Sewing system with thread draw tension adjusting capability and a method of adjusting the thread draw tension

Abstract

The combination of a bobbin assembly and a support for the bobbin assembly. The bobbin assembly has a core around which a supply of thread can be wrapped. The core has a rotational axis. The bobbin assembly further has a first flange with first and second oppositely facing surfaces, with the first surface bounding a storage space for thread wrapped around the core. The support allows the bobbin assembly to rotate around the rotational axis. The support has a third surface facing the second surface with the bobbin assembly operatively connected to the support. The bobbin assembly and support are magnetically attracted to each other with a force of a first magnitude with the bobbin assembly and support in a first state. The force resists rotation of the bobbin assembly around the rotational axis. At least one of the bobbin assembly and support is reconfigurable to cause the bobbin assembly and support to be one of a) not magnetically attracted to each other and b) magnetically attracted to each other with a force of a second magnitude, that is different than the first magnitude, with the bobbin assembly and a support in a second state.

1 . In combination: 
 a) a bobbin assembly comprising: 
 i) a core around which a supply of thread can be wrapped, the core having a rotational axis; and  
 ii) a first flange having first and second oppositely facing surfaces, with the first surface bounding a storage space for thread wrapped around the core; and  
   b) a support for the bobbin assembly to allow the bobbin assembly to rotate around the rotational axis, said support comprising: 
 a third surface facing the second surface with the bobbin assembly operatively connected to the support,  
 the bobbin assembly and support magnetically attracted to each other with a force of a first magnitude with the bobbin assembly and support in a first state,  
 the force resisting rotation of the bobbin assembly around the rotational axis,  
 at least one of the bobbin assembly and support reconfigurable to cause the bobbin assembly and support to be one of a) not magnetically attracted to each other and b) magnetically attracted to each other with a force of a second magnitude, that is different than the first magnitude, with the bobbin assembly and support in a second state.  
   
     
     
         2 . The combination according to  claim 1  wherein there is a magnetic assembly on one of the bobbin assembly and support that is attracted to a metallic portion on the other of the bobbin assembly and support, and the bobbin assembly and support are changed from the first state into the second state by separating a part of the magnetic assembly from the one of the bobbin assembly and support.  
     
     
         3 . The combination according to  claim 1  wherein there is a metallic assembly on one of the bobbin assembly and support that is attracted to a magnetic portion on the other of the bobbin assembly and support, and the bobbin assembly and support are changed from the first state into the second state by separating a part of the metallic assembly from the one of the bobbin assembly and support.  
     
     
         4 . The combination according to  claim 2  wherein the magnetic assembly comprises a first magnetic element and with the bobbin assembly and support in the second state, the first magnetic element is separated from the one of the bobbin assembly and support.  
     
     
         5 . The combination according to  claim 2  wherein the magnetic assembly comprises first and second magnetic elements and with the bobbin assembly and support in the second state, the first magnetic element is separated from the one of the bobbin assembly and support and the second magnetic element remains on the one of the bobbin assembly and support.  
     
     
         6 . The combination according to  claim 4  wherein the first magnetic element is maintained on the one of the bobbin assembly and support by being magnetically attracted to the one of the bobbin assembly and support.  
     
     
         7 . The combination according to  claim 4  wherein the first magnetic element is maintained on the one of the bobbin assembly and support by a releasable adhesive.  
     
     
         8 . The combination according to  claim 2  wherein the magnetic assembly comprises a first magnetic element and the first magnetic element is separable from the one of the bobbin assembly and support by tearing a portion of the magnetic assembly to thereby change the bobbin assembly and support from the first state into the second state.  
     
     
         9 . The combination according to  claim 2  wherein the magnetic assembly is provided on the second flange and the metallic portion is at the third surface.  
     
     
         10 . The combination according to  claim 2  wherein the support comprises a post which guides rotation of the bobbin assembly around the rotational axis and the magnetic assembly is on the post.  
     
     
         11 . The combination according to  claim 2  wherein the magnetic assembly comprises a first magnetic element that is releasably threadably attached to the one of the bobbin assembly and support.  
     
     
         12 . The combination according to  claim 4  wherein the magnetic assembly is maintained on the one of the bobbin assembly and support by cooperating releasably connecting parts on the magnetic assembly and the one of the bobbin assembly and support.  
     
     
         13 . The combination according to  claim 2  wherein the magnetic assembly comprises first and second magnetic elements and a carrier for the first and second magnetic elements.  
     
     
         14 . The combination according to  claim 13  wherein the carrier has a weakened portion that can be torn to separate the first magnetic element from the one of the bobbin assembly and support to thereby place the bobbin assembly and support in the second state.  
     
     
         15 . The combination according to  claim 13  wherein the carrier defines a first receptacle for the first magnetic element and a second receptacle from the second magnetic element.  
     
     
         16 . The combination according to  claim 13  wherein the carrier is adhesively bonded to the one of the bobbin assembly and support.  
     
     
         17 . The combination according to  claim 16  wherein the first magnetic element is bonded to the carrier.  
     
     
         18 . The combination according to  claim 2  wherein the magnetic assembly is frictionally maintained on the one of the bobbin assembly and support  
     
     
         19 . The combination according to  claim 1  further comprising a rotary loop taken for drawing thread on the bobbin assembly from the bobbin assembly.  
     
     
         20 . In combination: 
 a) a bobbin assembly comprising: 
 a core around which a supply of thread can be wrapped, the core having a rotational axis;  
   b) a support for the bobbin assembly to allow the bobbin assembly to rotate around the rotational axis, said support comprising: 
 the bobbin assembly and support magnetically attracted to each other with a force of a first magnitude with the bobbin assembly and support in a first state,  
 the force resisting rotation of the bobbin assembly around the rotational axis,  
 at least one of the bobbin assembly and support reconfigurable to cause the bobbin assembly and support to be one of a) not magnetically attracted to each other and b) magnetically attracted to each other with a force of a second magnitude, that is different than the first magnitude, with the bobbin assembly and support in a second state.  
   
     
     
         21 . A method of controlling draw tension on thread pulled from a supply of the thread, the method comprising the steps of: 
 providing a bobbin assembly comprising a core around which a supply of thread can be wrapped, the core having a rotational axis;    providing a support for the bobbin assembly to allow the bobbin assembly to rotate around the rotational axis;    producing a magnetic attractive force of a first magnitude between the bobbin assembly and support with the bobbin assembly and support in a first state to resist rotation of the bobbin assembly around the rotational axis; and    selectively changing the support and bobbin assembly to a second state wherein one of a) the bobbin assembly and support are not attracted to each other and b) a magnetic attractive force of a second magnitude is produced between the bobbin assembly and support.    
     
     
         22 . The method according to  claim 21  wherein the step of producing a magnetic attractive force comprises providing first and second magnetic elements on one of the bobbin assembly and support that are attracted to a metallic portion on the other of the bobbin assembly and support.  
     
     
         23 . The method according to  claim 22  wherein the step of selectively changing the support and bobbin assembly to the second state comprises separating the first magnetic element from the one of the bobbin assembly and support and leaving the second magnetic element on the one of the bobbin assembly and support.  
     
     
         24 . The method according to  claim 21  wherein the step of producing a magnetic attractive force comprises providing a first magnetic element on one of the bobbin assembly and support that is attracted to a metallic portion on the other of the bobbin assembly and support.  
     
     
         25 . The method according to  claim 24  wherein the step of selectively changing the bobbin assembly and support to the second state comprises separating the first magnetic element from the one of the bobbin assembly and support.  
     
     
         26 . The method according to  claim 24  wherein the step of providing a first magnetic element comprises providing a first magnetic element on a carrier and attaching the carrier to the one of the bobbin assembly and support.  
     
     
         27 . The method according to  claim 26  wherein the step of selectively changing the bobbin assembly and support comprises tearing the carrier to allow separation of the first magnetic element from the one of the bobbin assembly and support.  
     
     
         28 . The method according to  claim 24  wherein the step of providing a first magnetic element comprises releasably attaching the first magnetic element to the one of the bobbin assembly and support.  
     
     
         29 . The method according to  claim 21  wherein the step of producing a magnetic attractive force comprises providing first and second metallic elements on one of the bobbin assembly and support that are magnetically attractive to the other of the bobbin assembly and support.  
     
     
         30 . The method according to  claim 28  wherein the step of selectively changing the bobbin assembly and support to a second state comprises separating the first metallic element from the one of the bobbin assembly and support.