JPS607508B2 - Fabric edge cutting attachment for zigzag sewing machines - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fabric edge cutting attachment for cutting fabric edges prior to a sewing operation of a sewing machine.

When cutting the edge of the fabric prior to sewing, it is desirable to move the cutting blade as close as possible to the needle drop point to avoid creating a large gap between the cutting actuator and the sewing part.

However, in general household zigzag sewing machines, there are feed teeth extending forward from both sides of the needle hole in front of the needle drop point.
In the fabric edge cutting device shown in Utility Model No. 52-46388 and Utility Model 49-3156, etc., a cutting operation section consisting of a fixed blade and a movable blade is provided in front of the feed dog to avoid this feed dog. ing.

Therefore, there is a large distance between the cutting actuator and the needle drop point, and "after cutting the edge of the fabric, the work fabric has to travel a considerable distance to the needle drop point, which reduces the hem that is formed." In some cases, the blank seam may deviate from the cutting edge of the fabric to be processed, making it impossible to create a beautiful all-over hem, or a long blank stitch may be performed between cutting the edge of the fabric and starting sewing. There is a risk that the thread may get caught in the hook due to the difficulty of
As shown in No. 1, the work cloth is fed from above the top surface of the throat plate, and the edge of the work cloth fed in is cut by a cutting operation section provided above the top surface of the throat plate. A device has been proposed in which the cutting operation unit can be placed close to the needle drop point regardless of the feed dog, but this type of device feeds the work cloth from above the throat plate. Not only is it difficult to guide the transfer of the fabric by hand, making it difficult to form a green stitch along the sewing line, but also the fabric is bent while it reaches the needle drop point from the cutting section. If the cutting actuating part is too close to the sewing machine needle, the degree of bending will increase, causing trouble in fabric feeding, etc. Therefore, there is a practical limit to how close the cutting actuating part can be to the needle drop point.

Furthermore, by cutting off the front end of the feed dog located on the right side of the needle hole and positioning the cutting operation part at the cutting position,
A type in which the cutting operation part is located close to the needle drop point has also been proposed, but with this type the green overcasting is performed smoothly, but in normal sewing work, the cloth feed operation of the feed dog is difficult. This results in unevenness on the left and right sides of the needle hole, making fabric feeding unstable, making it difficult to form stitches along the sewing line, and creating a risk of creating seam wrinkles. The present invention has been made in view of these problems, and its purpose is to enable the sewing machine to be attached to a zigzag sewing machine during the entire sewing work, so that the sewing machine can be attached to a zigzag sewing machine during the entire sewing work. It is an object of the present invention to provide a fabric edge cutting attachment that can perform accurate overlock sewing work and, when removed from the sewing machine, can perform normal sewing work in exactly the same manner as a conventional sewing machine.More specifically, the above-mentioned When using the attachment, the right feed dog moves in the gap between the protruding arm and the fixed blade.
By positioning the upper edge of the fixed blade at almost the same height as the upper surface of the throat plate, the workpiece fabric can be bent along the upper surface of the throat plate without causing any hindrance to the cloth edge cutting work. It is possible to accurately and smoothly form overcut seams along the cutting line without deviating from the planned sewing line, and when the attachment is inconvenient, the notch in the cover plate allows the feeding dog to be To provide an attachment for cutting edge of cloth, which can cover an attachment mounting gate part with its cover plate without hindering movement. The present invention will be described in detail below based on an embodiment of an attachment-type cloth edge cutting device shown in the drawings.L in the drawings, reference numeral 11 is a sewing machine arm, and a needle bar attached to the head end of the sewing machine arm. A sewing machine needle 12 and a presser foot turtle 3 are attached to the lower end of the presser foot bar.

The presser foot 13 in this embodiment is biased clockwise in FIG. 1 by a spring 1W, and its tip also presses the work cloth, causing the work cloth to be cut by the cloth edge cutting attachment described later. This ensures that the operation can be performed reliably. The tortoise 5 is a sewing machine bed, and a top plate 16 is fixed to the upper surface of the bed, and a hook lid 17 is attached to the left end of the front surface so as to be openable and closable.

The turtle 8 is a throat plate attached to the front part of the upper surface of the upper plate 6 so as to cooperate with the upper plate 6 to form a workpiece support surface, and as shown in FIG. On the other side, there is a long and narrow needle hole 19 for zigzag sewing that extends in a direction perpendicular to the cloth feeding direction.
is formed. Reference numerals 20 and 21 denote a pair of left and right feed dog openings 0 and 22 formed so as to extend forward and backward of the needle hole ridge 9 along the cloth feeding direction at both left and right positions of the needle hole 19.
23 and 24 are a pair of feed dog gates formed to extend in the cloth feeding direction behind the needle hole 19;
The feed dog is disposed below the feed dog 8 and is adapted to apply a feed motion to the work cloth on the workpiece support surface through the feed dog openings 20 to 22.

Of the pair of longer feed dogs 23 of the same length located on both the left and right sides of the needle hole 19, the left feed dog 23 has its front end overlapped with a cutting operation section to be described later in the cloth feeding direction, so that the left feed dog 23 has the same length. It extends further forward than the corresponding feed dog of a conventional zigzag sewing machine so as to protrude forward from the inner protrusion piece 49b, which will be described later, and allows the work cloth to be fed smoothly when using the cloth edge cutting attachment. I'm starting to get it. Further, the feed dog 23 on the right side of the needle hole 19 has the same length as the feed dog of a conventional zigzag sewing machine and is arranged at the same position. Reference numeral 25 denotes a closure formed at the front part of the needle plate 18 on the right side in order to attach the cloth edge cutting attachment, and as shown in FIGS. A horizontal support plate part 27 that is continuous with the front end of the feed dog entrance 21 located on the right side of the hole 19 and has a pair of left and right engagement holes 26 between the rear edge of the approximately central part and both front and rear ends on the right side. are formed respectively.

28 is a support plate rotatably attached to the lower surface of the upper plate 16 so as to project slightly upward from the right end of the opening 25 of the throat plate 18; 29 is a support plate 28 for opening and closing the gate 25; The lid plate is hinged to the upper left end of the lid plate, and a locking plate 30 having elasticity for locking and holding the lid plate 29 in the closed position is attached to the free end of the lid plate. A notch 31 is formed on the rear edge of the cover plate 29 to coincide with the feed dog entrance 21 located on the right side of the needle hole 19 when the cover plate 29 is closed, and to constitute the front end of the entrance 21.

When attaching the fabric edge cutting attachment, the cover plate 29 is rotated to the open position as shown in FIG. 3, and when performing normal sewing work, the cover plate 29 is moved to the closed position. Rotate the opening 25 and close the upper plate 16.
The entire workpiece support surface formed on the upper surface of the needle plate 18 and the cover plate 29 can be used to smoothly perform sewing operations. Reference numeral 32 designates a hook 33 disposed in the sewing machine bed 15, which is an operating arm swingably supported in the sewing machine bed 15 by a fixed shaft 34, and a hook driving shaft (32) for driving the hook 32. As the shaft (not shown) rotates, it is oscillated via an operating cam, a forked engagement member (not shown), and the like.

Reference numeral 35 denotes an operating link rotatably attached to the front end of the operating arm 33, and as shown in FIG. 3, a linking pin 35a having a conical head is protruded from the left side surface of the upper end. As the actuating arm 33 moves, the regulating portion 36 in the sewing machine bed 15 restricts the swinging so that the sewing machine is substantially reciprocated only in the vertical direction.

Next, the lid plate 29 is opened and the throat plate 18 is closed 25.
The structure of the cloth edge cutting attachment which is detachably arranged and fixed on the throat plate 18 near the entrance 25 will be explained.

37 is an attachment frame, which is shown in FIGS.
As shown in the figure, a pair of vertical pins 38 for positioning are protruded from the lower surface of the needle plate 18 to fit into a pair of engagement holes 26 formed in the support slope 27 of the throat plate 18, and inside the pins 38 are provided downwardly. An open accommodating portion 39 is formed.

4. A locking bar is rotatably attached to the front right end of the attachment frame 37, and a horizontal engagement shaft fixed to the lower surface of the upper plate 16 is attached to the lower end of the locking bar. A lock upper part 40a for fixing the attachment frame 37 so as not to be able to move by relatively engaging with the attachment frame 41 from below is formed protrudingly.
An actuating portion 40b that protrudes inward is formed in a protruding manner.

Reference numeral 42 denotes a protruding arm integrally formed to protrude leftward from the lower left front end of the attachment frame 37, and as shown in FIGS. 2 and 3, a notch 42a is formed at the rear left end of the arm. and attachment frame 37
In the installed state, it is inserted into the entrance 25 of the throat plate 18 and extends in a direction intersecting the work cloth feeding direction, and its upper end surface is arranged on the same plane as the work cloth support surface, that is, the upper surface of the throat plate 18. It has become so.

43 is provided at the base end so as to extend to the left beyond the front end of the feed dog 23 on the right side of the needle hole 19 when the attachment frame 37 is attached, and to extend rearward from the left end toward the needle hole 19. A pair of mounting screws 44
The fixed blade is fixed to the front left end of the protruding arm 42 and has an approximately L-shaped planar shape, and as shown in FIGS. It is arranged close to the cloth feeding side with respect to the needle hole 19 on the same plane.

A gap 45 is formed on the left side between the blade portion 43a of the fixed blade 43 and the left end of the protruding arm 42 to allow the entry of the movable blade, which will be described later. A gap 46 for allowing the front end of the feed dog 23 on the right side of the needle hole 19 to protrude is formed by a notch 42a of the protruding arm 42, and is continuous with the gap 45 for entering the movable blade. 47 is a drive shaft rotatably supported near the rear end of the attachment frame 37 so as to extend in a direction perpendicular to the cloth feeding direction; 48 is attached to a protrusion at the left end of the drive shaft 47; The driving arm is approximately L-shaped in plan view, and is shown in Figures 2 to 4. Its front end arm extends parallel to and spaced from the protruding arm 42 directly above the protruding arm 42, and is moved up and down as the drive shaft 47 reciprocates.

Reference numeral 49 denotes a movable blade attached to the left end of the arm portion of the drive arm 48 so as to be located above the fixed blade 43, and the lower end thereof has a blade portion 49a extending obliquely and a guide protrusion 49b extending downward. is formed, and as the drive shaft 47 reciprocates, it cooperates with the fixed blade 43 to cut the edge of the work cloth being transferred in the cloth feeding direction prior to the hem warping.

5. A swinging arm fixed approximately at the center of the drive shaft 47 within the housing portion 39 of the attachment frame 37;
51 is a compression spring interposed between the drive shaft 47 and the right side of the housing part 39 so as to press the movable blade 49 toward the fixed blade 43; A linking arm is rotatably and movably attached to the front end of the arm 5, and as shown in FIG. 3, its lower end can engage with the linking pin 35a of the operating link 35. A connecting hole 52a is formed, and an engaging portion 52b that can be engaged with the actuating portion 40b of the locking bar 40 is bent at the front edge of the approximately central portion.
A compression spring 54 provided on 3 urges it to move rightward along the line.

Reference numeral 55 denotes a guide member fixed to the attachment frame 37, which substantially restricts the vertical movement of the link arm 52 and only allows vertical movement.

As shown in FIG. 3, when the attachment frame 37 is attached, the lower end of the linking arm 52 protrudes into the sewing machine bed 15 through the entrance 25 of the needle plate 18, and the locking rotation of the locking bar 40 is operated. At the same time that the attachment frame 37 is fixed on the throat plate 18, the operating portion 40b of the locking bar 40 is disengaged from the engaging portion 52b of the linking arm 52, and the linking arm 52 is moved by the action of the compression spring 54. The link pin 35a is pressed toward the operating link 35, and while the operating link 35 is moved up and down once as the sewing machine is operated, the link pin 35a is inserted into the link hole 52a of the link arm 52.
As a result, the shuttle drive shaft (not shown) in the movement mechanism of the sewing machine and the drive shaft 47 of the movable blade 49 are automatically and operatively connected.

Furthermore, when the locking bar 40 is released from the coin purse position shown in FIG. 3 in the counterclockwise direction, the attachment frame 3
7 is released from the fixed state, the "locking bar 40"
The actuating portion 40b of the linking arm 62 engages with the engaging portion 52b of the linking arm 62, and the linking arm 52 is urged to the left away from the operating link 35 against the action of the compression spring 54, and the linking pin 35a is removed from the connection hole 52a, and the above-mentioned operational connection is released. 56 is a casing that covers the attachment frame 37, and is shown in FIG.
As shown in FIGS. 3 and 4, a shielding plate 57 for covering the upper right side of the drive arm 48 is formed protruding from the upper surface of the left end thereof.

Reference numeral 58 denotes a transparent protective cover rotatably attached to the front surface of the attachment frame 37 near the left end of the front surface of the casing 56; When the sewing machine is rotated, the gap between the drive arm 48 and the protruding arm 42 is covered from the front, and the operator can touch the gap or the cutting operation section consisting of the fixed blade 43 and the movable blade 49 with their fingertips while the sewing machine is operating. It is designed to prevent the danger of inserting such items.

Reference numeral 59 denotes an elastic plate fixed to the upper surface of the left end of the projecting arm 42, and the projecting arm 42 and the fixed blade 43 are connected to the front part of the left end.
The movable blade 49 is configured to cover the gaps 45, 46 between the movable blade 49 and prevent cloth scraps etc. from entering the gap, and to come into contact with the movable blade 49 and bend into the gaps 45, 46. A cloth handling section 59a, which is formed upright at the rear left end, guides cloth waste and the like to the rear right side.

The operation of the sewing machine and cloth edge cutting attachment constructed as described above will be explained below.

Now, when using this cloth edge cutting attachment to perform hem stitching while cutting the edge green of the work cloth, open the cover plate 29 to open the opening □ 25 of the throat plate 18, The attachment frame 37 is placed on the throat plate 18 near the entrance 25, and is positioned in the stereotaxic position by engaging the vertical pin 38 on the lower surface with the engagement hole 26 on the throat plate 18.Then, lock it. When the bar 40 is rotated to the locking position, the locking portion 40a engages with the engagement shaft 41 on the lower surface of the upper plate 16 from below, and the attachment frame 37 is locked and fixed at the same time. When the actuating portion 40b of the locking bar 4Q is disengaged from the engaging portion 45b of the linking arm 52, the lower end of the linking arm 52 protrudes into the sewing machine bed 15 from the opening 25 of the throat plate The action of the spring 54 pushes it toward the operating link 35 in the sewing machine bed 15. Therefore, when the sewing machine starts operating in this state, the operating link 35 moves up and down once as the hook drive shaft (not shown) rotates. While being moved, the linking pin 35 of the actuating link 35
a is iron-fitted to the connecting hole 52a of the linking arm 52, and the hook drive shaft in the movement mechanism of the sewing machine and the drive shaft 47 of the movable blade 49 on the side of the cloth edge cutting attachment are operatively connected. Thereafter, if the sewing machine continues to operate, the link arm 62,
The movable blade 49 is reciprocated up and down via the swing arm 50 and the drive shaft 47 and the drive arm 48, and the movable blade 49 and the fixed blade 43
The edge of the work cloth is cut by the cooperation of the sewing machine needle 12 and the hook 32, and the hem is stitched immediately after the cutting operation part by the cooperation of the sewing machine needle 12 and the hook 32.

During this sewing work, the fixed blade 43 and the movable blade 4
9 is located between the left and right long feed dogs 23 and approaches the needle drop point. Since the upper surface and the upper end blade portion 43a of the fixed blade 43 are located at almost the same height as the upper surface of the throat plate 18, the oversewing is performed immediately after cutting the edge of the work cloth, and the green oversewing is performed. The stitches do not deviate from the planned sewing line and are beautifully formed along the cut edge.

Note that at the start of this sewing work, the workpiece cloth is not at the needle drop point and the sewing machine performs idle stitching, but this period is very short, and during this time the worker threads the upper and lower threads backwards. If you pull it up, those two threads won't get caught in the pot. At this time, the front end of the feed dog 23 on the left side of the needle hole 19 protrudes more forward than the guide protrusion 49b of the movable tooth 49 in the cloth feed direction, so that the work cloth can be fed smoothly when starting oversewing. be able to.

Also, at this time, a gap 46 is provided between the protruding arm 42 and the blade portion 43a of the fixed blade 43 corresponding to the front end of the feed dog 23 on the right side of the needle hole 19. It does not interfere with exercise. Next, when performing normal sewing work without using the fabric edge cutting attachment, the locking bar 40 can be unlocked by operating the locking bar 40 counterclockwise from the locking position shown in FIG. At the same time that the portion 40a is disengaged from the engagement shaft 41 and the attachment frame 37 is released from the fixed state, the actuating portion 4 of the locking bar 40 is released.
0b engages with the engaging portion 52b of the linking arm 52, and the linking arm 52 is moved to the left, and the linking pin 35 of the operating link 35
a separates from the connecting hole 52a of the connecting arm 52.

Therefore, in this state, the attachment frame 37 is lifted and removed from the throat plate 18, and then the lid plate 29 is closed to close the gate 25. In this way, as shown in FIG. 5, the notch 31 at the tip of the cover plate 29 is aligned with the feed dog opening □21 on the right side of the needle hole 19 formed in the throat plate 18, and the front end of the opening □21 is aligned. form a section.

If you drive the sewing machine in this state, the right feed dog 23
The sewing machine feeds the cloth together with the other feed dogs 23 and 24, so that the workpiece cloth is conveyed evenly from side to side, and sewing can be performed along the sewing line without creating any seam wrinkles or the like. In this way, when the frame of the fabric edge cutting attachment is removed and the frame mounting opening is closed with the cover plate, the front end of the right feed dog opening is cut out by the notch of the cover plate. With this configuration, the closing portion can be closed without interfering with the movement of the feed dog, and cloth feeding will not be hindered. Furthermore, when the attachment is in use, the blade of the fixed blade is located in almost the same plane as the upper surface of the throat plate, and is located close to the front of the needle hole. Since it moves in the gap between the protruding arm corresponding to the section and the fixed blade, it does not cause any hindrance to the L fabric edge cutting operation.A pair of left and right feed teeth with approximately the same length allows for smooth fabric feeding. It has excellent effects.

Furthermore, ``the present invention is not limited to the above-described embodiments.''
As shown in Fig. 6, when the attachment is installed, the protruding arm base 2 has its base end extending to the left, bending forward at the middle part, and further bending the tip end to the left, so that the entire protruding arm base 2 extends in the cloth feeding direction. A fixed blade turtle 3 extending toward the needle hole turtle 9 is fixed to the tip surface so that the front end of the right feed dog 23 closes the gap between the intermediate bent part of the protruding arm 42 and the fixed blade 43. The same effect as above can be obtained by exercising inside.

[Brief explanation of the drawing]

The official map is a perspective view of the main parts of the sewing machine showing the state in which the fabric edge cutting attachment is installed. Figure 2 is also a partial plan view with a part cut away, and Figure 3 is along the Sasaichi 3 line of the Mai map. Figure 4 is a cross-sectional view taken approximately along line 4 in Figure 3, and Figure 4 is a partial plan view showing the open state of the plate. It is a partial plan view showing an embodiment of the sewing machine bed...a5, throat plate...Kaoru 8, feed dog opening...
...2 Buddhas, 2 seedlings, feeding teeth...23 "Opening section...2 lid plate...
...29 also has a notch... 3 turtles ``Attachment frame...''
87 "Protruding arm...Mother's tip...Tsuru 2a" Fixed blade...4
3" Gap...4F 46L Movable blade...49. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6

Claims (1)

[Scope of Claims] 1. An elongated zigzag sewing needle hole extending in a direction perpendicular to the cloth feeding direction, and a pair of left and right needle holes located on at least the left and right sides of the needle hole and extending in front and back of the needle hole along the cloth feeding direction. In a zigzag sewing machine, a needle plate having a feed dog opening is provided on the sewing machine bed, and a pair of left and right feed dogs having substantially the same length imparts a feed motion to a workpiece cloth through the feed dog opening,
An opening 25 is formed on the sewing machine bed 15 including the throat plate 18.
A cover plate 29 is provided, the opening 25 of which can be closed, and which has a notch 31 that forms the front end of the right feed dog opening 21 of the throat plate 18 when the opening 25 is closed, and is located below. It has a fixed blade 43 and a movable blade 49 located above,
When the opening 25 of the sewing machine bed 15 is opened, the frame 37 of the fabric edge cutting attachment is removably disposed near the opening 25 and is operated in conjunction with the movement mechanism of the sewing machine. A protruding arm 42 having at least an upper end surface substantially flush with the upper surface of the throat plate 18 is provided, and a blade portion of the fixed blade 43 is provided on the distal end 42a of the protruding arm 42, and the blade portion of the fixed blade 43 is substantially flush with the upper surface of the throat plate 18. a gap 45 located in the plane and close to the front of the needle hole 19 and corresponding to the notch 31 of the cover plate 29 between the tip 42a of the protruding arm 42 and the fixed blade 43; 46, and the front end of the right feed dog 23, which feeds the fabric through the notch 31 of the cover plate 29 during normal sewing work, is connected to the fabric edge cutting attachment. A fabric for a zigzag sewing machine, characterized in that when in use, it moves in gaps 45, 46 between the protruding arm 42 and the fixed blade 43, and does not cause any hindrance to the fabric edge cutting operation. Attachment for cutting ends. 2. The protruding arm 42 extends in a direction intersecting the work cloth feeding direction when the attachment is attached to the sewing machine bed 15, and the fixed blade 43 extends from the protruding arm 4 at the base end.
The feed dog 23 is fixed to the front side of the needle 2 and is located to the right of the needle hole 19.
The fabric edge cutting attachment for a zigzag sewing machine according to claim 1, which has a substantially L-shaped planar shape extending to the left beyond the front end of the zigzag sewing machine and bent toward the needle hole 19. 3 The protruding arm 42 extends in a direction intersecting the workpiece cloth feeding direction when the attachment is attached to the sewing machine bed 15, and its tip end touches the feed dog 2 on the right side of the needle hole 19.
The fabric edge for a zigzag sewing machine according to claim 1, wherein the fixed blade 43 is located on the left beyond the front end of the needle hole 19 and has a fixed blade 43 fixed to the tip end thereof, which extends toward the needle hole 19. Cutting attachment.