Magnetized pre-wound sideless bobbins
AssigneeFil-Tec
InventorsVincent E. Schoeck, Edwin E. Fuller
Life of this patent
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Abstract
Magnetized bobbin cores are preferably wound with sewing thread to obtain sideless, pre-wound bobbins that have beneficial draw-off tensions, draw-off tension uniformity and overspin characteristics. The pre-wound sideless bobbins may thus be satisfactorily used in lock stitch sewing applications due to improved uniformity of draw-off tension combined with reduced bobbin overspin. The magnetized pre-wound sideless bobbins are also especially well suited for end-use sewing applications where automatic bobbin changing equipment is employed. Most preferably, the core is a cylinder formed of a thermoplastic or thermoset material in which magnetized particles are dispersed.
Claims39
A pre-wound flangeless, sideless bobbin comprising a core, and a continuous length thread wound about said core, wherein said core has at least one end which is permanently magnetized.
A pre-wound flangeless, sideless bobbin having a continuous length of tacked thread wound about a core having at least one end which is permanently magnetized.
The combination comprising a metal bobbin case having a central post, and a flangeless, sideless bobbin mounted in said case, said bobbin including:
- (i) a cylindrical bobbin core having at least one end thereof which is permanently magnetized and which is sleeved over said central post of said bobbin case, and
- (ii) a continuous length of sewing thread wound about said core, wherein
- (ii) said bobbin is mounted in said case such that said at least one permanently magnetized end of said bobbin core is adjacent said bobbin case.
The combination comprising a metal bobbin case having a central post, and a flangeless, sideless bobbin mounted in said case, said bobbin including a cylindrical bobbin core having at least one end thereof which is permanently magnetized and which is sleeved over said central post of said bobbin case, and a continuous length of tacked sewing thread wound about said core, wherein said bobbin is mounted in said case such that said at least one permanently magnetized end of said bobbin core is adjacent said bobbin case.
A prewound flangeless, sideless bobbin mountable within a bobbin case for spinning movement during thread unwinding, wherein said bobbin includes:
- a cylindrical core;
- and
- thread wound about said core;
- wherein
- said core is permanently magnetized to exhibit a magnetic field of sufficient strength to be magnetically attracted to the bobbin case in which the bobbin is mounted so as to minimize overspin of the bobbin in response to stoppage of spinning movement thereof while maintaining a desired unwinding draw-off tension of the thread.
Dependencies are inferred from the claim text.