JP2005334034A - Cloth cutter of sewing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily adjust the engagement angle of a fixed knife and a movable knife in a cloth cutter of a sewing machine. <P>SOLUTION: The cloth cutter of the sewing machine is provided with: a movable knife drive shaft 3 to be swung and rotated in linkage with the drive of the sewing machine; the movable knife 4 fixed to the end of the movable knife drive shaft whose end advances from and retreats to a sewing machine bed surface height by the swing and rotation of the movable knife drive shaft; an energizing means 31 for energizing the movable knife from the end of the movable knife drive shaft to the rear end; the fixed knife 7 fixed to a fixed knife attaching base 6 adjacent to the energizing direction side of the movable knife; a support 5 which is provided with a base part 51 journaled in a sewing machine frame 1 and a distal end part 52 inserted into and fixed to the fixed knife attaching base, the end part being provided with an axis in a direction crossing the axis of the base part, and which is rotatable to the sewing machine frame; and a fixing means 12 for fixing the base part to the sewing machine frame in a prescribed state. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a cloth cutting knife device for a sewing machine.

2. Description of the Related Art Conventionally, in a sewing machine, there is known a cloth cutting knife device in which a moving knife moves in and out of a sewing machine bed surface by a swinging rotation of a moving knife shaft that supports a moving knife and cuts a cloth with a fixed knife (for example, (See Patent Document 1).
Specifically, in the cloth cutting knife device, a fixed knife mounting base is provided on a sewing machine bed, and a fixed knife is fixed to the fixed knife mounting base. In addition, a moving knife shaft having a moving knife attached to one end is rotatably supported on the sewing machine bed. One end of the moving knife shaft to which the moving knife is attached is formed to be slightly inclined, and the moving knife is rotated and rotated in an eccentric state with respect to the axis of the moving knife shaft by the swinging rotation of the moving knife shaft. It is supposed to be. This is for maintaining good meshing between the moving knife and the fixed knife. The moving knife is provided adjacent to the fixed knife and is urged toward the fixed knife by a spring or the like. The cloth can be cut by sliding the moving knife with respect to the fixed knife.

Here, if there is a gap between the fixed knife and the moving knife, the cloth cannot be cut. Further, if the moving knife is directed to the fixed knife more than necessary, the blades come into contact with each other and cause blade spillage. Therefore, the meshing angle between the fixed knife and the moving knife is an important factor in cutting the cloth, and high precision is required for adjusting the meshing angle.
In adjusting the meshing angle, first, the moving knife shaft and the drive mechanism for swinging and rotating the moving knife shaft are disconnected, the position of the moving knife in the moving knife axis direction is adjusted, and the moving knife shaft to the moving knife shaft is adjusted. Adjust the mounting position. Then, the coupling position of the drive mechanism and the moving knife shaft is adjusted so that the moving knife rotates and rotates within the optimum range. That is, it is necessary to make adjustments at a plurality of different locations.
JP 2000-342874 A

  However, in the above-described adjustment of the meshing angle, position adjustment at a plurality of different locations is necessary. Therefore, it takes time to adjust the meshing angle with high accuracy, and skillful adjustment techniques are also required.

  Accordingly, the present invention has been made to solve the above-described problems, and an object of the present invention is to provide a sewing machine cloth cutting knife device that can easily adjust the meshing angle between a fixed knife and a moving knife. That is.

  In order to solve the above-described problems, the invention described in claim 1 is a cloth cutting knife device for a sewing machine, and includes a moving knife drive shaft that swings and rotates in conjunction with the drive of the sewing machine, and the moving knife drive shaft. A moving knife fixed to the tip and having its tip protruded and raised to the height of the sewing machine bed surface by the swinging rotation of the moving knife drive shaft, and a biasing force for moving the moving knife from the tip of the moving knife drive shaft toward the rear end. A biasing means, a fixed knife fixed to a fixed knife mounting base adjacent to the biasing direction side of the moving knife, a base portion pivotally supported by a sewing machine frame, and a tip portion inserted and fixed to the fixed knife mounting base. And a support body that has an axis in a direction intersecting the axis of the base and is rotatable with respect to the sewing machine frame, and a desired rotational position of the base on the sewing machine frame. And fixing means that can be fixed at the same time.

According to the first aspect of the present invention, by rotating the support body, the base portion and the tip portion rotate together, and the base portion rotates while being supported by the sewing machine frame. At this time, since the distal end portion of the support has an axis in a direction intersecting the axis of the base portion, the distal end portion rotates while being eccentric with respect to the base portion.
As a result, the fixed knife mounting base on which the distal end portion is inserted and fixed also rotates while being eccentric, and the meshing angle of the fixed knife fixed to the fixed knife mounting base changes with the rotation of the moving knife. Then, when the meshing angle between the fixed knife and the moving knife reaches the optimum meshing angle, the base is fixed to the sewing machine frame by the fixing means.

After the meshing angle of the fixed knife and moving knife is adjusted in this way, when the sewing machine is driven, the moving knife drive shaft swings and rotates in conjunction with the drive of the sewing machine, and is fixed to the tip of the moving knife drive shaft. The tip of the moving knife moved up and down at the height of the sewing machine bed by the swinging rotation of the moving knife drive shaft. At this time, since the moving knife is urged to the fixed knife side by the urging means, the moving knife slides while pressing the fixed knife, and the cloth on the sewing machine bed is sandwiched between the moving knife and the fixed knife. Disconnect with.
Therefore, the operator can easily adjust the meshing angle between the moving knife and the fixed knife only by rotating the support to the optimum position and fixing the base to the sewing machine frame by the fixing means.

According to a second aspect of the present invention, in the cloth cutting knife device of the sewing machine according to the first aspect, the distal end portion is inserted and fixed so that a distal end surface thereof is exposed to the outside from the fixed knife mounting base. An engaging portion that engages with a rotary operation tool that applies a rotational force to the support is formed on the surface.
Here, as long as the rotation operation tool is engaged with the engaging portion, the rotation operation tool may be operated electrically, or may be operated manually. Further, the shape of the engaging portion is not limited as long as it engages with the rotary operation tool. In short, it is only necessary that the rotary operation tool and the engaging portion are engaged to rotate the support.

According to the second aspect of the present invention, the rotational support tool is applied to the engagement portion formed on the distal end surface exposed to the outside of the distal end portion to apply the rotational force to the support body. As a result, the meshing angle between the moving knife and the fixed knife can be adjusted.
Accordingly, the support can be easily rotated without removing any parts of the cloth cutting knife device, and the meshing angle between the moving knife and the fixed knife can be easily adjusted.

  According to the first aspect of the present invention, the operator easily rotates the support body to the optimum position and easily fixes the meshing angle between the moving knife and the fixed knife by fixing the base to the sewing machine frame by the fixing means. The cloth can be cut accurately.

  According to the second aspect of the present invention, the support can be easily rotated without removing any parts of the cloth cutting knife device, and the meshing angle between the moving knife and the fixed knife can be easily adjusted.

  The best mode of a cloth cutting knife device for a sewing machine (hereinafter referred to as a cloth cutting knife device) according to the present invention will be described below in detail with reference to the drawings. In the present embodiment, a left knife device that cuts the cloth on the left side in the cloth feeding direction will be described as an example.

As shown in FIG. 1, the cloth cutting knife device 100 is provided in the sewing machine frame 1 and is installed so that the cloth cutting position is substantially the same height as the needle plate 2.
<Moving knife>
The cloth cutting knife device 100 is provided with a moving knife drive shaft 3 that swings and rotates in conjunction with the drive of the sewing machine.
The moving knife drive shaft 3 is rotatably inserted into the sewing machine frame 1 and is connected to a drive mechanism D provided on the sewing machine frame 1. The moving knife drive shaft 3 is linked to the drive mechanism D, and the drive mechanism D gives the moving knife drive shaft 3 reciprocal kinetic energy in the circumferential direction of the moving knife drive shaft 3. Oscillates and rotates.

At the tip of the moving knife drive shaft 3, a moving knife 4 whose tip protrudes and protrudes at the height of the needle plate 2 by the swinging rotation of the moving knife drive shaft 3 is attached.
The moving knife 4 has a blade 41 whose tip is curved in a bowl shape, and the moving knife drive shaft 3 is inserted into an insertion hole 42 formed in the base end. As shown in FIG. 2, the insertion hole 42 can adjust the size of the insertion hole 42 by the screwing amount of the screw 43, and can cope with a slight change in the diameter of the moving knife drive shaft 3. It is structured.

  As shown in FIG. 1, a spring 31 is provided at the rear end of the moving knife drive shaft 3 as an urging means for urging the moving knife 4 from the front end to the rear end of the moving knife drive shaft 3. . Specifically, the spring 31 is a coil spring through which the moving knife drive shaft 3 is passed. One end of the spring 31 is provided on the sewing machine frame 1 and is connected to a bracket B1 that supports the moving knife drive shaft 3 so as to be movable in the axial direction thereof. The other end of the spring 31 is connected to a bracket B 2 attached to the moving knife drive shaft 3. The distance between the bracket B1 and the bracket B2 is shorter than the natural length of the spring 31. The elastic force of the bracket B2 returning to the natural length of the spring 31 causes the moving knife drive shaft 3 to move from the front end toward the rear end. The moving knife drive shaft 3 is also urged from the front end toward the rear end together with the bracket B2. Thereby, the moving knife 3 attached to the tip of the moving knife drive shaft 3 is also urged backward from the tip of the moving knife drive shaft 3.

<Fixed knife>
As shown in FIGS. 1, 3, and 4, the cloth cutting knife device 100 is provided with a support 5 that can rotate with respect to the sewing machine frame 1.
As shown in FIGS. 3 and 4, the support 5 has a base portion 51 that is rotatably supported by the sewing machine frame 1 and a distal end portion that is inserted into and fixed to a fixed knife mounting base 6 (described later). 52 are provided.

The base 51 is formed in a substantially cylindrical shape, and is inserted into the insertion hole 11 formed in the sewing machine frame 1. A fixing hole 13 for inserting a screw 12 as a fixing means to fix the base 51 to the sewing machine frame 1 at a desired rotational position is provided above the insertion hole 11 in the sewing machine frame 1. 11 is formed through. That is, when the base 51 is inserted into the insertion hole 11 and the base 51 is rotated to reach the optimum position, the screw 51 can be inserted from the fixing hole 13 to fix the base 51.
The distal end portion 52 is formed in a substantially cylindrical shape having an outer diameter smaller than that of the base portion 51. The tip 52 has a shape slightly inclined with respect to the base 51 and has an axis that intersects the axis of the base 51.

  The front end surface 53 of the front end portion 52 is formed with an engaging portion 54 that engages with a rotary operation tool that applies a rotational force to the support 5 when the support 5 is rotated via the front end 52. . In addition, it is easy and preferable to use a general purpose flathead screwdriver etc. for a rotation operation tool, for example. When a minus driver is used as the rotary operation tool, the engaging portion 54 is formed with a straight groove that crosses the tip surface.

The distal end portion 52 is provided with a fixed knife mounting base 6 for mounting a fixed knife 7 (described later). The fixed knife mounting base 6 is adjacent to the urging direction side of the moving knife 4. Is provided.
The fixed knife mounting base 6 is formed from a plate material formed in a substantially trapezoidal shape, and an insertion hole 61 through which the front end portion 52 of the support 5 is inserted penetrates the rear surface at the upper right of the front surface. Is formed. In addition, a fixing hole 63 for inserting the screw 62 and fixing the distal end portion 52 of the support 5 is formed through the insertion hole 61 above the insertion hole 61 in the upper surface of the fixed knife mounting base 6. Has been.

In addition, a mounting hole 64 for mounting a fixing member 71 (described later) is formed on the left side of the insertion hole 61 at some distance on the fixed knife mounting base 6.
On the further left side of the mounting hole 64, a female guide 65 is formed which presses the fixed knife 7 to guide the mounting position of the fixed knife 7. The knife guide 65 is formed with a step so that the side on which the fixed knife 7 is attached is lowered, and is inclined from the upper end to the lower end of the fixed knife mounting base 6.

The fixed knife 7 is formed in a long plate shape, and a blade part 71 is formed on one side edge along the longitudinal direction. The blade part 71 of the fixed knife 7 is in sliding contact with the blade part 41 of the moving knife 4. The cloth can be cut. The fixed knife 7 is attached and fixed along the knife guide 65 by a fixing member 72 for attaching the fixed knife 7 to the fixed knife mounting base 6.
The fixing member 72 is a plate material formed in a substantially trapezoidal shape, and the side edge that presses the fixing knife 7 against the knife guide 65 is formed to be inclined along the side edge of the fixing knife 7. The fixing member 72 is formed with a fixing hole 74 for attaching the fixing member 72 to the fixing knife mounting base 6 via a screw 73.

Next, the operation | movement at the time of adjustment of the meshing angle of the moving knife 4 and the fixed knife 7 by the cloth cutting knife apparatus 100 is demonstrated, and the cutting method of a cloth is also demonstrated.
As shown in FIG. 5, first, the screw 12 is loosened so that the base 51 of the support 5 is rotatable within the sewing machine frame 1. Next, the tip of the flathead screwdriver is engaged with the engaging portion 54 and the flathead screwdriver is rotated to search for a position where the engagement between the blade 71 of the fixed knife 7 and the blade 41 of the moving knife 4 is optimal. When finely adjusting the meshing angle, the screw 62 may be loosened and the fixed knife mounting base 6 may be rotated with respect to the distal end portion of the support 5.
When the optimum meshing position between the blade 71 of the fixed knife 7 and the blade 41 of the moving knife 4 is determined, the screw 51 is tightened to fix the base 51 to the sewing machine frame 1.

Next, the cloth cutting operation by the cloth cutting knife device 100 will be described.
Before cutting the cloth, as shown in FIG. 6, the blade 41 of the moving knife 4 is located below the sewing machine frame 1, and this position is the bottom dead center. On the other hand, when cutting the cloth, as shown in FIG. 7, the blade portion 41 of the moving knife 4 is positioned so as to overlap the blade portion 71 of the fixed knife 7, and this position becomes the top dead center. .
That is, the moving knife drive shaft 3 is swung and rotated, and the moving knife 4 is swung and rotated within the range from the top dead center to the bottom dead center, so that it is sandwiched between the fixed knife 7 and the moving knife 4 at the top dead center. The cloth is cut.

FIG. 8 shows a cutting state of the cloth C by the fixed knife 7 and the moving knife 4. This cutting is performed on the cloth C fed to the needle drop position H of the needle plate 2 with the end edge E folded back, and the folded edge E is properly set before reaching the needle drop position H. Cut off the folded part of the width.
The moving knife 4 pushes up the cloth C from the back side when moving from the bottom dead center to the top dead center, catches the edge E folded back by the blade portion 41 curved in a bowl shape, and rotates downward in this state. . At this time, the edge E is pulled down together with the moving knife 4 and guided to the sliding contact portion between the blade 71 of the fixed knife 7 and the blade 41 of the moving knife 4 and is cut. Then, by synchronizing the swing rotation of the moving knife 4 and the cloth feed, the folded edge E is continuously cut.

As described above, according to the cloth cutting knife device 100 of the sewing machine according to the present invention, the base 51 and the tip 52 are rotated together by rotating the support 5, and the base 51 is pivotally supported by the sewing machine frame 1. It will rotate in the At this time, the distal end portion 52 of the support 5 has an axis in a direction intersecting with the axis of the base 51, so that the distal end 52 rotates while being bent with respect to the base 51.
Thereby, the fixed knife mounting base 6 to which the tip 52 is inserted and fixed also rotates according to the rotation of the axis inclined with respect to the axis of the base 51, and the fixed knife 7 fixed to the fixed knife mounting base 6 is The meshing angle with the moving knife 4 changes with rotation. Then, when the meshing angle between the fixed knife 7 and the moving knife 4 becomes the optimum meshing angle, the base 51 is fixed to the sewing machine frame 1 by the screw 12.

After the meshing angle between the fixed knife 7 and the moving knife 4 is adjusted in such a procedure, when the sewing machine is driven, the moving knife drive shaft 3 swings and rotates in conjunction with the drive of the sewing machine, and the moving knife drive shaft 3 The moving knife 4 fixed to the tip of the moving knife 4 moves up and down at the height of the sewing machine bed surface by the swinging rotation of the moving knife driving shaft 3. At this time, since the moving knife 4 is urged toward the fixed knife 7 by the spring 31, the moving knife 4 slides while pressing the fixed knife 7, and the cloth C on the sewing machine bed surface is moved to the moving knife 4. And sandwiched with a fixed knife 7 and cut.
Therefore, the operator can easily adjust the meshing angle between the moving knife 4 and the fixed knife 7 only by rotating the support 5 to the optimum rotation position and fixing the base 51 to the sewing machine frame 1 with the screw 12. .

Further, by applying a rotational force to the support 5 by engaging a rotary operation tool such as a minus driver with the engaging portion 54 formed on the front end surface 53 exposed to the outside of the front end 52 of the support 5. The support 5 can be rotated, and as a result, the meshing angle between the moving knife 4 and the fixed knife 7 can be adjusted.
Thereby, the support body 5 can be easily rotated without removing each part of the cloth cutting knife device 100, and the meshing angle between the moving knife 4 and the fixed knife 7 can be easily adjusted.
That is, in the conventional adjustment of the meshing angle, the position adjustment of the moving knife drive shaft, the attachment position of the moving knife to the moving knife drive shaft, and the attachment position of the drive mechanism to the moving knife drive shaft are not shifted in phase. In contrast to the adjustment of the meshing angle according to the present invention, since it is only necessary to adjust the fixed knife 7 so as to optimally mesh with the moving knife 4, the synchronization with other parts is necessary. Therefore, the time required for adjusting the meshing angle can be greatly reduced, and the meshing angle can be easily adjusted without the skill of the operator.

  In addition, this invention is not limited to the said embodiment, For example, it is applicable also to the right knife apparatus which cut | disconnects cloth on the right side of the feed direction of a cloth. Further, the method of fixing the support to the sewing machine frame and the method of fixing the fixed knife to the fixed knife mounting base are arbitrary, and the design can be changed freely. In addition, the base portion and the tip portion of the support may be integrally formed or may be provided separately. In addition, the present invention can be freely changed and improved without departing from the scope of the invention.

It is a perspective view of the cloth cutting knife device of the sewing machine concerning the present invention. It is a disassembled perspective view which shows the mechanism of the moving knife vicinity in the cloth cutting knife apparatus of the sewing machine which concerns on this invention. It is a perspective view which shows the mechanism of the fixed knife vicinity in the cloth cutting knife apparatus of the sewing machine which concerns on this invention. It is a disassembled perspective view which shows the mechanism of the fixed knife vicinity in the cloth cutting knife apparatus of the sewing machine which concerns on this invention. It is sectional drawing which shows the mechanism of the fixed knife vicinity in the cloth cutting knife apparatus of the sewing machine which concerns on this invention. It is a perspective view which shows a state when the moving knife in the cloth cutting knife apparatus of the sewing machine which concerns on this invention exists in a standby position. It is a perspective view which shows a state when the moving knife in the cloth cutting knife apparatus of the sewing machine which concerns on this invention exists in a cloth cutting position. It is a perspective view explaining the cloth cutting method in the cloth cutting knife apparatus of the sewing machine concerning the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Sewing machine frame 3 Moving knife drive shaft 4 Moving knife 5 Support body 6 Fixed knife mounting base 7 Fixed knife 12 Screw (fixing means)
31 Spring (biasing means)
51 base 52 front end 53 front end surface 54 engaging unit 100 cloth cutting knife device

Claims (2)

A moving knife drive shaft that swings and rotates in conjunction with the drive of the sewing machine;
A moving knife fixed to the tip of the moving knife drive shaft, the tip of the moving knife drive shaft swinging up and down at the height of the sewing machine bed surface,
An urging means for urging the moving knife toward the rear end of the moving knife drive shaft;
A fixed knife fixed to a fixed knife mounting base adjacent to the biasing direction side of the moving knife;
The sewing machine has a base that is pivotally supported by a sewing machine frame and a tip that is inserted and fixed to the fixed knife mount, and the tip has an axis that intersects the axis of the base. A support rotatable relative to the frame;
Fixing means capable of fixing the base to the sewing machine frame at a desired rotational position;
A cloth cutting knife device for a sewing machine, comprising: In the cloth cutting knife device of the sewing machine according to claim 1,
The distal end portion is inserted and fixed so that the distal end surface is exposed to the outside from the fixed knife mounting base, and an engaging portion that engages with a rotary operation tool that applies a rotational force to the support body is provided on the distal end surface. A cloth cutting knife device for a sewing machine characterized by being formed.

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