JPH0638876U - Lockstitch sewing machine hook - Google Patents

Abstract

(57) [Summary] [Purpose] In a lockstitch sewing machine, the needle thread residual thread length after cutting the upper thread is further increased as necessary. [Structure] A detachable picker 1 whose tip 2 comes into contact with a bobbin 14 through a cutout portion of a bobbin case 13 when the needle thread cutting signal is transmitted to the shuttle 12 side at the same time, and a tip of the bobbin case 13 The bobbin attaching / detaching claw 13c is detachably attached to the recess 13b at the rear of the base.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a hook holding device that secures a necessary needle thread residual thread length after cutting an upper thread in a lockstitch sewing machine having an upper thread cutting apparatus.

[0002]

[Prior art]

 Conventionally, in the needle thread cutting device of a lockstitch sewing machine, with the purpose of preventing the needle thread from coming off from the needle by pulling up the balance at the start of the next sewing operation and forming a firm knot between the needle thread and the bobbin thread. The picker increases the yarn path of the upper thread only during thread cutting to ensure a certain length of residual needle thread after the upper thread is cut.

[0003]

[Problems to be solved by the device]

 However, since the picker in the hook presser device of the conventional lockstitch sewing machine only needs to secure the needle thread residual thread length necessary for preventing thread removal and forming a firm knot, the needle thread residual thread length is not so long. When a needle thread holding device is installed to prevent bird's nests in which the upper thread is entangled with the lower thread underneath the cloth, a relatively large needle thread holding device must be installed near the needle base. The workability is poor because the hand or the sewing product is hit. Also, when using a bobbin thread that has a particularly high elasticity, the bobbin rotation is stopped by the picker when the upper thread is cut, and the required needle thread residual thread length cannot be secured. At the start of sewing operation after thread cutting, stitch skipping may occur or sewing may become impossible.

An object of the present invention is to provide a hook presser device for a lockstitch sewing machine that can further lengthen the needle thread residual thread length after the needle thread is cut.

[0005]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the hook presser device of the lockstitch sewing machine of the present invention moves the thread cutting signal to the hook side at the same time when the thread cutting signal is transmitted, and the tip of the hook moves to the bobbin through the notch of the bobbin case. It consists of a detachable picker that abuts and a detachable auxiliary picker whose tip abuts a recess behind the base of the bobbin case attaching / detaching claw in the bobbin case.

[0006]

[Work]

 In the hook presser device of the lockstitch sewing machine configured as described above, when the upper thread cutting signal is transmitted with the auxiliary picker attached, the picker and the auxiliary picker rotate to the hook side, and the tip of the picker Passes through the notch in the bobbin case and contacts the bobbin, and the tip of the auxiliary picker contacts the recess in the bobbin case. Then, when the outer hook rotates, the upper thread passes through the inner hook and is caught by the auxiliary picker to perform thread trimming. The upper thread is stretched from the knife through the auxiliary picker to the knife.

[0007]

【Example】

 1 to 3, a hook holding device for a lockstitch sewing machine according to the present invention will be described.

The hook presser device is provided below the needle plate 10 of the lockstitch sewing machine having the needle thread cutting device, and is rotated at the same time when the needle thread cutting signal is transmitted from the sewing machine controller, so that the bobbin presser 2 at the tip end is pressed. Is detachably attached to the picker 1 which passes through the notch 13a of the bobbin case 13 mounted on the hook 12 and comes into contact with the bobbin 14, and the picker arm 3 to which the picker 1 is fixed. The auxiliary picker 6 comes into contact with the recess 13b of the bobbin case 13 (which is present at the rear of the base of the bobbin attaching / detaching claw 13c) when it comes into contact with 14.

The needle thread cutting device is composed of a rotary knife 11, and is arranged below the needle plate 1 along the outer periphery of a vertical shuttle 12 composed of an inner shuttle 12a and an outer shuttle 12b.

The picker 1 has a U-shape and is detachably attached to the picker arm 3 with a screw or the like. The picker arm 3 is fixed to the picker shaft 5, and the stepped screw 3a of the picker arm 3 is connected to a connection link from a thread cutting solenoid (not shown). Therefore, the picker 1 rotates clockwise around the picker shaft 5 at the same time when the thread cutting solenoid is sucked by the transmission of the upper thread cutting signal. The bobbin presser 2 is axially slidably supported by the picker 1, and has a built-in spring 4 so that the bobbin presser 2 is pressed with a constant pressure when the bobbin presses the bobbin 14 when the suction of the thread cutting solenoid is completed. ing.

The auxiliary picker 6 is slidably inserted into a hole of a U-shaped auxiliary picker base 7 which is detachably attached to the picker arm 3 by a screw or the like, and is biased toward the bobbin by a spring 8. In addition, the movement is restricted by the E-ring 9. Instead of the auxiliary picker 6, as shown in FIG. 3, a wire 16 having a spring property is wound around the picker 1 so that when the picker 1 is rotated toward the hook 12, the bobbin case recess 13b is brought into contact with the picker 1. You can also do it.

In the hook presser device of the lockstitch sewing machine configured as described above, when the needle thread cutting signal is issued, the picker 1 is rotated to the hook 12 side, and the bobbin presser 2 moves the bobbin case cutout 13a. The bobbin 14 comes into contact therewith, and the auxiliary picker 6 also comes into contact with the bobbin case recess 13b in conjunction with the bobbin retainer 2 of the picker 1. At this time, the bobbin presser 2 is pressed against the bobbin 14 by the spring 4 with a constant pressure, and the auxiliary picker 6 is pressed against the bobbin case recess 13b by the spring 8 with a constant pressure. When the outer hook 12b is rotated by the rotation of the sewing machine, the upper thread (needle thread) passes through the inner hook 12a, is caught by the auxiliary picker 6, and the rotary knife 11 cuts the thread. Therefore, the needle thread is stretched from the rotary knife 11 through the auxiliary picker 6 to the rotary knife 11.

By the way, in a conventional sewing machine that does not have the auxiliary picker 6, the upper thread is cut while the upper thread is stretched from the rotary mesh 11 through the bobbin presser 2 of the picker 1 to the rotary knife 11. Therefore, by providing the auxiliary picker 6, the length of the upper thread remaining on the needle 15 side (needle thread residual thread length) is increased by a length approximately twice the distance between the bobbin presser 2 and the auxiliary picker 6. . Therefore, when a needle thread holding device is provided, the needle thread holding device can be installed at a position distant from the needle base by the length of the needle thread holding device, and a relatively large needle thread holding device is provided near the needle 15. The workability around the needle is improved by eliminating the problem. If the needle thread holding device is not provided, if the needle thread residual thread length is long, the sewing quality at the start of sewing operation will be deteriorated. Therefore, the auxiliary picker 6 is removed and the needle thread residual thread length after the upper thread is cut. Can be shortened and sewing can be performed.

In addition, when the auxiliary picker 6 is provided, the upper thread is stretched under the conventional upper thread cutting, the tension at the time of cutting the upper thread is increased, and the upper thread cutting device with a single knife is used. In this case, the upper thread can be reliably cut.

If a picker 1 is used when using a highly elastic bobbin thread, the bobbin presser 2 comes into contact with the bobbin 14 to stop the rotation when the upper thread is cut, and the remaining thread length of the bobbin thread after the upper thread is cut is reduced. It becomes extremely short and the knot of the upper thread and the lower thread is not performed at the start of the next sewing operation, resulting in skipped stitches or impossible sewing. However, the auxiliary picker 6 is left as it is and the picker 1 is removed. As a result, the required residual yarn length can be secured, and this problem can be solved.

[0016]

[Effect of device]

 Since the present invention is configured as described above, it has the following effects.

That is, it is possible to further lengthen the needle thread residual thread length by attaching the auxiliary picker, and when the needle thread holding device is provided, the needle thread residual thread length is increased and the needle thread residual thread length is separated from the needle base. Since the needle thread holding device can be installed at a different position, the space around the needle is widened and workability is improved. When the needle thread holding device is not provided, the auxiliary picker can be removed to shorten the needle thread residual thread length after bobbin thread cutting, and the sewing quality at the start of the sewing operation can be stabilized. Further, when the auxiliary picker is attached, the tension at the time of cutting the upper thread increases, so that the upper thread can be reliably cut. Furthermore, when using a bobbin thread with high elasticity, by attaching an auxiliary picker and removing the picker, it is possible to secure the required residual thread length without stopping the rotation of the bobbin when bobbin thread cutting. Since it is possible, stitch skipping and sewing are not impossible.

[Brief description of drawings]

FIG. 1 is a front view of a hook holding device of a lockstitch sewing machine according to the present invention.

FIG. 2 is a bottom view of the hook holding device of the lockstitch sewing machine of the present invention.

FIG. 3 is a bottom view showing another example of the hook holding device of the lockstitch sewing machine of the present invention.

[Explanation of symbols]

 1 Picker 6 Auxiliary Picker 12 hook 13 bobbin case 13a notch 13b recess 13c bobbin attaching / detaching claw 14 bobbin

Claims (1)

[Scope of utility model registration request] 1. A detachable picker, the tip of which comes into contact with a bobbin through a notch in the bobbin case when it moves to the hook side at the same time as the thread cutting signal is sent, and the tip is for attaching and detaching the bobbin case in the bobbin case. A hook holding device for a lockstitch sewing machine, which comprises a detachable auxiliary picker that comes into contact with a recessed portion at the rear of the base of the claw.