JPH0647427Y2 - Clamping mechanism of sewing machine and thread cutting device using the mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial Field of the Invention The present invention relates to a fixing member that is fixedly supported by a sewing machine, and a fixing member that is attached to the fixing member and moves in and out of the fixing member by the operation of an operating device to capture a thread at the tip. The present invention relates to a clamp mechanism for a sewing machine, which includes a movable member having a hook for pressing the movable member against a fixed member, and a thread cutting device using the clamp mechanism.

2. Description of the Related Art A thread trimming device is a typical example of a device including the above-mentioned clamp mechanism. This thread trimming device has a movable blade that has a hook knife portion at its tip to reciprocate, a fixed blade that is arranged on a path along which the hook knife portion reciprocates, and a clamp spring that presses the movable blade against the fixed blade. , The movable knife is reciprocated to move the hook knife part in and out of the fixed knife, which allows the hook knife part to catch the thread continuing to the seam and pull it to the fixed knife.
It is designed to cut in cooperation with a fixed blade.

In addition to the device provided with the clamp mechanism, there is also a yarn wiping device that catches the yarn by advancing and retracting the hook after cutting the yarn, performs the yarn wiping, and holds the shed yarn.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention In a thread trimming device, a clamp spring is usually a steel plate bent in a stepped shape and attached to a fixed blade, and a fixed blade made of a steel plate is interposed between the fixed spring and the fixed blade. Although the movable blade is sandwiched by forming the gap between the movable blade and the movable blade, the contact state with the movable blade is often point contact or line contact, and if the pressing action point is not appropriate, that is, the pressing action point. If is offset from the thread cutting action portion of the hook knife portion, the thread cutting action portion of the movable blade floats above the fixed blade, and a thread cutting error is likely to occur.

To ensure that the clamp spring always comes into surface contact with the movable blade to ensure that the movable blade presses against the fixed blade during thread cutting, homogenize quenching of the clamp spring and the movable blade, and improve the bending accuracy of the clamp spring. Improvement is required, but this involves a great increase in cost.

Similarly for the thread wiper, if the clamp spring makes surface contact with the hook and the hook is not pressed firmly against the fixing member, the thread that has been thread wiped may come off and fail to hold the thread. Homogenization of the clamp spring and hook quenching is required to solve the problem.

The present invention has been made in view of the above points, and appropriately presses a movable member with a spring, and in a thread cutting device, a thread cutting error is prevented from occurring. .

Means for Solving the Problems That is, the clamp mechanism of the present invention comprises a fixing member fixedly supported by the sewing machine, and a hook attached to the fixing member to move in and out of the fixing member by the operation of the actuating device and to catch a thread at the tip. In a clamp mechanism of a sewing machine, which includes a movable member and a base spring fixedly supported by the sewing machine and pressing the movable member against the fixed member at a free end, a through hole is formed at the free end of the plate spring. , A conical portion hooked in the through hole and a shaft portion having a diameter smaller than that of the through hole are formed between the leaf spring and the movable member to form a countersunk bolt shape, and a press-contact body having the shaft portion fitted in the through hole is provided, It is characterized in that the spring pressure of the spring is transmitted to the movable member via the pressure contact body.

Further, as the thread trimming device of the present invention, the movable blade reciprocating by the operation of the actuating device and having the hook knife portion at the tip, the fixed blade arranged on the path along which the hook knife portion reciprocates, and the base portion fixed to the sewing machine. In a thread trimming device of a sewing machine, which is supported and has a leaf spring that presses a movable blade against a fixed blade at a free end, a through hole is formed at the free end of the leaf spring, and a space between the leaf spring and the movable blade is formed. A conical part hooked on the through hole and a shaft part with a diameter smaller than the through hole are formed into a countersunk bolt shape, and a pressure contact body in which the shaft part is fitted into the through hole is provided. The feature is that it is transmitted to the movable blade.

Action When the leaf spring is tilted and directly acts on the movable member or the movable blade, even if the leaf spring is unbalanced and comes into point contact or line contact, the pressure contact body tilts with respect to the leaf spring to move the movable member or movable. The blade comes into surface contact with the blade, the spring properly acts on the movable member or the movable blade through this contact portion, and the pressing force is not biased.

Example FIG. Shows an example in which the thread cutting device equipped with the clamping device according to the present invention is used in a multi-needle tubular sewing machine used for sewing and covering thin tubular objects such as sleeves of a trainer. In the sewing machine, the needles 1 are arranged in a direction orthogonal to the cylinder axis of the cylindrical bed 2, and are flat in cooperation with a looper (not shown) that swings in the same direction in the bed and a decorative swing looper that reciprocates on the needle plate 3. Is designed to form a stitch and also has a feed dog 4
Through the through hole 5 of the needle plate 3 to perform a feeding movement in the cylinder axis direction of the bed 2.

The bottom of the needle plate is bent in a hook shape toward the feed dog 4, and the base of the movable blade 6 having a hook female portion 6a at the tip is adjacent to the through hole 5 at the front in the feeding direction (bed base side) with a stepped screw. 7, the movable blade 6 can be rotated along the back surface of the needle plate 3, and when the stepped screw 7 is rotated, the hook female portion 6a at the tip is orthogonal to the cylinder axis. Needle holes 8 aligned in the direction
You are going to move back and forth along.

On the back side of the throat plate, a fixed blade 9 and a leaf spring are provided on the front side of the through hole 5.
11 is fixed by a set screw 12, and a through hole 13 formed at the free end of the leaf spring 11 has a shaft portion 14a having a diameter smaller than the hole diameter and a conical portion 1.
The shaft portion 14a of the countersunk bolt-shaped pressure contact body 14 composed of 4b is loosely fitted, and the leaf spring 11 is engaged by the conical portion 14b to push up the pressure contact body 14 and press the movable blade 6 against the fixed blade 9. There is.

Since the engagement of the leaf spring 11 with the conical portion 14b is loose and its inclination can be changed, the upper surface of the pressure contact member 14 is always in contact with the movable blade 6 in parallel and can be pressed against the front surface thereof. In addition, at least a part thereof corresponds to the cutting action position where the movable blade 6 and the fixed blade 9 intersect, and the pressing force of the leaf spring 11 is applied to the cutting action portion.

Reference numeral 10 is a retaining ring for the press-contact body 14 that is fitted to the shaft portion 14a.

The actuating device for reciprocating the movable blade 6 is connected to the actuating plate 15 and the actuating plate 15 extending forward in the feeding direction of the feed dog 4, that is, toward the bed base, and the actuating plate is indicated by the arrow in FIG. And an actuator (not shown) such as a solenoid that reciprocates in the opposite direction, and the operating plate 15 is fitted in a long groove (not shown) formed in the cylinder axis direction on the back surface of the bed cover 16 to form a pair. Is supported slidably in the cylinder axis direction by the long holes 17 and a pair of stepped screws 18 fixed to the bed cover 16 through the long holes 17. A guide hole 19 is formed obliquely at the end on the feed dog side, and a pin 21 protruding from the movable blade 6 is slidably fitted in the elongated hole 19. When the actuating plate (not shown) is actuated to move the actuating plate 15 back and forth in the cylinder axis direction, the movable blade 6 horizontally reciprocates about the stepped screw 7. The cylindrical bed 2 is partially bulged toward the front side as shown in the drawing so as not to hinder the rotation of the movable blade 6.

At the time of thread cutting, thread cutting is performed in the same manner as the conventional thread cutting device. That is, when the needle 1 rises to reach the top dead center at the end of sewing and the sewing machine stops, the actuating plate 15 moves forward by the operation of the actuator, causing the movable blade 6 to move clockwise in FIG. 2 (see FIG. 3). Rotate counterclockwise). Along with this, the hook female portion 6a goes out between the fixed blade 9 and the pressure contact body 14 and advances toward the needle hole 8 to pass through each needle thread lube. After the hook female portion 6a reaches the forward end, the actuator 15 causes the actuating plate 15 to return in the arrow direction of FIGS. 2 and 3, and the movable blade 6 is rotated in the arrow direction. Along with this, the hook female part
6a also retreats, and on the way, each upper thread and looper thread are hooked, and they are pulled to the fixed blade 9 and cut. The cut end of the cut yarn is held between the movable blade 6 and the pressure contact body 14.

In the above embodiment, the leaf spring 11 is adapted to engage with the conical portion of the pressure contact body, but in another embodiment, a coil spring is provided instead of the leaf spring so as to engage with the conical portion. .

In the above embodiment, the present invention is applied to a thread cutting device used in a multi-needle tubular sewing machine, but any device that is a thread cutting device used in a sewing machine can be applied in the same manner. can do.

In the above embodiment, an example in which the present invention is applied to a thread cutting device is shown, but the present invention can also be applied to a thread removing device of a sewing machine having a hook that goes in and out between a fixing member and a clamp spring. .

Effect of the Invention As described above, in the clamp mechanism of the present invention, the spring acts on the movable member via the pressure contact member, and the pressure contact member can tilt with respect to the spring. Even if there is some problem in the accuracy of assembling, the pressing action of the spring on the movable member is appropriately performed by changing the inclination of the pressure contact body with respect to the spring or the movable member, and the yarn can be held securely. In the thread cutting device, it is possible to prevent a thread cutting error. Moreover, the clamp mechanism of the present invention has the base portion fixedly supported by the sewing machine, and the conventional clamp mechanism having the leaf spring for pressing the free end portion against the movable member or the movable blade has a through hole formed at the leaf spring free end portion. In addition, it is possible to achieve the above effect with a simple structural change by simply adding a countersunk bolt-shaped pressing body, and since no extra space is newly required, thread cutting in the tubular bed is possible. It can be applied to the device without changing the shape and size of the bed.

[Brief description of drawings]

FIG. 1 is an enlarged view of an essential part showing a part of a thread cutting device according to the present invention in section, and FIG. 2 is a perspective view of a tubular bed of a multi-needle tubular sewing machine equipped with the thread cutting device. FIG. 3 is an enlarged view of the throat plate viewed from the back side. 2 ... Cylindrical bed, 3 ... Needle plate, 6 ... Movable blade 8 ... Needle hole, 9 ... Fixed blade, 11 ... Leaf spring 14 ... Press contact body, 15 ... Actuation plate

Claims (5)

[Scope of utility model registration request] 1. A fixed member fixedly supported by a sewing machine, a movable member that is provided along with the fixed member, is provided with a hook that moves in and out of the fixed member by the operation of an actuating device, and has a hook for catching a thread at a tip, and a base portion. In a clamp mechanism of a sewing machine, which is fixedly supported by a sewing machine and has a leaf spring that presses a movable member against a fixed member at a free end, a through hole is formed at the free end of the leaf spring, and a leaf spring and a movable member are provided. A conical part hooked on the through hole and a shaft part with a diameter smaller than the through hole form a countersunk bolt shape.
A clamp mechanism for a sewing machine, characterized in that a press-contact body having a shaft portion fitted in the through hole is provided, and the spring pressure of a leaf spring is transmitted to the movable member via the press-contact body. 2. A thread removing device for a sewing machine, which uses the clamp mechanism according to claim 1. 3. A movable blade, which is reciprocated by the operation of an actuating device and has a hook knife portion at its tip, a fixed blade arranged on a path along which the hook knife portion reciprocates, and a base portion which is fixedly supported by a sewing machine. In a thread cutting device of a sewing machine including a leaf spring that presses a movable blade against a fixed blade at an end, a through hole is formed at a free end of the leaf spring, and a through hole is formed between the leaf spring and the movable blade. The conical part to be hooked and the shaft part with a smaller diameter than the through hole form a countersunk bolt shape, and a pressure contact body with the shaft part fitted in the through hole is provided, and the spring pressure of the leaf spring is applied to the movable blade via the pressure contact body. A thread cutting device for a sewing machine characterized by being transmitted. 4. The upper surface of the pressure contact member has at least a part thereof corresponding to a cutting action position where the movable blade and the fixed blade intersect.
The thread cutting device of the sewing machine described. 5. A sewing machine is a multi-needle tubular sewing machine, in which needles are arranged in a direction orthogonal to a tubular axis of a tubular bed, a movable blade is hook-shaped, and a base end thereof is forward in the feed direction of the feed dog. The thread cutting device for a sewing machine according to claim 3, which is supported.