US 2012/0097084 A1Published application

Sewing-machine bobbin thread tension controller, and sewing machine

AssigneeNsd Corporation

InventorsYoshichika Takizawa, Masayoshi Ono, Tatsuhiro Kurashima

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Abstract

There is provided a sewing-machine bobbin thread tension controller capable of elaborately, accurately controlling bobbin thread tension without depending on frictional force. A bobbin thread tension controller includes an outer shuttle 110, a middle shuttle presser 130, a middle shuttle 150, a bobbin thread tension control mechanism 200, a shuttle actuation unit 250, and a bobbin 300. The middle shuttle 150 has a magnet 190. A magnet 270 is disposed, in close proximity to the magnet 190, on an arm 260 attached to a rotary shaft of a shuttle actuation motor 252 provided in the shuttle actuation unit 250. The middle shuttle 150 is rotated by rotating the magnet 270 by means of the motor 252. Further, a rotary disc 210 is provided, in close proximity to the middle shuttle 150, on a rotary shaft of a bobbin thread tension control motor 202 of the bobbin thread tension control mechanism 200 and is provided with a magnet 214. A magnet is disposed on a part of the bobbin 300 facing the rotary disc 210. The motor 202 rotates the bobbin 300.

Claims20

Dependent claims

A sewing-machine bobbin thread tension controller, comprising:

an outer shuttle (110) that has a circular-arc inner peripheral surface and includes a guide groove formed on a front side which is one side of the inner peripheral surface in an axial direction;
a middle shuttle (150) that rotates along the guide groove of the outer shuttle, to thus hook a needle thread, and that includes
a race (152) formed into a circular arc along a circumferential edge of the middle shuttle and slidably supported by the guide groove,
a rear portion (161) continually extending from a rear-side edge of an inner circumferential edge of the race, and
a shaft (184) formed on a front surface of the rear portion and along a center of rotation of the rear portion, wherein at least the rear portion and the shaft are made of a non-magnetic substance;
a middle shuttle presser (130) that is provided on a front side of the outer shuttle in order to prevent the middle shuttle accommodated in the outer shuttle from falling from the outer shuttle;
a bobbin (300) that has a hole through which the shaft of the middle shuttle passes, that is axially supported in the middle shuttle as a result of the shaft being inserted into the hole, and that has a first magnet (310) provided on a rear surface which is a surface opposing a rear portion of the middle shuttle when the bobbin is axially supported by the shaft;
and
a bobbin thread tension control mechanism (200, 1200) that includes
a bobbin thread tension control motor (202, 1202) which is provided at a rear of the middle shuttle, which has a rotary shaft concentric to the center of rotation of the middle shuttle, and which rotates the rotary shaft in a direction opposite to a rotating direction of the bobbin achieved when a bobbin thread wound around the bobbin is withdrawn and
a second magnet (214, 1214) which is rotated by the bobbin thread tension control motor, which is disposed in close proximity to the rear portion of the middle shuttle, and which rotates the first magnet.

8 more elements

A sewing-machine bobbin thread tension controller, comprising:

an outer shuttle (110) that includes a guide groove formed on an inner peripheral surface thereof;
a middle shuttle (150) that rotates along the guide groove of the outer shuttle, to thus hook a needle thread, and that includes
a race (152) formed into a circular arc along a circumferential edge of the middle shuttle and slidably supported by the guide groove,
a main middle shuttle (160) that continually extends from an inner end of the race and that includes
a rear portion (161) continually extending from a rear-side end which is one end of an inner circumferential edge of the race achieved in a rotating an axial direction, and
a front-side tapered portion (166) which continually extends from a front-side end which is a remaining end of the inner circumferential edge of the race, and which is tapered so as to have a smaller diameter toward the front, wherein the rear portion (161) further includes
a substantially circular plate-like rear-side body (162) which is perpendicular to an axial line serving as a center of rotation of the middle shuttle and whose outer diameter is smaller than an inner diameter of the race and
a rear-side tapered portion (164) which is formed between a surrounding area of the rear-side body and the race and which is tapered so as to have a smaller diameter from the race toward the rear-side body,
a bobbin accommodation section (180) that is formed in a front surface of the rear-side body and that includes
a shaft (184) formed so as to extend from a center of the rear-side body along the center of rotation of the middle shuttle and
a cylindrical tubular portion (182) provided on a front surface of the rear-side body, and
a third magnet (190) disposed on a front or rear surface of the rear-side tapered portion, wherein the middle shuttle except the third magnet is made of a non-magnetic substance;
a middle shuttle presser (130) that is disposed on a front side of the outer shuttle in order to prevent the middle shuttle accommodated in the outer shuttle from falling from the outer shuttle;
a bobbin (300) that is accommodated in the bobbin accommodation section of the middle shuttle and that has a first magnet (310) disposed on a plane perpendicular to an axial line serving as a center of rotation;
a bobbin thread tension control mechanism (200) that includes
a bobbin thread tension control motor (202) which is disposed at a rear of the middle shuttle, which has a rotary shaft concentric to the center of rotation of the middle shuttle, and which rotates the rotary shaft in a direction opposite to a rotating direction of the bobbin achieved when a bobbin thread wound around the bobbin is withdrawn, and
a rotary disc (210) which is attached to a rotary shaft of the bobbin thread tension control motor and positioned in close proximity to the rear portion of the middle shuttle and which has a second magnet (214) for rotating the first magnet as a result of rotation of the rotary disc;
a shuttle actuation unit (250) that includes
a shuttle actuation motor (252) which is provided at a rear of the bobbin thread tension control motor and which has a second rotary shaft serving as a rotary shaft concentric to the center of rotation of the middle shuttle,
a substantially L-shaped arm (260) attached to the second rotary shaft and including
a base end (262) attached to the secondary shaft and perpendicular to an axial center core of the second rotary shaft and
a leading end (264) continually extending from the base end in parallel to the axial center core of the second rotary shaft, and
a fourth magnet (270) attached to an extremity of the arm and in close proximity to the third magnet;
and
a control section (40) for controlling rotation of the shuttle actuation motor such that the middle shuttle makes substantially half forward and backward rotations.

22 more elements

A sewing-machine bobbin thread tension controller, comprising:

an outer shuttle (110) that includes a guide groove formed on an inner peripheral surface thereof;
a middle shuttle (150) that rotate along the guide groove of the outer shuttle, to thus hook a needle thread, and that includes
a race (152) formed into a circular arc along a circumferential edge of the middle shuttle and slidably supported by the guide groove,
a main middle shuttle (160) that continually extends from an inner end of the race and that includes
a rear portion (161) continually extending from a rear-side end which is one end of an inner circumferential edge of the race achieved in an axial direction, and
a front-side tapered portion (166) which continually extends from a front-side end which is a remaining end of the inner circumferential edge of the race, and which is tapered so as to have a smaller diameter toward the front, wherein the rear portion (161) further includes
a substantially circular plate-like rear-side body (162), perpendicular to an axial line serving as a center of rotation of the middle shuttle, that has an outer diameter which is smaller than an inner diameter of the race and
a rear-side tapered portion (164) that is formed between a surrounding area of the rear-side body and the race and that is tapered so as to have a smaller diameter from the race toward the rear-side body,
a bobbin accommodation section (180) formed in a front surface of the rear-side body and that includes
a shaft (184) formed so as to extend from a center of the rear-side body along the center of rotation of the middle shuttle and
a cylindrical tubular portion (182) provided on a front surface of the rear-side body, and
a third magnet (190) disposed on a front or rear surface of the rear-side tapered portion, wherein the middle shuttle except the third magnet is made of a non-magnetic substance;
a middle shuttle presser (130) disposed on a front side of the outer shuttle in order to prevent the middle shuttle accommodated in the outer shuttle from falling from the outer shuttle;
a bobbin (300) that is accommodated in the bobbin accommodation section of the middle shuttle and that has a first magnet (310) disposed on a plane perpendicular to an axial line serving as a center of rotation;
a bobbin thread tension control mechanism (1200) that includes
a bobbin thread tension control motor (1202) which is disposed at a rear of the middle shuttle, which has a rotary shaft concentric to the center of rotation of the middle shuttle and which rotates the rotary shaft in a direction opposite to a rotating direction of the bobbin achieved when a bobbin thread wound around the bobbin is withdrawn, and
a rotary disc (1210) which is attached to a rotary shaft of the bobbin thread tension control motor and positioned in close proximity to the rear portion of the middle shuttle and which has a second magnet (1214) for rotating the first magnet as a result of rotation of the rotary disc;
a shuttle actuation unit (1250) that includes
a shuttle actuation motor (1252) which is interposed between the bobbin thread tension control motor and the middle shuttle and which has
an insert hole enabling insertion of a rotary shaft of the bobbin thread tension control motor and
a second rotary shaft, which is a rotary shaft of the shuttle actuation motor, is formed into a tubular shape so as to enable insertion of the rotary shaft of the bobbin thread tension control motor;
wherein an axial line of the second rotary shaft is concentric to an axial line of the rotary shaft of the bobbin thread tension control motor,
a substantially L-shaped arm (1260) which is attached to the second rotary shaft and which includes
a base end (1262) attached to the secondary rotary shaft perpendicular to an axial center core of the second rotary shaft and
a leading end (1264) continually extending from the base end in parallel to the axial center core of the second rotary shaft, and
a fourth magnet (1270) attached to an extremity of the arm and in close proximity to the third magnet;
and
a control section (40) for controlling rotation of the shuttle actuation motor such that the middle shuttle makes a full rotation.

25 more elements

Dependencies are inferred from the claim text.