JP2603393Y2 - Lower bobbin anti-spin device for horizontal hook of sewing machine - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bobbin bobbin idle rotation prevention device for a horizontal hook of a sewing machine. 2. Description of the Related Art In FIG. 3, a horizontal shuttle 2 includes a bobbin case 4 and an outer shuttle 6 rotating outside thereof.
The bobbin chamber 8 is opened at the upper side, the lower thread bobbin 10 (hereinafter referred to as the bobbin 10) is mounted from the opening side, and the lower thread 12 wound around the bobbin 10 is pulled out via the lower thread tensioner 14. Has become. The lower thread tensioner 14 disposed on the side of the bobbin chamber 8 includes a thread tension table 16 and a thread tension spring 1 as shown in FIG.
8, a set screw 20 and an adjustment screw 22. The thread tension table 16 has a lower thread 12 pulled out from the bobbin 10 attached thereto.
a and the lower thread outlet 2 for guiding the
6 are formed. The thread tension table 16 and the thread tension spring 18 are mounted on the bobbin case 4 by mounting screws 20, the urging force of the thread tension spring 18 is adjusted by adjusting screws 22, and between the guide groove 24 and the lower thread outlet 26. An adjusted lower thread tension is applied to a lower thread 12 when the lower thread 12 is pulled out. [0005] The lower thread tension is an important factor in forming a stitch which determines the tightness of the stitch in relation to the upper thread tension applied to the upper thread. Bobbin thread 12 wound on bobbin 10 during sewing
Is pulled out, the lower thread tension at the lower thread outlet 26 is 2
The lower thread tensioner 14 includes a lower thread tension provided by the lower thread tensioner 14 and a tension component resulting from the rotational frictional resistance of the bobbin 10. When the bobbin 10 wound on the bobbin 10 is pulled out, the bobbin 10 is rotated. However, if the rotation speed of the bobbin 10 is high, the bobbin 10 idles (overruns) due to its inertia, and the bobbin 10 is rotated. The slack occurs in the lower thread 12a between the lower thread tensioner 14 and the lower thread tensioner 14. As a result, the lower thread tension is given only by the lower thread tensioner 14 at the time of thread tightening, and the balance with the upper thread tension is lost. If the normal rotation and the idling of the bobbin coexist for some reason, the balance of the lower thread tension with respect to the upper thread tension is lost accordingly, and the thread tightening of the stitch becomes unstable. As a conventional example, as shown in FIG.
In the case of 0, a method is adopted in which the outer surface of the flange of the bobbin 32 is pressed by a leaf spring 34 to brake the bobbin 32 in order to prevent the bobbin 32 from spinning. It is necessary to close the opening of the bobbin chamber of the shuttle, which disadvantageously complicates the structure near the bobbin chamber and complicates the operation of mounting and removing the bobbin. As another conventional example, as shown in FIG. 7, a plate or wire-shaped spring 40 is attached to a bobbin shaft 38 of a vertical shuttle 36, and idling is prevented by a braking action between the spring 40 and the inner diameter of the bobbin 42. Although there is a method, there is a drawback that the braking force varies greatly and the thread tightening becomes unstable. Moreover, when the conventional method shown in FIG. 7 is applied to a horizontal shuttle and a plate or wire-like spring 48 is attached to a bobbin shaft 46 of a bobbin case 44 as shown in FIG.
When the lower thread 52 wound around the lower part of the bobbin 50 is pulled out, the bobbin 50 rises upward, and the upper thread 56 that is caught by the point of the outer hook 54 and circulates around the bobbin case 44 as shown in FIG. It becomes easy to enter, causing problems such as breakage of the upper thread. In the absence of the spring 48, such a problem is avoided because the bobbin quickly descends with its own weight 50. The problem to be solved by the present invention is to firstly prevent the bobbin from running idle, give a stable lower thread tension to the lower thread, and provide a good and stable lower thread. The purpose is to enable the formation of thread tight seams. Second, to prevent the bobbin from floating from the bobbin chamber of the bobbin case during operation of the sewing machine. In order to solve the above-mentioned problems in the prior art, the present invention provides a bobbin case in which a bobbin chamber in which a bobbin bobbin can be mounted is formed, the rotation of which is restricted, and In a horizontal shuttle of a sewing machine having an outer shuttle rotating outside the bobbin case, the lower thread bobbin is provided with a braking mechanism which is disposed on a bobbin shaft of the bobbin case and elastically presses an inner diameter portion of the mounted lower thread bobbin. The bobbin is prevented from floating by a regulating mechanism which prevents idling and prevents the bobbin thread bobbin mounted and mounted on the bobbin case from moving upward. According to the present invention, firstly, the lower bobbin can be prevented from running idle, so that a lower bobbin thread tension can be applied to the lower bobbin, and the tightening of the lower bobbin with the upper bobbin is stabilized. There is an effect that a good seam can be formed. Secondly, the lower thread bobbin is prevented from floating from the bobbin chamber of the bobbin case during the operation of the sewing machine, so that the upper thread caught by the point of the outer hook and orbiting the bobbin case is different from the conventional lower thread. This has the effect of preventing the bobbin from getting into the bobbin and avoiding the problem caused by this. Hereinafter, the present invention will be described with reference to embodiments. FIG.
, The horizontal shuttle 60 includes a bobbin case 62 and an outer shuttle 63.
The bobbin case 62 is provided with a bobbin chamber 68 in which a lower thread bobbin 66 around which a lower thread 64 is wound (hereinafter, a lower thread bobbin 66) is mounted. The radial position of the bobbin case 62 is regulated by an outer shuttle 63 rotating on the outside thereof, and the rotation thereof is regulated by a rotation stop (not shown) of the bobbin case. (Not shown) restricts its vertical position. On the side of the bobbin chamber 68, there is provided a lower thread tensioner 74 having a thread tension table 70 and a thread tension spring 72 as main elements, and applies a lower thread tension to a lower thread 64a pulled out from the bobbin 66. It is supposed to. The sliding plate 76 is slidably disposed above the horizontal shuttle. When the bobbin 66 is mounted on and removed from the bobbin case 62, the sliding plate 76 is slid in the direction opposite to the arrow A, and when the sewing machine is used, the sliding plate 76 slides. Slide and move in the direction of the arrow to the position shown in FIG. The sliding plate 76 has a lower projection 76a formed on the lower surface thereof. The function of the lower protrusion 76a will be described later. In FIG. 2, a bobbin shaft 80 of the bobbin case 62 is formed with a storage round hole 80a orthogonal to the shaft.
One end is provided with a wall portion 80b. A metal ball 82 and a coil spring 84 are inserted into the storage round hole 80, and a lid 86 is press-fitted. The wall portion 80b restricts the ball 82 pushed by the coil spring 84 from being exposed from the bobbin shaft 80 beyond a certain amount, and these constitute a braking mechanism 88. The ball 82 of the braking mechanism 88 exposed from the bobbin shaft 80 elastically presses the inner diameter portion 66a of the hole of the bobbin 66 mounted on the bobbin chamber 68 by the action of the coil spring 84 to rotate the bobbin 66. To be braked. The bobbin thread tension is usually a relatively small value of 10 to 20 g at the outlet of the bobbin thread tensioner. When the braking force acting on the bobbin 66 is increased, the pull-out radius of the bobbin thread 64 related to the bobbin winding amount is increased. The fluctuation of the bobbin thread tension due to the rotational resistance of the bobbin 66 greatly affects the overall bobbin thread tension including the bobbin thread tension by the bobbin thread tensioner. Is weak and stable enough to prevent idling. The bobbin case 62 has a storage round hole 68a, and has a wall 68b at one end. Storage round hole 68
A metal ball 90 and a coil spring 92 are inserted into a, and a lid 94 is press-fitted. The wall portion 68b has a configuration in which the ball 90 pushed by the coil spring 92 exceeds a certain amount and the bobbin chamber 68
Are restricted from being exposed from the inner wall of the vehicle, and these constitute a regulating mechanism 96. The regulating mechanism 96 is disposed at a position substantially opposite to the braking mechanism 88 on the horizontal projection plane of the bobbin case 62, and the ball 90 of the regulating mechanism 96 exposed from the inner wall of the bobbin chamber 68 is The bobbin 66 is located slightly above the end of the inner surface of the lower flange portion of the bobbin 66 mounted on the bobbin chamber 68, and when the bobbin 66 wound around the lower part of the bobbin 66 is pulled out, the bobbin 66 exceeds a certain amount. To prevent it from rising upward. That is, the lower thread 6 wound around the lower part of the bobbin 66
When the bobbin 66 is pulled out, the upward force acting on the bobbin 66 is small. In many cases, the bobbin 66 comes into contact with the ball 90 of the regulating mechanism 96 indicated by a solid line in FIG. The bobbin 66 floats only up to the contact position, and the upper thread caught by the point of the outer hook does not enter the inner surface of the upper flange portion of the bobbin 66 unlike the conventional example, and the bobbin 66 gradually descends to the original position. If, for some reason, an instantaneously large lifting force acts on the bobbin 66, the upper surface of the upper flange portion of the bobbin 66 is placed on the sliding
6, the ball 90 of the regulating mechanism 96 is locked.
Is retracted as shown by the two-dot chain line. In this state, the end of the inner surface of the lower flange portion of the bobbin 66 is brought into contact with the ball 90 of the regulating mechanism 96 below the center thereof. Of the coil 90 by the action of the coil spring 92,
The bobbin 66 returns to the solid line state in FIG. 2 while pressing the bobbin 66 downward, and the bobbin 66 gradually descends to its original position. For the lifting of the bobbin 66, instead of the regulating mechanism 96, a regulating projection which is a fixed projection having the same size and shape as the ball 90 exposed from the inner wall of the bobbin chamber 68 is provided. However, a similar effect can be obtained. The mounting and dismounting of the bobbin 66 with respect to the bobbin chamber 78 when the regulating protrusion is provided is possible. The reason for this is that there is some clearance between the diameters of the flange portions of the bobbin chamber 78 and the bobbin 66. When a regulating projection is provided instead of the regulating mechanism 90, the lower projection 76 of the sliding plate 76 is provided.
a becomes unnecessary. As described above, according to the present invention, firstly, the lower thread bobbin can be prevented from being idle, so that a stable lower thread tension can be applied to the lower thread and the lower thread can be prevented from slipping. The effect is obtained that a good seam can be formed stably with thread tightening. Second
The lower thread bobbin can be prevented from floating from the bobbin chamber of the bobbin case during operation of the sewing machine. It is possible to obtain the effect that it is not possible to penetrate inside, and the problem caused by this can be avoided.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal sectional view of a horizontal shuttle. FIG. 2 is an enlarged view of a main part of FIG. 1. FIG. 3 to FIG. 8 relate to a conventional example, and FIG. FIG. 4 is a sectional view taken along the line BB of FIG. 3. FIG. 5 is an exploded perspective view of the lower thread tensioner. FIG. 6 is a longitudinal sectional view of a vertical shuttle. FIG. 7 is a vertical sectional view of a vertical shuttle different from FIG. Figure [Figure 8] Longitudinal sectional view of the horizontal shuttle [Description of reference numerals] 62 Bobbin case 66 Bobbin thread bobbin 68 Bobbin chamber 80 Bobbin shaft 88 Braking mechanism 96 Restriction mechanism

Claims (1)

(57) [Claims for Registering Utility Model] A bobbin chamber in which a bobbin bobbin can be mounted is formed, and the rotation of the bobbin case is restricted, and the horizontal direction of a sewing machine having an outer shuttle rotating around the bobbin case A vertical bobbin shaft (80) provided at substantially the center of the bobbin chamber of the bobbin case (62) and having a horizontal hole formed therein, and fitted into a horizontal hole of the bobbin shaft (80). When the bobbin bobbin (66) is mounted on the bobbin shaft (80), the bobbin (82) comes into contact with the inner diameter of the bobbin bobbin (66) by the action of a spring (84). Case (62)
The lower thread bobbin (66) is attached to the bobbin shaft (80) so as to be close to at least one upper surface edge of the opposite flange of the lower thread bobbin when the lower thread bobbin (66) is mounted on the bobbin shaft (80). And a second ball (90) partially protruding in a state where the second ball (90) is pressed by the action of the spring (92) at the set position.