Thread pretension device for sewing machine

Abstract

The invention provides a prestressing device for sewing thread of a sewing machine, which comprises a guide wire seat, a preforce supply part, a propping part and a top cover. The part is made of elastic material, and the pre-force supply part is arranged in the accommodating groove. The pre-force supply part has a reversing part. The abutting part and the reversing part are set at the bottom of the groove, the abutting part is set on the pre-force supply part, the two abutting parts are abutted against the abutting part; the top cover is set on the abutting part, and the top cover is combined with the wire seat and located On the abutting member, a threading space is formed between the top cover and the abutting member, and the threading space is provided for the weaving suture to pass through; thus, the present invention mainly consists of making the pre-force supply member made of elastic material, and the form It is roughly V-shaped, so that the change of elastic force is relatively small, and it can provide appropriate line pressure.

Description

technical field [0001] The present invention relates to related components of a sewing machine, in particular to a sewing thread pre-tensioning device of the sewing machine. Background technique [0002] Generally, sewing machines will be equipped with a wire pre-force providing device. The wire pre-force providing device is used to provide appropriate pre-force for the sewing thread, so that the sewing thread can maintain an appropriate tension for subsequent sewing operations. Generally, the sewing machine of the prior art Suture pretensioning device such as Figure 11 shown, including: [0003] The base 70 has at least one groove 71; [0004] The sponge 81 is arranged in the groove 71; [0005] The propping member 82 is arranged on the sponge 81 for propping up the sponge 81; [0006] The top cover 83 is arranged on the abutment piece 82, and a threading space 84 is formed between the top cover 83 and the abutment piece 82, and the threading space 84 is provided for th...

AI Technical Summary

Problems solved by technology

[0008] However, the above-mentioned sponge 81 is prone to fatigue and deterioration after being used for a period of time, resulting in the inability to provide proper resistance force, and thus resulting in the inability to provide proper tension.

[0009] In addition, the two protrusions 831 of the top cover 83 are likely to interfere with the extension of the suture 90, and there is also a risk of pressing the suture 90.

[0010] Moreover, if the size of the two protrusions 831 of the top cover 83 is too large, it may cause the width of the threading space 84 to be too wide, so that sufficient tension cannot be provided for the stitching thread 90; otherwise, if the two of the top cover 83 If the size of the convex portion 831 is too small, the convex portion 831 may recover due to the restoring force of the metal, thereby failing to produce the corresponding effect;

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