Patent Publication Number: US-11396722-B2

Title: Cap frame

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority from Japanese Patent Application No. 2019-150442 filed on Aug. 20, 2019, the content of which is incorporated herein by reference in its entirety. 
     TECHNICAL FIELD 
     Aspects of the disclosure relate to a cap frame for holding a workpiece such as a cap and for use in an embroidery machine. 
     BACKGROUND 
     A known cap frame is configured to be attached to an embroidery machine. The cap frame is configured to hold a cap including a visor and a crown such as a baseball cap. The cap frame includes a body member and a retaining member. The body member has a tubular shape. The retaining member is made of material having flexibility. The retaining member has a shape conforming to a shape of the body member and extends along a circumferential direction of the body member. The retaining member is configured to be secured to the body member while receiving a visor of a cap through an opening of the retaining member and being deformed into an arc shape conforming to a crown of the cap in the vicinity of a boundary between the visor and the crown of the cap. More specifically, for example, the retaining member has one end portion and the other end portion in its longitudinal direction. The one end portion of the retaining member is fixed to the body member using a screw. The other end portion of the retaining member is movable between a retaining position and a release position. At the retaining position, the other end portion of the retaining member is in engagement with the body member and the retaining member may hold a cap in cooperation with the body member. At the release position, the other end portion of the retaining member is out of engagement with the body member. For setting a cap to the cap frame, a user places a cap onto the body member while maintaining the other end portion of the retaining member at the release position. Thereafter, the user inserts a visor of the cap into the opening of the retaining member to contact the one end portion and the other end portion of the retaining member to the cap in this order. The user then places the other end portion of the retaining member at the retaining position to engage the other end portion of the retaining member and the body member to each other. 
     SUMMARY 
     In the known cap frame, the user may contact the one end portion of the retaining member to the cap and then the other end portion of the retaining member to the cap to engage the retaining member and the body member to each other. Nevertheless, in the above known procedure, the center line of the cap may tend to go out of alignment with the center of the cap frame. 
     Accordingly, aspects of the disclosure provide a cap frame with respect to which a cylindrical workpiece such as a cap may be brought into alignment with a simpler procedure as compared with the known procedure. 
     In one or more aspects of the disclosure, a cap frame may include a body member, a retaining member, and an attaching portion. The body member may include a curved wall. The curved wall may have an arc shape and extend in a particular direction. The retaining member may be configured to, in a state where the retaining member is attached to the body member, hold a cap in cooperation with the body member to sandwich the cap therebetween. The retaining member may include a clamping portion, a first engagement portion, and a second engagement portio. The clamping portion may be made of elastic material. The clamping portion may be configured to, in a state where the retaining member is attached to the body member, be elastically deformed in conformance with the curved wall and press, toward the curved wall, the cap sandwiched between the curved wall and the clamping portion. The first engagement portion and the second engagement portion may be disposed at end portions of the clamping portion in the particular direction in a state where the retaining member is attached to the body member. The attaching portion may be disposed at at least one of the body member and the retaining member. The attaching portion may be configured to be removably attached to a moving mechanism of an embroidery machine. The body member may further include a third engagement portion, a fourth engagement portion, a first guide portion, and a second guide portion. The third engagement portion and the fourth engagement portion may be configured to engage the first engagement portion and the second engagement portion, respectively, of the retaining member. The third engagement portion and the fourth engagement portion may be further configured to, in a case where the third engagement portion and the fourth engagement portion are in engagement with the first engagement portion and the second engagement portion, respectively, of the retaining member with the clamping portion conforming to the curved wall, restrict the retaining member and the body member from moving relative to each other, thereby fastening the retaining member to the body member in conformance therewith. The third engagement portion and the fourth engagement portion may be further configured to, in a case where the third engagement portion and the fourth engagement portion are out of engagement with the first engagement portion and the second engagement portion, respectively, of the retaining member, allow the retaining member and the body member to move relative to each other. The first guide portion may define a movable direction of the first engagement portion as a first guide direction toward the third engagement portion and a direction opposite to the first guide direction. The second guide portion may define a movable direction of the second engagement portion as a second guide direction toward the fourth engagement portion and a direction opposite to the second guide direction. 
     According to the one or more aspects of the disclosure, in the cap frame, engaging the first and second engagement portions of the retaining member to the third and fourth engagement portions, respectively, of the body member may enable the retaining member to be attached to the body member with the retaining member conforming to the shape of the curved wall. Such an attaching manner may thus enable alignment of the cap with respect to the cap frame with a simpler procedure as compared with the known procedure in which a retaining member is attached to a body member with a one end portion of the retaining member fixed to the body member. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a sewing machine in which a cap frame holding a cap is attached to a moving mechanism in an illustrative embodiment according to one or more aspects of the disclosure. 
         FIG. 2  is a right side view of the sewing machine in which the cap frame holding the cap is attached to the moving mechanism in the illustrative embodiment according to one or more aspects of the disclosure. 
         FIG. 3A  is a perspective view of the cap frame and a frame unit in the illustrative embodiment according to one or more aspects of the disclosure, wherein the cap frame is located in front of the frame unit. 
         FIG. 3B  is a perspective view of the cap frame and the frame unit in the illustrative embodiment according to one or more aspects of the disclosure, wherein the cap frame is attached to the frame unit. 
         FIG. 4A  is a right side view of the cap frame and the frame unit in the illustrative embodiment according to one or more aspects of the disclosure, wherein the cap frame is located in front of the frame unit. 
         FIG. 4B  is a right side view of the cap frame and the frame unit in the illustrative embodiment according to one or more aspects of the disclosure, wherein the cap frame is attached to the frame unit. 
         FIG. 5A  is a front view of the cap frame and the frame unit in the illustrative embodiment according to one or more aspects of the disclosure, wherein the cap frame is attached to the frame unit. 
         FIG. 5B  is a partial sectional view taken along line A-A of  FIG. 5A  as viewed in a direction of arrows according to the illustrative embodiment of the disclosure. 
         FIG. 6  is a perspective view of a body member of the cap frame in the illustrative embodiment according to one or more aspects of the disclosure. 
         FIG. 7  is a rear view of the body member of the cap frame in the illustrative embodiment according to one or more aspects of the disclosure. 
         FIG. 8A  is a front view of the cap frame including engagement portions and a switch member in the illustrative embodiment according to one or more aspects of the disclosure, wherein the engagement portions are located at respective engaged positions. 
         FIG. 8B  is a front view of the cap frame including the engagement portions and the switch member in the illustrative embodiment according to one or more aspects of the disclosure, wherein the engagement portions are located at respective disengaged positions. 
         FIG. 9  is a front view of the cap frame in the illustrative embodiment according to one or more aspects of the disclosure, wherein the retaining member is located above the body member. 
         FIG. 10  illustrates a sectional view taken along line B-B of  FIG. 9  as viewed in a direction of arrows and a partial enlarged sectional view of the retaining member including protrusions for explaining an angle of a first surface, an angle of a second surface, and an angle of an inclined surface each with respect to an imaginary axis according to the illustrative embodiment of the disclosure. 
         FIG. 11  is a rear perspective view of the retaining member in the illustrative embodiment according to one or more aspects of the disclosure. 
         FIG. 12  is a top view of the retaining member in the illustrative embodiment according to one or more aspects of the disclosure. 
         FIG. 13  is a flowchart of embroidering on a cap using the cap frame and the sewing machine in the illustrative embodiment according to one or more aspects of the disclosure. 
         FIGS. 14A, 14B, and 14C  are explanatory front views illustrating a procedure of attaching the cap to the cap frame in the illustrative embodiment according to one or more aspects of the disclosure. 
         FIGS. 15A, 15B, and 15C  are explanatory right side views illustrating the procedure of attaching the cap to the cap frame in the illustrative embodiment according to one or more aspects of the disclosure. 
         FIG. 16  is an explanatory front view illustrating a procedure of attaching a cover to the cap held by the cap frame in the illustrative embodiment according to one or more aspects of the disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to the accompanying drawings, an illustrative embodiment of the disclosure will now be described. Referring to  FIGS. 1 and 2 , a description will be provided on a configuration of a multi-needle sewing machine (hereinafter, simply referred to as a “sewing machine”)  1  to which a cap frame  5  is removably attachable. In the following description, an upper side, a lower side, a lower left side, an upper right side, an upper left side, and a lower right side of the page of  FIG. 1  are defined respectively as upper, lower, front, rear, left, and right sides of the sewing machine  1  and the cap frame  5 . 
     As illustrated in  FIGS. 1 and 2 , the sewing machine  1  may be an embroidery machine including a plurality of, for example, 10 needle bars  22 . The sewing machine  1  includes a base  2 , an upright arm  3 , and a horizontal arm  4 . The base  2  has a substantially U-shape in plan view and supports the entire sewing machine  1 . The upright arm  3  extends upward from a rear end portion of the base  2 . The horizontal arm  4  extends frontward from an upper end of the upright arm  3 . A needle bar case  21  is disposed at a front end of the horizontal arm  4 . The needle bar case  21  is movable in a right-left direction. The 10 needle bars  22  extending in an up-down direction and presser bars are aligned in a row and evenly spaced in the right-left direction in the needle bar case  21 . The needle bars  22  are each configured such that a needle  23  is removably attachable to a lower end thereof. Presser feet  24  are attached to respective lower ends of the presser bars. Each presser foot  24  is configured to move together with a corresponding presser bar between a lower position at which the presser foot  24  holds a workpiece and an upper position at which the presser foot  24  is located higher than the pressure foot  24  at the lower position and out of contact with the workpiece. A workpiece may be, for example, a cap C including a crown C 1  and a visor C 2 . 
     As illustrated in  FIG. 1 , the sewing machine  1  further includes an operation interface  11  including a button  14 . The operation interface  11  is disposed at the horizontal arm  4 . The button  14  enables a user to provide an instruction to start or stop embroidering. The sewing machine  1  further includes a cylinder bed  10  below the horizontal arm  4 . The cylinder bed  10  has a cylindrical shape and extends frontward from a lower end of the upright arm  3 . A needle plate  16  is disposed at an upper surface of the cylinder bed  10 . The cylinder bed  10  includes inside a rotary hook for accommodating a bobbin around which a lower thread is wound. The needle plate  16  has a needle hole that allows a needle  23  to pass therethrough. The sewing machine  1  further includes a moving mechanism  20  below the horizontal arm  4 . The moving mechanism  20  includes a holder  25 , a Y-axis motor, a Y-axis carriage  26 , an X-axis motor, and an X-axis carriage. The holder  25  is configured such that the cap frame  5  is removably attachable to the holder  25  via a frame unit  6 . The cap frame  5  is configured to hold a cap C removably. The moving mechanism  20  is configured to move the cap frame  5  attached to the holder  25  to stop at a particular position represented in a unique X-Y coordinate system (e.g., an embroidery coordinate system). More specifically, for example, the X-axis carriage is connected to the holder  25 . The Y-axis carriage  26  supports the X-axis carriage such that the X-axis carriage is movable in an X-axis direction (e.g., the right-left direction). The moving mechanism  20  is configured to move the Y-axis carriage  26  in a Y-axis direction (e.g., a front-rear direction) by driving of the Y-axis motor. The moving mechanism  20  is further configured to move the X-axis carriage in the X-axis direction by driving of the X-axis motor. A pair of right and left spool stands  12  is disposed at an upper surface of a rear portion of the horizontal arm  4 . Upper threads  15  are supplied from respective spools  13  mounted on the spool stands  12  and are threaded through eyes of the respective needles  23  attached to the lower ends of the needle bars  22 . 
     Referring to  FIGS. 3A, 3B, 4A, 4B, 5A, and 5B , a description will be provided on the frame unit  6  to which the cap frame  5  is removably attachable. The frame unit  6  includes a movable member  61 , a main body frame  62 , rollers  65 ,  66 , and  67 , a rotary frame  63 , a rotary mechanism  64 , and screws  68  and  69 . The movable member  61  may have a rectangular shape elongated in the right-left direction. The movable member  61  may be made of metal (e.g., aluminum alloy). The main body frame  62  may be a plate-like member made of metal (e.g., aluminum alloy). The main body frame  62  is disposed below the movable member  61  and extends in both the right-left direction and the up-down direction. The main body frame  62  has a hole  621  (refer to  FIG. 5A ) penetrating therethrough in the front-rear direction. The rollers  65 ,  66 , and  67  may be made of resin material (e.g., acetal resin (“POM”)). The rollers  65 ,  66 , and  67  are supported by a front surface of the main body frame  62  with their axes extending in the front-rear direction. The rotary frame  63  may be a tubular member made of metal (e.g., aluminum alloy). The rotary frame  63  includes a guide groove  54 , engagement brackets  51 ,  52 , and  53 , and a roller groove  57  at its outer circumference. The guide groove  54  may be an annular groove defined in the outer circumference of the rotary frame  63 . The engagement brackets  51 ,  52 , and  53  are configured to, in a state where the cap frame  5  is attached to a front end portion of the rotary frame  63 , be engaged with engagement portions  881 ,  882 , and  883 , respectively, of the cap frame  5 . The engagement brackets  51 ,  52 , and  53  enable the cap frame  5  to be removably attached to the rotary frame  63 . The roller groove  57  may be an annular groove. The roller groove  57  is engaged with the rollers  65 ,  66 , and  67 . The outer circumference of the rotary frame  63  is in contact with outer circumferences of the rollers  65 ,  66 , and  67 . The rotary frame  63  is supported by the rollers  65 ,  66 , and  67  so as to be rotatable on an imaginary axis J extending in the front-rear direction. The rotary frame  63  has a diameter less than a dimension of the movable member  61  in the right-left direction. In a state where the frame unit  6  is attached to the sewing machine  1 , the cylinder bed  10  of the sewing machine  1  extends through the hole  621  of the main body frame  62  and the rotary frame  63 . 
     The rotary mechanism  64  includes a sting-like wire  59 . The rotary mechanism  64  is configured to convert movement of the holder  25  in the right-left direction into rotation of the rotary frame  63  on the imaginary axis J via the wire  59 . The wire  59  is wound around the rotary frame  63  in the guide groove  54 . The wire  59  has ends  591  and  592  connected to right and left end portions, respectively, of the movable member  61 . As the holder  25  moves in the right-left direction, the movable member  61  moves in the right-left direction together with the holder  25  and relative to the main body frame  62  and the rotary frame  63 . At that time, the wire  59  of which the ends  591  and  592  are connected to the movable member  61  also moves in the right-left direction, thereby causing the rotary frame  63  to rotate on the imaginary axis J by a particular angle correspondingly. The screws  68  and  69  are screwed into the movable member  61  and the holder  25  from below to removably fasten the frame unit  6  to the holder  25  of the moving mechanism  20 . 
     Referring to  FIGS. 3A to 12 , the cap frame  5  will be described. In the description below, a direction in which the cap frame  5  is moved relative to the sewing machine  1  for attaching the cap frame  5  to the sewing machine  1  via the frame unit  6  may be referred to as an attaching direction M (e.g., a rearward direction). A direction in which the cap frame  5  is moved relative to the sewing machine  1  for removing the cap frame  5  from the sewing machine  1  may be referred to as a removing direction R (e.g., a frontward direction). The removing direction R may be a direction from one side of the cap frame  5 , in which an attaching portion  88  of a body member  8  may be provided, to the other side of the cap frame  5 , in which a curved wall  81  of the body member  8  may be provided. The attaching direction M may be opposite to the removing direction R. That is, the attaching direction M may be a direction from the other side of the cap frame  5 , in which the curved wall  81  of the body member  8  may be provided, to the one side of cap frame  5 , in which the attaching portion  88  of the body member  8  may be provided. Thus, in the illustrative embodiment, a direction in which the cap frame  5  is attached to and removed from the sewing machine  1  may correspond to the front-rear direction. The cap frame  5  may be a hoopless frame that might not have an embroidery hoop for defining an embroidery area where the sewing machine  1  can embroider a pattern on a crown C 1  of a cap C held by the cap frame  5 . The cap frame  5  includes a retaining member  7  and the body member  8 . The retaining member  7  and the body member  8  may hold a cap C by sandwiching therebetween a boundary C 3  (refer to  FIG. 15 ) between a crown C 1  and a visor C 2  of the cap C. In the illustrative embodiment, the cap frame  5  has a substantially mirror-symmetrical structure with respect to a plane E (refer to  FIG. 9 ) extending in both the front-rear direction and the up-down direction and passing through the imaginary axis J in a state where the cap frame  5  is attached to the frame unit  6 . In the following description, therefore, one of right and left halves of the cap frame  5  will be described in detail and a description of the other half will be omitted. 
     Referring to  FIGS. 3A to 8B , the body member  8  may be made of, for example, metal plate such as steel plate cold commercial (“SPCC”). The body member  8  includes curved walls  81  and  82 , a flange  85 , and the attaching portion  88 . The body member  8  further includes a casing  86 , engagement portions  91  and  92 , guide portions  93  and  94 , a switch member  89 , an attaching frame  87 . The curved walls  81  and  82  are each curved into an arc shape. As illustrated in  FIG. 5A , when viewed from the front, shapes of the curved walls  81  and  82  coincide with an arc of an imaginary circle K having the imaginary axis J as its center. That is, the curved walls  81  and  82  extend in a circumferential direction D (an example of a particular direction) of the circle K. The curved wall  81  has end portions in the circumferential direction D. A maximum distance L 1  between the end portions of the curved wall  81  in a width direction W of the cap frame  5  may preferably be less than a diameter (e.g., between 16 cm and 20 cm) of a crown C 1  of a cap C, and more preferably, 13 cm or less. The width direction W (e.g., the right-left direction) is orthogonal to the attaching direction M (e.g., the rearward direction) and a convex direction P (e.g., an upward direction) of the curved wall  81  toward which the curved wall  81  is convex. In the illustrative embodiment, the maximum distance L 1  may be a distance between particular points of the respective end portions of the curved wall  81  in the right-left direction at a level corresponding to the imaginary axis J in the up-down direction. That is, in the illustrative embodiment, the maximum distance L 1  may correspond to the diameter of the circle K coinciding with the shape of the curved wall  81  in front view. 
     As illustrated in  FIG. 6 , the curved wall  81  has recessed portions  83 ,  811 , and  812  and a plurality of hooks  84 . The recessed portion  83  is defined in a particular portion of the curved wall  81 . The particular portion includes a center  80  of the curved wall  81  in the circumferential direction D. The recessed portion  83  may be a cutout extending in the attaching direction M from a leading end of the curved wall  81  in the removing direction R (e.g., a front end of the curved wall  81 ). The recessed portions  811  and  812  are defined in the respective end portions of the curved wall  81  in the circumferential direction D. The recessed portions  811  and  812  may each be a cutout extending in the attaching direction M from the leading end of the curved wall  81  in the removing direction R (e.g., the front end of the curved wall  81 ). A bottom of the recessed portion  83  is positioned further to the rear than bottoms of the recessed portions  811  and  812  in the front-rear direction. The curved wall  81  has, within its extension range, a particular section between the recessed portions  83  and  811  in the circumferential direction D. An extension range of the particular section is greater than an extension range of the recessed portion  811  in the circumferential direction D. The curved wall  81  further has, within its extension range, a further particular section between the recessed portions  83  and  812  in the circumferential direction D. An extension range of the further particular section is greater than an extension range of the recessed portion  812  in the circumferential direction D. The extension range of each of the recessed portions  811  and  812  is greater than an extension range of the recessed portion  83  in the circumferential direction D. In a state where the cap frame  5  is attached to the sewing machine  1  via the frame unit  6 , an embroidery area is defined at a position corresponding to an area between the recessed portion  811  and the recessed portion  812  within the extension range of the curved wall  81  in the circumferential direction D. The hooks  84  of the curved wall  81  are disposed at leading ends of the portions (e.g., the particular portion and the further particular portion) of the curved wall  81  in the removing direction R other than the portions where the recessed portions  83 ,  811 , and  812  are defined. The hooks  84  may be bent portions extending in a radial direction of the curved wall  81  from the leading end of the curved wall  81  in the removing direction R. The radial direction of the curved wall  81  includes directions extending radially away from the imaginary axis J of the curved wall  81 . As illustrated in  FIG. 4A , a dimension G 1  of each hook  84  in the circumferential direction D is smaller than an interval G 2  between adjacent hooks  84 . 
     A front end of the curved wall  82  coincides with the bottom of the recessed portion  83  of the curved wall  81  in the front-rear direction and is positioned further to the rear than the bottoms of the recessed portion  811  and  812  in the front-rear direction. An inner circumference of the curved wall  82  is in contact with an outer circumference of a rear end portion of the curved wall  81 . The curved wall  82  has a mark  821  and recessed portions  822  and  823 . The mark  821  is provided at the center of the curved wall  82  in the circumferential direction D. The mark  821  is used as a reference for alignment of a cap C with respect to the cap frame  5 . The mark  821  may be a pattern that may be a combination of a circle and a straight line. The recessed portions  822  and  823  are defined in the curved wall  82  at respective positions corresponding to the recessed portions  811  and  812 , respectively, in the up-down direction. The recessed portions  822  and  823  may each be a cutout extending in the attaching direction M from a leading end of the curved wall  82  in the removing direction R. As illustrated in  FIG. 6 , a recessed amount G 4  of each of the recessed portions  822  and  823  in the front-rear direction is greater than a recessed amount G 3  of each of the recessed portions  811  and  812  in the front-rear direction. 
     As illustrated in  FIGS. 4A, 6, and 7 , the attaching portion  88  is disposed behind the curved wall  82 . The attaching portion  88  may have a tubular shape. When viewed from the rear, the attaching portion  88  has a circular shape. A circle representing the attaching portion  88  has the center coinciding with the imaginary axis J. The attaching portion  88  includes the engagement portions  881 ,  882 , and  883 . The engagement portions  881 ,  882 , and  883  may be rectangular through holes. The engagement portions  881 ,  882 , and  883  are configured to engage the engagement brackets  51 ,  52 , and  53 , respectively, of the frame unit  6 . The flange  85  is disposed at a boundary between the curved wall  82  and the attaching portion  88  in the front-rear direction. The flange  85  protrudes from the curved wall  82  in the radial direction. The flange  85  has a mark  851  at a position corresponding to the mark  821  of the curved wall  82 . As with the mark  821 , the mark  851  is used as a reference for alignment of a cap C with respect to the cap frame  5 . The mark  851  may be a notch having a V shape in front view. The V-notch mark  851  extends toward the imaginary axis J (e.g., downward) from a circumference of the flange  85 . As illustrated in  FIG. 7 , the flange  85  includes a lower portion fastened to the casing  86  with screws  853 ,  854 , and  855 . In a state where the cap frame  5  is attached to the sewing machine  1  via the frame unit  6 , the cylinder bed  10  of the sewing machine  1  extends through the attaching portion  88 . 
     As illustrated in  FIGS. 5A, 8A and 8B , the casing  86  may be a box having an inverted trapezoid shape in front view. The casing  86  is disposed below the curved walls  81  and  82 . The casing  86  includes a plate member  861 , an accommodating portion  863 , and a contact portion  865 . The plate member  861  has a through hole  862  having a circular shape in front view. In  FIG. 8 , the plate member  861  is not illustrated. The accommodating portion  863  may be a box-shaped member with its front end opened. As illustrated in  FIG. 5A , the plate member  861  is fastened to the accommodating portion  863  with screws  866 ,  867 ,  868 , and  869  with an operating portion  891  of the switch member  89  passing through the through hole  862 . The contact portion  865  protrudes from a bottom surface  864  of the accommodating portion  863 . The contact portion  865  is disposed offset to the right from the center of the bottom surface  864  in the right-left direction. 
     As illustrated in  FIGS. 8A and 8B , the engagement portions  91  and  92  are accommodated in the casing  86  and configured to engage engagement portions  78  and  79  (refer to  FIG. 9 ) of the retaining member  7 . More specifically, for example, the retaining member  7  includes a clamping portion  72 . The engagement portions  91  and  92  are configured to, in a state where the clamping portion  72  is positioned extending along the curved wall  81 , be engaged with the respective corresponding engagement portions  78  and  79 . The engagement portions  91  and  92  are configured to, in a case where the engagement portions  91  and  92  of the casing  86  are in engagement with the respective engagement portions  78  and  79 , restrict the retaining member  7  and the body member  8  from moving relative to each other with respect to guide directions F 1  and F 2 , thereby fastening the retaining member to the body member in conformance with the body member. The engagement portions  91  and  92  are further configured to, in a case where the engagement portions  91  and  92  are out of engagement with the respective engagement portions  78  and  79 , allow the retaining member  7  to move relative to the body member  8  in the guide directions F 1  and F 2  and in their opposite directions. The engagement portions  91  and  92  are mirror images of each other and symmetrically disposed right and left with respect to the plane E (refer to  FIG. 9 ). The engagement portion  91  may be a plate-like member having an inverted L-shape. The engagement portion  91  includes a longer portion  911  and a shorter portion  912 . The longer portion  911  obliquely extends from the upper right to the lower left in front view. The shorter portion  912  obliquely extends from an upper end of the longer portion  911  to the lower right. The longer portion  911  has a U shape in cross section opening downward and to the right. The longer portion  911  has a lower end portion serving as a ratchet pawl  913 . The engagement portion  91  is pivotably supported by the casing  86  via a shaft  914  extending in the front-rear direction. The shaft  914  may be made of metal (e.g., SUM23 specified in JIS (Japanese Industrial standard): Free-cutting steels). The engagement portion  91  further includes a protrusion  915  protruding from a right end portion of a front surface of the shorter portion  912 . 
     As with the engagement portion  91 , the engagement portion  92  may be a plate-like member having an inverted L-shape. The engagement portion  92  includes a longer portion  921  and a shorter portion  922 . The longer portion  921  has a U shape in cross section opening downward and to the left. The longer portion  921  has a lower end portion serving as a ratchet pawl  923 . The engagement portion  92  is pivotably supported by the casing  86  via a shaft  924  extending in the front-rear direction. The engagement portion  92  further includes a protrusion  925  protruding from a left end portion of a front surface of the shorter portion  922 . The engagement portion  91  is configured to engage the engagement portion  78  at one of a plurality of engagement positions. The engagement portion  92  is configured to engage the engagement portion  79  at one of a plurality of engagement positions. Thus, the retaining member  7  and the body member  8  are allowed to be located at one of a plurality of relative positions. 
     The guide portion  93  is disposed at a left portion of the casing  86 . The guide portion  94  is disposed at a right portion of the casing  86 . The guide portion  93  is configured to guide the engagement portion  78 . The guide portion  93  defines a movable direction of the engagement portion  78  as the guide direction F 1  (e.g., from upper left to lower right) and its opposite direction. The guide direction F 1  may be a direction in which the engagement portion  78  moves toward the engagement portion  91 . The guide portion  94  is configured to guide the engagement portion  79 . The guide portion  94  defines a movable direction of the engagement portion  79  as the guide direction F 2  (e.g., from upper right to lower left) and its opposite direction. The guide direction F 2  may be a direction in which the engagement portion  79  moves toward the engagement portion  92 . The guide portion  93  includes walls  931 ,  932 ,  933 , and  935  and a slit  936 . The walls  931 ,  932 ,  933 , and  935  and the slit  936  extend along the guide direction F 1 . The wall  933  may be a left wall of the casing  86 . The walls  931  and  932  are spaced from each other in the up-down direction. The walls  931  and  932  are disposed to the right of the wall  933  and extend parallel to the wall  933 . The wall  935  may be a rear wall of the guide portion  93 . The slit  936  is defined in a front portion of the guide portion  93 . The silt  936  extends along the guide direction F 1  and has an opening that opens to the front. The ratchet pawl  913  of the engagement portion  91  is located between the walls  931  and  932  in the up-down direction. The wall  931  is disposed above the wall  932 . 
     The guide portion  94  includes walls  941 ,  942 ,  943 , and  945  and a slit  946 . The walls  941 ,  942 ,  943 , and  945  and the slit  946  extend along the guide direction F 2 . The wall  943  may be a right wall of the casing  86 . The walls  941  and  942  are spaced from each other in the up-down direction. The walls  941  and  942  are disposed to the left of the wall  943  and extend parallel to the wall  943 . The wall  941  is disposed above the wall  942 . The ratchet pawl  923  of the engagement portion  92  is located between the walls  941  and  942  in the up-down direction. The wall  945  may be a rear wall of the guide portion  94 . The slit  946  is defined in a front portion of the guide portion  94 . The silt  946  extends along the guide direction F 2  and has an opening that opens to the front. A distance between the guide portions  93  and  94  in the width direction W (e.g., the right-left direction) decreases as the guide portions  93  and  94  extend in a direction (e.g., the downward direction) opposite to the convex direction P (e.g., the upward direction). More specifically, for example, as illustrated in  FIG. 8A , a maximum distance L 2  between the walls  932  and  942  in the right-left direction is shorter than a minimum distance L 3  between the walls  931  and  941  in the right-left direction. The walls  931  and  941  are located higher than the walls  932  and  942 . 
     As illustrated in  FIGS. 5A, 8A, and 8B , the switch member  89  is configured to change the respective positions of the engagement portions  91  and  92  between an engaged position (refer to  FIG. 8A ) and a disengaged position (refer to  FIG. 8B ). When the engagement portions  91  and  92  are located at the respective engaged positions, the engagement portions  91  and  92  are capable of engaging the engagement portions  78  and  79 , respectively. When the engagement portions  91  and  92  are located at the respective disengaged positions, the engagement portions  91  and  92  are incapable of engaging the engagement portions  78  and  79 , respectively. In the illustrative embodiment, the switch member  89  includes the operating portion  891 , an eccentric cam  894 , and an urging member  895 . The operating portion  891  protrudes frontward beyond the plate member  861  of the casing  86 . The operating portion  891  may be a disk dial rotatable on a shaft Q extending in the front-rear direction. The operating portion  891  includes a knob  892  and a protrusion  893 . The knob  892  is disposed at a front surface of the operating portion  891 . The knob  892  may be a plate-like member protruding frontward. The protrusion  893  protrudes from a periphery of the operating portion  891  in a radial direction of the operating portion  891 . The eccentric cam  894  and the urging member  895  are accommodated in the casing  86 . The eccentric cam  894  is disposed further to the rear than the operating portion  891 . The eccentric cam  894  is coaxially fixed to the shaft Q supporting the operating portion  891  so as to be rotatable together with the operating portion  891 . A particular portion of a periphery of the eccentric cam  894  is farther from the shaft Q than the periphery of the operating portion  891  is from the shaft Q in the radial direction. In other words, the particular portion of the periphery of the eccentric cam  894  protrudes relative to the periphery of the operating portion  891  in the radial direction. The urging member  895  may be a tension coil spring. The urging member  895  has a left end and a right end. The left end of the urging member  895  is fixed to a corner of the L-shaped engagement portion  91  where the longer portion  911  and the shorter portion  912  meet. The right end of the urging member  895  is fixed to a corner of the L-shaped engagement portion  92  where the longer portion  921  and the shorter portion  922  meet. 
     The switch member  89  is configured to change the respective positions of the engagement portions  91  and  92  between the engaged position (refer to  FIG. 8A ) and the disengaged position (refer to  FIG. 8B ) in accordance with a user&#39;s operation on the operating portion  891 . Hereinafter, a description will be provided on how the switch member  89  behaves when viewed from the front. The operating portion  891  is configured to rotate on the shaft Q between a particular position at which the operating portion  891  is in a first state (refer to  FIG. 8A ) and a further particular position at which the operating portion  891  is in a second state (refer to  FIG. 8B ). When the operating portion  891  is in the first state, the engagement portions  91  and  92  are located at the respective engaged positions. When the operating portion  891  is in the second state, the engagement portions  91  and  92  are located at the respective disengaged positions. In a case where the operating portion  891  is in the first state, the eccentric cam  894  is in contact with the contact portion  865  of the casing  86  from the right. Thus, further clockwise rotation of the operating portion  891  is restricted by the contact portion  865 . In such a state, the eccentric cam  894  is out of contact with the engagement portions  91  and  92 . The operating portion  891  is thus free from forces of the engagement portions  91  and  92 . In response to the operating portion  891  being rotated counterclockwise from the particular position where the operating portion  891  is in the first state, the particular portion of the periphery of the eccentric cam  894  comes into contact with the protrusion  915  of the engagement portion  91  and the protrusion  925  of the engagement portion  92  in accordance with the state change of the operating portion  891 . 
     In response to the operating portion  891  being further rotated counterclockwise, the eccentric cam  894  presses the protrusions  915  and  925  upward. In response to this, the engagement portion  91  pivots on the shaft  914  against an urging force of the urging member  895  and the ratchet pawl  913  of the engagement portion  91  is thus located further to the right and lower than the ratchet pawl  913  of the engagement portion  91  located at the engaged position. The engagement portion  92  pivots on the shaft  924  against an urging force of the urging member  895  and the ratchet pawl  923  of the engagement portion  92  is thus located further to the left and lower than the ratchet pawl  923  of the engagement portion  92  located at the engaged position. In response to the operating portion  891  being further rotated counterclockwise, as illustrated in  FIG. 8B , the protrusion  893  of the operating portion  891  comes into contact with the contact portion  865  of the casing  86  from the left. Thus, further counterclockwise rotation of the operating portion  891  is restricted by the contact portion  865 . In a case where the operating portion  891  is in the second state, the operating portion  891  receives downward forces from the engagement portions  91  and  92 . After a user&#39;s operation on the operating portion  891  is finished, the operating portion  891  is thus maintained in the second state without rotating on the shaft Q. In a case where the engagement portions  91  and  92  are located at the respective disengaged positions, the engagement portions  91  and  92  are separate from the engagement portions  78  and  79 , respectively and thus not allowed to engage the respective corresponding engagement portions  78  and  79 . Consequently, the engagement portions  78  and  79  are allowed to move in the respective directions opposite to the guide directions F 1  and F 2 . In a case where the switch member  89  is operated for changing the respective positions of the engagement portions  91  and  92  from the engaged position to the disengaged position, the switch member  89  may behave in reverse order to the above-described order, and therefore, a description will be omitted for the switch member  89  behaving in the reverse order. 
     As illustrated in  FIGS. 5A and 9 , the attaching frame  87  may be a rectangular plate member extending in a horizontal direction. The attaching frame  87  may be used in a case where a crown C 1  of a cap C to be sandwiched by the retaining member  7  and the body member  8  is clipped to the attaching frame  87  using clips K 1  and K 2  to fasten the cap C to the body member  8  (refer to  FIG. 16 ). The attaching frame  87  is disposed between the right and left ends of the curved walls  81  and  82  in the right-left direction and below the imaginary axis J in the up-down direction. The attaching frame  87  includes a body portion  870  and a support portion  878 . The body portion  870  is supported by the support portion  878  such that the position of the body portion  870  is adjustable in the front-rear direction. More specifically, for example, the body portion  870  has slits  871  and  872  and further includes fastening portions  875  and  876  and a bent portion  877 . The body portion  870  is attached to the support portion  878  using screws  873  and  874  through the slits  871  and  872  such that the position of the body portion  870  is adjustable in the front-rear direction. The fastening portion  875  may be a left end portion of the body portion  870  bent downward into an L shape. The fastening portion  876  may be a right end portion of the body portion  870  bent downward into an L shape. For example, particular portions of a crown C 1  of a cap C held by the cap frame  5  may be clipped, using the clips K 1  and K 2 , to the fastening portions  875  and  876 , respectively, to maintain the crown C 1  under tension in the circumferential direction D. The particular portions of the crown C 1  of the cap C clipped by the clips K 1  and K 2  may face respective end portions of the clamping portion  72  in the circumferential direction D. The bent portion  877  may be a front end portion of the body portion  870  bent downward. The bent portion  877  is disposed at a middle portion of the front end of the body portion  870  in the right-left direction. The bent portion  877  may be held by the user. The bent portion  877  enables the user to adjust the position of the attaching frame  87  in the front-rear direction between a position indicated by a solid line in  FIG. 6  and another position indicated by a double-dotted-and-dashed line in  FIG. 6  in accordance with a dimension of a crown C 1  in the front-rear direction. 
     As illustrated in  FIGS. 9 to 12 , the retaining member  7  is configured to, in a state where the retaining member  7  is attached to the body member  8 , hold the cap C together with the body member  8  such that the retaining member  7  and the body member  8  sandwich the cap C therebetween. The retaining member  7  is deformable and detachably attachable to the body member  8 . Hereinafter, a description will be provided on a configuration of the retaining member  7  that is attached to the body member  8 . The retaining member  7  includes the clamping portion  72 , the engagement portions  78  and  79 , and shafts  76  and  77 . The clamping portion  72  may be made of elastic material (e.g., polyamide resin (PA)). In a state where the retaining member  7  is attached to the body member  8 , the clamping portion  72  elastically deforms in conformance with the shape of the curved wall  81  and presses, toward the curved wall  81 , the cap C positioned between the retaining member  7  and the body member  8 . The clamping portion  72  includes a facing portion  73 , a plurality of protrusions  74 , and support portions  721  and  722 . The facing portion  73  is configured to face the curved wall  81  of the body member  8 . The facing portion  73  has the center  70  in the circumferential direction D. The center  70  also serves as the center of the retaining member  7  in the circumferential direction D and the center of the clamping portion  72  in the circumferential direction D. The facing portion  73  includes a first surface  731 , a second surface  732 , a mark  733 , and a plurality of ribs  734 . 
     The facing portion  73  has the first surface  731  on one side thereof facing the body member  8 . As the first surface  731  extends in the removing direction R, the first surface  731  is inclined toward the body member  8 . The facing portion  73  has the second surface  732  on the other side thereof opposite to the one side thereof. That is, the second surface  732  is opposite to the first surface  731 . As the second surface  732  extends in the removing direction R, the second surface  732  is inclined toward the body member  8 . That is, as the first surface  731  and the second surface  732  extend toward the front, the first surface  731  and the second surface  732  become closer to the imaginary axis J. That is, the facing portion  73  has a tapered shape. In the illustrative embodiment, the first surface  731  and the second surface  732  extend substantially parallel to each other. The mark  733  is disposed on the center  70  of the facing portion  73  in the circumferential direction D. The mark  733  may be a protrusion extending in the front-rear direction. Each rib  734  is connected to the first surface  731  and a corresponding one of the protrusions  74  ( 741 ). Each rib  734  may have a plate-like shape. In the illustrative embodiment, for example, the retaining member  7  includes four ribs  734  substantially evenly spaced in the circumferential direction D. Each rib  734  has an inclined surface  735  that may face the body member  8 . As with the first surface  731  and the second surface  732 , as the inclined surface  735  extends in the removing direction R, the inclined surface  735  is inclined toward the body member  8 . 
     In the illustrative embodiment, as illustrated in  FIGS. 10 and 11 , the facing portion  73  further includes a projecting portion  75  on the side thereof facing the body member  8 . The projecting portion  75  protrudes toward the body member  8  from a particular area belonging to the facing portion  73  and including the center  70  in the circumferential direction D. The projecting portion  75  partially includes the first surface  731 . As the first surface  731  at the projecting portion  75  extends in the removing direction R, the first surface  731  is inclined toward the body member  8 . The facing portion  73  includes a cushioning  751  on the first surface  731  at the projecting portion  75 . The cushioning  751  is provided for protection of a visor C 2  of a cap C from damage. The cushioning  751  may be, for example, a sponge, a rubber sheet, or a resin sheet having a certain thickness. The cushioning  751  has a thickness (e.g., a dimension in the radial direction) less than a thickness (e.g., a dimension in the radial direction) of the facing portion  73 . 
     The protrusions  74  protrude toward the curved wall  81  of the body member  8  from a front end of the first surface  731  of the facing portion  73 . The protrusions  74  face the leading end of the curved wall  81  of the body member  8  in the removing direction R (e.g., the front end of the curved wall  81 ). The protrusions  74  are disposed at the second surface  732  of the facing portion  73  and aligned along the circumferential direction D. The leading end portion of the curved wall  81  in the removing direction R includes the front end of the curved wall  81  and is located further to the front than the center of the curved wall  81  in the front-rear direction. The situation where “the protrusions  74  face the leading end of the curved wall  81  in the removing direction R” includes a situation where the curved wall  81  is located further to the rear than the protrusions  74  and the protrusions  74  and the front end portion of the curved wall  81  face each other in the attaching direction M as well as a situation where the protrusions  74  and the front end portion of the curved wall  81  face each other in the radial direction of the curved wall  81 . As illustrated in  FIG. 9 , the retaining member  7  has four equally defined sections R 1 , R 2 , R 3 , and R 4  in the circumferential direction D. The retaining member  7  has the protrusions  74  at at least two sections R 2  and R 3  that are defined adjacent to the center  70  of the retaining member  7  in the circumferential direction D. The protrusions  74  includes two first protrusions  740 , a plurality of second protrusions  741 , and a plurality of third protrusions  745 . Each first protrusion  740  is disposed adjacent to the center  70  of the retaining member  7  in the circumferential direction D. The third protrusions  745  are disposed at the end portions (e.g., the sections R 1  and R 4 ) of the retaining member  7  in the circumferential direction D. The second protrusions  741  are disposed between the pair of first protrusions  740  and the plurality of third protrusions  745  disposed at the section R 1  and between the pair of first protrusions  740  and the plurality of third protrusions  745  disposed at the section R 4  in the circumferential direction D. 
     The first protrusions  740  and the second protrusions  741  may have substantially the same shape. The second protrusions  741  may have a different shape from the third protrusions  745 . As illustrated in  FIG. 9 , a protruding amount H 2  of each third protrusion  745  is greater than a protruding amount H 5  of each first protrusion  740  and a protruding amount H 1  of each second protrusion  741 . A distance H 4  between a bottom of a valley  746  between adjacent third protrusions  745  and the facing portion  73  is greater than a distance H 3  between a bottom of a valley  742  between adjacent second protrusions  741  and the facing portion  73 . The adjacent second protrusions  741  may be any second protrusions  741  not included in the particular area of the facing portion  73  where the projecting portion  75  is provided. Each of the first protrusions  740  and the second protrusions  741  has an inclined surface  743  on its rear side (e.g., on a side thereof facing the body member  8 ). Each of the third protrusions  745  has an inclined surface  747  on its rear side (e.g., on a side thereof facing the body member  8 ). As the inclined surfaces  743  and  747  extend in the removing direction R, the inclined surfaces  743  and  747  are inclined toward the body member  8 . An angle K 9  of the inclined surface  743  and an angle of the inclined surface  747  with respect to an extending direction of the imaginary axis J (e.g., the front-rear direction) are greater than an angle K 7  of the first surface  731  and an angle K 8  of the second surface  732  with respect to the extending direction of the imaginary axis J. The angle K 9  of the inclined surface  743  and the angle of the inclined surface  747  with respect to the extending direction of the imaginary axis J are substantially equal to an angle of the inclined surface  735  of the rib  734  with respect to the extending direction of the imaginary axis J. The support portions  721  and  722  each have a cylindrical shape. The support portion  721  extends toward the rear from the vicinity of a left end one of the plurality of protrusions  74  in the clamping portion  72 . The support portion  722  extends toward the rear from the vicinity of a right end one of the plurality of protrusions  74  in the clamping portion  72 . 
     As illustrated in  FIGS. 9 to 12 , the engagement portions  78  and  79  are disposed at the respective end portions of the clamping portion  72  in the circumferential direction D. More specifically, for example, the engagement portion  78  is disposed at the section R 1  of the retaining member  7  in the circumferential direction D. The engagement portion  79  is disposed at the section R 4  of the retaining member  7  in the circumferential direction D. The engagement portion  78  includes plate members  781 ,  783 , and  785  extending in the up-down direction. The plate members  781 ,  783 , and  785  may be made of metal (e.g., SPCC). As illustrated in  FIG. 9 , the plate member  781  includes a lower end portion  782  having a trapezoidal shape in front view. The lower end portion  782  has a right side that is inclined toward the left as the right side extends downward. As illustrated in  FIG. 10 , as the lower end portion  782  of the plate member  781  extends downward, the lower end portion  782  is inclined toward the rear. As illustrated in  FIGS. 10 to 12 , the plate member  783  is disposed behind the plate member  781 . The plate member  783  has ratchet teeth  784  at its right end. Each of the ratchet teeth  784  is configured to restrict the movable direction of the engagement portion  78  to the guide direction F 1 . More specifically, for example, each of the ratchet teeth  784  has a surface  788  and a surface  789 . An angle F 5  of the surface  788  with respect to the guide direction F 1  is smaller than an angle F 6  of the surface  789  with respect to the guide direction F 1 . The surface  788  is longer than the surface  789  in the guide direction F 1 . The ratchet pawl  913  of the body member  8  is configured to engage one of the ratchet teeth  784  in accordance with the relative position of the retaining member  7  and the body member  8 . In a case where an attempt is made to move the engagement portion  78  in the guide direction F 1 , the ratchet pawl  913  easily passes the ratchet tooth  784  that is in engagement with the ratchet pawl  913  and then comes into engagement with the next ratchet tooth  784 . In a case where an attempt is made to move the engagement portion  78  in the direction opposite to the guide direction F 1 , the ratchet pawl  913  is jammed against the ratchet tooth  784  that is in engagement with the ratchet pawl  913  so as not to pass the ratchet tooth  784 , thereby restricting the movement of the engagement portion  78  in the direction opposite to the guide direction F 1 . As illustrated in  FIG. 12 , when viewed from the top, the plate member  785  extends rearward beyond the plate member  783  from a left end of the plate member  781 . The plate member  785  is bent toward the right behind the plate member  783  and further bent toward the front. The plate member  785  may thus have a hook-like shape. 
     As with the engagement portion  78 , the engagement portion  79  includes plate members  791 ,  793 , and  795 . The plate member  793  has ratchet teeth  794  at its left end. As illustrated in  FIG. 9 , the plate member  791  includes a lower end portion  792  having a trapezoidal shape in front view. The lower end portion  792  has a left side that is inclined toward the right as the left side extends downward. In addition, as the lower end portion  792  extends downward, the lower end portion  792  is inclined toward the rear. The ratchet pawl  923  of the body member  8  is configured to engage one of the ratchet teeth  794  in accordance with the relative position of the retaining member  7  and the body member  8 . The engagement portion  78  includes a handle  41  protruding frontward. The engagement portion  79  includes a handle  42  protruding frontward. In a state where the engagement portions  91  and  92  are engaged with the engagement portions  78  and  79 , respectively, the handle  41  extends along the guide direction F 1  and the handle  42  extends along the guide direction F 2 . The handles  41  and  42  enable the user to handle the retaining member  7  in attachment of the retaining member  7  to the body member  8 . As illustrated in  FIGS. 5A, 8A, and 8B , in a state where the retaining member  7  is attached to the body member  8  with the clamping portion  72  conforming to the curved wall  81 , the distance between the engagement portions  78  and  79  in the width direction W decreases in the direction opposite to the convex direction P. For example, as illustrated in  FIG. 5A , a distance L 6  between a lower end portion of the handle  41  and a lower end portion of the handle  42  in the width direction W is shorter than a distance L 5  between an upper end portion of the handle  41  and an upper end portion of the handle  42  in the width direction W. 
     The shafts  76  and  77  are disposed at the respective end portions of the clamping portion  72  and extend along the attaching direction M. The shafts  76  and  77  may be made of metal (e.g., SUM23 specified in JIS (Japanese Industrial standard): Free-cutting steels). As illustrated in  FIG. 10 , the shafts  76  and  77  each extend (e.g., toward the front) beyond the clamping portion  72  in the removing direction R. The engagement portions  78  and  79  are supported by the shafts  76  and  77  at respective positions further to the rear than the facing portion  73  so as to be pivotable relative to the clamping portion  72 . More specifically, for example, the shaft  76  extends through holes of the plate members  781  and  783  of the engagement portion  78  and the cylindrical support portion  721 . The shaft  77  extends through holes of the plate members  791  and  793  of the engagement portion  79  and the cylindrical support portion  722 . 
     Referring to  FIGS. 12, 13, 14A, 14B, and 14C , a description will be provided on a procedure for embroidering on a cap C including a crown C 1  and a visor C 2  using the cap frame  5  and the sewing machine  1  to which the cap frame  5  is attachable. For setting a cap C to the cap frame  5 , a user contacts the protrusions  74  of the clamping portion  72  to a boundary C 3  between a crown C 1  and a visor C 2  of a cap C while orienting the retaining member  7  such that the end having the protrusions  74  serves as the leading end of the facing portion  73  in the removing direction R, and places the cap C between the curved wall  81  of the body member  8  and the clamping portion  72  such that that the curved wall  81  contacts the visor C 2 . The user then presses the cap C toward the curved wall  81  to allow the cap frame  5  to hold the cap C (e.g., step S 1 ). More specifically, for example, the user operates the operating portion  891  of the switch member  89  to position the engagement portions  91  and  92  at the respective engaged positions. If necessary, the user attaches an interfacing to the hooks  84  of the body member  8 . As illustrated in  FIGS. 14A and 15A , the user deforms the retaining member  7  by pulling the engagement portions  78  and  79  to the left and the right, respectively, while orienting the retaining member  7  such that the end having the protrusions  74  serves as the leading end of the facing portion  73  in the removing direction R. The user maintains such a state of the retaining member  7  and contacts the protrusions  74  to the boundary C 3 . At that time, the first protrusions  740  protruding greater than the second protrusions  741  from the facing portion  73  contact the boundary C 3  on opposite sides of the center C 5  of the boundary C 3  in the right-left direction. Thus, the retaining member  7  is aligned with respect to the cap C in the circumferential direction D. The projecting portion  75  contacts the visor C 2  around the center C 5  of the boundary C 3  via the cushioning  751 . The user then contacts the second protrusions  741  and the third protrusions  745  to the boundary C 3  of the cap C in the arrangement order from the center  70  of the retaining member  7  to the both end portions of the retaining member  7  in the circumferential direction D. 
     In a case where a cap C including a visor C 2  and a crown C 1  is for adults, a diameter of a circle in which an opening of the crown C 1  is inscribed is approximately 18 cm in most cases, which is greater than 13 cm that may be the maximum distance L 1  between the end portions of the curved wall  81  in the width direction W. In a case where the crown C 1  of such a cap C is sandwiched by the retaining member  7  and the body member  8  of the cap frame  5  in the vicinity of the opening of the crown C 1 , as illustrated in  FIGS. 14B and 15B , the crown C 1  is held by the retaining member  7  and the body member  8  with being deformed into an oval shape conforming to the shape of the curved wall  81  of the body member  8 . More specifically, for example, in the portion held by the retaining member  7  and the body member  8 , the boundary C 3  of the cap C is deformed to have a diameter smaller than the boundary C 3  of the undeformed cap C. The crown C 1  thus has an oval shape elongated in the up-down direction in front view. The user aligns the cap C with respect to the retaining member  7  in the circumferential direction D with reference to the mark  733 . 
     While maintaining a sweatband C 4  of the cap C lifted out from the inside of the cap C in the attaching direction M relative to the crown C 1  and pulling the engagement portions  78  and  79  of the retaining member  7  to the left and the right, respectively, the user relatively moves the retaining member  7  toward the body member  8  to insert the engagement portions  78  and  79  of the retaining member  7  into the guide portions  93  and  94 , respectively, of the body member  8 . In response to this, the handle  41  and the handle  42  are inserted into the slit  936  of the guide portion  93  and the slit  946  of the guide portion  94 , respectively, to protrude frontward relative to the casing  86 . As illustrated in  FIGS. 5A, 5B, and 8B , the engagement portion  79  contacts the walls  941 ,  942 , and  943  of the guide portion  94  in the right-left direction and also contacts the plate member  861  and the wall  945  in the front-rear direction. Such a configuration may thus enable the guide portion  94  to restrict the movable direction of the engagement portion  79  to the guide direction F 2  (e.g., a left downward direction) toward the engagement portion  92  and its opposite direction. As with the engagement portion  79 , the engagement portion  78  contacts the walls  931 ,  932 , and  933  of the guide portion  93  in the right-left direction and also contacts the plate member  861  and the wall  935  in the front-rear direction. Such a configuration may thus enable the guide portion  93  to restrict the movable direction of the engagement portion  78  to the guide direction F 1  (e.g., a right downward direction) toward the engagement portion  91  and its opposite direction. 
     As the user moves the engagement portions  78  and  79  in the guide directions F 1  and F 2 , respectively, relative to the body member  8  by holding the handles  41  and  42 , the engagement portions  78  and  79  are guided to the engagement portions  91  and  92  by the guide portions  93  and  94 , respectively. While the engagement portions  78  and  79  are guided by the guide portions  93  and  94 , respectively, the engagement portions  78  and  79  each pivot in a direction to decrease the distance between the engagement portions  78  and  79  in the width direction W. More specifically, for example, while the engagement portion  78  is guided to the engagement portion  91  by the guide portion  93 , the engagement portion  78  pivots counterclockwise on the shaft  76  when viewed from the front. While the engagement portion  79  is guided to the engagement portion  92  by the guide portion  94 , the engagement portion  79  pivots clockwise on the shaft  77  when viewed from the front. Once the lowest one of the ratchet teeth  784  of the engagement portion  78  engages the ratchet pawl  913 , the upward movement of the engagement portion  78  is restricted by the ratchet pawl  913  and the right-left movement and the front-rear movement of the engagement portion  78  are restricted by contact of the engagement portion  78  with the guide portion  93 . Thus, in a state where the lowest one of the ratchet teeth  784  of the engagement portion  78  is in engagement with the ratchet pawl  913 , the engagement portion  78  is allowed to move in the guide direction F 1  only. Similarly, once the lowest one of the ratchet teeth  794  of the engagement portion  79  engages the ratchet pawl  923 , the upward movement of the engagement portion  79  is restricted by the ratchet pawl  923  and the right-left movement and the front-rear movement of the engagement portion  79  are restricted by contact of the engagement portion  79  with the guide portion  94 . Thus, in a state where the lowest one of the ratchet teeth  794  of the engagement portion  79  is in engagement with the ratchet pawl  923 , the engagement portion  79  is allowed to move in the guide direction F 2  only. 
     As illustrated in  FIGS. 14C and 15C , the user appropriately changes the ratchet tooth  784  engaging the ratchet pawl  913  from one to another and the ratchet tooth  794  engaging the ratchet pawl  923  from one to another to align the cap C with respect to the cap frame  5  in the circumferential direction D with reference to the marks  821  and  851  of the body member  8  and the mark  733  of the retaining member  7 . For example, in a case where the center C 5  of the boundary C 3  of the cap C in the circumferential direction D and the center  70  of the retaining member  7  in the circumferential direction D are offset to the right from the center  80  of the curved wall  81  in the circumferential direction D, the user moves the engagement portion  78  relative to the engagement portion  91  in the guide direction F 1  to align both of the center C 5  and the center  70  with respect to the center  80  in the circumferential direction D. The user then confirms that the cap C is held taut in the circumferential direction D by the cap frame  5 . Thereafter, as illustrated in  FIG. 16 , the user fastens the crown C 1  to the attaching frame  87  by clipping particular portions of the crown C 1 , using the clips K 1  and K 2 , in the vicinity of the shafts  76  and  77 . In a state where the cap C is held by the cap frame  5 , the hooks  84  of the body member  8  are in contact with the boundary C 3  or the vicinity of the boundary C 3  of the crown C 1  from the side on which the imaginary axis J is provided. In a state where the cap C is held by the cap frame  5 , the curved wall  81  of the body member  8  and the clamping portion  72  of the retaining member  7  sandwich the cap C therebetween. In such a state, only the hooks  84  disposed at the front end of the curved wall  81  are located on the crown C 1  side with respect to the boundary C 3  between the crown C 1  and the visor C 2 . That is, in a state where the cap C is held by the cap frame  5 , the other portion of the curved wall  81  of the body member  8  and the clamping portion  72  of the retaining member  7  are located on the boundary C 3  or on the visor C 2  side with respect to the boundary C 3 . In a state where the cap C is held by the cap frame  5 , a distance between the boundary C 3  and the plurality of hooks  84  in the front-rear direction may be from 0.2 mm to 3.0 mm approximately. 
     If necessary, the user attaches a cover  30  to the visor C 2  of the cap C. The cover  30  may be removably attached to the visor C 2  of the cap C for protection of the visor C 2  from damage. The cover  30  may be, for example, a sector-shaped transparent member made of resin. The cover  30  has an arc-shaped inner peripheral edge  35  and an arc-shaped outer peripheral edge  34 . The cover  30  has a recessed portion  36  in the inner peripheral edge  35 . The recessed portion  36  is defined substantially at a middle of the inner peripheral edge  35  in a direction in which the inner peripheral edge  35  extends. The recessed portion  36  is recessed toward the outer peripheral edge  34 . The cover  30  includes attaching portions  31 ,  32 , and  33  in the vicinity of the outer peripheral edge  34 . For attaching the cover  30  to the cap C, the user inserts, from the rear, the inner peripheral edge  35  of the cover  30  between the visor C 2  and the facing portion  73  of the retaining member  7  such that the inner peripheral edge  35  of the cover  30  is positioned above the visor C 2  and below the facing portion  73 . At that time, the recessed portion  36  of the cover  30  is positioned in the vicinity of the projecting portion  75  of the facing portion  73 . The user then engages the attaching portions  31 ,  32 , and  33  with the edge of the visor C 2  of the cap C to attach the cover  30  to the cap C. 
     The user attaches, to the sewing machine  1 , the cap frame  5  holding the cap C (e.g., step S 2 ). More specifically, for example, the user engages the engagement brackets  51 ,  52 , and  53  of the frame unit  6  with the engagement portions  881 ,  882 , and  883 , respectively, of the cap frame  5  to couple the cap frame  5  holding the cap C to the rotary frame  63 . The user then attaches the frame unit  6  to the holder  25  of the sewing machine  1  using the screws  68  and  69 . As illustrated in  FIG. 2 , in a state where the cap frame  5  is attached to the sewing machine  1 , the cylinder bed  10  of the sewing machine  1  extends through the frame unit  6 , the cap frame  5  and the opening of the crown C 1 . An upper end of the crown C 1  of the cap C held by the cap frame  5  extends substantially parallel to the cylinder bed  10 . The visor C 2  is positioned behind the needle bars  22 . The visor C 2  is out of contact with the sewing machine  1 . 
     The user operates the button  14  and the operation interface  11  to start the sewing machine  1 . In response to the user&#39;s operation, the sewing machine  1  embroiders a pattern on the crown C 1  of the cap C with respect to the boundary C 3  between the crown C 1  and the visor C 2  by moving the cap frame  5  attached to the sewing machine  1  in predetermined two directions based on embroidery data (e.g., step S 3 ). Any suitable known method may be adopted for embroidering on a crown C 1  of a cap C using the sewing machine  1 . For example, in response to the sewing machine  1  detecting the attachment of the cap frame  5  thereto, the sewing machine  1  defines an embroidery area on the crown C 1  side with respect to the boundary C 3  (e.g., at a position further to the front than the boundary C 3 ) in accordance with the type of the cap frame  5  based on data prestored in the sewing machine  1 . The predetermined two directions may be directions in which the moving mechanism  20  of the sewing machine  1  moves the holder  25 . The predetermined two directions may be, for example, the right-left direction and the front-rear direction. As illustrated in  FIG. 2 , in the cap frame  5 , the facing portion  73  has the inclined second surface  732 . Such a configuration may thus prevent the parts of the sewing machine  1  such as a needle bar  22  and a presser foot  24  from interfering with the cap frame  5  in a case where the sewing machine  1  embroiders a pattern on the crown C 1  in the vicinity of the boundary C 3 . The cap frame  5  holds the cap C with the clamping portion  72  pressing, toward the curved wall  81 , the cap C placed between the curved wall  81  and the clamping portion  72 . More specifically, for example, in such a state, the protrusions  74  of the clamping portion  72  are in contact with the boundary C 3  between the crown C 1  and the visor C 2  of the cap C while the retaining member  7  is oriented such that the end having the protrusions  74  serves as the leading end of the facing portion  73  in the removing direction R. The curved wall  81  is in contact with the visor C 2 . As illustrated in  FIGS. 1 and 2 , in a state where the cap frame  5  holding the cap C is attached to the sewing machine  1 , the cap frame  5  may be positioned such that a distance from the boundary C 3  to a particular position on the needle plate  16  may be shortened as compared with the known cap frame. The particular position may correspond to the position at which the needle bars  22  are aligned. Thus, the cap frame  5  may enable the sewing machine  1  to define an embroidery area whose range may be extended in the attaching direction M as compared with an embroidery area defined using the known cap frame. The embroidery area may be defined as an area in which the sewing machine  1  can embroider a pattern on a crown C 1  of a cap C held by the cap frame  5 . In the illustrative embodiment, in a state where the cap C is held by the cap frame  5 , the curved wall  81  of the body member  8  and the clamping portion  72  of the retaining member  7  sandwich the cap C therebetween. In such a state, the hooks  84  disposed at the front end of the curved wall  81  are located on the crown C 1  side with respect to the boundary C 3  between the crown C 1  and the visor C 2 . A distance between the boundary C 3  and the plurality of hooks  84  in the front-rear direction may be approximately a few millimeters. The hooks  84  are in contact with the cap C from the imaginary axis J side. Thus, consideration might not be required to collision of one or more of the hooks  84  to a member or a component disposed above the needle plate  16  such as a presser foot  24  of the sewing machine  1 . Consequently, in the cap frame  5  of the illustrative embodiment, of the curved wall  81  of the body member  8  and the clamping portion  72  of the retaining member  7  that hold the cap C therebetween, a limit of the range of the embroidery area in the attaching direction M may be specified based on the position of the clamping portion  72 . After the sewing machine  1  completes embroidering on the cap C, the user removes the frame unit  6  from the sewing machine  1 . The user then operates the operating portion  891  of the switch member  89  to release the engagement between the engagement portions  78  and  91  and the engagement between the engagement portions  79  and  92  and removes the cap C from the cap frame  5 . Through the above-described steps, the crown C 1  of the cap C is embroidered with a pattern using the cap frame  5  and the sewing machine  1  to which the cap frame  5  is attachable. 
     According to the cap frame  5  of the illustrative embodiment, engaging the engagement portions  78  and  79  of the retaining member  7  to the engagement portions  91  and  92 , respectively, of the body member  8  may enable the retaining member  7  to be attached to the body member  8  with the retaining member  7  conforming to the shape of the curved wall  81 . Such an attaching manner may thus enable the alignment of a cap C with respect to the cap frame  5  with a simpler procedure as compared with the known procedure in which a retaining member is attached to a body member with a one end portion of the retaining member fixed to the body member. 
     In the cap frame  5 , the engagement portion  91  is configured to engage the engagement portion  78  at one of the plurality of engagement positions. The engagement portion  92  is configured to engage the engagement portion  79  at one of the plurality of engagement positions. Thus, the retaining member  7  and the body member  8  are allowed to be located at one of the plurality of relative positions. Such a configuration may thus enable adjustment of the engagement position between the engagement portion  91  and the engagement portion  78  and the engagement position between the engagement portion  92  and the engagement portion  79  in accordance with the size and thickness of a cap C held by the cap frame  5 . According to the cap frame  5 , the user may be allowed to adjust the engagement position between the engagement portion  91  and the engagement portion  78  and the engagement position between the engagement portion  92  and the engagement portion  79  individually in accordance with the size and thickness of a cap C held by the cap frame  5 . Such a configuration may thus enable the user to align the cap C to a desired position with respect to the cap frame  5  more readily as compared with a case where the engagement portion  91  is engaged with the engagement portion  78  at a single engagement position and the engagement portion  92  is engaged with the engagement portion  79  at a single engagement position. 
     The engagement portion  78  has the ratchet teeth  784  and the engagement portion  79  has the ratchet teeth  794 . The engagement portion  91  includes the ratchet pawl  913  configured to engage one of the ratchet teeth  784 . The engagement portion  92  includes the ratchet pawl  923  configured to engage one of the ratchet teeth  794 . Such a configuration may thus enable adjustment of the engagement position between the engagement portion  78  and the engagement portion  91  and the engagement position between the engagement portion  79  and the engagement portion  92  in accordance with the size and thickness of a cap C held by the cap frame  5  by changing the ratchet tooth  784  engaging the ratchet pawl  913  from one to another and the ratchet tooth  794  engaging the ratchet pawl  923  from one to another. According to the cap frame  5 , the user may be allowed to adjust stepwise the engagement position between the engagement portion  78  and the engagement portion  91  and the engagement position between the engagement portion  79  and the engagement portion  92  individually in accordance with the size and thickness of a cap C held by the cap frame  5  with a relatively simple manner of moving the engagement portions  78  and  79  in the guide directions F 1  and F 2 , respectively. 
     The cap frame  5  includes the switch member  89  configured to change the respective positions of the engagement portions  91  and  92  between the engaged position and the disengaged position. At the engaged position, the engagement portions  91  and  92  are capable of engaging the engagement portions  78  and  79 , respectively. At the disengaged position, the engagement portions  91  and  92  are incapable of engaging the engagement portions  78  and  79 , respectively. According to the cap frame  5 , the user is allowed to change the respective positions of the engagement portions  91  and  92  between the engaged position and the disengaged position simultaneously by a single operation of the switch member  89 . The cap frame  5  may thus enable the user to change the respective positions of the engagement portions  91  and  92  between the engaged position and the disengaged position more readily as compared with a case where the cap frame  5  has a configuration that may require the user to change the respective positions of the engagement portions  91  and  92  between the engaged position and the disengaged position individually. 
     In the cap frame  5 , the guide portion  93  includes the walls  931 ,  932 , and  933  extending along the guide direction F 1 . The guide portion  94  includes the walls  941 ,  942 , and  943  extending along the guide direction F 2 . The guide portion  93  is configured to guide the engagement portions  78  of the retaining member  7  to the engagement portion  91  of the body member  8  with a relatively simple configuration. The guide portion  94  is configured to guide the engagement portion  79  of the retaining member  7  to the engagement portion  92  of the body member  8  with a relatively simple configuration. While the guide portion  93  contacts the engagement portion  78  from all sides around the guide direction F 1 , the guide portion  93  allows the handle  41  of the engagement portion  78  to protrude frontward through the slit  936  of the guide portion  93 , thereby enabling the user to hold and operate the handle  41 . As with the guide portion  93 , while the guide portion  94  contacts the engagement portion  79  from all sides around the guide direction F 2 , the guide portion  94  allows the handle  42  of the engagement portion  79  to protrude frontward through the slit  946  of the guide portion  94 , thereby enabling the user to hold and operate the handle  42 . Thus, the cap frame  5  may define the movable directions of the engagement portions  78  and  79  to as the guide directions F 1  and F 2 , respectively, without loss of handleability of the retaining member  7  during attachment of the retaining member  7  to the body member  8 . 
     In the cap frame  5 , the distance between the guide portions  93  and  94  in the width direction W (e.g., the right-left direction) decreases as the guide portions  93  and  94  extend in the direction (e.g., the downward direction) opposite to the convex direction P (e.g., the upward direction). In the cap frame  5 , thus, the end portions of the clamping portion  72  in the circumferential direction D may be pressed toward the body member  8  more strongly as compared with a case where the distance between the guide portions  93  and  94  in the width direction W increases as the guide portions  93  and  94  extend in the direction opposite to the convex direction P. Consequently, the configuration according to the illustrative embodiment may reduce variations, in the circumferential direction D, in pressure applied by the retaining member  7  to a cap C held between the retaining member  7  and the body member  8  in a state where the retaining member  7  is attached to the body member  8  with the retaining member  7  conforming to the curved wall  81 . 
     In a state where the retaining member  7  is attached to the body member  8  with the clamping portion  72  conforming to the curved wall  81 , the distance between the engagement portions  78  and  79  in the width direction W decreases in the direction opposite to the convex direction P. In the cap frame  5 , thus, the end portions of the clamping portion  72  in the circumferential direction D may be press toward the body member  8  more strongly as compared with a case where the distance between the engagement portions  78  and  79  in the width direction W increases as the engagement portions  78  and  79  extend in the direction opposite to the convex direction P. Consequently, the configuration according to the illustrative embodiment may reduce variations, in the circumferential direction D, in pressure applied by the retaining member  7  to a cap C held between the retaining member  7  and the body member  8  in a state where the retaining member  7  is attached to the body member  8  with the retaining member  7  conforming to the curved wall  81 . 
     The retaining member  7  includes the shafts  76  and  77  extending along the attaching direction M at the respective end portions of the clamping portion  72 . The engagement portions  78  and  79  are pivotably supported by the shafts  76  and  77 , respectively. While the engagement portions  78  and  79  are guided to the engagement portions  91  and  92  by the guide portions  93  and  94 , respectively, the engagement portions  78  and  79  each pivot in the direction to decrease the distance between the engagement portions  78  and  79  in the width direction W. Such a configuration may thus enable the engagement portions  78  and  79  to change their postures in accordance with the respective shapes of the guide portions  93  and  94  even when the engagement portions  78  and  79  are made of nonelastic material. In the cap frame  5 , during attachment of the retaining member  7  to the body member  8 , the engagement portions  78  and  79  pivot on the respective shafts  76  and  77 . Thus, the distance between the engagement portions  78  and  79  in the width direction W may decrease as the engagement portions  78  and  79  extend in the direction opposite to the convex direction P, thereby enabling the end portions of the clamping portion  72  in the circumferential direction D to be pressed toward the body member  8 . Consequently, such a configuration may thus reduce variations, in the circumferential direction D, in pressure applied by the retaining member  7  to a cap C held between the retaining member  7  and the body member  8  in a state where the retaining member  7  is attached to the body member  8  with the retaining member  7  conforming to the curved wall  81 . 
     The shafts  76  and  77  each extend beyond the clamping portion  72  in the direction from the one side of the cap frame  5 , in which the attaching portion  88  of the body member  8  may be provided, to the other side of the cap frame  5 , in which the curved wall  81  of the body member  8  may be provided (e.g., the removing direction R). In the cap frame  5 , such a configuration may thus enable the retaining member  7  to maintain the shape of a boundary C 3  between a crown C 1  and a visor C 2  of a cap C deformed in conformance with the curved wall  81  in sandwiching of the cap C in cooperation with the body member  8 . 
     The maximum distance L 1  between the end portions of the curved wall  81  in the width direction W may be 13 cm or less. The cap frame  5  may thus be smaller in size than the known cap frame. In a case where a crown C 1  of a cap C for adults is sandwiched by the retaining member  7  and the body member  8  of the cap frame  5  in the vicinity of an opening of the crown C 1 , the crown C 1  is held by the retaining member  7  and the body member  8  while being deformed into an oval shape conforming to the shape of the curved wall  81  of the body member  8 . In response to the crown C 1  being deformed into such a shape, a visor C 2  of the cap C is deformed correspondingly. At that time, the visor C 2  moves toward the imaginary axis J relative to the crown C 1  so as to be closer to the imaginary axis J than the undeformed visor C 2  is to the imaginary axis J. In the cap C attached to the cap frame  5 , an angle C 8  (refer to  FIG. 2 ) of the visor C 2  with respect to the crown C 1  is greater than the angle C 8  in the cap C that is not attached to the cap frame  5 . The angle C 8  of the visor C 2  with respect to the crown C 1  may be an angle measure of an angle formed by a periphery of the crown C 1  and the visor C 2 . Consequently, in a case where the cap frame  5  holding the cap C is attached to the sewing machine  1 , the cap frame  5  may reduce possibility of occurrence of contact of the visor C 2  of the cap C with the sewing machine  1 . 
     The clamping portion  72  includes the protrusions  74  protruding toward the curved wall  81  in a state where the retaining member  7  is attached to the body member  8 . In a state where the retaining member  7  is attached to the body member  8 , the protrusions  74  are aligned along the circumferential direction D. The third protrusions  745  that are disposed at the end portions of the clamping portion  72  protrude toward the body member  8  more than the first protrusions  740  and the second protrusions  741  that are disposed closer to the center  70  of the clamping portion  72  in the circumferential direction D than the third protrusions  745  are to the center  70 . Such a configuration may thus enable the cap frame  5  to securely hold, by the third protrusions  745 , a boundary C 3  of a cap C at end portions of a visor C 2  in the circumferential direction D. The curved wall  81  according to the illustrative embodiment has the recessed portions  811  and  812  at the respective positions to face the corresponding third protrusions  745 . Such a configuration may thus enable the third protrusions  745  to press a boundary C 3  of a cap C to position end portions of the boundary C 3  in the circumferential direction D closer to the imaginary axis J than the curved wall  81  is to the imaginary axis J. In such a state, the third protrusions  745  face the front end of the curved wall  81  in the front-rear direction. In some case, a cap C attached to the cap frame  5  may have a seam between panels of a crown C 1  in the vicinity of the center C 5  of a boundary C 3  in the circumferential direction D. In such a case, the center C 5  and its surrounding portion of the boundary C 3  may be thicker than the other portion of the boundary C 3 . In the illustrative embodiment, the curved wall  81  has the recessed portion  83  defined in its particular portion that includes the center  80  of the curved wall  81  in the circumferential direction D. Such a configuration may thus enable the first protrusions  740  to press the center C 5  and its surrounding portion of the boundary C 3  to position the center C 5  of the boundary C 3  closer to the imaginary axis J than the curved wall  81  is to the imaginary axis J. In such a state, the first protrusions  740  face the front end of the curved wall  81  in the front-rear direction. Consequently, in the cap frame  5 , such a configuration may reduce uneven application of pressure to the body member  8  by the retaining member  7  caused by uneven thickness of a boundary C 3  of a cap C. 
     While the disclosure has been described in detail with reference to the specific embodiment thereof, this is merely an example, and various changes, arrangements and modifications may be made therein without departing from the spirit and scope of the disclosure. The cap frame  5  may have another suitable configuration. Each component of the cap frame  5  may be made of another suitable material. The sewing machine  1  to which the cap frame  5  is attachable may have another suitable configuration. The cap frame  5  may be in one piece with and inseparable from the frame unit  6 . The attaching portion  88  that enables the cap frame  5  to be attached to the frame unit  6  may have another suitable configuration. The cap frame  5  might not necessarily have a substantially mirror-symmetrical structure with respect to the plane E. The retaining member  7  of the cap frame  5  may have a similar configuration to the known cap frame. More specifically, for example, the retaining member  7  may have protrusions and an opening through which a visor C 2  of a cap C may pass. In a state where the retaining member  7  is oriented such that an end having the protrusions serves as a leading end of a facing portion in the attaching direction M, the retaining member  7  may press a cap C with the protrusions contacting a boundary C 3  between a crown C 1  and a visor C 2  of the cap C. 
     The engagement portion  91  might not necessarily be configured to engage the engagement portion  78  at one of the plurality of engagement positions. The engagement portion  92  might not necessarily be configured to engage the engagement portion  79  at one of the plurality of engagement positions. At least either one of the engagement portions  78  and  79  might not necessarily have a plurality of ratchet teeth. In other embodiments, for example, at least one of the engagement portions  78  and  79  may have a single ratchet tooth. At least either one of the engagement portions  91  and  92  might not necessarily include a ratchet pawl that may engage one of corresponding ratchet teeth. In other embodiments, for example, at least one of the engagement portions  91  and  92  may include a ratchet pawl that may engage a single ratchet tooth. The engagement portions  78  and  79  and the engagement portions  91  and  92  may each have another configuration as long as the engagement portions  78  and  79  and the engagement portions  91  and  92  may allow the retaining member  7  to be removably attachable to the body member  8 . For example, the engagement portions  78  and  79  and the engagement portions  91  and  92  may be toggle latches. 
     The cap frame  5  might not necessarily include the switch member  89 . In another example, the switch member  89  may be configured to change the respective positions of the engagement portions  91  and  92  between the engaged position and the disengaged position individually. In still another example, the switch member  89  may be configured to change the respective positions of the engagement portions  91  and  92  between the engaged position and the disengaged position in response to whether a user presses a button. The cap frame  5  might not necessarily include the guide portions  93  and  94 . The guide portions  93  and  94  may each have another suitable configuration. For example, at least one of the guide portions  93  and  94  may be a rail configured to engage the plate portion of a corresponding one of the engagement portions  78  and  79 . 
     The curved wall  81  of the body member  8  of the cap frame  5  might not necessarily include all of the recessed portions  83 ,  811 , and  812 . In the body member  8 , the curved walls  81  and  82  may be in one piece with and inseparable from each other. The body member  8  might not necessarily include the flange  85 . The curved wall  81  might not necessarily include the hooks  84  at its leading end in the removing direction R. The shape, arrangement, and number of the hooks  84  may be modified appropriately. The distance between the guide portions  93  and  94  in the width direction W may be constant at any position in the convex direction P. In another example, the distance between the guide portions  93  and  94  in the width direction W may increase as the guide portions  93  and  94  extend in the direction (e.g., the downward direction) opposite to the convex direction P (e.g., the upward direction). In a state where the retaining member  7  is attached to the body member  8  with the clamping portion  72  conforming to the curved wall  81 , the distance between the engagement portions  78  and  79  in the width direction W may be constant at any position in the convex direction P. In another example, the distance between the engagement portions  78  and  79  in the width direction W may increase as the engagement portions  78  and  79  extend in the direction (e.g., the downward direction) opposite to the convex direction P (e.g., the upward direction). The retaining member  7  might not necessarily include the shafts  76  and  77  extending along the attaching direction M at the respective end portions of the clamping portion  72 . In such a case, for example, the engagement portions  78  and  79  may be made of the same material used for the clamping portion  72  and may be in one piece with and inseparable from the clamping portion  72 . In another example, the engagement portions  78  and  79  may be made of different material from the material used for the clamping portion  72  and may be connected to the clamping portion  72  so as not to be pivotable. The shafts  76  and  77  each might not necessarily extend beyond the clamping portion  72  in the removing direction R. 
     The maximum distance L 1  between the end portions of the curved wall  81  in the width direction W may be greater than 13 cm. The clamping portion  72  might not necessarily include the protrusions  74 . The shape, arrangement, and number of the protrusions  74  may be modified appropriately. In one example, the protrusions  74  may protrude toward the imaginary axis J from a leading end of the facing portion  73  in the attaching direction M. All of the protrusions  74  may protrude from the facing portion  73  by the same amount regardless of the positions in the circumferential direction D. The retaining member  7  may have the protrusions  74  at a portion of each of the sections R 2  and R 3  defined adjacent to the center  70  of the retaining member  7  in the circumferential direction D.