JP4035544B2 - sewing machine - Google Patents

Description

  The present invention relates to a sewing machine capable of operating a movable knife in accordance with the vertical movement of a needle and overlocking a cut surface while cutting a cloth.

  When the fabric is cut, it is preferable to perform edge stitching in the cut process. Edge stitching is a method of stitching the edges while cutting the edges. However, since conventional sewing machines for household use cannot perform edge stitching while cutting, the stitch processing is performed by performing zigzag stitching.

  However, a material that easily expands and contracts, such as a knit material, has a problem that the yarn easily frays when zigzag sewing is performed. Such problems can be solved by using a lock sewing machine exclusively for edge stitching, but it is expensive to purchase a lock sewing machine in a general household.

In view of this, many sewing machines have been developed in which a lock cutter is provided on a household sewing machine and edge stitching can be performed while cutting the fabric. For example, in Non-Patent Document 1, a support portion having a pair of movable knife and fixed knife at the lower end is made movable so that it can be accommodated in the face plate. There is disclosed a sewing machine with a lock cutter that mechanically interlocks with a drive source that moves up and down, and operates a movable knife with a drive source that moves the needle up and down to cut the fabric.
"Popular lock built-in sewing machine", Kansai Sewing Machine Center, Yomiuri Shimbun Advertising, December 7, 2004

  However, the above-described sewing machine with a lock cutter has the following problems. First, the driving source of the movable knife that operates to cut the cloth is the same as the driving source that moves the needle up and down, for example, a motor. In addition, it is necessary to provide a coupling mechanism for operating the movable knife separately from the coupling mechanism for moving the needle up and down, which is complicated mechanically, and the size of the sewing machine main body is difficult to be reduced due to the increase in size of the mechanism. There was a problem.

  Even if the movable knife is not installed at an operable position, the coupling mechanism rotates, so the load on the motor that is the drive source for moving the needle up and down is reduced even when the lock cutter is not operated. There is also a problem that power is wasted.

  Further, since the coupling mechanism for operating the movable knife is housed inside the face plate, there is a problem that maintenance such as when a failure occurs is difficult. In order to solve such problems, for example, a sewing machine in which only a movable knife driving mechanism is externally attached has been developed. In this case, the drive mechanism of the movable knife attached externally operates the movable knife located at the point of action on the principle of lever by using the vertical movement of the mounting screw for fixing the needle to the needle body as a power point. Therefore, since the force point and the action point are close to each other, the fulcrum needs to be arranged at a certain distance from the force point and the action point, and it is difficult to reduce the size of the external mechanism. There was a new problem of complicated management.

The present invention has been made in view of such circumstances, and the movable knife can be operated by a simple mechanism in which the needle drop operation is transmitted to the movable knife through the partial gear, and the edge is trimmed while cutting the cloth. An object of the present invention is to provide a sewing machine that can perform sewing.

  In addition, the present invention provides a simple mechanism in which a knife mechanism constituted by a fixed knife and a movable knife is fixed by inserting a protruding portion into a hole provided in a needle plate when cutting the cloth. It is an object of the present invention to provide a sewing machine that can be cut with high precision by being firmly fixed to the sewing machine.

  In the present invention, when the support part is lowered, the knife mechanism is arranged so as to cut the cloth by allowing the support part to be retracted to a position where the other end of the knife power transmission part does not contact the shaft part. Another object of the present invention is to provide a sewing machine capable of preventing the shaft portion of the needle stop main body to fix the needle and the knife mechanism from interfering with each other.

In order to achieve the above object, the sewing machine according to the first aspect of the present invention is a needle that is movable up and down, has a support portion that supports a fixed knife and a movable knife at the lower end, and locks the needle by the shaft portion. In the sewing machine that cuts the workpiece by the movable knife moving in accordance with the needle up-and-down movement of the stop body, and overlocks the edge of the cut workpiece, the support portion is more than the area where the needle falls. The movable knife has a first partial gear, and is rotatable around the rotation center of the first partial gear, and is arranged at one end. A second partial gear meshing with the first partial gear, and a female power transmission portion rotatable about the rotation center of the second partial gear; and the other end of the female power transmission portion, Elastic force that causes the movable knife to rotate away from the fixed knife An elastic member that urges the female power transmission unit, when the support unit is moved to the lowermost part, the other end is located below the shaft unit, and the needle stop body is lowered, The other end of the knife power transmission portion is pushed down by the shaft portion, and the movable knife and the fixed knife are cut across the workpiece by the rotation of the second partial gear, and the needle stop main body is raised. In this case, the movable knife and the fixed knife are separated from each other by rotating the other end of the knife power transmission portion in a biasing direction by the elastic member.

  The sewing machine according to a second invention is the sewing machine according to the first invention, wherein a hole for fixing the support portion is provided on an upper surface of a needle plate on which a workpiece is placed, and the support portion is supported by the vertical movement of the support portion. A protruding portion that can be inserted into the hole when the portion is lowered to a position where the sewing product can be cut is provided at the lower end of the support portion.

  The sewing machine according to a third aspect of the present invention is the sewing machine according to the first or second aspect, wherein, when the support part is lowered by vertical movement, the support part is moved to a position where the other end of the female power transmission part does not contact the shaft part. Is characterized in that it can be retracted.

  In the first invention, the movable knife is rotatable about the rotation center of the integrally molded first partial gear. The movable knife and the shaft portion have a second partial gear meshing with the first partial gear at one end, and via a female power transmission portion that can rotate around the rotation center of the second partial gear. It is connected. The knife power transmission unit includes an elastic member that biases an elastic force that rotates the movable knife in a direction away from the fixed knife with respect to the other end. When the needle stop main body is lowered, the other end of the knife power transmission portion is pushed down by the shaft portion, and the movable knife and the fixed knife are cut across the workpiece by rotation of the second partial gear. When the needle stop main body is raised, the other end of the knife power transmission portion is rotated in the urging direction by the elastic force of the elastic member, and the movable knife and the fixed knife are separated. Thus, the operation of the movable knife can be controlled by the vertical movement of the shaft portion of the needle stop body, and in order to operate the movable knife, the motor that is a drive source for driving the needle stopper body and the movable knife are directly connected. There is no need for a coupling mechanism to be coupled to. Therefore, the movable knife can be operated by a simple mechanism of transmitting the needle drop operation to the movable knife through the partial gear, and the whole can be made compact.

  Further, the mechanism for operating the movable knife can be intensively arranged in the vicinity of the shaft portion of the needle stop body. In this case, the mechanism for operating the movable knife by moving the support portion downward is the face plate. Can be exposed outside. Therefore, maintenance at the time of occurrence of a failure relating to the mechanism for operating the movable knife is relatively easy. Furthermore, when the support part is pulled up, the drive source for moving the needle stop body up and down, for example, the motor, is not subjected to any load other than the vertical movement of the needle stop body, and the power consumption of the motor is minimized. Is possible.

  In the second invention, a hole for fixing the support portion is provided on the upper surface of the needle plate on which the workpiece is placed, and when the support portion is lowered to a position where the workpiece can be cut, for example, the support portion The protrusion provided in the fixed female member that is fixed is inserted into the hole. Accordingly, the support portion can be firmly fixed by a simple mechanism of inserting and fixing the protruding portion into the hole portion, and cutting with the movable knife can be performed with high accuracy.

  In the third aspect of the invention, when the support portion is lowered by the vertical movement, the support portion can be retracted to a position where one end of the female power transmission portion does not contact the shaft portion. Thereby, for example, when the support part is attached in the face plate, the knife power transmission part can move the support part at any position above and below by rotating the support part by a predetermined angle around the attachment position. The support portion can be lowered while avoiding interference with the shaft portion of the needle stop main body, and the movable knife can be disposed at a predetermined position.

  According to the first aspect of the invention, the operation of the movable knife can be controlled by the vertical movement of the shaft portion of the needle stop main body, and the motor and the movable knife as a drive source for driving the needle stop main body to operate the movable knife. There is no need for a coupling mechanism that directly couples the two. Therefore, the movable knife can be operated by a simple mechanism of transmitting the needle drop operation to the movable knife through the partial gear, and the whole can be made compact.

  Further, the mechanism for operating the movable knife can be intensively arranged in the vicinity of the shaft portion of the needle stop body. In this case, the mechanism for operating the movable knife by moving the support portion downward is the face plate. Can be exposed outside. Therefore, maintenance at the time of occurrence of a failure relating to the mechanism for operating the movable knife is relatively easy. Furthermore, when the support part is pulled up, the drive source for moving the needle stop body up and down, for example, the motor, is not subjected to any load other than the vertical movement of the needle stop body, and the power consumption of the motor is minimized. Is possible.

  According to the second invention, the support portion can be firmly fixed by a simple mechanism of inserting and fixing the protruding portion into the hole portion, and cutting with the movable knife can be performed with high accuracy.

  According to the third aspect of the invention, for example, when the support portion is mounted in the face plate, the knife power main body can be moved to any position in the upper and lower positions by rotating the support portion by a predetermined angle around the mounting position. In this case, the support portion can be lowered while avoiding interference with the shaft portion of the needle stop main body, and the movable knife can be disposed at a predetermined position.

  Hereinafter, the present invention will be described with reference to the drawings illustrating embodiments thereof. FIG. 1 is a one-side cross-sectional view in the front-rear direction including a needle bar showing the configuration of the arm portion of the sewing machine according to the embodiment of the present invention.

As shown in FIG. 1, the sewing machine according to the present embodiment includes a needle part drive mechanism 2 that moves a needle up and down in a face plate (not shown), and a support part 3 that has a knife mechanism 4 attached to a lower end part. I have. The needle portion drive mechanism 2 is connected to a drive mechanism that transmits the power of a motor (not shown) as a drive source, and the needle bar 21 moves up and down by the rotation of the motor. FIG. 2 is a front view showing the vicinity of the needle stop main body 22. A needle stop main body 22 is provided at the tip of the needle bar 21, and a needle 24 is attached by inserting a set screw or the like into a shaft portion 23 that is a protrusion protruding from the needle stop main body 22 in the horizontal direction.

  The needle 24 moves up and down with a predetermined stroke including up and down of the needle plate 5 according to the up and down movement of the needle bar 21 by the rotation of the motor. The presser foot 6 is lowered onto the needle plate 5 by a predetermined operation, and holds the fabric W fed from the near side between the needle plate 5. The fabric W thus held is fed by the vertical movement of the needle 24 and the operation of a hook mechanism and a feed mechanism (not shown) generated in the lower part of the needle plate 5 in synchronization with the vertical movement. Sewn.

  FIG. 3 is an exploded perspective view showing configurations of the support portion 3 and the knife mechanism 4. The knife mechanism 4 has a fixed knife 42 fixed on the front side of the area where the needle drops at the distal end, a rotation center on the upper part of the fixed knife 42, and a base end fitted to the rotation center. The movable knife 41 is arranged so as to be in sliding contact with the fixed knife 42 from above.

  FIG. 4 is a left side view showing the configuration of the movable knife 41. The movable knife 41 is provided with a blade part 411 at the lower part, and a rotation hole 413 is provided so as to be able to come into sliding contact with the fixed knife 42. The movable knife 41 is attached such that a set screw 50 is inserted into the rotation hole 413 so as to be in sliding contact with the fixed knife 42.

  The movable knife 41 is provided with a partial gear 412 above the blade portion 411. In FIG. 4, a partial gear having two teeth is provided, but the number of teeth is not limited to two, depending on the relative distance to the knife power transmission unit 44 described later and the rotation angle of the movable knife 41. Any suitable number of teeth may be used.

  FIG. 5 is a left side view showing the configuration of the fixed knife 42. The fixed knife 41 includes a blade portion 421 with a blade surface facing upward at a lower portion, and a rotation hole 422 is provided so that the movable knife 41 can be slidably contacted. The fixed knife 42 is attached so that the movable knife 41 can be brought into sliding contact by inserting a set screw 50 into the rotation hole 422 together with the movable knife 41.

  The fixed knife 42 has two screw holes 423 and 423 in the upper part, and is firmly attached by pins 51 and 51 communicating with two pin holes provided in the support member 31 described later.

  FIG. 6 is a left side view illustrating the configuration of the knife power transmission unit 44. The knife power transmission unit 44 rotates by the vertical movement of the shaft portion 23 of the needle stop main body 22. The knife power transmission portion 44 forms a lever 441 that receives the vertical movement of the shaft portion 23 below, and a rotation hole 443 is provided at the rotation center of the lever 441. When the lever 441 is pushed down by the lowering of the shaft portion 23, the knife power transmission portion 44 rotates around the rotation hole 443, and the partial gear 412 of the movable knife 41 rotates, so that the movable knife 41 and the fixed knife 42 are rotated. Cut across the dough W.

  The female power transmission unit 44 is provided with a partial gear 442 below the lever 441. In FIG. 6, the partial gear having the number of teeth of 2 is provided, but the number of teeth is not limited to 2 and is appropriate depending on the relative distance to the movable knife 41 and the rotation angle of the knife power transmission unit 44. Any number of teeth is acceptable.

  The movable knife 41 and the knife power transmission portion 44 are attached to the support portion 3 by engaging the partial gear 412 of the movable knife 41 and the partial gear 442 of the knife power transmission portion 44. FIG. 7 is a left side view showing the configuration of the support member 31 constituting the support portion 3. The support member 31 is provided with a pin hole 311 for attaching the fixed knife 42 in the lower part, and the fixed knife 42 is fixed by communicating the pins 51 and 51.

  The lever 441 of the female power transmission unit 44 is connected to the support member 31 via an elastic member that generates a tensile force, for example, a coil spring 47. As a result, when the shaft portion 23 rises, the lever 441 is pulled upward by the elastic force of the coil spring 47, and the female power transmission portion 44 rotates around the rotation hole 443. By such rotation, the partial gear 412 of the movable knife 41 is rotated, and the movable knife 41 and the fixed knife 42 are separated.

  Thus, the operation of the movable knife 41 can be controlled by the vertical movement of the shaft portion 23 of the needle stop main body 22, and a connection mechanism with a motor that is a drive source for driving the needle stop main body 22 is not required. Therefore, the movable knife 41 and the fixed knife 42 can be slidably contacted or separated by a simple mechanism, and the whole can be made compact.

  Further, the knife mechanism 4 that operates the movable knife 41 is centrally arranged in the vicinity of the shaft portion 23 of the needle stop main body 22 in the present embodiment. Therefore, the connecting mechanism portion is exposed to the outside of the face plate 1, and maintenance when a failure occurs is relatively easy. Further, when the support member 31 is pulled up, the needle stop main body 22 is not subjected to a load other than the vertical movement of the needle 24, and the power consumption of the motor can be minimized.

  The support portion 31 is provided with a long hole portion 312 in the vertical direction of the side portion so that the support portion 31 can move in the vertical direction, and two protrusions of the mounting plate 32 by two sets of E-type retaining rings, washers and the like. 321 and 322 are attached. Therefore, when the dough is cut using the knife mechanism 4, the protrusions 321 and 322 are positioned above the long hole portion 312, that is, the support member 31 is moved downward, and the knife is moved to a predetermined position. The mechanism 4 is lowered. When the knife mechanism 4 is not used, the knife mechanism 4 is raised to a predetermined position by moving the support member 31 upward so that the protrusions 321 and 322 are positioned below the elongated hole 312.

  In order to facilitate the vertical movement of the support member 31, for example, the knob member 45 is preferably fixed to the support member 31. Accordingly, the knife mechanism 4 can be easily moved up and down by gripping the knob member 45 and moving up and down.

  FIG. 8 is a left side view showing the operation of the knife mechanism 4. As shown in FIG. 8, the shaft portion 23 is lowered while the shaft portion 23 is located above the lever 441. When the shaft portion 23 is lowered, the lever 441 is pushed down by the lowering of the shaft portion 23, and the knife power transmission portion 44 rotates counterclockwise. Accordingly, the partial gear 412 of the movable knife 41 meshing with the partial gear 442 rotates in the clockwise direction, and the movable knife 41 comes into sliding contact with the fixed knife 42 so that the fabric W can be cut.

  When the shaft portion 23 is raised, the lever 441 is pulled up by the elastic force of the coil spring, and the female power transmission portion 44 rotates clockwise. Accordingly, the partial gear 412 of the movable knife 41 meshed with the partial gear 442 rotates counterclockwise, and the movable knife 41 moves away from the fixed knife 42.

  Further, when the dough is cut using the scalpel mechanism 4, that is, when the support member 31 is moved downward and the scalpel mechanism 4 is lowered to a predetermined position, the fixing knife 42 is fixed to fix the support member 31. A projecting portion 424 is formed in the lower portion, and a fixing hole 54 into which the projecting portion 424 can be inserted into the needle plate 5 is provided. When the support member 31 is moved downward, the protrusion 62 of the notch spring 61 fits into the inclined portion 313 formed on the upper portion of the support member 31 and is firmly fixed. When the support member 31 is pulled up, the protrusion 62 of the notch spring 61 fits into the inclined portion 314 formed at the substantially central portion of the support member 31 so that the support member 31 does not fall carelessly. is there.

  Further, when the support member 31 is moved downward to use the knife mechanism 4 and the knife mechanism 4 is lowered, the shaft portion 23 may interfere with the lever 441 depending on the position of the needle stop main body 22. The In the present embodiment, in order to prevent the shaft portion 23 and the lever 441 from interfering with each other, the elongated hole portion 312 of the support member 31 is formed so that the front side is substantially parallel to the moving direction of the support member 31. In contrast, the upper part on the needle side is tapered so that the width of the hole gradually increases downward.

  As a result, when the support member 31 is moved downward, the width of the elongated hole 312 is larger than the diameter of the protrusion 322 in the vicinity of the lower protrusion 322, and a predetermined value is obtained with the upper protrusion 321 as a center. The support member 31 can be swung only by this angle. Therefore, the shaft 23 is prevented from interfering with the lever 441 by moving the support member 31 downward while the support member 31 is swung so that the shaft 23 does not interfere with the lever 441. Is possible.

  FIG. 9 is a left side view showing the positional relationship between the shaft portion 23 and the lever 441 when the support portion 31 is swung using the long hole portion 312. As shown in FIG. 9A, when the support member 31 is moved downward along the projections 321 and 322 of the mounting plate 32 along the front side of the long hole portion 312, the lever 441 moves to the moving position. Since the part 23 is arranged, both interfere with each other.

  Therefore, as shown in FIG. 9B, when the support member 31 is moved downward along the protrusions 321 and 322 of the mounting plate 32 along the needle side of the long hole portion 312, the movement position of the lever 441 is The shaft portion 23 is not positioned, and the lever 441 can be moved to the lower side of the shaft portion without interference therebetween. After the movement, the support member 31 is swung to the needle side to be in the state shown in FIG. 9A. The lever 441 is operated by the vertical movement of the needle 24, that is, the vertical movement of the shaft portion 23, and the female mechanism 4 is operated. It becomes possible to make it.

It is a half sectional view in the field of the direction of order including the needle bar which shows the composition of the arm part of the sewing machine concerning an embodiment of the invention. It is a front view which shows the needle stop main body vicinity. It is a disassembled perspective view which shows the structure of the support part of a sewing machine which concerns on embodiment of this invention, and a knife mechanism. It is a left view which shows the structure of a movable knife. It is a left view which shows the structure of a fixed knife. It is a left view which shows the structure of a knife power transmission part. It is a left view which shows the structure of the support member which comprises a support part. It is a left view which shows the operation state of a knife mechanism. It is a left view which shows the positional relationship of a shaft part and a lever at the time of rocking | supporting a support part using a long hole part.

Explanation of symbols

2 Needle drive mechanism 3 Support section 4 Female mechanism 5 Needle plate 21 Needle bar 22 Needle stop main body 23 Shaft section 24 Needle 31 Support member 41 Movable knife 42 Fixed knife 44 Female power transmission section 47 Coil spring (elastic member)
54 Fixing holes 412, 442 Partial gears 423 Protruding part 441 Lever W Fabric (to be sewn)

Claims (3)

The movable knife is movable according to the needle up-and-down movement of the needle stop main body that is movable up and down, has a support part that supports the fixed knife and the movable knife at the lower end, and locks the needle by the shaft part. In a sewing machine that cuts the sewing product and overlocks the edge of the cut sewing product,
The support portion is arranged on the side of the direction in which the sewing product is sent from the needle drop area,
The movable knife has a first partial gear, and is rotatable around the rotation center of the first partial gear.
A female power transmission portion having a second partial gear meshing with the first partial gear at one end, rotatable about the rotation center of the second partial gear, and at the other end of the female power transmission portion On the other hand, an elastic member that biases an elastic force that rotates the movable knife in a direction away from the fixed knife,
The female power transmission part is located at the other end below the shaft part when the support part moves to the lowermost part.
When the needle stop body is lowered, the other end of the knife power transmission portion is pushed down by the shaft portion, and the movable knife and the fixed knife sandwich the workpiece by rotation of the second partial gear. When the needle stop main body is cut and the other end of the knife power transmission portion is rotated in the urging direction by the elastic member, the movable knife and the fixed knife are separated from each other. Sewing machine.   When a hole for fixing the support portion is provided on the upper surface of the needle plate on which the workpiece is placed, and the support portion is lowered to a position where the workpiece can be cut by the vertical movement of the support portion. 2. The sewing machine according to claim 1, wherein a protrusion that can be inserted into the hole is provided at a lower end of the support.   The said support part can be retracted | removed to the position where the other end of the said female power transmission part does not contact the said shaft part, when the said support part falls by an up-and-down movement. 2. The sewing machine according to 2.

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