Lower thread supply device for sewing machine

Abstract

The present invention relates to a lower thread supply device for a sewing machine, comprising: a housing (100) which is fixed to a main body of a sewing machine, has a cylindrical shape in which a front side and a back side are opened along a central axis, and has a (a housing cut out portion)(110) formed by cutting the outer circumferential surface of one side; a rotation plate (200) which is connected to a power shaft of a sewing machine, has a disk shape, has a power transmission protrusion (210) formed on the front surface of the disk, and is provided at the back inner lateral side of the housing (100) to rotate; a hook body (300) which is rotatably provided inside the housing (100), has a cylindrical shape with an opened front side, a protrusion receiving part (320) formed at the back outer portion to receive the torque of the rotation plate (200) by being engaged with the power transmission protrusion (210), a bobbin mounting post (330) formed at the back inner portion, and a hook (310) that passes through the loop formed by an upper thread descending along a needle of a sewing machine, thereby pulling the upper thread, provided at the outer circumferential surface of one side; a spool-shaped bobbin (400) which is inserted into the bobbin mounting post (330) of the hook body (300) to be rotatably provided, and to which a lower thread is wound; and a cap (500) which passes through the center of the bobbin (400) to be detachably coupled to the bobbin mounting post (330), thereby preventing the separation of the bobbin from the hook body (300).

Description

technical field

[0001] The present invention relates to a sewing machine bobbin thread supply device. The present invention is a new technology capable of increasing the primary loading capacity of the bobbin thread compared with the existing bobbin thread supply device while maintaining the structure of the existing sewing machine. Background technique

[0002] Such as figure 1 As shown, a rotary hook device 100 for supplying bobbins is usually provided on a sewing machine. The rotary hook device 100 is installed on the drive shaft 10 rotatably connected to the power device (power transmission gear) of the sewing machine, and consists of a hook body 20 (Hook Body), a bobbin box (Bobbin) accommodated in the hook body 20 Case: BC), bobbin 40 (Bobbin) wound with bobbin thread.

[0003] The bobbin case (BC) is accommodated in the hook body 20 and is composed of a bobbin case base 30 (Bobbin Case Base) and a bobbin case body 50 (Bobbin Case Body) on the outside of the bobbin c...

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