JP2000210488A - Cloth cutting device for hole-darning sewing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cloth cutting device for a hole-darning sewing machine, capable of increasing durability by preventing the deterioration of a cutter, and simply and surely fine-adjusting an approaching limit position where a hammer approaches the cutter during boring. SOLUTION: Based on the shape of the can body 25 of a cam mechanism 7, the moving amount of a hammer 4 per unit driving amount of an air cylinder 5 is set to be large until an approaching limit position where the hammer 4 approaches a cutter 2, and then small during a specified period when the hammer 4 is between a position near the approaching limit position and the approaching limit position. Thus, the hammer 4 is prevented from being strongly abutted on the cutter 2, the sound of contact between the hammer 4 and the cutter 2 is reduced, and the deterioration, such as damaging or cutting, of the cuter 2 is prevented to considerably increase durability.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cloth cutting device for a buttonhole sewing machine for punching a buttonhole, and more particularly, to a transmission mechanism for transmitting a driving force of an actuator to an arm member to drive a hammer. Cam mechanism including child,
The present invention relates to an apparatus having a fine adjustment mechanism capable of finely adjusting an approach limit position of a hammer approaching a scalpel.

[0002]

2. Description of the Related Art Conventionally, a buttonhole sewing machine is provided with a buttonhole inside a workcloth hole (or a seam formation scheduled portion) after forming (or before forming) a buttonhole seam on a work cloth. Many are equipped with a cloth cutting device to pierce, as this kind of cloth cutting device, a scalpel fixed to a sewing machine frame, a hammer fixed to an arm member pivotally supported by the sewing machine frame, An actuator provided with an actuator for driving the hammer and a transmission mechanism for transmitting the driving force of the actuator to the arm member has been put to practical use.

In the cloth cutting apparatus 100 shown in FIGS. 8 and 9 which has been put to practical use by the present applicant, the arm member 103 is attached to the sewing machine frame by the support shaft 10.
A transmission mechanism 110 is provided rotatably and pivotally via the link 4 and has link members 113 and 114. Link member 113
The base end of the link member 114 is pivotally supported on a support shaft 112, the distal end thereof is rotatably connected to a piston rod 111a of an air cylinder 111, and one end of a link member 114 is connected to the support shaft 112 of the link member 113. Is rotatably connected near the other end, and the other end is an arm member.
And operatively connected to 103.

As shown in FIG. 8, when the piston rod 111a of the air cylinder 111 is fully extended, the hammer 10
2 is held in the standby position, which is maximally separated from knife 101,
In this state, when the air cylinder 111 operates and the piston rod 111a is driven to retract, the driving force is transmitted to the transmission mechanism 110.
The arm member 103 is rotated through the link members 113 and 114, and the arm member 103 is rotated. The work cloth 119 is pressed against the knife 101 by the hammer 102, and as shown in FIG.
When the workpiece reaches the approach limit position where
A buttonhole is drilled at 119.

In order to drive and control the air cylinder 111, a shield plate 120 having a plurality of slits formed near the outer periphery is fixed to the tip end of the link member 113, and the shield plate 120 is attached to the sewing machine frame. A photo-interrupter 121 is attached with the slit of the photo-interrupter 121 therebetween, so that the rotation angle of the link member 113 can be detected.

[0006]

[Problems to be Solved by the Invention] The cloth cutting device 100
In the transmission mechanism 110 having the link members 113 and 114, since the movement amount of the hammer 102 per unit drive amount of the air cylinder 111 becomes substantially constant while the hammer 102 moves from the standby position to the approach limit position, When the hammer 102 hits the scalpel 101 strongly, the hammer 102
Problems such as an increase in the contact sound between the knife 102 and the knife 101, deterioration of the knife 102 due to breakage or chipping, and a decrease in the durability of the knife 102 occur.

Further, in order to prevent the scalpel 102 from deteriorating and to surely cut the work cloth, the hammer 102 substantially contacts the scalpel 101 when the piston rod 111a of the air cylinder 111 is fully extended. However, conventionally, the adjustment must be performed by finely adjusting the mounting position of the hammer 102 on the arm member 103. That is, there is a problem that fine adjustment of the approach limit position is extremely difficult and complicated.

SUMMARY OF THE INVENTION An object of the present invention is to improve the durability of a scalpel by preventing the scalpel from deteriorating, and to easily and surely finely adjust an approach limit position at which a hammer approaches a scalpel when piercing. The present invention provides a cloth cutting device.

[0009]

A cloth cutting device for a holing machine according to claim 1, comprising: a scalpel fixed to a sewing machine frame;
A hammer fixed to an arm member rotatably supported by a sewing machine frame, in a cloth cutting device of a boring machine for punching a buttonhole in a work cloth, an actuator for driving the hammer; A transmission mechanism for transmitting the driving force of the actuator to the arm member; and a cam mechanism interposed in the transmission mechanism for transmitting the driving force of the actuator to the arm member, the cam mechanism including a cam body and a cam follower. It is characterized by having.

In this cloth cutting apparatus, when the actuator is operated after forming (or before forming) the hole stitching on the work cloth, the cam mechanism including the transmission mechanism, the cam body interposed in the transmission mechanism, and the cam follower. Thereby, the driving force of the actuator is transmitted to the arm member, the arm member rotates, the work cloth is pressed by the knife by the hammer, and when the hammer reaches the approach limit position where the hammer approaches the knife, the hole of the work cloth of the work cloth is formed. A buttonhole is bored inside the overlock seam (or the seam formation planned portion).

Since the cam mechanism is provided in the transmission mechanism, the amount of movement of the hammer per unit drive amount of the actuator can be freely set depending on the shape of the cam body of the cam mechanism. For example, the amount of movement is large until the hammer approaches the approach limit position where the hammer approaches the knife at the time of perforation, and then decreases during a predetermined period in which the hammer is near the approach limit position and in the approach limit position. Can be set, thereby preventing the hammer from strongly hitting the scalpel, thereby reducing the contact sound between the hammer and the scalpel, and further preventing the scalpel from being damaged or chipped, thereby significantly increasing the durability. .

According to a second aspect of the present invention, in the cloth cutting apparatus of the first aspect, the cam mechanism moves the hammer per unit drive amount of the actuator so as to approach the knife when the hammer pierces. The hammer is large until it approaches the approaching limit position, and then becomes smaller between a position near the approaching limit position and a predetermined period of time in the approaching limit position. Therefore, it is possible to reliably prevent the hammer from strongly hitting the scalpel.

According to a third aspect of the present invention, in the cloth cutting device for a hole holing machine according to the second aspect of the present invention, the cam mechanism is arranged so that the hammer reaches the approach limit position when the drilling of the work cloth is completed by the hammer and the knife. It is characterized by having been constituted. Therefore, it is possible to reliably prevent the hammer from deteriorating, and to reliably punch the buttonhole in the work cloth.

According to a fourth aspect of the present invention, there is provided a cloth cutting device for a hoisting machine according to any one of the first to third aspects, wherein the transmission mechanism is pivotally mounted on a sewing machine frame and is rotated by the actuator. A rotating member that is driven and driven; and a follower holding member that is attached to the arm member and holds a cam follower at a lower end portion, wherein the cam body is fixed to the rotating member. Things.

When the rotating member is driven to rotate by the actuator, the cam body fixed to the rotating member also rotates integrally, and the cam body is held by the cam held at the lower end of the follower holding member. The follower follows, and the arm member on which the follower holding member is mounted rotates. That is, the transmission mechanism can be configured with a simple structure, and the driving force of the actuator can be reliably transmitted to the arm member by the transmission mechanism and the cam mechanism.

According to a fifth aspect of the present invention, there is provided a cloth cutting device for a hole holing machine according to any one of the second to fourth aspects, wherein the fine adjustment is provided on the transmission mechanism so as to finely adjust an approach limit position of the hammer. A mechanism is provided.

This fine adjustment mechanism can be configured to finely adjust the approach limit position of the hammer by adjusting the position of the cam body of the cam mechanism or the position of the cam follower. In other words, the fine adjustment mechanism fine-adjusts the approach limit position of the hammer to a position where the hammer almost contacts the knife when the actuator is at the maximum drive amount, thereby reliably preventing the hammer from deteriorating and providing a buttonhole on the work cloth. Can be reliably pierced.

According to a sixth aspect of the present invention, in the cloth cutting apparatus for a hole holing machine according to the fifth aspect, the fine adjustment mechanism is movably mounted on the arm member and finely adjusts a mounting position of the follower holding member with respect to the arm member. It has a movable member including a taper portion to be adjusted, and a screw member held by the arm member and capable of finely adjusting the position of the movable member.

By rotating the screw member to finely adjust the position of the movable member, the tapered portion of the movable member finely adjusts the mounting position of the follower holding member, that is, the position of the cam follower. Can easily and surely finely adjust the approach limit position. Furthermore, since the movement amount of the follower holding member can be made smaller than the movement amount of the movable member, the mounting position of the follower holding member can be finely adjusted with high precision by rotating the screw member. Become.

According to a seventh aspect of the present invention, a cloth cutting device for a hole holing machine comprises a scalpel fixed to a sewing machine frame and a hammer fixed to an arm member rotatably supported by the sewing machine frame. In a cloth cutting device of a hole-sewing machine for punching a buttonhole, an actuator for driving the hammer, a transmission mechanism for transmitting a driving force of the actuator to an arm member, and a transmission mechanism interposed in the transmission mechanism for drilling. A fine adjustment mechanism capable of finely adjusting the approach limit position of the hammer approaching the scalpel.

In the fine adjustment mechanism, the position of the cam body of the cam mechanism, the position of the cam follower, and the length of the members included in the transmission mechanism are changed to finely adjust the approach limit position of the hammer. It can be configured to adjust. In other words, the fine adjustment mechanism finely adjusts the approach limit position of the hammer so that the hammer almost contacts the knife when the actuator is at the maximum drive amount, thereby preventing deterioration of the knife and reliably cutting the work cloth. Becomes possible.

[0022]

Embodiments of the present invention will be described below with reference to the drawings. The present embodiment is provided with a buttonhole sewing machine, and after forming (or before forming) a buttonhole stitch on a work cloth, a buttonhole is punched inside a keyhole stitch (or a seam formation scheduled portion) of the work cloth. This is an example of a case where the present invention is applied to a cloth cutting device to be used.

As shown in FIGS. 1 to 7, a cloth cutting device 1 for a boring machine includes a scalpel 2 fixed to a sewing machine frame 1a via a scalpel base 2a and a pivotally rotatable support for the sewing machine frame. Arm member 3, hammer 4 fixed to arm member 3, air cylinder 5 for driving hammer 4, air cylinder 5
Transmission mechanism 6 for transmitting the driving force of
A cam mechanism 7 for transmitting the driving force of the air cylinder 5 to the arm member 3 and a scalpel 2
And a fine adjustment mechanism 8 that can finely adjust the approach limit position of the hammer 4 approaching the vehicle.

The arm member 3 has a pivot portion 10, an upwardly projecting arm portion 11 extending leftward from the pivot portion 10, and a lever portion 12 extending straight from the pivot portion 10 to the right.
Numeral 0 is pivotally supported by the sewing machine frame via a support shaft 13 oriented in the front-rear direction. A hammer 4 facing the knife 2 is detachably fixed to the lower left end of the arm 11. A buffer member 12a is fixed to the lower right end of the lever portion 12, and when the buffer member 12a abuts on the sewing machine frame 1b (see FIG. 1), the hammer 4 is located at a standby position which is maximally separated from the knife 2, The clockwise rotation of the arm member 3 from this state is restricted. In a state where the cam body 25 of the cam mechanism 7 and the cam follower 26 are not in contact with each other, the arm member 3 receives a clockwise turning force, so that the cushioning member 12a
Is maintained in contact with the sewing machine frame 1b.

The air cylinder 5 is, for example, a double-acting air cylinder. The air cylinder 5 is disposed downward on the right side of the arm member 3, and a bracket 15 at the upper end thereof is connected to a sewing machine frame via a support shaft 16 extending in the front-rear direction. Is rotatably supported.

The transmission mechanism 6 includes a cam mechanism 7, a rotation member 20 rotatably connected to the sewing machine frame and driven to rotate by the air cylinder 5, and a lower end mounted on the arm member 3. And a follower holding member 21 for holding the cam follower 26. A base end of the rotating member 20 is rotatably supported by the sewing machine frame via a support shaft 22 extending in the front-rear direction below the follower holding member 21, and a distal end of the rotating member 20 is connected to the air. It is rotatably connected to a connecting portion 5b at the tip of a piston rod 5a extending downward from the cylinder 5.

The cam mechanism 7 includes a cam body 25 and a cam follower 26 as shown in FIGS.
Is fixed to the counterclockwise end portion of the base end portion of the rotating member 20 on the support shaft 22 side with a bolt 29, and rises from the vicinity of the support shaft 22 and has a large gradient in the circumferential direction around the support shaft 22. It is formed in a mountain shape in a front view having one cam portion 25a and a second cam portion 25b connected to the first cam portion 25a and having a very small gradient. The cam follower 26 is connected to the follower holding member 2.
The first and second cam portions 25a and 25b of the cam body 25 are rotatably mounted on the cam member 25.

As shown in FIGS. 1 to 7, the fine adjustment mechanism 8 is mounted on the arm member 3 so as to be movable substantially in the left-right direction, and adjusts the mounting position of the follower holding member 21 with respect to the arm member 3 in the substantially vertical direction. A movable member 30 including a tapered portion 31 for fine adjustment;
And a screw member 50 held by the arm member 3 and capable of finely adjusting the left and right positions of the movable member 21. Lever part 1 of arm member 3
2, a guide groove 32 is formed in the left and right direction. A movable member 30 which is long in the left and right direction is slidably engaged in the guide groove 32 and supported by the guide.

On the other hand, the follower holding member 21 is
And a guide piece 4 extending upward from the rear end of the upper end of the main body 40
1 and the tapered portion 31 formed on the upper end surface of the main body 40.
The main body 40 and the guide piece 41
Are formed in the lever portion 12 of the arm member 3 and
Guide groove 45 and guide hole 4 that are vertically connected to
6 are respectively engaged and guided.

The lever portion 12 of the arm member 3, the movable member 30,
The front surface of the main body 40 of the driven holding member 21 is flush, and covers the movable member 30 and a part of the main body 40.
A rectangular plate member 47 made of metal is fixed to the front surface of the lever portion 12 with screws 47a. A tapered portion 43 is formed in the main body portion 40 so as to be deeper rearward toward the lower side. A leaf spring 48 formed by notching the plate member 47 is pressed against the tapered portion 43, and the follower holding member 21 is pressed by the leaf spring 48. Is urged substantially upward, so that the tapered portion 31 and the inclined portion 42 are always slidably in contact with each other.

The screw member 50 is inserted into the lever portion 12 from the left side near the pivot portion 10 of the arm member 3, and is inserted into the guide groove 32.
The screw portion formed at the tip of the arm member 3 is screwed to the movable member 30 in a state where the screw portion is supported by the arm member 3 so as to be immovable and rotatable in the left-right direction.
The head of the screw member 50 is prevented from rotating by a plate piece 51.

In order to drive and control the air cylinder 5,
An arcuate shield plate 55 having a plurality of slits formed in the vicinity of the outer periphery is fixed to the tip end side of the rotating member 20, and a photo interrupter 56 is attached to the sewing machine frame with the slit of the shield plate 55 interposed therebetween. As a result, the rotation member 20
That is, the rotation angle of the arm member 3 can be detected.

The operation and effect of the cloth cutting device 1 will be described. FIG. 1 shows a state in which the piston rod 5a of the air cylinder 5 is fully extended, the cam body 25 of the cam mechanism 7 does not engage with the cam follower 26, and the cushioning member 12a of the arm member 3 is The hammer 4 contacts the machine frame 1b.
Is located at a standby position which is separated from the scalpel 2 as much as possible, and in this state, it becomes possible to sew a hole sewing seam (other various seams) on the work cloth W by the hole sewing machine.

After forming (or before forming) the buttonhole stitches on the work cloth W, when the air cylinder 5 is operated and the piston rod 5a is driven to retreat with the work cloth positioned at a predetermined position, the air cylinder 5, the cam body 25 rotates counterclockwise together with the rotating member 20, and the cam follower 26 first moves the cam body 25 as shown in FIG. Engage with one cam portion 25a.

Subsequently, the cam 25 together with the rotating member 20
Is rotated counterclockwise, the cam follower 26 rolls the first cam portion 25a toward the second cam portion 25b, and the driving force of the air cylinder 5 is transmitted to the arm by the transmission mechanism 6 and the cam mechanism 7. The arm member 3 is rotated counterclockwise by being transmitted to the member 3, and the hammer 4 moves toward the knife 2.

Thereafter, when the cam follower 26 engages with the second cam portion 25b of the cam body 25, the hammer 4 is located at a position near the approach limit position where the knife 2 approaches the knife 2 (a position near the approach limit position). In the vicinity of the position, the work cloth W is pressed against the knife 2 by the hammer 4, and thereafter, as shown in FIG. 3, when the piston rod 5a of the air cylinder 5 is fully retracted, the hammer 4 reaches the approach limit position, and the work is performed. Cloth W
A buttonhole is bored inside the overhole stitch (or the stitch formation scheduled portion).

The movement amount of the hammer 4 per unit drive amount of the air cylinder 5 is large until the hammer 4 approaches the approach limit position where the hammer 4 approaches the knife 2 at the time of drilling. And the hammer 4 reaches the approach limit position when the work cloth W is completely pierced by the hammer 4 and the scalpel 2 during the predetermined period of time at the approach limit position. The hammer 4 can be prevented from strongly hitting the knife 2, and as a result, the contact sound between the hammer 4 and the knife 2 can be reduced, and the durability of the knife 2 can be significantly reduced by preventing the knife 2 from being damaged or chipped. The buttonhole can be reliably formed in the work cloth W.

The transmission mechanism 6 is rotatably connected to the sewing machine frame and is rotatably driven by the air cylinder 5. The rotation member 20 is mounted on the arm member 3 and has a cam follower 26 at its lower end.
And the follower holding member 21 for holding the cam member 25, and the cam body 25 is fixed to the rotating member 20, so that the transmission mechanism 6 can be configured with a simple structure. Can be reliably transmitted to the arm member 3.

In the fine adjustment mechanism 8 for finely adjusting the approach limit position of the hammer 4, the screw member 50 is rotated by a driver or the like to finely adjust the left and right positions of the movable member 30 so that the movable member 30 can be adjusted. The tapered portion 31 allows the follower holding member 21 to move in the up-down direction and finely adjust its vertical mounting position, that is, the vertical position of the cam follower 26, and finely adjust the approach limit position of the hammer 4.

FIG. 6 shows that the movable member 30 is located at the right limit position, the inclined portion 42 of the follower holding member 21 is engaged with the left end of the tapered portion 31 of the movable member 30, and the lever portion 1 of the arm member 3 is engaged.
7 is L1 (for example, L1 = 30 mm) from the lower right surface of the cam follower 26 to the rotation axis of the cam follower 26. FIG. The inclined portion 42 is engaged, and the distance from the lower right surface of the lever portion 12 to the rotation axis of the cam follower 26 is L2 (for example, L2 = 3).
During this time, the screw member 50 can be rotated to finely adjust the vertical mounting position of the follower holding member 21, that is, the vertical position of the cam follower 26.

That is, by providing the above-mentioned fine adjustment mechanism 8, the approach limit position of the hammer 4 can be easily and reliably finely adjusted so that the hammer 4 becomes the access limit position when the piston rod 5a of the air cylinder 5 is fully extended. Can be
Thereby, the work cloth W can be reliably cut without deteriorating the knife 2. Moreover, since the vertical movement amount of the follower holding member 21 is smaller than the horizontal movement amount of the movable member 30, the screw member 50 is rotated to finely adjust the vertical mounting position of the follower holding member 21 with high accuracy. It becomes possible to do.

Next, a modification of the above embodiment will be described. 1) Instead of the air cylinder 5, an electric motor such as a stepping motor may be used to rotate the rotating member 20. 2] The follower holding member 21 is fixedly attached to the arm member 3,
The approach limit position of the hammer 4 may be finely adjusted by mounting the cam body 25 variably in the length direction of the rotating member 20 and finely adjusting the position of the cam body 25. 3] Follower holding member 21 following tapered portion 31 of movable member 30
A biasing member other than the leaf spring 48, for example, a coil spring or the like, may be applied in order to always engage the inclined portion 42 of.

The cloth cutting apparatus according to the present invention is not limited to the cloth cutting apparatuses according to the above-described embodiments and modifications, and various modifications may be added without departing from the spirit of the present invention. Of course, it can be applied.

[0044]

According to the cloth cutting device of the hoist sewing machine according to the first aspect of the present invention, there is provided a cam mechanism for transmitting a driving force of an actuator to an arm member interposed in a transmission mechanism. Since the cam mechanism includes the cam mechanism, the moving amount of the hammer per unit driving amount of the actuator can be freely set depending on the shape of the cam body of the cam mechanism. For example, the moving amount is large until the hammer approaches the approach limit position where the hammer approaches the scalpel at the time of perforation, and then decreases during a predetermined period in which the hammer is near the approach limit position and in the approach limit position. Can be set, thereby preventing the hammer from strongly hitting the scalpel, thereby reducing the contact sound between the hammer and the scalpel, and further preventing the scalpel from being damaged or chipped, thereby significantly increasing the durability. .

According to the cloth cutting device of the second aspect, the same effect as that of the first aspect is obtained, but the cam mechanism is provided with a moving amount of the hammer per unit driving amount of the actuator. When the hammer approaches the scalpel, it is large until it approaches the scalpel limit, and then the hammer becomes smaller between the proximity limit position and the squeeze limit position for a predetermined period of time, thus preventing the hammer from strongly hitting the scalpel. it can.

According to the third aspect of the present invention, the same effect as that of the second aspect is obtained, but when the hammer and the scalpel complete the piercing of the work cloth by the hammer, the hammer has an approach limit. Since it is configured to reach the position, the deterioration of the hammer is reliably prevented, and the buttonhole can be reliably drilled in the work cloth.

According to the fourth aspect of the present invention, the cloth cutting apparatus for a hole holing machine has the same effect as any one of the first to third aspects, except that the transmission mechanism is pivotally attached to the sewing machine frame. And a follower holding member attached to the arm member and holding a cam follower at a lower end portion, and the cam body is fixed to the rotating member. The transmission mechanism can be configured with a simple structure, and the driving force of the actuator can be reliably transmitted to the arm member by the transmission mechanism and the cam mechanism.

According to the fifth aspect of the present invention, the same effect as any one of the second to fourth aspects is obtained, but the approach limit position of the hammer is finely adjusted by interposing the transmission mechanism. A possible fine adjustment mechanism is provided, and this fine adjustment mechanism allows fine adjustment of the approach limit position of the hammer to a position where the hammer almost contacts the knife at the maximum drive amount of the actuator, thereby ensuring deterioration of the hammer. In this way, the buttonhole can be reliably formed in the work cloth.

According to the cloth cutting device for a hole hoist sewing machine of the sixth aspect, the same effect as that of the fifth aspect is obtained, but the fine adjustment mechanism is movably mounted on the arm member and the follower holding member for the arm member. A movable member including a tapered portion for finely adjusting the mounting position of the hammer, and a screw member held by the arm member and capable of finely adjusting the position of the movable member. The approach limit position can be finely adjusted easily and reliably. Furthermore, since the movement amount of the follower holding member can be made smaller than the movement amount of the movable member, it is possible to finely adjust the mounting position of the follower holding member accurately by rotating the screw member. .

According to a seventh aspect of the present invention, there is provided a cloth cutting device for a hoist sewing machine, wherein an actuator for driving a hammer, a transmission mechanism for transmitting a driving force of the actuator to an arm member,
A fine adjustment mechanism is provided between the transmission mechanism and the fine adjustment mechanism that can finely adjust the approach limit position of the hammer that approaches the knife when drilling. Sometimes fine adjustment is made so that the hammer substantially contacts the scalpel, thereby preventing the scalpel from deteriorating and reliably cutting the work cloth.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a cloth cutting device according to an embodiment of the present invention (at the time of standby).
FIG.

FIG. 2 is a side view of the cloth cutting device (during operation).

FIG. 3 is a side view of the cloth cutting device (at the time of cutting).

FIG. 4 is an enlarged view of a main part of the cloth cutting device.

FIG. 5 is a sectional view taken along line VV of FIG. 4;

FIG. 6 is a longitudinal sectional view of a main part of the cloth cutting device (when the follower holding member is at maximum retreat).

FIG. 7 is a longitudinal sectional view of a main part of the cloth cutting device (when the follower holding member is maximally extended).

FIG. 8 is a side view of a cloth cutting device according to the related art (during standby).

FIG. 9 is a side view of a cloth cutting device (at the time of cutting) according to the related art.

[Explanation of symbols]

 Reference Signs List 1 cloth cutting device 1a sewing machine frame 2 knife 3 arm member 4 hammer 5 air cylinder 6 transmission mechanism 7 cam mechanism 8 fine adjustment mechanism 20 rotating member 21 follower holding member 25 cam body 26 cam follower 30 movable member 31 taper portion 50 Screw member

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Jun Kamano 15-1 Naeshiro-cho, Mizuho-ku, Nagoya F-term (reference) in Brother Industries, Ltd. 3B150 AA24 CE04 CE22 CE26 CE27 CE28 EE03 EE07 EE11 JA13 JA18

Claims (7)

[Claims] 1. A boring machine for boring a buttonhole in a work cloth with a scalpel fixed to a sewing machine frame and a hammer fixed to an arm member rotatably supported by the sewing machine frame. In the cutting device, an actuator for driving the hammer, a transmission mechanism for transmitting a driving force of the actuator to an arm member, and a cam mechanism interposed in the transmission mechanism and transmitting the driving force of the actuator to the arm member. And a cam mechanism including a cam body and a cam follower. 2. The cam mechanism according to claim 1, wherein the movement amount of the hammer per unit drive amount of the actuator is large until the hammer approaches the approach limit position where the hammer approaches the knife at the time of piercing, and thereafter, the hammer approaches the approach limit position. The machine according to claim 1, characterized in that it is configured to be small during a predetermined period of time between the position and the approach limit position. 3. The machine according to claim 2, wherein the cam mechanism is configured such that the hammer reaches the approach limit position when the work cloth is completely pierced by the hammer and the knife. Cloth cutting device. 4. A rotating member rotatably pivotally mounted on the sewing machine frame and rotatably driven by the actuator, and a cam follower mounted on the arm member at a lower end thereof. The cloth cutting device for a hole holing machine according to any one of claims 1 to 3, further comprising a follower holding member, wherein the cam body is fixed to a rotating member. 5. A sewing machine according to claim 2, further comprising a fine adjustment mechanism interposed between said transmission mechanism and capable of finely adjusting an approach limit position of said hammer. Cutting device. 6. A movable member movably mounted on the arm member and including a tapered portion for finely adjusting a mounting position of the follower holding member with respect to the arm member, and a movable member held by the arm member. The cloth holding device for a holing machine according to claim 5, further comprising a screw member capable of finely adjusting a position of the member. 7. A boring machine for boring a buttonhole in a work cloth with a scalpel fixed to a sewing machine frame and a hammer fixed to an arm member rotatably supported by the sewing machine frame. In the cutting device, an actuator for driving the hammer, a transmission mechanism for transmitting the driving force of the actuator to the arm member, and an approach limit position of the hammer that is interposed in the transmission mechanism and approaches the knife when drilling. A cloth cutting device for a holing machine, comprising: a fine adjustment mechanism capable of fine adjustment.