JP2555429Y2 - Sewing machine cloth fall prevention device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for preventing a cloth from falling off a sewing machine. 2. Description of the Related Art Conventionally, an overlock sewing machine has a cloth edge cutting device comprising a fixed knife and a movable knife, and the cutting device comprises a bed in which the movable knife is a cloth mounting surface of a sewing machine frame. There are two types, an upper type supported by a shaft disposed above the upper surface, and a lower type supported by a shaft disposed below the bed upper surface. Since the mechanism hinders the operation of the sewing cloth and obstructs the operation, in the above-described method, when the movable knife is released, the movable knife is retracted into the side edge of the needle plate, so that a space portion is generated. The edge of the sewn cloth W (see FIG. 13) is entangled in the space, causing the edge of the sewn cloth W (see FIG. 13) to be entangled. Further, the upper looper 11 and the lower looper 12 are driven by arrows R1 and Piercing when turned in the direction of R2 Looper from pierced into and NuiNaru fabric to a positional deviation relative to the support shaft, and caused problems such as phase mad. SUMMARY OF THE INVENTION The present invention prevents the occurrence of a phenomenon in which the edge of the cloth is entangled when the movable knife of the cloth cutting device of the type having the lower movable knife of the overlock sewing machine is released. Things. SUMMARY OF THE INVENTION [0005] The present invention is to prevent the edge of the cloth from falling below the needle plate when the lower movable knife of the overlock sewing machine is released, thereby preventing the winding phenomenon from occurring. A member is provided near the projecting port of the movable knife, that is, on the side of the needle plate between the position adjacent to the cloth feeding side of the fixed knife and the needle drop point, a member for preventing the edge of the cloth from dropping below the needle plate. Is what you do. According to the present invention, there is provided a drive shaft rotatably supported by a sewing machine frame, a needle bar and a needle which are moved up and down in association with the rotation of the drive shaft, and in association with the rotation of the drive shaft. And a looper for forming a seam in cooperation with the needle which is swung in conjunction with the rotation of the drive shaft, and a movable swingably supported by the bed machine frame. In an overlock sewing machine having a lower movable knife which cuts a sewing cloth in cooperation with a fixed knife fixed to the machine frame side and which is pivotally attached to a knife arm, the movable knife is rotated by a bed machine frame. A movable knife switching device which can be switched between a use state in which the fixed knife is cooperated with the fixed knife by operating the operating section and a release state released from the cooperative relationship with the fixed knife; The upper surface is formed above the trajectory of the sword tip, The movable knife is forgotten to be switched to the use state by providing a cloth end support piece that protrudes from the side of the needle plate in the direction perpendicular to the cloth feed direction between the adjacent position of the fixed knife on the cloth feeding side and the needle drop point. In this case, even if the sewing machine is operated, the edge of the cloth is prevented from dropping below the needle plate. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of an embodiment of the present invention will be described with reference to the drawings. A sewing machine frame 1 is composed of an upper arm frame 2 and a lower bed frame 3, and the arm frame 2 has a lower end. A needle bar to which the needle N is fixed is supported so as to be able to move up and down, a drive shaft 4 is rotatably supported by the bed machine frame 3, and a wedge wheel 5 is mounted on the drive shaft.
And three eccentric cams 6, 7, 8 are provided. The first eccentric cam 6 drives the upper looper shaft 9, the second eccentric cam 7 drives the lower looper shaft 10, and the upper looper shaft 9 An upper looper 11 is fixed to the end of the lower looper, and a lower looper 12 is fixed to the lower looper shaft 10. The third eccentric cam 8 drives the movable knife 13. The movable knife is fixed to one end of a movable knife shaft 15 supported at the tip of a movable knife arm 14 supported by the bed machine frame 3, and the movable knife arm 14 is fixed to the movable knife arm 14 by the action of a spring 16 attached to the shaft. Movable knife shaft 1 pressed against the side
At the other end of 5, an operation unit 17 for rotating the movable knife 13 in a use state (FIG. 1) and a release state (not shown) for retracting the movable knife 13 downward is mounted. A needle plate 18 is fixed to the cloth placing portion of the bed machine frame 3 (see FIGS. 3 to 6), and a fixed knife table 24 mounted on a part of the bed machine frame 3 has an upper end. A fixed knife 19 is fixedly attached to the side surface of the needle plate 18.
The movable knife 13 is brought into pressure contact with the fixed knife when the movable knife 13 is switched to the use state. A looper cover 20, which covers a looper mechanism mounted in the machine frame, is pivotally connected to an opening formed below the front surface of the machine frame 1 so as to be freely opened and closed (FIG. 2). On the upper side of the end portion of the looper cover on the needle plate side, a cut-off separating portion 21 having a concave portion and a warped portion is provided. The sewing cloth W is moved in the direction of the arrow J by the feed dog 22. A cloth end support 25 is fixed to a fixed knife table 24 to which the fixed knife 19 is fixed by a tightening screw 26.
The cloth end supporting portion has a mounting portion 25a formed at a base end and a horizontal cloth end supporting piece 25b formed at a distal end, and an eave-like portion 25c which is bent downward is formed on the cloth end supporting piece. The lower edge of the eave-shaped portion slides on the lowering movement of the needle N and the swinging movement of the lower looper 12, respectively, and guides the movement trajectory so as to be drawn correctly (see FIG. 6). The horizontal upper surface of the cloth end support piece 25b is located above the movement locus M of the blade point of the lower looper 12 and the needle plate 18
Is held at a position having a step T downward from the upper surface of the
In the lateral direction, the end protrudes from the side surface of the needle plate 18 and extends to the position X from the side surface of the fixed knife 19. Since the embodiment of the present invention is structured as described above, the movable knife 13 can be switched from the use state to the release state, and the release state is switched when performing pin tack sewing or when replacing the needle plate. Can be Other sewing operations are generally performed with the movable knife 13 in the used state. However, even when the sewing machine is operated in the released state by forgetting to switch to the used state, the cloth end supporting piece 25b is moved sideways from the side surface of the needle plate 18. The protruding direction prevents the edge of the cloth from falling below the needle plate. Next, another embodiment of the present invention will be described with reference to FIGS. In comparison with the general overlock sewing (FIG. 11), the edge of the soft cloth W such as dechin or gauze fabric has a weaker upper looper thread (Tu) and a lower looper thread (Tl).
Is made possible by adjusting the balance between the tensions of the looper threads Tu and Tl, and the cloth edge W is automatically wound down and sewn (FIG. 12). To perform winding sewing, the needle plate 28 for winding sewing of the present invention is replaced with a needle plate 18 for overcasting and mounted on the bed machine frame 3. The cloth feeding direction (arrow J) is provided on the needle plate 28 for winding sewing.
And a needle plate claw 29 whose free end is directed to the cloth feeding side is provided. Further, the free end protrudes laterally from the side edge of the fixed knife 19 to the position X integrally with the needle plate. , The edge on the cloth feed-out side is closer to the needle drop point P than Y
The cloth end support piece 30 formed is provided so as to be located at the position. Since the embodiment according to the present invention has the structure as described above, the conventional sewing needle plate 28 '(FIG. 10) can be used even when the sewing machine is operated to perform winding sewing while the movable knife is in the released state. In the case of winding sewing, the cloth edge fell below the side surface of the needle plate, causing an accident that the looper pierced the cloth edge. Since the edge of the cloth is prevented from dropping below the side surface of the needle plate, it is possible to prevent the occurrence of a looper accident due to the drop of the cloth. As described above, according to the present invention, the movable knife is released for pin tack sewing or needle plate replacement work, and the sewing machine is used when the movable knife is forgotten to be switched to the use state after the intended work is completed. Even when driving, since the cloth edge is prevented from dropping below the side surface of the needle plate by the cloth end supporting piece, no accidental piercing of the looper occurs at all, thus causing a phase shift of the looper shaft. In other words, it is possible to provide a user with a safe sewing machine that does not cause any accidents due to misuse, and thus has a large practical effect.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 to 6 show an embodiment of the present invention, FIG. 1 is a perspective view of a sewing machine to which the present invention is attached, and FIG. 2 is a perspective view of a main part of the present invention. FIG. 3 is a perspective view of a main part of the present invention, FIG. 4 is an exploded perspective view of a main part of the present invention, FIG. 5 is a sectional front view of a main part of the present invention, and FIG. 7 to 9 show another embodiment of the present invention. FIG. 7 is a perspective view of a main part of the present invention, FIG. 8 is a plan view of a main part of the present invention, and FIG. FIG. 10 is a perspective view of a conventional needle plate, and FIG.
Fig. 12 is a configuration diagram of standard overlock sewing, Fig. 12 is a configuration diagram of winding sewing, and Fig. 13 is a perspective view of a main part of a conventional sewing machine. , N is a needle, 1
Reference numerals 1 and 12 denote upper and lower loopers, 13 denotes a movable knife, 19 denotes a fixed knife, and 25b and 30 denote cloth end supporting pieces.

Claims (1)

(57) [Claims for registering utility model] A drive shaft that is supported and rotated by the sewing machine frame, a needle that moves up and down in conjunction with the rotation of the drive shaft, and a sewing machine that is linked in rotation with the drive shaft A feed dog which moves forward and backward from the needle plate on the bed frame to move the sewing cloth back and forth with respect to the needle, and a looper which swings in conjunction with the rotation of the drive shaft and cooperates with the needle to form a seam. A fixed scalpel fixed to the machine frame side close to one side edge of the needle plate and parallel to the moving direction of the feed dog, and provided with a blade portion on the side opposite to the needle plate side; An overlock sewing machine comprising a movable knife that is swingably supported by a shaft portion below the upper surface on the machine frame and cuts a sewing cloth in cooperation with the fixed knife, wherein the movable knife is defined as the fixed knife. Switching to switch between the cooperating use state and the non-use state released from the cooperative relationship with the fixed knife The fixing knife in a lateral direction with respect to the cloth feeding direction in a state where an upper surface is located above a movement locus of a sword point of the looper between a device and a front end of the fixing knife in a cloth feeding direction and a needle drop point of the needle. And a cloth end supporting member provided with a cloth end supporting piece protruding from the position of the blade portion of the sewing machine.