Patent Publication Number: US-11643766-B2

Title: Sewing machine

Description:
RELATED AND PRIORITY APPLICATIONS 
     This application is a continuation application of U.S. patent application Ser. No. 16/576,964, filed Sep. 20, 2019, which is a continuation application of International Application No. PCT/JP2017/030299, filed Aug. 24, 2017, which claims priority from Japanese Patent Application No. 2017-065880, filed on Mar. 29, 2017. The disclosures of each of the foregoing applications are hereby incorporated by reference in their entireties. 
    
    
     BACKGROUND 
     The present disclosure relates to a sewing machine. 
     A sewing machine from which a needle plate is detachable is known. The known sewing machine is provided with a needle plate adjustment mechanism configured to perform position adjustment of the needle plate mounted on a bed portion. The needle plate adjustment mechanism has a first adjustment portion provided on one end portion of the needle plate, a second adjustment portion provided on another end portion of the needle plate, and a fixing portion provided on an end portion other than the two end portions of the needle plate. The needle plate is fixed to the bed portion by the fixing portion, after the position adjustment is performed by the first adjustment portion and the second adjustment portion and the needle plate is provisionally fixed. 
     SUMMARY 
     In the known sewing machine, the needle plate is fixed to the bed portion using screws, and an operation to remove the screws is troublesome. 
     Various embodiments of the broad principles derived herein provide a sewing machine in which a needle plate can be removed from a bed portion by a simple operation. 
     Embodiments provide a sewing machine that includes a needle plate, a bed portion, a first urging member, a first engagement member, a second engagement member, and a lock release mechanism. The bed portion is configured to support the needle plate. The first urging member is provided inside the bed portion and configured to urge the needle plate upward. The first engagement member is provided on the needle plate. The second engagement member is provided inside the bed portion, and is configured to fix the needle plate in a fixed position by being engaged with the first engagement member of the needle plate pressed downward against an urging force of the first urging member. The lock release mechanism is configured to release the engagement of the first engagement member and the second engagement member. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments will be described below in detail with reference to the accompanying drawings in which: 
         FIG.  1    is a perspective view of a sewing machine; 
         FIG.  2    is a perspective view of the interior of a bed portion; 
         FIG.  3 A  is a plan view of a needle plate,  FIG.  3 B  is a front view of the needle plate, and  FIG.  3 C  is a bottom view of the needle plate; 
         FIG.  4 A  is a perspective view of the interior of the bed portion when an output shaft is in a reference position and a feed dog is in a normal position; 
         FIG.  4 B  is a perspective view of the interior of the bed portion in a state in which the output shaft is in a second actuated position, the feed dog is in a retracted position, and a lever is moved in a second direction in comparison to  FIG.  4 A ; 
         FIG.  5 A  is a plan view of a part of a lock release mechanism; 
         FIG.  5 B  is a front view of the part of the lock release mechanism; 
         FIG.  6 A  is a plan view of the interior of the bed portion when the output shaft is in the reference position and the feed dog is in the normal position; 
         FIG.  6 B  is a plan view of the interior of the bed portion when the output shaft is in a first actuated position and the feed dog is in the retracted position; 
         FIG.  6 C  is a plan view of the interior of the bed portion in a state in which the output shaft is in the second actuated position, the feed dog is in the retracted position, and the lever is rotated in the second direction in comparison to  FIG.  6 A  and  FIG.  6 B ; 
         FIG.  7 A  is a front view of the interior of the bed portion when the output shaft is in the reference position and the feed dog is in the normal position; 
         FIG.  7 B  is a front view of the interior of the bed portion when the output shaft is in the first actuated position and the feed dog is in the retracted position; 
         FIG.  7 C  is a front view of the interior of the bed portion in a state in which the output shaft is in the second actuated position, the feed dog is in the retracted position, and the lever is rotated in the second direction in comparison to  FIG.  7 A  and  FIG.  7 B ; 
         FIG.  8 A  is a bottom view of the interior of the bed portion when the output shaft is in the reference position and the feed dog is in the normal position; 
         FIG.  8 B  is a bottom view of the interior of the bed portion when the output shaft is in the first actuated position and the feed dog is in the retracted position; 
         FIG.  8 C  is a bottom view of the interior of the bed portion in a state in which the output shaft is in the second actuated position, the feed dog is in the retracted position, and the lever is rotated in the second direction in comparison to  FIG.  8 A  and  FIG.  8 B ; 
         FIG.  9 A  is a partial sectional view, taken in the direction of arrows along a line A-A shown in  FIG.  5   , that shows a state in which a first engagement member and a second engagement member are engaged with each other; and 
         FIG.  9 B  is a partial sectional view, taken in the direction of the arrows along the line A-A shown in  FIG.  5   , that shows a state in which the engagement of the first engagement member and the second engagement member is released by the lock release mechanism. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, a sewing machine  1  according to an embodiment of the present disclosure will be explained with reference to the drawings. The drawings referred to are used to explain technological features that can be adopted by the present disclosure, and device configurations and the like illustrated in the drawings are merely explanatory examples and are not intended to limit the present disclosure thereto. 
     A physical configuration of the sewing machine  1  will be explained with reference to  FIG.  1    to  FIG.  4   . In the explanation below, the lower left side, the upper right side, the upper left side and the lower right side in  FIG.  1    are respectively defined as the left side, the right side, the rear side and the front side of the sewing machine  1 . 
     As shown in  FIG.  1   , the sewing machine  1  is mainly configured by a bed portion  2 , a pillar  3  and an arm portion  4 . The pillar  3  is provided on the right end portion of the bed portion  2 , and extends in the vertical direction from the bed portion  2 . The arm portion  4  extends to the left from the upper end portion of the pillar  3  such that the arm portion  4  faces the bed portion  2 . The leading end portion of the arm portion  4  is a head portion  40 . 
     The bed portion  2  has an upper surface that extends horizontally, and removably supports a needle plate  11  and a cover  9 . The needle plate  11  is a rectangular plate in a plan view. The needle plate  11  is removably mounted in an opening  98  that is provided in the upper surface of the bed portion  2 . As shown in  FIG.  2    and  FIG.  3 A  to  FIG.  3 C , the needle plate  11  has a needle hole  6 , square holes  22 , holes  27  and  28 , a first engagement member  15 , and a pair of front and rear hook portions  97 . The needle hole  6  is provided in a substantially central portion of the needle plate  11 , and is a hole through which a sewing needle  95  to be described later can be inserted. The square holes  22  are arranged to the front, rear, left and right of the needle hole  6 , and are a plurality of holes that extend in the front-rear direction. The square holes  22  a hole through which a feed dog  5  can be inserted from below. The holes  27  and  28  are holes into which positioning pins  71  and  72  to be described later are inserted from below. The holes  27  and  28  of the present embodiment are circular holes in a plan view and penetrate the needle plate  11 . The hole  27  is provided to the rear and the left of the needle hole  6 , and the hole  28  is provided to the rear and the right of the needle hole  6 . The square holes  22  are disposed between the hole  27  and the hole  28 . 
     As shown in  FIG.  3 B  and  FIG.  3 C , the first engagement member  15  has a pin shape that extends from the lower surface of the needle plate  11  in a direction (a substantially vertical direction) that intersects an extending direction of the needle plate  11 . The first engagement member  15  has an engagement portion  18  and a first convex portion  19 . The engagement portion  18  engages with a second engagement member  16  to be described later. The first convex portion  19  is provided below the engagement portion  18 , and protrudes further in the horizontal direction (a direction that intersects the extending direction of the first engagement member  15 ) than the engagement portion  18 . A lower portion of the first convex portion  19  is chamfered. The first engagement member  15  further has a base portion  20 . The base portion  20  is provided above the engagement portion  18 , and protrudes further in the horizontal direction (the direction that intersects the extending direction of the first engagement member  15 ) than the engagement portion  18 . The base portion  20  is coupled to the lower surface of the needle plate  11 . In a plan view, outer peripheral portions of the first convex portion  19  and the base portion  20  are located outside an outer peripheral portion of the engagement portion  18 . 
     The pair of front and rear hook portions  97  extend to the left from the left end of the lower surface of the needle plate  11 , and are plate-shaped sections that extend in the left-right direction. When the needle plate  11  is disposed in a fixed position shown in  FIG.  1   , the pair of hook portions  97  are engaged with a left side portion of the rectangular opening  98 . The cover  9  is a rectangular plate-shaped member in a plan view, and is smaller than the needle plate  11 . On the right side of the needle plate  11 , the cover  9  is removably supported by the bed portion  2 . When the cover  9  is supported by the bed portion  2 , the cover  9  forms a horizontal plane that is substantially flush with the upper surface of the bed portion  2 , and covers a lever  64 , to be described later, from above. 
     As shown in  FIG.  4 A  and  FIG.  5 A , the sewing machine  1  is provided with a shuttle mechanism  12 , the feed dog  5 , a feed mechanism  13 , a feed dog retraction mechanism  14 , a first urging member  67 , the second engagement member  16 , a second urging member  66 , a cylindrical portion  80 , a lock release mechanism  17  and the positioning pins  71  and  72 , inside the bed portion  2  below the needle plate  11 . The shuttle mechanism  12  is provided below the needle plate  11 , and is configured to rotate in conjunction with an up-down movement of a needle bar  8 . The feed dog  5  moves a sewing object (for example, a work cloth) by a predetermined feed amount. The feed mechanism  13  is a known mechanism driven by a sewing machine motor as a drive source, and is configured to adjust the amount of feed by the feed dog  5 , using a feed amount adjustment motor  33  as a drive source. The feed dog retraction mechanism  14  is coupled to an output shaft  32  (refer to  FIGS.  8 A- 8 C ) of a movement motor  31 , and is configured to switch the feed dog  5  between a normal position and a retracted position using the driving force of the movement motor  31 . The movement motor  31  is a pulse motor. The normal position is a position in which the feed dog  5  is driven by the feed mechanism  13  and the feed dog  5  intermittently protrudes above the upper surface of the needle plate  11 . The retracted position is a position in which the driving force of the feed mechanism  13  is not transmitted to the feed dog  5  and the feed dog  5  is retracted below the upper surface of the needle plate  11 . For example, known mechanisms (for example, refer to Japanese Laid-Open Patent Publication No. 2007-244721, the relevant portions of which are herein incorporated by reference) can be adopted as the feed mechanism  13  and the feed dog retraction mechanism  14 . The feed dog retraction mechanism  14  will be described in more detail later. 
     As shown in  FIG.  5 A  and  FIG.  5 B , the first urging member  67  is provided inside the bed portion  2  and urges the needle plate  11  upward. The first urging member  67  of the present embodiment is a plate spring that is curved upward in a convex shape, and the right end the first urging member  67  is fixed using a screw  68 . The first urging member  67  upwardly urges a substantially central portion in the front-rear direction of the right end portion of the needle plate  11  on the opposite side to the side (the left side) of the needle plate  11  on which the hook portions  97  are provided. The second engagement member  16  is provided inside the bed portion  2 , and engages with the first engagement member  15  of the needle plate  11  that is pressed downward against an urging force of the first urging member  67 , thus fixing the needle plate  11  in the fixed position. When the needle plate  11  is in the fixed position, the upper surface of the needle plate  11  is on substantially the same horizontal plane as the upper surface of the bed portion  2 . The second engagement member  16  of the present embodiment is a plate-shaped member, and extends in the direction that intersects the extending direction of the first engagement member  15 . 
     The second urging member  66  is fixed to one end (the left end) of the second engagement member  16 , and urges the second engagement member  16  such that the second engagement member  16  can rotate in a first direction (a counterclockwise direction in a plan view) that intersects with the up-down direction. The first direction of the present embodiment is the horizontal direction. The second urging member  66  of the present embodiment is a coil spring, and the other end of the second urging member  66  is fixed to the left end portion of a plate portion  79  that extends substantially horizontally in a position to the front of the second engagement member  16 . The cylindrical portion  80  is a circular cylindrical section having a hole  81  that extends in the up-down direction. The diameter of the hole  81  is larger than the diameter of the first engagement member  15 . When the needle plate  11  is disposed in the fixed position, the first engagement member  15  is inserted through the hole  81  of the cylindrical portion  80  from above. The upper end of the cylindrical portion  80  is located higher than the upper surface of the second engagement member  16 . The second engagement member  16  extends in the left-right direction in a position to the rear of the cylindrical portion  80 . The cylindrical portion  80  has a cutout portion that is cut out in the up-down direction, in a section (namely, a back surface side) of the cylindrical portion  80  that faces the second engagement member  16 . As shown in  FIG.  5 A , the second engagement member  16  is urged in the counterclockwise direction in a plan view by an urging force of the second urging member  66 , and is inserted into the cutout portion from the rear. 
     The lock release mechanism  17  is configured to release the engagement of the first engagement member  15  and the second engagement member  16 . The lock release mechanism  17  will be described in detail later. The positioning pins  71  and  72  are columnar members that extend upward. When the second engagement member  16  and the first engagement member  15  are engaged with each other, the upper ends of the positioning pins  71  and  72  are lower than the height of the upper surface of the needle plate  11  in the fixed position. As shown in  FIG.  4 A , the upper ends of the positioning pins  71  and  72  are respectively provided with second convex portions  73  and  74  that protrude in the horizontal direction in positions below the needle plate  11  in the fixed position. The second convex portions  73  and  74  have a columnar shape, and have the same axial line as the positioning pins  71  and  72 . Cushion materials  75  and  76  are respectively disposed on the upper ends of the second convex portions  73  and  74 . The cushion materials  75  and  76  are elastic members, such as unwoven cloth, felt or the like. 
     As shown in  FIG.  1   , the sewing machine  1  is provided with the sewing machine motor (not shown in the drawings) below the pillar  3 . The driving force of the sewing machine motor is transmitted to a drive shaft (not shown in the drawings) via a drive belt (not shown in the drawings). The drive shaft extends in the left-right direction inside the arm portion  4 . The driving force of the sewing machine motor is also transmitted to a lower shaft (not shown in the drawings) by a transmission mechanism (not shown in the drawings) provided at a midway portion of the drive shaft. The lower shaft extends in the left-right direction inside the bed portion  2 . 
     The pillar  3  of the sewing machine  1  is provided with a vertically long liquid crystal display (hereinafter simply referred to as an “LCD”)  10  and a touch panel  26 . The LCD  10  displays function names to execute various functions necessary for sewing operations, such as selection and editing of a pattern to be sewn, various messages, and the like. The touch panel  26  is provided on the front surface of the LCD  10 . When a user selects an item displayed on the LCD  10  using a finger or a dedicated pen, which item is selected is detected by the touch panel  26 . The user can input various commands via the touch panel  26 . 
     An upper portion of the arm portion  4  is provided with a cover  92  that can be opened and closed.  FIG.  1    shows a state in which the cover  92  is open. A housing portion  94  is provided below the cover  92  in a closed state, namely, inside the arm portion  4 . The housing portion  94  is a recessed portion that houses a thread spool  96  around which an upper thread is wound. A thread spool pin  93  is disposed on an inner wall surface of the housing portion  94  on the pillar  3  side. The thread spool pin  93  protrudes toward the head portion  40  so that the thread spool  96  can be mounted on the thread spool pin  93 . The thread spool  96  is mounted on the sewing machine  1  by the thread spool pin  93  being inserted into an insertion hole provided in the thread spool  96 . The needle bar  8  is disposed on a lower portion of the head portion  40 . The sewing needle  95  can be mounted on the lower end of the needle bar  8 . A needle bar up-and-down movement mechanism (not shown in the drawings) and a thread take-up lever mechanism (not shown in the drawings) are provided inside the head portion  40 . The needle bar up-and-down movement mechanism causes the needle bar  8  having the sewing needle  95  mounted thereon to drive in the up-down direction. 
     A thread guide groove  7  is provided in the arm portion  4 . The thread guide groove  7  guides the upper thread pulled out from the thread spool  96 , finally, to the sewing needle  95 , via a tensioner mechanism, a thread take-up spring, a thread take-up lever and the like that are not shown in the drawings. A start/stop switch  91  is provided on the front surface of the arm portion  4 . The start/stop switch  91  is a switch to issue a command to start or stop a sewing operation. When the start/stop switch  91  is depressed, the sewing machine motor is driven, and respective elements including the needle bar up-and-down movement mechanism, the thread take-up lever mechanism, the shuttle mechanism  12  and the feed mechanism  13  are driven in synchronization with each other. Thus, stitches are formed on the sewing object. 
     The feed dog retraction mechanism  14  will be explained with reference to  FIGS.  7 A- 7 C  and  FIGS.  8 A- 8 C . The feed dog retraction mechanism  14  is provided with a gear  41 , a drop cam  42 , actuation pieces  43 ,  48  and  52 , a contactor  86  and an up-down feed cam  85 . The gear  41  is fixed to the leading end of the output shaft  32  of the movement motor  31 . The output shaft  32  extends in the up-down direction. The gear  41  meshes with gear teeth provided on the outer periphery of the drop cam  42 . The diameter of the drop cam  42  is larger than the diameter of the gear  41 . A shaft  47  of the drop cam  42  extends in the up-down direction. The drop cam  42  has a spiral groove portion  88  that extends from the shaft  47  in the counterclockwise direction in a bottom view. The actuation piece  43  extends in the left-right direction, and is provided with a columnar convex portion  87  that protrudes downward, a long hole  44  disposed in the left end portion of the actuation piece  43 , and a long hole  45  disposed in the right end portion of the actuation piece  43 . The long holes  44  and  45  are long in the left-right direction. The convex portion  87  is inserted into the groove portion  88  of the drop cam  42 . A pin  46  that extends in the up-down direction is inserted through the long hole  44 . The shaft  47  is inserted through the long hole  45 . When the gear  41  rotates, the drop cam  42  rotates and the arrangement of the groove portion  88  is changed. The actuation piece  43  is guided by the groove portion  88  and the long holes  44  and  45  in accordance with the rotation of the drop cam  42 , and can move in the left-right direction. 
     The left end portion of the actuation piece  43  is coupled to the actuation piece  48  by a pin  49  that extends in the up-down direction. The actuation piece  48  is a plate-shaped member that extends in the front-rear direction. A columnar pin  51 , which extends in the up-down direction, is inserted through a substantially central portion in the front-rear direction of the actuation piece  48 . The actuation piece  48  is fixed such that the actuation piece  48  can rotate around the pin  51 . The rear end portion of the actuation piece  48  is coupled to the actuation piece  52  by a pin  50  that extends in the up-down direction. The actuation piece  52  is a plate-shaped member that is long in the left-right direction and that is disposed at the rear end portion of the interior of the bed portion  2 . A left portion of the actuation piece  52  has a plate-shaped plate portion  53  that extends in the horizontal direction. Pins  54  and  55 , which extend upward from the upper surface of the plate portion  53 , are arranged side by side in the left-right direction on the plate portion  53 . The pin  55  disposed to the left of the pin  54  is inserted through a long hole  57  that is provided in a plate-shaped member  56  that extends in the horizontal direction above the plate portion  53 . The long hole  57  extends in the left-right direction. The actuation piece  52  is guided by the long hole  57  and can move in the left-right direction. The contactor  86  is fixed to the upper surface of the plate portion  53 . The contactor  86  is provided below the up-down feed cam  85 . The up-down feed cam  85  is an eccentric cam that is firmly fixed to the lower shaft (not shown in the drawings). As shown in  FIG.  8 A , the contactor  86  is disposed below the up-down feed cam  85 . When the contactor  86  comes into contact with the up-down feed cam  85 , the driving force of the up-down feed cam  85  is transmitted to the feed dog  5 , and the feed dog  5  is driven to swing in the front-rear direction and the up-down direction. In other words, when the contactor  86  comes into contact with the up-down feed cam  85 , the contactor  86  causes the feed dog  5  to be disposed in the normal position. As shown in  FIG.  8 B , when the contactor  86  does not come into contact with the up-down feed cam  85 , the contactor  86  causes the feed dog  5  to be disposed in the retracted position. 
     A procedure used when the needle plate  11  is disposed in the fixed position shown in  FIG.  1    will be explained. The user causes the hook portions  97  to be engaged with the left side portion of the opening  98  of the bed portion  2 , and presses down the right end portion of the needle plate  11  in a state in which the positioning pins  71  and  72  are respectively inserted through the holes  27  and  28 . When the user presses down the needle plate  11  against the urging force of the first urging member  67 , the second engagement member  16  is guided to the first convex portion  19  whose lower portion is chamfered, and is engaged with the engagement portion  18  of the first engagement member  15  of the needle plate  11  pressed down against the urging force of the first urging member  67 . When the user stops pressing down the needle plate  11 , the right end portion of the needle plate  11  is moved upward by the urging force of the first urging member  67  to a position at which an upper end  99  of the first convex portion  19  comes into contact with the lower surface of the second engagement member  16 . As a result, as shown in  FIG.  9 A , when the first engagement member  15  and the second engagement member  16  are engaged with each other, the second engagement member  16  comes into contact with the engagement portion  18  of the first engagement member  15  due to the urging force of the second urging member  66 , and also comes into contact with the upper end  99  of the first convex portion  19  of the first engagement member  15  due to the urging force of the first urging member  67 . 
     The lock release mechanism  17  will be explained with reference to  FIG.  4    to  FIG.  8 C . The lock release mechanism  17  is configured such that the engagement of the first engagement member  15  and the second engagement member  16  can be released manually. As shown in  FIG.  5 A  and  FIG.  5 B , the lock release mechanism  17  is provided with the lever  64 . The lever  64  is provided below the upper surface of the bed portion  2 . The lever  64  can rotate the second engagement member  16  in a second direction (a clockwise direction in a plan view) opposite to the first direction (the counterclockwise direction in a plan view). The lever  64  is a plate-shaped member that extends in the front-rear direction. The right end portion of the lever  64  bends upward. The lever  64  is covered by the cover  9  from above. When the cover  9  is removed from the bed portion  2 , the lever  64  can be exposed on the upper surface side of the bed portion  2 . The front end portion of the lever  64  is coupled to the right end of the second engagement member  16 . A coupling portion of the lever  64  and the second engagement member  16  is fixed by a pin  65 , which extends in the up-down direction, such that the coupling portion can rotate along the horizontal direction. The pin  65  is disposed to the right of the cylindrical portion  80 . The pin  65  is provided on an opposite side to the second urging member  66  with respect to the cylindrical portion  80 . The lever  64  and the second engagement member  16  can integrally rotate around the pin  65  along the horizontal plane. 
     When the engagement of the first engagement member  15  and the second engagement member  16  is released manually, the user removes the cover  9  from the bed portion  2 , and causes the lever  64  to be exposed on the upper surface side of the bed portion  2 . The user rotates the lever  64  in the second direction (the clockwise direction in a plan view). The second engagement member  16  rotates in the second direction around the pin  65  integrally with the lever  64 , against the urging force of the second urging member  66 . The second engagement member  16  separates from the engagement portion  18  of the first engagement member  15  in the horizontal direction. When the second engagement member  16  moves to a position at which the second engagement member  16  is not in contact with the upper end of the first convex portion  19 , the needle plate  11  is moved upward by the urging force of the first urging member  67 . As a result, as shown in  FIG.  9 B , the engagement of the first engagement member  15  and the second engagement member  16  is released. The right end portion of the needle plate  11  is positioned higher than the upper surface of the bed portion  2 . The user pinches the right end portion of the needle plate  11  and removes the needle plate  11 . 
     The lock release mechanism  17  of the present embodiment is further configured such that the engagement of the first engagement member  15  and the second engagement member  16  can be released using the movement motor  31  as the drive source. Specifically, as shown in  FIG.  5 A ,  FIG.  5 B  and  FIGS.  6 A- 6 C , the lock release mechanism  17  is further provided with a lever  63 , a pressing member  62  and a movement member  61 . The lever  63  has a plate shape that extends forward and diagonally to the right from the coupling portion of the lever  64  and the second engagement member  16 . The right end of the lever  63  bends downward. The length of the lever  63  in the front-rear direction is longer than the length of the lever  64  in the front-rear direction. The right end of the lever  63  is located further to the right than the right end of the lever  64 . When the cover  9  is removed from the bed portion  2 , the lever  63  is covered by the upper surface of the bed portion  2  from above. The lever  63  and the second engagement member  16  can integrally rotate around the pin  65  along the horizontal plane. 
     The pressing member  62  is a member that can move the right end of the lever  63  in the second direction in accordance with the position of the movement member  61 . The pressing member  62  is located to the right of the lever  63  and is supported such that the pressing member  62  can move in the left-right direction. Specifically, as shown in  FIGS.  7 A- 7 C , the pressing member  62  is provided with a main body portion  60 , a coupling portion  34  and a support portion  36 . The main body portion  60  is a plate-shaped section having a triangular shape in a plan view and extends horizontally. The main body portion  60  is provided to the right of the lever  63 . The front end of the main body portion  60  is coupled to the coupling portion  34 . The coupling portion  34  is a triangular section in a front view and extends downward from the front end of the main body portion  60 . The right end of the coupling portion  34  is coupled to the support portion  36 . The support portion  36  extends rearward from the right end of the coupling portion  34 , and further bends to the right. The support portion  36  is a plate-shaped section having an L shape in a plan view. The right end portion of the support portion  36  that extends in the left-right direction has a long hole that extends in the left-right direction. Two pins  35 , which extend in the front-rear direction, are inserted through the long hole. The two pins  35  are arranged side by side in the left-right direction, and are fixed to a plate-shaped support portion  24  that extends upward from the front left end portion of a fixing plate  25 . The fixing plate  25  is a plate member that extends horizontally, and the movement motor  31  is fixed to the right end portion of the fixing plate  25 . The pressing member  62  is fixed to the support portion  24  such that the pressing member  62  can move along the long hole. The right end portion of the support portion  36  has a fixing portion  37  which protrudes forward and to which one end of an urging member  39  is fixed. The other end of the urging member  39  is fixed to a plate-shaped support portion  38  that extends in the up-down direction from the front end portion of the fixing plate  25  in a position to the right of the support portion  24 . The urging member  39  is a coil spring. The pressing member  62  is urged by the urging member  39  in the rightward direction that is opposite to the movement direction (the leftward direction) when the lever  63  is rotated in the second direction. 
     The movement member  61  is configured to be movable in the left-right direction in accordance with the position of the output shaft  32  of the movement motor  31 . The movement member  61  is a plate-shaped section that extends upward from the front left end portion of the actuation piece  43 . The movement member  61  can move in the left-right direction integrally with the actuation piece  43  in accordance with a rotation angle of the movement motor  31 . The upper left end portion of the movement member  61  protrudes to the left in an arc shape. The left end portion of the support portion  36  of the pressing member  62  is disposed on the left side of the upper left end portion of the movement member  61 . The right end portion of the pressing member  62  is disposed on the rear side of the movement member  61 . 
     An operation to cause the feed dog retraction mechanism  14  to switch the feed dog  5  between the normal position and the retracted position using the movement motor  31  as the drive source, and an operation to cause the lock release mechanism  17  to release the engagement of the first engagement member  15  and the second engagement member  16  will be explained with reference to  FIGS.  6 A- 6 C,  7 A- 7 C and  8 A- 8 C . For example, when a command is input by the user via the touch panel  26 , the movement motor  31  is driven by an amount corresponding to the command. Via the touch panel  26 , the user can input each of a command to cause the feed dog retraction mechanism  14  to switch the feed dog  5  between the normal position and the retracted position, a command to cause the lock release mechanism  17  to release the engagement of the first engagement member  15  and the second engagement member  16 , and a command to cause the first engagement member  15  and the second engagement member  16  to be in an engageable state. In  FIGS.  6 A- 6 C , a virtual line L 1  indicates the central position of the pin  65 . A virtual line L 2  indicates the position of the right end of the lever  64  when the output shaft  32  is in a reference position. In  FIGS.  7 A- 7 C , a virtual line L 3  indicates the position of the left end portion of the movement member  61  when the output shaft  32  is in the reference position. A virtual line L 4  indicates the position of the left end portion of the movement member  61  when the output shaft  32  is in a first actuated position. A virtual line L 5  indicates the position of the left end portion of the movement member  61  when the output shaft  32  is in a second actuated position. In  FIGS.  8 A- 8 C , a virtual line L 7  indicates the central position of the shaft  47 . A virtual line L 8  indicates the position of the left end portion of the contactor  86  when the output shaft  32  is in the reference position. A virtual line L 9  indicates the position of the left end portion of the contactor  86  when the output shaft  32  is in the first actuated position. A virtual line L 10  indicates the position of the left end portion of the contactor  86  when the output shaft  32  is in the second actuated position. 
     As shown in  FIG.  4 A ,  FIG.  6 A ,  FIG.  7 A  and  FIG.  8 A , when the output shaft  32  of the movement motor  31  is in the reference position (at a reference angle), the contactor  86  comes into contact with the up-down feed cam  85 , and the feed dog retraction mechanism  14  causes the feed dog  5  to be disposed in the normal position. The pressing member  62  comes into contact with the lever  63 . The pressing member  62  separates from the movement member  61 . The second engagement member  16  is in a position in which the second engagement member  16  can engage with the first engagement member  15 . 
     When the command to cause the feed dog retraction mechanism  14  to switch the feed dog  5  from the normal position to the retracted position is input, the movement motor  31  is driven and the output shaft  32  of the movement motor  31  is rotated to the first actuated position (a first operating angle). The first actuated position is a position at which the output shaft  32  of the movement motor  31  is rotated by a predetermined angle, which is smaller than 360 degrees, in a predetermined direction from the reference position. In this case, as shown in  FIG.  6 B ,  FIG.  7 B  and  FIG.  8 B , the actuation piece  43  of the feed dog retraction mechanism  14  is moved further to the left than when the output shaft  32  is in the reference position. In accordance with the movement of the actuation piece  43 , the actuation piece  48  rotates around the pin  51  in the counterclockwise direction in a bottom view. In accordance with the rotation of the actuation piece  48 , the actuation piece  52  is guided by the long hole  57  and moves to the right. As a result, the contactor  86  moves to a position at which the left end of the contactor  86  reaches the position indicated by the virtual line L 9  in  FIGS.  8 A- 8 C , and separates from the up-down feed cam  85  in the left-right direction. The feed dog retraction mechanism  14  causes the feed dog  5  to be disposed in the retracted position. 
     The pressing member  62  comes into contact with the lever  63 . The movement member  61  moves to the position indicated by the virtual line L 4  in  FIG.  7 B , and comes into contact with the pressing member  62 . An operation performed when a command is input to cause the feed dog retraction mechanism  14  to switch the feed dog  5  from the retracted position to the normal position is the reverse of the above-described operation. 
     When the command to cause the lock release mechanism  17  to release the engagement of the first engagement member  15  and the second engagement member  16  is input, the output shaft  32  of the movement motor  31  is rotated to the second actuated position (a second operating angle). The second actuated position is a position at which the output shaft  32  is further rotated in the predetermined direction from the first actuated position. In this case, as shown in  FIG.  4 B ,  FIG.  6 C ,  FIG.  7 C  and  FIG.  8 C , the actuation piece  43  of the feed dog retraction mechanism  14  is moved slightly further to the left than when the output shaft  32  is in the first actuated position. In accordance with the movement of the actuation piece  43 , the actuation piece  48  rotates around the pin  51  in the counterclockwise direction in a bottom view. In accordance with the rotation of the actuation piece  48 , the actuation piece  52  is guided by the long hole  57  and moves to the right. As a result, the contactor  86  moves to a position at which the left end of the contactor  86  reaches the position indicated by the virtual line L 10  in  FIGS.  8 A- 8 C , and separates from the up-down feed cam  85  in the left-right direction. Then, the feed dog retraction mechanism  14  causes the feed dog  5  to be disposed in the retracted position. 
     The movement member  61  of the lock release mechanism  17  moves to the position indicated by the virtual line L 5  in  FIG.  7 C , while pressing the pressing member  62  to the left. The pressing member  62  moves to the left integrally with the movement member  61  against the urging force of the urging member  39 , and pushes the lever  63  to the left. The lever  63  rotates in the second direction (the clockwise direction in a plan view) around the pin  65  against the urging force of the second urging member  66 . Thus, in the same manner as in the case of the lever  64 , the lock release mechanism  17  releases the engagement of the first engagement member  15  and the second engagement member  16 . Due to the urging force of the first urging member  67 , a section of the needle plate  11  that comes into contact with the first urging member  67  moves upward, as shown in  FIG.  9 B . The upper surface of the right end portion of the needle plate  11  is positioned higher than the upper surface of the bed portion  2 . An operation performed when the command is input to cause the first engagement member  15  and the second engagement member  16  to be in the engageable state is the reverse of the above-described operation, except the operation of the needle plate  11  (the first engagement member  15 ). 
     In the sewing machine  1  of the above-described embodiment, when the user fixes the needle plate  11  to the bed portion  2 , it is sufficient that the user causes the first engagement member  15  and the second engagement member  16  to be engaged with each other. When the user removes the needle plate  11  from the bed portion  2 , it is sufficient that the user uses the lock release mechanism  17  to release the engagement of the first engagement member  15  and the second engagement member  16 . Thus, in the sewing machine  1 , it is possible to remove the needle plate  11  from the bed portion  2  with a simpler operation than in related art. 
     The sewing machine  1  is further provided with the second urging member  66  that urges the second engagement member  16  such that the second engagement member  16  can rotate in the first direction that intersects with the up-down direction. The first engagement member  15  extends downward from the lower surface of the needle plate  11 , and has the engagement portion  18  that engages with the second engagement member  16 , and the first convex portion  19  provided below the engagement portion  18  and protrudes further in the horizontal direction than the engagement portion  18 . The lock release mechanism  17  has the lever  64  configured to rotate the second engagement member  16  in the second direction that is opposite to the first direction. When the first engagement member  15  and the second engagement member  16  are engaged with each other, the second engagement member  16  comes into contact with the engagement portion  18  of the first engagement member  15  due to the urging force of the second urging member  66 , and also comes into contact with the upper end of the first convex portion  19  of the first engagement member  15  due to the urging force of the first urging member  67 . Thus, in the sewing machine  1 , the first engagement member  15  and the second engagement member  16  can have a relatively simple configuration. With a simple operation of pressing down the needle plate  11  against the urging force of the first urging member  67 , the user can cause the first engagement member  15  and the second engagement member  16  to be engaged with each other. 
     The sewing machine  1  is further provided with the positioning pins  71  and  72  that extend upward inside the bed portion  2 . The needle plate  11  is provided with the holes  27  and  28  into which the positioning pins  71  and  72  are inserted. Thus, by disposing the positioning pins  71  and  72  in the holes  27  and  28 , the sewing machine  1  can suppress positional displacement of the needle plate  11  in the horizontal direction with respect to the bed portion  2 . When the second engagement member  16  and the first engagement member  15  are engaged with each other, the upper ends of the positioning pins  71  and  72  are lower than the height of the upper surface of the needle plate  11  in the fixed position. Thus, in a state in which the needle plate  11  is in the fixed position, the sewing machine  1  can avoid the sewing being obstructed by the positioning pins  71  and  72 . 
     The positioning pins  71  and  72  are respectively provided with the second convex portions  73  and  74  that protrude in the horizontal direction in the position below the needle plate  11  in the fixed position shown in  FIG.  1   , and the cushion materials  75  and  76  that are respectively disposed on the upper ends of the second convex portions  73  and  74 . When the needle plate  11  is in the fixed position, the cushion materials  75  and  76  are disposed between the lower surface of the needle plate  11  and the upper surfaces of the second convex portions  73  and  74 . Therefore, the sewing machine  1  can suppress collision noise from occurring between the needle plate  11  and the positioning pins  71  and  72  due to vibration and the like at the time of sewing. 
     The lever  64  is provided inside the bed portion  2  such that the lever  64  can be exposed on the upper surface side of the bed portion  2 . In the sewing machine  1 , the user can easily operate the lever  64 . In the present embodiment, when the sewing is performed, the lever  64  can be covered by the cover  9  that forms the plane flush with the upper surface of the bed portion  2 . Therefore, the sewing is not obstructed by the lever  64 . The lever  64  is located on the opposite side (the right side) to the leading end portion (the left end portion) of the bed portion  2  with respect to the needle bar  8 . When the sewing is performed, the sewing object is placed on the opposite side to the leading end portion of the bed portion  2  with respect to the needle bar  8  less frequently than on the leading end portion side of the bed portion  2 . Thus, the user can easily operate the lever  64  in comparison to when the lever  64  is located on the leading end portion (the left end portion) side of the bed portion  2  with respect to the needle bar  8 . 
     The lever  64  is provided below the upper surface of the bed portion  2 . Therefore, the sewing machine  1  can avoid the sewing being obstructed by the lever  64 . In the sewing machine  1 , since the lever  64  can be covered by the cover  9  when the sewing is performed, it is possible to avoid the lever  64  being erroneously operated when the sewing is performed. 
     The sewing machine  1  is provided with the movement motor  31  as an actuator. Using the driving force of the movement motor  31 , the lock release mechanism  17  releases the engagement of the first engagement member  15  and the second engagement member  16 . Thus, in the sewing machine  1 , with a simple operation of inputting the command to drive the movement motor  31 , the user can automatically release the engagement of the first engagement member  15  and the second engagement member  16 . 
     The sewing machine  1  is provided with the feed dog  5  that moves the sewing object, and the feed dog retraction mechanism  14 . The feed dog retraction mechanism  14  is coupled to the movement motor  31 . Using the movement motor  31  as the drive source, the feed dog retraction mechanism  14  switches the feed dog  5  from the normal position, in which the feed dog  5  can move the sewing object, to the retracted position, in which the feed dog  5  is retracted below the upper surface of the needle plate  11 . In this way, using the driving force of the movement motor  31 , the sewing machine  1  can drive the feed dog retraction mechanism  14  and switch the feed dog  5  from the normal position to the retracted position. In comparison to when the drive source of the feed dog retraction mechanism  14  and the drive source of the lock release mechanism  17  are separately provided, the configuration of the sewing machine  1  can be made compact. 
     More specifically, when the feed dog retraction mechanism  14  is coupled to the output shaft  32  of the movement motor  31  and the output shaft  32  reaches the first actuated position shown in  FIG.  6 B ,  FIG.  7 B  and  FIG.  8 B  in which the output shaft  32  has been rotated in the predetermined direction from the reference position shown in  FIG.  6 A ,  FIG.  7 A  and  FIG.  8 A , the feed dog retraction mechanism  14  switches the feed dog  5  from the normal position to the retracted position. The lock release mechanism  17  is provided with the lever  63  that can rotate the second engagement member  16  in the second direction, and the pressing member  62 . As shown in  FIG.  4 B ,  FIG.  6 C ,  FIG.  7 C  and  FIG.  8 C , the pressing member  62  can press the lever  63  in the second direction when the output shaft  32  reaches the second actuated position in which the output shaft  32  has been rotated further in the predetermined direction than in the first actuated position. Therefore, with a relatively simple configuration, the sewing machine  1  can commonize the drive source of the feed dog retraction mechanism  14  and the drive source of the lock release mechanism  17 . In the sewing machine  1 , the drive source of the feed dog retraction mechanism  14  and the drive source of the lock release mechanism  17  can be commonized without the engagement of the first engagement member  15  and the second engagement member  16  being released unintentionally when the feed dog  5  is to be moved from the normal position to the retracted position. 
     The sewing machine of the present disclosure is not limited to the above-described embodiment and various changes may be made without departing from the spirit and scope of the present disclosure. For example, the following modifications may be made as appropriate. 
     The configuration of the sewing machine  1  may be changed as appropriate. The sewing machine  1  may be an industrial sewing machine or a multi-needle sewing machine. It is sufficient that the first engagement member  15  and the second engagement member  16  are configured such that, when the first engagement member  15  and the second engagement member  16  are engaged with each other, they can fix, in the up-down direction, the needle plate  11  urged upward by the first urging member  67 . For example, at least one of the engagement portion  18  and the first convex portion  19  need not necessarily be provided on the first engagement member  15 . The second engagement member  16  and the levers  63  and  64  may be separate members. The feed dog  5 , the movement motor  31  and the feed dog retraction mechanism  14  may be omitted, if necessary. 
     The positioning pins  71  and  72  may be omitted if necessary, and the shape, number, arrangement and the like thereof may be changed as appropriate. At least one of the second convex portions  73  and  74  and the cushion materials  75  and  76  need not necessarily be provided on the positioning pins  71  and  72 . It is sufficient that the holes  27  and  28  of the needle plate  11  are configured such that the positioning pins  71  and  72  can be inserted therethrough, and the holes  27  and  28  need not necessarily penetrate the needle plate  11  in the up-down direction. The cushion materials  75  and  76  may be provided on the lower surface of the needle plate  11 . When the needle plate  11  is fixed to the bed portion  2 , the positioning pins  71  and  72  may slightly protrude from the upper surface of the needle plate  11  in a range in which they do not obstruct the sewing. 
     The arrangement, configuration and the like of the lever  64  that is operated by the user may be changed as appropriate. The lever  64  need not necessarily be capable of being exposed on the upper surface side of the bed portion  2  inside the bed portion  2 . For example, inside the bed portion  2 , the lever  64  may be able to be exposed on the front surface side or on the left surface side of the bed portion  2 . When the lever  64  is able to be exposed on the upper surface side of the bed portion  2 , the lever  64  may have a section that is at the same height as the upper surface of the bed portion  2  or a section higher than the upper surface of the bed portion  2 . The lever  64  need not necessarily be covered by the cover  9  from above. When the lever  64  is covered by the cover  9  from above, the configuration of the cover  9  may be changed as appropriate. The cover  9  may be attached to the bed portion  2  using a hinge portion. The cover  9  may be movably attached to the bed portion  2  such that the cover  9  can slide in the horizontal direction. 
     It is sufficient that the lock release mechanism  17  can release the engagement of the first engagement member  15  and the second engagement member  16 , and it is sufficient that the lock release mechanism  17  is provided with at least one of the configuration capable of releasing the engagement manually and the configuration capable of releasing the engagement using the driving force of the actuator. In other words, one of the configuration capable of releasing the engagement manually and the configuration capable of releasing the engagement using the driving force of the actuator may be omitted, if necessary. In addition to the step motor, the actuator may be a power cylinder, a solenoid or the like. The actuator to drive the lock release mechanism  17  may be provided separately from the power source of another mechanism, such as the feed dog retraction mechanism  14 . The lock release mechanism  17  may be changed as appropriate in accordance with the configuration of the sewing machine  1 , the actuator and the like. For example, the movement member  61  and the pressing member  62  may be formed integrally. In the sewing machine  1 , the same lever may be moved in the configuration capable of releasing the engagement manually and the configuration capable of releasing the engagement using the driving force of the actuator. 
     The apparatus and methods described above with reference to the various embodiments are merely examples. It goes without saying that they are not confined to the depicted embodiments. While various features have been described in conjunction with the examples outlined above, various alternatives, modifications, variations, and/or improvements of those features and/or examples may be possible. Accordingly, the examples, as set forth above, are intended to be illustrative. Various changes may be made without departing from the broad spirit and scope of the underlying principles.