JPS633668Y2 - - Google Patents

Description

[Detailed description of the invention] Technical field This invention relates to a sewing machine that automatically forms continuous stitches on a workpiece cloth along the side edges of the workpiece cloth, and particularly relates to a workpiece cloth guiding device of the sewing machine. be.

Conventionally, in this type of sewing machine, for example, the side edge of the workpiece cloth is detected by a detection means provided on the cloth feeding side, and the rotational direction of a rotary wheel acting on the workpiece cloth is controlled in response to the detection signal. However, there is a method in which the rotating wheel and the presser foot work together to guide the side edge of the workpiece cloth to a predetermined position while the cloth is being fed, and automatically form a continuous seam on the side edge. .

However, in this conventional sewing machine, when the joint of two pieces of work cloth passes between the rotary wheel and the presser foot, the two seam allowances of the joint pass from one side to the other. The material is pushed down to the fabric side and guided to the seam forming point in a so-called one-sided state, and sewing is performed in that state, and as the material passes through the one-sided part of the seam allowance, resistance to the fabric feed suddenly increases. There is a problem in that the stitching pitch increases and the stitch pitch becomes disordered, which may reduce the commercial value of the processed fabric or make it completely useless as a commercial product.

Purpose of the invention This invention was made in order to eliminate the above-mentioned drawbacks, and its purpose is to prevent the seam allowance of the joined portion of two pieces of cloth from being pulled down on one side, and to prevent the seam forming point from being pulled down on one side. It is an object of the present invention to provide a novel work cloth guide device for a sewing machine, which can guide the work cloth smoothly up to the point where the work cloth is guided up to the sewing machine, and can prevent the occurrence of irregular stitch pitches.

Structure of the Device In order to achieve the above object, in this device, a detection means for detecting the side edge of the work cloth is arranged on the work cloth feeding side with respect to the work cloth feeding means, and the detection means Based on the detection signal, a rotating wheel is rotated around an axis parallel to the cloth feeding direction and below the work cloth support surface by a servo motor that is rotated in forward and backward directions to always guide the side edge of the work cloth to a predetermined position. A cloth engaging portion is provided on the outer periphery of the rotating ring, the upper end of which protrudes above the work cloth support surface, and is processed to have a large frictional resistance with the work cloth. An inclined guide surface of sufficient width is provided on the cloth feeding side and extends from the cloth engaging portion onto the work cloth support surface, and is further attached to a support supported vertically movably on the frame of the sewing machine. a cloth presser is provided for pressing the processed cloth against the cloth engaging portion of the rotating wheel;
In order to guide the work cloth introduced between the presser foot and the rotary wheel, a guide member body is provided which has an inclined guide portion that becomes lower as it approaches at least the introducing portion thereof.

Embodiment Hereinafter, an embodiment embodying this invention will be described with reference to the drawings. As shown in FIG. Stitch forming means are provided which include a needle 4 and a looper (not shown) for cooperating with it to form an overlock stitch. needle 4
Throat plate 5 equipped with a needle hole (not shown) passing through the needle hole (not shown)
is attached to the head 3 of the sewing machine frame 2 so that its upper surface coincides with the upper surface of the sewing machine table 1. The head 3 of the sewing machine frame 2 is provided with a feed dog 6 that appears and retracts on the throat plate 5 in synchronization with the vertical movement of the needle 4. A presser foot 8 is rotatably supported at the tip of a presser arm 7 provided on the side surface of the head 3, and is pressed against the throat plate 5 by a spring 9. Further, at the tip of the presser foot 8, an auxiliary presser foot 10 formed by bending a spring material is connected to a screw 10.
It is attached by a. The upper surface of the sewing machine table 1 and the upper surface of the throat plate 5 constitute a work cloth support surface. Further, the presser foot 8 and the feed dog 6 are used to feed the work cloth C for transporting the work cloth C from the front to the rear on the work cloth support surface so as to pass through the seam forming point, that is, the drop point of the needle 4. The means are configured.

Above the auxiliary presser foot 10, on the front surface of the head 3 of the sewing machine frame, a light emitting element such as a light emitting diode and a light receiving element such as a phototransistor are mounted via a support arm 11, and are activated when the sewing machine starts or stops. A sensor 12 is attached as a detection means. Further, the needle plate 5 is provided with a sensor 12.
A reflecting plate (not shown) is buried opposite to the. As shown in FIG. 3, a servo motor 14 is connected to the bottom surface of the sewing machine table 1 via a bracket 13.
The sensor 1 is provided at the end of the motor shaft 14a that rotates around one axis parallel to the cloth feeding direction.
A rotating wheel 15 located slightly in front of 2 is attached. The upper part of the rotary wheel 15 projects above the sewing machine table 1 through an opening 16 in the sewing machine table 1. On the outer periphery of this rotary wheel 15, a workpiece cloth C is located on the side of the sewing machine frame 2.
A cloth engaging portion 17 is provided which has been subjected to a process that creates a large frictional resistance, for example, a knurling process.
Further, on the cloth feeding side of the cloth engaging portion 17, an inclined guide surface 18 having a sufficient width is formed on the outer periphery of the rotary wheel 15 and extending from the cloth engaging portion 17 to the upper surface of the sewing machine table 1.

As shown in FIG. 2, a plurality of screws 19 are mounted on the sewing machine table 1 at the front of the sewing machine frame 2.
The support piece 19 is fixed by a, and the support piece 19
A swing lever 20 extending in the left-right direction is swingably supported near the center by a shaft 19b at the upper part of the swing lever 20. The lower edge of this swinging lever 20 has a rotation restriction that can restrict the clockwise rotation of the swinging lever 20 in FIG. 2 based on engagement with the locking portion 22 of the support piece 19. A piece 21 is provided protrudingly. Further, an air cylinder 23 is provided below the sewing machine table 1, and an end of a piston rod 24 of the air cylinder 23 is rotatably connected to one end of the swing lever 20.

A stepped shaft 27 is fixed to the bent portion 25 formed at the other end of the swing lever 20 with a screw 26, and a support lever 28 extending in the front-rear direction is attached to a small diameter portion of the stepped shaft 27. It is rotatably supported at the base end on the feeding side in a plane parallel to the cloth feeding direction. A substantially U-shaped support frame 30 is rotatably supported on the bent end portion 29 of the support lever 28 around a shaft 30a extending in the cloth feeding direction, and a pair of support protrusions 30b of the support frame 30. The shaft 30 is in between.
A presser roller 32 is provided as a cloth presser that rotates around an axis 31 perpendicular to a. This presser roller 32 has a drum shape and is provided with an arcuate surface 33 on its outer periphery that substantially coincides with the outer periphery of the rotating wheel 15. Further, an annular groove 34 is formed in the minimum diameter portion at the center of the presser roller 32 .

A support arm 41 extending in the front-rear direction is attached to the upper front side surface of the support frame 30 at a bent portion of the base end,
A guide member 42 extending toward the presser roller 32 is attached at its base end to its front end.
In order to guide the work cloth C introduced between the presser roller 32 and the rotary wheel 15,
The inclined guide part 4 becomes lower as it approaches 2, 15.
3 is formed. A guide tongue piece 44 that enters the annular groove 34 of the presser roller 32 is formed protruding from the rear edge of the inclined guide part 43.
A sewing machine table 1 is provided on both sides of the guide tongue piece 44.
A guide piece 45 is formed that extends parallel to the upper surface of. Furthermore, a pair of guide pieces 46 are integrally formed on both left and right edges of the inclined guide portion 43, and are bent so that the outer side faces upward.

On the other hand, another bent part 35 formed near the bent part 25 of the swing lever 20 has a part that protrudes upward and passes through a bent part 36 near the base end of the support lever 28. A support shaft 37 is provided, and a cylindrical body 39 that can move up and down along a guide groove 37a extending in the axial direction is inserted into the support shaft 37.
An operating knob 38 is screwed into the upper threaded portion. Further, a compression spring 40 is wound around the support shaft 37 between the cylindrical body 39 and the bent portion 36 of the support lever 28, and the compression spring 40 causes the support frame 30 to move together with the support lever 28 onto the stepped shaft 28. The holding roller 32 and the guide body 42 are urged downward by being urged to rotate in the counterclockwise direction in FIG. 1 about the center. Therefore, the presser roller 3
The work cloth C can be held between the rotating wheel 15 and the rotating wheel 15. Furthermore, the spring force of the compression spring 40 can be adjusted based on the rotation of the operating knob 38. Note that the bifurcated upper end threaded portion of the support shaft 37 has elasticity in the direction of being slightly expanded, and provides a weak resistance force to the operation knob 38 against rotational operation. ing.

Next, the operation of the sewing machine configured as described above will be explained. Now, when sewing work cloth C in which two work cloths Ca and Cb are joined together as shown in FIG. Fold it back to the Ca and Cb sides.
In this state, after placing the work cloth C on the sewing machine table 1, the presser foot 7 is rotated toward the feed dog 6 side, and a part of the work cloth C is placed between the presser foot 8 and the feed dog 6. , and place the side edge of the work cloth C on a reflecting plate (not shown) between the reflecting plate and the auxiliary presser foot 1.
It is held between 0 and 0. And air cylinder 23
The swinging lever 20 is rotated clockwise in FIG.
5, a part of the work cloth C is held between them. At this time, the presser pressure of the presser roller 32 against the rotary wheel 15 is adjusted as appropriate by rotating the operating knob 38 and adjusting the spring pressure of the compression spring 40 according to the thickness of the work cloth C to be sewn. be able to.

In this state, if an appropriate start switch (not shown) provided on the bottom surface of the sewing machine table 1 or the like is used to start the sewing machine motor and drive the main shaft of the sewing machine, and at the same time starts the sensor 12, the sensor 12 will cause the side edge of the fabric to be The servo motor 14 is rotated forward or reverse based on the detection signal. Based on the rotation of the servo motor 14, the rotating wheel 15 is rotated forward or reversely, and the workpiece cloth C fed between the rotating wheel 15 and the presser roller 30 is moved between the cloth engaging portion 17 of the rotating wheel 15 and the presser foot. The work cloth C is moved in the left-right direction in cooperation with the rollers 30, and the side edges of the work cloth C are always placed on the center line of the reflector. At the same time, the needle 4 and the looper (not shown) are operated together with the rotation of the sewing machine main shaft, and an overlock stitch is formed on the side edge of the workpiece cloth C, and the presser foot 8 and feed dog 6 are The work cloth C is fed in the cloth feeding direction by the cooperation of the two.

When the seam allowances S and T of the work cloths Ca and Cb are introduced to the needle drop point, that is, the seam formation point when performing this overlock stitch, the processing is performed as shown by the solid line in Fig. 3. As the fabric C is fed, one of the seam allowances T engages with the inclined guide part 43 of the guide body 42 from below and its folded state is maintained, and in this state, the workpiece fabric C is attached to the inclined guide surface of the rotating wheel 15. 18 and the guide tongue piece 44, the cloth engaging portion 17 and the presser roller 32
will be introduced between. Then, the rear presser roller 3 whose other seam allowance portion S is simultaneously engaged with the inclined guide portion 43
2 and the cloth engaging portion 17 of the rotating wheel 15. In this case, the seam allowance T on the cloth feeding side of the processed cloth C
engages with the lower surface of the inclined guide part 43 of the guide body 42, and is bent in a flat direction by the action of the slope of the inclined guide part 43 as the cloth is fed. Moreover, the inclined guide surface 18 located between the cloth engaging portion 17 and the workpiece cloth support surface is continuous with the workpiece cloth support surface, has a sufficient width, and has a gentle slope angle, so that the workpiece can be easily processed. The seam allowance T caused by the sudden rise of the cloth C is reliably held in a flat folded state, and passes between the rotating wheel 15 and the presser roller 30 in this state.
Note that, as a matter of course, there is no risk that the seam allowance S on the cloth feeding side will roll up in the direction opposite to the folding direction. Therefore, after that, both seam allowances T and S are
It is surely introduced between the auxiliary presser foot 10 and the throat plate 5 in close contact with Cb and Ca.

As described above, in this sewing machine, unlike the conventional example, each seam allowance S, T is pushed to one side on one work cloth Ca or Cb side at the joint part of each work cloth Ca, Cb. This makes it possible to reliably perform oversewing at the joint, and to prevent irregularities in the stitch pitch.

Further, in this embodiment, the guide tongue piece 44 is disposed within the annular groove 34 of the presser roller 32, and the lower surface of the guide tongue piece 44 is connected to the circular arc surface 34 of the presser roller 32.
Since it is substantially continuous, the work cloth C can be reliably held between the circular arc surface 33 and the guide tongue piece 44 and the cloth engaging portion 17 of the rotary ring 15. Therefore,
As the rotating wheel 15 rotates, the work cloth C can be smoothly moved in a direction substantially perpendicular to the cloth feeding direction, and the side edges of the work cloth C can be aligned. Furthermore, in this embodiment, the support lever 28 that supports the presser roller 32 and the guide body 42 is rotatable in a plane parallel to the cloth feeding direction in front of the presser roller 32 and the guide body 42. , the presser roller 32 and the guide member 42 can be moved up and down to follow the upper surface of the work cloth without difficulty as they pass through stepped portions such as the seam allowances S and T.

Effects of the invention As detailed above, this invention arranges a detection means for detecting the side edge of the work cloth on the work cloth feeding side with respect to the work cloth feeding means, and based on the detection signal from the detection means. A rotating wheel is provided, which is rotated by a servo motor that rotates forward and reverse around an axis parallel to the cloth feeding direction and below the work cloth support surface to always guide the side edge of the work cloth to a predetermined position. A cloth engaging portion is provided on the outer periphery, the upper end of which protrudes above the work cloth support surface, and the surrounding area is processed to have a large frictional resistance with the work cloth. A sloping guide surface of sufficient width is provided that extends from the cloth engaging portion onto the work cloth support surface, and the work cloth is connected to the support body supported vertically movably on the frame of the sewing machine. A presser foot is provided for pressing against the engaging portion, and an inclined guide portion that becomes lower toward at least an introduction portion for guiding the work cloth introduced between the presser foot and the rotating wheel is provided. By providing the guide body, when a workpiece cloth having a seam allowance is fed to a seam forming point by joining two workpiece cloths, the seam allowance is pushed to one side on one side of the workpiece cloth. It is possible to prevent the occurrence of sudden resistance to the feed of the work cloth due to the unilateral bending and the unevenness of the seam pitch caused by such resistance. It has this excellent effect.

[Brief explanation of drawings]

Figure 1 is a side sectional view showing the main parts of a sewing machine embodying this idea, Figure 2 is a sectional view taken along line A-A in Figure 1, and Figure 3 is a sectional view taken along line B-B in Figure 2. be. Sewing machine table 1, sewing machine frame 2, throat plate 5
(the above 1 and 5 constitute a work cloth support surface), a feed dog 6, a presser foot 8 (the above 6 and 8 constitute a work cloth feeding means), a sensor 12
(These 12 and others constitute the detection means), the servo motor 14, the rotating wheel 15, the cloth engaging part 17, the inclined guide surface 18, the swing lever 20, the support lever 28, the support frame 30 (the above 20, 28 , 30 constitute a support body), a presser roller 32 as a cloth presser, an arc surface 33, an annular groove 34, a guide body 42, an inclined guide portion 43, a guide tongue piece 44, and a work cloth C.

Claims (1)

[Claims for Utility Model Registration] 1 Work cloth feeding means 6, 8 for passing through the seam forming point and transporting the work cloth C in one direction on the work cloth support surfaces 1, 5; and the work cloth feeding means. 6 and 8, a detection means 12 or the like is arranged on the work cloth feed side to detect the side edge of the work cloth C, and a detection signal from the detection means 12 or the like is arranged near the detection means 12 or the like. Rotation is performed by a servo motor 14, which is rotated in forward and backward directions based on the rotation direction, around an axis parallel to the cloth feeding direction and below the work cloth support surfaces 1 and 5, so as to always guide the side edges of the work cloth C to a predetermined position. a ring 15; and a cloth engaging portion 17 on the outer periphery of the rotating wheel 15, the upper end of which protrudes above the work cloth support surfaces 1, 5, and the periphery of which is processed to have a large frictional resistance with the work cloth C;
and is located on the cloth feeding side of the cloth engaging portion 17 and extends from the cloth engaging portion 17 to the work cloth supporting surfaces 1, 5.
The work cloth C is rotated by being attached to supports 20, 28, and 30 which are vertically movably supported on the frame 2 of the sewing machine. A cloth presser foot 32 for pressing against the cloth engaging portion 17 of the ring 15; and a cloth presser foot 32 attached to the cloth feed side of the supports 20, 28, 30 of the cloth presser foot 32, and the cloth presser foot 32 and the rotating wheel 15. A workpiece cloth guide device for a sewing machine, characterized in that a guide member body 42 has an inclined guide portion 43 that becomes lower toward at least an introduction portion for guiding the workpiece cloth C introduced during the process. 2. A utility model characterized in that the presser foot is composed of a drum-shaped presser roller 32 that can rotate around a horizontal axis perpendicular to the cloth feeding direction and has an arcuate surface 33 that substantially coincides with the outer circumference of the rotating ring 15. A work cloth guide device for a sewing machine according to claim 1. 3. An annular groove 34 is formed in the smallest diameter portion of the central portion of the presser roller 32, and the guide portion body 42
Processing of a sewing machine according to claim 2, characterized in that a guide tongue piece 44 formed continuously with the inclined guide part 43 extends so as to enter into the annular groove 34. Cloth guiding device.