JPH08173659A - Needle thread cutter for sewing machine - Google Patents

Abstract

PURPOSE: To pull tight the needle thread for a precise cutting just under the presser and to form a gap between the presser foot and the material for the prevention of cutter-caused damage by lifting the sewing machine head for the cutting. CONSTITUTION: Upon termination of sewing FUTON (a thick bedquilt) or the like, a cylinder is actuated for a sewing machine head 23 to rise and for a rotary rod 43 of a cutter mechanism 41 to rotate to an operating position B. The needle thread P in a needle 22 is cut by a cutter 50 just under a presser 22a, when the needle thread P may be unerringly cut thanks to the tension given by the elevation of the sewing machine head 23. A gap is formed between the presser foot 22a and FUTON when the sewing machine head 23 rises, which prevents the FUTON from being damaged by the cutter 50. By the use of this system, the needle thread P is firmly held by a notch 48 spreading outward, even when its position changes to and fro, and is smoothly guide to the cutter 50.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention mainly relates to a needle thread cutting device installed in an automatic sewing machine used for binding a futon or the like.

[0002]

2. Description of the Related Art As a needle thread cutting device in a sewing machine, a hook metal fitting is provided on a sewing machine head so as to be vertically rotatable, and the needle thread is hooked on the hook metal fitting between a needle and a presser foot of the sewing machine head to provide a fixed blade. It is known to cut off by a joint action with (Japanese Patent Application Laid-Open No. 57-128195).

[0003]

Since the upper thread is cut between the needle and the presser foot, it is not possible to cut the upper thread with a margin for the length of the upper thread left on the needle side, and the hook metal fitting is used. When hooking the upper thread, it is necessary to pass the upper thread portion and largely rotate the hook fitting, so that there is a problem that the operation becomes large by the amount of the upper thread portion passing.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and is substantially horizontal to the frame portion of the support base between the sewing machine head portion and the base portion under the sewing machine head portion. In a sewing machine that sews a sewing object by synchronously moving the sewing head portion and the base portion relative to the sewing object that is stretched and set on the sewing machine head, the sewing machine head portion is raised and lowered by the base portion. The sewing machine head is provided with a rotary rod that is adjustable in expansion and contraction, and is rotatable about the pivot from the upper rear of the presser foot provided on the sewing machine head toward the lower part of the presser foot. And a holder plate having a substantially V-shaped notch on the front surface is attached to the tip of the rotating rod, and the needle thread passed through the needle of the sewing machine head is attached to the holder plate in a raised state. Sewing machine head The blade is under the presser foot cut by downward rotation of the pivot rod, and a configuration in which exposed to-out the cut-out. The rotating rod was provided with a base portion attached to the pivot shaft, and a movable portion in which a screw passed through the through hole was screwed into the screw hole to be attached to the base portion so as to be adjustable in expansion and contraction, and a holder plate was attached to the stay. It can be configured.

[0005]

The sewing machine head is moved upward by the cylinder and the rotary rod is rotated downward to press the needle thread through the needle with the blade provided in the V-shaped notch of the holder plate. Cut directly under. The thread left on the needle side will be cut with a sufficient length, and the upper thread will be tensioned by the upward movement of the sewing machine head, so that the thread can be pressed accurately. Since there is a gap between the presser foot and the futon due to the upward movement of the sewing machine head, there is less risk of the futon damaging the futon. Even if the position of the upper thread is deviated to the left or right, the notch having the outward spread shape surely catches the upper thread and guides it to the blade, so that the upper thread is also cut properly at this point.

[0006]

An embodiment of the present invention will be described below with reference to the drawings. 1 to 3 show an example of a sewing machine device 1 equipped with a needle thread cutting device according to the present invention. The sewing machine device 1 has a futon (a material to be sewn) in a substantially horizontal state at its central portion. A substantially horizontal base 5 on which a support base 4 supported by
And the right and left vertical members 2 of the base 5 which are parallel to each other and are orthogonal to each other, and are arranged so as to straddle these vertical members 2. Machine frame 7 that moves back and forth in the direction perpendicular to the plane of the paper (horizontal direction in FIG. 3) at 1
And a sewing machine main body 9 that moves left and right along the machine frame 7 by the left and right drive device 8 (FIG. 1) and stitches the futon supported by the support base 4 together.

The left and right two vertical members 2, 2 of the base 5 are connected to each other by a horizontal member 3 which is bridged between the longitudinal central portions of the vertical members 2. The H-shaped base 5 is placed on the floor F in a horizontal state. A triangular reinforcing plate 10 is fixed to each of the vertical members 2 and the horizontal members 3. A guide rail 11 is horizontally laid on the upper surface of each vertical member 2 along the length direction thereof.

On the base 5, the rectangular frame-shaped machine frame 7 having upper and lower beam members 7A and 7B is provided, and a slide shoe 12 provided at the lower end is movably attached to each of the guide rails 11. It is provided so as to be engaged and movable in the front-rear direction.

The slide shoe 12 is attached to the machine frame 7 via a thrust bearing 14. Further, stoppers 15 are integrally fixed to both ends of the bottom plate 7a of the machine frame 7 together with the bottom plate 7a, and these stoppers 15 have pulleys 16 arranged at both ends of each vertical member 2. The end portions of the timing belt 17 wound around are locked. Pulleys 16 arranged at one end of each vertical member 2 are connected by a transmission shaft 18 so that they can rotate integrally at the same time. When the front-rear drive unit 6 connected to the transmission shaft 18 via the drive belt 19 is operated,
The power is transmitted to each timing belt 1 via each pulley 16.
7, the machine frame 7 is pulled by the timing belts 17 to move in the front-rear direction along the guide rails 11.

Guide members 20 and 21 extending horizontally along the longitudinal direction (horizontal direction) of the machine frame 7 are provided on the front and rear surfaces of the upper girder material 7A and the upper surface of the lower girder material 7B of the machine frame 7. The upper guide member 20 is provided on each of the upper and lower guide members 20 and the presser foot 22a for pressing down the futon and the futon.
(See FIG. 4), and the lower guide member 21 is provided with a rotary hook and a bobbin cutter (both not shown), which is a separate base from the sewing machine head 23. The portion 24 is movably supported in the left-right direction along the guide members 20 and 21 via the sliders 23a and 24a, respectively.

The support base 4 is composed of a rectangular frame portion 4a along the outer periphery of the futon and a leg portion 4b on which the frame portion 4a is placed. The support base 4 is placed on the floor F across the lateral member 3. Has been done. The support base 4 is in a state in which the futon is floated by sandwiching the outer circumference of the futon with a clip (not shown) attached to the frame portion 4a, and the futon is formed by the sewing machine head portion 23 and the base portion 24 constituting the sewing machine body 9. Place it between and support it.

The sewing machine head portion 23 and the base portion 2
4, a pair of actuating pulse motors 25 and 26 that actuate both of them in synchronization with each other and a pair of revolving pulse motors 27 and 28 that rotate of both in synchronization with each other are individually provided.

Further, the sewing machine head portion 23 and the base portion 24 are connected to the left and right driving device 8 mounted on the machine frame 7 via feed mechanisms 29 and 30. Feed mechanism 2
The reference numerals 9 and 30 are timing pulleys 31 and 32 attached to the machine frame 7 and the timing pulleys 31 and 32 wound around the timing pulleys 31 and 32.
3 and the timing belt 33 and 34 locked to the base portion 24, respectively. The left-right drive device 8 is connected to the feed mechanism 29 on the sewing machine head 23 side via a pulley 35, a belt 36 and a pulley 37,
Further, it is connected to the feed mechanism 30 on the base portion 24 side via a pulley 38, a belt 39 and a pulley 40.

When the left and right drive device 8 is operated, the power thereof is converted into the pulling action of the timing belts 33 and 34 of the feed mechanisms 29 and 30 via the pulleys, the timing pulleys and the belts. , The sewing machine head portion 23 and the base portion 24 are provided for each timing belt 3
By being pulled by 3, 34, each guide member 20,
It is designed to move in the left-right direction in synchronization with each other along 21.

Next, the needle thread cutting device in the sewing machine according to the present invention will be described with reference to FIGS. 4 to 7. As shown in FIG. 4, the sewing machine head portion 23 is vertically movably attached to the slider 23a through a pair of left and right telescopic arms 60 extending vertically, and a cylinder (elevating mechanism) 61 set on the slider 23a It is designed to move up and down. Due to the upward movement of the sewing machine head portion 23, the distance between the needle 22 of the sewing machine head portion 23 and the base portion 24 is further increased, and the distance is such that the support base 4 is moved laterally with respect to the base 5 and the support base is provided therebetween. The height is set so that the four frame portions 4a can be taken in and out.

The sewing machine head 23 of the sewing machine body 9 is provided with a cutter mechanism 41 for cutting the upper thread. The cutter mechanism 41 is omitted in FIGS. 1 to 3.

As shown in FIGS. 5 and 6, the cutter mechanism 41 is a rotating rod provided on one side of the sewing machine head 23 so as to be rotatable along a substantially vertical plane via a horizontal pivot 42. 43 and a cutter 44 attached to the tip of the rotating rod 43.

The rotating rod 43 is composed of a base portion 45, one end of which is attached to the pivot shaft 42, and a movable portion 46 which is extendably and contractably screwed to the other end portion of the base portion 45. The other end portion of the base portion 45 and the movable portion 46. A plurality of screw holes 45a and a plurality of through holes 46a are formed in each of the holes at intervals in the length direction. The screw hole 45a and the through hole 46a are arbitrarily selected and aligned with each other, and the screw 47 passed through the through hole 46a is screwed into the screw hole 45a, whereby the length of the rotating rod 43 can be arbitrarily changed. ing. The rotation range of the rotation rod 43 is
As shown by an arrow (a) in FIG. 6, a forward rotation is performed from a standby position A that extends substantially horizontally behind the sewing machine head portion 23 (toward the upper portion of the presser foot 22a) that moves leftward in FIG. Operating position B that moves and extends substantially vertically below the presser foot 22a
It is a range that spans.

As shown in FIG. 7, the cutter 44 has a holder plate 49 having a triangular (V-shaped) notch 48 on the front surface when the rotating rod 43 is in the operating position B.
And a blade 50 held by the holder plate 49,
The holder plate 49 is connected to the movable portion 46 of the rotating rod 43 via the stay 51. Blade 50 has a notch 4
Exposed to 8.

In the cutter mechanism 41, when the rotating rod 43 is rotated from the standby position A to the operating position B at a predetermined speed, the upper thread P passed through the needle 22 at the top dead center of the sewing machine head portion 23. The portion immediately below the needle 22 is cut under the presser foot 22a. The operation of the rotating rod 43 is automatically performed by a control device (not shown) when the binding and sewing of the futon is completed.

Next, the operation of the needle thread cutting device in the sewing machine configured as described above will be described. First, the sewing machine head portion 23 is moved upward by the cylinder 61 and supported by the frame portion 4a of the support base 4. Is moved together with the support 4 onto the base 5. Since the sewing machine head 23 is moved upward, the futon supported by the frame portion 4a is set in the sewing machine device 1 without any hindrance. Then, when the sewing machine head 23 is moved downward and the operation pulse motors 25 and 26 are operated,
The sewing machine head portion 23 and the base portion 24 operate in synchronization with each other. When the front-rear drive unit 6 is operated in this state, the machine frame 7 moves in the front-rear direction along the guide rails 11 to move the sewing machine body 9 with respect to the futon,
The futon is sewn linearly in the moving direction of the machine frame 7, that is, in the front-back direction.

When the front-rear drive unit 6 is stopped and the left-right drive unit 8 is operated, the sewing machine main body 9 moves in the left-right direction along the guide members 20, 21 in synchronization with each other, and the futon becomes the sewing machine main body 9. Is sewn linearly in the moving direction, that is, in the left-right direction. The futon is sewn diagonally by combining the movements of the sewing machine body 9 in the front-rear direction and the left-right direction. Further, when performing zigzag stitching or embroidery on the futon, the turning pulse motors 27 and 28 are operated to turn the sewing machine head portion 23 and the base portion 24 in synchronization with each other, and the sewing machine main body 9 for the futon is moved. The directions of the sewing machine head portion 23 and the base portion 24 are matched with the relative movement direction. In addition, as shown in FIG. 8, the sewing of the futon is generally performed on the front and back cloth 6 with the batting material 62 such as feathers sandwiched therebetween.
3 is sewn in a grid pattern.

The front and rear drive device 6, the left and right drive device 8, the actuation pulse motors 25 and 26, and the turning pulse motors 27 and 28 are operated by a controller (not shown). It should be noted that the turning rod 43 of the cutter mechanism 41 is kept at the standby position A during sewing of the futon.

When the futon is sewn in this way, and when the sewing is completed, the sewing machine head 23 is moved upward by the cylinder 61, and the rotating rod 43 of the cutter mechanism 41 is rotated to the operating position B, whereby the needle 22 is moved. The needle thread P passed through the presser foot 22
Immediately below a, cut the length of the thread left on the needle 22 side with a margin. At this time, the upper thread P can be tensioned by the upward movement of the sewing machine head portion 23, and the upper thread P is properly pushed off by the blade 50. Moreover, since there is a gap between the presser foot 22a and the futon due to the upward movement of the sewing machine head portion 23, it is less likely that the blade 50 damages the futon. Further, even if the position of the upper thread P is deviated to the left or right, the notch 48 having the outward spread shape surely catches the upper thread P and guides it to the blade 50, so that the upper thread P is also accurately cut at this point. . The lower thread is cut by the lower thread cutter provided in the base portion 24.

[0025]

As described above, the needle thread cutting device in the sewing machine according to the present invention is substantially horizontal to the frame portion of the support base between the sewing machine head portion and the base portion under the sewing machine head portion. In a sewing machine device that sews a sewing object by synchronously moving the sewing head portion and the base portion relative to the sewing object that is stretched and set on the sewing machine head, the sewing machine head portion is raised and lowered by the base portion. The sewing machine head is provided with a rotary rod that is adjustable in expansion and contraction, and is rotatable about the pivot from the upper rear of the presser foot provided on the sewing machine head toward the lower side of the presser foot. A holder plate, which is movably provided and has a substantially V-shaped notch on the front surface, is attached to the tip of the rotating rod, and the holder plate is passed through the needle of the sewing machine head. Thread on Since the blade for cutting by the downward rotation of the rotating rod under the presser foot of the sewing machine head in the state is provided so as to be exposed in the notch, the sewing machine head is moved upward. With this, the upper thread can be tensioned, and the upper thread can be properly pushed down with a margin to the length of the thread left on the needle side. Moreover, since there is a gap between the presser foot and the futon due to the upward movement of the sewing machine head, it is less likely that the blade will damage the futon. Further, even if the position of the upper thread is deviated to the left and right, the outwardly extending notch surely catches the upper thread and guides it to the blade, so that the upper thread can be cut accurately also in this respect. In addition, since the push-cut method is used, the operating range of the blade can be minimized.

[Brief description of drawings]

FIG. 1 is a front view showing an example of a sewing machine equipped with a needle thread cutting device of the present invention.

FIG. 2 is a side view of the same.

FIG. 3 is a plan view of the same.

FIG. 4 is a front view showing an embodiment of the needle thread cutting device in the sewing machine according to the present invention.

5 is a front view of the cutter mechanism of FIG. 4. FIG.

FIG. 6 is a side view of the same.

FIG. 7 is a plan view of the cutter.

FIG. 8 is a cross-sectional view of the futon.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Sewing machine device, 4 ... Support stand, 4a ... Frame part, 22 ... Needle,
22a ... Presser foot, 23 ... Sewing machine head section, 24 ... Base section, 42 ... Axis, 43 ... Rotating rod, 45 ... Base section, 45
a ... screw hole, 46 ... movable part, 46a ... through hole, 47 ... screw, 48 ... notch, 49 ... holder plate, 50 ... blade,
51 ... Stay, 61 ... Cylinder (elevating mechanism), P ... Upper thread.

Claims (2)

[Claims] 1. A sewing machine which is relatively stretched between a sewing machine head portion and a base portion below the sewing machine head portion and which is stretched substantially horizontally on a frame portion of a support base. In a sewing machine for sewing a workpiece by synchronously moving a head portion and a base portion, the sewing machine head portion is vertically movable with respect to the base portion by an elevating mechanism, and the sewing machine head portion is adjustable for expansion and contraction. A rotary rod is rotatably provided from the upper rear of the presser foot provided on the sewing machine head toward the lower side of the presser foot around a pivot as a fulcrum. A holder plate having a V-shaped notch is attached to the holder plate, and the needle thread passed through the needle of the sewing machine head is attached to the rotating rod under a presser foot of the sewing machine head in a raised state. Rotation of the An upper thread cutting device in a sewing machine, wherein a cutting blade is provided so as to be exposed in the notch. 2. The rotating rod is attached to a base portion attached to a pivot, and a screw passed through a through hole is screwed into the screw hole so as to be adjustable in expansion and contraction. The holder plate is attached to a stay. The upper thread cutting device in the sewing machine according to claim 1, further comprising: