Sewing machine stitch length adjusting knob structure

Abstract

The invention provides a sewing machine stitch length adjusting knob structure which comprises a base, a knob, a dial, a rotating shaft and a stitch length adjusting rod, wherein the knob, the dial and the rotating shaft are rotatably arranged on the base, the stitch length adjusting rod is arranged on the base in a penetrating mode and can move forwards and backwards, and the stitch length adjusting rod pushes a stitch length adjusting arm to adjust the stitch length when moving forwards and backwards. The rear end of the rotary knob is in threaded connection with the stitch length adjustingrod, when the rotary knob rotates, rotation is converted into front-back movement of the stitch length adjusting rod through the rotary shaft, and the dial is further driven by the rotary shaft to rotate. A first limiting device for preventing the rotating shaft from axially moving is arranged on the rotating shaft, and a second limiting device for preventing the stitch length adjusting rod from axially rotating is arranged on the stitch length adjusting rod, then the dial is tightly matched with the base, damping force generated when the rotating shaft rotates is increased, the stitch lengthadjusting rod difficultly pushes the rotating shaft to rotate under high-frequency impact of the stitch length adjusting arm, the structure is high in self-locking capacity, a pin and a clamping groove are omitted, and the knob is not prone to abrasion; and the stitch length can be accurately adjusted.

Description

technical field [0001] The invention belongs to the field of sewing machine products, and in particular relates to a sewing machine stitch length adjusting knob structure. Background technique [0002] The stitch length adjustment of existing sewing machines mostly adopts the knob adjustment mode, and the rotation of the knob drives the screw rod to move back and forth, and pushes the stitch length adjustment arm located in the sewing machine housing to rotate the stitch length adjustment arm, thereby realizing the adjustment of the stitch length. The structure is very convenient to use. [0003] figure 1 It shows an existing structure of sewing machine needle pitch adjustment knob, which includes: screw (1), knob (2), screw rod (3), rubber ring (4), pin (5), spring (6), Among them, the screw (1) is used to fix the screw rod (3) on the knob (2), the rubber ring (4) is stuck in the annular groove of the screw rod (3) to increase the damping feeling, and the screw rod (3) is...

AI Technical Summary

Problems solved by technology

[0004] 1. The knob (2) is generally integrally formed of ABS material. During use, the rotation of the knob (2) will cause friction between the pin (5) and the rib of the card slot (9). Frequent use will easily wear out the card of the knob (2). slot (9), so that the pin (5) cannot be firmly fixed in the slot (9), and it is difficult to play the role of fixing the knob (2);

[0005] 2. The end of the pin (5) has a certain size, and the slot (9) also has a certain width. Only when the pin (5) is stuck in the slot (9) can the function of fixing the knob (2) be realized. When the knob ( 2) When the pin (5) is aligned with the rib of the card slot (9), the pin (5) cannot be stuck in the card slot (9), and the knob (2) cannot be fixed, so that the stitch pitch of the sewing machine cannot be adjusted. The needle distance corresponding to this position cannot be adjusted accurately;

[0006] 3. The self-locking ability of this structure is poor, which is specifically reflected in the following: due to the small gap between the stitch length adjustment arm (7) and the screw (3), the stitch length adjustment arm (7) will be very high during actual sewing. The frequency hits the screw (3), causing the screw (3) to vibrate. After a long time, it will cause the screw (3) to rotate relative to the sewing machine housing, and the pin (5), the slot (9) and the spring ( The combination of 6) provides a small damping force for the knob (2), and it is difficult to limit the rotation of the screw (3), which will gradually increase the needle pitch of the sewing machine

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