WO2005100666A1

WO2005100666A1 - Sewing machine

Info

Publication number: WO2005100666A1
Application number: PCT/JP2004/004799
Authority: WO
Inventors: Haruhiko Kinoshita
Original assignee: Kinoshita Precision Industrial Co. Ltd.
Priority date: 2004-04-01
Filing date: 2004-04-01
Publication date: 2005-10-27
Also published as: JPWO2005100666A1

Abstract

A sewing machine forming stitches on a fabric by passing a needle thread from a thread winding part installed at the top of a sewing machine frame to the fabric through a tension applying mechanism (7), a balance part, a needle bar, and a sewing needle, The tension applying mechanism (7) comprises a tension stud (17) having a pair of regulating trays (21) and (22) holding the needle thread through a thread tension spring (24) and a thread tension disk (18) rotatably installed on the tension bar (17) and allowing the needle thread to vertically pass therethrough. An unbalanced weight part (18a) is formed integrally with the thread tension disk (18) and a torque in a specified direction is applied to the thread tension disk (18) to apply a tension to the needle thread.

Description

Specification

Sewing sewing machine technical field

The present invention relates to a sewing machine provided with a tension applying mechanism in the middle of guiding an upper thread from a winding section through a balance section to a sewing needle. Background art

As described in Japanese Patent Application Laid-Open No. Hei 6-287854, the sewing machine uses a sewing machine that adjusts the upper thread according to various sewing methods, the fabric to be stimulated, or the properties of the thread or cloth to be used. A needle thread control device is provided to provide appropriate tension (sewing resistance). This needle thread control device is provided with first, second, and third tension applying mechanisms selectively driven by a driving mechanism in three stages, upper and lower. During the period from the top dead center to the bottom dead center of the balance unit, the upper thread is pulled, so that the third tension applying mechanism is in an inoperative state, and only the first and second tension applying mechanisms are driven. The tension applying force is set to “weak”. During the period from when the balance section passes the bottom dead center to immediately before it reaches the top dead center, the first, second, and third tension applying mechanisms are all driven to set the tension applying force to "strong". are doing. This eliminates the loosening of the upper thread that occurs when the upper thread is pulled up by the balance in the process of the balance section moving from bottom dead center to top dead center, and eliminates insufficient thread tightening in the stitch. ing.

At this time, each tension imparting mechanism adjusts the tension applied to the upper thread by tightening an adjustment plate with the upper thread interposed therebetween via a tension spring with an adjustment knob. For this reason, the upper thread control device of the above publication is It has a complicated structure including a first, second, and third tension applying mechanism and a driving mechanism, and is costly. For this reason, in recent years, a tension applying mechanism 50 with a simplified structure is provided as shown in (a) and (mouth) of FIG. In the tension applying mechanism 50, the thread take-up spring 51 is sandwiched between the thread take-up disk 52 and the adjustment plates 53, 54, and the tip of the thread take-up spring 51 is hooked on the upper thread 55. When the upper thread 55 is pulled out in the direction indicated by the arrow X, the thread take-up disc 52 rotates in the direction of the arrow Y, and the thread take-up spring 51 is reduced in diameter in the direction of tightening to reduce the diameter to the upper thread 55. The tension according to the amount of deformation is added.

However, the provision of the thread take-up spring 51 leads to an increase in the number of parts, which results in an increase in cost consciousness in the manufacturing industry in recent years. For this reason, there has been a demand for a sewing machine equipped with a tension applying mechanism 50 which is advantageous in terms of cost by reducing the number of parts by sharing parts.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a sewing machine capable of reducing the number of parts and realizing a tension applying mechanism which is advantageous in cost. It is in. Disclosure of the invention

(1) The tensioning mechanism in the sewing machine includes a tension bar that passes through an adjustment plate that sandwiches the upper thread through a thread tension spring, and a rotatably mounted upper and lower thread on the tension bar. The thread tension disc is formed integrally with an unbalanced weight portion, and a rotational moment in a predetermined direction is applied to the thread tension disc to apply a certain tension to the upper thread. The amount of thread required for the sickle is adjusted. Also, the balance pulls the upper thread. This eliminates the loosening of the thread at the sickle that occurs during the lifting process. In this case, since the unbalanced weight portion is formed integrally with the thread tension disk, the conventional thread take-up spring is not required, and the number of parts can be reduced by combining parts, which is advantageous in cost. Become.

(2) The unbalanced weight portion is a flange-shaped ear formed on the outer peripheral edge of the thread tension disk, and the balance portion has the largest thread tension disk during the process from bottom dead center to top dead center. Give the moment of rotation. For this reason, the structure of the unbalanced weight portion is simple, and the upper thread is not pulled out from the winding section during the operation of the balance in the process of the balance section moving from the bottom dead center to the top dead center. This eliminates the problem of insufficient thread tightening in stitches.

(3) The unbalanced weight portion is provided with a plurality of screw holes to which a male screw is detachably attached in a radial direction. By selectively attaching the male screw to the screw hole, the position of the center of gravity of the unbalanced weight portion can be changed to adjust the rotational moment applied to the thread tension disk. For this reason, an appropriate tension can be added to the upper thread according to the sewing method, the cloth to be stimulated, or the properties of the thread to be used or the cloth to be sewn.

(4) The unbalanced weight is provided with a movable lead. By selecting the mounting position of the lead to the unbalanced weight, the center of gravity of the unbalanced weight can be changed to adjust the rotational moment applied to the thread tension disk. Therefore, an appropriate tension can be applied to the upper thread, and the same effect as described in the item (3) can be obtained.

(5) A permanent magnet is detachably attached to the imbalanced weight. By selecting the mounting position of the permanent magnet on the unbalanced weight, the position of the center of gravity of the unbalanced weight can be changed to adjust the rotational moment applied to the thread tension disk. For this reason, an appropriate tension is applied to the upper thread. As a result, the same effect as described in the item (3) can be obtained.

(6) The unbalanced weight portion is provided with a thin lead plate portion having one end fixed to the unbalanced weight portion and the other end formed with a spiral roll. By winding the roll, the position of the center of gravity of the unbalanced weight is changed, and the rotation moment applied to the thread tension disc can be adjusted. Therefore, an appropriate tension can be applied to the upper thread, and the same effect as described in the item (3) can be obtained.

(7) The unbalanced weight part is provided with a screw rod to which a nut part is attached in the radial direction. By screwing the nut part back and forth along the screw rod, the position of the center of gravity of the unbalanced weight part is changed, and the rotational moment applied to the thread tension disk can be adjusted. For this reason, an appropriate tension can be added to the upper thread, and the same effect as described in the item (3) can be obtained.

(8) The thread tension disk is provided with a projecting stopper. With the rotation of the thread tension disk when cutting the upper thread, the stop of the sewing machine is stopped by bringing the stopper into contact with the switch. For this reason, the inconvenience that the operation of the sewing machine continues when cutting the upper thread can be eliminated. Brief Description of Drawings

FIG. 1 is a perspective view of a sewing machine (Example 1).

FIG. 2 is a side view of the sewing machine.

FIG. 3 is an enlarged exploded perspective view of the tension applying mechanism.

Fig. 4 shows the tension used to explain the operation of the thread tension disc. It is an expansion perspective view of a provision mechanism.

(A) to (f) of FIG. 5 are front views showing various thread tension discs (Example to Example 7).

(A) and (mouth) in Fig. 6 are a front view and a side view showing a conventional tension applying mechanism. BEST MODE FOR CARRYING OUT THE INVENTION

[Example 1]

1 to 4 show Embodiment 1 of the present invention. On the upper part of the sewing machine frame 2 of the sewing machine 1, there is provided a thread holder 3 on which a plurality of winding portions 4 are installed as shown in FIG. A flexible spiral tube 6 corresponding to the winding part 4 is provided between the support plate 5 provided above and the sewing machine frame. Below the spiral tube 6, tension applying mechanisms 7, which are attached to the sewing machine frame 2 and apply tension to the upper thread T described later, are provided according to the number of the winding portions 4. Below the tension applying mechanism 7, an intermediate plate portion 8 having guide holes 8a formed corresponding to the number of the winding portions 4 is attached. The balance section 9 is attached to the needle bar 10 in accordance with the number of the winding sections 4, and protrudes outside from the lower frame 2a of the sewing machine. A substantially U-shaped bracket 11 having a through hole 11a corresponding to the balance portion 9 is provided on the lower frame 2a of the sewing machine, and a sewing needle 12 of a needle bar 10 is provided below the bracket 11a. The upper thread T from the winding part 4 is provided with a hole 5a provided in the support plate 5, a spiral tube 6, a tensioning mechanism 7, a guide hole 8a of an intermediate plate part 8, a balance part 9, and a bracket. It passes through the through-holes 11a of 11 in order and is passed through the sewing needle 12. With the operation of the sewing machine 1, the sewing needle 1 2 is moved to the cloth held by the presser portion 13. 1 passes with needle thread T (see Fig. 2). The cloth 14 is fixed to a mounting frame 15 which is driven back and forth and right and left by a feed mechanism (both not shown) controlled based on a pattern displayed on a monitor in the evening. Below the feed mechanism, there is provided a cutting mechanism (both not shown) including a loop sickle and a cutting knife for cutting the upper thread T passing through the cloth 14 at a predetermined loop length. By the vertical drive of the sewing needle 12 with respect to the cloth 14, the needle thread T is stitched to the cloth 14 and a stimulus for applying various patterns 15 A is performed.

The tension applying mechanism 7 of the sewing machine frame 2 is fitted into the bar base 16 as shown in Fig. 3, and has a male thread 17a at the tip. And a cylindrical thread tension disc 18 inserted into the disc. In the tension I7, following the thread tension disc 18, a bar 19, a belt backing 20, a pair of adjustment plates 21 and 11, a plate holder 23, a thread tension spring 24, a washer 25 and The knob nut 26 is passed through. In this state, tighten the knob nut 26 to the male thread 17a of the tension bar 1 1 to clamp the adjustment plates 21 and 22 via the washer 15 and the thread tension spring 14. Adjust the tension to the upper thread T by adjusting the pressure.

As shown in Fig. 4, the thread tension disk 18 is made of metal such as stainless steel, and an unbalanced weight portion 18a is integrally formed on its outer peripheral edge as a flange-shaped ear. are doing. In addition, a threading ring portion 18b spaced apart from the unbalanced weight portion 18a by a predetermined angle is integrally attached to the thread tension disk 18 via an arm 18c. And guide it to adjustment plates I 1 and 2. The thread tension disk 18 is moved in the direction indicated by the arrow M in Fig. 4A due to the unbalanced weight of the unbalanced weight portion 18a. Is given, and a certain tension (sewing resistance) is applied to the upper thread T.

When the sewing machine 1 is in operation, the thread tension disk 18 is displaced obliquely upward as shown by the solid line in FIG. 4 (a) during the downward movement of the balance 9 from the top dead center to the bottom dead center. The rotation moment P 1 (= r G) is given from the weight portion 18a. In the ascending process of the balance section 9 from the bottom dead center to the top dead center, the thread tension disk 18 rotates in the direction of the arrow M to the right side as shown by the two-dot chain line in FIG. The rotational moment P 2 (= RG) is given from the displaced imbalance weight 18 a. Since the distance R and the distance r have a relationship of distance R≥distance r, P 2 ≥P 1 and the maximum rotational moment P 2 at the distance R.

However, point 0 is the center position of the thread tension disk 18, point G is the center of gravity of the unbalanced weight part 18 a, and distance r is the vertical line passing through the center position ◦ from the center of gravity G in the descending process of the balance 9. The vertical line segment, distance R, indicates the line segment from the center of gravity G to the center position ◦ in the process of ascending the balance 9. Also, when the sewing machine 1 is in operation, if the needle thread T is cut off for any reason as shown in Fig. 4 (opening), the thread tension disc 18 loses tension from the needle thread T. Due to the unbalanced weight of the unbalanced weight part 18a, it rotates in the direction of arrow M. For this reason, the thread tension disk 18 rotates in the direction of the arrow M until the convex portion I7 formed on the unbalanced weight portion 18a comes into contact with the open end portion 28 of the bar base 16. At this time, a projecting stopper (not shown) formed on the thread tension disk 18 presses the switch (not shown) to stop the operation of the sewing machine 1 made by 鏠. This eliminates the inconvenience that the operation of the sewing machine 1 continues while the upper thread cutter is cut. In the above configuration, the unbalanced weight portion 18a is formed integrally with the thread tension disk 18, eliminating the need for a separate thread take-up spring conventionally provided, reducing the number of parts and cost. This is advantageous. In particular, in the sewing machine 1 having a large number of sewing needles 1 and 2, the number of thread take-up springs is increased for each tension applying mechanism 7, so that the number of thread take-up springs is increased and the number of parts is reduced by eliminating the need for thread take-up springs. Doing so can lead to significant cost savings.

[Example 2]

FIG. 5A shows Example 1 of the present invention. In the embodiment, a plurality of screw holes 29 to which the male screw 30 is detachably attached are provided in the unbalanced weight portion 18a in the radial direction. By selectively attaching the male screw 30 to the screw hole 29, it is possible to change the position of the center of gravity of the unbalanced weight portion 18a. For this reason, the rotational moment applied to the thread tension disk 18 can be adjusted by the unbalanced weight portion 18a to a large or small value, and the sewing method, the fabric to be sewn, or the thread to be used or the cloth on the sewing can be adjusted. An appropriate tension can be added to the upper thread T according to the properties and the like.

[Example 3]

(Port) in FIG. 5 shows a third embodiment of the present invention. In the third embodiment, the unbalanced weight portion 18a is provided with a lead portion 31 that can be attached and moved. The position of the center of gravity of the unbalanced weight portion 18a can be changed by selecting the mounting position of the lead portion 31 with respect to the unbalanced weight portion 18a. For this reason, the rotational moment applied to the thread tension disk 18 can be adjusted by the imbalanced weight portion 18a.

[Example 4]

FIG. 5C shows Example 4 of the present invention. In Example 4, the imbalance The permanent magnet 32 is detachably attached to the weight portion 18a. By selecting the mounting position of the permanent magnet 32 with respect to the unbalanced weight portion 18a, the position of the center of gravity of the unbalanced weight portion 18a can be changed. For this reason, the rotational moment applied to the thread tension disk 18 by the unbalanced weight portion 18a can be adjusted in magnitude.

[Example 5]

FIG. 5 (2) shows a fifth embodiment of the present invention. The unbalanced weight part 18 & of Example 5 has one end fixed to the unbalanced weight part 18 a and a thin lead plate part 33 formed with a spiral roll part 33 a at the other end. ing. The center of gravity of the unbalanced weight part 18a can be changed by winding or unwinding the roll part 33a of the lead plate part 33. For this reason, the rotational moment applied to the thread tension disc # 8 can be adjusted by the imbalanced weight portion 18a.

[Example 6]

FIG. 5E shows a sixth embodiment of the present invention. A screw rod 35 to which a nut part 34 is attached is provided in a radial direction on the unbalanced weight part 18a of the sixth embodiment. By rotating the nut portion 34 along the screw rod 35 and retreating it, the position of the center of gravity of the unbalanced weight portion 18a can be changed. For this reason, it is possible to adjust the rotational moment applied to the thread tension disk 18 by the imbalanced weight portion 18a.

[Example 7]

FIG. 5F shows Example 7 of the present invention. In the thread tension disk 18 of the seventh embodiment, a separate unbalanced weight portion 18a is detachably provided to the base end 18d. An arc-shaped long groove 36 through which the screw member 37 is inserted is formed in the circumferential direction in the separate unbalanced weight portion 18a. Long groove By appropriately changing the position of the screw member 37 with respect to 36, the unbalanced weight portion 18a is eccentrically attached to the base end portion 18d. For this reason, the rotational moment applied to the thread tension disk 18 can be adjusted by the imbalanced weight portion 18a.

[Modification]

The thread tension disk 18 integrally formed with the unbalanced weight portion 18a is not limited to metal such as stainless steel, but may be formed of plastic, ceramic, tempered glass, or the like. Further, instead of the pair of adjusting plates 21 and 22, a pulley-shaped opening and a plate may be used as a single item. Further, in the present invention, a multi-needle type sewn sewing machine is applied as the sewing machine 1, but a single-needle type or three-dimensional sewn type sewn sewing machine may be used, and the sewing machine can be widely applied to home and industrial sewing machines. It is. Industrial applicability

In the sewing machine according to the present invention, an unbalanced weight portion is integrally formed on the thread tension disc to give a rotational moment in a predetermined direction to the thread tension disc, and a constant tension is applied to the upper thread. Since the unbalanced weight portion is formed integrally with the thread tension disk, a separate thread take-up spring conventionally provided is unnecessary. As a result, the number of parts can be reduced, which is advantageous in terms of cost, and can be widely applied to the sewing machine manufacturing industry.

Claims

The scope of the claims

1. In a sewing machine in which a needle is formed from a winding portion provided at an upper portion of a sewing machine frame into a stitch on a fabric through a tensioning mechanism, a balance portion, a needle bar and a sewing needle,

A tension bar that penetrates an adjustment plate that sandwiches the upper thread via a thread tension spring;

A thread tension disk rotatably mounted on the tension bar and allowing the upper thread to pass vertically.

A sewing machine characterized in that an unbalanced weight portion is formed integrally with the thread tension disc, and a rotational moment in a predetermined direction is applied to the thread tension disc to apply a constant tension to the upper thread.

2. The unbalanced weight portion is a flange-shaped ear portion formed on the outer peripheral edge of the thread tension disk, and the balance portion is maximally attached to the thread tension disk in a process from the bottom dead center to the top dead center. The sewing machine according to claim 1, wherein the sewing machine is arranged so as to provide a rotation moment.

3. The unbalanced weight portion is provided with a plurality of screw holes to which a male screw is removably attached in a radial direction, and by selectively attaching the male screw to the screw hole, the unbalanced weight is provided. The sewing machine according to claim 1, wherein the rotation moment applied to the thread tension disc is adjustable by changing the position of the center of gravity of the section.

4. The unbalanced weight portion is provided with a lead portion that is attachable and movable, and by selecting a mounting position of the lead portion with respect to the unbalanced weight portion, a center of gravity position of the unbalanced weight portion is provided. The rotational moment applied to the thread tension disc can be adjusted by changing the rotation of the thread tension disc. Sewing machine.

5. A permanent magnet is detachably attached to the unbalanced weight portion, and by selecting a mounting position of the permanent magnet with respect to the unbalanced weight portion, the position of the center of gravity of the unbalanced weight portion is determined. 2. The sewing machine according to claim 1, wherein the rotational moment applied to the thread tension disc can be adjusted to be adjustable.

6. The unbalanced weight portion has one end fixed to the unbalanced weight portion, and a thin-walled lead plate portion formed with a spiral roll portion at the other end, and the roll portion is wound up. 2. The sewing machine according to claim 1, wherein the rotational moment applied to the thread tension disc can be adjusted by changing the position of the center of gravity of the unbalanced weight portion.

7. A screw rod to which a nut portion is attached is provided in the unbalanced weight portion in a radial direction, and the nut portion is advanced and retracted along the screw rod to thereby provide the unbalanced weight. 2. The sewing machine according to claim 1, wherein a rotation moment applied to the thread tension disk can be adjusted by changing a position of a center of gravity of the section.

8. The thread tension disk is provided with a protrusion-shaped stopper for stopping the operation of the sewing machine by rotating the thread tension disk to abut on the switch when cutting the upper thread. The sewing machine according to claim 1, characterized in that: