Disclosed herein are a lower-thread supply device of sewing machine and a sewing method. The device includes a bobbin case (300) having an outlet (330) from which lower thread is drawn out, and a needle through-hole (340) through which a needle (600) moving downwards with upper thread (a) being fitted passes, and a hook body (200) in which the bobbin case (300) is mounted, the hook body being installed to be rotatable by a power device of a sewing machine, guiding upper thread (a2) on a sewn fabric side to a front area of the bobbin case (300) while catching and dragging the upper thread (a) via a hook (210), and guiding upper thread (a1) on a spool side to a rear area of the bobbin case (300). The bobbin case (300) is installed not to be rotated when the hook body (200) rotates.

Disclosed herein are a lower-thread supply device of sewing machine and a sewing method. The device includes a bobbin case (300) having an outlet (330) from which lower thread is drawn out, and a needle through-hole (340) through which a needle (600) moving downwards with upper thread (a) being fitted passes, and a hook body (200) in which the bobbin case (300) is mounted, the hook body being installed to be rotatable by a power device of a sewing machine, guiding upper thread (a2) on a sewn fabric side to a front area of the bobbin case (300) while catching and dragging the upper thread (a) via a hook (210), and guiding upper thread (a1) on a spool side to a rear area of the bobbin case (300). The bobbin case (300) is installed not to be rotated when the hook body (200) rotates.

A low-cost sewing machine capable of achieving a desired balance between needle thread consumption and bobbin thread consumption is described. A memory section stores needle thread requirement data having precorrected needle thread requirement and postcorrected needle thread requirement. In a torque control zone, rotating force is imparted to a turning arm so as to impart a tension on the needle thread according to a torque value, while closing an upstream grip section main body and while opening a downstream grip section main body. In a first position control zone, the needle thread is drawn according to the postcorrected needle thread requirement, while opening the upstream grip section main body and while closing the downstream grip section. In a second position control zone, the turning arm is returned to an initial position, while closing the upstream grip section main body and while opening the downstream grip section main body.

A low-cost sewing machine capable of achieving a desired balance between needle thread consumption and bobbin thread consumption is described. A memory section stores needle thread requirement data having precorrected needle thread requirement and postcorrected needle thread requirement. In a torque control zone, rotating force is imparted to a turning arm so as to impart a tension on the needle thread according to a torque value, while closing an upstream grip section main body and while opening a downstream grip section main body. In a first position control zone, the needle thread is drawn according to the postcorrected needle thread requirement, while opening the upstream grip section main body and while closing the downstream grip section. In a second position control zone, the turning arm is returned to an initial position, while closing the upstream grip section main body and while opening the downstream grip section main body.

In a sewing machine, an elevating unit is configured to be integrally raised and lowered with a threading lever of a threading apparatus. Furthermore, an operating lever is coupled to a lever interlocking mechanism that interlocks with the rotational operation of the operating lever. Upon pressing threading lever downward from an initial position when operating lever is at an operating position, an elevating unit engages with lever interlocking mechanism. Operating force applied to threading lever is transmitted to operating lever via lever interlocking mechanism, thereby turning operating lever from operating position to non-operating position. Accordingly, even when a presser is at a raised position, by pressing threading lever downward, operating lever is turnable from operating position to non-operating position, thereby allowing presser to return to pressing position.

In a sewing machine, an elevating unit is configured to be integrally raised and lowered with a threading lever of a threading apparatus. Furthermore, an operating lever is coupled to a lever interlocking mechanism that interlocks with the rotational operation of the operating lever. Upon pressing threading lever downward from an initial position when operating lever is at an operating position, an elevating unit engages with lever interlocking mechanism. Operating force applied to threading lever is transmitted to operating lever via lever interlocking mechanism, thereby turning operating lever from operating position to non-operating position. Accordingly, even when a presser is at a raised position, by pressing threading lever downward, operating lever is turnable from operating position to non-operating position, thereby allowing presser to return to pressing position.

In a sewing machine, an elevating unit is configured to be integrally raised and lowered with a threading lever of a threading apparatus. Furthermore, an operating lever is coupled to a lever interlocking mechanism that interlocks with the rotational operation of the operating lever. Upon pressing threading lever downward from an initial position when operating lever is at an operating position, an elevating unit engages with lever interlocking mechanism. Operating force applied to threading lever is transmitted to operating lever via lever interlocking mechanism, thereby turning operating lever from operating position to non-operating position. Accordingly, even when a presser is at a raised position, by pressing threading lever downward, operating lever is turnable from operating position to non-operating position, thereby allowing presser to return to pressing position.

In a sewing machine, an elevating unit is configured to be integrally raised and lowered with a threading lever of a threading apparatus. Furthermore, an operating lever is coupled to a lever interlocking mechanism that interlocks with the rotational operation of the operating lever. Upon pressing threading lever downward from an initial position when operating lever is at an operating position, an elevating unit engages with lever interlocking mechanism. Operating force applied to threading lever is transmitted to operating lever via lever interlocking mechanism, thereby turning operating lever from operating position to non-operating position. Accordingly, even when a presser is at a raised position, by pressing threading lever downward, operating lever is turnable from operating position to non-operating position, thereby allowing presser to return to pressing position.

A sewing machine includes at least one needle bar, a threading motor, a threading mechanism, a processor, and a memory. The threading mechanism is configured to pass an upper thread through an eye of a sewing needle. The memory is configured to store computer-readable instructions that, when executed by the processor, instruct the processor to perform processes. The processes include making one of a setting that prohibits operation of the threading mechanism and a setting that does not prohibit the operation of the threading mechanism. The processes include switching the operation of the threading mechanism by prohibiting the operation of the threading mechanism in a case where the setting that prohibits the operation of the threading mechanism is made, and permitting the operation of the threading mechanism in a case where the setting that does not prohibit the operation of the threading mechanism is made.

A sewing machine includes at least one needle bar, a threading motor, a threading mechanism, a processor, and a memory. The threading mechanism is configured to pass an upper thread through an eye of a sewing needle. The memory is configured to store computer-readable instructions that, when executed by the processor, instruct the processor to perform processes. The processes include making one of a setting that prohibits operation of the threading mechanism and a setting that does not prohibit the operation of the threading mechanism. The processes include switching the operation of the threading mechanism by prohibiting the operation of the threading mechanism in a case where the setting that prohibits the operation of the threading mechanism is made, and permitting the operation of the threading mechanism in a case where the setting that does not prohibit the operation of the threading mechanism is made.