CN1955357A - Thread clamping device for sewing machine - Google Patents

Abstract

The present invention provides a thread clip apparatus(1)for sewing machine, which comprises a tension release mechanism(3)capable of releasing the tension applied to sewing thread independent of the action of the thread-severing device(presser foot raising device), wherein the tension release mechanism(3)comprises a release member(31)entering between a pair of clamps(2, 2)clamping and holding sewing thread to release the holding of the sewing thread, a driving member(32)interlocked with the thread-severing device(presser foot raising device)(5)to move the release member(31), an ejection member for ejecting the release member(31). The release member(31)comprises an joint part(31d)against jointed with the driving member(32), a moving guide part(31e)for guiding the release member(31)to the position where the holding of the sewing thread is released during moving the release member(31). Thus, the tension release mechanism can be driven independently even when the thread-severing device(presser foot raising device)is connected with the tension release mechanism.

Description

Thread clamping device for sewing machine

technical field

The invention relates to a thread clamping device of a sewing machine.

Background technique

On the sewing machine, there is a thread clamping device that uses a spring to push two clamping plates toward each other, and clamps the yarn between these clamping plates to apply tension to the yarn. The thread clamping device is equipped with a tension release mechanism that overcomes the pushing force of the spring to separate the two clamping plates, and can release the tension given to the yarn as required.

The tension release mechanism is connected to, for example, an operation lever that presses the presser foot of the object to be sewn placed on the needle plate. The tension release mechanism releases the tension applied to the yarn in conjunction with the operation of the operating lever. Specifically, the tension release mechanism operates when the presser foot needs to be raised to release the tension of the yarn (for example, refer to Patent Document 1).

In addition, in a sewing machine provided with a thread cutting device, a tension releasing mechanism is connected to the thread cutting device, and the tension releasing mechanism releases the tension applied to the yarn in conjunction with the operation of the thread cutting device.

As shown in FIG. 6 , the thread clamping device 100 is arranged on the surface of the sewing machine frame 120 . The thread clamping device 100 is arranged in such a way that two thread clamping plates 101 face each other (inward and outward directions relative to the paper in FIG. 6 ), and a tension releasing plate 102 constituting a tension releasing mechanism is provided between the thread clamping plates 101 . The tension release plate 102 has a structure capable of sliding downward (arrow S direction) of the thread clamping device 100 . A claw portion 103 is formed on the tension release plate 102 at a position adjacent to the tension plate 101 . The claw portion 103 enters between the two tension plates 101 when the tension release plate 102 is moved downward to release the tension of the yarn.

By operating an operation lever (a thread cutting device in a sewing machine equipped with a thread cutting device) for lifting and lowering the presser foot (not shown), the driving projection 104 is applied to a direction in which a driving force is applied to move the tension release plate 102 downward, that is, FIG. 6 . When viewing the thread clamping device from the surface of the sewing machine frame 120 in the counterclockwise direction (arrow A direction), the tension release plate 102 engaged with the driving protrusion 104 slides downward due to the rotation of the driving protrusion 104 .

In this way, by interlocking the operation lever (thread cutting device) of the presser foot with the tension release plate 102, two operations can be performed simultaneously with one operation, so it is a convenient mechanism.

However, when a knot or knot of the yarn enters between the clamping plates 101 during sewing, it is necessary to enlarge the clamping plate only when the knot or knot or the like passes between the clamping plates 101 while continuing sewing. 101 intervals. This is to prevent tension from being higher than necessary due to knots, knots, etc. being caught between the tension plates 101 .

However, in order to expand the space between the clamping plates 101, it is necessary to operate the operating lever of the presser foot, so whether or not the sewing object cannot be pressed during sewing, and skipped stitches occur, which reduces the sewing quality or causes re-sewing. . In addition, in the case of interlocking with the thread cutting device, since the yarn has already been cut, sewing cannot be continued.

In addition, even if the tension release plate 102 is directly operated, the operation lever (thread cutting device) will be operated in conjunction with this operation, and the problem cannot be solved.

Therefore, there has been proposed a thread clamp device in which the linkage between the operation lever of the presser foot and the tension release plate 102 is eliminated (for example, refer to Patent Document 2).

[Patent Document 1] JP-A-2003-10580

[Patent Document 2] Publication of Publication No. 61-160878

However, in the invention described in Patent Document 2, although the above-mentioned problem can be solved by abolishing the interlocking operation of the operation lever of the presser foot and the tension release plate 102, a separate drive mechanism is required to drive them separately, and when the presser foot is lifted, a separate drive mechanism is required. It is necessary to control the release of the yarn tension during the operation or the thread trimming operation, so it inevitably leads to an increase in costs such as an increase in parts and an increase in the production process.

Contents of the invention

The present invention was made to solve the above problems, and an object of the present invention is to provide a thread clamping device for a sewing machine that can independently drive the tension release mechanism even when the operation lever of the presser foot is connected to the tension release mechanism.

Another object of the present invention is to provide a thread clamping device for a sewing machine capable of independently driving the tension release mechanism even when the thread cutting device and the tension release mechanism are connected.

In order to solve the above problems, the first technical solution is a thread clamping device of a sewing machine, which applies tension to the sewing thread, and releases the tension applied to the sewing thread in conjunction with the action of the thread cutting device 5 that cuts off the sewing thread. It is characterized by having a tension release mechanism 3 that releases the tension applied to the sewing thread independently of the operation of the thread cutting device.

According to the first technical solution, since the tension release mechanism releases the tension applied to the sewing thread independently of the action of the thread cutting device, even if the tension release mechanism is a structure that releases the tension applied to the sewing thread in conjunction with the action of cutting the sewing thread, it can independently actuate the tension release mechanism. Therefore, it is not necessary to provide separate driving mechanisms for driving the thread cutting device and the tension releasing mechanism, respectively. In addition, since it is not necessary to control the tension of the releasing yarn during the thread cutting operation, cost increases such as an increase in parts and an increase in production steps can be prevented.

According to the thread clamping device of the sewing machine according to the technical solution 1, the technical solution 2 is characterized in that the tension release mechanism has: a release member 31 which, by moving in a predetermined direction, enters into a pair of clamps holding the sewing thread. between the clamping plates to release the holding of the sewing thread; the driving member 32, which is linked with the action of the thread cutting device to move the releasing member to the prescribed direction; The release member is pushed in a direction opposite to the prescribed direction, and the release member has: an abutting portion 31d that abuts against the driving member; and a movement guide portion 31e that moves the release member toward the prescribed direction. When moving in the direction, guide the movement of the release member to the position where the holding of the sewing thread is released.

According to the second technical solution, since the release member has an abutment portion, when the drive member is driven by the thread cutting device, the drive member transmits the drive through the abutment portion, thereby being able to move the release member in a predetermined direction. In addition, since the release member has the movement guide portion, when the release member is moved in a predetermined direction, the movement of the release member to the position where the holding of the sewing thread is released is guided. That is, since the drive member does not come into contact with the release member even if the release member is moved in a predetermined direction, the movement of the release member is not hindered.

Therefore, even in the state where the thread cutting device and the tension release mechanism are connected, the release member can be driven independently, so that the thread tension plate can be released and the holding of the sewing thread can be released independently of the operation of the thread cutting device.

Technical Solution 3 A thread clamping device for a sewing machine, which applies tension to the sewing thread, and releases the tension applied to the sewing thread in conjunction with the action of the presser foot lifting device 6 for raising the presser foot, and is characterized in that , has a tension release mechanism 3, which releases the tension given to the sewing thread independently of the action of the presser foot lifting device.

According to the third technical solution, since the tension release mechanism releases the tension applied to the sewing thread independently of the action of the presser foot lifting device, even if the tension release mechanism is a structure that releases the tension applied to the sewing thread in conjunction with the presser foot lifting action, The tension release mechanism can also be driven independently. Accordingly, it is not necessary to provide separate drive mechanisms for driving the presser foot lifter and the tension release mechanism. In addition, since it is not necessary to control the tension of the release yarn during the lifting operation of the presser foot, it is possible to prevent an increase in costs such as an increase in components and an increase in production steps.

According to the thread clamping device of the sewing machine according to the third technical solution, the fourth technical solution is characterized in that the tension release mechanism has: a release member 31 which, by moving in a prescribed direction, enters into a pair of clamps and holds the sewing thread. between the clamping plates to release the holding of the sewing thread; the driving member 32, which is linked with the action of the presser foot lifting device to move the releasing member to the prescribed direction; and the pushing member 33, It pushes the release member in a direction opposite to the prescribed direction, and the release member has: an abutment portion abutting against the drive member; and a movement guide portion 31e that moves the release member toward the When moving in the predetermined direction, the release member is guided to move to a position where the holding of the sewing thread is released.

According to the fourth aspect, since the release member has the abutment portion, when the drive member is driven by the presser foot lifter, the drive member transmits the drive through the abutment portion, whereby the release member can be moved in a predetermined direction. In addition, since the release member has the movement guide portion, when the release member is moved in a predetermined direction, the movement of the release member to the position where the holding of the sewing thread is released is guided. That is, since the drive member does not come into contact with the release member even if the release member is moved in a predetermined direction, the movement of the release member is not hindered.

Therefore, even in the state where the presser foot lifter and the tension release mechanism are connected, the release member can be driven independently, thereby releasing the thread tension plate and releasing the holding of the sewing thread independently of the operation of the presser foot lifter.

According to the first technical solution, it is not necessary to provide separate driving mechanisms for driving the thread cutting device and the tension releasing mechanism respectively. In addition, since it is not necessary to control the tension of the releasing yarn even during the thread cutting operation, it is possible to prevent cost increases such as an increase in components and an increase in production steps.

According to the second technical solution, even in the state where the thread cutting device and the tension release mechanism are connected, the release member can be driven independently, so that the thread tension plate can be released and the holding of the sewing thread can be released independently of the action of the thread cutting device.

According to the third technical solution, it is not necessary to separately set up separate driving mechanisms for driving the presser foot lifting device and the tension releasing mechanism. In addition, since it is not necessary to control the tension of the release yarn during the lifting operation of the presser foot, it is possible to prevent cost increases such as an increase in parts and an increase in production steps.

According to the fourth technical solution, even in the state where the presser foot lifting device and the tension release mechanism are connected, the release member can be driven independently, so that the tension plate can be released and the sewing thread can be released independently of the action of the presser foot lifting device keep.

According to the fifth technical solution, the actions of the release member and the driving member can be stabilized.

Description of drawings

Fig. 1 is a front view of a thread clamping device of a sewing machine.

Fig. 2 is an enlarged perspective view of the tension release mechanism.

Fig. 3 is a perspective view of the thread clamping device of the sewing machine.

Fig. 4 is a partial front view of the thread cutting device.

Fig. 5 is a partial front view of the presser foot lifting device.

Fig. 6 is a front view of a thread clamping device of a conventional sewing machine.

In the figure: 1-thread clamping device, 2-thread clamping plate, 3-tension release mechanism, 5-thread trimming device, 6-presser foot lifting device, 31-release member, 31c-long hole, 31d-contact part, 31e-moving guide part, 32-driving member, 33-ejecting member.

Detailed ways

Hereinafter, specific embodiments of the thread clamping device of the sewing machine will be described in detail with reference to the drawings.

<Structure of thread clamping device>

As shown in FIG. 1 , on the surface of the sewing machine frame M, the following thread clamping device 1 is provided: the tension is applied to the sewing thread inserted through the needle hole of the machine needle, and the operation of the thread cutting device (described later) that cuts the sewing thread is provided. Linked to release the tension applied to the sewing thread.

The thread clamping device 1 has: a pair of thread clamping plates 2 and 2 for sandwiching and holding the sewing thread; a tension release mechanism 3 which can be operated in conjunction with the action of the thread cutting device and can be operated independently of the action of the thread cutting device , Release the holding of the sewing thread by the pair of clamping plates 2 and 2 to release the tension given to the sewing thread.

(plywood)

As shown in FIG. 2 and FIG. 3 , among a pair of clamping plates 2 , 2 , one clamping plate 2 is pushed toward the other clamping plate 2 by a spring or the like. And, the sewing thread is sandwiched and held by the thread tension plates 2, 2, thereby being given tension. The adjustment of the tension applied to the sewing thread by the tension plates 2 and 2 is performed by turning the knob 21 .

A pair of thread clamping plates 2, 2 is provided for each sewing thread, so that the tension applied to each sewing thread can be individually adjusted.

(tension release mechanism)

As shown in FIGS. 2 and 3 , the tension release mechanism 3 has: a release member 31 that enters between the pair of thread tension plates 2 and 2 to release the holding of the sewing thread by moving in a predetermined direction, and a driving action of the thread cutting device. The driving member 32 that moves the release member 31 in a predetermined direction and the push member 33 that pushes the release member 31 in a direction opposite to the predetermined direction are interlocked.

Here, the predetermined direction refers to a direction along the direction in which a plurality of pairs of tension plates 2, 2 are arranged (direction B in FIG.

The release member 31 is formed of a single plate extending in the B direction, and is provided on the lower side of the pair of clamping plates 2 , 2 . A pawl portion 31a is formed on the release member 31, and protrudes so as to be able to enter between the pair of clamping plates 2, 2 when moving in the B direction. The tip of the claw portion 31a is formed to extend in the moving direction (B direction) of the release member 31, and faces the pair of tension plates 2, 2 when the release member 31 is at the initial position. One claw portion 31a is formed for each pair of clamping plates 2, 2. When the release member 31 is moved, the front end of each claw portion 31a is squeezed into the corresponding pair of clamping plates 2, 2 respectively, A gap is formed between the wire plates 2 and 2 .

In the vicinity of the center in the longitudinal direction of the release member 31, a protrusion 31b whose side edge protrudes outward is formed. On this protruding portion 31b, a long hole 31c extending in the longitudinal direction of the release member 31 is formed.

A drive member 32 connected to the thread cutting device is fitted into the elongated hole 31c. The driving member 32 can be driven by the thread cutting device, along the arrangement direction of a pair of clamping plates 2, 2 among Fig. Counterclockwise direction of rack M) rotation. In this elongated hole 31c, a contact portion 31d that contacts the driving member 32 is formed, and a movement guide that guides the movement of the release member 31 to the position where the sewing thread is released when the release member 31 is moved in the B direction. Section 31e. That is, the movement guide portion 31e is a space formed on the opposite side of the contact portion 31d of the elongated hole 31c, and does not restrict the movement when the release member 31 is moved in the B direction alone. In addition, since the contact portion 31d of the drive member 32 and the long hole 31c contacts at a position eccentric from the rotation center of the drive member 32, the contact portion 31d of the release member 31 is pushed toward the B direction by the rotation of the drive member 32. , so that the release member 31 moves.

As shown in FIG. 4 , the driving member 32 sandwiches the sewing machine frame M and is connected to the thread cutting device 5 provided inside the sewing machine frame M. As shown in FIG. The thread cutting device 5 is provided with a drive cylinder 50 and a piston 51 that moves in and out of the drive cylinder 50 . A connecting rod 52 is connected to the front end of the piston 51 , and a connecting rod 53 is connected to the connecting rod 52 . A link 55 is connected to the link 53 via a stepped screw 54 , and the drive member 32 is connected to the link 55 . As a result, the driving member 32 rotates in the C direction as the piston 51 moves in the outward direction (D direction in FIG. 4 ) from the inside of the drive cylinder 50 .

As shown in FIG. 3 , the release member 31 is connected to a fixing plate 34 fixed to the sewing machine frame M via a pushing member 33 . A spring, rubber, or the like is used as the pushing member 33, and pushes the releasing member 31 in a direction opposite to the B direction. Therefore, even if the release member 31 is moved in the B direction, the force applied to the release member 31 for the movement can be released to return to the original position. In addition, in the initial position before the release member 31 moves, the driving member 32 and the contact portion 31d are brought into contact by the pushing force thereof.

<Operation of thread clamping device>

Next, the operation of the thread clamping device 1 will be described.

(When operating in conjunction with the thread trimmer)

When thread cutting is performed after sewing is finished, the thread cutting device 5 is driven to move the piston 51 in the D direction. When the piston 51 moves in the D direction, the link 52 also moves in the D direction, and the link 53 also moves in the D direction. As the link 53 moves in the D direction, the connection portion between the link 55 and the stepped screw 54 moves in the D direction, and the driving member 32 connected to the link 55 rotates in the C direction by this movement.

When the drive member 32 turns in the C direction, the drive member 32 presses the contact portion 31d of the release member 31 in the B direction in FIG. 2 . When the release member 31 moves in the B direction, the claw portion 31a enters between the pair of wire clamps 2, 2, and the distance between the wire clamps 2, 2 is widened.

As a result, the holding of the sewing thread by the pair of thread clamping plates 2, 2 is released, thereby releasing the tension applied to the sewing thread.

(When operating independently of the thread trimmer)

When the sewing thread produced knots or knots during sewing, this part was hung between the clamping plates 2, 2 to exert a large tension on the sewing thread. At this time, it is necessary not to drive the thread cutting device 5 to expand the gap between the thread clamping plates 2 and 2 .

In this case, the operator manually moves the release member 31 in the B direction. Here, since the long hole 31c is formed in the release member 31, and the drive member 32 is fitted into this long hole 31c, the release member 31 is guided by the movement guide part 31e, and moves to B direction. That is, since the movement guide portion 31e is formed, the movement of the release member 31 is not hindered by the driving member 32 in any way.

Therefore, even during sewing, the operator can move the release member 31 independently of the driving of the thread cutting device 5 .

<Effect>

According to the thread tension device 1 of the sewing machine of the embodiment, since the tension releasing mechanism 3 releases the tension applied to the sewing thread independently of the operation of the thread cutting device 5, even if the tension releasing mechanism 3 releases the tension applied to the sewing thread in conjunction with the operation of cutting the sewing thread, The tension can also drive the tension release mechanism 3 independently. Therefore, it is not necessary to provide separate driving mechanisms for driving the thread cutting device 5 and the tension release mechanism 3 . In addition, since it is not necessary to perform control to release the tension of the sewing thread during the thread cutting operation, it is possible to prevent cost increases such as an increase in parts and an increase in production steps.

In addition, since the release member 31 is formed with the abutment portion 31d, when the drive member 32 is driven by the thread cutting device 5, the drive member 32 transmits the drive through the abutment portion 31d, so that the release member 31 can be moved in the B direction. . In addition, since the movement guide part 31e is formed in the release member 31, when the release member 31 is moved in the B direction, the movement of the release member 31 to the position where the holding of the sewing thread is released is guided. That is, since the drive member 32 does not come into contact with the release member 31 even if the release member 31 is moved in the B direction, the movement of the release member 31 is not hindered.

Therefore, even in the state where the thread cutting device 5 and the tension release mechanism 3 are connected, the release member 31 can be driven independently, so that the thread tension plates 2 and 2 can be released independently of the operation of the thread cutting device 5 and the holding of the sewing thread can be released. .

Moreover, by using the long hole 31c as the movement guide part 31e, the drive member 32 is surrounded by the long hole 31c, and does not come off from the release member 31. As shown in FIG.

Therefore, the movement of the release member 31 and the drive member 32 can be stabilized.

<other>

In addition, the scope of the present invention is not limited to the above-mentioned embodiments. For example, as shown in FIG. 5, it can also be applied to a sewing machine without a thread cutting device, in which the release member 31 is linked with the operation of the presser foot lifter 6 that lifts the presser foot that presses the sewing object on the needle plate. , thereby releasing the holding structure of the thread clamping plates 2, 2 to the sewing thread.

Specifically, as shown in FIG. 5, one end of the presser foot lifting lever 61 constituting the presser foot lifting device 6 is rotatably mounted on the sewing machine frame M, and the other end can be operated by the operator to move up and down.

An elongated hole 61 a is formed in the presser foot lifting lever 61 , and one end portion of a link 63 is connected by a stepped screw 62 engaged with the elongated hole 61 a. The drive member 32 is coupled to the other end of the link 63 .

Then, by pushing the presser foot lifting lever 61 downward (direction E in FIG. 5 ), the connecting rod 63 is driven by the stepped screw 62 engaged with the presser foot lifting lever 61. With the driving of the connecting rod 63, the driving member 32 is rotated in the C direction, so that the release member 31 is moved in the B direction.

Even with such a configuration, the release member 31 can be moved independently of the operation of the presser foot lifting lever 61 .

According to such a structure, since the tension release mechanism 3 releases the tension applied to the sewing thread independently of the operation of the presser foot lifting lever 61, even if the tension release mechanism 3 releases the tension applied to the sewing thread in conjunction with the presser foot lifting action, structure, it is also possible to drive the tension release mechanism 3 independently. Accordingly, it is not necessary to provide separate drive mechanisms for driving the presser foot lift lever 61 and the tension release mechanism 3 , respectively. In addition, since it is not necessary to perform control to release the tension of the sewing thread even when the presser foot is raised, cost increases such as an increase in parts and an increase in production steps can be prevented.

In addition, since the release member 31 has the abutment portion 31d, when the drive member 32 is driven by the presser foot lifting lever 61, the drive member 32 transmits the drive through the abutment portion 31d, so that the release member 31 can be moved in the B direction. . In addition, since the release member 31 has the movement guide portion 31e, when the release member 31 is moved in the B direction, the movement of the release member 31 to the position where the holding of the sewing thread is released is guided. That is, even if the release member 31 is moved in the B direction, the drive member 32 does not come into contact with the release member 31 , so the movement of the release member 31 is not hindered.

Therefore, even in the state where the presser foot lift lever 61 and the tension release mechanism 3 are connected, the release member 31 can be driven independently, thereby enabling the pair of tension plates 2 to be released without depending on the operation of the presser foot lift lever 61. , 2 and release the hold of the sewing thread.

In addition, instead of the elongated hole 31 c formed in the release member 31 , a protrusion abutting against the drive member 32 may be formed only on the downstream side of the drive member 32 in the moving direction of the release member 31 . What is important is that the release member 31 only needs to have a structure that contacts the release member 31 on the rotation path of the drive member 32 .

In addition, the release member 31 is not limited to the structure manually operated by the operator, and the release member 31 may be moved by driving an actuator that moves the release member 31 in the B direction.

Others can be freely replaced and changed within the scope of the invention.

Claims (4)

1. A thread clamping device for a sewing machine, which applies tension to a sewing thread and releases the tension applied to the sewing thread in conjunction with the action of a thread cutting device that cuts the sewing thread, wherein There is a tension release mechanism that releases the tension applied to the sewing thread independently of the action of the thread cutting device. 2. The thread clamping device of the sewing machine according to claim 1, characterized in that, The tension release mechanism has: a release member that releases the holding of the sewing thread by moving in a prescribed direction and entering between a pair of clamping plates sandwiching and holding the sewing thread; a driving member that moves the release member in the prescribed direction in conjunction with the action of the thread cutting device; and an urging member that urges the release member in a direction opposite to the prescribed direction, The release member has: an abutting portion that abuts against the driving member; and a movement guide portion that guides the release member to a point where the sewing thread is released when the release member is moved in the predetermined direction. The movement of the held position. 3. A thread clamping device for a sewing machine that applies tension to a sewing thread and releases the tension applied to the sewing thread in conjunction with the operation of a presser foot lifting device for raising the presser foot, wherein: There is a tension release mechanism that releases the tension applied to the sewing thread independently of the operation of the presser foot lifter. 4. The thread clamping device of the sewing machine according to claim 3, characterized in that, The tension release mechanism has: a release member that releases the holding of the sewing thread by moving in a prescribed direction and entering between a pair of clamping plates sandwiching and holding the sewing thread; a driving member for moving the release member in the predetermined direction in conjunction with the operation of the presser foot lifter; and an urging member that urges the release member in a direction opposite to the prescribed direction, The release member has: an abutting portion that abuts against the driving member; and a movement guide portion that guides the release member to a point where the sewing thread is released when the release member is moved in the predetermined direction. The movement of the held position.

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