the Spannfe of the 62 so that the switching from the holding state of the upper thread to the release state thereof is carried out.

Regarding 9 . 11 and 16 a description will be given of the first adjoining member 64 , The first trailer 64 brings out a condition in which the holding part 21 and the intermediate piece 31 separating from each other when the thread holding tool 20 is placed at the under-the-needle position, and moves the holding part 21 and the intermediate piece 31 in such a direction as to approach each other when the thread holding tool is moved to the standby position from the sub-needle position, and to actuate the oscillating movement of the relative-position regulating link 63 such that it abuts at least a closer position to the sub-needle position than the thread release position.

To perform the procedure is the first adjoining member 64 arranged so that it is at the Relativpositionsübulierverbindungsglied 63 is applied, which is placed in the sub-needle position, starting from a front part between the Drehanliegeteil 72 the means of movement 40 and the turning abutment 71 of the intermediate member 32 , With the arrangement, in the case where a forward movement force is applied to the relative position regulating link 63 through the moving means 40 is applied to the thread holding tool 20 in the sub-needle position, the relative position regulating link 63 against the tension of the tension spring 62 oscillates, by inserting a contact point with the first abutment member 64 as a fulcrum. In this case, the turning abutment becomes 71 of the intermediate member 32 moved backwards, and the Drehanliegeteil 70 of the holding member 22 is moved forward, in comparison with those in the resting state. As the holding part 21 through the holding member 22 is moved forward and the Zwischenlegteil 31 through the intermediate member 32 are moved backwards, they are accordingly brought into a state separating from each other (see the double-dotted line in FIG 16 ). In the state, the end of the upper thread becomes between the holding part 21 and the intermediate piece 31 used.

When the thread holding tool 20 is moved backward from the under-the-needle position, the state of abutment of the first abutment member 64 at the relative position regulating link 63 gradually released. Therefore, the relative position regulating link becomes 63 by the tension of the tension spring 62 twisted clockwise. Accordingly, the part becomes between the holding part 21 and the intermediate piece 31 closed and the Relativpositionsübulierverbindungsglied 63 is rotated in a clockwise direction until the state of abutment on the first abutting member 64 fully released, and the intermediate piece 31 is through the intermediate member 32 moved forward, and the holding part 21 is through the holding member 22 moved backwards.

In the embodiment, the part between the holding part 21 and the intermediate piece 31 approached to a certain point when the abutment projection 52 is moved backwards, and the approach state of the holding part 21 and the intermediate piece 31 is maintained when the berth protrusion 52 continues to be moved backwards from this. In the sewing machine 100 becomes a position in which the part between the holding part 21 and the intermediate piece 31 first in the backward movement of the abutment projection 52 is closed, adjusted so that it is the thread release position. Since the Fadenabbiegeposition is set on this side of a position in which the part between the holding part 21 and the intermediate piece 31 has completely adjusted, it is further adjusted so that it is about an anterior position starting from the thread release position.

The second adjoining member 65 is related to 11 . 13 and 15 described. The second adjoining member 65 Regulates the oscillating motion of the relative position regulating link 63 to maintain the holding state when the thread holding tool 20 is moved from the thread release position to the standby position.

To perform the operation, the second adjuster member becomes 65 arranged so that it is in sliding contact with the Relativpositionsübulierverbindungsglied 63 passes from the (-) side in the X-axis direction, in a range through which the relative position regulating link 63 passes through when the thread holding tool 20 is moved from the thread release position to the standby position.

The second adjoining member 65 has a sliding contact surface which is smooth in the Y-axis direction. A sliding contact part 63a of the relative position regulating link 63 which is provided at one end on the (-) side in the X-axis direction is also smooth and is parallel to the Y-axis direction in the resting state of the holding member 21 and the intermediate piece 31 educated.

When the relative position regulating link 63 reaches the thread release position from the under-the-needle position in a state in which it is approximately in the X-axis direction, therefore passes the second adjuster member 65 in sliding contact with the sliding contact part 63a , In a stroke from the Fadelablöseposition in the ready The position of the sliding contact part becomes 63a held in a parallel state with the Y-axis direction, and the applied state of the holding part 21 and the intermediate piece 31 stay upright.

In a section from the thread releasing position to the standby position, it is possible to maintain the state in which the holding part 21 and the intermediate piece 31 by the tension of the tension spring 62 are approximated, even if the second landing member 65 is not provided. It is possible the holding part 21 and the intermediate piece 31 from being prevented by the influence of an inertial force due to rapid operation of the abutment projection 52 to be opened.

[Arrangement of the holding part and the intermediate piece in every movement position]

In the case where the thread holding tool 20 is placed at the sub-needle position, the holding part 21 and the intermediate piece 31 in such a direction as to separate from each other as described above. When the under-the-needle position is reached, the holding part becomes 21 positioned in front of the vertical movement path N of the needle, as in FIG 8th shown.

The front end part of the curved part 36 of the intermediate piece 31 is positioned at least on a back side of a straight line M. The straight line M is a line that is an upper end of the tread 128 , which is a back part of the inner boat 122 which is close to a back of the vertical trajectory N of the needle 104 is arranged, and a rear side edge portion at a lower end of the needle opening 108a connects (a position at one end on the (-) side in the Y-axis direction of a diameter in the Y-axis direction of the circular needle opening 108a , viewed from above). In the case where the arrangement of the front end portion of the Zwischenlegteils 31 is set so that an upper thread loop, which is formed by a first stitch in the sewing process, from the hook 121 of the inner boat 122 captured and expanded (stretched), through the thread-splitting section 124b the upper thread guide plate 124 , The front end portion of the Zwischenlegteils arrives 31 in contact with the upper thread, and the thread-splitting section 124b can be prevented in this way from disturbing the expansion of the loop. Accordingly, it is possible to effectively prevent the upper thread from being in contact with the tread 128 get.

The position of the holding part 21 and the front end part position of the intermediate piece 31 are determined by the lengths in the Y-axis direction of the holding member 21 and the intermediate member 32 , and the abutment position of the first abutment member 64 on the relative position regulating link 63 certainly. For example, if the abutment position of the first adjoining member 64 next to the turning abutment 72 the means of movement 40 is, the position of the holding member 21 placed further forward, and the front end position of the Zwischenlegteils 31 is placed more backwards. When the leaning position is close to the rotary grip part 72 of the intermediate member 32 is, the position of the holding part will continue 21 moved more backwards, and the front end position of the Zwischenlegteils 31 is placed more forward.

When the thread holding tool 20 reaches the thread release position from the under-the-needle position, the holding part is located 21 on the flat part 30 of the intermediate piece 31 and the hold state is continuously maintained until the standby position, which is more backward.

10 and 11 show a state in which the thread holding tool 20 is in the Fadenabbiegeposition, 12 and 13 show a state in which the thread holding tool 20 is placed in the standby position, and 14 and 15 show a state in which the thread holding tool 20 placed in the thread release position.

A relationship between the state of the upper thread in the standby position and the thread release position and the thread trimming mechanism 130 be related to 17 described. B denotes a button having at least two openings, and W denotes a workpiece (a workpiece), for example, fabrics to which the button is to be sewn.

17A shows an arrangement which is achieved in the moment in which the thread holding tool 20 positioned in the ready position and the movable knife 136 the thread trimming mechanism 130 is switched from a forward rotation in a reverse rotation. At this time, the sewing start end portion of the upper thread is stretched straight from the needle hole 108a to the front end portion of the thread holding tool 20 , and the thread holding tool 20 gets far back from the moving knife 136 positioned. In other words, the standby position of the thread holding tool is set at least in a position separating it from the movable knife such that the sewing start end portion of the upper thread is not away from the movable knife 136 is detected, even if the movable knife 136 performs a reverse rotational movement.

17B shows an arrangement which is obtained at the moment in which the thread holding tool 20 is moved from the standby position to the Fadenablöseposition, and the movable knife 136 the thread trimming mechanism 130 is switched from the forward rotation in the reverse rotation. At this time, the sewing start end portion of the upper thread generates looseness or loose to a lower position than the movable knife 136 between the needle opening 108 and the thread holding tool 20 such that the sewing start end portion of the upper thread enters a fan-shaped planar area which defines a rotation range of the movable knife 136 displays. When the movable knife 136 Accordingly, the reverse rotation is performed, the Nähstartendteil the upper thread from the movable blade 136 ( 17C ) and to the stationary knife 135 fed so that the Nähstartendteil the upper thread is cut off.

In other words, the thread releasing position is required to be a position in which the end of the upper thread which is held can be cut off, more specifically, a position in which the sewing start end portion of the upper thread can be made into Area at the level penetrate, which is a trajectory of the movable knife 136 indicates, by the lots of the upper thread, which is caused by a movement starting from the standby position.

When the sewing start end portion of the upper thread is merely cut off, it is sufficient that the thread loosening position is advanced to some extent from the standby position to meet the conditions. However, it is also desirable to cut off the sewing start end portion of the upper thread and a distance from the thread holding tool 20 perform as in 17C shown. Accordingly, in order to carry out the removal, it is required that the length of the looser caused at the sewing start end portion of the upper thread be smaller than a length consumed until the sewing start end portion of the upper thread from the movable blade 136 is detected and then reaches the stationary knife.

To take account of these conditions, the following is required:
(1) Here, there is included a moving direction component in which a direction for the movable knife 136 to the sewing start end part of the upper thread to the stationary knife 135 to deliver out, and a direction of movement starting from the under-the-needle position of the thread holding tool 20 to the standby position of the same are opposite each other (even more desirable that they are reversed to each other); and (2) a drawing frictional force generated at the sewing start end portion of the upper thread by the holding operation of the thread holding tool is at least equal to or less than a permanent tension of the upper thread.

[Operation control means]

The operation control means 80 be related to 18 described. 18 Fig. 10 is a block diagram showing a control system of the sewing machine 100 , The control means include: a CPU which executes various arithmetic processes, a ROM in which various programs for various processes, such as control and decision are stored, a RAM used as a work memory in various processes, and an EEPROM, the various Nähdaten are stored. The sewing machine motor 105 , the encoder 109 , the thread detection motor 42 , the first state sensor 47 and the second state sensor 48 in the movement position detecting means 46 , an SS (start-stop) switch 81 the sewing machine 100 , an operating panel 85 for entering proximity adjustment conditions and selecting sewing data, the actuating motor 82 which is a drive source for thread trimming, and the X-axis motor 83 as well as the Y-axis motor 84 , which serve to move a sewing material are with the control means 80 connected by a system bus and a drive circuit.

The control means 80 can be a rotation angle of the sewing machine motor 105 detect based on a pulse signal input from the encoder 109 attached to the output shaft of the sewing machine motor 105 is provided.

Furthermore, the control means 80 each of the movement positions of the thread holding tool 20 confirm based on detection signal inputs from the first state sensor 47 and the second state sensor 48 in the movement position detecting means 46 ,

If from the start switch 81 a sewing start signal is input, further control the control means 80 the drive operation of the thread detection motor 42 the means of movement 40 according to the angle of rotation of the sewing machine motor 105 wherein acknowledgment and recognition or the detection of an operating position of the movement position detecting means 46 is performed.

[Explanation the operation of the sewing machine]

An operation of the sewing machine 100 with the above configuration will be with reference to 8th to 19 described. 19 is a flowchart showing an operation panel tion of the sewing machine 100 , The following description will be made on the assumption that stitching data of puncture points for respective stitches and various parameters required for approaching a button are stored in advance.

The following process is performed by causing the CPU to execute the control program stored in the ROM of the control means 80 is stored.

When first the control means 80 receive an input while the S / S switch 81 is in an input waiting state (step S1), the operation motor becomes 82 rotated so that it is positioned at an angle at which "a downward movement of the material holding member" is performed, whereby the Nähguthalteglied 142 is moved down to hold a fabric and a button (step S2).

Then, by the moving position detecting means 46 detection of a sub-needle position (a determination of an initial position) is performed (step S3). The under-the-needle position is detected by whether both the first state sensor 47 as well as the second state sensor 48 are turned off or not while the thread detection motor 42 is driven in a direction in which the transmission link 45 and the berth 52 be moved forward. Accordingly, the thread holding tool 20 on the vertical movement path N of the needle 104 be arranged (see 8th and 9 ).

Next, the control means starts the drive of the sewing machine motor 105 (Step S4). The drive processes of the X-axis motor 83 and the Y-axis motor 84 are controlled in such a manner that sequential stitching is performed through the respective piercing points indicated by the sewing data.

When the sewing machine motor 105 is driven, a first stitch is formed, and the needle 104 gets into the needle opening 108a the needle plate 108 inserted, and the upper thread is between the holding part 21 and the intermediate piece 31 passed through. Furthermore, under the holding part 21 and the intermediate piece 31 the upper thread loop, which is on the side of the needle 104 is formed from the hook of the shuttle mechanism 120 captured. The upper thread loop is created by the rotation of the inner shuttle 122 and the upper thread guide plate 124 widened. At this time, the front end portion of the intermediate piece is 31 positioned sufficiently far to the rear. As a result, the leading end portion of the intermediate piece enters 31 not in collision with the enlargement of the upper thread loop by the upper thread guide plate 124 , Accordingly, the upper thread can be prevented from the rear tread 128 to touch.

If through the encoder 109 of the sewing machine motor 105 is displayed that the needle 104 in the first stitch is moved out of the fabric, control the operation control means 80 the thread detection motor 42 the means of movement 40 to the thread holding tool 20 to move to the Fadenabbiegeposition (step S5).

During the thread detection motor 42 is driven in such a direction that the transmission link 45 and the berth 52 are moved backward from the sub-needle position, the Fadenabbiegeposition is determined by whether both the first state sensor 47 as well as the second state sensor 48 in the switched-on state or not. Accordingly, the thread holding tool 20 be positioned at the Fadenabbiegeposition (see 10 and 11 ).

While the thread holding tool 20 is moved from the sub-needle position to the Fadenabbiegeposition, the Nähstartendteil the upper thread is held by the thread holding part. After moving to the Fadenabbiegeposition the upper thread of the Fadenaufnehmer 107 pulled upwards (step S6). At the Fadenabbiegeposition is a small gap between the holding part 21 and the intermediate piece 31 in front. Therefore, the upper thread slides between the holding part 21 and the intermediate piece 31 while experiencing some frictional resistance. Thus, a length between the held part of the upper thread and the end of the upper thread can be made as short as possible.

If subsequently through the encoder 109 of the sewing machine motor 105 is displayed that the needle 104 is moved out of the fabric in a second pass, control the operation control means 80 the thread detection motor 42 the means of movement 140 to the thread holding tool 20 to move to the standby position (step S7).

During the thread detection motor 42 is driven in such a direction that the transmission link 45 and the annexe projection 52 starting from the Fadenabbiegeposition be moved backwards, the standby position is determined by whether the first state sensor 47 in the off state and the second state sensor 48 are in the switched-on state. Accordingly, the thread holding tool 20 be positioned at the ready position (see 12 and 13 ).

While the thread holding tool 20 is moved to the standby position, the thread tension solenoid 46 controlled to reduce the thread tension applied to the thread tensioner 106 is applied so that it is smaller than a normal Nähspannung (step S8).

As a result of the movement of the thread holding tool 20 in the standby position, the sewing start end part of the upper thread becomes from the needle hole 108a pulled straight backwards.

After the thread holding tool 20 is moved to the standby position, the upper thread of the Fadenaufnehmer 107 mounted (step S9). In the ready position come the holding part 21 and the intermediate piece 31 in close contact with each other. Therefore, a knot of the upper thread and the lower thread is tightly solidified, so that a seam can be prevented from being frayed.

Subsequently, will decided if the next Stitch is the last stitch or not, based on the sewing data (Step S10). If the next one Stitch is not the last stitch, the sewing process is continuously in accordance with the sewing data continued.

If the next stitch is the last stitch, it will pass through the output of the encoder 109 decided whether the harmonic wave, that of the sewing machine motor 105 is circulated at a thread cutting angle or not (step S11). The thread cutting angle is an angle at which the needle thread loop from the needle 104 detected and through the thread-splitting section 124 are sufficiently separated in the thread section NF on the needle side and the thread section NB on the fabric side.

When the thread cutting angle from the encoder 109 is determined, twist the operation control means 80 the actuating motor 82 so that it is positioned at an angle at which "a first forward movement of the movable knife" is carried out, whereby the movable knife 136 twisted in such a direction that it is from the fixed knife 135 separates so that a thread is collected (step S12).

Then turn it after stopping the sewing machine motor 105 (Step S13) the operation control means 80 the actuating motor 82 so as to be positioned at an angle at which "a first backward movement of the movable knife" is performed, thereby rotating the movable knife in such a direction as to become the fixed knife 135 returns. Accordingly, the NB thread portion of the upper thread and the lower thread are cut off (step S14). At this time, the sewing start end part of the upper thread is straight and backward from the needle hole 108a is stretched out, as in 17A As shown, the upper thread can be prevented from being moved back and forth by the movable knife 136 to be recorded.

After the thread is cut, the operation control means rotates 80 the actuating motor 82 so that it is positioned at an angle at which "a reciprocating rotation of the thread wiper member" is performed, whereby the thread wiper member under the needle 104 is twisted. Accordingly, the thread portion NF of the upper thread is pulled out of the sewing material (step S15).

Then the operating control means decide 80 Whether or not the puncture point of the first stitch is the same as the puncture point of the last stitch, based on the selected sewing data (step S16).

If the puncture point of the first stitch is the same as the puncture point of the last stitch, the operation proceeds to step S18. If they are different from each other, the drive control of the X-axis motor 83 and the Y-axis motor 84 is performed in such a manner that the fabric and the button are moved to a position where the needle is located at the puncture point of the first stitch (step S17), and the process then proceeds to step S18.

In step S18, the thread detection motor 42 the means of movement 40 controlled to the thread holding tool 20 to move into the thread release position.

The thread release position is thereby detected whether or not the first state sensor 47 in the on state and the second state sensor 48 in the off state, while the thread detection motor 42 is driven in such a direction that the transmission link 45 and the berth 52 moving forward from the standby position. Accordingly, the thread holding tool 20 be positioned at the thread release position (see 14 and 15 ).

When the thread holding tool 20 is moved from the standby position to the thread releasing position, the upper thread between the needle opening 108a the needle plate 108 and the thread holding part 20 solved, as in 17B shown.

The operation control means 80 twist that operating motor 82 so that it is positioned at an angle at which "a second forward movement of the movable knife" is performed, and they continue to rotate the actuating motor 82 so that it is positioned at an angle at which "a second backward movement of the movable knife" is performed, whereby the movable knife 136 is rotated backwards and forwards. At this time, since the sewing start end portion of the upper thread loosens downwardly, it becomes the movable knife 136 which is twisted backwards and is pulled backwards ( 17C ). Therefore, the sewing start end portion of the upper thread becomes out of the thread holding tool 20 pulled out.

The sewing start end part of the upper thread is between the blade part 136c of the movable knife 136 and the blade part at the front end of the stationary knife 135 cut off ( 17D ). The sewing start end portion of the upper thread, which is cut off, falls into a cover of the sewing machine and is collected there. A detachable receptacle can be provided specifically in a bottom part in the sewing machine.

After cutting off the sewing start end portion of the upper thread, the operation control means turns 80 the actuating motor 82 so that it is positioned at an angle at which "a lifting of the material holding member" is performed from, whereby the Nähguthalteglied 142 lifted and the fabric are released with the button from the holding state (step S20).

As described above, in the sewing machine 100 the sewing start end part in the thread holding tool 20 held to a final state. Therefore, it is possible to effectively avoid a situation by causing a bird's nest state by tangling with the seam of the lower thread, as in the case where the release is performed in the middle.

After the last stitch, the thread holding tool 20 moved from the standby position to the thread release position, and the thread trimming mechanism 130 is then operated. Therefore, the sewing start end portion of the upper thread, which originates from the needle opening, generates 108a to the thread holding tool 20 out, a threadless and thus is slightly below the needle opening 108a suspended. As a result, the movable knife can 136 the thread trimming mechanism 130 cut off the sewing start end part. At this time, the sewing start end part of the upper thread is in the thread holding tool 20 not released. Therefore, unlike the case where the thread hanging in a free state is cut off, the thread trimming mechanism can be cut off 130 Carry out the thread trimming process well.

If the puncture point of the first stitch does not coincide with the puncture point of the last stitch, move the operation control means 80 the needle 104 so that it is positioned at the puncture point of the first stitch, by the driving operations of the X-axis motor 83 and the Y-axis motor 84 , and then move the thread holding tool 20 to the thread release position. As a result, a position to be a base on the cloth side of the sewing start end portion of the upper thread can be made to approach the needle opening of the needle plate. When the thread holding tool 20 Therefore, the Nähstartendteil the upper thread can be made more loose. Thus, the Nähstartendteil the upper thread using the thread trimming mechanism 130 be cut off more reliably.

Farther can the sewing start end part of the upper thread, which after the cutting process on the fabric side remains stronger shortened become.

In the above sewing machine 100 cut the operating controls 80 the upper and lower threads between the needle opening 108a and the inner boat 122 passed through and then cut the Nähstartendteil the upper thread by a separate drive operation. However, the top and bottom threads may be between the needle opening 108a and the inner boat 122 passed through, and the Nähstartendteil the upper thread within a single reciprocating rotation of the movable blade 136 be cut off. In such a case, it is necessary the shapes of the cams 131 . 143 such that "the downward movement of the fabric holding member", "the forward movement of the movable knife", "the backward movement of the movable knife", "the reciprocating rotation of the thread wiper member" and "the lifting of the fabric holding member" are performed in this order, by performing a rotation of the actuating motor 82 in a predetermined direction. In such a case, moreover, after step S11, steps S16 and S17 are executed, after step S12 or S13, step S18 is executed, after step S15, step S20 is executed, and step S19 is not executed.

Claims (4)

A sewing machine ( 100 ) comprising: a top thread holding device ( 10 ) operable to move a sewing start end portion of an upper thread under a throat plate (Fig. 108 ) and let go sen; a shuttle mechanism ( 120 ), which grasps the upper thread, so that a lower thread below a needle opening ( 108a ) of the throat plate ( 108 ) to involve; and a thread trimming mechanism ( 130 ), the upper thread and the lower thread between the needle opening ( 108a ) of the throat plate ( 108 ) and the shuttle mechanism ( 120 ), wherein a button (B) is sewn onto a fabric (W) by an alternating stitch formation between at least two openings of the button, characterized in that the upper thread holding apparatus ( 10 ) a thread holding tool ( 20 ) along an underside of the needle plate ( 108 ) between a sub-needle position, which is a position on a line along which a needle ( 104 ), and a standby position, which is a position that is shifted away from the sub-needle position, is movable, wherein the thread holding tool ( 20 ) in a thread release state when the thread holding tool ( 20 ) is in the under-the-needle position, and is brought into a thread holding state, while the thread holding tool ( 20 ) is moved from an intermediate position to the standby position, wherein the intermediate position between the sub-needle position and the standby position is, and in that the sewing machine ( 100 ) continue operating control means ( 80 ) which are operable to: 20 ) at the sub-needle position when the needle ( 104 ) penetrates through the sewing material (W) in a first pass; the thread holding tool ( 20 ) at least in the standby position when the needle ( 104 ) penetrates through the fabric (W) in a last stitch; the thread holding tool ( 20 ) to move from the ready position to the intermediate position after the last pass; and then the thread trimming mechanism ( 130 ) to cut off the sewing start end portion of the upper thread. The sewing machine ( 100 ) according to claim 1, wherein said operation control means ( 80 ) are still operable to control the needle trimming mechanism ( 130 ) while the thread holding tool ( 20 ) is held after the last stitch at the ready position to the upper and lower threads, which between the needle opening ( 108a ) of the throat plate ( 108 ) and the shuttle mechanism ( 120 ), cut, and then the thread holding tool ( 20 ) to the intermediate position to cut off the sewing start end portion of the upper thread. The sewing machine ( 100 ) according to claim 1, wherein said operation control means ( 80 ) are operable to remove the upper and lower threads between the needle opening ( 108a ) of the throat plate ( 108 ) and the shuttle mechanism ( 120 ) and the sewing start end portion of the upper thread after the last stitch by a single operation of the thread cutting mechanism (FIG. 130 ) to cut off. The sewing machine ( 100 ) according to one of claims 1 to 3, further comprising a movement mechanism ( 83 . 84 . 140 ), which holds the fabric (W) and moves it around the needle ( 104 ) at a predetermined position, wherein in a case where a puncture point of the first stitch and a puncture point of the last stitch do not coincide with each other, the operation control means (Fig. 80 ) are also operable to control the movement mechanism ( 83 . 84 . 140 ) to position the sewing material (W) such that the needle ( 104 ) after the last stitch, but before moving the thread holding tool ( 20 ) is arranged in the intermediate position, at the puncture point of the first stitch.