Pre-wound bobbin with magnetized flange
AssigneeJ. & P. Coats Limited
InventorsDennis A. Milanese, William C. Stuckey, Michael W. Moennig
Life of this patent
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Abstract
A pre-wound bobbin for sewing, having a single flange or a pair of flanges, in which one flange of the bobbin comprises a magnetized material such that the flange magnetically adheres to the end wall of a steel bobbin case in which the bobbin is carried in a sewing machine. The flange is sized to provide a contact area with the end wall that, in relation to the magnetic strength of the magnetized material, achieves a magnetic attraction force exceeding the weight of the bobbin so that the bobbin is held in the bobbin case. The flange preferably is flexible.
Claims26
A pre-wound bobbin for removably mounting in a steel bobbin case formed as a generally cup-shaped housing having an end wall at one end thereof and being open at the other end thereof and having a post mounted on the end wall, the pre-wound bobbin comprising:
- a hollow cylindrical core for fitting over the post of the bobbin case such that the core rotates freely relative to the post;
- a continuous length of thread wound onto the core;
- and
- a flange comprising a flexible sheet magnet attached to one end of the core and extending radially outwardly therefrom, the flange exerting a magnetic attraction force on the end wall of the bobbin case when the bobbin is mounted therein with the flange in contact with the end wall, the flange being configured to provide sufficient contact area with the end wall of the bobbin case and having a magnetic strength of sufficient magnitude such that said magnetic attraction force exceeds the weight of the pre-wound bobbin yet allows the bobbin to be rotated on the post by pulling the thread tangentially away from the bobbin.
A pre-wound bobbin for removably mounting in a steel bobbin case formed as a generally cup-shaped housing having an end wall at one end thereof and being open at the other end thereof and having a post mounted on the end wall, the pre-wound bobbin comprising:
- a hollow cylindrical core for fitting over the post of the bobbin case such that the core rotates freely relative to the post wherein the core is non-magnetized;
- a continuous length of thread wound onto the core;
- and
- a flange attached to one end of the core and extending radially outwardly therefrom, the flange comprising a magnetized material that exerts a magnetic attraction force on the end wall of the bobbin case when the bobbin is mounted therein with the flange in contact with the end wall, the flange being configured to provide sufficient contact area with the end wall of the bobbin case and the magnetized material having a magnetic strength of sufficient magnitude such that said magnetic attraction force exceeds the weight of the pre-wound bobbin yet allows the bobbin to be rotated on the post by pulling the thread tangentially away from the bobbin.
A pre-wound bobbin for removably mounting in a steel bobbin case formed as a generally cup-shaped housing having an end wall at one end thereof and being open at the other end thereof and having a post mounted on the end wall, the pre-wound bobbin comprising:
- a hollow cylindrical core for fitting over the post of the bobbin case such that the core rotates freely relative to the post;
- a continuous length of thread wound onto the core;
- and
- a flange attached to one end of the core and extending radially outwardly therefrom, the flange comprising a magnetized material that exerts a magnetic attraction force on the end wall of the bobbin case when the bobbin is mounted therein with the flange in contact with the end wall, the flange being configured to provide sufficient contact area with the end wall of the bobbin case and the magnetized material having a magnetic strength of sufficient magnitude such that said magnetic attraction force exceeds the weight of the pre-wound bobbin yet allows the bobbin to be rotated on the post by pulling the thread tangentially away from the bobbin;
- wherein the bobbin comprises a single-flange bobbin.
A pre-wound bobbin for removably mounting in a steel bobbin case formed as a generally cup-shaped housing having an end wall at one end thereof and being open at the other end thereof and having a post mounted on the end wall, the pre-wound bobbin comprising:
- a hollow cylindrical non-magnetized core for fitting over the post of the bobbin case such that the core rotates freely relative to the post;
- a continuous length of thread wound onto the core;
- and
- a magnetized flange attached to one end of the core and extending radially outwardly therefrom, the flange exerting a magnetic attraction force on the end wall of the bobbin case when the bobbin is mounted therein with the flange in contact with the end wall such that the flange provides a magnetic drag force resisting rotation of the bobbin.
A single-flange pre-wound bobbin for removably mounting in a steel bobbin case formed as a generally cup-shaped housing having an end wall at one end thereof and being open at the other end thereof and having a post mounted on the end wall, the pre-wound bobbin comprising:
- a hollow cylindrical non-magnetized core for fitting over the post of the bobbin case such that the core rotates freely relative to the post;
- a continuous length of thread wound onto the core;
- and
- a flange formed from a flexible sheet magnet attached to one end of the core and extending radially outwardly therefrom, the flange exerting a magnetic attraction force on the end wall of the bobbin case when the bobbin is mounted therein with the flange in contact with the end wall such that the flange provides a magnetic drag force resisting rotation of the bobbin.
A bobbin assembly for sewing, comprising:
- a steel bobbin case formed as a generally cup-shaped housing having a tubular cylindrical portion and an end wall closing one end of the tubular cylindrical portion, the other end of the tubular cylindrical portion being open, and the bobbin case having a post mounted on the end wall and extending toward the open end of the tubular cylindrical portion;
- and
- a pre-wound bobbin mounted in the bobbin case, the bobbin comprising a hollow cylindrical nonmagnetized core that fits loosely over the post such that the core rotates freely relative to the post, a continuous length of thread wound onto the core, and a magnetized flange attached to one end of the core and extending radially outwardly therefrom, the flange contacting the end wall of the bobbin case and exerting a magnetic attraction force on the end wall such that the flange provides a magnetic drag force resisting rotation of the bobbin, wherein the flange is sized to have a surface area in contact with the end wall and the flange is formed of a magnetized material selected to have a magnetic strength such that the magnetic attraction force exceeds the weight of the pre-wound bobbin so as to retain the bobbin in the bobbin case.
Dependencies are inferred from the claim text.