Patent Publication Number: US-11661693-B2

Title: Embroidery apparatus

Description:
BACKGROUND OF INVENTION 
     1. Field of the Invention 
     The present invention relates to an embroidery apparatus to be mounted on a sewing machine that is switchable between embroidery stitching and standard stitching, and more specifically, relates to an embroidery apparatus in which a carriage unit (Y-direction translation mechanism) with an embroidery frame mounted thereon can be evacuated during standard stitching. 
     2. Description of the Related Art 
     A sewing machine accompanied by an embroidery apparatus is known. This type of the sewing machine is capable of both standard and embroidery stitching and is configured such that an embroidery frame is detachably mounted on the sewing machine to enable embroidery stitching of various patterns. In the case of performing standard stitching using the embroidery apparatus mounted on the sewing machine that is switchable between standard stitching and embroidery stitching, it is sometimes necessary to detach the embroidery apparatus from the sewing machine or detach a carriage unit with the embroidery frame mounted thereon from the embroidery apparatus. 
     A known embroidery apparatus (see Japanese Patent No. 4330728), which is used with a sewing machine switchable between embroidery stitching and standard stitching, has a carriage A that is disposed on a work bed  2  during embroidery stitching and that moves an embroidery frame  19  in the X and Y directions. The carriage A is driven by a carriage driving unit B accommodated in the work bed  2 . In standard stitching, the carriage A is slid to an end side of the work bed  2  and is laid down there for storage. 
     Another known embroidery apparatus (see Japanese Unexamined Patent Application Publication No. 2007-135663) includes a Y-direction drive mechanism  34  that has a carriage  52  on which an embroidery frame  28  is detachably mounted and that moves the carriage  52  in the Y direction that orthogonally intersects the X direction. The embroidery apparatus also includes a first switching mechanism  61  that switches the Y-direction drive mechanism  34  between a stitching position where the horizontally positioned Y-direction drive mechanism  34  is enabled to perform embroidery stitching near the upper surface of a main unit  31  and a standing position where the Y-direction drive mechanism  34  stands vertically. The embroidery apparatus further includes a second switching mechanism  65  that switches the Y-direction drive mechanism  34  between the standing position and a storage position where the Y-direction drive mechanism  34  is laid horizontally along the front side of the main unit  31 . When the Y-direction drive mechanism  34  is switched to the storage position, the upper surface of the body cover  35  of the Y-direction drive mechanism  34  is substantially flush with the upper surface of the body cover of the main unit  31 . 
     In the embroidery apparatus described in Japanese Patent No. 4330728, slit-like throughholes  2   d  are formed in the work bed  2 , and carriage-laying-down arms  5   b  passes through the slit-like throughholes  2   d  to move the carriage A over the work bed  2  in the X direction. When the work bed  2  is used as an auxiliary table during standard stitching, a cloth to be stitched may enter a slit-like throughhole  2   d  and get caught therein. 
     In the embroidery apparatus described in Japanese Unexamined Patent Application Publication No. 2007-135663, when the stitching mode is changed from embroidery stitching to standard stitching, a Y-direction cover  33  accommodating the Y-direction drive mechanism  34  is automatically moved to a switching position. It is necessary, however, for a user to manually move the Y-direction drive mechanism  34  to the standing position or to the storage position, which takes time and is inconvenient. Moreover, a downward-pointing abutting pin  85  is fixed to a left end portion of a non-engagement plate  81 , and the main unit  31  has a straight slit  31   a  that is formed in the right-left direction and through which the abutting pin  85  is movable in the right-left direction together with an engagement plate  80 . Due to such an arrangement, when the main unit  31  is used as an auxiliary table during standard stitching, a cloth to be stitched may enter the straight slit  31   a  and get caught therein, as is the case for the embroidery apparatus of Japanese Patent No. 4330728. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is an object to provide an embroidery apparatus that can be detachably mounted on a sewing machine switchable between embroidery stitching and standard stitching, that does not have a slit used for supporting a carriage unit on the upper surface of the main unit, and that can automatically store the carriage unit with an embroidery frame mounted thereon at a position outside the main unit during standard stitching. 
     According to an aspect of the invention, an embroidery apparatus includes a main unit to be detachably mounted on a bed section of a sewing machine, a first translation mechanism that moves an embroidery frame holder with an embroidery frame mounted thereon in a first direction, a second translation mechanism that moves the first translation mechanism along an upper surface of the main unit in a second direction that orthogonally intersects the first direction, and an elevator mechanism that is supported by the second translation mechanism at opposite sides of the main unit and that raises and lowers the first translation mechanism. 
     In the embroidery apparatus, the elevator mechanism may include a pair of hinge arms that are swingably supported by the second translation mechanism. The hinge arms are swingable so as to move closer to each other and away from each other, and the swing movement of the hinge arms raises and lowers the first translation mechanism horizontally. In addition, the first translation mechanism may have an elevator driving shaft that rotates with a rotation axis extending in the first direction, and a pair of first support seats that move in the first direction due to rotation of the elevator driving shaft. In addition, each of the hinge arms may have a first end portion pivotally supported by the second translation mechanism using a fulcrum shaft, and a second end portion pivotally connected to a corresponding one of the first support seats. Moreover, the elevator mechanism may have an elevator shaft that is rotatably supported by the second translation mechanism and configured to rotate forward and backward and thereby raise and lower the first translation mechanism. In addition, the elevator mechanism may have a drive unit that is disposed at the second translation mechanism and that rotates the elevator shaft and also may have a second support seat that supports the first translation mechanism using the elevator shaft so as to be able to raise and lower the first translation mechanism. 
     In the embroidery apparatus, upon receiving a storage instruction, the first translation mechanism may move the embroidery frame holder to an end of the first translation mechanism and issue a first storage-ready notification, and the second translation mechanism may move the first translation mechanism in the second direction to a position outside the main unit and issue a second storage-ready notification. In addition, upon receiving the first storage-ready notification and the second storage-ready notification, the elevator mechanism may lower the first translation mechanism until an upper surface of the first translation mechanism is flush with the upper surface of the main unit. 
     The embroidery apparatus configured as described above does not have a slit used for supporting the first translation mechanism on the upper surface of the main unit. This reduces the likelihood of a cloth to be stitched entering the slit when the upper surface of the main unit is used as the auxiliary table during standard stitching. In addition, when the stitching mode is switched from embroidery stitching to standard stitching, the first translation mechanism is automatically evacuated from the upper surface of the main unit and stored at a position outside the main unit. Moreover, the upper surface of the first translation mechanism is positioned so as to be flush with the upper surface of the main unit, which enables both the upper surface of the first translation mechanism and the upper surface of the main unit to be used as the auxiliary table. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a perspective view illustrating an overall external appearance of a sewing machine on which an embroidery apparatus according to a first example of the present invention is mounted. 
         FIG.  2    is a perspective view illustrating an internal structure of the embroidery apparatus of the first example. 
         FIG.  3    is a perspective view illustrating an internal structure of an X-direction translation mechanism of the embroidery apparatus of the first example. 
         FIG.  4    is a perspective view illustrating an internal structure of a Y-direction translation mechanism of the embroidery apparatus of the first example. 
         FIG.  5    is a perspective view illustrating an elevator mechanism disposed in the Y-direction translation mechanism of the embroidery apparatus of the first example. 
         FIG.  6    is an exploded view illustrating part of the elevator mechanism of the embroidery apparatus of the first example. 
         FIG.  7 A  is a left side view illustrating the elevator mechanism of the embroidery apparatus of the first example. 
         FIG.  7 B  is an enlarged perspective view illustrating part of the elevator mechanism of the embroidery apparatus of the first example. 
         FIG.  8    is a perspective view illustrating an external appearance of the embroidery apparatus of the first example. 
         FIG.  9 A  is a front view illustrating a carriage unit of the embroidery apparatus of the first example, in which the carriage unit is positioned at a home position. 
         FIG.  9 B  is a front view illustrating the carriage unit of the embroidery apparatus of the first example, in which the carriage unit is positioned at a storage-ready position. 
         FIG.  9 C  is a front view illustrating the carriage unit of the embroidery apparatus of the first example, in which the carriage unit is positioned at a storage-completion position. 
         FIG.  10 A  is a perspective view illustrating a home position of the X-direction translation mechanism of the embroidery apparatus of the first example. 
         FIG.  10 B  is a perspective view illustrating a storage position of the X-direction translation mechanism of the embroidery apparatus of the first example. 
         FIG.  10 C  is a perspective view illustrating the Y-direction translation mechanism of the embroidery apparatus of the first example, in which the Y-direction translation mechanism is positioned at a home position. 
         FIG.  10 D  is a perspective view illustrating the Y-direction translation mechanism of the embroidery apparatus of the first example, in which the Y-direction translation mechanism is positioned at a storage position. 
         FIG.  10 E  is a perspective view illustrating an upper position of the elevator mechanism of the embroidery apparatus of the first example. 
         FIG.  10 F  is a perspective view illustrating a lower position of the elevator mechanism of the embroidery apparatus of the first example. 
         FIG.  11 A  is a top view illustrating an internal structure of an embroidery apparatus according to a second example of the present invention. 
         FIG.  11 B  is a front view illustrating the internal structure of the embroidery apparatus according to the second example. 
         FIG.  12 A  is a view illustrating part of an assembled elevator mechanism of the embroidery apparatus of the second example. 
         FIG.  12 B  is an exploded view illustrating part of the elevator mechanism of the embroidery apparatus of the second example. 
         FIG.  13 A  is a sectional side view illustrating part of the elevator mechanism of the embroidery apparatus of the second example. 
         FIG.  13 B  is an enlarged view illustrating part of the elevator mechanism of the embroidery apparatus of the second example, in which the part of the mechanism is indicated in  FIG.  13 A . 
         FIG.  14    is a perspective view illustrating a state in which the elevator mechanism of the embroidery apparatus of the second example is lowered. 
         FIG.  15    is a left side view illustrating the embroidery apparatus of the second example. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     An embroidery apparatus according to an embodiment of the present invention will be described with reference to the drawings pertaining to examples. In the perspective view of  FIG.  1   , a direction extending vertically in the illustration is the up-down direction of a sewing machine. A direction extending from the upper right to the lower left in the illustration is the right-left direction or the X direction of the sewing machine. A direction extending from the lower right to the upper left in the illustration is the front-rear direction or the Y direction of the sewing machine. 
     First Example 
     In  FIG.  1   , reference A denotes a sewing machine body. The sewing machine body A includes a bed section  1  disposed at a lower part of the sewing machine body, a column section  2  extending upward from the right end of the bed section  1 , an arm section  3  extending leftward from the upper end of the column section  2  so as to oppose the bed section  1 , and a head section  4  disposed at the left end of the arm section  3 . Reference B denotes an embroidery apparatus that is detachably mounted onto the sewing machine body A. The embroidery apparatus B includes a main unit C that can serve as an auxiliary table when the main unit C is mounted on the sewing machine body A. The upper surface of the main unit C is disposed so as to be flush with the bed section  1 . The embroidery apparatus B also includes a carriage unit D (a first translation mechanism) that can move in the X direction (in the second direction) along the upper surface of the main unit C. 
     In the sewing machine body A, as illustrated in  FIG.  1   , a needle plate  5  through which a feed dog is intermittently raised for feeding a cloth is disposed at the upper surface of the bed section  1 . A display  6  is disposed in the column section  2 . The display  6  displays, for example, various selection buttons and information of a currently selected stitching pattern. A transparent touch panel that serves as a touch switch is laminated in a front portion of the display  6 . A needle bar and a presser bar are disposed in the head section  4 . The needle bar has a needle attached at the bottom end thereof. The needle bar moves up and down reciprocally. The presser bar has a presser foot for pressing a cloth at the upper surface of the needle plate  5 . 
     As illustrated in  FIGS.  1  and  2   , the main unit C of the embroidery apparatus B includes an X-direction translation mechanism  10  (second translation mechanism) and a Y-direction translation mechanism  30  (first translation mechanism). The X-direction translation mechanism  10  reciprocally moves the carriage unit D supported by an elevator mechanism  50  (to be described later) in the X direction that orthogonally intersects the Y direction (first direction). The Y-direction translation mechanism  30 , which is accommodated in the carriage unit D, reciprocally moves an embroidery frame holder  34  in the Y direction. An embroidery frame (not illustrated) is attached to the embroidery frame holder  34 . The main unit C has a body cover  8  of which an upper surface  8   a  serves as an auxiliary table. A recess  8   b  is formed in the body cover  8 . The recess  8   b  is configured to fit the side surfaces of the bed section  1  of the sewing machine body A. Slits  8   c  are also formed in the body cover  8  so as to extend horizontally at the front and rear surfaces thereof, respectively. 
     As illustrated in  FIGS.  2  and  3   , the X-direction translation mechanism  10  is disposed on a base plate  11  that is mounted in a lower portion of the body cover  8 . The X-direction translation mechanism  10  includes a pair of first guide rails  12 , a pair of first X-carriage guides  13 , and an X-drive motor  14 . The first guide rails  12  extend parallel to the X direction, and the first X-carriage guides  13  are mounted on respective first guide rails  12  so as to slide along in the X direction. The X-drive motor  14  drives the first X-carriage guides  13  using a first drive belt  16  and second drive belts  17 . 
     The X-drive motor  14  rotates an X-idler pulley  15  that moves the first drive belt  16  reciprocally, and the reciprocal movement of the first drive belt  16  moves the second drive belts  17  reciprocally. The first X-carriage guides  13  include respective X-belt fixation bases  18  that are fixed to the second drive belts  17 . Accordingly, the first X-carriage guides  13  move along the first guide rails  12  due to the reciprocal movement of the second drive belts  17 . 
     An X-sensor screen  20  is attached to a first X-carriage guide  13 . A first X-sensor  21  for detecting a home position and a second X-sensor  22  for detecting a storage position are disposed on the base plate  11  along the course of movement of the X-sensor screen  20 . The first X-sensor  21  and the second X-sensor  22  serve as reference positions when the carriage unit D containing the Y-direction translation mechanism  30  (to be described later) moves in the X direction. X-pulley mounting plates  19  are provided for adjustment of the tension of respective second drive belts  17 . 
     As illustrated in  FIGS.  2  and  4   , the Y-direction translation mechanism  30  is disposed on a Y-carriage base plate  31  that is mounted in a lower portion of a carriage cover  29 . The Y-direction translation mechanism  30  includes a second guide rail  32 , a Y-carriage guide  33 , and a Y-drive motor  35 . The second guide rail  32  extends in the Y direction, and the Y-carriage guide  33  is mounted on the second guide rail  32  so as to slide the embroidery frame holder  34  along in the Y direction. The Y-drive motor  35  drives the Y-carriage guide  33  using a Y-drive belt  37 . 
     The Y-drive motor  35  rotates a Y-idler pulley  36  that moves a Y-drive belt  37  reciprocally. The Y-carriage guide  33  includes a Y-belt fixation base  38  that is fixed to the Y-drive belt  37 . Accordingly, the Y-carriage guide  33  moves along the second guide rail  32  in the Y direction due to the reciprocal movement of the Y-drive belt  37 . 
     A Y-sensor screen  40  is attached to the Y-carriage guide  33 . A first Y-sensor  41  for detecting a home position and a second Y-sensor  42  for detecting a storage position are disposed on the Y-carriage base plate  31  along the course of movement of the Y-sensor screen  40 . The first Y-sensor  41  and the second Y-sensor  42  serve as reference positions when the embroidery frame holder  34  moves in the Y direction. A Y-pulley mounting plate  39  is provided for adjustment of the tension of the Y-drive belt  37 . 
     As illustrated in  FIGS.  2 ,  5 , and  6   , an elevator mechanism  50  is disposed between the first X-carriage guides  13  of the X-direction translation mechanism  10  and the Y-carriage base plate  31  of the Y-direction translation mechanism  30 . To begin with, a portion of the elevator mechanism  50  near the Y-direction translation mechanism  30  is described as below. As illustrated in  FIG.  5   , the elevator mechanism  50  includes a pair of third guide rails  51  and a pair of first Y-carriage seats  52  at the bottom surface of the Y-carriage base plate  31 . The elevator mechanism  50  also include an elevator driving shaft  54  and a first elevator motor  53 . The third guide rails  51  are disposed respectively in front and rear portions of the Y-carriage base plate  31  so as to extend in the Y direction. The first Y-carriage seats  52  are mounted on respective third guide rails  51  and slide along in the Y direction. The elevator driving shaft  54  is disposed with the rotation axis extending in the Y direction, and the rotation of the elevator driving shaft  54  causes the first Y-carriage seats  52  to move. The first elevator motor  53  rotates the elevator driving shaft  54 . 
     The first elevator motor  53  is attached to a standing plate  31   a  that stands at the Y-carriage base plate  31  and that extends in the Y direction. A worm gear  55  is fixed to the revolving shaft of the first elevator motor  53 . The worm gear  55  of the first elevator motor  53  engages a worm wheel  56  that is fixed to a central portion of the elevator driving shaft  54  that are rotatably supported by drive shaft supports  57 . A pair of bushes  58  being in sliding contact with corresponding drive shaft supports  57  prevent the elevator driving shaft  54  from being displaced in the thrusting directions. 
     The elevator driving shaft  54  has male screw portions  54   a  foamed at both ends thereof. The opposite male screw portions  54   a  are threaded in the opposite directions. The male screw portions  54   a  engage the internal threads of respective drive bases  59  that are fixed to the corresponding first Y-carriage seats  52 . The worm gear  55  of the first elevator motor  53  rotates the worm wheel  56  fixed to the elevator driving shaft  54  at a reduced rotation speed. Rotation of the elevator driving shaft  54  thrusts the drive bases  59  in opposite directions along the third guide rails  51 , thereby moving the first Y-carriage seats  52  fixed to the drive bases  59  in the corresponding thrusting directions along the third guide rails  51 . 
     An elevator sensor screen  60  is attached to a drive base  59 . An elevator sensor  61  for detecting a lower position is disposed at the standing plate  31   a  of the Y-carriage base plate  31  along the course of movement of the elevator sensor screen  60 . The elevator sensor  61  serves as the reference position when the drive base  59  moves downward. A guide tab  62  is fixed to a rear portion of the Y-carriage base plate  31  at the bottom surface thereof. The guide tab  62  is configured to slide along a guiding groove  67  of the main unit C, which will be described later. 
     Next, the connection between the first Y-carriage seats  52  of the elevator mechanism  50  and the first X-carriage guides  13  of the X-direction translation mechanism  10  is described below. As illustrated in  FIGS.  6  and  7   , each first X-carriage guide  13  of the X-direction translation mechanism  10  has a fulcrum shaft bearing  13   a . A Y-carriage support  63 , which is a hinge arm, has a fulcrum engagement portion  63   a  formed at a first end of the Y-carriage support  63 . The Y-carriage support  63  is pivotally connected to the first X-carriage guide  13  with a fulcrum shaft  64  engaging the fulcrum engagement portion  63   a  and the fulcrum shaft bearing  13   a . In addition, each first Y-carriage seat  52 , to which a corresponding drive base  59  is fixed, has a pivot bearing  52   a . The Y-carriage support  63  also has a pivot engagement portion  63   b  formed at a second end of the Y-carriage support  63 . The Y-carriage support  63  is pivotally connected to the first Y-carriage seat  52  with a pivot  65  engaging the pivot engagement portion  63   b  and the pivot bearing  52   a . An abutting member  66  is fixed to a lower portion of the Y-carriage support  63  at the inside surface thereof. 
     The abutting member  66  is a device having the following function. As illustrated in  FIG.  7 A , a pair of the Y-carriage supports  63  movably connect between a pair of the first X-carriage guides  13  of the X-direction translation mechanism  10  and a pair of the first Y-carriage seats  52  of the elevator mechanism  50 , respectively, using the fulcrum shafts  64  and the pivots  65 , which forms a four-node link mechanism. Accordingly, the carriage unit D on which the first Y-carriage seats  52  are mounted moves freely within a certain range. The carriage unit D, however, needs to stay fixedly at a predetermined position in order to prevent a cloth from moving during stitching. Accordingly, as illustrated in detail in  FIG.  7 B , when the carriage unit D is raised and stays on the upper surface of the main unit C during embroidery stitching, the abutting members  66  prevent the Y-carriage support  63  from moving unstably. 
     A fixation portion of the Y-carriage support  63  to which each abutting member  66  is fixed is adjustable to change the height position of the abutting member  66 . Accordingly, each of the right and left abutting members  66  is adjusted appropriately so that each abutting member  66  can abut a flat surface  13   b  of the corresponding first X-carriage guide  13  at an appropriate position, which thereby enables the carriage unit D to be stably fixed to the Y-carriage support  63 . 
     Moreover, as illustrated in  FIG.  8   , the body cover  8  of the main unit C has the guiding groove  67  that is formed at the upper surface  8   a  and the left side surface of the body cover  8  so as to extend in the X direction in a rear end portion of the body cover  8 . In addition, the guide tab  62  is formed at the bottom surface of the Y-carriage base plate  31  at a position immediately above the guiding groove  67 . The guide tab  62  engages the guiding groove  67 , which can prevent the carriage unit D from moving in the front-rear direction (Y direction). 
     Next, operation and advantageous effects of the present example will be described. In the case of the embroidery apparatus B starting embroidery stitching, as illustrated in  FIG.  9 A , the carriage unit D is at the home position at which embroidery stitching can be started at the upper surface  8   a  of the main unit C. Here, as illustrated in  FIGS.  2  and  3   , the first X-carriage guides  13  of the X-direction translation mechanism  10  support the carriage unit D using the elevator mechanism  50 . 
     The first X-carriage guides  13  are fixed to respective second drive belts  17  that are reciprocally moved by the reciprocal movement of the first drive belt  16  driven by the X-drive motor  14 . The first X-carriage guides  13  are thereby movable along the first guide rails  12  in the X direction. When the carriage unit D is at the home position as illustrated in  FIG.  10 A , the X-sensor screen  20  attached to a first X-carriage guide  13  masks the first X-sensor  21  disposed at the base plate  11  for detecting the home position. 
     Similarly, as illustrated in  FIG.  4   , the Y-direction translation mechanism  30  has the Y-carriage guide  33  configured to slide the embroidery frame holder  34  in the Y direction. The Y-carriage guide  33  is fixed to the Y-drive belt  37  that is reciprocally moved by the Y-drive motor  35 . The Y-carriage guide  33  is thereby movable along the second guide rail  32  in the Y direction. When the embroidery frame holder  34  of the Y-direction translation mechanism  30  is at the home position as illustrated in  FIG.  10 C , the Y-sensor screen  40  attached to the Y-carriage guide  33  masks the first Y-sensor  41  disposed at the Y-carriage base plate  31  for detecting the home position. The elevator sensor screen  60  attached to a drive base  59  of the elevator mechanism  50 , however, does not mask the elevator sensor  61  for detecting the lower position, as illustrated in  FIG.  10 E . Note that at the start of embroidery stitching using the embroidery apparatus B, a user needs to mount an embroidery frame with a cloth (not illustrated) onto the embroidery frame holder  34 . 
     Next, an operation for switching to standard stitching after the embroidery stitching is completed is described as follows. When the embroidery stitching is completed, the carriage unit D automatically returns to the home position illustrated in  FIG.  9 A , while the guide tab  62  fixed at the lower surface of the carriage unit D engages the guiding groove  67  formed at the upper surface of the main unit C as illustrated in  FIG.  8   . The user subsequently detaches the embroidery frame with a stitched cloth from the embroidery frame holder  34  of the Y-direction translation mechanism  30 . Subsequently, when the user touches a switching button for switching to the standard stitching, which is displayed at the display  6  of the sewing machine body A, a control device in the sewing machine body A issues a storage instruction to the embroidery apparatus B upon receiving the request of switching to the standard stitching from the switching button. 
     Upon receiving the storage instruction, the embroidery apparatus B starts the Y-drive motor  35  of the Y-direction translation mechanism  30  disposed in the carriage unit D, which causes the Y-carriage guide  33  with the embroidery frame holder  34  mounted thereon to move rearward. As illustrated in  FIG.  10 D , the Y-carriage guide  33  moves, and the Y-sensor screen  40  attached to the Y-carriage guide  33  subsequently masks the second Y-sensor  42  disposed at the Y-carriage base plate  31  for detecting the storage position. As a result, the Y-drive motor  35  stops moving the Y-carriage guide  33  rearward, and the carriage unit D holding the embroidery frame holder  34  stops at the storage position outside the main unit C, as illustrated in  FIG.  8   . 
     Simultaneously, the embroidery apparatus B starts the X-drive motor  14  of the X-direction translation mechanism  10  disposed in the main unit C, which moves the first X-carriage guides  13  leftward. As illustrated in  FIG.  10 B , the first X-carriage guides  13  move, and the X-sensor screen  20  attached to the corresponding first X-carriage guide  13  subsequently masks the second X-sensor  22  disposed at the base plate  11  for detecting the storage position. As a result, the X-drive motor  14  stops moving the first X-carriage guides  13  leftward, and the main unit C holds the carriage unit D at the storage position outside the main unit C by using the elevator mechanism  50 , as illustrated in  FIG.  9 B . 
     The embroidery apparatus B issues a first storage-ready notification when the Y-sensor screen  40  attached to the Y-carriage guide  33  of the Y-direction translation mechanism  30  masks the second Y-sensor  42  for detecting the storage position. The embroidery apparatus B issues a second storage-ready notification when the X-sensor screen  20  attached to the first X-carriage guide  13  of the X-direction translation mechanism  10  masks the second X-sensor  22  for detecting the storage position. 
     Upon receiving the first storage-ready notification and the second storage-ready notification, the elevator mechanism  50  starts the first elevator motor  53  to rotate the elevator driving shaft  54 . The elevator driving shaft  54  is screwed into the drive bases  59  that are fixed to respective first Y-carriage seats  52 . The rotation of the elevator driving shaft  54  moves the first Y-carriage seats  52  along the carriage unit D in opposite directions, in other words, in directions away from each other. Each first Y-carriage seat  52  is pivotally connected to the second end (pivot engagement portion  63   b ) of the corresponding Y-carriage support  63  using the pivot  65 , and the first end (fulcrum engagement portion  63   a ) of the Y-carriage support  63  is pivotally connected to the corresponding first X-carriage guide  13  using fulcrum shaft  64 . When the first Y-carriage seats  52  move toward the opposite ends of the carriage unit D, each Y-carriage support  63  turns outward while pivoting on the first end (fulcrum engagement portion  63   a ) so as to increase the distance between the second ends (pivot engagement portions  63   b ) of respective Y-carriage supports  63 . This causes the carriage unit D to descend with the guide tab  62  of the carriage unit D sliding along the guiding groove  67  formed at the left surface of the main unit C. 
     As illustrated in  FIG.  10 F , the first Y-carriage seats  52  move, and the carriage unit D descends horizontally. The elevator sensor screen  60  attached to the corresponding drive base  59  masks the elevator sensor  61  disposed at the standing plate  31   a  of the Y-carriage base plate  31  for detecting the lower position. The first elevator motor  53  stops moving the drive bases  59  toward the opposite ends. As a result, as illustrated in  FIG.  9 C , the carriage unit D is stored such that the upper surface of the carriage cover  29  is flush with the upper surface  8   a  of the body cover  8  of the main unit C. In this state, the user can perform standard stitching on the bed section  1  of the sewing machine body A while utilizing the upper surface  8   a  of the body cover  8  of the main unit C and the upper surface of the carriage cover  29  of the carriage unit D as an auxiliary table. 
     Next, an operation for switching to the embroidery stitching after the standard stitching is completed is described as follows. When the user returns to the embroidery stitching from the standard stitching, the user touches a switching button for switching to the embroidery stitching, which is displayed at the display  6  of the sewing machine body A, the control device in the sewing machine body A issues a returning-to-home-position instruction to the embroidery apparatus B upon receiving the request of switching to the embroidery stitching from the switching button. 
     Upon receiving the returning-to-home-position instruction, the embroidery apparatus B starts the first elevator motor  53  of the elevator mechanism  50  to rotate the elevator driving shaft  54 . The elevator driving shaft  54  is screwed into the drive bases  59  that are fixed to the first Y-carriage seats  52 . Rotation of the elevator driving shaft  54  moves the first Y-carriage seats  52  closer to each other toward the center of the carriage unit D. Each first Y-carriage seat  52  is pivotally connected to the second end (pivot engagement portion  63   b ) of the corresponding Y-carriage support  63  using the pivot  65 , and the first end (fulcrum engagement portion  63   a ) of the Y-carriage support  63  is pivotally connected to the corresponding first X-carriage guide  13  using fulcrum shaft  64 . When the first Y-carriage seats  52  move toward the center of the carriage unit D, each Y-carriage support  63  turns inward while pivoting on the first end (fulcrum engagement portion  63   a ) so as to decrease the distance between the second ends (pivot engagement portions  63   b ) of respective Y-carriage supports  63 . The carriage unit D thereby ascends with the guide tab  62  of the carriage unit D sliding along the guiding groove  67  of the main unit C. 
     As illustrated in  FIG.  7 A , the first Y-carriage seats  52  move and the carriage unit D ascends horizontally. Here, the number of rotation of the elevator driving shaft  54  is counted to the upper position from the lower position that has been detected by the elevator sensor  61  for detecting the lower position. The number counted is compared with a predetermined number of rotation of the elevator driving shaft  54 . The first elevator motor  53  stops moving the drive bases  59  toward the center of the carriage unit D when the number counted reaches the predetermined number. As a result, as illustrated in  FIG.  9 B , the carriage unit D is held at a position higher than the upper surface  8   a  of the body cover  8  of the main unit C. Upon completion of this return-preparation operation, the elevator mechanism  50  issues a return-preparation completion notification to the embroidery apparatus B. 
     Upon receiving the return-preparation completion notification, the embroidery apparatus B starts the Y-drive motor  35  of the Y-direction translation mechanism  30  disposed in the carriage unit D, which causes the Y-carriage guide  33  with the embroidery frame holder  34  attached thereto to move frontward. As illustrated in  FIG.  10 C , the Y-carriage guide  33  moves, and the Y-sensor screen  40  attached to the Y-carriage guide  33  masks the first Y-sensor  41  disposed at the Y-carriage base plate  31  for detecting the home position. As a result, the Y-drive motor  35  thereby stops moving the Y-carriage guide  33  frontward, and the carriage unit D holding the embroidery frame holder  34  stops at the home position. 
     Simultaneously, the embroidery apparatus B starts the X-drive motor  14  of the X-direction translation mechanism  10  disposed in the main unit C, which moves the first X-carriage guides  13  rightward. As illustrated in  FIG.  10 A , the first X-carriage guides  13  move, and the X-sensor screen  20  attached to the corresponding first X-carriage guide  13  subsequently masks the first X-sensor  21  disposed at the base plate  11  for detecting the home position. As a result, the X-drive motor  14  stops moving the first X-carriage guides  13  rightward, and the main unit C holds the carriage unit D at the home position by using the elevator mechanism  50 , as illustrated in  FIG.  9 A . Note that a normal spur gear may be used to connect the first elevator motor  53  with the elevator driving shaft  54  in the elevator mechanism  50 . In this case, energizing the first elevator motor  53  can prevent the carriage unit D from descending due to its own load when the elevator driving shaft  54  stops. In the present example, however, the first elevator motor  53  and the elevator driving shaft  54  are connected using the worm gear  55  and the worm wheel  56 . This self-locking mechanism can prevent the elevator driving shaft  54  from rotating unexpectedly, which eliminates the necessity of energizing the first elevator motor  53  while the elevator driving shaft  54  stops. 
     As described above, the embroidery apparatus B of the present example is able to execute the switching operation automatically from the embroidery stitching to the standard stitching and also from the standard stitching to the embroidery stitching. In addition, in the embroidery apparatus B, the carriage unit D is supported by the elevator mechanism  50  at the sides of the main unit C. This enables the upper surface  8   a  of the body cover  8  of the main unit C and the upper surface of the carriage cover  29  of the carriage unit D to be used as the auxiliary table during the standard stitching. 
     Second Example 
     Next, a second example will be described. In the second example, the structure of the elevator mechanism  50  of the first example is changed. In the present example, the same elements as those described in the first example will be denoted by the same reference symbols. Description of the second example is directed to differences from the first example, while duplicated description is omitted. 
     In  FIGS.  11  and  15   , reference Ba denotes an embroidery apparatus. The embroidery apparatus Ba includes the main unit C in which the X-direction translation mechanism  10  is disposed. The X-direction translation mechanism  10  supports the carriage unit D using an elevator mechanism  70  (to be described later) and reciprocally moves the carriage unit D in the X direction. The embroidery apparatus Ba also includes the carriage unit D in which the Y-direction translation mechanism  30  is disposed. The carriage unit D moves along the upper surface of the main unit C in the X direction. The Y-direction translation mechanism  30  reciprocally moves the embroidery frame holder  34  in the Y direction. 
     As illustrated in  FIG.  11   , the X-direction translation mechanism  10 , which is disposed on the base plate  11 , includes a pair of the first guide rails  12 , a pair of second X-carriage guides  23 , and the X-drive motor  14 . The first guide rails  12  extend parallel to the X direction, and the second X-carriage guides  23  are mounted on respective first guide rails  12  so as to slide along in the X direction. The X-drive motor  14  drives the second X-carriage guides  23  using the first drive belt  16  and the second drive belts  17 . The X-sensor screen  20  is attached to a second X-carriage guide  23 . The first X-sensor  21  for detecting the home position and the second X-sensor  22  for detecting the storage position are disposed on the base plate  11  along the course of movement of the X-sensor screen  20 . 
     The Y-direction translation mechanism  30  is disposed on the Y-carriage base plate  31 . The Y-direction translation mechanism  30  includes the second guide rail  32 , the Y-carriage guide  33 , and the Y-drive motor  35 . The second guide rail  32  extends in the Y direction, and the Y-carriage guide  33  is mounted on the second guide rail  32  and slides the embroidery frame holder  34  along in the Y direction. The Y-drive motor  35  drives the Y-carriage guide  33  using the Y-drive belt  37 . The Y-sensor screen  40  is attached to the Y-carriage guide  33 . The first Y-sensor  41  for detecting the home position and the second I-sensor  42  for detecting the storage position are disposed on the Y-carriage base plate  31  along the course of movement of the Y-sensor screen  40 . 
     As illustrated in  FIGS.  11 A,  11 B, and  15   , an elevator mechanism  70  is disposed between each second X-carriage guide  23  of the X-direction translation mechanism  10  and the Y-carriage base plate  31  of the Y-direction translation mechanism  30 . As illustrated in  FIGS.  12 A to  14   , the elevator mechanism  70  includes a pair of second Y-carriage seats  71  that support respective front and rear portions of the Y-carriage base plate  31  of the Y-direction translation mechanism  30  at the bottom surface of the Y-carriage base plate  31 . Each second Y-carriage seat  71  has a first throughhole  71   a  and a second throughhole  71   b . An elevator shaft  72  and a guide shaft  73  are disposed at each second X-carriage guide  23  of the X-direction translation mechanism  10 . The elevator shaft  72  and the guide shaft  73  of each second X-carriage guide  23  engage the first throughhole  71   a  and the second throughhole  71   b  of the corresponding second Y-carriage seat  71 , respectively. 
     As illustrated in  FIGS.  12 A and  12 B , each elevator shaft  72   a  has a spiral groove  72   a  formed on the surface thereof, and the spiral groove  72   a  has horizontal upper and lower dead ends. The elevator shaft  72  is rotatably supported by elevator shaft bearings  24  formed at the second X-carriage guide  23 . Each guide shaft  73  is fixed to a guide shaft holder  25  attached to the second X-carriage guide  23  so as not to rotate. 
     As illustrated in  FIGS.  12 A to  13 B , a cam mounting plate  75  is attached to each second Y-carriage seat  71 , and a cam roller shaft  75   a  is fixed to the cam mounting plate  75 . The cam roller  74  is rotatably fitted to the cam roller shaft  75   a , and the cam roller  74  engages the spiral groove  72   a  of the elevator shaft  72 . When the elevator shaft  72  rotates, the cam roller  74  slides along the spiral groove  72   a . The second Y-carriage seat  71  having the cam mounting plate  75  to which the cam roller  74  is fitted thereby moves up and down. 
     As illustrated in  FIGS.  12 A and  12 B , the elevator shaft  72  has a drive gear  76  attached to the bottom end. External power is provided to rotate the elevator shaft  72 . In addition, a stopper  77  to engage the drive gear  76  is provided to prevent the elevator shaft  72  from rotating due to the load of the second Y-carriage seat  71  when the drive gear  76  is not connected to the external power. The stopper  77  that has a hook  77   a  and a disengagement tab  77   b  is rotatably supported by a stopper shaft bearing  26  of the second X-carriage guide  23 . An urging spring  78  connecting between the stopper  77  and a spring hook  27  urges the hook  77   a  of the stopper  77  in the direction in which the hook  77   a  engages the drive gear  76 . A disengagement-tab-abutting member  28  is disposed at the base plate  11  so as to stand in the course of movement of the stopper  77 . 
     As illustrated in  FIG.  14   , when the second X-carriage guide  23  is moved to the storage position, the drive gear  76  engages an elevator gear  79  to rotate the elevator shaft  72 . A second elevator motor  80  rotates the elevator gear  79  using an elevator driving belt  81 . The elevator gear  79  is mounted on a swing plate  83  that is urged by a swing spring  82  in the direction in which the elevator gear  79  engages the drive gear  76 . This arrangement is provided to prevent gear teeth from breaking when the drive gear  76  and the elevator gear  79  engage each other. Note that as illustrated in  FIG.  15   , the elevator shafts  72  and members for driving the elevator shafts  72 , such as the elevator gears  79 , the swing springs  82 , and the swing plates  83  are provided generally symmetrically in respective front and rear portions of the base plate  11 . 
     An elevator sensor screen  84  is attached to a second Y-carriage seat  71 . An elevator sensor  85  for detecting an upper position is attached to a sensor mounting plate  86  disposed so as to stand at the base plate  11  along the course of movement of the elevator sensor screen  84 . The elevator sensor  85  serves as the reference position when the second Y-carriage seat  71  reaches the upper position and the cam roller  74  reaches the horizontal groove at the upper dead end of the spiral groove  72   a.    
     Next, operation and advantageous effects of the present example will be described. During embroidery stitching, the carriage unit D of the embroidery apparatus Ba is held by the elevator mechanism  70  over the main unit C. The hook  77   a  of the stopper  77  urged by the urging spring  78  engages each drive gear  76 , which prevents the elevator shaft  72  from rotating unexpectedly and thereby prevents the carriage unit D from descending. When the embroidery stitching is completed, the carriage unit D automatically returns to the home position illustrated in  FIG.  11   . The user detaches the embroidery frame from the embroidery frame holder  34  of the Y-direction translation mechanism  30 . Subsequently, when the user touches a switching button for switching to the standard stitching, which is displayed at the display  6  of the sewing machine body A, the control device in the sewing machine body A issues the storage instruction to the embroidery apparatus Ba upon receiving the request of switching to the standard stitching from the switching button, as is the case for the first example. 
     Upon receiving the storage instruction, the embroidery apparatus Ba starts the Y-drive motor  35  of the Y-direction translation mechanism  30 , which causes the Y-carriage guide  33  having the embroidery frame holder  34  to move rearward. The Y-sensor screen  40  attached to the Y-carriage guide  33  subsequently masks the second Y-sensor  42  for detecting the storage position. As a result, the I-drive motor  35  stops moving the Y-carriage guide  33  rearward, and the Y-direction translation mechanism  30  holds the embroidery frame holder  34  at the storage position outside the main unit C. 
     Simultaneously, the embroidery apparatus Ba starts the X-drive motor  14  of the X-direction translation mechanism  10 , which moves the second X-carriage guides  23  leftward. The X-sensor screen  20  attached to the corresponding second X-carriage guide  23  subsequently masks the second X-sensor  22  for detecting the storage position. As a result, the X-drive motor  14  stops moving the second X-carriage guides  23  leftward, and the X-direction translation mechanism  10  and the elevator mechanism  70  holds the Y-direction translation mechanism  30  at the storage position outside the main unit C. 
     When the embroidery apparatus Ba causes the X-direction translation mechanism  10  to move the carriage unit D to the storage position, the drive gear  76  of each elevator shaft  72  of the elevator mechanism  70  engages the corresponding elevator gear  79 . Simultaneously, the disengagement tab  77   b  of each stopper  77  abuts the corresponding disengagement-tab-abutting member  28  disposed on the base plate  11 , which enables the elevator gear  79  to rotate. 
     The embroidery apparatus Ba issues the first storage-ready notification when the Y-sensor screen  40  attached to the Y-carriage guide  33  of the Y-direction translation mechanism  30  masks the second Y-sensor  42  for detecting the storage position. The embroidery apparatus B issues the second storage-ready notification when the second X-sensor  22  for detecting the storage position of the second X-carriage guides  23  of the X-direction translation mechanism  10  is masked. 
     Upon receiving the first storage-ready notification and the second storage-ready notification, the elevator mechanism  70  starts the second elevator motor  80  to rotate each elevator gear  79  using the elevator driving belt  81 . Each elevator gear  79  engages the drive gear  76  and rotates the corresponding elevator shaft  72 , which causes the each second Y-carriage seat  71  to descend. Rotation of each elevator shaft  72  lowers the cam roller  74  that engages the spiral groove  72   a  of the elevator shaft  72 , which causes the corresponding second Y-carriage seat  71  to descend together with the cam roller  74 . 
     When the second Y-carriage seats  71  descend, the number of rotation of each elevator shaft  72  is counted to the lower position from the upper position that has been detected by the elevator sensor  85  for detecting the upper position. The number counted is compared with a predetermined number of rotation of the elevator shaft  72 . When the number counted reaches the predetermined number, the second elevator motor  80  stops rotating the elevator gear  79 . Each second Y-carriage seat  71  reaches the lower position, and the cam roller  74  reaches the horizontal groove formed at the lower dead end of the spiral groove  72   a . Consequently, the upper surface of the carriage unit D becomes flush with the upper surface of the body cover of the main unit C, as illustrated in  FIG.  9 C . 
     The operation for switching to the embroidery stitching after the standard stitching is completed is the same as that described in the first example, and detailed description will be omitted. In short, the elevator mechanism  70  raises the carriage unit D to the upper position, and subsequently the X-direction translation mechanism  10  and the Y-direction translation mechanism  30  move the carriage unit D to the home position. In the present example, the elevator mechanism  70  includes the stopper  77  to engage the drive gear  76  of each elevator shaft  72 , which prevents the elevator shaft  72  from rotating unexpectedly. In addition, the grooves at the upper and lower dead ends of the spiral groove  72   a  of each elevator shaft  72  are formed horizontally. This prevents the carriage unit D from descending due to its own load when the drive gear  76  of the elevator shaft  72  is not connected to the external power. 
     As described above, the embroidery apparatus Ba of the present example is able to execute the switching operation automatically from the embroidery stitching to the standard stitching and also from the standard stitching to the embroidery stitching. In addition, in the embroidery apparatus Ba, the carriage unit D is raised and lowered by the rotation of the elevator shafts  72  of the elevator mechanism  70  at the sides of the main unit C. This enables the upper surface of the main unit C and the upper surface of the carriage unit D to be used as the auxiliary table during the standard stitching. 
     The embroidery apparatus of the present invention is advantageous. The embroidery apparatus can be applied to sewing machines capable of both embroidery and standard stitching. When the stitching mode is switched from embroidery stitching to standard stitching, the first translation mechanism is automatically evacuated from the upper surface of the main unit and stored at a position outside the main unit. Subsequently, the upper surface of the first translation mechanism is positioned so as to be flush with the upper surface of the main unit, which enables both the upper surface of the first translation mechanism and the upper surface of the main unit to be used as the auxiliary table.