JP2004321532A - Cloth cutting device of sewing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cloth cutting device of a sewing machine capable of changing a cloth cutting position without taking a large space. <P>SOLUTION: The cloth cutting device comprises: an abutting member 34 freely position adjustably fixed to a supporting shaft 25 and abutted to a machine frame on one end side for limiting movement in a direction of separating a movable knife to a fixed knife; a fixed knife base 12 supported by the supporting shaft movably along the axial direction for holding the fixed knife; a groove part 12d formed on the fixed knife base; an eccentric pin 30 whose head part is turnably supported by the machine frame and eccentric shaft part is engaged with the fixed knife base groove part; and a fixing screw 31 for fixing the fixed knife base to the machine frame. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sewing machine cloth cutting device for cutting an end of a work cloth before sewing.
[0002]
[Prior art]
2. Description of the Related Art When sewing an upper cloth such as a lace to a body cloth (lower cloth), a cloth cutting device of a sewing machine that cuts and trims an excess portion of the body cloth before sewing is known. The apparatus includes a fixed knife fixed to the side of the needle plate, and a moving knife disposed adjacent to the fixed knife and cutting the cloth in cooperation with the fixed knife. When the adjustment knife attached to the apparatus is rotated, the fixed knife and the moving knife move in the left-right direction with respect to the needle drop point according to the cam shape, and can change the cutting position of the cloth.
[0003]
[Patent Document 1]
JP-A-6-190169 (FIG. 1)
[0004]
[Problems to be solved by the invention]
However, in the conventional sewing machine cutting device, a cloth cutting position changing mechanism including a cam or the like provided on an adjustment dial occupies a large space. Further, in the conventional apparatus, when cutting a thick cloth, the moving knife is separated from the fixed knife more than necessary, and there is a possibility that a cutting failure of the cloth occurs.
[0005]
SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to provide a cloth cutting device for a sewing machine that can change a cloth cutting position without taking up a large space. Another object of the present invention is to provide a sewing machine cloth cutting device that does not cause a cutting failure even when cutting a thick cloth. Still another object of the present invention is to provide a sewing machine cloth cutting device in which a cutting position can be easily adjusted.
[0006]
[Means for Solving the Problems]
In order to solve the above problems, the invention according to claim 1 is:
A support shaft (25) rotatably supported by the sewing machine frame and movable along the axial direction;
A fixed knife (9) arranged on the side of the needle plate and supported by the support shaft;
A moving knife (10) disposed adjacent to the fixed knife and fixed to the support shaft; an elastic member (35) for urging the moving knife toward the fixed knife;
A cloth cutting device for a sewing machine, comprising: driving means (17) for rotating the support knife in the vertical direction by rotating the support shaft in synchronization with the vertical movement of the needle.
An abutment member (34) fixed to the support shaft so as to be adjustable in position, one end of which abuts the machine frame, and restricts movement of the moving knife in a direction away from the fixed knife;
A fixed knife base (12) supported movably along the axial direction of the support shaft and holding the fixed knife;
An engaging portion (12d) formed by opening in the radial direction of the fixed knife base;
An eccentric pin (30) whose head is rotatably supported by the sewing machine frame and whose eccentric shaft portion engages with the engaging portion of the fixed knife base;
A fixing screw (31) for fixing the fixed knife base to the machine frame, wherein the left and right positions of the fixed knife and the moving knife can be adjusted by rotating the eccentric pin.
[0007]
According to the first aspect of the invention, when the eccentric pin is rotated, the fixed knife and the moving knife move via the fixed knife base and the support shaft, and the cutting position of the cloth is changed. Since the cloth cutting position is changed by using the eccentric pin, the structure is simplified and the space can be saved. Further, the movement of the moving knife in the direction away from the fixed knife is restricted by the contact member. For this reason, even when cutting a thick cloth, cutting failure does not occur.
[0008]
According to a second aspect of the present invention, in the sewing machine cloth cutting apparatus according to the first aspect,
The eccentric pin and the fixing screw are arranged so as to face the operator side and can be operated from outside the sewing machine frame.
[0009]
According to the second aspect of the invention, when the cloth cutting position is changed in accordance with the change of the needle drop position, the adjustment work can be performed while watching the needle drop point, so that the workability is improved.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
A first embodiment of the present invention will be described with reference to FIGS.
A needle bed 2 is fixed to the upper surface of a sewing bed 1 that supports a sewing product. Around the needle plate 2, an upper surface cover 3 is arranged on the rear side as viewed from the operator side, a cloth cutting base 4 is arranged on the left front side, and a main cover 5 is arranged on the right front side. A side cover 6 is arranged below the cloth cutting base 4. The main cover 5 has a cutout 5a on the left side. The inclined cover 7 is disposed in the cover notch 5a. The inclined cover 7 has an inclined surface 7a which is inclined downward from the needle plate 2 side toward the machine frame (frame) side where the operator is located.
[0011]
A plurality of rectangular openings 2b are formed in the needle plate 2 in parallel along the cloth feeding direction X. The feed dog 8 protrudes and retracts from the opening 2b, and feeds the sewing product in the cloth feed direction X. The needle plate 2 has a needle hole 2c formed in the center thereof. A needle plate notch 2d is formed in the right side surface 2a on the front side of the needle hole 2c. A fixed knife 9, a moving knife 10, and a cloth dust cover 11 are arranged in the needle plate notch 2d in the order away from the needle plate in the Y direction orthogonal to the cloth feeding direction.
[0012]
As shown in FIG. 3, the fixed knife 9 is a plate-shaped member, and has a blade 9a at its upper end. The fixed knife base 12 has a cylindrical main body 12a and a holding part 12b. The holding portion 12b is formed with a slanting groove that is directed obliquely upward. The fixed knife base 12 is fixed to the cloth cutting base 4 via the main body 12a. A fixed knife 9 is mounted in the inclined groove. Then, the fixed knife 9 is fixed to the fixed knife base 12 by the pressing member 13 and the screw 14 at a position where the blade portion 9a of the fixed knife contacts the upper surface of the needle plate.
[0013]
A moving knife 10 is arranged on the right side of the fixed knife 9. As shown in FIG. 4, the moving knife 10 has a U-shape in a right side view, and includes a knife portion 10a located on the upper side and a main body portion 10b extending downward continuously from the knife portion 10a. The scalpel portion 10a includes an arc portion 10aa extending toward the operator side, and a blade portion 10ab extending horizontally from the end of the arc portion and having an inclined cutting edge. The main body 10b is disposed downward from the edge 10ac on the inner side of the cutting edge.
[0014]
The main body 10b of the moving knife 10 is formed with a guide wall 10ba extending downward from the blade inner end 10ac. The guide wall 10ba is provided with a tapered surface 10c formed so as to be gradually separated in a direction Y orthogonal to the cloth feeding direction. The tapered surface 10c is formed so as to expand as the distance from the needle plate increases, and to spread over the entire area of the guide wall 10ba in the vertical direction. A mounting hole 10bb is formed in the center of the main body 10b. The moving knife 10 is fixed to the moving knife base 16 with the screws 15 (shown in FIG. 3) inserted through the mounting holes 10bb.
[0015]
On the right side of the moving knife 10, a cloth dust cover 11 is arranged. The cloth dust cover 11 has an inverted letter shape when viewed from the right side, and includes an upper end portion 11a, an arc portion 11b, and a fixing portion 11c from the upper side. The upper end 11a of the cloth dust cover 11 is located above the blade 10ab of the moving knife.
[0016]
The arc portion 11b is arranged such that the left end side surface 11ba does not protrude from the open end 10ca of the tapered surface of the moving knife guide wall. The arc portion 11b itself has a linear shape along the Y direction, or a tapered surface that is inclined so as to be separated in the X direction. The support portion 11c is inclined toward the working side, and is fixed to the moving knife base 16 with screws. The moving knife 10 is fixed to the left side surface of the moving knife base 16 and the cloth dust cover 11 is fixed to the right side surface thereof. The moving knife 10 and the cloth dust cover 11 are arranged adjacent to each other and swing up and down integrally.
[0017]
The cloth edge cut by the blade portion 10ab of the moving knife 10 is guided by the guide wall 10ba of the moving knife main body, its tapered surface 10c, and the cloth cover-arc portion 11b as the cloth is fed in the X direction. , In the Y direction. Thereafter, it falls outside the machine frame via the inclined surface of the inclined cover 7.
[0018]
As shown in FIGS. 2 and 3, the driving means 17 for vertically swinging the moving knife 10 includes a lower shaft 18, a connecting arm 19, a knife operating shaft 20, a connecting link 21, a connecting pin 22, a square piece 23, It comprises a piece cover 24, a moving knife base 16, and a moving knife base support shaft (support shaft) 25. The driving means 17 rotates the moving knife base support shaft 25 in synchronization with the vertical movement of the needle to lower the moving knife 10 in the vertical direction. And is rotatably supported by a metal bearing provided on the machine frame. An eccentric cam 26 is fixed to the lower shaft 18. The rear end side of the connecting arm 19 is mounted on the eccentric cam 26, and is rotatably supported. The front end side of the connecting arm 19 is rotatably connected to the female operating shaft 20. The lower end of the connecting link 21 is fixed to the female operating shaft 20. The upper end of the connection link 21 holds one end of the connection pin 22. The other end of the connecting pin 22 is inserted into a through hole of the square piece 23.
[0019]
As shown in FIGS. 3 and 5, the moving knife base 16 has a triangular shape in a side view, and the moving knife 10 is fixed to the upper apex 16a side. A female support shaft 25 is inserted into the through hole 16ba on the lower left apex 16b side, and is fixed with a screw 27. The other end of the support shaft 25 is rotatably supported by the cloth cutting base 4. A projection 16e is formed at the lower right apex 16c of the moving knife base 16. A groove 16d is formed in the protruding portion 16e toward the lower left apex 16b. A square piece 23 is mounted in the groove 16d. The square piece 23 is slidably supported by the groove 16d.
[0020]
A square piece cover 24 is provided on the front side of the square piece 23. The square piece cover 24 has a hole 24a on the front side through which the support pin 22 passes. The square piece cover 24 has a box lid shape and has bent pieces 24b and 24c on the side of the square piece sliding direction and bent pieces 24d on the lower side. The square piece cover 24 is set in the groove 16d so as to cover the groove 16d and the surface side of the square piece 23 after the square piece 23 is mounted in the groove 16d of the moving knife base 16, and is fixed to the moving knife base 16 by the screw 27. Fixed.
[0021]
A configuration for changing the cloth cutting position of the moving knife 10 and the fixed knife 9 will be described with reference to FIGS. 2, 3, and 6. FIG. FIG. 6 is a perspective view in which the cloth cutting base 4 is omitted from FIG. 2 for explanation.
[0022]
A support shaft 25 is attached to the cloth cutting base (machine frame) 4 along the illustrated Y direction. The moving knife base 16, the fixed knife base 12, the compression spring (elastic member) 35, the first thrust collar 32, the metal bearing 33, and the second thrust collar (contact member) 34 are sequentially provided on the support shaft 25 from the right end side in the figure. Is arranged.
[0023]
The cloth cutting base (machine frame) 4 is box-shaped, and has a mounting hole 4e formed along the Y direction, and a fitting hole 4f formed coaxially with the mounting hole 4e. The cloth cutting base 4 has a split groove 4g formed from the outer periphery toward the mounting hole 4e. After the adjustment of the left and right position (Y direction) of the fixed knife base 12 set in the mounting hole 4 e is completed, the fixed knife base 12 is fixed to the cloth cutting base 4 with the fixing screw 31.
[0024]
A metal bearing 33 is press-fitted and fixed in the fitting hole 4f in FIG. The cloth cutting base 4 is fixed to a sewing machine frame (sewing machine frame) by screws (not shown), and forms a part thereof. In addition, a mounting hole 4 a for the eccentric pin 30, a mounting hole 4 b for the fixing screw 31, and a length for adjusting the left and right positions of the first thrust collar 32 are provided on the worker facing surface 4 h facing the worker of the cloth cutting base 4. A hole-shaped adjustment hole 4c and a long hole-shaped adjustment hole 4d for adjusting the left and right positions of the second thrust collar 32 are provided.
[0025]
The moving knife base 16 is fixed to the right end of the support shaft 25 by screws 27. On the left side of the moving knife base 16, the fixed knife base 12 is arranged. The fixed knife base 12 includes a cylindrical main body 12a, a holding part 12b, and a support part 12c. The main body 12a has a cylindrical shape, and the support shaft 25 is inserted through an inner peripheral portion thereof. The support portion 12c protruding downward from the main body portion 12a at the outer periphery is bifurcated when viewed from the Y direction. The head of a reference pin 36 having one end fixed to the cloth cutting base 4 is fitted into the bifurcated support portion 12c. The reference pin 36 is arranged in parallel with the support shaft 25. For this reason, the fixed knife base 12 is movable along the axial direction Y of the support shaft 25. A groove (engaging portion) 12d is formed in the main body 12a along the vertical direction on the outer peripheral portion (radiation direction).
[0026]
The shaft of the eccentric pin 30 is engaged with the groove 12d. The eccentric pin 30 includes a head and a shaft formed at a position eccentric from the axis thereof. The eccentric pin 30 is mounted in the mounting hole 4a of the cloth feed base, and its head is rotatably supported. Further, the shaft portion engages with the groove portion 12d. When the operator rotates the eccentric pin 30 with the driver, the fixed knife base 12 moves in the left-right direction (Y direction) when viewed from the worker side.
[0027]
On the left side of the fixed knife base 12, a compression spring (elastic member) 35 is arranged. The first thrust collar 32 is arranged on the left side of the compression spring 35. The first thrust collar 32 is cylindrical, and has a female screw 32a penetrating the outer periphery thereof. Then, a screw inserted through the adjustment hole 4c of the cloth feed base 4 is attached to the female screw 32a of the first thrust collar, and fixes the first thrust collar 32 at a predetermined position of the support shaft 25.
[0028]
The compression spring 35 is mounted on the support shaft 25, and one end of the compression spring 35 is in contact with the fixed female base 12, and the other end is in contact with the first thrust collar 32. The fixed knife base 12 on one end side is fixed to the cloth feed base 4. For this reason, the compression spring 35 urges the support shaft 25 and the moving knife base 16 in the left direction (y1) in the drawing via the first thrust collar 32, but the moving knife 10 contacts the fixed knife 9 and stops. . The compression spring 35 presses the moving knife 10 against the fixed knife 9. This urging force can be increased or decreased by changing the fixed position of the first thrust collar 32.
[0029]
On the left side of the first thrust collar 32, a metal bearing 33 press-fitted and fixed to the cloth feed base 4 is arranged. On the left side of the metal bearing 33, a second thrust collar 34 (contact member) is arranged. The second thrust collar 34 (contact member) is cylindrical, and has a female screw 34a penetrating the outer periphery thereof. Then, a screw (not shown) inserted through the adjustment hole 4d of the cloth feed base 4 is attached to the female screw 34a of the second thrust collar, and the second thrust collar 34 is fixed at a position on the left end side of the support shaft 25. When the support shaft 25 and the moving knife 10 move in the direction away from the fixed knife 10, that is, rightward in the drawing, the right side surface of the second thrust collar 34 contacts the metal bearing 33 to stop the moving knife 10.
[0030]
The operation of the first embodiment will be described.
When the sewing machine motor is driven, the lower shaft 18 rotates. When the lower shaft 18 rotates, the female operating shaft 20 swings via the eccentric cam 26 and the connecting arm 19. When the female operating shaft 20 swings, the square piece 23 swings via the connecting link 21 and the connecting pin 22. The swinging motion about the axis of the knife operating shaft 20 is imparted to the moving knife base 16 by the square piece 23. However, the moving knife base 16 is rotatably supported by the machine frame about the support shaft 25. For this reason, the swinging motion imparted by the square piece 23 other than the rotation direction about the support shaft 25 is absorbed by the sliding of the groove of the moving knife base 16 of the square piece 23. As a result, the moving knife base 16 and the moving knife 10 swing up and down around the support shaft 25 as the center of rotation.
[0031]
The operator moves the upper and lower two cloths in the cloth feeding direction X. At this time, the moving knife 10 swings up and down by the sewing machine driving, and cuts and trims the cloth edge of the lower cloth. The upper cloth and the lower cloth whose ends are trimmed form decorative stitches and the like at the needle drop point behind the moving knife. Further, the end of the lower cloth cut by the fixed knife 9 and the moving knife 10 is smoothly moved in the Y direction through the guide wall 10ba, the tapered surface 10c, and the cloth dust cover arc 11b as the sewing material moves. Will be sent to Then, it falls out of the sewing machine frame via the inclined surface 7a of the inclined cover 7.
[0032]
As described above, according to the first embodiment, the cloth edge cut by the fixed knife 9 and the moving knife 10 moves the sewing product in the X direction and swings the moving knife 10 and the cloth dust cover 11 up and down. Accordingly, the movable knife main body portion guide wall 10ba, its tapered surface 10c, and the cloth dust cover arc portion 11b smoothly guide the inclined blade 7 to the inclined cover 7, and then fall outside the machine frame.
[0033]
A driving means 17 for swinging the moving knife 10 is built in the bed. However, lint, cotton dust, and the like are scattered in the lower portion of the needle plate 2 and in the vicinity thereof due to cloth cutting and sewing before sewing. However, on the surface side of the square piece 22 and the moving knife base groove 16d, a square piece cover 24 that covers them is provided. For this reason, lint and cotton dust generated at the time of sewing do not adhere to the moving knife base groove 16 d or the square piece 23. In addition, since the bent pieces 24b and 24c of the square piece cover 24 hold the grease applied to the square piece 22 and the moving knife base groove 16d, the moving knife base 16 and the moving knife 10 can be smoothly moved for a long time. Rocks.
[0034]
Next, a case where the cloth cutting positions of the moving knife 10 and the fixed knife 9 are changed will be described.
First, the screw passing through the adjustment hole 4d is loosened to release the fixing between the second thrust collar 34 and the support shaft 25. Next, the fixing screw 31 is loosened to release the holding of the fixed knife base 12 by the cloth cutting base 4.
[0035]
Next, when the eccentric pin 30 is rotated, the left and right positions of the fixed knife 9 and the moving knife 10 change along the Y direction. When the fixed knife 9 and the moving knife 10 move to the target cutting positions, the fixing screws 31 are tightened, and the fixed knife base 12 is held by the cloth cutting base 4. Next, the position of the second thrust collar 34 is moved and fixed to the support shaft 25 with screws while taking into account the thickness of the cloth and the occurrence of defective cutting. By this operation, the change of the cutting position of the moving knife 10 and the fixed knife 9 ends. When the urging force (blade pressure) of the fixed knife 9 and the moving knife 10 is adjusted, the fixing position of the first thrust collar 32 may be changed.
[0036]
As described above, according to this embodiment, when the eccentric pin 30 is rotated, the fixed knife 9 and the moving knife 10 move via the fixed knife base 12 and the support shaft 25, and the cutting position of the cloth is changed. I do. As described above, since the cloth cutting position is changed by using the eccentric pin, the structure is simplified and the space can be saved.
[0037]
In addition, since the eccentric pin 30 and the fixing screw 31 are arranged in a direction facing the operator, the adjustment work with the eccentric pin can be performed while observing the needle drop, and the workability is improved.
[0038]
Further, since the position adjustment of the first thrust collar 32 and the second thrust collar 34 in the left-right direction can be operated by screws arranged in the direction facing the operator, workability is good.
[0039]
【The invention's effect】
According to the first aspect of the invention, when the eccentric pin is rotated, the fixed knife and the moving knife move via the fixed knife base and the support shaft, and the cutting position of the cloth is changed. Since the cloth cutting position is changed by using the eccentric pin, the structure is simplified and the space can be saved. Further, the movement of the moving knife in the direction away from the fixed knife is restricted by the contact member. For this reason, even when cutting a thick cloth, cutting failure does not occur.
[0040]
According to the second aspect of the invention, when the cloth cutting position is changed in accordance with the change of the needle drop position, the adjustment work can be performed while watching the needle drop point, so that the workability is improved.
[Brief description of the drawings]
FIG. 1 is a perspective view of a first embodiment.
FIG. 2 is a perspective view in which a sewing machine cover of FIG. 1 is removed.
FIG. 3 is an exploded perspective view of the first embodiment for each part.
FIG. 4 is a partially enlarged view of a moving knife and a cloth dust cover.
FIG. 5 is an enlarged perspective view of a moving knife base and a square piece.
FIG. 6 is a perspective view in which the cloth cutting base of FIG. 2 is removed.
[Explanation of symbols]
4. Cloth base (machine frame)
25 support shaft 9 fixed knife 10 moving knife 35 compression spring (elastic member)
17 ... driving means 34 ... second thrust collar (contact member)
12: Fixed female base 12d Groove (engagement part)
30 ... eccentric pin 31 ... fixing screw

Claims (2)

A support shaft rotatably supported by the sewing machine frame and movable along the axial direction thereof;
A fixed scalpel arranged on the side of the needle plate and supported by the support shaft,
A moving knife that is arranged adjacent to the fixed knife and fixed to the support shaft,
An elastic member for urging the moving knife toward the fixed knife,
In synchronization with the vertical movement of the needle, the cloth cutting device of the sewing machine, comprising: a driving unit that pivots the support shaft to swing the moving knife vertically.
Positionally fixed to the support shaft, one end of which is in contact with the machine frame,
A contact member that restricts movement of the moving knife relative to the fixed knife in a direction away from the fixed knife;
A fixed knife base that is movably supported along the axial direction of the support shaft and holds the fixed knife,
In the radial direction of the fixed knife base, an engaging portion formed by opening,
An eccentric pin whose head is rotatably supported by the sewing machine frame and whose eccentric shaft portion engages with the engaging portion of the fixed knife base,
And a fixing screw for fixing the fixed knife base to a machine frame, wherein the left and right positions of the fixed knife and the moving knife can be adjusted by rotating the eccentric pin. The cloth cutting device for a sewing machine according to claim 1,
The cloth cutting device for a sewing machine, wherein the eccentric pin and the fixing screw are arranged so as to face an operator and can be operated from outside the sewing machine frame.

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