Sewing machine

A sewing machine includes a thread cutter. The thread cutter includes a cutter blade having a blade edge configured to cut a thread, and a movable member. The movable member includes a guide having a guide surface adjacent to the cutter blade. The guide is configured to receive force from the thread at the guide surface during the course of cutting the thread with the cutter blade and to move in a moving direction which is a longitudinal direction of the blade edge.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority from Japanese Patent Application No. 2018-225279 filed on Nov. 30, 2018, the content of which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

Aspects described herein relate to a sewing machine.

BACKGROUND

A known sewing machine includes a thread cutter provided at a face plate of the sewing machine for cutting a thread manually. The thread cutter includes a cutter blade and a thread guide groove. The cutter blade is fixed to the sewing machine such that a blade edge of the cutter blade faces upward. The thread guide groove is configured to guide a thread to be cut toward the cutter blade. A user guides a thread toward the cutter blade through the thread guide groove. While contacting the thread with the blade edge of the cutter blade, the user pulls the thread downward, to cut the thread with the cutter blade.

SUMMARY

In the known sewing machine, a thread slidably moves downward along the blade edge to its end portion where the thread is pulled down and cut. Since the end portion of the blade edge is particularly used for cutting threads, the end portion may be worn. This may result in unsmooth thread cutting.

One or more aspects described herein provide a sewing machine that may eliminate or reduce influences of wear of a cutter blade of a thread cutter.

According to one or more aspects, a sewing machine may comprise a thread cutter. The thread cutter may include a cutter blade having a blade edge configured to cut a thread, and a movable member. The movable member may include a guide having a guide surface adjacent to the cutter blade. The guide may be configured to receive force from the thread at the guide surface during the course of cutting the thread with the cutter blade and to move in a moving direction which is a longitudinal direction of the blade edge.

The sewing machine may include the guide having the guide surface. The guide may receive force from the thread at the guide surface, during the course of cutting the thread with the cutter blade and to move in a longitudinal direction of the blade edge. The thread may slidably move in the longitudinal direction of the blade edge while pushing the guide surface, and be cut with a sharp portion (e.g., unworn portion) of the blade edge. The sewing machine may prevent or reduce wear of a particular portion of the blade edge of the cutter blade. This may eliminate or reduce influences of the wear of the cutter blade of the thread cutter when cutting a thread with the cutter blade.

DETAILED DESCRIPTION

First, second and third illustrative embodiments will be described with reference to the accompanying drawings. Referring toFIG. 1, a physical configuration of a sewing machine1that is common to the first to third illustrative embodiments will be described. In the following description, directional terminology, such as “up/upper,” “down/lower,” “front,” “rear,” “left,” “right” etc., as labeled in the drawings, may be used. In the page ofFIG. 1, an upper side, a lower side, a lower right side, an upper left side, a lower left side, and an upper right side respectively correspond to an upper side, a lower side, a front side, a rear side, a left side, and a right side of the sewing machine1. A longitudinal direction of a bed2and a horizontal arm4corresponds to a left-right direction of the sewing machine1. A side of the sewing machine1on which an upright arm3is disposed is the right side. A direction in which the upright arm3is elongated is an up-down direction of the sewing machine1.

As depicted inFIG. 1, the sewing machine1includes the bed2, the upright arm3, and the horizontal arm4. The bed2is a base portion of the sewing machine1, and extends in the left-right direction. The upright arm3extends upward from a right end portion of the bed2. The horizontal arm4extends leftward from an upper end of the upright arm3and faces the bed2. The sewing machine1includes a face plate5at an end (e.g., a left end) of the horizontal arm4.

The bed2includes a needle plate6at an upper surface thereof. The needle plate6has a needle hole41that allows a needle7(described below) to pass therethrough. The needle plate6has a rear end69. The sewing machine1includes a feed unit60and a shuttle mechanism that are housed in the bed2. The feed unit60includes a feed dog42and a feed mechanism. The feed unit60is configured to feed a workpiece by a predetermined amount in a feed direction (e.g., toward the rear). The shuttle mechanism causes an upper thread to be entwined or intertwined with a lower thread underneath the needle plate6. A dial31and a lever32are disposed at a front surface of the upright arm3. The dial31is used to select one of stitch patterns, such as straight stitch patterns and zigzag stitch patterns. The lever32is used to input an instruction to sew reversely.

A needle bar8, a presser bar9, a needle bar drive mechanism, and a presser bar drive mechanism are disposed at an end portion of the horizontal arm4. The needle bar8is located above the needle hole41and extends in the up-down direction. The needle7is removably attached to a lower end of the needle bar8. The presser bar9is located behind the needle bar8and extends in the up-down direction. A presser foot10is removably attached to a lower end of the presser bar9. The presser foot10is configured to move, together with the presser bar9, between a lower position and an upper position. At the lower position, the presser foot10presses the workpiece down. At the upper position, the presser foot10is located at a higher position than when the presser foot9is located at the lower position, and is spaced from the workpiece. The presser foot10is configured to intermittently press the workpiece down in association with the up-down movement of the needle bar8. The face plate5has a flat surface extending in the up-down direction, as well as the front-rear direction.

Referring toFIGS. 2 through 7, a configuration of a thread cutter50according to the first illustrative embodiment will now be described. The thread cutter50is configured to cut a thread, which may be either an upper thread or a lower thread. The thread cutter50is fixed to a fixing surface (e.g., the face plate5) of the horizontal arm4. The thread cutter50is fixed to a lower portion of the face plate5, at a generally middle position of the face plate5in the front-rear direction. The thread cutter50includes a cutter blade51, a movable member53, a protrusion59, a holder61, a holding plate63, a fixing portion70, and a screw67. The cutter blade51has a blade edge52. The cutter blade51has a parallelogram shape elongated in the up-down direction in a front view. The blade edge52is located at an upper end portion of the cutter blade51. The blade edge52extends obliquely in a blade length direction Y (e.g., a longitudinal direction of the blade edge52) from the left upper side to the lower right side. The blade length direction Y crosses an extending surface of the needle plate6. The cutter blade51has a thickness in the front-rear direction. In other words, a thickness direction of the cutter blade51corresponds to the front-rear direction. The cutter blade51has an extending surface that extends generally perpendicular to the face plate5. The cutter blade51is located further to the rear than the needle bar8(or the needle hole41) and further to the front than the presser bar9. An angle B (inFIG. 2) defined by the blade edge52and the face plate5is an acute angle (e.g., 10-90 degrees). The cutter blade51is held by the holder61and the holding plate63from the front and the rear sides, such that the middle portion of the blade edge52in the blade length direction Y is exposed to an exterior of the sewing machine1(e.g., toward the protrusion59). Opposite ends of the cutter blade51in the blade length direction Y and the lower end of the cutter blade51are held between the holder61and the holding plate63and are not exposed to an exterior of the sewing machine1.

The movable member53includes a guide54having a guide surface54adisposed adjacent to (e.g., in contact with or with a space from) the cutter blade51. In the space between the guide54and the cutter blade51, no member may be disposed. The guide surface54ais a surface that contacts a thread to be cut during the course of cutting the thread with the cutter blade51. The guide54is configured to receive force from the thread at the guide surface54aduring the course of cutting the thread with the cutter blade51and move in a moving direction E (as inFIG. 7) which is a longitudinal direction of the blade edge52(e.g., the blade length direction Y). The moving direction E of the guide54may include a component of the blade length direction Y, and may be a downward-and-rightward direction or a lower-right direction in the illustrative embodiment. The guide54may be located, relative to the cutter blade51, to a side closer to the rear end69of the needle plate6. In other words, the guide54may be located closer to the rear end69of the needle plate6than the cutter blade51. The rear end69corresponds to a downstream end of the needle plate6in the feed direction of the feed unit60.

The movable member53in the illustrative embodiment includes a metal wire having elasticity. An example of metal includes stainless steel. The movable member53has an annular first end portion55inserted over the fixing portion70. The first end portion55of the movable member53is disposed between a holding portion71(described below) of the fixing portion70and the holding plate63, and is fixed by the screw67. The movable member53has a second end portion56opposite to the first end portion55. The second end portion56has a second end, which is a free end, and the guide54having the guide surface54a. As depicted inFIG. 5B, the second end portion56of the movable member53is bent or deformed, relative to the first end portion55of the movable member53, such that an angle D defined between the first end portion55and the second end portion56is approximately 1 to 10 degree(s). The movable member53has a middle portion57bent into a “U” shape. The middle portion57is held between the cutter blade51and the holding plate63, and is pressed toward the cutter blade51such that the middle portion57is in a substantially same plane as the first end portion55. The movable member53is fixed to the fixing portion70such that the second end portion56of the movable member53is urged or pressed toward the cutter blade51in the thickness direction of the cutter blade51. The second end portion56having the guide54may thus be brought into contact with the cutter blade51. As long as the guide surface54aof the guide54is disposed adjacent to the cutter blade51as described above, the guide54and the cutter blade51may be separated from each other. In this configuration, a distance between the guide54and the cutter blade51may preferably be shorter than a dimension of an exposed portion80of the blade edge52in the blade length direction Y, more preferably, equal to or shorter than one-half of the dimension of the exposed portion80in the blade length direction Y. The exposed portion80is a portion of the blade edge52of the cutter blade51that is not held between the holder61and the holding plate63.

As depicted inFIG. 2, the exposed portion80has a center M in the blade length direction Y. A portion of the guide54(e.g., the guide surface54a) of the movable member53closest to the blade edge52is located upstream of the center M in the moving direction E (e.g., located to the upper left of the center M). The guide54of the movable member53is configured to elastically move in the blade length direction Y toward the horizontal arm4, based on the reception of the force from a thread at the guide surface54a(e.g., in response to the application of the force from the thread to the guide surface54a).

The guide54extends leftward from the top to the bottom in a front view. In the front view, the guide surface54acrosses the blade edge52at a point Q. In other words, when the guide54and the cutter blade51are projected onto a plane perpendicular to the thickness direction of the cutter blade51, the projected guide surface54acrosses the projected blade edge52of the cutter blade51at the point Q. In short, the guide54includes a portion extending in the up-down direction from the blade edge52toward a direction away from the blade edge52(e.g., from a portion corresponding to the point Q to the second end of the movable member53). A portion of the guide54having the guide surface54athat is closest to the blade edge52corresponds to the point Q. The point Q is located upstream of the center M in the moving direction E (e.g., located to the upper left of the center M). The guide surface54aand the blade edge52define an angle C that is an acute angle.

The protrusion59protrudes from the face plate5in a direction in which the horizontal arm4is elongated (e.g., toward the left). The protrusion59is located downstream of the point Q in the moving direction E. As depicted inFIG. 6, the second end of the movable member53, which is a part of the guide54, overlaps with the protrusion59in a direction (e.g., the up-down direction) parallel to the face plate5and perpendicular to the thickness direction (e.g., the front-rear direction) of the cutter blade51. A portion of the guide54overlapping with the protrusion59in the up-down direction is located between the blade edge52and the protrusion59in the up-down direction. The protrusion59may help the thread to contact the guide surface54aand may prevent the thread from being located between the guide54and the face plate5. The lower end of the protrusion59is located above the upper end of the cutter blade51and slightly above the upper end of the holder61.

The holder61together with the holding plate63hold the cutter blade51and the movable member53. The holder61may be integral with the face plate5. The holder61includes a front wall81, a peripheral portion82, and a right wall83. The front wall81extends perpendicularly leftward from the face plate5. The front wall81has a recess62at an upper end portion thereof. The front wall81faces the front surface of the cutter blade51. The peripheral portion82extends rearward from a periphery of the front wall81. The peripheral portion82faces the upper left end, the left end, and the lower end of the cutter blade51. The peripheral portion82has a dimension in the front-rear direction that is greater than the thickness of the cutter blade51. The right wall83extends in the up-down direction and faces the right end of the cutter blade51. The right wall83has a dimension (e.g., a thickness) in the front-rear direction that is approximately equal to the thickness of the cutter blade51. The holding plate63is disposed in parallel with an extending surface of the cutter blade51. The holding plate63faces the rear surface of the cutter blade51. The holding plate63has a recess64and a hole65. Each of the recesses62and64has the same shape and defines the exposed portion80of the blade edge52. The hole65is located at a right portion of the holding plate63and extends through the holding plate63in the front-rear direction. The screw67is inserted into the hole65. The fixing portion70has a tubular shape extending in the front-rear direction. The fixing portion70includes the holding portion71and a screw hole72. The holding portion71extends leftward from a left portion of a peripheral surface of the fixing portion70. The holding portion71has a rear end that positions, in the front-rear direction, the first end portion55of the movable member53inserted over the fixing portion70. With the cutter blade51positioned in the holder61and the first end portion55of the movable member53inserted over the fixing portion70, the screw67may be inserted into the screw hole72of the fixing portion70through the hole65. This may position the cutter blade51, which is held between the holder61and the holding plate63, in the up-down direction, the front-rear direction, and the left-right direction.

Referring toFIGS. 7A and 7B, an operation of cutting a thread U using the thread cutter50according to the first illustrative embodiment will now be described. As depicted inFIG. 7A, a user of the sewing machine1may pass the thread U through the thread cutter50from the rear toward the front of the thread cutter50. The thread U may be guided by the protrusion59, and contact the guide surface54aof the movable member53from the left, and the blade edge52of the cutter blade51. In this case, the movement of the thread U in the blade length direction Y may be restricted by the movable member53, so that the thread U may contact the blade edge52at a position upstream of a downstream end, in the moving direction E, of the exposed portion80of the blade edge52. The user brings a portion of the thread U to be cut into contact with the blade edge52and pulls the thread U in the moving direction E of the guide54(e.g., in a lower-right direction). As depicted inFIG. 7B, the guide54may elastically move in the blade length direction Y toward the horizontal arm4based on the reception of the force from the thread U at the guide surface54a. The thread U may be pressed onto the blade edge52of the cutter blade51while pushing the guide surface54ain the moving direction E, and be cut by the blade edge52. After the thread U has been cut, the guide54of the movable member53may move, due to its elasticity, toward a direction opposite to the moving direction E. As depicted inFIG. 7A, the guide54may move back to its initial position, due to the elasticity.

Referring toFIG. 8, a thread cutter150according to the second illustrative embodiment will now be described. It is to be noted that the reference numerals inFIG. 8designate similar components of the thread cutter50according to the first illustrative embodiment, and a detailed explanation thereof with respect to the second illustrative embodiment, is omitted herein. The thread cutter150according to the second illustrative embodiment has a similar configuration to the thread cutter50according to the first illustrative embodiment, except for a movable member. The thread cutter150includes a movable member93, which is different from the movable member53of the first illustrative embodiment, with respect to a guide94provided at a second end portion96. The guide94has an arch shape when projected onto a plane perpendicular to the thickness direction (e.g., the front-rear direction) of the cutter blade51. The guide94has a guide surface94athat contacts a thread to be cut during the course of cutting the thread with the cutter blade51. The movable member93has a fixed first end portion55and an opposite second end portion96, which is a free end. In one example, the guide94when projected onto a plane, may have an arch shape curving convexly in a direction opposite to the moving direction E. The guide surface94aand the blade edge52define an angle C which is an acute angle. An operation of cutting a thread using the thread cutter150according to the second illustrative embodiment may be performed similarly to the operation as is performed using the thread cutter50of the first illustrative embodiment.

Referring toFIG. 9, a thread cutter250according to the third illustrative embodiment will be described. The thread cutter250has a similar configuration to the thread cutter50according to the first illustrative embodiment, except for a fixing surface to which the thread cutter250is fixed and an orientation of the thread cutter250. The thread cutter250includes a blade edge52that extends upward from the rear to the front. In the third illustrative embodiment, the longitudinal direction of the blade edge52(e.g., a blade length direction Y) corresponds to a direction from lower rear to upper front. The thread cutter250is fixed to a fixing surface, e.g., a lower surface58of the horizontal arm4. The blade length direction crosses the extending surface of the needle plate6. The cutter blade51has a thickness in the left-right direction. In other words, a thickness direction of the cutter blade51in the third illustrative embodiment extends in the left-right direction. The guide54is located closer to the needle hole41in the left-right direction, than the cutter blade51is to the needle hole41. In the third illustrative embodiment, the guide54is located to the right of the cutter blade51. The guide54of the movable member53is configured to move in an upper-front direction.

An operation of cutting a thread using the thread cutter250will now be described. A user may pass the thread through the thread cutter250from the right toward the left. The thread may be guided by the protrusion59, and contact the guide surface54aof the movable member53from the rear and the blade edge52of the cutter blade51. In this case, the movement of the thread in the blade length direction Y may be restricted by the movable member53, so that the thread may contact the blade edge52at a position further to the rear than the front end portion of the exposed portion of the blade edge52. The user brings a portion of the thread to be cut into contact with the blade edge52and pulls the thread in the moving direction of the guide54(e.g., in an upper-front direction). The guide54may elastically move in the blade length direction Y toward the horizontal arm4based on the reception of the force from the thread at the guide surface54a. The thread may be pressed onto the blade edge52while pushing the guide surface54ain an upper-front direction, and be cut by the blade edge52. After the thread has been cut, the guide54of the movable member53may move, due to its elasticity, toward a direction opposite to the moving direction of the movable member53(e.g., in a lower-rear direction). The guide54may move back to its initial position, due to the elasticity.

The sewing machine1according to the first to third illustrative embodiments may allow the guide54,94of the movable member53,93to move in the blade length direction Y, based on the reception of the force from a thread during the course of the thread cutting with the cutter blade51. The thread may slidably move in the blade length direction Y while pushing the guide surface54a,94a, and be cut with a sharp portion (e.g., unworn portion) of the blade edge52. The sewing machine1may prevent or reduce wear of a particular portion of the blade edge52of the cutter blade51. This may eliminate or reduce influences of the wear of the cutter blade51of the thread cutter50when cutting a thread with the cutter blade51.

The sewing machine1according to the first and second illustrative embodiments includes the needle plate6and the feed unit60configured to feed a workpiece placed on the needle plate6in the feed direction. The guide54,94is located, relative to the cutter blade51, closer to the rear end69of the needle plate6. In other words, the guide54,94is located closer to the rear end69of the needle plate6than the cutter blade51. When a user passes a thread to be cut from the rear side toward the front side (e.g., from a side closer to the rear end69toward a side further away from the rear end69), the sewing machine1according to the first and second illustrative embodiments may allow the thread to be pressed onto the cutter blade51more readily as compared with a configuration in which the guide54,94is located further away from the rear end69of the needle plate6than the cutter blade51. For example, in a case where the user cuts both an upper thread and a lower thread using the thread cutter50,150after the end of sewing, the user may pull the upper thread and the lower thread toward a downstream side in the feed direction of the feed unit60. In such case, it may be easier for the user to pass the threads over the cutter blade51from a side closer to the rear end69(e.g., a downstream end in the feed direction) of the needle plate6, toward a side away from the rear end69, as compared with a case in which the user passes the threads over the cutter blade51from the side further away from the rear end69toward the side closer to the rear end69.

The sewing machine1according to the third illustrative embodiment includes the needle plate6having the needle hole41. The guide54is located closer to the needle hole41than the cutter blade51. When a user passes a thread to be cut over the cutter blade51from a side closer to the needle hole41toward a side further away from the needle hole41, the configuration of the third illustrative embodiment may allow the thread to be pressed onto the cutter blade51more readily, as compared with a configuration in which the guide54is located further away from the needle hole41than the cutter blade51. For example, a user of the sewing machine1may cut an upper thread and a lower thread using the thread cutter250after the end of sewing. It may be easier for the user to pass the threads over the cutter blade51from a side closer to the needle hole41toward a side further away from the needle hole41, as compared with a case in which the user passes the threads over the cutter blade51from the side further away from the needle hole41toward the side closer to the needle hole41.

In the sewing machine1according to the first to the third illustrative embodiments, when the guide54,94and the cutter blade51are projected onto a plane perpendicular to the thickness direction of the cutter blade51, the guide54,94crosses the blade edge52of the cutter blade51. The guide surface54a,94aof the movable member53,93and the blade edge52define an acute angle. This configuration may allow the guide surface54a,94ato receive force from the thread more readily and move in the moving direction E more readily, as compared with a configuration in which an angle defined by the guide surface54a,94a and the blade edge52is an obtuse angle.

The sewing machine1according to the first to third illustrative embodiments, a portion of the guide54,94of the movable member53,93that is closest to the blade edge52(e.g., the portion corresponding to the point Q) is located upstream, in the moving direction E, of the center M of the exposed portion80(indicted by an arrow R inFIG. 2) in the blade length direction Y. This configuration may allow the blade edge52of the cutter blade51to be used widely to cut a thread, as compared with a configuration in which a portion of the guide54,94of the movable member53,93that is closest to the blade edge52is located downstream, in the moving direction E, of the center M of the exposed portion80in the blade length direction Y.

The sewing machine1according to the first to the third illustrative embodiments includes the horizontal arm4including the face plate5that covers an end portion of the sewing machine1. The thread cutter50,150,250is fixed on a fixing surface of the horizontal arm4. The guide54,94of the movable member53,93is configured to elastically move in the blade length direction Y toward the horizontal arm4based on the reception of force from a thread. The sewing machine1includes the movable member53,93with a relatively simple configuration. After the thread has been cut, the guide54,94may move, due to its elasticity, in a direction away from the horizontal arm4.

In the sewing machine1according to the first to the third illustrative embodiments, an angle defined by the blade edge52and the fixing surface of the horizontal arm4is an acute angle. This configuration may reduce a space between the cutter blade51and the fixing surface of the horizontal arm4, as compared with a configuration in which an angle defined by the blade edge52and the fixing surface of the horizontal arm4is an obtuse angle. Reduction of the space between the cutter blade51and the fixing surface of the horizontal arm4may prevent or reduce entrance of an object other than a thread into the space. Further, the sewing machine1may allow the guide54,94to move toward the horizontal arm4more readily, as compared with a configuration in which an angle defined by the blade edge52and the fixing surface of the horizontal arm4is an obtuse angle.

The sewing machine1, according to the first to the third illustrative embodiments, includes the horizontal arm4including the fixing surface and the protrusion59that protrudes from the fixing surface toward a direction in which the horizontal arm4is elongated. A portion of the guide54,94overlaps with the protrusion59in a direction parallel to the fixing surface and perpendicular to the thickness direction of the cutter blade51. The protrusion59may prevent a thread from being located closer to the horizontal arm4than the guide54,94.

In the sewing machine1according to the second illustrative embodiment, the guide94, when projected onto a plane perpendicular to the thickness direction of the cutter blade51, has an arch shape. This configuration may allow a user to put a thread between the guide94(e.g., the guide surface94a) and the blade edge52more readily, as compared with a guide extending linearly when projected onto a plane.

In the sewing machine1according to the second illustrative embodiment, the guide94, when projected onto a plane perpendicular to the thickness direction of the cutter blade51, has an arch shape curving convexly in a direction opposite to the moving direction E. The guide94of the sewing machine1may receive force from a thread more readily and move in the blade length direction Y more readily, as compared with a guide with an arch shape curving convexly in the moving direction E when projected onto the plane perpendicular to the thickness direction of the cutter blade51.

The sewing machine1according to the first to third illustrative embodiments includes the movable member53,93including the guide54,94including an elastic wire. The guide54,94is configured to be elastically deformed in the moving direction E by the application of force from a thread to the guide surface54a,94a. The sewing machine1includes the movable member53,93that is formed by processing (e.g., curving/bending) a single member, and has a simpler configuration than a movable member including a plurality of members.

The sewing machine1according to the first to third illustrative embodiments, includes the movable member53,93having the first end portion55and the second end portion56,96. The first end portion55is fixed to the sewing machine1while the second end portion56,96is not fixed and is free. The sewing machine1may facilitate a configuration to fix the movable member53,93.

The sewing machine1according to the first to third illustrative embodiments, includes the movable member53,93that is fixed such that the second end portion56,96may be urged toward the cutter blade51in the thickness direction of the cutter blade51. This configuration may prevent or reduce a gap between the cutter blade51and the movable member53,93. Accordingly, the sewing machine1may cut a thread more stably, as compared with a configuration in which a gap is provided between the cutter blade51and the movable member53,93.

While aspects are described in detail with reference to the specific embodiments thereof, this is merely an example, and various changes, arrangements and modifications may be made therein without departing from the spirit and scope of the disclosure. For example, the following modifications may be made.

Configuration of the sewing machine1may be modified as desired. The sewing machine1may be an industrial sewing machine, an embroidery sewing machine, or a multiple needle sewing machine. The feed direction of the feed unit60may be changed as desired. A direction in which the horizontal arm is elongated may be the same as or cross the feed direction in which a workpiece is fed by the feed unit.

A position where the thread cutter is located, and an orientation of the thread cutter relative to the sewing machine may be changed as desired. For example, a thread cutter may be fixed to at least one of the bed and the horizontal arm of the sewing machine in an orientation in which the extending surface of the cutter blade is parallel with the extending surface of the needle plate. The cutter blade may be configured to cut a lower thread on the needle plate. In this configuration, a movable member may be disposed, for example, below a cutter blade (e.g., opposite to the horizontal arm4relative to the cutter blade). The longitudinal direction of the blade edge (e.g., the blade length direction) may cross the needle plate or be parallel to the extending surface of the needle plate. An angle defined by the blade edge and the fixing surface may be a right angle or an obtuse angle. An angle defined by the guide surface of the movable member and the blade edge may be a right angle or an obtuse angle.

The movable member may include any guide that has a guide surface disposed adjacent to a cutter blade. The guide may be configured to receive force from a thread at the guide surface during the course of cutting the thread with the cutter blade and move in a moving direction which is a longitudinal direction of the blade edge (e.g., the blade length direction). For a movable member, a plurality of members or components may be combined. In this configuration, the movable member may include, for example, an urging member, and a member that is connected to the urging member and has a guide surface. Examples of the urging member include a compression spring, a tension spring, a link, and a magnet. The spring may not be limited to, for example, a coil spring, but may be a plate spring. Material of the urging member may be metal, plastic, or rubber. The movable member may not necessarily have elasticity. In this configuration, the movable member may, for example, include a guide that has a guide surface disposed adjacent to the cutter blade and that is configured to move along a rail extending in the blade length direction. The moving direction of the guide may include a component of the blade length direction, and may or may not be parallel to the blade length direction.

The shape of the guide of the movable member may be changed as desired. For example, the guide may be curved or flat. A guide, when projected onto a plane perpendicular to the thickness direction of the cutter blade, has an arch shape curving convexly in the moving direction. A length of a portion of a movable member having a guide may be changed as desired. The second end portion of the guide54may protrude, relative to a portion of the face plate5above the blade edge52, toward the blade edge52in a direction away from the face plate5. In this configuration, a position where the blade edge cuts a thread may also be restricted by bringing the thread into contact with the guide surface. The guide may be located closer to an upstream end of the needle plate in the feed direction of the feed unit, than the cutter blade. In other words, a portion of the movable member53(e.g., the guide54) may be located in front of the cutter blade51unlike the above-described illustrative embodiment in which a portion of the movable member53(e.g., the guide54) is located behind the cutter blade51.

In some embodiments, the guide may be located further away from the needle hole, than the cutter blade.

A portion of the guide of the movable member closest to the blade edge may be located at the same position as a center, in the blade length direction, of an exposed portion of the blade edge or downstream, in the moving direction, of the center of the exposed portion of the blade edge. An end portion of the cutter blade opposite to the blade edge may be fixed to the sewing machine such that the blade edge may be fully exposed to an exterior of the sewing machine.

The sewing machine may not necessarily include the protrusion. In this configuration, a movable member may be configured of an urging member including rubber cord. The movable member may be located crossing the cutter blade when projected onto a plane perpendicular to the thickness direction of the cutter blade, and a second end portion of the movable member may be fixed to the fixing surface of the horizontal arm. In another embodiment, a movable member may be configured of a wire, similar to the first illustrative embodiment. When the guide and the cutter blade are projected onto a plane perpendicular to the thickness direction of the cutter blade, the guide may be located crossing the cutter blade and a second end portion of the guide may overlap with the cutter blade. This configuration may also prevent a thread to be cut from being located closer to the fixing surface than the guide. The shape and location of the protrusion may be changed as desired. For a wire movable member, both the first end portion and the second end portion may be fixed to the sewing machine. In this configuration, a guide may be located at a middle portion of the movable member. For a wire movable member, both the first end portion and the second end portion may not be fixed but free. In this configuration, a middle portion of the movable member may be fixed to the sewing machine. The second end portion of the movable member may not necessarily be urged toward the cutter blade in the thickness direction of the cutter blade. A portion of the guide of the movable member may be disposed at a position not overlapping with the protrusion in a direction parallel to the fixing surface and perpendicular to the thickness direction of the cutter blade. In this configuration, for example, a portion of the guide may be disposed at a position overlapping with the protrusion in the thickness direction of the cutter blade.

The sewing machine1may include one or more cutter blades51and one or more movable members53. For example, one movable member53may be located between two cutter blades51, or one cutter blade51may be located between two movable members53.