US 7,490,567 B2Granted

Seam puckering preventing shuttle device of sewing machine

AssigneeSuzuki Manufacturing, Ltd.

InventorKouichi Sakuma

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Abstract

A puckering preventing shuttle device of a sewing machine capable of providing high quality stitches without producing puckering by eliminating needle thread extraction resistance on the outer periphery of a rotating hook bobbin case holder to reduce the tension of a needle thread so as to keep a balance between the needle thread and a bobbin thread and also enabling the proper tightening of the threads even in an extra-soft fabric. The device comprises the rotating hook bobbin case holder (80) storing a bobbin case storing a bobbin around which the bobbin thread is wrapped and detachably fixed to a machine frame and locked to the machine frame by rotating hook bobbin case holder stopper (90) to stop its rotation and a rotating hook (70) in which the rotating hook bobbin case holder (80) is installed, having a sword tip (75), and rotated by a lower shaft. A needle thread inlet (EN1) and a needle thread outlet (EX1) are formed at circumferentially different positions between the rotating hook bobbin case holder stopper (90) and the rotating hook bobbin case holder (80) where the loop of the needle thread picked up by the sword tip (75) for each rotation of the rotatingly driven rotating hook (70) forms a clearance for guiding in and out the needle thread on the outer periphery of the rotating hook bobbin case holder (80) by eccentrically disposing the rotating center (O1) of the rotating hook (70) relative to the rotating center of the lower shaft.

Claims25

Dependent claims

A seam puckering preventing shuttle device of a sewing machine, which uses an upper thread inserted into a needle moving upward and downward while drawing a trace vertically of a throat plate, and a lower thread accommodated in a full rotation hook, which is disposed below the throat plate and accommodates the lower thread, and which picks up the upper thread, at the time when the upper thread inserted into the needle extending through a work placed on the throat plate and performing reciprocating movements in the vertical direction is raised from the lower dead center of the needle for each feed of the work, with a loop-taker point of the full rotation hook to interlace the upper thread and the lower thread thereby to form lock stitches in the work,

wherein the full rotation hook includes:
an inner hook accommodating a shuttle bobbin having the lower thread wound thereon and fixed removably, and prevented from rotating relative to the frame by an inner hook stopper;
and an outer hook mounting the inner hook therein, having the loop-taker point and rotated by a rotation driving portion;
wherein the inner hook is arranged to have its rotation center eccentric to the rotation center of the rotation driving portion so that an upper thread entrance and an upper thread exit are formed between the inner hook stopper and the inner hook at circumferentially different positions where clearances are formed to guide in and guide out the loop of the upper thread on the outer circumference of the inner hook after the loop of the upper thread picked up by the loop-taker point for every predetermined rotations of the outer hook rotationally driven as pulled out to the maximum by the outer circumference of the inner hook;
wherein the upper thread entrance is arranged at the position where the loop of the upper thread picked up by the loop-taker point is guided in on the outer circumference of the inner hook whereas the upper thread exit is arranged at the position where the loop of the upper thread is guided out on the outer circumference of the inner hook and pulled upward of the throat plate;
wherein the upper thread entrance and the upper thread exit are arranged at an angular space of 120 degrees to 160 degrees;
and
wherein the rotation center of the inner hook is eccentric in the direction at the angular space between the upper thread entrance and the upper thread exit with respect to the rotation center of the rotation driving portion.

5 more elements

A seam puckering preventing shuffle device of a sewing machine, which uses an upper thread inserted into a needle moving upward and downward while drawing a trace vertically of a throat plate, and a lower thread accommodated in a full rotation hook , which is disposed below the throat plate and accommodates the lower thread, and which picks up the upper thread, at the time when the upper thread inserted into the needle extending through a work placed on the throat plate and performing reciprocating movements in the vertical direction is raised from the lower dead center of the needle for each feed of the work, with a loop-taker point of the full rotation hook to interlace the upper thread and the lower thread thereby to form lock stitches in the work,

wherein the full rotation hook includes:
an inner hook accommodating a shuffle bobbin case accommodating a shuffle bobbin having the lower thread wound thereon and removably fixed, and prevented from rotating relative to the frame by an inner hook stopper;
and an outer hook mounting the inner hook therein, having the loop-taker point and rotated by a rotation driving portion;
wherein the inner hook is arranged to have its rotation center eccentric to the rotation center of the rotation driving portion so that an upper thread entrance and an upper thread exit are formed between the inner hook stopper and the inner hook at circumferentially different positions where clearances are formed to guide in and guide out the loop of the upper thread on the outer circumference of the inner hook after the loop of the upper thread picked up by the loop-taker point for every predetermined rotations of the outer hook rotationally driven was pulled out to the maximum by the outer circumference of the inner hook;
wherein the upper thread entrance is arranged at the position where the loop of the upper thread picked up by the loop-taker point is guided in on the outer circumference of the inner hook whereas the upper thread exit is arranged at the position where the loop of the upper thread is guided out on the outer circumference of the inner hook and pulled upward of the throat plate;
wherein the upper thread entrance and the upper thread exit are arranged at an angular space of 120 degrees to 160 degrees ;
and
wherein the rotation center of the inner hook is eccentric in the direction at the angular space between the upper thread entrance and the upper thread exit with respect to the rotation center of the rotation driving portion.

5 more elements

A seam puckering preventing shuttle device of a sewing machine, which uses an upper thread inserted into a needle moving upward and downward while drawing a trace vertically of a throat plate, and a lower thread accommodated in a full rotation hook, which is disposed below the throat plate and accommodates the lower thread, and which picks up the upper thread, at the time when the upper thread inserted into the needle, extending through a work placed on the throat plate and performing reciprocating movements in the vertical directions is raised from the lower dead center of the needle for each feed of the work, with a loop-taker point of the full rotation hook to interlace the upper thread and the lower thread thereby to form lock stitches in the work,

wherein the full rotation hook includes:
an inner hooks;
a shuttle bobbin having the lower thread wound thereon and removably fixed within the inner hook;
and
the loop-taker point;
a rotary member, defining a rotation center, for rotatably driving the inner hook;
and
a non-rotatable outer hook mounting the inner hook rotatably therein;
wherein the inner hook includes two driven portions arranged at circumferentially spaced positions, and the rotary member includes two driving portions individually loosely fitted to the driven portions, as pairs of a driven portion and a driving portion, for rotatably driving the inner hook;
wherein the driven portions are arranged with a rotation center eccentric to the rotation center of the rotary member so that, when one pair of a the driving portion and a driven portion are engaged to rotatably drive the inner hook, the driving portion and the driven portion of the other pair have a clearance therebetween, before the loop of the upper thread is pulled to the maximum by the loop-taker point of the inner hook for guiding in and out the loop of the upper thread on the side of the driving portions of the inner hook;
wherein the upper thread entrance is arranged at the phase where the loop of the upper thread picked up by the loop-taker point is guided onto the outer circumference of the inner hook whereas the upper thread exit is arranged at the phase where the loop of the upper thread is guided off of the outer circumference of the inner hook and pulled upward of the throat plate;
wherein the upper thread entrance and the upper thread exit are angularly spaced 90 degrees to 130 degrees at circumferentially different positions across the upper dead center of the loop-taker point;
and
wherein the rotation center of the driven portions is eccentric, in a direction backward of the upper dead center of the loop-taker point, with respect to the rotation center of the rotary member.

11 more elements

A seam puckering preventing shuttle device of a sewing machine, which uses an upper thread inserted into a needle moving upward and downward while drawing a trace vertically of a throat plate, and a lower thread accommodated in a full rotation hook, which is disposed below the throat plate and accommodates the lower thread, and which picks up the upper thread, at the time when the upper thread inserted into the needle1 extending through a work placed on the throat plate and performing reciprocating movements in the vertical direction1 is raised from a the lower dead center of the needle for each feed of the work, with a loop-taker point of the full rotation hook to interlace the upper thread and the lower thread thereby to form lock stitches in the work,

wherein the full rotation hook includes, a shuttle bobbin case accommodated within the inner hook, a shuttle bobbin removably fixed within the shuttle bobbin case and having the lower thread wound thereon;
a loop-taker point;
a rotary member, defining a rotation center, for rotatably driving the inner hook;
and a non-rotatable outer hook mounting the inner hook for rotation therein;
wherein the inner hook includes two driven portions arranged at circumferentially spaced different positions, and two driving portions circumferentially spaced and individually loosely fitted to the driven portions, as pairs of a driven portion and a driving portion, for rotatably driving the inner hook;
wherein the driven portions are arranged with a rotation center eccentric to the rotation center of the rotary member so that, when one pair of a the driving portion and a driven portion are engaged to rotatably drive the inner hook, the driving portion and the driven portion of the other pair have a clearance therebetween, before the loop of the upper thread is pulled to the maximum by the loop-taker point of the inner hook, for guiding in and out the loop of the upper thread on the side of the driving portions of the inner hook;
wherein the upper thread entrance is arranged where the loop of the upper thread picked up by the loop-taker point is guided onto the outer circumference of the inner hooks whereas the upper thread exit is arranged where the loop of the upper thread is guided off of the outer circumference of the inner hook and pulled upward of the throat plate;
wherein the upper thread entrance and the upper thread exit are angularly spaced 90 degrees to 130 degrees at circumferentially different positions across the upper dead center of the loop-taker point;
and
wherein the rotation center of the driven portions is eccentric, in a direction backward of the upper dead center of the loop-taker point, with respect to the rotation center of the rotary member.

7 more elements

A seam puckering preventing horizontal shuttle device of a sewing machine, which uses an upper thread inserted into a needle moving upward and downward while drawing a trace vertically of a throat plate, and a lower thread accommodated in a full rotation horizontal hook, which is disposed below the throat plate and accommodates the lower thread, and which picks up the upper thread, at the time when the upper thread inserted into the needle extending through a work placed on the throat plate and performing reciprocating movements in the vertical direction is raised from the lower dead center of the needle for each feed of the work, with a loop-taker point of the full rotation horizontal hook to interlace the upper thread and the lower thread thereby to form lock stitches in the work,

wherein the full rotation horizontal hook includes:
an inner hook accommodating a shuttle bobbin having the lower thread wound thereon and fixed removably, and prevented from rotating relative to the frame by an inner hook stopper;
and an outer hook mounting the inner hook therein, having the loop-taker point and rotated by a rotation driving portion;
wherein the inner hook is arranged to have its rotation center eccentric to the rotation center of the rotation driving portion so that an upper thread entrance and an upper thread exit are formed between the inner hook stopper and the inner hook at circumferentially different positions where clearances are formed to guide in and guide out the loop of the upper thread on the outer circumference of the inner hook after the loop of the upper thread picked up by the loop-taker point for every predetermined rotations of the outer hook rotationally driven was pulled out to the maximum by the outer circumference of the inner hook;
wherein the upper thread entrance is arranged in a rotational direction of 180 degrees to 210 degrees, of the loop-taker point from the needle drop point of the needle and at the position where the loop of the upper thread picked up by the loop-taker point is guided in on the outer circumference of the inner hook, whereas the upper thread exit is arranged in a rotational direction of 90 degrees to 180 degrees, from the upper thread entrance and at the position where the loop of the upper thread is guided out on the outer circumference of the inner hook and pulled upward of the throat plate;
and
wherein the rotation center of the inner hook is eccentric in the direction at the angular space between the upper thread entrance and the upper thread exit with respect to the rotation center of the rotation driving portion.

4 more elements

Dependencies are inferred from the claim text.