Abstract:
A sewing machine presser foot includes: a presser foot body including an attachment portion attached to a presser bar of a sewing machine, a supporting portion extending downward from the attachment portion , and a pressing portion in which, at a lower end of the supporting portion, a needle guiding hole having a string guiding groove for guiding a string is formed; and a cover member including a groove covering portion that crosses and covers the string guiding groove of the pressing portion, a supporting plate portion formed along the supporting portion continuously from the groove covering portion, and an attachment portion formed at an end of the supporting plate portion so as to be attached to the presser foot body. A right-side portion of the supporting plate portion of the cover member is fixed to the presser foot body A by the attachment portion.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to a sewing machine presser foot which is attached to a presser bar of the sewing machine and used to sew a decorative string of wool yarn or the like on a cloth, and which makes it easier to pass the decorative string through a needle guiding hole while reducing the probability of the decorative string detaching from the needle guiding hole. 
         [0003]    2. Description of the Related Art 
         [0004]    Some conventional home sewing machines are designed for what is called “couch stitching”, which is a type of stitching means for sewing decorative wool yarn, embroidery threads, ribbons, etc. on a cloth. A couch stitching operation involves setting an upper thread, a lower thread, and an embroidery frame, passing a third decorative string through a presser foot attached to a sewing machine, and then performing stitching. In this couch stitching operation, a presser foot dedicated for the couch stitching is used. 
       SUMMARY OF THE INVENTION 
       [0005]    As disclosed in Japanese Patent Application Publication No. 2007-130056, a presser foot dedicated for couch stitching typically includes a pressing portion in which a circular needle guiding hole is formed at the center of a disk and an attachment portion that is connected to a presser bar attached to a sewing machine body. In this type of presser foot, a decorative string needs to be inserted through the needle guiding hole, and especially when wool yarn or the like is used as the decorative string, inserting the string through the needle guiding hole of the presser foot becomes extremely difficult, because of the fluffiness of the string. 
         [0006]    In Japanese Utility Model Application Publication No. H5-60477, a passage that provides communication between the inside and outside of a needle guiding hole of a pressing plate is provided so that a decorative string can be inserted from a horizontal direction in relation to the presser foot, thereby facilitating insertion of the decorative string into the needle guiding hole. This type of presser foot can make it easier for the decorative string to be inserted into the needle guiding hole of the presser foot, but unfavorably, the decorative string also detaches more easily from the needle guiding hole. 
         [0007]    Under these circumstances, an object of the present invention is to provide a sewing machine presser foot dedicated for couch stitching, with which it is easier to insert the decorative string into a needle guiding hole of the presser foot in the setup process of couch stitching, while it is also possible to reduce the probability of the already-inserted string detaching from the needle guiding hole. 
         [0008]    As a result of intensive studies to solve the above problems, the present inventor solved the problems by providing, as a first embodiment of the present invention, a sewing machine presser foot including: a presser foot body including an attachment portion attached to a presser bar of a sewing machine, a supporting portion extending downward from the attachment portion, and a pressing portion in which, at a lower end of the supporting portion, a needle guiding hole having a string guiding groove for guiding a string is formed; and a cover member including a groove covering portion that crosses and covers the string guiding groove of the pressing portion, a supporting plate portion formed along the supporting portion continuously from the groove covering portion, and an attachment portion formed at an end of the supporting plate portion so as to be attached to the presser foot body, wherein a right-side portion of the supporting plate portion of the cover member fixed to the presser foot body by the attachment portion is configured to be displaced from the supporting portion. 
         [0009]    A second embodiment of the present invention solves the problems by the bobbin holder according to the first embodiment, in which a bent portion provided in the supporting plate portion is formed to be bent in such a direction that the supporting plate portion is displaced from the supporting portion in a left-right direction of the supporting plate portion of the cover member. A third embodiment of the present invention solves the problems by the bobbin holder according to the first or second embodiment, in which a string guide is formed to be erected continuously from the groove covering portion of the cover member so as to correspond to a thread insertion opening of the string guiding groove of the pressing portion. 
         [0010]    A fourth embodiment of the present invention solves the problems by the bobbin holder according to the first or second embodiment, in which a front-rear deflection restricting portion is provided in the supporting plate portion of the cover member fixed to the supporting portion of the presser foot body, the front-rear deflection restricting portion restricting deflection of the supporting plate portion in a front-rear direction and having a rear restricting plate that is bent toward a rear side of the supporting portion and is positioned so as to be separated from a rear surface of the supporting portion. 
         [0011]    In the present invention, the sewing machine presser foot includes: a presser foot body including an attachment portion attached to a presser bar of a sewing machine, a supporting portion extending downward from the attachment portion, and a pressing portion in which, at a lower end of the supporting portion, a needle guiding hole having a string guiding groove for guiding a string is formed; and a cover member including a groove covering portion that crosses and covers the string guiding groove of the pressing portion, a supporting plate portion formed along the supporting portion continuously from the groove covering portion, and an attachment portion formed at an end of the supporting plate portion so as to be attached to the presser foot body, in which a right-side portion of the supporting plate portion of the cover member fixed to the presser foot body by the attachment portion is configured to be displaced from the supporting portion. 
         [0012]    Thus, the upper side of the string guiding groove of the pressing portion is covered by the groove covering portion and the groove covering portion can always put the string guiding groove in a closed state by the elastic property of the supporting plate portion. Moreover, a bent portion is provided in the supporting plate portion of the cover member fixed to the presser foot body by the attachment portion, and the right-side portion of the cover member is displaced from the supporting portion. 
         [0013]    Due to this, in the process of inserting the decorative string into the needle guiding hole, the groove covering portion is moved from the left side toward the right side by pressing force of the decorative string, and due to the bent portion provided in the supporting plate portion, the right-side region of the supporting plate portion is displaced from the supporting portion of the presser foot body. In this case, the groove covering portion also floats from the pressing portion. 
         [0014]    In this case, when the decorative string is inserted into the string guiding groove, the right-side portion of the groove covering portion in relation to the cover member serves as a refuge for overall deformation of the groove covering portion, and the groove covering portion can be easily deformed. Thus, a gap in which the decorative string can be inserted is formed between the string guiding groove and the groove covering portion. In this manner, a state in which the decorative string can be easily moved to the position of the string guiding groove can be created. Therefore, a state in which the decorative string is easily inserted into the needle guiding hole is created, and the inserting operation can be performed easily and quickly. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]      FIG. 1A  is a schematic view illustrating a state in which a presser foot of the present invention is attached to a sewing machine,  FIG. 1B  is an enlarged view of (a)-part in  FIG. 1A ,  FIG. 1C  is an enlarged perspective view of the presser foot of the present invention, and  FIG. 1D  is an enlarged perspective view illustrating a presser foot body of the presser foot of the present invention and a cover member in a separated state; 
           [0016]      FIG. 2A  is a front view of the presser foot of the present invention,  FIG. 2B  is a partial cross-sectional view along arrow Y 1  in  FIG. 2A ,  FIG. 2C  is a partial cross-sectional view along arrow Y 2  in  FIG. 2A ,  FIG. 2D  is an enlarged cross-sectional view along arrow X 1 -X 1  in  FIG. 2A , and  FIG. 2E  is an enlarged cross-sectional view along arrow X 2 -X 2  in  FIG. 2A ; 
           [0017]      FIG. 3  is an enlarged side view of main parts, illustrating a state in which a supporting plate portion and a groove covering portion of a cover member of the present invention are displaced from a supporting portion and a pressing portion of a body portion; 
           [0018]      FIG. 4  is an enlarged front view of main parts, illustrating another embodiment of the shape of a string guide of the presser foot of the present invention; 
           [0019]      FIG. 5A  is a plan view of main parts associated with a first cycle of inserting a decorative string into the presser foot of the present invention,  FIG. 5B  is a cross-sectional view along arrow X 3 -X 3  in  FIG. 5A , and  FIG. 5C  is a view along arrow Y 3  in  FIG. 5A ; 
           [0020]      FIG. 6A  is a plan view of main parts associated with a second cycle of inserting a decorative string into the presser foot of the present invention,  FIG. 6B  is a cross-sectional view along arrow X 4 -X 4  in  FIG. 6A , and  FIG. 6C  is a view along arrow Y 3  in  FIG. 6A ; and 
           [0021]      FIG. 7A  is a plan view of main parts associated with a third cycle of inserting a decorative string into the presser foot of the present invention,  FIG. 7B  is a cross-sectional view along arrow X 5 -X 5  in  FIG. 7A , and  FIG. 7C  is a view along arrow Y 3  in  FIG. 7A . 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0022]    Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The present invention relates to a sewing machine presser foot which is used as a presser foot dedicated for couch stitching, particularly. As illustrated in  FIGS. 1A to 1D  and  FIGS. 2A to 2E , the presser foot of the present invention mainly includes a presser foot body A and a cover member B. In the description of the presser foot of the present invention, the directions such as left and right sides and the up-down direction are defined when an operator sees a sewing machine on the front side. The front and rear sides, the left and right sides, the up-down direction, and the like are described in major drawings. These wordings indicating the directions are described in  FIGS. 1A and 1B . 
         [0023]    The presser foot body A includes a pressing portion  1 , a supporting portion  2 , and an attachment portion  3  (see  FIGS. 1C and 1D  and  FIGS. 2A, 2B, and 2C ). The pressing portion  1 , the supporting portion  2 , and the attachment portion  3  are integrally molded by bending a metal plate, for example. The pressing portion  1  includes a pressing plate  11 , a needle guiding hole  12 , and a string guiding groove  13  connected to the needle guiding hole  12 . 
         [0024]    The pressing plate  11  is an approximately circular plate and the needle guiding hole  12  is formed substantially at the center of the plate. A sewing machine needle  93  passes through the needle guiding hole  12  (see  FIG. 1B ). A string guiding groove  13  is formed in a predetermined portion of the needle guiding hole  12 , the peripheral portion of the pressing plate  11  and the needle guiding hole  12  communicate with each other through the string guiding groove  13 , and a decorative string n is inserted into the needle guiding hole  12  through the string guiding groove  13  from the outside of the pressing portion  1 . 
         [0025]    The width of the string guiding groove  13  is slightly smaller than the diameter of the needle guiding hole  12  (see  FIG. 2E ) and has such a size that one decorative string n such as wool yarn can pass through the string guiding groove  13 . Moreover, the string guiding groove  13  is formed on a left side surface of the pressing portion  1  as a groove which faces toward the front side from the vicinity of the rear side. The supporting portion  2  is formed continuous with the rear side of the pressing plate  11  so as to extend upward. Further, the supporting portion  2  is formed so as to extend upward from the rear side of the pressing portion  1  in a state of being inclined toward the rear side. 
         [0026]    Moreover, the attachment portion  3  is formed so as to extend upward from the upper end of the supporting portion  2 . The attachment portion  3  is a portion which plays a role of attaching the presser foot to the presser bar  92 . The attachment portion  3  is formed in a vertical form in a state of being shifted to the right side of the supporting portion  2  so as to extend from the upper end of the supporting portion  2  with the interposition of an inclined plate piece  31 . Fixing pieces  32  for attaching and fixing the presser foot to the presser bar  92  are formed in an upper portion of the attachment portion  3  (see  FIGS. 1C and 1D  and  FIGS. 2A to 2C ). 
         [0027]    The cover member B includes a groove covering portion  4 , a supporting plate portion  5 , a front-rear deflection restricting portion  51 , and a width-direction deflection restricting portion  52  (see  FIGS. 1C and 1D  and  FIGS. 2A to 2C ). The cover member B is formed by bending an elastic thin metal plate. The groove covering portion  4  has a circular arc-shaped edge  41 , the front edge of which has a circular arc shape. When the groove covering portion  4  is disposed on the string guiding groove  13  of the pressing portion  1 , this circular arc-shaped edge  41  plays a role of compensating for the missing peripheral portion of the needle guiding hole  12  resulting from the formation of the string guiding groove  13 . 
         [0028]    A string guide  42  which is bent to be erected is formed on the left side surface of the groove covering portion  4 . Specifically, the string guide  42  is formed to be erected continuously from the groove covering portion  4  of the cover member B so as to correspond to an insertion opening  13   a  for a thread (the decorative string n), of the string guiding groove  13  of the pressing portion  1  (see  FIG. 2E ). The string guide  42  is a portion that plays such a role that the decorative string n to be inserted into the needle guiding hole  12  makes contact with the string guide  42  so that the string guide  42  is pressed by pressing force P of the decorative string n and the groove covering portion  4  is moved on the pressing portion  1 . The string guide  42  is erected by being bent at an acute angle. Moreover, as another embodiment, the string guide  42  may be formed in an arc form (see  FIG. 4 ). 
         [0029]    The supporting plate portion  5  is formed so as to extend further upward than a portion of the groove covering portion  4 . Moreover, the front-rear deflection restricting portion  51  and the width-direction deflection restricting portion  52  are formed on the supporting plate portion  5  (see  FIGS. 1C and 1D  and  FIGS. 2A to 2C ). An attachment portion  6  is formed in a vertical form to be continuous from the upper end of the supporting plate portion  5 . 
         [0030]    The attachment portion  6  is fixed to the attachment portion  3  of the presser foot body A by a fixing tool  7  such as a rivet. In a state in which the cover member B is fixed to the presser foot body A, the groove covering portion  4  is arranged on the pressing portion  1  and the supporting plate portion  5  is arranged on the supporting portion  2 . 
         [0031]    In a state in which the cover member B is fixed by the fixing tool  7  with an operation of inserting the decorative string n, the supporting plate portion  5  and the groove covering portion  4  float by being displaced from the supporting portion  2  and the pressing portion  1 . By the elastic force of the supporting plate portion  5 , the groove covering portion  4  is provided so as to always cover the string guiding groove  13  of the pressing portion  1 . In this case, the groove covering portion  4  is in a state of making contact with or approaching the pressing portion  1  (see  FIG. 3 ). 
         [0032]    The front-rear deflection restricting portion  51  of the supporting plate portion  5  includes a front restricting plate  51   a,  a rear restricting plate  51   b,  and a connecting piece  51   c  that connects both restricting plates (see  FIG. 2D ). The front-rear deflection restricting portion  51  is formed at the left end of the supporting plate portion  5  and is configured to restrict the movement in the front-rear direction of the supporting portion  2  with allowance with the aid of the front restricting plate  51   a  and the rear restricting plate  51   b  of the front-rear deflection restricting portion  51  (see  FIG. 2D ). The rear restricting plate  51   b  is normally separated from the rear surface of the supporting plate portion  5  and plays a role of restricting the amount of torsion of the supporting plate portion  5  to fall within a predetermined range when torsion occurs in the supporting plate portion  5  with an operation of inserting the decorative string n. 
         [0033]    The interval L between the front restricting plate  51   a  and the rear restricting plate  51   b  is set to be larger than the thickness T of the supporting portion  2 . 
         [0034]    That is, L&gt;T. 
         [0035]    Due to this, the supporting plate portion  5  is configured to be deformable within the range restricted by the front-rear deflection restricting portion  51 . 
         [0036]    Further, the width-direction deflection restricting portion  52  is formed on the right side of the supporting plate portion  5 . The width-direction deflection restricting portion  52  and the front-rear deflection restricting portion  51  sandwich both sides in the width direction of the supporting portion  2 . The interval between the width-direction deflection restricting portion  52  and the connecting piece  51   c  of the front-rear deflection restricting portion  51  is larger than the width of the supporting portion  2  and is set to increase on the side where the connecting piece  51   c  is formed (see  FIG. 2D ). 
         [0037]    Due to this, the movement in the left-right direction and the front-rear direction of the cover member B in relation to the presser foot body A is elastically restricted at the position of the fixing tool  7 . That is, although the position of the groove covering portion  4  can be moved by elastic deformation of the supporting plate portion  5 , the cover member B restricts the magnitude of deformation of the supporting plate portion  5 . Due to this, the cover member B can be prevented from being unnecessarily elastically deformed when the decorative string n is inserted into the needle guiding hole  12  of the pressing portion  1 , and durability of the cover member B can be secured. 
         [0038]    Moreover, a bent portion  53  is formed at a position close to the left side of the supporting plate portion  5  of the cover member B (see  FIGS. 1C and 1D  and  FIGS. 2A and 2D ). Specifically, the bent portion  53  is formed as a linear bent line at the boundary of the front restricting plate  51   a  of the supporting plate portion  5 . 
         [0039]    A right-side region of the supporting plate portion  5  about the bent portion  53  as a boundary is set to float by being displaced from the supporting portion  2  of the presser foot body A (see  FIGS. 2C and 2D ). Due to this, in an operation of inserting the decorative string n into the needle guiding hole  12 , when the groove covering portion  4  is moved from the left side to the right side, the groove covering portion  4  is easily displaced from the string guiding groove  13 . 
         [0040]    Next, a cycle of inserting the decorative string n into the needle guiding hole  12  of the presser foot of the present invention will be described with reference to  FIGS. 5A to 5C  and  FIGS. 6A to 6C . First, the groove covering portion  4  of the cover member B is disposed so as to cover the string guiding groove  13  of the pressing portion  1  of the presser foot body A. In this state, the decorative string n such as wool yarn is brought into contact with the string guide  42  of the groove covering portion  4 . Moreover, the decorative string n is stretched to create pressing force P (see  FIGS. 5A to 5C ). The decorative string n is bent at the position of the string guide  42  (see  FIG. 5B ). 
         [0041]    Subsequently, when the decorative string n having the pressing force P is continuously pressed against the string guide  42 , the groove covering portion  4  and the string guide  42  start moving from the left side (the side close to the insertion opening  13   a ) toward the right side (the side close to the needle guiding hole  12 ) through the string guiding groove  13  of the pressing portion  1  (see  FIGS. 6A to 6C ). In this case, the decorative string n is bent at the position of the string guide  42 , the pressing force P is applied to the groove covering portion  4  to raise the groove covering portion  4  upward. The groove covering portion  4  disposed to cover the string guiding groove  13  of the pressing portion  1  is displaced upward from the string guiding groove  13  (see  FIGS. 6B and 6C ). 
         [0042]    Subsequently, when the decorative string n is further moved from the left side of the pressing portion  1  toward the right side, the groove covering portion  4  moves while being displaced further from the string guiding groove  13  and the decorative string n reaches the needle guiding hole  12  from the string guiding groove  13  (see  FIGS. 7A to 7C ). When the decorative string n is completely inserted into the needle guiding hole  12 , the decorative string n detaches from the string guide  42  and the groove covering portion  4  approaches the string guiding groove  13  to close the string guiding groove  13 . In this way, the decorative string n is prevented from detaching from the needle guiding hole  12 . 
         [0043]    Here, in the process of inserting the decorative string n into the needle guiding hole  12 , the groove covering portion  4  is moved from the left side toward the right side by the pressing force P of the decorative string n, and the right-side region of the supporting plate portion  5  is displaced from the supporting portion  2  of the presser foot body A by the bent portion  53  formed in the supporting plate portion  5 . In this case, the groove covering portion  4  also floats from the pressing portion  1 . 
         [0044]    In this way, when the decorative string n is inserted into the string guiding groove  13 , the right-side portion of the groove covering portion  4  in relation to the cover member B serves as a refuge for overall deformation of the groove covering portion  4 , and the groove covering portion  4  can be easily deformed. Thus, a gap in which the decorative string n can be inserted is formed between the string guiding groove  13  and the groove covering portion  4 . In this manner, a state in which the decorative string n can be easily moved to the position of the string guiding groove  13  can be created. 
         [0045]    In the second embodiment, since the bent portion is formed at a position near the left end in the left-right direction of the supporting plate portion of the cover member, substantially the entire portion of the supporting plate portion except the left end in the left-right direction floats by being displaced elastically from the supporting portion of the presser foot body. Due to this, the groove covering portion can be more easily displaced in relation to the upper side of the string guiding groove of the pressing portion and the operation of inserting the decorative string can be performed more easily and quickly. 
         [0046]    In the third embodiment, since the string guide is formed at the left end of the groove covering portion of the cover member, in the process of inserting the decorative string into the needle guiding hole, the decorative string makes substantially surface-contact with the string guide. Thus, it is possible to protect the decorative string so that intensive load is not applied to the decorative string especially during the insertion operation. 
         [0047]    In the fourth embodiment, the restricting portion which includes the front restricting plate and the rear restricting plate and has a C-shaped cross-sectional shape is formed on the left side in the width direction of the supporting plate portion of the cover member, and the interval between the front restricting plate and the rear restricting plate is larger than the thickness of the supporting portion. Thus, it is possible to restrict a separation distance of the cover member from the supporting portion of the presser foot body, restrict a separation distance of the groove covering portion from the upper surface of the string guiding groove, and prevent deformation resulting from too much displacement.