JPS6258758B2 - - Google Patents

Description

[Detailed Description of the Invention] Purpose of the Invention (Field of Industrial Application) This invention provides a workpiece cloth supporting surface in which a presser foot and a feed dog for transporting a workpiece cloth are disposed near the needle drop point, and The present invention relates to a workpiece cloth guide device for a sewing machine in which a feed roller is disposed near a needle drop point and is rotatably driven while in contact with the upper surface of the workpiece cloth to apply a feed force to the workpiece cloth.

(Prior art) Generally, when sewing two pieces of processed fabric one on top of the other,
It is known that sewing errors can be prevented by arranging a feed roller on the work cloth feed side from the needle drop point and feeding both work cloths to the needle drop point with the feed roller before forming a stitch. In addition, when forming a seam on a thin cloth, by placing a feed roller on the workpiece cloth feeding side from the needle drop point and pulling the workpiece cloth after the seam is formed based on the rotation of the feed roller, the thread tension can be increased. It is also known that shrinkage due to can be prevented.

(Problem to be Solved by the Invention) However, in conventional sewing machines, the feed roller is fixedly placed either before or after the seam forming point, so the feed roller may be adjusted depending on the type of workpiece cloth to be sewn. When it is necessary to change the position of the machine, it is necessary to have two types of sewing machines, each with a feed roller in the front or the rear. It was something that would happen.

Structure of the Invention (Means for Solving the Problems) In order to solve the above problems, the present invention provides a presser foot 7 and a feed dog for transporting the work cloth W on the work cloth support surface 5. The support member 28 is disposed near the needle drop point, and the support member 28 is disposed on one side of the sewing machine frame 1 so that its position can be adjusted between two positions, front and back along the cloth feeding direction, and is in contact with the upper surface of the workpiece cloth W. A feed roller 33 that applies a feeding force to the work cloth W by being rotationally driven by the support member 28 is rotatably supported on the support member 28 around an axis extending in a direction perpendicular to the cloth feed direction. is placed in the front position, the feed roller 33 is placed on the cloth feeding side from the needle drop point,
Further, when the support member 28 is disposed at the rear position, the feed roller 33 is disposed on the cloth feeding side from the needle drop point.

(Function) With the above configuration, in the present invention, the feed roller 33 can be arranged on the cloth feed side or the cloth feed side from the needle drop point, depending on the type of work cloth to be sewn.

(Example) An example in which the present invention is embodied in an overlock sewing machine will be described below with reference to the drawings.

Now, as shown in FIG. 1, a needle bar 3 having needles 2 at its lower end is supported on the head 1a of the sewing machine frame 1 so as to be able to move up and down in conjunction with a main shaft 4 shown in FIG. A looper (not shown) is provided in the bed portion 1b of the frame 1 for forming an overlock stitch in the work cloth W on the work cloth support surface 5 in cooperation with the needle 2.

A presser foot 6 extending back and forth is swingably supported at its rear end on the left side of the head 1a, and a presser foot 7 located near the needle drop point is attached to its front end. This presser foot 7 has a needle hole 8 that allows the needle 2 to pass therethrough, and a notch 9 that opens at the front.
are formed respectively. A presser bar 10 is supported on the head 1a above the front end of the presser arm 6 so as to be movable up and down, and the presser bar 10 is supported on the head 1a above the front end of the presser arm 6.
is connected to the front end of the An operating knob 11 is rotatably supported on the head 1a above the presser bar 10, and between the operating knob 11 and the middle step of the presser bar 10, pressure is applied to the presser bar 10. A spring 12 is wound around it.
The spring force of the spring 12 is changed and set based on the rotation operation of the operation knob 11. In FIG. 1, reference numeral 13 denotes a lock ring for fixing the operating knob 11 at the rotation adjustment position.

As shown in FIG. 1, an operating rod 15 is supported by a bracket 14 on the head 1a adjacent to the presser rod 10 so as to be movable up and down, and an operating piece 16 is attached to the upper end of the operating rod 15.
is rotatably attached, and an engaging piece 17 is formed at the lower end to engage with the protrusion 10a of the presser bar 10 from below. The operating rod 15 is urged to move downward by a spring 18, and when the operating piece 16 is placed in the position shown in FIG. 1, the operating rod 15 is placed in the lower position; Spring 12 on presser bar 10
Based on the spring force, the presser foot 7 is placed in the lower use position. Then, the work cloth W is pressed against the work cloth support surface 5 by the presser foot 7.

Also, based on the rotational operation of the operating piece 16, the operating rod 15
is moved to an upper position (not shown), the presser bar 10 is moved upward through the engagement between the engagement piece 17 and the protrusion 10a of the presser bar 10, whereby the presser foot 7 is moved to support the workpiece cloth. It is moved to a non-use position above the surface 5.

A feed dog (not shown) is disposed in the bed portion 1b corresponding to the presser foot 7, and the feed dog and the presser foot 7 cooperate to operate in conjunction with the vertical movement of the needle 2. As a result, the work cloth W on the work cloth support surface 5 is transferred rearward along the cloth feeding direction.

A support bracket 20 extending rearward is attached and fixed to the left side of the head 1a, and vertically extending through holes 21 and 22 are bored at predetermined intervals at two positions in the front and rear of the support bracket 20, respectively. has been done. A notch 23 is formed in the upper surface of the support bracket 20 so as to communicate with the front through hole 22.
One support body 24 is selectively attached to each of the through holes 21 and 22. As shown in FIG. 4, this support body 24 is composed of a shaft portion 24a and a cylindrical portion 24b extending in a direction perpendicular to the shaft portion 24a.
The support bracket 2 is connected to the support bracket 2 by a screw 25 which is inserted into the shaft portion 24a from below and is screwed into the shaft portion 24a.
Attached to 0.

A stepped shaft 26 extending left and right is inserted through the cylindrical portion 24b of the support body 24 at its small diameter portion 26a, and is detachably fixed to the support body 24 by a screw 27 screwed into the small diameter portion 26a. . A support member 2 extending back and forth is provided on the large diameter portion 26b of the stepped shaft 26.
8 is attached near the rear end so as to be able to rotate up and down, and is prevented from coming off by the flange portion 26c of the stepped shaft 26. Rotating shafts 29a, 30a extending left and right are rotatably supported at both front and rear ends of the support member 28, and toothed pulleys 29, 30 are fixed to the left ends of the rotating shafts 29a, 30a, respectively. A timing belt 31 is hung between each of the toothed pulleys 29 and 30. A rotating shaft 32 extending parallel to the rotating shaft 30a of the toothed pulley 30 is rotatably supported at the front end of the support member 28 near the front toothed pulley 30, and a feed roller 33 is attached to the right end thereof. There is. On the other hand, a driving gear 34 is fitted and fixed to the rotating shaft 30a of the front toothed pulley 30, and a driven gear 3 that meshes with the driving gear 34 is fitted to the rotating shaft 32.
5 is formed.

As shown in FIG. 2, an operating shaft 36 extending left and right is rotatably disposed at the rear of the right side of the head 1a.
The left end of the operating shaft 36 is connected to the rotating shaft 29a of the rear toothed pulley 29 via a first universal joint 37, a telescopic connecting rod 38, and a second universal joint 39.
is operatively connected to. A toothed pulley 4 is provided at the right end of the operating shaft 36 and the right end of the main shaft 4, respectively.
0, 41 is installed, double-toothed pulleys 40, 41
A timing belt 42 is hung between them.

As the main shaft 4 rotates, the toothed pulley 4
1, timing belt 42, toothed pulley 40,
operating shaft 36, first universal joint 37, connecting rod 38,
The rear rotating shaft 29a on the support member 28 is rotated in a predetermined direction via the second universal joint 39, and the rotational movement is reflected by the toothed pulley 2 on the rotating shaft 29a.
9. It is transmitted to the feed roller 33 via the timing belt 31, the front toothed pulley 30, the rotating shaft 30a, the drive gear 34, and the driven gear 35, and the feed roller 33 is rotated in the cloth feeding direction.

As shown in FIGS. 1 and 3, a pair of front and rear positioning recesses 43 and 44 are formed in the upper edge of the support member 28 at substantially the same interval as the through holes 21 and 22. ing. A pair of screw holes 45 and 46 are formed on the inner surface of the support member 28 in correspondence with the respective positioning recesses 43 and 44, and each screw hole 45 in either the front or rear corresponds to the mounting position of the support body 24. , 46, the engagement plate 47 is removably attached to the support member 28 at two positions, front and rear. The upper edge of this engagement plate 47 is formed into a chevron-shaped cross section as shown in FIG.

A rotary lever 49 is rotatably supported on the left side surface of the support bracket 20 at its intermediate portion by a stepped shaft 50, and a cross section V is formed on the outer periphery at the lower front end of the lever.
A presser roller 51 having a letter-shaped groove portion 51a is rotatably supported around an axis extending left and right. An engagement shaft 5 is provided at the upper front end of the rotating lever 49.
2 is provided in a protruding manner, and an operating piece 55 is provided in a protruding manner at the rear end. A leaf spring 53 is attached to the support bracket 20 below the rotating lever 49 with a screw 54 at its rear end attachment portion, and its tip is engaged with an engagement shaft 52 from above. Therefore,
The rotary lever 49 is urged to rotate clockwise in FIG. 1 by this leaf spring 53. Further, a rotation regulating piece 56 having a protrusion 56a projecting leftward is attached to the upper surface of the support bracket 20, and the operating piece 55 of the rotation lever 49 touches the protrusion 5 of the rotation regulating piece 56.
6a from below, the rotation of the rotation lever 49 is restricted. An adjustment rod 57 extending vertically is screwed into the support bracket 20 so as to be able to adjust its vertical position so as to pass through the rotation restriction piece 56 and the support bracket 20, and its lower end is engaged with the upper surface of the leaf spring 53. There is.
The spring pressure of the leaf spring 53 can be changed and adjusted by rotating the operating knob at the upper end of the adjustment rod 57.

Then, as shown in FIG.
When the support body 24 is attached to the through hole 21 at the rear of the needle 0 and the rear end of the support member 28 is supported by the support body 24 by the stepped shaft 26, the feed roller 33 moves near the needle drop point. The presser foot 7 is disposed closer to the cloth feeding side than the presser foot 7. And support member 2
The presser roller 51 on the rotary lever 49 is disposed in the front positioning recess 44 on the upper side of the positioning recess 44, and the groove 51a of the presser roller 51 is formed on the upper edge of the engagement plate 47 attached to the side of the positioning recess 44. are engaged, and through this engagement, the spring force of the leaf spring 53 is transmitted to the feed roller 33, so that the feed roller 33 is brought into pressure contact with the upper surface of the work cloth W.

On the other hand, as shown in FIG. 3, when the support body 24 is attached to the front through hole 22 and the support member 28 is disposed at the front position via the stepped shaft 26, the feed roller 33 is It is arranged in the notch 9 of the presser foot 7. That is, it is arranged on the cloth feeding side from the needle drop point. At the same time, a presser roller 51 is disposed in the rear positioning recess 43, and is engaged with the replaced engagement plate 47 on the side of the positioning recess 43, so that the leaf spring 53 is closed as in the previous case. Spring pressure is transmitted to the feed roller 33.

Next, the operation of the overlock sewing machine constructed as described above will be explained. Now, in FIG. 1, in order to form an overlock stitch on the side edge of the thin work cloth W, the support member 28 is placed at the rear position, and the feed roller 33 feeds the cloth from the needle drop point behind the presser foot 7. This shows the state where it is placed on the side. Also, based on the rotation operation of the operation piece 16, the presser bar 1
0 is moved downward, and the presser foot 7 is placed in the lower use position.

When the sewing machine is operated in this state, a stitch is formed by the cooperation of the needle 2 and the looper, and the work cloth W is moved along the cloth feeding direction by the cooperation of the presser foot 7 and the feed dog (not shown). and then transported to the rear.
Further, the feed roller 33 is rotated in the cloth feed direction in synchronization with the feed dog, so that the presser foot 7
Tension can be applied to the work cloth W located between the feed roller 33 and the feed roller 33, and it is possible to prevent the work cloth W from shrinking after the stitches are formed.

Next, a case will be described in which two pieces of work cloth W are sewn one on top of the other. In this case, first, while the operation of the sewing machine is stopped, the screw 25 is loosened and the support body 24 is removed from the rear through hole 21. Thereby,
The support member 28 can be removed from the support bracket 20, and the press roller 51 and the engagement plate 4 can be removed.
The engagement with 7 can be released.

Next, after loosening the two screws 48 and removing the engagement plate 47 from the support member 28, the engagement plate 47 is replaced near the rear positioning recess 43 using the screws 48.

Then, the feed roller 33 is moved to the notch 9 of the presser foot 7.
In addition to the rear positioning recess 43
is relatively arranged below the pressing roller 51, and in this state, the shaft portion 24a of the support body 24 is inserted into the front through hole 22 from below. Thereafter, when the support body 24 is fixed to the support bracket 20 with the screws 25, the feed roller 33 is placed and held in the notch 9 of the presser foot 7, and the engagement plate 47 is engaged with the groove 51a of the presser roller 51. , and its presser roller 51 is positioned and held within the rear notch 43. Note that, as shown in FIG. 2, the rear rotating shaft 29a and the operating shaft 36 are connected by a pair of universal joints 37, 39 and a retractable connecting rod 38. The support member 28 can be freely moved when switching from the rear position of FIG. 3 to the front position of FIG. And the support member 28
When the universal joints 37, 39 and the connecting rod 38 are placed in the forward position shown in FIG. 3, the universal joints 37, 39 and the connecting rod 38 are placed in the positions shown by chain lines in FIG.

After that, if the sewing machine is operated with the two pieces of work cloth W placed one on top of the other on the work cloth support surface 5 as shown in FIG. Since the two workpiece cloths W can be fed to the needle drop point by the rotationally driven feed roller 33, it is possible to prevent the occurrence of sagging.

Effects of the Invention As detailed above, in the present invention, when the support member is disposed at the above position, the feed roller is disposed on the cloth feeding side from the needle drop point, and when the support member is disposed at the rear position, the Since the feed roller is configured to be placed on the fabric feed side from the needle drop point, the placement position of the feed roller can be changed as appropriate depending on the type of workpiece fabric to be sewn, making it possible to sew thin workpiece fabrics. In this case, shrinkage can be prevented from occurring, and when two pieces of work cloth are sewn together, it is possible to prevent seams from occurring. Therefore, in the present invention, the above-mentioned two functions can be fulfilled by one sewing machine, so unlike the conventional sewing machine, the user does not need to make a large investment in equipment.

[Brief explanation of the drawing]

Fig. 1 is a side view showing the main parts of an overlock sewing machine embodying the present invention, with the support member placed at the rear position, Fig. 2 is a plan view of the main parts, and Fig. 3 4 is an enlarged cross-sectional view taken along the line -- in FIG. 1, and FIG. 5 is an enlarged cross-sectional view taken along the line -- in FIG. 1. In the figure, 1 is a sewing machine frame, 5 is a work cloth support surface, 7 is a presser foot, 28 is a support member, 33 is a feed roller, and W is a work cloth.

Claims (1)

[Claims] 1. A presser foot 7 and a feed dog arranged near the needle drop point and for transporting the work cloth W on the work cloth support surface 5; and a cloth feed dog on one side of the sewing machine frame 1. a support member 28 disposed so as to be adjustable between two positions along the direction; a support member 28 rotatably supported on the support member 28 around an axis extending in a direction perpendicular to the cloth feeding direction;
It consists of a feed roller 33 that applies a feeding force to the work cloth W by being rotationally driven while in contact with the upper surface of the work cloth W, and when the support member 28 is disposed at the forward position, the feed roller 33 moves toward the needle. A sewing machine characterized in that the feed roller 33 is arranged on the cloth feed side from the needle drop point, and when the support member 28 is placed at a rear position, the feed roller 33 is arranged on the cloth feed side from the needle drop point. Processing cloth guide device.