Abstract: A motor control device is used to control an electric motor that drives a presser mechanism of a sewing machine and includes a knee lever mechanism and a control module. The knee lever mechanism includes a switch component, an actuator rotatable to actuate the switch component at a predetermined angular position, and a rotatable knee lever operable by knee contact to rotate and to drive rotation of the actuator. When the control module determines that the switch component is actuated, the control module controls the electric motor to move the presser mechanism to dispose a presser foot of the presser mechanism at a predetermined height relative to a bed of the sewing machine.

Abstract: A clutch device used to couple/decouple a reciprocating force of a drive member to/from a needle bar in a sewing machine includes an actuating lever actuated by an electromechanical unit to be pivotable between an idle position to disengage from an actuated end of a clutch lever so as to leave a grasp end of the clutch lever in a coupled state, where the grasp end is engaged with a coupled portion disposed on a drive member, thereby transmit the reciprocating force to the needle bar, and an actuating position to be in pressing engagement with the actuated end so as to displace the grasp end to a decoupled state, where the grasp end is disengaged from the coupled portion.

Abstract: A sewing machine includes a thread holding device disposed downstream of a thread take-up lever and upstream of a needle bar in terms of a threading path of a needle thread, and including a fixed first disc and a movable second disc movable by an electromechanical unit between holding and releasing positions to be closer to and remote from the first disc, respectively. The first and second discs respectively have first and second holding surfaces cooperatively defining a thread holding clearance to permit passage of the needle thread therethrough. The needle thread can be clamped in the thread holding clearance so as to prevent the needle thread being pulled out of the needle during a thread cutting procedure. A required amount of the needle thread remaining on the needle can be secured.

Abstract: A feed dog device for a sewing machine includes a feed dog mount mounted under a needle plate and having a feed dog mounted thereon to permit the feed dog to extend through slots in the needle plate. The feed dog mount is coupled with a lever through a force transmitting unit to couple an increased torque generated by a pivotal movement of the lever to the feed dog mount so as to enable a weight end of the lever to drive the feed dog mount to move reciprocatingly in a transverse direction perpendicular to a normal feeding direction of a fabric. The lever is actuated by a cam follower with a torque generated as a result of transmission through a rotary cam member which is rotated with an output shaft of the drive member. Since the feed dog can be reciprocatingly moved in the transverse direction, the sewing machine can perform a variety of sewing operations.

Abstract: A sewing machine includes a thread holding device disposed downstream of a thread take-up lever and upstream of a needle bar in terms of a threading path of a needle thread, and including a fixed first disc and a movable second disc movable by an electromechanical unit between holding and releasing positions to be closer to and remote from the first disc, respectively. The first and second discs respectively have first and second holding surfaces cooperatively defining a thread holding clearance to permit passage of the needle thread therethrough. The needle thread can be clamped in the thread holding clearance so as to prevent the needle thread being pulled out of the needle during a thread cutting procedure. A required amount of the needle thread remaining on the needle can be secured.

Abstract: An embroidery sewing machine includes a machine body carrying a needle, a shuttle and a bobbin. A cutter is disposed in proximity to the needle to cut a thread end portion of an upper thread that extends out of an eye of the needle so that the thread end portion has an adjusted length after being cut by the cutter. The needle, shuttle and bobbin are controlled to perform an initial stitching operation that pulls the thread end portion from an upper side of a fabric to an under side thereof and that produces a fixing stitch beneath the fabric to prevent the upper thread from being loosened. An embroidering method is also disclosed.

Abstract: A bypass-type motor protecting device includes: a casing fitted into a bypass opening in a body housing of a vacuum cleaner and having an inner abutment wall; a seat body having a bypass entry port; a valve body unit movable within the casing relative to the bypass entry port and including a valve disc to be engaged with and disengaged from the seat body, a plunger body having an externally accessible operated head and an axially extending threaded shank, and an abutment member threadedly engaged with the shank such that rotation of the operated head results in a change of an axial distance between the abutment member and the inner abutment wall; and a biasing member disposed to bias the abutment member and the inner abutment wall such that a biasing force thereof is varied in strength by the change of the axial distance.

Abstract: A device for driving movement of a piece of cloth to be embroidered includes a driving unit for driving a mounting seat to move relative to a base unit. A cloth-holding frame device holds tensionally the piece of cloth between inner and outer frames, and includes an identification module mounted to a connecting block of the outer frame that is mounted detachably to mounting seat for generating an identification output corresponding to an embroidery area defined in the cloth-holding frame device. When the connecting block is connected to the mounting seat, the identification module is coupled to a control unit via a connecting port of the mounting seat. The control unit controls the driving unit based on the identification output from the identification module so that embroidery operation is performed on the piece of cloth disposed within the embroidery area in the cloth-holding frame device.

Abstract: A thread cutting device is adapted to be mounted under a bed of a sewing machine, and includes a mount having a marginal region which confronts a thread fetching zone, and a guide slot which is elongated parallel to a stroke path, a fixed knife disposed on the marginal region and having a blade aligned with the stroke path, a movable knife having a shank body which extends along the stroke path to terminate at actuated and hook ends, a drive unit disposed under the mount and having a rotatable output shaft to deliver a rotational force, and a rotation/translation conversion mechanism disposed to convert the rotational force into a translational force that is transmitted through the guide slot to actuate a translation of the actuated end of the shank body to thereby move the shank body between fetching and thread cutting positions.

Abstract: A bobbin case is used in a sewing machine for mounting a bobbin, and includes a case body having a base wall, a case shaft extending along a central line from the base wall for rotatably mounting the bobbin, and a rim having entry and exit holes to define a tensioning path therebetween, and a diverting concaivity configured to divert a running route which is disposed downstream of the tensioning path. A lead-out member is disposed downstream of the running route. A leaf spring is positioned on the rim, and is configured to guide an under thread of the bobbin to run along the tensioning path with an urging force, and continued on running along the running route to the lead-out member to be interlocked with an upper thread for a sewing action.

Abstract: A clutch device used to couple/decouple a reciprocating force of a drive member to/from a needle bar in a sewing machine includes an actuating lever actuated by an electromechanical unit to be pivotable between an idle position to disengage from an actuated end of a clutch lever so as to leave a grasp end of the clutch lever in a coupled state, where the grasp end is engaged with a coupled portion disposed on a drive member, thereby transmit the reciprocating force to the needle bar, and an actuating position to be in pressing engagement with the actuated end so as to displace the grasp end to a decoupled state, where the grasp end is disengaged from the coupled portion.

Abstract: A thread cutting device is adapted to be mounted under a bed of a sewing machine, and includes a mount having a marginal region which confronts a thread fetching zone, and a guide slot which is elongated parallel to a stroke path, a fixed knife disposed on the marginal region and having a blade aligned with the stroke path, a movable knife having a shank body which extends along the stroke path to terminate at actuated and hook ends, a drive unit disposed under the mount and having a rotatable output shaft to deliver a rotational force, and a rotation/translation conversion mechanism disposed to convert the rotational force into a translational force that is transmitted through the guide slot to actuate a translation of the actuated end of the shank body to thereby move the shank body between fetching and thread cutting positions.

Abstract: A feed dog device for a sewing machine includes a feed dog mount mounted under a needle plate and having a feed dog mounted thereon to permit the feed dog to extend through slots in the needle plate. The feed dog mount is coupled with a lever through a force transmitting unit to couple an increased torque generated by a pivotal movement of the lever to the feed dog mount so as to enable a weight end of the lever to drive the feed dog mount to move reciprocatingly in a transverse direction perpendicular to a normal feeding direction of a fabric. The lever is actuated by a cam follower with a torque generated as a result of transmission through a rotary cam member which is rotated with an output shaft of the drive member. Since the feed dog can be reciprocatingly moved in the transverse direction, the sewing machine can perform a variety of sewing operations.

Abstract: A stationary thread-cutting device for a sewing machine includes a guiding member and a cutter. The guiding member is mounted on a needle plate, and has a major wall defining a thread guiding route. The guiding route includes a lead-in area having an entry slot to permit entry of a leading end of a bobbin thread, a turn-around area for guiding the leading end, a corner piece disposed at the turn-around area, and a cutting station disposed adjacent to a lateral edge of the needle plate to define a lead-out path with the corner piece. The cutter is disposed under the major wall and adjacent to the cutting station, and has a cutting blade. After the bobbin thread is advanced beyond the cutting station, the bobbin thread is cut, thereby ensuring that a predetermined length of the bobbin thread is available for initial interlacing with a needle thread in a sewing operation.

Abstract: A device for driving movement of a piece of cloth to be embroidered includes a driving unit for driving a mounting seat to move relative to a base unit. A cloth-holding frame device holds tensionally the piece of cloth between inner and outer frames, and includes an identification module mounted to a connecting block of the outer frame that is mounted detachably to mounting seat for generating an identification output corresponding to an embroidery area defined in the cloth-holding frame device. When the connecting block is connected to the mounting seat, the identification module is coupled to a control unit via a connecting port of the mounting seat. The control unit controls the driving unit based on the identification output from the identification module so that embroidery operation is performed on the piece of cloth disposed within the embroidery area in the cloth-holding frame device.

Abstract: A thread cutting device for a sewing machine with a hook rotatable in a vertical plane includes a drive motor, a fixed knife which has a working-side wall extending towards a thread fetching zone of the sewing machine to terminate at a first cutting edge, and a movable knife which is driven by the drive motor to angularly move between fetching and thread cutting positions in a vertical plane. The movable knife has a lateral edge surface defining a cavity in an intermediate segment thereof to engage lower and upper threads when the movable knife reaches the fetching position. The movable knife has a second cutting edge disposed to press the first cutting edge so as to complete a cutting action.

Abstract: A bypass-type motor protecting device includes: a casing fitted into a bypass opening in a body housing of a vacuum cleaner and having an inner abutment wall; a seat body having a bypass entry port; a valve body unit movable within the casing relative to the bypass entry port and including a valve disc to be engaged with and disengaged from the seat body, a plunger body having an externally accessible operated head and an axially extending threaded shank, and an abutment member threadedly engaged with the shank such that rotation of the operated head results in a change of an axial distance between the abutment member and the inner abutment wall; and a biasing member disposed to bias the abutment member and the inner abutment wall such that a biasing force thereof is varied in strength by the change of the axial distance.