Patent Publication Number: US-6986317-B2

Title: Bobbin case tool and method of use

Description:
CROSS REFERENCES TO RELATED APPLICATIONS 
   U.S. Provisional Application for Patent No. 60/546,652, filed Feb. 23, 2004, with title “Bobbin Case Tool and Method of Use” which is hereby incorporated by reference. Applicant claims priority pursuant to 35 U.S.C. Par. 119(e)(i). 

   STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT 
   Not Applicable 
   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   This invention relates to a tool for facilitating removal and installation of a sewing machine bobbin case. 
   2. Brief Description of Prior Art 
   Sewing machines which sew and form a seam with upper and lower thread, particularly industrial sewing machines that consume a large amount of lower thread, require frequent replacements of a lower-thread bobbin. Usually, the bobbin replacement has been conducted manually: an operator stops the sewing machine, manually removes the bobbin case from the shuttle, disengages the bobbin from the bobbin case, replaces it with another wound lower-thread bobbin, and packs the other bobbin into the bobbin case. 
   Removal and reinstallation of a bobbin case and bobbin is a necessary, but often tedious, manual procedure for many sewing machines. A manual operation to change a bobbin, particularly in the middle of a sewing job, requires that a machine operator stop the operation, and remove the bobbin case with the empty thread spool. Thereafter, the machine operator must install a bobbin case with a full thread spool. Such a bobbin case changing operation is labor intensive, time consuming, inefficient, and extends the time required for part production in the workplace and thus, add significant cost to the production of the workpiece. 
   Therefore, there is a need to provide apparatus and methods for changing a bobbin case on a sewing machine, thereby substantially improving its efficiency. 
   As will be seen from the subsequent description, the preferred embodiments of the present invention are an aid in the removal and subsequent reinstallation of a sewing machine bobbin case. 
   SUMMARY OF THE INVENTION 
   The present invention is a bobbin case tool to assist in the manual removal and installation of a bobbin case on a sewing machine. In particular, the bobbin case tool is directed to an apparatus for removal and reinstallation of a prior art bobbin case of a sewing machine. The bobbin case tool includes an elongated arm having a grip means. The grip means includes a clearance, a pair of lead in chamfers, a locking tooth, and a locking tooth face. In application, the grip means of the bobbin case tool engages a releasing lever of the bobbin case and operatively pivots the releasing lever to an unlock position, thereby easing loading and unloading of the bobbin case and increasing the operational efficiency while the bobbin case is loaded and ejected. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of the preferred embodiment of the present invention, a bobbin case tool. 
       FIG. 2  is a perspective view of a prior art bobbin spindle with a cut-a-way illustration of a bobbin case. 
       FIGS. 3 ,  4 ,  5  and  6  illustrate application of the bobbin tool with the prior art bobbin case. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENT 
   In accordance with the present invention, a bobbin case tool and method of use is disclosed. The bobbin tool is directed to an apparatus to assist in the manual removal and installation of a bobbin case and bobbin on a sewing machine. In the preferred embodiment, the apparatus of the present invention reduces obstacles relating to an operator&#39;s hand in disengaging the bobbin case in order to replace the bobbin on a sewing machine. In the broadest context, the bobbin case tool of the present invention consists of components configured and correlated with respect to each other so as to attain the desired objective. 
     FIGS. 1–6  illustrate a preferred embodiment of a bobbin case tool  1  made in accordance with the present invention. In the preferred embodiment, the bobbin case tool  1  is directed to an apparatus for removal and reinstallation of a prior art bobbin case  100  of a sewing machine (not shown). 
   As best shown in  FIG. 1 , the bobbin case tool  1  includes an elongated arm  5 , providing a grip means  7  disposed at a distal end of the arm  5 . The grip means  7  preferably includes a clearance  10 , a pair of lead in chamfers  11 , a locking tooth  12  sandwiched between the pair of lead in chamfers  11 , and a locking tooth face  12 A disposed at a distal end of the locking tooth  12 . 
   Referring to  FIG. 2 , the prior art bobbin case  100  is shown with a bobbin holder  200  which includes a spindle locking groove  201 . The bobbin case  100  and the bobbin holder  200  are prior art. As illustrated, the bobbin case  100  is operatively mounted to the bobbin holder  200  in a known manner. 
   The bobbin case  100  includes a releasing lever  110  and a locking plate  113 . The releasing lever  110  includes a forward edge  111  and a spindle clearance  112 . The releasing lever  110  is pivotally mounted to the bobbin case  100 , and an upward or sometimes outward pivoting motion of the lever  110  (some bobbin cases are removed horizontally and some vertically, most are horizontally removed and re-inserted) causes the locking plate  113  to translate to an unlocked position so that the bobbin case  100  can be removed from the bobbin holder  200 . 
   In prior art application, in order to remove the bobbin case  100 , the operator must manually grasp the forward edge  111  of the releasing lever  110  and move the releasing lever  110  to an unlock position, thereby permitting the bobbin case  100  to be removed from the bobbin holder  200 . The embodiment of the present invention reduces obstacles to an operator&#39;s hand in properly grasping the releasing lever  110  and positioning the releasing lever  110  to an unlock position. As will be further described, the grip means  7  of the bobbin case tool  1  of the present invention engages the releasing lever  110  and operatively pivots the releasing lever  110  to the unlock position, thereby easing loading and unloading of the bobbin case  100  and increasing the operational efficiency while the bobbin case  100  is loaded and ejected. 
   Referring now to  FIGS. 3–6 , in application, the forward edge  111  of the releasing lever  110  is engaged with one of the lead in chamfers  11 . Once engaged, the operator then translates the tool  1  so that the releasing lever  110  pivots upward or outward to the unlock position as best shown in  FIG. 4 . As the forward edge  111  is lifted, the releasing lever  110  of the bobbin case  100  is lifted until the lever  110  moves the locking plate  113  out of the spindle locking groove  201 . In particular, lifting the releasing lever  110  as described, applies a force against the locking plate  113 , thereby moving the locking plate  113  out of the groove  201 . Thus, pivoting the releasing lever  110  from a first, lock position upward to a second unlock position, thereby unlocking the bobbin case  100  from the bobbin holder  200  and permitting the bobbin case  100  to be removed therefrom. 
   During application as described, the bobbin case tool  1  is positioned so that the locking tooth  12  is engaged in the spindle clearance  112  as best shown in  FIGS. 5 and 6 , thereby supporting the releasing lever  110  at the unlock position. 
   As the bobbin case tool  1  is lifted upwards or outward to the releasing lever&#39;s  110  unlock position as described above, the bobbin case  100  is lifted off the bobbin holder  200 . Thus, the bobbin case tool  1  operates to translate the releasing lever  110  along an axis of motion, for example, in the vertical direction. After a bobbin (not shown) is replaced, an operator can then reinstall the bobbin case  100  by reversing the above-described removal procedure. 
   With the releasing lever  110  of the bobbin case  100  pivoted upward to its unlock position, the bobbin case  100  can readily be removed from the sewing machine. After the bobbin case  100  is mounted on the bobbin holder  200 , the releasing lever  110  is released; and as the releasing lever  110  returns to its lock position, it moves the locking plate  113  into the spindle locking groove  201 , thereby prohibiting the bobbin case  100  from being moved upward or outward from the bobbin holder  200 . The sewing machine is then ready to resume its sewing operation. 
   While a clear structural plastic is a preferred material of construction for the bobbin tool  1 , as obvious to one skilled in the art, there are a number of resilient materials, including metals that can serve the same purpose. 
   Although the description above contains many specificities, these should not be construed as limiting the scope of the invention but as merely providing illustrations of some of the presently preferred embodiments of this invention. 
   It will be obvious to one skilled in the art that modifications may be made to the embodiments described above without departing from the scope of the present invention. Thus the scope of the invention should be determined by the appended claims in the formal application and their legal equivalents, rather than by the examples given.